Since commit c84bf6dd2b ("mm: introduce new .mmap_prepare() file
callback"), the f_op->mmap() hook has been deprecated in favour of
f_op->mmap_prepare().
This callback is invoked in the mmap() logic far earlier, so error handling
can be performed more safely without complicated and bug-prone state
unwinding required should an error arise.
This hook also avoids passing a pointer to a not-yet-correctly-established
VMA avoiding any issues with referencing this data structure.
It rather provides a pointer to the new struct vm_area_desc descriptor type
which contains all required state and allows easy setting of required
parameters without any consideration needing to be paid to locking or
reference counts.
Note that nested filesystems like overlayfs are compatible with an
.mmap_prepare() callback since commit bb666b7c27 ("mm: add mmap_prepare()
compatibility layer for nested file systems").
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Link: https://lore.kernel.org/5abfe526032a6698fd1bcd074a74165cda7ea57c.1750099179.git.lorenzo.stoakes@oracle.com
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
This is a prerequisite for adapting those filesystems to use the
.mmap_prepare() hook for mmap()'ing which invoke this check as this hook
does not have access to a VMA pointer.
To effect this, change the signature of daxdev_mapping_supported() and
update its callers (ext4 and xfs mmap()'ing hook code).
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Link: https://lore.kernel.org/b09de1e8544384074165d92d048e80058d971286.1750099179.git.lorenzo.stoakes@oracle.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Move this API to the canonical timer_*() namespace.
[ tglx: Redone against pre rc1 ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/aB2X0jCKQO56WdMt@gmail.com
* Fast commit performance improvements
* Multi-fsblock atomic write support for bigalloc file systems
* Large folio support for regular files
This last can result in really stupendous performance for the right
workloads. For example, see [1] where the Kernel Test Robot reported
over 37% improvement on a large sequential I/O workload.
[1] https://lore.kernel.org/all/202505161418.ec0d753f-lkp@intel.com/
There are also the usual bug fixes and cleanups. Of note are cleanups
of the extent status tree to fix potential races that could result in
the extent status tree getting corrupted under heavy siulatneous
allocation and deallocation to a single file.
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Merge tag 'ext4_for_linus-6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 updates from Ted Ts'o:
"New ext4 features and performance improvements:
- Fast commit performance improvements
- Multi-fsblock atomic write support for bigalloc file systems
- Large folio support for regular files
This last can result in really stupendous performance for the right
workloads. For example, see [1] where the Kernel Test Robot reported
over 37% improvement on a large sequential I/O workload.
There are also the usual bug fixes and cleanups. Of note are cleanups
of the extent status tree to fix potential races that could result in
the extent status tree getting corrupted under heavy simultaneous
allocation and deallocation to a single file"
Link: https://lore.kernel.org/all/202505161418.ec0d753f-lkp@intel.com/ [1]
* tag 'ext4_for_linus-6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (52 commits)
ext4: Add a WARN_ON_ONCE for querying LAST_IN_LEAF instead
ext4: Simplify flags in ext4_map_query_blocks()
ext4: Rename and document EXT4_EX_FILTER to EXT4_EX_QUERY_FILTER
ext4: Simplify last in leaf check in ext4_map_query_blocks
ext4: Unwritten to written conversion requires EXT4_EX_NOCACHE
ext4: only dirty folios when data journaling regular files
ext4: Add atomic block write documentation
ext4: Enable support for ext4 multi-fsblock atomic write using bigalloc
ext4: Add multi-fsblock atomic write support with bigalloc
ext4: Add support for EXT4_GET_BLOCKS_QUERY_LEAF_BLOCKS
ext4: Make ext4_meta_trans_blocks() non-static for later use
ext4: Check if inode uses extents in ext4_inode_can_atomic_write()
ext4: Document an edge case for overwrites
jbd2: remove journal_t argument from jbd2_superblock_csum()
jbd2: remove journal_t argument from jbd2_chksum()
ext4: remove sb argument from ext4_superblock_csum()
ext4: remove sbi argument from ext4_chksum()
ext4: enable large folio for regular file
ext4: make online defragmentation support large folios
ext4: make the writeback path support large folios
...
Signed-off-by: Carlos Maiolino <cem@kernel.org>
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Merge tag 'xfs-merge-6.16' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs updates from Carlos Maiolino:
- Atomic writes for XFS
- Remove experimental warnings for pNFS, scrub and parent pointers
* tag 'xfs-merge-6.16' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (26 commits)
xfs: add inode to zone caching for data placement
xfs: free the item in xfs_mru_cache_insert on failure
xfs: remove the EXPERIMENTAL warning for pNFS
xfs: remove some EXPERIMENTAL warnings
xfs: Remove deprecated xfs_bufd sysctl parameters
xfs: stop using set_blocksize
xfs: allow sysadmins to specify a maximum atomic write limit at mount time
xfs: update atomic write limits
xfs: add xfs_calc_atomic_write_unit_max()
xfs: add xfs_file_dio_write_atomic()
xfs: commit CoW-based atomic writes atomically
xfs: add large atomic writes checks in xfs_direct_write_iomap_begin()
xfs: add xfs_atomic_write_cow_iomap_begin()
xfs: refine atomic write size check in xfs_file_write_iter()
xfs: refactor xfs_reflink_end_cow_extent()
xfs: allow block allocator to take an alignment hint
xfs: ignore HW which cannot atomic write a single block
xfs: add helpers to compute transaction reservation for finishing intent items
xfs: add helpers to compute log item overhead
xfs: separate out setting buftarg atomic writes limits
...
We added the documentation in ext4_map_blocks() for usage of
EXT4_GET_BLOCKS_QUERY_LAST_IN_LEAF flag. But It's better to add
a WARN_ON_ONCE in case if anyone tries using this flag with CREATE to
avoid a random issue later. Since depth can change with CREATE and it
needs to be re-calculated before using it in there.
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/ee6e82a224c50b432df9ce1ce3333c50182d8473.1747677758.git.ritesh.list@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Now that we have EXT4_EX_QUERY_FILTER mask, let's use that to simplify
the filtering of flags for passing to ext4_ext_map_blocks() in
ext4_map_query_blocks() function. This allows us to kill the query_flags
local variable which is not needed anymore.
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://patch.msgid.link/4ae735e83e6f43341e53e2d289e59156a8360134.1747677758.git.ritesh.list@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Rename EXT4_EX_FILTER to EXT4_EX_QUERY_FILTER to better describe its
purpose as a filter mask used specifically in ext4_map_query_blocks().
Add a comment explaining that this macro is used to filter flags needed
when querying the on-disk extent tree.
We will later use EXT4_EX_QUERY_FILTER mask to add another
EXT4_GET_BLOCKS_QUERY needed to lookup in on-disk extent tree.
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://patch.msgid.link/51f05d0ba286372eb8693af95bd4b10194b53141.1747677758.git.ritesh.list@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This fixes the atomic write patch series after it was rebased on top of
extent status cache cleanup series i.e.
'commit 402e38e6b7 ("ext4: prevent stale extent cache entries caused by
concurrent I/O writeback")'
After the above series, EXT4_GET_BLOCKS_IO_CONVERT_EXT flag which has
EXT4_GET_BLOCKS_IO_SUBMIT flag set, requires that the io submit context
of any kind should pass EXT4_EX_NOCACHE to avoid caching unncecessary
extents in the extent status cache.
This patch fixes that by adding the EXT4_EX_NOCACHE flag in
ext4_convert_unwritten_extents_atomic() for unwritten to written
conversion calls to ext4_map_blocks().
Fixes: b86629c2b2 ("ext4: Add multi-fsblock atomic write support with bigalloc")
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/ea0ad9378ff6d31d73f4e53f87548e3a20817689.1747677758.git.ritesh.list@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
fstest generic/388 occasionally reproduces a crash that looks as
follows:
BUG: kernel NULL pointer dereference, address: 0000000000000000
...
Call Trace:
<TASK>
ext4_block_zero_page_range+0x30c/0x380 [ext4]
ext4_truncate+0x436/0x440 [ext4]
ext4_process_orphan+0x5d/0x110 [ext4]
ext4_orphan_cleanup+0x124/0x4f0 [ext4]
ext4_fill_super+0x262d/0x3110 [ext4]
get_tree_bdev_flags+0x132/0x1d0
vfs_get_tree+0x26/0xd0
vfs_cmd_create+0x59/0xe0
__do_sys_fsconfig+0x4ed/0x6b0
do_syscall_64+0x82/0x170
...
This occurs when processing a symlink inode from the orphan list. The
partial block zeroing code in the truncate path calls
ext4_dirty_journalled_data() -> folio_mark_dirty(). The latter calls
mapping->a_ops->dirty_folio(), but symlink inodes are not assigned an
a_ops vector in ext4, hence the crash.
To avoid this problem, update the ext4_dirty_journalled_data() helper to
only mark the folio dirty on regular files (for which a_ops is
assigned). This also matches the journaling logic in the ext4_symlink()
creation path, where ext4_handle_dirty_metadata() is called directly.
Fixes: d84c9ebdac ("ext4: Mark pages with journalled data dirty")
Signed-off-by: Brian Foster <bfoster@redhat.com>
Link: https://patch.msgid.link/20250516173800.175577-1-bfoster@redhat.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@kernel.org
Last couple of patches added the needed support for multi-fsblock atomic
writes using bigalloc. This patch ensures that filesystem advertizes the
needed atomic write unit min and max values for enabling multi-fsblock
atomic write support with bigalloc.
Acked-by: Darrick J. Wong <djwong@kernel.org>
Co-developed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://patch.msgid.link/5e45d7ed24499024b9079436ba6698dae5298e29.1747337952.git.ritesh.list@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
EXT4 supports bigalloc feature which allows the FS to work in size of
clusters (group of blocks) rather than individual blocks. This patch
adds atomic write support for bigalloc so that systems with bs = ps can
also create FS using -
mkfs.ext4 -F -O bigalloc -b 4096 -C 16384 <dev>
With bigalloc ext4 can support multi-fsblock atomic writes. We will have to
adjust ext4's atomic write unit max value to cluster size. This can then support
atomic write of size anywhere between [blocksize, clustersize]. This
patch adds the required changes to enable multi-fsblock atomic write
support using bigalloc in the next patch.
