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2026-08-21ext4: Avoid entering writeback paths during fastcommit replayJan Kara1-3/+8
Fastcommit replay effectively happens in nojournal mode. This results in ext4_mark_iloc_dirty() setting I_METADATA_WRITEBACK flag and as a result we end up entering filesystem writeback functions. However during fastcommit replay s_writepages_rwsem isn't initialized yet and hence we crash. Fix the problem by avoiding setting I_METADATA_WRITEBACK during fastcommit replay. Journal replay flushes the whole block device after replay anyway so all metadata is properly persisted and replay is faster this way as a bonus. Fixes: c26339e1df33 ("ext4: Fix data integrity writeout issues in nojournal mode") Reported-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com> Reported-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260804104112.93202-2-jack@suse.cz Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com> Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-08-20Merge tag 'ext4_for_linus-7.3-rc1' of ↵Linus Torvalds1-55/+152
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 updates from Ted Ts'o: - Improve performance by allowing parallel DIO writes when we were previously being overly conservative when checking whether it was safe to avoid requiring an exclusive lock - Improve the performance of ext4_mb_prefetch() used by fallocate() by avoiding work when it is not needed - Remove the unnecessary custom end_io function ext4_end_buffer_io_sync() - Improve performance when performing an overwrite to an already uptodate folio - Clean up how we handle deallocating EA inodes to avoid a potential lock ordering issue when there is a failed mount while an EA inode is still being evicted - Use str_plural() instead of a custom macro - Avoid soft lockups or RCU stalls if there are many busy buffers (caused by heavy I/O) while checkpointing - Use scoped NOFS when starting a handle in nojournal mode - Align fields in handle structure to optimize setting and getting the h_type and h_line_no fields - Fix documentation of the meta_bg block group layout - Bug fixes: - Fix a potential out-of-bounds read in ext4_read_inline_dir() - Fix a potential deadlock when concurrent xattr operations are racing with each other when some of the xattrs are using the ea_inode feature - Fix a spurious warning with data=journal that can be triggered when writeback races with remounting the file system read-only - Fix a potential deadlock when EXT4_IOC_MIGRATE races with a file system freeze operation - Make sure all in-flight direct I/O operations are complete before falling back to buffered I/O - Handle IOCB_NOWAIT properly when performing a extending DAX write - Prevent potentially sleeping on a block allocation when IOCB_NOWAIT is set - Fix potential races when racing an inline data write with a page fault - Propagate errors when adding or removing extent ranges during a fast commit replay - Avoid trying to expand an inode's extra size when it is being evicted to avoid a number of corner case or deadlocks - Avoid spurious error when retrying inode extra size expansion - Fix corner cases where we underestimate the number of journal credits needed - Avoid hangs/crashes/WARNINGS caused by maliciously corrupted file systems - Don't issue spurious orphan clean message on RO file systems - Avoid leaving the file system in an inconsistent state after a crash when a WRITE_ZEROS in progress converting an unwritten extent to a written extent - Handle WRITE_ZEROS correctly when there are some partially dirtied regions in the page cache - Pass errors during zero-rage, truncate, or punch hole to the caller if ext4_get_block() fails - Wait for writeback to finish when triggered by zero-range or zero-range for those devices that require stable writes - If the reserved gid superblock field is set, set the reserved gid instead of the reserved uid * tag 'ext4_for_linus-7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (56 commits) ext4: fix estimate extent index blocks in ext4_ext_index_trans_blocks() ext4: fix transaction overflow during writeback ext4: teach ext4_meta_trans_blocks() about number of allocated extents ext4: guard against NULL s_group_info in ext4_get_group_info ext4: fix spurious message about orphan cleanup on RO fs ext4: stop retrying saturated xattr cache entries ext4: don't enable DAX on new encrypted files ext4: protect WRITE_ZEROES written extents with orphan list ext4: export converted block count from ext4_convert_unwritten_extents() ext4: fix incorrect function call when initializing s_resgid ext4: validate EA inode i_nlink in ext4_xattr_inode_iget jbd2: align h_type and h_line_no in the handle structure on byte boundaries ext4: enable scoped NOFS when starting a handle in nojournal mode ext4: write back partial-zeroed edges in WRITE_ZEROES ext4: zero out whole block for clean edges in WRITE_ZEROES ext4: track partial-zero outcome per edge in ext4_zero_partial_blocks() ext4: clarify return semantics of ext4_load_tail_bh() ext4: move partial block zeroing earlier in ext4_zero_range() ext4: check return value of ext4_get_block() in ext4_load_tail_bh() ext4: skip tail block zeroing for inline data files ...
2026-08-17Merge tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/linuxLinus Torvalds1-57/+14
Pull fscrypt updates from Eric Biggers: "The main change this cycle is a significant simplification that's been overdue for a while now: standardizing on a single file contents encryption implementation in ext4 and f2fs, instead of having two. Specifically, the original filesystem-layer file contents encryption implementation is removed, and the blk-crypto implementation is now used unconditionally. blk-crypto delegates either to inline crypto hardware or to the CPU via blk-crypto-fallback. The latter is functionally equivalent to the original filesystem-layer code. The blk-crypto implementation already existed, but previously it was used only when the filesystem was mounted with "-o inlinecrypt". Now, "-o inlinecrypt" just selects whether inline crypto hardware is used. To allow maintaining that user control over hardware use, the blk-crypto API is extended with a new flag BLK_CRYPTO_CFG_ALLOW_HW. Overall, this removes quite a bit of redundant code from ext4, f2fs, and fs/crypto/. It should make things easier for ongoing filesystem efforts such as iomap support, large folios, and btrfs encryption (btrfs had already been planning to use blk-crypto exclusively.) There are two small behavior changes of note: - Direct I/O now works on encrypted files even without "-o inlinecrypt", rather than falling back to buffered I/O. This is effectively a bugfix, though I'll continue to keep an eye out for any user that may have been depending on the buffered I/O fallback. - IV_INO_LBLK_32 policies are no longer supported in certain cases that didn't make sense and have no known uses. This has been in linux-next since July 22 with no reported issues. All encryption xfstests pass on ext4 and f2fs. As usual I've also been using it on a system with an fscrypt-encrypted home directory. Of course, the blk-crypto code paths also aren't new and were already being used on many systems via the inlinecrypt mount option. In addition to the main change described above, there are a few other cleanups such as using lock guards for mutexes, improving documentation, and removing a workaround for outdated gcc versions" * tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/linux: (29 commits) blk-crypto: Update docs for blk-crypto-fallback motivation blk-crypto: Remove unused function blk_crypto_config_supported() fscrypt: Update docs for data path fscrypt: Remove unused function fscrypt_finalize_bounce_page() f2fs: Update outdated comment in f2fs_write_begin() fs: Update outdated comment for SB_INLINECRYPT fscrypt: Update encryption policy version docs fscrypt: Replace some variable-size memsets with fixed-size fscrypt: Add safety checks to non-block-based en/decryption fscrypt: Merge bio.c and inline_crypt.c into block.c fscrypt: Remove unused functions and workqueue fscrypt: Remove fs-layer zeroout code fscrypt: Remove fscrypt_dio_supported() fscrypt: Replace calls to fscrypt_inode_uses_inline_crypto() fs/buffer: Remove fs-layer decryption code f2fs: Remove fs-layer file contents en/decryption code ext4: Further de-generalize the bio postprocessing code ext4: Make ext4_bio_write_folio() return void ext4: Remove fs-layer file contents en/decryption code Documentation: fscrypt: Update docs for inlinecrypt ...
