[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20150722150047.5c5d59df@noble>
Date: Wed, 22 Jul 2015 15:00:47 +1000
From: NeilBrown <neilb@...e.com>
To: Christoph Hellwig <hch@....de>
Cc: Jens Axboe <axboe@...nel.dk>,
"Martin K. Petersen" <martin.petersen@...cle.com>,
Neil Brown <neilb@...e.de>, Liu Bo <bo.li.liu@...cle.com>,
linux-raid@...r.kernel.org, dm-devel@...hat.com,
linux-btrfs@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] block: add a bi_error field to struct bio
On Mon, 20 Jul 2015 15:29:37 +0200 Christoph Hellwig <hch@....de> wrote:
> Currently we have two different ways to signal an I/O error on a BIO:
>
> (1) by clearing the BIO_UPTODATE flag
> (2) by returning a Linux errno value to the bi_end_io callback
>
> The first one has the drawback of only communicating a single possible
> error (-EIO), and the second one has the drawback of not beeing persistent
> when bios are queued up, and are not passed along from child to parent
> bio in the ever more popular chaining scenario. Having both mechanisms
> available has the additional drawback of utterly confusing driver authors
> and introducing bugs where various I/O submitters only deal with one of
> them, and the others have to add boilerplate code to deal with both kinds
> of error returns.
>
> So add a new bi_error field to store an errno value directly in struct
> bio and remove the existing mechanisms to clean all this up.
>
> Signed-off-by: Christoph Hellwig <hch@....de>
> ---
Reviewed-by: NeilBrown <neilb@...e.com> (umem and md/raid).
i.e. these files.
> drivers/block/umem.c | 4 +--
> drivers/md/faulty.c | 4 +--
> drivers/md/linear.c | 2 +-
> drivers/md/md.c | 18 +++++------
> drivers/md/multipath.c | 12 +++----
> drivers/md/raid0.c | 2 +-
> drivers/md/raid1.c | 53 ++++++++++++++++---------------
> drivers/md/raid10.c | 55 +++++++++++++++-----------------
> drivers/md/raid5.c | 52 +++++++++++++++----------------
Thanks,
NeilBrown
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists