Since we have switched to sync way to handle METADATA_UPDATED
msg for md-cluster, then process_metadata_update is depended
on mddev->thread->wqueue.
With the new change, clustered raid could possible hang if
array received a METADATA_UPDATED msg after array unregistered
mddev->thread, so we need to stop clustered raid earlier
than before.
And this change should be safe for non-clustered raid since
all writes are stopped before the destroy. Also in md_run,
we activate the personality (pers->run()) before activating
the bitmap (bitmap_create()). So it is pleasingly symmetric
to stop the bitmap (bitmap_destroy()) before stopping the
personality (__md_stop() calls pers->free()).
Reviewed-by: NeilBrown <neilb@xxxxxxxx>
Signed-off-by: Guoqing Jiang <gqjiang@xxxxxxxx>
---
drivers/md/md.c | 30 +++++++++++++++++-------------
1 file changed, 17 insertions(+), 13 deletions(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 44206bc6e3aa..e1d9116044ae 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -5574,8 +5574,8 @@ void md_stop(struct mddev *mddev)
/* stop the array and free an attached data structures.
* This is called from dm-raid
*/
- __md_stop(mddev);
bitmap_destroy(mddev);
+ __md_stop(mddev);
if (mddev->bio_set)
bioset_free(mddev->bio_set);
}
@@ -5688,6 +5688,22 @@ static int do_md_stop(struct mddev *mddev, int mode,
set_disk_ro(disk, 0);
__md_stop_writes(mddev);
+
+ /*
+ * Destroy bitmap after all writes are stopped
+ */
+ if (mode == 0) {
+ bitmap_destroy(mddev);
+ if (mddev->bitmap_info.file) {
+ struct file *f = mddev->bitmap_info.file;
+ spin_lock(&mddev->lock);
+ mddev->bitmap_info.file = NULL;
+ spin_unlock(&mddev->lock);
+ fput(f);
+ }
+ mddev->bitmap_info.offset = 0;
+ }
+
__md_stop(mddev);
mddev->queue->backing_dev_info->congested_fn = NULL;
@@ -5712,19 +5728,7 @@ static int do_md_stop(struct mddev *mddev, int mode,
*/
if (mode == 0) {
pr_info("md: %s stopped.\n", mdname(mddev));
-
- bitmap_destroy(mddev);
- if (mddev->bitmap_info.file) {
- struct file *f = mddev->bitmap_info.file;
- spin_lock(&mddev->lock);
- mddev->bitmap_info.file = NULL;
- spin_unlock(&mddev->lock);
- fput(f);
- }
- mddev->bitmap_info.offset = 0;
-
export_array(mddev);
-
md_clean(mddev);
if (mddev->hold_active == UNTIL_STOP)
mddev->hold_active = 0;
--
2.6.2
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