History log of /openbmc/linux/include/linux/buffer_head.h (Results 1 – 25 of 222)
Revision (<<< Hide revision tags) (Show revision tags >>>) Date Author Comments
Revision tags: v6.6.25, v6.6.24, v6.6.23, v6.6.16, v6.6.15, v6.6.14, v6.6.13, v6.6.12, v6.6.11, v6.6.10, v6.6.9, v6.6.8, v6.6.7, v6.6.6, v6.6.5, v6.6.4, v6.6.3, v6.6.2, v6.5.11, v6.6.1, v6.5.10, v6.6, v6.5.9, v6.5.8, v6.5.7, v6.5.6, v6.5.5, v6.5.4, v6.5.3
# f94cf220 07-Sep-2023 Matthew Wilcox (Oracle) <willy@infradead.org>

buffer: Make bh_offset() work for compound pages

If the buffer pointed to by the buffer_head is part of a compound page,
bh_offset() assumes that b_page is the precise page that contains
the data.

buffer: Make bh_offset() work for compound pages

If the buffer pointed to by the buffer_head is part of a compound page,
bh_offset() assumes that b_page is the precise page that contains
the data. A recent change to jbd2 inadvertently violated that assumption.

By using page_size(), we support both b_page being set to the head page
(as page_size() will return the size of the entire folio) and the precise
page (as it will return PAGE_SIZE for a tail page).

Fixes: 8147c4c4546f ("jbd2: use a folio in jbd2_journal_write_metadata_buffer()")
Reported-by: Zorro Lang <zlang@kernel.org>
Tested-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

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Revision tags: v6.5.2, v6.1.51, v6.5.1, v6.1.50, v6.5, v6.1.49, v6.1.48, v6.1.46, v6.1.45, v6.1.44, v6.1.43, v6.1.42, v6.1.41, v6.1.40, v6.1.39
# 5f6d2862 12-Jul-2023 Matthew Wilcox (Oracle) <willy@infradead.org>

buffer: remove set_bh_page()

With all users converted to folio_set_bh(), remove this function.

Link: https://lkml.kernel.org/r/20230713035512.4139457-8-willy@infradead.org
Signed-off-by: Matthew Wi

buffer: remove set_bh_page()

With all users converted to folio_set_bh(), remove this function.

Link: https://lkml.kernel.org/r/20230713035512.4139457-8-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Sterba <dsterba@suse.com>
Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Pankaj Raghav <p.raghav@samsung.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Tom Rix <trix@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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Revision tags: v6.1.38, v6.1.37, v6.1.36
# a524fcfe 26-Jun-2023 Bean Huo <beanhuo@micron.com>

fs: convert block_commit_write to return void

block_commit_write() always returns 0, this patch changes it to return
void.

Link: https://lkml.kernel.org/r/20230626055518.842392-3-beanhuo@iokpp.de
S

fs: convert block_commit_write to return void

block_commit_write() always returns 0, this patch changes it to return
void.

Link: https://lkml.kernel.org/r/20230626055518.842392-3-beanhuo@iokpp.de
Signed-off-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Luís Henriques <ocfs2-devel@oss.oracle.com>
Cc: Mark Fasheh <mark@fasheh.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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# 925c86a1 01-Aug-2023 Christoph Hellwig <hch@lst.de>

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

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>

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# 2ba39cc4 01-Aug-2023 Christoph Hellwig <hch@lst.de>

fs: rename and move block_page_mkwrite_return

block_page_mkwrite_return is neither block nor mkwrite specific, and
should not be under CONFIG_BLOCK. Move it to mm.h and rename it to
vmf_fs_error.

fs: rename and move block_page_mkwrite_return

block_page_mkwrite_return is neither block nor mkwrite specific, and
should not be under CONFIG_BLOCK. Move it to mm.h and rename it to
vmf_fs_error.

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>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230801172201.1923299-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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Revision tags: v6.4, v6.1.35, v6.1.34
# 4a9622f2 12-Jun-2023 Matthew Wilcox (Oracle) <willy@infradead.org>

buffer: convert page_zero_new_buffers() to folio_zero_new_buffers()

Most of the callers already have a folio; convert reiserfs_write_end() to
have a folio. Removes a couple of hidden calls to compo

buffer: convert page_zero_new_buffers() to folio_zero_new_buffers()

Most of the callers already have a folio; convert reiserfs_write_end() to
have a folio. Removes a couple of hidden calls to compound_head().

