Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1693365 > unrolled thread

[PATCH] f2fs: let background GC being aware of freezing

Started byChao Yu <yuchao0@huawei.com>
First post2017-07-21 05:40 +0200
Last post2017-07-22 02:50 +0200
Articles 3 — 3 participants

Back to article view | Back to linux.kernel


Contents

  [PATCH] f2fs: let background GC being aware of freezing Chao Yu <yuchao0@huawei.com> - 2017-07-21 05:40 +0200
    Re: [PATCH] f2fs: let background GC being aware of freezing Jaegeuk Kim <jaegeuk@kernel.org> - 2017-07-21 23:00 +0200
      Re: [PATCH] f2fs: let background GC being aware of freezing Chao Yu <chao@kernel.org> - 2017-07-22 02:50 +0200

#1693365 — [PATCH] f2fs: let background GC being aware of freezing

FromChao Yu <yuchao0@huawei.com>
Date2017-07-21 05:40 +0200
Subject[PATCH] f2fs: let background GC being aware of freezing
Message-ID<u5wXg-7XN-3@gated-at.bofh.it>
When ->freeze_fs is called from lvm for doing snapshot, it needs to
make sure there will be no more changes in filesystem's data, however,
previously, background GC wasn't aware of freezing, so in environment
with active background GC thread, data of snapshot becomes unstable.

This patch fixes this issue by adding sb_{start,end}_intwrite in GC
flow.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
---
 fs/f2fs/gc.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 76ad2c3d88db..1c0117f60083 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -55,6 +55,8 @@ static int gc_thread_func(void *data)
 		}
 #endif
 
+		sb_start_intwrite(sbi->sb);
+
 		/*
 		 * [GC triggering condition]
 		 * 0. GC is not conducted currently.
@@ -69,12 +71,12 @@ static int gc_thread_func(void *data)
 		 * So, I'd like to wait some time to collect dirty segments.
 		 */
 		if (!mutex_trylock(&sbi->gc_mutex))
-			continue;
+			goto next;
 
 		if (!is_idle(sbi)) {
 			increase_sleep_time(gc_th, &wait_ms);
 			mutex_unlock(&sbi->gc_mutex);
-			continue;
+			goto next;
 		}
 
 		if (has_enough_invalid_blocks(sbi))
@@ -93,6 +95,8 @@ static int gc_thread_func(void *data)
 
 		/* balancing f2fs's metadata periodically */
 		f2fs_balance_fs_bg(sbi);
+next:
+		sb_end_intwrite(sbi->sb);
 
 	} while (!kthread_should_stop());
 	return 0;
-- 
2.13.1.388.g69e6b9b4f4a9

[toc] | [next] | [standalone]


#1693984

FromJaegeuk Kim <jaegeuk@kernel.org>
Date2017-07-21 23:00 +0200
Message-ID<u5NbI-18q-37@gated-at.bofh.it>
In reply to#1693365
Hi Chao,

On 07/21, Chao Yu wrote:
> When ->freeze_fs is called from lvm for doing snapshot, it needs to
> make sure there will be no more changes in filesystem's data, however,
> previously, background GC wasn't aware of freezing, so in environment
> with active background GC thread, data of snapshot becomes unstable.

What about flush/discard threads?

Thanks,

> 
> This patch fixes this issue by adding sb_{start,end}_intwrite in GC
> flow.
> 
> Signed-off-by: Chao Yu <yuchao0@huawei.com>
> ---
>  fs/f2fs/gc.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> index 76ad2c3d88db..1c0117f60083 100644
> --- a/fs/f2fs/gc.c
> +++ b/fs/f2fs/gc.c
> @@ -55,6 +55,8 @@ static int gc_thread_func(void *data)
>  		}
>  #endif
>  
> +		sb_start_intwrite(sbi->sb);
> +
>  		/*
>  		 * [GC triggering condition]
>  		 * 0. GC is not conducted currently.
> @@ -69,12 +71,12 @@ static int gc_thread_func(void *data)
>  		 * So, I'd like to wait some time to collect dirty segments.
>  		 */
>  		if (!mutex_trylock(&sbi->gc_mutex))
> -			continue;
> +			goto next;
>  
>  		if (!is_idle(sbi)) {
>  			increase_sleep_time(gc_th, &wait_ms);
>  			mutex_unlock(&sbi->gc_mutex);
> -			continue;
> +			goto next;
>  		}
>  
>  		if (has_enough_invalid_blocks(sbi))
> @@ -93,6 +95,8 @@ static int gc_thread_func(void *data)
>  
>  		/* balancing f2fs's metadata periodically */
>  		f2fs_balance_fs_bg(sbi);
> +next:
> +		sb_end_intwrite(sbi->sb);
>  
>  	} while (!kthread_should_stop());
>  	return 0;
> -- 
> 2.13.1.388.g69e6b9b4f4a9

[toc] | [prev] | [next] | [standalone]


#1694080

FromChao Yu <chao@kernel.org>
Date2017-07-22 02:50 +0200
Message-ID<u5QMh-3me-1@gated-at.bofh.it>
In reply to#1693984
Hi Jaegeuk,

On 2017/7/22 4:54, Jaegeuk Kim wrote:
> Hi Chao,
> 
> On 07/21, Chao Yu wrote:
>> When ->freeze_fs is called from lvm for doing snapshot, it needs to
>> make sure there will be no more changes in filesystem's data, however,
>> previously, background GC wasn't aware of freezing, so in environment
>> with active background GC thread, data of snapshot becomes unstable.
> 
> What about flush/discard threads?

Updated.

Thanks,

> 
> Thanks,
> 
>>
>> This patch fixes this issue by adding sb_{start,end}_intwrite in GC
>> flow.
>>
>> Signed-off-by: Chao Yu <yuchao0@huawei.com>
>> ---
>>  fs/f2fs/gc.c | 8 ++++++--
>>  1 file changed, 6 insertions(+), 2 deletions(-)
>>
>> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
>> index 76ad2c3d88db..1c0117f60083 100644
>> --- a/fs/f2fs/gc.c
>> +++ b/fs/f2fs/gc.c
>> @@ -55,6 +55,8 @@ static int gc_thread_func(void *data)
>>  		}
>>  #endif
>>  
>> +		sb_start_intwrite(sbi->sb);
>> +
>>  		/*
>>  		 * [GC triggering condition]
>>  		 * 0. GC is not conducted currently.
>> @@ -69,12 +71,12 @@ static int gc_thread_func(void *data)
>>  		 * So, I'd like to wait some time to collect dirty segments.
>>  		 */
>>  		if (!mutex_trylock(&sbi->gc_mutex))
>> -			continue;
>> +			goto next;
>>  
>>  		if (!is_idle(sbi)) {
>>  			increase_sleep_time(gc_th, &wait_ms);
>>  			mutex_unlock(&sbi->gc_mutex);
>> -			continue;
>> +			goto next;
>>  		}
>>  
>>  		if (has_enough_invalid_blocks(sbi))
>> @@ -93,6 +95,8 @@ static int gc_thread_func(void *data)
>>  
>>  		/* balancing f2fs's metadata periodically */
>>  		f2fs_balance_fs_bg(sbi);
>> +next:
>> +		sb_end_intwrite(sbi->sb);
>>  
>>  	} while (!kthread_should_stop());
>>  	return 0;
>> -- 
>> 2.13.1.388.g69e6b9b4f4a9

[toc] | [prev] | [standalone]


Back to top | Article view | linux.kernel


csiph-web