2026-08-17Merge tag 'vfs-7.3-rc1.sync' of ↵Linus Torvalds1-34/+68
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs writeback updates from Christian Brauner: "This makes sync_inode_metadata() and writeback_single_inode() persist not only the inode but all metadata associated with it. A new .sync_inode_metadata superblock operation is called from __writeback_single_inode(). Alongside it a new I_METADATA_WRITEBACK state flag is added. Filesystems no longer need their own mmb_fsync() implementations and can just use simple_fsync(). All metadata is now written for IS_SYNC and IS_DIRSYNC inodes. Races where several fsyncs raced and mmb_sync() could return before all buffers were really persisted are fixed since I_SYNC now serializes properly. The I_METADATA_WRITEBACK scheme also fixes the case where a WB_SYNC_NONE writeback landing between write(2) and fsync(2) left fsync(2) failing to persist the inode. That problem is not specific to filesystems using the generic metadata bh tracking, and the ones that do not are left alone. ext2, udf, bfs, minix, fat and ext4 in nojournal mode have their data integrity writeout fixed and are converted. affs drops metadata bh tracking and mmb_fsync() is removed. A few other fixes came out of this: - a UAF in mark_buffer_write_io_error() - missed inode writeback when racing with __writeback_single_inode() - ext4 allocating the mapping_metadata_bhs struct on demand - three fat fixes: a lost inode update in do_msdos_rename() with DIRSYNC, inode buffer write errors not propagating out of fat_sync_inode_metadata() and directory entries not being persisted on fsync(2) of the root directory" * tag 'vfs-7.3-rc1.sync' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (24 commits) writeback: Export __inode_attach_wb() fat: Fix persisting directory entries on fsync(2) of the root directory fat: Propagate inode buffer write errors from fat_sync_inode_metadata() fat: Fix lost inode update in do_msdos_rename() with DIRSYNC vfs: Remove mmb_fsync() fat: Replace fat_sync_inode() with sync_inode_metadata() fat: Fix missed inode writeback during fsync(2) ext4: Fix data integrity writeout issues in nojournal mode minix: Fix data integrity writeout issues bfs: Fix data integrity writeout issues udf: Fold udf_update_inode() into udf_write_inode() udf: Use sync_inode_metadata() in udf_evict_inode() udf: Drop udf_sync_inode() udf: Use sync_inode_metadata() to writeout IS_SYNC inode udf: Fix data integrity writeout issues ext2: Fix data integrity writeout issues ext2: Avoid unnecessary inode buffer writeback for sync(2) ext2: Drop __ext2_write_inode() ext2: Fix lost inode updates for IS_SYNC inodes fs: Provide way for filesystem to wait for metadata writeback ...
2026-08-06ext4: fix transaction overflow during writebackJan Kara1-3/+3
Commit 95ad8ee45cdb ("ext4: correct the reserved credits for extent conversion") was correct to note that we need to reserve enough credits for all extents possibly underlying a large folio. However it was too eager to reduce the number of reserved credits. Extent conversion may not only need to touch several leaf extent blocks, it may also need to split extents - for example a single large unwritten extent may need to be split into many small written ones in case of sparse folio dirtying. This can thus result not only in extent leaf modifications but also in a need to allocate new extent tree nodes. As a result the reserved transaction credits were not sufficient in some corner cases. Use ext4_meta_trans_blocks() for correct upper bound credit estimate. Fixes: 95ad8ee45cdb ("ext4: correct the reserved credits for extent conversion") Signed-off-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260805153605.166545-5-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-08-06ext4: teach ext4_meta_trans_blocks() about number of allocated extentsJan Kara1-15/+15
So far ext4_meta_trans_blocks() expects that each extent counted in @pextents will be allocated in the transaction we estimate credits for. This is correct for the use in ext4_chunk_trans_blocks() and ext4_chunk_trans_extent() however the use in atomic write path (ext4_convert_unwritten_extents_atomic() and ext4_iomap_alloc() for IOMAP_ATOMIC) unnecessarily overestimates the number of necessary credits as neither of them allocates any data. Add argument to ext4_meta_trans_blocks() for number of extents that are going to be allocated in the transaction. Signed-off-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260805153605.166545-4-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-07-31ext4: convert iomap ops to ->iomap_next()Joanne Koong1-2/+6
Convert ext4 iomap_ops to the new ->iomap_next() callback. Each callback is generated with the DEFINE_IOMAP_ITER_NEXT() macro, which wraps the iomap_iter_next() helper to finish the previous mapping if needed and produce the next one. No functional changes are intended. Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Baokun Li <libaokun@linux.alibaba.com> Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Link: https://patch.msgid.link/20260729192737.3190206-11-joannelkoong@gmail.com Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-07-31iomap: decouple simple direct I/O reads from iomap_dio_rwChristoph Hellwig1-1/+1
The pending iomap_iter_next conversion creates performance issues for the new simple direct I/O read fast path, because it assumes a model where the iterator must be advanced at the end, which the direct I/O read fast path tries to avoid. Side step this by splitting the simple path from iomap_dio_rw, and require the file systems to call into it explicitly, and pass only a ->begin callback. This allows to drop various checks for incompatible features while creating a requirement for the file system to only call the simple path for cases that it can handle. As a side-benefit we can now inline the initial part of the simple direct I/O read fast path and let the compiler convert the indirect call to ->begin into a direct call. Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Reviewed-by: Fengnan Chang <changfengnan@bytedance.com> Reviewed-by: Joanne Koong <joannelkoong@gmail.com> Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/20260729192737.3190206-4-joannelkoong@gmail.com Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-07-27ext4: Fix data integrity writeout issues in nojournal modeJan Kara1-30/+60
Several racing fsyncs on ext4 in nojournal mode could result in some fsync returning earlier than all metadata buffers were properly persisted. Also ext4_fsync() in nojournal mode was somewhat inefficient because it was always writing out the inode regardless whether it was dirty or not. Fix these issues by using new .sync_inode_metadata method which makes sure all inode related metadata is written to disk during any WB_SYNC_ALL writeback in nojournal mode. This also somewhat simplifies the nojournal mode fsync handling. Signed-off-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260727104923.3828017-37-jack@suse.cz Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-07-27ext4: Allocate mapping_metadata_bhs struct on demandJan Kara1-4/+8
Currently every ext4 inode gets mapping_metadata_bhs struct although it is only needed when running without a journal and only for inodes where any metadata was dirtied. Allocate mapping_metadata_bhs struct on demand when dirtying the first metadata buffer for the inode. Acked-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260727104923.3828017-24-jack@suse.cz Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-07-22ext4: track partial-zero outcome per edge in ext4_zero_partial_blocks()Zhang Yi1-6/+30
Replace the single bool did_zero output of ext4_zero_partial_blocks() with a bitmask that records which edge (start, end, or both in the single-block case) was actually partial-zeroed. This allows callers to distinguish which edges have been zeroed, preparing for unaligned FALLOC_FL_WRITE_ZEROES handling in later patches. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260714080044.4038124-7-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-07-22ext4: clarify return semantics of ext4_load_tail_bh()Zhang Yi1-1/+10
ext4_load_tail_bh() returns NULL for both holes and clean unwritten buffers, but the conditions that lead to this are not obvious from the code alone. Document this behavior to clarify the return value, so that readers do not mistakenly assume that only holes result in a NULL return. Also update the inline comment following the ext4_get_block() call to reflect this, and note that a lookup-only get_block (without EXT4_GET_BLOCKS_CREATE) never sets BH_Mapped for clean unwritten extents, which is why a clean unwritten bh falls through to the "nothing to do" path. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260714080044.4038124-6-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-07-22ext4: check return value of ext4_get_block() in ext4_load_tail_bh()Zhang Yi1-1/+3
