From 017e5369eb353559d68a11d4a718faa634533821 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Mon, 28 Jul 2008 15:32:51 -0400 Subject: Btrfs: Leaf reference cache update This changes the reference cache to make a single cache per root instead of one cache per transaction, and to key by the byte number of the disk block instead of the keys inside. This makes it much less likely to have cache misses if a snapshot or something has an extra reference on a higher node or a leaf while the first transaction that added the leaf into the cache is dropping. Some throttling is added to functions that free blocks heavily so they wait for old transactions to drop. Signed-off-by: Chris Mason --- fs/btrfs/extent-tree.c | 18 ++++++------------ 1 file changed, 6 insertions(+), 12 deletions(-) (limited to 'fs/btrfs/extent-tree.c') diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 7b24f1511654..0e294cfaa60c 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -1004,8 +1004,6 @@ int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, goto out; } - btrfs_item_key_to_cpu(buf, &ref->key, 0); - ref->bytenr = buf->start; ref->owner = btrfs_header_owner(buf); ref->generation = btrfs_header_generation(buf); @@ -2387,19 +2385,15 @@ static void noinline reada_walk_down(struct btrfs_root *root, } } -/* - * we want to avoid as much random IO as we can with the alloc mutex - * held, so drop the lock and do the lookup, then do it again with the - * lock held. - */ int drop_snap_lookup_refcount(struct btrfs_root *root, u64 start, u64 len, u32 *refs) { + int ret; mutex_unlock(&root->fs_info->alloc_mutex); - lookup_extent_ref(NULL, root, start, len, refs); + ret = lookup_extent_ref(NULL, root, start, len, refs); cond_resched(); mutex_lock(&root->fs_info->alloc_mutex); - return lookup_extent_ref(NULL, root, start, len, refs); + return ret; } /* @@ -2468,11 +2462,11 @@ static int noinline walk_down_tree(struct btrfs_trans_handle *trans, BUG_ON(ret); continue; } - + if (*level == 1) { struct btrfs_key key; btrfs_node_key_to_cpu(cur, &key, path->slots[*level]); - ref = btrfs_lookup_leaf_ref(root, &key); + ref = btrfs_lookup_leaf_ref(root, bytenr); if (ref) { ret = drop_leaf_ref(trans, root, ref); BUG_ON(ret); @@ -2482,7 +2476,6 @@ static int noinline walk_down_tree(struct btrfs_trans_handle *trans, break; } } - next = btrfs_find_tree_block(root, bytenr, blocksize); if (!next || !btrfs_buffer_uptodate(next, ptr_gen)) { free_extent_buffer(next); @@ -2672,6 +2665,7 @@ int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root ret = -EAGAIN; break; } + wake_up(&root->fs_info->transaction_throttle); } for (i = 0; i <= orig_level; i++) { if (path->nodes[i]) { -- cgit v1.2.3