[PATCH 5.11 743/775] cifs: fix nodfs mount option

From: Greg Kroah-Hartman
Date: Tue Mar 02 2021 - 01:41:40 EST


From: Paulo Alcantara <pc@xxxxxx>

commit d01132ae50207bb6fd94e08e80c2d7b839408086 upstream.

Skip DFS resolving when mounting with 'nodfs' even if
CONFIG_CIFS_DFS_UPCALL is enabled.

Signed-off-by: Paulo Alcantara (SUSE) <pc@xxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # 5.11
Reviewed-by: Shyam Prasad N <sprasad@xxxxxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/cifs/connect.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -3366,15 +3366,15 @@ int cifs_mount(struct cifs_sb_info *cifs

rc = mount_get_conns(ctx, cifs_sb, &xid, &server, &ses, &tcon);
/*
- * Unconditionally try to get an DFS referral (even cached) to determine whether it is an
- * DFS mount.
+ * If called with 'nodfs' mount option, then skip DFS resolving. Otherwise unconditionally
+ * try to get an DFS referral (even cached) to determine whether it is an DFS mount.
*
* Skip prefix path to provide support for DFS referrals from w2k8 servers which don't seem
* to respond with PATH_NOT_COVERED to requests that include the prefix.
*/
- if (dfs_cache_find(xid, ses, cifs_sb->local_nls, cifs_remap(cifs_sb), ctx->UNC + 1, NULL,
+ if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) ||
+ dfs_cache_find(xid, ses, cifs_sb->local_nls, cifs_remap(cifs_sb), ctx->UNC + 1, NULL,
NULL)) {
- /* No DFS referral was returned. Looks like a regular share. */
if (rc)
goto error;
/* Check if it is fully accessible and then mount it */