NFSv4.1: Select the "most recent locking state" for read/write/setattr stateids

Follow the practice described in section 8.2.2 of RFC5661: When sending a
read/write or setattr stateid, set the seqid field to zero in order to
signal that the NFS server should apply the most recent locking state.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

3 files changed, 5 insertions, 1 deletions

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 22c80f9ed824..625a729ebcca 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -6841,7 +6841,8 @@ static const struct nfs4_minor_version_ops nfs_v4_1_minor_ops = {
         .init_caps = NFS_CAP_READDIRPLUS
                 | NFS_CAP_ATOMIC_OPEN
                 | NFS_CAP_CHANGE_ATTR
-                | NFS_CAP_POSIX_LOCK,
+                | NFS_CAP_POSIX_LOCK
+                | NFS_CAP_STATEID_NFSV41,
         .call_sync = nfs4_call_sync_sequence,
         .match_stateid = nfs41_match_stateid,
         .find_root_sec = nfs41_find_root_sec,
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 4e95bd72f480..685b1e953ed8 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -1053,6 +1053,8 @@ int nfs4_select_rw_stateid(nfs4_stateid *dst, struct nfs4_state *state,
                 goto out;
         ret = nfs4_copy_open_stateid(dst, state);
 out:
+        if (nfs_server_capable(state->inode, NFS_CAP_STATEID_NFSV41))
+                dst->seqid = 0;
         return ret;
 }
 
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index 6c6ed153a9b4..74c9e52c9338 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -197,5 +197,6 @@ struct nfs_server {
 #define NFS_CAP_MTIME           (1U << 13)
 #define NFS_CAP_POSIX_LOCK      (1U << 14)
 #define NFS_CAP_UIDGID_NOMAP    (1U << 15)
+#define NFS_CAP_STATEID_NFSV41  (1U << 16)
 
 #endif