#
dc53d9ea |
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25-Mar-2024 |
John Garry <john.g.garry@oracle.com> |
block: Make blk_rq_set_mixed_merge() static Since commit 8e756373d7c8 ("block: Move bio merge related functions into blk-merge.c"), blk_rq_set_mixed_merge() has only been referenced in blk-merge.c, so make it static. Signed-off-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20240325083501.2816408-1-john.g.garry@oracle.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
44981351 |
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02-Feb-2024 |
Bart Van Assche <bvanassche@acm.org> |
block, fs: Restore the per-bio/request data lifetime fields Restore support for passing data lifetime information from filesystems to block drivers. This patch reverts commit b179c98f7697 ("block: Remove request.write_hint") and commit c75e707fe1aa ("block: remove the per-bio/request write hint"). This patch does not modify the size of struct bio because the new bi_write_hint member fills a hole in struct bio. pahole reports the following for struct bio on an x86_64 system with this patch applied: /* size: 112, cachelines: 2, members: 20 */ /* sum members: 110, holes: 1, sum holes: 2 */ /* last cacheline: 48 bytes */ Reviewed-by: Kanchan Joshi <joshi.k@samsung.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20240202203926.2478590-7-bvanassche@acm.org Signed-off-by: Christian Brauner <brauner@kernel.org>
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#
928a5dd3 |
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28-Dec-2023 |
Christoph Hellwig <hch@lst.de> |
block: remove two comments in bio_split_discard A zero discard_granularity is not treated the same as a single-block one, and not having any segments after taking alignment is perfectly fine and does not need a warning. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20231228075545.362768-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
9cd1e566 |
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15-Mar-2023 |
Eric Biggers <ebiggers@google.com> |
blk-mq: release crypto keyslot before reporting I/O complete Once all I/O using a blk_crypto_key has completed, filesystems can call blk_crypto_evict_key(). However, the block layer currently doesn't call blk_crypto_put_keyslot() until the request is being freed, which happens after upper layers have been told (via bio_endio()) the I/O has completed. This causes a race condition where blk_crypto_evict_key() can see 'slot_refs != 0' without there being an actual bug. This makes __blk_crypto_evict_key() hit the 'WARN_ON_ONCE(atomic_read(&slot->slot_refs) != 0)' and return without doing anything, eventually causing a use-after-free in blk_crypto_reprogram_all_keys(). (This is a very rare bug and has only been seen when per-file keys are being used with fscrypt.) There are two options to fix this: either release the keyslot before bio_endio() is called on the request's last bio, or make __blk_crypto_evict_key() ignore slot_refs. Let's go with the first solution, since it preserves the ability to report bugs (via WARN_ON_ONCE) where a key is evicted while still in-use. Fixes: a892c8d52c02 ("block: Inline encryption support for blk-mq") Cc: stable@vger.kernel.org Reviewed-by: Nathan Huckleberry <nhuck@google.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Eric Biggers <ebiggers@google.com> Link: https://lore.kernel.org/r/20230315183907.53675-2-ebiggers@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
49d24398 |
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28-Feb-2023 |
Uday Shankar <ushankar@purestorage.com> |
blk-mq: enforce op-specific segment limits in blk_insert_cloned_request The block layer might merge together discard requests up until the max_discard_segments limit is hit, but blk_insert_cloned_request checks the segment count against max_segments regardless of the req op. This can result in errors like the following when discards are issued through a DM device and max_discard_segments exceeds max_segments for the queue of the chosen underlying device. blk_insert_cloned_request: over max segments limit. (256 > 129) Fix this by looking at the req_op and enforcing the appropriate segment limit - max_discard_segments for REQ_OP_DISCARDs and max_segments for everything else. Signed-off-by: Uday Shankar <ushankar@purestorage.com> Reviewed-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20230301000655.48112-1-ushankar@purestorage.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
f3ca7386 |
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16-Feb-2023 |
Jens Axboe <axboe@kernel.dk> |
block: use proper return value from bio_failfast() kernel test robot complains about a type mismatch: block/blk-merge.c:984:42: sparse: expected restricted blk_opf_t const [usertype] ff block/blk-merge.c:984:42: sparse: got unsigned int block/blk-merge.c:1010:42: sparse: sparse: incorrect type in initializer (different base types) @@ expected restricted blk_opf_t const [usertype] ff @@ got unsigned int @@ block/blk-merge.c:1010:42: sparse: expected restricted blk_opf_t const [usertype] ff block/blk-merge.c:1010:42: sparse: got unsigned int because bio_failfast() is return an unsigned int rather than the appropriate blk_opt_f type. Fix it up. Fixes: 3ce6a115980c ("block: sync mixed merged request's failfast with 1st bio's") Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/oe-kbuild-all/202302170743.GXypM9Rt-lkp@intel.com/ Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
3ce6a115 |
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09-Feb-2023 |
Ming Lei <ming.lei@redhat.com> |
block: sync mixed merged request's failfast with 1st bio's We support mixed merge for requests/bios with different fastfail settings. When request fails, each time we only handle the portion with same failfast setting, then bios with failfast can be failed immediately, and bios without failfast can be retried. The idea is pretty good, but the current implementation has several defects: 1) initially RA bio doesn't set failfast, however bio merge code doesn't consider this point, and just check its failfast setting for deciding if mixed merge is required. Fix this issue by adding helper of bio_failfast(). 2) when merging bio to request front, if this request is mixed merged, we have to sync request's faifast setting with 1st bio's failfast. Fix it by calling blk_update_mixed_merge(). 3) when merging bio to request back, if this request is mixed merged, we have to mark the bio as failfast, because blk_update_request simply updates request failfast with 1st bio's failfast. Fix it by calling blk_update_mixed_merge(). Fixes one normal EXT4 READ IO failure issue, because it is observed that the normal READ IO is merged with RA IO, and the mixed merged request has different failfast setting with 1st bio's, so finally the normal READ IO doesn't get retried. Cc: Tejun Heo <tj@kernel.org> Fixes: 80a761fd33cf ("block: implement mixed merge of different failfast requests") Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20230209125527.667004-1-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
fd8f8ede |
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20-Jan-2023 |
Christoph Hellwig <hch@lst.de> |
block: export bio_split_rw bio_split_rw can be used by file systems to split and incoming write bio into multiple bios fitting the hardware limit for use as ZONE_APPEND bios. Export it for initial use in btrfs. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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#
9cea62b2 |
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04-Jan-2023 |
Jens Axboe <axboe@kernel.dk> |
block: don't allow splitting of a REQ_NOWAIT bio If we split a bio marked with REQ_NOWAIT, then we can trigger spurious EAGAIN if constituent parts of that split bio end up failing request allocations. Parts will complete just fine, but just a single failure in one of the chained bios will yield an EAGAIN final result for the parent bio. Return EAGAIN early if we end up needing to split such a bio, which allows for saner recovery handling. Cc: stable@vger.kernel.org # 5.15+ Link: https://github.com/axboe/liburing/issues/766 Reported-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
613b1488 |
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04-Jan-2023 |
Jens Axboe <axboe@kernel.dk> |
block: handle bio_split_to_limits() NULL return This can't happen right now, but in preparation for allowing bio_split_to_limits() returning NULL if it ended the bio, check for it in all the callers. Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
95465318 |
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25-Oct-2022 |
Bart Van Assche <bvanassche@acm.org> |
block: Micro-optimize get_max_segment_size() This patch removes a conditional jump from get_max_segment_size(). The x86-64 assembler code for this function without this patch is as follows: 206 return min_not_zero(mask - offset + 1, 0x0000000000000118 <+72>: not %rax 0x000000000000011b <+75>: and 0x8(%r10),%rax 0x000000000000011f <+79>: add $0x1,%rax 0x0000000000000123 <+83>: je 0x138 <bvec_split_segs+104> 0x0000000000000125 <+85>: cmp %rdx,%rax 0x0000000000000128 <+88>: mov %rdx,%r12 0x000000000000012b <+91>: cmovbe %rax,%r12 0x000000000000012f <+95>: test %rdx,%rdx 0x0000000000000132 <+98>: mov %eax,%edx 0x0000000000000134 <+100>: cmovne %r12d,%edx With this patch applied: 206 return min(mask - offset, (unsigned long)lim->max_segment_size - 1) + 1; 0x000000000000003f <+63>: mov 0x28(%rdi),%ebp 0x0000000000000042 <+66>: not %rax 0x0000000000000045 <+69>: and 0x8(%rdi),%rax 0x0000000000000049 <+73>: sub $0x1,%rbp 0x000000000000004d <+77>: cmp %rbp,%rax 0x0000000000000050 <+80>: cmova %rbp,%rax 0x0000000000000054 <+84>: add $0x1,%eax Reviewed-by: Ming Lei <ming.lei@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Keith Busch <kbusch@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20221025191755.1711437-4-bvanassche@acm.org Reviewed-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
aa261f20 |
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25-Oct-2022 |
Bart Van Assche <bvanassche@acm.org> |
block: Constify most queue limits pointers Document which functions do not modify the queue limits. Reviewed-by: Ming Lei <ming.lei@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Keith Busch <kbusch@kernel.org> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20221025191755.1711437-3-bvanassche@acm.org Reviewed-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
c55ddd90 |
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26-Jul-2022 |
Christoph Hellwig <hch@lst.de> |
block: pass struct queue_limits to the bio splitting helpers Allow using the splitting helpers on just a queue_limits instead of a full request_queue structure. This will eventually allow file systems or remapping drivers to split REQ_OP_ZONE_APPEND bios based on limits calculated as the minimum common capabilities over multiple devices. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20220727162300.3089193-7-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
b6dc6198 |
|
26-Jul-2022 |
Christoph Hellwig <hch@lst.de> |
block: move bio_allowed_max_sectors to blk-merge.c Move this helper into the only file where it is used. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20220727162300.3089193-6-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
a85b3637 |
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26-Jul-2022 |
Christoph Hellwig <hch@lst.de> |
block: move the call to get_max_io_size out of blk_bio_segment_split Prepare for reusing blk_bio_segment_split for (file system controlled) splits of REQ_OP_ZONE_APPEND bios by letting the caller control the maximum size of the bio. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20220727162300.3089193-5-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
46754bd0 |
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26-Jul-2022 |
Christoph Hellwig <hch@lst.de> |
block: move ->bio_split to the gendisk Only non-passthrough requests are split by the block layer and use the ->bio_split bio_set. Move it from the request_queue to the gendisk. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20220727162300.3089193-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
5a97806f |
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26-Jul-2022 |
Christoph Hellwig <hch@lst.de> |
block: change the blk_queue_split calling convention The double indirect bio leads to somewhat suboptimal code generation. Instead return the (original or split) bio, and make sure the request_queue arguments to the lower level helpers is passed after the bio to avoid constant reshuffling of the argument passing registers. Also give it and the helpers used to implement it more descriptive names. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220727162300.3089193-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
16458cf3 |
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14-Jul-2022 |
Bart Van Assche <bvanassche@acm.org> |
block: Use the new blk_opf_t type Use the new blk_opf_t type for arguments and variables that represent request flags or a bitwise combination of a request operation and request flags. Rename the function arguments and also a structure member that hold a request operation and flags from 'rw' into 'opf'. This patch does not change any functionality. Cc: Christoph Hellwig <hch@lst.de> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Damien Le Moal <damien.lemoal@wdc.com> Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220714180729.1065367-7-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
2d9b02be |
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14-Jul-2022 |
Bart Van Assche <bvanassche@acm.org> |
block: Change the type of req_op() and bio_op() into enum req_op Improve static type checking by changing the type of the value returned by req_op() and bio_op() from unsigned int into enum req_op. Insert 'default: break;' in switch statements on the enum req_op type to prevent that the compiler warns about these switch statements. Cc: Christoph Hellwig <hch@lst.de> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Damien Le Moal <damien.lemoal@wdc.com> Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com> Cc: Tim Waugh <tim@cyberelk.net> Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@kernel.org> Cc: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220714180729.1065367-5-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
6deacb3b |
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06-Jul-2022 |
Christoph Hellwig <hch@lst.de> |
block: simplify blk_mq_plug Drop the unused q argument, and invert the check to move the exception into a branch and the regular path as the normal return. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20220706070350.1703384-5-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
efef739d |
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14-Jun-2022 |
Christoph Hellwig <hch@lst.de> |
block: fold blk_max_size_offset into get_max_io_size Now that blk_max_size_offset has a single caller left, fold it into that and clean up the naming convention for the local variables there. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Pankaj Raghav <p.raghav@samsung.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220614090934.570632-6-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
84613bed |
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14-Jun-2022 |
Christoph Hellwig <hch@lst.de> |
block: cleanup variable naming in get_max_io_size get_max_io_size has a very odd choice of variables names and initialization patterns. Switch to more descriptive names and more clear initialization of them. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220614090934.570632-5-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
c8875190 |
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14-Jun-2022 |
Christoph Hellwig <hch@lst.de> |
block: open code blk_max_size_offset in blk_rq_get_max_sectors blk_rq_get_max_sectors always uses q->limits.chunk_sectors as the chunk_sectors argument, and already checks for max_sectors through the call to blk_queue_get_max_sectors. That means much of blk_max_size_offset is not needed and open coding it simplifies the code. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220614090934.570632-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
67927d22 |
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10-Jun-2022 |
Keith Busch <kbusch@kernel.org> |
block/merge: count bytes instead of sectors Individual bv_len's may not be a sector size. Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20220610195830.3574005-7-kbusch@fb.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
957a2b34 |
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13-Jul-2022 |
Muchun Song <songmuchun@bytedance.com> |
block: fix missing blkcg_bio_issue_init The commit 513616843d73 ("block: remove superfluous calls to blkcg_bio_issue_init") has removed blkcg_bio_issue_init from __bio_clone since submit_bio will override ->bi_issue. However, __blk_queue_split is called after blkcg_bio_issue_init (see blk_mq_submit_bio) in submit_bio. In this case, the ->bi_issue is 0. Fix it. Fixes: 513616843d73 ("block: remove superfluous calls to blkcg_bio_issue_init") Signed-off-by: Muchun Song <songmuchun@bytedance.com> Link: https://lore.kernel.org/r/20220713140226.68135-1-songmuchun@bytedance.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
c75e707f |
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04-Mar-2022 |
Christoph Hellwig <hch@lst.de> |
block: remove the per-bio/request write hint With the NVMe support for this gone, there are no consumers of these hints left, so remove them. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220304175556.407719-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
73bd66d9 |
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09-Feb-2022 |
Christoph Hellwig <hch@lst.de> |
scsi: block: Remove REQ_OP_WRITE_SAME support No more users of REQ_OP_WRITE_SAME or drivers implementing it are left, so remove the infrastructure. [mkp: fold in and tweak sysfs reporting fix] Link: https://lore.kernel.org/r/20220209082828.2629273-8-hch@lst.de Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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#
6b2b0459 |
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14-Mar-2022 |
Tejun Heo <tj@kernel.org> |
block: don't merge across cgroup boundaries if blkcg is enabled blk-iocost and iolatency are cgroup aware rq-qos policies but they didn't disable merges across different cgroups. This obviously can lead to accounting and control errors but more importantly to priority inversions - e.g. an IO which belongs to a higher priority cgroup or IO class may end up getting throttled incorrectly because it gets merged to an IO issued from a low priority cgroup. Fix it by adding blk_cgroup_mergeable() which is called from merge paths and rejects cross-cgroup and cross-issue_as_root merges. Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: d70675121546 ("block: introduce blk-iolatency io controller") Cc: stable@vger.kernel.org # v4.19+ Cc: Josef Bacik <jbacik@fb.com> Link: https://lore.kernel.org/r/Yi/eE/6zFNyWJ+qd@slm.duckdns.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
5b205071 |
|
11-Mar-2022 |
Jens Axboe <axboe@kernel.dk> |
block: ensure plug merging checks the correct queue at least once Song reports that a RAID rebuild workload runs much slower recently, and it is seeing a lot less merging than it did previously. The reason is that a previous commit reduced the amount of work we do for plug merging. RAID rebuild interleaves requests between disks, so a last-entry check in plug merging always misses a merge opportunity since we always find a different disk than what we are looking for. Modify the logic such that it's still a one-hit cache, but ensure that we check enough to find the right target before giving up. Fixes: d38a9c04c0d5 ("block: only check previous entry for plug merge attempt") Reported-and-tested-by: Song Liu <song@kernel.org> Reviewed-by: Song Liu <songliubraving@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
9f5ede3c |
|
15-Feb-2022 |
Ming Lei <ming.lei@redhat.com> |
block: throttle split bio in case of iops limit Commit 111be8839817 ("block-throttle: avoid double charge") marks bio as BIO_THROTTLED unconditionally if __blk_throtl_bio() is called on this bio, then this bio won't be called into __blk_throtl_bio() any more. This way is to avoid double charge in case of bio splitting. It is reasonable for read/write throughput limit, but not reasonable for IOPS limit because block layer provides io accounting against split bio. Chunguang Xu has already observed this issue and fixed it in commit 4f1e9630afe6 ("blk-throtl: optimize IOPS throttle for large IO scenarios"). However, that patch only covers bio splitting in __blk_queue_split(), and we have other kind of bio splitting, such as bio_split() & submit_bio_noacct() and other ways. This patch tries to fix the issue in one generic way by always charging the bio for iops limit in blk_throtl_bio(). This way is reasonable: re-submission & fast-cloned bio is charged if it is submitted to same disk/queue, and BIO_THROTTLED will be cleared if bio->bi_bdev is changed. This new approach can get much more smooth/stable iops limit compared with commit 4f1e9630afe6 ("blk-throtl: optimize IOPS throttle for large IO scenarios") since that commit can't throttle current split bios actually. Also this way won't cause new double bio iops charge in blk_throtl_dispatch_work_fn() in which blk_throtl_bio() won't be called any more. Reported-by: Ning Li <lining2020x@163.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Chunguang Xu <brookxu@tencent.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20220216044514.2903784-7-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
79bb1dbd |
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26-Nov-2021 |
Christoph Hellwig <hch@lst.de> |
block: don't check ->rq_disk in merges There is a 1:1 relationship between request_queues and gendisks now, so no need for these extra checks. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20211126121802.2090656-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
82d981d4 |
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23-Nov-2021 |
Christoph Hellwig <hch@lst.de> |
block: don't include <linux/part_stat.h> in blk.h Not needed, shift it into the source files that need it instead. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211123185312.1432157-9-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
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2aa7745b |
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23-Nov-2021 |
Christoph Hellwig <hch@lst.de> |
block: don't include blk-mq-sched.h in blk.h No needed, shift it into the source files that need it instead. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211123185312.1432157-5-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
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0c5bcc92 |
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23-Nov-2021 |
Christoph Hellwig <hch@lst.de> |
blk-mq: simplify the plug handling in blk_mq_submit_bio blk_mq_submit_bio has two different plug cases, one that uses full plugging and a limited plugging one. The limited plugging case is only used for a corner case that does not matter in real life: - no ->commit_rqs (so not NVMe) - no shared tags (so not SCSI) - not rotational (so no old disk or floppy driver) - must have multiple queues (so no eMMC) Remove the limited merging case and all the related junk to simplify blk_mq_submit_bio and the functions called from it. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211123160443.1315598-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
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a1cb6537 |
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02-Nov-2021 |
Ming Lei <ming.lei@redhat.com> |
blk-mq: only try to run plug merge if request has same queue with incoming bio It is obvious that io merge can't be done between two different queues, so just try to run io merge in case of same queue. Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20211102133502.3619184-2-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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859897c3 |
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19-Oct-2021 |
Pavel Begunkov <asml.silence@gmail.com> |
block: convert leftovers to bdev_get_queue Convert bdev->bd_disk->queue to bdev_get_queue(), which is faster. Apparently, there are a few such spots in block that got lost during rebases. Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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bc490f81 |
