From: Ed Cashin <ecashin@coraid.com>
Date: Fri, 5 Oct 2012 00:16:34 +0000 (-0700)
Subject: aoe: increase net_device reference count while using it
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=1b86fda9adf1b691a76f8ceddfc59d0c8386257c;p=deliverable%2Flinux.git

aoe: increase net_device reference count while using it

This change eliminates the danger that the user could rmmod the driver for
a network interface that is being used for AoE by the aoe driver.

Signed-off-by: Ed Cashin <ecashin@coraid.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c
index cc692fee7ce1..2f19b9bba913 100644
--- a/drivers/block/aoe/aoecmd.c
+++ b/drivers/block/aoe/aoecmd.c
@@ -494,12 +494,15 @@ static void
 ejectif(struct aoetgt *t, struct aoeif *ifp)
 {
 	struct aoeif *e;
+	struct net_device *nd;
 	ulong n;
 
+	nd = ifp->nd;
 	e = t->ifs + NAOEIFS - 1;
 	n = (e - ifp) * sizeof *ifp;
 	memmove(ifp, ifp+1, n);
 	e->nd = NULL;
+	dev_put(nd);
 }
 
 static int
@@ -1317,6 +1320,7 @@ setifbcnt(struct aoetgt *t, struct net_device *nd, int bcnt)
 			pr_err("aoe: device setifbcnt failure; too many interfaces.\n");
 			return;
 		}
+		dev_hold(nd);
 		p->nd = nd;
 		p->bcnt = bcnt;
 	}
diff --git a/drivers/block/aoe/aoedev.c b/drivers/block/aoe/aoedev.c
index 3968fe6c0077..6be7b3858340 100644
--- a/drivers/block/aoe/aoedev.c
+++ b/drivers/block/aoe/aoedev.c
@@ -295,6 +295,13 @@ freetgt(struct aoedev *d, struct aoetgt *t)
 {
 	struct frame *f;
 	struct list_head *pos, *nx, *head;
+	struct aoeif *ifp;
+
+	for (ifp = t->ifs; ifp < &t->ifs[NAOEIFS]; ++ifp) {
+		if (!ifp->nd)
+			break;
+		dev_put(ifp->nd);
+	}
 
 	head = &t->ffree;
 	list_for_each_safe(pos, nx, head) {