From: "Chris Murphy" <lists@colorremedies.com>
To: "Btrfs BTRFS" <linux-btrfs@vger.kernel.org>
Subject: Re: 6.17rc5: btrfs scrub, Freezing user space processes failed
Date: Mon, 15 Sep 2025 19:16:43 -0400 [thread overview]
Message-ID: <dcb5d446-adaa-4a6c-b212-619d286d01ad@app.fastmail.com> (raw)
In-Reply-To: <d93b2a2d-6ad9-4c49-809f-11d769a6f30a@app.fastmail.com>
The storage stack may be relevant: USB flash drive -> dm-crypt -> Btrfs
Darrick Wong notes that in https://elixir.bootlin.com/linux/v6.15/source/fs/btrfs/ioctl.c#L3159
btrfs_ioctl_scrub calls mnt_want_write_file for the duration of the scrub, and mnt_want_write_file takes SB_FREEZE_WRITE and holds that all the way to the end, which means you can't fsfreeze the filesystem
So how did this ever work? Folks do use btrfsmaintenance with scrub and trim timers, and a laptop can sleep at any time. We can't inhibit this indefinitely.
Perhaps scrub and balance can be paused if pm suspend/hibernate is requested? Just make it a non-factor.
Chris Murphy
next prev parent reply other threads:[~2025-09-15 23:17 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-13 21:57 6.17rc5: btrfs scrub, Freezing user space processes failed Chris Murphy
2025-09-15 23:16 ` Chris Murphy [this message]
2025-09-15 23:37 ` Qu Wenruo
2025-09-15 23:51 ` Chris Murphy
2025-10-12 8:52 ` Askar Safin
2025-10-12 22:10 ` Chris Murphy
2025-10-16 22:15 ` Chris Murphy
2025-10-17 11:01 ` Askar Safin
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