pnfs: don't check sequence on new stateids in layoutget

When layoutget returns an entirely new layout stateid it should not
check the generation counter as the new stateid will start with a new
counter entirely unrelated to old one.

The current behavior causes constant layoutget failures against a block
server which allocates a new stateid after an recall that removed all
outstanding layouts.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

1 files changed, 19 insertions, 17 deletions

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 0e0364ca877d..ff7fabe33529 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -682,17 +682,6 @@ static bool pnfs_seqid_is_newer(u32 s1, u32 s2)
         return (s32)(s1 - s2) > 0;
 }
 
-static void
-pnfs_verify_layout_stateid(struct pnfs_layout_hdr *lo,
-                const nfs4_stateid *new,
-                struct list_head *free_me_list)
-{
-        if (nfs4_stateid_match_other(&lo->plh_stateid, new))
-                return;
-        /* Layout is new! Kill existing layout segments */
-        pnfs_mark_matching_lsegs_invalid(lo, free_me_list, NULL);
-}
-
 /* update lo->plh_stateid with new if is more recent */
 void
 pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo, const nfs4_stateid *new,
@@ -1367,16 +1356,29 @@ pnfs_layout_process(struct nfs4_layoutget *lgp)
                 goto out_forget_reply;
         }
 
-        if (pnfs_layoutgets_blocked(lo, 1) ||
-            pnfs_layout_stateid_blocked(lo, &res->stateid)) {
+        if (pnfs_layoutgets_blocked(lo, 1)) {
                 dprintk("%s forget reply due to state\n", __func__);
                 goto out_forget_reply;
         }
 
-        /* Check that the new stateid matches the old stateid */
-        pnfs_verify_layout_stateid(lo, &res->stateid, &free_me);
-        /* Done processing layoutget. Set the layout stateid */
-        pnfs_set_layout_stateid(lo, &res->stateid, false);
+        if (nfs4_stateid_match_other(&lo->plh_stateid, &res->stateid)) {
+                /* existing state ID, make sure the sequence number matches. */
+                if (pnfs_layout_stateid_blocked(lo, &res->stateid)) {
+                        dprintk("%s forget reply due to sequence\n", __func__);
+                        goto out_forget_reply;
+                }
+                pnfs_set_layout_stateid(lo, &res->stateid, false);
+        } else {
+                /*
+                 * We got an entirely new state ID.  Mark all segments for the
+                 * inode invalid, and don't bother validating the stateid
+                 * sequence number.
+                 */
+                pnfs_mark_matching_lsegs_invalid(lo, &free_me, NULL);
+
+                nfs4_stateid_copy(&lo->plh_stateid, &res->stateid);
+                lo->plh_barrier = be32_to_cpu(res->stateid.seqid);
+        }
 
         pnfs_get_lseg(lseg);
         pnfs_layout_insert_lseg(lo, lseg);