pNFS: pnfs_roc_drain() fix a race with open

If a process reopens the file before we can send off the CLOSE/DELEGRETURN,
then pnfs_roc_drain() may end up waiting for a new set of layout segments
that are marked as return-on-close, but haven't yet been returned.

Fix this by only waiting for those layout segments that were invalidated in
pnfs_roc().

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 27e2bca..b02e32e 100644 (file)
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1159,12 +1159,15 @@ bool pnfs_roc_drain(struct inode *ino, u32 *barrier, struct rpc_task *task)
        bool layoutreturn = false;
 
        spin_lock(&ino->i_lock);
-       list_for_each_entry(lseg, &nfsi->layout->plh_segs, pls_list)
-               if (test_bit(NFS_LSEG_ROC, &lseg->pls_flags)) {
-                       rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL);
-                       spin_unlock(&ino->i_lock);
-                       return true;
-               }
+       list_for_each_entry(lseg, &nfsi->layout->plh_segs, pls_list) {
+               if (!test_bit(NFS_LSEG_ROC, &lseg->pls_flags))
+                       continue;
+               if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags))
+                       continue;
+               rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL);
+               spin_unlock(&ino->i_lock);
+               return true;
+       }
        lo = nfsi->layout;
        current_seqid = be32_to_cpu(lo->plh_stateid.seqid);