[SCSI] correct transport class abstraction to work outside SCSI

I recently tried to construct a totally generic transport class and found there were certain features missing from the current abstract transport class. Most notable is that you have to hang the data on the class_device but most of the API is framed in terms of the generic device, not the class_device. These changes are two fold - Provide the class_device to all of the setup and configure APIs - Provide and extra API to take the device and the attribute class and return the corresponding class_device Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] correct transport class abstraction to work outside SCSI
I recently tried to construct a totally generic transport class and found there were certain features missing from the current abstract transport class. Most notable is that you have to hang the data on the class_device but most of the API is framed in terms of the generic device, not the class_device. These changes are two fold - Provide the class_device to all of the setup and configure APIs - Provide and extra API to take the device and the attribute class and return the corresponding class_device Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
James Bottomley · James Bottomley
1 parent 10c1b88987
Showing 6 changed files with 72 additions and 20 deletions Side-by-side Diff
drivers/base/attribute_container.c
drivers/base/transport_class.c
drivers/scsi/scsi_transport_fc.c
drivers/scsi/scsi_transport_spi.c
include/linux/attribute_container.h
include/linux/transport_class.h
@@ -58,6 +58,7 @@
 {
 	INIT_LIST_HEAD(&cont->node);
 	INIT_LIST_HEAD(&cont->containers);
+	spin_lock_init(&cont->containers_lock);
  
 	down(&attribute_container_mutex);
 	list_add_tail(&cont->node, &attribute_container_list);
  
@@ -77,11 +78,13 @@
 {
 	int retval = -EBUSY;
 	down(&attribute_container_mutex);
+	spin_lock(&cont->containers_lock);
 	if (!list_empty(&cont->containers))
 		goto out;
 	retval = 0;
 	list_del(&cont->node);
  out:
+	spin_unlock(&cont->containers_lock);
 	up(&attribute_container_mutex);
 	return retval;
  
  
@@ -151,7 +154,9 @@
 			fn(cont, dev, &ic->classdev);
 		else
 			attribute_container_add_class_device(&ic->classdev);
+		spin_lock(&cont->containers_lock);
 		list_add_tail(&ic->node, &cont->containers);
+		spin_unlock(&cont->containers_lock);
 	}
 	up(&attribute_container_mutex);
 }
@@ -189,6 +194,7 @@
  
 		if (!cont->match(cont, dev))
 			continue;
+		spin_lock(&cont->containers_lock);
 		list_for_each_entry_safe(ic, tmp, &cont->containers, node) {
 			if (dev != ic->classdev.dev)
 				continue;
@@ -200,6 +206,7 @@
 				class_device_unregister(&ic->classdev);
 			}
 		}
+		spin_unlock(&cont->containers_lock);
 	}
 	up(&attribute_container_mutex);
 }
  
@@ -230,10 +237,12 @@
 		if (!cont->match(cont, dev))
 			continue;
  
+		spin_lock(&cont->containers_lock);
 		list_for_each_entry_safe(ic, tmp, &cont->containers, node) {
 			if (dev == ic->classdev.dev)
 				fn(cont, dev, &ic->classdev);
 		}
+		spin_unlock(&cont->containers_lock);
 	}
 	up(&attribute_container_mutex);
 }
@@ -367,6 +376,35 @@
 	class_device_del(classdev);
 }
 EXPORT_SYMBOL_GPL(attribute_container_class_device_del);
+
+/**
+ * attribute_container_find_class_device - find the corresponding class_device
+ *
+ * @cont:	the container
+ * @dev:	the generic device
+ *
+ * Looks up the device in the container's list of class devices and returns
+ * the corresponding class_device.
+ */
+struct class_device *
+attribute_container_find_class_device(struct attribute_container *cont,
+				      struct device *dev)
+{
+	struct class_device *cdev = NULL;
+	struct internal_container *ic;
+
+	spin_lock(&cont->containers_lock);
+	list_for_each_entry(ic, &cont->containers, node) {
+		if (ic->classdev.dev == dev) {
+			cdev = &ic->classdev;
+			break;
+		}
+	}
+	spin_unlock(&cont->containers_lock);
+
+	return cdev;
+}
+EXPORT_SYMBOL_GPL(attribute_container_find_class_device);
  
 int __init
 attribute_container_init(void)
@@ -64,7 +64,9 @@
 }
 EXPORT_SYMBOL_GPL(transport_class_unregister);
  
