Patch "cifs: Fix duplicate fscache cookie warnings" has been added to the 6.8-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

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

    cifs: Fix duplicate fscache cookie warnings

to the 6.8-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-fix-duplicate-fscache-cookie-warnings.patch
and it can be found in the queue-6.8 subdirectory.

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



commit 8549dbd991285d93f326bd2f6d941716fb8cdb7d
Author: David Howells <dhowells@xxxxxxxxxx>
Date:   Wed Mar 27 14:13:24 2024 +0000

    cifs: Fix duplicate fscache cookie warnings
    
    [ Upstream commit 8876a37277cb832e1861c35f8c661825179f73f5 ]
    
    fscache emits a lot of duplicate cookie warnings with cifs because the
    index key for the fscache cookies does not include everything that the
    cifs_find_inode() function does.  The latter is used with iget5_locked() to
    distinguish between inodes in the local inode cache.
    
    Fix this by adding the creation time and file type to the fscache cookie
    key.
    
    Additionally, add a couple of comments to note that if one is changed the
    other must be also.
    
    Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
    Fixes: 70431bfd825d ("cifs: Support fscache indexing rewrite")
    cc: Shyam Prasad N <nspmangalore@xxxxxxxxx>
    cc: Rohith Surabattula <rohiths.msft@xxxxxxxxx>
    cc: Jeff Layton <jlayton@xxxxxxxxxx>
    cc: linux-cifs@xxxxxxxxxxxxxxx
    cc: netfs@xxxxxxxxxxxxxxx
    cc: linux-fsdevel@xxxxxxxxxxxxxxx
    Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/fs/smb/client/fscache.c b/fs/smb/client/fscache.c
index c4a3cb736881a..340efce8f0529 100644
--- a/fs/smb/client/fscache.c
+++ b/fs/smb/client/fscache.c
@@ -12,6 +12,16 @@
 #include "cifs_fs_sb.h"
 #include "cifsproto.h"
 
+/*
+ * Key for fscache inode.  [!] Contents must match comparisons in cifs_find_inode().
+ */
+struct cifs_fscache_inode_key {
+
+	__le64  uniqueid;	/* server inode number */
+	__le64  createtime;	/* creation time on server */
+	u8	type;		/* S_IFMT file type */
+} __packed;
+
 static void cifs_fscache_fill_volume_coherency(
 	struct cifs_tcon *tcon,
 	struct cifs_fscache_volume_coherency_data *cd)
@@ -97,15 +107,19 @@ void cifs_fscache_release_super_cookie(struct cifs_tcon *tcon)
 void cifs_fscache_get_inode_cookie(struct inode *inode)
 {
 	struct cifs_fscache_inode_coherency_data cd;
+	struct cifs_fscache_inode_key key;
 	struct cifsInodeInfo *cifsi = CIFS_I(inode);
 	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
 	struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
 
+	key.uniqueid	= cpu_to_le64(cifsi->uniqueid);
+	key.createtime	= cpu_to_le64(cifsi->createtime);
+	key.type	= (inode->i_mode & S_IFMT) >> 12;
 	cifs_fscache_fill_coherency(&cifsi->netfs.inode, &cd);
 
 	cifsi->netfs.cache =
 		fscache_acquire_cookie(tcon->fscache, 0,
-				       &cifsi->uniqueid, sizeof(cifsi->uniqueid),
+				       &key, sizeof(key),
 				       &cd, sizeof(cd),
 				       i_size_read(&cifsi->netfs.inode));
 	if (cifsi->netfs.cache)
diff --git a/fs/smb/client/inode.c b/fs/smb/client/inode.c
index 7f28edf4b20f3..4c3dec384f922 100644
--- a/fs/smb/client/inode.c
+++ b/fs/smb/client/inode.c
@@ -1414,6 +1414,8 @@ cifs_find_inode(struct inode *inode, void *opaque)
 {
 	struct cifs_fattr *fattr = opaque;
 
+	/* [!] The compared values must be the same in struct cifs_fscache_inode_key. */
+
 	/* don't match inode with different uniqueid */
 	if (CIFS_I(inode)->uniqueid != fattr->cf_uniqueid)
 		return 0;