Commit b95cd1bd authored by Paulo Alcantara's avatar Paulo Alcantara Committed by Steve French
Browse files

smb: client: fix missing timestamp updates after utime(2) 



Don't reuse open handle when changing timestamps to prevent the server
from disabling automatic timestamp updates 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.utime(fd, None)
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 14:01:21 2025 Fri Oct  3 14:01:21 2025
new :  Fri Oct  3 14:01:21 2025 Fri Oct  3 14:01:21 2025

After patch:

$ mount.cifs //srv/share /mnt -o ...
$ python3 run.py
old :  Fri Oct  3 17:03:34 2025 Fri Oct  3 17:03:34 2025
new :  Fri Oct  3 17:03:36 2025 Fri Oct  3 17:03:36 2025

Fixes: b6f2a0f8 ("cifs: for compound requests, use open handle if possible")
Signed-off-by: default avatarPaulo Alcantara (Red Hat) <pc@manguebit.org>
Cc: Frank Sorenson <sorenson@redhat.com>
Reviewed-by: default avatarDavid Howells <dhowells@redhat.com>
Cc: linux-cifs@vger.kernel.org
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 57ce9f77

fs/smb/client/smb2inode.c

+12 −10
Original line number Diff line number Diff line
@@ -1382,31 +1382,33 @@ int 
smb2_set_file_info(struct inode *inode, const char *full_path,

		   FILE_BASIC_INFO *buf, const unsigned int xid)

{

	struct cifs_open_parms oparms;

	struct kvec in_iov = { .iov_base = buf, .iov_len = sizeof(*buf), };

	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);

	struct cifsFileInfo *cfile = NULL;

	struct cifs_open_parms oparms;

	struct tcon_link *tlink;

	struct cifs_tcon *tcon;

	struct cifsFileInfo *cfile;

	struct kvec in_iov = { .iov_base = buf, .iov_len = sizeof(*buf), };

	int rc;



	if ((buf->CreationTime == 0) && (buf->LastAccessTime == 0) &&

	    (buf->LastWriteTime == 0) && (buf->ChangeTime == 0) &&

	    (buf->Attributes == 0))

		return 0; /* would be a no op, no sense sending this */

	int rc = 0;



	tlink = cifs_sb_tlink(cifs_sb);

	if (IS_ERR(tlink))

		return PTR_ERR(tlink);

	tcon = tlink_tcon(tlink);



	if ((buf->CreationTime == 0) && (buf->LastAccessTime == 0) &&

	    (buf->LastWriteTime == 0) && (buf->ChangeTime == 0)) {

		if (buf->Attributes == 0)

			goto out; /* would be a no op, no sense sending this */

		cifs_get_writable_path(tcon, full_path, FIND_WR_ANY, &cfile);

	}



	oparms = CIFS_OPARMS(cifs_sb, tcon, full_path, FILE_WRITE_ATTRIBUTES,

			     FILE_OPEN, 0, ACL_NO_MODE);

	rc = smb2_compound_op(xid, tcon, cifs_sb,

			      full_path, &oparms, &in_iov,

			      &(int){SMB2_OP_SET_INFO}, 1,

			      cfile, NULL, NULL, NULL);

out:

	cifs_put_tlink(tlink);

	return rc;

}