1 files changed, 78 insertions, 39 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 5cf405b0828d..23e7d36ff325 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -276,7 +276,7 @@ loop_lock:
 		 * is now congested.  Back off and let other work structs
 		 * run instead
 		 */
-		if (pending && bdi_write_congested(bdi) && batch_run > 32 &&
+		if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
 		    fs_info->fs_devices->open_devices > 1) {
 			struct io_context *ioc;
 
@@ -719,10 +719,9 @@ error:
  * called very infrequently and that a given device has a small number
  * of extents
  */
-static noinline int find_free_dev_extent(struct btrfs_trans_handle *trans,
-					 struct btrfs_device *device,
-					 u64 num_bytes, u64 *start,
-					 u64 *max_avail)
+int find_free_dev_extent(struct btrfs_trans_handle *trans,
+			 struct btrfs_device *device, u64 num_bytes,
+			 u64 *start, u64 *max_avail)
 {
 	struct btrfs_key key;
 	struct btrfs_root *root = device->dev_root;
@@ -1736,6 +1735,10 @@ static int btrfs_relocate_chunk(struct btrfs_root *root,
 	extent_root = root->fs_info->extent_root;
 	em_tree = &root->fs_info->mapping_tree.map_tree;
 
+	ret = btrfs_can_relocate(extent_root, chunk_offset);
+	if (ret)
+		return -ENOSPC;
+
 	/* step one, relocate all the extents inside this chunk */
 	ret = btrfs_relocate_block_group(extent_root, chunk_offset);
 	BUG_ON(ret);
@@ -1749,9 +1752,9 @@ static int btrfs_relocate_chunk(struct btrfs_root *root,
 	 * step two, delete the device extents and the
 	 * chunk tree entries
 	 */
-	spin_lock(&em_tree->lock);
+	read_lock(&em_tree->lock);
 	em = lookup_extent_mapping(em_tree, chunk_offset, 1);
-	spin_unlock(&em_tree->lock);
+	read_unlock(&em_tree->lock);
 
 	BUG_ON(em->start > chunk_offset ||
 	       em->start + em->len < chunk_offset);
@@ -1780,9 +1783,9 @@ static int btrfs_relocate_chunk(struct btrfs_root *root,
 	ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
 	BUG_ON(ret);
 
-	spin_lock(&em_tree->lock);
+	write_lock(&em_tree->lock);
 	remove_extent_mapping(em_tree, em);
-	spin_unlock(&em_tree->lock);
+	write_unlock(&em_tree->lock);
 
 	kfree(map);
 	em->bdev = NULL;
@@ -1807,12 +1810,15 @@ static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
 	struct btrfs_key found_key;
 	u64 chunk_tree = chunk_root->root_key.objectid;
 	u64 chunk_type;
+	bool retried = false;
+	int failed = 0;
 	int ret;
 
 	path = btrfs_alloc_path();
 	if (!path)
 		return -ENOMEM;
 
+again:
 	key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
 	key.offset = (u64)-1;
 	key.type = BTRFS_CHUNK_ITEM_KEY;
@@ -1842,7 +1848,10 @@ static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
 			ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
 						   found_key.objectid,
 						   found_key.offset);
-			BUG_ON(ret);
+			if (ret == -ENOSPC)
+				failed++;
+			else if (ret)
+				BUG();
 		}
 
 		if (found_key.offset == 0)
@@ -1850,6 +1859,14 @@ static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
 		key.offset = found_key.offset - 1;
 	}
 	ret = 0;
+	if (failed && !retried) {
+		failed = 0;
+		retried = true;
+		goto again;
+	} else if (failed && retried) {
+		WARN_ON(1);
+		ret = -ENOSPC;
+	}
 error:
 	btrfs_free_path(path);
 	return ret;
@@ -1894,6 +1911,8 @@ int btrfs_balance(struct btrfs_root *dev_root)
 			continue;
 
 		ret = btrfs_shrink_device(device, old_size - size_to_free);
+		if (ret == -ENOSPC)
+			break;
 		BUG_ON(ret);
 
 		trans = btrfs_start_transaction(dev_root, 1);
@@ -1938,9 +1957,8 @@ int btrfs_balance(struct btrfs_root *dev_root)
 		chunk = btrfs_item_ptr(path->nodes[0],
 				       path->slots[0],
 				       struct btrfs_chunk);
-		key.offset = found_key.offset;
 		/* chunk zero is special */
-		if (key.offset == 0)
+		if (found_key.offset == 0)
 			break;
 
 		btrfs_release_path(chunk_root, path);
@@ -1948,7 +1966,8 @@ int btrfs_balance(struct btrfs_root *dev_root)
 					   chunk_root->root_key.objectid,
 					   found_key.objectid,
 					   found_key.offset);
-		BUG_ON(ret);
+		BUG_ON(ret && ret != -ENOSPC);
+		key.offset = found_key.offset - 1;
 	}
 	ret = 0;
 error:
@@ -1974,10 +1993,13 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
 	u64 chunk_offset;
 	int ret;
 	int slot;
+	int failed = 0;
+	bool retried = false;
 	struct extent_buffer *l;
 	struct btrfs_key key;
 	struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
 	u64 old_total = btrfs_super_total_bytes(super_copy);
+	u64 old_size = device->total_bytes;
 	u64 diff = device->total_bytes - new_size;
 
 	if (new_size >= device->total_bytes)
@@ -1987,12 +2009,6 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
 	if (!path)
 		return -ENOMEM;
 
