This is a note to let you know that I've just added the patch titled
btrfs: forbid creating subvol qgroups
to the 5.4-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-forbid-creating-subvol-qgroups.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 0c309d66dacddf8ce939b891d9ead4a8e21ad6f0 Mon Sep 17 00:00:00 2001
From: Boris Burkov <boris@xxxxxx>
Date: Wed, 10 Jan 2024 17:51:26 -0800
Subject: btrfs: forbid creating subvol qgroups
From: Boris Burkov <boris@xxxxxx>
commit 0c309d66dacddf8ce939b891d9ead4a8e21ad6f0 upstream.
Creating a qgroup 0/subvolid leads to various races and it isn't
helpful, because you can't specify a subvol id when creating a subvol,
so you can't be sure it will be the right one. Any requirements on the
automatic subvol can be gratified by using a higher level qgroup and the
inheritance parameters of subvol creation.
Fixes: cecbb533b5fc ("btrfs: record simple quota deltas in delayed refs")
CC: stable@xxxxxxxxxxxxxxx # 4.14+
Reviewed-by: Qu Wenruo <wqu@xxxxxxxx>
Signed-off-by: Boris Burkov <boris@xxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/btrfs/ioctl.c | 5 +++++
1 file changed, 5 insertions(+)
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -4974,6 +4974,11 @@ static long btrfs_ioctl_qgroup_create(st
goto out;
}
+ if (sa->create && is_fstree(sa->qgroupid)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
Patches currently in stable-queue which might be from boris@xxxxxx are
queue-5.4/btrfs-forbid-creating-subvol-qgroups.patch
queue-5.4/btrfs-forbid-deleting-live-subvol-qgroup.patch
