Commit 97f76d3d authored Apr 02, 2009 by Nikanth Karthikesan Committed by Linus Torvalds Apr 02, 2009

vfs: check bh->b_blocknr only if BH_Mapped is set



Check bh->b_blocknr only if BH_Mapped is set.

akpm: I doubt if b_blocknr is ever uninitialised here, but it could
conceivably cause a problem if we're doing a lookup for block zero.

Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 9a896c9a

fs/buffer.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -199,13 +199,13 @@ __find_get_block_slow(struct block_device *bdev, sector_t block)
		head = page_buffers(page);
		bh = head;
		do {
		if (bh->b_blocknr == block) {
		if (!buffer_mapped(bh))
		all_mapped = 0;
		else if (bh->b_blocknr == block) {
		ret = bh;
		get_bh(bh);
		goto out_unlock;
		}
		if (!buffer_mapped(bh))
		all_mapped = 0;
		bh = bh->b_this_page;
		} while (bh != head);