From d6b55805ac4ffbcd63bf74ce572cc7a94f15be9e Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Sat, 15 Feb 2014 22:42:25 -0500 Subject: [PATCH] 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" Reported-by: Jon Bernard Signed-off-by: Greg Kroah-Hartman --- fs/ext4/resize.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index 6bb7943..c503850 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -404,7 +404,7 @@ static int set_flexbg_block_bitmap(struct super_block *sb, handle_t *handle, start = ext4_group_first_block_no(sb, group); group -= flex_gd->groups[0].group; - count2 = sb->s_blocksize * 8 - (block - start); + count2 = EXT4_BLOCKS_PER_GROUP(sb) - (block - start); if (count2 > count) count2 = count; -- 2.7.4