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>

2 files changed, 11 insertions, 0 deletions

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) {