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| author | Alexander Aring <aahringo@redhat.com> | 2022-08-15 15:43:14 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-10-26 13:19:21 +0200 |
| commit | d1ae006b485151888559b6beef3e0d153b86214b (patch) | |
| tree | 47e8ca6d0faaf71f3e6e006e6e4e08aad5ec035e | |
| parent | 6aeb500bb07af24fc6d4cdfba2bebc7cbf8d00a1 (diff) | |
| download | linux-stable-d1ae006b485151888559b6beef3e0d153b86214b.tar.gz | |
fs: dlm: fix race between test_bit() and queue_work()
commit eef6ec9bf390e836a6c4029f3620fe49528aa1fe upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/dlm/ast.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/fs/dlm/ast.c b/fs/dlm/ast.c index 47ee66d70109..0b6fc9f8e8a7 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); @@ -286,7 +286,9 @@ 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); |