linux-kernel - Re: [PATCH v2] f2fs: fix to avoid use SSR allocate when do defragment

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Date: Wed, 29 May 2024 17:57:30 +0800
From: Chao Yu <chao@...nel.org>
To: Zhiguo Niu <zhiguo.niu@...soc.com>, jaegeuk@...nel.org
Cc: linux-f2fs-devel@...ts.sourceforge.net, linux-kernel@...r.kernel.org,
 niuzhiguo84@...il.com, ke.wang@...soc.com, Hao_hao.Wang@...soc.com
Subject: Re: [PATCH v2] f2fs: fix to avoid use SSR allocate when do defragment

On 2024/5/29 17:47, Zhiguo Niu wrote:
> SSR allocate mode will be used when doing file defragment
> if ATGC is working at the same time, that is because
> set_page_private_gcing may make CURSEG_ALL_DATA_ATGC segment
> type got in f2fs_allocate_data_block when defragment page
> is writeback, which may cause file fragmentation is worse.
> 
> A file with 2 fragmentations is changed as following after defragment:
> 
> ----------------file info-------------------
> sensorsdata :
> --------------------------------------------
> dev       [254:48]
> ino       [0x    3029 : 12329]
> mode      [0x    81b0 : 33200]
> nlink     [0x       1 : 1]
> uid       [0x    27e6 : 10214]
> gid       [0x    27e6 : 10214]
> size      [0x  242000 : 2367488]
> blksize   [0x    1000 : 4096]
> blocks    [0x    1210 : 4624]
> --------------------------------------------
> 
> file_pos   start_blk     end_blk        blks
>         0    11361121    11361207          87
>    356352    11361215    11361216           2
>    364544    11361218    11361218           1
>    368640    11361220    11361221           2
>    376832    11361224    11361225           2
>    385024    11361227    11361238          12
>    434176    11361240    11361252          13
>    487424    11361254    11361254           1
>    491520    11361271    11361279           9
>    528384     3681794     3681795           2
>    536576     3681797     3681797           1
>    540672     3681799     3681799           1
>    544768     3681803     3681803           1
>    548864     3681805     3681805           1
>    552960     3681807     3681807           1
>    557056     3681809     3681809           1
> 
> Signed-off-by: Zhiguo Niu <zhiguo.niu@...soc.com>

Reviewed-by: Chao Yu <chao@...nel.org>

Thanks,