btrfs: split dev-replace locking helpers for read and write

The current calls are unclear in what way btrfs_dev_replace_lock takes
the locks, so drop the argument, split the helpers and use similar
naming as for read and write locks.
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/dev-replace.h

@@ -36,8 +36,10 @@ int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info);
 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info);
 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info);
 int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace);
-void btrfs_dev_replace_lock(struct btrfs_dev_replace *dev_replace, int rw);
-void btrfs_dev_replace_unlock(struct btrfs_dev_replace *dev_replace, int rw);
+void btrfs_dev_replace_read_lock(struct btrfs_dev_replace *dev_replace);
+void btrfs_dev_replace_read_unlock(struct btrfs_dev_replace *dev_replace);
+void btrfs_dev_replace_write_lock(struct btrfs_dev_replace *dev_replace);
+void btrfs_dev_replace_write_unlock(struct btrfs_dev_replace *dev_replace);
 void btrfs_dev_replace_set_lock_blocking(struct btrfs_dev_replace *dev_replace);
 void btrfs_dev_replace_clear_lock_blocking(
 					struct btrfs_dev_replace *dev_replace);

fs/btrfs/reada.c

@@ -395,20 +395,20 @@ static struct reada_extent *reada_find_extent(struct btrfs_fs_info *fs_info,
 		goto error;
 
 	/* insert extent in reada_tree + all per-device trees, all or nothing */
-	btrfs_dev_replace_lock(&fs_info->dev_replace, 0);
+	btrfs_dev_replace_read_lock(&fs_info->dev_replace);
 	spin_lock(&fs_info->reada_lock);
 	ret = radix_tree_insert(&fs_info->reada_tree, index, re);
 	if (ret == -EEXIST) {
 		re_exist = radix_tree_lookup(&fs_info->reada_tree, index);
 		re_exist->refcnt++;
 		spin_unlock(&fs_info->reada_lock);
-		btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);
+		btrfs_dev_replace_read_unlock(&fs_info->dev_replace);
 		radix_tree_preload_end();
 		goto error;
 	}
 	if (ret) {
 		spin_unlock(&fs_info->reada_lock);
-		btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);
+		btrfs_dev_replace_read_unlock(&fs_info->dev_replace);
 		radix_tree_preload_end();
 		goto error;
 	}
@@ -451,13 +451,13 @@ static struct reada_extent *reada_find_extent(struct btrfs_fs_info *fs_info,
 			}
 			radix_tree_delete(&fs_info->reada_tree, index);
 			spin_unlock(&fs_info->reada_lock);
-			btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);
+			btrfs_dev_replace_read_unlock(&fs_info->dev_replace);
 			goto error;
 		}
 		have_zone = 1;
 	}
 	spin_unlock(&fs_info->reada_lock);
-	btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);
+	btrfs_dev_replace_read_unlock(&fs_info->dev_replace);
 
 	if (!have_zone)
 		goto error;

fs/btrfs/scrub.c

@@ -3935,11 +3935,11 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx,
 			break;
 		}
 
-		btrfs_dev_replace_lock(&fs_info->dev_replace, 1);
+		btrfs_dev_replace_write_lock(&fs_info->dev_replace);
 		dev_replace->cursor_right = found_key.offset + length;
 		dev_replace->cursor_left = found_key.offset;
 		dev_replace->item_needs_writeback = 1;
-		btrfs_dev_replace_unlock(&fs_info->dev_replace, 1);
+		btrfs_dev_replace_write_unlock(&fs_info->dev_replace);
 		ret = scrub_chunk(sctx, scrub_dev, chunk_offset, length,
 				  found_key.offset, cache, is_dev_replace);
 
@@ -3975,10 +3975,10 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx,
 
 		scrub_pause_off(fs_info);
 