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18-Oct-2021 |
Jens Axboe <axboe@kernel.dk> |
block: change plugging to use a singly linked list Use a singly linked list for the blk_plug. This saves 8 bytes in the blk_plug struct, and makes for faster list manipulations than doubly linked lists. As we don't use the doubly linked lists for anything, singly linked is just fine. This yields a bump in default (merging enabled) performance from 7.0 to 7.1M IOPS, and ~7.5M IOPS with merging disabled. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
87c037d1 |
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18-Oct-2021 |
Jens Axboe <axboe@kernel.dk> |
block: return whether or not to unplug through boolean Instead of returning the same queue request through a request pointer, use a boolean to accomplish the same. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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abd45c15 |
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13-Oct-2021 |
Jens Axboe <axboe@kernel.dk> |
block: handle fast path of bio splitting inline The fast path is no splitting needed. Separate the handling into a check part we can inline, and an out-of-line handling path if we do need to split. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
6ce913fe |
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12-Oct-2021 |
Christoph Hellwig <hch@lst.de> |
block: rename REQ_HIPRI to REQ_POLLED Unlike the RWF_HIPRI userspace ABI which is intentionally kept vague, the bio flag is specific to the polling implementation, so rename and document it properly. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Tested-by: Mark Wunderlich <mark.wunderlich@intel.com> Link: https://lore.kernel.org/r/20211012111226.760968-12-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
d38a9c04 |
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14-Oct-2021 |
Jens Axboe <axboe@kernel.dk> |
block: only check previous entry for plug merge attempt Currently we scan the entire plug list, which is potentially very expensive. In an IOPS bound workload, we can drive about 5.6M IOPS with merging enabled, and profiling shows that the plug merge check is the (by far) most expensive thing we're doing: Overhead Command Shared Object Symbol + 20.89% io_uring [kernel.vmlinux] [k] blk_attempt_plug_merge + 4.98% io_uring [kernel.vmlinux] [k] io_submit_sqes + 4.78% io_uring [kernel.vmlinux] [k] blkdev_direct_IO + 4.61% io_uring [kernel.vmlinux] [k] blk_mq_submit_bio Instead of browsing the whole list, just check the previously inserted entry. That is enough for a naive merge check and will catch most cases, and for devices that need full merging, the IO scheduler attached to such devices will do that anyway. The plug merge is meant to be an inexpensive check to avoid getting a request, but if we repeatedly scan the list for every single insert, it is very much not a cheap check. With this patch, the workload instead runs at ~7.0M IOPS, providing a 25% improvement. Disabling merging entirely yields another 5% improvement. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
ff18d77b |
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12-Oct-2021 |
Christoph Hellwig <hch@lst.de> |
block: move bio_get_{first,last}_bvec out of bio.h bio_get_first_bvec and bio_get_last_bvec are only used in blk-merge.c, so move them there. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211012161804.991559-8-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
a7b36ee6 |
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05-Oct-2021 |
Jens Axboe <axboe@kernel.dk> |
block: move blk-throtl fast path inline Even if no policies are defined, we spend ~2% of the total IO time checking. Move the fast path inline. Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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fe45e630 |
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20-Sep-2021 |
Christoph Hellwig <hch@lst.de> |
block: move integrity handling out of <linux/blkdev.h> Split the integrity/metadata handling definitions out into a new header. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20210920123328.1399408-17-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
badf7f64 |
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20-Sep-2021 |
Christoph Hellwig <hch@lst.de> |
block: move a few merge helpers out of <linux/blkdev.h> These are block-layer internal helpers, so move them to block/blk.h and block/blk-merge.c. Also update a comment a bit to use better grammar. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20210920123328.1399408-16-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
270a1c91 |
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12-Aug-2021 |
Jens Axboe <axboe@kernel.dk> |
block: provide bio_clear_hipri() helper Any case that turns off REQ_HIPRI must also clear BIO_PERCPU_CACHE, as non-polled IO may complete through hard/soft IRQ and hence isn't safe for our polled bio alloc cache. Provide a helper that does just that, and use it in the merging code as well if we split a bio and turn off polling. Fixes: be863b9e4348 ("block: clear BIO_PERCPU_CACHE flag if polling isn't supported") Reported-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
4f1e9630 |
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01-Aug-2021 |
Chunguang Xu <brookxu@tencent.com> |
blk-throtl: optimize IOPS throttle for large IO scenarios After patch 54efd50 (block: make generic_make_request handle arbitrarily sized bios), the IO through io-throttle may be larger, and these IOs may be further split into more small IOs. However, IOPS throttle does not seem to be aware of this change, which makes the calculation of IOPS of large IOs incomplete, resulting in disk-side IOPS that does not meet expectations. Maybe we should fix this problem. We can reproduce it by set max_sectors_kb of disk to 128, set blkio.write_iops_throttle to 100, run a dd instance inside blkio and use iostat to watch IOPS: dd if=/dev/zero of=/dev/sdb bs=1M count=1000 oflag=direct As a result, without this change the average IOPS is 1995, with this change the IOPS is 98. Signed-off-by: Chunguang Xu <brookxu@tencent.com> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/65869aaad05475797d63b4c3fed4f529febe3c26.1627876014.git.brookxu@tencent.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
866663b7 |
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28-Jul-2021 |
Ming Lei <ming.lei@redhat.com> |
block: return ELEVATOR_DISCARD_MERGE if possible When merging one bio to request, if they are discard IO and the queue supports multi-range discard, we need to return ELEVATOR_DISCARD_MERGE because both block core and related drivers(nvme, virtio-blk) doesn't handle mixed discard io merge(traditional IO merge together with discard merge) well. Fix the issue by returning ELEVATOR_DISCARD_MERGE in this situation, so both blk-mq and drivers just need to handle multi-range discard. Reported-by: Oleksandr Natalenko <oleksandr@natalenko.name> Signed-off-by: Ming Lei <ming.lei@redhat.com> Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Fixes: 2705dfb20947 ("block: fix discard request merge") Link: https://lore.kernel.org/r/20210729034226.1591070-1-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
2705dfb2 |
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27-Jun-2021 |
Ming Lei <ming.lei@redhat.com> |
block: fix discard request merge ll_new_hw_segment() is reached only in case of single range discard merge, and we don't have max discard segment size limit actually, so it is wrong to run the following check: if (req->nr_phys_segments + nr_phys_segs > blk_rq_get_max_segments(req)) it may be always false since req->nr_phys_segments is initialized as one, and bio's segment count is still 1, blk_rq_get_max_segments(reg) is 1 too. Fix the issue by not doing the check and bypassing the calculation of discard request's nr_phys_segments. Based on analysis from Wang Shanker. Cc: Christoph Hellwig <hch@lst.de> Reported-by: Wang Shanker <shankerwangmiao@gmail.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20210628023312.1903255-1-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
fd2ef39c |
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23-Jun-2021 |
Jan Kara <jack@suse.cz> |
blk: Fix lock inversion between ioc lock and bfqd lock Lockdep complains about lock inversion between ioc->lock and bfqd->lock: bfqd -> ioc: put_io_context+0x33/0x90 -> ioc->lock grabbed blk_mq_free_request+0x51/0x140 blk_put_request+0xe/0x10 blk_attempt_req_merge+0x1d/0x30 elv_attempt_insert_merge+0x56/0xa0 blk_mq_sched_try_insert_merge+0x4b/0x60 bfq_insert_requests+0x9e/0x18c0 -> bfqd->lock grabbed blk_mq_sched_insert_requests+0xd6/0x2b0 blk_mq_flush_plug_list+0x154/0x280 blk_finish_plug+0x40/0x60 ext4_writepages+0x696/0x1320 do_writepages+0x1c/0x80 __filemap_fdatawrite_range+0xd7/0x120 sync_file_range+0xac/0xf0 ioc->bfqd: bfq_exit_icq+0xa3/0xe0 -> bfqd->lock grabbed put_io_context_active+0x78/0xb0 -> ioc->lock grabbed exit_io_context+0x48/0x50 do_exit+0x7e9/0xdd0 do_group_exit+0x54/0xc0 To avoid this inversion we change blk_mq_sched_try_insert_merge() to not free the merged request but rather leave that upto the caller similarly to blk_mq_sched_try_merge(). And in bfq_insert_requests() we make sure to free all the merged requests after dropping bfqd->lock. Fixes: aee69d78dec0 ("block, bfq: introduce the BFQ-v0 I/O scheduler as an extra scheduler") Reviewed-by: Ming Lei <ming.lei@redhat.com> Acked-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20210623093634.27879-3-jack@suse.cz Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
a958937f |
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11-Feb-2021 |
David Jeffery <djeffery@redhat.com> |
block: recalculate segment count for multi-segment discards correctly When a stacked block device inserts a request into another block device using blk_insert_cloned_request, the request's nr_phys_segments field gets recalculated by a call to blk_recalc_rq_segments in blk_cloned_rq_check_limits. But blk_recalc_rq_segments does not know how to handle multi-segment discards. For disk types which can handle multi-segment discards like nvme, this results in discard requests which claim a single segment when it should report several, triggering a warning in nvme and causing nvme to fail the discard from the invalid state. WARNING: CPU: 5 PID: 191 at drivers/nvme/host/core.c:700 nvme_setup_discard+0x170/0x1e0 [nvme_core] ... nvme_setup_cmd+0x217/0x270 [nvme_core] nvme_loop_queue_rq+0x51/0x1b0 [nvme_loop] __blk_mq_try_issue_directly+0xe7/0x1b0 blk_mq_request_issue_directly+0x41/0x70 ? blk_account_io_start+0x40/0x50 dm_mq_queue_rq+0x200/0x3e0 blk_mq_dispatch_rq_list+0x10a/0x7d0 ? __sbitmap_queue_get+0x25/0x90 ? elv_rb_del+0x1f/0x30 ? deadline_remove_request+0x55/0xb0 ? dd_dispatch_request+0x181/0x210 __blk_mq_do_dispatch_sched+0x144/0x290 ? bio_attempt_discard_merge+0x134/0x1f0 __blk_mq_sched_dispatch_requests+0x129/0x180 blk_mq_sched_dispatch_requests+0x30/0x60 __blk_mq_run_hw_queue+0x47/0xe0 __blk_mq_delay_run_hw_queue+0x15b/0x170 blk_mq_sched_insert_requests+0x68/0xe0 blk_mq_flush_plug_list+0xf0/0x170 blk_finish_plug+0x36/0x50 xlog_cil_committed+0x19f/0x290 [xfs] xlog_cil_process_committed+0x57/0x80 [xfs] xlog_state_do_callback+0x1e0/0x2a0 [xfs] xlog_ioend_work+0x2f/0x80 [xfs] process_one_work+0x1b6/0x350 worker_thread+0x53/0x3e0 ? process_one_work+0x350/0x350 kthread+0x11b/0x140 ? __kthread_bind_mask+0x60/0x60 ret_from_fork+0x22/0x30 This patch fixes blk_recalc_rq_segments to be aware of devices which can have multi-segment discards. It calculates the correct discard segment count by counting the number of bio as each discard bio is considered its own segment. Fixes: 1e739730c5b9 ("block: optionally merge discontiguous discard bios into a single request") Signed-off-by: David Jeffery <djeffery@redhat.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Laurence Oberman <loberman@redhat.com> Link: https://lore.kernel.org/r/20210211143807.GA115624@redhat Signed-off-by: Jens Axboe <axboe@kernel.dk>
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309dca30 |
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24-Jan-2021 |
Christoph Hellwig <hch@lst.de> |
block: store a block_device pointer in struct bio Replace the gendisk pointer in struct bio with a pointer to the newly improved struct block device. From that the gendisk can be trivially accessed with an extra indirection, but it also allows to directly look up all information related to partition remapping. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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cc29e1bf |
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26-Nov-2020 |
Jeffle Xu <jefflexu@linux.alibaba.com> |
block: disable iopoll for split bio iopoll is initially for small size, latency sensitive IO. It doesn't work well for big IO, especially when it needs to be split to multiple bios. In this case, the returned cookie of __submit_bio_noacct_mq() is indeed the cookie of the last split bio. The completion of *this* last split bio done by iopoll doesn't mean the whole original bio has completed. Callers of iopoll still need to wait for completion of other split bios. Besides bio splitting may cause more trouble for iopoll which isn't supposed to be used in case of big IO. iopoll for split bio may cause potential race if CPU migration happens during bio submission. Since the returned cookie is that of the last split bio, polling on the corresponding hardware queue doesn't help complete other split bios, if these split bios are enqueued into different hardware queues. Since interrupts are disabled for polling queues, the completion of these other split bios depends on timeout mechanism, thus causing a potential hang. iopoll for split bio may also cause hang for sync polling. Currently both the blkdev and iomap-based fs (ext4/xfs, etc) support sync polling in direct IO routine. These routines will submit bio without REQ_NOWAIT flag set, and then start sync polling in current process context. The process may hang in blk_mq_get_tag() if the submitted bio has to be split into multiple bios and can rapidly exhaust the queue depth. The process are waiting for the completion of the previously allocated requests, which should be reaped by the following polling, and thus causing a deadlock. To avoid these subtle trouble described above, just disable iopoll for split bio and return BLK_QC_T_NONE in this case. The side effect is that non-HIPRI IO also returns BLK_QC_T_NONE now. It should be acceptable since the returned cookie is never used for non-HIPRI IO. Suggested-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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3ee16db3 |
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30-Nov-2020 |
Mike Snitzer <snitzer@redhat.com> |
dm: fix IO splitting Commit 882ec4e609c1 ("dm table: stack 'chunk_sectors' limit to account for target-specific splitting") caused a couple regressions: 1) Using lcm_not_zero() when stacking chunk_sectors was a bug because chunk_sectors must reflect the most limited of all devices in the IO stack. 2) DM targets that set max_io_len but that do _not_ provide an .iterate_devices method no longer had there IO split properly. And commit 5091cdec56fa ("dm: change max_io_len() to use blk_max_size_offset()") also caused a regression where DM no longer supported varied (per target) IO splitting. The implication being the potential for severely reduced performance for IO stacks that use a DM target like dm-cache to hide performance limitations of a slower device (e.g. one that requires 4K IO splitting). Coming full circle: Fix all these issues by discontinuing stacking chunk_sectors up using ti->max_io_len in dm_calculate_queue_limits(), add optional chunk_sectors override argument to blk_max_size_offset() and update DM's max_io_len() to pass ti->max_io_len to its blk_max_size_offset() call. Passing in an optional chunk_sectors override to blk_max_size_offset() allows for code reuse of block's centralized calculation for max IO size based on provided offset and split boundary. Fixes: 882ec4e609c1 ("dm table: stack 'chunk_sectors' limit to account for target-specific splitting") Fixes: 5091cdec56fa ("dm: change max_io_len() to use blk_max_size_offset()") Cc: stable@vger.kernel.org Reported-by: John Dorminy <jdorminy@redhat.com> Reported-by: Bruce Johnston <bjohnsto@redhat.com> Reported-by: Kirill Tkhai <ktkhai@virtuozzo.com> Reviewed-by: John Dorminy <jdorminy@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Reviewed-by: Jens Axboe <axboe@kernel.dk>
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a54895fa |
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03-Dec-2020 |
Christoph Hellwig <hch@lst.de> |
block: remove the request_queue to argument request based tracepoints The request_queue can trivially be derived from the request. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
eb6f7f7c |
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03-Dec-2020 |
Christoph Hellwig <hch@lst.de> |
block: remove the request_queue argument to the block_split tracepoint The request_queue can trivially be derived from the bio. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
e8a676d6 |
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03-Dec-2020 |
Christoph Hellwig <hch@lst.de> |
block: simplify and extend the block_bio_merge tracepoint class The block_bio_merge tracepoint class can be reused for most bio-based tracepoints. For that it just needs to lose the superfluous q and rq parameters. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
cb8432d6 |
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26-Nov-2020 |
Christoph Hellwig <hch@lst.de> |
block: allocate struct hd_struct as part of struct bdev_inode Allocate hd_struct together with struct block_device to pre-load the lifetime rule changes in preparation of merging the two structures. Note that part0 was previously embedded into struct gendisk, but is a separate allocation now, and already points to the block_device instead of the hd_struct. The lifetime of struct gendisk is still controlled by the struct device embedded in the part0 hd_struct. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
eda5cc99 |
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06-Oct-2020 |
Christoph Hellwig <hch@lst.de> |
block: move blk_mq_sched_try_merge to blk-merge.c Move blk_mq_sched_try_merge to blk-merge.c, which allows to mark a lot of the merge infrastructure static there. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
265600b7 |
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01-Sep-2020 |
Baolin Wang <baolin.wang@linux.alibaba.com> |
block: Remove a duplicative condition Remove a duplicative condition to remove below cppcheck warnings: "warning: Redundant condition: sched_allow_merge. '!A || (A && B)' is equivalent to '!A || B' [redundantCondition]" Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
7d7ca7c5 |
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27-Aug-2020 |
Baolin Wang <baolin.wang@linux.alibaba.com> |
block: Add a new helper to attempt to merge a bio There are lots of duplicated code when trying to merge a bio from plug list and sw queue, we can introduce a new helper to attempt to merge a bio, which can simplify the blk_bio_list_merge() and blk_attempt_plug_merge(). Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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bdc6a287 |
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27-Aug-2020 |
Baolin Wang <baolin.wang@linux.alibaba.com> |
block: Move blk_mq_bio_list_merge() into blk-merge.c Move the blk_mq_bio_list_merge() into blk-merge.c and rename it as a generic name. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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8e756373 |
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27-Aug-2020 |
Baolin Wang <baolin.wang@linux.alibaba.com> |
block: Move bio merge related functions into blk-merge.c It's better to move bio merge related functions into blk-merge.c, which contains all merge related functions. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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e4b469c6 |
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06-Aug-2020 |
Keith Busch <kbusch@kernel.org> |
block: fix get_max_io_size() A previous commit aligning splits to physical block sizes inadvertently modified one return case such that that it now returns 0 length splits when the number of sectors doesn't exceed the physical offset. This later hits a BUG in bio_split(). Restore the previous working behavior. Fixes: 9cc5169cd478b ("block: Improve physical block alignment of split bios") Reported-by: Eric Deal <eric.deal@wdc.com> Signed-off-by: Keith Busch <kbusch@kernel.org> Cc: Bart Van Assche <bvanassche@acm.org> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
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943b40c8 |
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17-Aug-2020 |
Ming Lei <ming.lei@redhat.com> |
block: respect queue limit of max discard segment When queue_max_discard_segments(q) is 1, blk_discard_mergable() will return false for discard request, then normal request merge is applied. However, only queue_max_segments() is checked, so max discard segment limit isn't respected. Check max discard segment limit in the request merge code for fixing the issue. Discard request failure of virtio_blk is fixed. Fixes: 69840466086d ("block: fix the DISCARD request merge") Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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3f649ab7 |
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03-Jun-2020 |
Kees Cook <keescook@chromium.org> |
treewide: Remove uninitialized_var() usage Using uninitialized_var() is dangerous as it papers over real bugs[1] (or can in the future), and suppresses unrelated compiler warnings (e.g. "unused variable"). If the compiler thinks it is uninitialized, either simply initialize the variable or make compiler changes. In preparation for removing[2] the[3] macro[4], remove all remaining needless uses with the following script: git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \ xargs perl -pi -e \ 's/\buninitialized_var\(([^\)]+)\)/\1/g; s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;' drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid pathological white-space. No outstanding warnings were found building allmodconfig with GCC 9.3.0 for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64, alpha, and m68k. [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5 Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs Signed-off-by: Kees Cook <keescook@chromium.org>
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ed00aabd |
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01-Jul-2020 |
Christoph Hellwig <hch@lst.de> |
block: rename generic_make_request to submit_bio_noacct generic_make_request has always been very confusingly misnamed, so rename it to submit_bio_noacct to make it clear that it is submit_bio minus accounting and a few checks. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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f695ca38 |
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01-Jul-2020 |
Christoph Hellwig <hch@lst.de> |
block: remove the request_queue argument from blk_queue_split The queue can be trivially derived from the bio, so pass one less argument. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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f3bdc62f |
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17-Jun-2020 |
Jan Kara <jack@suse.cz> |
blktrace: Provide event for request merging Currently blk-mq does not report any event when two requests get merged in the elevator. This then results in difficult to understand sequence of events like: ... 8,0 34 1579 0.608765271 2718 I WS 215023504 + 40 [dbench] 8,0 34 1584 0.609184613 2719 A WS 215023544 + 56 <- (8,4) 2160568 8,0 34 1585 0.609184850 2719 Q WS 215023544 + 56 [dbench] 8,0 34 1586 0.609188524 2719 G WS 215023544 + 56 [dbench] 8,0 3 602 0.609684162 773 D WS 215023504 + 96 [kworker/3:1H] 8,0 34 1591 0.609843593 0 C WS 215023504 + 96 [0] and you can only guess (after quite some headscratching since the above excerpt is intermixed with a lot of other IO) that request 215023544+56 got merged to request 215023504+40. Provide proper event for request merging like we used to do in the legacy block layer. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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524f9ffd |
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26-May-2020 |
Christoph Hellwig <hch@lst.de> |
block: reduce part_stat_lock() scope We only need the stats lock (aka preempt_disable()) for updating the states, not for looking up or dropping the hd_struct reference. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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b9c54f56 |
