@@ -161,6 +161,8 @@ static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
struct rb_node *parent = NULL;
struct btrfs_block_group *cache;
+ ASSERT(block_group->length != 0);
+
spin_lock(&info->block_group_cache_lock);
p = &info->block_group_cache_tree.rb_node;
@@ -1768,7 +1770,7 @@ static void link_block_group(struct btrfs_block_group *cache)
}
static struct btrfs_block_group *btrfs_create_block_group_cache(
- struct btrfs_fs_info *fs_info, u64 start, u64 size)
+ struct btrfs_fs_info *fs_info, u64 start)
{
struct btrfs_block_group *cache;
@@ -1784,7 +1786,6 @@ static struct btrfs_block_group *btrfs_create_block_group_cache(
}
cache->start = start;
- cache->length = size;
cache->fs_info = fs_info;
cache->full_stripe_len = btrfs_full_stripe_len(fs_info, start);
@@ -1864,25 +1865,44 @@ static int check_chunk_block_group_mappings(struct btrfs_fs_info *fs_info)
return ret;
}
+static int read_block_group_item(struct btrfs_block_group *cache,
+ struct btrfs_path *path,
+ const struct btrfs_key *key)
+{
+ struct extent_buffer *leaf = path->nodes[0];
+ struct btrfs_block_group_item bgi;
+ int slot = path->slots[0];
+
+ cache->length = key->offset;
+
+ read_extent_buffer(leaf, &bgi, btrfs_item_ptr_offset(leaf, slot),
+ sizeof(bgi));
+ cache->used = btrfs_stack_block_group_used(&bgi);
+ cache->flags = btrfs_stack_block_group_flags(&bgi);
+
+ return 0;
+}
+
static int read_one_block_group(struct btrfs_fs_info *info,
struct btrfs_path *path,
const struct btrfs_key *key,
int need_clear)
{
- struct extent_buffer *leaf = path->nodes[0];
struct btrfs_block_group *cache;
struct btrfs_space_info *space_info;
- struct btrfs_block_group_item bgi;
const bool mixed = btrfs_fs_incompat(info, MIXED_GROUPS);
- int slot = path->slots[0];
int ret;
ASSERT(key->type == BTRFS_BLOCK_GROUP_ITEM_KEY);
- cache = btrfs_create_block_group_cache(info, key->objectid, key->offset);
+ cache = btrfs_create_block_group_cache(info, key->objectid);
if (!cache)
return -ENOMEM;
+ ret = read_block_group_item(cache, path, key);
+ if (ret < 0)
+ goto error;
+
if (need_clear) {
/*
* When we mount with old space cache, we need to
@@ -1897,10 +1917,6 @@ static int read_one_block_group(struct btrfs_fs_info *info,
if (btrfs_test_opt(info, SPACE_CACHE))
cache->disk_cache_state = BTRFS_DC_CLEAR;
}
- read_extent_buffer(leaf, &bgi, btrfs_item_ptr_offset(leaf, slot),
- sizeof(bgi));
- cache->used = btrfs_stack_block_group_used(&bgi);
- cache->flags = btrfs_stack_block_group_flags(&bgi);
if (!mixed && ((cache->flags & BTRFS_BLOCK_GROUP_METADATA) &&
(cache->flags & BTRFS_BLOCK_GROUP_DATA))) {
btrfs_err(info,
@@ -1928,15 +1944,15 @@ static int read_one_block_group(struct btrfs_fs_info *info,
* are empty, and we can just add all the space in and be done with it.
* This saves us _a_lot_ of time, particularly in the full case.
*/
- if (key->offset == cache->used) {
+ if (cache->length == cache->used) {
cache->last_byte_to_unpin = (u64)-1;
cache->cached = BTRFS_CACHE_FINISHED;
btrfs_free_excluded_extents(cache);
} else if (cache->used == 0) {
cache->last_byte_to_unpin = (u64)-1;
cache->cached = BTRFS_CACHE_FINISHED;
- add_new_free_space(cache, key->objectid,
- key->objectid + key->offset);
+ add_new_free_space(cache, cache->start,
+ cache->start + cache->length);
btrfs_free_excluded_extents(cache);
}
@@ -1946,7 +1962,7 @@ static int read_one_block_group(struct btrfs_fs_info *info,
goto error;
}
trace_btrfs_add_block_group(info, cache, 0);
- btrfs_update_space_info(info, cache->flags, key->offset,
+ btrfs_update_space_info(info, cache->flags, cache->length,
cache->used, cache->bytes_super, &space_info);
cache->space_info = space_info;
@@ -2093,10 +2109,11 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans, u64 bytes_used,
btrfs_set_log_full_commit(trans);
- cache = btrfs_create_block_group_cache(fs_info, chunk_offset, size);
+ cache = btrfs_create_block_group_cache(fs_info, chunk_offset);
if (!cache)
return -ENOMEM;
+ cache->length = size;
cache->used = bytes_used;
cache->flags = type;
cache->last_byte_to_unpin = (u64)-1;
Structure btrfs_block_group has the following members which are currently read from on-disk block group item and key: - Length From item key. - Used - Flags From block group item. However for incoming skinny block group tree, we are going to read those members from different sources. This patch will refactor such read by: - Don't initialize btrfs_block_group::length at allocation Caller should initialize them manually. Also to avoid possible (well, only two callers) missing initialization, add extra ASSERT() in btrfs_add_block_group_cache(). - Refactor length/used/flags initialization into one function The new function, fill_one_block_group() will handle the initialization of such members. - Use btrfs_block_group::length to replace key::offset Since skinny block group item would have a different meaning for its key offset. Signed-off-by: Qu Wenruo <wqu@suse.com> --- fs/btrfs/block-group.c | 47 ++++++++++++++++++++++++++++-------------- 1 file changed, 32 insertions(+), 15 deletions(-)