Bring in an overlayfs fix for v6.13-rc1 that fixes a bug introduced by
the overlayfs changes merged for v6.13.
Signed-off-by: Christian Brauner <brauner@kernel.org>
* convert perag to use xarrays
* create a new generic allocation group structure
* Add metadata inode dir trees
* Create in-core rt allocation groups
* Shard the RT section into allocation groups
* Persist quota options with the enw metadata dir tree
* Enable quota for RT volumes
* Enable metadata directory trees
* Some bugfixes
Signed-off-by: Carlos Maiolino <cem@kernel.org>
-----BEGIN PGP SIGNATURE-----
iJUEABMJAB0WIQQMHYkcUKcy4GgPe2RGdaER5QtfpgUCZzyNwAAKCRBGdaER5Qtf
psV3AYCncK/pVhFfKQSFbnCvgPSoAe7N9n0Wt5gmjy0Ill2mbQXVl9ADXkH6a015
gcGM3t4BgIHLJQndL/Uz+3a0L5IriEb9QkAfzmx8t3vjiRBzBe3WfywEx9Yt7kZe
xbxEJ2HQpA==
=3ngC
-----END PGP SIGNATURE-----
Merge tag 'xfs-6.13-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs updates from Carlos Maiolino:
"The bulk of this pull request is a major rework that Darrick and
Christoph have been doing on XFS's real-time volume, coupled with a
few features to support this rework. It does also includes some bug
fixes.
- convert perag to use xarrays
- create a new generic allocation group structure
- add metadata inode dir trees
- create in-core rt allocation groups
- shard the RT section into allocation groups
- persist quota options with the enw metadata dir tree
- enable quota for RT volumes
- enable metadata directory trees
- some bugfixes"
* tag 'xfs-6.13-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (146 commits)
xfs: port ondisk structure checks from xfs/122 to the kernel
xfs: separate space btree structures in xfs_ondisk.h
xfs: convert struct typedefs in xfs_ondisk.h
xfs: enable metadata directory feature
xfs: enable realtime quota again
xfs: update sb field checks when metadir is turned on
xfs: reserve quota for realtime files correctly
xfs: create quota preallocation watermarks for realtime quota
xfs: report realtime block quota limits on realtime directories
xfs: persist quota flags with metadir
xfs: advertise realtime quota support in the xqm stat files
xfs: scrub quota file metapaths
xfs: fix chown with rt quota
xfs: use metadir for quota inodes
xfs: refactor xfs_qm_destroy_quotainos
xfs: use rtgroup busy extent list for FITRIM
xfs: implement busy extent tracking for rtgroups
xfs: port the perag discard code to handle generic groups
xfs: move the min and max group block numbers to xfs_group
xfs: adjust min_block usage in xfs_verify_agbno
...
iomap zero range flushes pagecache in certain situations to
determine which parts of the range might require zeroing if dirty
data is present in pagecache. The kernel robot recently reported a
regression associated with this flushing in the following stress-ng
workload on XFS:
stress-ng --timeout 60 --times --verify --metrics --no-rand-seed --metamix 64
This workload involves repeated small, strided, extending writes. On
XFS, this produces a pattern of post-eof speculative preallocation,
conversion of preallocation from delalloc to unwritten, dirtying
pagecache over newly unwritten blocks, and then rinse and repeat
from the new EOF. This leads to repetitive flushing of the EOF folio
via the zero range call XFS uses for writes that start beyond
current EOF.
To mitigate this problem, special case EOF block zeroing to prefer
zeroing the folio over a flush when the EOF folio is already dirty.
To do this, split out and open code handling of an unaligned start
offset. This brings most of the performance back by avoiding flushes
on zero range calls via write and truncate extension operations. The
flush doesn't occur in these situations because the entire range is
post-eof and therefore the folio that overlaps EOF is the only one
in the range.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Link: https://lore.kernel.org/r/20241115200155.593665-4-bfoster@redhat.com
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
In preparation for special handling of subranges, lift the zeroed
mapping logic from the iterator into the caller. Since this puts the
pagecache dirty check and flushing in the same place, streamline the
comments a bit as well.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Link: https://lore.kernel.org/r/20241115200155.593665-3-bfoster@redhat.com
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
iomap_zero_range() uses buffered writes for manual zeroing, no
longer updates i_size for such writes, but is still explicitly
called for post-eof ranges. The historical use case for this is
zeroing post-eof speculative preallocation on extending writes from
XFS. However, XFS also recently changed to convert all post-eof
delalloc mappings to unwritten in the iomap_begin() handler, which
means it now never expects manual zeroing of post-eof mappings. In
other words, all post-eof mappings should be reported as holes or
unwritten.
This is a subtle dependency that can be hard to detect if violated
because associated codepaths are likely to update i_size after folio
locks are dropped, but before writeback happens to occur. For
example, if XFS reverts back to some form of manual zeroing of
post-eof blocks on write extension, writeback of those zeroed folios
will now race with the presumed i_size update from the subsequent
buffered write.
