[PATCH] elevator_t lifetime rules and sysfs fixes

Al Viro
1 parent 1cc9be68eb
Showing 5 changed files with 160 additions and 202 deletions Side-by-side Diff
block/as-iosched.c
block/cfq-iosched.c
block/deadline-iosched.c
block/elevator.c
include/linux/elevator.h
@@ -1709,11 +1709,6 @@
 /*
  * sysfs parts below
  */
-struct as_fs_entry {
-	struct attribute attr;
-	ssize_t (*show)(struct as_data *, char *);
-	ssize_t (*store)(struct as_data *, const char *, size_t);
-};
  
 static ssize_t
 as_var_show(unsigned int var, char *page)
  
@@ -1730,8 +1725,9 @@
 	return count;
 }
  
-static ssize_t as_est_show(struct as_data *ad, char *page)
+static ssize_t as_est_show(elevator_t *e, char *page)
 {
+	struct as_data *ad = e->elevator_data;
 	int pos = 0;
  
 	pos += sprintf(page+pos, "%lu %% exit probability\n",
  
@@ -1747,8 +1743,9 @@
 }
  
 #define SHOW_FUNCTION(__FUNC, __VAR)				\
-static ssize_t __FUNC(struct as_data *ad, char *page)		\
+static ssize_t __FUNC(elevator_t *e, char *page)		\
 {								\
+	struct as_data *ad = e->elevator_data;			\
 	return as_var_show(jiffies_to_msecs((__VAR)), (page));	\
 }
 SHOW_FUNCTION(as_readexpire_show, ad->fifo_expire[REQ_SYNC]);
  
@@ -1759,9 +1756,10 @@
 #undef SHOW_FUNCTION
  
 #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX)				\
-static ssize_t __FUNC(struct as_data *ad, const char *page, size_t count)	\
+static ssize_t __FUNC(elevator_t *e, const char *page, size_t count)	\
 {									\
-	int ret = as_var_store(__PTR, (page), count);		\
+	struct as_data *ad = e->elevator_data;				\
+	int ret = as_var_store(__PTR, (page), count);			\
 	if (*(__PTR) < (MIN))						\
 		*(__PTR) = (MIN);					\
 	else if (*(__PTR) > (MAX))					\
  
  
  
  
  
  
@@ -1778,37 +1776,37 @@
 			&ad->batch_expire[REQ_ASYNC], 0, INT_MAX);
 #undef STORE_FUNCTION
  
-static struct as_fs_entry as_est_entry = {
+static struct elv_fs_entry as_est_entry = {
 	.attr = {.name = "est_time", .mode = S_IRUGO },
 	.show = as_est_show,
 };
-static struct as_fs_entry as_readexpire_entry = {
+static struct elv_fs_entry as_readexpire_entry = {
 	.attr = {.name = "read_expire", .mode = S_IRUGO | S_IWUSR },
 	.show = as_readexpire_show,
 	.store = as_readexpire_store,
 };
-static struct as_fs_entry as_writeexpire_entry = {
+static struct elv_fs_entry as_writeexpire_entry = {
 	.attr = {.name = "write_expire", .mode = S_IRUGO | S_IWUSR },
 	.show = as_writeexpire_show,
 	.store = as_writeexpire_store,
 };
-static struct as_fs_entry as_anticexpire_entry = {
+static struct elv_fs_entry as_anticexpire_entry = {
 	.attr = {.name = "antic_expire", .mode = S_IRUGO | S_IWUSR },
 	.show = as_anticexpire_show,
 	.store = as_anticexpire_store,
 };
-static struct as_fs_entry as_read_batchexpire_entry = {
+static struct elv_fs_entry as_read_batchexpire_entry = {
 	.attr = {.name = "read_batch_expire", .mode = S_IRUGO | S_IWUSR },
 	.show = as_read_batchexpire_show,
 	.store = as_read_batchexpire_store,
 };
-static struct as_fs_entry as_write_batchexpire_entry = {
+static struct elv_fs_entry as_write_batchexpire_entry = {
 	.attr = {.name = "write_batch_expire", .mode = S_IRUGO | S_IWUSR },
 	.show = as_write_batchexpire_show,
 	.store = as_write_batchexpire_store,
 };
  
-static struct attribute *default_attrs[] = {
+static struct attribute *as_attrs[] = {
 	&as_est_entry.attr,
 	&as_readexpire_entry.attr,
 	&as_writeexpire_entry.attr,
@@ -1818,43 +1816,6 @@
 	NULL,
 };
  
-#define to_as(atr) container_of((atr), struct as_fs_entry, attr)
-
-static ssize_t
-as_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
-{
-	elevator_t *e = container_of(kobj, elevator_t, kobj);
-	struct as_fs_entry *entry = to_as(attr);
-
-	if (!entry->show)
-		return -EIO;
-
-	return entry->show(e->elevator_data, page);
-}
-
-static ssize_t
-as_attr_store(struct kobject *kobj, struct attribute *attr,
-		    const char *page, size_t length)
-{
-	elevator_t *e = container_of(kobj, elevator_t, kobj);
-	struct as_fs_entry *entry = to_as(attr);
-
-	if (!entry->store)
-		return -EIO;
-
-	return entry->store(e->elevator_data, page, length);
-}
-
-static struct sysfs_ops as_sysfs_ops = {
-	.show	= as_attr_show,
-	.store	= as_attr_store,
-};
-
-static struct kobj_type as_ktype = {
-	.sysfs_ops	= &as_sysfs_ops,
-	.default_attrs	= default_attrs,
-};
-
 static struct elevator_type iosched_as = {
 	.ops = {
 		.elevator_merge_fn = 		as_merge,
@@ -1876,7 +1837,7 @@
 		.trim =				as_trim,
 	},
  
-	.elevator_ktype = &as_ktype,
+	.elevator_attrs = as_attrs,
 	.elevator_name = "anticipatory",
 	.elevator_owner = THIS_MODULE,
 };
@@ -2275,11 +2275,6 @@
 /*
  * sysfs parts below -->
  */
-struct cfq_fs_entry {
-	struct attribute attr;
-	ssize_t (*show)(struct cfq_data *, char *);
-	ssize_t (*store)(struct cfq_data *, const char *, size_t);
-};
  
 static ssize_t
 cfq_var_show(unsigned int var, char *page)
  
@@ -2297,8 +2292,9 @@
 }
  
 #define SHOW_FUNCTION(__FUNC, __VAR, __CONV)				\
-static ssize_t __FUNC(struct cfq_data *cfqd, char *page)		\
+static ssize_t __FUNC(elevator_t *e, char *page)			\
 {									\
+	struct cfq_data *cfqd = e->elevator_data;			\
 	unsigned int __data = __VAR;					\
 	if (__CONV)							\
 		__data = jiffies_to_msecs(__data);			\
  
@@ -2318,8 +2314,9 @@
 #undef SHOW_FUNCTION
  
 #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV)			\
-static ssize_t __FUNC(struct cfq_data *cfqd, const char *page, size_t count)	\
+static ssize_t __FUNC(elevator_t *e, const char *page, size_t count)	\
 {									\
+	struct cfq_data *cfqd = e->elevator_data;			\
 	unsigned int __data;						\
 	int ret = cfq_var_store(&__data, (page), count);		\
 	if (__data < (MIN))						\
  