-	trans = btrfs_start_transaction(root, 1);
-	if (!trans) {
-		ret = -ENOMEM;
-		goto done;
-	}
-
 	path->reada = 2;
 
 	lock_chunks(root);
@@ -2001,8 +2017,8 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
 	if (device->writeable)
 		device->fs_devices->total_rw_bytes -= diff;
 	unlock_chunks(root);
-	btrfs_end_transaction(trans, root);
 
+again:
 	key.objectid = device->devid;
 	key.offset = (u64)-1;
 	key.type = BTRFS_DEV_EXTENT_KEY;
@@ -2017,6 +2033,7 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
 			goto done;
 		if (ret) {
 			ret = 0;
+			btrfs_release_path(root, path);
 			break;
 		}
 
@@ -2024,14 +2041,18 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
 		slot = path->slots[0];
 		btrfs_item_key_to_cpu(l, &key, path->slots[0]);
 
-		if (key.objectid != device->devid)
+		if (key.objectid != device->devid) {
+			btrfs_release_path(root, path);
 			break;
+		}
 
 		dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
 		length = btrfs_dev_extent_length(l, dev_extent);
 
-		if (key.offset + length <= new_size)
+		if (key.offset + length <= new_size) {
+			btrfs_release_path(root, path);
 			break;
+		}
 
 		chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
 		chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
@@ -2040,8 +2061,26 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
 
 		ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
 					   chunk_offset);
-		if (ret)
+		if (ret && ret != -ENOSPC)
 			goto done;
+		if (ret == -ENOSPC)
+			failed++;
+		key.offset -= 1;
+	}
+
+	if (failed && !retried) {
+		failed = 0;
+		retried = true;
+		goto again;
+	} else if (failed && retried) {
+		ret = -ENOSPC;
+		lock_chunks(root);
+
+		device->total_bytes = old_size;
+		if (device->writeable)
+			device->fs_devices->total_rw_bytes += diff;
+		unlock_chunks(root);
+		goto done;
 	}
 
 	/* Shrinking succeeded, else we would be at "done". */
@@ -2294,9 +2333,9 @@ again:
 	em->block_len = em->len;
 
 	em_tree = &extent_root->fs_info->mapping_tree.map_tree;
-	spin_lock(&em_tree->lock);
+	write_lock(&em_tree->lock);
 	ret = add_extent_mapping(em_tree, em);
-	spin_unlock(&em_tree->lock);
+	write_unlock(&em_tree->lock);
 	BUG_ON(ret);
 	free_extent_map(em);
 
@@ -2491,9 +2530,9 @@ int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
 	int readonly = 0;
 	int i;
 
-	spin_lock(&map_tree->map_tree.lock);
+	read_lock(&map_tree->map_tree.lock);
 	em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
-	spin_unlock(&map_tree->map_tree.lock);
+	read_unlock(&map_tree->map_tree.lock);
 	if (!em)
 		return 1;
 
@@ -2518,11 +2557,11 @@ void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
 	struct extent_map *em;
 
 	while (1) {
-		spin_lock(&tree->map_tree.lock);
+		write_lock(&tree->map_tree.lock);
 		em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
 		if (em)
 			remove_extent_mapping(&tree->map_tree, em);
-		spin_unlock(&tree->map_tree.lock);
+		write_unlock(&tree->map_tree.lock);
 		if (!em)
 			break;
 		kfree(em->bdev);
@@ -2540,9 +2579,9 @@ int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
 	struct extent_map_tree *em_tree = &map_tree->map_tree;
 	int ret;
 
-	spin_lock(&em_tree->lock);
+	read_lock(&em_tree->lock);
 	em = lookup_extent_mapping(em_tree, logical, len);
-	spin_unlock(&em_tree->lock);
+	read_unlock(&em_tree->lock);
 	BUG_ON(!em);
 
 	BUG_ON(em->start > logical || em->start + em->len < logical);
@@ -2604,9 +2643,9 @@ again:
 		atomic_set(&multi->error, 0);
 	}
 
-	spin_lock(&em_tree->lock);
+	read_lock(&em_tree->lock);
 	em = lookup_extent_mapping(em_tree, logical, *length);
-	spin_unlock(&em_tree->lock);
+	read_unlock(&em_tree->lock);
 
 	if (!em && unplug_page)
 		return 0;
@@ -2763,9 +2802,9 @@ int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
 	u64 stripe_nr;
 	int i, j, nr = 0;
 
-	spin_lock(&em_tree->lock);
+	read_lock(&em_tree->lock);
 	em = lookup_extent_mapping(em_tree, chunk_start, 1);
-	spin_unlock(&em_tree->lock);
+	read_unlock(&em_tree->lock);
 
 	BUG_ON(!em || em->start != chunk_start);
 	map = (struct map_lookup *)em->bdev;
@@ -3053,9 +3092,9 @@ static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
 	logical = key->offset;
 	length = btrfs_chunk_length(leaf, chunk);
 
-	spin_lock(&map_tree->map_tree.lock);
+	read_lock(&map_tree->map_tree.lock);
 	em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
-	spin_unlock(&map_tree->map_tree.lock);
+	read_unlock(&map_tree->map_tree.lock);
 
 	/* already mapped? */
 	if (em && em->start <= logical && em->start + em->len > logical) {
@@ -3114,9 +3153,9 @@ static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
 		map->stripes[i].dev->in_fs_metadata = 1;
 	}
 
-	spin_lock(&map_tree->map_tree.lock);
+	write_lock(&map_tree->map_tree.lock);
 	ret = add_extent_mapping(&map_tree->map_tree, em);
-	spin_unlock(&map_tree->map_tree.lock);
+	write_unlock(&map_tree->map_tree.lock);
 	BUG_ON(ret);
 	free_extent_map(em);