In this patch for block allocation:
we first query the underlying region of the requested range by calling
ext4_map_blocks() call. Here are the various cases which we then handle
depending upon the underlying mapping type:
1. If the underlying region for the entire requested range is a mapped extent,
then we don't call ext4_map_blocks() to allocate anything. We don't need to
even start the jbd2 txn in this case.
2. For an append write case, we create a mapped extent.
3. If the underlying region is entirely a hole, then we create an unwritten
extent for the requested range.
4. If the underlying region is a large unwritten extent, then we split the
extent into 2 unwritten extent of required size.
5. If the underlying region has any type of mixed mapping, then we call
ext4_map_blocks() in a loop to zero out the unwritten and the hole regions
within the requested range. This then provide a single mapped extent type
mapping for the requested range.
Note: We invoke ext4_map_blocks() in a loop with the EXT4_GET_BLOCKS_ZERO
flag only when the underlying extent mapping of the requested range is
not entirely a hole, an unwritten extent, or a fully mapped extent. That
is, if the underlying region contains a mix of hole(s), unwritten
extent(s), and mapped extent(s), we use this loop to ensure that all the
short mappings are zeroed out. This guarantees that the entire requested
range becomes a single, uniformly mapped extent. It is ok to do so
because we know this is being done on a bigalloc enabled filesystem
where the block bitmap represents the entire cluster unit.
Note having a single contiguous underlying region of type mapped,
unwrittn or hole is not a problem. But the reason to avoid writing on
top of mixed mapping region is because, atomic writes requires all or
nothing should get written for the userspace pwritev2 request. So if at
any point in time during the write if a crash or a sudden poweroff
occurs, the region undergoing atomic write should read either complete
old data or complete new data. But it should never have a mix of both
old and new data.
So, we first convert any mixed mapping region to a single contiguous
mapped extent before any data gets written to it. This is because
normally FS will only convert unwritten extents to written at the end of
the write in ->end_io() call. And if we allow the writes over a mixed
mapping and if a sudden power off happens in between, we will end up
reading mix of new data (over mapped extents) and old data (over
unwritten extents), because unwritten to written conversion never went
through.
So to avoid this and to avoid writes getting torned due to mixed
mapping, we first allocate a single contiguous block mapping and then
do the write.
Acked-by: Darrick J. Wong <djwong@kernel.org>
Co-developed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://patch.msgid.link/c4965ac3407cbc773f0bc954d0966d9696f5038a.1747337952.git.ritesh.list@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
There can be a case where there are contiguous extents on the adjacent
leaf nodes of on-disk extent trees. So when someone tries to write to
this contiguous range, ext4_map_blocks() call will split by returning
1 extent at a time if this is not already cached in extent_status tree
cache (where if these extents when cached can get merged since they are
contiguous).
This is fine for a normal write however in case of atomic writes, it
can't afford to break the write into two. Now this is also something
that will only happen in the slow write case where we call
ext4_map_blocks() for each of these extents spread across different leaf
nodes. However, there is no guarantee that these extent status cache
cannot be reclaimed before the last call to ext4_map_blocks() in
ext4_map_blocks_atomic_write_slow().
Hence this patch adds support of EXT4_GET_BLOCKS_QUERY_LEAF_BLOCKS.
This flag checks if the requested range can be fully found in extent
status cache and return. If not, it looks up in on-disk extent
tree via ext4_map_query_blocks(). If the found extent is the last entry
in the leaf node, then it goes and queries the next lblk to see if there
is an adjacent contiguous extent in the adjacent leaf node of the
on-disk extent tree.
Even though there can be a case where there are multiple adjacent extent
entries spread across multiple leaf nodes. But we only read an adjacent
leaf block i.e. in total of 2 extent entries spread across 2 leaf nodes.
The reason for this is that we are mostly only going to support atomic
writes with upto 64KB or maybe max upto 1MB of atomic write support.
Acked-by: Darrick J. Wong <djwong@kernel.org>
Co-developed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://patch.msgid.link/6bb563e661f5fbd80e266a9e6ce6e29178f555f6.1747337952.git.ritesh.list@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Let's make ext4_meta_trans_blocks() non-static for use in later
functions during ->end_io conversion for atomic writes.
We will need this function to estimate journal credits for a special
case. Instead of adding another wrapper around it, let's make this
non-static.
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://patch.msgid.link/23ce80d4286f792831ce99d13558182ee228fedb.1747337952.git.ritesh.list@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
EXT4 only supports doing atomic write on inodes which uses extents, so
add a check in ext4_inode_can_atomic_write() which gets called during
open.
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://patch.msgid.link/86bb502c979398a736ab371d8f35f6866a477f6c.1747337952.git.ritesh.list@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
ext4_iomap_overwrite_begin() clears the flag for IOMAP_WRITE before
calling ext4_iomap_begin(). Document this above ext4_map_blocks() call
as it is easy to miss it when focusing on write paths alone.
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://patch.msgid.link/fd50ba05440042dff77d555e463a620a79f8d0e9.1747337952.git.ritesh.list@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Since ext4_superblock_csum() no longer uses its sb argument, remove it.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Link: https://patch.msgid.link/20250513053809.699974-3-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Since ext4_chksum() no longer uses its sbi argument, remove it.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Link: https://patch.msgid.link/20250513053809.699974-2-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Besides fsverity, fscrypt, and the data=journal mode, ext4 now supports
large folios for regular files. Enable this feature by default. However,
since we cannot change the folio order limitation of mappings on active
inodes, setting the journal=data mode via ioctl on an active inode will
not take immediate effect in non-delalloc mode.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250512063319.3539411-9-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
move_extent_per_page() currently assumes that each folio is the size of
PAGE_SIZE and only copies data for one page. ext4_move_extents() should
call move_extent_per_page() for each page. To support larger folios,
simply modify the calculations for the block start and end offsets
within the folio based on the provided range of 'data_offset_in_page'
and 'block_len_in_page'. This function will continue to handle PAGE_SIZE
of data at a time and will not convert this function to manage an entire
folio. Additionally, we use the source folio to copy data, so it doesn't
matter if the source and dest folios are different in size.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250512063319.3539411-8-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
In mpage_map_and_submit_buffers(), the 'lblk' is now aligned to
PAGE_SIZE. Convert it to be aligned to folio size. Additionally, modify
the wbc->nr_to_write update to reduce the number of pages in a single
folio, ensuring that the entire writeback path can support large folios.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250512063319.3539411-7-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The journal credits calculation in ext4_ext_index_trans_blocks() is
currently inadequate. It only multiplies the depth of the extents tree
and doesn't account for the blocks that may be required for adding the
leaf extents themselves.
After enabling large folios, we can easily run out of handle credits,
triggering a warning in jbd2_journal_dirty_metadata() on filesystems
with a 1KB block size. This occurs because we may need more extents when
iterating through each large folio in
ext4_do_writepages()->mpage_map_and_submit_extent(). Therefore, we
should modify ext4_ext_index_trans_blocks() to include a count of the
leaf extents in the worst case as well.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250512063319.3539411-6-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
jbd2_journal_blocks_per_page() returns the number of blocks in a single
page. Rename it to jbd2_journal_blocks_per_folio() and make it returns
the number of blocks in the largest folio, preparing for the calculation
of journal credits blocks when allocating blocks within a large folio in
the writeback path.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250512063319.3539411-5-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The partial block zero range helper __ext4_block_zero_page_range()
currently only supports folios of PAGE_SIZE in size. The calculations
for the start block and the offset within a folio for the given range
are incorrect. Modify the implementation to use offset_in_folio()
instead of directly masking PAGE_SIZE - 1, which will be able to support
for large folios.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250512063319.3539411-4-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The current buffered write path in ext4 can only allocate and handle
folios of PAGE_SIZE size. To support larger folios, modify
ext4_da_write_begin() and ext4_write_begin() to allocate higher-order
folios, and trim the write length if it exceeds the folio size.
Additionally, in ext4_da_do_write_end(), use offset_in_folio() instead
of PAGE_SIZE.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250512063319.3539411-3-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
ext4_mpage_readpages() currently assumes that each folio is the size of
PAGE_SIZE. Modify it to atomically calculate the number of blocks per
folio and iterate through the blocks in each folio, which would allow
for support of larger folios.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250512063319.3539411-2-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The inode i_size cannot be larger than maxbytes, check it while loading
inode from the disk.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Link: https://patch.msgid.link/20250506012009.3896990-4-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
There are several locations that get the correct maxbytes value based on
the inode's block type. It would be beneficial to extract a common
helper function to make the code more clear.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Link: https://patch.msgid.link/20250506012009.3896990-3-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
For the extents based inodes, the maxbytes should be sb->s_maxbytes
instead of sbi->s_bitmap_maxbytes. Additionally, for the calculation of
max_end, the -sb->s_blocksize operation is necessary only for
indirect-block based inodes. Correct the maxbytes and max_end value to
correct the behavior of punch hole.
Fixes: 2da376228a ("ext4: limit length to bitmap_maxbytes - blocksize in punch_hole")
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Link: https://patch.msgid.link/20250506012009.3896990-2-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Use writeback_iter directly instead of write_cache_pages for a nicer
code structure and less indirect calls.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250505091604.3449879-1-hch@lst.de
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Luis and David are reporting that after running generic/750 test for 90+
hours on 2k ext4 filesystem, they are able to trigger a warning in
jbd2_journal_dirty_metadata() complaining that there are not enough
credits in the running transaction started in ext4_do_writepages().
Indeed the code in ext4_do_writepages() is racy and the extent tree can
change between the time we compute credits necessary for extent tree
computation and the time we actually modify the extent tree. Thus it may
happen that the number of credits actually needed is higher. Modify
ext4_ext_index_trans_blocks() to count with the worst case of maximum
tree depth. This can reduce the possible number of writers that can
operate in the system in parallel (because the credit estimates now won't
fit in one transaction) but for reasonably sized journals this shouldn't
really be an issue. So just go with a safe and simple fix.
