From: Anand Suveer Jain <asj@kernel.org>
To: David Woodhouse <dwmw2@infradead.org>,
dsterba@suse.cz, linux-btrfs@vger.kernel.org
Cc: thiago.macieira@intel.com, dave.hansen@intel.com
Subject: Re: [PATCH] btrfs: derive f_fsid with dev_t only when temp_fsid is active
Date: Mon, 14 Sep 2026 16:28:25 +0800 [thread overview]
Message-ID: <c04f73b1-cf55-40ef-bb47-d518603bcd8c@kernel.org> (raw)
In-Reply-To: <91E0EA5B-BFD2-4B8A-8408-4F561D5E0777@infradead.org>
>> . For stable kernels, this flag will keep the new f_fsid derivation
>> disabled by default.
> No. That still gives you a broken fsid on upgrading to the next major kernel, doesn't it?
Upgrading to a _major_ kernel would require an extra step to re-encrypt
with the new FSID _for some configs_.
A one-time operational overhead.
> Maybe a new flag on the file system itself to indicate that its
> stable FSID is computed using the new scheme.
A mkfs-time or runtime switch, something like:
/sys/fs/btrfs/<UUID>/enable_collision_free_fsid
(just as an example) is an option.
However, persisting an on-disk flag for this feels like using a cannon
to kill a mosquito.
Feedback/suggestions are welcome.
next prev parent reply other threads:[~2026-09-14 8:28 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-12 18:06 [PATCH] btrfs: derive f_fsid with dev_t only when temp_fsid is active Anand Jain
2026-09-12 21:58 ` Dave Hansen
2026-09-13 1:05 ` Anand Suveer Jain
2026-09-13 1:13 ` Dave Hansen
2026-09-13 2:43 ` Anand Suveer Jain
2026-09-14 3:42 ` Anand Suveer Jain
2026-09-14 5:28 ` David Woodhouse
2026-09-14 8:28 ` Anand Suveer Jain [this message]
2026-09-14 10:47 ` David Woodhouse
2026-09-14 12:28 ` Anand Suveer Jain
2026-09-14 16:41 ` David Sterba
2026-09-14 16:39 ` David Sterba
2026-09-14 16:46 ` David Sterba
2026-09-18 8:59 ` Anand Suveer Jain
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