Linux-CIFS Archive mirror
 help / color / mirror / Atom feed
From: Paulo Alcantara <pc@manguebit.org>
To: smfrench@gmail.com
Cc: "Paulo Alcantara (Red Hat)" <pc@manguebit.org>,
	Frank Sorenson <sorenson@redhat.com>,
	David Howells <dhowells@redhat.com>,
	linux-cifs@vger.kernel.org
Subject: [PATCH v2 3/3] smb: client: fix missing timestamp updates after utime(2)
Date: Mon,  6 Oct 2025 16:08:54 -0300	[thread overview]
Message-ID: <20251006190854.103483-3-pc@manguebit.org> (raw)
In-Reply-To: <20251006190854.103483-1-pc@manguebit.org>

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: b6f2a0f89d7e ("cifs: for compound requests, use open handle if possible")
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Cc: Frank Sorenson <sorenson@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: linux-cifs@vger.kernel.org
---
 fs/smb/client/smb2inode.c | 32 +++++++++++++++++---------------
 1 file changed, 17 insertions(+), 15 deletions(-)

diff --git a/fs/smb/client/smb2inode.c b/fs/smb/client/smb2inode.c
index 0985db9f86e5..e441fa2e7689 100644
--- a/fs/smb/client/smb2inode.c
+++ b/fs/smb/client/smb2inode.c
@@ -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 cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
-	struct tcon_link *tlink;
-	struct cifs_tcon *tcon;
-	struct cifsFileInfo *cfile;
 	struct kvec in_iov = { .iov_base = buf, .iov_len = sizeof(*buf), };
-	int rc;
+	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;
+	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) &&
-	    (buf->Attributes == 0))
-		return 0; /* would be a no op, no sense sending this */
+	    (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);
+	}
 
-	tlink = cifs_sb_tlink(cifs_sb);
-	if (IS_ERR(tlink))
-		return PTR_ERR(tlink);
-	tcon = tlink_tcon(tlink);
-
-	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;
 }
-- 
2.51.0


      parent reply	other threads:[~2025-10-06 19:08 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-10-06 19:08 [PATCH v2 1/3] smb: client: fix missing timestamp updates with O_TRUNC Paulo Alcantara
2025-10-06 19:08 ` [PATCH v2 2/3] smb: client: fix missing timestamp updates after ftruncate(2) Paulo Alcantara
2025-10-06 19:08 ` Paulo Alcantara [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20251006190854.103483-3-pc@manguebit.org \
    --to=pc@manguebit.org \
    --cc=dhowells@redhat.com \
    --cc=linux-cifs@vger.kernel.org \
    --cc=smfrench@gmail.com \
    --cc=sorenson@redhat.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).