> On Tue, 23 Mar 2010 20:47:39 +0800, jing zhang <zj.barak@gmail.com> wrote:
>> 2010/3/22,
tytso@mit.edu <tytso@mit.edu>:
>> > On Sun, Mar 21, 2010 at 10:01:06PM +0800, jing zhang wrote:
>> >> From: Jing Zhang <zj.barak@gmail.com>
>> >>
>> >> Date: Sun Mar 21 21:59:35 2010
>> >>
>> >> Cc: Theodore Ts'o <tytso@mit.edu>
>> >> Cc: Andreas Dilger <adilger@sun.com>
>> >> Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
>> >> Signed-off-by: Jing Zhang <zj.barak@gmail.com>
>> >>
>> >> ---
>> >>
>> >> --- linux-2.6.32/fs/ext4/mballoc.c 2009-12-03 11:51:22.000000000 +0800
>> >> +++ ext4_mm_leak/mballoc3.c 2010-03-21 21:37:18.000000000 +0800
>> >> @@ -2360,6 +2360,24 @@ err_freesgi:
>> >> return -ENOMEM;
>> >> }
>> >>
>> >> +static void ext4_mb_destroy_backend(struct super_block *sb)
>> >> +{
>> >> + ext4_group_t ngroups = ext4_get_groups_count(sb);
>> >> + ext4_group_t i;
>> >> + struct ext4_sb_info *sbi = EXT4_SB(sb);
>> >> + int j;
>> >> + int num_meta_group_infos = (ngroups + EXT4_DESC_PER_BLOCK(sb) -1)
>> >> + >> EXT4_DESC_PER_BLOCK_BITS(sb);
>> >> + for (i = 0; i < ngroups; i++)
>> >> + kfree(ext4_get_group_info(sb, i));
>> >> +
>> >> + for (j = 0; j < num_meta_group_infos; j++)
>> >> + kfree(sbi->s_group_info[j]);
>> >> +
>> >> + kfree(sbi->s_group_info);
>> >> + iput(sbi->s_buddy_cache);
>> >> +}
>> >> +
>> >
>> > It would be better if this could be done by making ext4_mb_release()
>> > more flexible, and then calling ext4_mb_release() if there is an error
>> > setting up the data structures in ext4_mb_init().
>> >
>> > - Ted
>> >
>>
>> Yeah, Ted, going through ext4_mb_release() is clearer.
>>
>> ---
>>
>> diff --git a/linux-2.6.32/fs/ext4/mballoc.c b/ext4_mm_leak/mballoc3.c
>> index bba1282..99ca2de 100644
>> --- a/linux-2.6.32/fs/ext4/mballoc.c
>> +++ b/ext4_mm_leak/mballoc3.c
>> @@ -2417,8 +2417,7 @@ int ext4_mb_init(struct super_block *sb, int
>> needs_recovery)
>>
>> sbi->s_locality_groups = alloc_percpu(struct ext4_locality_group);
>> if (sbi->s_locality_groups == NULL) {
>> - kfree(sbi->s_mb_offsets);
>> - kfree(sbi->s_mb_maxs);
>> + ext4_mb_release(sb);
>
> We may want to make sure that we can safely call ext4_mb_release that
> early. what i would suggest is to move s_locality_group allocation
> before ext4_mb_init. that makes error handling easy
>
