gfs2: Fixes to "Implement iomap for block_map" (2)

It turns out that commit 3229c18c0d6b2 'Fixes to "Implement iomap for block_map"' introduced another bug in gfs2_iomap_begin that can cause gfs2_block_map to set bh->b_size of an actual buffer to 0. This can lead to arbitrary incorrect behavior including crashes or disk corruption. Revert the incorrect part of that commit.

---
 fs/gfs2/bmap.c | 3 ---
 1 file changed, 3 deletions(-)

index 86d6a4435c87..51f940e76c5e 100644
@@ -807,9 +807,6 @@ int gfs2_iomap_begin(struct inode *inode, loff_t pos, loff_t length,
 			iomap->length = hole_size(inode, lblock, &mp);
 		else
 			iomap->length = size - pos;
-	} else {
-		if (height <= ip->i_height)
-			iomap->length = hole_size(inode, lblock, &mp);
 	}
 	goto out_release;
 }

2.14.3

----- Original Message -----

| It turns out that commit 3229c18c0d6b2 'Fixes to "Implement iomap for
| block_map"' introduced another bug in gfs2_iomap_begin that can cause
| gfs2_block_map to set bh->b_size of an actual buffer to 0.  This can
| lead to arbitrary incorrect behavior including crashes or disk
| corruption.  Revert the incorrect part of that commit.
| 
| Signed-off-by: Andreas Gruenbacher <[email protected]>
| ---

Hi,

Thanks. This is now pushed to the for-next branch of the linux-gfs2 tree:
https://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2.git/commit/fs/gfs2?h=for-next&id=dc49cacbdc4eecae05713c03e3ab6ac0b7c06c1c

Regards,

Bob Peterson
Red Hat File Systems