block: remove bdev_handle completely

We just need to use the holder to indicate whether a block device open
was exclusive or not. We did use to do that before but had to give that
up once we switched to struct bdev_handle. Before struct bdev_handle we
only stashed stuff in file->private_data if this was an exclusive open
but after struct bdev_handle we always set file->private_data to a
struct bdev_handle and so we had to use bdev_handle->mode or
bdev_handle->holder. Now that we don't use struct bdev_handle anymore we
can revert back to the old behavior.

Link: https://lore.kernel.org/r/20240123-vfs-bdev-file-v2-32-adbd023e19cc@kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>

bdev: remove bdev pointer from struct bdev_handle

We can always go directly via:

* I_BDEV(bdev_file->f_inode)
* I_BDEV(bdev_file->f_mapping->host)

So keeping struct bdev in struct bdev_handle is redundant.

Link: https://lore.kernel.org/r/20240123-vfs-bdev-file-v2-30-adbd023e19cc@kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>

bdev: make struct bdev_handle private to the block layer

Link: https://lore.kernel.org/r/20240123-vfs-bdev-file-v2-29-adbd023e19cc@kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>

block, fs: Restore the per-bio/request data lifetime fields

Restore support for passing data lifetime information from filesystems to
block drivers. This patch reverts commit b179c98f7697 ("block: Remove
request.write_hint") and commit c75e707fe1aa ("block: remove the
per-bio/request write hint").

This patch does not modify the size of struct bio because the new
bi_write_hint member fills a hole in struct bio. pahole reports the
following for struct bio on an x86_64 system with this patch applied:

/* size: 112, cachelines: 2, members: 20 */
/* sum members: 110, holes: 1, sum holes: 2 */
/* last cacheline: 48 bytes */

Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240202203926.2478590-7-bvanassche@acm.org
Signed-off-by: Christian Brauner <brauner@kernel.org>

iomap: pass the length of the dirty region to ->map_blocks

Let the file system know how much dirty data exists at the passed
in offset. This allows file systems to allocate the right amount
of space that actually is written back if they can't eagerly
convert (e.g. because they don't support unwritten extents).

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20231207072710.176093-15-hch@lst.de
Signed-off-by: Christian Brauner <brauner@kernel.org>

fs: convert block_write_full_page to block_write_full_folio

Convert the function to be compatible with writepage_t so that it can be
passed to write_cache_pages() by blkdev. This removes a call to
compound_head(). We can also remove the function export as both callers
are built-in.

Link: https://lkml.kernel.org/r/20231215200245.748418-14-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

fs: convert error_remove_page to error_remove_folio

There were already assertions that we were not passing a tail page to
error_remove_page(), so make the compiler enforce that by converting
everything to pass and use a folio.

Link: https://lkml.kernel.org/r/20231117161447.2461643-7-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

block: Use bdev_open_by_dev() in blkdev_open()

Convert blkdev_open() to use bdev_open_by_dev(). To be able to propagate
handle from blkdev_open() to blkdev_release() we need to stop using
existence of file->private_data to determine exclusive block device
opens. Use bdev_handle->mode for this purpose since file->f_flags
isn't usable for this (O_EXCL is cleared from the flags during open).

Acked-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230927093442.25915-2-jack@suse.cz
Signed-off-by: Christian Brauner <brauner@kernel.org>

block: Don't invalidate pagecache for invalid falloc modes

Only call truncate_bdev_range() if the fallocate mode is supported. This
fixes a bug where data in the pagecache could be invalidated if the
fallocate() was called on the block device with an invalid mode.

Fixes: 25f4c41415e5 ("block: implement (some of) fallocate for block devices")
Cc: stable@vger.kernel.org
Reported-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Sarthak Kukreti <sarthakkukreti@chromium.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Fixes: line? I've never seen those wrapped.
Link: https://lore.kernel.org/r/20231011201230.750105-1-sarthakkukreti@chromium.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: remove the call to file_remove_privs in blkdev_write_iter

file_remove_privs instantly returns 0 when not called for regular files,
so don't bother.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20230831121911.280155-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs: add CONFIG_BUFFER_HEAD

Add a new config option that controls building the buffer_head code, and
select it from all file systems and stacking drivers that need it.

