Commit 5a51d427 authored by Filipe Manana's avatar Filipe Manana Committed by sanglipeng
Browse files

btrfs: don't start transaction when joining with TRANS_JOIN_NOSTART 

stable inclusion
from stable-v5.10.195
commit f2873a18c235e48247284d7cb7802634613fb9c0
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I95JOC

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f2873a18c235e48247284d7cb7802634613fb9c0



--------------------------------

commit 4490e803 upstream.

When joining a transaction with TRANS_JOIN_NOSTART, if we don't find a
running transaction we end up creating one. This goes against the purpose
of TRANS_JOIN_NOSTART which is to join a running transaction if its state
is at or below the state TRANS_STATE_COMMIT_START, otherwise return an
-ENOENT error and don't start a new transaction. So fix this to not create
a new transaction if there's no running transaction at or below that
state.

CC: stable@vger.kernel.org # 4.14+
Fixes: a6d155d2 ("Btrfs: fix deadlock between fiemap and transaction commits")
Signed-off-by: default avatarFilipe Manana <fdmanana@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarsanglipeng <sanglipeng1@jd.com>
parent ef73277d

fs/btrfs/transaction.c

+4 −3
Original line number Diff line number Diff line
@@ -301,10 +301,11 @@ static noinline int join_transaction(struct btrfs_fs_info *fs_info, 
	spin_unlock(&fs_info->trans_lock);



	/*

	 * If we are ATTACH, we just want to catch the current transaction,

	 * and commit it. If there is no transaction, just return ENOENT.

	 * If we are ATTACH or TRANS_JOIN_NOSTART, we just want to catch the

	 * current transaction, and commit it. If there is no transaction, just

	 * return ENOENT.

	 */

	if (type == TRANS_ATTACH)

	if (type == TRANS_ATTACH || type == TRANS_JOIN_NOSTART)

		return -ENOENT;



	/*