From: Kent Overstreet <koverstreet@google.com>
To: Hillf Danton <dhillf@gmail.com>
Cc: linux-kernel@vger.kernel.org, linux-aio@kvack.org,
linux-fsdevel@vger.kernel.org, Zach Brown <zab@redhat.com>,
bcrl@kvack.org, jmoyer@redhat.com, axboe@kernel.dk,
viro@zeniv.linux.org.uk, tytso@mit.edu
Subject: Re: [PATCH 04/32] aio: remove retry-based AIO
Date: Mon, 7 Jan 2013 14:15:21 -0800 [thread overview]
Message-ID: <20130107221521.GD26407@google.com> (raw)
In-Reply-To: <CAJd=RBCHJSkA0UChN+41HknLgi=NOM32jq3L9+Rse_a66FrP4g@mail.gmail.com>
On Sat, Dec 29, 2012 at 03:47:37PM +0800, Hillf Danton wrote:
> On Thu, Dec 27, 2012 at 9:59 AM, Kent Overstreet <koverstreet@google.com> wrote:
> > @@ -1585,18 +1278,27 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
> > * don't see ctx->dead set here, io_destroy() waits for our IO to
> > * finish.
> > */
> > - if (ctx->dead) {
> > - spin_unlock_irq(&ctx->ctx_lock);
> > + if (ctx->dead)
> > ret = -EINVAL;
> > + spin_unlock_irq(&ctx->ctx_lock);
> > + if (ret)
> > goto out_put_req;
> > +
> > + if (unlikely(kiocbIsCancelled(req))) {
> > + ret = -EINTR;
> > + } else {
> > + ret = req->ki_retry(req);
> > }
> > - aio_run_iocb(req);
> > - if (!list_empty(&ctx->run_list)) {
> > - /* drain the run list */
> > - while (__aio_run_iocbs(ctx))
> > - ;
> > + if (ret != -EIOCBQUEUED) {
> > + /*
> > + * There's no easy way to restart the syscall since other AIO's
> > + * may be already running. Just fail this IO with EINTR.
> > + */
> > + if (unlikely(ret == -ERESTARTSYS || ret == -ERESTARTNOINTR ||
> > + ret == -ERESTARTNOHAND || ret == -ERESTART_RESTARTBLOCK))
> > + ret = -EINTR;
> > + aio_complete(req, ret, 0);
> > }
> > - spin_unlock_irq(&ctx->ctx_lock);
> >
> > aio_put_req(req); /* drop extra ref to req */
> > return 0;
>
> return ret; yes?
No - and this code is _really_ confusing. If we get an error we can
return it in two different ways:
1) By making the io_submit() call fail
2) Through the io_event that aio_complete() delivers
Note the return 0 coming after the aio_complete() call - we don't want
to return ret because then we'd be delivering an error twice.
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next prev parent reply other threads:[~2013-01-07 22:15 UTC|newest]
Thread overview: 77+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-27 1:59 [PATCH 00/32] AIO performance improvements/cleanups, v3 Kent Overstreet
2012-12-27 1:59 ` [PATCH 01/32] mm: remove old aio use_mm() comment Kent Overstreet
2012-12-27 1:59 ` [PATCH 02/32] aio: remove dead code from aio.h Kent Overstreet
2012-12-27 1:59 ` [PATCH 03/32] gadget: remove only user of aio retry Kent Overstreet
2012-12-27 1:59 ` [PATCH 04/32] aio: remove retry-based AIO Kent Overstreet
2012-12-29 7:36 ` Hillf Danton
2013-01-07 22:12 ` Kent Overstreet
2012-12-29 7:47 ` Hillf Danton
2013-01-07 22:15 ` Kent Overstreet [this message]
2012-12-27 1:59 ` [PATCH 05/32] char: add aio_{read,write} to /dev/{null,zero} Kent Overstreet
2012-12-27 1:59 ` [PATCH 06/32] aio: Kill return value of aio_complete() Kent Overstreet
2012-12-27 1:59 ` [PATCH 07/32] aio: kiocb_cancel() Kent Overstreet
2012-12-27 1:59 ` [PATCH 08/32] aio: Move private stuff out of aio.h Kent Overstreet
2012-12-27 1:59 ` [PATCH 09/32] aio: dprintk() -> pr_debug() Kent Overstreet
2012-12-27 1:59 ` [PATCH 10/32] aio: do fget() after aio_get_req() Kent Overstreet
