From f0486c68e4bd9a06a5904d3eeb3a0d73a83befb8 Mon Sep 17 00:00:00 2001 From: "Yan, Zheng" Date: Sun, 16 May 2010 10:46:25 -0400 Subject: 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 --- fs/btrfs/ctree.c | 104 +++++++++++++++++++++++++++++++++---------------------- 1 file changed, 63 insertions(+), 41 deletions(-) (limited to 'fs/btrfs/ctree.c') diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 6795a713b205..6bee8e5204fb 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -280,7 +280,8 @@ int btrfs_block_can_be_shared(struct btrfs_root *root, static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *buf, - struct extent_buffer *cow) + struct extent_buffer *cow, + int *last_ref) { u64 refs; u64 owner; @@ -366,6 +367,7 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, BUG_ON(ret); } clean_tree_block(trans, root, buf); + *last_ref = 1; } return 0; } @@ -392,6 +394,7 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, struct btrfs_disk_key disk_key; struct extent_buffer *cow; int level; + int last_ref = 0; int unlock_orig = 0; u64 parent_start; @@ -442,7 +445,7 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, (unsigned long)btrfs_header_fsid(cow), BTRFS_FSID_SIZE); - update_ref_for_cow(trans, root, buf, cow); + update_ref_for_cow(trans, root, buf, cow, &last_ref); if (buf == root->node) { WARN_ON(parent && parent != buf); @@ -457,8 +460,8 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, extent_buffer_get(cow); spin_unlock(&root->node_lock); - btrfs_free_tree_block(trans, root, buf->start, buf->len, - parent_start, root->root_key.objectid, level); + btrfs_free_tree_block(trans, root, buf, parent_start, + last_ref); free_extent_buffer(buf); add_root_to_dirty_list(root); } else { @@ -473,8 +476,8 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, btrfs_set_node_ptr_generation(parent, parent_slot, trans->transid); btrfs_mark_buffer_dirty(parent); - btrfs_free_tree_block(trans, root, buf->start, buf->len, - parent_start, root->root_key.objectid, level); + btrfs_free_tree_block(trans, root, buf, parent_start, + last_ref); } if (unlock_orig) btrfs_tree_unlock(buf); @@ -949,6 +952,22 @@ int btrfs_bin_search(struct extent_buffer *eb, struct btrfs_key *key, return bin_search(eb, key, level, slot); } +static void root_add_used(struct btrfs_root *root, u32 size) +{ + spin_lock(&root->accounting_lock); + btrfs_set_root_used(&root->root_item, + btrfs_root_used(&root->root_item) + size); + spin_unlock(&root->accounting_lock); +} + +static void root_sub_used(struct btrfs_root *root, u32 size) +{ + spin_lock(&root->accounting_lock); + btrfs_set_root_used(&root->root_item, + btrfs_root_used(&root->root_item) - size); + spin_unlock(&root->accounting_lock); +} + /* given a node and slot number, this reads the blocks it points to. The * extent buffer is returned with a reference taken (but unlocked). * NULL is returned on error. @@ -1019,7 +1038,11 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, btrfs_tree_lock(child); btrfs_set_lock_blocking(child); ret = btrfs_cow_block(trans, root, child, mid, 0, &child); - BUG_ON(ret); + if (ret) { + btrfs_tree_unlock(child); + free_extent_buffer(child); + goto enospc; + } spin_lock(&root->node_lock); root->node = child; @@ -1034,11 +1057,12 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, btrfs_tree_unlock(mid); /* once for the path */ free_extent_buffer(mid); - ret = btrfs_free_tree_block(trans, root, mid->start, mid->len, - 0, root->root_key.objectid, level); + + root_sub_used(root, mid->len); + btrfs_free_tree_block(trans, root, mid, 0, 1); /* once for the root ptr */ free_extent_buffer(mid); - return ret; + return 0; } if (btrfs_header_nritems(mid) > BTRFS_NODEPTRS_PER_BLOCK(root) / 4) @@ -1088,23 +1112,16 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, if (wret < 0 && wret != -ENOSPC) ret = wret; if (btrfs_header_nritems(right) == 0) { - u64 bytenr = right->start; - u32 blocksize = right->len; - clean_tree_block(trans, root, right); btrfs_tree_unlock(right); - free_extent_buffer(right); - right = NULL; wret = del_ptr(trans, root, path, level + 1, pslot + 1); if (wret) ret = wret; - wret = btrfs_free_tree_block(trans, root, - bytenr, blocksize, 0, - root->root_key.objectid, - level); - if (wret) - ret = wret; + root_sub_used(root, right->len); + btrfs_free_tree_block(trans, root, right, 0, 1); + free_extent_buffer(right); + right = NULL; } else { struct btrfs_disk_key right_key; btrfs_node_key(right, &right_key, 0); @@ -1136,21 +1153,15 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, BUG_ON(wret == 1); } if (btrfs_header_nritems(mid) == 0) { - /* we've managed to empty the middle node, drop it */ - u64 bytenr = mid->start; - u32 blocksize = mid->len; - clean_tree_block(trans, root, mid); btrfs_tree_unlock(mid); - free_extent_buffer(mid); - mid = NULL; wret = del_ptr(trans, root, path, level + 1, pslot); if (wret) ret = wret; - wret = btrfs_free_tree_block(trans, root, bytenr, blocksize, - 0, root->root_key.objectid, level); - if (wret) - ret = wret; + root_sub_used(root, mid->len); + btrfs_free_tree_block(trans, root, mid, 0, 1); + free_extent_buffer(mid); + mid = NULL; } else { /* update the parent key to reflect our changes */ struct btrfs_disk_key mid_key; @@ -1740,7 +1751,6 @@ again: p->nodes[level + 1], p->slots[level + 1], &b); if (err) { - free_extent_buffer(b); ret = err; goto done; } @@ -2076,6 +2086,8 @@ static noinline int insert_new_root(struct btrfs_trans_handle *trans, if (IS_ERR(c)) return PTR_ERR(c); + root_add_used(root, root->nodesize); + memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header)); btrfs_set_header_nritems(c, 1); btrfs_set_header_level(c, level); @@ -2134,6 +2146,7 @@ static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root int nritems; BUG_ON(!path->nodes[level]); + btrfs_assert_tree_locked(path->nodes[level]); lower = path->nodes[level]; nritems = btrfs_header_nritems(lower); BUG_ON(slot > nritems); @@ -2202,6 +2215,8 @@ static noinline int split_node(struct btrfs_trans_handle *trans, if (IS_ERR(split)) return PTR_ERR(split); + root_add_used(root, root->nodesize); + memset_extent_buffer(split, 0, 0, sizeof(struct btrfs_header)); btrfs_set_header_level(split, btrfs_header_level(c)); btrfs_set_header_bytenr(split, split->start); @@ -2415,6 +2430,9 @@ static noinline int __push_leaf_right(struct btrfs_trans_handle *trans, if (left_nritems) btrfs_mark_buffer_dirty(left); + else + clean_tree_block(trans, root, left); + btrfs_mark_buffer_dirty(right); btrfs_item_key(right, &disk_key, 0); @@ -2660,6 +2678,8 @@ static noinline int __push_leaf_left(struct btrfs_trans_handle *trans, btrfs_mark_buffer_dirty(left); if (right_nritems) btrfs_mark_buffer_dirty(right); + else + clean_tree_block(trans, root, right); btrfs_item_key(right, &disk_key, 0); wret = fixup_low_keys(trans, root, path, &disk_key, 1); @@ -2669,8 +2689,6 @@ static noinline int __push_leaf_left(struct btrfs_trans_handle *trans, /* then fixup the leaf pointer in the path */ if (path->slots[0] < push_items) { path->slots[0] += old_left_nritems; - if (btrfs_header_nritems(path->nodes[0]) == 0) - clean_tree_block(trans, root, path->nodes[0]); btrfs_tree_unlock(path->nodes[0]); free_extent_buffer(path->nodes[0]); path->nodes[0] = left; @@ -2932,10 +2950,10 @@ again: right = btrfs_alloc_free_block(trans, root, root->leafsize, 0, root->root_key.objectid, &disk_key, 0, l->start, 0); - if (IS_ERR(right)) { - BUG_ON(1); + if (IS_ERR(right)) return PTR_ERR(right); - } + + root_add_used(root, root->leafsize); memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header)); btrfs_set_header_bytenr(right, right->start); @@ -3054,7 +3072,8 @@ static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans, btrfs_set_path_blocking(path); ret = split_leaf(trans, root, &key, path, ins_len, 1); - BUG_ON(ret); + if (ret) + goto err; path->keep_locks = 0; btrfs_unlock_up_safe(path, 1); @@ -3796,9 +3815,10 @@ static noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans, */ btrfs_unlock_up_safe(path, 0); - ret = btrfs_free_tree_block(trans, root, leaf->start, leaf->len, - 0, root->root_key.objectid, 0); - return ret; + root_sub_used(root, leaf->len); + + btrfs_free_tree_block(trans, root, leaf, 0, 1); + return 0; } /* * delete the item at the leaf level in path. If that empties @@ -3865,6 +3885,8 @@ int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, if (leaf == root->node) { btrfs_set_header_level(leaf, 0); } else { + btrfs_set_path_blocking(path); + clean_tree_block(trans, root, leaf); ret = btrfs_del_leaf(trans, root, path, leaf); BUG_ON(ret); } -- cgit v1.2.3