#
05bdb996 |
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08-Jun-2023 |
Christoph Hellwig <hch@lst.de> |
block: replace fmode_t with a block-specific type for block open flags The only overlap between the block open flags mapped into the fmode_t and other uses of fmode_t are FMODE_READ and FMODE_WRITE. Define a new blk_mode_t instead for use in blkdev_get_by_{dev,path}, ->open and ->ioctl and stop abusing fmode_t. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Jack Wang <jinpu.wang@ionos.com> [rnbd] Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Christian Brauner <brauner@kernel.org> Link: https://lore.kernel.org/r/20230608110258.189493-28-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
b362c733 |
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18-Mar-2023 |
Yangtao Li <frank.li@vivo.com> |
dm: push error reporting down to dm_register_target() Simplifies each DM target's init method by making dm_register_target() responsible for its error reporting (on behalf of targets). Signed-off-by: Yangtao Li <frank.li@vivo.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
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#
76227f6d |
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16-Feb-2023 |
Mike Snitzer <snitzer@kernel.org> |
dm cache: add cond_resched() to various workqueue loops Otherwise on resource constrained systems these workqueues may be too greedy. Signed-off-by: Mike Snitzer <snitzer@kernel.org>
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#
774f13ac |
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07-Feb-2023 |
Heinz Mauelshagen <heinzm@redhat.com> |
dm: declare variables static when sensible Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
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#
23fda2ef |
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07-Feb-2023 |
Heinz Mauelshagen <heinzm@redhat.com> |
dm: fix suspect indent whitespace Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
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#
0ef0b471 |
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01-Feb-2023 |
Heinz Mauelshagen <heinzm@redhat.com> |
dm: add missing empty lines Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
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#
8ca817c4 |
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01-Feb-2023 |
Heinz Mauelshagen <heinzm@redhat.com> |
dm: avoid spaces before function arguments or in favour of tabs Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
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#
a4a82ce3 |
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26-Jan-2023 |
Heinz Mauelshagen <heinzm@redhat.com> |
dm: correct block comments format. Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
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#
86a3238c |
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25-Jan-2023 |
Heinz Mauelshagen <heinzm@redhat.com> |
dm: change "unsigned" to "unsigned int" Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
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#
3bd94003 |
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25-Jan-2023 |
Heinz Mauelshagen <heinzm@redhat.com> |
dm: add missing SPDX-License-Indentifiers 'GPL-2.0-only' is used instead of 'GPL-2.0' because SPDX has deprecated its use. Suggested-by: John Wiele <jwiele@redhat.com> Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
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#
6b997386 |
|
30-Nov-2022 |
Mike Snitzer <snitzer@kernel.org> |
dm cache: set needs_check flag after aborting metadata Otherwise the commit that will be aborted will be associated with the metadata objects that will be torn down. Must write needs_check flag to metadata with a reset block manager. Found through code-inspection (and compared against dm-thin.c). Cc: stable@vger.kernel.org Fixes: 028ae9f76f29 ("dm cache: add fail io mode and needs_check flag") Signed-off-by: Mike Snitzer <snitzer@kernel.org>
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#
6a459d8e |
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28-Nov-2022 |
Luo Meng <luomeng12@huawei.com> |
dm cache: Fix UAF in destroy() Dm_cache also has the same UAF problem when dm_resume() and dm_destroy() are concurrent. Therefore, cancelling timer again in destroy(). Cc: stable@vger.kernel.org Fixes: c6b4fcbad044e ("dm: add cache target") Signed-off-by: Luo Meng <luomeng12@huawei.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
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#
5c29e784 |
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21-Jun-2022 |
Steven Lung <1030steven@gmail.com> |
dm cache: fix typo in 2 comment blocks Replace neccessarily with necessarily. Signed-off-by: Steven Lung <1030steven@gmail.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
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#
70200574 |
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14-Apr-2022 |
Christoph Hellwig <hch@lst.de> |
block: remove QUEUE_FLAG_DISCARD Just use a non-zero max_discard_sectors as an indicator for discard support, similar to what is done for write zeroes. The only places where needs special attention is the RAID5 driver, which must clear discard support for security reasons by default, even if the default stacking rules would allow for it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> [drbd] Acked-by: Jan Höppner <hoeppner@linux.ibm.com> [s390] Acked-by: Coly Li <colyli@suse.de> [bcache] Acked-by: David Sterba <dsterba@suse.com> [btrfs] Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Link: https://lore.kernel.org/r/20220415045258.199825-25-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
69596f55 |
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08-Mar-2022 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: use dm_submit_bio_remap Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
385411ff |
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01-Mar-2022 |
Christoph Hellwig <hch@lst.de> |
dm: stop using bdevname Just use the %pg format specifier instead. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
abfc426d |
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02-Feb-2022 |
Christoph Hellwig <hch@lst.de> |
block: pass a block_device to bio_clone_fast Pass a block_device to bio_clone_fast and __bio_clone_fast and give the functions more suitable names. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Link: https://lore.kernel.org/r/20220202160109.108149-14-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
3c4b455e |
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02-Feb-2022 |
Christoph Hellwig <hch@lst.de> |
dm-cache: remove __remap_to_origin_clear_discard Fold __remap_to_origin_clear_discard into the two callers to prepare for bio cloning refactoring. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Link: https://lore.kernel.org/r/20220202160109.108149-10-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
6dcbb52c |
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17-Oct-2021 |
Christoph Hellwig <hch@lst.de> |
dm: use bdev_nr_sectors and bdev_nr_bytes instead of open coding them Use the proper helpers to read the block device size. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Mike Snitzer <snitzer@redhat.com> Link: https://lore.kernel.org/r/20211018101130.1838532-6-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
8ec45662 |
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12-Jul-2021 |
Tushar Sugandhi <tusharsu@linux.microsoft.com> |
dm: update target status functions to support IMA measurement For device mapper targets to take advantage of IMA's measurement capabilities, the status functions for the individual targets need to be updated to handle the status_type_t case for value STATUSTYPE_IMA. Update status functions for the following target types, to log their respective attributes to be measured using IMA. 01. cache 02. crypt 03. integrity 04. linear 05. mirror 06. multipath 07. raid 08. snapshot 09. striped 10. verity For rest of the targets, handle the STATUSTYPE_IMA case by setting the measurement buffer to NULL. For IMA to measure the data on a given system, the IMA policy on the system needs to be updated to have the following line, and the system needs to be restarted for the measurements to take effect. /etc/ima/ima-policy measure func=CRITICAL_DATA label=device-mapper template=ima-buf The measurements will be reflected in the IMA logs, which are located at: /sys/kernel/security/integrity/ima/ascii_runtime_measurements /sys/kernel/security/integrity/ima/binary_runtime_measurements These IMA logs can later be consumed by various attestation clients running on the system, and send them to external services for attesting the system. The DM target data measured by IMA subsystem can alternatively be queried from userspace by setting DM_IMA_MEASUREMENT_FLAG with DM_TABLE_STATUS_CMD. Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
dc4fa29f |
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24-Jun-2021 |
Mike Snitzer <snitzer@redhat.com> |
dm io tracker: factor out IO tracker Allow other code to use dm_io_tracker. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
63508e38 |
|
19-Mar-2021 |
Xu Wang <vulab@iscas.ac.cn> |
dm cache: remove needless request_queue NULL pointer checks Since commit ff9ea323816d ("block, bdi: an active gendisk always has a request_queue associated with it") the request_queue pointer returned from bdev_get_queue() shall never be NULL. Signed-off-by: Xu Wang <vulab@iscas.ac.cn> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
b7770923 |
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10-Dec-2020 |
Zheng Yongjun <zhengyongjun3@huawei.com> |
dm cache: simplify the return expression of load_mapping() Simplify the return expression. Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
35d2835d |
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10-Nov-2020 |
Nick Desaulniers <ndesaulniers@google.com> |
Revert "dm cache: fix arm link errors with inline" This reverts commit 43aeaa29573924df76f44eda2bbd94ca36e407b5. Since commit 0bddd227f3dc ("Documentation: update for gcc 4.9 requirement") the minimum supported version of GCC is gcc-4.9. It's now safe to remove this code. Link: https://github.com/ClangBuiltLinux/linux/issues/427 Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Acked-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
d4a512ed |
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19-Sep-2020 |
Mike Snitzer <snitzer@redhat.com> |
dm: use dm_table_get_device_name() where appropriate in targets dm_table_get_device_name() avoids calling dm_table_get_md() followed by dm_device_name() -- saves intermediate dm_table_get_md() call. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
21cf8661 |
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01-Jul-2020 |
Christoph Hellwig <hch@lst.de> |
writeback: remove bdi->congested_fn Except for pktdvd, the only places setting congested bits are file systems that allocate their own backing_dev_info structures. And pktdvd is a deprecated driver that isn't useful in stack setup either. So remove the dead congested_fn stacking infrastructure. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Song Liu <song@kernel.org> Acked-by: David Sterba <dsterba@suse.com> [axboe: fixup unused variables in bcache/request.c] Signed-off-by: Jens Axboe <axboe@kernel.dk>
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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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#
636be424 |
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27-Feb-2020 |