Since iomap_zero_range() can't correctly zero post-eof mappings
beyond EOF without updating i_size, warn if this ever occurs. This
serves as minimal indication that if this use case is reintroduced
by a filesystem, iomap_zero_range() might need to reconsider i_size
updates for write extending use cases.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Link: https://lore.kernel.org/r/20241115145931.535207-1-bfoster@redhat.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZzcToAAKCRCRxhvAZXjc
osL9AP948FFumJRC28gDJ4xp+X4eohNOfkgoEG8FTbF2zU6ulwD+O0pr26FqpFli
pqlG+38UdATImpfqqWjPbb72sBYcfQg=
=wLUh
-----END PGP SIGNATURE-----
Merge tag 'vfs-6.13.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull misc vfs updates from Christian Brauner:
"Features:
- Fixup and improve NLM and kNFSD file lock callbacks
Last year both GFS2 and OCFS2 had some work done to make their
locking more robust when exported over NFS. Unfortunately, part of
that work caused both NLM (for NFS v3 exports) and kNFSD (for
NFSv4.1+ exports) to no longer send lock notifications to clients
This in itself is not a huge problem because most NFS clients will
still poll the server in order to acquire a conflicted lock
It's important for NLM and kNFSD that they do not block their
kernel threads inside filesystem's file_lock implementations
because that can produce deadlocks. We used to make sure of this by
only trusting that posix_lock_file() can correctly handle blocking
lock calls asynchronously, so the lock managers would only setup
their file_lock requests for async callbacks if the filesystem did
not define its own lock() file operation
However, when GFS2 and OCFS2 grew the capability to correctly
handle blocking lock requests asynchronously, they started
signalling this behavior with EXPORT_OP_ASYNC_LOCK, and the check
for also trusting posix_lock_file() was inadvertently dropped, so
now most filesystems no longer produce lock notifications when
exported over NFS
Fix this by using an fop_flag which greatly simplifies the problem
and grooms the way for future uses by both filesystems and lock
managers alike
- Add a sysctl to delete the dentry when a file is removed instead of
making it a negative dentry
Commit 681ce86235 ("vfs: Delete the associated dentry when
deleting a file") introduced an unconditional deletion of the
associated dentry when a file is removed. However, this led to
performance regressions in specific benchmarks, such as
ilebench.sum_operations/s, prompting a revert in commit
4a4be1ad3a ("Revert "vfs: Delete the associated dentry when
deleting a file""). This reintroduces the concept conditionally
through a sysctl
- Expand the statmount() system call:
* Report the filesystem subtype in a new fs_subtype field to
e.g., report fuse filesystem subtypes
* Report the superblock source in a new sb_source field
* Add a new way to return filesystem specific mount options in an
option array that returns filesystem specific mount options
separated by zero bytes and unescaped. This allows caller's to
retrieve filesystem specific mount options and immediately pass
them to e.g., fsconfig() without having to unescape or split
them
* Report security (LSM) specific mount options in a separate
security option array. We don't lump them together with
filesystem specific mount options as security mount options are
generic and most users aren't interested in them
The format is the same as for the filesystem specific mount
option array
- Support relative paths in fsconfig()'s FSCONFIG_SET_STRING command
- Optimize acl_permission_check() to avoid costly {g,u}id ownership
checks if possible
- Use smp_mb__after_spinlock() to avoid full smp_mb() in evict()
- Add synchronous wakeup support for ep_poll_callback.
Currently, epoll only uses wake_up() to wake up task. But sometimes
there are epoll users which want to use the synchronous wakeup flag
to give a hint to the scheduler, e.g., the Android binder driver.
