Btrfs: Add run time btree defrag, and an ioctl to force btree defrag
This adds two types of btree defrag, a run time form that tries to
defrag recently allocated blocks in the btree when they are still in ram,
and an ioctl that forces defrag of all btree blocks.
File data blocks are not defragged yet, but this can make a huge difference
in sequential btree reads.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index ebf44f3..8b2714e 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -70,5 +70,6 @@
void btrfs_init_transaction_sys(void);
void btrfs_exit_transaction_sys(void);
int btrfs_add_dead_root(struct btrfs_root *root, struct list_head *dead_list);
+int btrfs_defrag_dirty_roots(struct btrfs_fs_info *info);
#endif