ext4_load_tail_bh() ignores the return value of ext4_get_block(), so an I/O or allocation failure is silently discarded. buffer_mapped(bh) stays false and the function returns NULL, which callers such as ext4_block_do_zero_range() treat as "nothing to do" and return success. This can mask real failures during zero-range, truncate, or punch-hole operations, potentially exposing stale data if the block was not actually a hole and needed zeroing. So propagate the error to the callers. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260714080044.4038124-4-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-07-22ext4: skip tail block zeroing for inline data filesZhang Yi1-0/+8
ext4_block_zero_eof() is called from ext4_write_checks() on every append write beyond EOF. For inline data files, ext4_get_block() returns -ERANGE when ext4_load_tail_bh() looks up the tail block. However, this error is currently ignored because the return value of ext4_get_block() in ext4_load_tail_bh() is discarded. Before we fix ext4_load_tail_bh() to properly propagate the error, skip the zeroing for inline data inodes to avoid unnecessary failures or confusion. Fixes: 3f60efd65412d ("ext4: zero post-EOF partial block before appending write") Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260714080044.4038124-3-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-07-22ext4: use FGP_WRITEBEGIN for tail block zeroingZhang Yi1-1/+1
ext4_load_tail_bh() returns a locked folio that callers immediately mutate through folio_zero_range() and mark_buffer_dirty(). Use FGP_WRITEBEGIN so that, on backing devices that require stable writes, __filemap_get_folio() waits for writeback to finish before returning the folio; on regular devices the wait is a no-op. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260714080044.4038124-2-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-07-22ext4: remove ea_inode_array mechanism in favor of ext4_put_ea_inode()Yun Zhou1-5/+1
Now that ext4_put_ea_inode() handles deferred iput safely for all cases (using iput_if_not_last + embedded llist_node), the ea_inode_array mechanism for batching deferred iputs is redundant. Remove: - ext4_expand_inode_array() and ext4_xattr_inode_array_free() - struct ext4_xattr_inode_array and EIA_INCR/EIA_MASK defines - ea_inode_array parameter from ext4_xattr_inode_dec_ref_all(), ext4_xattr_release_block(), and ext4_xattr_delete_inode() - ea_inode_array variable from ext4_evict_inode() Instead, ext4_xattr_inode_dec_ref_all() now calls ext4_put_ea_inode() directly after processing each EA inode. This simplifies the code by eliminating multi-layer parameter threading and removes the need for callers to manage array lifetime. Signed-off-by: Yun Zhou <yun.zhou@windriver.com> Suggested-by: Jan Kara <jack@suse.cz> Reviewed-by: Jan Kara <jack@suse.cz> Tested-by: syzbot@syzkaller.appspotmail.com Link: https://patch.msgid.link/20260710030851.2791589-5-yun.zhou@windriver.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-07-22ext4: cleanup unused CONVERT_INLINE_DATA flagAditya Prakash Srivastava1-1/+1
After implementing bitwise flags for tracking the inline data write state in the address space fsdata parameter, the CONVERT_INLINE_DATA state flag is left unused and can be removed. Perform this clean-up by: 1) Deleting the CONVERT_INLINE_DATA definition from ext4.h. 2) Removing the void **fsdata argument from both the forward declaration and the definition of the internal helper ext4_da_convert_inline_data_to_extent(). 3) Removing the void **fsdata argument from the declaration and definition of ext4_generic_write_inline_data() and updating the caller ext4_try_to_write_inline_data() and the internal re-alloc retry logic accordingly. 4) Updating ext4_da_write_begin() to call ext4_generic_write_inline_data() without the fsdata parameter. Suggested-by: Jan Kara <jack@suse.cz> Signed-off-by: Aditya Prakash Srivastava <aditya.ansh182@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260703045414.1768-2-aditya.ansh182@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-07-22ext4: use fsdata to track inline data write state and fix raceAditya Prakash Srivastava1-11/+13
Instead of checking the live inode state (ext4_has_inline_data(inode) and ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) in the write_end handlers, use the fsdata parameter of the address space operations to explicitly pass down the state in which write_begin prepared the write. A concurrent thread (such as ext4_page_mkwrite()) can convert the inline data to an extent between write_begin and write_end. If this happens, the write_end handlers would previously miss the inline write_end path and fall through to extent-based write_end logic. However, since block buffers were never allocated in write_begin, this resulted in NULL pointer dereferences or data loss because folio_buffers(folio) was NULL. Define EXT4_WRITE_DATA_INLINE (4) as a bit flag (Bit 2), treating fsdata as bitwise flags rather than mutually exclusive enums to keep states of the write path independent. Communicate this state via fsdata: 1) ext4_write_begin() and ext4_da_write_begin() set the EXT4_WRITE_DATA_INLINE bit in *fsdata via bitwise OR when an inline write is successfully prepared. 2) On entry, ext4_write_begin() clears the EXT4_WRITE_DATA_INLINE bit to safely handle VFS retries (where generic_perform_write() bypasses the fsdata initialization on its retry jump). 3) The write_end handlers perform a bitwise AND to check if the EXT4_WRITE_DATA_INLINE bit is set and invoke the inline write_end helper accordingly. Furthermore, during a buffered write, ext4_write_inline_data_end() acquires the xattr lock after preparing the write. If a concurrent page fault (ext4_page_mkwrite()) converts the inline data to an extent after the write_end handlers check the state but before ext4_write_inline_data_end() acquires the xattr write lock, the subsequent check will trigger a kernel panic via BUG_ON(!ext4_has_inline_data(inode)). To keep git history working and bisectability clean, replace the BUG_ON check in ext4_write_inline_data_end() with a graceful error- handling retry path in this same commit. If the inline data is cleared after locking the xattr, we safely release all resources (releasing iloc.bh, unlocking/putting the folio, stopping the active journal transaction handle) and return 0 (VFS retry) to let the generic write path retry the operation safely. Reported-by: syzbot+0c89d865531d053abb2d@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=0c89d865531d053abb2d Fixes: 3fdcfb668fd7 ("ext4: add journalled write support for inline data") Suggested-by: Jan Kara <jack@suse.cz> Signed-off-by: Aditya Prakash Srivastava <aditya.ansh182@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260703045414.1768-1-aditya.ansh182@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-07-22ext4: prevent sleeping allocation in NOWAIT write pathBaokun Li1-0/+3
Block allocation requires journal access which may sleep, violating NOWAIT semantics. Return -EAGAIN early when IOMAP_NOWAIT is set, allowing the caller to retry without the NOWAIT constraint. This ensures that write paths using IOMAP_NOWAIT (e.g., DIO with RWF_NOWAIT) will not block on journal operations when blocks need to be allocated. Reported-by: Sashiko <sashiko-bot@kernel.org> Closes: https://sashiko.dev/#/patchset/20260611163441.2431805-1-libaokun@linux.alibaba.com?part=1 Reviewed-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Baokun Li <libaokun@linux.alibaba.com> Link: https://patch.msgid.link/20260629113827.4074335-2-libaokun@linux.alibaba.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-07-22ext4: clear stale xarray tags on folios skipped during writebackGerald Yang1-3/+15
