kernel/linux.git/fs/ext4/file.c, branch v6.6.132

ext4: fix checks for orphan inodes

2025-10-15T09:58:08+00:00

commit acf943e9768ec9d9be80982ca0ebc4bfd6b7631e upstream. When orphan file feature is enabled, inode can be tracked as orphan either in the standard orphan list or in the orphan file. The first can be tested by checking ei->i_orphan list head, the second is recorded by EXT4_STATE_ORPHAN_FILE inode state flag. There are several places where we want to check whether inode is tracked as orphan and only some of them properly check for both possibilities. Luckily the consequences are mostly minor, the worst that can happen is that we track an inode as orphan although we don't need to and e2fsck then complains (resulting in occasional ext4/307 xfstest failures). Fix the problem by introducing a helper for checking whether an inode is tracked as orphan and use it in appropriate places. Fixes: 4a79a98c7b19 ("ext4: Improve scalability of ext4 orphan file handling") Cc: stable@kernel.org Signed-off-by: Jan Kara Reviewed-by: Zhang Yi Message-ID: <20250925123038.20264-2-jack@suse.cz> Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

ext4: factor out ext4_get_maxbytes()

2025-06-27T10:08:47+00:00

commit dbe27f06fa38b9bfc598f8864ae1c5d5831d9992 upstream. 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 Reviewed-by: Jan Kara Reviewed-by: Baokun Li Link: https://patch.msgid.link/20250506012009.3896990-3-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman

ext4: dax: fix overflowing extents beyond inode size when partially writing

2024-10-10T09:57:47+00:00

commit dda898d7ffe85931f9cca6d702a51f33717c501e upstream. The dax_iomap_rw() does two things in each iteration: map written blocks and copy user data to blocks. If the process is killed by user(See signal handling in dax_iomap_iter()), the copied data will be returned and added on inode size, which means that the length of written extents may exceed the inode size, then fsck will fail. An example is given as: dd if=/dev/urandom of=file bs=4M count=1 dax_iomap_rw iomap_iter // round 1 ext4_iomap_begin ext4_iomap_alloc // allocate 0~2M extents(written flag) dax_iomap_iter // copy 2M data iomap_iter // round 2 iomap_iter_advance iter->pos += iter->processed // iter->pos = 2M ext4_iomap_begin ext4_iomap_alloc // allocate 2~4M extents(written flag) dax_iomap_iter fatal_signal_pending done = iter->pos - iocb->ki_pos // done = 2M ext4_handle_inode_extension ext4_update_inode_size // inode size = 2M fsck reports: Inode 13, i_size is 2097152, should be 4194304. Fix? Fix the problem by truncating extents if the written length is smaller than expected. Fixes: 776722e85d3b ("ext4: DAX iomap write support") CC: stable@vger.kernel.org Link: https://bugzilla.kernel.org/show_bug.cgi?id=219136 Signed-off-by: Zhihao Cheng Reviewed-by: Jan Kara Reviewed-by: Zhihao Cheng Link: https://patch.msgid.link/20240809121532.2105494-1-chengzhihao@huaweicloud.com Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

ext4: fix warning in ext4_dio_write_end_io()

2023-12-20T16:01:42+00:00

[ Upstream commit 619f75dae2cf117b1d07f27b046b9ffb071c4685 ] The syzbot has reported that it can hit the warning in ext4_dio_write_end_io() because i_size < i_disksize. Indeed the reproducer creates a race between DIO IO completion and truncate expanding the file and thus ext4_dio_write_end_io() sees an inconsistent inode state where i_disksize is already updated but i_size is not updated yet. Since we are careful when setting up DIO write and consider it extending (and thus performing the IO synchronously with i_rwsem held exclusively) whenever it goes past either of i_size or i_disksize, we can use the same test during IO completion without risking entering ext4_handle_inode_extension() without i_rwsem held. This way we make it obvious both i_size and i_disksize are large enough when we report DIO completion without relying on unreliable WARN_ON. Reported-by: Fixes: 91562895f803 ("ext4: properly sync file size update after O_SYNC direct IO") Signed-off-by: Jan Kara Reviewed-by: Ritesh Harjani (IBM) Link: https://lore.kernel.org/r/20231130095653.22679-1-jack@suse.cz Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin

ext4: fix racy may inline data check in dio write

2023-11-28T17:20:16+00:00

commit ce56d21355cd6f6937aca32f1f44ca749d1e4808 upstream. syzbot reports that the following warning from ext4_iomap_begin() triggers as of the commit referenced below: if (WARN_ON_ONCE(ext4_has_inline_data(inode))) return -ERANGE; This occurs during a dio write, which is never expected to encounter an inode with inline data. To enforce this behavior, ext4_dio_write_iter() checks the current inline state of the inode and clears the MAY_INLINE_DATA state flag to either fall back to buffered writes, or enforce that any other writers in progress on the inode are not allowed to create inline data. The problem is that the check for existing inline data and the state flag can span a lock cycle. For example, if the ilock is originally locked shared and subsequently upgraded to exclusive, another writer may have reacquired the lock and created inline data before the dio write task acquires the lock and proceeds. The commit referenced below loosens the lock requirements to allow some forms of unaligned dio writes to occur under shared lock, but AFAICT the inline data check was technically already racy for any dio write that would have involved a lock cycle. Regardless, lift clearing of the state bit to the same lock critical section that checks for preexisting inline data on the inode to close the race. Cc: stable@kernel.org Reported-by: syzbot+307da6ca5cb0d01d581a@syzkaller.appspotmail.com Fixes: 310ee0902b8d ("ext4: allow concurrent unaligned dio overwrites") Signed-off-by: Brian Foster Link: https://lore.kernel.org/r/20231002185020.531537-1-bfoster@redhat.com Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

ext4: properly sync file size update after O_SYNC direct IO

2023-11-28T17:20:16+00:00

commit 91562895f8030cb9a0470b1db49de79346a69f91 upstream. Gao Xiang has reported that on ext4 O_SYNC direct IO does not properly sync file size update and thus if we crash at unfortunate moment, the file can have smaller size although O_SYNC IO has reported successful completion. The problem happens because update of on-disk inode size is handled in ext4_dio_write_iter() *after* iomap_dio_rw() (and thus dio_complete() in particular) has returned and generic_file_sync() gets called by dio_complete(). Fix the problem by handling on-disk inode size update directly in our ->end_io completion handler. References: https://lore.kernel.org/all/02d18236-26ef-09b0-90ad-030c4fe3ee20@linux.alibaba.com Reported-by: Gao Xiang CC: stable@vger.kernel.org Fixes: 378f32bab371 ("ext4: introduce direct I/O write using iomap infrastructure") Signed-off-by: Jan Kara Tested-by: Joseph Qi Reviewed-by: "Ritesh Harjani (IBM)" Link: https://lore.kernel.org/r/20231013121350.26872-1-jack@suse.cz Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

Merge tag 'ext4_for_linus-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2023-08-31T22:18:15+00:00

Pull ext4 updates from Ted Ts'o: "Many ext4 and jbd2 cleanups and bug fixes: - Cleanups in the ext4 remount code when going to and from read-only - Cleanups in ext4's multiblock allocator - Cleanups in the jbd2 setup/mounting code paths - Performance improvements when appending to a delayed allocation file - Miscellaneous syzbot and other bug fixes" * tag 'ext4_for_linus-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (60 commits) ext4: fix slab-use-after-free in ext4_es_insert_extent() libfs: remove redundant checks of s_encoding ext4: remove redundant checks of s_encoding ext4: reject casefold inode flag without casefold feature ext4: use LIST_HEAD() to initialize the list_head in mballoc.c ext4: do not mark inode dirty every time when appending using delalloc ext4: rename s_error_work to s_sb_upd_work ext4: add periodic superblock update check ext4: drop dio overwrite only flag and associated warning ext4: add correct group descriptors and reserved GDT blocks to system zone ext4: remove unused function declaration ext4: mballoc: avoid garbage value from err ext4: use sbi instead of EXT4_SB(sb) in ext4_mb_new_blocks_simple() ext4: change the type of blocksize in ext4_mb_init_cache() ext4: fix unttached inode after power cut with orphan file feature enabled jbd2: correct the end of the journal recovery scan range ext4: ext4_get_{dev}_journal return proper error value ext4: cleanup ext4_get_dev_journal() and ext4_get_journal() jbd2: jbd2_journal_init_{dev,inode} return proper error return value jbd2: drop useless error tag in jbd2_journal_wipe() ...

