From: Don Dutile <ddutile@redhat.com>
Date: Mon, 23 Feb 2009 18:49:50 -0500
Subject: [xen] pv-block: remove anaconda workaround
Message-id: 49A3361E.3070204@redhat.com
O-Subject: [RHEL5.4 PATCH] Remove xen pv-block workaround for anaconda in bare-metal / FV kernel
Bugzilla: 477005
RH-Acked-by: Chris Lalancette <clalance@redhat.com>

BZ 477005
 -- this bz complains about a possible cyclic lock dependency.
    -- this code is the culprit & removes these warnings.

The following patches are a backport of the ones done to rhel4.8,
for bz 474667.
It removes the hack put into the xen pv block code to workaround
an anaconda installation failure when the xen-platform-pci.ko support
was built into the kernel.
Now that xen-platform-pci.ko is not built-in (loadable), and it is
not in anaconda's rhel5 initrd, the installation failure is not possible.
So, removing the code make the modules much closer to upstream,
common to rhel4.8, and gets rid of the kernel-debug warnings
in the aformentioned bz.

While I was cleaing up the xen pv block code, I also
fixed two build warnings introduced in the original
make xen-platform-pci.ko a loadable module in netfront.c
(looking to correct the errors of my ways, and improve status w/dzickus! ;-) ).

Also passed the patch along to Chris Lalancette so he can include it in
his virttest rpm's.  This patch is needed *before* the extend xen device
connect timeout to 5mins is done, because when it is, a FV kernel waits that
long for the non-spec, CD drive to timeout.... (ugh!).

Brew build:
https://brewweb.devel.redhat.com/taskinfo?taskID=1701561

Testing:
(1) x86_64, FV; did several block-attach, mount xvdb1, ls, umount xvdb1, block-detach
(2) x86_64, PV;  ditto
(3) i386 FV; ditto
(4) x86_64 FV -debug kernel -- ensure warnings listed in bz477005 no longer appeared
    on boot up by inspecting log files.

Please review & ACK.

- Don

diff --git a/drivers/xen/blkfront/blkfront.c b/drivers/xen/blkfront/blkfront.c
index febf734..6b4b0c2 100644
--- a/drivers/xen/blkfront/blkfront.c
+++ b/drivers/xen/blkfront/blkfront.c
@@ -860,21 +860,10 @@ static struct xenbus_driver blkfront = {
 
 static int __init xlblk_init(void)
 {
-	int rtn_val;
-#ifdef CONFIG_XEN_PV_ON_HVM
-	extern void xvd_dev_shutdown(void);
-#endif
-
 	if (!is_running_on_xen())
 		return -ENODEV;
 
-	rtn_val = xenbus_register_frontend(&blkfront);
-
-#ifdef CONFIG_XEN_PV_ON_HVM
-	/* remove any xvd's in xvd_rem_list after all dev's configured */
-	xvd_dev_shutdown();
-#endif
-	return rtn_val;
+	return xenbus_register_frontend(&blkfront);
 }
 module_init(xlblk_init);
 
diff --git a/drivers/xen/blkfront/vbd.c b/drivers/xen/blkfront/vbd.c
index ba9fa45..36d8d0f 100644
--- a/drivers/xen/blkfront/vbd.c
+++ b/drivers/xen/blkfront/vbd.c
@@ -334,7 +334,6 @@ xlvbd_add(blkif_sector_t capacity, int vdevice, u16 vdisk_info,
 	struct block_device *bd;
 	int err = 0;
 	int major, minor;
-	extern void xendev_rem_add(struct xenbus_device *dev);
 
 	if ((vdevice>>EXT_SHIFT) > 1) {
 		/* this is above the extended range; something is wrong */
@@ -359,12 +358,6 @@ xlvbd_add(blkif_sector_t capacity, int vdevice, u16 vdisk_info,
 	err = xlvbd_alloc_gendisk(major, minor, capacity, vdevice, vdisk_info,
 				  sector_size, info);
 
-#ifdef CONFIG_XEN_PV_ON_HVM
-	/* tag these devices for removal; unconnected hd's */
-	if (err) {
-		xendev_rem_add(info->xbdev);
-	}
-#endif
 	bdput(bd);
 	return err;
 }
diff --git a/drivers/xen/netfront/netfront.c b/drivers/xen/netfront/netfront.c
index d4aa1b9..4df5cca 100644
--- a/drivers/xen/netfront/netfront.c
+++ b/drivers/xen/netfront/netfront.c
@@ -1163,13 +1163,12 @@ static int xennet_get_responses(struct netfront_info *np,
 				struct page *page =
 					skb_shinfo(skb)->frags[0].page;
 				unsigned long pfn = page_to_pfn(page);
-				void *vaddr = page_address(page);
 
 				mcl = np->rx_mcl + pages_flipped;
 				mmu = np->rx_mmu + pages_flipped;
 
 				MULTI_update_va_mapping(mcl,
-							(unsigned long)vaddr,
+							(unsigned long)page_address(page),
 							pfn_pte_ma(mfn,
 								   PAGE_KERNEL),
 							0);
@@ -1539,9 +1538,9 @@ static void netif_release_rx_bufs_flip(struct netfront_info *np)
 			/* Remap the page. */
 			struct page *page = skb_shinfo(skb)->frags[0].page;
 			unsigned long pfn = page_to_pfn(page);
-			void *vaddr = page_address(page);
 
-			MULTI_update_va_mapping(mcl, (unsigned long)vaddr,
+			MULTI_update_va_mapping(mcl, 
+						(unsigned long)page_address(page),
 						pfn_pte_ma(mfn, PAGE_KERNEL),
 						0);
 
diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
index 04f1fd3..4648e88 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -67,24 +67,9 @@ static unsigned long xen_store_mfn;
 
 extern struct mutex xenwatch_mutex;
 