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26-May-2020 |
Konstantin Khlebnikov <koct9i@gmail.com> |
block: account merge of two requests Also rename blk_account_io_merge() into blk_account_io_merge_request() to distinguish it from merging request and bio. [hch: rebased] Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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76268f3a |
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12-May-2020 |
Christoph Hellwig <hch@lst.de> |
block: don't call part_{inc,dec}_in_flight for blk-mq devices part_inc_in_flight and part_dec_in_flight are no-ops for blk-mq queues, so remove the calls in purely blk-mq callers. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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a892c8d5 |
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13-May-2020 |
Satya Tangirala <satyat@google.com> |
block: Inline encryption support for blk-mq We must have some way of letting a storage device driver know what encryption context it should use for en/decrypting a request. However, it's the upper layers (like the filesystem/fscrypt) that know about and manages encryption contexts. As such, when the upper layer submits a bio to the block layer, and this bio eventually reaches a device driver with support for inline encryption, the device driver will need to have been told the encryption context for that bio. We want to communicate the encryption context from the upper layer to the storage device along with the bio, when the bio is submitted to the block layer. To do this, we add a struct bio_crypt_ctx to struct bio, which can represent an encryption context (note that we can't use the bi_private field in struct bio to do this because that field does not function to pass information across layers in the storage stack). We also introduce various functions to manipulate the bio_crypt_ctx and make the bio/request merging logic aware of the bio_crypt_ctx. We also make changes to blk-mq to make it handle bios with encryption contexts. blk-mq can merge many bios into the same request. These bios need to have contiguous data unit numbers (the necessary changes to blk-merge are also made to ensure this) - as such, it suffices to keep the data unit number of just the first bio, since that's all a storage driver needs to infer the data unit number to use for each data block in each bio in a request. blk-mq keeps track of the encryption context to be used for all the bios in a request with the request's rq_crypt_ctx. When the first bio is added to an empty request, blk-mq will program the encryption context of that bio into the request_queue's keyslot manager, and store the returned keyslot in the request's rq_crypt_ctx. All the functions to operate on encryption contexts are in blk-crypto.c. Upper layers only need to call bio_crypt_set_ctx with the encryption key, algorithm and data_unit_num; they don't have to worry about getting a keyslot for each encryption context, as blk-mq/blk-crypto handles that. Blk-crypto also makes it possible for request-based layered devices like dm-rq to make use of inline encryption hardware by cloning the rq_crypt_ctx and programming a keyslot in the new request_queue when necessary. Note that any user of the block layer can submit bios with an encryption context, such as filesystems, device-mapper targets, etc. Signed-off-by: Satya Tangirala <satyat@google.com> Reviewed-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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0376e9ef |
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28-Apr-2020 |
Christoph Hellwig <hch@lst.de> |
block: replace BIO_QUEUE_ENTERED with BIO_CGROUP_ACCT BIO_QUEUE_ENTERED is only used for cgroup accounting now, so rename the flag and move setting it into the cgroup code. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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bdf8710d |
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14-Apr-2020 |
Christoph Hellwig <hch@lst.de> |
block: move dma_pad handling from blk_rq_map_sg into the callers There are only two callers of blk_rq_map_sg/__blk_rq_map_sg that set the dma_pad value in the queue. Move the handling into those callers instead of burdening the common code, and move the ->extra_len field from struct request to struct scsi_cmnd. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
cc97923a |
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14-Apr-2020 |
Christoph Hellwig <hch@lst.de> |
block: move dma drain handling to scsi Don't burden the common block code with with specifics of the libata DMA draining mechanism. Instead move most of the code to the scsi midlayer. That also means the nr_phys_segments adjustments in the blk-mq fast path can go away entirely, given that SCSI never looks at nr_phys_segments after mapping the request to a scatterlist. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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89de1504 |
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14-Apr-2020 |
Christoph Hellwig <hch@lst.de> |
block: provide a blk_rq_map_sg variant that returns the last element To be able to move some of the special purpose hacks in blk_rq_map_sg into the callers we need a variant that returns the last mapped S/G list element to the caller. Add that variant as __blk_rq_map_sg and make blk_rq_map_sg a trivial inline wrapper around it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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e64a0e16 |
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14-Apr-2020 |
Christoph Hellwig <hch@lst.de> |
block: remove RQF_COPY_USER The RQF_COPY_USER is set for bio where the passthrough request mapping helpers decided that bounce buffering is required. It is then used to pad scatterlist for drivers that required it. But given that non-passthrough requests are per definition aligned, and directly mapped pass-through request must be aligned it is not actually required at all. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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4a2f704e |
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11-Jan-2020 |
Ming Lei <ming.lei@redhat.com> |
block: fix get_max_segment_size() overflow on 32bit arch Commit 429120f3df2d starts to take account of segment's start dma address when computing max segment size, and data type of 'unsigned long' is used to do that. However, the segment mask may be 0xffffffff, so the figured out segment size may be overflowed in case of zero physical address on 32bit arch. Fix the issue by returning queue_max_segment_size() directly when that happens. Fixes: 429120f3df2d ("block: fix splitting segments on boundary masks") Reported-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Guenter Roeck <linux@roeck-us.net> Cc: Christoph Hellwig <hch@lst.de> Tested-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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429120f3 |
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28-Dec-2019 |
Ming Lei <ming.lei@redhat.com> |
block: fix splitting segments on boundary masks We ran into a problem with a mpt3sas based controller, where we would see random (and hard to reproduce) file corruption). The issue seemed specific to this controller, but wasn't specific to the file system. After a lot of debugging, we find out that it's caused by segments spanning a 4G memory boundary. This shouldn't happen, as the default setting for segment boundary masks is 4G. Turns out there are two issues in get_max_segment_size(): 1) The default segment boundary mask is bypassed 2) The segment start address isn't taken into account when checking segment boundary limit Fix these two issues by removing the bypass of the segment boundary check even if the mask is set to the default value, and taking into account the actual start address of the request when checking if a segment needs splitting. Cc: stable@vger.kernel.org # v5.1+ Reviewed-by: Chris Mason <clm@fb.com> Tested-by: Chris Mason <clm@fb.com> Fixes: dcebd755926b ("block: use bio_for_each_bvec() to compute multi-page bvec count") Signed-off-by: Ming Lei <ming.lei@redhat.com> Dropped const on the page pointer, ppc page_to_phys() doesn't mark the page as const... Signed-off-by: Jens Axboe <axboe@kernel.dk>
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1e279153 |
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21-Nov-2019 |
Jens Axboe <axboe@kernel.dk> |
Revert "block: split bio if the only bvec's length is > SZ_4K" We really don't need this, as the slow path will do the right thing anyway. This reverts commit 6952a7f8446ee85ea9d10ab87b64797a031eaae3. Signed-off-by: Jens Axboe <axboe@kernel.dk>
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6952a7f8 |
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08-Nov-2019 |
Ming Lei <ming.lei@redhat.com> |
block: split bio if the only bvec's length is > SZ_4K 64K PAGE_SIZE is popular on ARM64 or other ARCHs, and 64K has been big enough to break some devices probably, so change the logic to split bio if the only bvec's length is > SZ_4K instead of PAGE_SIZE. Fixes: fa5322872187 (block: avoid blk_bio_segment_split for small I/O operations) Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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59db8ba2 |
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08-Nov-2019 |
Ming Lei <ming.lei@redhat.com> |
block: still try to split bio if the bvec crosses pages Some device may set segment boundary as PAGE_SIZE - 1. If the bvec crosses pages, and meantime its length is <= PAGE_SIZE, we still need to split the bvec into 2 segments. Fixes this issue by still splitting bio if the single bvec crosses pages. Reported-by: kernel test robot <lkp@intel.com> Fixes: fa5322872187 (block: avoid blk_bio_segment_split for small I/O operations) Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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fa532287 |
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04-Nov-2019 |
Christoph Hellwig <hch@lst.de> |
block: avoid blk_bio_segment_split for small I/O operations __blk_queue_split() adds significant overhead for small I/O operations. Add a shortcut to avoid it for cases where we know we never need to split. Based on a patch from Ming Lei. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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9cc5169c |
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01-Aug-2019 |
Bart Van Assche <bvanassche@acm.org> |
block: Improve physical block alignment of split bios Consider the following example: * The logical block size is 4 KB. * The physical block size is 8 KB. * max_sectors equals (16 KB >> 9) sectors. * A non-aligned 4 KB and an aligned 64 KB bio are merged into a single non-aligned 68 KB bio. The current behavior is to split such a bio into (16 KB + 16 KB + 16 KB + 16 KB + 4 KB). The start of none of these five bio's is aligned to a physical block boundary. This patch ensures that such a bio is split into four aligned and one non-aligned bio instead of being split into five non-aligned bios. This improves performance because most block devices can handle aligned requests faster than non-aligned requests. Since the physical block size is larger than or equal to the logical block size, this patch preserves the guarantee that the returned value is a multiple of the logical block size. Cc: Christoph Hellwig <hch@infradead.org> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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708b25b3 |
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01-Aug-2019 |
Bart Van Assche <bvanassche@acm.org> |
block: Simplify blk_bio_segment_split() Move the max_sectors check into bvec_split_segs() such that a single call to that function can do all the necessary checks. This patch optimizes the fast path further, namely if a bvec fits in a page. Cc: Christoph Hellwig <hch@lst.de> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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ff9811b3 |
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01-Aug-2019 |
Bart Van Assche <bvanassche@acm.org> |
block: Simplify bvec_split_segs() Simplify this function by by removing two if-tests. Other than requiring that the @sectors pointer is not NULL, this patch does not change the behavior of bvec_split_segs(). Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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dad77584 |
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01-Aug-2019 |
Bart Van Assche <bvanassche@acm.org> |
block: Document the bio splitting functions Since what the bio splitting functions do is nontrivial, document these functions. Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Cc: Christoph Hellwig <hch@infradead.org> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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af2c68fe |
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01-Aug-2019 |
Bart Van Assche <bvanassche@acm.org> |
block: Declare several function pointer arguments 'const' Make it clear to the compiler and also to humans that the functions that query request queue properties do not modify any member of the request_queue data structure. Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Cc: Christoph Hellwig <hch@infradead.org> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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d665e12a |
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03-Jul-2019 |
Christoph Hellwig <hch@lst.de> |
block: nr_phys_segments needs to be zero for REQ_OP_WRITE_ZEROES Fix a regression introduced when removing bi_phys_segments for Write Zeroes requests, which need to have a segment count of zero, as they don't have a payload. Fixes: 14ccb66b3f58 ("block: remove the bi_phys_segments field in struct bio") Reported-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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d627065d |
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05-Jun-2019 |
Christoph Hellwig <hch@lst.de> |
block: untangle the end of blk_bio_segment_split Now that we don't need to assign the front/back segment sizes, we can duplicating the segs assignment for the split vs no-split case and remove a whole chunk of boilerplate code. Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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e9cd19c0 |
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05-Jun-2019 |
Christoph Hellwig <hch@lst.de> |
block: simplify blk_recalc_rq_segments Return the segement and let the callers assign them, which makes the code a littler more obvious. Also pass the request instead of q plus bio chain, allowing for the use of rq_for_each_bvec. Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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14ccb66b |
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05-Jun-2019 |
Christoph Hellwig <hch@lst.de> |
block: remove the bi_phys_segments field in struct bio We only need the number of segments in the blk-mq submission path. Remove the field from struct bio, and return it from a variant of blk_queue_split instead of that it can passed as an argument to those functions that need the value. This also means we stop recounting segments except for cloning and partial segments. To keep the number of arguments in this how path down remove pointless struct request_queue arguments from any of the functions that had it and grew a nr_segs argument. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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6869875f |
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21-May-2019 |
Christoph Hellwig <hch@lst.de> |
block: remove the bi_seg_{front,back}_size fields in struct bio At this point these fields aren't used for anything, so we can remove them. Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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200a9aff |
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21-May-2019 |
Christoph Hellwig <hch@lst.de> |
block: remove the segment size check in bio_will_gap We fundamentally do not have a maximum segement size for devices with a virt boundary. So don't bother checking it, especially given that the existing checks didn't properly work to start with as we never fully update the front/back segment size and miss the bi_seg_front_size that wuld have been required for some cases. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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eded341c |
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21-May-2019 |
Christoph Hellwig <hch@lst.de> |
block: don't decrement nr_phys_segments for physically contigous segments Currently ll_merge_requests_fn, unlike all other merge functions, reduces nr_phys_segments by one if the last segment of the previous, and the first segment of the next segement are contigous. While this seems like a nice solution to avoid building smaller than possible requests it causes a mismatch between the segments actually present in the request and those iterated over by the bvec iterators, including __rq_for_each_bio. This can for example mistrigger the single segment optimization in the nvme-pci driver, and might lead to mismatching nr_phys_segments number when recalculating the number of request when inserting a cloned request. We could possibly work around this by making the bvec iterators take the front and back segment size into account, but that would require moving them from the bio to the bio_iter and spreading this mess over all users of bvecs. Or we could simply remove this optimization under the assumption that most users already build good enough bvecs, and that the bio merge patch never cared about this optimization either. The latter is what this patch does. dff824b2aadb ("nvme-pci: optimize mapping of small single segment requests"). Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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f9f76879 |
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19-Apr-2019 |
Christoph Hellwig <hch@lst.de> |
block: avoid scatterlist offsets > PAGE_SIZE While we generally allow scatterlists to have offsets larger than page size for an entry, and other subsystems like the crypto code make use of that, the block layer isn't quite ready for that. Flip the switch back to avoid them for now, and revisit that decision early in a merge window once the known offenders are fixed. Fixes: 8a96a0e40810 ("block: rewrite blk_bvec_map_sg to avoid a nth_page call") Reviewed-by: Ming Lei <ming.lei@redhat.com> Tested-by: Guenter Roeck <linux@roeck-us.net> Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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8a96a0e4 |
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11-Apr-2019 |
Christoph Hellwig <hch@lst.de> |
block: rewrite blk_bvec_map_sg to avoid a nth_page call The offset in scatterlists is allowed to be larger than the page size, so don't go to great length to avoid that case and simplify the arithmetics. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
b21e11c5 |
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01-Apr-2019 |
Ming Lei <ming.lei@redhat.com> |
block: fix build warning in merging bvecs Commit f6970f83ef79 ("block: don't check if adjacent bvecs in one bio can be mergeable") changes bvec merge by only considering two bvecs from different bios. However, if the former bio doesn't inlcude any io bvec, then the following warning may be triggered: warning: ‘bvec.bv_offset’ may be used uninitialized in this function [-Wmaybe-uninitialized] In practice, it shouldn't be triggered. Fixes it by adding check on former bio, the check shouldn't add any cost given 'bio->bi_iter' can be hit in cache. Reported-by: Jens Axboe <axboe@kernel.dk> Fixes: f6970f83ef79 ("block: don't check if adjacent bvecs in one bio can be mergeable") Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
f6970f83 |
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17-Mar-2019 |
Ming Lei <ming.lei@redhat.com> |
block: don't check if adjacent bvecs in one bio can be mergeable Now both passthrough and FS IO have supported multi-page bvec, and bvec merging has been handled actually when adding page to bio, then adjacent bvecs won't be mergeable any more if they belong to same bio. So only try to merge bvecs if they are from different bios. Cc: Omar Sandoval <osandov@fb.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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16e3e418 |
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17-Mar-2019 |
Ming Lei <ming.lei@redhat.com> |
block: reuse __blk_bvec_map_sg() for mapping page sized bvec Inside __blk_segment_map_sg(), page sized bvec mapping is optimized a bit with one standalone branch. So reuse __blk_bvec_map_sg() to do that. Cc: Omar Sandoval <osandov@fb.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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cae6c2e5 |
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17-Mar-2019 |
Ming Lei <ming.lei@redhat.com> |
block: remove argument of 'request_queue' from __blk_bvec_map_sg The argument of 'request_queue' isn't used by __blk_bvec_map_sg(), so remove it. Cc: Omar Sandoval <osandov@fb.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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fd7d8d42 |
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17-Mar-2019 |
Ming Lei <ming.lei@redhat.com> |
block: don't merge adjacent bvecs to one segment in bio blk_queue_split For normal filesystem IO, each page is added via blk_add_page(), in which bvec(page) merge has been handled already, and basically not possible to merge two adjacent bvecs in one bio. So not try to merge two adjacent bvecs in blk_queue_split(). Cc: Omar Sandoval <osandov@fb.com> Cc: Christoph Hellwig <hch@lst.de> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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05b700ba |
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03-Mar-2019 |
Ming Lei <ming.lei@redhat.com> |
block: fix segment calculation for passthrough IO blk_recount_segments() can be called in bio_add_pc_page() for calculating how many segments this bio will has after one page is added to this bio. If the resulted segment number is beyond the queue limit, the added page will be removed. The try-and-fix policy requires blk_recount_segments(__blk_recalc_rq_segments) to not consider the segment number limit. Unfortunately bvec_split_segs() does check this limit, and causes small segment number returned to bio_add_pc_page(), then page still may be added to the bio even though segment number limit becomes broken. Fixes this issue by not considering segment number limit when calcualting bio's segment number. Fixes: dcebd755926b ("block: use bio_for_each_bvec() to compute multi-page bvec count") Cc: Christoph Hellwig <hch@lst.de> Cc: Omar Sandoval <osandov@fb.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
aaeee62c |
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02-Mar-2019 |
Ming Lei <ming.lei@redhat.com> |
block: fix updating bio's front segment size When the current bvec can be merged to the 1st segment, the bio's front segment size has to be updated. However, dcebd755926b doesn't consider that case, then bio's front segment size may not be correct. This patch fixes this issue. Cc: Christoph Hellwig <hch@lst.de> Cc: Omar Sandoval <osandov@fb.com> Fixes: dcebd755926b ("block: use bio_for_each_bvec() to compute multi-page bvec count") Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
bbcbbd56 |
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27-Feb-2019 |
Ming Lei <ming.lei@redhat.com> |
block: optimize blk_bio_segment_split for single-page bvec Introduce a fast path for single-page bvec IO, then we can avoid to call bvec_split_segs() unnecessarily. Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
48d7727c |
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27-Feb-2019 |
Ming Lei <ming.lei@redhat.com> |
block: optimize __blk_segment_map_sg() for single-page bvec Introduce a fast path for single-page bvec IO, then blk_bvec_map_sg() can be avoided. Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
4d633062 |
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27-Feb-2019 |
Ming Lei <ming.lei@redhat.com> |
block: introduce bvec_nth_page() Single-page bvec can often be seen in small BS workloads, so introduce bvec_nth_page() for avoiding to call nth_page() unnecessarily, which looks not cheap. Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
49b1f22b |
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18-Feb-2019 |
Ming Lei <ming.lei@redhat.com> |