Link: https://lkml.kernel.org/r/20230612210141.730128-10-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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# 53418a18 12-Jun-2023 Matthew Wilcox (Oracle) <willy@infradead.org>

buffer: convert __block_write_full_page() to __block_write_full_folio()

Remove nine hidden calls to compound_head() by using a folio instead of a
page.

Link: https://lkml.kernel.org/r/2023061221014

buffer: convert __block_write_full_page() to __block_write_full_folio()

Remove nine hidden calls to compound_head() by using a folio instead of a
page.

Link: https://lkml.kernel.org/r/20230612210141.730128-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Bob Peterson <rpeterso@redhat.com>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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Revision tags: v6.1.33, v6.1.32, v6.1.31, v6.1.30, v6.1.29, v6.1.28, v6.1.27, v6.1.26, v6.3
# 31b2ebc0 21-Apr-2023 Ritesh Harjani (IBM) <ritesh.list@gmail.com>

fs/buffer.c: Add generic_buffers_fsync*() implementation

Some of the higher layers like iomap takes inode_lock() when calling
generic_write_sync().
Also writeback already happens from other paths wi

fs/buffer.c: Add generic_buffers_fsync*() implementation

Some of the higher layers like iomap takes inode_lock() when calling
generic_write_sync().
Also writeback already happens from other paths without inode lock,
so it's difficult to say that we really need sync_mapping_buffers() to
take any inode locking here. Having said that, let's add
generic_buffers_fsync/_noflush() implementation in buffer.c with no
inode_lock/unlock() for now so that filesystems like ext2 and
ext4's nojournal mode can use it.

Ext4 when got converted to iomap for direct-io already copied it's own
variant of __generic_file_fsync() without lock.

This patch adds generic_buffers_fsync()
& generic_buffers_fsync_noflush() implementations for use in filesystems
like ext2 & ext4 respectively.

Later we can review other filesystems as well to see if we can make
generic_buffers_fsync/_noflush() which does not take any inode_lock() as
the default path.

Tested-by: Disha Goel <disgoel@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Message-Id: <d573408ac8408627d23a3d2d166e748c172c4c9e.1682069716.git.ritesh.list@gmail.com>

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Revision tags: v6.1.25
# 8e2e1756 17-Apr-2023 Pankaj Raghav <p.raghav@samsung.com>

fs/buffer: add folio_create_empty_buffers helper

Folio version of create_empty_buffers(). This is required to convert
create_page_buffers() to folio_create_buffers() later in the series.

It remove

fs/buffer: add folio_create_empty_buffers helper

Folio version of create_empty_buffers(). This is required to convert
create_page_buffers() to folio_create_buffers() later in the series.

It removes several calls to compound_head() as it works directly on folio
compared to create_empty_buffers(). Hence, create_empty_buffers() has
been modified to call folio_create_empty_buffers().

Link: https://lkml.kernel.org/r/20230417123618.22094-4-p.raghav@samsung.com
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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# c71124a8 17-Apr-2023 Pankaj Raghav <p.raghav@samsung.com>

buffer: add folio_alloc_buffers() helper

Folio version of alloc_page_buffers() helper. This is required to convert
create_page_buffers() to folio_create_buffers() later in the series.

alloc_page_b

buffer: add folio_alloc_buffers() helper

Folio version of alloc_page_buffers() helper. This is required to convert
create_page_buffers() to folio_create_buffers() later in the series.

alloc_page_buffers() has been modified to call folio_alloc_buffers() which
adds one call to compound_head() but folio_alloc_buffers() removes one
call to compound_head() compared to the existing alloc_page_buffers()
implementation.

Link: https://lkml.kernel.org/r/20230417123618.22094-3-p.raghav@samsung.com
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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# 465e5e6a 17-Apr-2023 Pankaj Raghav <p.raghav@samsung.com>

fs/buffer: add folio_set_bh helper

Patch series "convert create_page_buffers to folio_create_buffers".

One of the first kernel panic we hit when we try to increase the block
size > 4k is inside cre

fs/buffer: add folio_set_bh helper

Patch series "convert create_page_buffers to folio_create_buffers".

One of the first kernel panic we hit when we try to increase the block
size > 4k is inside create_page_buffers()[1]. Even though buffer.c
function do not support large folios (folios > PAGE_SIZE) at the moment,
these changes are required when we want to remove that constraint.


This patch (of 4):

The folio version of set_bh_page(). This is required to convert
create_page_buffers() to folio_create_buffers() later in the series.

Link: https://lkml.kernel.org/r/20230417123618.22094-1-p.raghav@samsung.com
Link: https://lkml.kernel.org/r/20230417123618.22094-2-p.raghav@samsung.com
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

show more ...


