[PATCH v2] f2fs: fix uninitialized skipped_gc_rwsem

[PATCH v2] f2fs: fix uninitialized skipped_gc_rwsem

[Yonggil Song]

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")
Cc: stable@vger.kernel.org
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

Re: [PATCH v2] f2fs: fix uninitialized skipped_gc_rwsem

[gregkh]

On Thu, Feb 16, 2023 at 04:44:27PM +0900, 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")
> Cc: stable@vger.kernel.org
> 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

Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
a patch that has triggered this response.  He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created.  Hopefully you will not take offence and will fix the problem
in your patch and resubmit it so that it can be accepted into the Linux
kernel tree.

You are receiving this message because of the following common error(s)
as indicated below:

- This looks like a new version of a previously submitted patch, but you
  did not list below the --- line any changes from the previous version.
  Please read the section entitled "The canonical patch format" in the
  kernel file, Documentation/process/submitting-patches.rst for what
  needs to be done here to properly describe this.

If you wish to discuss this problem further, or you have questions about
how to resolve this issue, please feel free to respond to this email and
Greg will reply once he has dug out from the pending patches received
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thanks,

greg k-h's patch email bot

Re: [f2fs-dev] [PATCH v2] f2fs: fix uninitialized skipped_gc_rwsem

[patchwork-bot+f2fs]

Hello:

This patch was applied to jaegeuk/f2fs.git (dev)
by Jaegeuk Kim <jaegeuk@kernel.org>:

On Thu, 16 Feb 2023 16:44:27 +0900 you 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")
> Cc: stable@vger.kernel.org
> Signed-off-by: Yonggil Song <yonggil.song@samsung.com>

Here is the summary with links:
  - [f2fs-dev,v2] f2fs: fix uninitialized skipped_gc_rwsem
    https://git.kernel.org/jaegeuk/f2fs/c/196036c45f8c

You are awesome, thank you!
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