NFSv4: Don't update the open stateid unless it is newer than the old one

This patch is in preparation for the NFSv4.1 parallel open capability.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index a5b27c2d9689..df81fcc138a7 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -500,6 +500,16 @@ static inline bool nfs4_stateid_match(const nfs4_stateid *dst, const nfs4_statei
         return memcmp(dst, src, sizeof(*dst)) == 0;
 }
 
+static inline bool nfs4_stateid_match_other(const nfs4_stateid *dst, const nfs4_stateid *src)
+{
+        return memcmp(dst->other, src->other, NFS4_STATEID_OTHER_SIZE) == 0;
+}
+
+static inline bool nfs4_stateid_is_newer(const nfs4_stateid *s1, const nfs4_stateid *s2)
+{
+        return (s32)(be32_to_cpu(s1->seqid) - be32_to_cpu(s2->seqid)) > 0;
+}
+
 static inline bool nfs4_valid_open_stateid(const struct nfs4_state *state)
 {
         return test_bit(NFS_STATE_RECOVERY_FAILED, &state->flags) == 0;