Mike Snitzer <snitzer@redhat.com> |
dm: bump version of core and various targets Changes made during the 5.6 cycle warrant bumping the version number for DM core and the targets modified by this commit. It should be noted that dm-thin, dm-crypt and dm-raid already had their target version bumped during the 5.6 merge window. Signed-off-by; Mike Snitzer <snitzer@redhat.com>
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#
7cdf6a0a |
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19-Feb-2020 |
Mikulas Patocka <mpatocka@redhat.com> |
dm cache: fix a crash due to incorrect work item cancelling The crash can be reproduced by running the lvm2 testsuite test lvconvert-thin-external-cache.sh for several minutes, e.g.: while :; do make check T=shell/lvconvert-thin-external-cache.sh; done The crash happens in this call chain: do_waker -> policy_tick -> smq_tick -> end_hotspot_period -> clear_bitset -> memset -> __memset -- which accesses an invalid pointer in the vmalloc area. The work entry on the workqueue is executed even after the bitmap was freed. The problem is that cancel_delayed_work doesn't wait for the running work item to finish, so the work item can continue running and re-submitting itself even after cache_postsuspend. In order to make sure that the work item won't be running, we must use cancel_delayed_work_sync. Also, change flush_workqueue to drain_workqueue, so that if some work item submits itself or another work item, we are properly waiting for both of them. Fixes: c6b4fcbad044 ("dm: add cache target") Cc: stable@vger.kernel.org # v3.9 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
26b924b9 |
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23-Oct-2019 |
Mikulas Patocka <mpatocka@redhat.com> |
dm cache: replace spin_lock_irqsave with spin_lock_irq If we are in a place where it is known that interrupts are enabled, functions spin_lock_irq/spin_unlock_irq should be used instead of spin_lock_irqsave/spin_unlock_irqrestore. spin_lock_irq and spin_unlock_irq are faster because they don't need to push and pop the flags register. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
13bd677a |
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16-Oct-2019 |
Mikulas Patocka <mpatocka@redhat.com> |
dm cache: fix bugs when a GFP_NOWAIT allocation fails GFP_NOWAIT allocation can fail anytime - it doesn't wait for memory being available and it fails if the mempool is exhausted and there is not enough memory. If we go down this path: map_bio -> mg_start -> alloc_migration -> mempool_alloc(GFP_NOWAIT) we can see that map_bio() doesn't check the return value of mg_start(), and the bio is leaked. If we go down this path: map_bio -> mg_start -> mg_lock_writes -> alloc_prison_cell -> dm_bio_prison_alloc_cell_v2 -> mempool_alloc(GFP_NOWAIT) -> mg_lock_writes -> mg_complete the bio is ended with an error - it is unacceptable because it could cause filesystem corruption if the machine ran out of memory temporarily. Change GFP_NOWAIT to GFP_NOIO, so that the mempool code will properly wait until memory becomes available. mempool_alloc with GFP_NOIO can't fail, so remove the code paths that deal with allocation failure. Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
de7180ff |
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25-Feb-2019 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: add support for discard passdown to the origin device DM cache now defaults to passing discards down to the origin device. User may disable this using the "no_discard_passdown" feature when creating the cache device. If the cache's underlying origin device doesn't support discards then passdown is disabled (with warning). Similarly, if the underlying origin device's max_discard_sectors is less than a cache block discard passdown will be disabled (this is required because sizing of the cache internal discard bitset depends on it). Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
61697a6a |
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18-Jan-2019 |
Mike Snitzer <snitzer@redhat.com> |
dm: eliminate 'split_discard_bios' flag from DM target interface There is no need to have DM core split discards on behalf of a DM target now that blk_queue_split() handles splitting discards based on the queue_limits. A DM target just needs to set max_discard_sectors, discard_granularity, etc, in queue_limits. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
c7cd5550 |
|
07-Oct-2018 |
Shenghui Wang <shhuiw@foxmail.com> |
dm cache: destroy migration_cache if cache target registration failed Commit 7e6358d244e47 ("dm: fix various targets to dm_register_target after module __init resources created") inadvertently introduced this bug when it moved dm_register_target() after the call to KMEM_CACHE(). Fixes: 7e6358d244e47 ("dm: fix various targets to dm_register_target after module __init resources created") Cc: stable@vger.kernel.org Signed-off-by: Shenghui Wang <shhuiw@foxmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
5d07384a |
|
25-Sep-2018 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: fix resize crash if user doesn't reload cache table A reload of the cache's DM table is needed during resize because otherwise a crash will occur when attempting to access smq policy entries associated with the portion of the cache that was recently extended. The reason is cache-size based data structures in the policy will not be resized, the only way to safely extend the cache is to allow for a proper cache policy initialization that occurs when the cache table is loaded. For example the smq policy's space_init(), init_allocator(), calc_hotspot_params() must be sized based on the extended cache size. The fix for this is to disallow cache resizes of this pattern: 1) suspend "cache" target's device 2) resize the fast device used for the cache 3) resume "cache" target's device Instead, the last step must be a full reload of the cache's DM table. Fixes: 66a636356 ("dm cache: add stochastic-multi-queue (smq) policy") Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
7209049d |
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31-Jul-2018 |
Mike Snitzer <snitzer@redhat.com> |
dm kcopyd: return void from dm_kcopyd_copy() dm_kcopyd_copy() only ever returns 0 so there is no need for callers to account for possible failure. Same goes for dm_kcopyd_zero(). Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
af9313c3 |
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21-Jun-2018 |
John Pittman <jpittman@redhat.com> |
dm cache: only allow a single io_mode cache feature to be requested More than one io_mode feature can be requested when creating a dm cache device (as is: last one wins). The io_mode selections are incompatible with one another, we should force them to be selected exclusively. Add a counter to check for more than one io_mode selection. Fixes: 629d0a8a1a10 ("dm cache metadata: add "metadata2" feature") Signed-off-by: John Pittman <jpittman@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
72d711c8 |
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22-May-2018 |
Mike Snitzer <snitzer@redhat.com> |
dm: adjust structure members to improve alignment Eliminate most holes in DM data structures that were modified by commit 6f1c819c21 ("dm: convert to bioset_init()/mempool_init()"). Also prevent structure members from unnecessarily spanning cache lines. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
6f1c819c |
|
20-May-2018 |
Kent Overstreet <kent.overstreet@gmail.com> |
dm: convert to bioset_init()/mempool_init() Convert dm to embedded bio sets. Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
1eb5fa84 |
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28-Feb-2018 |
Mike Snitzer <snitzer@redhat.com> |
dm: allow targets to return output from messages they are sent Could be useful for a target to return stats or other information. If a target does DMEMIT() anything to @result from its .message method then it must return 1 to the caller. Signed-off-By: Mike Snitzer <snitzer@redhat.com>
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#
7e6358d2 |
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24-Nov-2017 |
monty_pavel@sina.com <monty_pavel@sina.com> |
dm: fix various targets to dm_register_target after module __init resources created A NULL pointer is seen if two concurrent "vgchange -ay -K <vg name>" processes race to load the dm-thin-pool module: PID: 25992 TASK: ffff883cd7d23500 CPU: 4 COMMAND: "vgchange" #0 [ffff883cd743d600] machine_kexec at ffffffff81038fa9 0000001 [ffff883cd743d660] crash_kexec at ffffffff810c5992 0000002 [ffff883cd743d730] oops_end at ffffffff81515c90 0000003 [ffff883cd743d760] no_context at ffffffff81049f1b 0000004 [ffff883cd743d7b0] __bad_area_nosemaphore at ffffffff8104a1a5 0000005 [ffff883cd743d800] bad_area at ffffffff8104a2ce 0000006 [ffff883cd743d830] __do_page_fault at ffffffff8104aa6f 0000007 [ffff883cd743d950] do_page_fault at ffffffff81517bae 0000008 [ffff883cd743d980] page_fault at ffffffff81514f95 [exception RIP: kmem_cache_alloc+108] RIP: ffffffff8116ef3c RSP: ffff883cd743da38 RFLAGS: 00010046 RAX: 0000000000000004 RBX: ffffffff81121b90 RCX: ffff881bf1e78cc0 RDX: 0000000000000000 RSI: 00000000000000d0 RDI: 0000000000000000 RBP: ffff883cd743da68 R8: ffff881bf1a4eb00 R9: 0000000080042000 R10: 0000000000002000 R11: 0000000000000000 R12: 00000000000000d0 R13: 0000000000000000 R14: 00000000000000d0 R15: 0000000000000246 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 0000009 [ffff883cd743da70] mempool_alloc_slab at ffffffff81121ba5 0000010 [ffff883cd743da80] mempool_create_node at ffffffff81122083 0000011 [ffff883cd743dad0] mempool_create at ffffffff811220f4 0000012 [ffff883cd743dae0] pool_ctr at ffffffffa08de049 [dm_thin_pool] 0000013 [ffff883cd743dbd0] dm_table_add_target at ffffffffa0005f2f [dm_mod] 0000014 [ffff883cd743dc30] table_load at ffffffffa0008ba9 [dm_mod] 0000015 [ffff883cd743dc90] ctl_ioctl at ffffffffa0009dc4 [dm_mod] The race results in a NULL pointer because: Process A (vgchange -ay -K): a. send DM_LIST_VERSIONS_CMD ioctl; b. pool_target not registered; c. modprobe dm_thin_pool and wait until end. Process B (vgchange -ay -K): a. send DM_LIST_VERSIONS_CMD ioctl; b. pool_target registered; c. table_load->dm_table_add_target->pool_ctr; d. _new_mapping_cache is NULL and panic. Note: 1. process A and process B are two concurrent processes. 2. pool_target can be detected by process B but _new_mapping_cache initialization has not ended. To fix dm-thin-pool, and other targets (cache, multipath, and snapshot) with the same problem, simply dm_register_target() after all resources created during module init (as labelled with __init) are finished. Cc: stable@vger.kernel.org Signed-off-by: monty <monty_pavel@sina.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
ef7afb36 |
|
09-Nov-2017 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: lift common migration preparation code to alloc_migration() Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
ede6507d |
|
09-Nov-2017 |
Joe Thornber <ejt@redhat.com> |
dm cache: remove usused deferred_cells member from struct cache Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
693b960e |
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19-Oct-2017 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: simplify get_per_bio_data() by removing data_size argument There is only one per_bio_data size now that writethrough-specific data was removed from the per_bio_data structure. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
9958f1d9 |
