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

97f76d3d · Nikanth Karthikesan <[email protected]> · 2009-04-02 16:56:46 -07:00

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 <[email protected]>
Cc: Nick Piggin <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Commit: 97f76d3d197f201ac8a8a3ced5b8fef81568e50e
Parents: 9a896c9a

Changes

1 files changed · +3 −3

File	Status	Add	Del	Content
fs/buffer.c	modified	+3	−3	View file

fs/buffer.c

View file

diff --git a/fs/buffer.c b/fs/buffer.c
index f5f8b15..2963858 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -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);
 