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From: Bart Van Assche <Bart.VanAssche@sandisk.com>
To: "songliubraving@fb.com" <songliubraving@fb.com>
Cc: "linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
	"hch@infradead.org" <hch@infradead.org>
Subject: Re: [RFC] scsi: reduce protection of scan_mutex in scsi_remove_device
Date: Tue, 25 Apr 2017 22:17:38 +0000	[thread overview]
Message-ID: <1493158657.2628.26.camel@sandisk.com> (raw)
In-Reply-To: <3B06D0B6-825E-4788-9B87-BE3F35055DB2@fb.com>

On Tue, 2017-04-25 at 21:17 +0000, Song Liu wrote:
> I am not sure I fully understand the problem here. If I understand the logic 
> correctly, when a device is being removed, it will stay in scsi_host->__devices
> until fully the remove routine is finished. And LUN scanning in parallel will
> find the device with scsi_device_lookup_by_target(), and thus it would not 
> rescan the device until the device is fully removed? Did I miss anything here?

Hello Song,

The SCSI core is already complicated enough. Please don't complicate it further
by making subtle changes to the semantics of scan_mutex. Please also note that
I have proposed an alternative, namely to make the START STOP UNIT command
asynchronous.

Bart.

  reply	other threads:[~2017-04-25 22:17 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-21 21:13 [RFC] scsi: reduce protection of scan_mutex in scsi_remove_device Song Liu
2017-04-21 21:17 ` Bart Van Assche
2017-04-21 22:20   ` Song Liu
2017-04-21 21:20 ` Bart Van Assche
2017-04-21 22:31   ` Song Liu
2017-04-25 20:59     ` Bart Van Assche
2017-04-25 21:29       ` Song Liu
2017-04-24 15:28 ` Christoph Hellwig
2017-04-25 17:23 ` Bart Van Assche
2017-04-25 17:42   ` Song Liu
2017-04-25 17:52     ` Bart Van Assche
2017-04-25 21:17       ` Song Liu
2017-04-25 22:17         ` Bart Van Assche [this message]
2017-04-26  0:41           ` Song Liu

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