Link: https://lore.kernel.org/all/20250415013641.f2ppw6wov4kn4wq2@offworld
Reported-by: Davidlohr Bueso <dave@stgolabs.net>
Reported-by: Luis Chamberlain <mcgrof@kernel.org>
Tested-by: kdevops@lists.linux.dev
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250429175535.23125-2-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
check_igot_inode() prints a variable string, which causes a harmless
warning with 'make W=1':
fs/ext4/inode.c:4763:45: error: format string is not a string literal (potentially insecure) [-Werror,-Wformat-security]
4763 | ext4_error_inode(inode, function, line, 0, err_str);
Use a trivial "%s" format string instead.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20250423164354.2780635-1-arnd@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Add a comment at the beginning of extents_status.c to clarify the rules
for loading, mapping, modifying, and removing extents and blocks.
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250423085257.122685-10-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Add ext4_check_map_extents_env() to the places where loading extents,
mapping blocks, removing blocks, and modifying extents, excluding the
I/O writeback context. This function will verify whether the locking
mechanisms in place are adequate.
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250423085257.122685-9-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Loading and modifying the extents tree and extent status tree without
holding the inode's i_rwsem or the mapping's invalidate_lock is not
permitted, except during the I/O writeback. Add a new debug helper
ext4_check_map_extents_env(), it will verify whether the extent
loading/modifying context is safe.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250423085257.122685-8-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The EXT4_IOC_GET_ES_CACHE and EXT4_IOC_PRECACHE_EXTENTS currently
invokes ext4_ext_precache() to preload the extent cache without holding
the inode's i_rwsem. This can result in stale extent cache entries when
competing with operations such as ext4_collapse_range() which calls
ext4_ext_remove_space() or ext4_ext_shift_extents().
The problem arises when ext4_ext_remove_space() temporarily releases
i_data_sem due to insufficient journal credits. During this interval, a
concurrent EXT4_IOC_GET_ES_CACHE or EXT4_IOC_PRECACHE_EXTENTS may cache
extent entries that are about to be deleted. As a result, these cached
entries become stale and inconsistent with the actual extents.
Loading the extents cache without holding the inode's i_rwsem or the
mapping's invalidate_lock is not permitted besides during the writeback.
Fix this by holding the i_rwsem during EXT4_IOC_GET_ES_CACHE and
EXT4_IOC_PRECACHE_EXTENTS.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250423085257.122685-6-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The ext4_fiemap() currently invokes ext4_ext_precache() and
iomap_fiemap() to preload the extent cache and query mapping information
without holding the inode's i_rwsem. This can result in stale extent
cache entries when competing with operations such as
ext4_collapse_range() which calls ext4_ext_remove_space() or
ext4_ext_shift_extents().
The problem arises when ext4_ext_remove_space() temporarily releases
i_data_sem due to insufficient journal credits. During this interval, a
concurrent ext4_fiemap() may cache extent entries that are about to be
deleted. As a result, these cached entries become stale and inconsistent
with the actual extents.
Loading the extents cache without holding the inode's i_rwsem or the
mapping's invalidate_lock is not permitted besides during the writeback.
Fix this by holding the i_rwsem in ext4_fiemap().
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250423085257.122685-5-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Currently, in the I/O writeback path, ext4_map_blocks() may attempt to
cache additional unrelated extents in the extent status tree without
holding the inode's i_rwsem and the mapping's invalidate_lock. This can
lead to stale extent status entries remaining in certain scenarios,
potentially causing data corruption.
For example, when performing a collapse range in ext4_collapse_range(),
it clears the extent cache and dirty pages before removing blocks and
shifting extents. It also holds the i_data_sem during these two
operations. However, both ext4_ext_remove_space() and
ext4_ext_shift_extents() may briefly release the i_data_sem if journal
credits are insufficient (ext4_datasem_ensure_credits()). If another
writeback process writes dirty pages from other regions during this
interval, it may cache extents that are about to be modified. Unless
ext4_collapse_range() explicitly clears the extent cache again, these
cached entries can become stale and inconsistent with the actual
extents.
0 a n b c m
| | | | | |
[www][wwwwww][wwwwwwww]...[wwwww][wwww]...
| |
N M
Assume that block a is dirty. The collapse range operation is removing
data from n to m and drops i_data_sem immediately after removing the
extent from b to c. At the same time, a concurrent writeback begins to
write back block a; it will reloads the extent from [n, b) into the
extent status tree since it does not hold the i_rwsem or the
invalidate_lock. After the collapse range operation, it left the stale
extent [n, b), which points logical block n to N, but the actual
physical block of n should be M.
Similarly, both ext4_insert_range() and ext4_truncate() have the same
problem. ext4_punch_hole() survived since it re-add a hole extent entry
after removing space since commit 9f1118223a ("ext4: add a hole extent
entry in cache after punch").
In most cases, during dirty page writeback, the block mapping
information is likely to be found in the extent cache, making it less
necessary to search for physical extents. Consequently, loading
unrelated extent caches during writeback appears to be ineffective.
Therefore, fix this by adds EXT4_EX_NOCACHE in the writeback path to
prevent caching of unrelated extents, eliminating this potential source
of corruption.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250423085257.122685-4-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Currently, the EXT4_GET_BLOCKS_IO_SUBMIT flag is only used during data
writeback to indicate that in ordered mode, the journal commit thread
should skip re-submitting data and simply wait for I/O completion.
To prepare for later patches that need to detect I/O submission context
in ext4_map_blocks(), generalizes the meaning of
EXT4_GET_BLOCKS_IO_SUBMIT. This flag will be set during:
1) data I/O writeback,
2) I/O completion extents conversion,
3) journal performing commit in fast_commit.
This change doesn't affect current usage of this flag and provides a
clear way to identify I/O submission context.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250423085257.122685-3-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
When removing space, we should use EXT4_EX_NOCACHE because we don't
need to cache extents, and we should also use EXT4_EX_NOFAIL to prevent
metadata inconsistencies that may arise from memory allocation failures.
While ext4_ext_remove_space() already uses these two flags in most
places, they are missing in ext4_ext_search_right() and
read_extent_tree_block() calls. Unify the flags to ensure consistent
behavior throughout the extent removal process.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250423085257.122685-2-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Leaving s_fc_lock in between during commit in ext4_fc_perform_commit()
function leaves room for subtle concurrency bugs where ext4_fc_del() may
delete an inode from the fast commit list, leaving list in an inconsistent
state.
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20250508175908.1004880-10-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This allows us to hold s_fc_lock during kmem_cache_* functions, which
is needed in the following patch.
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20250508175908.1004880-9-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Unlike JBD2 based full commits, there is no dedicated journal thread
for fast commits. Thus to reduce scheduling delays between IO
submission and completion, temporarily elevate the committer thread's
priority to match the configured priority of the JBD2 journal
thread.
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20250508175908.1004880-8-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This patch updates code documentation to reflect the commit path changes
made in this series.
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
code docs
Link: https://patch.msgid.link/20250508175908.1004880-7-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The new logic introduced in this series does not require tracking number
of active handles open on an inode. So, drop it.
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20250508175908.1004880-6-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This patch reworks fast commit's commit path to remove locking the
journal for the entire duration of a fast commit. Instead, we only lock
the journal while marking all the eligible inodes as "committing". This
allows handles to make progress in parallel with the fast commit.
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://patch.msgid.link/20250508175908.1004880-5-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
If the inode that's being requested to track using ext4_fc_track_inode
is being committed, then wait until the inode finishes the
commit. Also, add calls to ext4_fc_track_inode at the right places.
With this patch, now calling ext4_reserve_inode_write() results in
inode being tracked for next fast commit. This ensures that by the
time ext4_reserve_inode_write() returns, it is ready to be modified
and won't be committed until the corresponding handle is open.
A subtle lock ordering requirement with i_data_sem (which is
documented in the code) requires that ext4_fc_track_inode() be called
before grabbing i_data_sem. So, this patch also adds explicit
ext4_fc_track_inode() calls in places where i_data_sem grabbed.
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://patch.msgid.link/20250508175908.1004880-3-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Convert ext4_inode_info->i_fc_lock to spinlock to avoid sleeping
in invalid contexts.
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://patch.msgid.link/20250508175908.1004880-2-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
XFS will be able to support large atomic writes (atomic write > 1x block)
in future. This will be achieved by using different operating methods,
depending on the size of the write.
Specifically a new method of operation based in FS atomic extent remapping
will be supported in addition to the current HW offload-based method.
The FS method will generally be appreciably slower performing than the
HW-offload method. However the FS method will be typically able to
contribute to achieving a larger atomic write unit max limit.
XFS will support a hybrid mode, where HW offload method will be used when
possible, i.e. HW offload is used when the length of the write is
supported, and for other times FS-based atomic writes will be used.
As such, there is an atomic write length at which the user may experience
appreciably slower performance.
Advertise this limit in a new statx field, stx_atomic_write_unit_max_opt.
When zero, it means that there is no such performance boundary.
Masks STATX{_ATTR}_WRITE_ATOMIC can be used to get this new field. This is
ok for older kernels which don't support this new field, as they would
report 0 in this field (from zeroing in cp_statx()) already. Furthermore
those older kernels don't support large atomic writes - apart from block
fops, but there would be consistent performance there for atomic writes
in range [unit min, unit max].
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: John Garry <john.g.garry@oracle.com>
The large folio + buffer head noref migration scenarios are
being naughty and blocking while holding a spinlock.
As a consequence of the pagecache lookup path taking the
folio lock this serializes against migration paths, so
they can wait for each other. For the private_lock
atomic case, a new BH_Migrate flag is introduced which
enables the lookup to bail.
This allows the critical region of the private_lock on
the migration path to be reduced to the way it was before
ebdf4de564 ("mm: migrate: fix reference check race
between __find_get_block() and migration"), that is covering
the count checks.
The scope is always noref migration.
Reported-by: kernel test robot <oliver.sang@intel.com>
Reported-by: syzbot+f3c6fda1297c748a7076@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/oe-lkp/202503101536.27099c77-lkp@intel.com
Fixes: 3c20917120 ("block/bdev: enable large folio support for large logical block sizes")
Reviewed-by: Jan Kara <jack@suse.cz>
Co-developed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Link: https://kdevops.org/ext4/v6.15-rc2.html # [0]
Link: https://lore.kernel.org/all/aAAEvcrmREWa1SKF@bombadil.infradead.org/ # [1]
Link: https://lore.kernel.org/20250418015921.132400-8-dave@stgolabs.net
Tested-by: kdevops@lists.linux.dev # [0] [1]
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
syzbot failures and fixing a stale file handing refeencing an inode
previously used as a regular file, but which has been deleted and
reused as an ea_inode would result in ext4 erroneously consider this a
case of fs corrupotion.
