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From: Anand Jain <anand.jain@oracle.com>
To: "Guilherme G. Piccoli" <gpiccoli@igalia.com>,
	linux-btrfs@vger.kernel.org
Cc: clm@fb.com, josef@toxicpanda.com, dsterba@suse.com,
	dsterba@suse.cz, linux-fsdevel@vger.kernel.org,
	kernel@gpiccoli.net, kernel-dev@igalia.com, david@fromorbit.com,
	kreijack@libero.it, johns@valvesoftware.com,
	ludovico.denittis@collabora.com, quwenruo.btrfs@gmx.com,
	wqu@suse.com, vivek@collabora.com
Subject: Re: [PATCH v4 2/2] btrfs: Introduce the temp-fsid feature
Date: Tue, 19 Sep 2023 19:06:38 +0800	[thread overview]
Message-ID: <f976c005-29fe-4f7e-e1d2-5262d638761a@oracle.com> (raw)
In-Reply-To: <20230913224402.3940543-3-gpiccoli@igalia.com>



> +
> +static void prepare_random_fsid(struct btrfs_super_block *disk_super,
> +				 const char *path)
> +{
> +	struct btrfs_fs_devices *fs_devices;
> +	u8 vfsid[BTRFS_FSID_SIZE];
> +	bool dup_fsid = true;
> +
> +	while (dup_fsid) {
> +		dup_fsid = false;
> +		generate_random_uuid(vfsid);
> +
> +		list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
> +			if (!memcmp(vfsid, fs_devices->fsid, BTRFS_FSID_SIZE) ||
> +			    !memcmp(vfsid, fs_devices->metadata_uuid,
> +				    BTRFS_FSID_SIZE))
> +				dup_fsid = true;
> +		}
		

I've noticed this section of the code a few times, but I don't believe
I've mentioned it before. We've been using generate_random_guid() and
generate_random_uuid() without checking for UUID clashes. Why extra
uuid clash check here?

Thanks, Anand

  parent reply	other threads:[~2023-09-19 11:07 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-09-13 22:36 [PATCH v4 0/2] Supporting same fsid mounting through the temp-fsid feature Guilherme G. Piccoli
2023-09-13 22:36 ` [PATCH v4 1/2] btrfs-progs: Add the temp-fsid feature (to both mkfs/tune) Guilherme G. Piccoli
2023-09-13 22:36 ` [PATCH v4 2/2] btrfs: Introduce the temp-fsid feature Guilherme G. Piccoli
2023-09-18 21:52   ` David Sterba
2023-09-18 22:21     ` Guilherme G. Piccoli
2023-09-19  5:01       ` Anand Jain
2023-09-20 12:16         ` Guilherme G. Piccoli
2023-09-20 18:37           ` David Sterba
2023-09-21  0:21             ` Anand Jain
2023-09-21 22:36             ` Guilherme G. Piccoli
2023-09-19 11:06   ` Anand Jain [this message]
2023-09-20 12:03     ` Guilherme G. Piccoli
2023-09-20 18:23       ` David Sterba

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