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19-Oct-2017 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: remove all obsolete writethrough-specific code Now that the writethrough code is much simpler there is no need to track so much state or cascade bio submission (as was done, via writethrough_endio(), to issue origin then cache IO in series). As such the obsolete writethrough list and workqueue is also removed. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
2df3bae9 |
|
19-Oct-2017 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: submit writethrough writes in parallel to origin and cache Discontinue issuing writethrough write IO in series to the origin and then cache. Use bio_clone_fast() to create a new origin clone bio that will be mapped to the origin device and then bio_chain() it to the bio that gets remapped to the cache device. The origin clone bio does _not_ have a copy of the per_bio_data -- as such check_if_tick_bio_needed() will not be called. The cache bio (parent bio) will not complete until the origin bio has completed -- this fulfills bio_clone_fast()'s requirements as well as the requirement to not complete the original IO until the write IO has completed to both the origin and cache device. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
8e3c3827 |
|
19-Oct-2017 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: pass cache structure to mode functions No functional changes, just a bit cleaner than passing cache_features structure. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
d1260e2a |
|
10-Nov-2017 |
Joe Thornber <ejt@redhat.com> |
dm cache: fix race condition in the writeback mode overwrite_bio optimisation When a DM cache in writeback mode moves data between the slow and fast device it can often avoid a copy if the triggering bio either: i) covers the whole block (no point copying if we're about to overwrite it) ii) the migration is a promotion and the origin block is currently discarded Prior to this fix there was a race with case (ii). The discard status was checked with a shared lock held (rather than exclusive). This meant another bio could run in parallel and write data to the origin, removing the discard state. After the promotion the parallel write would have been lost. With this fix the discard status is re-checked once the exclusive lock has been aquired. If the block is no longer discarded it falls back to the slower full copy path. Fixes: b29d4986d ("dm cache: significant rework to leverage dm-bio-prison-v2") Cc: stable@vger.kernel.org # v4.12+ Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
5916a22b |
|
22-Jun-2017 |
Eric Biggers <ebiggers@google.com> |
dm: constify argument arrays The arrays of 'struct dm_arg' are never modified by the device-mapper core, so constify them so that they are placed in .rodata. (Exception: the args array in dm-raid cannot be constified because it is allocated on the stack and modified.) Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
74d46992 |
|
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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#
4e4cbee9 |
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03-Jun-2017 |
Christoph Hellwig <hch@lst.de> |
block: switch bios to blk_status_t Replace bi_error with a new bi_status to allow for a clear conversion. Note that device mapper overloaded bi_error with a private value, which we'll have to keep arround at least for now and thus propagate to a proper blk_status_t value. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
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#
1be56909 |
|
03-Jun-2017 |
Christoph Hellwig <hch@lst.de> |
dm: change ->end_io calling convention Turn the error paramter into a pointer so that target drivers can change the value, and make sure only DM_ENDIO_* values are returned from the methods. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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#
49b7f768 |
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11-May-2017 |
Joe Thornber <ejt@redhat.com> |
dm cache: simplify the IDLE vs BUSY state calculation Drop the MODERATE state since it wasn't buying us much. Also, in check_migrations(), prepare for the next commit ("dm cache policy smq: don't do any writebacks unless IDLE") by deferring to the policy to make the final decision on whether writebacks can be serviced. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
|
#
701e03e4 |
|
11-May-2017 |
Joe Thornber <ejt@redhat.com> |
dm cache: track all IO to the cache rather than just the origin device's IO IO tracking used to throttle writebacks when the origin device is busy. Even if all the IO is going to the fast device, writebacks can significantly degrade performance. So track all IO to gauge whether the cache is busy or not. Otherwise, synthetic IO tests (e.g. fio) that might send all IO to the fast device wouldn't cause writebacks to get throttled. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
|
#
072792dc |
|
11-May-2017 |
Joe Thornber <ejt@redhat.com> |
dm cache: fix incorrect 'idle_time' reset in IO tracker Some bios have no payload (eg, a FLUSH), don't reset the idle_time when these come in. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
48920ff2 |
|
05-Apr-2017 |
Christoph Hellwig <hch@lst.de> |
block: remove the discard_zeroes_data flag Now that we use the proper REQ_OP_WRITE_ZEROES operation everywhere we can kill this hack. 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>
|
#
449b668c |
|
31-Mar-2017 |
Joe Thornber <ejt@redhat.com> |
dm cache: set/clear the cache core's dirty_bitset when loading mappings When loading metadata make sure to set/clear the dirty bits in the cache core's dirty_bitset as well as the policy. Otherwise the cache core is unaware that any blocks were dirty when the cache was last shutdown. A very serious side-effect being that the cleaner policy would therefore never be tasked with writing back dirty data from a cache that was in writeback mode (e.g. when switching from smq policy to cleaner policy when decommissioning a writeback cache). This fixes a serious data corruption bug associated with writeback mode. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
|
#
b29d4986 |
|
15-Dec-2016 |
Joe Thornber <ejt@redhat.com> |
dm cache: significant rework to leverage dm-bio-prison-v2 The cache policy interfaces have been updated to work well with the new bio-prison v2 interface's ability to queue work immediately (promotion, demotion, etc) -- overriding benefit being reduced latency on processing IO through the cache. Previously such work would be left for the DM cache core to queue on various lists and then process in batches later -- this caused a serious delay in latency for IO driven by the cache. The background tracker code was factored out so that all cache policies can make use of it. Also, the "cleaner" policy has been removed and is now a variant of the smq policy that simply disallows migrations. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
742c8fdc |
|
21-Oct-2016 |
Joe Thornber <ejt@redhat.com> |
dm bio prison v2: new interface for the bio prison The deferred set is gone and all methods have _v2 appended to the end of their names to allow for continued use of the original bio prison in DM thin-provisioning. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
|
#
629d0a8a |
|
22-Sep-2016 |
Joe Thornber <ejt@redhat.com> |
dm cache metadata: add "metadata2" feature If "metadata2" is provided as a table argument when creating/loading a cache target a more compact metadata format, with separate dirty bits, is used. "metadata2" improves speed of shutting down a cache target. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
|
#
ca763d0a |
|
09-Feb-2017 |
Joe Thornber <ejt@redhat.com> |
dm cache: fix corruption seen when using cache > 2TB A rounding bug due to compiler generated temporary being 32bit was found in remap_to_cache(). A localized cast in remap_to_cache() fixes the corruption but this preferred fix (changing from uint32_t to sector_t) eliminates potential for future rounding errors elsewhere. Cc: stable@vger.kernel.org Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
|
#
dc3b17cc |
|
02-Feb-2017 |
Jan Kara <jack@suse.cz> |
block: Use pointer to backing_dev_info from request_queue We will want to have struct backing_dev_info allocated separately from struct request_queue. As the first step add pointer to backing_dev_info to request_queue and convert all users touching it. No functional changes in this patch. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
|
#
f73f44eb |
|
27-Jan-2017 |
Christoph Hellwig <hch@lst.de> |
block: add a op_is_flush helper This centralizes the checks for bios that needs to be go into the flush state machine. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Jens Axboe <axboe@fb.com>
|
#
23cab26d |
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03-Oct-2016 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: add missing cache device name to DMERR in set_cache_mode() Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
1eff9d32 |
|
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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#
28a8f0d3 |
|
05-Jun-2016 |
Mike Christie <mchristi@redhat.com> |
block, drivers, fs: rename REQ_FLUSH to REQ_PREFLUSH To avoid confusion between REQ_OP_FLUSH, which is handled by request_fn drivers, and upper layers requesting the block layer perform a flush sequence along with possibly a WRITE, this patch renames REQ_FLUSH to REQ_PREFLUSH. 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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#
e6047149 |
|
05-Jun-2016 |
Mike Christie <mchristi@redhat.com> |
dm: use bio op accessors Separate the op from the rq_flag_bits and have dm set/get the bio using bio_set_op_attrs/bio_op. 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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#
843f0f2e |
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10-Mar-2016 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: bump the target version Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
d14fcf3d |
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10-Mar-2016 |
Joe Thornber <ejt@redhat.com> |
dm cache: make sure every metadata function checks fail_io Otherwise operations may be attempted that will only ever go on to crash (since the metadata device is either missing or unreliable if 'fail_io' is set). Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
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#
30187e1d |
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31-Jan-2016 |
Mike Snitzer <snitzer@redhat.com> |
dm: rename target's per_bio_data_size to per_io_data_size Request-based DM will also make use of per_bio_data_size. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
fe3265b1 |
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25-Nov-2015 |
Mikulas Patocka <mpatocka@redhat.com> |
dm: don't save and restore bi_private Device mapper used the field bi_private to point to dm_target_io. However, since kernel 3.15, the bi_private field is unused, and so the targets do not need to save and restore this field. This patch removes code that saves and restores bi_private from dm-cache, dm-snapshot and dm-verity. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
6f65985e |
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13-Sep-2015 |
Julia Lawall <Julia.Lawall@lip6.fr> |
dm: drop NULL test before kmem_cache_destroy() and mempool_destroy() Remove DM's unneeded NULL tests before calling these destroy functions, now that they check for NULL, thanks to these v4.3 commits: 3942d2991 ("mm/slab_common: allow NULL cache pointer in kmem_cache_destroy()") 4e3ca3e03 ("mm/mempool: allow NULL `pool' pointer in mempool_destroy()") The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ expression x; @@ -if (x != NULL) \(kmem_cache_destroy\|mempool_destroy\|dma_pool_destroy\)(x); // </smpl> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
