dm log: clean interface

Clean up the dm-log interface to prepare for publishing it in include/linux.

Signed-off-by: Heinz Mauelshagen <hjm@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

4 files changed, 112 insertions, 103 deletions

diff --git a/drivers/md/dm-log.c b/drivers/md/dm-log.c
index 14f785fc308a..b776701cc8fa 100644
--- a/drivers/md/dm-log.c
+++ b/drivers/md/dm-log.c
@@ -12,13 +12,14 @@
 
 #include "dm-log.h"
 #include "dm-io.h"
+#include "dm.h"
 
 #define DM_MSG_PREFIX "dirty region log"
 
 static LIST_HEAD(_log_types);
 static DEFINE_SPINLOCK(_lock);
 
-int dm_register_dirty_log_type(struct dirty_log_type *type)
+int dm_dirty_log_type_register(struct dm_dirty_log_type *type)
 {
         spin_lock(&_lock);
         type->use_count = 0;
@@ -27,8 +28,9 @@ int dm_register_dirty_log_type(struct dirty_log_type *type)
 
         return 0;
 }
+EXPORT_SYMBOL(dm_dirty_log_type_register);
 
-int dm_unregister_dirty_log_type(struct dirty_log_type *type)
+int dm_dirty_log_type_unregister(struct dm_dirty_log_type *type)
 {
         spin_lock(&_lock);
 
@@ -41,10 +43,11 @@ int dm_unregister_dirty_log_type(struct dirty_log_type *type)
 
         return 0;
 }
+EXPORT_SYMBOL(dm_dirty_log_type_unregister);
 
-static struct dirty_log_type *_get_type(const char *type_name)
+static struct dm_dirty_log_type *_get_type(const char *type_name)
 {
-        struct dirty_log_type *type;
+        struct dm_dirty_log_type *type;
 
         spin_lock(&_lock);
         list_for_each_entry (type, &_log_types, list)
@@ -79,10 +82,10 @@ 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_type *type;
 
         type = _get_type(type_name);
         if (type)
@@ -111,7 +114,7 @@ static struct dirty_log_type *get_type(const char *type_name)
         return type;
 }
 
-static void put_type(struct dirty_log_type *type)
+static void put_type(struct dm_dirty_log_type *type)
 {
         spin_lock(&_lock);
         if (!--type->use_count)
@@ -119,11 +122,12 @@ static void put_type(struct dirty_log_type *type)
         spin_unlock(&_lock);
 }
 
-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)
@@ -144,13 +148,15 @@ 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.
@@ -216,7 +222,7 @@ 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;
 }
@@ -303,7 +309,7 @@ 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)
 {
@@ -435,7 +441,7 @@ 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);
@@ -448,7 +454,7 @@ 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;
 
@@ -461,7 +467,7 @@ 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;
@@ -486,7 +492,7 @@ 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;
 
@@ -515,7 +521,7 @@ 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;
@@ -571,38 +577,38 @@ 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;
@@ -620,19 +626,19 @@ 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;
 
@@ -655,7 +661,7 @@ 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;
@@ -670,7 +676,7 @@ 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;
 
@@ -681,7 +687,7 @@ 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;
@@ -701,7 +707,7 @@ 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;
@@ -723,7 +729,7 @@ 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,
@@ -741,7 +747,7 @@ 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,
@@ -764,14 +770,14 @@ 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;
@@ -779,15 +785,10 @@ int __init dm_dirty_log_init(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);
 
diff --git a/drivers/md/dm-log.h b/drivers/md/dm-log.h
index 3fae87eb5963..2da48a857cb9 100644
--- a/drivers/md/dm-log.h
+++ b/drivers/md/dm-log.h
@@ -1,52 +1,58 @@
 /*
  * Copyright (C) 2003 Sistina Software
+ * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
+ *
+ * Device-Mapper dirty region log.
  *
  * This file is released under the LGPL.
  */
 
-#ifndef DM_DIRTY_LOG
-#define DM_DIRTY_LOG
+#ifndef _LINUX_DM_DIRTY_LOG
+#define _LINUX_DM_DIRTY_LOG
+
+#ifdef __KERNEL__
 