  
  
  
  
  
  
  
  
  
  
@@ -2345,63 +2342,63 @@
 STORE_FUNCTION(cfq_max_depth_store, &cfqd->cfq_max_depth, 1, UINT_MAX, 0);
 #undef STORE_FUNCTION
  
-static struct cfq_fs_entry cfq_quantum_entry = {
+static struct elv_fs_entry cfq_quantum_entry = {
 	.attr = {.name = "quantum", .mode = S_IRUGO | S_IWUSR },
 	.show = cfq_quantum_show,
 	.store = cfq_quantum_store,
 };
-static struct cfq_fs_entry cfq_queued_entry = {
+static struct elv_fs_entry cfq_queued_entry = {
 	.attr = {.name = "queued", .mode = S_IRUGO | S_IWUSR },
 	.show = cfq_queued_show,
 	.store = cfq_queued_store,
 };
-static struct cfq_fs_entry cfq_fifo_expire_sync_entry = {
+static struct elv_fs_entry cfq_fifo_expire_sync_entry = {
 	.attr = {.name = "fifo_expire_sync", .mode = S_IRUGO | S_IWUSR },
 	.show = cfq_fifo_expire_sync_show,
 	.store = cfq_fifo_expire_sync_store,
 };
-static struct cfq_fs_entry cfq_fifo_expire_async_entry = {
+static struct elv_fs_entry cfq_fifo_expire_async_entry = {
 	.attr = {.name = "fifo_expire_async", .mode = S_IRUGO | S_IWUSR },
 	.show = cfq_fifo_expire_async_show,
 	.store = cfq_fifo_expire_async_store,
 };
-static struct cfq_fs_entry cfq_back_max_entry = {
+static struct elv_fs_entry cfq_back_max_entry = {
 	.attr = {.name = "back_seek_max", .mode = S_IRUGO | S_IWUSR },
 	.show = cfq_back_max_show,
 	.store = cfq_back_max_store,
 };
-static struct cfq_fs_entry cfq_back_penalty_entry = {
+static struct elv_fs_entry cfq_back_penalty_entry = {
 	.attr = {.name = "back_seek_penalty", .mode = S_IRUGO | S_IWUSR },
 	.show = cfq_back_penalty_show,
 	.store = cfq_back_penalty_store,
 };
-static struct cfq_fs_entry cfq_slice_sync_entry = {
+static struct elv_fs_entry cfq_slice_sync_entry = {
 	.attr = {.name = "slice_sync", .mode = S_IRUGO | S_IWUSR },
 	.show = cfq_slice_sync_show,
 	.store = cfq_slice_sync_store,
 };
-static struct cfq_fs_entry cfq_slice_async_entry = {
+static struct elv_fs_entry cfq_slice_async_entry = {
 	.attr = {.name = "slice_async", .mode = S_IRUGO | S_IWUSR },
 	.show = cfq_slice_async_show,
 	.store = cfq_slice_async_store,
 };
-static struct cfq_fs_entry cfq_slice_async_rq_entry = {
+static struct elv_fs_entry cfq_slice_async_rq_entry = {
 	.attr = {.name = "slice_async_rq", .mode = S_IRUGO | S_IWUSR },
 	.show = cfq_slice_async_rq_show,
 	.store = cfq_slice_async_rq_store,
 };
-static struct cfq_fs_entry cfq_slice_idle_entry = {
+static struct elv_fs_entry cfq_slice_idle_entry = {
 	.attr = {.name = "slice_idle", .mode = S_IRUGO | S_IWUSR },
 	.show = cfq_slice_idle_show,
 	.store = cfq_slice_idle_store,
 };
-static struct cfq_fs_entry cfq_max_depth_entry = {
+static struct elv_fs_entry cfq_max_depth_entry = {
 	.attr = {.name = "max_depth", .mode = S_IRUGO | S_IWUSR },
 	.show = cfq_max_depth_show,
 	.store = cfq_max_depth_store,
 };
  
-static struct attribute *default_attrs[] = {
+static struct attribute *cfq_attrs[] = {
 	&cfq_quantum_entry.attr,
 	&cfq_queued_entry.attr,
 	&cfq_fifo_expire_sync_entry.attr,
@@ -2416,43 +2413,6 @@
 	NULL,
 };
  
-#define to_cfq(atr) container_of((atr), struct cfq_fs_entry, attr)
-
-static ssize_t
-cfq_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
-{
-	elevator_t *e = container_of(kobj, elevator_t, kobj);
-	struct cfq_fs_entry *entry = to_cfq(attr);
-
-	if (!entry->show)
-		return -EIO;
-
-	return entry->show(e->elevator_data, page);
-}
-
-static ssize_t
-cfq_attr_store(struct kobject *kobj, struct attribute *attr,
-	       const char *page, size_t length)
-{
-	elevator_t *e = container_of(kobj, elevator_t, kobj);
-	struct cfq_fs_entry *entry = to_cfq(attr);
-
-	if (!entry->store)
-		return -EIO;
-
-	return entry->store(e->elevator_data, page, length);
-}
-
-static struct sysfs_ops cfq_sysfs_ops = {
-	.show	= cfq_attr_show,
-	.store	= cfq_attr_store,
-};
-
-static struct kobj_type cfq_ktype = {
-	.sysfs_ops	= &cfq_sysfs_ops,
-	.default_attrs	= default_attrs,
-};
-
 static struct elevator_type iosched_cfq = {
 	.ops = {
 		.elevator_merge_fn = 		cfq_merge,
@@ -2473,7 +2433,7 @@
 		.elevator_exit_fn =		cfq_exit_queue,
 		.trim =				cfq_trim,
 	},
-	.elevator_ktype =	&cfq_ktype,
+	.elevator_attrs =	cfq_attrs,
 	.elevator_name =	"cfq",
 	.elevator_owner =	THIS_MODULE,
 };
@@ -694,11 +694,6 @@
 /*
  * sysfs parts below
  */
-struct deadline_fs_entry {
-	struct attribute attr;
-	ssize_t (*show)(struct deadline_data *, char *);
-	ssize_t (*store)(struct deadline_data *, const char *, size_t);
-};
  
 static ssize_t
 deadline_var_show(int var, char *page)
  
@@ -716,9 +711,10 @@
 }
  
 #define SHOW_FUNCTION(__FUNC, __VAR, __CONV)				\
-static ssize_t __FUNC(struct deadline_data *dd, char *page)		\
+static ssize_t __FUNC(elevator_t *e, char *page)			\
 {									\
-	int __data = __VAR;					\
+	struct deadline_data *dd = e->elevator_data;			\
+	int __data = __VAR;						\
 	if (__CONV)							\
 		__data = jiffies_to_msecs(__data);			\
 	return deadline_var_show(__data, (page));			\
  
@@ -731,8 +727,9 @@
 #undef SHOW_FUNCTION
  
 #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV)			\
-static ssize_t __FUNC(struct deadline_data *dd, const char *page, size_t count)	\
+static ssize_t __FUNC(elevator_t *e, const char *page, size_t count)	\
 {									\
+	struct deadline_data *dd = e->elevator_data;			\
 	int __data;							\
 	int ret = deadline_var_store(&__data, (page), count);		\
 	if (__data < (MIN))						\
  
