1 files changed, 164 insertions, 90 deletions

diff --git a/drivers/md/dm-log.c b/drivers/md/dm-log.c
index 2a74b2142f50..67a6f31b7fc3 100644
--- a/drivers/md/dm-log.c
+++ b/drivers/md/dm-log.c
@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2003 Sistina Software
+ * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
  *
  * This file is released under the LGPL.
  */
@@ -8,64 +9,58 @@
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/vmalloc.h>
+#include <linux/dm-io.h>
+#include <linux/dm-dirty-log.h>
 
-#include "dm-log.h"
-#include "dm-io.h"
+#include "dm.h"
 
-#define DM_MSG_PREFIX "mirror log"
+#define DM_MSG_PREFIX "dirty region log"
 
-static LIST_HEAD(_log_types);
-static DEFINE_SPINLOCK(_lock);
+struct dm_dirty_log_internal {
+	struct dm_dirty_log_type *type;
 
-int dm_register_dirty_log_type(struct dirty_log_type *type)
-{
-	spin_lock(&_lock);
-	type->use_count = 0;
-	list_add(&type->list, &_log_types);
-	spin_unlock(&_lock);
+	struct list_head list;
+	long use;
+};
 
-	return 0;
-}
+static LIST_HEAD(_log_types);
+static DEFINE_SPINLOCK(_lock);
 
-int dm_unregister_dirty_log_type(struct dirty_log_type *type)
+static struct dm_dirty_log_internal *__find_dirty_log_type(const char *name)
 {
-	spin_lock(&_lock);
-
-	if (type->use_count)
-		DMWARN("Attempt to unregister a log type that is still in use");
-	else
-		list_del(&type->list);
+	struct dm_dirty_log_internal *log_type;
 
-	spin_unlock(&_lock);
+	list_for_each_entry(log_type, &_log_types, list)
+		if (!strcmp(name, log_type->type->name))
+			return log_type;
 
-	return 0;
+	return NULL;
 }
 
-static struct dirty_log_type *_get_type(const char *type_name)
+static struct dm_dirty_log_internal *_get_dirty_log_type(const char *name)
 {
-	struct dirty_log_type *type;
+	struct dm_dirty_log_internal *log_type;
 
 	spin_lock(&_lock);
-	list_for_each_entry (type, &_log_types, list)
-		if (!strcmp(type_name, type->name)) {
-			if (!type->use_count && !try_module_get(type->module)){
-				spin_unlock(&_lock);
-				return NULL;
-			}
-			type->use_count++;
-			spin_unlock(&_lock);
-			return type;
-		}
+
+	log_type = __find_dirty_log_type(name);
+	if (log_type) {
+		if (!log_type->use && !try_module_get(log_type->type->module))
+			log_type = NULL;
+		else
+			log_type->use++;
+	}
 
 	spin_unlock(&_lock);
-	return NULL;
+
+	return log_type;
 }
 
 /*
  * get_type
  * @type_name
  *
- * Attempt to retrieve the dirty_log_type by name.  If not already
+ * Attempt to retrieve the dm_dirty_log_type by name.  If not already
  * available, attempt to load the appropriate module.
  *
  * Log modules are named "dm-log-" followed by the 'type_name'.
@@ -78,14 +73,17 @@ static struct dirty_log_type *_get_type(const char *type_name)
  *
  * Returns: dirty_log_type* on success, NULL on failure
  */
-static struct dirty_log_type *get_type(const char *type_name)
+static struct dm_dirty_log_type *get_type(const char *type_name)
 {
 	char *p, *type_name_dup;
-	struct dirty_log_type *type;
+	struct dm_dirty_log_internal *log_type;
+
+	if (!type_name)
+		return NULL;
 
-	type = _get_type(type_name);
-	if (type)
-		return type;
+	log_type = _get_dirty_log_type(type_name);
+	if (log_type)
+		return log_type->type;
 
 	type_name_dup = kstrdup(type_name, GFP_KERNEL);
 	if (!type_name_dup) {
@@ -95,34 +93,106 @@ static struct dirty_log_type *get_type(const char *type_name)
 	}
 
 	while (request_module("dm-log-%s", type_name_dup) ||
-	       !(type = _get_type(type_name))) {
+	       !(log_type = _get_dirty_log_type(type_name))) {
 		p = strrchr(type_name_dup, '-');
 		if (!p)
 			break;
 		p[0] = '\0';
 	}
 
-	if (!type)
+	if (!log_type)
 		DMWARN("Module for logging type \"%s\" not found.", type_name);
 
 	kfree(type_name_dup);
 