Revision tags: v6.1.24, v6.1.23, v6.1.22, v6.1.21, v6.1.20, v6.1.19, v6.1.18, v6.1.17, v6.1.16, v6.1.15, v6.1.14, v6.1.13, v6.2, v6.1.12, v6.1.11, v6.1.10, v6.1.9, v6.1.8, v6.1.7, v6.1.6, v6.1.5, v6.0.19, v6.0.18, v6.1.4, v6.1.3, v6.0.17, v6.1.2, v6.0.16, v6.1.1, v6.0.15, v6.0.14
# d685c668 15-Dec-2022 Matthew Wilcox (Oracle) <willy@infradead.org>

buffer: add b_folio as an alias of b_page

Patch series "Start converting buffer_heads to use folios".

I was hoping that filesystems would convert from buffer_heads to iomap,
but that's not happenin

buffer: add b_folio as an alias of b_page

Patch series "Start converting buffer_heads to use folios".

I was hoping that filesystems would convert from buffer_heads to iomap,
but that's not happening particularly quickly. So the buffer_head
infrastructure needs to be converted from being page-based to being
folio-based.


This patch (of 12):

Buffer heads point to the allocation (ie the folio), not the page. This
is currently the same thing for all filesystems that use buffer heads, so
this is a safe transitional step.

Link: https://lkml.kernel.org/r/20221215214402.3522366-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20221215214402.3522366-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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Revision tags: v6.0.13, v6.1, v6.0.12, v6.0.11, v6.0.10, v5.15.80, v6.0.9, v5.15.79, v6.0.8, v5.15.78, v6.0.7, v5.15.77, v5.15.76, v6.0.6, v6.0.5, v5.15.75, v6.0.4, v6.0.3, v6.0.2, v5.15.74, v5.15.73, v6.0.1, v5.15.72, v6.0, v5.15.71, v5.15.70, v5.15.69, v5.15.68, v5.15.67, v5.15.66, v5.15.65, v5.15.64, v5.15.63, v5.15.62
# 5bdf402a 18-Aug-2022 Ritesh Harjani (IBM) <ritesh.list@gmail.com>

fs/buffer: make submit_bh & submit_bh_wbc return type as void

submit_bh/submit_bh_wbc are non-blocking functions which just submit
the bio and return. The caller of submit_bh/submit_bh_wbc needs to

fs/buffer: make submit_bh & submit_bh_wbc return type as void

submit_bh/submit_bh_wbc are non-blocking functions which just submit
the bio and return. The caller of submit_bh/submit_bh_wbc needs to wait
on buffer till I/O completion and then check buffer head's b_state field
to know if there was any I/O error.

Hence there is no need for these functions to have any return type.
Even now they always returns 0. Hence drop the return value and make
their return type as void to avoid any confusion.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/cb66ef823374cdd94d2d03083ce13de844fffd41.1660788334.git.ritesh.list@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

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# 454552d0 01-Sep-2022 Zhang Yi <yi.zhang@huawei.com>

fs/buffer: remove bh_submit_read() helper

bh_submit_read() has no user anymore, just remove it.

Link: https://lkml.kernel.org/r/20220901133505.2510834-15-yi.zhang@huawei.com
Signed-off-by: Zhang Yi

fs/buffer: remove bh_submit_read() helper

bh_submit_read() has no user anymore, just remove it.

Link: https://lkml.kernel.org/r/20220901133505.2510834-15-yi.zhang@huawei.com
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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# 79f59784 01-Sep-2022 Zhang Yi <yi.zhang@huawei.com>

fs/buffer: remove ll_rw_block() helper

Now that all ll_rw_block() users has been replaced to new safe helpers,
we just remove it here.

Link: https://lkml.kernel.org/r/20220901133505.2510834-13-yi.z

fs/buffer: remove ll_rw_block() helper

Now that all ll_rw_block() users has been replaced to new safe helpers,
we just remove it here.

Link: https://lkml.kernel.org/r/20220901133505.2510834-13-yi.zhang@huawei.com
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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# fdee117e 01-Sep-2022 Zhang Yi <yi.zhang@huawei.com>

fs/buffer: add some new buffer read helpers

Current ll_rw_block() helper is fragile because it assumes that locked
buffer means it's under IO which is submitted by some other who holds
the lock, it

fs/buffer: add some new buffer read helpers

Current ll_rw_block() helper is fragile because it assumes that locked
buffer means it's under IO which is submitted by some other who holds
the lock, it skip buffer if it failed to get the lock, so it's only
safe on the readahead path. Unfortunately, now that most filesystems
still use this helper mistakenly on the sync metadata read path. There
is no guarantee that the one who holds the buffer lock always submit IO
(e.g. buffer_migrate_folio_norefs() after commit 88dbcbb3a484 ("blkdev:
avoid migration stalls for blkdev pages"), it could lead to false
positive -EIO when submitting reading IO.