  
  
  
  
@@ -752,33 +749,33 @@
 STORE_FUNCTION(deadline_fifobatch_store, &dd->fifo_batch, 0, INT_MAX, 0);
 #undef STORE_FUNCTION
  
-static struct deadline_fs_entry deadline_readexpire_entry = {
+static struct elv_fs_entry deadline_readexpire_entry = {
 	.attr = {.name = "read_expire", .mode = S_IRUGO | S_IWUSR },
 	.show = deadline_readexpire_show,
 	.store = deadline_readexpire_store,
 };
-static struct deadline_fs_entry deadline_writeexpire_entry = {
+static struct elv_fs_entry deadline_writeexpire_entry = {
 	.attr = {.name = "write_expire", .mode = S_IRUGO | S_IWUSR },
 	.show = deadline_writeexpire_show,
 	.store = deadline_writeexpire_store,
 };
-static struct deadline_fs_entry deadline_writesstarved_entry = {
+static struct elv_fs_entry deadline_writesstarved_entry = {
 	.attr = {.name = "writes_starved", .mode = S_IRUGO | S_IWUSR },
 	.show = deadline_writesstarved_show,
 	.store = deadline_writesstarved_store,
 };
-static struct deadline_fs_entry deadline_frontmerges_entry = {
+static struct elv_fs_entry deadline_frontmerges_entry = {
 	.attr = {.name = "front_merges", .mode = S_IRUGO | S_IWUSR },
 	.show = deadline_frontmerges_show,
 	.store = deadline_frontmerges_store,
 };
-static struct deadline_fs_entry deadline_fifobatch_entry = {
+static struct elv_fs_entry deadline_fifobatch_entry = {
 	.attr = {.name = "fifo_batch", .mode = S_IRUGO | S_IWUSR },
 	.show = deadline_fifobatch_show,
 	.store = deadline_fifobatch_store,
 };
  
-static struct attribute *default_attrs[] = {
+static struct attribute *deadline_attrs[] = {
 	&deadline_readexpire_entry.attr,
 	&deadline_writeexpire_entry.attr,
 	&deadline_writesstarved_entry.attr,
@@ -787,43 +784,6 @@
 	NULL,
 };
  
-#define to_deadline(atr) container_of((atr), struct deadline_fs_entry, attr)
-
-static ssize_t
-deadline_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
-{
-	elevator_t *e = container_of(kobj, elevator_t, kobj);
-	struct deadline_fs_entry *entry = to_deadline(attr);
-
-	if (!entry->show)
-		return -EIO;
-
-	return entry->show(e->elevator_data, page);
-}
-
-static ssize_t
-deadline_attr_store(struct kobject *kobj, struct attribute *attr,
-		    const char *page, size_t length)
-{
-	elevator_t *e = container_of(kobj, elevator_t, kobj);
-	struct deadline_fs_entry *entry = to_deadline(attr);
-
-	if (!entry->store)
-		return -EIO;
-
-	return entry->store(e->elevator_data, page, length);
-}
-
-static struct sysfs_ops deadline_sysfs_ops = {
-	.show	= deadline_attr_show,
-	.store	= deadline_attr_store,
-};
-
-static struct kobj_type deadline_ktype = {
-	.sysfs_ops	= &deadline_sysfs_ops,
-	.default_attrs	= default_attrs,
-};
-
 static struct elevator_type iosched_deadline = {
 	.ops = {
 		.elevator_merge_fn = 		deadline_merge,
@@ -840,7 +800,7 @@
 		.elevator_exit_fn =		deadline_exit_queue,
 	},
  
-	.elevator_ktype = &deadline_ktype,
+	.elevator_attrs = deadline_attrs,
 	.elevator_name = "deadline",
 	.elevator_owner = THIS_MODULE,
 };
@@ -120,15 +120,10 @@
 	return e;
 }
  
-static int elevator_attach(request_queue_t *q, struct elevator_type *e,
-			   struct elevator_queue *eq)
+static int elevator_attach(request_queue_t *q, struct elevator_queue *eq)
 {
 	int ret = 0;
  
-	memset(eq, 0, sizeof(*eq));
-	eq->ops = &e->ops;
-	eq->elevator_type = e;
-
 	q->elevator = eq;
  
 	if (eq->ops->elevator_init_fn)
@@ -154,6 +149,32 @@
  
 __setup("elevator=", elevator_setup);
  
+static struct kobj_type elv_ktype;
+
+static elevator_t *elevator_alloc(struct elevator_type *e)
+{
+	elevator_t *eq = kmalloc(sizeof(elevator_t), GFP_KERNEL);
+	if (eq) {
+		memset(eq, 0, sizeof(*eq));
+		eq->ops = &e->ops;
+		eq->elevator_type = e;
+		kobject_init(&eq->kobj);
+		snprintf(eq->kobj.name, KOBJ_NAME_LEN, "%s", "iosched");
+		eq->kobj.ktype = &elv_ktype;
+		mutex_init(&eq->sysfs_lock);
+	} else {
+		elevator_put(e);
+	}
+	return eq;
+}
+
+static void elevator_release(struct kobject *kobj)
+{
+	elevator_t *e = container_of(kobj, elevator_t, kobj);
+	elevator_put(e->elevator_type);
+	kfree(e);
+}
+
 int elevator_init(request_queue_t *q, char *name)
 {
 	struct elevator_type *e = NULL;
  
  
  
  
  
@@ -176,29 +197,26 @@
 		e = elevator_get("noop");
 	}
  
-	eq = kmalloc(sizeof(struct elevator_queue), GFP_KERNEL);
-	if (!eq) {
-		elevator_put(e);
+	eq = elevator_alloc(e);
+	if (!eq)
 		return -ENOMEM;
-	}
  
-	ret = elevator_attach(q, e, eq);
-	if (ret) {
-		kfree(eq);
-		elevator_put(e);
-	}
+	ret = elevator_attach(q, eq);
+	if (ret)
+		kobject_put(&eq->kobj);
  
 	return ret;
 }
  
 void elevator_exit(elevator_t *e)
 {
+	mutex_lock(&e->sysfs_lock);
 	if (e->ops->elevator_exit_fn)
 		e->ops->elevator_exit_fn(e);
+	e->ops = NULL;
+	mutex_unlock(&e->sysfs_lock);
  
-	elevator_put(e->elevator_type);
-	e->elevator_type = NULL;
-	kfree(e);
+	kobject_put(&e->kobj);
 }
  
 /*
  
  
  
  
@@ -627,26 +645,78 @@
 	}
 }
  
+#define to_elv(atr) container_of((atr), struct elv_fs_entry, attr)
+
+static ssize_t
+elv_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
+{
+	elevator_t *e = container_of(kobj, elevator_t, kobj);
+	struct elv_fs_entry *entry = to_elv(attr);
+	ssize_t error;
+
+	if (!entry->show)
+		return -EIO;
+
+	mutex_lock(&e->sysfs_lock);
+	error = e->ops ? entry->show(e, page) : -ENOENT;
+	mutex_unlock(&e->sysfs_lock);
+	return error;
+}
+
+static ssize_t
+elv_attr_store(struct kobject *kobj, struct attribute *attr,
+	       const char *page, size_t length)
+{
+	elevator_t *e = container_of(kobj, elevator_t, kobj);
+	struct elv_fs_entry *entry = to_elv(attr);
+	ssize_t error;
+
+	if (!entry->store)
+		return -EIO;
+
+	mutex_lock(&e->sysfs_lock);
+	error = e->ops ? entry->store(e, page, length) : -ENOENT;
+	mutex_unlock(&e->sysfs_lock);
+	return error;
+}
+
+static struct sysfs_ops elv_sysfs_ops = {
+	.show	= elv_attr_show,
+	.store	= elv_attr_store,
+};
+
+static struct kobj_type elv_ktype = {
+	.sysfs_ops	= &elv_sysfs_ops,
+	.release	= elevator_release,
+};
+
 int elv_register_queue(struct request_queue *q)
 {
 	elevator_t *e = q->elevator;
+	int error;
  
