From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8BB442EACF0; Tue, 15 Jul 2025 13:34:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752586499; cv=none; b=KYMwKYz3gLihp9IPN+HWbzPlkOeLUxyUvhaBaXFb/Ov6qF9yM4vvWwMqoyOVQDmRABCJ0QiTVk8tJhh6+7czuTwA6YAsQ2UyNxSWV/EkaYShD9n7E+EhvdoGg6uwceRnpxZEpnXrd1n8d8bdxWZHmnBtYKkjzFC7CPUOlrnElro= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752586499; c=relaxed/simple; bh=NEBpKIrwfgwCf7U8Z85JxsjHOWdKbK1GwntGNEH+v7E=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=PHyZ/WnxOyS7wwSqm3sCB3WLSX5oXwzrktPJldYvxLNvJYjUgZ6DL3yjwXmMssi/dLeRoohGU5yDQz1t00HxzwKDKEA8jQMVQlPnOK9pqOJZ4VQFJClIsEYVBVHiIWT0NKVj5Cb9wpyvmv2W5xtZBbpkd9oDMsOWW8IcTgRIUV4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=N2niaYzo; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="N2niaYzo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 217D1C4CEF7; Tue, 15 Jul 2025 13:34:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1752586499; bh=NEBpKIrwfgwCf7U8Z85JxsjHOWdKbK1GwntGNEH+v7E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=N2niaYzoTZTvQjBo9qoPudPQQBCr1ts13xVh9t4Q166i2LREBGB/Qvkp/wtu36R7f 2X1lgs07iKgSSM6akkKIDoHxFFQy87ngRinA4C2r8EiFwag7ce6DW5yxHbn6h49H8l M9efLYKijBpmKBD7VowBiDyRUAMzlvAPOwNE0bRU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Johannes Thumshirn , Filipe Manana , David Sterba , Sasha Levin Subject: [PATCH 5.4 088/148] btrfs: propagate last_unlink_trans earlier when doing a rmdir Date: Tue, 15 Jul 2025 15:13:30 +0200 Message-ID: <20250715130803.839714528@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250715130800.293690950@linuxfoundation.org> References: <20250715130800.293690950@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Filipe Manana [ Upstream commit c466e33e729a0ee017d10d919cba18f503853c60 ] In case the removed directory had a snapshot that was deleted, we are propagating its inode's last_unlink_trans to the parent directory after we removed the entry from the parent directory. This leaves a small race window where someone can log the parent directory after we removed the entry and before we updated last_unlink_trans, and as a result if we ever try to replay such a log tree, we will fail since we will attempt to remove a snapshot during log replay, which is currently not possible and results in the log replay (and mount) to fail. This is the type of failure described in commit 1ec9a1ae1e30 ("Btrfs: fix unreplayable log after snapshot delete + parent dir fsync"). So fix this by propagating the last_unlink_trans to the parent directory before we remove the entry from it. Fixes: 44f714dae50a ("Btrfs: improve performance on fsync against new inode after rename/unlink") Reviewed-by: Johannes Thumshirn Signed-off-by: Filipe Manana Signed-off-by: David Sterba Signed-off-by: Sasha Levin --- fs/btrfs/inode.c | 36 ++++++++++++++++++------------------ 1 file changed, 18 insertions(+), 18 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 004894e6dd23b..8f92f998dc37b 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -4747,7 +4747,6 @@ static int btrfs_rmdir(struct inode *dir, struct dentry *dentry) int err = 0; struct btrfs_root *root = BTRFS_I(dir)->root; struct btrfs_trans_handle *trans; - u64 last_unlink_trans; if (inode->i_size > BTRFS_EMPTY_DIR_SIZE) return -ENOTEMPTY; @@ -4758,6 +4757,23 @@ static int btrfs_rmdir(struct inode *dir, struct dentry *dentry) if (IS_ERR(trans)) return PTR_ERR(trans); + /* + * Propagate the last_unlink_trans value of the deleted dir to its + * parent directory. This is to prevent an unrecoverable log tree in the + * case we do something like this: + * 1) create dir foo + * 2) create snapshot under dir foo + * 3) delete the snapshot + * 4) rmdir foo + * 5) mkdir foo + * 6) fsync foo or some file inside foo + * + * This is because we can't unlink other roots when replaying the dir + * deletes for directory foo. + */ + if (BTRFS_I(inode)->last_unlink_trans >= trans->transid) + BTRFS_I(dir)->last_unlink_trans = BTRFS_I(inode)->last_unlink_trans; + if (unlikely(btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) { err = btrfs_unlink_subvol(trans, dir, dentry); goto out; @@ -4767,28 +4783,12 @@ static int btrfs_rmdir(struct inode *dir, struct dentry *dentry) if (err) goto out; - last_unlink_trans = BTRFS_I(inode)->last_unlink_trans; - /* now the directory is empty */ err = btrfs_unlink_inode(trans, root, BTRFS_I(dir), BTRFS_I(d_inode(dentry)), dentry->d_name.name, dentry->d_name.len); - if (!err) { + if (!err) btrfs_i_size_write(BTRFS_I(inode), 0); - /* - * Propagate the last_unlink_trans value of the deleted dir to - * its parent directory. This is to prevent an unrecoverable - * log tree in the case we do something like this: - * 1) create dir foo - * 2) create snapshot under dir foo - * 3) delete the snapshot - * 4) rmdir foo - * 5) mkdir foo - * 6) fsync foo or some file inside foo - */ - if (last_unlink_trans >= trans->transid) - BTRFS_I(dir)->last_unlink_trans = last_unlink_trans; - } out: btrfs_end_transaction(trans); btrfs_btree_balance_dirty(root->fs_info); -- 2.39.5