kernel/linux.git/fs/ext4/file.c, branch v6.12.80

ext4: fix checks for orphan inodes

2025-10-15T10:00:22+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()

2025-06-27T10:11:20+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: keep orphan list before truncate overflow allocated blocks

2024-09-04T02:14:16+00:00

Any extending write for ext4 requires the inode to be placed on the orphan list before the actual write. In addition, the inode can be actually removed from the orphan list only after all writes are completed. Otherwise we'd leave allocated blocks beyond i_disksize if we could not copy all the data into allocated block and e2fsck would complain. Currently, direct IO and buffered IO comply with this logic(buffered IO will truncate all overflow allocated blocks that has not been written successfully, and direct IO will truncate all allocated blocks when error occurs). However, dax write break this since dax write will remove the inode from the orphan list by calling ext4_handle_inode_extension unconditionally during extending write. We add a argument to help determine does we do a fully write, and for the case not fully write, we leave the inode on the orphan list, and the latter ext4_inode_extension_cleanup will help us truncate the overflow allocated blocks, and then remove the inode from the orphan list. Signed-off-by: yangerkun Reviewed-by: Jan Kara Link: https://patch.msgid.link/20240829110222.126685-1-yangerkun@huaweicloud.com Signed-off-by: Theodore Ts'o

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

2024-08-27T03:56:49+00:00

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

Merge tag 'ext4_for_linus-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2024-05-18T21:11:54+00:00

Pull ext4 updates from Ted Ts'o: - more folio conversion patches - add support for FS_IOC_GETFSSYSFSPATH - mballoc cleaups and add more kunit tests - sysfs cleanups and bug fixes - miscellaneous bug fixes and cleanups * tag 'ext4_for_linus-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (40 commits) ext4: fix error pointer dereference in ext4_mb_load_buddy_gfp() jbd2: add prefix 'jbd2' for 'shrink_type' jbd2: use shrink_type type instead of bool type for __jbd2_journal_clean_checkpoint_list() ext4: fix uninitialized ratelimit_state->lock access in __ext4_fill_super() ext4: remove calls to to set/clear the folio error flag ext4: propagate errors from ext4_sb_bread() in ext4_xattr_block_cache_find() ext4: fix mb_cache_entry's e_refcnt leak in ext4_xattr_block_cache_find() jbd2: remove redundant assignement to variable err ext4: remove the redundant folio_wait_stable() ext4: fix potential unnitialized variable ext4: convert ac_buddy_page to ac_buddy_folio ext4: convert ac_bitmap_page to ac_bitmap_folio ext4: convert ext4_mb_init_cache() to take a folio ext4: convert bd_buddy_page to bd_buddy_folio ext4: convert bd_bitmap_page to bd_bitmap_folio ext4: open coding repeated check in next_linear_group ext4: use correct criteria name instead stale integer number in comment ext4: call ext4_mb_mark_free_simple to free continuous bits in found chunk ext4: add test_mb_mark_used_cost to estimate cost of mb_mark_used ext4: keep "prefetch_grp" and "nr" consistent ...

ext4: replace deprecated strncpy with alternatives

2024-05-03T03:55:10+00:00

strncpy() is deprecated for use on NUL-terminated destination strings [1] and as such we should prefer more robust and less ambiguous string interfaces. in file.c: s_last_mounted is marked as __nonstring meaning it does not need to be NUL-terminated. Let's instead use strtomem_pad() to copy bytes from the string source to the byte array destination -- while also ensuring to pad with zeroes. in ioctl.c: We can drop the memset and size argument in favor of using the new 2-argument version of strscpy_pad() -- which was introduced with Commit e6584c3964f2f ("string: Allow 2-argument strscpy()"). This guarantees NUL-termination and NUL-padding on the destination buffer -- which seems to be a requirement judging from this comment: | static int ext4_ioctl_getlabel(struct ext4_sb_info *sbi, char __user *user_label) | { | char label[EXT4_LABEL_MAX + 1]; | | /* | * EXT4_LABEL_MAX must always be smaller than FSLABEL_MAX because | * FSLABEL_MAX must include terminating null byte, while s_volume_name | * does not have to. | */ in super.c: s_first_error_func is marked as __nonstring meaning we can take the same approach as in file.c; just use strtomem_pad() Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@vger.kernel.org Signed-off-by: Justin Stitt Reviewed-by: Kees Cook Link: https://lore.kernel.org/r/20240321-strncpy-fs-ext4-file-c-v1-1-36a6a09fef0c@google.com Signed-off-by: Theodore Ts'o

ext4: set FMODE_CAN_ODIRECT instead of a dummy direct_IO method

2024-05-02T14:53:32+00:00

Since commit a2ad63daa88b ("VFS: add FMODE_CAN_ODIRECT file flag") file systems can just set the FMODE_CAN_ODIRECT flag at open time instead of wiring up a dummy direct_IO method to indicate support for direct I/O. Signed-off-by: Christoph Hellwig [RH: Rebased to upstream] Signed-off-by: Ritesh Harjani (IBM) Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/e5797bb597219a49043e53e4e90aa494b97dc328.1709215665.git.ritesh.list@gmail.com Signed-off-by: Theodore Ts'o

fs: claw back a few FMODE_* bits

2024-04-07T11:49:02+00:00

There's a bunch of flags that are purely based on what the file operations support while also never being conditionally set or unset. IOW, they're not subject to change for individual files. Imho, such flags don't need to live in f_mode they might as well live in the fops structs itself. And the fops struct already has that lonely mmap_supported_flags member. We might as well turn that into a generic fop_flags member and move a few flags from FMODE_* space into FOP_* space. That gets us four FMODE_* bits back and the ability for new static flags that are about file ops to not have to live in FMODE_* space but in their own FOP_* space. It's not the most beautiful thing ever but it gets the job done. Yes, there'll be an additional pointer chase but hopefully that won't matter for these flags. I suspect there's a few more we can move into there and that we can also redirect a bunch of new flag suggestions that follow this pattern into the fop_flags field instead of f_mode. Link: https://lore.kernel.org/r/20240328-gewendet-spargel-aa60a030ef74@brauner Reviewed-by: Christoph Hellwig Reviewed-by: Jan Kara Reviewed-by: Jens Axboe Signed-off-by: Christian Brauner

ext4: remove unnecessary parameter "needed" in ext4_discard_preallocations

2024-01-18T15:52:45+00:00

The "needed" controls the number of ext4_prealloc_space to discard in ext4_discard_preallocations. Function ext4_discard_preallocations is supposed to discard all non-used preallocated blocks when "needed" is 0 and now ext4_discard_preallocations is always called with "needed" = 0. Remove unnecessary parameter "needed" and remove all non-used preallocated spaces in ext4_discard_preallocations to simplify the code. Note: If count of non-used preallocated spaces could be more than UINT_MAX, there was a memory leak as some non-used preallocated spaces are left ununsed and this commit will fix it. Otherwise, there is no behavior change. Signed-off-by: Kemeng Shi Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20240105092102.496631-9-shikemeng@huaweicloud.com Signed-off-by: Theodore Ts'o

ext4: fix warning in ext4_dio_write_end_io()

2023-12-01T04:29:34+00:00

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