[PATCH] f2fs: get victim segment again after new cp

[PATCH] f2fs: get victim segment again after new cp

[Yunlei He]

previous segment selected may become free after write_checkpoint,
so here, we select victim again.

Signed-off-by: Yunlei He <heyunlei@huawei.com>
---
 fs/f2fs/gc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index de6c41c..704e2e1 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -914,7 +914,7 @@ gc_more:
 			write_checkpoint(sbi, &cpc);
 	}
 
-	if (segno == NULL_SEGNO && !__get_victim(sbi, &segno, gc_type))
+	if (!__get_victim(sbi, &segno, gc_type) && segno == NULL_SEGNO)
 		goto stop;
 	ret = 0;
 
-- 
1.9.1


------------------------------------------------------------------------------
What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic
patterns at an interface-level. Reveals which users, apps, and protocols are 
consuming the most bandwidth. Provides multi-vendor support for NetFlow, 
J-Flow, sFlow and other flows. Make informed decisions using capacity planning
reports.http://sdm.link/zohodev2dev

Re: [PATCH] f2fs: get victim segment again after new cp

[Jaegeuk Kim]

Hi Yunlei,

The problem may be the above stale segno.
How about this?

---
 fs/f2fs/gc.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index de6c41c..8a0ed89 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -908,10 +908,12 @@ gc_more:
 		 * enough free sections, we should flush dent/node blocks and do
 		 * garbage collections.
 		 */
-		if (__get_victim(sbi, &segno, gc_type) || prefree_segments(sbi))
+		if (__get_victim(sbi, &segno, gc_type) || prefree_segments(sbi)) {
+			segno = NULL_SEGNO;
 			write_checkpoint(sbi, &cpc);
-		else if (has_not_enough_free_secs(sbi, 0))
+		} else if (has_not_enough_free_secs(sbi, 0)) {
 			write_checkpoint(sbi, &cpc);
+		}
 	}
 
 	if (segno == NULL_SEGNO && !__get_victim(sbi, &segno, gc_type))
-- 
2.8.3

On Thu, Jul 21, 2016 at 09:30:29PM +0800, Yunlei He wrote:
> previous segment selected may become free after write_checkpoint,
> so here, we select victim again.
> 
> Signed-off-by: Yunlei He <heyunlei@huawei.com>
> ---
>  fs/f2fs/gc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> index de6c41c..704e2e1 100644
> --- a/fs/f2fs/gc.c
> +++ b/fs/f2fs/gc.c
> @@ -914,7 +914,7 @@ gc_more:
>  			write_checkpoint(sbi, &cpc);
>  	}
>  
> -	if (segno == NULL_SEGNO && !__get_victim(sbi, &segno, gc_type))
> +	if (!__get_victim(sbi, &segno, gc_type) && segno == NULL_SEGNO)
>  		goto stop;
>  	ret = 0;
>  
> -- 
> 1.9.1

------------------------------------------------------------------------------
What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic
patterns at an interface-level. Reveals which users, apps, and protocols are 
consuming the most bandwidth. Provides multi-vendor support for NetFlow, 
J-Flow, sFlow and other flows. Make informed decisions using capacity planning
reports.http://sdm.link/zohodev2dev