For the block device nodes and alternative iomap based buffered I/O path
is provided when buffer_head support is not enabled, and iomap needs a
a small tweak to define the IOMAP_F_BUFFER_HEAD flag to 0 to not call
into the buffer_head code when it doesn't exist.

Otherwise this is just Kconfig and ifdef changes.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20230801172201.1923299-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: use iomap for writes to block devices

Use iomap in buffer_head compat mode to write to block devices.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230801172201.1923299-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: stop setting ->direct_IO

Direct I/O on block devices now nevers goes through aops->direct_IO.
Stop setting it and set the FMODE_CAN_ODIRECT in ->open instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20230801172201.1923299-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: open code __generic_file_write_iter for blkdev writes

Open code __generic_file_write_iter to remove the indirect call into
->direct_IO and to prepare using the iomap based write code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20230801172201.1923299-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: don't make REQ_POLLED imply REQ_NOWAIT

Normally these two flags do go together, as the issuer of polled IO
generally cannot wait for resources that will get freed as part of IO
completion. This is because that very task is the one that will complete
the request and free those resources, hence that would introduce a
deadlock.

But it is possible to have someone else issue the polled IO, eg via
io_uring if the request is punted to io-wq. For that case, it's fine to
have the task block on IO submission, as it is not the same task that
will be completing the IO.

It's completely up to the caller to ask for both polled and nowait IO
separately! If we don't allow polled IO where IOCB_NOWAIT isn't set in
the kiocb, then we can run into repeated -EAGAIN submissions and not
make any progress.

Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: store the holder in file->private_data

Store the file struct used as the holder in file->private_data as an
indicator that this file descriptor was opened exclusively to remove
the last use of FMODE_EXCL.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20230608110258.189493-30-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: always use I_BDEV on file->f_mapping->host to find the bdev

Always use I_BDEV(file->f_mapping->host) to find the bdev for a file to
free up file->private_data for other uses.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-29-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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>

block: use the holder as indication for exclusive opens

The current interface for exclusive opens is rather confusing as it
requires both the FMODE_EXCL flag and a holder. Remove the need to pass
FMODE_EXCL and just key off the exclusive open off a non-NULL holder.

For blkdev_put this requires adding the holder argument, which provides
better debug checking that only the holder actually releases the hold,
but at the same time allows removing the now superfluous mode argument.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Acked-by: David Sterba <dsterba@suse.com> [btrfs]
Acked-by: Jack Wang <jinpu.wang@ionos.com> [rnbd]
Link: https://lore.kernel.org/r/20230608110258.189493-16-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: rename blkdev_close to blkdev_release

Make the function name match the method name.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-11-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

filemap: add a kiocb_write_and_wait helper

Factor out a helper that does filemap_write_and_wait_range for the range
covered by a read kiocb, or returns -EAGAIN if the kiocb is marked as
nowait and there would be pages to write.

Link: https://lkml.kernel.org/r/20230601145904.1385409-5-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Chao Yu <chao@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

block: introduce holder ops

Add a new blk_holder_ops structure, which is passed to blkdev_get_by_* and
installed in the block_device for exclusive claims. It will be used to
allow the block layer to call back into the user of the block device for
thing like notification of a removed device or a device resize.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Link: https://lore.kernel.org/r/20230601094459.1350643-10-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

splice: Use filemap_splice_read() instead of generic_file_splice_read()

Replace pointers to generic_file_splice_read() with calls to
filemap_splice_read().

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
cc: Jens Axboe <axboe@kernel.dk>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: David Hildenbrand <david@redhat.com>
cc: John Hubbard <jhubbard@nvidia.com>
cc: linux-mm@kvack.org
cc: linux-block@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20230522135018.2742245-29-dhowells@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: don't plug in blkdev_write_iter

For direct I/O writes that issues more than a single bio, the plugging
is already done in __blkdev_direct_IO.
For synchronous buffered writes the plugging is done deep down in
writeback_inodes_wb / wb_writeback.

For the other cases there is no point in plugging as as single bio or no
bio at all is submitted.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230520044503.334444-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Deny writable memory mapping if block is read-only

User should not be able to write block device if it is read-only at
block level (e.g force_ro attribute). This is ensured in the regular
fops write operation (blkdev_write_iter) but not when writing via
user mapping (mmap), allowing user to actually write a read-only
block device via a PROT_WRITE mapping.

Example: This can lead to integrity issue of eMMC boot partition
(e.g mmcblk0boot0) which is read-only by default.

