NFSv4: Follow a referral

Respond to a moved error on NFS lookup by setting up the referral.
Note: We don't actually follow the referral during lookup/getattr, but
later when we detect fsid mismatch in inode revalidation (similar to the
processing done for cloning submounts). Referrals will have fake attributes
until they are actually followed or traversed.

Signed-off-by: Manoj Naik <manoj@almaden.ibm.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

2 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 09271b10f9a8..152798949113 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -409,6 +409,7 @@ extern void nfs_unregister_sysctl(void);
  */
 extern struct list_head nfs_automount_list;
 extern struct inode_operations nfs_mountpoint_inode_operations;
+extern struct inode_operations nfs_referral_inode_operations;
 extern int nfs_mountpoint_expiry_timeout;
 extern void nfs_release_automount_timer(void);
 
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index d6eea8348728..7c7320fa51aa 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -63,6 +63,7 @@ struct nfs_fattr {
 #define NFS_ATTR_FATTR          0x0002          /* post-op attributes */
 #define NFS_ATTR_FATTR_V3       0x0004          /* NFSv3 attributes */
 #define NFS_ATTR_FATTR_V4       0x0008          /* NFSv4 change attribute */
+#define NFS_ATTR_FATTR_V4_REFERRAL      0x0010          /* NFSv4 referral */
 
 /*
  * Info on the file system