-	e->kobj.parent = kobject_get(&q->kobj);
-	if (!e->kobj.parent)
-		return -EBUSY;
+	e->kobj.parent = &q->kobj;
  
-	snprintf(e->kobj.name, KOBJ_NAME_LEN, "%s", "iosched");
-	e->kobj.ktype = e->elevator_type->elevator_ktype;
-
-	return kobject_register(&e->kobj);
+	error = kobject_add(&e->kobj);
+	if (!error) {
+		struct attribute **attr = e->elevator_type->elevator_attrs;
+		if (attr) {
+			while (*attr) {
+				if (sysfs_create_file(&e->kobj,*attr++))
+					break;
+			}
+		}
+		kobject_uevent(&e->kobj, KOBJ_ADD);
+	}
+	return error;
 }
  
 void elv_unregister_queue(struct request_queue *q)
 {
 	if (q) {
 		elevator_t *e = q->elevator;
-		kobject_unregister(&e->kobj);
-		kobject_put(&q->kobj);
+		kobject_uevent(&e->kobj, KOBJ_REMOVE);
+		kobject_del(&e->kobj);
 	}
 }
  
  
  
@@ -697,16 +767,16 @@
  * need for the new one. this way we have a chance of going back to the old
  * one, if the new one fails init for some reason.
  */
-static void elevator_switch(request_queue_t *q, struct elevator_type *new_e)
+static int elevator_switch(request_queue_t *q, struct elevator_type *new_e)
 {
 	elevator_t *old_elevator, *e;
  
 	/*
 	 * Allocate new elevator
 	 */
-	e = kmalloc(sizeof(elevator_t), GFP_KERNEL);
+	e = elevator_alloc(new_e);
 	if (!e)
-		goto error;
+		return 0;
  
 	/*
 	 * Turn on BYPASS and drain all requests w/ elevator private data
@@ -737,7 +807,7 @@
 	/*
 	 * attach and start new elevator
 	 */
-	if (elevator_attach(q, new_e, e))
+	if (elevator_attach(q, e))
 		goto fail;
  
 	if (elv_register_queue(q))
@@ -748,7 +818,7 @@
 	 */
 	elevator_exit(old_elevator);
 	clear_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags);
-	return;
+	return 1;
  
 fail_register:
 	/*
@@ -761,10 +831,9 @@
 	q->elevator = old_elevator;
 	elv_register_queue(q);
 	clear_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags);
-	kfree(e);
-error:
-	elevator_put(new_e);
-	printk(KERN_ERR "elevator: switch to %s failed\n",new_e->elevator_name);
+	if (e)
+		kobject_put(&e->kobj);
+	return 0;
 }
  
 ssize_t elv_iosched_store(request_queue_t *q, const char *name, size_t count)
@@ -791,7 +860,8 @@
 		return count;
 	}
  
-	elevator_switch(q, e);
+	if (!elevator_switch(q, e))
+		printk(KERN_ERR "elevator: switch to %s failed\n",elevator_name);
 	return count;
 }
  
@@ -61,7 +61,7 @@
 	struct list_head list;
 	struct elevator_ops ops;
 	struct elevator_type *elevator_type;
-	struct kobj_type *elevator_ktype;
+	struct attribute **elevator_attrs;
 	char elevator_name[ELV_NAME_MAX];
 	struct module *elevator_owner;
 };
@@ -75,6 +75,7 @@
 	void *elevator_data;
 	struct kobject kobj;
 	struct elevator_type *elevator_type;
+	struct mutex sysfs_lock;
 };
  
 /*
@@ -139,6 +140,12 @@
 	ELV_MQUEUE_MAY,
 	ELV_MQUEUE_NO,
 	ELV_MQUEUE_MUST,
+};
+
+struct elv_fs_entry {
+	struct attribute attr;
+	ssize_t (*show)(elevator_t *, char *);
+	ssize_t (*store)(elevator_t *, const char *, size_t);
 };
  
