[PATCH 5.1 253/371] cifs: Properly handle auto disabling of serverino option

[Greg Kroah-Hartman]

From: Paulo Alcantara (SUSE) <pa...@paulo.ac>

commit 29fbeb7a908a60a5ae8c50fbe171cb8fdcef1980 upstream.

Fix mount options comparison when serverino option is turned off later
in cifs_autodisable_serverino() and thus avoiding mismatch of new cifs
mounts.

Cc: sta...@vger.kernel.org
Signed-off-by: Paulo Alcantara (SUSE) <pa...@paulo.ac>
Signed-off-by: Steve French <stfre...@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshil...@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 fs/cifs/cifs_fs_sb.h |    5 +++++
 fs/cifs/connect.c    |    8 ++++++--
 fs/cifs/misc.c       |    1 +
 3 files changed, 12 insertions(+), 2 deletions(-)

--- a/fs/cifs/cifs_fs_sb.h
+++ b/fs/cifs/cifs_fs_sb.h
@@ -83,5 +83,10 @@ struct cifs_sb_info {
         * failover properly.
         */
        char *origin_fullpath; /* \\HOST\SHARE\[OPTIONAL PATH] */
+       /*
+        * Indicate whether serverino option was turned off later
+        * (cifs_autodisable_serverino) in order to match new mounts.
+        */
+       bool mnt_cifs_serverino_autodisabled;
 };
 #endif                         /* _CIFS_FS_SB_H */
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -3455,12 +3455,16 @@ compare_mount_options(struct super_block
 {
        struct cifs_sb_info *old = CIFS_SB(sb);
        struct cifs_sb_info *new = mnt_data->cifs_sb;
+       unsigned int oldflags = old->mnt_cifs_flags & CIFS_MOUNT_MASK;
+       unsigned int newflags = new->mnt_cifs_flags & CIFS_MOUNT_MASK;
 
        if ((sb->s_flags & CIFS_MS_MASK) != (mnt_data->flags & CIFS_MS_MASK))
                return 0;
 
-       if ((old->mnt_cifs_flags & CIFS_MOUNT_MASK) !=
-           (new->mnt_cifs_flags & CIFS_MOUNT_MASK))
+       if (old->mnt_cifs_serverino_autodisabled)
+               newflags &= ~CIFS_MOUNT_SERVER_INUM;
+
+       if (oldflags != newflags)
                return 0;
 
        /*
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -539,6 +539,7 @@ cifs_autodisable_serverino(struct cifs_s
                        tcon = cifs_sb_master_tcon(cifs_sb);
 
                cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
+               cifs_sb->mnt_cifs_serverino_autodisabled = true;
                cifs_dbg(VFS, "Autodisabling the use of server inode numbers on 
%s.\n",
                         tcon ? tcon->treeName : "new server");
                cifs_dbg(VFS, "The server doesn't seem to support them properly 
or the files might be on different servers (DFS).\n");