block: avoid to READ fields of null bio rq->bio can be NULL sometimes, such as flush request, so don't read bio->bi_seg_front_size until this 'bio' is checked as valid. Cc: Bart Van Assche <bvanassche@acm.org> Reported-by: Bart Van Assche <bvanassche@acm.org> Fixes: dcebd755926b0f39dd1e ("block: use bio_for_each_bvec() to compute multi-page bvec count") Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
2705c937 |
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15-Feb-2019 |
Ming Lei <ming.lei@redhat.com> |
block: kill QUEUE_FLAG_NO_SG_MERGE Since bdced438acd83ad83a6c ("block: setup bi_phys_segments after splitting"), physical segment number is mainly figured out in blk_queue_split() for fast path, and the flag of BIO_SEG_VALID is set there too. Now only blk_recount_segments() and blk_recalc_rq_segments() use this flag. Basically blk_recount_segments() is bypassed in fast path given BIO_SEG_VALID is set in blk_queue_split(). For another user of blk_recalc_rq_segments(): - run in partial completion branch of blk_update_request, which is an unusual case - run in blk_cloned_rq_check_limits(), still not a big problem if the flag is killed since dm-rq is the only user. Multi-page bvec is enabled now, not doing S/G merging is rather pointless with the current setup of the I/O path, as it isn't going to save you a significant amount of cycles. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
862e5a5e |
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15-Feb-2019 |
Ming Lei <ming.lei@redhat.com> |
block: use bio_for_each_bvec() to map sg It is more efficient to use bio_for_each_bvec() to map sg, meantime we have to consider splitting multipage bvec as done in blk_bio_segment_split(). Reviewed-by: Omar Sandoval <osandov@fb.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
dcebd755 |
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15-Feb-2019 |
Ming Lei <ming.lei@redhat.com> |
block: use bio_for_each_bvec() to compute multi-page bvec count First it is more efficient to use bio_for_each_bvec() in both blk_bio_segment_split() and __blk_recalc_rq_segments() to compute how many multi-page bvecs there are in the bio. Secondly once bio_for_each_bvec() is used, the bvec may need to be splitted because its length can be very longer than max segment size, so we have to split the big bvec into several segments. Thirdly when splitting multi-page bvec into segments, the max segment limit may be reached, so the bio split need to be considered under this situation too. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
1a67356e |
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15-Feb-2019 |
Ming Lei <ming.lei@redhat.com> |
block: don't use bio->bi_vcnt to figure out segment number It is wrong to use bio->bi_vcnt to figure out how many segments there are in the bio even though CLONED flag isn't set on this bio, because this bio may be splitted or advanced. So always use bio_segments() in blk_recount_segments(), and it shouldn't cause any performance loss now because the physical segment number is figured out in blk_queue_split() and BIO_SEG_VALID is set meantime since bdced438acd83ad83a6c ("block: setup bi_phys_segments after splitting"). Reviewed-by: Omar Sandoval <osandov@fb.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Fixes: 76d8137a3113 ("blk-merge: recaculate segment if it isn't less than max segments") Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
947b7ac1 |
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27-Jan-2019 |
Jens Axboe <axboe@kernel.dk> |
Revert "block: cover another queue enter recursion via BIO_QUEUE_ENTERED" We can't touch a bio after ->make_request_fn(), for all we know it could already have been completed by the time this function returns. This reverts commit 698cef173983b086977e633e46476e0f925ca01e. Reported-by: syzbot+4df6ca820108fd248943@syzkaller.appspotmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
698cef17 |
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22-Jan-2019 |
Ming Lei <ming.lei@redhat.com> |
block: cover another queue enter recursion via BIO_QUEUE_ENTERED Except for blk_queue_split(), bio_split() is used for splitting bio too, then the remained bio is often resubmit to queue via generic_make_request(). So the same queue enter recursion exits in this case too. Unfortunatley commit cd4a4ae4683dc2 doesn't help this case. This patch covers the above case by setting BIO_QUEUE_ENTERED before calling q->make_request_fn. In theory the per-bio flag is used to simulate one stack variable, it is just fine to clear it after q->make_request_fn is returned. Especially the same bio can't be submitted from another context. Fixes: cd4a4ae4683dc2 ("block: don't use blocking queue entered for recursive bio submits") Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: NeilBrown <neilb@suse.com> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
38417468 |
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13-Dec-2018 |
Christoph Hellwig <hch@lst.de> |
scsi: block: remove the cluster flag Now that the the SCSI layer replaced the use of the cluster flag with segment size limits and the DMA boundary we can remove the cluster flag from the block layer. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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#
637b60ad |
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13-Dec-2018 |
Christoph Hellwig <hch@lst.de> |
block: remove the blk_recount_segments export Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
5b18b5a7 |
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06-Dec-2018 |
Mikulas Patocka <mpatocka@redhat.com> |
block: delete part_round_stats and switch to less precise counting We want to convert to per-cpu in_flight counters. The function part_round_stats needs the in_flight counter every jiffy, it would be too costly to sum all the percpu variables every jiffy, so it must be deleted. part_round_stats is used to calculate two counters - time_in_queue and io_ticks. time_in_queue can be calculated without part_round_stats, by adding the duration of the I/O when the I/O ends (the value is almost as exact as the previously calculated value, except that time for in-progress I/Os is not counted). io_ticks can be approximated by increasing the value when I/O is started or ended and the jiffies value has changed. If the I/Os take less than a jiffy, the value is as exact as the previously calculated value. If the I/Os take more than a jiffy, io_ticks can drift behind the previously calculated value. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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112f158f |
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06-Dec-2018 |
Mike Snitzer <snitzer@redhat.com> |
block: stop passing 'cpu' to all percpu stats methods All of part_stat_* and related methods are used with preempt disabled, so there is no need to pass cpu around to allow of them. Just call smp_processor_id() as needed. Suggested-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
2a5cf35c |
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30-Nov-2018 |
Ming Lei <ming.lei@redhat.com> |
block: fix single range discard merge There are actually two kinds of discard merge: - one is the normal discard merge, just like normal read/write request, and call it single-range discard - another is the multi-range discard, queue_max_discard_segments(rq->q) > 1 For the former case, queue_max_discard_segments(rq->q) is 1, and we should handle this kind of discard merge like the normal read/write request. This patch fixes the following kernel panic issue[1], which is caused by not removing the single-range discard request from elevator queue. Guangwu has one raid discard test case, in which this issue is a bit easier to trigger, and I verified that this patch can fix the kernel panic issue in Guangwu's test case. [1] kernel panic log from Jens's report BUG: unable to handle kernel NULL pointer dereference at 0000000000000148 PGD 0 P4D 0. Oops: 0000 [#1] SMP PTI CPU: 37 PID: 763 Comm: kworker/37:1H Not tainted \ 4.20.0-rc3-00649-ge64d9a554a91-dirty #14 Hardware name: Wiwynn \ Leopard-Orv2/Leopard-DDR BW, BIOS LBM08 03/03/2017 Workqueue: kblockd \ blk_mq_run_work_fn RIP: \ 0010:blk_mq_get_driver_tag+0x81/0x120 Code: 24 \ 10 48 89 7c 24 20 74 21 83 fa ff 0f 95 c0 48 8b 4c 24 28 65 48 33 0c 25 28 00 00 00 \ 0f 85 96 00 00 00 48 83 c4 30 5b 5d c3 <48> 8b 87 48 01 00 00 8b 40 04 39 43 20 72 37 \ f6 87 b0 00 00 00 02 RSP: 0018:ffffc90004aabd30 EFLAGS: 00010246 \ RAX: 0000000000000003 RBX: ffff888465ea1300 RCX: ffffc90004aabde8 RDX: 00000000ffffffff RSI: ffffc90004aabde8 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffff888465ea1348 R09: 0000000000000000 R10: 0000000000001000 R11: 00000000ffffffff R12: ffff888465ea1300 R13: 0000000000000000 R14: ffff888465ea1348 R15: ffff888465d10000 FS: 0000000000000000(0000) GS:ffff88846f9c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000148 CR3: 000000000220a003 CR4: 00000000003606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: blk_mq_dispatch_rq_list+0xec/0x480 ? elv_rb_del+0x11/0x30 blk_mq_do_dispatch_sched+0x6e/0xf0 blk_mq_sched_dispatch_requests+0xfa/0x170 __blk_mq_run_hw_queue+0x5f/0xe0 process_one_work+0x154/0x350 worker_thread+0x46/0x3c0 kthread+0xf5/0x130 ? process_one_work+0x350/0x350 ? kthread_destroy_worker+0x50/0x50 ret_from_fork+0x1f/0x30 Modules linked in: sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel \ kvm switchtec irqbypass iTCO_wdt iTCO_vendor_support efivars cdc_ether usbnet mii \ cdc_acm i2c_i801 lpc_ich mfd_core ipmi_si ipmi_devintf ipmi_msghandler acpi_cpufreq \ button sch_fq_codel nfsd nfs_acl lockd grace auth_rpcgss oid_registry sunrpc nvme \ nvme_core fuse sg loop efivarfs autofs4 CR2: 0000000000000148 \ ---[ end trace 340a1fb996df1b9b ]--- RIP: 0010:blk_mq_get_driver_tag+0x81/0x120 Code: 24 10 48 89 7c 24 20 74 21 83 fa ff 0f 95 c0 48 8b 4c 24 28 65 48 33 0c 25 28 \ 00 00 00 0f 85 96 00 00 00 48 83 c4 30 5b 5d c3 <48> 8b 87 48 01 00 00 8b 40 04 39 43 \ 20 72 37 f6 87 b0 00 00 00 02 Fixes: 445251d0f4d329a ("blk-mq: fix discard merge with scheduler attached") Reported-by: Jens Axboe <axboe@kernel.dk> Cc: Guangwu Zhang <guazhang@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Jianchao Wang <jianchao.w.wang@oracle.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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668ffc03 |
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19-Nov-2018 |
Damien Le Moal <damien.lemoal@wdc.com> |
block: prevent merging of requests with different priorities Growing in size a high priority request by merging it with a lower priority BIO or request will increase the request execution time. This is the opposite result of the desired effect of high I/O priorities, namely getting low I/O latencies. Prevent merging of requests and BIOs that have different I/O priorities to fix this. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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e96c0d83 |
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14-Nov-2018 |
Eric Biggers <ebiggers@google.com> |
block: make blk_try_req_merge() static blk_try_req_merge() is only used in block/blk-merge.c, so make it static. This addresses a gcc warning when -Wmissing-prototypes is enabled. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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1adfc5e4 |
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29-Oct-2018 |
Ming Lei <ming.lei@redhat.com> |
block: make sure discard bio is aligned with logical block size Obviously the created discard bio has to be aligned with logical block size. This patch introduces the helper of bio_allowed_max_sectors() for this purpose. Cc: stable@vger.kernel.org Cc: Mike Snitzer <snitzer@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Xiao Ni <xni@redhat.com> Cc: Mariusz Dabrowski <mariusz.dabrowski@intel.com> Fixes: 744889b7cbb56a6 ("block: don't deal with discard limit in blkdev_issue_discard()") Fixes: a22c4d7e34402cc ("block: re-add discard_granularity and alignment checks") Reported-by: Rui Salvaterra <rsalvaterra@gmail.com> Tested-by: Rui Salvaterra <rsalvaterra@gmail.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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9cf2bab6 |
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31-Oct-2018 |
Jens Axboe <axboe@kernel.dk> |
block: kill request ->cpu member This was used for completion placement for the legacy path, but for mq we have rq->mq_ctx->cpu for that. Add a helper to get the request CPU assignment, as the mq_ctx type is private to blk-mq. Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
8b98a97f |
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20-Oct-2018 |
Jens Axboe <axboe@kernel.dk> |
blk-merge: kill dead queue lock held check This is dead code, any queue reaching this part has mq_ops attached. Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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2081a56b |
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12-Oct-2018 |
Jens Axboe <axboe@kernel.dk> |
block: remove req_no_special_merge() from merging code It'll always be false at this point, just remove it. Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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92bc5a24 |
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24-Oct-2018 |
Jens Axboe <axboe@kernel.dk> |
block: remove __blk_put_request() Now there's no difference between blk_put_request() and __blk_put_request() anymore, get rid of the underscore version and convert the few callers. Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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a1ce35fa |
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29-Oct-2018 |
Jens Axboe <axboe@kernel.dk> |
block: remove dead elevator code This removes a bunch of core and elevator related code. On the core front, we remove anything related to queue running, draining, initialization, plugging, and congestions. We also kill anything related to request allocation, merging, retrieval, and completion. Remove any checking for single queue IO schedulers, as they no longer exist. This means we can also delete a bunch of code related to request issue, adding, completion, etc - and all the SQ related ops and helpers. Also kill the load_default_modules(), as all that did was provide for a way to load the default single queue elevator. Tested-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
df376b2e |
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07-Nov-2018 |
Johannes Thumshirn <jthumshirn@suse.de> |
block: respect virtual boundary mask in bvecs With drivers that are settting a virtual boundary constrain, we are seeing a lot of bio splitting and smaller I/Os being submitted to the driver. This happens because the bio gap detection code does not account cases where PAGE_SIZE - 1 is bigger than queue_virt_boundary() and thus will split the bio unnecessarily. Cc: Jan Kara <jack@suse.cz> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Ming Lei <ming.lei@redhat.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> Acked-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
69840466 |
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27-Oct-2018 |
Jianchao Wang <jianchao.w.wang@oracle.com> |
block: fix the DISCARD request merge There are two cases when handle DISCARD merge. If max_discard_segments == 1, the bios/requests need to be contiguous to merge. If max_discard_segments > 1, it takes every bio as a range and different range needn't to be contiguous. But now, attempt_merge screws this up. It always consider contiguity for DISCARD for the case max_discard_segments > 1 and cannot merge contiguous DISCARD for the case max_discard_segments == 1, because rq_attempt_discard_merge always returns false in this case. This patch fixes both of the two cases above. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jianchao Wang <jianchao.w.wang@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
3dccdae5 |
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24-Sep-2018 |
Christoph Hellwig <hch@lst.de> |
block: merge BIOVEC_SEG_BOUNDARY into biovec_phys_mergeable These two checks should always be performed together, so merge them into a single helper. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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6a9f5f24 |
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24-Sep-2018 |
Christoph Hellwig <hch@lst.de> |
block: simplify BIOVEC_PHYS_MERGEABLE Turn the macro into an inline, move it to blk.h and simplify the arch hooks a bit. Also rename the function to biovec_phys_mergeable as there is no need to shout. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
e9907009 |
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24-Sep-2018 |
Christoph Hellwig <hch@lst.de> |
block: move req_gap_{back,front}_merge to blk-merge.c Keep it close to the actual users instead of exposing the function to all drivers. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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cd4a4ae4 |
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02-Jun-2018 |
Jens Axboe <axboe@kernel.dk> |
block: don't use blocking queue entered for recursive bio submits If we end up splitting a bio and the queue goes away between the initial submission and the later split submission, then we can block forever in blk_queue_enter() waiting for the reference to drop to zero. This will never happen, since we already hold a reference. Mark a split bio as already having entered the queue, so we can just use the live non-blocking queue enter variant. Thanks to Tetsuo Handa for the analysis. Reported-by: syzbot+c4f9cebf9d651f6e54de@syzkaller.appspotmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
338aa96d |
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20-May-2018 |
Kent Overstreet <kent.overstreet@gmail.com> |
block: convert bounce, q->bio_split to bioset_init()/mempool_init() Convert the core block functionality to embedded bio sets. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
522a7775 |
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09-May-2018 |
Omar Sandoval <osandov@fb.com> |
block: consolidate struct request timestamp fields Currently, struct request has four timestamp fields: - A start time, set at get_request time, in jiffies, used for iostats - An I/O start time, set at start_request time, in ktime nanoseconds, used for blk-stats (i.e., wbt, kyber, hybrid polling) - Another start time and another I/O start time, used for cfq and bfq These can all be consolidated into one start time and one I/O start time, both in ktime nanoseconds, shaving off up to 16 bytes from struct request depending on the kernel config. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
445251d0 |
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01-Feb-2018 |
Jens Axboe <axboe@kernel.dk> |
blk-mq: fix discard merge with scheduler attached I ran into an issue on my laptop that triggered a bug on the discard path: WARNING: CPU: 2 PID: 207 at drivers/nvme/host/core.c:527 nvme_setup_cmd+0x3d3/0x430 Modules linked in: rfcomm fuse ctr ccm bnep arc4 binfmt_misc snd_hda_codec_hdmi nls_iso8859_1 nls_cp437 vfat snd_hda_codec_conexant fat snd_hda_codec_generic iwlmvm snd_hda_intel snd_hda_codec snd_hwdep mac80211 snd_hda_core snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq x86_pkg_temp_thermal intel_powerclamp kvm_intel uvcvideo iwlwifi btusb snd_seq_device videobuf2_vmalloc btintel videobuf2_memops kvm snd_timer videobuf2_v4l2 bluetooth irqbypass videobuf2_core aesni_intel aes_x86_64 crypto_simd cryptd snd glue_helper videodev cfg80211 ecdh_generic soundcore hid_generic usbhid hid i915 psmouse e1000e ptp pps_core xhci_pci xhci_hcd intel_gtt CPU: 2 PID: 207 Comm: jbd2/nvme0n1p7- Tainted: G U 4.15.0+ #176 Hardware name: LENOVO 20FBCTO1WW/20FBCTO1WW, BIOS N1FET59W (1.33 ) 12/19/2017 RIP: 0010:nvme_setup_cmd+0x3d3/0x430 RSP: 0018:ffff880423e9f838 EFLAGS: 00010217 RAX: 0000000000000000 RBX: ffff880423e9f8c8 RCX: 0000000000010000 RDX: ffff88022b200010 RSI: 0000000000000002 RDI: 00000000327f0000 RBP: ffff880421251400 R08: ffff88022b200000 R09: 0000000000000009 R10: 0000000000000000 R11: 0000000000000000 R12: 000000000000ffff R13: ffff88042341e280 R14: 000000000000ffff R15: ffff880421251440 FS: 0000000000000000(0000) GS:ffff880441500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055b684795030 CR3: 0000000002e09006 CR4: 00000000001606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: nvme_queue_rq+0x40/0xa00 ? __sbitmap_queue_get+0x24/0x90 ? blk_mq_get_tag+0xa3/0x250 ? wait_woken+0x80/0x80 ? blk_mq_get_driver_tag+0x97/0xf0 blk_mq_dispatch_rq_list+0x7b/0x4a0 ? deadline_remove_request+0x49/0xb0 blk_mq_do_dispatch_sched+0x4f/0xc0 blk_mq_sched_dispatch_requests+0x106/0x170 __blk_mq_run_hw_queue+0x53/0xa0 __blk_mq_delay_run_hw_queue+0x83/0xa0 blk_mq_run_hw_queue+0x6c/0xd0 blk_mq_sched_insert_request+0x96/0x140 __blk_mq_try_issue_directly+0x3d/0x190 blk_mq_try_issue_directly+0x30/0x70 blk_mq_make_request+0x1a4/0x6a0 generic_make_request+0xfd/0x2f0 ? submit_bio+0x5c/0x110 submit_bio+0x5c/0x110 ? __blkdev_issue_discard+0x152/0x200 submit_bio_wait+0x43/0x60 ext4_process_freed_data+0x1cd/0x440 ? account_page_dirtied+0xe2/0x1a0 ext4_journal_commit_callback+0x4a/0xc0 jbd2_journal_commit_transaction+0x17e2/0x19e0 ? kjournald2+0xb0/0x250 kjournald2+0xb0/0x250 ? wait_woken+0x80/0x80 ? commit_timeout+0x10/0x10 kthread+0x111/0x130 ? kthread_create_worker_on_cpu+0x50/0x50 ? do_group_exit+0x3a/0xa0 ret_from_fork+0x1f/0x30 Code: 73 89 c1 83 ce 10 c1 e1 10 09 ca 83 f8 04 0f 87 0f ff ff ff 8b 4d 20 48 8b 7d 00 c1 e9 09 48 01 8c c7 00 08 00 00 e9 f8 fe ff ff <0f> ff 4c 89 c7 41 bc 0a 00 00 00 e8 0d 78 d6 ff e9 a1 fc ff ff ---[ end trace 50d361cc444506c8 ]--- print_req_error: I/O error, dev nvme0n1, sector 847167488 Decoding the assembly, the request claims to have 0xffff segments, while nvme counts two. This turns out to be because we don't check for a data carrying request on the mq scheduler path, and since blk_phys_contig_segment() returns true for a non-data request, we decrement the initial segment count of 0 and end up with 0xffff in the unsigned short. There are a few issues here: 1) We should initialize the segment count for a discard to 1. 2) The discard merging is currently using the data limits for segments and sectors. Fix this up by having attempt_merge() correctly identify the request, and by initializing the segment count correctly for discards. This can only be triggered with mq-deadline on discard capable devices right now, which isn't a common configuration. Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
b4b6cb61 |
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09-Jan-2018 |
Ming Lei <ming.lei@redhat.com> |
Revert "block: blk-merge: try to make front segments in full size" This reverts commit a2d37968d784363842f87820a21e106741d28004. If max segment size isn't 512-aligned, this patch won't work well. Also once multipage bvec is enabled, adjacent bvecs won't be physically contiguous if page is added via bio_add_page(), so we don't need this kind of complicated logic. Reported-by: Dmitry Osipenko <digetx@gmail.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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cf8c0c6a |
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18-Dec-2017 |
Ming Lei <ming.lei@redhat.com> |
block: blk-merge: remove unnecessary check In this case, 'sectors' can't be zero at all, so remove the check and let the bio be split. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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a2d37968 |
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18-Dec-2017 |
Ming Lei <ming.lei@redhat.com> |
block: blk-merge: try to make front segments in full size When merging one bvec into segment, if the bvec is too big to merge, current policy is to move the whole bvec into another new segment. This patchset changes the policy into trying to maximize size of front segments, that means in above situation, part of bvec is merged into current segment, and the remainder is put into next segment. This patch prepares for support multipage bvec because it can be quite common to see this case and we should try to make front segments in full size. Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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6a501bf0 |
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18-Dec-2017 |
Ming Lei <ming.lei@redhat.com> |
blk-merge: compute bio->bi_seg_front_size efficiently It is enough to check and compute bio->bi_seg_front_size just after the 1st segment is found, but current code checks that for each bvec, which is inefficient. This patch follows the way in __blk_recalc_rq_segments() for computing bio->bi_seg_front_size, and it is more efficient and code becomes more readable too. Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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b2441318 |
