| commit | ca9ca1a5d5a980550db1001ea825f9fdfa550b83 | [log] [tgz] |
|---|---|---|
| author | David Howells <[email protected]> | Mon Jan 29 09:49:19 2024 +0000 |
| committer | Christian Brauner <[email protected]> | Mon Jan 29 14:53:21 2024 +0100 |
| tree | 8581ba3b07f5f16066883d3d566bc35c5e314120 | |
| parent | 2147caaac7349698f2a392c5e2911a6861a09650 [diff] |
netfs: Fix missing zero-length check in unbuffered write
Fix netfs_unbuffered_write_iter() to return immediately if
generic_write_checks() returns 0, indicating there's nothing to write.
Note that netfs_file_write_iter() already does this.
Also, whilst we're at it, put in checks for the size being zero before we
even take the locks. Note that generic_write_checks() can still reduce the
size to zero, so we still need that check.
Without this, a warning similar to the following is logged to dmesg:
netfs: Zero-sized write [R=1b6da]
and the syscall fails with EIO, e.g.:
/sbin/ldconfig.real: Writing of cache extension data failed: Input/output error
This can be reproduced on 9p by:
xfs_io -f -c 'pwrite 0 0' /xfstest.test/foo
Fixes: 153a9961b551 ("netfs: Implement unbuffered/DIO write support")
Reported-by: Eric Van Hensbergen <[email protected]>
Link: https://lore.kernel.org/r/ZbQUU6QKmIftKsmo@FV7GG9FTHL/
Signed-off-by: David Howells <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Tested-by: Dominique Martinet <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: Dominique Martinet <[email protected]>
cc: Jeff Layton <[email protected]>
cc: <[email protected]>
cc: <[email protected]>
cc: <[email protected]>
cc: <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>