-#include "dm.h"
+#include <linux/types.h>
+#include <linux/device-mapper.h>
 
 typedef sector_t region_t;
 
-struct dirty_log_type;
+struct dm_dirty_log_type;
 
-struct dirty_log {
-        struct dirty_log_type *type;
+struct dm_dirty_log {
+        struct dm_dirty_log_type *type;
         void *context;
 };
 
-struct dirty_log_type {
+struct dm_dirty_log_type {
         struct list_head list;
         const char *name;
         struct module *module;
-        unsigned int use_count;
+        unsigned use_count;
 
-        int (*ctr)(struct dirty_log *log, struct dm_target *ti,
-                   unsigned int argc, char **argv);
-        void (*dtr)(struct dirty_log *log);
+        int (*ctr)(struct dm_dirty_log *log, struct dm_target *ti,
+                   unsigned argc, char **argv);
+        void (*dtr)(struct dm_dirty_log *log);
 
         /*
          * There are times when we don't want the log to touch
          * the disk.
          */
-        int (*presuspend)(struct dirty_log *log);
-        int (*postsuspend)(struct dirty_log *log);
-        int (*resume)(struct dirty_log *log);
+        int (*presuspend)(struct dm_dirty_log *log);
+        int (*postsuspend)(struct dm_dirty_log *log);
+        int (*resume)(struct dm_dirty_log *log);
 
         /*
          * Retrieves the smallest size of region that the log can
          * deal with.
          */
-        uint32_t (*get_region_size)(struct dirty_log *log);
+        uint32_t (*get_region_size)(struct dm_dirty_log *log);
 
-        /*
+        /*
          * A predicate to say whether a region is clean or not.
          * May block.
          */
-        int (*is_clean)(struct dirty_log *log, region_t region);
+        int (*is_clean)(struct dm_dirty_log *log, region_t region);
 
         /*
          *  Returns: 0, 1, -EWOULDBLOCK, < 0
@@ -59,13 +65,14 @@ struct dirty_log_type {
          * passed to a daemon to deal with, since a daemon is
          * allowed to block.
          */
-        int (*in_sync)(struct dirty_log *log, region_t region, int can_block);
+        int (*in_sync)(struct dm_dirty_log *log, region_t region,
+                       int can_block);
 
         /*
          * Flush the current log state (eg, to disk).  This
          * function may block.
          */
-        int (*flush)(struct dirty_log *log);
+        int (*flush)(struct dm_dirty_log *log);
 
         /*
          * Mark an area as clean or dirty.  These functions may
@@ -73,8 +80,8 @@ struct dirty_log_type {
          * be extremely rare (eg, allocating another chunk of
          * memory for some reason).
          */
-        void (*mark_region)(struct dirty_log *log, region_t region);
-        void (*clear_region)(struct dirty_log *log, region_t region);
+        void (*mark_region)(struct dm_dirty_log *log, region_t region);
+        void (*clear_region)(struct dm_dirty_log *log, region_t region);
 
         /*
          * Returns: <0 (error), 0 (no region), 1 (region)
@@ -88,44 +95,39 @@ struct dirty_log_type {
          * tells you if an area is synchronised, the other
          * assigns recovery work.
         */
-        int (*get_resync_work)(struct dirty_log *log, region_t *region);
+        int (*get_resync_work)(struct dm_dirty_log *log, region_t *region);
 
         /*
          * This notifies the log that the resync status of a region
          * has changed.  It also clears the region from the recovering
          * list (if present).
          */
-        void (*set_region_sync)(struct dirty_log *log,
+        void (*set_region_sync)(struct dm_dirty_log *log,
                                 region_t region, int in_sync);
 
-        /*
+        /*
          * Returns the number of regions that are in sync.
-         */
-        region_t (*get_sync_count)(struct dirty_log *log);
+         */
+        region_t (*get_sync_count)(struct dm_dirty_log *log);
 
         /*
          * Support function for mirror status requests.
          */
-        int (*status)(struct dirty_log *log, status_type_t status_type,
-                      char *result, unsigned int maxlen);
+        int (*status)(struct dm_dirty_log *log, status_type_t status_type,
+                      char *result, unsigned maxlen);
 };
 