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01-Nov-2017 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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74d46992 |
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23-Aug-2017 |
Christoph Hellwig <hch@lst.de> |
block: replace bi_bdev with a gendisk pointer and partitions index This way we don't need a block_device structure to submit I/O. The block_device has different life time rules from the gendisk and request_queue and is usually only available when the block device node is open. Other callers need to explicitly create one (e.g. the lightnvm passthrough code, or the new nvme multipathing code). For the actual I/O path all that we need is the gendisk, which exists once per block device. But given that the block layer also does partition remapping we additionally need a partition index, which is used for said remapping in generic_make_request. Note that all the block drivers generally want request_queue or sometimes the gendisk, so this removes a layer of indirection all over the stack. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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d62e26b3 |
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30-Jun-2017 |
Jens Axboe <axboe@kernel.dk> |
block: pass in queue to inflight accounting No functional change in this patch, just in preparation for basing the inflight mechanism on the queue in question. Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
cb6934f8 |
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27-Jun-2017 |
Jens Axboe <axboe@kernel.dk> |
block: add support for write hints in a bio No functional changes in this patch, we just use up some holes in the bio and request structures to define a write hint that we psas down the stack. Ensure that we don't merge requests that have different life time hints assigned to them, and that we inherit the write hint when cloning a bio. Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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2fff8a92 |
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20-Jun-2017 |
Bart Van Assche <bvanassche@acm.org> |
block: Check locking assumptions at runtime Instead of documenting the locking assumptions of most block layer functions as a comment, use lockdep_assert_held() to verify locking assumptions at runtime. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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58c94cc1 |
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17-Jun-2017 |
NeilBrown <neilb@suse.com> |
block: don't check for BIO_MAX_PAGES in blk_bio_segment_split() blk_bio_segment_split() makes sure bios have no more than BIO_MAX_PAGES entries in the bi_io_vec. This was done because bio_clone_bioset() (when given a mempool bioset) could not handle larger io_vecs. No driver uses bio_clone_bioset() any more, they all use bio_clone_fast() if anything, and bio_clone_fast() doesn't clone the bi_io_vec. The main user of of bio_clone_bioset() at this level is bounce.c, and bouncing now happens before blk_bio_segment_split(), so that is not of concern. So remove the big helpful comment and the code. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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9b10f6a9 |
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17-Jun-2017 |
NeilBrown <neilb@suse.com> |
block: remove bio_clone() and all references. bio_clone() is no longer used. Only bio_clone_bioset() or bio_clone_fast(). This is for the best, as bio_clone() used fs_bio_set, and filesystems are unlikely to want to use bio_clone(). So remove bio_clone() and all references. This includes a fix to some incorrect documentation. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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a8821f3f |
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17-Jun-2017 |
NeilBrown <neilb@suse.com> |
block: Improvements to bounce-buffer handling Since commit 23688bf4f830 ("block: ensure to split after potentially bouncing a bio") blk_queue_bounce() is called *before* blk_queue_split(). This means that: 1/ the comments blk_queue_split() about bounce buffers are irrelevant, and 2/ a very large bio (more than BIO_MAX_PAGES) will no longer be split before it arrives at blk_queue_bounce(), leading to the possibility that bio_clone_bioset() will fail and a NULL will be dereferenced. Separately, blk_queue_bounce() shouldn't use fs_bio_set as the bio being copied could be from the same set, and this could lead to a deadlock. So: - allocate 2 private biosets for blk_queue_bounce, one for splitting enormous bios and one for cloning bios. - add code to split a bio that exceeds BIO_MAX_PAGES. - Fix up the comments in blk_queue_split() Credit-to: Ming Lei <tom.leiming@gmail.com> (suggested using single bio_for_each_segment loop) Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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af67c31f |
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17-Jun-2017 |
NeilBrown <neilb@suse.com> |
blk: remove bio_set arg from blk_queue_split() blk_queue_split() is always called with the last arg being q->bio_split, where 'q' is the first arg. Also blk_queue_split() sometimes uses the passed-in 'bs' and sometimes uses q->bio_split. This is inconsistent and unnecessary. Remove the last arg and always use q->bio_split inside blk_queue_split() Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Credit-to: Javier González <jg@lightnvm.io> (Noticed that lightnvm was missed) Reviewed-by: Javier González <javier@cnexlabs.com> Tested-by: Javier González <javier@cnexlabs.com> Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
885fa13f |
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05-Apr-2017 |
Christoph Hellwig <hch@lst.de> |
block: implement splitting of REQ_OP_WRITE_ZEROES bios Copy and past the REQ_OP_WRITE_SAME code to prepare to implementations that limit the write zeroes size. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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1e739730 |
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08-Feb-2017 |
Christoph Hellwig <hch@lst.de> |
block: optionally merge discontiguous discard bios into a single request Add a new merge strategy that merges discard bios into a request until the maximum number of discard ranges (or the maximum discard size) is reached from the plug merging code. I/O scheduler merging is not wired up yet but might also be useful, although not for fast devices like NVMe which are the only user for now. Note that for now we don't support limiting the size of each discard range, but if needed that can be added later. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
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34fe7c05 |
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08-Feb-2017 |
Christoph Hellwig <hch@lst.de> |
block: enumify ELEVATOR_*_MERGE Switch these constants to an enum, and make let the compiler ensure that all callers of blk_try_merge and elv_merge handle all potential values. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
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6cf7677f |
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08-Feb-2017 |
Christoph Hellwig <hch@lst.de> |
block: move req_set_nomerge to blk.h This makes it available outside of blk-merge.c, and inlining such a trivial helper seems pretty useful to start with. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
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e4d750c9 |
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03-Feb-2017 |
Jens Axboe <axboe@fb.com> |
block: free merged request in the caller If we end up doing a request-to-request merge when we have completed a bio-to-request merge, we free the request from deep down in that path. For blk-mq-sched, the merge path has to hold the appropriate lock, but we don't need it for freeing the request. And in fact holding the lock is problematic, since we are now calling the mq sched put_rq_private() hook with the lock held. Other call paths do not hold this lock. Fix this inconsistency by ensuring that the caller frees a merged request. Then we can do it outside of the lock, making it both more efficient and fixing the blk-mq-sched problem of invoking parts of the scheduler with an unknown lock state. Reported-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@fb.com> Reviewed-by: Omar Sandoval <osandov@fb.com>
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b973cb7e |
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02-Feb-2017 |
Jens Axboe <axboe@fb.com> |
blk-merge: return the merged request When we attempt to merge request-to-request, we return a 0/1 if we ended up merging or not. Change that to return the pointer to the request that we freed. We will use this to move the freeing of that request out of the merge logic, so that callers can drop locks before freeing the request. There should be no functional changes in this patch. Signed-off-by: Jens Axboe <axboe@fb.com> Reviewed-by: Omar Sandoval <osandov@fb.com>
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bd166ef1 |
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17-Jan-2017 |
Jens Axboe <axboe@fb.com> |
blk-mq-sched: add framework for MQ capable IO schedulers This adds a set of hooks that intercepts the blk-mq path of allocating/inserting/issuing/completing requests, allowing us to develop a scheduler within that framework. We reuse the existing elevator scheduler API on the registration side, but augment that with the scheduler flagging support for the blk-mq interfce, and with a separate set of ops hooks for MQ devices. We split driver and scheduler tags, so we can run the scheduling independently of device queue depth. Signed-off-by: Jens Axboe <axboe@fb.com> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Omar Sandoval <osandov@fb.com>
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c51ca6cf |
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10-Dec-2016 |
Jens Axboe <axboe@fb.com> |
block: move existing elevator ops to union Prep patch for adding MQ ops as well, since doing anon unions with named initializers doesn't work on older compilers. Signed-off-by: Jens Axboe <axboe@fb.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Omar Sandoval <osandov@fb.com>
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f9d03f96 |
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08-Dec-2016 |
Christoph Hellwig <hch@lst.de> |
block: improve handling of the magic discard payload Instead of allocating a single unused biovec for discard requests, send them down without any payload. Instead we allow the driver to add a "special" payload using a biovec embedded into struct request (unioned over other fields never used while in the driver), and overloading the number of segments for this case. This has a couple of advantages: - we don't have to allocate the bio_vec - the amount of special casing for discard requests in the block layer is significantly reduced - using this same scheme for other request types is trivial, which will be important for implementing the new WRITE_ZEROES op on devices where it actually requires a payload (e.g. SCSI) - we can get rid of playing games with the request length, as we'll never touch it and completions will work just fine - it will allow us to support ranged discard operations in the future by merging non-contiguous discard bios into a single request - last but not least it removes a lot of code This patch is the common base for my WIP series for ranges discards and to remove discard_zeroes_data in favor of always using REQ_OP_WRITE_ZEROES, so it would be good to get it in quickly. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
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e0c72300 |
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01-Dec-2016 |
Ritesh Harjani <riteshh@codeaurora.org> |
block: factor out req_set_nomerge Factor out common code for setting REQ_NOMERGE flag which is being used out at certain places and make it a helper instead, req_set_nomerge(). Signed-off-by: Ritesh Harjani <riteshh@codeaurora.org> Get rid of the inline. Signed-off-by: Jens Axboe <axboe@fb.com>
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#
a6f0788e |
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30-Nov-2016 |
Chaitanya Kulkarni <chaitanya.kulkarni@hgst.com> |
block: add support for REQ_OP_WRITE_ZEROES This adds a new block layer operation to zero out a range of LBAs. This allows to implement zeroing for devices that don't use either discard with a predictable zero pattern or WRITE SAME of zeroes. The prominent example of that is NVMe with the Write Zeroes command, but in the future, this should also help with improving the way zeroing discards work. For this operation, suitable entry is exported in sysfs which indicate the number of maximum bytes allowed in one write zeroes operation by the device. Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@hgst.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
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e8064021 |
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20-Oct-2016 |
Christoph Hellwig <hch@lst.de> |
block: split out request-only flags into a new namespace A lot of the REQ_* flags are only used on struct requests, and only of use to the block layer and a few drivers that dig into struct request internals. This patch adds a new req_flags_t rq_flags field to struct request for them, and thus dramatically shrinks the number of common requests. It also removes the unfortunate situation where we have to fit the fields from the same enum into 32 bits for struct bio and 64 bits for struct request. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Shaun Tancheff <shaun.tancheff@seagate.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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4d70dca4 |
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23-Aug-2016 |
Ming Lei <ming.lei@canonical.com> |
block: make sure a big bio is split into at most 256 bvecs After arbitrary bio size was introduced, the incoming bio may be very big. We have to split the bio into small bios so that each holds at most BIO_MAX_PAGES bvecs for safety reason, such as bio_clone(). This patch fixes the following kernel crash: > [ 172.660142] BUG: unable to handle kernel NULL pointer dereference at 0000000000000028 > [ 172.660229] IP: [<ffffffff811e53b4>] bio_trim+0xf/0x2a > [ 172.660289] PGD 7faf3e067 PUD 7f9279067 PMD 0 > [ 172.660399] Oops: 0000 [#1] SMP > [...] > [ 172.664780] Call Trace: > [ 172.664813] [<ffffffffa007f3be>] ? raid1_make_request+0x2e8/0xad7 [raid1] > [ 172.664846] [<ffffffff811f07da>] ? blk_queue_split+0x377/0x3d4 > [ 172.664880] [<ffffffffa005fb5f>] ? md_make_request+0xf6/0x1e9 [md_mod] > [ 172.664912] [<ffffffff811eb860>] ? generic_make_request+0xb5/0x155 > [ 172.664947] [<ffffffffa0445c89>] ? prio_io+0x85/0x95 [bcache] > [ 172.664981] [<ffffffffa0448252>] ? register_cache_set+0x355/0x8d0 [bcache] > [ 172.665016] [<ffffffffa04497d3>] ? register_bcache+0x1006/0x1174 [bcache] The issue can be reproduced by the following steps: - create one raid1 over two virtio-blk - build bcache device over the above raid1 and another cache device and bucket size is set as 2Mbytes - set cache mode as writeback - run random write over ext4 on the bcache device Fixes: 54efd50(block: make generic_make_request handle arbitrarily sized bios) Reported-by: Sebastian Roesner <sroesner-kernelorg@roesner-online.de> Reported-by: Eric Wheeler <bcache@lists.ewheeler.net> Cc: stable@vger.kernel.org (4.3+) Cc: Shaohua Li <shli@fb.com> Acked-by: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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7afafc8a |
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16-Aug-2016 |
Adrian Hunter <adrian.hunter@intel.com> |
block: Fix secure erase Commit 288dab8a35a0 ("block: add a separate operation type for secure erase") split REQ_OP_SECURE_ERASE from REQ_OP_DISCARD without considering all the places REQ_OP_DISCARD was being used to mean either. Fix those. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Fixes: 288dab8a35a0 ("block: add a separate operation type for secure erase") Signed-off-by: Jens Axboe <axboe@fb.com>
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1eff9d32 |
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05-Aug-2016 |
Jens Axboe <axboe@fb.com> |
block: rename bio bi_rw to bi_opf Since commit 63a4cc24867d, bio->bi_rw contains flags in the lower portion and the op code in the higher portions. This means that old code that relies on manually setting bi_rw is most likely going to be broken. Instead of letting that brokeness linger, rename the member, to force old and out-of-tree code to break at compile time instead of at runtime. No intended functional changes in this commit. Signed-off-by: Jens Axboe <axboe@fb.com>
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17007f39 |
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20-Jul-2016 |
Damien Le Moal <damien.lemoal@hgst.com> |
block: Fix front merge check For a front merge, the maximum number of sectors of the request must be checked against the front merge BIO sector, not the current sector of the request. Signed-off-by: Damien Le Moal <damien.lemoal@hgst.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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72ef799b |
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07-Jul-2016 |
Tahsin Erdogan <tahsin@google.com> |
block: do not merge requests without consulting with io scheduler Before merging a bio into an existing request, io scheduler is called to get its approval first. However, the requests that come from a plug flush may get merged by block layer without consulting with io scheduler. In case of CFQ, this can cause fairness problems. For instance, if a request gets merged into a low weight cgroup's request, high weight cgroup now will depend on low weight cgroup to get scheduled. If high weigt cgroup needs that io request to complete before submitting more requests, then it will also lose its timeslice. Following script demonstrates the problem. Group g1 has a low weight, g2 and g3 have equal high weights but g2's requests are adjacent to g1's requests so they are subject to merging. Due to these merges, g2 gets poor disk time allocation. cat > cfq-merge-repro.sh << "EOF" #!/bin/bash set -e IO_ROOT=/mnt-cgroup/io mkdir -p $IO_ROOT if ! mount | grep -qw $IO_ROOT; then mount -t cgroup none -oblkio $IO_ROOT fi cd $IO_ROOT for i in g1 g2 g3; do if [ -d $i ]; then rmdir $i fi done mkdir g1 && echo 10 > g1/blkio.weight mkdir g2 && echo 495 > g2/blkio.weight mkdir g3 && echo 495 > g3/blkio.weight RUNTIME=10 (echo $BASHPID > g1/cgroup.procs && fio --readonly --name name1 --filename /dev/sdb \ --rw read --size 64k --bs 64k --time_based \ --runtime=$RUNTIME --offset=0k &> /dev/null)& (echo $BASHPID > g2/cgroup.procs && fio --readonly --name name1 --filename /dev/sdb \ --rw read --size 64k --bs 64k --time_based \ --runtime=$RUNTIME --offset=64k &> /dev/null)& (echo $BASHPID > g3/cgroup.procs && fio --readonly --name name1 --filename /dev/sdb \ --rw read --size 64k --bs 64k --time_based \ --runtime=$RUNTIME --offset=256k &> /dev/null)& sleep $((RUNTIME+1)) for i in g1 g2 g3; do echo ---- $i ---- cat $i/blkio.time done EOF # ./cfq-merge-repro.sh ---- g1 ---- 8:16 162 ---- g2 ---- 8:16 165 ---- g3 ---- 8:16 686 After applying the patch: # ./cfq-merge-repro.sh ---- g1 ---- 8:16 90 ---- g2 ---- 8:16 445 ---- g3 ---- 8:16 471 Signed-off-by: Tahsin Erdogan <tahsin@google.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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288dab8a |
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09-Jun-2016 |
Christoph Hellwig <hch@lst.de> |
block: add a separate operation type for secure erase Instead of overloading the discard support with the REQ_SECURE flag. Use the opportunity to rename the queue flag as well, and remove the dead checks for this flag in the RAID 1 and RAID 10 drivers that don't claim support for secure erase. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
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8fe0d473 |
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05-Jun-2016 |
Mike Christie <mchristi@redhat.com> |
block: convert merge/insert code to check for REQ_OPs. This patch converts the block layer merging code to use separate variables for the operation and flags, and to check req_op for the REQ_OP. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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95fe6c1a |
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05-Jun-2016 |
Mike Christie <mchristi@redhat.com> |
block, fs, mm, drivers: use bio set/get op accessors This patch converts the simple bi_rw use cases in the block, drivers, mm and fs code to set/get the bio operation using bio_set_op_attrs/bio_op These should be simple one or two liner cases, so I just did them in one patch. The next patches handle the more complicated cases in a module per patch. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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a8ebb056 |
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05-Jun-2016 |
Mike Christie <mchristi@redhat.com> |
block, drivers, cgroup: use op_is_write helper instead of checking for REQ_WRITE We currently set REQ_WRITE/WRITE for all non READ IOs like discard, flush, writesame, etc. In the next patches where we no longer set up the op as a bitmap, we will not be able to detect a operation direction like writesame by testing if REQ_WRITE is set. This patch converts the drivers and cgroup to use the op_is_write helper. This should just cover the simple cases. I did dm, md and bcache in their own patches because they were more involved. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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e827091c |
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26-Feb-2016 |
Ming Lei <ming.lei@canonical.com> |
block: merge: get the 1st and last bvec via helpers This patch applies the two introduced helpers to figure out the 1st and last bvec. Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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d0e5fbb0 |
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22-Jan-2016 |
Ming Lei <tom.leiming@gmail.com> |
block: fix bio splitting on max sectors After commit e36f62042880(block: split bios to maxpossible length), bio can be splitted in the middle of a vector entry, then it is easy to split out one bio which size isn't aligned with block size, especially when the block size is bigger than 512. This patch fixes the issue by making the max io size aligned to logical block size. Fixes: e36f62042880(block: split bios to maxpossible length) Reported-by: Stefan Haberland <sth@linux.vnet.ibm.com> Cc: Keith Busch <keith.busch@intel.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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e36f6204 |
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12-Jan-2016 |
Keith Busch <kbusch@kernel.org> |
block: split bios to max possible length This splits bio in the middle of a vector to form the largest possible bio at the h/w's desired alignment, and guarantees the bio being split will have some data. The criteria for splitting is changed from the max sectors to the h/w's optimal sector alignment if it is provided. For h/w that advertise their block storage's underlying chunk size, it's a big performance win to not submit commands that cross them. If sector alignment is not provided, this patch uses the max sectors as before. This addresses the performance issue commit d380561113 attempted to fix, but was reverted due to splitting logic error. Signed-off-by: Keith Busch <keith.busch@intel.com> Cc: Jens Axboe <axboe@fb.com> Cc: Ming Lei <tom.leiming@gmail.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: <stable@vger.kernel.org> # 4.4.x- Signed-off-by: Jens Axboe <axboe@fb.com>
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6126eb24 |
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08-Jan-2016 |
Jens Axboe <axboe@fb.com> |
Revert "block: Split bios on chunk boundaries" This reverts commit d3805611130af9b911e908af9f67a3f64f4f0914. If we end up splitting on the first segment, we don't adjust the sector count. That results in hitting a BUG() with attempting to split 0 sectors. As this is just a performance issue and not a regression since 4.3 release, let's just rever this change. That gives us more time to test a real fix for 4.5, which would be marked for stable anyway.
