Commit afbaa90b authored Apr 12, 2012 by NeilBrown

md/bitmap: prevent bitmap_daemon_work running while initialising bitmap



If a bitmap is added while the array is active, it is possible
for bitmap_daemon_work to run while the bitmap is being
initialised.
This is particularly a problem if bitmap_daemon_work sees
bitmap->filemap as non-NULL before it has been filled in properly.
So hold bitmap_info.mutex while filling in ->filemap
to prevent problems.

This patch is suitable for any -stable kernel, though it might not
apply cleanly before about 3.1.

Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>

parent f4380a91

drivers/md/bitmap.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -1785,7 +1785,9 @@ int bitmap_load(struct mddev *mddev)
		* re-add of a missing device */
		start = mddev->recovery_cp;

		mutex_lock(&mddev->bitmap_info.mutex);
		err = bitmap_init_from_disk(bitmap, start);
		mutex_unlock(&mddev->bitmap_info.mutex);

		if (err)
		goto out;

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