dm: export struct dm_dev

Split struct dm_dev in two and publish the part that other targets need in
include/linux/device-mapper.h.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

4 files changed, 49 insertions, 40 deletions

diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index b262c0042de3..90e19f13f269 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -1131,7 +1131,7 @@ static void retrieve_deps(struct dm_table *table,
         unsigned int count = 0;
         struct list_head *tmp;
         size_t len, needed;
-        struct dm_dev *dd;
+        struct dm_dev_internal *dd;
         struct dm_target_deps *deps;
 
         deps = get_result_buffer(param, param_size, &len);
@@ -1157,7 +1157,7 @@ static void retrieve_deps(struct dm_table *table,
         deps->count = count;
         count = 0;
         list_for_each_entry (dd, dm_table_get_devices(table), list)
-                deps->dev[count++] = huge_encode_dev(dd->bdev->bd_dev);
+                deps->dev[count++] = huge_encode_dev(dd->dm_dev.bdev->bd_dev);
 
         param->data_size = param->data_start + needed;
 }
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 61f441409234..5dd32b8a57ac 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -250,7 +250,8 @@ static void free_devices(struct list_head *devices)
         struct list_head *tmp, *next;
 
         list_for_each_safe(tmp, next, devices) {
-                struct dm_dev *dd = list_entry(tmp, struct dm_dev, list);
+                struct dm_dev_internal *dd =
+                    list_entry(tmp, struct dm_dev_internal, list);
                 kfree(dd);
         }
 }
@@ -327,12 +328,12 @@ static int lookup_device(const char *path, dev_t *dev)
 /*
  * See if we've already got a device in the list.
  */
-static struct dm_dev *find_device(struct list_head *l, dev_t dev)
+static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev)
 {
-        struct dm_dev *dd;
+        struct dm_dev_internal *dd;
 
         list_for_each_entry (dd, l, list)
-                if (dd->bdev->bd_dev == dev)
+                if (dd->dm_dev.bdev->bd_dev == dev)
                         return dd;
 
         return NULL;
@@ -341,45 +342,47 @@ static struct dm_dev *find_device(struct list_head *l, dev_t dev)
 /*
  * Open a device so we can use it as a map destination.
  */
-static int open_dev(struct dm_dev *d, dev_t dev, struct mapped_device *md)
+static int open_dev(struct dm_dev_internal *d, dev_t dev,
+                    struct mapped_device *md)
 {
         static char *_claim_ptr = "I belong to device-mapper";
         struct block_device *bdev;
 
         int r;
 
-        BUG_ON(d->bdev);
+        BUG_ON(d->dm_dev.bdev);
 
-        bdev = open_by_devnum(dev, d->mode);
+        bdev = open_by_devnum(dev, d->dm_dev.mode);
         if (IS_ERR(bdev))
                 return PTR_ERR(bdev);
         r = bd_claim_by_disk(bdev, _claim_ptr, dm_disk(md));
         if (r)
                 blkdev_put(bdev);
         else
-                d->bdev = bdev;
+                d->dm_dev.bdev = bdev;
         return r;
 }
 
 /*
  * Close a device that we've been using.
  */
-static void close_dev(struct dm_dev *d, struct mapped_device *md)
+static void close_dev(struct dm_dev_internal *d, struct mapped_device *md)
 {
-        if (!d->bdev)
+        if (!d->dm_dev.bdev)
                 return;
 
-        bd_release_from_disk(d->bdev, dm_disk(md));
-        blkdev_put(d->bdev);
-        d->bdev = NULL;
+        bd_release_from_disk(d->dm_dev.bdev, dm_disk(md));
+        blkdev_put(d->dm_dev.bdev);
+        d->dm_dev.bdev = NULL;
 }
 
 /*
  * If possible, this checks an area of a destination device is valid.
  */
-static int check_device_area(struct dm_dev *dd, sector_t start, sector_t len)
+static int check_device_area(struct dm_dev_internal *dd, sector_t start,
+                             sector_t len)
 {
-        sector_t dev_size = dd->bdev->bd_inode->i_size >> SECTOR_SHIFT;
+        sector_t dev_size = dd->dm_dev.bdev->bd_inode->i_size >> SECTOR_SHIFT;
 
         if (!dev_size)
                 return 1;
@@ -392,16 +395,17 @@ static int check_device_area(struct dm_dev *dd, sector_t start, sector_t len)
  * careful to leave things as they were if we fail to reopen the
  * device.
  */
-static int upgrade_mode(struct dm_dev *dd, int new_mode, struct mapped_device *md)
+static int upgrade_mode(struct dm_dev_internal *dd, int new_mode,
+                        struct mapped_device *md)
 {
         int r;
-        struct dm_dev dd_copy;
-        dev_t dev = dd->bdev->bd_dev;
+        struct dm_dev_internal dd_copy;
+        dev_t dev = dd->dm_dev.bdev->bd_dev;
 
         dd_copy = *dd;
 
