pNFS: Don't forget the layout stateid if there are outstanding LAYOUT…

…GETs If there are outstanding LAYOUTGET rpc calls, then we want to ensure that we keep the layout stateid around so we that don't inadvertently pick up an old/misordered sequence id. The race is as follows: Client Server ====== ====== LAYOUTGET(seqid) LAYOUTGET(seqid) return LAYOUTGET(seqid+1) return LAYOUTGET(seqid+2) process LAYOUTGET(seqid+2) forget layout process LAYOUTGET(seqid+1) If it forgets the layout stateid before processing seqid+1, then the client will not check the layout->plh_barrier, and so will set the stateid with seqid+1. Signed-off-by: Trond Myklebust <[email protected]>
redbrain17 · Sep 4, 2016 · 334a8f3 · 334a8f3
1 parent 52ec7be
commit 334a8f3
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
@@ -365,7 +365,8 @@ pnfs_layout_remove_lseg(struct pnfs_layout_hdr *lo,
 	/* Matched by pnfs_get_layout_hdr in pnfs_layout_insert_lseg */
 	atomic_dec(&lo->plh_refcount);
 	if (list_empty(&lo->plh_segs)) {
-		set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
+		if (atomic_read(&lo->plh_outstanding) == 0)
+			set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 		clear_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 	}
 	rpc_wake_up(&NFS_SERVER(inode)->roc_rpcwaitq);