2012-12-27 1:59 ` [PATCH 11/32] aio: Make aio_put_req() lockless Kent Overstreet
2012-12-27 1:59 ` [PATCH 12/32] aio: Refcounting cleanup Kent Overstreet
2012-12-27 1:59 ` [PATCH 13/32] wait: Add wait_event_hrtimeout() Kent Overstreet
2012-12-27 10:37 ` Fubo Chen
2013-01-03 23:08 ` Andrew Morton
2013-01-08 0:09 ` Kent Overstreet
2012-12-27 1:59 ` [PATCH 14/32] aio: Make aio_read_evt() more efficient, convert to hrtimers Kent Overstreet
2013-01-03 23:19 ` Andrew Morton
2013-01-08 0:28 ` Kent Overstreet
2013-01-08 1:00 ` Andrew Morton
2013-01-08 1:28 ` Kent Overstreet
2012-12-27 1:59 ` [PATCH 15/32] aio: Use flush_dcache_page() Kent Overstreet
2012-12-27 1:59 ` [PATCH 16/32] aio: Use cancellation list lazily Kent Overstreet
2012-12-27 1:59 ` [PATCH 17/32] aio: Change reqs_active to include unreaped completions Kent Overstreet
2012-12-27 1:59 ` [PATCH 18/32] aio: Kill batch allocation Kent Overstreet
2012-12-27 1:59 ` [PATCH 19/32] aio: Kill struct aio_ring_info Kent Overstreet
2012-12-27 1:59 ` [PATCH 20/32] aio: Give shared kioctx fields their own cachelines Kent Overstreet
2013-01-03 23:25 ` Andrew Morton
2013-01-07 23:48 ` Kent Overstreet
2012-12-27 2:00 ` [PATCH 21/32] aio: reqs_active -> reqs_available Kent Overstreet
2012-12-27 2:00 ` [PATCH 22/32] aio: percpu reqs_available Kent Overstreet
2012-12-27 2:00 ` [PATCH 23/32] Generic dynamic per cpu refcounting Kent Overstreet
2013-01-03 22:48 ` Andrew Morton
2013-01-07 23:47 ` Kent Overstreet
2013-01-08 1:03 ` [PATCH] percpu-refcount: Sparse fixes Kent Overstreet
2013-01-25 0:51 ` [PATCH 23/32] Generic dynamic per cpu refcounting Tejun Heo
2013-01-25 1:13 ` Kent Overstreet
2013-01-25 2:03 ` Tejun Heo
2013-01-25 2:09 ` Tejun Heo
2013-01-28 17:48 ` Kent Overstreet
2013-01-28 18:18 ` Tejun Heo
2013-01-25 6:15 ` Rusty Russell
2013-01-28 17:53 ` Kent Overstreet
2013-01-28 17:59 ` Tejun Heo
2013-01-28 18:32 ` Kent Overstreet
2013-01-28 18:57 ` Christoph Lameter
2013-02-08 14:44 ` Tejun Heo
2013-02-08 14:49 ` Jens Axboe
2013-02-08 17:50 ` Andrew Morton
2013-02-08 21:27 ` Kent Overstreet
2013-02-11 14:21 ` Jeff Moyer
2013-02-08 21:17 ` Kent Overstreet
2012-12-27 2:00 ` [PATCH 24/32] aio: Percpu ioctx refcount Kent Overstreet
2012-12-27 2:00 ` [PATCH 25/32] aio: use xchg() instead of completion_lock Kent Overstreet
2013-01-03 23:34 ` Andrew Morton
2013-01-07 23:21 ` Kent Overstreet
2013-01-07 23:35 ` Andrew Morton
2013-01-08 0:01 ` Kent Overstreet
2012-12-27 2:00 ` [PATCH 26/32] aio: Don't include aio.h in sched.h Kent Overstreet
2012-12-27 2:00 ` [PATCH 27/32] aio: Kill ki_key Kent Overstreet
2012-12-27 2:00 ` [PATCH 28/32] aio: Kill ki_retry Kent Overstreet
2012-12-27 2:00 ` [PATCH 29/32] block, aio: Batch completion for bios/kiocbs Kent Overstreet
2013-01-04 9:22 ` Jens Axboe
2013-01-07 23:34 ` Kent Overstreet
2013-01-08 15:33 ` Jeff Moyer
2013-01-08 16:06 ` Kent Overstreet
2013-01-08 16:15 ` Jeff Moyer
2013-01-08 16:48 ` Kent Overstreet
2012-12-27 2:00 ` [PATCH 30/32] virtio-blk: Convert to batch completion Kent Overstreet
2012-12-27 2:00 ` [PATCH 31/32] mtip32xx: " Kent Overstreet
2012-12-27 2:00 ` [PATCH 32/32] aio: Smoosh struct kiocb Kent Overstreet
2013-01-04 9:22 ` [PATCH 00/32] AIO performance improvements/cleanups, v3 Jens Axboe
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