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d3805611 |
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22-Dec-2015 |
Keith Busch <kbusch@kernel.org> |
block: Split bios on chunk boundaries For h/w that advertise their block storage's underlying chunk size, it's a big performance win to not submit commands that cross them. This patch uses that criteria if it is provided. If it is not provided, this patch uses the max sectors as before. Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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cda22646 |
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03-Dec-2015 |
Mike Krinkin <krinkin.m.u@gmail.com> |
block: add call to split trace point There is a split tracepoint that is supposed to be called when bio is splitted, and it was called in bio_split function until commit 4b1faf931650d4a35b2a ("block: Kill bio_pair_split()"). But now, no one reports splits, so this patch adds call to trace_block_split back in blk_queue_split right after split. Signed-off-by: Mike Krinkin <krinkin.m.u@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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a88d32af |
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30-Nov-2015 |
Ming Lei <ming.lei@canonical.com> |
blk-merge: fix computing bio->bi_seg_front_size in case of single segment When bio has only one physical segment, we should set bio's bi_seg_front_size as the real(final) size of the single segment. Fixes: 02e707424c2ea(blk-merge: fix blk_bio_segment_split) Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de> Tested-by: Markus Trippelsdorf <markus@trippelsdorf.de> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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12e57f59 |
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23-Nov-2015 |
Ming Lei <ming.lei@canonical.com> |
blk-merge: warn if figured out segment number is bigger than nr_phys_segments We had seen lots of reports of this kind issue, so add one warnning in blk-merge, then it can be triggered easily and avoid to depend on warning/bug from drivers. Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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02e70742 |
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23-Nov-2015 |
Ming Lei <ming.lei@canonical.com> |
blk-merge: fix blk_bio_segment_split Commit bdced438acd83a(block: setup bi_phys_segments after splitting) introduces function of computing bio->bi_phys_segments during bio splitting. Unfortunately both bio->bi_seg_front_size and bio->bi_seg_back_size arn't computed, so too many physical segments may be obtained for one request since both the two are used to check if one segment across two bios can be possible. This patch fixes the issue by computing the two variables in blk_bio_segment_split(). Fixes: bdced438acd83a(block: setup bi_phys_segments after splitting) Reported-by: Michael Ellerman <mpe@ellerman.id.au> Reported-by: Mark Salter <msalter@redhat.com> Tested-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Tested-by: Mark Salter <msalter@redhat.com> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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578270bf |
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23-Nov-2015 |
Ming Lei <ming.lei@canonical.com> |
block: fix segment split Inside blk_bio_segment_split(), previous bvec pointer(bvprvp) always points to the iterator local variable, which is obviously wrong, so fix it by pointing to the local variable of 'bvprv'. Fixes: 5014c311baa2b(block: fix bogus compiler warnings in blk-merge.c) Cc: stable@kernel.org #4.3 Reported-by: Michael Ellerman <mpe@ellerman.id.au> Reported-by: Mark Salter <msalter@redhat.com> Tested-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Tested-by: Mark Salter <msalter@redhat.com> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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6ac45aeb |
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20-Oct-2015 |
Ming Lei <ming.lei@canonical.com> |
block: avoid to merge splitted bio The splitted bio has been already too fat to merge, so mark it as NOMERGE. Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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bdced438 |
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20-Oct-2015 |
Ming Lei <ming.lei@canonical.com> |
block: setup bi_phys_segments after splitting The number of bio->bi_phys_segments is always obtained during bio splitting, so it is natural to setup it just after bio splitting, then we can avoid to compute nr_segment again during merge. Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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52cc6eea |
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17-Sep-2015 |
Ming Lei <ming.lei@canonical.com> |
block: blk-merge: fast-clone bio when splitting rw bios biovecs has become immutable since v3.13, so it isn't necessary to allocate biovecs for the new cloned bios, then we can save one extra biovecs allocation/copy, and the allocation is often not fixed-length and a bit more expensive. For example, if the 'max_sectors_kb' of null blk's queue is set as 16(32 sectors) via sysfs just for making more splits, this patch can increase throught about ~70% in the sequential read test over null_blk(direct io, bs: 1M). Cc: Christoph Hellwig <hch@infradead.org> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Ming Lin <ming.l@ssi.samsung.com> Cc: Dongsu Park <dpark@posteo.net> Signed-off-by: Ming Lei <ming.lei@canonical.com> This fixes a performance regression introduced by commit 54efd50bfd, and allows us to take full advantage of the fact that we have immutable bio_vecs. Hand applied, as it rejected violently with commit 5014c311baa2. Signed-off-by: Jens Axboe <axboe@fb.com>
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7f39add3 |
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11-Sep-2015 |
Sagi Grimberg <sagig@mellanox.com> |
block: Refuse request/bio merges with gaps in the integrity payload If a driver sets the block queue virtual boundary mask, it means that it cannot handle gaps so we must not allow those in the integrity payload as well. Signed-off-by: Sagi Grimberg <sagig@mellanox.com> Fixed up by me to have duplicate integrity merge functions, depending on whether block integrity is enabled or not. Fixes a compilations issue with CONFIG_BLK_DEV_INTEGRITY unset. Signed-off-by: Jens Axboe <axboe@fb.com>
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5e7c4274 |
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03-Sep-2015 |
Jens Axboe <axboe@fb.com> |
block: Check for gaps on front and back merges We are checking for gaps to previous bio_vec, which can only detect back merges gaps. Moreover, at the point where we check for a gap, we don't know if we will attempt a back or a front merge. Thus, check for gap to prev in a back merge attempt and check for a gap to next in a front merge attempt. Signed-off-by: Jens Axboe <axboe@fb.com> [sagig: Minor rename change] Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
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5014c311 |
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02-Sep-2015 |
Jens Axboe <axboe@fb.com> |
block: fix bogus compiler warnings in blk-merge.c The compiler can't figure out that bvprv is initialized whenever 'prev' is set to 1 as well. Use a pointer to bvprv instead, setting it to NULL initially, and get rid of the 'prev' tracking. This dumbs it down enough that gcc is happy. Signed-off-by: Jens Axboe <axboe@fb.com>
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2ca495ac |
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01-Sep-2015 |
Keith Busch <kbusch@kernel.org> |
blk: Fix bio_io_vec index when checking bvec gaps Corrects a coding error from earlier patch. Reported by: Sagi Grimberg <sagig@dev.mellanox.co.il> Signed-off-by: Keith Busch <keith.busch@intel.com> Fixes: 03100aada96f ("block: Replace SG_GAPS with new queue limits mask") Signed-off-by: Jens Axboe <axboe@fb.com>
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03100aad |
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19-Aug-2015 |
Keith Busch <kbusch@kernel.org> |
block: Replace SG_GAPS with new queue limits mask The SG_GAPS queue flag caused checks for bio vector alignment against PAGE_SIZE, but the device may have different constraints. This patch adds a queue limits so a driver with such constraints can set to allow requests that would have been unnecessarily split. The new gaps check takes the request_queue as a parameter to simplify the logic around invoking this function. This new limit makes the queue flag redundant, so removing it and all usage. Device-mappers will inherit the correct settings through blk_stack_limits(). Signed-off-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
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da81ed16 |
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07-Aug-2015 |
Dan Williams <dan.j.williams@intel.com> |
scatterlist: remove open coded sg_unmark_end instances Signed-off-by: Dan Williams <dan.j.williams@intel.com> [hch: split from a larger patch by Dan] Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
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8ae12666 |
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28-Apr-2015 |
Kent Overstreet <kent.overstreet@gmail.com> |
block: kill merge_bvec_fn() completely As generic_make_request() is now able to handle arbitrarily sized bios, it's no longer necessary for each individual block driver to define its own ->merge_bvec_fn() callback. Remove every invocation completely. Cc: Jens Axboe <axboe@kernel.dk> Cc: Lars Ellenberg <drbd-dev@lists.linbit.com> Cc: drbd-user@lists.linbit.com Cc: Jiri Kosina <jkosina@suse.cz> Cc: Yehuda Sadeh <yehuda@inktank.com> Cc: Sage Weil <sage@inktank.com> Cc: Alex Elder <elder@kernel.org> Cc: ceph-devel@vger.kernel.org Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: dm-devel@redhat.com Cc: Neil Brown <neilb@suse.de> Cc: linux-raid@vger.kernel.org Cc: Christoph Hellwig <hch@infradead.org> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Acked-by: NeilBrown <neilb@suse.de> (for the 'md' bits) Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> [dpark: also remove ->merge_bvec_fn() in dm-thin as well as dm-era-target, and resolve merge conflicts] Signed-off-by: Dongsu Park <dpark@posteo.net> Signed-off-by: Ming Lin <ming.l@ssi.samsung.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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54efd50b |
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23-Apr-2015 |
Kent Overstreet <kent.overstreet@gmail.com> |
block: make generic_make_request handle arbitrarily sized bios The way the block layer is currently written, it goes to great lengths to avoid having to split bios; upper layer code (such as bio_add_page()) checks what the underlying device can handle and tries to always create bios that don't need to be split. But this approach becomes unwieldy and eventually breaks down with stacked devices and devices with dynamic limits, and it adds a lot of complexity. If the block layer could split bios as needed, we could eliminate a lot of complexity elsewhere - particularly in stacked drivers. Code that creates bios can then create whatever size bios are convenient, and more importantly stacked drivers don't have to deal with both their own bio size limitations and the limitations of the (potentially multiple) devices underneath them. In the future this will let us delete merge_bvec_fn and a bunch of other code. We do this by adding calls to blk_queue_split() to the various make_request functions that need it - a few can already handle arbitrary size bios. Note that we add the call _after_ any call to blk_queue_bounce(); this means that blk_queue_split() and blk_recalc_rq_segments() don't need to be concerned with bouncing affecting segment merging. Some make_request_fn() callbacks were simple enough to audit and verify they don't need blk_queue_split() calls. The skipped ones are: * nfhd_make_request (arch/m68k/emu/nfblock.c) * axon_ram_make_request (arch/powerpc/sysdev/axonram.c) * simdisk_make_request (arch/xtensa/platforms/iss/simdisk.c) * brd_make_request (ramdisk - drivers/block/brd.c) * mtip_submit_request (drivers/block/mtip32xx/mtip32xx.c) * loop_make_request * null_queue_bio * bcache's make_request fns Some others are almost certainly safe to remove now, but will be left for future patches. Cc: Jens Axboe <axboe@kernel.dk> Cc: Christoph Hellwig <hch@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Ming Lei <ming.lei@canonical.com> Cc: Neil Brown <neilb@suse.de> Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: dm-devel@redhat.com Cc: Lars Ellenberg <drbd-dev@lists.linbit.com> Cc: drbd-user@lists.linbit.com Cc: Jiri Kosina <jkosina@suse.cz> Cc: Geoff Levand <geoff@infradead.org> Cc: Jim Paris <jim@jtan.com> Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Oleg Drokin <oleg.drokin@intel.com> Cc: Andreas Dilger <andreas.dilger@intel.com> Acked-by: NeilBrown <neilb@suse.de> (for the 'md/md.c' bits) Acked-by: Mike Snitzer <snitzer@redhat.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> [dpark: skip more mq-based drivers, resolve merge conflicts, etc.] Signed-off-by: Dongsu Park <dpark@posteo.net> Signed-off-by: Ming Lin <ming.l@ssi.samsung.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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b7c44ed9 |
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24-Jul-2015 |
Jens Axboe <axboe@fb.com> |
block: manipulate bio->bi_flags through helpers Some places use helpers now, others don't. We only have the 'is set' helper, add helpers for setting and clearing flags too. It was a bit of a mess of atomic vs non-atomic access. With BIO_UPTODATE gone, we don't have any risk of concurrent access to the flags. So relax the restriction and don't make any of them atomic. The flags that do have serialization issues (reffed and chained), we already handle those separately. Signed-off-by: Jens Axboe <axboe@fb.com>
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beefa6ba |
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29-May-2015 |
Jens Axboe <axboe@fb.com> |
block: only honor SG gap prevention for merges that contain data We can safely merge anything that wont generate an SG list entry, so if the bio is data-less (discard), don't look at potential SG gaps. Signed-off-by: Jens Axboe <axboe@fb.com>
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7ee8e4f3 |
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19-Mar-2015 |
Wenbo Wang <wenbo.wang@memblaze.com> |
Fix bug in blk_rq_merge_ok Use the right array index to reference the last element of rq->biotail->bi_io_vec[] Signed-off-by: Wenbo Wang <wenbo.wang@memblaze.com> Reviewed-by: Chong Yuan <chong.yuan@memblaze.com> Fixes: 66cb45aa41315 ("block: add support for limiting gaps in SG lists") Cc: stable@kernel.org Signed-off-by: Jens Axboe <axboe@fb.com>
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d427e3c8 |
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11-Feb-2015 |
Christoph Hellwig <hch@lst.de> |
block: remove unused function blk_bio_map_sg Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
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854fbb9c |
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11-Feb-2015 |
Keith Busch <kbusch@kernel.org> |
block: prevent request-to-request merging with gaps if not allowed If the queue has SG_GAPS set, we must not merge across an sg gap. This is caught for the bio case, but currently not for the more rare case of merging two requests directly. Signed-off-by: Keith Busch <keith.busch@intel.com> Cut the dm bits, those will go through the dm tree, and fixed the test_bit() test. Signed-off-by: Jens Axboe <axboe@fb.com>
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7f60dcaa |
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11-Nov-2014 |
Ming Lei <tom.leiming@gmail.com> |
block: blk-merge: fix blk_recount_segments() For cloned bio, bio->bi_vcnt can't be used at all, and we have resort to bio_segments() to figure out how many segment there are in the bio. Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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76d8137a |
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21-Oct-2014 |
Ming Lei <tom.leiming@gmail.com> |
blk-merge: recaculate segment if it isn't less than max segments The problem is introduced by commit 764f612c6c3c231b(blk-merge: don't compute bi_phys_segments from bi_vcnt for cloned bio), and merge is needed if number of current segment isn't less than max segments. Strictly speaking, bio->bi_vcnt shouldn't be used here since it may not be accurate in cases of both cloned bio or bio cloned from, but bio_segments() is a bit expensive, and bi_vcnt is still the biggest number, so the approach should work. Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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764f612c |
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09-Oct-2014 |
Ming Lei <ming.lei@canonical.com> |
blk-merge: don't compute bi_phys_segments from bi_vcnt for cloned bio It isn't correct to figure out req->bi_phys_segments from bio->bi_vcnt if the bio is cloned. Signed-off-by: Ming Lei <ming.lei@canonical.com> Tested-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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4eaf99be |
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26-Sep-2014 |
Martin K. Petersen <martin.petersen@oracle.com> |
block: Don't merge requests if integrity flags differ We'd occasionally merge requests with conflicting integrity flags. Introduce a merge helper which checks that the requests have compatible integrity payloads. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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07388549 |
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02-Sep-2014 |
Ming Lei <ming.lei@canonical.com> |
blk-merge: fix blk_recount_segments QUEUE_FLAG_NO_SG_MERGE is set at default for blk-mq devices, so bio->bi_phys_segment computed may be bigger than queue_max_segments(q) for blk-mq devices, then drivers will fail to handle the case, for example, BUG_ON() in virtio_queue_rq() can be triggerd for virtio-blk: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1359146 This patch fixes the issue by ignoring the QUEUE_FLAG_NO_SG_MERGE flag if the computed bio->bi_phys_segment is bigger than queue_max_segments(q), and the regression is caused by commit 05f1dd53152173(block: add queue flag for disabling SG merging). Reported-by: Kick In <pierre-andre.morey@canonical.com> Tested-by: Chris J Arges <chris.j.arges@canonical.com> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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66cb45aa |
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24-Jun-2014 |
Jens Axboe <axboe@fb.com> |
block: add support for limiting gaps in SG lists Another restriction inherited for NVMe - those devices don't support SG lists that have "gaps" in them. Gaps refers to cases where the previous SG entry doesn't end on a page boundary. For NVMe, all SG entries must start at offset 0 (except the first) and end on a page boundary (except the last). Signed-off-by: Jens Axboe <axboe@fb.com>
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05f1dd53 |
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29-May-2014 |
Jens Axboe <axboe@fb.com> |
block: add queue flag for disabling SG merging If devices are not SG starved, we waste a lot of time potentially collapsing SG segments. Enough that 1.5% of the CPU time goes to this, at only 400K IOPS. Add a queue flag, QUEUE_FLAG_NO_SG_MERGE, which just returns the number of vectors in a bio instead of looping over all segments and checking for collapsible ones. Add a BLK_MQ_F_SG_MERGE flag so that drivers can opt-in on the sg merging, if they so desire. Signed-off-by: Jens Axboe <axboe@fb.com>
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5cb8850c |
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07-Feb-2014 |
Kent Overstreet <kmo@daterainc.com> |
block: Explicitly handle discard/write same segments Immutable biovecs changed the way biovecs are interpreted - drivers no longer use bi_vcnt, they have to go by bi_iter.bi_size (to allow for using part of an existing segment without modifying it). This breaks with discards and write_same bios, since for those bi_size has nothing to do with segments in the biovec. So for now, we need a fairly gross hack - we fortunately know that there will never be more than one segment for the entire request, so we can special case discard/write_same. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Tested-by: Hugh Dickins <hughd@google.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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2b8221e1 |
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03-Dec-2013 |
Kent Overstreet <kmo@daterainc.com> |
block: Really silence spurious compiler warnings The uninitialized_var() macro appears to not work on structs... Get rid of it, and manually initialize instead. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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3f273d30 |
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26-Nov-2013 |
Kent Overstreet <kmo@daterainc.com> |
block: Silence spurious compiler warnings Signed-off-by: Kent Overstreet <kmo@daterainc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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f619d254 |
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07-Aug-2013 |
Kent Overstreet <kmo@daterainc.com> |
block: Kill bio_iovec_idx(), __bio_iovec() bio_iovec_idx() and __bio_iovec() don't have any valid uses anymore - previous users have been converted to bio_iovec_iter() or other methods. __BVEC_END() has to go too - the bvec array can't be used directly for the last biovec because we might only be using the first portion of it, we have to iterate over the bvec array with bio_for_each_segment() which checks against the current value of bi_iter.bi_size. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk>
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7988613b |
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23-Nov-2013 |
Kent Overstreet <kmo@daterainc.com> |
block: Convert bio_for_each_segment() to bvec_iter More prep work for immutable biovecs - with immutable bvecs drivers won't be able to use the biovec directly, they'll need to use helpers that take into account bio->bi_iter.bi_bvec_done. This updates callers for the new usage without changing the implementation yet. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: "Ed L. Cashin" <ecashin@coraid.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Lars Ellenberg <drbd-dev@lists.linbit.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Paul Clements <Paul.Clements@steeleye.com> Cc: Jim Paris <jim@jtan.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Yehuda Sadeh <yehuda@inktank.com> Cc: Sage Weil <sage@inktank.com> Cc: Alex Elder <elder@inktank.com> Cc: ceph-devel@vger.kernel.org Cc: Joshua Morris <josh.h.morris@us.ibm.com> Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Neil Brown <neilb@suse.de> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux390@de.ibm.com Cc: Nagalakshmi Nandigama <Nagalakshmi.Nandigama@lsi.com> Cc: Sreekanth Reddy <Sreekanth.Reddy@lsi.com> Cc: support@lsi.com Cc: "James E.J. Bottomley" <JBottomley@parallels.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> Cc: Tejun Heo <tj@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Guo Chao <yan@linux.vnet.ibm.com> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Keith Busch <keith.busch@intel.com> Cc: Stephen Hemminger <shemminger@vyatta.com> Cc: Quoc-Son Anh <quoc-sonx.anh@intel.com> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Seth Jennings <sjenning@linux.vnet.ibm.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: "Darrick J. Wong" <darrick.wong@oracle.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Jan Kara <jack@suse.cz> Cc: linux-m68k@lists.linux-m68k.org Cc: linuxppc-dev@lists.ozlabs.org Cc: drbd-user@lists.linbit.com Cc: nbd-general@lists.sourceforge.net Cc: cbe-oss-dev@lists.ozlabs.org Cc: xen-devel@lists.xensource.com Cc: virtualization@lists.linux-foundation.org Cc: linux-raid@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: DL-MPTFusionLinux@lsi.com Cc: linux-scsi@vger.kernel.org Cc: devel@driverdev.osuosl.org Cc: linux-fsdevel@vger.kernel.org Cc: cluster-devel@redhat.com Cc: linux-mm@kvack.org Acked-by: Geoff Levand <geoff@infradead.org>
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4f024f37 |
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11-Oct-2013 |
Kent Overstreet <kmo@daterainc.com> |