In data=journal mode, the writeback thread can hit the WARN_ON_ONCE(sb_rdonly(sb)) in ext4_journal_check_start() while the superblock is being remounted read-only during reboot: Workqueue: writeback wb_workfn (flush-253:0) RIP: 0010:ext4_journal_check_start+0x8b/0xd0 Call Trace: __ext4_journal_start_sb+0x3c/0x1e0 mpage_prepare_extent_to_map+0x4af/0x580 ext4_do_writepages+0x3c0/0x1080 ext4_writepages+0xc8/0x1a0 do_writepages+0xc4/0x180 __writeback_single_inode+0x45/0x2f0 writeback_sb_inodes+0x26b/0x5d0 __writeback_inodes_wb+0x54/0x100 wb_writeback+0x1ac/0x320 wb_workfn+0x394/0x470 And followed by the warning: EXT4-fs warning (device vda1): ext4_evict_inode:195: inode #6263: comm (sd-umount): data will be lost This issue is not reproduced every time, but frequently. The reproduction step is to create a VM with 8 CPUs, 16G memory and setup data=journal: sudo tune2fs -o journal_data /dev/vda1 Run fio: rm -f fiotest fio --name=fiotest --rw=randwrite --bs=4k --runtime=6 --ioengine=libaio --iodepth=256 --numjobs=8 --filename=fiotest --filesize=30G --group_reporting Reboot the VM, and check the console output from: virsh console testvm But there is no dirty inode, folio_clear_dirty_for_io clears PG_dirty but leaves tags PAGECACHE_TAG_DIRTY and PAGECACHE_TAG_TOWRITE set which are only cleared by __folio_start_writeback. In data=journal mode, jbd2 checkpoints the journalled data to its final location and clears its own dirty flag without touching folio PG_dirty or xarray dirty flags. The commit f4a2b42e7891 ("ext4: fix stale xarray tags after writeback") fixes when PG_dirty is still set but there is no dirty page. Another case is PG_dirty is cleared, but PAGECACHE_TAG_DIRTY and PAGECACHE_TAG_TOWRITE is still set. In this case, writeback thread checks clean folio and skips it in mpage_prepare_extent_to_map: if (!folio_test_dirty(folio) || ... folio_unlcok(folio); continue And never reaches ext4_bio_write_folio where the commit f4a2b42e7891 clears the stale xarray tags. Print debug logs after the filesystem is remounted read-only: writepages RDONLY nrpages=2048 dirtytag=1 wbtag=0 towrite=1 sync=0 And all folios are actually clean: folio idx=3 dirty=0 wb=0 checked=0 dirtybuf=0 jbddirty=0 mapped=1 ... We need to clear the xarray stale tags for such clean folios by cycling them through writeback in the skip path, the same way f4a2b42e7891 does in ext4_bio_write_folio. Fixes: dff4ac75eeee ("ext4: move keep_towrite handling to ext4_bio_write_page()") Signed-off-by: Gerald Yang <gerald.yang@canonical.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260625160127.162272-1-gerald.yang@canonical.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-07-22ext4: fix ABBA deadlock in ext4_xattr_inode_cache_find()Aditya Prakash Srivastava1-3/+32
Syzbot/stress-ng reported an ABBA deadlock in ext4 when exercising concurrent xattr workloads (using the ea_inode mount/format option). The deadlock occurs between the running transaction and the eviction thread: - Task 1 (stress-ng): Holds a reference to a shared mbcache_entry (ce) and calls ext4_xattr_inode_cache_find() -> ext4_iget() to retrieve the corresponding EA inode. Since the EA inode is currently being evicted, ext4_iget() blocks in __wait_on_freeing_inode() waiting for eviction to complete. - Task 2 (eviction thread): Currently evicting the same EA inode in ext4_evict_ea_inode(). It calls mb_cache_entry_wait_unused(oe) which blocks waiting for Task 1 to release the reference to the mbcache_entry. To break this deadlock, implement a new ext4_iget() configuration flag named EXT4_IGET_NOWAIT. When set, perform a non-blocking lookup of the inode via VFS's find_inode_nowait() API. If the inode is currently being evicted (marked with I_FREEING or I_WILL_FREE) or created (I_CREATING), or if it is not present in the VFS inode cache (cache miss), simply skip it (returning -ENOENT) rather than waiting for eviction/creation to complete, breaking the ABBA cycle. Since we return -ENOENT immediately on a cache miss, we never attempt to allocate a new inode or call iget_locked(), completely eliminating any TOCTOU race window. If the returned inode is I_NEW, wait for its initialization to clear via wait_on_new_inode(). If initialization fails and the inode is unhashed during wait_on_new_inode() waking up (e.g., due to an I/O read error in another thread), safely drop the reference and return -ENOENT. This unhashed check is executed unconditionally on all cache-hit pathways to properly handle concurrent initialization failures. Finally, standard validation checks (including is_bad_inode, EXT4_EA_INODE_FL, file_acl, and xattr flags) are executed as normal inside check_igot_inode() to fully guarantee VFS-layer safety. In ext4_xattr_inode_cache_find(), invoke ext4_iget() with the new EXT4_IGET_NOWAIT flag to perform the non-blocking cache search. Suggested-by: Jan Kara <jack@suse.cz> Reported-by: Colin Ian King <colin.i.king@gmail.com> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219283 Fixes: 0a46ef234756 ("ext4: do not create EA inode under buffer lock") Signed-off-by: Aditya Prakash Srivastava <aditya.ansh182@gmail.com> Tested-by: Colin Ian King <colin.i.king@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260626054821.1729-1-aditya.ansh182@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-07-21ext4: set EXT4_STATE_NO_EXPAND in ext4_evict_inodeYun Zhou1-0/+1
An inode being evicted will never need its extra isize expanded. Set EXT4_STATE_NO_EXPAND before ext4_mark_inode_dirty() in ext4_evict_inode() to make this explicit and prevent any unnecessary work in ext4_try_to_expand_extra_isize(). This also provides defense-in-depth for the s_writepages_rwsem deadlock during mount-time orphan cleanup, ensuring the expand path is blocked for inodes under eviction regardless of how they are reached. Signed-off-by: Yun Zhou <yun.zhou@windriver.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260623061903.2148767-2-yun.zhou@windriver.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-07-21ext4: skip extra isize expansion during mount to prevent deadlockYun Zhou1-0/+10
ext4_try_to_expand_extra_isize() is called from __ext4_mark_inode_dirty() while holding an active jbd2 handle. During mount (!SB_ACTIVE), the expand path may move xattrs to external blocks and release ea_inodes via iput(). When !SB_ACTIVE, iput() calls write_inode_now() which acquires s_writepages_rwsem, creating a circular lock dependency: s_writepages_rwsem --> jbd2_handle --> xattr_sem --> s_writepages_rwsem This can be triggered via: ext4_process_orphan() -> ext4_truncate() -> ext4_mark_inode_dirty() -> ext4_try_to_expand_extra_isize() or: ext4_evict_inode() -> ext4_mark_inode_dirty() -> ext4_try_to_expand_extra_isize() Skip expansion when !SB_ACTIVE. This is a minor loss of functionality (extra isize won't grow for these inodes during mount), which e2fsck can resolve later if needed. Reported-by: syzbot+5d19358d7eb30ffb0cc5@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=5d19358d7eb30ffb0cc5 Fixes: c8585c6fcaf2 ("ext4: fix races between changing inode journal mode and ext4_writepages") Signed-off-by: Yun Zhou <yun.zhou@windriver.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260623061903.2148767-1-yun.zhou@windriver.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-07-21ext4: avoid tail write_begin walk for uptodate foliosJia Zhu1-5/+6
Ext4 buffered writes into large folios also pay a full buffer_head walk in ext4_block_write_begin(). For a small overwrite of an existing cached folio, the folio is already uptodate and the write only needs to prepare the buffers through the written range. Walking the suffix still makes the write_begin cost proportional to the folio size. Before ext4 enabled large folios for regular files, the same loop was bounded by a single page of buffers. That commit made the existing full-folio walk visible as a regression for cached small overwrites. The suffix walk is needed for non-uptodate folios, where ext4 may have to submit reads for partial blocks, preserve new-buffer cleanup, and run error zeroing. Keep those folios on the old full walk. For already-uptodate folios, keep the walk starting at the first buffer rather than seeking directly to from. This preserves the existing prefix buffer state handling. Stop once block_start reaches the end of the write range, because the skipped suffix would only repeat the outside-range uptodate handling for buffers beyond @to. On current master, the libMicro ext4 large-folio overwrite test shows the following full-series result. Results are median usecs/call over 10 runs, lower is better: case nofix this series improvement write_u1k 1.418 0.3405 76.0% write_u10k 1.887 0.4175 77.9% pwrite_u1k 1.6775 0.3390 79.8% pwrite_u10k 1.9035 0.4130 78.3% Fixes: 7ac67301e82f0 ("ext4: enable large folio for regular file") Cc: stable@vger.kernel.org # v6.16+ Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Jia Zhu <zhujia.zj@bytedance.com> Link: https://patch.msgid.link/20260609035202.90669-3-zhujia.zj@bytedance.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-07-20fscrypt: Remove fscrypt_dio_supported()Eric Biggers1-9/+2
