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");