cc7da0ba |
|
01-Sep-2015 |
Joe Thornber <ejt@redhat.com> |
dm cache: fix use after freeing migrations Both free_io_migration() and issue_discard() dereference a migration that was just freed. Fix those by saving off the migrations's cache object before freeing the migration. Also cleanup needless mg->cache dereferences now that the cache object is available directly. Fixes: e44b6a5a3c ("dm cache: move wake_waker() from free_migrations() to where it is needed") Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
dc9cee5d |
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31-Aug-2015 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: small cleanups related to deferred prison cell cleanup Eliminate __cell_release() since it only had one caller that always released the cell holder. Switch cell_error_with_code() to using free_prison_cell() for the sake of consistency. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
9153df74 |
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31-Aug-2015 |
Joe Thornber <ejt@redhat.com> |
dm cache: fix leaking of deferred bio prison cells There were two cases where dm_cell_visit_release() was being called, which removes the cell from the prison's rbtree, but the callers didn't also return the cell to the mempool. Fix this by having them call free_prison_cell(). This leak manifested as the 'kmalloc-96' slab growing until OOM. Fixes: 651f5fa2a3 ("dm cache: defer whole cells") Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # 4.1+
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#
8ae12666 |
|
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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#
e44b6a5a |
|
30-Jul-2015 |
Joe Thornber <ejt@redhat.com> |
dm cache: move wake_waker() from free_migrations() to where it is needed This stops spurious wake ups from calls to prealloc_free_structs(). Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
795e633a |
|
29-Jul-2015 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: fix device destroy hang due to improper prealloc_used accounting Commit 665022d72f9 ("dm cache: avoid calls to prealloc_free_structs() if possible") introduced a regression that caused the removal of a DM cache device to hang in cache_postsuspend()'s call to wait_for_migrations() with the following stack trace: [<ffffffff81651457>] schedule+0x37/0x80 [<ffffffffa041e21b>] cache_postsuspend+0xbb/0x470 [dm_cache] [<ffffffff810ba970>] ? prepare_to_wait_event+0xf0/0xf0 [<ffffffffa0006f77>] dm_table_postsuspend_targets+0x47/0x60 [dm_mod] [<ffffffffa0001eb5>] __dm_destroy+0x215/0x250 [dm_mod] [<ffffffffa0004113>] dm_destroy+0x13/0x20 [dm_mod] [<ffffffffa00098cd>] dev_remove+0x10d/0x170 [dm_mod] [<ffffffffa00097c0>] ? dev_suspend+0x240/0x240 [dm_mod] [<ffffffffa0009f85>] ctl_ioctl+0x255/0x4d0 [dm_mod] [<ffffffff8127ac00>] ? SYSC_semtimedop+0x280/0xe10 [<ffffffffa000a213>] dm_ctl_ioctl+0x13/0x20 [dm_mod] [<ffffffff811fd432>] do_vfs_ioctl+0x2d2/0x4b0 [<ffffffff81117d5f>] ? __audit_syscall_entry+0xaf/0x100 [<ffffffff81022636>] ? do_audit_syscall_entry+0x66/0x70 [<ffffffff811fd689>] SyS_ioctl+0x79/0x90 [<ffffffff81023e58>] ? syscall_trace_leave+0xb8/0x110 [<ffffffff81654f6e>] entry_SYSCALL_64_fastpath+0x12/0x71 Fix this by accounting for the call to prealloc_data_structs() immediately _before_ the call as opposed to after. This is needed because it is possible to break out of the control loop after the call to prealloc_data_structs() but before prealloc_used was set to true. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
3508e659 |
|
29-Jul-2015 |
Mike Snitzer <snitzer@redhat.com> |
Revert "dm cache: do not wake_worker() in free_migration()" This reverts commit 386cb7cdeeef97e0bf082a8d6bbfc07a2ccce07b. Taking the wake_worker() out of free_migration() will slow writeback dramatically, and hence adaptability. Say we have 10k blocks that need writing back, but are only able to issue 5 concurrently due to the migration bandwidth: it's imperative that we wake_worker() immediately after migration completion; waiting for the next 1 second wake up (via do_waker) means it'll take a long time to write that all back. Reported-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
4246a0b6 |
|
20-Jul-2015 |
Christoph Hellwig <hch@lst.de> |
block: add a bi_error field to struct bio Currently we have two different ways to signal an I/O error on a BIO: (1) by clearing the BIO_UPTODATE flag (2) by returning a Linux errno value to the bi_end_io callback The first one has the drawback of only communicating a single possible error (-EIO), and the second one has the drawback of not beeing persistent when bios are queued up, and are not passed along from child to parent bio in the ever more popular chaining scenario. Having both mechanisms available has the additional drawback of utterly confusing driver authors and introducing bugs where various I/O submitters only deal with one of them, and the others have to add boilerplate code to deal with both kinds of error returns. So add a new bi_error field to store an errno value directly in struct bio and remove the existing mechanisms to clean all this up. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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#
665022d7 |
|
16-Jul-2015 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: avoid calls to prealloc_free_structs() if possible If no work was performed then prealloc_data_structs() wasn't ever called so there isn't any need to call prealloc_free_structs(). Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
e782eff5 |
|
16-Jul-2015 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: avoid preallocation if no work in writeback_some_dirty_blocks() Refactor writeback_some_dirty_blocks() to avoid prealloc_data_structs() if the policy doesn't have any dirty blocks ready for writeback. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
386cb7cd |
|
16-Jul-2015 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: do not wake_worker() in free_migration() All methods that queue work call wake_worker() as you'd expect. E.g. cell_defer, defer_bio, quiesce_migration (which is called by writeback, promote, demote_then_promote, invalidate, discard, etc). Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
255eac20 |
|
15-Jul-2015 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: display 'needs_check' in status if it is set There is currently no way to see that the needs_check flag has been set in the metadata. Display 'needs_check' in the cache status if it is set in the cache metadata. Also, update cache documentation. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
fba10109 |
|
29-May-2015 |
Joe Thornber <ejt@redhat.com> |
dm cache: age and write back cache entries even without active IO The policy tick() method is normally called from interrupt context. Both the mq and smq policies do some bottom half work for the tick method in their map functions. However if no IO is going through the cache, then that bottom half work doesn't occur. With these policies this means recently hit entries do not age and do not get written back as early as we'd like. Fix this by introducing a new 'can_block' parameter to the tick() method. When this is set the bottom half work occurs immediately. 'can_block' is set when the tick method is called every second by the core target (not in interrupt context). Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
b61d9509 |
|
22-Apr-2015 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: prefix all DMERR and DMINFO messages with cache device name Having the DM device name associated with the ERR or INFO message is very helpful. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
028ae9f7 |
|
22-Apr-2015 |
Joe Thornber <ejt@redhat.com> |
dm cache: add fail io mode and needs_check flag If a cache metadata operation fails (e.g. transaction commit) the cache's metadata device will abort the current transaction, set a new needs_check flag, and the cache will transition to "read-only" mode. If aborting the transaction or setting the needs_check flag fails the cache will transition to "fail-io" mode. Once needs_check is set the cache device will not be allowed to activate. Activation requires write access to metadata. Future work is needed to add proper support for running the cache in read-only mode. Once in fail-io mode the cache will report a status of "Fail". Also, add commit() wrapper that will disallow commits if in read_only or fail mode. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
88bf5184 |
|
27-May-2015 |
Joe Thornber <ejt@redhat.com> |
dm cache: wake the worker thread every time we free a migration object When the cache is idle, writeback work was only being issued every second. With this change outstanding writebacks are streamed constantly. This offers a writeback performance improvement. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
40775257 |
|
15-May-2015 |
Joe Thornber <ejt@redhat.com> |
dm cache: boost promotion of blocks that will be overwritten When considering whether to move a block to the cache we already give preferential treatment to discarded blocks, since they are cheap to promote (no read of the origin required since the data is junk). The same is true of blocks that are about to be completely overwritten, so we likewise boost their promotion chances. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
651f5fa2 |
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15-May-2015 |
Joe Thornber <ejt@redhat.com> |
dm cache: defer whole cells Currently individual bios are deferred to the worker thread if they cannot be processed immediately (eg, a block is in the process of being moved to the fast device). This patch passes whole cells across to the worker. This saves reaquiring the cell, and also collects bios destined for the same block together, which allows them to be mapped with a single look up to the policy. This reduces the overhead of using dm-cache. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
451b9e00 |
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15-May-2015 |
Joe Thornber <ejt@redhat.com> |
dm cache: pull out some bitset utility functions for reuse Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
20f6814b |
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15-May-2015 |
Joe Thornber <ejt@redhat.com> |
dm cache: pass a new 'critical' flag to the policies when requesting writeback work We only allow non critical writeback if the origin is idle. It is up to the policy to decide what writeback work is critical. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
066dbaa3 |
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15-May-2015 |
Joe Thornber <ejt@redhat.com> |
dm cache: track IO to the origin device using io_tracker Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
77289d32 |
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15-May-2015 |
Joe Thornber <ejt@redhat.com> |
dm cache: add io_tracker A little class that keeps track of the volume of io that is in flight, and the length of time that a device has been idle for. FIXME: rather than jiffes, may be best to use ktime_t (to support faster devices). Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
fb4100ae |
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20-May-2015 |
Joe Thornber <ejt@redhat.com> |
