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authorYu Kuai <yukuai3@huawei.com>2023-05-29 16:20:33 +0300
committerSong Liu <song@kernel.org>2023-07-27 10:13:28 +0300
commit64e5e09afc14f8cc9058b0ed5c9cc4c8cd126b85 (patch)
treec8448cc9fa87c6e007a76f8c65bb97423c7e8785 /drivers/md
parenta865b96c513bcaeec49669010d67c40aa8e58619 (diff)
downloadlinux-64e5e09afc14f8cc9058b0ed5c9cc4c8cd126b85.tar.xz
md: refactor action_store() for 'idle' and 'frozen'
Prepare to handle 'idle' and 'frozen' differently to fix a deadlock, there are no functional changes except that MD_RECOVERY_RUNNING is checked again after 'reconfig_mutex' is held. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230529132037.2124527-3-yukuai1@huaweicloud.com
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/md.c61
1 files changed, 45 insertions, 16 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c
index d445d5fb7a01..7fa91f0e5620 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -4747,6 +4747,46 @@ action_show(struct mddev *mddev, char *page)
return sprintf(page, "%s\n", type);
}
+static void stop_sync_thread(struct mddev *mddev)
+{
+ if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
+ return;
+
+ if (mddev_lock(mddev))
+ return;
+
+ /*
+ * Check again in case MD_RECOVERY_RUNNING is cleared before lock is
+ * held.
+ */
+ if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) {
+ mddev_unlock(mddev);
+ return;
+ }
+
+ if (work_pending(&mddev->del_work))
+ flush_workqueue(md_misc_wq);
+
+ if (mddev->sync_thread) {
+ set_bit(MD_RECOVERY_INTR, &mddev->recovery);
+ md_reap_sync_thread(mddev);
+ }
+
+ mddev_unlock(mddev);
+}
+
+static void idle_sync_thread(struct mddev *mddev)
+{
+ clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+ stop_sync_thread(mddev);
+}
+
+static void frozen_sync_thread(struct mddev *mddev)
+{
+ set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+ stop_sync_thread(mddev);
+}
+
static ssize_t
action_store(struct mddev *mddev, const char *page, size_t len)
{
@@ -4754,22 +4794,11 @@ action_store(struct mddev *mddev, const char *page, size_t len)
return -EINVAL;
- if (cmd_match(page, "idle") || cmd_match(page, "frozen")) {
- if (cmd_match(page, "frozen"))
- set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
- else
- clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
- if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
- mddev_lock(mddev) == 0) {
- if (work_pending(&mddev->del_work))
- flush_workqueue(md_misc_wq);
- if (mddev->sync_thread) {
- set_bit(MD_RECOVERY_INTR, &mddev->recovery);
- md_reap_sync_thread(mddev);
- }
- mddev_unlock(mddev);
- }
- } else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
+ if (cmd_match(page, "idle"))
+ idle_sync_thread(mddev);
+ else if (cmd_match(page, "frozen"))
+ frozen_sync_thread(mddev);
+ else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
return -EBUSY;
else if (cmd_match(page, "resync"))
clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);