-	return type;
+	return log_type ? log_type->type : NULL;
 }
 
-static void put_type(struct dirty_log_type *type)
+static void put_type(struct dm_dirty_log_type *type)
 {
+	struct dm_dirty_log_internal *log_type;
+
+	if (!type)
+		return;
+
 	spin_lock(&_lock);
-	if (!--type->use_count)
+	log_type = __find_dirty_log_type(type->name);
+	if (!log_type)
+		goto out;
+
+	if (!--log_type->use)
 		module_put(type->module);
+
+	BUG_ON(log_type->use < 0);
+
+out:
 	spin_unlock(&_lock);
 }
 
-struct dirty_log *dm_create_dirty_log(const char *type_name, struct dm_target *ti,
-				      unsigned int argc, char **argv)
+static struct dm_dirty_log_internal *_alloc_dirty_log_type(struct dm_dirty_log_type *type)
 {
-	struct dirty_log_type *type;
-	struct dirty_log *log;
+	struct dm_dirty_log_internal *log_type = kzalloc(sizeof(*log_type),
+							 GFP_KERNEL);
+
+	if (log_type)
+		log_type->type = type;
+
+	return log_type;
+}
+
+int dm_dirty_log_type_register(struct dm_dirty_log_type *type)
+{
+	struct dm_dirty_log_internal *log_type = _alloc_dirty_log_type(type);
+	int r = 0;
+
+	if (!log_type)
+		return -ENOMEM;
+
+	spin_lock(&_lock);
+	if (!__find_dirty_log_type(type->name))
+		list_add(&log_type->list, &_log_types);
+	else {
+		kfree(log_type);
+		r = -EEXIST;
+	}
+	spin_unlock(&_lock);
+
+	return r;
+}
+EXPORT_SYMBOL(dm_dirty_log_type_register);
+
+int dm_dirty_log_type_unregister(struct dm_dirty_log_type *type)
+{
+	struct dm_dirty_log_internal *log_type;
+
+	spin_lock(&_lock);
+
+	log_type = __find_dirty_log_type(type->name);
+	if (!log_type) {
+		spin_unlock(&_lock);
+		return -EINVAL;
+	}
+
+	if (log_type->use) {
+		spin_unlock(&_lock);
+		return -ETXTBSY;
+	}
+
+	list_del(&log_type->list);
+
+	spin_unlock(&_lock);
+	kfree(log_type);
+
+	return 0;
+}
+EXPORT_SYMBOL(dm_dirty_log_type_unregister);
+
+struct dm_dirty_log *dm_dirty_log_create(const char *type_name,
+					 struct dm_target *ti,
+					 unsigned int argc, char **argv)
+{
+	struct dm_dirty_log_type *type;
+	struct dm_dirty_log *log;
 
 	log = kmalloc(sizeof(*log), GFP_KERNEL);
 	if (!log)
@@ -143,13 +213,15 @@ struct dirty_log *dm_create_dirty_log(const char *type_name, struct dm_target *t
 
 	return log;
 }
+EXPORT_SYMBOL(dm_dirty_log_create);
 
-void dm_destroy_dirty_log(struct dirty_log *log)
+void dm_dirty_log_destroy(struct dm_dirty_log *log)
 {
 	log->type->dtr(log);
 	put_type(log->type);
 	kfree(log);
 }
+EXPORT_SYMBOL(dm_dirty_log_destroy);
 
 /*-----------------------------------------------------------------
  * Persistent and core logs share a lot of their implementation.
@@ -207,7 +279,7 @@ struct log_c {
 	struct dm_dev *log_dev;
 	struct log_header header;
 
-	struct io_region header_location;
+	struct dm_io_region header_location;
 	struct log_header *disk_header;
 };
 
@@ -215,7 +287,7 @@ struct log_c {
  * The touched member needs to be updated every time we access
  * one of the bitsets.
  */
-static  inline int log_test_bit(uint32_t *bs, unsigned bit)
+static inline int log_test_bit(uint32_t *bs, unsigned bit)
 {
 	return ext2_test_bit(bit, (unsigned long *) bs) ? 1 : 0;
 }
@@ -302,7 +374,7 @@ static inline int write_header(struct log_c *log)
  * argv contains region_size followed optionally by [no]sync
  *--------------------------------------------------------------*/
 #define BYTE_SHIFT 3
-static int create_log_context(struct dirty_log *log, struct dm_target *ti,
+static int create_log_context(struct dm_dirty_log *log, struct dm_target *ti,
 			      unsigned int argc, char **argv,
 			      struct dm_dev *dev)
 {
@@ -315,7 +387,7 @@ static int create_log_context(struct dirty_log *log, struct dm_target *ti,
 	int r;
 
 	if (argc < 1 || argc > 2) {
-		DMWARN("wrong number of arguments to mirror log");
+		DMWARN("wrong number of arguments to dirty region log");
 		return -EINVAL;
 	}
 