-int dm_register_dirty_log_type(struct dirty_log_type *type);
-int dm_unregister_dirty_log_type(struct dirty_log_type *type);
-
+int dm_dirty_log_type_register(struct dm_dirty_log_type *type);
+int dm_dirty_log_type_unregister(struct dm_dirty_log_type *type);
 
 /*
  * Make sure you use these two functions, rather than calling
  * type->constructor/destructor() directly.
  */
-struct dirty_log *dm_create_dirty_log(const char *type_name, struct dm_target *ti,
-                                      unsigned int argc, char **argv);
-void dm_destroy_dirty_log(struct dirty_log *log);
-
-/*
- * init/exit functions.
- */
-int dm_dirty_log_init(void);
-void dm_dirty_log_exit(void);
+struct dm_dirty_log *dm_dirty_log_create(const char *type_name,
+                                         struct dm_target *ti,
+                                         unsigned argc, char **argv);
+void dm_dirty_log_destroy(struct dm_dirty_log *log);
 
-#endif
+#endif  /* __KERNEL__ */
+#endif  /* _LINUX_DM_DIRTY_LOG_H */
diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
index 32c7c6d10939..5beeced4e522 100644
--- a/drivers/md/dm-raid1.c
+++ b/drivers/md/dm-raid1.c
@@ -74,7 +74,7 @@ struct region_hash {
         unsigned region_shift;
 
         /* holds persistent region state */
-        struct dirty_log *log;
+        struct dm_dirty_log *log;
 
         /* hash table */
         rwlock_t hash_lock;
@@ -184,7 +184,7 @@ static void queue_bio(struct mirror_set *ms, struct bio *bio, int rw);
 #define MIN_REGIONS 64
 #define MAX_RECOVERY 1
 static int rh_init(struct region_hash *rh, struct mirror_set *ms,
-                   struct dirty_log *log, uint32_t region_size,
+                   struct dm_dirty_log *log, uint32_t region_size,
                    region_t nr_regions)
 {
         unsigned int nr_buckets, max_buckets;
@@ -249,7 +249,7 @@ static void rh_exit(struct region_hash *rh)
         }
 
         if (rh->log)
-                dm_destroy_dirty_log(rh->log);
+                dm_dirty_log_destroy(rh->log);
         if (rh->region_pool)
                 mempool_destroy(rh->region_pool);
         vfree(rh->buckets);
@@ -831,7 +831,7 @@ static void do_recovery(struct mirror_set *ms)
 {
         int r;
         struct region *reg;
-        struct dirty_log *log = ms->rh.log;
+        struct dm_dirty_log *log = ms->rh.log;
 
         /*
          * Start quiescing some regions.
@@ -1017,7 +1017,7 @@ static void __bio_mark_nosync(struct mirror_set *ms,
 {
         unsigned long flags;
         struct region_hash *rh = &ms->rh;
-        struct dirty_log *log = ms->rh.log;
+        struct dm_dirty_log *log = ms->rh.log;
         struct region *reg;
         region_t region = bio_to_region(rh, bio);
         int recovering = 0;
@@ -1301,7 +1301,7 @@ static void do_mirror(struct work_struct *work)
 static struct mirror_set *alloc_context(unsigned int nr_mirrors,
                                         uint32_t region_size,
                                         struct dm_target *ti,
-                                        struct dirty_log *dl)
+                                        struct dm_dirty_log *dl)
 {
         size_t len;
         struct mirror_set *ms = NULL;
@@ -1401,12 +1401,12 @@ static int get_mirror(struct mirror_set *ms, struct dm_target *ti,
 /*
  * Create dirty log: log_type #log_params <log_params>
  */
-static struct dirty_log *create_dirty_log(struct dm_target *ti,
+static struct dm_dirty_log *create_dirty_log(struct dm_target *ti,
                                           unsigned int argc, char **argv,
                                           unsigned int *args_used)
 {
         unsigned int param_count;
-        struct dirty_log *dl;
+        struct dm_dirty_log *dl;
 
         if (argc < 2) {
                 ti->error = "Insufficient mirror log arguments";
@@ -1425,7 +1425,7 @@ static struct dirty_log *create_dirty_log(struct dm_target *ti,
                 return NULL;
         }
 