 #define rq_end_sector(rq)	((rq)->sector + (rq)->nr_sectors)
...	...	@@ -1709,11 +1709,6 @@
1709	1709	/*
1710	1710	* sysfs parts below
1711	1711	*/
1712		-struct as_fs_entry {
1713		- struct attribute attr;
1714		- ssize_t (show)(struct as_data , char *);
1715		- ssize_t (store)(struct as_data , const char *, size_t);
1716		-};
1717	1712
1718	1713	static ssize_t
1719	1714	as_var_show(unsigned int var, char *page)
1720	1715
...	...	@@ -1730,8 +1725,9 @@
1730	1725	return count;
1731	1726	}
1732	1727
1733		-static ssize_t as_est_show(struct as_data ad, char page)
	1728	+static ssize_t as_est_show(elevator_t e, char page)
1734	1729	{
	1730	+ struct as_data *ad = e->elevator_data;
1735	1731	int pos = 0;
1736	1732
1737	1733	pos += sprintf(page+pos, "%lu %% exit probability\n",
1738	1734
...	...	@@ -1747,8 +1743,9 @@
1747	1743	}
1748	1744
1749	1745	#define SHOW_FUNCTION(__FUNC, __VAR) \
1750		-static ssize_t __FUNC(struct as_data ad, char page) \
	1746	+static ssize_t __FUNC(elevator_t e, char page) \
1751	1747	{ \
	1748	+ struct as_data *ad = e->elevator_data; \
1752	1749	return as_var_show(jiffies_to_msecs((__VAR)), (page)); \
1753	1750	}
1754	1751	SHOW_FUNCTION(as_readexpire_show, ad->fifo_expire[REQ_SYNC]);
1755	1752
...	...	@@ -1759,9 +1756,10 @@
1759	1756	#undef SHOW_FUNCTION
1760	1757
1761	1758	#define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX) \
1762		-static ssize_t __FUNC(struct as_data ad, const char page, size_t count) \
	1759	+static ssize_t __FUNC(elevator_t e, const char page, size_t count) \
1763	1760	{ \
1764		- int ret = as_var_store(__PTR, (page), count); \
	1761	+ struct as_data *ad = e->elevator_data; \
	1762	+ int ret = as_var_store(__PTR, (page), count); \
1765	1763	if (*(__PTR) < (MIN)) \
1766	1764	*(__PTR) = (MIN); \
1767	1765	else if (*(__PTR) > (MAX)) \
1768	1766
1769	1767
1770	1768
1771	1769
1772	1770
1773	1771
...	...	@@ -1778,37 +1776,37 @@
1778	1776	&ad->batch_expire[REQ_ASYNC], 0, INT_MAX);
1779	1777	#undef STORE_FUNCTION
1780	1778
1781		-static struct as_fs_entry as_est_entry = {
	1779	+static struct elv_fs_entry as_est_entry = {
1782	1780	.attr = {.name = "est_time", .mode = S_IRUGO },
1783	1781	.show = as_est_show,
1784	1782	};
1785		-static struct as_fs_entry as_readexpire_entry = {
	1783	+static struct elv_fs_entry as_readexpire_entry = {
1786	1784	.attr = {.name = "read_expire", .mode = S_IRUGO \| S_IWUSR },
1787	1785	.show = as_readexpire_show,
1788	1786	.store = as_readexpire_store,
1789	1787	};
1790		-static struct as_fs_entry as_writeexpire_entry = {
	1788	+static struct elv_fs_entry as_writeexpire_entry = {
1791	1789	.attr = {.name = "write_expire", .mode = S_IRUGO \| S_IWUSR },
1792	1790	.show = as_writeexpire_show,
1793	1791	.store = as_writeexpire_store,
1794	1792	};
1795		-static struct as_fs_entry as_anticexpire_entry = {
	1793	+static struct elv_fs_entry as_anticexpire_entry = {
1796	1794	.attr = {.name = "antic_expire", .mode = S_IRUGO \| S_IWUSR },
1797	1795	.show = as_anticexpire_show,
1798	1796	.store = as_anticexpire_store,
1799	1797	};
1800		-static struct as_fs_entry as_read_batchexpire_entry = {
	1798	+static struct elv_fs_entry as_read_batchexpire_entry = {
1801	1799	.attr = {.name = "read_batch_expire", .mode = S_IRUGO \| S_IWUSR },
1802	1800	.show = as_read_batchexpire_show,
1803	1801	.store = as_read_batchexpire_store,
1804	1802	};
1805		-static struct as_fs_entry as_write_batchexpire_entry = {
	1803	+static struct elv_fs_entry as_write_batchexpire_entry = {
1806	1804	.attr = {.name = "write_batch_expire", .mode = S_IRUGO \| S_IWUSR },
1807	1805	.show = as_write_batchexpire_show,
1808	1806	.store = as_write_batchexpire_store,
1809	1807	};
1810	1808
1811		-static struct attribute *default_attrs[] = {
	1809	+static struct attribute *as_attrs[] = {
1812	1810	&as_est_entry.attr,
1813	1811	&as_readexpire_entry.attr,
1814	1812	&as_writeexpire_entry.attr,
...	...	@@ -1818,43 +1816,6 @@
1818	1816	NULL,
1819	1817	};
1820	1818
1821		-#define to_as(atr) container_of((atr), struct as_fs_entry, attr)
1822		-
1823		-static ssize_t
1824		-as_attr_show(struct kobject kobj, struct attribute attr, char *page)
1825		-{
1826		- elevator_t *e = container_of(kobj, elevator_t, kobj);
1827		- struct as_fs_entry *entry = to_as(attr);
1828		-
1829		- if (!entry->show)
1830		- return -EIO;
1831		-
1832		- return entry->show(e->elevator_data, page);
1833		-}
1834		-
1835		-static ssize_t
1836		-as_attr_store(struct kobject kobj, struct attribute attr,
1837		- const char *page, size_t length)
1838		-{
1839		- elevator_t *e = container_of(kobj, elevator_t, kobj);
1840		- struct as_fs_entry *entry = to_as(attr);
1841		-
1842		- if (!entry->store)
1843		- return -EIO;
1844		-
1845		- return entry->store(e->elevator_data, page, length);
1846		-}
1847		-
1848		-static struct sysfs_ops as_sysfs_ops = {
1849		- .show = as_attr_show,
1850		- .store = as_attr_store,
1851		-};
1852		-
1853		-static struct kobj_type as_ktype = {
1854		- .sysfs_ops = &as_sysfs_ops,
1855		- .default_attrs = default_attrs,
1856		-};
1857		-
1858	1819	static struct elevator_type iosched_as = {
1859	1820	.ops = {
1860	1821	.elevator_merge_fn = as_merge,
...	...	@@ -1876,7 +1837,7 @@
1876	1837	.trim = as_trim,
1877	1838	},
1878	1839
1879		- .elevator_ktype = &as_ktype,
	1840	+ .elevator_attrs = as_attrs,
1880	1841	.elevator_name = "anticipatory",
1881	1842	.elevator_owner = THIS_MODULE,
1882	1843	};
...	...	@@ -2275,11 +2275,6 @@
2275	2275	/*
2276	2276	* sysfs parts below -->
2277	2277	*/
2278		-struct cfq_fs_entry {
2279		- struct attribute attr;
2280		- ssize_t (show)(struct cfq_data , char *);
2281		- ssize_t (store)(struct cfq_data , const char *, size_t);
2282		-};
2283	2278
2284	2279	static ssize_t
2285	2280	cfq_var_show(unsigned int var, char *page)
2286	2281
...	...	@@ -2297,8 +2292,9 @@
2297	2292	}
2298	2293
2299	2294	#define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \
2300		-static ssize_t __FUNC(struct cfq_data cfqd, char page) \
	2295	+static ssize_t __FUNC(elevator_t e, char page) \
2301	2296	{ \
	2297	+ struct cfq_data *cfqd = e->elevator_data; \
