* [PATCH v2] btrfs: add missing check after link_free_space
@ 2019-12-09 3:41 Dinghao Liu
2019-12-09 18:25 ` David Sterba
0 siblings, 1 reply; 2+ messages in thread
From: Dinghao Liu @ 2019-12-09 3:41 UTC (permalink / raw)
To: dinghao.liu, kjlu
Cc: Chris Mason, Josef Bacik, David Sterba, linux-btrfs, linux-kernel
The return value of link_free_space is checked out-sync.
One branch of an if statement uses an extra check after
WARN_ON() but its peer branch does not. WARN_ON() does
not change the control flow, thus only using this check
might be insufficient.
Fix this by simply adding a check on ret.
Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
--
Changes in v2:
- Add memory free for free space entry.
---
fs/btrfs/free-space-cache.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 3283da419200..ba2e6cea5233 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -2437,6 +2437,10 @@ int btrfs_remove_free_space(struct btrfs_block_group *block_group,
if (info->bytes) {
ret = link_free_space(ctl, info);
WARN_ON(ret);
+ if (ret) {
+ kmem_cache_free(btrfs_free_space_cachep, info);
+ goto out_lock;
+ }
} else {
kmem_cache_free(btrfs_free_space_cachep, info);
}
--
2.21.0 (Apple Git-122)
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v2] btrfs: add missing check after link_free_space
2019-12-09 3:41 [PATCH v2] btrfs: add missing check after link_free_space Dinghao Liu
@ 2019-12-09 18:25 ` David Sterba
0 siblings, 0 replies; 2+ messages in thread
From: David Sterba @ 2019-12-09 18:25 UTC (permalink / raw)
To: Dinghao Liu
Cc: kjlu, Chris Mason, Josef Bacik, David Sterba, linux-btrfs, linux-kernel
On Mon, Dec 09, 2019 at 11:41:14AM +0800, Dinghao Liu wrote:
> The return value of link_free_space is checked out-sync.
> One branch of an if statement uses an extra check after
> WARN_ON() but its peer branch does not. WARN_ON() does
> not change the control flow, thus only using this check
> might be insufficient.
>
> Fix this by simply adding a check on ret.
>
> Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
> --
> Changes in v2:
> - Add memory free for free space entry.
> ---
> fs/btrfs/free-space-cache.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
> index 3283da419200..ba2e6cea5233 100644
> --- a/fs/btrfs/free-space-cache.c
> +++ b/fs/btrfs/free-space-cache.c
> @@ -2437,6 +2437,10 @@ int btrfs_remove_free_space(struct btrfs_block_group *block_group,
> if (info->bytes) {
> ret = link_free_space(ctl, info);
> WARN_ON(ret);
> + if (ret) {
> + kmem_cache_free(btrfs_free_space_cachep, info);
> + goto out_lock;
> + }
> } else {
> kmem_cache_free(btrfs_free_space_cachep, info);
There are two link_free_space followed by WARN_ON instances in the
function, please remove both.
In the above case, the branches can be merged together so there's not
repeated kmem_cache_free, like
if (info->bytes)
ret = link_free_space(...);
kmem_cache_free(btrfs_free_space_cachep, info);
if (ret)
goto out_unlock;
^ permalink raw reply [flat|nested] 2+ messages in thread
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2019-12-09 3:41 [PATCH v2] btrfs: add missing check after link_free_space Dinghao Liu
2019-12-09 18:25 ` David Sterba
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