dm cache: fix race when issuing a POLICY_REPLACE operation There is a race between a policy deciding to replace a cache entry, the core target writing back any dirty data from this block, and other IO threads doing IO to the same block. This sort of problem is avoided most of the time by the core target grabbing a bio prison cell before making the request to the policy. But for a demotion the core target doesn't know which block will be demoted, so can't do this in advance. Fix this demotion race by introducing a callback to the policy interface that allows the policy to grab the cell on behalf of the core target. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
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#
326e1dbb |
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22-May-2015 |
Mike Snitzer <snitzer@redhat.com> |
block: remove management of bi_remaining when restoring original bi_end_io Commit c4cf5261 ("bio: skip atomic inc/dec of ->bi_remaining for non-chains") regressed all existing callers that followed this pattern: 1) saving a bio's original bi_end_io 2) wiring up an intermediate bi_end_io 3) restoring the original bi_end_io from intermediate bi_end_io 4) calling bio_endio() to execute the restored original bi_end_io The regression was due to BIO_CHAIN only ever getting set if bio_inc_remaining() is called. For the above pattern it isn't set until step 3 above (step 2 would've needed to establish BIO_CHAIN). As such the first bio_endio(), in step 2 above, never decremented __bi_remaining before calling the intermediate bi_end_io -- leaving __bi_remaining with the value 1 instead of 0. When bio_inc_remaining() occurred during step 3 it brought it to a value of 2. When the second bio_endio() was called, in step 4 above, it should've called the original bi_end_io but it didn't because there was an extra reference that wasn't dropped (due to atomic operations being optimized away since BIO_CHAIN wasn't set upfront). Fix this issue by removing the __bi_remaining management complexity for all callers that use the above pattern -- bio_chain() is the only interface that _needs_ to be concerned with __bi_remaining. For the above pattern callers just expect the bi_end_io they set to get called! Remove bio_endio_nodec() and also remove all bio_inc_remaining() calls that aren't associated with the bio_chain() interface. Also, the bio_inc_remaining() interface has been moved local to bio.c. Fixes: c4cf5261 ("bio: skip atomic inc/dec of ->bi_remaining for non-chains") Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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#
c4cf5261 |
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17-Apr-2015 |
Jens Axboe <axboe@fb.com> |
bio: skip atomic inc/dec of ->bi_remaining for non-chains Struct bio has an atomic ref count for chained bio's, and we use this to know when to end IO on the bio. However, most bio's are not chained, so we don't need to always introduce this atomic operation as part of ending IO. Add a helper to elevate the bi_remaining count, and flag the bio as now actually needing the decrement at end_io time. Rename the field to __bi_remaining to catch any current users of this doing the incrementing manually. For high IOPS workloads, this reduces the overhead of bio_endio() substantially. Tested-by: Robert Elliott <elliott@hp.com> Acked-by: Kent Overstreet <kent.overstreet@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
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#
0f30af98 |
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22-May-2014 |
Manuel Schölling <manuel.schoelling@gmx.de> |
dm: use time_in_range() and time_after() To be future-proof and for better readability the time comparisons are modified to use time_in_range() and time_after() instead of plain, error-prone math. Signed-off-by: Manuel Schölling <manuel.schoelling@gmx.de> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
a59db676 |
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23-Jan-2015 |
Joe Thornber <ejt@redhat.com> |
dm cache: fix problematic dual use of a single migration count variable Introduce a new variable to count the number of allocated migration structures. The existing variable cache->nr_migrations became overloaded. It was used to: i) track of the number of migrations in flight for the purposes of quiescing during suspend. ii) to estimate the amount of background IO occuring. Recent discard changes meant that REQ_DISCARD bios are processed with a migration. Discards are not background IO so nr_migrations was not incremented. However this could cause quiescing to complete early. (i) is now handled with a new variable cache->nr_allocated_migrations. cache->nr_migrations has been renamed cache->nr_io_migrations. cleanup_migration() is now called free_io_migration(), since it decrements that variable. Also, remove the unused cache->next_migration variable that got replaced with with prealloc_structs a while ago. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
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#
f824a2af |
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28-Nov-2014 |
Joe Thornber <ejt@redhat.com> |
dm cache: fix spurious cell_defer when dealing with partial block at end of device We never bother caching a partial block that is at the back end of the origin device. No cell ever gets locked, but the calling code was assuming it was and trying to release it. Now the code only releases if the cell has been set to a non NULL value. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
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#
1e32134a |
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26-Nov-2014 |
Joe Thornber <ejt@redhat.com> |
dm cache: dirty flag was mistakenly being cleared when promoting via overwrite If the incoming bio is a WRITE and completely covers a block then we don't bother to do any copying for a promotion operation. Once this is done the cache block and origin block will be different, so we need to set it to 'dirty'. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
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#
f29a3147 |
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26-Nov-2014 |
Joe Thornber <ejt@redhat.com> |
dm cache: only use overwrite optimisation for promotion when in writeback mode Overwrite causes the cache block and origin blocks to diverge, which is only allowed in writeback mode. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
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#
2bb812df |
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26-Nov-2014 |
Joe Thornber <ejt@redhat.com> |
dm cache: discard block size must be a multiple of cache block size Otherwise the cache blocks may span two discard blocks, which we don't handle when doing the discard lookup. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
43c32bf2 |
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25-Nov-2014 |
Joe Thornber <ejt@redhat.com> |
dm cache: fix a harmless race when working out if a block is discarded It is more correct to hold the cell before checking the discard state. These flags are only used as hints to the policy so this change will have negligable effect. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
3e2e1c30 |
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24-Nov-2014 |
Joe Thornber <ejt@redhat.com> |
dm cache: when reloading a discard bitset allow for a different discard block size The discard block size can change if the origin changes size or if an old DM cache is upgraded from using a discard block size that was equal to cache block size. To fix this an extent of discarded blocks is established for the purpose of translating the old discard block size to the new in-core discard block size and set bits. The old (potentially huge) discard bitset is left ondisk until it is re-written using the new in-core information on the next successful DM cache shutdown. Fixes: 7ae34e777896 ("dm cache: improve discard support") Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
2572629a |
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24-Nov-2014 |
Joe Thornber <ejt@redhat.com> |
dm cache: fix some issues with the new discard range support Commit 7ae34e777 ("dm cache: improve discard support") needed to also: - discontinue having DM core split the discard bios on cache block boundaries - calculate the cache's discard_nr_blocks relative to the determined discard_block_size rather than using oblock_to_dblock() Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
d1d9220c |
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11-Nov-2014 |
Joe Thornber <ejt@redhat.com> |
dm cache: emit a warning message if there are a lot of cache blocks Loading and saving millions of block mappings takes time. We may as well explain what's going on, and encourage people to use a larger cache block size. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
7ae34e77 |
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06-Nov-2014 |
Joe Thornber <ejt@redhat.com> |
dm cache: improve discard support Safely allow the discard blocksize to be larger than the cache blocksize by using the bio prison's range locking support. This also improves discard performance considerly because larger discards are issued to the dm-cache device. The discard blocksize was always intended to be greater than the cache blocksize. But until now it wasn't implemented safely. Also, by safely restoring the ability to have discard blocksize larger than cache blocksize we're able to significantly reduce the memory used for the cache's discard bitset. Before, with a small discard blocksize, the discard bitset could get quite large because its size is a function of the discard blocksize and the origin device's size. For example, previously, using a 32KB cache blocksize with a 40TB origin resulted in 1280MB of incore memory use for the discard bitset! Now, the discard blocksize is scaled up accordingly to ensure the discard bitset is capped at 2**14 bits, or 16KB. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
08b18451 |
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06-Nov-2014 |
Joe Thornber <ejt@redhat.com> |
dm cache: revert "prevent corruption caused by discard_block_size > cache_block_size" This reverts commit d132cc6d9e92424bb9d4fd35f5bd0e55d583f4be because we actually do want to allow the discard blocksize to be larger than the cache blocksize. Further dm-cache discard changes will make this possible. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
1bad9bc4 |
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07-Nov-2014 |
Joe Thornber <ejt@redhat.com> |
dm cache: revert "remove remainder of distinct discard block size" This reverts commit 64ab346a360a4b15c28fb8531918d4a01f4eabd9 because we actually do want to allow the discard blocksize to be larger than the cache blocksize. Further dm-cache discard changes will make this possible. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
5f274d88 |
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17-Sep-2014 |
Joe Thornber <ejt@redhat.com> |
dm bio prison: introduce support for locking ranges of blocks Ranges will be placed in the same cell if they overlap. Range locking is a prerequisite for more efficient multi-block discard support in both the cache and thin-provisioning targets. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
a195db2d |
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06-Oct-2014 |
Joe Thornber <ejt@redhat.com> |
dm bio prison: switch to using a red black tree Previously it was using a fixed sized hash table. There are times when very many concurrent cells are held (such as when processing a very large discard). When this happens the hash table performance becomes very poor. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
40aa978e |
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04-Sep-2014 |