To fix this issue, simply deny shared writable mapping if the block
is readonly.

Note: Block remains writable if switch to read-only is performed
after the initial mapping, but this is expected behavior according
to commit a32e236eb93e ("Partially revert "block: fail op_is_write()
requests to read-only partitions"")'.

Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230510074223.991297-1-loic.poulain@linaro.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: mark bdev files as FMODE_NOWAIT if underlying device supports it

We set this unconditionally, but it really should be dependent on if
the underlying device is nowait compliant.

Cc: linux-block@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230509151910.183637-3-axboe@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: don't allow multiple bios for IOCB_NOWAIT issue

If we're doing a large IO request which needs to be split into multiple
bios for issue, then we can run into the same situation as the below
marked commit fixes - parts will complete just fine, one or more parts
will fail to allocate a request. This will result in a partially
completed read or write request, where the caller gets EAGAIN even though
parts of the IO completed just fine.

Do the same for large bios as we do for splits - fail a NOWAIT request
with EAGAIN. This isn't technically fixing an issue in the below marked
patch, but for stable purposes, we should have either none of them or
both.

This depends on: 613b14884b85 ("block: handle bio_split_to_limits() NULL return")

Cc: stable@vger.kernel.org # 5.15+
Fixes: 9cea62b2cbab ("block: don't allow splitting of a REQ_NOWAIT bio")
Link: https://github.com/axboe/liburing/issues/766
Reported-and-tested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: remove blkdev_writepages

While the block device code should switch to implementing
->writepages instead of ->writepage eventually, the current
implementation is entirely pointless as it does the same looping over
->writepage as the generic code if no ->writepages is present.

Remove blkdev_writepages so that we can eventually unexport
generic_writepages.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221116132035.2192924-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

new iov_iter flavour - ITER_UBUF

Equivalent of single-segment iovec. Initialized by iov_iter_ubuf(),
checked for by iter_is_ubuf(), otherwise behaves like ITER_IOVEC
ones.

We are going to expose the things like ->write_iter() et.al. to those
in subsequent commits.

New predicate (user_backed_iter()) that is true for ITER_IOVEC and
ITER_UBUF; places like direct-IO handling should use that for
checking that pages we modify after getting them from iov_iter_get_pages()
would need to be dirtied.

DO NOT assume that replacing iter_is_iovec() with user_backed_iter()
will solve all problems - there's code that uses iter_is_iovec() to
decide how to poke around in iov_iter guts and for that the predicate
replacement obviously won't suffice.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

mm/migrate: Convert buffer_migrate_page() to buffer_migrate_folio()

Use a folio throughout __buffer_migrate_folio(), add kernel-doc for
buffer_migrate_folio() and buffer_migrate_folio_norefs(), move their
declarations to buffer.h and switch all filesystems that have wired
them up.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

iocb: delay evaluation of IS_SYNC(...) until we want to check IOCB_DSYNC

New helper to be used instead of direct checks for IOCB_DSYNC:
iocb_is_dsync(iocb). Checks converted, which allows to avoid
the IS_SYNC(iocb->ki_filp->f_mapping->host) part (4 cache lines)
from iocb_flags() - it's checked in iocb_is_dsync() instead

Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

block: Use the new blk_opf_t type

Use the new blk_opf_t type for arguments and variables that represent
request flags or a bitwise combination of a request operation and
request flags. Rename the function arguments and also a structure member
that hold a request operation and flags from 'rw' into 'opf'.

This patch does not change any functionality.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-7-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: relax direct io memory alignment

Use the address alignment requirements from the block_device for direct
io instead of requiring addresses be aligned to the block size. User
space can discover the alignment requirements from the dma_alignment
queue attribute.

User space can specify any hardware compatible DMA offset for each
segment, but every segment length is still required to be a multiple of
the block size.

Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220610195830.3574005-11-kbusch@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: add a helper function for dio alignment

This will make it easier to add more complex acceptable alignment
criteria in the future.

Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220610195830.3574005-6-kbusch@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs: Convert block_read_full_page() to block_read_full_folio()

This function is NOT converted to handle large folios, so include
an assert that the filesystem isn't passing one in. Otherwise, use
the folio functions instead of the page functions, where they exist.
Convert all filesystems which use block_read_full_page().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

fs: Remove flags parameter from aops->write_begin

There are no more aop flags left, so remove the parameter.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

fs: Remove aop flags parameter from block_write_begin()

There are no more aop flags left, so remove the parameter.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

block: ignore RWF_HIPRI hint for sync dio

So far bio is marked as REQ_POLLED if RWF_HIPRI/IOCB_HIPRI is passed
from userspace sync io interface, then block layer tries to poll until
the bio is completed. But the current implementation calls
blk_io_schedule() if bio_poll() returns 0, and this way causes io hang or
timeout easily.

But looks no one reports this kind of issue, which should have been
triggered in normal io poll sanity test or blktests block/007 as
observed by Changhui, that means it is very likely that no one uses it
or no one cares it.

Also after io_uring is invented, io poll for sync dio becomes legacy
interface.

So ignore RWF_HIPRI hint for sync dio.

CC: linux-mm@kvack.org
Cc: linux-xfs@vger.kernel.org
Reported-by: Changhui Zhong <czhong@redhat.com>
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Changhui Zhong <czhong@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220420143110.2679002-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: decouple REQ_OP_SECURE_ERASE from REQ_OP_DISCARD

Secure erase is a very different operation from discard in that it is
a data integrity operation vs hint. Fully split the limits and helper
infrastructure to make the separation more clear.

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: Ryusuke Konishi <konishi.ryusuke@gmail.com> [nifs2]
Acked-by: Jaegeuk Kim <jaegeuk@kernel.org> [f2fs]
Acked-by: Coly Li <colyli@suse.de> [bcache]
Acked-by: David Sterba <dsterba@suse.com> [btrfs]
Acked-by: Chao Yu <chao@kernel.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220415045258.199825-27-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: allow using the per-cpu bio cache from bio_alloc_bioset

Replace the BIO_PERCPU_CACHE bio-internal flag with a REQ_ALLOC_CACHE
one that can be passed to bio_alloc / bio_alloc_bioset, and implement
the percpu cache allocation logic in a helper called from
bio_alloc_bioset. This allows any bio_alloc_bioset user to use the
percpu caches instead of having the functionality tied to struct kiocb.

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
[hch: refactored a bit]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220324203526.62306-2-snitzer@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: remove the per-bio/request write hint

With the NVMe support for this gone, there are no consumers of these hints
left, so remove them.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220304175556.407719-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs: Convert __set_page_dirty_buffers to block_dirty_folio

Convert all callers; mostly this is just changing the aops to point
at it, but a few implementations need a little more work.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs
Tested-by: David Howells <dhowells@redhat.com> # afs

fs: Turn block_invalidatepage into block_invalidate_folio

Remove special-casing of a NULL invalidatepage, since there is no
more block_invalidatepage.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs
Tested-by: David Howells <dhowells@redhat.com> # afs

block: pass a block_device and opf to bio_init

Pass the block_device that we plan to use this bio for and the
operation to bio_init to optimize the assignment. A NULL block_device
can be passed, both for the passthrough case on a raw request_queue and
to temporarily avoid refactoring some nasty code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-19-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: pass a block_device and opf to bio_alloc

Pass the block_device and operation that we plan to use this bio for to
bio_alloc to optimize the assignment. NULL/0 can be passed, both for the
passthrough case on a raw request_queue and to temporarily avoid
refactoring some nasty code.

Also move the gfp_mask argument after the nr_vecs argument for a much
more logical calling convention matching what most of the kernel does.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-18-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: pass a block_device and opf to bio_alloc_kiocb

Pass the block_device and operation that we plan to use this bio for to
bio_alloc_kiocb to optimize the assigment.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-17-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: clear iocb->private in blkdev_bio_end_io_async()

iocb_bio_iopoll() expects iocb->private to be cleared before
releasing the bio.

We already do this in blkdev_bio_end_io(), but we forgot in the
recently added blkdev_bio_end_io_async().