-----BEGIN PGP SIGNATURE-----
iQEzBAABCAAdFiEEK2m5VNv+CHkogTfJ8vlZVpUNgaMFAmf7r3YACgkQ8vlZVpUN
gaPl9QgApwE5BAQdO6miW0sDMPj5b4sMc25aG4OPlfKhFqiIJB0Ub4zC2n0OFnaf
HXk8P5oVeepH9ciTnYFF30X20Ythzjwmd9j5eyq2wsfYASQUjfcvmR9WovbqZtGQ
3Zerd9QFp7SvZa+K4sADBhEb/7HAnxDGfiqSQptY6WQTwD+it1bnuhmzG0m6AH4m
R1ItREDx7D2QrudDToFBd8XQ+FgRETZ8Qrs7PqIznw/dBNMdHRnAiw2eiyuoPU/S
T8cmCxii3Z9sJ6LtohKYuWOmOmdxg951V5ZcekVRuaFSljSUsRsIplO7OlaMvQDs
9vGVKiiZLdU2B0Wd90IeQUdJmP4xPg==
=I8qx
-----END PGP SIGNATURE-----
Merge tag 'ext4_for_linus-6.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 fixes from Ted Ts'o:
"A few more miscellaneous ext4 bug fixes and cleanups including some
syzbot failures and fixing a stale file handing refeencing an inode
previously used as a regular file, but which has been deleted and
reused as an ea_inode would result in ext4 erroneously considering
this a case of fs corruption"
* tag 'ext4_for_linus-6.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: fix off-by-one error in do_split
ext4: make block validity check resistent to sb bh corruption
ext4: avoid -Wflex-array-member-not-at-end warning
Documentation: ext4: Add fields to ext4_super_block documentation
ext4: don't treat fhandle lookup of ea_inode as FS corruption
Syzkaller detected a use-after-free issue in ext4_insert_dentry that was
caused by out-of-bounds access due to incorrect splitting in do_split.
BUG: KASAN: use-after-free in ext4_insert_dentry+0x36a/0x6d0 fs/ext4/namei.c:2109
Write of size 251 at addr ffff888074572f14 by task syz-executor335/5847
CPU: 0 UID: 0 PID: 5847 Comm: syz-executor335 Not tainted 6.12.0-rc6-syzkaller-00318-ga9cda7c0ffed #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:377 [inline]
print_report+0x169/0x550 mm/kasan/report.c:488
kasan_report+0x143/0x180 mm/kasan/report.c:601
kasan_check_range+0x282/0x290 mm/kasan/generic.c:189
__asan_memcpy+0x40/0x70 mm/kasan/shadow.c:106
ext4_insert_dentry+0x36a/0x6d0 fs/ext4/namei.c:2109
add_dirent_to_buf+0x3d9/0x750 fs/ext4/namei.c:2154
make_indexed_dir+0xf98/0x1600 fs/ext4/namei.c:2351
ext4_add_entry+0x222a/0x25d0 fs/ext4/namei.c:2455
ext4_add_nondir+0x8d/0x290 fs/ext4/namei.c:2796
ext4_symlink+0x920/0xb50 fs/ext4/namei.c:3431
vfs_symlink+0x137/0x2e0 fs/namei.c:4615
do_symlinkat+0x222/0x3a0 fs/namei.c:4641
__do_sys_symlink fs/namei.c:4662 [inline]
__se_sys_symlink fs/namei.c:4660 [inline]
__x64_sys_symlink+0x7a/0x90 fs/namei.c:4660
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
</TASK>
The following loop is located right above 'if' statement.
for (i = count-1; i >= 0; i--) {
/* is more than half of this entry in 2nd half of the block? */
if (size + map[i].size/2 > blocksize/2)
break;
size += map[i].size;
move++;
}
'i' in this case could go down to -1, in which case sum of active entries
wouldn't exceed half the block size, but previous behaviour would also do
split in half if sum would exceed at the very last block, which in case of
having too many long name files in a single block could lead to
out-of-bounds access and following use-after-free.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
Cc: stable@vger.kernel.org
Fixes: 5872331b3d ("ext4: fix potential negative array index in do_split()")
Signed-off-by: Artem Sadovnikov <a.sadovnikov@ispras.ru>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20250404082804.2567-3-a.sadovnikov@ispras.ru
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Block validity checks need to be skipped in case they are called
for journal blocks since they are part of system's protected
zone.
Currently, this is done by checking inode->ino against
sbi->s_es->s_journal_inum, which is a direct read from the ext4 sb
buffer head. If someone modifies this underneath us then the
s_journal_inum field might get corrupted. To prevent against this,
change the check to directly compare the inode with journal->j_inode.
**Slight change in behavior**: During journal init path,
check_block_validity etc might be called for journal inode when
sbi->s_journal is not set yet. In this case we now proceed with
ext4_inode_block_valid() instead of returning early. Since systems zones
have not been set yet, it is okay to proceed so we can perform basic
checks on the blocks.
Suggested-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/0c06bc9ebfcd6ccfed84a36e79147bf45ff5adc1.1743142920.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
-Wflex-array-member-not-at-end was introduced in GCC-14, and we are
getting ready to enable it, globally.
Use the `DEFINE_RAW_FLEX()` helper for an on-stack definition of
a flexible structure where the size of the flexible-array member
is known at compile-time, and refactor the rest of the code,
accordingly.
So, with these changes, fix the following warning:
fs/ext4/mballoc.c:3041:40: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Link: https://patch.msgid.link/Z-SF97N3AxcIMlSi@kspp
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
A file handle that userspace provides to open_by_handle_at() can
legitimately contain an outdated inode number that has since been reused
for another purpose - that's why the file handle also contains a generation
number.
But if the inode number has been reused for an ea_inode, check_igot_inode()
will notice, __ext4_iget() will go through ext4_error_inode(), and if the
inode was newly created, it will also be marked as bad by iget_failed().
This all happens before the point where the inode generation is checked.
ext4_error_inode() is supposed to only be used on filesystem corruption; it
should not be used when userspace just got unlucky with a stale file
handle. So when this happens, let __ext4_iget() just return an error.
Fixes: b3e6bcb945 ("ext4: add EA_INODE checking to ext4_iget()")
Signed-off-by: Jann Horn <jannh@google.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20241129-ext4-ignore-ea-fhandle-v1-1-e532c0d1cee0@google.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree
over and remove the historical wrapper inlines.
Conversion was done with coccinelle plus manual fixups where necessary.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Uros Bizjak uses x86 named address space qualifiers to provide
compile-time checking of percpu area accesses.
This has caused a small amount of fallout - two or three issues were
reported. In all cases the calling code was founf to be incorrect.
- The 4 patch series "Some cleanup for memcg" from Chen Ridong
implements some relatively monir cleanups for the memcontrol code.
- The 17 patch series "mm: fixes for device-exclusive entries (hmm)"
from David Hildenbrand fixes a boatload of issues which David found then
using device-exclusive PTE entries when THP is enabled. More work is
needed, but this makes thins better - our own HMM selftests now succeed.
- The 2 patch series "mm: zswap: remove z3fold and zbud" from Yosry
Ahmed remove the z3fold and zbud implementations. They have been
deprecated for half a year and nobody has complained.
- The 5 patch series "mm: further simplify VMA merge operation" from
Lorenzo Stoakes implements numerous simplifications in this area. No
runtime effects are anticipated.
- The 4 patch series "mm/madvise: remove redundant mmap_lock operations
from process_madvise()" from SeongJae Park rationalizes the locking in
the madvise() implementation. Performance gains of 20-25% were observed
in one MADV_DONTNEED microbenchmark.
- The 12 patch series "Tiny cleanup and improvements about SWAP code"
from Baoquan He contains a number of touchups to issues which Baoquan
noticed when working on the swap code.
- The 2 patch series "mm: kmemleak: Usability improvements" from Catalin
Marinas implements a couple of improvements to the kmemleak user-visible
output.
- The 2 patch series "mm/damon/paddr: fix large folios access and
schemes handling" from Usama Arif provides a couple of fixes for DAMON's
handling of large folios.
- The 3 patch series "mm/damon/core: fix wrong and/or useless
damos_walk() behaviors" from SeongJae Park fixes a few issues with the
accuracy of kdamond's walking of DAMON regions.
- The 3 patch series "expose mapping wrprotect, fix fb_defio use" from
Lorenzo Stoakes changes the interaction between framebuffer deferred-io
and core MM. No functional changes are anticipated - this is
preparatory work for the future removal of page structure fields.
- The 4 patch series "mm/damon: add support for hugepage_size DAMOS
filter" from Usama Arif adds a DAMOS filter which permits the filtering
by huge page sizes.
- The 4 patch series "mm: permit guard regions for file-backed/shmem
mappings" from Lorenzo Stoakes extends the guard region feature from its
present "anon mappings only" state. The feature now covers shmem and
file-backed mappings.
- The 4 patch series "mm: batched unmap lazyfree large folios during
reclamation" from Barry Song cleans up and speeds up the unmapping for
pte-mapped large folios.
- The 18 patch series "reimplement per-vma lock as a refcount" from
Suren Baghdasaryan puts the vm_lock back into the vma. Our reasons for
pulling it out were largely bogus and that change made the code more
messy. This patchset provides small (0-10%) improvements on one
microbenchmark.
- The 5 patch series "Docs/mm/damon: misc DAMOS filters documentation
fixes and improves" from SeongJae Park does some maintenance work on the
DAMON docs.
- The 27 patch series "hugetlb/CMA improvements for large systems" from
Frank van der Linden addresses a pile of issues which have been observed
when using CMA on large machines.
- The 2 patch series "mm/damon: introduce DAMOS filter type for unmapped
pages" from SeongJae Park enables users of DMAON/DAMOS to filter my the
page's mapped/unmapped status.
- The 19 patch series "zsmalloc/zram: there be preemption" from Sergey
Senozhatsky teaches zram to run its compression and decompression
operations preemptibly.
- The 12 patch series "selftests/mm: Some cleanups from trying to run
them" from Brendan Jackman fixes a pile of unrelated issues which
Brendan encountered while runnimg our selftests.
