Re: [PATCH] btrfs: adjust order of unlocks in do_trimming()

[David Sterba]

On Wed, Nov 28, 2018 at 11:21:12AM +0800, Su Yue wrote:
> In function do_trimming(), block_group->lock should be unlocked first.

Please also write why this is correct and if there are any bad
consequences of the current behaviour. Thanks.

Re: [PATCH] btrfs: adjust order of unlocks in do_trimming()

[Nikolay Borisov]

On 28.11.18 г. 5:21 ч., Su Yue wrote:
> In function do_trimming(), block_group->lock should be unlocked first.
> 
> Fixes: 7fe1e6415026 ("Btrfs: rewrite btrfs_trim_block_group()")
> Signed-off-by: Su Yue 

Reviewed-by: Nikolay Borisov 

> ---
>  fs/btrfs/free-space-cache.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
> index 4ba0aedc878b..3731fa92df56 100644
> --- a/fs/btrfs/free-space-cache.c
> +++ b/fs/btrfs/free-space-cache.c
> @@ -3149,8 +3149,8 @@ static int do_trimming(struct btrfs_block_group_cache 
> *block_group,
>   space_info->bytes_readonly += reserved_bytes;
>   block_group->reserved -= reserved_bytes;
>   space_info->bytes_reserved -= reserved_bytes;
> - spin_unlock(_info->lock);
>   spin_unlock(_group->lock);
> + spin_unlock(_info->lock);
>   }
>  
>   return ret;
> 

[PATCH] btrfs: adjust order of unlocks in do_trimming()

[Su Yue]

In function do_trimming(), block_group->lock should be unlocked first.

Fixes: 7fe1e6415026 ("Btrfs: rewrite btrfs_trim_block_group()")
Signed-off-by: Su Yue 
---
 fs/btrfs/free-space-cache.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 4ba0aedc878b..3731fa92df56 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -3149,8 +3149,8 @@ static int do_trimming(struct btrfs_block_group_cache 
*block_group,
space_info->bytes_readonly += reserved_bytes;
block_group->reserved -= reserved_bytes;
space_info->bytes_reserved -= reserved_bytes;
-   spin_unlock(_info->lock);
spin_unlock(_group->lock);
+   spin_unlock(_info->lock);
}
 
return ret;
-- 
2.19.1