ext4: drop dio overwrite only flag and associated warning

2023-08-27T15:27:12+00:00

The commit referenced below opened up concurrent unaligned dio under shared locking for pure overwrites. In doing so, it enabled use of the IOMAP_DIO_OVERWRITE_ONLY flag and added a warning on unexpected -EAGAIN returns as an extra precaution, since ext4 does not retry writes in such cases. The flag itself is advisory in this case since ext4 checks for unaligned I/Os and uses appropriate locking up front, rather than on a retry in response to -EAGAIN. As it turns out, the warning check is susceptible to false positives because there are scenarios where -EAGAIN can be expected from lower layers without necessarily having IOCB_NOWAIT set on the iocb. For example, one instance of the warning has been seen where io_uring sets IOCB_HIPRI, which in turn results in REQ_POLLED|REQ_NOWAIT on the bio. This results in -EAGAIN if the block layer is unable to allocate a request, etc. [Note that there is an outstanding patch to untangle REQ_POLLED and REQ_NOWAIT such that the latter relies on IOCB_NOWAIT, which would also address this instance of the warning.] Another instance of the warning has been reproduced by syzbot. A dio write is interrupted down in __get_user_pages_locked() waiting on the mm lock and returns -EAGAIN up the stack. If the iomap dio iteration layer has made no progress on the write to this point, -EAGAIN returns up to the filesystem and triggers the warning. This use of the overwrite flag in ext4 is precautionary and half-baked. I.e., ext4 doesn't actually implement overwrite checking in the iomap callbacks when the flag is set, so the only extra verification it provides are i_size checks in the generic iomap dio layer. Combined with the tendency for false positives, the added verification is not worth the extra trouble. Remove the flag, associated warning, and update the comments to document when concurrent unaligned dio writes are allowed and why said flag is not used. Cc: stable@kernel.org Reported-by: syzbot+5050ad0fb47527b1808a@syzkaller.appspotmail.com Reported-by: Pengfei Xu Fixes: 310ee0902b8d ("ext4: allow concurrent unaligned dio overwrites") Signed-off-by: Brian Foster Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20230810165559.946222-1-bfoster@redhat.com Signed-off-by: Theodore Ts'o

mm: remove enum page_entry_size

2023-08-24T23:20:30+00:00

Remove the unnecessary encoding of page order into an enum and pass the page order directly. That lets us get rid of pe_order(). The switch constructs have to be changed to if/else constructs to prevent GCC from warning on builds with 3-level page tables where PMD_ORDER and PUD_ORDER have the same value. If you are looking at this commit because your driver stopped compiling, look at the previous commit as well and audit your driver to be sure it doesn't depend on mmap_lock being held in its ->huge_fault method. [willy@infradead.org: use "order %u" to match the (non dev_t) style] Link: https://lkml.kernel.org/r/ZOUYekbtTv+n8hYf@casper.infradead.org Link: https://lkml.kernel.org/r/20230818202335.2739663-4-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton

ext4: make ext4_forced_shutdown() take struct super_block

2023-07-29T22:37:24+00:00

Currently ext4_forced_shutdown() takes struct ext4_sb_info but most callers need to get it from struct super_block anyway. So just pass in struct super_block to save all callers from some boilerplate code. No functional changes. Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20230616165109.21695-3-jack@suse.cz Signed-off-by: Theodore Ts'o