Anssi Hannula <anssi.hannula@iki.fi> |
dm cache: fix race causing dirty blocks to be marked as clean When a writeback or a promotion of a block is completed, the cell of that block is removed from the prison, the block is marked as clean, and the clear_dirty() callback of the cache policy is called. Unfortunately, performing those actions in this order allows an incoming new write bio for that block to come in before clearing the dirty status is completed and therefore possibly causing one of these two scenarios: Scenario A: Thread 1 Thread 2 cell_defer() . - cell removed from prison . - detained bios queued . . incoming write bio . remapped to cache . set_dirty() called, . but block already dirty . => it does nothing clear_dirty() . - block marked clean . - policy clear_dirty() called . Result: Block is marked clean even though it is actually dirty. No writeback will occur. Scenario B: Thread 1 Thread 2 cell_defer() . - cell removed from prison . - detained bios queued . clear_dirty() . - block marked clean . . incoming write bio . remapped to cache . set_dirty() called . - block marked dirty . - policy set_dirty() called - policy clear_dirty() called . Result: Block is properly marked as dirty, but policy thinks it is clean and therefore never asks us to writeback it. This case is visible in "dmsetup status" dirty block count (which normally decreases to 0 on a quiet device). Fix these issues by calling clear_dirty() before calling cell_defer(). Incoming bios for that block will then be detained in the cell and released only after clear_dirty() has completed, so the race will not occur. Found by inspecting the code after noticing spurious dirty counts (scenario B). Signed-off-by: Anssi Hannula <anssi.hannula@iki.fi> Acked-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
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#
b0246530 |
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19-Jul-2014 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: set minimum_io_size to cache's data block size Before, if the block layer's limit stacking didn't establish an optimal_io_size that was compatible with the cache's data block size we'd set optimal_io_size to the data block size and minimum_io_size to 0 (which the block layer adjusts to be physical_block_size). Update cache_io_hints() to set both minimum_io_size and optimal_io_size to the cache's data block size. This fixes an issue where mkfs.xfs would create more XFS Allocation Groups on cache volumes than on a normal linear LV of comparable size. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
895b47d7 |
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14-Jul-2014 |
Mike Snitzer <snitzer@redhat.com> |
dm cache metadata: use dm-space-map-metadata.h defined size limits Commit 7d48935e cleaned up the persistent-data's space-map-metadata limits by elevating them to dm-space-map-metadata.h. Update dm-cache-metadata to use these same limits. The calculation for DM_CACHE_METADATA_MAX_SECTORS didn't account for the sizeof the disk_bitmap_header. So the supported maximum metadata size is a bit smaller (reduced from 33423360 to 33292800 sectors). Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
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#
304affaa |
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24-Jun-2014 |
Joe Thornber <ejt@redhat.com> |
dm cache: fail migrations in the do_worker error path Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
8c081b52 |
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13-May-2014 |
Joe Thornber <ejt@redhat.com> |
dm cache: simplify deferred set reference count increments Factor out inc_and_issue and inc_ds helpers to simplify deferred set reference count increments. Also cleanup cache_map to consistently call cell_defer and inc_ds when the bio is DM_MAPIO_REMAPPED. No functional change. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
44fa816b |
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01-Aug-2014 |
Anssi Hannula <anssi.hannula@iki.fi> |
dm cache: fix race affecting dirty block count nr_dirty is updated without locking, causing it to drift so that it is non-zero (either a small positive integer, or a very large one when an underflow occurs) even when there are no actual dirty blocks. This was due to a race between the workqueue and map function accessing nr_dirty in parallel without proper protection. People were seeing under runs due to a race on increment/decrement of nr_dirty, see: https://lkml.org/lkml/2014/6/3/648 Fix this by using an atomic_t for nr_dirty. Reported-by: roma1390@gmail.com Signed-off-by: Anssi Hannula <anssi.hannula@iki.fi> Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
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#
f1daa838 |
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23-May-2014 |
Heinz Mauelshagen <heinzm@redhat.com> |
dm cache: always split discards on cache block boundaries The DM cache target cannot cope with discards that span multiple cache blocks, so each discard bio that spans more than one cache block must get split by the DM core. Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # v3.9+
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#
131cd131 |
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01-May-2014 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: fix writethrough mode quiescing in cache_map Commit 2ee57d58735 ("dm cache: add passthrough mode") inadvertently removed the deferred set reference that was taken in cache_map()'s writethrough mode support. Restore taking this reference. This issue was found with code inspection. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com> Cc: stable@vger.kernel.org # 3.13+
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#
0596661f |
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03-Apr-2014 |
Joe Thornber <ejt@redhat.com> |
dm cache: fix a lock-inversion When suspending a cache the policy is walked and the individual policy hints written to the metadata via sync_metadata(). This led to this lock order: policy->lock cache_metadata->root_lock When loading the cache target the policy is populated while the metadata lock is held: cache_metadata->root_lock policy->lock Fix this potential lock-inversion (ABBA) deadlock in sync_metadata() by ensuring the cache_metadata root_lock is held whilst all the hints are written, rather than being repeatedly locked while policy->lock is held (as was the case with each callout that policy_walk_mappings() made to the old save_hint() method). Found by turning on the CONFIG_PROVE_LOCKING ("Lock debugging: prove locking correctness") build option. However, it is not clear how the LOCKDEP reported paths can lead to a deadlock since the two paths, suspending a target and loading a target, never occur at the same time. But that doesn't mean the same lock-inversion couldn't have occurred elsewhere. Reported-by: Marian Csontos <mcsontos@redhat.com> Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
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#
64ab346a |
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27-Mar-2014 |
Heinz Mauelshagen <heinzm@redhat.com> |
dm cache: remove remainder of distinct discard block size Discard block size not being equal to cache block size causes data corruption by erroneously avoiding migrations in issue_copy() because the discard state is being cleared for a group of cache blocks when it should not. Completely remove all code that enabled a distinction between the cache block size and discard block size. Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
d132cc6d |
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20-Mar-2014 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: prevent corruption caused by discard_block_size > cache_block_size If the discard block size is larger than the cache block size we will not properly quiesce IO to a region that is about to be discarded. This results in a race between a cache migration where no copy is needed, and a write to an adjacent cache block that's within the same large discard block. Workaround this by limiting the discard_block_size to cache_block_size. Also limit the max_discard_sectors to cache_block_size. A more comprehensive fix that introduces range locking support in the bio_prison and proper quiescing of a discard range that spans multiple cache blocks is already in development. Reported-by: Morgan Mears <Morgan.Mears@netapp.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com> Acked-by: Heinz Mauelshagen <heinzm@redhat.com> Cc: stable@vger.kernel.org
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#
e893fba9 |
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12-Mar-2014 |
Heinz Mauelshagen <heinzm@redhat.com> |
dm cache: fix access beyond end of origin device In order to avoid wasting cache space a partial block at the end of the origin device is not cached. Unfortunately, the check for such a partial block at the end of the origin device was flawed. Fix accesses beyond the end of the origin device that occured due to attempted promotion of an undetected partial block by: - initializing the per bio data struct to allow cache_end_io to work properly - recognizing access to the partial block at the end of the origin device - avoiding out of bounds access to the discard bitset Otherwise, users can experience errors like the following: attempt to access beyond end of device dm-5: rw=0, want=20971520, limit=20971456 ... device-mapper: cache: promotion failed; couldn't copy block Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
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#
8b9d9666 |
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11-Mar-2014 |
Heinz Mauelshagen <heinzm@redhat.com> |
dm cache: fix truncation bug when copying a block to/from >2TB fast device During demotion or promotion to a cache's >2TB fast device we must not truncate the cache block's associated sector to 32bits. The 32bit temporary result of from_cblock() caused a 32bit multiplication when calculating the sector of the fast device in issue_copy_real(). Use an intermediate 64bit type to store the 32bit from_cblock() to allow for proper 64bit multiplication. Here is an example of how this bug manifests on an ext4 filesystem: EXT4-fs error (device dm-0): ext4_mb_generate_buddy:756: group 17136, 32768 clusters in bitmap, 30688 in gd; block bitmap corrupt. JBD2: Spotted dirty metadata buffer (dev = dm-0, blocknr = 0). There's a risk of filesystem corruption in case of system crash. Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
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#
e0d849fa |
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27-Feb-2014 |
Heinz Mauelshagen <heinzm@redhat.com> |
dm cache: fix truncation bug when mapping I/O to >2TB fast device When remapping a block to the cache's fast device that is larger than 2TB we must not truncate the destination sector to 32bits. The 32bit temporary result of from_cblock() was being overflowed in remap_to_cache() due to the logical left shift. Use an intermediate 64bit type to store the 32bit from_cblock() result to fix the overflow. Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
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#
80ae49aa |
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31-Jan-2014 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: do not add migration to completed list before unhooking bio When completing an overwrite bio, in overwrite_endio(), the associated migration should not be added to the 'completed_migrations' until the bio's fields are restored with dm_unhook_bio(). Otherwise, do_worker() can race to process 'completed_migrations' before dm_unhook_bio() -- so the bio's bi_end_io is incorrect. This is unlikely to cause any problems given the current code but should be fixed on the basis of correctness. Also, the cache's spinlock only needs to be held when manipulating the 'completed_migrations' list -- other changes don't need protection. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
