diff mbox series

[5/8] md: stop using for_each_mddev in md_notify_reboot

Message ID 20220712070331.1390700-6-hch@lst.de (mailing list archive)
State Superseded, archived
Delegated to: Song Liu
Headers show
Series [1/8] md: fix kobject_add error handling | expand

Commit Message

Christoph Hellwig July 12, 2022, 7:03 a.m. UTC 
Just do a simple list_for_each_entry_safe on all_mddevs, and only grab a
reference when we drop the lock.

Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 drivers/md/md.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/drivers/md/md.c b/drivers/md/md.c
index d22608dcb25fe..73abeaed0b6fc 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -9547,11 +9547,13 @@  EXPORT_SYMBOL_GPL(rdev_clear_badblocks);
 static int md_notify_reboot(struct notifier_block *this,
 			    unsigned long code, void *x)
 {
-	struct list_head *tmp;
-	struct mddev *mddev;
+	struct mddev *mddev, *n;
 	int need_delay = 0;
 
-	for_each_mddev(mddev, tmp) {
+	spin_lock(&all_mddevs_lock);
+	list_for_each_entry_safe(mddev, n, &all_mddevs, all_mddevs) {
+		mddev_get(mddev);
+		spin_unlock(&all_mddevs_lock);
 		if (mddev_trylock(mddev)) {
 			if (mddev->pers)
 				__md_stop_writes(mddev);
@@ -9560,7 +9562,11 @@  static int md_notify_reboot(struct notifier_block *this,
 			mddev_unlock(mddev);
 		}
 		need_delay = 1;
+		mddev_put(mddev);
+		spin_lock(&all_mddevs_lock);
 	}
+	spin_unlock(&all_mddevs_lock);
+
 	/*
 	 * certain more exotic SCSI devices are known to be
 	 * volatile wrt too early system reboots. While the