/*
* Copyright (C) 2003 Sistina Software
+ * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
*
* This file is released under the LGPL.
*/
#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"
+
+struct dm_dirty_log_internal {
+ struct dm_dirty_log_type *type;
+
+ struct list_head list;
+ long use;
+};
static LIST_HEAD(_log_types);
static DEFINE_SPINLOCK(_lock);
-int dm_register_dirty_log_type(struct dirty_log_type *type)
+static struct dm_dirty_log_internal *__find_dirty_log_type(const char *name)
+{
+ struct dm_dirty_log_internal *log_type;
+
+ list_for_each_entry(log_type, &_log_types, list)
+ if (!strcmp(name, log_type->type->name))
+ return log_type;
+
+ return NULL;
+}
+
+static struct dm_dirty_log_internal *_get_dirty_log_type(const char *name)
{
+ struct dm_dirty_log_internal *log_type;
+
spin_lock(&_lock);
- type->use_count = 0;
- list_add(&type->list, &_log_types);
+
+ 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 0;
+ return log_type;
}
-int dm_unregister_dirty_log_type(struct dirty_log_type *type)
+/*
+ * get_type
+ * @type_name
+ *
+ * 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'.
+ * Modules may contain multiple types.
+ * This function will first try the module "dm-log-<type_name>",
+ * then truncate 'type_name' on the last '-' and try again.
+ *
+ * For example, if type_name was "clustered-disk", it would search
+ * 'dm-log-clustered-disk' then 'dm-log-clustered'.
+ *
+ * Returns: dirty_log_type* on success, NULL on failure
+ */
+static struct dm_dirty_log_type *get_type(const char *type_name)
{
+ char *p, *type_name_dup;
+ struct dm_dirty_log_internal *log_type;
+
+ if (!type_name)
+ return NULL;
+
+ 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) {
+ DMWARN("No memory left to attempt log module load for \"%s\"",
+ type_name);
+ return NULL;
+ }
+
+ while (request_module("dm-log-%s", type_name_dup) ||
+ !(log_type = _get_dirty_log_type(type_name))) {
+ p = strrchr(type_name_dup, '-');
+ if (!p)
+ break;
+ p[0] = '\0';
+ }
+
+ if (!log_type)
+ DMWARN("Module for logging type \"%s\" not found.", type_name);
+
+ kfree(type_name_dup);
+
+ return log_type ? log_type->type : NULL;
+}
+
+static void put_type(struct dm_dirty_log_type *type)
+{
+ struct dm_dirty_log_internal *log_type;
+
+ if (!type)
+ return;
+
spin_lock(&_lock);
+ log_type = __find_dirty_log_type(type->name);
+ if (!log_type)
+ goto out;
- if (type->use_count)
- DMWARN("Attempt to unregister a log type that is still in use");
- else
- list_del(&type->list);
+ if (!--log_type->use)
+ module_put(type->module);
+ BUG_ON(log_type->use < 0);
+
+out:
spin_unlock(&_lock);
+}
- return 0;
+static struct dm_dirty_log_internal *_alloc_dirty_log_type(struct dm_dirty_log_type *type)
+{
+ struct dm_dirty_log_internal *log_type = kzalloc(sizeof(*log_type),
+ GFP_KERNEL);
+
+ if (log_type)
+ log_type->type = type;
+
+ return log_type;
}
-static struct dirty_log_type *get_type(const char *type_name)
+int dm_dirty_log_type_register(struct dm_dirty_log_type *type)
{
- struct dirty_log_type *type;
+ struct dm_dirty_log_internal *log_type = _alloc_dirty_log_type(type);
+ int r = 0;
- 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;
- }
+ 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 NULL;
+
+ return r;
}
+EXPORT_SYMBOL(dm_dirty_log_type_register);
-static void put_type(struct dirty_log_type *type)
+int dm_dirty_log_type_unregister(struct dm_dirty_log_type *type)
{
+ struct dm_dirty_log_internal *log_type;
+
spin_lock(&_lock);
- if (!--type->use_count)
- module_put(type->module);
+
+ 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 dirty_log *dm_create_dirty_log(const char *type_name, struct dm_target *ti,
- unsigned int argc, char **argv)
+struct dm_dirty_log *dm_dirty_log_create(const char *type_name,
+ struct dm_target *ti,
+ unsigned int argc, char **argv)
{
- struct dirty_log_type *type;
- struct dirty_log *log;
+ struct dm_dirty_log_type *type;
+ struct dm_dirty_log *log;
log = kmalloc(sizeof(*log), GFP_KERNEL);
if (!log)
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.
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;
};
* 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;
}
* 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)
{
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;
}
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;
}
}
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);
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;
*
* 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;
}
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;
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;
/* 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);
/*
/* 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);
}
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;
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;
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;
}
}
-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;
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;
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;
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,
.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,
.status = disk_status,
};
-int __init dm_dirty_log_init(void)
+static 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)
+static 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");
git.openpandora.org / pandora-kernel.git / blobdiff