From: Dan Williams <dan.j.williams@intel.com>
Date: Thu, 22 Sep 2011 05:05:34 +0000 (-0700)
Subject: [SCSI] libsas: fix port->dev_list locking
X-Git-Tag: v3.2-rc1~125^2~47
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1a34c0640137eed8dabdac3a68a7a84116ac9e0d;p=pandora-kernel.git

[SCSI] libsas: fix port->dev_list locking

port->dev_list maintains a list of devices attached to a given sas root port.
It needs to be mutated under a lock as contexts outside of the
single-threaded-libsas-workqueue access the list via sas_find_dev_by_rphy().
Fixup locations where the list was being mutated without a lock.

This is a follow-up to commit 5911e963 "[SCSI] libsas: remove expander
from dev list on error", where Luben noted [1]:

    > 2/ We have unlocked list manipulations in sas_ex_discover_end_dev(),
    > sas_unregister_common_dev(), and sas_ex_discover_end_dev()

    Yes, I can see that and that is very unfortunate.

[1]: http://marc.info/?l=linux-scsi&m=131480962006471&w=2

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
---

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