nfs: Fix ugly referral attributes

Before traversing a referral and performing a mount, the mounted-on
directory looks strange:

dr-xr-xr-x. 2 4294967294 4294967294 0 Dec 31  1969 dir.0

nfs4_get_referral is wiping out any cached attributes with what was
returned via GETATTR(fs_locations), but the bit mask for that
operation does not request any file attributes.

Retrieve owner and timestamp information so that the memcpy in
nfs4_get_referral fills in more attributes.

Changes since v1:
- Don't request attributes that the client unconditionally replaces
- Request only MOUNTED_ON_FILEID or FILEID attribute, not both
- encode_fs_locations() doesn't use the third bitmask word

Fixes: 6b97fd3da1ea ("NFSv4: Follow a referral")
Suggested-by: Pradeep Thomas <pradeepthomas@gmail.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

1 files changed, 8 insertions, 10 deletions

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 2c9c22579610..6b23a032ee1e 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -258,15 +258,12 @@ const u32 nfs4_fsinfo_bitmap[3] = { FATTR4_WORD0_MAXFILESIZE
 };
 
 const u32 nfs4_fs_locations_bitmap[3] = {
-        FATTR4_WORD0_TYPE
-        | FATTR4_WORD0_CHANGE
+        FATTR4_WORD0_CHANGE
         | FATTR4_WORD0_SIZE
         | FATTR4_WORD0_FSID
         | FATTR4_WORD0_FILEID
         | FATTR4_WORD0_FS_LOCATIONS,
-        FATTR4_WORD1_MODE
-        | FATTR4_WORD1_NUMLINKS
-        | FATTR4_WORD1_OWNER
+        FATTR4_WORD1_OWNER
         | FATTR4_WORD1_OWNER_GROUP
         | FATTR4_WORD1_RAWDEV
         | FATTR4_WORD1_SPACE_USED
@@ -6907,9 +6904,7 @@ static int _nfs4_proc_fs_locations(struct rpc_clnt *client, struct inode *dir,
                                    struct page *page)
 {
         struct nfs_server *server = NFS_SERVER(dir);
-        u32 bitmask[3] = {
-                [0] = FATTR4_WORD0_FSID | FATTR4_WORD0_FS_LOCATIONS,
-        };
+        u32 bitmask[3];
         struct nfs4_fs_locations_arg args = {
                 .dir_fh = NFS_FH(dir),
                 .name = name,
@@ -6928,12 +6923,15 @@ static int _nfs4_proc_fs_locations(struct rpc_clnt *client, struct inode *dir,
 
         dprintk("%s: start\n", __func__);
 
+        bitmask[0] = nfs4_fattr_bitmap[0] | FATTR4_WORD0_FS_LOCATIONS;
+        bitmask[1] = nfs4_fattr_bitmap[1];
+
         /* Ask for the fileid of the absent filesystem if mounted_on_fileid
          * is not supported */
         if (NFS_SERVER(dir)->attr_bitmask[1] & FATTR4_WORD1_MOUNTED_ON_FILEID)
-                bitmask[1] |= FATTR4_WORD1_MOUNTED_ON_FILEID;
+                bitmask[0] &= ~FATTR4_WORD0_FILEID;
         else
-                bitmask[0] |= FATTR4_WORD0_FILEID;
+                bitmask[1] &= ~FATTR4_WORD1_MOUNTED_ON_FILEID;
 
         nfs_fattr_init(&fs_locations->fattr);
         fs_locations->server = server;