When f2fs skipped a gc round during victim migration, there was a bug which
would skip all upcoming gc rounds unconditionally because skipped_gc_rwsem
was not initialized. It fixes the bug by correctly initializing the
skipped_gc_rwsem inside the gc loop.

Fixes: 3db1de0e582c ("f2fs: change the current atomic write way")
Signed-off-by: Yonggil Song <yonggil.song@samsung.com>

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index b22f49a6f128..81d326abaac1 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -1786,8 +1786,8 @@ int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control)
 				prefree_segments(sbi));
 
 	cpc.reason = __get_cp_reason(sbi);
-	sbi->skipped_gc_rwsem = 0;
 gc_more:
+	sbi->skipped_gc_rwsem = 0;
 	if (unlikely(!(sbi->sb->s_flags & SB_ACTIVE))) {
 		ret = -EINVAL;
 		goto stop;
-- 
2.34.1

On 02/16, Yonggil Song wrote:
> When f2fs skipped a gc round during victim migration, there was a bug which
> would skip all upcoming gc rounds unconditionally because skipped_gc_rwsem
> was not initialized. It fixes the bug by correctly initializing the
> skipped_gc_rwsem inside the gc loop.
> 
> Fixes: 3db1de0e582c ("f2fs: change the current atomic write way")

Applied with the below fix.

Fixes: 6f8d4455060d ("f2fs: avoid fi->i_gc_rwsem[WRITE] lock in f2fs_gc"

> Signed-off-by: Yonggil Song <yonggil.song@samsung.com>
> 
> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> index b22f49a6f128..81d326abaac1 100644
> --- a/fs/f2fs/gc.c
> +++ b/fs/f2fs/gc.c
> @@ -1786,8 +1786,8 @@ int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control)
>  				prefree_segments(sbi));
>  
>  	cpc.reason = __get_cp_reason(sbi);
> -	sbi->skipped_gc_rwsem = 0;
>  gc_more:
> +	sbi->skipped_gc_rwsem = 0;
>  	if (unlikely(!(sbi->sb->s_flags & SB_ACTIVE))) {
>  		ret = -EINVAL;
>  		goto stop;
> -- 
> 2.34.1

On 2023/3/7 5:51, Jaegeuk Kim wrote:

> Applied with the below fix.
> 
> Fixes: 6f8d4455060d ("f2fs: avoid fi->i_gc_rwsem[WRITE] lock in f2fs_gc"

')' was missed.

> 
>> Signed-off-by: Yonggil Song <yonggil.song@samsung.com>

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

Thanks,