This is a note to let you know that I've just added the patch titled
btrfs: don't start transaction when joining with TRANS_JOIN_NOSTART
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
btrfs-don-t-start-transaction-when-joining-with-trans_join_nostart.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 4490e803e1fe9fab8db5025e44e23b55df54078b Mon Sep 17 00:00:00 2001
From: Filipe Manana <fdmanana@xxxxxxxx>
Date: Wed, 26 Jul 2023 16:56:57 +0100
Subject: btrfs: don't start transaction when joining with TRANS_JOIN_NOSTART
From: Filipe Manana <fdmanana@xxxxxxxx>
commit 4490e803e1fe9fab8db5025e44e23b55df54078b 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@xxxxxxxxxxxxxxx # 4.14+
Fixes: a6d155d2e363 ("Btrfs: fix deadlock between fiemap and transaction commits")
Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/btrfs/transaction.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -200,10 +200,11 @@ loop:
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;
/*
Patches currently in stable-queue which might be from fdmanana@xxxxxxxx are
queue-4.19/btrfs-don-t-start-transaction-when-joining-with-trans_join_nostart.patch
