在 2024/3/1 22:31, David Sterba 写道:
On Tue, Feb 27, 2024 at 01:45:35PM +1030, Qu Wenruo wrote:
[BUG]
Currently btrfs can create subvolume with an invalid qgroup inherit
without triggering any error:
# mkfs.btrfs -O quota -f $dev
# mount $dev $mnt
# btrfs subvolume create -i 2/0 $mnt/subv1
# btrfs qgroup show -prce --sync $mnt
Qgroupid Referenced Exclusive Path
-------- ---------- --------- ----
0/5 16.00KiB 16.00KiB <toplevel>
0/256 16.00KiB 16.00KiB subv1
[CAUSE]
We only do a very basic size check for btrfs_qgroup_inherit structure,
but never really verify if the values are correct.
Thus in btrfs_qgroup_inherit() function, we have to skip non-existing
qgroups, and never return any error.
[FIX]
Fix the behavior and introduce extra checks:
- Introduce early check for btrfs_qgroup_inherit structure
Not only the size, but also all the qgroup ids would be verifyed.
And the timing is very early, so we can return error early.
This early check is very important for snapshot creation, as snapshot
is delayed to transaction commit.
- Drop support for btrfs_qgroup_inherit::num_ref_copies and
num_excl_copies
Those two members are used to specify to copy refr/excl numbers from
other qgroups.
This would definitely mark qgroup inconsistent, and btrfs-progs has
dropped the support for them for a long time.
It's time to drop the support for kernel.
- Verify the supported btrfs_qgroup_inherit::flags
Just in case we want to add extra flags for btrfs_qgroup_inherit.
Now above subvolume creation would fail with -ENOENT other than silently
ignore the non-existing qgroup.
CC: stable@xxxxxxxxxxxxxxx
Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Just one thing to notice, this would cause certain test cases to fail,
as previously any incorrect qgroup inherit would just be ignored, but
now it would error out explicitly.
IIRC there are 2 or 3 failures, one already fixed.
I'll send out the remaining fixes for fstests.
Thanks,
Qu
