diff mbox series

[6/9] md: stop using for_each_mddev in md_notify_reboot

Message ID 20220713113125.2232975-7-hch@lst.de (mailing list archive)
State New, archived
Headers show
Series [1/9] md: fix error handling in md_alloc | expand

Commit Message

Christoph Hellwig July 13, 2022, 11:31 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(-)

Comments

Guoqing Jiang July 15, 2022, 9:02 a.m. UTC | #1 
On 7/13/22 7:31 PM, Christoph Hellwig wrote:
> 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>

I suppose it actually means SoB
diff mbox series

Patch

diff --git a/drivers/md/md.c b/drivers/md/md.c
index a2c2e45cb4c18..d3e587271ef3f 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -9588,11 +9588,13 @@  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);
@@ -9601,7 +9603,11 @@  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