ext4: fix online resize with a non-standard blocks per group setting
authorTheodore Ts'o <tytso@mit.edu>
Sun, 16 Feb 2014 03:42:25 +0000 (22:42 -0500)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 7 Mar 2014 05:30:00 +0000 (21:30 -0800)
commitd6b55805ac4ffbcd63bf74ce572cc7a94f15be9e
treecfc19c7fb27a9dafaa18e49c473f474810d2f113
parent94a197c6bc4976fdec2ea37a0612df226839c541
ext4: fix online resize with a non-standard blocks per group setting

commit 3d2660d0c9c2f296837078c189b68a47f6b2e3b5 upstream.

The set_flexbg_block_bitmap() function assumed that the number of
blocks in a blockgroup was sb->blocksize * 8, which is normally true,
but not always!  Use EXT4_BLOCKS_PER_GROUP(sb) instead, to fix block
bitmap corruption after:

mke2fs -t ext4 -g 3072 -i 4096 /dev/vdd 1G
mount -t ext4 /dev/vdd /vdd
resize2fs /dev/vdd 8G

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reported-by: Jon Bernard <jbernard@tuxion.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fs/ext4/resize.c