2302	2298	unsigned int __data = __VAR; \
2303	2299	if (__CONV) \
2304	2300	__data = jiffies_to_msecs(__data); \
2305	2301
...	...	@@ -2318,8 +2314,9 @@
2318	2314	#undef SHOW_FUNCTION
2319	2315
2320	2316	#define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \
2321		-static ssize_t __FUNC(struct cfq_data cfqd, const char page, size_t count) \
	2317	+static ssize_t __FUNC(elevator_t e, const char page, size_t count) \
2322	2318	{ \
	2319	+ struct cfq_data *cfqd = e->elevator_data; \
2323	2320	unsigned int __data; \
2324	2321	int ret = cfq_var_store(&__data, (page), count); \
2325	2322	if (__data < (MIN)) \
2326	2323
2327	2324
2328	2325
2329	2326
2330	2327
2331	2328
2332	2329
2333	2330
2334	2331
2335	2332
2336	2333
...	...	@@ -2345,63 +2342,63 @@
2345	2342	STORE_FUNCTION(cfq_max_depth_store, &cfqd->cfq_max_depth, 1, UINT_MAX, 0);
2346	2343	#undef STORE_FUNCTION
2347	2344
2348		-static struct cfq_fs_entry cfq_quantum_entry = {
	2345	+static struct elv_fs_entry cfq_quantum_entry = {
2349	2346	.attr = {.name = "quantum", .mode = S_IRUGO \| S_IWUSR },
2350	2347	.show = cfq_quantum_show,
2351	2348	.store = cfq_quantum_store,
2352	2349	};
2353		-static struct cfq_fs_entry cfq_queued_entry = {
	2350	+static struct elv_fs_entry cfq_queued_entry = {
2354	2351	.attr = {.name = "queued", .mode = S_IRUGO \| S_IWUSR },
2355	2352	.show = cfq_queued_show,
2356	2353	.store = cfq_queued_store,
2357	2354	};
2358		-static struct cfq_fs_entry cfq_fifo_expire_sync_entry = {
	2355	+static struct elv_fs_entry cfq_fifo_expire_sync_entry = {
2359	2356	.attr = {.name = "fifo_expire_sync", .mode = S_IRUGO \| S_IWUSR },
2360	2357	.show = cfq_fifo_expire_sync_show,
2361	2358	.store = cfq_fifo_expire_sync_store,
2362	2359	};
2363		-static struct cfq_fs_entry cfq_fifo_expire_async_entry = {
	2360	+static struct elv_fs_entry cfq_fifo_expire_async_entry = {
2364	2361	.attr = {.name = "fifo_expire_async", .mode = S_IRUGO \| S_IWUSR },
2365	2362	.show = cfq_fifo_expire_async_show,
2366	2363	.store = cfq_fifo_expire_async_store,
2367	2364	};
2368		-static struct cfq_fs_entry cfq_back_max_entry = {
	2365	+static struct elv_fs_entry cfq_back_max_entry = {
2369	2366	.attr = {.name = "back_seek_max", .mode = S_IRUGO \| S_IWUSR },
2370	2367	.show = cfq_back_max_show,
2371	2368	.store = cfq_back_max_store,
2372	2369	};
2373		-static struct cfq_fs_entry cfq_back_penalty_entry = {
	2370	+static struct elv_fs_entry cfq_back_penalty_entry = {
2374	2371	.attr = {.name = "back_seek_penalty", .mode = S_IRUGO \| S_IWUSR },
2375	2372	.show = cfq_back_penalty_show,
2376	2373	.store = cfq_back_penalty_store,
2377	2374	};
2378		-static struct cfq_fs_entry cfq_slice_sync_entry = {
	2375	+static struct elv_fs_entry cfq_slice_sync_entry = {
2379	2376	.attr = {.name = "slice_sync", .mode = S_IRUGO \| S_IWUSR },
2380	2377	.show = cfq_slice_sync_show,
2381	2378	.store = cfq_slice_sync_store,
2382	2379	};
2383		-static struct cfq_fs_entry cfq_slice_async_entry = {
	2380	+static struct elv_fs_entry cfq_slice_async_entry = {
2384	2381	.attr = {.name = "slice_async", .mode = S_IRUGO \| S_IWUSR },
2385	2382	.show = cfq_slice_async_show,
2386	2383	.store = cfq_slice_async_store,
2387	2384	};
2388		-static struct cfq_fs_entry cfq_slice_async_rq_entry = {
	2385	+static struct elv_fs_entry cfq_slice_async_rq_entry = {
2389	2386	.attr = {.name = "slice_async_rq", .mode = S_IRUGO \| S_IWUSR },
2390	2387	.show = cfq_slice_async_rq_show,
2391	2388	.store = cfq_slice_async_rq_store,
2392	2389	};
2393		-static struct cfq_fs_entry cfq_slice_idle_entry = {
	2390	+static struct elv_fs_entry cfq_slice_idle_entry = {
2394	2391	.attr = {.name = "slice_idle", .mode = S_IRUGO \| S_IWUSR },
2395	2392	.show = cfq_slice_idle_show,
2396	2393	.store = cfq_slice_idle_store,
2397	2394	};
2398		-static struct cfq_fs_entry cfq_max_depth_entry = {
	2395	+static struct elv_fs_entry cfq_max_depth_entry = {
2399	2396	.attr = {.name = "max_depth", .mode = S_IRUGO \| S_IWUSR },
2400	2397	.show = cfq_max_depth_show,
2401	2398	.store = cfq_max_depth_store,
2402	2399	};
2403	2400
2404		-static struct attribute *default_attrs[] = {
	2401	+static struct attribute *cfq_attrs[] = {
2405	2402	&cfq_quantum_entry.attr,
2406	2403	&cfq_queued_entry.attr,
2407	2404	&cfq_fifo_expire_sync_entry.attr,
...	...	@@ -2416,43 +2413,6 @@
2416	2413	NULL,
2417	2414	};
2418	2415
2419		-#define to_cfq(atr) container_of((atr), struct cfq_fs_entry, attr)
2420		-
2421		-static ssize_t
2422		-cfq_attr_show(struct kobject kobj, struct attribute attr, char *page)
2423		-{
2424		- elevator_t *e = container_of(kobj, elevator_t, kobj);
2425		- struct cfq_fs_entry *entry = to_cfq(attr);
2426		-
2427		- if (!entry->show)
2428		- return -EIO;
2429		-
2430		- return entry->show(e->elevator_data, page);
2431		-}
2432		-
2433		-static ssize_t
2434		-cfq_attr_store(struct kobject kobj, struct attribute attr,
2435		- const char *page, size_t length)
2436		-{
2437		- elevator_t *e = container_of(kobj, elevator_t, kobj);
2438		- struct cfq_fs_entry *entry = to_cfq(attr);
2439		-
2440		- if (!entry->store)
2441		- return -EIO;
2442		-
2443		- return entry->store(e->elevator_data, page, length);
2444		-}
2445		-
2446		-static struct sysfs_ops cfq_sysfs_ops = {
2447		- .show = cfq_attr_show,
2448		- .store = cfq_attr_store,
2449		-};
2450		-
2451		-static struct kobj_type cfq_ktype = {
2452		- .sysfs_ops = &cfq_sysfs_ops,
2453		- .default_attrs = default_attrs,
2454		-};
2455		-
2456	2416	static struct elevator_type iosched_cfq = {
2457	2417	.ops = {
2458	2418	.elevator_merge_fn = cfq_merge,
...	...	@@ -2473,7 +2433,7 @@
2473	2433	.elevator_exit_fn = cfq_exit_queue,
2474	2434	.trim = cfq_trim,
2475	2435	},
2476		- .elevator_ktype = &cfq_ktype,
	2436	+ .elevator_attrs = cfq_attrs,
2477	2437	.elevator_name = "cfq",
2478	2438	.elevator_owner = THIS_MODULE,
2479	2439	};
...	...	@@ -694,11 +694,6 @@
694	694	/*
695	695	* sysfs parts below
696	696	*/
697		-struct deadline_fs_entry {
698		- struct attribute attr;
699		- ssize_t (show)(struct deadline_data , char *);
