From: Dan Williams <dan.j.williams@intel.com>
Date: Fri, 8 Apr 2016 02:59:27 +0000 (-0700)
Subject: libnvdimm, pfn: fix uuid validation
X-Git-Tag: firefly_0821_release~176^2~4^2~49^2~124
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=966bf1bea449c9f0ef89051b2025c748d28baa2b;p=firefly-linux-kernel-4.4.55.git

libnvdimm, pfn: fix uuid validation

commit e5670563f588ed1c0603819350c0f02cec23f5c5 upstream.

If we detect a namespace has a stale info block in the init path, we
should overwrite with the latest configuration.  In fact, we already
return -ENODEV when the parent uuid is invalid, the same should be done
for the 'self' uuid.  Otherwise we can get into a condition where
userspace is unable to reconfigure the pfn-device without directly /
manually invalidating the info block.

Reported-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index 71805a1aa0f3..9d3974591cd6 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -275,7 +275,7 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn)
 	} else {
 		/* from init we validate */
 		if (memcmp(nd_pfn->uuid, pfn_sb->uuid, 16) != 0)
-			return -EINVAL;
+			return -ENODEV;
 	}
 
 	/*