From b5a7c4f5835ae2805d00ca39709002cb03364143 Mon Sep 17 00:00:00 2001 From: Glauber de Oliveira Costa Date: Fri, 24 Mar 2006 03:18:37 -0800 Subject: [PATCH] [PATCH] ext3: Properly report backup block present in a group In filesystems with the meta block group flag on, ext3_bg_num_gdb() fails to report the correct number of blocks used to store the group descriptor backups in a given group. It happens because meta_bg follows a different logic from the original ext3 backup placement in groups multiples of 3, 5 and 7. Signed-off-by: Glauber de Oliveira Costa Cc: Andreas Dilger Cc: "Stephen C. Tweedie" Cc: Alex Tomas Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ext3/balloc.c | 40 +++++++++++++++++++++++++++++++++------- 1 file changed, 33 insertions(+), 7 deletions(-) diff --git a/fs/ext3/balloc.c b/fs/ext3/balloc.c index 6250fcdf14a1..46623f77666b 100644 --- a/fs/ext3/balloc.c +++ b/fs/ext3/balloc.c @@ -1493,12 +1493,33 @@ static int ext3_group_sparse(int group) */ int ext3_bg_has_super(struct super_block *sb, int group) { - if (EXT3_HAS_RO_COMPAT_FEATURE(sb,EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER)&& - !ext3_group_sparse(group)) + if (EXT3_HAS_RO_COMPAT_FEATURE(sb, + EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER) && + !ext3_group_sparse(group)) return 0; return 1; } +static unsigned long ext3_bg_num_gdb_meta(struct super_block *sb, int group) +{ + unsigned long metagroup = group / EXT3_DESC_PER_BLOCK(sb); + unsigned long first = metagroup * EXT3_DESC_PER_BLOCK(sb); + unsigned long last = first + EXT3_DESC_PER_BLOCK(sb) - 1; + + if (group == first || group == first + 1 || group == last) + return 1; + return 0; +} + +static unsigned long ext3_bg_num_gdb_nometa(struct super_block *sb, int group) +{ + if (EXT3_HAS_RO_COMPAT_FEATURE(sb, + EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER) && + !ext3_group_sparse(group)) + return 0; + return EXT3_SB(sb)->s_gdb_count; +} + /** * ext3_bg_num_gdb - number of blocks used by the group table in group * @sb: superblock for filesystem @@ -1510,9 +1531,14 @@ int ext3_bg_has_super(struct super_block *sb, int group) */ unsigned long ext3_bg_num_gdb(struct super_block *sb, int group) { - if (EXT3_HAS_RO_COMPAT_FEATURE(sb,EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER)&& - !ext3_group_sparse(group)) - return 0; - return EXT3_SB(sb)->s_gdb_count; -} + unsigned long first_meta_bg = + le32_to_cpu(EXT3_SB(sb)->s_es->s_first_meta_bg); + unsigned long metagroup = group / EXT3_DESC_PER_BLOCK(sb); + + if (!EXT3_HAS_INCOMPAT_FEATURE(sb,EXT3_FEATURE_INCOMPAT_META_BG) || + metagroup < first_meta_bg) + return ext3_bg_num_gdb_nometa(sb,group); + return ext3_bg_num_gdb_meta(sb,group); + +} -- 2.39.5