From: Jeff Garzik <jgarzik@redhat.com>
Subject: Re: [RHEL5.1] SATA patch update
Date: Thu, 19 Jul 2007 16:41:03 -0400
Bugzilla: 248382
Message-Id: <20070719204103.GD20801@devserv.devel.redhat.com>
Changelog: [sata] regression in support for third party modules


The easiest is to replace the two members added to struct device:


diff -urp ../kernel-2.6.18.orig/linux-2.6.18.i686/drivers/base/core.c linux-2.6.18.i686/drivers/base/core.c
--- ../kernel-2.6.18.orig/linux-2.6.18.i686/drivers/base/core.c	2007-07-19 15:09:29.000000000 -0400
+++ linux-2.6.18.i686/drivers/base/core.c	2007-07-19 15:24:21.000000000 -0400
@@ -271,8 +271,6 @@ void device_initialize(struct device *de
 	INIT_LIST_HEAD(&dev->dma_pools);
 	INIT_LIST_HEAD(&dev->node);
 	init_MUTEX(&dev->sem);
-	spin_lock_init(&dev->devres_lock);
-	INIT_LIST_HEAD(&dev->devres_head);
 	device_init_wakeup(dev, 0);
 }
 
diff -urp ../kernel-2.6.18.orig/linux-2.6.18.i686/drivers/base/dd.c linux-2.6.18.i686/drivers/base/dd.c
--- ../kernel-2.6.18.orig/linux-2.6.18.i686/drivers/base/dd.c	2007-07-19 15:09:29.000000000 -0400
+++ linux-2.6.18.i686/drivers/base/dd.c	2007-07-19 15:24:17.000000000 -0400
@@ -77,7 +77,6 @@ int driver_probe_device(struct device_dr
 
 	pr_debug("%s: Matched Device %s with Driver %s\n",
 		 drv->bus->name, dev->bus_id, drv->name);
-	WARN_ON(!list_empty(&dev->devres_head));
 
 	dev->driver = drv;
 	if (dev->bus->probe) {
diff -urp ../kernel-2.6.18.orig/linux-2.6.18.i686/drivers/base/devres.c linux-2.6.18.i686/drivers/base/devres.c
--- ../kernel-2.6.18.orig/linux-2.6.18.i686/drivers/base/devres.c	2007-07-19 15:09:29.000000000 -0400
+++ linux-2.6.18.i686/drivers/base/devres.c	2007-07-19 16:26:22.000000000 -0400
@@ -32,6 +32,66 @@ struct devres_group {
 	/* -- 8 pointers */
 };
 
+struct devres_head_ent {
+	struct device			*dev;
+	struct list_head		devres_head;
+
+	struct list_head		devres_head_list_node;
+};
+
+static DEFINE_SPINLOCK(devres_lock);
+static LIST_HEAD(devres_head_list);
+
+/* all these called inside spin_lock_irqsave(devres_lock) */
+static struct devres_head_ent *dh_find_dev(struct device *dev)
+{
+	struct devres_head_ent *ent;
+	struct list_head *tmp;
+
+	list_for_each(tmp, &devres_head_list) {
+		ent = list_entry(tmp, struct devres_head_ent, 
+				 devres_head_list_node);
+		if (ent->dev == dev)
+			return ent;
+	}
+
+	return NULL;
+}
+
+static struct list_head *get_devres_head(struct device *dev)
+{
+	struct devres_head_ent *ent = dh_find_dev(dev);
+	if (ent)
+		goto out;
+
+	ent = kmalloc(sizeof(*ent), GFP_ATOMIC);
+	if (!ent)
+		return NULL;
+
+	ent->dev = dev;
+	INIT_LIST_HEAD(&ent->devres_head);
+	INIT_LIST_HEAD(&ent->devres_head_list_node);
+
+	list_add(&ent->devres_head_list_node, &devres_head_list);
+
+out:
+	return &ent->devres_head;
+}
+
+static void put_devres_head(struct device *dev)
+{
+	struct devres_head_ent *ent;
+
+	ent = dh_find_dev(dev);
+	if (!ent)
+		return;
+
+	list_del(&ent->devres_head_list_node);
+
+	ent->dev = NULL;
+	kfree(ent);
+}
+
 #ifdef CONFIG_DEBUG_DEVRES
 static int log_devres = 0;
 module_param_named(log, log_devres, int, S_IRUGO | S_IWUSR);
@@ -98,7 +158,7 @@ static void add_dr(struct device *dev, s
 {
 	devres_log(dev, node, "ADD");
 	BUG_ON(!list_empty(&node->entry));
-	list_add_tail(&node->entry, &dev->devres_head);
+	list_add_tail(&node->entry, get_devres_head(dev));
 }
 
