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| author | Namjae Jeon <linkinjeon@kernel.org> | 2026-07-01 23:59:29 +0900 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2026-07-06 07:55:41 -0500 |
| commit | a0b765030f6ba37aaac59618d4f39dac18d42757 (patch) | |
| tree | d833cd7edce58cebfee36471c1c2d16ae3d10b9a /fs | |
| parent | 4b706360ffb7e459cb3d3edae30b06a584f6eddd (diff) | |
| download | linux-next-a0b765030f6ba37aaac59618d4f39dac18d42757.tar.gz linux-next-a0b765030f6ba37aaac59618d4f39dac18d42757.zip | |
ksmbd: coalesce sub-15ms write time updates on close
Windows reports automatic write-time updates with a resolution of roughly
15 milliseconds. If a file is written and closed within that interval, a
close response requesting full information can report the write time from
the open rather than the filesystem's finer-grained mtime update.
ksmbd currently converts the filesystem mtime directly in SMB2 CLOSE, so
even a sub-millisecond write is visible to the client. This makes
smb2.timestamp_resolution.resolution1 fail because the immediate write
changes LastWriteTime.
Save the write time returned by SMB2 CREATE in the file handle. When CLOSE
requests post-query attributes, coalesce a positive mtime change smaller
than 15 milliseconds to that saved value. Larger changes remain visible,
including the test's write after a 20 millisecond delay.
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/smb/server/smb2pdu.c | 7 | ||||
| -rw-r--r-- | fs/smb/server/vfs_cache.h | 1 |
2 files changed, 8 insertions, 0 deletions
diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c index 9c00f944fa3b..b1204d1d3cdd 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -61,6 +61,9 @@ static void __wbuf(struct ksmbd_work *work, void **req, void **rsp) (FILE_ATTRIBUTE_MASK & ~(FILE_ATTRIBUTE_INTEGRITY_STREAM | \ FILE_ATTRIBUTE_NO_SCRUB_DATA)) +/* Windows reports automatic write-time updates at roughly 15 ms resolution. */ +#define KSMBD_WRITE_TIME_RESOLUTION (15ULL * 10000) + /** * check_session_id() - check for valid session id in smb header * @conn: connection instance @@ -3985,6 +3988,7 @@ reconnected_fp: time = ksmbd_UnixTimeToNT(stat.atime); rsp->LastAccessTime = cpu_to_le64(time); time = ksmbd_UnixTimeToNT(stat.mtime); + fp->open_mtime = time; rsp->LastWriteTime = cpu_to_le64(time); rsp->ChangeTime = cpu_to_le64(fp->change_time); /* @@ -6451,6 +6455,9 @@ int smb2_close(struct ksmbd_work *work) time = ksmbd_UnixTimeToNT(stat.atime); rsp->LastAccessTime = cpu_to_le64(time); time = ksmbd_UnixTimeToNT(stat.mtime); + if (time > fp->open_mtime && + time - fp->open_mtime < KSMBD_WRITE_TIME_RESOLUTION) + time = fp->open_mtime; rsp->LastWriteTime = cpu_to_le64(time); rsp->ChangeTime = cpu_to_le64(fp->change_time); ksmbd_fd_put(work, fp); diff --git a/fs/smb/server/vfs_cache.h b/fs/smb/server/vfs_cache.h index 287f3e675cd3..b9e27307a26c 100644 --- a/fs/smb/server/vfs_cache.h +++ b/fs/smb/server/vfs_cache.h @@ -105,6 +105,7 @@ struct ksmbd_file { __u64 change_time; __u64 allocation_size; __u64 itime; + __u64 open_mtime; bool is_nt_open; bool attrib_only; |