[PATCH] aoe [2/8]: support dynamic resizing of AoE devices

Allow the driver to recognize AoE devices that have changed size.
Devices not in use are updated automatically, and devices that are in
use are updated at user request.

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

1 files changed, 119 insertions, 58 deletions

diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c
index 4ab01ce..150eb78 100644
--- a/drivers/block/aoe/aoecmd.c
+++ b/drivers/block/aoe/aoecmd.c
@@ -8,6 +8,7 @@
 #include <linux/blkdev.h>
 #include <linux/skbuff.h>
 #include <linux/netdevice.h>
+#include <linux/genhd.h>
 #include <asm/unaligned.h>
 #include "aoe.h"
 
@@ -189,12 +190,67 @@ aoecmd_ata_rw(struct aoedev *d, struct frame *f)
 	}
 }
 
+/* some callers cannot sleep, and they can call this function,
+ * transmitting the packets later, when interrupts are on
+ */
+static struct sk_buff *
+aoecmd_cfg_pkts(ushort aoemajor, unsigned char aoeminor, struct sk_buff **tail)
+{
+	struct aoe_hdr *h;
+	struct aoe_cfghdr *ch;
+	struct sk_buff *skb, *sl, *sl_tail;
+	struct net_device *ifp;
+
+	sl = sl_tail = NULL;
+
+	read_lock(&dev_base_lock);
+	for (ifp = dev_base; ifp; dev_put(ifp), ifp = ifp->next) {
+		dev_hold(ifp);
+		if (!is_aoe_netif(ifp))
+			continue;
+
+		skb = new_skb(ifp, sizeof *h + sizeof *ch);
+		if (skb == NULL) {
+			printk(KERN_INFO "aoe: aoecmd_cfg: skb alloc failure\n");
+			continue;
+		}
+		if (sl_tail == NULL)
+			sl_tail = skb;
+		h = (struct aoe_hdr *) skb->mac.raw;
+		memset(h, 0, sizeof *h + sizeof *ch);
+
+		memset(h->dst, 0xff, sizeof h->dst);
+		memcpy(h->src, ifp->dev_addr, sizeof h->src);
+		h->type = __constant_cpu_to_be16(ETH_P_AOE);
+		h->verfl = AOE_HVER;
+		h->major = cpu_to_be16(aoemajor);
+		h->minor = aoeminor;
+		h->cmd = AOECMD_CFG;
+
+		skb->next = sl;
+		sl = skb;
+	}
+	read_unlock(&dev_base_lock);
+
+	if (tail != NULL)
+		*tail = sl_tail;
+	return sl;
+}
+
 /* enters with d->lock held */
 void
 aoecmd_work(struct aoedev *d)
 {
 	struct frame *f;
 	struct buf *buf;
+
+	if (d->flags & DEVFL_PAUSE) {
+		if (!aoedev_isbusy(d))
+			d->sendq_hd = aoecmd_cfg_pkts(d->aoemajor,
+						d->aoeminor, &d->sendq_tl);
+		return;
+	}
+
 loop:
 	f = getframe(d, FREETAG);
 	if (f == NULL)
@@ -306,6 +362,37 @@ tdie:		spin_unlock_irqrestore(&d->lock, flags);
 	aoenet_xmit(sl);
 }
 
+/* this function performs work that has been deferred until sleeping is OK
+ */
+void
+aoecmd_sleepwork(void *vp)
+{
+	struct aoedev *d = (struct aoedev *) vp;
+
+	if (d->flags & DEVFL_GDALLOC)
+		aoeblk_gdalloc(d);
+
+	if (d->flags & DEVFL_NEWSIZE) {
+		struct block_device *bd;
+		unsigned long flags;
+		u64 ssize;
+
+		ssize = d->gd->capacity;
+		bd = bdget_disk(d->gd, 0);
+
+		if (bd) {
+			mutex_lock(&bd->bd_inode->i_mutex);
+			i_size_write(bd->bd_inode, (loff_t)ssize<<9);
+			mutex_unlock(&bd->bd_inode->i_mutex);
+			bdput(bd);
+		}
+		spin_lock_irqsave(&d->lock, flags);
+		d->flags |= DEVFL_UP;
+		d->flags &= ~DEVFL_NEWSIZE;
+		spin_unlock_irqrestore(&d->lock, flags);
+	}
+}
+
 static void
 ataid_complete(struct aoedev *d, unsigned char *id)
 {
@@ -340,21 +427,29 @@ ataid_complete(struct aoedev *d, unsigned char *id)
 		d->geo.heads = le16_to_cpu(get_unaligned((__le16 *) &id[55<<1]));
 		d->geo.sectors = le16_to_cpu(get_unaligned((__le16 *) &id[56<<1]));
 	}
+
+	if (d->ssize != ssize)
+		printk(KERN_INFO "aoe: %012llx e%lu.%lu v%04x has %llu "
+			"sectors\n", (unsigned long long)mac_addr(d->addr),
+			d->aoemajor, d->aoeminor,
+			d->fw_ver, (long long)ssize);
 	d->ssize = ssize;
 	d->geo.start = 0;
 	if (d->gd != NULL) {
 		d->gd->capacity = ssize;
-		d->flags |= DEVFL_UP;
-		return;
-	}
-	if (d->flags & DEVFL_WORKON) {
-		printk(KERN_INFO "aoe: ataid_complete: can't schedule work, it's already on!  "
-			"(This really shouldn't happen).\n");
-		return;
+		d->flags |= DEVFL_NEWSIZE;
+	} else {
+		if (d->flags & DEVFL_GDALLOC) {
+			printk(KERN_INFO "aoe: %s: %s e%lu.%lu, %s\n",
+			       __FUNCTION__,
+			       "can't schedule work for",
+			       d->aoemajor, d->aoeminor,
+			       "it's already on! (This really shouldn't happen).\n");
+			return;
+		}
+		d->flags |= DEVFL_GDALLOC;
 	}
-	INIT_WORK(&d->work, aoeblk_gdalloc, d);
 	schedule_work(&d->work);
-	d->flags |= DEVFL_WORKON;
 }
 
