diff mbox series

[07/21] ext4: protect pa->pa_free in ext4_discard_allocated_blocks

Message ID 20230209194825.511043-8-shikemeng@huaweicloud.com
State New
Headers
Series Some bugfix and cleanup to mballoc |

Commit Message

Kemeng Shi Feb. 9, 2023, 7:48 p.m. UTC 
  If ext4_mb_mark_diskspace_used fails in ext4_mb_new_blocks, we may
discard pa already in list. Protect pa with pa_lock to avoid race.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
---
 fs/ext4/mballoc.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Comments

Ojaswin Mujoo Feb. 13, 2023, 8:42 a.m. UTC | #1 
On Fri, Feb 10, 2023 at 03:48:11AM +0800, Kemeng Shi wrote:
> If ext4_mb_mark_diskspace_used fails in ext4_mb_new_blocks, we may
> discard pa already in list. Protect pa with pa_lock to avoid race.
> 
> Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
> ---
>  fs/ext4/mballoc.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
> index 433337ac8da2..4e1caac74b44 100644
> --- a/fs/ext4/mballoc.c
> +++ b/fs/ext4/mballoc.c
> @@ -4263,8 +4263,11 @@ static void ext4_discard_allocated_blocks(struct ext4_allocation_context *ac)
>  		ext4_mb_unload_buddy(&e4b);
>  		return;
>  	}
> -	if (pa->pa_type == MB_INODE_PA)
> +	if (pa->pa_type == MB_INODE_PA) {
> +		spin_lock(&pa->pa_lock);
>  		pa->pa_free += ac->ac_b_ex.fe_len;
> +		spin_unlock(&pa->pa_lock);
> +	}
>  }
>  
>  /*
> -- 
> 2.30.0
> 
Looks correct. Feel free to add:

Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
diff mbox series

Patch

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 433337ac8da2..4e1caac74b44 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -4263,8 +4263,11 @@  static void ext4_discard_allocated_blocks(struct ext4_allocation_context *ac)
 		ext4_mb_unload_buddy(&e4b);
 		return;
 	}
-	if (pa->pa_type == MB_INODE_PA)
+	if (pa->pa_type == MB_INODE_PA) {
+		spin_lock(&pa->pa_lock);
 		pa->pa_free += ac->ac_b_ex.fe_len;
+		spin_unlock(&pa->pa_lock);
+	}
 }
 
 /*