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#
c6eda5e8 |
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31-Jan-2014 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: move hook_info into common portion of per_bio_data structure Commit c9d28d5d ("dm cache: promotion optimisation for writes") incorrectly placed the 'hook_info' member in the writethrough-only portion of the per_bio_data structure. Given that the overwrite optimization may be used for writeback the 'hook_info' member must be placed above the 'cache' member of the per_bio_data structure. Any members above 'cache' are available from both writeback and writethrough modes' per_bio_data structure. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com> Cc: stable@vger.kernel.org # 3.13+
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#
2e68c4e6 |
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15-Jan-2014 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: add policy name to status output The cache's policy may have been established using the "default" alias, which is currently the "mq" policy but the default policy may change in the future. It is useful to know exactly which policy is being used. Add a 'real' member to the dm_cache_policy_type structure and have the "default" dm_cache_policy_type point to the real "mq" dm_cache_policy_type. Update dm_cache_policy_get_name() to check if real is set, if so report the name of the real policy (not the alias). Requested-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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#
6a388618 |
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09-Jan-2014 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: add block sizes and total cache blocks to status output Improve cache_status to emit: <metadata block size> <#used metadata blocks>/<#total metadata blocks> <cache block size> <#used cache blocks>/<#total cache blocks> ... Adding the block sizes allows for easier calculation of the overall size of both the metadata and cache devices. Adding <#total cache blocks> provides useful context for how much of the cache is used. Unfortunately these additions to the status will require updates to users' scripts that monitor the cache status. But these changes help provide more comprehensive information about the cache device and will simplify tools that are being developed to manage dm-cache devices -- because they won't need to issue 3 operations to cobble together the information that we can easily provide via a single status ioctl. While updating the status documentation in cache.txt spaces were tabify'd. Requested-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
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#
08844800 |
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29-Nov-2013 |
Vincent Pelletier <plr.vincent@gmail.com> |
dm cache: actually resize cache Commit f494a9c6b1b6dd9a9f21bbb75d9210d478eeb498 ("dm cache: cache shrinking support") broke cache resizing support. dm_cache_resize() is called with cache->cache_size before it gets updated to new_size, so it is a no-op. But the dm-cache superblock is updated with the new_size even though the backing dm-array is not resized. Fix this by passing the new_size to dm_cache_resize(). Signed-off-by: Vincent Pelletier <plr.vincent@gmail.com> Acked-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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8d307269 |
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03-Dec-2013 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: increment bi_remaining when bi_end_io is restored Move the bio->bi_remaining increment into dm_unhook_bio() so the overwrite_endio() handler works as expected. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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196d38bc |
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23-Nov-2013 |
Kent Overstreet <kmo@daterainc.com> |
block: Generic bio chaining This adds a generic mechanism for chaining bio completions. This is going to be used for a bio_split() replacement, and it turns out to be very useful in a fair amount of driver code - a fair number of drivers were implementing this in their own roundabout ways, often painfully. Note that this means it's no longer to call bio_endio() more than once on the same bio! This can cause problems for drivers that save/restore bi_end_io. Arguably they shouldn't be saving/restoring bi_end_io at all - in all but the simplest cases they'd be better off just cloning the bio, and immutable biovecs is making bio cloning cheaper. But for now, we add a bio_endio_nodec() for these cases. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk>
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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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7b6b2bc9 |
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11-Nov-2013 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: resolve small nits and improve Documentation Document passthrough mode, cache shrinking, and cache invalidation. Also, use strcasecmp() and hlist_unhashed(). Reported-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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65790ff9 |
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08-Nov-2013 |
Joe Thornber <ejt@redhat.com> |
dm cache: add cache block invalidation support Cache block invalidation is removing an entry from the cache without writing it back. Cache blocks can be invalidated via the 'invalidate_cblocks' message, which takes an arbitrary number of cblock ranges: invalidate_cblocks [<cblock>|<cblock begin>-<cblock end>]* E.g. dmsetup message my_cache 0 invalidate_cblocks 2345 3456-4567 5678-6789 Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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2ee57d58 |
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24-Oct-2013 |
Joe Thornber <ejt@redhat.com> |
dm cache: add passthrough mode "Passthrough" is a dm-cache operating mode (like writethrough or writeback) which is intended to be used when the cache contents are not known to be coherent with the origin device. It behaves as follows: * All reads are served from the origin device (all reads miss the cache) * All writes are forwarded to the origin device; additionally, write hits cause cache block invalidates This mode decouples cache coherency checks from cache device creation, largely to avoid having to perform coherency checks while booting. Boot scripts can create cache devices in passthrough mode and put them into service (mount cached filesystems, for example) without having to worry about coherency. Coherency that exists is maintained, although the cache will gradually cool as writes take place. Later, applications can perform coherency checks, the nature of which will depend on the type of the underlying storage. If coherency can be verified, the cache device can be transitioned to writethrough or writeback mode while still warm; otherwise, the cache contents can be discarded prior to transitioning to the desired operating mode. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Morgan Mears <Morgan.Mears@netapp.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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f494a9c6 |
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31-Oct-2013 |
Joe Thornber <ejt@redhat.com> |
dm cache: cache shrinking support Allow a cache to shrink if the blocks being removed from the cache are not dirty. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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c9d28d5d |
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31-Oct-2013 |
Joe Thornber <ejt@redhat.com> |
dm cache: promotion optimisation for writes If a write block triggers promotion and covers a whole block we can avoid a copy. Introduce dm_{hook,unhook}_bio to simplify saving and restoring bio fields (bi_private is now used by overwrite). Switch writethrough support over to using these helpers too. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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ffcbcb67 |
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14-Oct-2013 |
Heinz Mauelshagen <heinzm@redhat.com> |
dm cache: optimize commit_if_needed Check commit_requested flag _before_ calling dm_cache_changed_this_transaction() superfluously. Also, be sure to set last_commit_jiffies _after_ dm_cache_commit() completes. Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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2c2263c9 |
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14-Oct-2013 |
Heinz Mauelshagen <heinzm@redhat.com> |
dm cache: log error message if dm_kcopyd_copy() fails A migration failure should be logged (albeit limited). Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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80f659f3 |
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14-Oct-2013 |
Heinz Mauelshagen <heinzm@redhat.com> |
dm cache: use cell_defer() boolean argument consistently Fix a few cell_defer() calls that weren't passing a bool. Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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4cb3e1db |
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01-Oct-2013 |
Mikulas Patocka <mpatocka@redhat.com> |
dm cache: return -EINVAL if the user specifies unknown cache policy Return -EINVAL when the specified cache policy is unknown rather than returning -ENOMEM. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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238f8363 |
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30-Oct-2013 |
Joe Thornber <ejt@redhat.com> |
dm cache: improve efficiency of quiescing flag management Make the quiescing flag an atomic_t and stop protecting it with a spin lock. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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66cb1910 |
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30-Oct-2013 |
Joe Thornber <ejt@redhat.com> |
dm cache: fix a race condition between queuing new migrations and quiescing for a shutdown The code that was trying to do this was inadequate. The postsuspend method (in ioctl context), needs to wait for the worker thread to acknowledge the request to quiesce. Otherwise the migration count may drop to zero temporarily before the worker thread realises we're quiescing. In this case the target will be taken down, but the worker thread may have issued a new migration, which will cause an oops when it completes. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # 3.9+
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f8e5f01a |
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20-Oct-2013 |
Joe Thornber <ejt@redhat.com> |
dm cache: io destined for the cache device can now serve as tick bios Previously only origin bios could trigger ticks, which meant if all the io was destined for the cache no ticks were generated. If no ticks are generated then multiple hits, and movements in general, are attributed to the same tick. Only a stop gap fix, we need a better solution. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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c9ec5d7c |
