Btrfs: Add chunk uuids and update multi-device back references

Block headers now store the chunk tree uuid

Chunk items records the device uuid for each stripes

Device extent items record better back refs to the chunk tree

Block groups record better back refs to the chunk tree

The chunk tree format has also changed.  The objectid of BTRFS_CHUNK_ITEM_KEY
used to be the logical offset of the chunk.  Now it is a chunk tree id,
with the logical offset being stored in the offset field of the key.

This allows a single chunk tree to record multiple logical address spaces,
upping the number of bytes indexed by a chunk tree from 2^64 to
2^128.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 8 insertions, 14 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index e49147e767df..71f045c63493 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -35,10 +35,6 @@ static int finish_current_insert(struct btrfs_trans_handle *trans, struct
                                  btrfs_root *extent_root);
 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
                                btrfs_root *extent_root);
-int btrfs_make_block_group(struct btrfs_trans_handle *trans,
-                           struct btrfs_root *root, u64 bytes_used,
-                           u64 type, u64 chunk_tree, u64 chunk_objectid,
-                           u64 size);
 
 
 static int cache_block_group(struct btrfs_root *root,
@@ -980,7 +976,6 @@ int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
                 ret = get_state_private(block_group_cache, start, &ptr);
                 if (ret)
                         break;
-
                 cache = (struct btrfs_block_group_cache *)(unsigned long)ptr;
                 err = write_one_cache_group(trans, root,
                                             path, cache);
@@ -1094,8 +1089,7 @@ printk("space info full %Lu\n", flags);
         BUG_ON(ret);
 
         ret = btrfs_make_block_group(trans, extent_root, 0, flags,
-                     extent_root->fs_info->chunk_root->root_key.objectid,
-                     start, num_bytes);
+                     BTRFS_FIRST_CHUNK_TREE_OBJECTID, start, num_bytes);
         BUG_ON(ret);
 
         return 0;
@@ -2782,7 +2776,7 @@ error:
 
 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
                            struct btrfs_root *root, u64 bytes_used,
-                           u64 type, u64 chunk_tree, u64 chunk_objectid,
+                           u64 type, u64 chunk_objectid, u64 chunk_offset,
                            u64 size)
 {
         int ret;
@@ -2796,14 +2790,14 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans,
 
         cache = kmalloc(sizeof(*cache), GFP_NOFS);
         BUG_ON(!cache);
-        cache->key.objectid = chunk_objectid;
+        cache->key.objectid = chunk_offset;
         cache->key.offset = size;
         cache->cached = 0;
         cache->pinned = 0;
+
         btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
         memset(&cache->item, 0, sizeof(cache->item));
         btrfs_set_block_group_used(&cache->item, bytes_used);
-        btrfs_set_block_group_chunk_tree(&cache->item, chunk_tree);
         btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
         cache->flags = type;
         btrfs_set_block_group_flags(&cache->item, type);
@@ -2813,12 +2807,12 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans,
         BUG_ON(ret);
 
         bit = block_group_state_bits(type);
-        set_extent_bits(block_group_cache, chunk_objectid,
-                        chunk_objectid + size - 1,
+        set_extent_bits(block_group_cache, chunk_offset,
+                        chunk_offset + size - 1,
                         bit | EXTENT_LOCKED, GFP_NOFS);
-        set_state_private(block_group_cache, chunk_objectid,
-                          (unsigned long)cache);
 
+        set_state_private(block_group_cache, chunk_offset,
+                          (unsigned long)cache);
         ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
                                 sizeof(cache->item));
         BUG_ON(ret);