Fixes: 54a88eb838d3 ("block: add single bio async direct IO helper")
Cc: asml.silence@gmail.com
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220211090136.44471-1-sgarzare@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: fix DIO handling regressions in blkdev_read_iter()

Commit ceaa762527f4 ("block: move direct_IO into our own read_iter
handler") introduced several regressions for bdev DIO:

1. read spanning EOF always returns 0 instead of the number of bytes
read. This is because "count" is assigned early and isn't updated
when the iterator is truncated:

$ lsblk -o name,size /dev/vdb
NAME SIZE
vdb 1G
$ xfs_io -d -c 'pread -b 4M 1021M 4M' /dev/vdb
read 0/4194304 bytes at offset 1070596096
0.000000 bytes, 0 ops; 0.0007 sec (0.000000 bytes/sec and 0.0000 ops/sec)

instead of

$ xfs_io -d -c 'pread -b 4M 1021M 4M' /dev/vdb
read 3145728/4194304 bytes at offset 1070596096
3 MiB, 1 ops; 0.0007 sec (3.865 GiB/sec and 1319.2612 ops/sec)

2. truncated iterator isn't reexpanded
3. iterator isn't reverted on blkdev_direct_IO() error
4. zero size read no longer skips atime update

Fixes: ceaa762527f4 ("block: move direct_IO into our own read_iter handler")
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220201100420.25875-1-idryomov@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: move direct_IO into our own read_iter handler

Don't call into generic_file_read_iter() if we know it's O_DIRECT, just
set it up ourselves and call our own handler. This avoids an indirect call
for O_DIRECT.

Fall back to filemap_read() if we fail.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: fix single bio async DIO error handling

BUG: KASAN: use-after-free in io_submit_one+0x496/0x2fe0 fs/aio.c:1882
CPU: 2 PID: 15100 Comm: syz-executor873 Not tainted 5.16.0-rc1-syzk #1
Hardware name: Red Hat KVM, BIOS 1.13.0-2.module+el8.3.0+7860+a7792d29
04/01/2014
Call Trace:
[...]
refcount_dec_and_test include/linux/refcount.h:333 [inline]
iocb_put fs/aio.c:1161 [inline]
io_submit_one+0x496/0x2fe0 fs/aio.c:1882
__do_sys_io_submit fs/aio.c:1938 [inline]
__se_sys_io_submit fs/aio.c:1908 [inline]
__x64_sys_io_submit+0x1c7/0x4a0 fs/aio.c:1908
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3a/0x80 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae

__blkdev_direct_IO_async() returns errors from bio_iov_iter_get_pages()
directly, in which case upper layers won't be expecting ->ki_complete
to be called by the block layer and will terminate the request. However,
there is also bio_endio() leading to a second ->ki_complete and a double
free.

Fixes: 54a88eb838d37 ("block: add single bio async direct IO helper")
Reported-by: George Kennedy <george.kennedy@oracle.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/c9eb786f6cef041e159e6287de131bec0719ad5c.1638907997.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

treewide: Add missing includes masked by cgroup -> bpf dependency

cgroup.h (therefore swap.h, therefore half of the universe)
includes bpf.h which in turn includes module.h and slab.h.
Since we're about to get rid of that dependency we need
to clean things up.

v2: drop the cpu.h include from cacheinfo.h, it's not necessary
and it makes riscv sensitive to ordering of include files.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Krzysztof Wilczyński <kw@linux.com>
Acked-by: Peter Chen <peter.chen@kernel.org>
Acked-by: SeongJae Park <sj@kernel.org>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/all/20211120035253.72074-1-kuba@kernel.org/ # v1
Link: https://lore.kernel.org/all/20211120165528.197359-1-kuba@kernel.org/ # cacheinfo discussion
Link: https://lore.kernel.org/bpf/20211202203400.1208663-1-kuba@kernel.org

block: use new bdev_nr_bytes() helper for blkdev_{read,write}_iter()

We have new helpers for this, use them rather than the slower inode
size reads. This makes the read/write path consistent with most of
the rest of block as well.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/a72767cd-3c6d-47f7-80f4-aa025a17b2cb@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: add async version of bio_set_polled

If we know that a iocb is async we can optimise bio_set_polled() a bit,
add a new helper bio_set_polled_async().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/8fa137885164a5d05fadcff4c3521da8d5a83d00.1635337135.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: kill DIO_MULTI_BIO

Now __blkdev_direct_IO() serves only multi-bio I/O, thus remove
not used anymore single bio refcounting optimisations.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/88eb488aae9ed4852a30f3a7132f296f56e43b80.1635337135.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: kill unused polling bits in __blkdev_direct_IO()

With addition of __blkdev_direct_IO_async(), __blkdev_direct_IO() now
serves only multio-bio I/O, which we don't poll. Now we can remove
anything related to I/O polling from it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/b8c597a6b7ee612df394853bfd24726aee5b898e.1635337135.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: avoid extra iter advance with async iocb

Nobody cares about iov iterators state if we return -EIOCBQUEUED, so as
the we now have __blkdev_direct_IO_async(), which gets pages only once,
we can skip expensive iov_iter_advance(). It's around 1-2% of all CPU
spent.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/a6158edfbfa2ae3bc24aed29a72f035df18fad2f.1635337135.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs: get rid of the res2 iocb->ki_complete argument

The second argument was only used by the USB gadget code, yet everyone
pays the overhead of passing a zero to be passed into aio, where it
ends up being part of the aio res2 value.

