From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rakesh Pandit Subject: [PATCH] bfs: Fix sanity checks for empty files Date: Wed, 15 Jan 2014 19:35:08 +0200 Message-ID: <20140115173507.GA3300@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: , To: Return-path: Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org 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 --- 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