NFSv4.1: Keep a reference on lock states while checking
While walking the list of lock_states, keep a reference on each
nfs4_lock_state to be checked, otherwise the lock state could be removed
while the check performs TEST_STATEID and possible FREE_STATEID.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 2d1481e..e6dc95e 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2564,15 +2564,23 @@
static int nfs41_check_expired_locks(struct nfs4_state *state)
{
int status, ret = NFS_OK;
- struct nfs4_lock_state *lsp;
+ struct nfs4_lock_state *lsp, *prev = NULL;
struct nfs_server *server = NFS_SERVER(state->inode);
if (!test_bit(LK_STATE_IN_USE, &state->flags))
goto out;
+
+ spin_lock(&state->state_lock);
list_for_each_entry(lsp, &state->lock_states, ls_locks) {
if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags)) {
struct rpc_cred *cred = lsp->ls_state->owner->so_cred;
+ atomic_inc(&lsp->ls_count);
+ spin_unlock(&state->state_lock);
+
+ nfs4_put_lock_state(prev);
+ prev = lsp;
+
status = nfs41_test_and_free_expired_stateid(server,
&lsp->ls_stateid,
cred);
@@ -2585,10 +2593,14 @@
set_bit(NFS_LOCK_LOST, &lsp->ls_flags);
} else if (status != NFS_OK) {
ret = status;
- break;
+ nfs4_put_lock_state(prev);
+ goto out;
}
+ spin_lock(&state->state_lock);
}
- };
+ }
+ spin_unlock(&state->state_lock);
+ nfs4_put_lock_state(prev);
out:
return ret;
}