So add a wake_up_sync() define, and use wake_up_sync() when sync is
true in ep_poll_callback()
Fixes:
- Fix kernel documentation for inode_insert5() and iget5_locked()
- Annotate racy epoll check on file->f_ep
- Make F_DUPFD_QUERY associative
- Avoid filename buffer overrun in initramfs
- Don't let statmount() return empty strings
- Add a cond_resched() to dump_user_range() to avoid hogging the CPU
- Don't query the device logical blocksize multiple times for hfsplus
- Make filemap_read() check that the offset is positive or zero
Cleanups:
- Various typo fixes
- Cleanup wbc_attach_fdatawrite_inode()
- Add __releases annotation to wbc_attach_and_unlock_inode()
- Add hugetlbfs tracepoints
- Fix various vfs kernel doc parameters
- Remove obsolete TODO comment from io_cancel()
- Convert wbc_account_cgroup_owner() to take a folio
- Fix comments for BANDWITH_INTERVAL and wb_domain_writeout_add()
- Reorder struct posix_acl to save 8 bytes
- Annotate struct posix_acl with __counted_by()
- Replace one-element array with flexible array member in freevxfs
- Use idiomatic atomic64_inc_return() in alloc_mnt_ns()"
* tag 'vfs-6.13.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (35 commits)
statmount: retrieve security mount options
vfs: make evict() use smp_mb__after_spinlock instead of smp_mb
statmount: add flag to retrieve unescaped options
fs: add the ability for statmount() to report the sb_source
writeback: wbc_attach_fdatawrite_inode out of line
writeback: add a __releases annoation to wbc_attach_and_unlock_inode
fs: add the ability for statmount() to report the fs_subtype
fs: don't let statmount return empty strings
fs:aio: Remove TODO comment suggesting hash or array usage in io_cancel()
hfsplus: don't query the device logical block size multiple times
freevxfs: Replace one-element array with flexible array member
fs: optimize acl_permission_check()
initramfs: avoid filename buffer overrun
fs/writeback: convert wbc_account_cgroup_owner to take a folio
acl: Annotate struct posix_acl with __counted_by()
acl: Realign struct posix_acl to save 8 bytes
epoll: Add synchronous wakeup support for ep_poll_callback
coredump: add cond_resched() to dump_user_range
mm/page-writeback.c: Fix comment of wb_domain_writeout_add()
mm/page-writeback.c: Update comment for BANDWIDTH_INTERVAL
...
File systems might have boundaries over which merges aren't possible.
In fact these are very common, although most of the time some kind of
header at the beginning of this region (e.g. XFS alloation groups, ext4
block groups) automatically create a merge barrier. But if that is
not present, say for a device purely used for data we need to manually
communicate that to iomap.
Add a IOMAP_F_BOUNDARY flag to never merge I/O into a previous mapping.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZyTGVAAKCRCRxhvAZXjc
oltEAP9r8cWa3Tdv8DzMNWu/jezTUXoW/mX5Qe+c1L6faqj0WQD/dIVtBtG37Tfq
3Ci9F/GEWjKijtCQ5lwMGUq27jQJ1gk=
=/0iA
-----END PGP SIGNATURE-----
Merge tag 'vfs-6.12-rc6.iomap' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs
Pull iomap fixes from Christian Brauner:
"Fixes for iomap to prevent data corruption bugs in the fallocate
unshare range implementation of fsdax and a small cleanup to turn
iomap_want_unshare_iter() into an inline function"
* tag 'vfs-6.12-rc6.iomap' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs:
iomap: turn iomap_want_unshare_iter into an inline function
fsdax: dax_unshare_iter needs to copy entire blocks
fsdax: remove zeroing code from dax_unshare_iter
iomap: share iomap_unshare_iter predicate code with fsdax
xfs: don't allocate COW extents when unsharing a hole
Most of the callers of wbc_account_cgroup_owner() are converting a folio
to page before calling the function. wbc_account_cgroup_owner() is
converting the page back to a folio to call mem_cgroup_css_from_folio().
Convert wbc_account_cgroup_owner() to take a folio instead of a page,
and convert all callers to pass a folio directly except f2fs.
Convert the page to folio for all the callers from f2fs as they were the
only callers calling wbc_account_cgroup_owner() with a page. As f2fs is
already in the process of converting to folios, these call sites might
also soon be calling wbc_account_cgroup_owner() with a folio directly in
the future.
No functional changes. Only compile tested.
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Link: https://lore.kernel.org/r/20240926140121.203821-1-kernel@pankajraghav.com
Acked-by: David Sterba <dsterba@suse.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
iomap_want_unshare_iter currently sits in fs/iomap/buffered-io.c, which
depends on CONFIG_BLOCK. It is also in used in fs/dax.c whіch has no
such dependency. Given that it is a trivial check turn it into an inline
in include/linux/iomap.h to fix the DAX && !BLOCK build.
Fixes: 6ef6a0e821 ("iomap: share iomap_unshare_iter predicate code with fsdax")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20241015041350.118403-1-hch@lst.de
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
XFS (which currently is the only user of iomap_write_delalloc_release)
already holds invalidate_lock for most zeroing operations. To be able
to avoid a deadlock it needs to stop taking the lock, but doing so
in iomap would leak XFS locking details into iomap.
To avoid this require the caller to hold invalidate_lock when calling
iomap_write_delalloc_release instead of taking it there.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
Currently iomap_file_buffered_write_punch_delalloc can be called from
XFS either with the invalidate lock held or not. To fix this while
keeping the locking in the file system and not the iomap library
code we'll need to life the locking up into the file system.
To prepare for that, open code iomap_file_buffered_write_punch_delalloc
in the only caller, and instead export iomap_write_delalloc_release.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
Split out a pice of logic from iomap_file_buffered_write_punch_delalloc
that is useful for all iomap_end implementations.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
The predicate code that iomap_unshare_iter uses to decide if it's really
needs to unshare a file range mapping should be shared with the fsdax
version, because right now they're opencoded and inconsistent.
