linux-kernel - [PATCH AUTOSEL 6.12 05/19] btrfs: avoid starting new transaction when cleaning qgroup during subvolume drop

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20250211013047.4096767-5-sashal@kernel.org>
Date: Mon, 10 Feb 2025 20:30:33 -0500
From: Sasha Levin <sashal@...nel.org>
To: linux-kernel@...r.kernel.org,
	stable@...r.kernel.org
Cc: Filipe Manana <fdmanana@...e.com>,
	Qu Wenruo <wqu@...e.com>,
	David Sterba <dsterba@...e.com>,
	Sasha Levin <sashal@...nel.org>,
	clm@...com,
	josef@...icpanda.com,
	linux-btrfs@...r.kernel.org
Subject: [PATCH AUTOSEL 6.12 05/19] btrfs: avoid starting new transaction when cleaning qgroup during subvolume drop

From: Filipe Manana <fdmanana@...e.com>

[ Upstream commit fdef89ce6fada462aef9cb90a140c93c8c209f0f ]

At btrfs_qgroup_cleanup_dropped_subvolume() all we want to commit the
current transaction in order to have all the qgroup rfer/excl numbers up
to date. However we are using btrfs_start_transaction(), which joins the
current transaction if there is one that is not yet committing, but also
starts a new one if there is none or if the current one is already
committing (its state is >= TRANS_STATE_COMMIT_START). This later case
results in unnecessary IO, wasting time and a pointless rotation of the
backup roots in the super block.

So instead of using btrfs_start_transaction() followed by a
btrfs_commit_transaction(), use btrfs_commit_current_transaction() which
achieves our purpose and avoids starting and committing new transactions.

Reviewed-by: Qu Wenruo <wqu@...e.com>
Signed-off-by: Filipe Manana <fdmanana@...e.com>
Signed-off-by: David Sterba <dsterba@...e.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 fs/btrfs/qgroup.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 4fcd6cd4c1c24..887e34559a1fa 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -1899,11 +1899,7 @@ int btrfs_qgroup_cleanup_dropped_subvolume(struct btrfs_fs_info *fs_info, u64 su
 	 * Commit current transaction to make sure all the rfer/excl numbers
 	 * get updated.
 	 */
-	trans = btrfs_start_transaction(fs_info->quota_root, 0);
-	if (IS_ERR(trans))
-		return PTR_ERR(trans);
-
-	ret = btrfs_commit_transaction(trans);
+	ret = btrfs_commit_current_transaction(fs_info->quota_root);
 	if (ret < 0)
 		return ret;

-- 
2.39.5