dm thin metadata: add wrappers for managing write locking of metadata

No functional change, but this prepares to hook off of pmd_write_lock()
with additional functionality (as provided in next commit).
Suggested-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

drivers/md/dm-thin-metadata.c

@@ -367,6 +367,26 @@ static int subtree_equal(void *context, const void *value1_le, const void *value
 
 /*----------------------------------------------------------------*/
 
+static inline void __pmd_write_lock(struct dm_pool_metadata *pmd)
+	__acquires(pmd->root_lock)
+{
+	down_write(&pmd->root_lock);
+}
+#define pmd_write_lock_in_core(pmd) __pmd_write_lock((pmd))
+
+static inline void pmd_write_lock(struct dm_pool_metadata *pmd)
+{
+	__pmd_write_lock(pmd);
+}
+
+static inline void pmd_write_unlock(struct dm_pool_metadata *pmd)
+	__releases(pmd->root_lock)
+{
+	up_write(&pmd->root_lock);
+}
+
+/*----------------------------------------------------------------*/
+
 static int superblock_lock_zero(struct dm_pool_metadata *pmd,
 				struct dm_block **sblock)
 {
@@ -1032,10 +1052,10 @@ int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev)
 {
 	int r = -EINVAL;
 
-	down_write(&pmd->root_lock);
+	pmd_write_lock(pmd);
 	if (!pmd->fail_io)
 		r = __create_thin(pmd, dev);
-	up_write(&pmd->root_lock);
+	pmd_write_unlock(pmd);
 
 	return r;
 }
@@ -1123,10 +1143,10 @@ int dm_pool_create_snap(struct dm_pool_metadata *pmd,
 {
 	int r = -EINVAL;
 
-	down_write(&pmd->root_lock);
+	pmd_write_lock(pmd);
 	if (!pmd->fail_io)
 		r = __create_snap(pmd, dev, origin);
-	up_write(&pmd->root_lock);
+	pmd_write_unlock(pmd);
 
 	return r;
 }
@@ -1166,10 +1186,10 @@ int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd,
 {
 	int r = -EINVAL;
 
-	down_write(&pmd->root_lock);
+	pmd_write_lock(pmd);
 	if (!pmd->fail_io)
 		r = __delete_device(pmd, dev);
-	up_write(&pmd->root_lock);
+	pmd_write_unlock(pmd);
 
 	return r;
 }
@@ -1180,7 +1200,7 @@ int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd,
 {
 	int r = -EINVAL;
 
-	down_write(&pmd->root_lock);
+	pmd_write_lock(pmd);
 
 	if (pmd->fail_io)
 		goto out;
@@ -1194,7 +1214,7 @@ int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd,
 	r = 0;
 
 out:
-	up_write(&pmd->root_lock);
+	pmd_write_unlock(pmd);
 
 	return r;
 }
@@ -1288,10 +1308,10 @@ int dm_pool_reserve_metadata_snap(struct dm_pool_metadata *pmd)
 {
 	int r = -EINVAL;
 
-	down_write(&pmd->root_lock);
+	pmd_write_lock(pmd);
 	if (!pmd->fail_io)
 		r = __reserve_metadata_snap(pmd);
-	up_write(&pmd->root_lock);
+	pmd_write_unlock(pmd);
 
 	return r;
 }
@@ -1336,10 +1356,10 @@ int dm_pool_release_metadata_snap(struct dm_pool_metadata *pmd)
 {
 	int r = -EINVAL;
 
-	down_write(&pmd->root_lock);
+	pmd_write_lock(pmd);
 	if (!pmd->fail_io)
 		r = __release_metadata_snap(pmd);
-	up_write(&pmd->root_lock);
+	pmd_write_unlock(pmd);
 
 	return r;
 }
@@ -1382,19 +1402,19 @@ int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev,
 {
 	int r = -EINVAL;
 
-	down_write(&pmd->root_lock);
+	pmd_write_lock_in_core(pmd);
 	if (!pmd->fail_io)
 		r = __open_device(pmd, dev, 0, td);
-	up_write(&pmd->root_lock);
+	pmd_write_unlock(pmd);
 
 	return r;
 }
 
 int dm_pool_close_thin_device(struct dm_thin_device *td)
 {
-	down_write(&td->pmd->root_lock);
+	pmd_write_lock_in_core(td->pmd);
 	__close_device(td);
-	up_write(&td->pmd->root_lock);
+	pmd_write_unlock(td->pmd);
 
 	return 0;
 }
@@ -1575,10 +1595,10 @@ int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block,
 {
 	int r = -EINVAL;
 
-	down_write(&td->pmd->root_lock);
+	pmd_write_lock(td->pmd);
 	if (!td->pmd->fail_io)
 		r = __insert(td, block, data_block);
-	up_write(&td->pmd->root_lock);
+	pmd_write_unlock(td->pmd);
 
 	return r;
 }
@@ -1662,10 +1682,10 @@ int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block)
 {
 	int r = -EINVAL;
 
-	down_write(&td->pmd->root_lock);
+	pmd_write_lock(td->pmd);
 	if (!td->pmd->fail_io)
 		r = __remove(td, block);
-	up_write(&td->pmd->root_lock);
+	pmd_write_unlock(td->pmd);
 
 	return r;
 }
@@ -1675,10 +1695,10 @@ int dm_thin_remove_range(struct dm_thin_device *td,
 {
 	int r = -EINVAL;
 