Note that we simplify the predicate logic a bit -- we no longer allow
unsharing of inline data mappings, but there aren't any filesystems that
allow shared inline data currently.
This is a fix in the sense that it should have been ported to fsdax.
Fixes: b53fdb215d ("iomap: improve shared block detection in iomap_unshare_iter")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/172796813294.1131942.15762084021076932620.stgit@frogsfrogsfrogs
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
File contents can only be shared (i.e. reflinked) below EOF, so it makes
no sense to try to unshare ranges beyond EOF. Constrain the file range
parameters here so that we don't have to do that in the callers.
Fixes: 5f4e5752a8 ("fs: add iomap_file_dirty")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20241002150213.GC21853@frogsfrogsfrogs
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
If unshare encounters a delalloc reservation in the srcmap, that means
that the file range isn't shared because delalloc reservations cannot be
reflinked. Therefore, don't try to unshare them.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20241002150040.GB21853@frogsfrogsfrogs
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZuQEvwAKCRCRxhvAZXjc
ohg3APwJWQnqFlBddcRl4yrPJ/cgcYSYAOdHb+E+blomSwdxcwEAmwsnLPNQOtw2
rxKvQfZqhVT437bl7RpPPZrHGxwTng8=
=6v1r
-----END PGP SIGNATURE-----
Merge tag 'vfs-6.12.blocksize' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs
Pull vfs blocksize updates from Christian Brauner:
"This contains the vfs infrastructure as well as the xfs bits to enable
support for block sizes (bs) larger than page sizes (ps) plus a few
fixes to related infrastructure.
There has been efforts over the last 16 years to enable enable Large
Block Sizes (LBS), that is block sizes in filesystems where bs > page
size. Through these efforts we have learned that one of the main
blockers to supporting bs > ps in filesystems has been a way to
allocate pages that are at least the filesystem block size on the page
cache where bs > ps.
Thanks to various previous efforts it is possible to support bs > ps
in XFS with only a few changes in XFS itself. Most changes are to the
page cache to support minimum order folio support for the target block
size on the filesystem.
A motivation for Large Block Sizes today is to support high-capacity
(large amount of Terabytes) QLC SSDs where the internal Indirection
Unit (IU) are typically greater than 4k to help reduce DRAM and so in
turn cost and space. In practice this then allows different
architectures to use a base page size of 4k while still enabling
support for block sizes aligned to the larger IUs by relying on high
order folios on the page cache when needed.
It also allows to take advantage of the drive's support for atomics
larger than 4k with buffered IO support in Linux. As described this
year at LSFMM, supporting large atomics greater than 4k enables
databases to remove the need to rely on their own journaling, so they
can disable double buffered writes, which is a feature different cloud
providers are already enabling through custom storage solutions"
* tag 'vfs-6.12.blocksize' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: (22 commits)
Documentation: iomap: fix a typo
iomap: remove the iomap_file_buffered_write_punch_delalloc return value
iomap: pass the iomap to the punch callback
iomap: pass flags to iomap_file_buffered_write_punch_delalloc
iomap: improve shared block detection in iomap_unshare_iter
iomap: handle a post-direct I/O invalidate race in iomap_write_delalloc_release
docs:filesystems: fix spelling and grammar mistakes in iomap design page
filemap: fix htmldoc warning for mapping_align_index()
iomap: make zero range flush conditional on unwritten mappings
iomap: fix handling of dirty folios over unwritten extents
iomap: add a private argument for iomap_file_buffered_write
iomap: remove set_memor_ro() on zero page
xfs: enable block size larger than page size support
xfs: make the calculation generic in xfs_sb_validate_fsb_count()
xfs: expose block size in stat
xfs: use kvmalloc for xattr buffers
iomap: fix iomap_dio_zero() for fs bs > system page size
filemap: cap PTE range to be created to allowed zero fill in folio_map_range()
mm: split a folio in minimum folio order chunks
readahead: allocate folios with mapping_min_order in readahead
...
iomap_file_buffered_write_punch_delalloc can only return errors if either
the ->punch callback returned an error, or if someone changed the API of
mapping_seek_hole_data to return a negative error code that is not
-ENXIO.
As the only instance of ->punch never returns an error, an such an error
would be fatal anyway remove the entire error propagation and don't
return an error code from iomap_file_buffered_write_punch_delalloc.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240910043949.3481298-6-hch@lst.de
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
XFS will need to look at the flags in the iomap structure, so pass it
down all the way to the callback.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240910043949.3481298-5-hch@lst.de
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
To fix short write error handling, We'll need to figure out what operation
iomap_file_buffered_write_punch_delalloc is called for. Pass the flags
argument on to it, and reorder the argument list to match that of
->iomap_end so that the compiler only has to add the new punch argument
to the end of it instead of reshuffling the registers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240910043949.3481298-4-hch@lst.de
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Currently iomap_unshare_iter relies on the IOMAP_F_SHARED flag to detect
blocks to unshare. This is reasonable, but IOMAP_F_SHARED is also useful
for the file system to do internal book keeping for out of place writes.