Now that everybody is passing in zero, kill off the extra argument.

Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: add single bio async direct IO helper

As with __blkdev_direct_IO_simple(), we can implement direct IO more
efficiently if there is only one bio. Add __blkdev_direct_IO_async() and
blkdev_bio_end_io_async(). This patch brings me from 4.45-4.5 MIOPS with
nullblk to 4.7+.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/f0ae4109b7a6934adede490f84d188d53b97051b.1635006010.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: convert fops.c magic constants to SHIFT_SECTOR

Don't use shifting by a magic number 9 but replace with a more
descriptive SHIFT_SECTOR.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/068782b9f7e97569fb59a99529b23bb17ea4c5e2.1634755800.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: optimise boundary blkdev_read_iter's checks

Combine pos and len checks and mark unlikely. Also, don't reexpand if
it's not truncated.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/fff34e613aeaae1ad12977dc4592cb1a1f5d3190.1634755800.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: align blkdev_dio inlined bio to a cacheline

We get all sorts of unreliable and funky results since the bio is
designed to align on a cacheline, which it does not when inlined like
this.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: use bdev_nr_bytes instead of open coding it in blkdev_fallocate

Use the proper helper to read the block device size.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20211018101130.1838532-25-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: add a struct io_comp_batch argument to fops->iopoll()

struct io_comp_batch contains a list head and a completion handler, which
will allow completions to more effciently completed batches of IO.

For now, no functional changes in this patch, we just define the
io_comp_batch structure and add the argument to the file_operations iopoll
handler.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: use flags instead of bit fields for blkdev_dio

This generates a lot better code for me, and bumps performance from
7650K IOPS to 7750K IOPS. Looking at profiles for the run and running
perf diff, it confirms that we're now sending a lot less time there:

6.38% -2.80% [kernel.vmlinux] [k] blkdev_direct_IO

Taking it from the 2nd most cycle consumer to only the 9th most at
3.35% of the CPU time.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: cache bdev in struct file for raw bdev IO

bdev = &BDEV_I(file->f_mapping->host)->bdev

Getting struct block_device from a file requires 2 memory dereferences
as illustrated above, that takes a toll on performance, so cache it in
yet unused file->private_data. That gives a noticeable peak performance
improvement.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/8415f9fe12e544b9da89593dfbca8de2b52efe03.1634115360.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: switch polling to be bio based

Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: replace the spin argument to blk_iopoll with a flags argument

Switch the boolean spin argument to blk_poll to passing a set of flags
instead. This will allow to control polling behavior in a more fine
grained way.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-10-hch@lst.de
[axboe: adapt to changed io_uring iopoll]
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: don't try to poll multi-bio I/Os in __blkdev_direct_IO

If an iocb is split into multiple bios we can't poll for both. So don't
even bother to try to poll in that case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211012111226.760968-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: merge block_ioctl into blkdev_ioctl

Simplify the ioctl path and match the code structure on the compat side.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211012104450.659013-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: hold ->invalidate_lock in blkdev_fallocate

When running ->fallocate(), blkdev_fallocate() should hold
mapping->invalidate_lock to prevent page cache from being accessed,
otherwise stale data may be read in page cache.

Without this patch, blktests block/009 fails sometimes. With this patch,
block/009 can pass always.

Also as Jan pointed out, no pages can be created in the discarded area
while you are holding the invalidate_lock, so remove the 2nd
truncate_bdev_range().

Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210923023751.1441091-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: split out operations on block special files

Add a new block/fops.c for all the file and address_space operations
that provide the block special file support.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210907141303.1371844-2-hch@lst.de
[axboe: correct trailing whitespace while at it]
Signed-off-by: Jens Axboe <axboe@kernel.dk>