diff options
| author | Paulo Alcantara <pc@manguebit.org> | 2025-10-07 16:23:23 -0300 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2025-10-09 10:42:14 -0500 |
| commit | 57ce9f7793b714fb14a97d502ce926162c3b96b1 (patch) | |
| tree | 06a5a3622a66ff5ad67fef466a3c4adf641bb285 | |
| parent | 110fee6b9bb58a5c50047fc2594d415f741b591e (diff) | |
smb: client: fix missing timestamp updates after ftruncate(2)
Mask off ATTR_MTIME|ATTR_CTIME bits on ATTR_SIZE (e.g. ftruncate(2))
to prevent the client from sending set info calls and then disabling
automatic timestamp updates on server side as per MS-FSA 2.1.4.17.
---8<---
import os
import time
filename = '/mnt/foo'
def print_stat(prefix):
st = os.stat(filename)
print(prefix, ': ', time.ctime(st.st_atime), time.ctime(st.st_ctime))
fd = os.open(filename, os.O_CREAT|os.O_TRUNC|os.O_WRONLY, 0o644)
print_stat('old')
os.ftruncate(fd, 10)
time.sleep(2)
os.write(fd, b'foo')
os.close(fd)
time.sleep(2)
print_stat('new')
---8<---
Before patch:
$ mount.cifs //srv/share /mnt -o ...
$ python3 run.py
old : Fri Oct 3 13:47:03 2025 Fri Oct 3 13:47:03 2025
new : Fri Oct 3 13:47:00 2025 Fri Oct 3 13:47:03 2025
After patch:
$ mount.cifs //srv/share /mnt -o ...
$ python3 run.py
old : Fri Oct 3 13:48:39 2025 Fri Oct 3 13:48:39 2025
new : Fri Oct 3 13:48:41 2025 Fri Oct 3 13:48:41 2025
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Cc: Frank Sorenson <sorenson@redhat.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Cc: linux-cifs@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
| -rw-r--r-- | fs/smb/client/inode.c | 18 |
1 files changed, 8 insertions, 10 deletions
diff --git a/fs/smb/client/inode.c b/fs/smb/client/inode.c index ce88bef4e44c..fbfd5b556815 100644 --- a/fs/smb/client/inode.c +++ b/fs/smb/client/inode.c @@ -3156,12 +3156,11 @@ cifs_setattr_unix(struct dentry *direntry, struct iattr *attrs) if (rc != 0) goto out; /* - * The man page of truncate says if the size changed, - * then the st_ctime and st_mtime fields for the file - * are updated. + * Avoid setting timestamps on the server for ftruncate(2) to + * prevent it from disabling automatic timestamp updates as per + * MS-FSA 2.1.4.17. */ - attrs->ia_ctime = attrs->ia_mtime = current_time(inode); - attrs->ia_valid |= ATTR_CTIME | ATTR_MTIME; + attrs->ia_valid &= ~(ATTR_CTIME | ATTR_MTIME); } /* skip mode change if it's just for clearing setuid/setgid */ @@ -3335,12 +3334,11 @@ cifs_setattr_nounix(struct dentry *direntry, struct iattr *attrs) if (rc != 0) goto cifs_setattr_exit; /* - * The man page of truncate says if the size changed, - * then the st_ctime and st_mtime fields for the file - * are updated. + * Avoid setting timestamps on the server for ftruncate(2) to + * prevent it from disabling automatic timestamp updates as per + * MS-FSA 2.1.4.17. */ - attrs->ia_ctime = attrs->ia_mtime = current_time(inode); - attrs->ia_valid |= ATTR_CTIME | ATTR_MTIME; + attrs->ia_valid &= ~(ATTR_CTIME | ATTR_MTIME); } if (attrs->ia_valid & ATTR_UID) |