XFS used to that, until it got removed in commit 72a048c105
("xfs: only set IOMAP_F_SHARED when providing a srcmap to a write")
because unshare for incorrectly unshare such blocks.
Add an extra safeguard by checking the explicitly provided srcmap instead
of the fallback to the iomap for valid data, as that catches the case
where we'd just copy from the same place we'd write to easily, allowing
to reinstate setting IOMAP_F_SHARED for all XFS writes that go to the
COW fork.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240910043949.3481298-3-hch@lst.de
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
When direct I/O completions invalidates the page cache it holds neither the
i_rwsem nor the invalidate_lock so it can be racing with
iomap_write_delalloc_release. If the search for the end of the region that
contains data returns the start offset we hit such a race and just need to
look for the end of the newly created hole instead.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240910043949.3481298-2-hch@lst.de
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
iomap_zero_range() flushes pagecache to mitigate consistency
problems with dirty pagecache and unwritten mappings. The flush is
unconditional over the entire range because checking pagecache state
after mapping lookup is racy with writeback and reclaim. There are
ways around this using iomap's mapping revalidation mechanism, but
this is not supported by all iomap based filesystems and so is not a
generic solution.
There is another way around this limitation that is good enough to
filter the flush for most cases in practice. If we check for dirty
pagecache over the target range (instead of unconditionally flush),
we can keep track of whether the range was dirty before lookup and
defer the flush until/unless we see a combination of dirty cache
backed by an unwritten mapping. We don't necessarily know whether
the dirty cache was backed by the unwritten maping or some other
(written) part of the range, but the impliciation of a false
positive here is a spurious flush and thus relatively harmless.
Note that we also flush for hole mappings because iomap_zero_range()
is used for partial folio zeroing in some cases. For example, if a
folio straddles EOF on a sub-page FSB size fs, the post-eof portion
is hole-backed and dirtied/written via mapped write, and then i_size
increases before writeback can occur (which otherwise zeroes the
post-eof portion of the EOF folio), then the folio becomes
inconsistent with disk until reclaimed. A flush in this case
executes partial zeroing from writeback, and iomap knows that there
is otherwise no I/O to submit for hole backed mappings.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Link: https://lore.kernel.org/r/20240830145634.138439-3-bfoster@redhat.com
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
The iomap zero range implementation doesn't properly handle dirty
pagecache over unwritten mappings. It skips such mappings as if they
were pre-zeroed. If some part of an unwritten mapping is dirty in
pagecache from a previous write, the data in cache should be zeroed
as well. Instead, the data is left in cache and creates a stale data
exposure problem if writeback occurs sometime after the zero range.
Most callers are unaffected by this because the higher level
filesystem contexts that call zero range typically perform a filemap
flush of the target range for other reasons. A couple contexts that
don't otherwise need to flush are write file size extension and
truncate in XFS. The former path is currently susceptible to the
stale data exposure problem and the latter performs a flush
specifically to work around it.
This is clearly inconsistent and incomplete. As a first step toward
correcting behavior, lift the XFS workaround to iomap_zero_range()
and unconditionally flush the range before the zero range operation
proceeds. While this appears to be a bit of a big hammer, most all
users already do this from calling context save for the couple of
exceptions noted above. Future patches will optimize or elide this
flush while maintaining functional correctness.
Fixes: ae259a9c85 ("fs: introduce iomap infrastructure")
Signed-off-by: Brian Foster <bfoster@redhat.com>
Link: https://lore.kernel.org/r/20240830145634.138439-2-bfoster@redhat.com
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
In order to switch fuse over to using iomap for buffered writes we need
to be able to have the struct file for the original write, in case we
have to read in the page to make it uptodate. Handle this by using the
existing private field in the iomap_iter, and add the argument to
iomap_file_buffered_write. This will allow us to pass the file in
through the iomap buffered write path, and is flexible for any other
file systems needs.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/7f55c7c32275004ba00cddf862d970e6e633f750.1724755651.git.josef@toxicpanda.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
iomap_dio_zero() will pad a fs block with zeroes if the direct IO size
< fs block size. iomap_dio_zero() has an implicit assumption that fs block
size < page_size. This is true for most filesystems at the moment.
If the block size > page size, this will send the contents of the page
next to zero page(as len > PAGE_SIZE) to the underlying block device,
causing FS corruption.
iomap is a generic infrastructure and it should not make any assumptions
about the fs block size and the page size of the system.
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Link: https://lore.kernel.org/r/20240822135018.1931258-7-kernel@pankajraghav.com
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Daniel Gomez <da.gomez@samsung.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
All callers now have a folio, so pass it in instead of converting
from a folio to a page and back to a folio again. Saves a call
to compound_head().