On block-based filesystems, fscrypt file contents encryption is now always implemented using blk-crypto. This implementation supports direct I/O. Therefore, fscrypt_dio_supported() now always returns true, except in the edge case where statx(STATX_DIOALIGN) is called on an encrypted regular file that hasn't had its key set up. But that was really a workaround rather than the desired behavior, so we can disregard it. Thus, fscrypt_dio_supported() is no longer needed. Remove it. Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/20260713023708.9245-14-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-07-20ext4: Make ext4_bio_write_folio() return voidEric Biggers1-23/+9
Since the fs-layer file contents encryption implementation was removed, ext4_bio_write_folio() now always returns 0. Change it to return void, and likewise for its caller mpage_submit_folio(). Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/20260713023708.9245-9-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-07-20ext4: Remove fs-layer file contents en/decryption codeEric Biggers1-25/+3
Now that fscrypt's file contents en/decryption is always implemented using blk-crypto when the filesystem is block-based, the fs-layer en/decryption code in ext4 is unused code. Remove it. Note that this makes possible some additional cleanups, but they're left to later commits: - Making ext4_bio_write_folio() return void - Renaming bio_post_read_ctx to fsverity_ctx or similar, and allocating the pool only when fsverity support is needed Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/20260713023708.9245-8-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-06-10ext4: fix kernel BUG in ext4_write_inline_data_endAditya Prakash Srivastava1-1/+2
When the data=journal mount option is used, the ext4_journalled_write_end() function incorrectly calls ext4_write_inline_data_end() without checking if the EXT4_STATE_MAY_INLINE_DATA flag is still set on the inode. If a previous attempt to convert the inline data to an extent failed (e.g. due to ENOSPC), the EXT4_STATE_MAY_INLINE_DATA flag is cleared, but the EXT4_INODE_INLINE_DATA flag remains set. In this scenario, the next call to ext4_write_begin() will not prepare the inline data xattr for writing, but ext4_journalled_write_end() will incorrectly attempt to write to it, triggering a BUG_ON(pos + len > EXT4_I(inode)->i_inline_size) in ext4_write_inline_data() since i_inline_size was not expanded. Fix this by ensuring that ext4_journalled_write_end() only calls ext4_write_inline_data_end() if the EXT4_STATE_MAY_INLINE_DATA flag is set, mirroring the behavior of ext4_write_end() and ext4_da_write_end(). Reported-by: syzbot+0c89d865531d053abb2d@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=0c89d865531d053abb2d Fixes: 3fdcfb668fd7 ("ext4: add journalled write support for inline data") Signed-off-by: Aditya Prakash Srivastava <aditya.ansh182@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260608065227.3018-1-aditya.ansh182@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-06-03ext4: fast commit: snapshot inode state before writing logLi Chen1-0/+51
Fast commit writes inode metadata and data range updates after unlocking journal updates. New handles can start at that point, so the log writing path must not look at live inode state. Add a commit-time per-inode snapshot and populate it while journal updates are locked and existing handles are drained. Store the snapshot behind ext4_inode_info->i_fc_snap so ext4_inode_info only grows by one pointer. The snapshot contains a copy of the on-disk inode plus the data range records needed for fast commit TLVs. Snapshotting runs under jbd2_journal_lock_updates(). Avoid triggering I/O there by using ext4_get_inode_loc_noio() and falling back to full commit if the inode table block is not present or not uptodate. Log writing then only serializes the snapshot, so it no longer needs to call ext4_map_blocks() and take i_data_sem under s_fc_lock. The snapshot is installed and freed under s_fc_lock and is released from fast commit cleanup and inode eviction. Signed-off-by: Li Chen <chenl311@chinatelecom.cn> Link: https://patch.msgid.link/20260515091829.194810-2-me@linux.beauty Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-04-17Merge tag 'ext4_for_linux-7.0-rc1' of ↵Linus Torvalds1-107/+197
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 updates from Ted Ts'o: - Refactor code paths involved with partial block zero-out in prearation for converting ext4 to use iomap for buffered writes - Remove use of d_alloc() from ext4 in preparation for the deprecation of this interface - Replace some J_ASSERTS with a journal abort so we can avoid a kernel panic for a localized file system error - Simplify various code paths in mballoc, move_extent, and fast commit - Fix rare deadlock in jbd2_journal_cancel_revoke() that can be triggered by generic/013 when blocksize < pagesize - Fix memory leak when releasing an extended attribute when its value is stored in an ea_inode - Fix various potential kunit test bugs in fs/ext4/extents.c - Fix potential out-of-bounds access in check_xattr() with a corrupted file system - Make the jbd2_inode dirty range tracking safe for lockless reads - Avoid a WARN_ON when writeback files due to a corrupted file system; we already print an ext4 warning indicatign that data will be lost, so the WARN_ON is not necessary and doesn't add any new information * tag 'ext4_for_linux-7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (37 commits) jbd2: fix deadlock in jbd2_journal_cancel_revoke() ext4: fix missing brelse() in ext4_xattr_inode_dec_ref_all() ext4: fix possible null-ptr-deref in mbt_kunit_exit() ext4: fix possible null-ptr-deref in extents_kunit_exit() ext4: fix the error handling process in extents_kunit_init). ext4: call deactivate_super() in extents_kunit_exit() ext4: fix miss unlock 'sb->s_umount' in extents_kunit_init() ext4: fix bounds check in check_xattrs() to prevent out-of-bounds access ext4: zero post-EOF partial block before appending write ext4: move pagecache_isize_extended() out of active handle ext4: remove ctime/mtime update from ext4_alloc_file_blocks() ext4: unify SYNC mode checks in fallocate paths ext4: ensure zeroed partial blocks are persisted in SYNC mode ext4: move zero partial block range functions out of active handle ext4: pass allocate range as loff_t to ext4_alloc_file_blocks() ext4: remove handle parameters from zero partial block functions ext4: move ordered data handling out of ext4_block_do_zero_range() ext4: rename ext4_block_zero_page_range() to ext4_block_zero_range() ext4: factor out journalled block zeroing range ext4: rename and extend ext4_block_truncate_page() ...
2026-04-15Merge tag 'mm-stable-2026-04-13-21-45' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - "maple_tree: Replace big node with maple copy" (Liam Howlett) Mainly prepararatory work for ongoing development but it does reduce stack usage and is an improvement. - "mm, swap: swap table phase III: remove swap_map" (Kairui Song) Offers memory savings by removing the static swap_map. It also yields some CPU savings and implements several cleanups. - "mm: memfd_luo: preserve file seals" (Pratyush Yadav) File seal preservation to LUO's memfd code - "mm: zswap: add per-memcg stat for incompressible pages" (Jiayuan Chen) Additional userspace stats reportng to zswap - "arch, mm: consolidate empty_zero_page" (Mike Rapoport) Some cleanups for our handling of ZERO_PAGE() and zero_pfn - "mm/kmemleak: Improve scan_should_stop() implementation" (Zhongqiu Han) A robustness improvement and some cleanups in the kmemleak code - "Improve khugepaged scan logic" (Vernon Yang) Improve khugepaged scan logic and reduce CPU consumption by prioritizing scanning tasks that access memory frequently - "Make KHO Stateless" (Jason Miu) Simplify Kexec Handover by transitioning KHO from an xarray-based metadata tracking system with serialization to a radix tree data structure that can be passed directly to the next kernel - "mm: vmscan: add PID and cgroup ID to vmscan tracepoints" (Thomas Ballasi and Steven Rostedt) Enhance vmscan's tracepointing - "mm: arch/shstk: Common shadow stack mapping helper and VM_NOHUGEPAGE" (Catalin Marinas) Cleanup for the shadow stack code: remove per-arch code in favour of a generic implementation - "Fix KASAN support for KHO restored vmalloc regions" (Pasha Tatashin) Fix a WARN() which can be emitted the KHO restores a vmalloc area - "mm: Remove stray references to pagevec" (Tal Zussman) Several cleanups, mainly udpating references to "struct pagevec", which became