block: Abstract out bvec iterator Immutable biovecs are going to require an explicit iterator. To implement immutable bvecs, a later patch is going to add a bi_bvec_done member to this struct; for now, this patch effectively just renames things. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: "Ed L. Cashin" <ecashin@coraid.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Lars Ellenberg <drbd-dev@lists.linbit.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Yehuda Sadeh <yehuda@inktank.com> Cc: Sage Weil <sage@inktank.com> Cc: Alex Elder <elder@inktank.com> Cc: ceph-devel@vger.kernel.org Cc: Joshua Morris <josh.h.morris@us.ibm.com> Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Neil Brown <neilb@suse.de> Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: dm-devel@redhat.com Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux390@de.ibm.com Cc: Boaz Harrosh <bharrosh@panasas.com> Cc: Benny Halevy <bhalevy@tonian.com> Cc: "James E.J. Bottomley" <JBottomley@parallels.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Chris Mason <chris.mason@fusionio.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Jaegeuk Kim <jaegeuk.kim@samsung.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Dave Kleikamp <shaggy@kernel.org> Cc: Joern Engel <joern@logfs.org> Cc: Prasad Joshi <prasadjoshi.linux@gmail.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Ben Myers <bpm@sgi.com> Cc: xfs@oss.sgi.com Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Guo Chao <yan@linux.vnet.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Cc: "Roger Pau Monné" <roger.pau@citrix.com> Cc: Jan Beulich <jbeulich@suse.com> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Cc: Ian Campbell <Ian.Campbell@citrix.com> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Jerome Marchand <jmarchand@redhat.com> Cc: Joe Perches <joe@perches.com> Cc: Peng Tao <tao.peng@emc.com> Cc: Andy Adamson <andros@netapp.com> Cc: fanchaoting <fanchaoting@cn.fujitsu.com> Cc: Jie Liu <jeff.liu@oracle.com> Cc: Sunil Mushran <sunil.mushran@gmail.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Namjae Jeon <namjae.jeon@samsung.com> Cc: Pankaj Kumar <pankaj.km@samsung.com> Cc: Dan Magenheimer <dan.magenheimer@oracle.com> Cc: Mel Gorman <mgorman@suse.de>6
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e7e24500 |
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29-Oct-2013 |
Jens Axboe <axboe@kernel.dk> |
blk-mq: don't disallow request merges for req->special being set For blk-mq, if a driver has requested per-request payload data to carry command structures, they are stuffed into req->special. For an old style request based driver, req->special is used for the same purpose but indicates that a per-driver request structure has been prepared for the request already. So for the old style driver, we do not merge such requests. As most/all blk-mq drivers will use the payload feature, and since we have no problem merging on these, make this check dependent on whether it's a blk-mq enabled driver or not. Reported-by: Shaohua Li <shli@fusionio.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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c8164d89 |
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19-Mar-2013 |
Paolo Bonzini <pbonzini@redhat.com> |
scatterlist: introduce sg_unmark_end This is useful in places that recycle the same scatterlist multiple times, and do not want to incur the cost of sg_init_table every time in hot paths. Acked-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
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4363ac7c |
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17-Sep-2012 |
Martin K. Petersen <martin.petersen@oracle.com> |
block: Implement support for WRITE SAME The WRITE SAME command supported on some SCSI devices allows the same block to be efficiently replicated throughout a block range. Only a single logical block is transferred from the host and the storage device writes the same data to all blocks described by the I/O. This patch implements support for WRITE SAME in the block layer. The blkdev_issue_write_same() function can be used by filesystems and block drivers to replicate a buffer across a block range. This can be used to efficiently initialize software RAID devices, etc. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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f31dc1cd |
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17-Sep-2012 |
Martin K. Petersen <martin.petersen@oracle.com> |
block: Consolidate command flag and queue limit checks for merges - blk_check_merge_flags() verifies that cmd_flags / bi_rw are compatible. This function is called for both req-req and req-bio merging. - blk_rq_get_max_sectors() and blk_queue_get_max_sectors() can be used to query the maximum sector count for a given request or queue. The calls will return the right value from the queue limits given the type of command (RW, discard, write same, etc.) Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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e2a60da7 |
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17-Sep-2012 |
Martin K. Petersen <martin.petersen@oracle.com> |
block: Clean up special command handling logic Remove special-casing of non-rw fs style requests (discard). The nomerge flags are consolidated in blk_types.h, and rq_mergeable() and bio_mergeable() have been modified to use them. bio_is_rw() is used in place of bio_has_data() a few places. This is done to to distinguish true reads and writes from other fs type requests that carry a payload (e.g. write same). Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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85b9f66a |
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02-Aug-2012 |
Asias He <asias@redhat.com> |
block: Add blk_bio_map_sg() helper Add a helper to map a bio to a scatterlist, modelled after blk_rq_map_sg. This helper is useful for any driver that wants to create a scatterlist from its ->make_request_fn method. Changes in v2: - Use __blk_segment_map_sg to avoid duplicated code - Add cocbook style function comment Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Christoph Hellwig <hch@lst.de> Cc: Tejun Heo <tj@kernel.org> Cc: Shaohua Li <shli@kernel.org> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: virtualization@lists.linux-foundation.org Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Asias He <asias@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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963ab9e5 |
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02-Aug-2012 |
Asias He <asias@redhat.com> |
block: Introduce __blk_segment_map_sg() helper Split the mapping code in blk_rq_map_sg() to a helper __blk_segment_map_sg(), so that other mapping function, e.g. blk_bio_map_sg(), can share the code. Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Christoph Hellwig <hch@lst.de> Cc: Tejun Heo <tj@kernel.org> Cc: Shaohua Li <shli@kernel.org> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: virtualization@lists.linux-foundation.org Suggested-by: Jens Axboe <axboe@kernel.dk> Suggested-by: Tejun Heo <tj@kernel.org> Signed-off-by: Asias He <asias@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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050c8ea8 |
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08-Feb-2012 |
Tejun Heo <tj@kernel.org> |
block: separate out blk_rq_merge_ok() and blk_try_merge() from elevator functions blk_rq_merge_ok() is the elevator-neutral part of merge eligibility test. blk_try_merge() determines merge direction and expects the caller to have tested elv_rq_merge_ok() previously. elv_rq_merge_ok() now wraps blk_rq_merge_ok() and then calls elv_iosched_allow_merge(). elv_try_merge() is removed and the two callers are updated to call elv_rq_merge_ok() explicitly followed by blk_try_merge(). While at it, make rq_merge_ok() functions return bool. This is to prepare for plug merge update and doesn't introduce any behavior change. This is based on Jens' patch to skip elevator_allow_merge_fn() from plug merge. Signed-off-by: Tejun Heo <tj@kernel.org> LKML-Reference: <4F16F3CA.90904@kernel.dk> Original-patch-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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5e84ea3a |
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21-Mar-2011 |
Jens Axboe <jaxboe@fusionio.com> |
block: attempt to merge with existing requests on plug flush One of the disadvantages of on-stack plugging is that we potentially lose out on merging since all pending IO isn't always visible to everybody. When we flush the on-stack plugs, right now we don't do any checks to see if potential merge candidates could be utilized. Correct this by adding a new insert variant, ELEVATOR_INSERT_SORT_MERGE. It works just ELEVATOR_INSERT_SORT, but first checks whether we can merge with an existing request before doing the insertion (if we fail merging). This fixes a regression with multiple processes issuing IO that can be merged. Thanks to Shaohua Li <shaohua.li@intel.com> for testing and fixing an accounting bug. Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
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6c23a968 |
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07-Jan-2011 |
Jens Axboe <jaxboe@fusionio.com> |
block: add internal hd part table references We can't use krefs since it's apparently restricted to very basic reference counting. This reverts commit e4a683c8. Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
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09e099d4 |
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05-Jan-2011 |
Jerome Marchand <jmarchan@redhat.com> |
block: fix accounting bug on cross partition merges /proc/diskstats would display a strange output as follows. $ cat /proc/diskstats |grep sda 8 0 sda 90524 7579 102154 20464 0 0 0 0 0 14096 20089 8 1 sda1 19085 1352 21841 4209 0 0 0 0 4294967064 15689 4293424691 ~~~~~~~~~~ 8 2 sda2 71252 3624 74891 15950 0 0 0 0 232 23995 1562390 8 3 sda3 54 487 2188 92 0 0 0 0 0 88 92 8 4 sda4 4 0 8 0 0 0 0 0 0 0 0 8 5 sda5 81 2027 2130 138 0 0 0 0 0 87 137 Its reason is the wrong way of accounting hd_struct->in_flight. When a bio is merged into a request belongs to different partition by ELEVATOR_FRONT_MERGE. The detailed root cause is as follows. Assuming that there are two partition, sda1 and sda2. 1. A request for sda2 is in request_queue. Hence sda1's hd_struct->in_flight is 0 and sda2's one is 1. | hd_struct->in_flight --------------------------- sda1 | 0 sda2 | 1 --------------------------- 2. A bio belongs to sda1 is issued and is merged into the request mentioned on step1 by ELEVATOR_BACK_MERGE. The first sector of the request is changed from sda2 region to sda1 region. However the two partition's hd_struct->in_flight are not changed. | hd_struct->in_flight --------------------------- sda1 | 0 sda2 | 1 --------------------------- 3. The request is finished and blk_account_io_done() is called. In this case, sda2's hd_struct->in_flight, not a sda1's one, is decremented. | hd_struct->in_flight --------------------------- sda1 | -1 sda2 | 1 --------------------------- The patch fixes the problem by caching the partition lookup inside the request structure, hence making sure that the increment and decrement will always happen on the same partition struct. This also speeds up IO with accounting enabled, since it cuts down on the number of lookups we have to do. Also add a refcount to struct hd_struct to keep the partition in memory as long as users exist. We use kref_test_and_get() to ensure we don't add a reference to a partition which is going away. Signed-off-by: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: stable@kernel.org Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
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e692cb66 |
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01-Dec-2010 |
Martin K. Petersen <martin.petersen@oracle.com> |
block: Deprecate QUEUE_FLAG_CLUSTER and use queue_limits instead When stacking devices, a request_queue is not always available. This forced us to have a no_cluster flag in the queue_limits that could be used as a carrier until the request_queue had been set up for a metadevice. There were several problems with that approach. First of all it was up to the stacking device to remember to set queue flag after stacking had completed. Also, the queue flag and the queue limits had to be kept in sync at all times. We got that wrong, which could lead to us issuing commands that went beyond the max scatterlist limit set by the driver. The proper fix is to avoid having two flags for tracking the same thing. We deprecate QUEUE_FLAG_CLUSTER and use the queue limit directly in the block layer merging functions. The queue_limit 'no_cluster' is turned into 'cluster' to avoid double negatives and to ease stacking. Clustering defaults to being enabled as before. The queue flag logic is removed from the stacking function, and explicitly setting the cluster flag is no longer necessary in DM and MD. Reported-by: Ed Lin <ed.lin@promise.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@kernel.org Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
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f253b86b |
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24-Oct-2010 |
Jens Axboe <jaxboe@fusionio.com> |
Revert "block: fix accounting bug on cross partition merges" This reverts commit 7681bfeeccff5efa9eb29bf09249a3c400b15327. Conflicts: include/linux/genhd.h It has numerous issues with the cleanup path and non-elevator devices. Revert it for now so we can come up with a clean version without rushing things. Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
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7681bfee |
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19-Oct-2010 |
Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> |
block: fix accounting bug on cross partition merges /proc/diskstats would display a strange output as follows. $ cat /proc/diskstats |grep sda 8 0 sda 90524 7579 102154 20464 0 0 0 0 0 14096 20089 8 1 sda1 19085 1352 21841 4209 0 0 0 0 4294967064 15689 4293424691 ~~~~~~~~~~ 8 2 sda2 71252 3624 74891 15950 0 0 0 0 232 23995 1562390 8 3 sda3 54 487 2188 92 0 0 0 0 0 88 92 8 4 sda4 4 0 8 0 0 0 0 0 0 0 0 8 5 sda5 81 2027 2130 138 0 0 0 0 0 87 137 Its reason is the wrong way of accounting hd_struct->in_flight. When a bio is merged into a request belongs to different partition by ELEVATOR_FRONT_MERGE. The detailed root cause is as follows. Assuming that there are two partition, sda1 and sda2. 1. A request for sda2 is in request_queue. Hence sda1's hd_struct->in_flight is 0 and sda2's one is 1. | hd_struct->in_flight --------------------------- sda1 | 0 sda2 | 1 --------------------------- 2. A bio belongs to sda1 is issued and is merged into the request mentioned on step1 by ELEVATOR_BACK_MERGE. The first sector of the request is changed from sda2 region to sda1 region. However the two partition's hd_struct->in_flight are not changed. | hd_struct->in_flight --------------------------- sda1 | 0 sda2 | 1 --------------------------- 3. The request is finished and blk_account_io_done() is called. In this case, sda2's hd_struct->in_flight, not a sda1's one, is decremented. | hd_struct->in_flight --------------------------- sda1 | -1 sda2 | 1 --------------------------- The patch fixes the problem by caching the partition lookup inside the request structure, hence making sure that the increment and decrement will always happen on the same partition struct. This also speeds up IO with accounting enabled, since it cuts down on the number of lookups we have to do. When reloading partition tables, quiesce IO to ensure that no request references to the partition struct exists. When it is safe to free the partition table, the IO for that device is restarted again. Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: stable@kernel.org Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
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f281fb5f |
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24-Sep-2010 |
Adrian Hunter <adrian.hunter@nokia.com> |
block: prevent merges of discard and write requests Add logic to prevent two I/O requests being merged if only one of them is a discard. Ditto secure discard. Without this fix, it is possible for write requests to transform into discard requests. For example: Submit bio 1 to discard 8 sectors from sector n Submit bio 2 to write 8 sectors from sector n + 16 Submit bio 3 to write 8 sectors from sector n + 8 Bio 1 becomes request 1. Bio 2 becomes request 2. Bio 3 is merged with request 2, and then subsequently request 2 is merged with request 1 resulting in just one I/O request which discards all 24 sectors. Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com> (Moved the checks above the position checks /Jens) Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
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13f05c8d |
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10-Sep-2010 |
Martin K. Petersen <martin.petersen@oracle.com> |
block/scsi: Provide a limit on the number of integrity segments Some controllers have a hardware limit on the number of protection information scatter-gather list segments they can handle. Introduce a max_integrity_segments limit in the block layer and provide a new scsi_host_template setting that allows HBA drivers to provide a value suitable for the hardware. Add support for honoring the integrity segment limit when merging both bios and requests. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@carl.home.kernel.dk>
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2c8919de |
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21-Jun-2010 |
Andi Kleen <andi@firstfloor.org> |
gcc-4.6: block: fix unused but set variables in blk-merge Just some dead code. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
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7b6d91da |
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07-Aug-2010 |
Christoph Hellwig <hch@lst.de> |
block: unify flags for struct bio and struct request Remove the current bio flags and reuse the request flags for the bio, too. This allows to more easily trace the type of I/O from the filesystem down to the block driver. There were two flags in the bio that were missing in the requests: BIO_RW_UNPLUG and BIO_RW_AHEAD. Also I've renamed two request flags that had a superflous RW in them. Note that the flags are in bio.h despite having the REQ_ name - as blkdev.h includes bio.h that is the only way to go for now. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
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33659ebb |
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07-Aug-2010 |
Christoph Hellwig <hch@lst.de> |
block: remove wrappers for request type/flags Remove all the trivial wrappers for the cmd_type and cmd_flags fields in struct requests. This allows much easier grepping for different request types instead of unwinding through macros. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
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8a78362c |
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25-Feb-2010 |
Martin K. Petersen <martin.petersen@oracle.com> |
block: Consolidate phys_segment and hw_segment limits Except for SCSI no device drivers distinguish between physical and hardware segment limits. Consolidate the two into a single segment limit. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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316d315b |
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06-Oct-2009 |
Nikanth Karthikesan <knikanth@suse.de> |
block: Seperate read and write statistics of in_flight requests v2 Commit a9327cac440be4d8333bba975cbbf76045096275 added seperate read and write statistics of in_flight requests. And exported the number of read and write requests in progress seperately through sysfs. But Corrado Zoccolo <czoccolo@gmail.com> reported getting strange output from "iostat -kx 2". Global values for service time and utilization were garbage. For interval values, utilization was always 100%, and service time is higher than normal. So this was reverted by commit 0f78ab9899e9d6acb09d5465def618704255963b The problem was in part_round_stats_single(), I missed the following: if (now == part->stamp) return; - if (part->in_flight) { + if (part_in_flight(part)) { __part_stat_add(cpu, part, time_in_queue, part_in_flight(part) * (now - part->stamp)); __part_stat_add(cpu, part, io_ticks, (now - part->stamp)); With this chunk included, the reported regression gets fixed. Signed-off-by: Nikanth Karthikesan <knikanth@suse.de> -- Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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0f78ab98 |
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04-Oct-2009 |
Jens Axboe <jens.axboe@oracle.com> |
Revert "Seperate read and write statistics of in_flight requests" This reverts commit a9327cac440be4d8333bba975cbbf76045096275. Corrado Zoccolo <czoccolo@gmail.com> reports: "with 2.6.32-rc1 I started getting the following strange output from "iostat -kx 2": Linux 2.6.31bisect (et2) 04/10/2009 _i686_ (2 CPU) avg-cpu: %user %nice %system %iowait %steal %idle 10,70 0,00 3,16 15,75 0,00 70,38 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util sda 18,22 0,00 0,67 0,01 14,77 0,02 43,94 0,01 10,53 39043915,03 2629219,87 sdb 60,89 9,68 50,79 3,04 1724,43 50,52 65,95 0,70 13,06 488437,47 2629219,87 avg-cpu: %user %nice %system %iowait %steal %idle 2,72 0,00 0,74 0,00 0,00 96,53 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util sda 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 100,00 sdb 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 100,00 avg-cpu: %user %nice %system %iowait %steal %idle 6,68 0,00 0,99 0,00 0,00 92,33 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util sda 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 100,00 sdb 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 100,00 avg-cpu: %user %nice %system %iowait %steal %idle 4,40 0,00 0,73 1,47 0,00 93,40 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util sda 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 100,00 sdb 0,00 4,00 0,00 3,00 0,00 28,00 18,67 0,06 19,50 333,33 100,00 Global values for service time and utilization are garbage. For interval values, utilization is always 100%, and service time is higher than normal. I bisected it down to: [a9327cac440be4d8333bba975cbbf76045096275] Seperate read and write statistics of in_flight requests and verified that reverting just that commit indeed solves the issue on 2.6.32-rc1." So until this is debugged, revert the bad commit. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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a9327cac |
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11-Sep-2009 |
Nikanth Karthikesan <knikanth@suse.de> |
Seperate read and write statistics of in_flight requests Currently, there is a single in_flight counter measuring the number of requests in the request_queue. But some monitoring tools would like to know how many read requests and write requests are in progress. Split the current in_flight counter into two seperate counters for read and write. This information is exported as a sysfs attribute, as changing the currently available stat files would break the existing tools. Signed-off-by: Nikanth Karthikesan <knikanth@suse.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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da6c5c72 |
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11-Sep-2009 |
Tejun Heo <tj@kernel.org> |
scsi,block: update SCSI to handle mixed merge failures Update scsi_io_completion() such that it only fails requests till the next error boundary and retry the leftover. This enables block layer to merge requests with different failfast settings and still behave correctly on errors. Allow merge of requests of different failfast settings. As SCSI is currently the only subsystem which follows failfast status, there's no need to worry about other block drivers for now. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Niel Lambrechts <niel.lambrechts@gmail.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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80a761fd |
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03-Jul-2009 |
Tejun Heo <tj@kernel.org> |
block: implement mixed merge of different failfast requests Failfast has characteristics from other attributes. When issuing, executing and successuflly completing requests, failfast doesn't make any difference. It only affects how a request is handled on failure. Allowing requests with different failfast settings to be merged cause normal IOs to fail prematurely while not allowing has performance penalties as failfast is used for read aheads which are likely to be located near in-flight or to-be-issued normal IOs. This patch introduces the concept of 'mixed merge'. A request is a mixed merge if it is merge of segments which require different handling on failure. Currently the only mixable attributes are failfast ones (or lack thereof). When a bio with different failfast settings is added to an existing request or requests of different failfast settings are merged, the merged request is marked mixed. Each bio carries failfast settings and the request always tracks failfast state of the first bio. When the request fails, blk_rq_err_bytes() can be used to determine how many bytes can be safely failed without crossing into an area which requires further retrials. This allows request merging regardless of failfast settings while keeping the failure handling correct. This patch only implements mixed merge but doesn't enable it. The next one will update SCSI to make use of mixed merge. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Niel Lambrechts <niel.lambrechts@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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ab0fd1de |
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02-Jul-2009 |
Tejun Heo <tj@kernel.org> |
