[PATCH 4.4 26/96] nfs: Fix ugly referral attributes

Greg Kroah-Hartman
2017-11-28T10:29:11Z

From: Chuck Lever <chuck.lever@oracle.com>

commit c05cefcc72416a37eba5a2b35f0704ed758a9145 upstream.

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>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/nfs/nfs4proc.c | 18 ++++++++----------
1 file changed, 8 insertions(+), 10 deletions(-)

--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -242,15 +242,12 @@ const u32 nfs4_fsinfo_bitmap[3] = { FATT
};

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
@@ -6351,9 +6348,7 @@ static int _nfs4_proc_fs_locations(struc
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,
@@ -6372,12 +6367,15 @@ static int _nfs4_proc_fs_locations(struc

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;