This patch add some friendly buffer read helpers to prepare replacing
ll_rw_block() and similar calls. We can only call bh_readahead_[]
helpers for the readahead paths.

Link: https://lkml.kernel.org/r/20220901133505.2510834-3-yi.zhang@huawei.com
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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# 214f8796 01-Sep-2022 Zhang Yi <yi.zhang@huawei.com>

fs/buffer: remove __breadahead_gfp()

Patch series "fs/buffer: remove ll_rw_block()", v2.

ll_rw_block() will skip locked buffer before submitting IO, it assumes
that locked buffer means it is under

fs/buffer: remove __breadahead_gfp()

Patch series "fs/buffer: remove ll_rw_block()", v2.

ll_rw_block() will skip locked buffer before submitting IO, it assumes
that locked buffer means it is under IO. This assumption is not always
true because we cannot guarantee every buffer lock path would submit IO.
After commit 88dbcbb3a484 ("blkdev: avoid migration stalls for blkdev
pages"), buffer_migrate_folio_norefs() becomes one exceptional case, and
there may be others. So ll_rw_block() is not safe on the sync read path,
we could get false positive EIO return value when filesystem reading
metadata. It seems that it could be only used on the readahead path.

Unfortunately, many filesystem misuse the ll_rw_block() on the sync read
path. This patch set just remove ll_rw_block() and add new friendly
helpers, which could prevent false positive EIO on the read metadata path.
Thanks for the suggestion from Jan, the original discussion is at [1].

patch 1: remove unused helpers in fs/buffer.c
patch 2: add new bh_read_[*] helpers
patch 3-11: remove all ll_rw_block() calls in filesystems
patch 12-14: do some leftover cleanups.

[1]. https://lore.kernel.org/linux-mm/20220825080146.2021641-1-chengzhihao1@huawei.com/


This patch (of 14):

No one use __breadahead_gfp() and sb_breadahead_unmovable() any more,
remove them.

Link: https://lkml.kernel.org/r/20220901133505.2510834-1-yi.zhang@huawei.com
Link: https://lkml.kernel.org/r/20220901133505.2510834-2-yi.zhang@huawei.com
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Evgeniy Dushistov <dushistov@mail.ru>
Cc: Heming Zhao <ocfs2-devel@oss.oracle.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Yu Kuai <yukuai3@huawei.com>
Cc: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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# 2f79cdfe 31-Aug-2022 Linus Torvalds <torvalds@linux-foundation.org>

fs: only do a memory barrier for the first set_buffer_uptodate()

Commit d4252071b97d ("add barriers to buffer_uptodate and
set_buffer_uptodate") added proper memory barriers to the buffer head
BH_Up

fs: only do a memory barrier for the first set_buffer_uptodate()

Commit d4252071b97d ("add barriers to buffer_uptodate and
set_buffer_uptodate") added proper memory barriers to the buffer head
BH_Uptodate bit, so that anybody who tests a buffer for being up-to-date
will be guaranteed to actually see initialized state.

However, that commit didn't _just_ add the memory barrier, it also ended
up dropping the "was it already set" logic that the BUFFER_FNS() macro
had.

That's conceptually the right thing for a generic "this is a memory
barrier" operation, but in the case of the buffer contents, we really
only care about the memory barrier for the _first_ time we set the bit,
in that the only memory ordering protection we need is to avoid anybody
seeing uninitialized memory contents.

Any other access ordering wouldn't be about the BH_Uptodate bit anyway,
and would require some other proper lock (typically BH_Lock or the folio
lock). A reader that races with somebody invalidating the buffer head
isn't an issue wrt the memory ordering, it's a serialization issue.

Now, you'd think that the buffer head operations don't matter in this
day and age (and I certainly thought so), but apparently some loads
still end up being heavy users of buffer heads. In particular, the
kernel test robot reported that not having this bit access optimization
in place caused a noticeable direct IO performance regression on ext4:

fxmark.ssd_ext4_no_jnl_DWTL_54_directio.works/sec -26.5% regression

although you presumably need a fast disk and a lot of cores to actually
notice.