-static int anon_transport_dummy_function(struct device *dev)
+static int anon_transport_dummy_function(struct transport_container *tc,
+					 struct device *dev,
+					 struct class_device *cdev)
 {
 	/* do nothing */
 	return 0;
  
@@ -115,9 +117,10 @@
 				    struct class_device *classdev)
 {
 	struct transport_class *tclass = class_to_transport_class(cont->class);
+	struct transport_container *tcont = attribute_container_to_transport_container(cont);
  
 	if (tclass->setup)
-		tclass->setup(dev);
+		tclass->setup(tcont, dev, classdev);
  
 	return 0;
 }
  
  
@@ -178,12 +181,14 @@
 EXPORT_SYMBOL_GPL(transport_add_device);
  
 static int transport_configure(struct attribute_container *cont,
-			       struct device *dev)
+			       struct device *dev,
+			       struct class_device *cdev)
 {
 	struct transport_class *tclass = class_to_transport_class(cont->class);
+	struct transport_container *tcont = attribute_container_to_transport_container(cont);
  
 	if (tclass->configure)
-		tclass->configure(dev);
+		tclass->configure(tcont, dev, cdev);
  
 	return 0;
 }
@@ -202,7 +207,7 @@
  */
 void transport_configure_device(struct device *dev)
 {
-	attribute_container_trigger(dev, transport_configure);
+	attribute_container_device_trigger(dev, transport_configure);
 }
 EXPORT_SYMBOL_GPL(transport_configure_device);
  
@@ -215,7 +220,7 @@
 	struct transport_class *tclass = class_to_transport_class(cont->class);
  
 	if (tclass->remove)
-		tclass->remove(dev);
+		tclass->remove(tcont, dev, classdev);
  
 	if (tclass->remove != anon_transport_dummy_function) {
 		if (tcont->statistics)
@@ -252,7 +252,8 @@
  
 #define to_fc_internal(tmpl)	container_of(tmpl, struct fc_internal, t)
  
-static int fc_target_setup(struct device *dev)
+static int fc_target_setup(struct transport_container *tc, struct device *dev,
+			   struct class_device *cdev)
 {
 	struct scsi_target *starget = to_scsi_target(dev);
 	struct fc_rport *rport = starget_to_rport(starget);
@@ -281,7 +282,8 @@
 			       NULL,
 			       NULL);
  
-static int fc_host_setup(struct device *dev)
+static int fc_host_setup(struct transport_container *tc, struct device *dev,
+			 struct class_device *cdev)
 {
 	struct Scsi_Host *shost = dev_to_shost(dev);
  
@@ -162,7 +162,8 @@
 	return SPI_SIGNAL_UNKNOWN;
 }
  
-static int spi_host_setup(struct device *dev)
+static int spi_host_setup(struct transport_container *tc, struct device *dev,
+			  struct class_device *cdev)
 {
 	struct Scsi_Host *shost = dev_to_shost(dev);
  
@@ -196,7 +197,9 @@
 	return &i->t.host_attrs.ac == cont;
 }
  
-static int spi_device_configure(struct device *dev)
+static int spi_device_configure(struct transport_container *tc,
+				struct device *dev,
+				struct class_device *cdev)
 {
 	struct scsi_device *sdev = to_scsi_device(dev);
 	struct scsi_target *starget = sdev->sdev_target;
@@ -214,7 +217,9 @@
 	return 0;
 }
  