block: don't merge requests of different failfast settings Block layer used to merge requests and bios with different failfast settings. This caused regular IOs to fail prematurely when they were merged into failfast requests for readahead. Niel Lambrechts could trigger the problem semi-reliably on ext4 when resuming from STR. ext4 uses readahead when reading inodes and combined with the deterministic extra SATA PHY exception cycle during resume on the specific configuration, non-readahead inode read would fail causing ext4 errors. Please read the following thread for details. http://lkml.org/lkml/2009/5/23/21 This patch makes block layer reject merging if the failfast settings don't match. This is correct but likely to lower IO performance by preventing regular IOs from mingling into surrounding readahead requests. Changes to allow such mixed merges and handle errors correctly will be added later. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Niel Lambrechts <niel.lambrechts@gmail.com> Cc: Theodore Tso <tytso@mit.edu> Signed-off-by: Jens Axboe <axboe@carl.(none)>
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ae03bf63 |
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22-May-2009 |
Martin K. Petersen <martin.petersen@oracle.com> |
block: Use accessor functions for queue limits Convert all external users of queue limits to using wrapper functions instead of poking the request queue variables directly. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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a2dec7b3 |
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07-May-2009 |
Tejun Heo <tj@kernel.org> |
block: hide request sector and data_len Block low level drivers for some reason have been pretty good at abusing block layer API. Especially struct request's fields tend to get violated in all possible ways. Make it clear that low level drivers MUST NOT access or manipulate rq->sector and rq->data_len directly by prefixing them with double underscores. This change is also necessary to break build of out-of-tree codes which assume the previous block API where internal fields can be manipulated and rq->data_len carries residual count on completion. [ Impact: hide internal fields, block API change ] Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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2e46e8b2 |
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07-May-2009 |
Tejun Heo <tj@kernel.org> |
block: drop request->hard_* and *nr_sectors struct request has had a few different ways to represent some properties of a request. ->hard_* represent block layer's view of the request progress (completion cursor) and the ones without the prefix are supposed to represent the issue cursor and allowed to be updated as necessary by the low level drivers. The thing is that as block layer supports partial completion, the two cursors really aren't necessary and only cause confusion. In addition, manual management of request detail from low level drivers is cumbersome and error-prone at the very least. Another interesting duplicate fields are rq->[hard_]nr_sectors and rq->{hard_cur|current}_nr_sectors against rq->data_len and rq->bio->bi_size. This is more convoluted than the hard_ case. rq->[hard_]nr_sectors are initialized for requests with bio but blk_rq_bytes() uses it only for !pc requests. rq->data_len is initialized for all request but blk_rq_bytes() uses it only for pc requests. This causes good amount of confusion throughout block layer and its drivers and determining the request length has been a bit of black magic which may or may not work depending on circumstances and what the specific LLD is actually doing. rq->{hard_cur|current}_nr_sectors represent the number of sectors in the contiguous data area at the front. This is mainly used by drivers which transfers data by walking request segment-by-segment. This value always equals rq->bio->bi_size >> 9. However, data length for pc requests may not be multiple of 512 bytes and using this field becomes a bit confusing. In general, having multiple fields to represent the same property leads only to confusion and subtle bugs. With recent block low level driver cleanups, no driver is accessing or manipulating these duplicate fields directly. Drop all the duplicates. Now rq->sector means the current sector, rq->data_len the current total length and rq->bio->bi_size the current segment length. Everything else is defined in terms of these three and available only through accessors. * blk_recalc_rq_sectors() is collapsed into blk_update_request() and now handles pc and fs requests equally other than rq->sector update. This means that now pc requests can use partial completion too (no in-kernel user yet tho). * bio_cur_sectors() is replaced with bio_cur_bytes() as block layer now uses byte count as the primary data length. * blk_rq_pos() is now guranteed to be always correct. In-block users converted. * blk_rq_bytes() is now guaranteed to be always valid as is blk_rq_sectors(). In-block users converted. * blk_rq_sectors() is now guaranteed to equal blk_rq_bytes() >> 9. More convenient one is used. * blk_rq_bytes() and blk_rq_cur_bytes() are now inlined and take const pointer to request. [ Impact: API cleanup, single way to represent one property of a request ] Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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83096ebf |
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07-May-2009 |
Tejun Heo <tj@kernel.org> |
block: convert to pos and nr_sectors accessors With recent cleanups, there is no place where low level driver directly manipulates request fields. This means that the 'hard' request fields always equal the !hard fields. Convert all rq->sectors, nr_sectors and current_nr_sectors references to accessors. While at it, drop superflous blk_rq_pos() < 0 test in swim.c. [ Impact: use pos and nr_sectors accessors ] Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com> Tested-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Grant Likely <grant.likely@secretlab.ca> Tested-by: Adrian McMenamin <adrian@mcmen.demon.co.uk> Acked-by: Adrian McMenamin <adrian@mcmen.demon.co.uk> Acked-by: Mike Miller <mike.miller@hp.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Cc: Borislav Petkov <petkovbb@googlemail.com> Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com> Cc: Eric Moore <Eric.Moore@lsi.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Pete Zaitcev <zaitcev@redhat.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Paul Clements <paul.clements@steeleye.com> Cc: Tim Waugh <tim@cyberelk.net> Cc: Jeff Garzik <jgarzik@pobox.com> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Alex Dubov <oakad@yahoo.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Dario Ballabio <ballabio_dario@emc.com> Cc: David S. Miller <davem@davemloft.net> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: unsik Kim <donari75@gmail.com> Cc: Laurent Vivier <Laurent@lvivier.info> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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42dad764 |
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22-Apr-2009 |
Jerome Marchand <jmarchan@redhat.com> |
block: simplify I/O stat accounting This simplifies I/O stat accounting switching code and separates it completely from I/O scheduler switch code. Requests are accounted according to the state of their request queue at the time of the request allocation. There is no need anymore to flush the request queue when switching I/O accounting state. Signed-off-by: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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26308eab |
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27-Mar-2009 |
Jerome Marchand <jmarchan@redhat.com> |
block: fix inconsistency in I/O stat accounting code This forces in_flight to be zero when turning off or on the I/O stat accounting and stops updating I/O stats in attempt_merge() when accounting is turned off. Signed-off-by: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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1cd96c24 |
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23-Mar-2009 |
Boaz Harrosh <bharrosh@panasas.com> |
block: WARN in __blk_put_request() for potential bio leak Put a WARN_ON in __blk_put_request if it is about to leak bio(s). This is a serious bug that can happen in error handling code paths. For this to work I have fixed a couple of places in block/ where request->bio != NULL ownership was not honored. And a small cleanup at sg_io() while at it. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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59247eae |
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06-Mar-2009 |
Jens Axboe <jens.axboe@oracle.com> |
block: fix missing bio back/front segment size setting in blk_recount_segments() Commit 1e42807918d17e8c93bf14fbb74be84b141334c1 introduced a bug where we don't get front/back segment sizes in the bio in blk_recount_segments(). Fix this by tracking the back bio as well as the front bio in __blk_recalc_rq_segments(), this also cleans up the interface by getting rid of the segment size pointer passing. Tested-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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1e428079 |
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23-Feb-2009 |
Jens Axboe <jens.axboe@oracle.com> |
block: reduce stack footprint of blk_recount_segments() blk_recalc_rq_segments() requires a request structure passed in, which we don't have from blk_recount_segments(). So the latter allocates one on the stack, using > 400 bytes of stack for that. This can cause us to spill over one page of stack from ext4 at least: 0) 4560 400 blk_recount_segments+0x43/0x62 1) 4160 32 bio_phys_segments+0x1c/0x24 2) 4128 32 blk_rq_bio_prep+0x2a/0xf9 3) 4096 32 init_request_from_bio+0xf9/0xfe 4) 4064 112 __make_request+0x33c/0x3f6 5) 3952 144 generic_make_request+0x2d1/0x321 6) 3808 64 submit_bio+0xb9/0xc3 7) 3744 48 submit_bh+0xea/0x10e 8) 3696 368 ext4_mb_init_cache+0x257/0xa6a [ext4] 9) 3328 288 ext4_mb_regular_allocator+0x421/0xcd9 [ext4] 10) 3040 160 ext4_mb_new_blocks+0x211/0x4b4 [ext4] 11) 2880 336 ext4_ext_get_blocks+0xb61/0xd45 [ext4] 12) 2544 96 ext4_get_blocks_wrap+0xf2/0x200 [ext4] 13) 2448 80 ext4_da_get_block_write+0x6e/0x16b [ext4] 14) 2368 352 mpage_da_map_blocks+0x7e/0x4b3 [ext4] 15) 2016 352 ext4_da_writepages+0x2ce/0x43c [ext4] 16) 1664 32 do_writepages+0x2d/0x3c 17) 1632 144 __writeback_single_inode+0x162/0x2cd 18) 1488 96 generic_sync_sb_inodes+0x1e3/0x32b 19) 1392 16 sync_sb_inodes+0xe/0x10 20) 1376 48 writeback_inodes+0x69/0xb3 21) 1328 208 balance_dirty_pages_ratelimited_nr+0x187/0x2f9 22) 1120 224 generic_file_buffered_write+0x1d4/0x2c4 23) 896 176 __generic_file_aio_write_nolock+0x35f/0x393 24) 720 80 generic_file_aio_write+0x6c/0xc8 25) 640 80 ext4_file_write+0xa9/0x137 [ext4] 26) 560 320 do_sync_write+0xf0/0x137 27) 240 48 vfs_write+0xb3/0x13c 28) 192 64 sys_write+0x4c/0x74 29) 128 128 system_call_fastpath+0x16/0x1b Split the segment counting out into a __blk_recalc_rq_segments() helper to avoid allocating an onstack request just for checking the physical segment count. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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43381785 |
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20-Oct-2008 |
FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> |
block: remove unused ll_new_mergeable() Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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86771427 |
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13-Oct-2008 |
FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> |
block: fix nr_phys_segments miscalculation bug This fixes the bug reported by Nikanth Karthikesan <knikanth@suse.de>: http://lkml.org/lkml/2008/10/2/203 The root cause of the bug is that blk_phys_contig_segment miscalculates q->max_segment_size. blk_phys_contig_segment checks: req->biotail->bi_size + next_req->bio->bi_size > q->max_segment_size But blk_recalc_rq_segments might expect that req->biotail and the previous bio in the req are supposed be merged into one segment. blk_recalc_rq_segments might also expect that next_req->bio and the next bio in the next_req are supposed be merged into one segment. In such case, we merge two requests that can't be merged here. Later, blk_rq_map_sg gives more segments than it should. We need to keep track of segment size in blk_recalc_rq_segments and use it to see if two requests can be merged. This patch implements it in the similar way that we used to do for hw merging (virtual merging). Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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ab780f1e |
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26-Aug-2008 |
Jens Axboe <jens.axboe@oracle.com> |
block: inherit CPU completion on bio->rq and rq->rq merges Somewhat incomplete, as we do allow merges of requests and bios that have different completion CPUs given. This is done on the assumption that a larger IO is still more beneficial than CPU locality. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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074a7aca |
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25-Aug-2008 |
Tejun Heo <tj@kernel.org> |
block: move stats from disk to part0 Move stats related fields - stamp, in_flight, dkstats - from disk to part0 and unify stat handling such that... * part_stat_*() now updates part0 together if the specified partition is not part0. ie. part_stat_*() are now essentially all_stat_*(). * {disk|all}_stat_*() are gone. * part_round_stats() is updated similary. It handles part0 stats automatically and disk_round_stats() is killed. * part_{inc|dec}_in_fligh() is implemented which automatically updates part0 stats for parts other than part0. * disk_map_sector_rcu() is updated to return part0 if no part matches. Combined with the above changes, this makes NULL special case handling in callers unnecessary. * Separate stats show code paths for disk are collapsed into part stats show code paths. * Rename disk_stat_lock/unlock() to part_stat_lock/unlock() While at it, reposition stat handling macros a bit and add missing parentheses around macro parameters. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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c9959059 |
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25-Aug-2008 |
Tejun Heo <tj@kernel.org> |
block: fix diskstats access There are two variants of stat functions - ones prefixed with double underbars which don't care about preemption and ones without which disable preemption before manipulating per-cpu counters. It's unclear whether the underbarred ones assume that preemtion is disabled on entry as some callers don't do that. This patch unifies diskstats access by implementing disk_stat_lock() and disk_stat_unlock() which take care of both RCU (for partition access) and preemption (for per-cpu counter access). diskstats access should always be enclosed between the two functions. As such, there's no need for the versions which disables preemption. They're removed and double underbars ones are renamed to drop the underbars. As an extra argument is added, there's no danger of using the old version unconverted. disk_stat_lock() uses get_cpu() and returns the cpu index and all diskstat functions which access per-cpu counters now has @cpu argument to help RT. This change adds RCU or preemption operations at some places but also collapses several preemption ops into one at others. Overall, the performance difference should be negligible as all involved ops are very lightweight per-cpu ones. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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e71bf0d0 |
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03-Sep-2008 |
Tejun Heo <tj@kernel.org> |
block: fix disk->part[] dereferencing race disk->part[] is protected by its matching bdev's lock. However, non-critical accesses like collecting stats and printing out sysfs and proc information used to be performed without any locking. As partitions can come and go dynamically, partitions can go away underneath those non-critical accesses. As some of those accesses are writes, this theoretically can lead to silent corruption. This patch fixes the race by using RCU for the partition array and dev reference counter to hold partitions. * Rename disk->part[] to disk->__part[] to make sure no one outside genhd layer proper accesses it directly. * Use RCU for disk->__part[] dereferencing. * Implement disk_{get|put}_part() which can be used to get and put partitions from gendisk respectively. * Iterators are implemented to help iterate through all partitions safely. * Functions which require RCU readlock are marked with _rcu suffix. * Use disk_put_part() in __blkdev_put() instead of directly putting the contained kobject. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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310a2c10 |
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25-Aug-2008 |
Tejun Heo <tj@kernel.org> |
block: misc updates This patch makes the following misc updates in preparation for disk->part dereference fix and extended block devt support. * implment part_to_disk() * fix comment about gendisk->part indexing * rename get_part() to disk_map_sector() * don't use n which is always zero while printing disk information in diskstats_show() Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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5df97b91 |
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15-Aug-2008 |
Mikulas Patocka <mpatocka@redhat.com> |
drop vmerge accounting Remove hw_segments field from struct bio and struct request. Without virtual merge accounting they have no purpose. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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b8b3e16c |
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15-Aug-2008 |
Mikulas Patocka <mpatocka@redhat.com> |
block: drop virtual merging accounting Remove virtual merge accounting. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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e17fc0a1 |
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09-Aug-2008 |
David Woodhouse <David.Woodhouse@intel.com> |
Allow elevators to sort/merge discard requests But blkdev_issue_discard() still emits requests which are interpreted as soft barriers, because naïve callers might otherwise issue subsequent writes to those same sectors, which might cross on the queue (if they're reallocated quickly enough). Callers still _can_ issue non-barrier discard requests, but they have to take care of queue ordering for themselves. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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7ba1ba12 |
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30-Jun-2008 |
Martin K. Petersen <martin.petersen@oracle.com> |
block: Block layer data integrity support Some block devices support verifying the integrity of requests by way of checksums or other protection information that is submitted along with the I/O. This patch implements support for generating and verifying integrity metadata, as well as correctly merging, splitting and cloning bios and requests that have this extra information attached. See Documentation/block/data-integrity.txt for more information. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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2cdf79ca |
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07-May-2008 |
Jens Axboe <jens.axboe@oracle.com> |
block: get rid of likely/unlikely predictions in merge logic They tend to depend a lot on the workload, so not a clear-cut likely or unlikely fit. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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75ad23bc |
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29-Apr-2008 |
Nick Piggin <npiggin@suse.de> |
block: make queue flags non-atomic We can save some atomic ops in the IO path, if we clearly define the rules of how to modify the queue flags. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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f18573ab |
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10-Apr-2008 |
FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> |
block: move the padding adjustment to blk_rq_map_sg blk_rq_map_user adjusts bi_size of the last bio. It breaks the rule that req->data_len (the true data length) is equal to sum(bio). It broke the scsi command completion code. commit e97a294ef6938512b655b1abf17656cf2b26f709 was introduced to fix the above issue. However, the partial completion code doesn't work with it. The commit is also a layer violation (scsi mid-layer should not know about the block layer's padding). This patch moves the padding adjustment to blk_rq_map_sg (suggested by James). The padding works like the drain buffer. This patch breaks the rule that req->data_len is equal to sum(sg), however, the drain buffer already broke it. So this patch just restores the rule that req->data_len is equal to sub(bio) without breaking anything new. Now when a low level driver needs padding, blk_rq_map_user and blk_rq_map_user_iov guarantee there's enough room for padding. blk_rq_map_sg can safely extend the last entry of a scatter list. blk_rq_map_sg must extend the last entry of a scatter list only for a request that got through bio_copy_user_iov. This patches introduces new REQ_COPY_USER flag. Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Tejun Heo <htejun@gmail.com> Cc: Mike Christie <michaelc@cs.wisc.edu> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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7a85f889 |
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04-Mar-2008 |
FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> |
block: restore the meaning of rq->data_len to the true data length The meaning of rq->data_len was changed to the length of an allocated buffer from the true data length. It breaks SG_IO friends and bsg. This patch restores the meaning of rq->data_len to the true data length and adds rq->extra_len to store an extended length (due to drain buffer and padding). This patch also removes the code to update bio in blk_rq_map_user introduced by the commit 40b01b9bbdf51ae543a04744283bf2d56c4a6afa. The commit adjusts bio according to memory alignment (queue_dma_alignment). However, memory alignment is NOT padding alignment. This adjustment also breaks SG_IO friends and bsg. Padding alignment needs to be fixed in a proper way (by a separate patch). Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Jens Axboe <axboe@carl.home.kernel.dk>
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db0a2e00 |
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19-Feb-2008 |
Tejun Heo <htejun@gmail.com> |
block: clear drain buffer if draining for write command Clear drain buffer before chaining if the command in question is a write. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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2fb98e84 |
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19-Feb-2008 |
Tejun Heo <htejun@gmail.com> |
block: implement request_queue->dma_drain_needed Draining shouldn't be done for commands where overflow may indicate data integrity issues. Add dma_drain_needed callback to request_queue. Drain buffer is appened iff this function returns non-zero. Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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6b00769f |
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19-Feb-2008 |
Tejun Heo <htejun@gmail.com> |
block: add request->raw_data_len With padding and draining moved into it, block layer now may extend requests as directed by queue parameters, so now a request has two sizes - the original request size and the extended size which matches the size of area pointed to by bios and later by sgs. The latter size is what lower layers are primarily interested in when allocating, filling up DMA tables and setting up the controller. Both padding and draining extend the data area to accomodate controller characteristics. As any controller which speaks SCSI can handle underflows, feeding larger data area is safe. So, this patch makes the primary data length field, request->data_len, indicate the size of full data area and add a separate length field, request->raw_data_len, for the unmodified request size. The latter is used to report to higher layer (userland) and where the original request size should be fed to the controller or device. Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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6f2576af |
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08-Feb-2008 |
Jerome Marchand <jmarchan@redhat.com> |
Enhanced partition statistics: update partition statitics Updates the enhanced partition statistics in generic block layer besides the disk statistics. Signed-off-by: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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6728cb0e |
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31-Jan-2008 |
Jens Axboe <jens.axboe@oracle.com> |
block: make core bits checkpatch compliant Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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d6d48196 |
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29-Jan-2008 |
Jens Axboe <jens.axboe@oracle.com> |
block: ll_rw_blk.c split, add blk-merge.c Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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