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/transaction.h b/fs/btrfs/transaction.h
index 93c7ccb..56e728d 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -45,13 +45,13 @@
struct btrfs_trans_handle {
u64 transid;
+ u64 block_group;
+ u64 bytes_reserved;
unsigned long blocks_reserved;
unsigned long blocks_used;
- struct btrfs_transaction *transaction;
- u64 block_group;
- u64 alloc_exclude_start;
- u64 alloc_exclude_nr;
unsigned long delayed_ref_updates;
+ struct btrfs_transaction *transaction;
+ struct btrfs_block_rsv *block_rsv;
};
struct btrfs_pending_snapshot {