Patch "cifs: release cached dentries only if mount is complete" has been added to the 5.17-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    cifs: release cached dentries only if mount is complete

to the 5.17-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     cifs-release-cached-dentries-only-if-mount-is-comple.patch
and it can be found in the queue-5.17 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit b05b16c6bb5133c5b925b435bfe76267527a43b6
Author: Shyam Prasad N <sprasad@xxxxxxxxxxxxx>
Date:   Fri Apr 1 06:25:17 2022 +0000

    cifs: release cached dentries only if mount is complete
    
    [ Upstream commit d788e51636462e61c6883f7d96b07b06bc291650 ]
    
    During cifs_kill_sb, we first dput all the dentries that we have cached.
    However this function can also get called for mount failures.
    So dput the cached dentries only if the filesystem mount is complete.
    i.e. cifs_sb->root is populated.
    
    Fixes: 5e9c89d43fa6 ("cifs: Grab a reference for the dentry of the cached directory during the lifetime of the cache")
    Signed-off-by: Shyam Prasad N <sprasad@xxxxxxxxxxxxx>
    Reviewed-by: Ronnie Sahlberg <lsahlber@xxxxxxxxxx>
    Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 6e5246122ee2..9f0f6bdb3a4d 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -266,22 +266,24 @@ static void cifs_kill_sb(struct super_block *sb)
 	 * before we kill the sb.
 	 */
 	if (cifs_sb->root) {
+		node = rb_first(root);
+		while (node != NULL) {
+			tlink = rb_entry(node, struct tcon_link, tl_rbnode);
+			tcon = tlink_tcon(tlink);
+			cfid = &tcon->crfid;
+			mutex_lock(&cfid->fid_mutex);
+			if (cfid->dentry) {
+				dput(cfid->dentry);
+				cfid->dentry = NULL;
+			}
+			mutex_unlock(&cfid->fid_mutex);
+			node = rb_next(node);
+		}
+
+		/* finally release root dentry */
 		dput(cifs_sb->root);
 		cifs_sb->root = NULL;
 	}
-	node = rb_first(root);
-	while (node != NULL) {
-		tlink = rb_entry(node, struct tcon_link, tl_rbnode);
-		tcon = tlink_tcon(tlink);
-		cfid = &tcon->crfid;
-		mutex_lock(&cfid->fid_mutex);
-		if (cfid->dentry) {
-			dput(cfid->dentry);
-			cfid->dentry = NULL;
-		}
-		mutex_unlock(&cfid->fid_mutex);
-		node = rb_next(node);
-	}
 
 	kill_anon_super(sb);
 	cifs_umount(cifs_sb);