linux-ext4 - Re: [PATCH] ext4: Automatic setting of {INODE,BLOCK}

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Message-ID: <CAGBYx2YbtPmCc5=OEKZoLHDj90oboUfBXBXm+BMVF-XMS8z0kg@mail.gmail.com>
Date:	Thu, 25 Oct 2012 19:39:06 +0800
From:	Yongqiang Yang <xiaoqiangnk@...il.com>
To:	Lukáš Czerner <lczerner@...hat.com>
Cc:	Tomas Racek <tracek@...hat.com>, linux-ext4@...r.kernel.org
Subject: Re: [PATCH] ext4: Automatic setting of {INODE,BLOCK}_UNINIT flags

>
> So my question is, why do you think this might not make sense in no
> journal mode ? Maybe I am missing something.
Yep, advantage is obvious, in no journal mode, if we delete a file
which is the last inode in a block group, and the uninit flag of inode
bitmap is flused to disk and directory referring the inode is not
flushed,  I don't know how fsck handles the situation currently.  If
fsck handles the situation, everything is ok. I meant maybe we should
check fsck too.

Yongqiang.
>
> Thanks!
> -Lukas
>
>>
>> Thanks,
>> Yongqiang.
>>
>> On Thu, Oct 25, 2012 at 3:25 PM, Tomas Racek <tracek@...hat.com> wrote:
>> > When last inode from bg is freed, set the INODE_UNINIT flag, similarly
>> > when last block is freed, set BLOCK_UNINIT flag. This can speed up
>> > subsequent fsck run.
>> >
>> > Signed-off-by: Tomas Racek <tracek@...hat.com>
>> > ---
>> >  fs/ext4/ialloc.c  | 4 ++++
>> >  fs/ext4/mballoc.c | 4 ++++
>> >  2 files changed, 8 insertions(+)
>> >
>> > diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
>> > index 4facdd2..6e4b982 100644
>> > --- a/fs/ext4/ialloc.c
>> > +++ b/fs/ext4/ialloc.c
>> > @@ -289,6 +289,10 @@ void ext4_free_inode(handle_t *handle, struct inode *inode)
>> >
>> >         count = ext4_free_inodes_count(sb, gdp) + 1;
>> >         ext4_free_inodes_set(sb, gdp, count);
>> > +
>> > +       if (count == EXT4_INODES_PER_GROUP(sb))
>> > +               gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_UNINIT);
>> > +
>> >         if (is_directory) {
>> >                 count = ext4_used_dirs_count(sb, gdp) - 1;
>> >                 ext4_used_dirs_set(sb, gdp, count);
>> > diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
>> > index 526e553..28bce35 100644
>> > --- a/fs/ext4/mballoc.c
>> > +++ b/fs/ext4/mballoc.c
>> > @@ -4665,6 +4665,10 @@ do_more:
>> >
>> >         ret = ext4_free_group_clusters(sb, gdp) + count_clusters;
>> >         ext4_free_group_clusters_set(sb, gdp, ret);
>> > +
>> > +       if(ret == EXT4_BLOCKS_PER_GROUP(sb))
>> > +               gdp->bg_flags |= cpu_to_le16(EXT4_BG_BLOCK_UNINIT);
>> > +
>> >         ext4_block_bitmap_csum_set(sb, block_group, gdp, bitmap_bh);
>> >         ext4_group_desc_csum_set(sb, block_group, gdp);
>> >         ext4_unlock_group(sb, block_group);
>> > --
>> > 1.7.11.7
>> >
>> > --
>> > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
>> > the body of a message to majordomo@...r.kernel.org
>> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>
>>
>>
>>



-- 
Best Wishes
Yongqiang Yang
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