NFSv4: Pin the superblock while we're returning the delegation
This patch ensures that the superblock doesn't go ahead and disappear
underneath us while the state manager thread is returning delegations.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index 5ca502b..be313e7 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -474,14 +474,20 @@
super_list) {
if (!nfs_delegation_need_return(delegation))
continue;
- inode = nfs_delegation_grab_inode(delegation);
- if (inode == NULL)
+ if (!nfs_sb_active(server->super))
continue;
+ inode = nfs_delegation_grab_inode(delegation);
+ if (inode == NULL) {
+ rcu_read_unlock();
+ nfs_sb_deactive(server->super);
+ goto restart;
+ }
delegation = nfs_start_delegation_return_locked(NFS_I(inode));
rcu_read_unlock();
err = nfs_end_delegation_return(inode, delegation, 0);
iput(inode);
+ nfs_sb_deactive(server->super);
if (!err)
goto restart;
set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
@@ -815,9 +821,14 @@
if (test_bit(NFS_DELEGATION_NEED_RECLAIM,
&delegation->flags) == 0)
continue;
- inode = nfs_delegation_grab_inode(delegation);
- if (inode == NULL)
+ if (!nfs_sb_active(server->super))
continue;
+ inode = nfs_delegation_grab_inode(delegation);
+ if (inode == NULL) {
+ rcu_read_unlock();
+ nfs_sb_deactive(server->super);
+ goto restart;
+ }
delegation = nfs_start_delegation_return_locked(NFS_I(inode));
rcu_read_unlock();
if (delegation != NULL) {
@@ -827,6 +838,7 @@
nfs_free_delegation(delegation);
}
iput(inode);
+ nfs_sb_deactive(server->super);
goto restart;
}
}