This patch adds device-mapper generic queue feature (dm_queue)
so that targets can use it instead of using its own queuing mechanism.
The patch is for 2.6.18-rc1-mm1.
Regards,
Kiyoshi Ueda
Signed-off-by: Kiyoshi Ueda <k-ueda@xxxxxxxxxxxxx>
Signed-off-by: Jun'ichi Nomura <j-nomura@xxxxxxxxxxxxx>
diff -rupN 2.6.18-rc1-mm1/drivers/md/dm-queue.c 2.6.18-rc1-mm1.dmq/drivers/md/dm-queue.c
--- 2.6.18-rc1-mm1/drivers/md/dm-queue.c 1969-12-31 19:00:00.000000000 -0500
+++ 2.6.18-rc1-mm1.dmq/drivers/md/dm-queue.c 2006-07-10 13:51:38.000000000 -0400
@@ -0,0 +1,168 @@
+/*
+ * Copyright (C) 2006 NEC Corporation
+ *
+ * This file is released under the GPL.
+ */
+
+#include "dm.h"
+#include "dm-bio-list.h"
+
+#include <linux/workqueue.h>
+
+struct workqueue_struct *kdmqd;
+
+struct dm_queue {
+ spinlock_t lock; /* protects .bios and .size */
+ struct bio_list bios;
+ unsigned int size;
+
+ struct dm_target *ti;
+ struct work_struct work;
+};
+
+int dm_queue_init()
+{
+ kdmqd = create_workqueue("dm_queue");
+ if (!kdmqd)
+ return -ENOMEM;
+
+ return 0;
+}
+
+void dm_queue_exit()
+{
+ destroy_workqueue(kdmqd);
+}
+
+struct dm_queue *dm_queue_alloc(int nr)
+{
+ struct dm_queue *qs;
+
+ if (!nr)
+ return NULL;
+
+ qs = kzalloc(sizeof(struct dm_queue) * nr, GFP_KERNEL);
+
+ return qs;
+}
+EXPORT_SYMBOL_GPL(dm_queue_alloc);
+
+void dm_queue_free(struct dm_queue *qs)
+{
+ if (qs)
+ kfree(qs);
+}
+EXPORT_SYMBOL_GPL(dm_queue_free);
+
+void dm_queue_flush(struct dm_queue *q)
+{
+ /*
+ * The work queue is shared by multiple targets and we cannot
+ * flush the specific queue.
+ */
+ flush_workqueue(kdmqd);
+}
+EXPORT_SYMBOL_GPL(dm_queue_flush);
+
+struct dm_queue *dm_queue_find(struct dm_queue *qs, unsigned int index)
+{
+ if (!qs)
+ return NULL;
+
+ return qs + index;
+}
+EXPORT_SYMBOL_GPL(dm_queue_find);
+
+int dm_queue_setup(struct dm_queue *q, void (*work)(void *),
+ struct dm_target *ti)
+{
+ spin_lock_init(&q->lock);
+ bio_list_init(&q->bios);
+ q->size = 0;
+ q->ti = ti;
+ INIT_WORK(&q->work, work, q);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(dm_queue_setup);
+
+int dm_queue_add_bio(struct dm_queue *q, struct bio *bio)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&q->lock, flags);
+ bio_list_add(&q->bios, bio);
+ q->size++;
+ spin_unlock_irqrestore(&q->lock, flags);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(dm_queue_add_bio);
+
+struct bio *dm_queue_pop_bio(struct dm_queue *q)
+{
+ struct bio *bio = NULL;
+ unsigned long flags;
+
+ spin_lock_irqsave(&q->lock, flags);
+
+ bio = bio_list_pop(&q->bios);
+ if (bio)
+ q->size--;
+
+ spin_unlock_irqrestore(&q->lock, flags);
+
+ return bio;
+}
+EXPORT_SYMBOL_GPL(dm_queue_pop_bio);
+
+struct bio *dm_queue_get_bios(struct dm_queue *q)
+{
+ struct bio *bio = NULL;
+ unsigned long flags;
+
+ spin_lock_irqsave(&q->lock, flags);
+
+ bio = bio_list_get(&q->bios);
+ q->size = 0;
+
+ spin_unlock_irqrestore(&q->lock, flags);
+
+ return bio;
+}
+EXPORT_SYMBOL_GPL(dm_queue_get_bios);
+
+unsigned int dm_queue_size(struct dm_queue *q)
+{
+ unsigned int s;
+ unsigned long flags;
+
+ spin_lock_irqsave(&q->lock, flags);
+ s = q->size;
+ spin_unlock_irqrestore(&q->lock, flags);
+
+ return s;
+}
+EXPORT_SYMBOL_GPL(dm_queue_size);
+
+struct dm_target *dm_queue_get_target(struct dm_queue *q)
+{
+ return q->ti;
+}
+EXPORT_SYMBOL_GPL(dm_queue_get_target);
+
+void dm_queue_process(struct dm_queue *q)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&q->lock, flags);
+
+ if (!q->size)
+ goto out;
+
+ queue_work(kdmqd, &q->work);
+
+out:
+ spin_unlock_irqrestore(&q->lock, flags);
+}
+EXPORT_SYMBOL_GPL(dm_queue_process);
diff -rupN 2.6.18-rc1-mm1/include/linux/device-mapper.h 2.6.18-rc1-mm1.dmq/include/linux/device-mapper.h
--- 2.6.18-rc1-mm1/include/linux/device-mapper.h 2006-07-10 09:05:42.000000000 -0400
+++ 2.6.18-rc1-mm1.dmq/include/linux/device-mapper.h 2006-07-10 13:54:31.000000000 -0400
@@ -10,6 +10,7 @@
#ifdef __KERNEL__
+struct dm_queue;
struct dm_target;
struct dm_table;
struct dm_dev;
@@ -131,6 +132,10 @@ struct dm_target {
/* Used to provide an error string from the ctr */
char *error;
+
+ /* Generic queue for target */
+ struct dm_queue *queues;
+ unsigned int num_queues;
};
int dm_register_target(struct target_type *t);
@@ -239,5 +244,54 @@ int dm_swap_table(struct mapped_device *
*/
int dm_create_error_table(struct dm_table **result, struct mapped_device *md);
+
+/*-----------------------------------------------------------------
+ * Functions for manipulating device-mapper queues.
