Btrfs: Introduce contexts for metadata reservation
Introducing metadata reseravtion contexts has two major advantages.
First, it makes metadata reseravtion more traceable. Second, it can
reclaim freed space and re-add them to the itself after transaction
committed.
Besides add btrfs_block_rsv structure and related helper functions,
This patch contains following changes:
Move code that decides if freed tree block should be pinned into
btrfs_free_tree_block().
Make space accounting more accurate, mainly for handling read only
block groups.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 05f26ac..574594c 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -903,6 +903,7 @@
root->name = NULL;
root->in_sysfs = 0;
root->inode_tree = RB_ROOT;
+ root->block_rsv = NULL;
INIT_LIST_HEAD(&root->dirty_list);
INIT_LIST_HEAD(&root->orphan_list);
@@ -910,6 +911,7 @@
spin_lock_init(&root->node_lock);
spin_lock_init(&root->list_lock);
spin_lock_init(&root->inode_lock);
+ spin_lock_init(&root->accounting_lock);
mutex_init(&root->objectid_mutex);
mutex_init(&root->log_mutex);
init_waitqueue_head(&root->log_writer_wait);
@@ -1620,6 +1622,13 @@
INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
INIT_LIST_HEAD(&fs_info->space_info);
btrfs_mapping_init(&fs_info->mapping_tree);
+ btrfs_init_block_rsv(&fs_info->global_block_rsv);
+ btrfs_init_block_rsv(&fs_info->delalloc_block_rsv);
+ btrfs_init_block_rsv(&fs_info->trans_block_rsv);
+ btrfs_init_block_rsv(&fs_info->chunk_block_rsv);
+ btrfs_init_block_rsv(&fs_info->empty_block_rsv);
+ INIT_LIST_HEAD(&fs_info->durable_block_rsv_list);
+ mutex_init(&fs_info->durable_block_rsv_mutex);
atomic_set(&fs_info->nr_async_submits, 0);
atomic_set(&fs_info->async_delalloc_pages, 0);
atomic_set(&fs_info->async_submit_draining, 0);