-	down_write(&td->pmd->root_lock);
+	pmd_write_lock(td->pmd);
 	if (!td->pmd->fail_io)
 		r = __remove_range(td, begin, end);
-	up_write(&td->pmd->root_lock);
+	pmd_write_unlock(td->pmd);
 
 	return r;
 }
@@ -1701,13 +1721,13 @@ int dm_pool_inc_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_
 {
 	int r = 0;
 
-	down_write(&pmd->root_lock);
+	pmd_write_lock(pmd);
 	for (; b != e; b++) {
 		r = dm_sm_inc_block(pmd->data_sm, b);
 		if (r)
 			break;
 	}
-	up_write(&pmd->root_lock);
+	pmd_write_unlock(pmd);
 
 	return r;
 }
@@ -1716,13 +1736,13 @@ int dm_pool_dec_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_
 {
 	int r = 0;
 
-	down_write(&pmd->root_lock);
+	pmd_write_lock(pmd);
 	for (; b != e; b++) {
 		r = dm_sm_dec_block(pmd->data_sm, b);
 		if (r)
 			break;
 	}
-	up_write(&pmd->root_lock);
+	pmd_write_unlock(pmd);
 
 	return r;
 }
@@ -1770,10 +1790,10 @@ int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result)
 {
 	int r = -EINVAL;
 
-	down_write(&pmd->root_lock);
+	pmd_write_lock(pmd);
 	if (!pmd->fail_io)
 		r = dm_sm_new_block(pmd->data_sm, result);
-	up_write(&pmd->root_lock);
+	pmd_write_unlock(pmd);
 
 	return r;
 }
@@ -1782,7 +1802,7 @@ int dm_pool_commit_metadata(struct dm_pool_metadata *pmd)
 {
 	int r = -EINVAL;
 
-	down_write(&pmd->root_lock);
+	pmd_write_lock(pmd);
 	if (pmd->fail_io)
 		goto out;
 
@@ -1795,7 +1815,7 @@ int dm_pool_commit_metadata(struct dm_pool_metadata *pmd)
 	 */
 	r = __begin_transaction(pmd);
 out:
-	up_write(&pmd->root_lock);
+	pmd_write_unlock(pmd);
 	return r;
 }
 
@@ -1811,7 +1831,7 @@ int dm_pool_abort_metadata(struct dm_pool_metadata *pmd)
 {
 	int r = -EINVAL;
 
-	down_write(&pmd->root_lock);
+	pmd_write_lock(pmd);
 	if (pmd->fail_io)
 		goto out;
 
@@ -1822,7 +1842,7 @@ int dm_pool_abort_metadata(struct dm_pool_metadata *pmd)
 		pmd->fail_io = true;
 
 out:
-	up_write(&pmd->root_lock);
+	pmd_write_unlock(pmd);
 
 	return r;
 }
@@ -1953,10 +1973,10 @@ int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
 {
 	int r = -EINVAL;
 
-	down_write(&pmd->root_lock);
+	pmd_write_lock(pmd);
 	if (!pmd->fail_io)
 		r = __resize_space_map(pmd->data_sm, new_count);
-	up_write(&pmd->root_lock);
+	pmd_write_unlock(pmd);
 
 	return r;
 }
@@ -1965,29 +1985,29 @@ int dm_pool_resize_metadata_dev(struct dm_pool_metadata *pmd, dm_block_t new_cou
 {
 	int r = -EINVAL;
 
-	down_write(&pmd->root_lock);
+	pmd_write_lock(pmd);
 	if (!pmd->fail_io) {
 		r = __resize_space_map(pmd->metadata_sm, new_count);
 		if (!r)
 			__set_metadata_reserve(pmd);
 	}
-	up_write(&pmd->root_lock);
+	pmd_write_unlock(pmd);
 
 	return r;
 }
 
 void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd)
 {
-	down_write(&pmd->root_lock);
+	pmd_write_lock_in_core(pmd);
 	dm_bm_set_read_only(pmd->bm);
-	up_write(&pmd->root_lock);
+	pmd_write_unlock(pmd);
 }
 
 void dm_pool_metadata_read_write(struct dm_pool_metadata *pmd)
 {
-	down_write(&pmd->root_lock);
+	pmd_write_lock_in_core(pmd);
 	dm_bm_set_read_write(pmd->bm);
-	up_write(&pmd->root_lock);
+	pmd_write_unlock(pmd);
 }
 
 int dm_pool_register_metadata_threshold(struct dm_pool_metadata *pmd,
@@ -1997,9 +2017,9 @@ int dm_pool_register_metadata_threshold(struct dm_pool_metadata *pmd,
 {
 	int r;
 
-	down_write(&pmd->root_lock);
+	pmd_write_lock_in_core(pmd);
 	r = dm_sm_register_threshold_callback(pmd->metadata_sm, threshold, fn, context);
-	up_write(&pmd->root_lock);
+	pmd_write_unlock(pmd);
 
 	return r;
 }
@@ -2010,7 +2030,7 @@ int dm_pool_metadata_set_needs_check(struct dm_pool_metadata *pmd)
 	struct dm_block *sblock;
 	struct thin_disk_superblock *disk_super;
 
-	down_write(&pmd->root_lock);
+	pmd_write_lock(pmd);
 	pmd->flags |= THIN_METADATA_NEEDS_CHECK_FLAG;
 
 	r = superblock_lock(pmd, &sblock);
@@ -2024,7 +2044,7 @@ int dm_pool_metadata_set_needs_check(struct dm_pool_metadata *pmd)
 
 	dm_bm_unlock(sblock);
 out:
-	up_write(&pmd->root_lock);
+	pmd_write_unlock(pmd);
 	return r;
 }