-static int spi_setup_transport_attrs(struct device *dev)
+static int spi_setup_transport_attrs(struct transport_container *tc,
+				     struct device *dev,
+				     struct class_device *cdev)
 {
 	struct scsi_target *starget = to_scsi_target(dev);
  
@@ -11,10 +11,12 @@
  
 #include <linux/device.h>
 #include <linux/list.h>
+#include <linux/spinlock.h>
  
 struct attribute_container {
 	struct list_head	node;
 	struct list_head	containers;
+	spinlock_t		containers_lock;
 	struct class		*class;
 	struct class_device_attribute **attrs;
 	int (*match)(struct attribute_container *, struct device *);
@@ -62,12 +64,7 @@
 						 struct class_device *classdev);
 void attribute_container_remove_attrs(struct class_device *classdev);
 void attribute_container_class_device_del(struct class_device *classdev);
-
-
-
-
-
-
+struct class_device *attribute_container_find_class_device(struct attribute_container *, struct device *);
 struct class_device_attribute **attribute_container_classdev_to_attrs(const struct class_device *classdev);
  
 #endif
@@ -12,11 +12,16 @@
 #include <linux/device.h>
 #include <linux/attribute_container.h>
  
+struct transport_container;
+
 struct transport_class {
 	struct class class;
-	int (*setup)(struct device *);
-	int (*configure)(struct device *);
-	int (*remove)(struct device *);
+	int (*setup)(struct transport_container *, struct device *,
+		     struct class_device *);
+	int (*configure)(struct transport_container *, struct device *,
+			 struct class_device *);
+	int (*remove)(struct transport_container *, struct device *,
+		      struct class_device *);
 };
  
