linux-kernel - Re: [PATCH 2/4] fs: return writeback errors for IOCB_DONTCACHE in generic_write

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20251029181213.GI3356773@frogsfrogsfrogs>
Date: Wed, 29 Oct 2025 11:12:13 -0700
From: "Darrick J. Wong" <djwong@...nel.org>
To: Christoph Hellwig <hch@....de>
Cc: Carlos Maiolino <cem@...nel.org>,
	Christian Brauner <brauner@...nel.org>, Jan Kara <jack@...e.cz>,
	"Martin K. Petersen" <martin.petersen@...cle.com>,
	linux-kernel@...r.kernel.org, linux-xfs@...r.kernel.org,
	linux-fsdevel@...r.kernel.org, linux-raid@...r.kernel.org,
	linux-block@...r.kernel.org
Subject: Re: [PATCH 2/4] fs: return writeback errors for IOCB_DONTCACHE in
 generic_write_sync

On Wed, Oct 29, 2025 at 05:37:08PM +0100, Christoph Hellwig wrote:
> On Wed, Oct 29, 2025 at 09:01:01AM -0700, Darrick J. Wong wrote:
> > Hum.  So we kick writeback but don't wait for any of it to start, and
> > immediately sample wberr.  Does that mean that in the "bdev died" case,
> > the newly initiated writeback will have failed so quickly that
> > file_check_and_advance_wb_err will see that?
> 
> Yes, this is primarily about catching errors in the submission path
> before it reaches the device, which are returned synchronously.

Ah, ok.

> > Or are we only reflecting
> > past write failures back to userspace on the *second* write after the
> > device dies?
> > 
> > It would be helpful to know which fstests break, btw.
> 
> generic/252 generic/329 xfs/237

Would you mind putting that in the commit message as a breadcrumb for
anyone who comes looking later?

--D