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZpEHLQAKCRCRxhvAZXjc
ot3sAP9TBUM+vzUcQ5SVcUnSX+y3dhOGYnquORBbRc/Y6AzLMAEAu3TcsvdoaWfy
6ImUaju6iLqy9cCY3uDlNmJR16E4IgE=
=Bwpy
-----END PGP SIGNATURE-----
Merge tag 'vfs-6.11.iomap' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull iomap updates from Christian Brauner:
"This contains some minor work for the iomap subsystem:
- Add documentation on the design of iomap and how to port to it
- Optimize iomap_read_folio()
- Bring back the change to iomap_write_end() to no increase i_size.
This is accompanied by a change to xfs to reserve blocks for
truncating large realtime inodes to avoid exposing stale data when
iomap_write_end() stops increasing i_size"
* tag 'vfs-6.11.iomap' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
iomap: don't increase i_size in iomap_write_end()
xfs: reserve blocks for truncating large realtime inode
Documentation: the design of iomap and how to port
iomap: Optimize iomap_read_folio
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZpEGSgAKCRCRxhvAZXjc
opvwAQCBfq5sxn/P34MNheHAVJOkQlozaflLIRM/CRN60HXV3AEAiph0RJBszvDu
VhJ9VZ21zypvpS34enBfPKp1ZmyHPwI=
=hNqR
-----END PGP SIGNATURE-----
Merge tag 'vfs-6.11.pg_error' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull PG_error removal updates from Christian Brauner:
"This contains work to remove almost all remaining users of PG_error
from filesystems and filesystem helper libraries. An additional patch
will be coming in via the jfs tree which tests the PG_error bit.
Afterwards nothing will be testing it anymore and it's safe to remove
all places which set or clear the PG_error bit.
The goal is to fully remove PG_error by the next merge window"
* tag 'vfs-6.11.pg_error' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
buffer: Remove calls to set and clear the folio error flag
iomap: Remove calls to set and clear folio error flag
vboxsf: Convert vboxsf_read_folio() to use a folio
ufs: Remove call to set the folio error flag
romfs: Convert romfs_read_folio() to use a folio
reiserfs: Remove call to folio_set_error()
orangefs: Remove calls to set/clear the error flag
nfs: Remove calls to folio_set_error
jffs2: Remove calls to set/clear the folio error flag
hostfs: Convert hostfs_read_folio() to use a folio
isofs: Convert rock_ridge_symlink_read_folio to use a folio
hpfs: Convert hpfs_symlink_read_folio to use a folio
efs: Convert efs_symlink_read_folio to use a folio
cramfs: Convert cramfs_read_folio to use a folio
coda: Convert coda_symlink_filler() to use folio_end_read()
befs: Convert befs_symlink_read_folio() to use folio_end_read()
This reverts commit '0841ea4a3b41 ("iomap: keep on increasing i_size in
iomap_write_end()")'.
After xfs could zero out the tail blocks aligned to the allocation
unitsize and convert the tail blocks to unwritten for realtime inode on
truncate down, it couldn't expose any stale data when unaligned truncate
down realtime inodes, so we could keep on keeping i_size for
IOMAP_UNSHARE and IOMAP_ZERO in iomap_write_end().
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20240618142112.1315279-3-yi.zhang@huaweicloud.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
iomap_readpage_iter() handles "uptodate blocks" and "not uptodate blocks"
within a folio separately. This makes iomap_read_folio() to call into
->iomap_begin() to request for extent mapping even though it might already
have an extent which is not fully processed.
This happens when we either have a large folio or with bs < ps. In these
cases we can have sub blocks which can be uptodate (say for e.g. due to
previous writes). With iomap_read_folio_iter(), this is handled more
efficiently by not calling ->iomap_begin() call until all the sub blocks
with the current folio are processed.
iomap_read_folio_iter() handles multiple sub blocks within a given
folio but it's implementation logic is similar to how
iomap_readahead_iter() handles multiple folios within a single mapped
extent. Both of them iterate over a given range of folio/mapped extent
and call iomap_readpage_iter() for reading.
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/92ae9f3333c9a7e66214568d08f45664261c899c.1715067055.git.ritesh.list@gmail.com
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
cc: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
If the extent spans the block that contains i_size, we need to handle
both halves separately so that we properly zero data in the page cache
for blocks that are entirely outside of i_size. But this is needed only
when i_size is within the current folio under processing.
"orig_pos + length > isize" can be true for all folios if the mapped
extent length is greater than the folio size. That is making plen to
break for every folio instead of only the last folio.
So use orig_plen for checking if "orig_pos + orig_plen > isize".
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/a32e5f9a4fcfdb99077300c4020ed7ae61d6e0f9.1715067055.git.ritesh.list@gmail.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
cc: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Commit '943bc0882ceb ("iomap: don't increase i_size if it's not a write
operation")' breaks xfs with realtime device on generic/561, the problem
is when unaligned truncate down a xfs realtime inode with rtextsize > 1
fs block, xfs only zero out the EOF block but doesn't zero out the tail
blocks that aligned to rtextsize, so if we don't increase i_size in
iomap_write_end(), it could expose stale data after we do an append
write beyond the aligned EOF block.
xfs should zero out the tail blocks when truncate down, but before we
finish that, let's fix the issue by just revert the changes in
iomap_write_end().
Fixes: 943bc0882c ("iomap: don't increase i_size if it's not a write operation")
Reported-by: Chandan Babu R <chandanbabu@kernel.org>
Link: https://lore.kernel.org/linux-xfs/0b92a215-9d9b-3788-4504-a520778953c2@huaweicloud.com
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20240603112222.2109341-1-yi.zhang@huaweicloud.com
Tested-by: Chandan Babu R <chandanbabu@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
The folio error flag is not checked anywhere, so we can remove the calls
to set and clear it.
Cc: Christian Brauner <brauner@kernel.org>
Cc: linux-xfs@vger.kernel.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20240530202110.2653630-16-willy@infradead.org
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Since commit (5d8edfb900 "iomap: Copy larger chunks from userspace"),
iomap will try to copy in larger chunks than PAGE_SIZE. However, if the
mapping doesn't support large folio, only one page of maximum 4KB will
be created and 4KB data will be writen to pagecache each time. Then,
next 4KB will be handled in next iteration. This will cause potential
write performance problem.
If chunk is 2MB, total 512 pages need to be handled finally. During this
period, fault_in_iov_iter_readable() is called to check iov_iter readable
validity. Since only 4KB will be handled each time, below address space
will be checked over and over again:
start end
-
buf, buf+2MB
buf+4KB, buf+2MB
buf+8KB, buf+2MB
...
buf+2044KB buf+2MB
Obviously the checking size is wrong since only 4KB will be handled each
time. So this will get a correct chunk to let iomap work well in non-large
folio case.
With this change, the write speed will be stable. Tested on ARM64 device.
Before:
- dd if=/dev/zero of=/dev/sda bs=400K count=10485 (334 MB/s)
- dd if=/dev/zero of=/dev/sda bs=800K count=5242 (278 MB/s)
- dd if=/dev/zero of=/dev/sda bs=1600K count=2621 (204 MB/s)
- dd if=/dev/zero of=/dev/sda bs=2200K count=1906 (170 MB/s)
- dd if=/dev/zero of=/dev/sda bs=3000K count=1398 (150 MB/s)
- dd if=/dev/zero of=/dev/sda bs=4500K count=932 (139 MB/s)
After:
- dd if=/dev/zero of=/dev/sda bs=400K count=10485 (339 MB/s)
- dd if=/dev/zero of=/dev/sda bs=800K count=5242 (330 MB/s)
- dd if=/dev/zero of=/dev/sda bs=1600K count=2621 (332 MB/s)
- dd if=/dev/zero of=/dev/sda bs=2200K count=1906 (333 MB/s)
- dd if=/dev/zero of=/dev/sda bs=3000K count=1398 (333 MB/s)
- dd if=/dev/zero of=/dev/sda bs=4500K count=932 (333 MB/s)
Fixes: 5d8edfb900 ("iomap: Copy larger chunks from userspace")
Cc: stable@vger.kernel.org
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Link: https://lore.kernel.org/r/20240521114939.2541461-2-xu.yang_2@nxp.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Since iomap_write_end() can never return a partial write length, the
comparison between written, copied and bytes becomes useless, just
merge them with the unwritten branch.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20240320110548.2200662-10-yi.zhang@huaweicloud.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
For now, we can make sure iomap_write_end() always return 0 or copied
bytes, so instead of return written bytes, convert to return a boolean
to indicate the copied bytes have been written to the pagecache.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20240320110548.2200662-9-yi.zhang@huaweicloud.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
In iomap_write_iter(), the status variable used to receive the return
value from iomap_write_end() is confusing, replace it with a new written
variable to represent the written bytes in each cycle, no logic changes.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20240320110548.2200662-8-yi.zhang@huaweicloud.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Increase i_size in iomap_zero_range() and iomap_unshare_iter() is not
needed, the caller should handle it. Especially, when truncate partial
block, we should not increase i_size beyond the new EOF here. It doesn't
affect xfs and gfs2 now because they set the new file size after zero
out, it doesn't matter that a transient increase in i_size, but it will
affect ext4 because it set file size before truncate. So move the i_size
updating logic to iomap_write_iter().
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20240320110548.2200662-7-yi.zhang@huaweicloud.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Unsharing and zeroing can only happen within EOF, so there is never a
need to perform posteof pagecache truncation if write begin fails, also
partial write could never theoretically happened from iomap_write_end(),
so remove both of them.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20240320110548.2200662-6-yi.zhang@huaweicloud.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
This removes one indirect function call per folio, and adds type safety
by not casting through a void pointer.