 #define DECLARE_TRANSPORT_CLASS(cls, nm, su, rm, cfg)			\
...	...	@@ -58,6 +58,7 @@
58	58	{
59	59	INIT_LIST_HEAD(&cont->node);
60	60	INIT_LIST_HEAD(&cont->containers);
	61	+ spin_lock_init(&cont->containers_lock);
61	62
62	63	down(&attribute_container_mutex);
63	64	list_add_tail(&cont->node, &attribute_container_list);
64	65
...	...	@@ -77,11 +78,13 @@
77	78	{
78	79	int retval = -EBUSY;
79	80	down(&attribute_container_mutex);
	81	+ spin_lock(&cont->containers_lock);
80	82	if (!list_empty(&cont->containers))
81	83	goto out;
82	84	retval = 0;
83	85	list_del(&cont->node);
84	86	out:
	87	+ spin_unlock(&cont->containers_lock);
85	88	up(&attribute_container_mutex);
86	89	return retval;
87	90
88	91
...	...	@@ -151,7 +154,9 @@
151	154	fn(cont, dev, &ic->classdev);
152	155	else
153	156	attribute_container_add_class_device(&ic->classdev);
	157	+ spin_lock(&cont->containers_lock);
154	158	list_add_tail(&ic->node, &cont->containers);
	159	+ spin_unlock(&cont->containers_lock);
155	160	}
156	161	up(&attribute_container_mutex);
157	162	}
...	...	@@ -189,6 +194,7 @@
189	194
190	195	if (!cont->match(cont, dev))
191	196	continue;
	197	+ spin_lock(&cont->containers_lock);
192	198	list_for_each_entry_safe(ic, tmp, &cont->containers, node) {
193	199	if (dev != ic->classdev.dev)
194	200	continue;
...	...	@@ -200,6 +206,7 @@
200	206	class_device_unregister(&ic->classdev);
201	207	}
202	208	}
	209	+ spin_unlock(&cont->containers_lock);
203	210	}
204	211	up(&attribute_container_mutex);
205	212	}
206	213
...	...	@@ -230,10 +237,12 @@
230	237	if (!cont->match(cont, dev))
231	238	continue;
232	239
	240	+ spin_lock(&cont->containers_lock);
233	241	list_for_each_entry_safe(ic, tmp, &cont->containers, node) {
234	242	if (dev == ic->classdev.dev)
235	243	fn(cont, dev, &ic->classdev);
236	244	}
	245	+ spin_unlock(&cont->containers_lock);
237	246	}
238	247	up(&attribute_container_mutex);
239	248	}
...	...	@@ -367,6 +376,35 @@
367	376	class_device_del(classdev);
368	377	}
369	378	EXPORT_SYMBOL_GPL(attribute_container_class_device_del);
	379	+
	380	+/**
	381	+ * attribute_container_find_class_device - find the corresponding class_device
	382	+ *
	383	+ * @cont: the container
	384	+ * @dev: the generic device
	385	+ *
	386	+ * Looks up the device in the container's list of class devices and returns
	387	+ * the corresponding class_device.
	388	+ */
	389	+struct class_device *
	390	+attribute_container_find_class_device(struct attribute_container *cont,
	391	+ struct device *dev)
	392	+{
	393	+ struct class_device *cdev = NULL;
	394	+ struct internal_container *ic;
	395	+
	396	+ spin_lock(&cont->containers_lock);
	397	+ list_for_each_entry(ic, &cont->containers, node) {
	398	+ if (ic->classdev.dev == dev) {
	399	+ cdev = &ic->classdev;
	400	+ break;
	401	+ }
	402	+ }
	403	+ spin_unlock(&cont->containers_lock);
	404	+
	405	+ return cdev;
	406	+}
	407	+EXPORT_SYMBOL_GPL(attribute_container_find_class_device);
370	408
371	409	int __init
372	410	attribute_container_init(void)
...	...	@@ -64,7 +64,9 @@
64	64	}
65	65	EXPORT_SYMBOL_GPL(transport_class_unregister);
66	66
67		-static int anon_transport_dummy_function(struct device *dev)
	67	+static int anon_transport_dummy_function(struct transport_container *tc,
	68	+ struct device *dev,
	69	+ struct class_device *cdev)
68	70	{
69	71	/* do nothing */
70	72	return 0;
71	73
...	...	@@ -115,9 +117,10 @@
115	117	struct class_device *classdev)
116	118	{
117	119	struct transport_class *tclass = class_to_transport_class(cont->class);
	120	+ struct transport_container *tcont = attribute_container_to_transport_container(cont);
118	121
119	122	if (tclass->setup)
120		- tclass->setup(dev);
	123	+ tclass->setup(tcont, dev, classdev);
121	124
122	125	return 0;
123	126	}
124	127
125	128
...	...	@@ -178,12 +181,14 @@
178	181	EXPORT_SYMBOL_GPL(transport_add_device);
179	182
180	183	static int transport_configure(struct attribute_container *cont,
181		- struct device *dev)
	184	+ struct device *dev,
	185	+ struct class_device *cdev)
182	186	{
183	187	struct transport_class *tclass = class_to_transport_class(cont->class);
	188	+ struct transport_container *tcont = attribute_container_to_transport_container(cont);
