From: Sagi Grimberg <sagi@grimberg.me>
To: Bart Van Assche <bart.vanassche@sandisk.com>,
James Bottomley <jejb@linux.vnet.ibm.com>,
"Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Hannes Reinecke <hare@suse.de>,
Johannes Thumshirn <jthumshirn@suse.de>,
"linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>
Subject: Re: [PATCH] Avoid that SCSI device removal through sysfs triggers a deadlock
Date: Thu, 27 Oct 2016 12:36:30 +0300 [thread overview]
Message-ID: <2b64c1d7-e6b4-01a9-0c6e-1d8590714595@grimberg.me> (raw)
In-Reply-To: <14379fd1-c9bd-ad75-ca7c-0632f3e3c5d1@sandisk.com>
Hey Bart,
> The solution I prefer is to modify the SCSI scanning code such that
> the scan_mutex is only held while performing the actual LUN scanning
> and while ensuring that no SCSI device has been created yet for a
> certain LUN number but not while the Linux device and its sysfs
> attributes are created. Since that approach would require extensive
> changes in the SCSI scanning code, another approach has been chosen,
> namely to make self-removal asynchronous. This patch avoids that
> self-removal triggers the following deadlock:
Is this a real deadlock? or just a lockdep complaint?
Wouldn't making scsi_remove_device() taking single depth
mutex_lock_nested suffice here?
next prev parent reply other threads:[~2016-10-27 14:58 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-26 18:44 [PATCH] Avoid that SCSI device removal through sysfs triggers a deadlock Bart Van Assche
2016-10-27 9:36 ` Sagi Grimberg [this message]
2016-10-27 15:39 ` Bart Van Assche
2016-10-27 9:46 ` Johannes Thumshirn
2016-10-27 15:38 ` Bart Van Assche
2016-10-29 0:12 ` Johannes Thumshirn
2016-10-29 2:08 ` James Bottomley
2016-10-30 19:22 ` Bart Van Assche
2016-10-30 20:25 ` James Bottomley
2016-11-03 22:27 ` Bart Van Assche
2016-11-04 13:47 ` James Bottomley
2016-11-04 18:17 ` Bart Van Assche
2016-11-07 20:51 ` James Bottomley
-- strict thread matches above, loose matches on Subject: below --
2016-11-08 0:32 Bart Van Assche
2016-11-08 7:01 ` Greg KH
2016-11-08 15:34 ` James Bottomley
2016-11-08 15:28 ` James Bottomley
2016-11-08 16:52 ` Bart Van Assche
2016-11-08 18:01 ` James Bottomley
2016-11-08 19:13 ` Eric W. Biederman
2016-11-08 23:33 ` Bart Van Assche
2016-11-09 1:22 ` Eric W. Biederman
2016-11-08 23:44 ` James Bottomley
2016-11-09 0:57 ` Eric W. Biederman
2016-11-09 1:43 ` James Bottomley
2016-11-09 2:10 ` Eric W. Biederman
2016-11-11 1:37 ` James Bottomley
2016-11-11 4:13 ` Eric W. Biederman
2018-06-26 22:25 Bart Van Assche
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