- The 2 patch series "fs/proc/task_mmu: add guard region bit to pagemap"
from Lorenzo Stoakes permits userspace to use /proc/pid/pagemap to
determine whether a particular page is a guard page.
- The 7 patch series "mm, swap: remove swap slot cache" from Kairui Song
removes the swap slot cache from the allocation path - it simply wasn't
being effective.
- The 5 patch series "mm: cleanups for device-exclusive entries (hmm)"
from David Hildenbrand implements a number of unrelated cleanups in this
code.
- The 5 patch series "mm: Rework generic PTDUMP configs" from Anshuman
Khandual implements a number of preparatoty cleanups to the
GENERIC_PTDUMP Kconfig logic.
- The 8 patch series "mm/damon: auto-tune aggregation interval" from
SeongJae Park implements a feedback-driven automatic tuning feature for
DAMON's aggregation interval tuning.
- The 5 patch series "Fix lazy mmu mode" from Ryan Roberts fixes some
issues in powerpc, sparc and x86 lazy MMU implementations. Ryan did
this in preparation for implementing lazy mmu mode for arm64 to optimize
vmalloc.
- The 2 patch series "mm/page_alloc: Some clarifications for migratetype
fallback" from Brendan Jackman reworks some commentary to make the code
easier to follow.
- The 3 patch series "page_counter cleanup and size reduction" from
Shakeel Butt cleans up the page_counter code and fixes a size increase
which we accidentally added late last year.
- The 3 patch series "Add a command line option that enables control of
how many threads should be used to allocate huge pages" from Thomas
Prescher does that. It allows the careful operator to significantly
reduce boot time by tuning the parallalization of huge page
initialization.
- The 3 patch series "Fix calculations in trace_balance_dirty_pages()
for cgwb" from Tang Yizhou fixes the tracing output from the dirty page
balancing code.
- The 9 patch series "mm/damon: make allow filters after reject filters
useful and intuitive" from SeongJae Park improves the handling of allow
and reject filters. Behaviour is made more consistent and the
documention is updated accordingly.
- The 5 patch series "Switch zswap to object read/write APIs" from Yosry
Ahmed updates zswap to the new object read/write APIs and thus permits
the removal of some legacy code from zpool and zsmalloc.
- The 6 patch series "Some trivial cleanups for shmem" from Baolin Wang
does as it claims.
- The 20 patch series "fs/dax: Fix ZONE_DEVICE page reference counts"
from Alistair Popple regularizes the weird ZONE_DEVICE page refcount
handling in DAX, permittig the removal of a number of special-case
checks.
- The 4 patch series "refactor mremap and fix bug" from Lorenzo Stoakes
is a preparatoty refactoring and cleanup of the mremap() code.
- The 20 patch series "mm: MM owner tracking for large folios (!hugetlb)
+ CONFIG_NO_PAGE_MAPCOUNT" from David Hildenbrand reworks the manner in
which we determine whether a large folio is known to be mapped
exclusively into a single MM.
- The 8 patch series "mm/damon: add sysfs dirs for managing DAMOS
filters based on handling layers" from SeongJae Park adds a couple of
new sysfs directories to ease the management of DAMON/DAMOS filters.
- The 13 patch series "arch, mm: reduce code duplication in mem_init()"
from Mike Rapoport consolidates many per-arch implementations of
mem_init() into code generic code, where that is practical.
- The 13 patch series "mm/damon/sysfs: commit parameters online via
damon_call()" from SeongJae Park continues the cleaning up of sysfs
access to DAMON internal data.
- The 3 patch series "mm: page_ext: Introduce new iteration API" from
Luiz Capitulino reworks the page_ext initialization to fix a boot-time
crash which was observed with an unusual combination of compile and
cmdline options.
- The 8 patch series "Buddy allocator like (or non-uniform) folio split"
from Zi Yan reworks the code to split a folio into smaller folios. The
main benefit is lessened memory consumption: fewer post-split folios are
generated.
- The 2 patch series "Minimize xa_node allocation during xarry split"
from Zi Yan reduces the number of xarray xa_nodes which are generated
during an xarray split.
- The 2 patch series "drivers/base/memory: Two cleanups" from Gavin Shan
performs some maintenance work on the drivers/base/memory code.
- The 3 patch series "Add tracepoints for lowmem reserves, watermarks
and totalreserve_pages" from Martin Liu adds some more tracepoints to
the page allocator code.
- The 4 patch series "mm/madvise: cleanup requests validations and
classifications" from SeongJae Park cleans up some warts which SeongJae
observed during his earlier madvise work.
- The 3 patch series "mm/hwpoison: Fix regressions in memory failure
handling" from Shuai Xue addresses two quite serious regressions which
Shuai has observed in the memory-failure implementation.
- The 5 patch series "mm: reliable huge page allocator" from Johannes
Weiner makes huge page allocations cheaper and more reliable by reducing
fragmentation.
- The 5 patch series "Minor memcg cleanups & prep for memdescs" from
Matthew Wilcox is preparatory work for the future implementation of
memdescs.
- The 4 patch series "track memory used by balloon drivers" from Nico
Pache introduces a way to track memory used by our various balloon
drivers.
- The 2 patch series "mm/damon: introduce DAMOS filter type for active
pages" from Nhat Pham permits users to filter for active/inactive pages,
separately for file and anon pages.
- The 2 patch series "Adding Proactive Memory Reclaim Statistics" from
Hao Jia separates the proactive reclaim statistics from the direct
reclaim statistics.
- The 2 patch series "mm/vmscan: don't try to reclaim hwpoison folio"
from Jinjiang Tu fixes our handling of hwpoisoned pages within the
reclaim code.
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Merge tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- The series "Enable strict percpu address space checks" from Uros
Bizjak uses x86 named address space qualifiers to provide
compile-time checking of percpu area accesses.
This has caused a small amount of fallout - two or three issues were
reported. In all cases the calling code was found to be incorrect.
- The series "Some cleanup for memcg" from Chen Ridong implements some
relatively monir cleanups for the memcontrol code.
- The series "mm: fixes for device-exclusive entries (hmm)" from David
Hildenbrand fixes a boatload of issues which David found then using
device-exclusive PTE entries when THP is enabled. More work is
needed, but this makes thins better - our own HMM selftests now
succeed.
- The series "mm: zswap: remove z3fold and zbud" from Yosry Ahmed
remove the z3fold and zbud implementations. They have been deprecated
for half a year and nobody has complained.
- The series "mm: further simplify VMA merge operation" from Lorenzo
Stoakes implements numerous simplifications in this area. No runtime
effects are anticipated.
- The series "mm/madvise: remove redundant mmap_lock operations from
process_madvise()" from SeongJae Park rationalizes the locking in the
madvise() implementation. Performance gains of 20-25% were observed
in one MADV_DONTNEED microbenchmark.
- The series "Tiny cleanup and improvements about SWAP code" from
Baoquan He contains a number of touchups to issues which Baoquan
noticed when working on the swap code.
- The series "mm: kmemleak: Usability improvements" from Catalin
Marinas implements a couple of improvements to the kmemleak
user-visible output.
- The series "mm/damon/paddr: fix large folios access and schemes
handling" from Usama Arif provides a couple of fixes for DAMON's
handling of large folios.
- The series "mm/damon/core: fix wrong and/or useless damos_walk()
behaviors" from SeongJae Park fixes a few issues with the accuracy of
kdamond's walking of DAMON regions.
- The series "expose mapping wrprotect, fix fb_defio use" from Lorenzo
Stoakes changes the interaction between framebuffer deferred-io and
core MM. No functional changes are anticipated - this is preparatory
work for the future removal of page structure fields.
- The series "mm/damon: add support for hugepage_size DAMOS filter"
from Usama Arif adds a DAMOS filter which permits the filtering by
huge page sizes.
- The series "mm: permit guard regions for file-backed/shmem mappings"
from Lorenzo Stoakes extends the guard region feature from its
present "anon mappings only" state. The feature now covers shmem and
file-backed mappings.
- The series "mm: batched unmap lazyfree large folios during
reclamation" from Barry Song cleans up and speeds up the unmapping
for pte-mapped large folios.
- The series "reimplement per-vma lock as a refcount" from Suren
Baghdasaryan puts the vm_lock back into the vma. Our reasons for
pulling it out were largely bogus and that change made the code more
messy. This patchset provides small (0-10%) improvements on one
microbenchmark.
- The series "Docs/mm/damon: misc DAMOS filters documentation fixes and
improves" from SeongJae Park does some maintenance work on the DAMON
docs.
- The series "hugetlb/CMA improvements for large systems" from Frank
van der Linden addresses a pile of issues which have been observed
when using CMA on large machines.
- The series "mm/damon: introduce DAMOS filter type for unmapped pages"
from SeongJae Park enables users of DMAON/DAMOS to filter my the
page's mapped/unmapped status.
- The series "zsmalloc/zram: there be preemption" from Sergey
Senozhatsky teaches zram to run its compression and decompression
operations preemptibly.
- The series "selftests/mm: Some cleanups from trying to run them" from
Brendan Jackman fixes a pile of unrelated issues which Brendan
encountered while runnimg our selftests.
- The series "fs/proc/task_mmu: add guard region bit to pagemap" from
Lorenzo Stoakes permits userspace to use /proc/pid/pagemap to
determine whether a particular page is a guard page.
- The series "mm, swap: remove swap slot cache" from Kairui Song
removes the swap slot cache from the allocation path - it simply
wasn't being effective.
- The series "mm: cleanups for device-exclusive entries (hmm)" from
David Hildenbrand implements a number of unrelated cleanups in this
code.
- The series "mm: Rework generic PTDUMP configs" from Anshuman Khandual
implements a number of preparatoty cleanups to the GENERIC_PTDUMP
Kconfig logic.
- The series "mm/damon: auto-tune aggregation interval" from SeongJae
Park implements a feedback-driven automatic tuning feature for
DAMON's aggregation interval tuning.
- The series "Fix lazy mmu mode" from Ryan Roberts fixes some issues in
powerpc, sparc and x86 lazy MMU implementations. Ryan did this in
preparation for implementing lazy mmu mode for arm64 to optimize
vmalloc.
