Re: [PATCH] btrfs: Allow non-privileged user to delete empty subvolume by default

From: Goffredo Baroncelli <kreijack@inwind.it>
To: "Austin S. Hemmelgarn" <ahferroin7@gmail.com>,
	Nikolay Borisov <nborisov@suse.com>,
	"Misono, Tomohiro" <misono.tomohiro@jp.fujitsu.com>,
	linux-btrfs <linux-btrfs@vger.kernel.org>
Subject: Re: [PATCH] btrfs: Allow non-privileged user to delete empty subvolume by default
Date: Wed, 21 Mar 2018 21:38:06 +0100	[thread overview]
Message-ID: <cf65350d-1985-ac5b-2fb6-72fedfa9adf0@inwind.it> (raw)
In-Reply-To: <5ce4f667-e97f-c87e-466d-37d488f2abbb@gmail.com>

On 03/21/2018 12:47 PM, Austin S. Hemmelgarn wrote:
> I agree as well, with the addendum that I'd love to see a new ioctl that does proper permissions checks.  While letting rmdir(2) work for an empty subvolume with the appropriate permissions would be great (it will let rm -r work correctly), it doesn't address the usefulness of being able to just `btrfs subvolume delete` and not have to wait for the command to finish before you can reuse the name.

How this could work ? 

If you want to check all the subvolumes files permissions, this will require some time: you need to traverse all the subvolume-filesystem; and only if all the checks are passed, you can delete the subvolume.

Unfortunately I think that only two options exist:
- don't check permissions, and you can quick remove a subvolume
- check all the permissions, i.e. check all the files permissions, and only if all the permissions are OK, you can delete the subvolume. However this cannot be a "quick" subvolume delete

BR
G.Baroncelli

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