 static void
@@ -452,7 +547,7 @@ aoecmd_ata_rsp(struct sk_buff *skb)
 				return;
 			}
 			ataid_complete(d, (char *) (ahin+1));
-			/* d->flags |= DEVFL_WC_UPDATE; */
+			d->flags &= ~DEVFL_PAUSE;
 			break;
 		default:
 			printk(KERN_INFO "aoe: aoecmd_ata_rsp: unrecognized "
@@ -485,51 +580,19 @@ aoecmd_ata_rsp(struct sk_buff *skb)
 	f->tag = FREETAG;
 
 	aoecmd_work(d);
-
 	sl = d->sendq_hd;
 	d->sendq_hd = d->sendq_tl = NULL;
 
 	spin_unlock_irqrestore(&d->lock, flags);
-
 	aoenet_xmit(sl);
 }
 
 void
 aoecmd_cfg(ushort aoemajor, unsigned char aoeminor)
 {
-	struct aoe_hdr *h;
-	struct aoe_cfghdr *ch;
-	struct sk_buff *skb, *sl;
-	struct net_device *ifp;
-
-	sl = NULL;
-
-	read_lock(&dev_base_lock);
-	for (ifp = dev_base; ifp; dev_put(ifp), ifp = ifp->next) {
-		dev_hold(ifp);
-		if (!is_aoe_netif(ifp))
-			continue;
-
-		skb = new_skb(ifp, sizeof *h + sizeof *ch);
-		if (skb == NULL) {
-			printk(KERN_INFO "aoe: aoecmd_cfg: skb alloc failure\n");
-			continue;
-		}
-		h = (struct aoe_hdr *) skb->mac.raw;
-		memset(h, 0, sizeof *h + sizeof *ch);
-
-		memset(h->dst, 0xff, sizeof h->dst);
-		memcpy(h->src, ifp->dev_addr, sizeof h->src);
-		h->type = __constant_cpu_to_be16(ETH_P_AOE);
-		h->verfl = AOE_HVER;
-		h->major = cpu_to_be16(aoemajor);
-		h->minor = aoeminor;
-		h->cmd = AOECMD_CFG;
+	struct sk_buff *sl;
 
-		skb->next = sl;
-		sl = skb;
-	}
-	read_unlock(&dev_base_lock);
+	sl = aoecmd_cfg_pkts(aoemajor, aoeminor, NULL);
 
 	aoenet_xmit(sl);
 }
@@ -562,9 +625,6 @@ aoecmd_ata_id(struct aoedev *d)
 	f->waited = 0;
 	f->writedatalen = 0;
 
-	/* this message initializes the device, so we reset the rttavg */
-	d->rttavg = MAXTIMER;
-
 	/* set up ata header */
 	ah->scnt = 1;
 	ah->cmdstat = WIN_IDENTIFY;
@@ -572,12 +632,8 @@ aoecmd_ata_id(struct aoedev *d)
 
 	skb = skb_prepare(d, f);
 
-	/* we now want to start the rexmit tracking */
-	d->flags &= ~DEVFL_TKILL;
-	d->timer.data = (ulong) d;
+	d->rttavg = MAXTIMER;
 	d->timer.function = rexmit_timer;
-	d->timer.expires = jiffies + TIMERTICK;
-	add_timer(&d->timer);
 
 	return skb;
 }
@@ -619,23 +675,28 @@ aoecmd_cfg_rsp(struct sk_buff *skb)
 	if (bufcnt > MAXFRAMES)	/* keep it reasonable */
 		bufcnt = MAXFRAMES;
 
-	d = aoedev_set(sysminor, h->src, skb->dev, bufcnt);
+	d = aoedev_by_sysminor_m(sysminor, bufcnt);
 	if (d == NULL) {
-		printk(KERN_INFO "aoe: aoecmd_cfg_rsp: device set failure\n");
+		printk(KERN_INFO "aoe: aoecmd_cfg_rsp: device sysminor_m failure\n");
 		return;
 	}
 
 	spin_lock_irqsave(&d->lock, flags);
 
-	if (d->flags & (DEVFL_UP | DEVFL_CLOSEWAIT)) {
+	/* permit device to migrate mac and network interface */
+	d->ifp = skb->dev;
+	memcpy(d->addr, h->src, sizeof d->addr);
+
+	/* don't change users' perspective */
+	if (d->nopen && !(d->flags & DEVFL_PAUSE)) {
 		spin_unlock_irqrestore(&d->lock, flags);
 		return;
 	}
-
+	d->flags |= DEVFL_PAUSE;	/* force pause */
 	d->fw_ver = be16_to_cpu(ch->fwver);
 
-	/* we get here only if the device is new */
-	sl = aoecmd_ata_id(d);
+	/* check for already outstanding ataid */
+	sl = aoedev_isbusy(d) == 0 ? aoecmd_ata_id(d) : NULL;
 
 	spin_unlock_irqrestore(&d->lock, flags);