From: James Bottomley <James.Bottomley@HansenPartnership.com>
To: Bart Van Assche <Bart.VanAssche@sandisk.com>,
"bblock@linux.vnet.ibm.com" <bblock@linux.vnet.ibm.com>
Cc: "linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
"maxg@mellanox.com" <maxg@mellanox.com>,
"israelr@mellanox.com" <israelr@mellanox.com>,
"hare@suse.de" <hare@suse.de>,
"martin.petersen@oracle.com" <martin.petersen@oracle.com>
Subject: Re: [PATCH v3 3/4] sd: Make synchronize cache upon shutdown asynchronous
Date: Tue, 18 Apr 2017 17:05:55 -0700 [thread overview]
Message-ID: <1492560355.3306.64.camel@HansenPartnership.com> (raw)
In-Reply-To: <1492560140.2689.30.camel@sandisk.com>
On Wed, 2017-04-19 at 00:02 +0000, Bart Van Assche wrote:
> On Tue, 2017-04-18 at 16:56 -0700, James Bottomley wrote:
> > Actually, I think 3/3 is wrong. You need to start the queue as
> > soon as we see it's blocked and the device has gone into DEL. This
> > is safe because DEL ensures nothing ever gets from the generic
> > request function to queuecommand, so the device driver never sees
> > anything.
>
> Hello James,
>
> I agree that restarting the queue earlier is safe but I do not agree
> that patch 3/3 is wrong. Can you explain why you think that patch 3/3
> is wrong?
The shutdown occurs in driver removal, which precedes the queue start
in 3/3. To avoid hangs and timeouts, we need the queue to be started
before the driver shutdown tries to inject commands. They're not
fatal, but they will likely show up as annoying messages (and time
delays) which we can avoid by starting the queue the moment we go into
DEL.
James
next prev parent reply other threads:[~2017-04-19 0:05 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-17 17:34 [PATCH v3 0/4] Avoid that __scsi_remove_device() hangs Bart Van Assche
2017-04-17 17:34 ` [PATCH v3 1/4] Introduce scsi_start_queue() Bart Van Assche
2017-04-17 17:34 ` [PATCH v3 2/4] Introduce scsi_execute_async() Bart Van Assche
2017-04-17 17:34 ` [PATCH v3 3/4] sd: Make synchronize cache upon shutdown asynchronous Bart Van Assche
2017-04-18 14:44 ` Benjamin Block
2017-04-18 15:34 ` Bart Van Assche
2017-04-18 15:56 ` James Bottomley
2017-04-18 16:06 ` Bart Van Assche
2017-04-18 23:47 ` Bart Van Assche
2017-04-18 23:56 ` James Bottomley
2017-04-19 0:02 ` Bart Van Assche
2017-04-19 0:05 ` James Bottomley [this message]
2017-04-19 18:42 ` Bart Van Assche
2017-04-20 21:59 ` Bart Van Assche
2017-04-20 22:13 ` James Bottomley
2017-04-20 22:27 ` Bart Van Assche
2017-04-20 22:52 ` Bart Van Assche
2017-04-23 17:28 ` James Bottomley
2017-04-24 21:46 ` Bart Van Assche
2017-04-26 18:53 ` Bart Van Assche
2017-04-28 18:45 ` James Bottomley
2017-04-24 7:14 ` [lkp-robot] [sd] ab1218235c: INFO:possible_recursive_locking_detected kernel test robot
2017-04-17 17:34 ` [PATCH v3 4/4] Avoid that __scsi_remove_device() hangs Bart Van Assche
2017-04-18 11:58 ` [PATCH v3 0/4] " Israel Rukshin
2017-04-18 15:40 ` Bart Van Assche
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