- The series "mm/page_alloc: Some clarifications for migratetype
fallback" from Brendan Jackman reworks some commentary to make the
code easier to follow.
- The series "page_counter cleanup and size reduction" from Shakeel
Butt cleans up the page_counter code and fixes a size increase which
we accidentally added late last year.
- The series "Add a command line option that enables control of how
many threads should be used to allocate huge pages" from Thomas
Prescher does that. It allows the careful operator to significantly
reduce boot time by tuning the parallalization of huge page
initialization.
- The series "Fix calculations in trace_balance_dirty_pages() for cgwb"
from Tang Yizhou fixes the tracing output from the dirty page
balancing code.
- The series "mm/damon: make allow filters after reject filters useful
and intuitive" from SeongJae Park improves the handling of allow and
reject filters. Behaviour is made more consistent and the documention
is updated accordingly.
- The series "Switch zswap to object read/write APIs" from Yosry Ahmed
updates zswap to the new object read/write APIs and thus permits the
removal of some legacy code from zpool and zsmalloc.
- The series "Some trivial cleanups for shmem" from Baolin Wang does as
it claims.
- The series "fs/dax: Fix ZONE_DEVICE page reference counts" from
Alistair Popple regularizes the weird ZONE_DEVICE page refcount
handling in DAX, permittig the removal of a number of special-case
checks.
- The series "refactor mremap and fix bug" from Lorenzo Stoakes is a
preparatoty refactoring and cleanup of the mremap() code.
- The series "mm: MM owner tracking for large folios (!hugetlb) +
CONFIG_NO_PAGE_MAPCOUNT" from David Hildenbrand reworks the manner in
which we determine whether a large folio is known to be mapped
exclusively into a single MM.
- The series "mm/damon: add sysfs dirs for managing DAMOS filters based
on handling layers" from SeongJae Park adds a couple of new sysfs
directories to ease the management of DAMON/DAMOS filters.
- The series "arch, mm: reduce code duplication in mem_init()" from
Mike Rapoport consolidates many per-arch implementations of
mem_init() into code generic code, where that is practical.
- The series "mm/damon/sysfs: commit parameters online via
damon_call()" from SeongJae Park continues the cleaning up of sysfs
access to DAMON internal data.
- The series "mm: page_ext: Introduce new iteration API" from Luiz
Capitulino reworks the page_ext initialization to fix a boot-time
crash which was observed with an unusual combination of compile and
cmdline options.
- The series "Buddy allocator like (or non-uniform) folio split" from
Zi Yan reworks the code to split a folio into smaller folios. The
main benefit is lessened memory consumption: fewer post-split folios
are generated.
- The series "Minimize xa_node allocation during xarry split" from Zi
Yan reduces the number of xarray xa_nodes which are generated during
an xarray split.
- The series "drivers/base/memory: Two cleanups" from Gavin Shan
performs some maintenance work on the drivers/base/memory code.
- The series "Add tracepoints for lowmem reserves, watermarks and
totalreserve_pages" from Martin Liu adds some more tracepoints to the
page allocator code.
- The series "mm/madvise: cleanup requests validations and
classifications" from SeongJae Park cleans up some warts which
SeongJae observed during his earlier madvise work.
- The series "mm/hwpoison: Fix regressions in memory failure handling"
from Shuai Xue addresses two quite serious regressions which Shuai
has observed in the memory-failure implementation.
- The series "mm: reliable huge page allocator" from Johannes Weiner
makes huge page allocations cheaper and more reliable by reducing
fragmentation.
- The series "Minor memcg cleanups & prep for memdescs" from Matthew
Wilcox is preparatory work for the future implementation of memdescs.
- The series "track memory used by balloon drivers" from Nico Pache
introduces a way to track memory used by our various balloon drivers.
- The series "mm/damon: introduce DAMOS filter type for active pages"
from Nhat Pham permits users to filter for active/inactive pages,
separately for file and anon pages.
- The series "Adding Proactive Memory Reclaim Statistics" from Hao Jia
separates the proactive reclaim statistics from the direct reclaim
statistics.
- The series "mm/vmscan: don't try to reclaim hwpoison folio" from
Jinjiang Tu fixes our handling of hwpoisoned pages within the reclaim
code.
* tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (431 commits)
mm/page_alloc: remove unnecessary __maybe_unused in order_to_pindex()
x86/mm: restore early initialization of high_memory for 32-bits
mm/vmscan: don't try to reclaim hwpoison folio
mm/hwpoison: introduce folio_contain_hwpoisoned_page() helper
cgroup: docs: add pswpin and pswpout items in cgroup v2 doc
mm: vmscan: split proactive reclaim statistics from direct reclaim statistics
selftests/mm: speed up split_huge_page_test
selftests/mm: uffd-unit-tests support for hugepages > 2M
docs/mm/damon/design: document active DAMOS filter type
mm/damon: implement a new DAMOS filter type for active pages
fs/dax: don't disassociate zero page entries
MM documentation: add "Unaccepted" meminfo entry
selftests/mm: add commentary about 9pfs bugs
fork: use __vmalloc_node() for stack allocation
docs/mm: Physical Memory: Populate the "Zones" section
xen: balloon: update the NR_BALLOON_PAGES state
hv_balloon: update the NR_BALLOON_PAGES state
balloon_compaction: update the NR_BALLOON_PAGES state
meminfo: add a per node counter for balloon drivers
mm: remove references to folio in __memcg_kmem_uncharge_page()
...
* hardening against maliciously fuzzed file systems
* backwards compatibility for the brief period when we attempted to
ignore zero-width characters
* avoid potentially BUG'ing if there is a file system corruption found
during the file system unmount
* fix free space reporting by statfs when project quotas are enabled
and the free space is less than the remaining project quota
Also improve performance when replaying a journal with a very large
number of revoke records (applicable for Lustre volumes).
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Merge tag 'ext4-for_linus-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 updates from Ted Ts'o:
"Ext4 bug fixes and cleanups, including:
- hardening against maliciously fuzzed file systems
- backwards compatibility for the brief period when we attempted to
ignore zero-width characters
- avoid potentially BUG'ing if there is a file system corruption
found during the file system unmount
- fix free space reporting by statfs when project quotas are enabled
and the free space is less than the remaining project quota
Also improve performance when replaying a journal with a very large
number of revoke records (applicable for Lustre volumes)"
* tag 'ext4-for_linus-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (71 commits)
ext4: fix OOB read when checking dotdot dir
ext4: on a remount, only log the ro or r/w state when it has changed
ext4: correct the error handle in ext4_fallocate()
ext4: Make sb update interval tunable
ext4: avoid journaling sb update on error if journal is destroying
ext4: define ext4_journal_destroy wrapper
ext4: hash: simplify kzalloc(n * 1, ...) to kzalloc(n, ...)
jbd2: add a missing data flush during file and fs synchronization
ext4: don't over-report free space or inodes in statvfs
ext4: clear DISCARD flag if device does not support discard
jbd2: remove jbd2_journal_unfile_buffer()
ext4: reorder capability check last
ext4: update the comment about mb_optimize_scan
jbd2: fix off-by-one while erasing journal
ext4: remove references to bh->b_page
ext4: goto right label 'out_mmap_sem' in ext4_setattr()
ext4: fix out-of-bound read in ext4_xattr_inode_dec_ref_all()
ext4: introduce ITAIL helper
jbd2: remove redundant function jbd2_journal_has_csum_v2or3_feature
ext4: remove redundant function ext4_has_metadata_csum
...
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Merge tag 'vfs-6.15-rc1.ceph' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs ceph updates from Christian Brauner:
"This contains the work to remove access to page->index from ceph
and fixes the test failure observed for ceph with generic/421 by
refactoring ceph_writepages_start()"
* tag 'vfs-6.15-rc1.ceph' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
fscrypt: Change fscrypt_encrypt_pagecache_blocks() to take a folio
ceph: Fix error handling in fill_readdir_cache()
fs: Remove page_mkwrite_check_truncate()
ceph: Pass a folio to ceph_allocate_page_array()
ceph: Convert ceph_move_dirty_page_in_page_array() to move_dirty_folio_in_page_array()
ceph: Remove uses of page from ceph_process_folio_batch()
ceph: Convert ceph_check_page_before_write() to use a folio
ceph: Convert writepage_nounlock() to write_folio_nounlock()
ceph: Convert ceph_readdir_cache_control to store a folio
ceph: Convert ceph_find_incompatible() to take a folio
ceph: Use a folio in ceph_page_mkwrite()
ceph: Remove ceph_writepage()
ceph: fix generic/421 test failure
ceph: introduce ceph_submit_write() method
ceph: introduce ceph_process_folio_batch() method
ceph: extend ceph_writeback_ctl for ceph_writepages_start() refactoring
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Merge tag 'vfs-6.15-rc1.async.dir' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs async dir updates from Christian Brauner:
"This contains cleanups that fell out of the work from async directory
handling:
- Change kern_path_locked() and user_path_locked_at() to never return
a negative dentry. This simplifies the usability of these helpers
in various places
- Drop d_exact_alias() from the remaining place in NFS where it is
still used. This also allows us to drop the d_exact_alias() helper
completely
- Drop an unnecessary call to fh_update() from nfsd_create_locked()
- Change i_op->mkdir() to return a struct dentry
Change vfs_mkdir() to return a dentry provided by the filesystems
which is hashed and positive. This allows us to reduce the number
of cases where the resulting dentry is not positive to very few
cases. The code in these places becomes simpler and easier to
understand.
- Repack DENTRY_* and LOOKUP_* flags"
* tag 'vfs-6.15-rc1.async.dir' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
doc: fix inline emphasis warning
VFS: Change vfs_mkdir() to return the dentry.
nfs: change mkdir inode_operation to return alternate dentry if needed.
fuse: return correct dentry for ->mkdir
ceph: return the correct dentry on mkdir
hostfs: store inode in dentry after mkdir if possible.
Change inode_operations.mkdir to return struct dentry *
nfsd: drop fh_update() from S_IFDIR branch of nfsd_create_locked()
nfs/vfs: discard d_exact_alias()
VFS: add common error checks to lookup_one_qstr_excl()
VFS: change kern_path_locked() and user_path_locked_at() to never return negative dentry
VFS: repack LOOKUP_ bit flags.
