[PATCH 2/5] NFSv4/pnfs: Fix layoutget behaviour after invalidation

[trondmy@kernel.org]

From: Trond Myklebust <trond.myklebust@hammerspace.com>

If the layout gets invalidated, we should wait for any outstanding
layoutget requests for that layout to complete, and we should resend
them only after re-establishing the layout stateid.

Fixes: d29b468da4f9 ("pNFS/NFSv4: Improve rejection of out-of-order layouts")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/pnfs.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index ffe02e43f8c0..be960e47d7f6 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -2014,7 +2014,7 @@ pnfs_update_layout(struct inode *ino,
 	 * If the layout segment list is empty, but there are outstanding
 	 * layoutget calls, then they might be subject to a layoutrecall.
 	 */
-	if (list_empty(&lo->plh_segs) &&
+	if ((list_empty(&lo->plh_segs) || !pnfs_layout_is_valid(lo)) &&
 	    atomic_read(&lo->plh_outstanding) != 0) {
 		spin_unlock(&ino->i_lock);
 		lseg = ERR_PTR(wait_var_event_killable(&lo->plh_outstanding,
@@ -2390,11 +2390,13 @@ pnfs_layout_process(struct nfs4_layoutget *lgp)
 		goto out_forget;
 	}
 
+	if (!pnfs_layout_is_valid(lo) && !pnfs_is_first_layoutget(lo))
+		goto out_forget;
+
 	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)) {
-			if (!pnfs_layout_is_valid(lo) &&
-			    pnfs_is_first_layoutget(lo))
+			if (!pnfs_layout_is_valid(lo))
 				lo->plh_barrier = 0;
 			dprintk("%s forget reply due to sequence\n", __func__);
 			goto out_forget;
@@ -2413,8 +2415,6 @@ pnfs_layout_process(struct nfs4_layoutget *lgp)
 		goto out_forget;
 	} else {
 		/* We have a completely new layout */
-		if (!pnfs_is_first_layoutget(lo))
-			goto out_forget;
 		pnfs_set_layout_stateid(lo, &res->stateid, lgp->cred, true);
 	}
 
-- 
2.31.1