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 20:28:12 +0800 [thread overview]
Message-ID: <6e78fa81-3bc1-4821-b41c-5c18d9fe8a53@kernel.org> (raw)
In-Reply-To: <f130860f8e12c46688a7fcc158f3f34fa042e47e.camel@infradead.org>
> The documentation is fairly poor, but historical
> behaviour and expectation is that the FSID is supposed to be *stable*.
It's definitely messy.
Statfs f_fsid was never strictly guaranteed to be persistent across
reboots when derived from dev_t, filesystems like XFS and F2FS share the
same design.
Historically, the documentation around f_fsid has been ambiguous,
leading to different expectations across filesystems.
Breaking tools that rely on a stable {fsid, ino} is a real problem.
The idea with this patch is to restore the original behavior as the
default, and an option to mix in dev_t when needed to avoid collisions.
next prev parent reply other threads:[~2026-09-14 12:28 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
2026-09-14 10:47 ` David Woodhouse
2026-09-14 12:28 ` Anand Suveer Jain [this message]
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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