Author: Trond Myklebust 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 --- fs/lockd/clntlock.c | 7 ++++--- fs/lockd/clntproc.c | 15 ++++++--------- fs/lockd/host.c | 7 +++++-- 3 files changed, 15 insertions(+), 14 deletions(-) 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 @@ reclaimer(void *ptr) /* 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 @@ nlmclnt_test(struct nlm_rqst *req, struc 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 @@ static void nlmclnt_locks_init_private(s 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 @@ nlmclnt_lock(struct nlm_rqst *req, struc 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 @@ nlmclnt_unlock(struct nlm_rqst *req, str 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 @@ void nlm_release_host(struct nlm_host *h { 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 @@ nlm_gc_hosts(void) rpc_destroy_client(host->h_rpcclnt); } } - BUG_ON(!list_empty(&host->h_lockowners)); kfree(host); nrhosts--; }