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Commit b5e07d44 authored by Jack Wang's avatar Jack Wang Committed by Greg Kroah-Hartman
Browse files

md: fix memleak for mempool 



[ Upstream commit 6aaa58c994277647f8b05ffef3b9b225a2d08f36 ]

I noticed kmemleak report memory leak when run create/stop
md in a loop, backtrace:
[<000000001ca975e7>] mempool_create_node+0x86/0xd0
[<0000000095576bcd>] md_run+0x1057/0x1410 [md_mod]
[<000000007b45c5fc>] do_md_run+0x15/0x130 [md_mod]
[<000000001ede9ec0>] md_ioctl+0x1f49/0x25d0 [md_mod]
[<000000004142cacf>] blkdev_ioctl+0x680/0xd00

The root cause is we alloc mddev->flush_pool and
mddev->flush_bio_pool in md_run, but from do_md_stop
will not call into md_stop but __md_stop, move the
mempool_destroy to __md_stop fixes the problem for me.

The bug was introduced in 5a409b4f, the fixes should go to
4.18+

Fixes: 5a409b4f ("MD: fix lock contention for flush bios")
Signed-off-by: default avatarJack Wang <jinpu.wang@profitbricks.com>
Reviewed-by: default avatarXiao Ni <xni@redhat.com>
Signed-off-by: default avatarShaohua Li <shli@fb.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent fbf975ef

drivers/md/md.c

+8 −8
Original line number Diff line number Diff line
@@ -5906,14 +5906,6 @@ static void __md_stop(struct mddev *mddev) 
		mddev->to_remove = &md_redundancy_group;

	module_put(pers->owner);

	clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);

}



void md_stop(struct mddev *mddev)

{

	/* stop the array and free an attached data structures.

	 * This is called from dm-raid

	 */

	__md_stop(mddev);

	if (mddev->flush_bio_pool) {

		mempool_destroy(mddev->flush_bio_pool);

		mddev->flush_bio_pool = NULL;
@@ -5922,6 +5914,14 @@ void md_stop(struct mddev *mddev) 
		mempool_destroy(mddev->flush_pool);

		mddev->flush_pool = NULL;

	}

}



void md_stop(struct mddev *mddev)

{

	/* stop the array and free an attached data structures.

	 * This is called from dm-raid

	 */

	__md_stop(mddev);

	bioset_exit(&mddev->bio_set);

	bioset_exit(&mddev->sync_set);

}