@@ -325,8 +397,8 @@ static int create_log_context(struct dirty_log *log, struct dm_target *ti,
 		else if (!strcmp(argv[1], "nosync"))
 			sync = NOSYNC;
 		else {
-			DMWARN("unrecognised sync argument to mirror log: %s",
-			       argv[1]);
+			DMWARN("unrecognised sync argument to "
+			       "dirty region log: %s", argv[1]);
 			return -EINVAL;
 		}
 	}
@@ -434,7 +506,7 @@ static int create_log_context(struct dirty_log *log, struct dm_target *ti,
 	return 0;
 }
 
-static int core_ctr(struct dirty_log *log, struct dm_target *ti,
+static int core_ctr(struct dm_dirty_log *log, struct dm_target *ti,
 		    unsigned int argc, char **argv)
 {
 	return create_log_context(log, ti, argc, argv, NULL);
@@ -447,7 +519,7 @@ static void destroy_log_context(struct log_c *lc)
 	kfree(lc);
 }
 
-static void core_dtr(struct dirty_log *log)
+static void core_dtr(struct dm_dirty_log *log)
 {
 	struct log_c *lc = (struct log_c *) log->context;
 
@@ -460,14 +532,14 @@ static void core_dtr(struct dirty_log *log)
  *
  * argv contains log_device region_size followed optionally by [no]sync
  *--------------------------------------------------------------*/
-static int disk_ctr(struct dirty_log *log, struct dm_target *ti,
+static int disk_ctr(struct dm_dirty_log *log, struct dm_target *ti,
 		    unsigned int argc, char **argv)
 {
 	int r;
 	struct dm_dev *dev;
 
 	if (argc < 2 || argc > 3) {
-		DMWARN("wrong number of arguments to disk mirror log");
+		DMWARN("wrong number of arguments to disk dirty region log");
 		return -EINVAL;
 	}
 
@@ -485,7 +557,7 @@ static int disk_ctr(struct dirty_log *log, struct dm_target *ti,
 	return 0;
 }
 
-static void disk_dtr(struct dirty_log *log)
+static void disk_dtr(struct dm_dirty_log *log)
 {
 	struct log_c *lc = (struct log_c *) log->context;
 
@@ -514,7 +586,7 @@ static void fail_log_device(struct log_c *lc)
 	dm_table_event(lc->ti->table);
 }
 
-static int disk_resume(struct dirty_log *log)
+static int disk_resume(struct dm_dirty_log *log)
 {
 	int r;
 	unsigned i;
@@ -524,7 +596,7 @@ static int disk_resume(struct dirty_log *log)
 	/* read the disk header */
 	r = read_header(lc);
 	if (r) {
-		DMWARN("%s: Failed to read header on mirror log device",
+		DMWARN("%s: Failed to read header on dirty region log device",
 		       lc->log_dev->name);
 		fail_log_device(lc);
 		/*
@@ -562,7 +634,7 @@ static int disk_resume(struct dirty_log *log)
 	/* write the new header */
 	r = write_header(lc);
 	if (r) {
-		DMWARN("%s: Failed to write header on mirror log device",
+		DMWARN("%s: Failed to write header on dirty region log device",
 		       lc->log_dev->name);
 		fail_log_device(lc);
 	}
@@ -570,38 +642,38 @@ static int disk_resume(struct dirty_log *log)
 	return r;
 }
 
-static uint32_t core_get_region_size(struct dirty_log *log)
+static uint32_t core_get_region_size(struct dm_dirty_log *log)
 {
 	struct log_c *lc = (struct log_c *) log->context;
 	return lc->region_size;
 }
 
-static int core_resume(struct dirty_log *log)
+static int core_resume(struct dm_dirty_log *log)
 {
 	struct log_c *lc = (struct log_c *) log->context;
 	lc->sync_search = 0;
 	return 0;
 }
 
-static int core_is_clean(struct dirty_log *log, region_t region)
+static int core_is_clean(struct dm_dirty_log *log, region_t region)
 {
 	struct log_c *lc = (struct log_c *) log->context;
 	return log_test_bit(lc->clean_bits, region);
 }
 
-static int core_in_sync(struct dirty_log *log, region_t region, int block)
+static int core_in_sync(struct dm_dirty_log *log, region_t region, int block)
 {
 	struct log_c *lc = (struct log_c *) log->context;
 	return log_test_bit(lc->sync_bits, region);
 }
 
-static int core_flush(struct dirty_log *log)
+static int core_flush(struct dm_dirty_log *log)
 {
 	/* no op */
 	return 0;
 }
 
-static int disk_flush(struct dirty_log *log)
+static int disk_flush(struct dm_dirty_log *log)
 {
 	int r;
 	struct log_c *lc = (struct log_c *) log->context;
@@ -619,19 +691,19 @@ static int disk_flush(struct dirty_log *log)
 	return r;
 }
 
