[PATCH] aoe 12/12: send outgoing packets in order

I can't use list.h, since sk_buff doesn't have a list_head but instead
has two struct sk_buff pointers, and I want to avoid any extra memory
allocation.

send outgoing packets in order

Signed-off-by: Ed L. Cashin <ecashin@coraid.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 21 insertions, 12 deletions

diff --git a/drivers/block/aoe/aoe.h b/drivers/block/aoe/aoe.h
index 2e92cfb4997c..aa8b547ffafa 100644
--- a/drivers/block/aoe/aoe.h
+++ b/drivers/block/aoe/aoe.h
@@ -131,7 +131,8 @@ struct aoedev {
         struct timer_list timer;
         spinlock_t lock;
         struct net_device *ifp; /* interface ed is attached to */
-        struct sk_buff *skblist;/* packets needing to be sent */
+        struct sk_buff *sendq_hd; /* packets needing to be sent, list head */
+        struct sk_buff *sendq_tl;
         mempool_t *bufpool;     /* for deadlock-free Buf allocation */
         struct list_head bufq;  /* queue of bios to work on */
         struct buf *inprocess;  /* the one we're currently working on */
diff --git a/drivers/block/aoe/aoeblk.c b/drivers/block/aoe/aoeblk.c
index a2735d975846..4780f7926d42 100644
--- a/drivers/block/aoe/aoeblk.c
+++ b/drivers/block/aoe/aoeblk.c
@@ -147,8 +147,8 @@ aoeblk_make_request(request_queue_t *q, struct bio *bio)
         list_add_tail(&buf->bufs, &d->bufq);
         aoecmd_work(d);
 
-        sl = d->skblist;
-        d->skblist = NULL;
+        sl = d->sendq_hd;
+        d->sendq_hd = d->sendq_tl = NULL;
 
         spin_unlock_irqrestore(&d->lock, flags);
 
diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c
index 60beb8db4612..b5be4b7d7b5b 100644
--- a/drivers/block/aoe/aoecmd.c
+++ b/drivers/block/aoe/aoecmd.c
@@ -178,8 +178,12 @@ aoecmd_ata_rw(struct aoedev *d, struct frame *f)
 
         skb = skb_prepare(d, f);
         if (skb) {
-                skb->next = d->skblist;
-                d->skblist = skb;
+                skb->next = NULL;
+                if (d->sendq_hd)
+                        d->sendq_tl->next = skb;
+                else
+                        d->sendq_hd = skb;
+                d->sendq_tl = skb;
         }
 }
 
@@ -227,8 +231,12 @@ rexmit(struct aoedev *d, struct frame *f)
 
         skb = skb_prepare(d, f);
         if (skb) {
-                skb->next = d->skblist;
-                d->skblist = skb;
+                skb->next = NULL;
+                if (d->sendq_hd)
+                        d->sendq_tl->next = skb;
+                else
+                        d->sendq_hd = skb;
+                d->sendq_tl = skb;
         }
 }
 
@@ -280,8 +288,8 @@ tdie:		spin_unlock_irqrestore(&d->lock, flags);
                 }
         }
 
-        sl = d->skblist;
-        d->skblist = NULL;
+        sl = d->sendq_hd;
+        d->sendq_hd = d->sendq_tl = NULL;
         if (sl) {
                 n = d->rttavg <<= 1;
                 if (n > MAXTIMER)
@@ -481,8 +489,8 @@ aoecmd_ata_rsp(struct sk_buff *skb)
 
         aoecmd_work(d);
 
-        sl = d->skblist;
-        d->skblist = NULL;
+        sl = d->sendq_hd;
+        d->sendq_hd = d->sendq_tl = NULL;
 
         spin_unlock_irqrestore(&d->lock, flags);
 
@@ -531,7 +539,7 @@ aoecmd_cfg(ushort aoemajor, unsigned char aoeminor)
  
 /*
  * Since we only call this in one place (and it only prepares one frame)
- * we just return the skb.  Usually we'd chain it up to the d->skblist.
+ * we just return the skb.  Usually we'd chain it up to the aoedev sendq.
  */
 static struct sk_buff *
 aoecmd_ata_id(struct aoedev *d)