Commit 23397844 authored by Heinz Mauelshagen's avatar Heinz Mauelshagen Committed by Mike Snitzer
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dm raid: fix panic when attempting to force a raid to sync 



Requesting a sync on an active raid device via a table reload
(see 'sync' parameter in Documentation/device-mapper/dm-raid.txt)
skips the super_load() call that defines the superblock size
(rdev->sb_size) -- resulting in an oops if/when super_sync()->memset()
is called.

Fix by moving the initialization of the superblock start and size
out of super_load() to the caller (analyse_superblocks).

Signed-off-by: default avatarHeinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent 95b1369a

drivers/md/dm-raid.c

+11 −10
Original line number Diff line number Diff line
@@ -2143,13 +2143,6 @@ static int super_load(struct md_rdev *rdev, struct md_rdev *refdev) 
	struct dm_raid_superblock *refsb;

	uint64_t events_sb, events_refsb;



	rdev->sb_start = 0;

	rdev->sb_size = bdev_logical_block_size(rdev->meta_bdev);

	if (rdev->sb_size < sizeof(*sb) || rdev->sb_size > PAGE_SIZE) {

		DMERR("superblock size of a logical block is no longer valid");

		return -EINVAL;

	}



	r = read_disk_sb(rdev, rdev->sb_size, false);

	if (r)

		return r;
@@ -2494,6 +2487,17 @@ static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs) 
		if (test_bit(Journal, &rdev->flags))

			continue;



		if (!rdev->meta_bdev)

			continue;



		/* Set superblock offset/size for metadata device. */

		rdev->sb_start = 0;

		rdev->sb_size = bdev_logical_block_size(rdev->meta_bdev);

		if (rdev->sb_size < sizeof(struct dm_raid_superblock) || rdev->sb_size > PAGE_SIZE) {

			DMERR("superblock size of a logical block is no longer valid");

			return -EINVAL;

		}



		/*

		 * Skipping super_load due to CTR_FLAG_SYNC will cause

		 * the array to undergo initialization again as
@@ -2506,9 +2510,6 @@ static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs) 
		if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags))

			continue;



		if (!rdev->meta_bdev)

			continue;



		r = super_load(rdev, freshest);



		switch (r) {

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