-        dd->mode |= new_mode;
-        dd->bdev = NULL;
+        dd->dm_dev.mode |= new_mode;
+        dd->dm_dev.bdev = NULL;
         r = open_dev(dd, dev, md);
         if (!r)
                 close_dev(&dd_copy, md);
@@ -421,7 +425,7 @@ static int __table_get_device(struct dm_table *t, struct dm_target *ti,
 {
         int r;
         dev_t uninitialized_var(dev);
-        struct dm_dev *dd;
+        struct dm_dev_internal *dd;
         unsigned int major, minor;
 
         BUG_ON(!t);
@@ -443,20 +447,20 @@ static int __table_get_device(struct dm_table *t, struct dm_target *ti,
                 if (!dd)
                         return -ENOMEM;
 
-                dd->mode = mode;
-                dd->bdev = NULL;
+                dd->dm_dev.mode = mode;
+                dd->dm_dev.bdev = NULL;
 
                 if ((r = open_dev(dd, dev, t->md))) {
                         kfree(dd);
                         return r;
                 }
 
-                format_dev_t(dd->name, dev);
+                format_dev_t(dd->dm_dev.name, dev);
 
                 atomic_set(&dd->count, 0);
                 list_add(&dd->list, &t->devices);
 
-        } else if (dd->mode != (mode | dd->mode)) {
+        } else if (dd->dm_dev.mode != (mode | dd->dm_dev.mode)) {
                 r = upgrade_mode(dd, mode, t->md);
                 if (r)
                         return r;
@@ -465,11 +469,11 @@ static int __table_get_device(struct dm_table *t, struct dm_target *ti,
 
         if (!check_device_area(dd, start, len)) {
                 DMWARN("device %s too small for target", path);
-                dm_put_device(ti, dd);
+                dm_put_device(ti, &dd->dm_dev);
                 return -EINVAL;
         }
 
-        *result = dd;
+        *result = &dd->dm_dev;
 
         return 0;
 }
@@ -540,8 +544,11 @@ int dm_get_device(struct dm_target *ti, const char *path, sector_t start,
 /*
  * Decrement a devices use count and remove it if necessary.
  */
-void dm_put_device(struct dm_target *ti, struct dm_dev *dd)
+void dm_put_device(struct dm_target *ti, struct dm_dev *d)
 {
+        struct dm_dev_internal *dd = container_of(d, struct dm_dev_internal,
+                                                  dm_dev);
+
         if (atomic_dec_and_test(&dd->count)) {
                 close_dev(dd, ti->table->md);
                 list_del(&dd->list);
@@ -937,12 +944,12 @@ int dm_table_resume_targets(struct dm_table *t)
 
 int dm_table_any_congested(struct dm_table *t, int bdi_bits)
 {
-        struct dm_dev *dd;
+        struct dm_dev_internal *dd;
         struct list_head *devices = dm_table_get_devices(t);
         int r = 0;
 
         list_for_each_entry(dd, devices, list) {
-                struct request_queue *q = bdev_get_queue(dd->bdev);
+                struct request_queue *q = bdev_get_queue(dd->dm_dev.bdev);
                 r |= bdi_congested(&q->backing_dev_info, bdi_bits);
         }
 
@@ -951,11 +958,11 @@ int dm_table_any_congested(struct dm_table *t, int bdi_bits)
 
 void dm_table_unplug_all(struct dm_table *t)
 {
-        struct dm_dev *dd;
+        struct dm_dev_internal *dd;
         struct list_head *devices = dm_table_get_devices(t);
 
         list_for_each_entry(dd, devices, list) {
-                struct request_queue *q = bdev_get_queue(dd->bdev);
+                struct request_queue *q = bdev_get_queue(dd->dm_dev.bdev);
 
                 blk_unplug(q);
         }
diff --git a/drivers/md/dm.h b/drivers/md/dm.h
index 1e59a0b0a78a..65f2f562220e 100644
--- a/drivers/md/dm.h
+++ b/drivers/md/dm.h
@@ -25,13 +25,10 @@
 /*
  * List of devices that a metadevice uses and should open/close.
  */
-struct dm_dev {
+struct dm_dev_internal {
         struct list_head list;
-
         atomic_t count;
-        int mode;
-        struct block_device *bdev;
-        char name[16];
+        struct dm_dev dm_dev;
 };
 
 struct dm_table;
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index a90222e3297d..178390de195e 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -13,7 +13,6 @@
 
 struct dm_target;
 struct dm_table;
-struct dm_dev;
 struct mapped_device;
 struct bio_vec;
 
@@ -84,6 +83,12 @@ void dm_error(const char *message);
  */
 void dm_set_device_limits(struct dm_target *ti, struct block_device *bdev);
 
+struct dm_dev {
+        struct block_device *bdev;
+        int mode;
+        char name[16];
+};
+
 /*
  * Constructors should call these functions to ensure destination devices
  * are opened/closed correctly.