 #ifdef CONFIG_DEBUG_DEVRES
@@ -171,9 +231,9 @@ void devres_add(struct device *dev, void
 	struct devres *dr = container_of(res, struct devres, data);
 	unsigned long flags;
 
-	spin_lock_irqsave(&dev->devres_lock, flags);
+	spin_lock_irqsave(&devres_lock, flags);
 	add_dr(dev, &dr->node);
-	spin_unlock_irqrestore(&dev->devres_lock, flags);
+	spin_unlock_irqrestore(&devres_lock, flags);
 }
 EXPORT_SYMBOL_GPL(devres_add);
 
@@ -182,7 +242,7 @@ static struct devres *find_dr(struct dev
 {
 	struct devres_node *node;
 
-	list_for_each_entry_reverse(node, &dev->devres_head, entry) {
+	list_for_each_entry_reverse(node, get_devres_head(dev), entry) {
 		struct devres *dr = container_of(node, struct devres, node);
 
 		if (node->release != release)
@@ -215,9 +275,9 @@ void * devres_find(struct device *dev, d
 	struct devres *dr;
 	unsigned long flags;
 
-	spin_lock_irqsave(&dev->devres_lock, flags);
+	spin_lock_irqsave(&devres_lock, flags);
 	dr = find_dr(dev, release, match, match_data);
-	spin_unlock_irqrestore(&dev->devres_lock, flags);
+	spin_unlock_irqrestore(&devres_lock, flags);
 
 	if (dr)
 		return dr->data;
@@ -246,14 +306,14 @@ void * devres_get(struct device *dev, vo
 	struct devres *dr;
 	unsigned long flags;
 
-	spin_lock_irqsave(&dev->devres_lock, flags);
+	spin_lock_irqsave(&devres_lock, flags);
 	dr = find_dr(dev, new_dr->node.release, match, match_data);
 	if (!dr) {
 		add_dr(dev, &new_dr->node);
 		dr = new_dr;
 		new_dr = NULL;
 	}
-	spin_unlock_irqrestore(&dev->devres_lock, flags);
+	spin_unlock_irqrestore(&devres_lock, flags);
 	devres_free(new_dr);
 
 	return dr->data;
@@ -281,13 +341,13 @@ void * devres_remove(struct device *dev,
 	struct devres *dr;
 	unsigned long flags;
 
-	spin_lock_irqsave(&dev->devres_lock, flags);
+	spin_lock_irqsave(&devres_lock, flags);
 	dr = find_dr(dev, release, match, match_data);
 	if (dr) {
 		list_del_init(&dr->node.entry);
 		devres_log(dev, &dr->node, "REM");
 	}
-	spin_unlock_irqrestore(&dev->devres_lock, flags);
+	spin_unlock_irqrestore(&devres_lock, flags);
 
 	if (dr)
 		return dr->data;
@@ -401,7 +461,7 @@ static int release_nodes(struct device *
 
 	cnt = remove_nodes(dev, first, end, &todo);
 
-	spin_unlock_irqrestore(&dev->devres_lock, flags);
+	spin_unlock_irqrestore(&devres_lock, flags);
 
 	/* Release.  Note that both devres and devres_group are
 	 * handled as devres in the following loop.  This is safe.
@@ -424,11 +484,23 @@ static int release_nodes(struct device *
  */
 int devres_release_all(struct device *dev)
 {
+	struct list_head *head;
 	unsigned long flags;
+	int rc;
+
+	spin_lock_irqsave(&devres_lock, flags);
 