+ *---------------------------------------------------------------*/
+
+/*
+ * First alloc queues.
+ */
+struct dm_queue *dm_queue_alloc(int nr);
+
+/*
+ * Then call this to get a specific queue from the allocated queues.
+ */
+struct dm_queue *dm_queue_find(struct dm_queue *qs, unsigned int index);
+
+/*
+ * Finally call this to make the queue ready for use.
+ */
+int dm_queue_setup(struct dm_queue *q, void (*fn)(void *),
+ struct dm_target *ti);
+
+/*
+ * Free allocated queues.
+ */
+void dm_queue_free(struct dm_queue *qs);
+
+/*
+ * Flush the queue.
+ */
+void dm_queue_flush(struct dm_queue *q);
+
+/*
+ * Manipulations.
+ */
+int dm_queue_add_bio(struct dm_queue *q, struct bio *bio);
+struct bio *dm_queue_pop_bio(struct dm_queue *q);
+struct bio *dm_queue_get_bios(struct dm_queue *q);
+
+/*
+ * Info.
+ */
+unsigned int dm_queue_size(struct dm_queue *q);
+struct dm_target *dm_queue_get_target(struct dm_queue *q);
+
+/*
+ * Start processing a queue.
+ */
+void dm_queue_process(struct dm_queue *q);
+
#endif /* __KERNEL__ */
#endif /* _LINUX_DEVICE_MAPPER_H */
diff -rupN 2.6.18-rc1-mm1/drivers/md/dm.h 2.6.18-rc1-mm1.dmq/drivers/md/dm.h
--- 2.6.18-rc1-mm1/drivers/md/dm.h 2006-07-06 00:09:49.000000000 -0400
+++ 2.6.18-rc1-mm1.dmq/drivers/md/dm.h 2006-07-10 13:42:23.000000000 -0400
@@ -58,6 +58,12 @@ void dm_table_unplug_all(struct dm_table
int dm_table_flush_all(struct dm_table *t);
/*-----------------------------------------------------------------
+ * Queue functions.
+ *---------------------------------------------------------------*/
+int dm_queue_init(void);
+void dm_queue_exit(void);
+
+/*-----------------------------------------------------------------
* A registry of target types.
*---------------------------------------------------------------*/
int dm_target_init(void);
diff -rupN 2.6.18-rc1-mm1/drivers/md/dm.c 2.6.18-rc1-mm1.dmq/drivers/md/dm.c
--- 2.6.18-rc1-mm1/drivers/md/dm.c 2006-07-10 09:05:42.000000000 -0400
+++ 2.6.18-rc1-mm1.dmq/drivers/md/dm.c 2006-07-10 13:40:13.000000000 -0400
@@ -177,6 +177,7 @@ static void local_exit(void)
int (*_inits[])(void) __initdata = {
local_init,
+ dm_queue_init,
dm_target_init,
dm_linear_init,
dm_stripe_init,
@@ -185,6 +186,7 @@ int (*_inits[])(void) __initdata = {
void (*_exits[])(void) = {
local_exit,
+ dm_queue_exit,
dm_target_exit,
dm_linear_exit,
dm_stripe_exit,
diff -rupN 2.6.18-rc1-mm1/drivers/md/Makefile 2.6.18-rc1-mm1.dmq/drivers/md/Makefile
--- 2.6.18-rc1-mm1/drivers/md/Makefile 2006-07-06 00:09:49.000000000 -0400
+++ 2.6.18-rc1-mm1.dmq/drivers/md/Makefile 2006-07-10 13:30:37.000000000 -0400
@@ -3,7 +3,7 @@
#
dm-mod-objs := dm.o dm-table.o dm-target.o dm-linear.o dm-stripe.o \
- dm-ioctl.o dm-io.o kcopyd.o
+ dm-ioctl.o dm-io.o kcopyd.o dm-queue.o
dm-multipath-objs := dm-hw-handler.o dm-path-selector.o dm-mpath.o
dm-snapshot-objs := dm-snap.o dm-exception-store.o
dm-mirror-objs := dm-log.o dm-raid1.o
--
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