Re: [PATCH v2] f2fs: fix max orphan inodes calculation

[Wanpeng Li]

Hi Changman,
On Fri, Mar 06, 2015 at 11:37:28AM +0800, Chao Yu wrote:
>Hi Changman,
>
>> -----Original Message-----
>> From: Changman Lee [mailto:cm224.lee@xxxxxxxxxxx]
>> Sent: Tuesday, March 03, 2015 9:40 AM
>> To: linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx
>> Cc: Jaegeuk Kim; Chao Yu; linux-fsdevel@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
>> Subject: Re: [PATCH v2] f2fs: fix max orphan inodes calculation
>> 
>> On Fri, Feb 27, 2015 at 05:38:13PM +0800, Wanpeng Li wrote:
>> > cp_payload is introduced for sit bitmap to support large volume, and it is
>> > just after the block of f2fs_checkpoint + nat bitmap, so the first segment
>> > should include F2FS_CP_PACKS + NR_CURSEG_TYPE + cp_payload + orphan blocks.
>> > However, current max orphan inodes calculation don't consider cp_payload,
>> > this patch fix it by reducing the number of cp_payload from total blocks of
>> > the first segment when calculate max orphan inodes.
>> >
>> > Signed-off-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxxxxxx>
>> > ---
>> > v1 -> v2:
>> >  * adjust comments above the codes
>> >  * fix coding style issue
>> >
>> >  fs/f2fs/checkpoint.c | 12 +++++++-----
>> >  1 file changed, 7 insertions(+), 5 deletions(-)
>> >
>> > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
>> > index db82e09..a914e99 100644
>> > --- a/fs/f2fs/checkpoint.c
>> > +++ b/fs/f2fs/checkpoint.c
>> > @@ -1103,13 +1103,15 @@ void init_ino_entry_info(struct f2fs_sb_info *sbi)
>> >  	}
>> >
>> >  	/*
>> > -	 * considering 512 blocks in a segment 8 blocks are needed for cp
>> > -	 * and log segment summaries. Remaining blocks are used to keep
>> > -	 * orphan entries with the limitation one reserved segment
>> > -	 * for cp pack we can have max 1020*504 orphan entries
>> > +	 * considering 512 blocks in a segment 8+cp_payload blocks are
>> > +	 * needed for cp and log segment summaries. Remaining blocks are
>> > +	 * used to keep orphan entries with the limitation one reserved
>> > +	 * segment for cp pack we can have max 1020*(504-cp_payload)
>> > +	 * orphan entries
>> >  	 */
>> 
>> Hi all,
>> 
>> I think below code give us information enough so it doesn't need to
>> describe above comments. And someone could get confused by 1020 constants.
>> How do you think about removing comments.
>
>I agree with you.
>
>There are nothing special need to be pay attention for the below statement,
>all meaning of statement could be easily readed as each macro in statement
>can indicate meaning of itself clearly.
>
>So could you send another patch to remove it?

Agreed. You can cleanup it. ;-)

Regards,
Wanpeng Li

>
>Thanks,
>
>> 
>> Regards,
>> Changman
>> 
>> >  	sbi->max_orphans = (sbi->blocks_per_seg - F2FS_CP_PACKS -
>> > -			NR_CURSEG_TYPE) * F2FS_ORPHANS_PER_BLOCK;
>> > +			NR_CURSEG_TYPE - __cp_payload(sbi)) *
>> > +				F2FS_ORPHANS_PER_BLOCK;
>> >  }
>> >
>> >  int __init create_checkpoint_caches(void)
>> > --
>> > 1.9.1
>
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