-static void core_mark_region(struct dirty_log *log, region_t region)
+static void core_mark_region(struct dm_dirty_log *log, region_t region)
 {
 	struct log_c *lc = (struct log_c *) log->context;
 	log_clear_bit(lc, lc->clean_bits, region);
 }
 
-static void core_clear_region(struct dirty_log *log, region_t region)
+static void core_clear_region(struct dm_dirty_log *log, region_t region)
 {
 	struct log_c *lc = (struct log_c *) log->context;
 	log_set_bit(lc, lc->clean_bits, region);
 }
 
-static int core_get_resync_work(struct dirty_log *log, region_t *region)
+static int core_get_resync_work(struct dm_dirty_log *log, region_t *region)
 {
 	struct log_c *lc = (struct log_c *) log->context;
 
@@ -654,7 +726,7 @@ static int core_get_resync_work(struct dirty_log *log, region_t *region)
 	return 1;
 }
 
-static void core_set_region_sync(struct dirty_log *log, region_t region,
+static void core_set_region_sync(struct dm_dirty_log *log, region_t region,
 				 int in_sync)
 {
 	struct log_c *lc = (struct log_c *) log->context;
@@ -669,7 +741,7 @@ static void core_set_region_sync(struct dirty_log *log, region_t region,
 	}
 }
 
-static region_t core_get_sync_count(struct dirty_log *log)
+static region_t core_get_sync_count(struct dm_dirty_log *log)
 {
         struct log_c *lc = (struct log_c *) log->context;
 
@@ -680,7 +752,7 @@ static region_t core_get_sync_count(struct dirty_log *log)
 	if (lc->sync != DEFAULTSYNC) \
 		DMEMIT("%ssync ", lc->sync == NOSYNC ? "no" : "")
 
-static int core_status(struct dirty_log *log, status_type_t status,
+static int core_status(struct dm_dirty_log *log, status_type_t status,
 		       char *result, unsigned int maxlen)
 {
 	int sz = 0;
@@ -700,7 +772,7 @@ static int core_status(struct dirty_log *log, status_type_t status,
 	return sz;
 }
 
-static int disk_status(struct dirty_log *log, status_type_t status,
+static int disk_status(struct dm_dirty_log *log, status_type_t status,
 		       char *result, unsigned int maxlen)
 {
 	int sz = 0;
@@ -722,7 +794,7 @@ static int disk_status(struct dirty_log *log, status_type_t status,
 	return sz;
 }
 
-static struct dirty_log_type _core_type = {
+static struct dm_dirty_log_type _core_type = {
 	.name = "core",
 	.module = THIS_MODULE,
 	.ctr = core_ctr,
@@ -740,7 +812,7 @@ static struct dirty_log_type _core_type = {
 	.status = core_status,
 };
 
-static struct dirty_log_type _disk_type = {
+static struct dm_dirty_log_type _disk_type = {
 	.name = "disk",
 	.module = THIS_MODULE,
 	.ctr = disk_ctr,
@@ -763,26 +835,28 @@ int __init dm_dirty_log_init(void)
 {
 	int r;
 
-	r = dm_register_dirty_log_type(&_core_type);
+	r = dm_dirty_log_type_register(&_core_type);
 	if (r)
 		DMWARN("couldn't register core log");
 
-	r = dm_register_dirty_log_type(&_disk_type);
+	r = dm_dirty_log_type_register(&_disk_type);
 	if (r) {
 		DMWARN("couldn't register disk type");
-		dm_unregister_dirty_log_type(&_core_type);
+		dm_dirty_log_type_unregister(&_core_type);
 	}
 
 	return r;
 }
 
-void dm_dirty_log_exit(void)
+void __exit dm_dirty_log_exit(void)
 {
-	dm_unregister_dirty_log_type(&_disk_type);
-	dm_unregister_dirty_log_type(&_core_type);
+	dm_dirty_log_type_unregister(&_disk_type);
+	dm_dirty_log_type_unregister(&_core_type);
 }
 
-EXPORT_SYMBOL(dm_register_dirty_log_type);
-EXPORT_SYMBOL(dm_unregister_dirty_log_type);
-EXPORT_SYMBOL(dm_create_dirty_log);
-EXPORT_SYMBOL(dm_destroy_dirty_log);
+module_init(dm_dirty_log_init);
+module_exit(dm_dirty_log_exit);
+
+MODULE_DESCRIPTION(DM_NAME " dirty region log");
+MODULE_AUTHOR("Joe Thornber, Heinz Mauelshagen <dm-devel@redhat.com>");
+MODULE_LICENSE("GPL");