pNFS: Fix LAYOUTGET handling of NFS4ERR_BAD_STATEID and NFS4ERR_EXPIRED

We want to recover the open stateid if there is no layout stateid
and/or the stateid argument matches an open stateid.
Otherwise throw out the existing layout and recover from scratch, as
the layout stateid is bad.

Fixes: 183d9e7b112aa ("pnfs: rework LAYOUTGET retry handling")
Cc: stable@vger.kernel.org # 4.7
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>

1 files changed, 15 insertions, 19 deletions

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index ee8efe0a5202..a1a3b4c9a563 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -7886,6 +7886,7 @@ nfs4_layoutget_handle_exception(struct rpc_task *task,
         struct pnfs_layout_hdr *lo;
         int nfs4err = task->tk_status;
         int err, status = 0;
+        LIST_HEAD(head);
 
         dprintk("--> %s tk_status => %d\n", __func__, -task->tk_status);
 
@@ -7930,30 +7931,25 @@ nfs4_layoutget_handle_exception(struct rpc_task *task,
         case -NFS4ERR_BAD_STATEID:
                 exception->timeout = 0;
                 spin_lock(&inode->i_lock);
-                if (nfs4_stateid_match(&lgp->args.stateid,
+                lo = NFS_I(inode)->layout;
+                /* If the open stateid was bad, then recover it. */
+                if (!lo || test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags) ||
+                    nfs4_stateid_match_other(&lgp->args.stateid,
                                         &lgp->args.ctx->state->stateid)) {
                         spin_unlock(&inode->i_lock);
-                        /* If the open stateid was bad, then recover it. */
                         exception->state = lgp->args.ctx->state;
                         break;
                 }
-                lo = NFS_I(inode)->layout;
-                if (lo && !test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags) &&
-                    nfs4_stateid_match_other(&lgp->args.stateid, &lo->plh_stateid)) {
-                        LIST_HEAD(head);
-
-                        /*
-                         * Mark the bad layout state as invalid, then retry
-                         * with the current stateid.
-                         */
-                        set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
-                        pnfs_mark_matching_lsegs_invalid(lo, &head, NULL, 0);
-                        spin_unlock(&inode->i_lock);
-                        pnfs_free_lseg_list(&head);
-                        status = -EAGAIN;
-                        goto out;
-                } else
-                        spin_unlock(&inode->i_lock);
+
+                /*
+                 * Mark the bad layout state as invalid, then retry
+                 */
+                set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
+                pnfs_mark_matching_lsegs_invalid(lo, &head, NULL, 0);
+                spin_unlock(&inode->i_lock);
+                pnfs_free_lseg_list(&head);
+                status = -EAGAIN;
+                goto out;
         }
 
         err = nfs4_handle_exception(server, nfs4err, exception);