[v5,9/9] btrfs: Use sb_want_write() to protect sysfs feature change.
diff mbox

Message ID 1422609654-19519-10-git-send-email-quwenruo@cn.fujitsu.com
State New, archived
Headers show

Commit Message

Qu Wenruo Jan. 30, 2015, 9:20 a.m. UTC
Just like label change, use sb_want_write() to do a correct protection.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
---
v4:
  Newly introduced.
v5:
  Change to sb_want_write().
---
 fs/btrfs/sysfs.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

Comments

David Sterba Jan. 30, 2015, 6:35 p.m. UTC | #1
On Fri, Jan 30, 2015 at 05:20:54PM +0800, Qu Wenruo wrote:
> --- a/fs/btrfs/sysfs.c
> +++ b/fs/btrfs/sysfs.c
> @@ -154,9 +154,15 @@ static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
>  	btrfs_info(fs_info, "%s %s feature flag",
>  		   val ? "Setting" : "Clearing", fa->kobj_attr.attr.name);
>  
> +	ret = sb_want_write(fs_info->sb);
> +	if (ret)
> +		return ret;

Same here, move it to the beginning, right after fs_info is validated.

> +
>  	trans = btrfs_start_transaction(fs_info->fs_root, 0);
> -	if (IS_ERR(trans))
> -		return PTR_ERR(trans);
> +	if (IS_ERR(trans)) {
> +		ret = PTR_ERR(trans);
> +		goto out;
> +	}
>  
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Patch
diff mbox

diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 3218245..64f876e 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -154,9 +154,15 @@  static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
 	btrfs_info(fs_info, "%s %s feature flag",
 		   val ? "Setting" : "Clearing", fa->kobj_attr.attr.name);
 
+	ret = sb_want_write(fs_info->sb);
+	if (ret)
+		return ret;
+
 	trans = btrfs_start_transaction(fs_info->fs_root, 0);
-	if (IS_ERR(trans))
-		return PTR_ERR(trans);
+	if (IS_ERR(trans)) {
+		ret = PTR_ERR(trans);
+		goto out;
+	}
 
 	spin_lock(&fs_info->super_lock);
 	features = get_features(fs_info, fa->feature_set);
@@ -168,10 +174,12 @@  static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
 	spin_unlock(&fs_info->super_lock);
 
 	ret = btrfs_commit_transaction(trans, fs_info->fs_root);
-	if (ret)
-		return ret;
 
-	return count;
+out:
+	sb_drop_write(fs_info->sb);
+	if (!ret)
+		return count;
+	return ret;
 }
 
 static umode_t btrfs_feature_visible(struct kobject *kobj,