VFS: repack DENTRY_ flags.
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Merge tag 'vfs-6.15-rc1.iomap' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs iomap updates from Christian Brauner:
- Allow the filesystem to submit the writeback bios.
- Allow the filsystem to track completions on a per-bio bases
instead of the entire I/O.
- Change writeback_ops so that ->submit_bio can be done by the
filesystem.
- A new ANON_WRITE flag for writes that don't have a block number
assigned to them at the iomap level leaving the filesystem to do
that work in the submission handler.
- Incremental iterator advance
The folio_batch support for zero range where the filesystem provides
a batch of folios to process that might not be logically continguous
requires more flexibility than the current offset based iteration
currently offers.
Update all iomap operations to advance the iterator within the
operation and thus remove the need to advance from the core iomap
iterator.
- Make buffered writes work with RWF_DONTCACHE
If RWF_DONTCACHE is set for a write, mark the folios being written as
uncached. On writeback completion the pages will be dropped.
- Introduce infrastructure for large atomic writes
This will eventually be used by xfs and ext4.
* tag 'vfs-6.15-rc1.iomap' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (42 commits)
iomap: rework IOMAP atomic flags
iomap: comment on atomic write checks in iomap_dio_bio_iter()
iomap: inline iomap_dio_bio_opflags()
iomap: fix inline data on buffered read
iomap: Lift blocksize restriction on atomic writes
iomap: Support SW-based atomic writes
iomap: Rename IOMAP_ATOMIC -> IOMAP_ATOMIC_HW
xfs: flag as supporting FOP_DONTCACHE
iomap: make buffered writes work with RWF_DONTCACHE
iomap: introduce a full map advance helper
iomap: rename iomap_iter processed field to status
iomap: remove unnecessary advance from iomap_iter()
dax: advance the iomap_iter on pte and pmd faults
dax: advance the iomap_iter on dedupe range
dax: advance the iomap_iter on unshare range
dax: advance the iomap_iter on zero range
dax: push advance down into dax_iomap_iter() for read and write
dax: advance the iomap_iter in the read/write path
iomap: convert misc simple ops to incremental advance
iomap: advance the iter on direct I/O
...
Mounting a corrupted filesystem with directory which contains '.' dir
entry with rec_len == block size results in out-of-bounds read (later
on, when the corrupted directory is removed).
ext4_empty_dir() assumes every ext4 directory contains at least '.'
and '..' as directory entries in the first data block. It first loads
the '.' dir entry, performs sanity checks by calling ext4_check_dir_entry()
and then uses its rec_len member to compute the location of '..' dir
entry (in ext4_next_entry). It assumes the '..' dir entry fits into the
same data block.
If the rec_len of '.' is precisely one block (4KB), it slips through the
sanity checks (it is considered the last directory entry in the data
block) and leaves "struct ext4_dir_entry_2 *de" point exactly past the
memory slot allocated to the data block. The following call to
ext4_check_dir_entry() on new value of de then dereferences this pointer
which results in out-of-bounds mem access.
Fix this by extending __ext4_check_dir_entry() to check for '.' dir
entries that reach the end of data block. Make sure to ignore the phony
dir entries for checksum (by checking name_len for non-zero).
Note: This is reported by KASAN as use-after-free in case another
structure was recently freed from the slot past the bound, but it is
really an OOB read.
This issue was found by syzkaller tool.
Call Trace:
[ 38.594108] BUG: KASAN: slab-use-after-free in __ext4_check_dir_entry+0x67e/0x710
[ 38.594649] Read of size 2 at addr ffff88802b41a004 by task syz-executor/5375
[ 38.595158]
[ 38.595288] CPU: 0 UID: 0 PID: 5375 Comm: syz-executor Not tainted 6.14.0-rc7 #1
[ 38.595298] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[ 38.595304] Call Trace:
[ 38.595308] <TASK>
[ 38.595311] dump_stack_lvl+0xa7/0xd0
[ 38.595325] print_address_description.constprop.0+0x2c/0x3f0
[ 38.595339] ? __ext4_check_dir_entry+0x67e/0x710
[ 38.595349] print_report+0xaa/0x250
[ 38.595359] ? __ext4_check_dir_entry+0x67e/0x710
[ 38.595368] ? kasan_addr_to_slab+0x9/0x90
[ 38.595378] kasan_report+0xab/0xe0
[ 38.595389] ? __ext4_check_dir_entry+0x67e/0x710
[ 38.595400] __ext4_check_dir_entry+0x67e/0x710
[ 38.595410] ext4_empty_dir+0x465/0x990
[ 38.595421] ? __pfx_ext4_empty_dir+0x10/0x10
[ 38.595432] ext4_rmdir.part.0+0x29a/0xd10
[ 38.595441] ? __dquot_initialize+0x2a7/0xbf0
[ 38.595455] ? __pfx_ext4_rmdir.part.0+0x10/0x10
[ 38.595464] ? __pfx___dquot_initialize+0x10/0x10
[ 38.595478] ? down_write+0xdb/0x140
[ 38.595487] ? __pfx_down_write+0x10/0x10
[ 38.595497] ext4_rmdir+0xee/0x140
[ 38.595506] vfs_rmdir+0x209/0x670
[ 38.595517] ? lookup_one_qstr_excl+0x3b/0x190
[ 38.595529] do_rmdir+0x363/0x3c0
[ 38.595537] ? __pfx_do_rmdir+0x10/0x10
[ 38.595544] ? strncpy_from_user+0x1ff/0x2e0
[ 38.595561] __x64_sys_unlinkat+0xf0/0x130
[ 38.595570] do_syscall_64+0x5b/0x180
[ 38.595583] entry_SYSCALL_64_after_hwframe+0x76/0x7e
Fixes: ac27a0ec11 ("[PATCH] ext4: initial copy of files from ext3")
Signed-off-by: Jakub Acs <acsjakub@amazon.de>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: linux-ext4@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Mahmoud Adam <mngyadam@amazon.com>
Cc: stable@vger.kernel.org
Cc: security@kernel.org
Link: https://patch.msgid.link/b3ae36a6794c4a01944c7d70b403db5b@amazon.de
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
A user complained that a message such as:
EXT4-fs (nvme0n1p3): re-mounted UUID ro. Quota mode: none.
implied that the file system was previously mounted read/write and was
now remounted read-only, when it could have been some other mount
state that had changed by the "mount -o remount" operation. Fix this
by only logging "ro"or "r/w" when it has changed.
https://bugzilla.kernel.org/show_bug.cgi?id=219132
Signed-off-by: Nicolas Bretz <bretznic@gmail.com>
Link: https://patch.msgid.link/20250319171011.8372-1-bretznic@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The error out label of file_modified() should be out_inode_lock in
ext4_fallocate().
Fixes: 2890e5e0f4 ("ext4: move out common parts into ext4_fallocate()")
Reported-by: Baokun Li <libaokun1@huawei.com>
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Link: https://patch.msgid.link/20250319023557.2785018-1-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Currently, outside error paths, we auto commit the super block after 1
hour has passed and 16MB worth of updates have been written since last
commit. This is a policy decision so make this tunable while keeping the
defaults same. This is useful if user wants to tweak the superblock
behavior or for debugging the codepath by allowing to trigger it more
frequently.
We can now tweak the super block update using sb_update_sec and
sb_update_kb files in /sys/fs/ext4/<dev>/
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/950fb8c9b2905620e16f02a3b9eeea5a5b6cb87e.1742279837.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Presently we always BUG_ON if trying to start a transaction on a journal marked
with JBD2_UNMOUNT, since this should never happen. However, while ltp running
stress tests, it was observed that in case of some error handling paths, it is
possible for update_super_work to start a transaction after the journal is
destroyed eg:
(umount)
ext4_kill_sb
kill_block_super
generic_shutdown_super
sync_filesystem /* commits all txns */
evict_inodes
/* might start a new txn */
ext4_put_super
flush_work(&sbi->s_sb_upd_work) /* flush the workqueue */
jbd2_journal_destroy
journal_kill_thread
journal->j_flags |= JBD2_UNMOUNT;
jbd2_journal_commit_transaction
jbd2_journal_get_descriptor_buffer
jbd2_journal_bmap
ext4_journal_bmap
ext4_map_blocks
...
ext4_inode_error
ext4_handle_error
schedule_work(&sbi->s_sb_upd_work)
/* work queue kicks in */
update_super_work
jbd2_journal_start
start_this_handle
BUG_ON(journal->j_flags &
JBD2_UNMOUNT)
Hence, introduce a new mount flag to indicate journal is destroying and only do
a journaled (and deferred) update of sb if this flag is not set. Otherwise, just
fallback to an un-journaled commit.
Further, in the journal destroy path, we have the following sequence:
1. Set mount flag indicating journal is destroying
2. force a commit and wait for it
3. flush pending sb updates
This sequence is important as it ensures that, after this point, there is no sb
update that might be journaled so it is safe to update the sb outside the
journal. (To avoid race discussed in 2d01ddc866)
Also, we don't need a similar check in ext4_grp_locked_error since it is only
called from mballoc and AFAICT it would be always valid to schedule work here.
Fixes: 2d01ddc866 ("ext4: save error info to sb through journal if available")
Reported-by: Mahesh Kumar <maheshkumar657g@gmail.com>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/9613c465d6ff00cd315602f99283d5f24018c3f7.1742279837.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Define an ext4 wrapper over jbd2_journal_destroy to make sure we
have consistent behavior during journal destruction. This will also
come useful in the next patch where we add some ext4 specific logic
in the destroy path.
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/c3ba78c5c419757e6d5f2d8ebb4a8ce9d21da86a.1742279837.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This fixes an analogus bug that was fixed in xfs in commit
4b8d867ca6 ("xfs: don't over-report free space or inodes in
statvfs") where statfs can report misleading / incorrect information
where project quota is enabled, and the free space is less than the
remaining quota.
This commit will resolve a test failure in generic/762 which tests for
this bug.
Cc: stable@kernel.org
Fixes: 689c958cbe ("ext4: add project quota support")
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Flag IOMAP_ATOMIC_SW is not really required. The idea of having this flag
is that the FS ->iomap_begin callback could check if this flag is set to
decide whether to do a SW (FS-based) atomic write. But the FS can set
which ->iomap_begin callback it wants when deciding to do a FS-based
atomic write.
