kernel/linux.git/fs/fat/misc.c, branch v7.1

fat: add KUnit tests for timestamp conversion helpers

2026-03-24T22:37:16+00:00

Extend fat_test with coverage for FAT timestamp edge cases that are not currently exercised. Add tests for fat_time_unix2fat() clamping at the UTC boundaries and when time_offset pushes an otherwise valid timestamp outside the FAT date range. Also cover the NULL time_cs path used by existing callers, and verify fat_truncate_atime() truncation across timezone offsets. Link: https://patch.msgid.link/20260315222404.9678-1-aviv.daum@gmail.com Acked-by: OGAWA Hirofumi Signed-off-by: avivdaum Signed-off-by: Christian Brauner

fs: refactor ->update_time handling

2026-01-12T13:01:32+00:00

Pass the type of update (atime vs c/mtime plus version) as an enum instead of a set of flags that caused all kinds of confusion. Because inode_update_timestamps now can't return a modified version of those flags, return the I_DIRTY_* flags needed to persist the update, which is what the main caller in generic_update_time wants anyway, and which is suitable for the other callers that only want to know if an update happened. The whole update_time path keeps the flags argument, which will be used to support non-blocking updates soon even if it is unused, and (the slightly renamed) inode_update_time also gains the possibility to return a negative errno to support this. Signed-off-by: Christoph Hellwig Link: https://patch.msgid.link/20260108141934.2052404-6-hch@lst.de Reviewed-by: Jan Kara Signed-off-by: Christian Brauner

fat: cleanup the flags for fat_truncate_time

2026-01-12T13:01:32+00:00

Fat only has a single on-disk timestamp covering ctime and mtime. Add fat-specific flags that indicate which timestamp fat_truncate_time should update to make this more clear. This allows removing no-op fat_truncate_time calls with the S_CTIME flag and prepares for removing the S_* flags. Signed-off-by: Christoph Hellwig Link: https://patch.msgid.link/20260108141934.2052404-5-hch@lst.de Acked-by: OGAWA Hirofumi Signed-off-by: Christian Brauner

fat: fix too many log in fat_chain_add()

2025-08-02T19:01:40+00:00

This log was excessive for a serial console. So use the ratelimited version instead. Link: https://lkml.kernel.org/r/87qzy611d9.fsf@mail.parknet.co.jp Signed-off-by: OGAWA Hirofumi Reported-by: syzbot+fa7ef54f66c189c04b73@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=fa7ef54f66c189c04b73 Cc: Namjae Jeon Cc: Sungjong Seo Signed-off-by: Andrew Morton

fat: convert to new timestamp accessors

2023-10-18T12:08:03+00:00

Convert to using the new inode timestamp accessor functions. Signed-off-by: Jeff Layton Link: https://lore.kernel.org/r/20231004185347.80880-35-jlayton@kernel.org Tested-by: Klara Modin Signed-off-by: Christian Brauner

fs: drop the timespec64 argument from update_time

2023-08-11T07:04:57+00:00

Now that all of the update_time operations are prepared for it, we can drop the timespec64 argument from the update_time operation. Do that and remove it from some associated functions like inode_update_time and inode_needs_update_time. Signed-off-by: Jeff Layton Reviewed-by: Jan Kara Message-Id: <20230807-mgctime-v7-8-d1dec143a704@kernel.org> Signed-off-by: Christian Brauner

fat: make fat_update_time get its own timestamp

2023-08-11T07:04:56+00:00

In later patches, we're going to drop the "now" parameter from the update_time operation. Fix fat_update_time to fetch its own timestamp. It turns out that this is easily done by just passing a NULL timestamp pointer to fat_truncate_time. Signed-off-by: Jeff Layton Acked-by: OGAWA Hirofumi Reviewed-by: Jan Kara Reviewed-by: Frank Sorenson Message-Id: <20230810-ctime-fat-v1-2-327598fd1de8@kernel.org> Signed-off-by: Christian Brauner

fat: remove i_version handling from fat_update_time

2023-08-11T07:04:56+00:00

commit 6bb885ecd746 (fat: add functions to update and truncate timestamps appropriately") added an update_time routine for fat. That patch added a section for handling the S_VERSION bit, even though FAT doesn't enable SB_I_VERSION and the S_VERSION bit will never be set when calling it. Remove the section for handling S_VERSION since it's effectively dead code, and will be problematic vs. future changes. Cc: Frank Sorenson Signed-off-by: Jeff Layton Acked-by: OGAWA Hirofumi Reviewed-by: Jan Kara Reviewed-by: Frank Sorenson Message-Id: <20230810-ctime-fat-v1-1-327598fd1de8@kernel.org> Signed-off-by: Christian Brauner

fat: convert to ctime accessor functions

2023-07-24T08:29:59+00:00

In later patches, we're going to change how the inode's ctime field is used. Switch to using accessor functions instead of raw accesses of inode->i_ctime. Signed-off-by: Jeff Layton Message-Id: <20230705190309.579783-42-jlayton@kernel.org> Signed-off-by: Christian Brauner

fat: remove time truncations in vfat_create/vfat_mkdir

2022-05-19T21:10:31+00:00

All the timestamps in vfat_create() and vfat_mkdir() come from fat_time_fat2unix() which ensures time granularity. We don't need to truncate them to fit FAT's format. Moreover, fat_truncate_crtime() and fat_timespec64_trunc_10ms() are also removed because there is no caller anymore. Link: https://lkml.kernel.org/r/20220503152536.2503003-4-cccheng@synology.com Signed-off-by: Chung-Chiang Cheng Acked-by: OGAWA Hirofumi Signed-off-by: Andrew Morton