Merge v7.1.5linux-rolling-stable

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 8 insertions, 1 deletions

diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index 122fb3f14ffb..9546d2195c25 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -173,6 +173,7 @@ int nfs4_check_delegation(struct inode *inode, fmode_t type)
 static int nfs_delegation_claim_locks(struct nfs4_state *state, const nfs4_stateid *stateid)
 {
 	struct inode *inode = state->inode;
+	struct nfs_inode *nfsi = NFS_I(inode);
 	struct file_lock *fl;
 	struct file_lock_context *flctx = locks_inode_context(inode);
 	struct list_head *list;
@@ -182,6 +183,9 @@ static int nfs_delegation_claim_locks(struct nfs4_state *state, const nfs4_state
 		goto out;
 
 	list = &flctx->flc_posix;
+
+	/* Guard against reclaim and new lock/unlock calls */
+	down_write(&nfsi->rwsem);
 	spin_lock(&flctx->flc_lock);
 restart:
 	for_each_file_lock(fl, list) {
@@ -189,8 +193,10 @@ restart:
 			continue;
 		spin_unlock(&flctx->flc_lock);
 		status = nfs4_lock_delegation_recall(fl, state, stateid);
-		if (status < 0)
+		if (status < 0) {
+			up_write(&nfsi->rwsem);
 			goto out;
+		}
 		spin_lock(&flctx->flc_lock);
 	}
 	if (list == &flctx->flc_posix) {
@@ -198,6 +204,7 @@ restart:
 		goto restart;
 	}
 	spin_unlock(&flctx->flc_lock);
+	up_write(&nfsi->rwsem);
 out:
 	return status;
 }