Furthermore, it was thought that IOMAP_ATOMIC_HW is not a proper name, as
the block driver can use SW-methods to emulate an atomic write. So change
back to IOMAP_ATOMIC.
The ->iomap_begin callback needs though to indicate to iomap core that
REQ_ATOMIC needs to be set, so add IOMAP_F_ATOMIC_BIO for that.
These changes were suggested by Christoph Hellwig and Dave Chinner.
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20250320120250.4087011-4-john.g.garry@oracle.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
File systems call dax_break_mapping() prior to reallocating file system
blocks to ensure the page is not undergoing any DMA or other accesses.
Generally this is needed when a file is truncated to ensure that if a
block is reallocated nothing is writing to it. However filesystems
currently don't call this when an FS DAX inode is evicted.
This can cause problems when the file system is unmounted as a page can
continue to be under going DMA or other remote access after unmount. This
means if the file system is remounted any truncate or other operation
which requires the underlying file system block to be freed will not wait
for the remote access to complete. Therefore a busy block may be
reallocated to a new file leading to corruption.
Link: https://lkml.kernel.org/r/2d3cf575bbd095084993154be2f0aa7442e5cd28.1740713401.git-series.apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Tested-by: Alison Schofield <alison.schofield@intel.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Asahi Lina <lina@asahilina.net>
Cc: Balbir Singh <balbirs@nvidia.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chunyan Zhang <zhang.lyra@gmail.com>
Cc: Dan Wiliams <dan.j.williams@intel.com>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: linmiaohe <linmiaohe@huawei.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Matthew Wilcow (Oracle) <willy@infradead.org>
Cc: Michael "Camp Drill Sergeant" Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Ted Ts'o <tytso@mit.edu>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Prior to freeing a block file systems supporting FS DAX must check that
the associated pages are both unmapped from user-space and not undergoing
DMA or other access from eg. get_user_pages(). This is achieved by
unmapping the file range and scanning the FS DAX page-cache to see if any
pages within the mapping have an elevated refcount.
This is done using two functions - dax_layout_busy_page_range() which
returns a page to wait for the refcount to become idle on. Rather than
open-code this introduce a common implementation to both unmap and wait
for the page to become idle.
Link: https://lkml.kernel.org/r/c4d381e41fc618296cee2820403c166d80599d5c.1740713401.git-series.apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Alison Schofield <alison.schofield@intel.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Asahi Lina <lina@asahilina.net>
Cc: Balbir Singh <balbirs@nvidia.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chunyan Zhang <zhang.lyra@gmail.com>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: linmiaohe <linmiaohe@huawei.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Matthew Wilcow (Oracle) <willy@infradead.org>
Cc: Michael "Camp Drill Sergeant" Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Ted Ts'o <tytso@mit.edu>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
A FS DAX page is considered idle when its refcount drops to one. This is
currently open-coded in all file systems supporting FS DAX. Move the idle
detection to a common function to make future changes easier.
Link: https://lkml.kernel.org/r/c2c9d269110b90224eeb1dc661ffbc1d82aa20c9.1740713401.git-series.apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Theodore Ts'o <tytso@mit.edu>
Tested-by: Alison Schofield <alison.schofield@intel.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Asahi Lina <lina@asahilina.net>
Cc: Balbir Singh <balbirs@nvidia.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Chunyan Zhang <zhang.lyra@gmail.com>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: linmiaohe <linmiaohe@huawei.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Matthew Wilcow (Oracle) <willy@infradead.org>
Cc: Michael "Camp Drill Sergeant" Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
commit 79add3a3f7 ("ext4: notify when discard is not supported")
noted that keeping the DISCARD flag is for possibility that the underlying
device might change in future even without file system remount. However,
this scenario has rarely occurred in practice on the device side. Even if
it does occur, it can be resolved with remount. Clearing the DISCARD flag
not only prevents confusion caused by mount options but also avoids
sending unnecessary discard commands.
Signed-off-by: Diangang Li <lidiangang@bytedance.com>
Link: https://patch.msgid.link/20250311021310.669524-1-lidiangang@bytedance.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
capable() calls refer to enabled LSMs whether to permit or deny the
request. This is relevant in connection with SELinux, where a
capability check results in a policy decision and by default a denial
message on insufficient permission is issued.
It can lead to three undesired cases:
1. A denial message is generated, even in case the operation was an
unprivileged one and thus the syscall succeeded, creating noise.
2. To avoid the noise from 1. the policy writer adds a rule to ignore
those denial messages, hiding future syscalls, where the task
performs an actual privileged operation, leading to hidden limited
functionality of that task.
3. To avoid the noise from 1. the policy writer adds a rule to permit
the task the requested capability, while it does not need it,
violating the principle of least privilege.
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20250302160657.127253-2-cgoettsche@seltendoof.de
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Commit 196e402adf ("ext4: improve cr 0 / cr 1 group scanning") introduces
the sysfs control interface "mb_max_linear_groups" to address the problem
that rotational devices performance degrades when the "mb_optimize_scan"
feature is enabled, which may result in distant block group allocation.
However, the name of the interface was incorrect in the comment to the
ext4/mballoc.c file, and this patch fixes it, without further changes.
Signed-off-by: Zizhi Wo <wozizhi@huawei.com>
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250224012005.689549-1-wozizhi@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Buffer heads are attached to folios, not to pages. Also
flush_dcache_page() is now deprecated in favour of flush_dcache_folio().
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20250213182303.2133205-1-willy@infradead.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Otherwise, if ext4_inode_attach_jinode() fails, a hung task will
happen because filemap_invalidate_unlock() isn't called to unlock
mapping->invalidate_lock. Like this:
EXT4-fs error (device sda) in ext4_setattr:5557: Out of memory
INFO: task fsstress:374 blocked for more than 122 seconds.
Not tainted 6.14.0-rc1-next-20250206-xfstests-dirty #726
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:fsstress state:D stack:0 pid:374 tgid:374 ppid:373
task_flags:0x440140 flags:0x00000000
Call Trace:
<TASK>
__schedule+0x2c9/0x7f0
schedule+0x27/0xa0
schedule_preempt_disabled+0x15/0x30
rwsem_down_read_slowpath+0x278/0x4c0
down_read+0x59/0xb0
page_cache_ra_unbounded+0x65/0x1b0
filemap_get_pages+0x124/0x3e0
filemap_read+0x114/0x3d0
vfs_read+0x297/0x360
ksys_read+0x6c/0xe0
do_syscall_64+0x4b/0x110
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Fixes: c7fc0366c6 ("ext4: partial zero eof block on unaligned inode size extension")
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Link: https://patch.msgid.link/20250213112247.3168709-1-libaokun@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Since commit f2b4fa1964 ("ext4: switch to using the crc32c library"),
ext4_has_metadata_csum() is just an alias for
ext4_has_feature_metadata_csum(). ext4_has_feature_metadata_csum() is
generated by EXT4_FEATURE_RO_COMPAT_FUNCS and uses the regular naming
convention for checking a single ext4 feature. Therefore, remove
ext4_has_metadata_csum() and update all its callers to use
ext4_has_feature_metadata_csum() directly.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Link: https://patch.msgid.link/20250207031335.42637-1-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
All callers now have a folio, so pass it in instead of converting
folio->page->folio.
Link: https://lkml.kernel.org/r/20250217192009.437916-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Now, if dmesg is cleared, we have no way of knowing if the file system has
been shutdown. Moreover, ext4 allows directory reads even after the file
system has been shutdown, so when reading a file returns -EIO, we cannot
determine whether this is a hardware issue or if the file system has been
shutdown.
Therefore, when ext4 file system is shutdown, we're adding a 'shutdown'
hint to commands like mount so users can easily check the file system's
status.
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250122114130.229709-8-libaokun@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
After commit d3476f3dad ("ext4: don't set SB_RDONLY after filesystem
errors") in v6.12-rc1, the 'errors=remount-ro' mode no longer sets
SB_RDONLY on errors, which results in us seeing the filesystem is still
in rw state after errors.
Therefore, after setting EXT4_FLAGS_EMERGENCY_RO, display the emergency_ro
option so that users can query whether the current file system has become
emergency read-only due to errors through commands such as 'mount' or
'cat /proc/fs/ext4/sdx/options'.
Fixes: d3476f3dad ("ext4: don't set SB_RDONLY after filesystem errors")
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250122114130.229709-7-libaokun@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
And after commit 95257987a6 ("ext4: drop EXT4_MF_FS_ABORTED flag") in
v6.6-rc1, the EXT4_FLAGS_SHUTDOWN bit is set in ext4_handle_error() under
errors=remount-ro mode. This causes the read to fail even when the error
is triggered in errors=remount-ro mode.
To correct the behavior under errors=remount-ro, EXT4_FLAGS_SHUTDOWN is
replaced by the newly introduced EXT4_FLAGS_EMERGENCY_RO. This new flag
only prevents writes, matching the previous behavior with SB_RDONLY.
Fixes: 95257987a6 ("ext4: drop EXT4_MF_FS_ABORTED flag")
Closes: https://lore.kernel.org/all/22d652f6-cb3c-43f5-b2fe-0a4bb6516a04@huawei.com/
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20250122114130.229709-6-libaokun@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Some functions check sb_rdonly() to make sure the file system isn't
modified after it's read-only. Since we also don't want the file system
modified if it's in an emergency state (shutdown or emergency_ro),
we're adding additional ext4_emergency_state() checks where sb_rdonly()
is checked.
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20250122114130.229709-5-libaokun@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Since both SHUTDOWN and EMERGENCY_RO are emergency states of the ext4 file
system, and they are checked in similar locations, we have added a helper
function, ext4_emergency_state(), to determine whether the current file
system is in one of these two emergency states.
Then, replace calls to ext4_forced_shutdown() with ext4_emergency_state()
in those functions that could potentially trigger write operations.
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250122114130.229709-4-libaokun@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
EXT4_FLAGS_EMERGENCY_RO Indicates that the current file system has become
read-only due to some error. Compared to SB_RDONLY, setting it does not
require a lock because we won't clear it, which avoids over-coupling with
vfs freeze. Also, add a helper function ext4_emergency_ro() to check if
the bit is set.
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250122114130.229709-3-libaokun@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