184	189
185	190	if (tclass->configure)
186		- tclass->configure(dev);
	191	+ tclass->configure(tcont, dev, cdev);
187	192
188	193	return 0;
189	194	}
...	...	@@ -202,7 +207,7 @@
202	207	*/
203	208	void transport_configure_device(struct device *dev)
204	209	{
205		- attribute_container_trigger(dev, transport_configure);
	210	+ attribute_container_device_trigger(dev, transport_configure);
206	211	}
207	212	EXPORT_SYMBOL_GPL(transport_configure_device);
208	213
...	...	@@ -215,7 +220,7 @@
215	220	struct transport_class *tclass = class_to_transport_class(cont->class);
216	221
217	222	if (tclass->remove)
218		- tclass->remove(dev);
	223	+ tclass->remove(tcont, dev, classdev);
219	224
220	225	if (tclass->remove != anon_transport_dummy_function) {
221	226	if (tcont->statistics)
...	...	@@ -252,7 +252,8 @@
252	252
253	253	#define to_fc_internal(tmpl) container_of(tmpl, struct fc_internal, t)
254	254
255		-static int fc_target_setup(struct device *dev)
	255	+static int fc_target_setup(struct transport_container tc, struct device dev,
	256	+ struct class_device *cdev)
256	257	{
257	258	struct scsi_target *starget = to_scsi_target(dev);
258	259	struct fc_rport *rport = starget_to_rport(starget);
...	...	@@ -281,7 +282,8 @@
281	282	NULL,
282	283	NULL);
283	284
284		-static int fc_host_setup(struct device *dev)
	285	+static int fc_host_setup(struct transport_container tc, struct device dev,
	286	+ struct class_device *cdev)
285	287	{
286	288	struct Scsi_Host *shost = dev_to_shost(dev);
287	289
...	...	@@ -162,7 +162,8 @@
162	162	return SPI_SIGNAL_UNKNOWN;
163	163	}
164	164
165		-static int spi_host_setup(struct device *dev)
	165	+static int spi_host_setup(struct transport_container tc, struct device dev,
	166	+ struct class_device *cdev)
166	167	{
167	168	struct Scsi_Host *shost = dev_to_shost(dev);
168	169
...	...	@@ -196,7 +197,9 @@
196	197	return &i->t.host_attrs.ac == cont;
197	198	}
198	199
199		-static int spi_device_configure(struct device *dev)
	200	+static int spi_device_configure(struct transport_container *tc,
	201	+ struct device *dev,
	202	+ struct class_device *cdev)
200	203	{
201	204	struct scsi_device *sdev = to_scsi_device(dev);
202	205	struct scsi_target *starget = sdev->sdev_target;
...	...	@@ -214,7 +217,9 @@
214	217	return 0;
215	218	}
216	219
217		-static int spi_setup_transport_attrs(struct device *dev)
	220	+static int spi_setup_transport_attrs(struct transport_container *tc,
	221	+ struct device *dev,
	222	+ struct class_device *cdev)
218	223	{
219	224	struct scsi_target *starget = to_scsi_target(dev);
220	225
...	...	@@ -11,10 +11,12 @@
11	11
12	12	#include <linux/device.h>
13	13	#include <linux/list.h>
	14	+#include <linux/spinlock.h>
14	15
15	16	struct attribute_container {
16	17	struct list_head node;
17	18	struct list_head containers;
	19	+ spinlock_t containers_lock;
18	20	struct class *class;
19	21	struct class_device_attribute **attrs;
20	22	int (match)(struct attribute_container , struct device *);
...	...	@@ -62,12 +64,7 @@
62	64	struct class_device *classdev);
63	65	void attribute_container_remove_attrs(struct class_device *classdev);
64	66	void attribute_container_class_device_del(struct class_device *classdev);
65		-
66		-
67		-
68		-
69		-
70		-
	67	+struct class_device attribute_container_find_class_device(struct attribute_container , struct device *);
71	68	struct class_device_attribute *attribute_container_classdev_to_attrs(const struct class_device classdev);
72	69
73	70	#endif
...	...	@@ -12,11 +12,16 @@
12	12	#include <linux/device.h>
13	13	#include <linux/attribute_container.h>
14	14
	15	+struct transport_container;
	16	+
15	17	struct transport_class {
16	18	struct class class;
17		- int (setup)(struct device );
18		- int (configure)(struct device );
19		- int (remove)(struct device );
	19	+ int (setup)(struct transport_container , struct device *,
	20	+ struct class_device *);
	21	+ int (configure)(struct transport_container , struct device *,
	22	+ struct class_device *);
	23	+ int (remove)(struct transport_container , struct device *,
	24	+ struct class_device *);
20	25	};
21	26
22	27	#define DECLARE_TRANSPORT_CLASS(cls, nm, su, rm, cfg) \