-#ifdef CONFIG_XEN_PV_ON_HVM
-extern int xenpv_notify_ide_disable;
-#else
-static int xenpv_notify_ide_disable = 0;
-#endif
-
-/* struct & lock to remove unconnected vbd's at boostrap */
-struct xendev_rem {
-	struct list_head list;
-	struct xenbus_device* xendev;
-};
-struct xendev_rem xendev_rem_hd;
-static spinlock_t xendev_rem_lock = SPIN_LOCK_UNLOCKED;
-
 static BLOCKING_NOTIFIER_HEAD(xenstore_notifier_list);
 
 static void wait_for_devices(struct xenbus_driver *xendrv);
-int boot_wait_for_devices(void);
 
 static int xenbus_probe_frontend(const char *type, const char *name);
 #ifdef CONFIG_XEN
@@ -95,7 +80,6 @@ static int xenbus_probe_backend(const char *type, const char *domid);
 static int xenbus_dev_probe(struct device *_dev);
 static int xenbus_dev_remove(struct device *_dev);
 static void xenbus_dev_shutdown(struct device *_dev);
-static int print_device_status(struct device *dev, void *data);
 
 /* If something in array of ids matches this device, return it. */
 static const struct xenbus_device_id *
@@ -1253,56 +1237,6 @@ static int exists_disconnected_device(struct device_driver *drv)
 				is_disconnected_device);
 }
 
-void xendev_rem_add(struct xenbus_device *dev)
-{
-	struct xendev_rem *new;
-	struct xendev_rem *ptr;
-
-	/*
-	 * do nothing if ide is disabled, since
-	 * may need vbd in this case;
-	 */
-	if (xenpv_notify_ide_disable == 1) {
-		printk("xenpv_notify_ide_disable set \n");
-		return;
-	}
-
-	/* only add vbd devices */
-	if (strncmp(dev->dev.bus_id, "vbd", 3)) 
-		return;
-
-	new = kmalloc(sizeof(*new), GFP_KERNEL);
-	if (new == 0L) {
-		printk(KERN_INFO "XENBUS: failed xendev_rem struct alloc\n");
-		printk(KERN_INFO "- couldn't removed %s from avail dev list\n",
-			dev->nodename);
-		return;
-	}
-	new->xendev = dev;
-
-	/* need to init if not done so already; for xen-platform-pci build */
-	if (xendev_rem_hd.list.next == NULL) {
-		INIT_LIST_HEAD(&xendev_rem_hd.list);
-	}
-
-	spin_lock(&xendev_rem_lock);
-	/* make sure xendev not already on the list */
-	list_for_each_entry(ptr, &xendev_rem_hd.list, list) {
-		struct xenbus_device *xendev = ptr->xendev;
-		if (xendev == dev) {
-			/* ok to have dev added via multiple code paths */
-			spin_unlock(&xendev_rem_lock);
-			kfree(new);
-			return;
-		}
-	}
-	list_add_tail(&new->list, &xendev_rem_hd.list);
-	spin_unlock(&xendev_rem_lock);
-
-	return;
-}
-EXPORT_SYMBOL_GPL(xendev_rem_add);
-
 static int print_device_status(struct device *dev, void *data)
 {
 	struct xenbus_device *xendev = to_xenbus_device(dev);
@@ -1320,42 +1254,11 @@ static int print_device_status(struct device *dev, void *data)
 		printk(KERN_WARNING "XENBUS: Timeout connecting "
 		       "to device: %s (state %d)\n",
 		       xendev->nodename, xendev->state);
-		xendev_rem_add(xendev);
 	}
 
 	return 0;
 }
 
-#ifdef CONFIG_XEN_PV_ON_HVM
-/*
- * Remove unused xvd's (vbd devices) at bootstrap so anaconda
- * doesn't have a nutty seeing xvd's that are not connected
- */
-void xvd_dev_shutdown(void)
-{
-	struct xendev_rem *ptr;
-	struct xendev_rem *tmp;
-	
-	if (xendev_rem_hd.list.next == NULL)
-		return;
-
-	spin_lock(&xendev_rem_lock);
-	list_for_each_entry_safe(ptr, tmp, &xendev_rem_hd.list, list) {
-		struct device *dev = &ptr->xendev->dev;
-		device_remove_file(dev, &dev_attr_devtype);
-		device_remove_file(dev, &dev_attr_nodename);
-		device_unregister(dev);
-/*		put_device(dev); */
-		/* remove list entry once processed */
-		list_del(&ptr->list);
-		/* free memory of this list entry */
-		kfree(ptr);
-	}
-	spin_unlock(&xendev_rem_lock);
-}
-EXPORT_SYMBOL_GPL(xvd_dev_shutdown);
-#endif
-
 /* We only wait for device setup after most initcalls have run. */
 static int ready_to_wait_for_devices;
 
@@ -1378,11 +1281,6 @@ static void wait_for_devices(struct xenbus_driver *xendrv)
 	unsigned long timeout = jiffies + 10*HZ;
 	struct device_driver *drv = xendrv ? &xendrv->driver : NULL;
 
-#ifdef CONFIG_XEN_PV_ON_HVM
-	/* force wait_for_devices check */
-	ready_to_wait_for_devices = 1;
-#endif
-
 	if (!ready_to_wait_for_devices || !is_running_on_xen())
 		return;
 
@@ -1398,7 +1296,6 @@ static void wait_for_devices(struct xenbus_driver *xendrv)
 #ifndef MODULE
 int boot_wait_for_devices(void)
 {
-	INIT_LIST_HEAD(&xendev_rem_hd.list);
 	if (!xenbus_frontend.error) {
 		ready_to_wait_for_devices = 1;
 		wait_for_devices(NULL);