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Date: Wed, 29 Oct 2025 17:37:08 +0100
From: Christoph Hellwig <hch@lst.de>
To: "Darrick J. Wong" <djwong@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>, Carlos Maiolino <cem@kernel.org>,
	Christian Brauner <brauner@kernel.org>, Jan Kara <jack@suse.cz>,
	"Martin K. Petersen" <martin.petersen@oracle.com>,
	linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org,
	linux-fsdevel@vger.kernel.org, linux-raid@vger.kernel.org,
	linux-block@vger.kernel.org
Subject: Re: [PATCH 2/4] fs: return writeback errors for IOCB_DONTCACHE in
 generic_write_sync
Message-ID: <20251029163708.GC26985@lst.de>
References: <20251029071537.1127397-1-hch@lst.de> <20251029071537.1127397-3-hch@lst.de> <20251029160101.GE3356773@frogsfrogsfrogs>
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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.

> 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