700		- ssize_t (store)(struct deadline_data , const char *, size_t);
701		-};
702	697
703	698	static ssize_t
704	699	deadline_var_show(int var, char *page)
705	700
...	...	@@ -716,9 +711,10 @@
716	711	}
717	712
718	713	#define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \
719		-static ssize_t __FUNC(struct deadline_data dd, char page) \
	714	+static ssize_t __FUNC(elevator_t e, char page) \
720	715	{ \
721		- int __data = __VAR; \
	716	+ struct deadline_data *dd = e->elevator_data; \
	717	+ int __data = __VAR; \
722	718	if (__CONV) \
723	719	__data = jiffies_to_msecs(__data); \
724	720	return deadline_var_show(__data, (page)); \
725	721
...	...	@@ -731,8 +727,9 @@
731	727	#undef SHOW_FUNCTION
732	728
733	729	#define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \
734		-static ssize_t __FUNC(struct deadline_data dd, const char page, size_t count) \
	730	+static ssize_t __FUNC(elevator_t e, const char page, size_t count) \
735	731	{ \
	732	+ struct deadline_data *dd = e->elevator_data; \
736	733	int __data; \
737	734	int ret = deadline_var_store(&__data, (page), count); \
738	735	if (__data < (MIN)) \
739	736
740	737
741	738
742	739
743	740
...	...	@@ -752,33 +749,33 @@
752	749	STORE_FUNCTION(deadline_fifobatch_store, &dd->fifo_batch, 0, INT_MAX, 0);
753	750	#undef STORE_FUNCTION
754	751
755		-static struct deadline_fs_entry deadline_readexpire_entry = {
	752	+static struct elv_fs_entry deadline_readexpire_entry = {
756	753	.attr = {.name = "read_expire", .mode = S_IRUGO \| S_IWUSR },
757	754	.show = deadline_readexpire_show,
758	755	.store = deadline_readexpire_store,
759	756	};
760		-static struct deadline_fs_entry deadline_writeexpire_entry = {
	757	+static struct elv_fs_entry deadline_writeexpire_entry = {
761	758	.attr = {.name = "write_expire", .mode = S_IRUGO \| S_IWUSR },
762	759	.show = deadline_writeexpire_show,
763	760	.store = deadline_writeexpire_store,
764	761	};
765		-static struct deadline_fs_entry deadline_writesstarved_entry = {
	762	+static struct elv_fs_entry deadline_writesstarved_entry = {
766	763	.attr = {.name = "writes_starved", .mode = S_IRUGO \| S_IWUSR },
767	764	.show = deadline_writesstarved_show,
768	765	.store = deadline_writesstarved_store,
769	766	};
770		-static struct deadline_fs_entry deadline_frontmerges_entry = {
	767	+static struct elv_fs_entry deadline_frontmerges_entry = {
771	768	.attr = {.name = "front_merges", .mode = S_IRUGO \| S_IWUSR },
772	769	.show = deadline_frontmerges_show,
773	770	.store = deadline_frontmerges_store,
774	771	};
775		-static struct deadline_fs_entry deadline_fifobatch_entry = {
	772	+static struct elv_fs_entry deadline_fifobatch_entry = {
776	773	.attr = {.name = "fifo_batch", .mode = S_IRUGO \| S_IWUSR },
777	774	.show = deadline_fifobatch_show,
778	775	.store = deadline_fifobatch_store,
779	776	};
780	777
781		-static struct attribute *default_attrs[] = {
	778	+static struct attribute *deadline_attrs[] = {
782	779	&deadline_readexpire_entry.attr,
783	780	&deadline_writeexpire_entry.attr,
784	781	&deadline_writesstarved_entry.attr,
...	...	@@ -787,43 +784,6 @@
787	784	NULL,
788	785	};
789	786
790		-#define to_deadline(atr) container_of((atr), struct deadline_fs_entry, attr)
791		-
792		-static ssize_t
793		-deadline_attr_show(struct kobject kobj, struct attribute attr, char *page)
794		-{
795		- elevator_t *e = container_of(kobj, elevator_t, kobj);
796		- struct deadline_fs_entry *entry = to_deadline(attr);
797		-
798		- if (!entry->show)
799		- return -EIO;
800		-
801		- return entry->show(e->elevator_data, page);
802		-}
803		-
804		-static ssize_t
805		-deadline_attr_store(struct kobject kobj, struct attribute attr,
806		- const char *page, size_t length)
807		-{
808		- elevator_t *e = container_of(kobj, elevator_t, kobj);
809		- struct deadline_fs_entry *entry = to_deadline(attr);
810		-
811		- if (!entry->store)
812		- return -EIO;
813		-
814		- return entry->store(e->elevator_data, page, length);
815		-}
816		-
817		-static struct sysfs_ops deadline_sysfs_ops = {
818		- .show = deadline_attr_show,
819		- .store = deadline_attr_store,
820		-};
821		-
822		-static struct kobj_type deadline_ktype = {
823		- .sysfs_ops = &deadline_sysfs_ops,
824		- .default_attrs = default_attrs,
825		-};
826		-
827	787	static struct elevator_type iosched_deadline = {
828	788	.ops = {
829	789	.elevator_merge_fn = deadline_merge,
...	...	@@ -840,7 +800,7 @@
840	800	.elevator_exit_fn = deadline_exit_queue,
841	801	},
842	802
843		- .elevator_ktype = &deadline_ktype,
	803	+ .elevator_attrs = deadline_attrs,
844	804	.elevator_name = "deadline",
845	805	.elevator_owner = THIS_MODULE,
846	806	};
...	...	@@ -120,15 +120,10 @@
120	120	return e;
121	121	}
122	122
123		-static int elevator_attach(request_queue_t q, struct elevator_type e,
124		- struct elevator_queue *eq)
	123	+static int elevator_attach(request_queue_t q, struct elevator_queue eq)
125	124	{
126	125	int ret = 0;
127	126
128		- memset(eq, 0, sizeof(*eq));
129		- eq->ops = &e->ops;
130		- eq->elevator_type = e;
131		-
132	127	q->elevator = eq;
133	128
134	129	if (eq->ops->elevator_init_fn)
...	...	@@ -154,6 +149,32 @@
154	149
155	150	__setup("elevator=", elevator_setup);
156	151
	152	+static struct kobj_type elv_ktype;
	153	+
	154	+static elevator_t elevator_alloc(struct elevator_type e)
	155	+{
	156	+ elevator_t *eq = kmalloc(sizeof(elevator_t), GFP_KERNEL);
	157	+ if (eq) {
	158	+ memset(eq, 0, sizeof(*eq));
	159	+ eq->ops = &e->ops;
	160	+ eq->elevator_type = e;
	161	+ kobject_init(&eq->kobj);
	162	+ snprintf(eq->kobj.name, KOBJ_NAME_LEN, "%s", "iosched");
	163	+ eq->kobj.ktype = &elv_ktype;
	164	+ mutex_init(&eq->sysfs_lock);
	165	+ } else {
	166	+ elevator_put(e);
	167	+ }
	168	+ return eq;
	169	+}
	170	+
	171	+static void elevator_release(struct kobject *kobj)
	172	+{
	173	+ elevator_t *e = container_of(kobj, elevator_t, kobj);
	174	+ elevator_put(e->elevator_type);
	175	+ kfree(e);
	176	+}
	177	+
157	178	int elevator_init(request_queue_t q, char name)
158	179	{
159	180	struct elevator_type *e = NULL;
160	181
161	182
162	183
