ext4: don't load the block bitmap for block groups which have no space

Add a short circuit check to ext4_mb_group_group() so that we don't
bother to load the block bitmap for a block group which does not have
any space available.  (Or which does not have enough space until we
are in desperation mode, i.e., when cr == 3.)

Resolves-bug: https://bugzilla.kernel.org/show_bug.cgi?id=45741
Reported-by: mirek@me.com
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Theodore Ts'o 2012-08-17 09:46:17 -04:00
Родитель ecb94f5fdf
Коммит 01fc48e892
1 изменённых файлов: 6 добавлений и 3 удалений

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@ -1862,6 +1862,12 @@ static int ext4_mb_good_group(struct ext4_allocation_context *ac,
BUG_ON(cr < 0 || cr >= 4);
free = grp->bb_free;
if (free == 0)
return 0;
if (cr <= 2 && free < ac->ac_g_ex.fe_len)
return 0;
/* We only do this if the grp has never been initialized */
if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
int ret = ext4_mb_init_group(ac->ac_sb, group);
@ -1869,10 +1875,7 @@ static int ext4_mb_good_group(struct ext4_allocation_context *ac,
return 0;
}
free = grp->bb_free;
fragments = grp->bb_fragments;
if (free == 0)
return 0;
if (fragments == 0)
return 0;