Mount fails if file system image has empty files because of sanity
check while reading superblock. For empty files disk offset to end of
file (i_eoffset) is cpu_to_le32(-1). Sanity check comparison, which
compares disk offset with file system size isn't valid for this value
and hence is ignored with this patch.

Steps to reproduce:

$  dd if=/dev/zero of=bfs-image count=204800
$  mkfs.bfs bfs-image
$  mkdir bfs-mount-point
$  sudo mount -t bfs -o loop bfs-image bfs-mount-point/
$  cd bfs-mount-point/
$  sudo touch a
$  cd ..
$  sudo umount bfs-mount-point/
$  sudo mount -t bfs -o loop bfs-image bfs-mount-point/
mount: /dev/loop0: can't read superblock

$  dmesg
[25526.689580] BFS-fs: bfs_fill_super(): Inode 0x00000003 corrupted

Signed-off-by: Rakesh Pandit <rak...@tuxera.com>
---
 fs/bfs/inode.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/bfs/inode.c b/fs/bfs/inode.c
index 8defc6b..d69c464 100644
--- a/fs/bfs/inode.c
+++ b/fs/bfs/inode.c
@@ -420,7 +420,7 @@ static int bfs_fill_super(struct super_block *s, void 
*data, int silent)
                if (i_sblock > info->si_blocks ||
                        i_eblock > info->si_blocks ||
                        i_sblock > i_eblock ||
-                       i_eoff > s_size ||
+                       (i_eoff != le32_to_cpu(-1) && i_eoff > s_size) ||
                        i_sblock * BFS_BSIZE > i_eoff) {
 
                        printf("Inode 0x%08x corrupted\n", i);
-- 
1.7.11.7
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to