[PATCH v2 6/9] pNFS: Handle NFS4ERR_OLD_STATEID on layoutreturn by bumping the state seqid

[Trond Myklebust <trondmy@xxxxxxxxx>]

If a LAYOUTRETURN receives a reply of NFS4ERR_OLD_STATEID then assume we've
missed an update, and just bump the stateid.

Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
---
 fs/nfs/nfs4proc.c |  2 +-
 fs/nfs/pnfs.c     | 18 ++++++++++++++----
 fs/nfs/pnfs.h     |  4 ++--
 3 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index a5deb00b5ad1..cbaf6b7ac128 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -9069,7 +9069,7 @@ static void nfs4_layoutreturn_done(struct rpc_task *task, void *calldata)
 	server = NFS_SERVER(lrp->args.inode);
 	switch (task->tk_status) {
 	case -NFS4ERR_OLD_STATEID:
-		if (nfs4_layoutreturn_refresh_stateid(&lrp->args.stateid,
+		if (nfs4_layout_refresh_old_stateid(&lrp->args.stateid,
 					&lrp->args.range,
 					lrp->args.inode))
 			goto out_restart;
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index abc7188f1853..bb80034a7661 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -359,9 +359,10 @@ pnfs_clear_lseg_state(struct pnfs_layout_segment *lseg,
 }
 
 /*
- * Update the seqid of a layout stateid
+ * Update the seqid of a layout stateid after receiving
+ * NFS4ERR_OLD_STATEID
  */
-bool nfs4_layoutreturn_refresh_stateid(nfs4_stateid *dst,
+bool nfs4_layout_refresh_old_stateid(nfs4_stateid *dst,
 		struct pnfs_layout_range *dst_range,
 		struct inode *inode)
 {
@@ -377,7 +378,15 @@ bool nfs4_layoutreturn_refresh_stateid(nfs4_stateid *dst,
 
 	spin_lock(&inode->i_lock);
 	lo = NFS_I(inode)->layout;
-	if (lo && nfs4_stateid_match_other(dst, &lo->plh_stateid)) {
+	if (lo &&  pnfs_layout_is_valid(lo) &&
+	    nfs4_stateid_match_other(dst, &lo->plh_stateid)) {
+		/* Is our call using the most recent seqid? If so, bump it */
+		if (!nfs4_stateid_is_newer(&lo->plh_stateid, dst)) {
+			nfs4_stateid_seqid_inc(dst);
+			ret = true;
+			goto out;
+		}
+		/* Try to update the seqid to the most recent */
 		err = pnfs_mark_matching_lsegs_return(lo, &head, &range, 0);
 		if (err != -EBUSY) {
 			dst->seqid = lo->plh_stateid.seqid;
@@ -385,6 +394,7 @@ bool nfs4_layoutreturn_refresh_stateid(nfs4_stateid *dst,
 			ret = true;
 		}
 	}
+out:
 	spin_unlock(&inode->i_lock);
 	pnfs_free_lseg_list(&head);
 	return ret;
@@ -1475,7 +1485,7 @@ int pnfs_roc_done(struct rpc_task *task, struct inode *inode,
 		*ret = -NFS4ERR_NOMATCHING_LAYOUT;
 		return 0;
 	case -NFS4ERR_OLD_STATEID:
-		if (!nfs4_layoutreturn_refresh_stateid(&arg->stateid,
+		if (!nfs4_layout_refresh_old_stateid(&arg->stateid,
 					&arg->range, inode))
 			break;
 		*ret = -NFS4ERR_NOMATCHING_LAYOUT;
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index 3ef3756d437c..f8a38065c7e4 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -261,7 +261,7 @@ int pnfs_destroy_layouts_byfsid(struct nfs_client *clp,
 		bool is_recall);
 int pnfs_destroy_layouts_byclid(struct nfs_client *clp,
 		bool is_recall);
-bool nfs4_layoutreturn_refresh_stateid(nfs4_stateid *dst,
+bool nfs4_layout_refresh_old_stateid(nfs4_stateid *dst,
 		struct pnfs_layout_range *dst_range,
 		struct inode *inode);
 void pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo);
@@ -798,7 +798,7 @@ static inline void nfs4_pnfs_v3_ds_connect_unload(void)
 {
 }
 
-static inline bool nfs4_layoutreturn_refresh_stateid(nfs4_stateid *dst,
+static inline bool nfs4_layout_refresh_old_stateid(nfs4_stateid *dst,
 		struct pnfs_layout_range *dst_range,
 		struct inode *inode)
 {
-- 
2.21.0