lockd: Fix Oopses due to list manipulation errors.
The patch "stop abusing file_lock_list introduces a couple of bugs since
the locks may be copied and need to be removed from the lists when they are
destroyed.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/lockd/clntlock.c b/fs/lockd/clntlock.c
index 0fc0ee2..7cf41c1 100644
--- a/fs/lockd/clntlock.c
+++ b/fs/lockd/clntlock.c
@@ -213,11 +213,12 @@
/* First, reclaim all locks that have been marked. */
restart:
list_for_each_entry_safe(fl, next, &host->h_reclaim, fl_u.nfs_fl.list) {
- list_del(&fl->fl_u.nfs_fl.list);
+ list_del_init(&fl->fl_u.nfs_fl.list);
- nlmclnt_reclaim(host, fl);
if (signalled())
- break;
+ continue;
+ if (nlmclnt_reclaim(host, fl) == 0)
+ list_add_tail(&fl->fl_u.nfs_fl.list, &host->h_granted);
goto restart;
}
diff --git a/fs/lockd/clntproc.c b/fs/lockd/clntproc.c
index cb46943..3e90356 100644
--- a/fs/lockd/clntproc.c
+++ b/fs/lockd/clntproc.c
@@ -446,12 +446,14 @@
static void nlmclnt_locks_copy_lock(struct file_lock *new, struct file_lock *fl)
{
- memcpy(&new->fl_u.nfs_fl, &fl->fl_u.nfs_fl, sizeof(new->fl_u.nfs_fl));
- nlm_get_lockowner(new->fl_u.nfs_fl.owner);
+ new->fl_u.nfs_fl.state = fl->fl_u.nfs_fl.state;
+ new->fl_u.nfs_fl.owner = nlm_get_lockowner(fl->fl_u.nfs_fl.owner);
+ list_add_tail(&new->fl_u.nfs_fl.list, &fl->fl_u.nfs_fl.owner->host->h_granted);
}
static void nlmclnt_locks_release_private(struct file_lock *fl)
{
+ list_del(&fl->fl_u.nfs_fl.list);
nlm_put_lockowner(fl->fl_u.nfs_fl.owner);
fl->fl_ops = NULL;
}
@@ -466,6 +468,7 @@
BUG_ON(fl->fl_ops != NULL);
fl->fl_u.nfs_fl.state = 0;
fl->fl_u.nfs_fl.owner = nlm_find_lockowner(host, fl->fl_owner);
+ INIT_LIST_HEAD(&fl->fl_u.nfs_fl.list);
fl->fl_ops = &nlmclnt_lock_ops;
}
@@ -552,7 +555,7 @@
if (resp->status == NLM_LCK_GRANTED) {
fl->fl_u.nfs_fl.state = host->h_state;
fl->fl_flags |= FL_SLEEP;
- list_add_tail(&fl->fl_u.nfs_fl.list, &host->h_granted);
+ /* Ensure the resulting lock will get added to granted list */
do_vfs_lock(fl);
}
status = nlm_stat_to_errno(resp->status);
@@ -619,12 +622,6 @@
int status;
/*
- * Remove from the granted list now so the lock doesn't get
- * reclaimed while we're stuck in the unlock call.
- */
- list_del(&fl->fl_u.nfs_fl.list);
-
- /*
* Note: the server is supposed to either grant us the unlock
* request, or to deny it with NLM_LCK_DENIED_GRACE_PERIOD. In either
* case, we want to unlock.
diff --git a/fs/lockd/host.c b/fs/lockd/host.c
index f456f8e..112ebf8 100644
--- a/fs/lockd/host.c
+++ b/fs/lockd/host.c
@@ -245,8 +245,12 @@
{
if (host != NULL) {
dprintk("lockd: release host %s\n", host->h_name);
- atomic_dec(&host->h_count);
BUG_ON(atomic_read(&host->h_count) < 0);
+ if (atomic_dec_and_test(&host->h_count)) {
+ BUG_ON(!list_empty(&host->h_lockowners));
+ BUG_ON(!list_empty(&host->h_granted));
+ BUG_ON(!list_empty(&host->h_reclaim));
+ }
}
}
@@ -334,7 +338,6 @@
rpc_destroy_client(host->h_rpcclnt);
}
}
- BUG_ON(!list_empty(&host->h_lockowners));
kfree(host);
nrhosts--;
}