Based on a patch by Matthew Wilcox.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240412061614.1511629-1-hch@lst.de
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZdcKwQAKCRCRxhvAZXjc
oldXAP4uzKixPvJeJmmuLs8Yl2X4g4SnxXFoLwMjCOxGSH1DWQD+Oj0nGs81lIKm
iLCZwk09JzfVEat/6KVmkjiqLLTwNgw=
=TmTQ
-----END PGP SIGNATURE-----
gpgsig -----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZeYHOAAKCRCRxhvAZXjc
opwvAP0fqxfEAS04/MNdYSf0dA5GMr8v+8RBablWtkVuOMMbRQD/RMFJKXK02afq
B4YUemRHtYETdbV69+yzninHy8y4gQQ=
=ThqF
-----END PGP SIGNATURE-----
Merge tag 'vfs-6.9.rw_hint' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs
Pull write hint fix from Christian Brauner:
UFS devices are widely used in mobile applications, e.g. in smartphones.
UFS vendors need data lifetime information to achieve good performance.
Providing data lifetime information to UFS devices can result in up to
40% lower write amplification. Hence this patch series that restores the
bi_write_hint member in struct bio. After this patch series has been
merged, patches that implement data lifetime support in the SCSI disk
(sd) driver will be sent to the Linux kernel SCSI maintainer.
The following changes are included in this patch series:
- Improvements for the F_GET_RW_HINT and F_SET_RW_HINT fcntls.
- Move enum rw_hint into a new header file.
- Support F_SET_RW_HINT for block devices to make it easy to test data
lifetime support.
- Restore the bio.bi_write_hint member and restore support in the VFS
layer and also in the block layer for data lifetime information.
The shell script that has been used to test the patch series combined
with the SCSI patches is available at the end of this cover letter.
* tag 'vfs-6.9.rw_hint' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs:
block, fs: Restore the per-bio/request data lifetime fields
fs: Propagate write hints to the struct block_device inode
fs: Move enum rw_hint into a new header file
fs: Split fcntl_rw_hint()
fs: Verify write lifetime constants at compile time
fs: Fix rw_hint validation
Signed-off-by: Christian Brauner <brauner@kernel.org>
Since commit fd07e0aa23c4 ("iomap: map multiple blocks at a time"), we
could map multi-blocks once a time, and the dirty_len indicates the
expected map length, map_len won't large than it. The pos and dirty_len
means the dirty range that should be mapped to write, add them into
trace_iomap_writepage_map() could be more useful for debug.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20240220115759.3445025-1-yi.zhang@huaweicloud.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Restore support for passing data lifetime information from filesystems to
block drivers. This patch reverts commit b179c98f76 ("block: Remove
request.write_hint") and commit c75e707fe1 ("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>
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>
The ->map_blocks interface returns a valid range for writeback, but we
still call back into it for every block, which is a bit inefficient.
Change iomap_writepage_map to use the valid range in the map until the
end of the folio or the dirty range inside the folio instead of calling
back into every block.
Note that the range is not used over folio boundaries as we need to be
able to check the mapping sequence count under the folio lock.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20231207072710.176093-14-hch@lst.de
Signed-off-by: Christian Brauner <brauner@kernel.org>
Currently the writeback code delays submitting fill ioends until we
reach the end of the folio. The reason for that is that otherwise
the end I/O handler could clear the writeback bit before we've even
finished submitting all I/O for the folio.
Add a bias to ifs->write_bytes_pending while we are submitting I/O
for a folio so that it never reaches zero until all I/O is completed
to prevent the early writeback bit clearing, and remove the now
superfluous submit_list.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20231207072710.176093-13-hch@lst.de
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Split the loop body that calls into the file system to map a block and
add it to the ioend into a separate helper to prefer for refactoring of
the surrounding code.
Note that this was the only place in iomap_writepage_map that could
return an error, so include the call to ->discard_folio into the new
helper as that will help to avoid code duplication in the future.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20231207072710.176093-12-hch@lst.de
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Instead of clling mapping_set_error once per folio, only do that once
per bio, and consolidate all the writeback error handling code in
iomap_finish_ioend.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20231207072710.176093-11-hch@lst.de
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Back in the days when a single bio could only be filled to the hardware
limits, and we scheduled a work item for each bio completion, chaining
multiple bios for a single ioend made a lot of sense to reduce the number
of completions. But these days bios can be filled until we reach the
number of vectors or total size limit, which means we can always fit at
least 1 megabyte worth of data in the worst case, but usually a lot more
due to large folios. The only thing bio chaining is buying us now is
to reduce the size of the allocation from an ioend with an embedded bio
into a plain bio, which is a 52 bytes differences on 64-bit systems.
This is not worth the added complexity, so remove the bio chaining and
only use the bio embedded into the ioend. This will help to simplify
further changes to the iomap writeback code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20231207072710.176093-10-hch@lst.de
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