163	184
164	185
...	...	@@ -176,29 +197,26 @@
176	197	e = elevator_get("noop");
177	198	}
178	199
179		- eq = kmalloc(sizeof(struct elevator_queue), GFP_KERNEL);
180		- if (!eq) {
181		- elevator_put(e);
	200	+ eq = elevator_alloc(e);
	201	+ if (!eq)
182	202	return -ENOMEM;
183		- }
184	203
185		- ret = elevator_attach(q, e, eq);
186		- if (ret) {
187		- kfree(eq);
188		- elevator_put(e);
189		- }
	204	+ ret = elevator_attach(q, eq);
	205	+ if (ret)
	206	+ kobject_put(&eq->kobj);
190	207
191	208	return ret;
192	209	}
193	210
194	211	void elevator_exit(elevator_t *e)
195	212	{
	213	+ mutex_lock(&e->sysfs_lock);
196	214	if (e->ops->elevator_exit_fn)
197	215	e->ops->elevator_exit_fn(e);
	216	+ e->ops = NULL;
	217	+ mutex_unlock(&e->sysfs_lock);
198	218
199		- elevator_put(e->elevator_type);
200		- e->elevator_type = NULL;
201		- kfree(e);
	219	+ kobject_put(&e->kobj);
202	220	}
203	221
204	222	/*
205	223
206	224
207	225
208	226
...	...	@@ -627,26 +645,78 @@
627	645	}
628	646	}
629	647
	648	+#define to_elv(atr) container_of((atr), struct elv_fs_entry, attr)
	649	+
	650	+static ssize_t
	651	+elv_attr_show(struct kobject kobj, struct attribute attr, char *page)
	652	+{
	653	+ elevator_t *e = container_of(kobj, elevator_t, kobj);
	654	+ struct elv_fs_entry *entry = to_elv(attr);
	655	+ ssize_t error;
	656	+
	657	+ if (!entry->show)
	658	+ return -EIO;
	659	+
	660	+ mutex_lock(&e->sysfs_lock);
	661	+ error = e->ops ? entry->show(e, page) : -ENOENT;
	662	+ mutex_unlock(&e->sysfs_lock);
	663	+ return error;
	664	+}
	665	+
	666	+static ssize_t
	667	+elv_attr_store(struct kobject kobj, struct attribute attr,
	668	+ const char *page, size_t length)
	669	+{
	670	+ elevator_t *e = container_of(kobj, elevator_t, kobj);
	671	+ struct elv_fs_entry *entry = to_elv(attr);
	672	+ ssize_t error;
	673	+
	674	+ if (!entry->store)
	675	+ return -EIO;
	676	+
	677	+ mutex_lock(&e->sysfs_lock);
	678	+ error = e->ops ? entry->store(e, page, length) : -ENOENT;
	679	+ mutex_unlock(&e->sysfs_lock);
	680	+ return error;
	681	+}
	682	+
	683	+static struct sysfs_ops elv_sysfs_ops = {
	684	+ .show = elv_attr_show,
	685	+ .store = elv_attr_store,
	686	+};
	687	+
	688	+static struct kobj_type elv_ktype = {
	689	+ .sysfs_ops = &elv_sysfs_ops,
	690	+ .release = elevator_release,
	691	+};
	692	+
630	693	int elv_register_queue(struct request_queue *q)
631	694	{
632	695	elevator_t *e = q->elevator;
	696	+ int error;
633	697
634		- e->kobj.parent = kobject_get(&q->kobj);
635		- if (!e->kobj.parent)
636		- return -EBUSY;
	698	+ e->kobj.parent = &q->kobj;
637	699
638		- snprintf(e->kobj.name, KOBJ_NAME_LEN, "%s", "iosched");
639		- e->kobj.ktype = e->elevator_type->elevator_ktype;
640		-
641		- return kobject_register(&e->kobj);
	700	+ error = kobject_add(&e->kobj);
	701	+ if (!error) {
	702	+ struct attribute **attr = e->elevator_type->elevator_attrs;
	703	+ if (attr) {
	704	+ while (*attr) {
	705	+ if (sysfs_create_file(&e->kobj,*attr++))
	706	+ break;
	707	+ }
	708	+ }
	709	+ kobject_uevent(&e->kobj, KOBJ_ADD);
	710	+ }
	711	+ return error;
642	712	}
643	713
644	714	void elv_unregister_queue(struct request_queue *q)
645	715	{
646	716	if (q) {
647	717	elevator_t *e = q->elevator;
648		- kobject_unregister(&e->kobj);
649		- kobject_put(&q->kobj);
	718	+ kobject_uevent(&e->kobj, KOBJ_REMOVE);
	719	+ kobject_del(&e->kobj);
650	720	}
651	721	}
652	722
653	723
654	724
...	...	@@ -697,16 +767,16 @@
697	767	* need for the new one. this way we have a chance of going back to the old
698	768	* one, if the new one fails init for some reason.
699	769	*/
700		-static void elevator_switch(request_queue_t q, struct elevator_type new_e)
	770	+static int elevator_switch(request_queue_t q, struct elevator_type new_e)
701	771	{
702	772	elevator_t old_elevator, e;
703	773
704	774	/*
705	775	* Allocate new elevator
706	776	*/
707		- e = kmalloc(sizeof(elevator_t), GFP_KERNEL);
	777	+ e = elevator_alloc(new_e);
708	778	if (!e)
709		- goto error;
	779	+ return 0;
710	780
711	781	/*
712	782	* Turn on BYPASS and drain all requests w/ elevator private data
...	...	@@ -737,7 +807,7 @@
737	807	/*
738	808	* attach and start new elevator
739	809	*/
740		- if (elevator_attach(q, new_e, e))
	810	+ if (elevator_attach(q, e))
741	811	goto fail;
742	812
743	813	if (elv_register_queue(q))
...	...	@@ -748,7 +818,7 @@
748	818	*/
749	819	elevator_exit(old_elevator);
750	820	clear_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags);
751		- return;
	821	+ return 1;
752	822
753	823	fail_register:
754	824	/*
...	...	@@ -761,10 +831,9 @@
761	831	q->elevator = old_elevator;
762	832	elv_register_queue(q);
763	833	clear_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags);
764		- kfree(e);
765		-error:
766		- elevator_put(new_e);
767		- printk(KERN_ERR "elevator: switch to %s failed\n",new_e->elevator_name);
	834	+ if (e)
	835	+ kobject_put(&e->kobj);
	836	+ return 0;
768	837	}
769	838
770	839	ssize_t elv_iosched_store(request_queue_t q, const char name, size_t count)
...	...	@@ -791,7 +860,8 @@
791	860	return count;
792	861	}
793	862
794		- elevator_switch(q, e);
	863	+ if (!elevator_switch(q, e))
	864	+ printk(KERN_ERR "elevator: switch to %s failed\n",elevator_name);
795	865	return count;
796	866	}
797	867
...	...	@@ -61,7 +61,7 @@
61	61	struct list_head list;
62	62	struct elevator_ops ops;
63	63	struct elevator_type *elevator_type;
64		- struct kobj_type *elevator_ktype;
	64	+ struct attribute **elevator_attrs;
65	65	char elevator_name[ELV_NAME_MAX];
66	66	struct module *elevator_owner;
67	67	};
...	...	@@ -75,6 +75,7 @@
75	75	void *elevator_data;
76	76	struct kobject kobj;
77	77	struct elevator_type *elevator_type;
	78	+ struct mutex sysfs_lock;
78	79	};
79	80
80	81	/*
...	...	@@ -139,6 +140,12 @@
139	140	ELV_MQUEUE_MAY,
140	141	ELV_MQUEUE_NO,
141	142	ELV_MQUEUE_MUST,
	143	+};
	144	+
	145	+struct elv_fs_entry {
	146	+ struct attribute attr;
	147	+ ssize_t (show)(elevator_t , char *);
	148	+ ssize_t (store)(elevator_t , const char *, size_t);
142	149	};
143	150
144	151	#define rq_end_sector(rq) ((rq)->sector + (rq)->nr_sectors)