-		btrfs_dev_replace_lock(&fs_info->dev_replace, 1);
+		btrfs_dev_replace_write_lock(&fs_info->dev_replace);
 		dev_replace->cursor_left = dev_replace->cursor_right;
 		dev_replace->item_needs_writeback = 1;
-		btrfs_dev_replace_unlock(&fs_info->dev_replace, 1);
+		btrfs_dev_replace_write_unlock(&fs_info->dev_replace);
 
 		if (ro_set)
 			btrfs_dec_block_group_ro(cache);
@@ -4194,16 +4194,16 @@ int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
 		return -EIO;
 	}
 
-	btrfs_dev_replace_lock(&fs_info->dev_replace, 0);
+	btrfs_dev_replace_read_lock(&fs_info->dev_replace);
 	if (dev->scrub_ctx ||
 	    (!is_dev_replace &&
 	     btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) {
-		btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);
+		btrfs_dev_replace_read_unlock(&fs_info->dev_replace);
 		mutex_unlock(&fs_info->scrub_lock);
 		mutex_unlock(&fs_info->fs_devices->device_list_mutex);
 		return -EINPROGRESS;
 	}
-	btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);
+	btrfs_dev_replace_read_unlock(&fs_info->dev_replace);
 
 	ret = scrub_workers_get(fs_info, is_dev_replace);
 	if (ret) {

fs/btrfs/volumes.c

@@ -1936,12 +1936,12 @@ int btrfs_rm_device(struct btrfs_fs_info *fs_info, const char *device_path,
 	mutex_lock(&uuid_mutex);
 
 	num_devices = fs_info->fs_devices->num_devices;
-	btrfs_dev_replace_lock(&fs_info->dev_replace, 0);
+	btrfs_dev_replace_read_lock(&fs_info->dev_replace);
 	if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {
 		WARN_ON(num_devices < 1);
 		num_devices--;
 	}
-	btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);
+	btrfs_dev_replace_read_unlock(&fs_info->dev_replace);
 
 	ret = btrfs_check_raid_min_devices(fs_info, num_devices - 1);
 	if (ret)
@@ -3910,12 +3910,12 @@ int btrfs_balance(struct btrfs_balance_control *bctl,
 	}
 
 	num_devices = fs_info->fs_devices->num_devices;
-	btrfs_dev_replace_lock(&fs_info->dev_replace, 0);
+	btrfs_dev_replace_read_lock(&fs_info->dev_replace);
 	if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {
 		BUG_ON(num_devices < 1);
 		num_devices--;
 	}
-	btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);
+	btrfs_dev_replace_read_unlock(&fs_info->dev_replace);
 	allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE | BTRFS_BLOCK_GROUP_DUP;
 	if (num_devices > 1)
 		allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
@@ -5241,11 +5241,11 @@ int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len)
 		ret = 1;
 	free_extent_map(em);
 
-	btrfs_dev_replace_lock(&fs_info->dev_replace, 0);
+	btrfs_dev_replace_read_lock(&fs_info->dev_replace);
 	if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace) &&
 	    fs_info->dev_replace.tgtdev)
 		ret++;
-	btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);
+	btrfs_dev_replace_read_unlock(&fs_info->dev_replace);
 
 	return ret;
 }
@@ -5823,10 +5823,10 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
 	if (!bbio_ret)
 		goto out;
 
-	btrfs_dev_replace_lock(dev_replace, 0);
+	btrfs_dev_replace_read_lock(dev_replace);
 	dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace);
 	if (!dev_replace_is_ongoing)
-		btrfs_dev_replace_unlock(dev_replace, 0);
+		btrfs_dev_replace_read_unlock(dev_replace);
 	else
 		btrfs_dev_replace_set_lock_blocking(dev_replace);
 
@@ -6024,7 +6024,7 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
 out:
 	if (dev_replace_is_ongoing) {
 		btrfs_dev_replace_clear_lock_blocking(dev_replace);
-		btrfs_dev_replace_unlock(dev_replace, 0);
+		btrfs_dev_replace_read_unlock(dev_replace);
 	}
 	free_extent_map(em);
 	return ret;