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Message-ID: <e879da72-4c4f-4aed-8081-784f2de5c887@kernel.org>
Date: Mon, 29 Jan 2024 09:27:44 +0800
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Subject: Re: [f2fs-dev] [PATCH] f2fs-tools: allocate logs after conventional
 area for HM zoned devices
Content-Language: en-US
To: Daeho Jeong <daeho43@gmail.com>
Cc: linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net,
 kernel-team@android.com, Daeho Jeong <daehojeong@google.com>,
 Yongpeng Yang <yangyongpeng1@oppo.com>
References: <20240117230032.2312067-1-daeho43@gmail.com>
 <df9645d9-1e9a-4bd2-88bb-26425cf45811@kernel.org>
 <CACOAw_yjEuGSvo_qyoA13U0HwOr3gOzGtNf2Twhes01SNSGQeg@mail.gmail.com>
 <b18c286a-cc72-439c-b373-98e0d6504618@kernel.org>
 <CACOAw_yqrtEhq4wtJbs7CVn260h7iZyC7koCWH1iMyeQo5140g@mail.gmail.com>
From: Chao Yu <chao@kernel.org>
In-Reply-To: <CACOAw_yqrtEhq4wtJbs7CVn260h7iZyC7koCWH1iMyeQo5140g@mail.gmail.com>
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On 2024/1/27 2:17, Daeho Jeong wrote:
> On Thu, Jan 25, 2024 at 5:27 PM Chao Yu <chao@kernel.org> wrote:
>>
>> On 2024/1/26 0:25, Daeho Jeong wrote:
>>> On Wed, Jan 24, 2024 at 7:34 PM Chao Yu <chao@kernel.org> wrote:
>>>>
>>>> +Cc Yongpeng Yang
>>>>
>>>> Daeho,
>>>>
>>>> Yongpeng reports a potential issue: if c.devices[0].total_segments is
>>>> larger than segments of mainarea, c.cur_seg[CURSEG_HOT_NODE] will exceed
>>>> end boundary of mainarea. Could you please check that? though it's a corner
>>>> case.
>>>
>>> Can you elaborate more?
>>
>> Since c.cur_seg[CURSEG_HOT_NODE] is an offset started from main_blkaddr.
> 
> Oh, Got it.
> Then, how about this?
> 
>           c.cur_seg[CURSEG_HOT_NODE] = c.zoned_model == F2FS_ZONED_HM ?
>                           (c.devices[1].start_blkaddr -
> get_sb(main_blkaddr)) / c.blks_per_seg : 0;

Better, but log header should align to start blkaddr of zone?

Thanks,

> 
>> If c.cur_seg[CURSEG_HOT_NODE] was assigned w/ c.devices[0].total_segments,
>> and c.devices[0].total_segments is larger than segments of mainare,
>> c.cur_seg[CURSEG_HOT_NODE] will exceed the end boundary of mainarea.
>>
>>          c.cur_seg[CURSEG_HOT_NODE] = c.zoned_model == F2FS_ZONED_HM ?
>>                          c.devices[0].total_segments : 0;
>>
>>> In the case of F2FS_ZONED_HM, we have the devices[1].
>>> Do you mean the case we format the filesystem intentionally smaller
>>> than what devices have?
>>
>> I mean blew case:
>> device[0]: conventional device size = 10240 MB
>> device[1]: zone device size = 2 MB
>>
>> Thanks,
>>
>>>
>>>>
>>>> On 2024/1/18 7:00, Daeho Jeong wrote:
>>>>> From: Daeho Jeong <daehojeong@google.com>
>>>>>
>>>>> Make to allocate logs after conventional area for HM zoned devices to
>>>>> spare them for file pinning support.
>>>>>
>>>>> Signed-off-by: Daeho Jeong <daehojeong@google.com>
>>>>> ---
>>>>>     mkfs/f2fs_format.c | 3 ++-
>>>>>     1 file changed, 2 insertions(+), 1 deletion(-)
>>>>>
>>>>> diff --git a/mkfs/f2fs_format.c b/mkfs/f2fs_format.c
>>>>> index f2840c8..91a7f4b 100644
>>>>> --- a/mkfs/f2fs_format.c
>>>>> +++ b/mkfs/f2fs_format.c
>>>>> @@ -557,7 +557,8 @@ static int f2fs_prepare_super_block(void)
>>>>>                 c.cur_seg[CURSEG_COLD_DATA] = 0;
>>>>>                 c.cur_seg[CURSEG_WARM_DATA] = next_zone(CURSEG_COLD_DATA);
>>>>>         } else if (c.zoned_mode) {
>>>>> -             c.cur_seg[CURSEG_HOT_NODE] = 0;
>>>>> +             c.cur_seg[CURSEG_HOT_NODE] = c.zoned_model == F2FS_ZONED_HM ?
>>>>> +                     c.devices[0].total_segments : 0;
>>>>>                 c.cur_seg[CURSEG_WARM_NODE] = next_zone(CURSEG_HOT_NODE);
>>>>>                 c.cur_seg[CURSEG_COLD_NODE] = next_zone(CURSEG_WARM_NODE);
>>>>>                 c.cur_seg[CURSEG_HOT_DATA] = next_zone(CURSEG_COLD_NODE);