1. fix unbalanced parentheses.
2. add more description about that MD_CLUSTER_SEND_LOCKED_ALREADY
will be cleared after set it in add_new_disk.
Signed-off-by: Guoqing Jiang <gqjiang@xxxxxxxx>
---
drivers/md/md-cluster.c | 23 ++++++++++++++++++-----
1 file changed, 18 insertions(+), 5 deletions(-)
diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c
index ad3ec7d..0ded8e9 100644
--- a/drivers/md/md-cluster.c
+++ b/drivers/md/md-cluster.c
@@ -53,11 +53,12 @@ struct resync_info {
* accomodate lock and hold. See next comment.
*/
#define MD_CLUSTER_SEND_LOCK 4
-/* If cluster operations must lock the communication channel,
- * so as to perform extra operations (and no other operation
- * is allowed on the MD, such as adding a disk. Token needs
- * to be locked and held until the operation completes with
- * a md_update_sb(), which would eventually release the lock.
+/* If cluster operations (such as adding a disk) must lock the
+ * communication channel, so as to perform extra operations
+ * (update metadata) and no other operation is allowed on the
+ * MD. Token needs to be locked and held until the operation
+ * completes witha md_update_sb(), which would eventually release
+ * the lock.
*/
#define MD_CLUSTER_SEND_LOCKED_ALREADY 5
@@ -1021,6 +1022,18 @@ static int add_new_disk(struct mddev *mddev, struct md_rdev *rdev)
unlock_comm(cinfo);
else {
dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_CR);
+ /* Since MD_CHANGE_DEVS will be set in add_bound_rdev which
+ * will run soon after add_new_disk, the below path will be
+ * invoked:
+ * md_wakeup_thread(mddev->thread)
+ * -> conf->thread (raid1d)
+ * -> md_check_recovery -> md_update_sb
+ * -> metadata_update_start/finish
+ * MD_CLUSTER_SEND_LOCKED_ALREADY will be cleared eventually.
+ *
+ * For other failure cases, metadata_update_cancel and
+ * add_new_disk_cancel also clear below bit as well.
+ * */
set_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state);
wake_up(&cinfo->wait);
}
--
2.1.4
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