Link: https://lore.kernel.org/all/Yw8L7HTZ%2FdE2%2Fo9C@xsang-OptiPlex-9020/
Reported-by: kernel test robot <oliver.sang@intel.com>
Tested-by: Fengwei Yin <fengwei.yin@intel.com>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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# 8238b457 26-Aug-2022 Mikulas Patocka <mpatocka@redhat.com>

wait_on_bit: add an acquire memory barrier

There are several places in the kernel where wait_on_bit is not followed
by a memory barrier (for example, in drivers/md/dm-bufio.c:new_read).

On architec

wait_on_bit: add an acquire memory barrier

There are several places in the kernel where wait_on_bit is not followed
by a memory barrier (for example, in drivers/md/dm-bufio.c:new_read).

On architectures with weak memory ordering, it may happen that memory
accesses that follow wait_on_bit are reordered before wait_on_bit and
they may return invalid data.

Fix this class of bugs by introducing a new function "test_bit_acquire"
that works like test_bit, but has acquire memory ordering semantics.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Will Deacon <will@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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Revision tags: v5.15.61, v5.15.60
# d4252071 09-Aug-2022 Mikulas Patocka <mpatocka@redhat.com>

add barriers to buffer_uptodate and set_buffer_uptodate

Let's have a look at this piece of code in __bread_slow:

get_bh(bh);
bh->b_end_io = end_buffer_read_sync;
submit_bh(REQ_OP_READ, 0, bh);

add barriers to buffer_uptodate and set_buffer_uptodate

Let's have a look at this piece of code in __bread_slow:

get_bh(bh);
bh->b_end_io = end_buffer_read_sync;
submit_bh(REQ_OP_READ, 0, bh);
wait_on_buffer(bh);
if (buffer_uptodate(bh))
return bh;

Neither wait_on_buffer nor buffer_uptodate contain any memory barrier.
Consequently, if someone calls sb_bread and then reads the buffer data,
the read of buffer data may be executed before wait_on_buffer(bh) on
architectures with weak memory ordering and it may return invalid data.

Fix this bug by adding a memory barrier to set_buffer_uptodate and an
acquire barrier to buffer_uptodate (in a similar way as
folio_test_uptodate and folio_mark_uptodate).

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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Revision tags: v5.15.59, v5.19, v5.15.58, v5.15.57, v5.15.56, v5.15.55, v5.15.54, v5.15.53, v5.15.52, v5.15.51, v5.15.50, v5.15.49, v5.15.48, v5.15.47
# cc9cf350 13-Jun-2022 Christoph Hellwig <hch@lst.de>

fs: remove the nobh helpers

All callers are gone, so remove the now dead code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Matthew Wilcox (Orac

fs: remove the nobh helpers

All callers are gone, so remove the now dead code.

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

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Revision tags: v5.15.46
# 67235182 06-Jun-2022 Matthew Wilcox (Oracle) <willy@infradead.org>

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

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>

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# 1420c4a5 14-Jul-2022 Bart Van Assche <bvanassche@acm.org>

fs/buffer: Combine two submit_bh() and ll_rw_block() arguments

Both submit_bh() and ll_rw_block() accept a request operation type and
request flags as their first two arguments. Micro-optimize these

fs/buffer: Combine two submit_bh() and ll_rw_block() arguments

Both submit_bh() and ll_rw_block() accept a request operation type and
request flags as their first two arguments. Micro-optimize these two
functions by combining these first two arguments into a single argument.
This patch does not change the behavior of any of the modified code.

Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jan Kara <jack@suse.cz>
Acked-by: Song Liu <song@kernel.org> (for the md changes)
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-48-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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# 3ae72869 14-Jul-2022 Bart Van Assche <bvanassche@acm.org>

fs/buffer: Use the new blk_opf_t type

Improve static type checking by using the new blk_opf_t type for block layer
request flags. Change WRITE into REQ_OP_WRITE. This patch does not change
any funct

fs/buffer: Use the new blk_opf_t type

Improve static type checking by using the new blk_opf_t type for block layer
request flags. Change WRITE into REQ_OP_WRITE. This patch does not change
any functionality since REQ_OP_WRITE == WRITE == 1.

Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-47-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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Revision tags: v5.15.45, v5.15.44, v5.15.43, v5.15.42, v5.18, v5.15.41, v5.15.40, v5.15.39, v5.15.38, v5.15.37
# 68189fef 01-May-2022 Matthew Wilcox (Oracle) <willy@infradead.org>

fs: Change try_to_free_buffers() to take a folio

All but two of the callers already have a folio; pass a folio into
try_to_free_buffers(). This removes the last user of cancel_dirty_page()
so remov

fs: Change try_to_free_buffers() to take a folio

All but two of the callers already have a folio; pass a folio into
try_to_free_buffers(). This removes the last user of cancel_dirty_page()
so remove that wrapper function too.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>

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