Commit 147e0b6a authored Aug 06, 2010 by Dan Williams Committed by NeilBrown Aug 08, 2010

md: move revalidate_disk() back outside open_mutex



Commit b821eaa5 "md: remove ->changed and related code" moved
revalidate_disk() under open_mutex, and lockdep noticed.

[ INFO: possible circular locking dependency detected ]
2.6.32-mdadm-locking #1
-------------------------------------------------------
mdadm/3640 is trying to acquire lock:
 (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff811acecb>] revalidate_disk+0x5b/0x90

but task is already holding lock:
 (&mddev->open_mutex){+.+...}, at: [<ffffffffa055e07a>] do_md_stop+0x4a/0x4d0 [md_mod]

which lock already depends on the new lock.

It is suitable for 2.6.35.x

Cc: <stable@kernel.org>
Reported-by: Przemyslaw Czarnowski <przemyslaw.hawrylewicz.czarnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>

parent 51e9ac77

drivers/md/md.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -4765,7 +4765,7 @@ out:
		*/
		static int do_md_stop(mddev_t * mddev, int mode, int is_open)
		{
		int err = 0;
		int err = 0, revalidate = 0;
		struct gendisk *disk = mddev->gendisk;
		mdk_rdev_t *rdev;

		@@ -4795,7 +4795,7 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open)
		}

		set_capacity(disk, 0);
		revalidate_disk(disk);
		revalidate = 1;

		if (mddev->ro)
		mddev->ro = 0;
		@@ -4803,6 +4803,8 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open)
		err = 0;
		}
		mutex_unlock(&mddev->open_mutex);
		if (revalidate)
		revalidate_disk(disk);
		if (err)
		return err;
		/*

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