folio_batch three years ago - "mm: Eliminate fake head pages from vmemmap optimization" (Kiryl Shutsemau) Simplify the HugeTLB vmemmap optimization (HVO) by changing how tail pages encode their relationship to the head page - "mm/damon/core: improve DAMOS quota efficiency for core layer filters" (SeongJae Park) Improve two problematic behaviors of DAMOS that makes it less efficient when core layer filters are used - "mm/damon: strictly respect min_nr_regions" (SeongJae Park) Improve DAMON usability by extending the treatment of the min_nr_regions user-settable parameter - "mm/page_alloc: pcp locking cleanup" (Vlastimil Babka) The proper fix for a previously hotfixed SMP=n issue. Code simplifications and cleanups ensued - "mm: cleanups around unmapping / zapping" (David Hildenbrand) A bunch of cleanups around unmapping and zapping. Mostly simplifications, code movements, documentation and renaming of zapping functions - "support batched checking of the young flag for MGLRU" (Baolin Wang) Batched checking of the young flag for MGLRU. It's part cleanups; one benchmark shows large performance benefits for arm64 - "memcg: obj stock and slab stat caching cleanups" (Johannes Weiner) memcg cleanup and robustness improvements - "Allow order zero pages in page reporting" (Yuvraj Sakshith) Enhance free page reporting - it is presently and undesirably order-0 pages when reporting free memory. - "mm: vma flag tweaks" (Lorenzo Stoakes) Cleanup work following from the recent conversion of the VMA flags to a bitmap - "mm/damon: add optional debugging-purpose sanity checks" (SeongJae Park) Add some more developer-facing debug checks into DAMON core - "mm/damon: test and document power-of-2 min_region_sz requirement" (SeongJae Park) An additional DAMON kunit test and makes some adjustments to the addr_unit parameter handling - "mm/damon/core: make passed_sample_intervals comparisons overflow-safe" (SeongJae Park) Fix a hard-to-hit time overflow issue in DAMON core - "mm/damon: improve/fixup/update ratio calculation, test and documentation" (SeongJae Park) A batch of misc/minor improvements and fixups for DAMON - "mm: move vma_(kernel|mmu)_pagesize() out of hugetlb.c" (David Hildenbrand) Fix a possible issue with dax-device when CONFIG_HUGETLB=n. Some code movement was required. - "zram: recompression cleanups and tweaks" (Sergey Senozhatsky) A somewhat random mix of fixups, recompression cleanups and improvements in the zram code - "mm/damon: support multiple goal-based quota tuning algorithms" (SeongJae Park) Extend DAMOS quotas goal auto-tuning to support multiple tuning algorithms that users can select - "mm: thp: reduce unnecessary start_stop_khugepaged()" (Breno Leitao) Fix the khugpaged sysfs handling so we no longer spam the logs with reams of junk when starting/stopping khugepaged - "mm: improve map count checks" (Lorenzo Stoakes) Provide some cleanups and slight fixes in the mremap, mmap and vma code - "mm/damon: support addr_unit on default monitoring targets for modules" (SeongJae Park) Extend the use of DAMON core's addr_unit tunable - "mm: khugepaged cleanups and mTHP prerequisites" (Nico Pache) Cleanups to khugepaged and is a base for Nico's planned khugepaged mTHP support - "mm: memory hot(un)plug and SPARSEMEM cleanups" (David Hildenbrand) Code movement and cleanups in the memhotplug and sparsemem code - "mm: remove CONFIG_ARCH_ENABLE_MEMORY_HOTREMOVE and cleanup CONFIG_MIGRATION" (David Hildenbrand) Rationalize some memhotplug Kconfig support - "change young flag check functions to return bool" (Baolin Wang) Cleanups to change all young flag check functions to return bool - "mm/damon/sysfs: fix memory leak and NULL dereference issues" (Josh Law and SeongJae Park) Fix a few potential DAMON bugs - "mm/vma: convert vm_flags_t to vma_flags_t in vma code" (Lorenzo Stoakes) Convert a lot of the existing use of the legacy vm_flags_t data type to the new vma_flags_t type which replaces it. Mainly in the vma code. - "mm: expand mmap_prepare functionality and usage" (Lorenzo Stoakes) Expand the mmap_prepare functionality, which is intended to replace the deprecated f_op->mmap hook which has been the source of bugs and security issues for some time. Cleanups, documentation, extension of mmap_prepare into filesystem drivers - "mm/huge_memory: refactor zap_huge_pmd()" (Lorenzo Stoakes) Simplify and clean up zap_huge_pmd(). Additional cleanups around vm_normal_folio_pmd() and the softleaf functionality are performed. * tag 'mm-stable-2026-04-13-21-45' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits) mm: fix deferred split queue races during migration mm/khugepaged: fix issue with tracking lock mm/huge_memory: add and use has_deposited_pgtable() mm/huge_memory: add and use normal_or_softleaf_folio_pmd() mm: add softleaf_is_valid_pmd_entry(), pmd_to_softleaf_folio() mm/huge_memory: separate out the folio part of zap_huge_pmd() mm/huge_memory: use mm instead of tlb->mm mm/huge_memory: remove unnecessary sanity checks mm/huge_memory: deduplicate zap deposited table call mm/huge_memory: remove unnecessary VM_BUG_ON_PAGE() mm/huge_memory: add a common exit path to zap_huge_pmd() mm/huge_memory: handle buggy PMD entry in zap_huge_pmd() mm/huge_memory: have zap_huge_pmd return a boolean, add kdoc mm/huge: avoid big else branch in zap_huge_pmd() mm/huge_memory: simplify vma_is_specal_huge() mm: on remap assert that input range within the proposed VMA mm: add mmap_action_map_kernel_pages[_full]() uio: replace deprecated mmap hook with mmap_prepare in uio_info drivers: hv: vmbus: replace deprecated mmap hook with mmap_prepare mm: allow handling of stacked mmap_prepare hooks in more drivers ...
2026-04-13Merge tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/linuxLinus Torvalds1-1/+4
Pull fscrypt updates from Eric Biggers: - Various cleanups for the interface between fs/crypto/ and filesystems, from Christoph Hellwig - Simplify and optimize the implementation of v1 key derivation by using the AES library instead of the crypto_skcipher API * tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/linux: fscrypt: use AES library for v1 key derivation ext4: use a byte granularity cursor in ext4_mpage_readpages fscrypt: pass a real sector_t to fscrypt_zeroout_range fscrypt: pass a byte length to fscrypt_zeroout_range fscrypt: pass a byte offset to fscrypt_zeroout_range fscrypt: pass a byte length to fscrypt_zeroout_range_inline_crypt fscrypt: pass a byte offset to fscrypt_zeroout_range_inline_crypt fscrypt: pass a byte offset to fscrypt_set_bio_crypt_ctx fscrypt: pass a byte offset to fscrypt_mergeable_bio fscrypt: pass a byte offset to fscrypt_generate_dun fscrypt: move fscrypt_set_bio_crypt_ctx_bh to buffer.c ext4, fscrypt: merge fscrypt_mergeable_bio_bh into io_submit_need_new_bio ext4: factor out a io_submit_need_new_bio helper ext4: open code fscrypt_set_bio_crypt_ctx_bh ext4: initialize the write hint in io_submit_init_bio
2026-04-13Merge tag 'vfs-7.1-rc1.bh.metadata' of ↵Linus Torvalds1-5/+4
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs buffer_head updates from Christian Brauner: "This cleans up the mess that has accumulated over the years in metadata buffer_head tracking for inodes. It moves the tracking into dedicated structure in filesystem-private part of the inode (so that we don't use private_list, private_data, and private_lock in struct address_space), and also moves couple other users of private_data and private_list so these are removed from struct address_space saving 3 longs in struct inode for 99% of inodes" * tag 'vfs-7.1-rc1.bh.metadata' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (42 commits) fs: Drop i_private_list from address_space fs: Drop mapping_metadata_bhs from address space ext4: Track metadata bhs in fs-private inode part minix: Track metadata bhs in fs-private inode part udf: Track metadata bhs in fs-private inode part fat: Track metadata bhs in fs-private inode part bfs: Track metadata bhs in fs-private inode part affs: Track metadata bhs in fs-private inode part ext2: Track metadata bhs in fs-private inode part fs: Provide functions for handling mapping_metadata_bhs directly fs: Switch inode_has_buffers() to take mapping_metadata_bhs fs: Make bhs point to mapping_metadata_bhs fs: Move metadata bhs tracking to a separate struct fs: Fold fsync_buffers_list() into sync_mapping_buffers() fs: Drop osync_buffers_list() kvm: Use private inode list instead of i_private_list fs: Remove i_private_data aio: Stop using i_private_data and i_private_lock hugetlbfs: Stop using i_private_data fs: Stop using i_private_data for metadata bh tracking ...