-        dl = dm_create_dirty_log(argv[0], ti, param_count, argv + 2);
+        dl = dm_dirty_log_create(argv[0], ti, param_count, argv + 2);
         if (!dl) {
                 ti->error = "Error creating mirror dirty log";
                 return NULL;
@@ -1433,7 +1433,7 @@ static struct dirty_log *create_dirty_log(struct dm_target *ti,
 
         if (!_check_region_size(ti, dl->type->get_region_size(dl))) {
                 ti->error = "Invalid region size";
-                dm_destroy_dirty_log(dl);
+                dm_dirty_log_destroy(dl);
                 return NULL;
         }
 
@@ -1494,7 +1494,7 @@ static int mirror_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         int r;
         unsigned int nr_mirrors, m, args_used;
         struct mirror_set *ms;
-        struct dirty_log *dl;
+        struct dm_dirty_log *dl;
 
         dl = create_dirty_log(ti, argc, argv, &args_used);
         if (!dl)
@@ -1506,7 +1506,7 @@ static int mirror_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         if (!argc || sscanf(argv[0], "%u", &nr_mirrors) != 1 ||
             nr_mirrors < 2 || nr_mirrors > DM_KCOPYD_MAX_REGIONS + 1) {
                 ti->error = "Invalid number of mirrors";
-                dm_destroy_dirty_log(dl);
+                dm_dirty_log_destroy(dl);
                 return -EINVAL;
         }
 
@@ -1514,13 +1514,13 @@ static int mirror_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 
         if (argc < nr_mirrors * 2) {
                 ti->error = "Too few mirror arguments";
-                dm_destroy_dirty_log(dl);
+                dm_dirty_log_destroy(dl);
                 return -EINVAL;
         }
 
         ms = alloc_context(nr_mirrors, dl->type->get_region_size(dl), ti, dl);
         if (!ms) {
-                dm_destroy_dirty_log(dl);
+                dm_dirty_log_destroy(dl);
                 return -ENOMEM;
         }
 
@@ -1732,7 +1732,7 @@ out:
 static void mirror_presuspend(struct dm_target *ti)
 {
         struct mirror_set *ms = (struct mirror_set *) ti->private;
-        struct dirty_log *log = ms->rh.log;
+        struct dm_dirty_log *log = ms->rh.log;
 
         atomic_set(&ms->suspend, 1);
 
@@ -1761,7 +1761,7 @@ static void mirror_presuspend(struct dm_target *ti)
 static void mirror_postsuspend(struct dm_target *ti)
 {
         struct mirror_set *ms = ti->private;
-        struct dirty_log *log = ms->rh.log;
+        struct dm_dirty_log *log = ms->rh.log;
 
         if (log->type->postsuspend && log->type->postsuspend(log))
                 /* FIXME: need better error handling */
@@ -1771,7 +1771,7 @@ static void mirror_postsuspend(struct dm_target *ti)
 static void mirror_resume(struct dm_target *ti)
 {
         struct mirror_set *ms = ti->private;
-        struct dirty_log *log = ms->rh.log;
+        struct dm_dirty_log *log = ms->rh.log;
 
         atomic_set(&ms->suspend, 0);
         if (log->type->resume && log->type->resume(log))
@@ -1809,7 +1809,7 @@ static int mirror_status(struct dm_target *ti, status_type_t type,
 {
         unsigned int m, sz = 0;
         struct mirror_set *ms = (struct mirror_set *) ti->private;
-        struct dirty_log *log = ms->rh.log;
+        struct dm_dirty_log *log = ms->rh.log;
         char buffer[ms->nr_mirrors + 1];
 
         switch (type) {
diff --git a/drivers/md/dm.h b/drivers/md/dm.h
index b4584a39383b..17f2d6a8b124 100644
--- a/drivers/md/dm.h
+++ b/drivers/md/dm.h
@@ -189,4 +189,10 @@ int dm_lock_for_deletion(struct mapped_device *md);
 
 void dm_kobject_uevent(struct mapped_device *md);
 
+/*
+ * Dirty log
+ */
+int dm_dirty_log_init(void);
+void dm_dirty_log_exit(void);
+
 #endif