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authorAlexander Aring <aahringo@redhat.com>2022-08-15 22:43:14 +0300
committerDavid Teigland <teigland@redhat.com>2022-08-23 22:37:14 +0300
commiteef6ec9bf390e836a6c4029f3620fe49528aa1fe (patch)
tree58944a50286630dcff9c3122552b9fe556d19e28 /fs/dlm
parent30ea3257e8766027c4d8d609dcbd256ff9a76073 (diff)
downloadlinux-eef6ec9bf390e836a6c4029f3620fe49528aa1fe.tar.xz
fs: dlm: fix race between test_bit() and queue_work()
This patch fixes a race by using ls_cb_mutex around the bit operations and conditional code blocks for LSFL_CB_DELAY. The function dlm_callback_stop() expects to stop all callbacks and flush all currently queued onces. The set_bit() is not enough because there can still be queue_work() after the workqueue was flushed. To avoid queue_work() after set_bit(), surround both by ls_cb_mutex. Cc: stable@vger.kernel.org Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
Diffstat (limited to 'fs/dlm')
-rw-r--r--fs/dlm/ast.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/fs/dlm/ast.c b/fs/dlm/ast.c
index 19ef136f9e4f..a44cc42b6317 100644
--- a/fs/dlm/ast.c
+++ b/fs/dlm/ast.c
@@ -200,13 +200,13 @@ void dlm_add_cb(struct dlm_lkb *lkb, uint32_t flags, int mode, int status,
if (!prev_seq) {
kref_get(&lkb->lkb_ref);
+ mutex_lock(&ls->ls_cb_mutex);
if (test_bit(LSFL_CB_DELAY, &ls->ls_flags)) {
- mutex_lock(&ls->ls_cb_mutex);
list_add(&lkb->lkb_cb_list, &ls->ls_cb_delay);
- mutex_unlock(&ls->ls_cb_mutex);
} else {
queue_work(ls->ls_callback_wq, &lkb->lkb_cb_work);
}
+ mutex_unlock(&ls->ls_cb_mutex);
}
out:
mutex_unlock(&lkb->lkb_cb_mutex);
@@ -288,7 +288,9 @@ void dlm_callback_stop(struct dlm_ls *ls)
void dlm_callback_suspend(struct dlm_ls *ls)
{
+ mutex_lock(&ls->ls_cb_mutex);
set_bit(LSFL_CB_DELAY, &ls->ls_flags);
+ mutex_unlock(&ls->ls_cb_mutex);
if (ls->ls_callback_wq)
flush_workqueue(ls->ls_callback_wq);