2026-04-13Merge tag 'vfs-7.1-rc1.kino' of ↵Linus Torvalds1-11/+11
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs i_ino updates from Christian Brauner: "For historical reasons, the inode->i_ino field is an unsigned long, which means that it's 32 bits on 32 bit architectures. This has caused a number of filesystems to implement hacks to hash a 64-bit identifier into a 32-bit field, and deprives us of a universal identifier field for an inode. This changes the inode->i_ino field from an unsigned long to a u64. This shouldn't make any material difference on 64-bit hosts, but 32-bit hosts will see struct inode grow by at least 4 bytes. This could have effects on slabcache sizes and field alignment. The bulk of the changes are to format strings and tracepoints, since the kernel itself doesn't care that much about the i_ino field. The first patch changes some vfs function arguments, so check that one out carefully. With this change, we may be able to shrink some inode structures. For instance, struct nfs_inode has a fileid field that holds the 64-bit inode number. With this set of changes, that field could be eliminated. I'd rather leave that sort of cleanups for later just to keep this simple" * tag 'vfs-7.1-rc1.kino' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: nilfs2: fix 64-bit division operations in nilfs_bmap_find_target_in_group() EVM: add comment describing why ino field is still unsigned long vfs: remove externs from fs.h on functions modified by i_ino widening treewide: fix missed i_ino format specifier conversions ext4: fix signed format specifier in ext4_load_inode trace event treewide: change inode->i_ino from unsigned long to u64 nilfs2: widen trace event i_ino fields to u64 f2fs: widen trace event i_ino fields to u64 ext4: widen trace event i_ino fields to u64 zonefs: widen trace event i_ino fields to u64 hugetlbfs: widen trace event i_ino fields to u64 ext2: widen trace event i_ino fields to u64 cachefiles: widen trace event i_ino fields to u64 vfs: widen trace event i_ino fields to u64 net: change sock.sk_ino and sock_i_ino() to u64 audit: widen ino fields to u64 vfs: widen inode hash/lookup functions to u64
2026-04-09ext4: zero post-EOF partial block before appending writeZhang Yi1-14/+7
In cases of appending write beyond EOF, ext4_zero_partial_blocks() is called within ext4_*_write_end() to zero out the partial block beyond EOF. This prevents exposing stale data that might be written through mmap. However, supporting only the regular buffered write path is insufficient. It is also necessary to support the DAX path as well as the upcoming iomap buffered write path. Therefore, move this operation to ext4_write_checks(). In addition, this may introduce a race window in which a post-EOF buffered write can race with an mmap write after the old EOF block has been zeroed. As a result, the data in this block written by the buffer-write and the data written by the mmap-write may be mixed. However, this is safe because users should not rely on the result of the race condition. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260327102939.1095257-14-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-04-09ext4: unify SYNC mode checks in fallocate pathsZhang Yi1-1/+1
In the ext4 fallocate call chain, SYNC mode handling is inconsistent: some places check the inode state, while others check the open file descriptor state. Unify these checks by evaluating both conditions to ensure consistent behavior across all fallocate operations. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260327102939.1095257-11-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-04-09ext4: ensure zeroed partial blocks are persisted in SYNC modeZhang Yi1-5/+14
In ext4_zero_range() and ext4_punch_hole(), when operating in SYNC mode and zeroing a partial block, only data=journal modes guarantee that the zeroed data is synchronously persisted after the operation completes. For data=ordered/writeback mode and non-journal modes, this guarantee is missing. Introduce a partial_zero parameter to explicitly trigger writeback for all scenarios where a partial block is zeroed, ensuring the zeroed data is durably persisted. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Link: https://patch.msgid.link/20260327102939.1095257-10-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-04-09ext4: move zero partial block range functions out of active handleZhang Yi1-21/+26
Move ext4_block_zero_eof() and ext4_zero_partial_blocks() calls out of the active handle context, making them independent operations, and also add return value checks. This is safe because it still ensures data is updated before metadata for data=ordered mode and data=journal mode because we still zero data and ordering data before modifying the metadata. This change is required for iomap infrastructure conversion because the iomap buffered I/O path does not use the same journal infrastructure for partial block zeroing. The lock ordering of folio lock and starting transactions is "folio lock -> transaction start", which is opposite of the current path. Therefore, zeroing partial blocks cannot be performed under the active handle. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260327102939.1095257-9-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-04-09ext4: remove handle parameters from zero partial block functionsZhang Yi1-27/+42
Only journal data mode requires an active journal handle when zeroing partial blocks. Stop passing handle_t *handle to ext4_zero_partial_blocks() and related functions, and make ext4_block_journalled_zero_range() start a handle independently. This change has no practical impact now because all callers invoke these functions within the context of an active handle. It prepares for moving ext4_block_zero_eof() out of an active handle in the next patch, which is a prerequisite for converting block zero range operations to iomap infrastructure. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260327102939.1095257-7-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-04-09ext4: move ordered data handling out of ext4_block_do_zero_range()Zhang Yi1-29/+32
Remove the handle parameter from ext4_block_do_zero_range() and move the ordered data handling to ext4_block_zero_eof(). This is necessary for truncate up and append writes across a range extending beyond EOF. The ordered data must be committed before updating i_disksize to prevent exposing stale on-disk data from concurrent post-EOF mmap writes during previous folio writeback or in case of system crash during append writes. This is unnecessary for partial block hole punching because the entire punch operation does not provide atomicity guarantees and can already expose intermediate results in case of crash. Hole punching can only ever expose data that was there before the punch but missed zeroing during append / truncate could expose data that was not visible in the file before the operation. Since ordered data handling is no longer performed inside ext4_zero_partial_blocks(), ext4_punch_hole() no longer needs to attach jinode. This is prepared for the conversion to the iomap infrastructure, which does not use ordered data mode while zeroing post-EOF partial blocks. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260327102939.1095257-6-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-04-09ext4: rename ext4_block_zero_page_range() to ext4_block_zero_range()Zhang Yi1-19/+14
Rename ext4_block_zero_page_range() to ext4_block_zero_range() since the "page" naming is no longer appropriate for current context. Also change its signature to take an inode pointer instead of an address_space. This aligns with the caller ext4_block_zero_eof() and ext4_zero_partial_blocks(). Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260327102939.1095257-5-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-04-09ext4: factor out journalled block zeroing rangeZhang Yi1-29/+69
Refactor __ext4_block_zero_page_range() by separating the block zeroing operations for ordered data mode and journal data mode into two distinct functions: - ext4_block_do_zero_range(): handles non-journal data mode with ordered data support - ext4_block_journalled_zero_range(): handles journal data mode Also extract a common helper, ext4_load_tail_bh(), to handle buffer head and folio retrieval, along with the associated error handling. This prepares for converting the partial block zero range to the iomap infrastructure. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260327102939.1095257-4-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-04-09ext4: rename and extend ext4_block_truncate_page()Zhang Yi1-19/+24
Rename ext4_block_truncate_page() to ext4_block_zero_eof() and extend its signature to accept an explicit 'end' offset instead of calculating the block boundary. This helper function now can replace all cases requiring zeroing of the partial EOF block, including the append buffered write paths in ext4_*_write_end(). Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260327102939.1095257-3-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-04-09ext4: add did_zero output parameter to ext4_block_zero_page_range()Zhang Yi1-9/+14
