From 3212a80a58062056bb922811071062be58d8fee1 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Fri, 9 Sep 2011 18:46:51 -0400 Subject: ext4: convert block group-relative offsets to use clusters Certain parts of the ext4 code base, primarily in mballoc.c, use a block group number and offset from the beginning of the block group. This offset is invariably used to index into the allocation bitmap, so change the offset to be denominated in units of clusters. Signed-off-by: "Theodore Ts'o" --- fs/ext4/balloc.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'fs/ext4/balloc.c') diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c index 1c6d777b35a2..89abf1f7b253 100644 --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -28,7 +28,8 @@ */ /* - * Calculate the block group number and offset, given a block number + * Calculate the block group number and offset into the block/cluster + * allocation bitmap, given a block number */ void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr, ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp) @@ -37,7 +38,8 @@ void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr, ext4_grpblk_t offset; blocknr = blocknr - le32_to_cpu(es->s_first_data_block); - offset = do_div(blocknr, EXT4_BLOCKS_PER_GROUP(sb)); + offset = do_div(blocknr, EXT4_BLOCKS_PER_GROUP(sb)) >> + EXT4_SB(sb)->s_cluster_bits; if (offsetp) *offsetp = offset; if (blockgrpp) -- cgit v1.2.3