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| author | Baokun Li <libaokun@linux.alibaba.com> | 2026-06-29 19:38:22 +0800 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2026-07-22 11:45:36 -0400 |
| commit | 07d62890ef19e41a87735b8fe1ec65922b5ecd8c (patch) | |
| tree | a93feb111729092300f5d6edf97673de4ca7c1b1 | |
| parent | 91949729befb819c8748f9bd75c74ad5696dc090 (diff) | |
| download | linux-07d62890ef19e41a87735b8fe1ec65922b5ecd8c.tar.gz linux-07d62890ef19e41a87735b8fe1ec65922b5ecd8c.zip | |
ext4: prevent sleeping allocation in NOWAIT write path
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>
| -rw-r--r-- | fs/ext4/inode.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 72a334978f69..fd86d536ff27 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3687,6 +3687,9 @@ static int ext4_iomap_alloc(struct inode *inode, struct ext4_map_blocks *map, int ret, dio_credits, m_flags = 0, retries = 0; bool force_commit = false; + if (flags & IOMAP_NOWAIT) + return -EAGAIN; + /* * Trim the mapping request to the maximum value that we can map at * once for direct I/O. |