Add a bool *did_zero output parameter to ext4_block_zero_page_range() and __ext4_block_zero_page_range(). The parameter reports whether a partial block was zeroed out, which is needed for the upcoming iomap buffered I/O conversion. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260327102939.1095257-2-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-04-09ext4: use jbd2 jinode dirty range accessorLi Chen1-2/+8
ext4 journal commit callbacks access jbd2_inode dirty range fields without holding journal->j_list_lock. Use jbd2_jinode_get_dirty_range() to get the range in bytes, and read i_transaction with READ_ONCE() in the redirty check. Suggested-by: Jan Kara <jack@suse.cz> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Li Chen <me@linux.beauty> Link: https://patch.msgid.link/20260306085643.465275-3-me@linux.beauty Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-04-09ext4: unmap invalidated folios from page tables in mpage_release_unused_pages()Deepanshu Kartikey1-1/+15
When delayed block allocation fails (e.g., due to filesystem corruption detected in ext4_map_blocks()), the writeback error handler calls mpage_release_unused_pages(invalidate=true) which invalidates affected folios by clearing their uptodate flag via folio_clear_uptodate(). However, these folios may still be mapped in process page tables. If a subsequent operation (such as ftruncate calling ext4_block_truncate_page) triggers a write fault, the existing page table entry allows access to the now-invalidated folio. This leads to ext4_page_mkwrite() being called with a non-uptodate folio, which then gets marked dirty, triggering: WARNING: CPU: 0 PID: 5 at mm/page-writeback.c:2960 __folio_mark_dirty+0x578/0x880 Call Trace: fault_dirty_shared_page+0x16e/0x2d0 do_wp_page+0x38b/0xd20 handle_pte_fault+0x1da/0x450 The sequence leading to this warning is: 1. Process writes to mmap'd file, folio becomes uptodate and dirty 2. Writeback begins, but delayed allocation fails due to corruption 3. mpage_release_unused_pages(invalidate=true) is called: - block_invalidate_folio() clears dirty flag - folio_clear_uptodate() clears uptodate flag - But folio remains mapped in page tables 4. Later, ftruncate triggers ext4_block_truncate_page() 5. This causes a write fault on the still-mapped folio 6. ext4_page_mkwrite() is called with folio that is !uptodate 7. block_page_mkwrite() marks buffers dirty 8. fault_dirty_shared_page() tries to mark folio dirty 9. block_dirty_folio() calls __folio_mark_dirty(warn=1) 10. WARNING triggers: WARN_ON_ONCE(warn && !uptodate && !dirty) Fix this by unmapping folios from page tables before invalidating them using unmap_mapping_pages(). This ensures that subsequent accesses trigger new page faults rather than reusing invalidated folios through stale page table entries. Note that this results in data loss for any writes to the mmap'd region that couldn't be written back, but this is expected behavior when writeback fails due to filesystem corruption. The existing error message already states "This should not happen!! Data will be lost". Reported-by: syzbot+b0a0670332b6b3230a0a@syzkaller.appspotmail.com Tested-by: syzbot+b0a0670332b6b3230a0a@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=b0a0670332b6b3230a0a Suggested-by: Matthew Wilcox <willy@infradead.org> Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com> Link: https://patch.msgid.link/20251205055914.1393799-1-kartikey406@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-04-05folio_batch: rename pagevec.h to folio_batch.hTal Zussman1-1/+1
struct pagevec was removed in commit 1e0877d58b1e ("mm: remove struct pagevec"). Rename include/linux/pagevec.h to reflect reality and update includes tree-wide. Add the new filename to MAINTAINERS explicitly, as it no longer matches the "include/linux/page[-_]*" pattern in MEMORY MANAGEMENT - CORE. Link: https://lkml.kernel.org/r/20260225-pagevec_cleanup-v2-3-716868cc2d11@columbia.edu Signed-off-by: Tal Zussman <tz2294@columbia.edu> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Cc: Chris Li <chrisl@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-03-27ext4: test if inode's all dirty pages are submitted to diskYe Bin1-0/+8
The commit aa373cf55099 ("writeback: stop background/kupdate works from livelocking other works") introduced an issue where unmounting a filesystem in a multi-logical-partition scenario could lead to batch file data loss. This problem was not fixed until the commit d92109891f21 ("fs/writeback: bail out if there is no more inodes for IO and queued once"). It took considerable time to identify the root cause. Additionally, in actual production environments, we frequently encountered file data loss after normal system reboots. Therefore, we are adding a check in the inode release flow to verify whether all dirty pages have been flushed to disk, in order to determine whether the data loss is caused by a logic issue in the filesystem code. Signed-off-by: Ye Bin <yebin10@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260303012242.3206465-1-yebin@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org
2026-03-27ext4: publish jinode after initializationLi Chen1-4/+11
ext4_inode_attach_jinode() publishes ei->jinode to concurrent users. It used to set ei->jinode before jbd2_journal_init_jbd_inode(), allowing a reader to observe a non-NULL jinode with i_vfs_inode still unset. The fast commit flush path can then pass this jinode to jbd2_wait_inode_data(), which dereferences i_vfs_inode->i_mapping and may crash. Below is the crash I observe: ``` BUG: unable to handle page fault for address: 000000010beb47f4 PGD 110e51067 P4D 110e51067 PUD 0 Oops: Oops: 0000 [#1] SMP NOPTI CPU: 1 UID: 0 PID: 4850 Comm: fc_fsync_bench_ Not tainted 6.18.0-00764-g795a690c06a5 #1 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.17.0-2-2 04/01/2014 RIP: 0010:xas_find_marked+0x3d/0x2e0 Code: e0 03 48 83 f8 02 0f 84 f0 01 00 00 48 8b 47 08 48 89 c3 48 39 c6 0f 82 fd 01 00 00 48 85 c9 74 3d 48 83 f9 03 77 63 4c 8b 0f <49> 8b 71 08 48 c7 47 18 00 00 00 00 48 89 f1 83 e1 03 48 83 f9 02 RSP: 0018:ffffbbee806e7bf0 EFLAGS: 00010246 RAX: 000000000010beb4 RBX: 000000000010beb4 RCX: 0000000000000003 RDX: 0000000000000001 RSI: 0000002000300000 RDI: ffffbbee806e7c10 RBP: 0000000000000001 R08: 0000002000300000 R09: 000000010beb47ec R10: ffff9ea494590090 R11: 0000000000000000 R12: 0000002000300000 R13: ffffbbee806e7c90 R14: ffff9ea494513788 R15: ffffbbee806e7c88 FS: 00007fc2f9e3e6c0(0000) GS:ffff9ea6b1444000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000010beb47f4 CR3: 0000000119ac5000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: <TASK> filemap_get_folios_tag+0x87/0x2a0 __filemap_fdatawait_range+0x5f/0xd0 ? srso_alias_return_thunk+0x5/0xfbef5 ? __schedule+0x3e7/0x10c0 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? preempt_count_sub+0x5f/0x80 ? srso_alias_return_thunk+0x5/0xfbef5 ? cap_safe_nice+0x37/0x70 ? srso_alias_return_thunk+0x5/0xfbef5 ? preempt_count_sub+0x5f/0x80 ? srso_alias_return_thunk+0x5/0xfbef5 filemap_fdatawait_range_keep_errors+0x12/0x40 ext4_fc_commit+0x697/0x8b0 ? ext4_file_write_iter+0x64b/0x950 ? srso_alias_return_thunk+0x5/0xfbef5 ? preempt_count_sub+0x5f/0x80 ? srso_alias_return_thunk+0x5/0xfbef5 ? vfs_write+0x356/0x480 ? srso_alias_return_thunk+0x5/0xfbef5 ? preempt_count_sub+0x5f/0x80 ext4_sync_file+0xf7/0x370 do_fsync+0x3b/0x80 ? syscall_trace_enter+0x108/0x1d0 __x64_sys_fdatasync+0x16/0x20 do_syscall_64+0x62/0x2c0 entry_SYSCALL_64_after_hwframe+0x76/0x7e ... ``` Fix this by initializing the jbd2_inode first. Use smp_wmb() and WRITE_ONCE() to publish ei->jinode after initialization. Readers use READ_ONCE() to fetch the pointer. Fixes: a361293f5fede ("jbd2: Fix oops in jbd2_journal_file_inode()") Cc: stable@vger.kernel.org Signed-off-by: Li Chen <me@linux.beauty> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260225082617.147957-1-me@linux.beauty Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org
2026-03-27ext4: convert inline data to extents when truncate exceeds inline sizeDeepanshu Kartikey1-0/+12
Add a check in ext4_setattr() to convert files from inline data storage to extent-based storage when truncate() grows the file size beyond the inline capacity. This prevents the filesystem from entering an inconsistent state where the inline data flag is set but the file size exceeds what can be stored inline. Without this fix, the following sequence causes a kernel BUG_ON(): 1. Mount filesystem with inode that has inline flag set and small size 2. truncate(file, 50MB) - grows size but inline flag remains set 3. sendfile() attempts to write data 4. ext4_write_inline_data() hits BUG_ON(write_size > inline_capacity) The crash occurs because ext4_write_inline_data() expects inline storage to accommodate the write, but the actual inline capacity (~60 bytes for i_block + ~96 bytes for xattrs) is far smaller than the file size and write request. The fix checks if the new size from setattr exceeds the inode's actual inline capacity (EXT4_I(inode)->i_inline_size) and converts the file to extent-based storage before proceeding with the size change. This addresses the root cause by ensuring the inline data flag and file size remain consistent during truncate operations. Reported-by: syzbot+7de5fe447862fc37576f@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=7de5fe447862fc37576f Tested-by: syzbot+7de5fe447862fc37576f@syzkaller.appspotmail.com Signed-off-by: Deepanshu Kartikey <Kartikey406@gmail.com> Link: https://patch.msgid.link/20260207043607.1175976-1-kartikey406@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org