-	spin_lock_irqsave(&dev->devres_lock, flags);
-	return release_nodes(dev, dev->devres_head.next, &dev->devres_head,
+	head = get_devres_head(dev);
+	rc = release_nodes(dev, head->next, head,
 			     flags);
+
+	/* lock released in release_nodes() */
+
+	spin_lock_irqsave(&devres_lock, flags);
+	put_devres_head(dev);
+	spin_unlock_irqrestore(&devres_lock, flags);
+
+	return rc;
 }
 
 /**
@@ -463,9 +535,9 @@ void * devres_open_group(struct device *
 	if (id)
 		grp->id = id;
 
-	spin_lock_irqsave(&dev->devres_lock, flags);
+	spin_lock_irqsave(&devres_lock, flags);
 	add_dr(dev, &grp->node[0]);
-	spin_unlock_irqrestore(&dev->devres_lock, flags);
+	spin_unlock_irqrestore(&devres_lock, flags);
 	return grp->id;
 }
 EXPORT_SYMBOL_GPL(devres_open_group);
@@ -475,7 +547,7 @@ static struct devres_group * find_group(
 {
 	struct devres_node *node;
 
-	list_for_each_entry_reverse(node, &dev->devres_head, entry) {
+	list_for_each_entry_reverse(node, get_devres_head(dev), entry) {
 		struct devres_group *grp;
 
 		if (node->release != &group_open_release)
@@ -506,7 +578,7 @@ void devres_close_group(struct device *d
 	struct devres_group *grp;
 	unsigned long flags;
 
-	spin_lock_irqsave(&dev->devres_lock, flags);
+	spin_lock_irqsave(&devres_lock, flags);
 
 	grp = find_group(dev, id);
 	if (grp)
@@ -514,7 +586,7 @@ void devres_close_group(struct device *d
 	else
 		WARN_ON(1);
 
-	spin_unlock_irqrestore(&dev->devres_lock, flags);
+	spin_unlock_irqrestore(&devres_lock, flags);
 }
 EXPORT_SYMBOL_GPL(devres_close_group);
 
@@ -532,7 +604,7 @@ void devres_remove_group(struct device *
 	struct devres_group *grp;
 	unsigned long flags;
 
-	spin_lock_irqsave(&dev->devres_lock, flags);
+	spin_lock_irqsave(&devres_lock, flags);
 
 	grp = find_group(dev, id);
 	if (grp) {
@@ -542,7 +614,7 @@ void devres_remove_group(struct device *
 	} else
 		WARN_ON(1);
 
-	spin_unlock_irqrestore(&dev->devres_lock, flags);
+	spin_unlock_irqrestore(&devres_lock, flags);
 
 	kfree(grp);
 }
@@ -566,12 +638,12 @@ int devres_release_group(struct device *
 	unsigned long flags;
 	int cnt = 0;
 
-	spin_lock_irqsave(&dev->devres_lock, flags);
+	spin_lock_irqsave(&devres_lock, flags);
 
 	grp = find_group(dev, id);
 	if (grp) {
 		struct list_head *first = &grp->node[0].entry;
-		struct list_head *end = &dev->devres_head;
+		struct list_head *end = get_devres_head(dev);
 
 		if (!list_empty(&grp->node[1].entry))
 			end = grp->node[1].entry.next;
@@ -579,7 +651,7 @@ int devres_release_group(struct device *
 		cnt = release_nodes(dev, first, end, flags);
 	} else {
 		WARN_ON(1);
-		spin_unlock_irqrestore(&dev->devres_lock, flags);
+		spin_unlock_irqrestore(&devres_lock, flags);
 	}
 
 	return cnt;
diff -urp ../kernel-2.6.18.orig/linux-2.6.18.i686/include/linux/device.h linux-2.6.18.i686/include/linux/device.h
--- ../kernel-2.6.18.orig/linux-2.6.18.i686/include/linux/device.h	2007-07-19 15:09:29.000000000 -0400
+++ linux-2.6.18.i686/include/linux/device.h	2007-07-19 15:27:23.000000000 -0400
@@ -375,11 +375,6 @@ struct device {
 	dev_t			devt;		/* dev_t, creates the sysfs "dev" */
 
 	void	(*release)(struct device * dev);
-
-#ifndef __GENKSYMS__
-	spinlock_t		devres_lock;
-	struct list_head	devres_head;
-#endif
 };
 
 static inline void *