From 16648bac862fd9c6490a465533345fbeaa6466e0 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Tue, 19 Jul 2022 11:18:22 +0200
Subject: [PATCH] md: stop using for_each_mddev in md_exit
Git-commit: 16648bac862fd9c6490a465533345fbeaa6466e0
Patch-mainline: v6.0-rc1
References: jsc#PED-2766
Just do a simple list_for_each_entry_safe on all_mddevs, and only grab a
reference when we drop the lock and delete the now unused for_each_mddev
macro.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Coly Li <colyli@suse.de>
---
drivers/md/md.c | 39 +++++++++++----------------------------
1 file changed, 11 insertions(+), 28 deletions(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index f5d46694a506..709df9045476 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -368,28 +368,6 @@ EXPORT_SYMBOL_GPL(md_new_event);
static LIST_HEAD(all_mddevs);
static DEFINE_SPINLOCK(all_mddevs_lock);
-/*
- * iterates through all used mddevs in the system.
- * We take care to grab the all_mddevs_lock whenever navigating
- * the list, and to always hold a refcount when unlocked.
- * Any code which breaks out of this loop while own
- * a reference to the current mddev and must mddev_put it.
- */
-#define for_each_mddev(_mddev,_tmp) \
- \
- for (({ spin_lock(&all_mddevs_lock); \
- _tmp = all_mddevs.next; \
- _mddev = NULL;}); \
- ({ if (_tmp != &all_mddevs) \
- mddev_get(list_entry(_tmp, struct mddev, all_mddevs));\
- spin_unlock(&all_mddevs_lock); \
- if (_mddev) mddev_put(_mddev); \
- _mddev = list_entry(_tmp, struct mddev, all_mddevs); \
- _tmp != &all_mddevs;}); \
- ({ spin_lock(&all_mddevs_lock); \
- _tmp = _tmp->next;}) \
- )
-
/* Rather than calling directly into the personality make_request function,
* IO requests come here first so that we can check if the device is
* being suspended pending a reconfiguration.
@@ -9923,8 +9901,7 @@ void md_autostart_arrays(int part)
static __exit void md_exit(void)
{
- struct mddev *mddev;
- struct list_head *tmp;
+ struct mddev *mddev, *n;
int delay = 1;
unregister_blkdev(MD_MAJOR,"md");
@@ -9944,17 +9921,23 @@ static __exit void md_exit(void)
}
remove_proc_entry("mdstat", NULL);
- 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);
export_array(mddev);
mddev->ctime = 0;
mddev->hold_active = 0;
/*
- * for_each_mddev() will call mddev_put() at the end of each
- * iteration. As the mddev is now fully clear, this will
- * schedule the mddev for destruction by a workqueue, and the
+ * As the mddev is now fully clear, mddev_put will schedule
+ * the mddev for destruction by a workqueue, and the
* destroy_workqueue() below will wait for that to complete.
*/
+ mddev_put(mddev);
+ spin_lock(&all_mddevs_lock);
}
+ spin_unlock(&all_mddevs_lock);
+
destroy_workqueue(md_rdev_misc_wq);
destroy_workqueue(md_misc_wq);
destroy_workqueue(md_wq);
--
2.35.3