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16-Aug-2013 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: eliminate holes in cache structure Reorder members in the cache structure to eliminate 6 out of 7 holes (reclaiming 24 bytes). Also, the 'worker' and 'waker' members no longer straddle cachelines. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
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f6109372 |
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20-Aug-2013 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: fix stacking of geometry limits Do not blindly override the queue limits (specifically io_min and io_opt). Allow traditional stacking of these limits if io_opt is a factor of the cache's data block size. Without this patch mkfs.xfs does not recognize the cache device's provided limits as a useful geometry (e.g. raid) so these hints are ignored. This was due to setting io_min to a useless value. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
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05473044 |
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16-Aug-2013 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: add data block size limits to code and Documentation Place upper bound on the cache's data block size (1GB). Inform users that the data block size can't be any arbitrary number, i.e. its value must be between 32KB and 1GB. Also, it should be a multiple of 32KB. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
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43aeaa29 |
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10-Jul-2013 |
Mikulas Patocka <mpatocka@redhat.com> |
dm cache: fix arm link errors with inline Use __always_inline to avoid a link failure with gcc 4.6 on ARM. gcc 4.7 is OK. It creates a function block_div.part.8, it references __udivdi3 and __umoddi3 and it is never called. The references to __udivdi3 and __umoddi3 cause a link failure. Reported-by: Rob Herring <robherring2@gmail.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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2f14f4b5 |
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10-May-2013 |
Joe Thornber <ejt@redhat.com> |
dm cache: set config value Share configuration option processing code between the dm cache ctr and message functions. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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2c73c471 |
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10-May-2013 |
Alasdair G Kergon <agk@redhat.com> |
dm cache: move config fns Move process_config_option() in dm-cache-target.c to make the next patch more readable. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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8c5008fa |
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10-May-2013 |
Joe Thornber <ejt@redhat.com> |
dm cache: replace memcpy with struct assignment Use struct assignment rather than memcpy in dm cache. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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aeed1420 |
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10-May-2013 |
Joe Thornber <ejt@redhat.com> |
dm cache: fix typos in comments Fix up some typos in dm-cache comments. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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f8350daf |
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10-May-2013 |
Joe Thornber <ejt@redhat.com> |
dm cache: tune migration throttling Tune the dm cache migration throttling. i) Issue a tick every second, just in case there's no i/o going through. ii) Drop the migration threshold right down to something suitable for background work. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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fa4d683a |
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10-May-2013 |
Wei Yongjun <yongjun_wei@trendmicro.com.cn> |
dm cache: fix error return code in cache_create Return -ENOMEM if memory allocation fails in cache_create instead of 0 (to avoid NULL pointer dereference). Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Cc: stable@vger.kernel.org Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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19b0092e |
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05-Apr-2013 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: reduce bio front_pad size in writeback mode A recent patch to fix the dm cache target's writethrough mode extended the bio's front_pad to include a 1056-byte struct dm_bio_details. Writeback mode doesn't need this, so this patch reduces the per_bio_data_size to 16 bytes in this case instead of 1096. The dm_bio_details structure was added in "dm cache: fix writes to cache device in writethrough mode" which fixed commit e2e74d617e ("dm cache: fix race in writethrough implementation"). In writeback mode we avoid allocating the writethrough-specific members of the per_bio_data structure (the dm_bio_details structure included). Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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b844fe69 |
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05-Apr-2013 |
Darrick J. Wong <darrick.wong@oracle.com> |
dm cache: fix writes to cache device in writethrough mode The dm-cache writethrough strategy introduced by commit e2e74d617eadc15 ("dm cache: fix race in writethrough implementation") issues a bio to the origin device, remaps and then issues the bio to the cache device. This more conservative in-series approach was selected to favor correctness over performance (of the previous parallel writethrough). However, this in-series implementation that reuses the same bio to write both the origin and cache device didn't take into account that the block layer's req_bio_endio() modifies a completing bio's bi_sector and bi_size. So the new writethrough strategy needs to preserve these bio fields, and restore them before submission to the cache device, otherwise nothing gets written to the cache (because bi_size is 0). This patch adds a struct dm_bio_details field to struct per_bio_data, and uses dm_bio_record() and dm_bio_restore() to ensure the bio is restored before reissuing to the cache device. Adding such a large structure to the per_bio_data is not ideal but we can improve this later, for now correctness is the important thing. This problem initially went unnoticed because the dm-cache test-suite uses a linear DM device for the dm-cache device's origin device. Writethrough worked as expected because DM submits a *clone* of the original bio, so the original bio which was reused for the cache was never touched. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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ea2dd8c1 |
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20-Mar-2013 |
Mike Snitzer <snitzer@redhat.com> |
dm cache: policy ignore hints if generated by different version When reading the dm cache metadata from disk, ignore the policy hints unless they were generated by the same major version number of the same policy module. The hints are considered to be private data belonging to the specific module that generated them and there is no requirement for them to make sense to different versions of the policy that generated them. Policy modules are all required to work fine if no previous hints are supplied (or if existing hints are lost). Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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e2e74d61 |
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20-Mar-2013 |
Joe Thornber <ejt@redhat.com> |
dm cache: fix race in writethrough implementation We have found a race in the optimisation used in the dm cache writethrough implementation. Currently, dm core sends the cache target two bios, one for the origin device and one for the cache device and these are processed in parallel. This patch avoids the race by changing the code back to a simpler (slower) implementation which processes the two writes in series, one after the other, until we can develop a complete fix for the problem. When the cache is in writethrough mode it needs to send WRITE bios to both the origin and cache devices. Previously we've been implementing this by having dm core query the cache target on every write to find out how many copies of the bio it wants. The cache will ask for two bios if the block is in the cache, and one otherwise. Then main problem with this is it's racey. At the time this check is made the bio hasn't yet been submitted and so isn't being taken into account when quiescing a block for migration (promotion or demotion). This means a single bio may be submitted when two were needed because the block has since been promoted to the cache (catastrophic), or two bios where only one is needed (harmless). I really don't want to start entering bios into the quiescing system (deferred_set) in the get_num_write_bios callback. Instead this patch simplifies things; only one bio is submitted by the core, this is first written to the origin and then the cache device in series. Obviously this will have a latency impact. deferred_writethrough_bios is introduced to record bios that must be later issued to the cache device from the worker thread. This deferred submission, after the origin bio completes, is required given that we're in interrupt context (writethrough_endio). Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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b978440b |
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20-Mar-2013 |
Heinz Mauelshagen <heinzm@redhat.com> |
dm cache: avoid calling policy destructor twice on error If the cache policy's config values are not able to be set we must set the policy to NULL after destroying it in create_cache_policy() so we don't attempt to destroy it a second time later. Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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617a0b89 |
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20-Mar-2013 |
Heinz Mauelshagen <heinzm@redhat.com> |
dm cache: detect cache_create failure Return error if cache_create() fails. A missing return check made cache_ctr continue even after an error in cache_create() resulting in the cache object being destroyed. So a simple failure like an odd number of cache policy config value arguments would result in an oops. Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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414dd67d |
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20-Mar-2013 |
Joe Thornber <ejt@redhat.com> |
dm cache: avoid 64 bit division on 32 bit Squash various 32bit link errors. >> on i386: >> drivers/built-in.o: In function `is_discarded_oblock': >> dm-cache-target.c:(.text+0x1ea28e): undefined reference to `__udivdi3' ... Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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c6b4fcba |
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01-Mar-2013 |
Joe Thornber <ejt@redhat.com> |
dm: add cache target Add a target that allows a fast device such as an SSD to be used as a cache for a slower device such as a disk. A plug-in architecture was chosen so that the decisions about which data to migrate and when are delegated to interchangeable tunable policy modules. The first general purpose module we have developed, called "mq" (multiqueue), follows in the next patch. Other modules are under development. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Heinz Mauelshagen <mauelshagen@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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