[PATCH 07/10] md: stop using for_each_mddev in md_notify_reboot
From: Christoph Hellwig <hch@lst.de>
Date: 2022-07-19 09:19:54
Also in:
linux-block
Subsystem:
software raid (multiple disks) support, the rest · Maintainers:
Song Liu, Yu Kuai, Linus Torvalds
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> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Hannes Reinecke <hare@suse.de> --- drivers/md/md.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index bd87d59086947..ede817286cacd 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c@@ -9585,11 +9585,13 @@ 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);
@@ -9598,7 +9600,11 @@ 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
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2.30.2