From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:54711 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965631AbeFOLGM (ORCPT ); Fri, 15 Jun 2018 07:06:12 -0400 From: Nikolay Borisov To: linux-btrfs@vger.kernel.org Cc: osandov@osandov.com, Nikolay Borisov Subject: [PATCH 3/6] btrfs-progs: Pull free space tree related code from kernel Date: Fri, 15 Jun 2018 14:05:59 +0300 Message-Id: <1529060762-4372-4-git-send-email-nborisov@suse.com> In-Reply-To: <1529060762-4372-1-git-send-email-nborisov@suse.com> References: <1529060762-4372-1-git-send-email-nborisov@suse.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: To help implement free space tree checker in user space some kernel function are necessary, namely iterating/deleting/adding freespace items, some internal search functions. Functions to populate a block group based on the extent tree. The code is largely copy/paste from the kernel with locking eliminated (i.e free_space_lock). It supports reading/writing of both bitmap and extent based FST trees. Signed-off-by: Nikolay Borisov --- ctree.c | 77 +++++ ctree.h | 4 + free-space-tree.c | 893 +++++++++++++++++++++++++++++++++++++++++++++++++++++- free-space-tree.h | 10 +- 4 files changed, 977 insertions(+), 7 deletions(-) diff --git a/ctree.c b/ctree.c index d8a6883aa85f..aa1568620205 100644 --- a/ctree.c +++ b/ctree.c @@ -1226,6 +1226,83 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root } /* + * helper to use instead of search slot if no exact match is needed but + * instead the next or previous item should be returned. + * When find_higher is true, the next higher item is returned, the next lower + * otherwise. + * When return_any and find_higher are both true, and no higher item is found, + * return the next lower instead. + * When return_any is true and find_higher is false, and no lower item is found, + * return the next higher instead. + * It returns 0 if any item is found, 1 if none is found (tree empty), and + * < 0 on error + */ +int btrfs_search_slot_for_read(struct btrfs_root *root, + const struct btrfs_key *key, + struct btrfs_path *p, int find_higher, + int return_any) +{ + int ret; + struct extent_buffer *leaf; + +again: + ret = btrfs_search_slot(NULL, root, key, p, 0, 0); + if (ret <= 0) + return ret; + /* + * a return value of 1 means the path is at the position where the + * item should be inserted. Normally this is the next bigger item, + * but in case the previous item is the last in a leaf, path points + * to the first free slot in the previous leaf, i.e. at an invalid + * item. + */ + leaf = p->nodes[0]; + + if (find_higher) { + if (p->slots[0] >= btrfs_header_nritems(leaf)) { + ret = btrfs_next_leaf(root, p); + if (ret <= 0) + return ret; + if (!return_any) + return 1; + /* + * no higher item found, return the next + * lower instead + */ + return_any = 0; + find_higher = 0; + btrfs_release_path(p); + goto again; + } + } else { + if (p->slots[0] == 0) { + ret = btrfs_prev_leaf(root, p); + if (ret < 0) + return ret; + if (!ret) { + leaf = p->nodes[0]; + if (p->slots[0] == btrfs_header_nritems(leaf)) + p->slots[0]--; + return 0; + } + if (!return_any) + return 1; + /* + * no lower item found, return the next + * higher instead + */ + return_any = 0; + find_higher = 1; + btrfs_release_path(p); + goto again; + } else { + --p->slots[0]; + } + } + return 0; +} + +/* * adjust the pointers going up the tree, starting at level * making sure the right key of each node is points to 'key'. * This is used after shifting pointers to the left, so it stops diff --git a/ctree.h b/ctree.h index 3e9ca2ca8432..ade883fecbd6 100644 --- a/ctree.h +++ b/ctree.h @@ -2619,6 +2619,10 @@ int btrfs_split_item(struct btrfs_trans_handle *trans, int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_key *key, struct btrfs_path *p, int ins_len, int cow); +int btrfs_search_slot_for_read(struct btrfs_root *root, + const struct btrfs_key *key, + struct btrfs_path *p, int find_higher, + int return_any); int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *found_path, u64 iobjectid, u64 ioff, u8 key_type, struct btrfs_key *found_key); diff --git a/free-space-tree.c b/free-space-tree.c index 139a031e8483..6acb71378110 100644 --- a/free-space-tree.c +++ b/free-space-tree.c @@ -47,8 +47,7 @@ search_free_space_info(struct btrfs_trans_handle *trans, } static int free_space_test_bit(struct btrfs_block_group_cache *block_group, - struct btrfs_path *path, u64 offset, - u64 sectorsize) + struct btrfs_path *path, u64 offset) { struct extent_buffer *leaf; struct btrfs_key key; @@ -64,10 +63,756 @@ static int free_space_test_bit(struct btrfs_block_group_cache *block_group, ASSERT(offset >= found_start && offset < found_end); ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); - i = (offset - found_start) / sectorsize; + i = (offset - found_start) / leaf->fs_info->sectorsize; return !!extent_buffer_test_bit(leaf, ptr, i); } +/* + * btrfs_search_slot() but we're looking for the greatest key less than the + * passed key. + */ +static int btrfs_search_prev_slot(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_key *key, struct btrfs_path *p, + int ins_len, int cow) +{ + int ret; + + ret = btrfs_search_slot(trans, root, key, p, ins_len, cow); + if (ret < 0) + return ret; + + if (ret == 0) { + ASSERT(0); + return -EIO; + } + + if (p->slots[0] == 0) { + ASSERT(0); + return -EIO; + } + p->slots[0]--; + + return 0; +} + +static int add_new_free_space_info(struct btrfs_trans_handle *trans, + struct btrfs_block_group_cache *block_group, + struct btrfs_path *path) +{ + struct btrfs_root *root = trans->fs_info->free_space_root; + struct btrfs_free_space_info *info; + struct btrfs_key key; + struct extent_buffer *leaf; + int ret; + + key.objectid = block_group->key.objectid; + key.type = BTRFS_FREE_SPACE_INFO_KEY; + key.offset = block_group->key.offset; + + ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(*info)); + if (ret) + goto out; + + leaf = path->nodes[0]; + info = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_free_space_info); + btrfs_set_free_space_extent_count(leaf, info, 0); + btrfs_set_free_space_flags(leaf, info, 0); + btrfs_mark_buffer_dirty(leaf); + + ret = 0; +out: + btrfs_release_path(path); + return ret; +} + +static int update_free_space_extent_count(struct btrfs_trans_handle *trans, + struct btrfs_block_group_cache *block_group, + struct btrfs_path *path, + int new_extents) +{ + struct btrfs_free_space_info *info; + u32 extent_count; + int ret = 0; + + if (new_extents == 0) + return 0; + + info = search_free_space_info(trans, trans->fs_info, block_group, path, + 1); + if (IS_ERR(info)) { + ret = PTR_ERR(info); + goto out; + } + extent_count = btrfs_free_space_extent_count(path->nodes[0], info); + + extent_count += new_extents; + btrfs_set_free_space_extent_count(path->nodes[0], info, extent_count); + btrfs_mark_buffer_dirty(path->nodes[0]); + btrfs_release_path(path); +out: + return ret; +} + + +static void free_space_set_bits(struct btrfs_block_group_cache *block_group, + struct btrfs_path *path, u64 *start, u64 *size, + int bit) +{ + struct extent_buffer *leaf = path->nodes[0]; + struct btrfs_fs_info *fs_info = leaf->fs_info; + struct btrfs_key key; + u64 end = *start + *size; + u64 found_start, found_end; + unsigned long ptr, first, last; + + btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); + ASSERT(key.type == BTRFS_FREE_SPACE_BITMAP_KEY); + + found_start = key.objectid; + found_end = key.objectid + key.offset; + ASSERT(*start >= found_start && *start < found_end); + ASSERT(end > found_start); + + if (end > found_end) + end = found_end; + + ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); + first = (*start - found_start) / fs_info->sectorsize; + last = (end - found_start) / fs_info->sectorsize; + if (bit) + extent_buffer_bitmap_set(leaf, ptr, first, last - first); + else + extent_buffer_bitmap_clear(leaf, ptr, first, last - first); + btrfs_mark_buffer_dirty(leaf); + + *size -= end - *start; + *start = end; +} + +/* + * We can't use btrfs_next_item() in modify_free_space_bitmap() because + * btrfs_next_leaf() doesn't get the path for writing. We can forgo the fancy + * tree walking in btrfs_next_leaf() anyways because we know exactly what we're + * looking for. + */ +static int free_space_next_bitmap(struct btrfs_trans_handle *trans, + struct btrfs_root *root, struct btrfs_path *p) +{ + struct btrfs_key key; + + if (p->slots[0] + 1 < btrfs_header_nritems(p->nodes[0])) { + p->slots[0]++; + return 0; + } + + btrfs_item_key_to_cpu(p->nodes[0], &key, p->slots[0]); + btrfs_release_path(p); + + key.objectid += key.offset; + key.type = (u8)-1; + key.offset = (u64)-1; + + return btrfs_search_prev_slot(trans, root, &key, p, 0, 1); +} + +/* + * If remove is 1, then we are removing free space, thus clearing bits in the + * bitmap. If remove is 0, then we are adding free space, thus setting bits in + * the bitmap. + */ +static int modify_free_space_bitmap(struct btrfs_trans_handle *trans, + struct btrfs_block_group_cache *block_group, + struct btrfs_path *path, + u64 start, u64 size, int remove) +{ + struct btrfs_root *root = trans->fs_info->free_space_root; + struct btrfs_key key; + u64 end = start + size; + u64 cur_start, cur_size; + int prev_bit, next_bit; + int new_extents; + int ret; + + /* + * Read the bit for the block immediately before the extent of space if + * that block is within the block group. + */ + if (start > block_group->key.objectid) { + u64 prev_block = start - trans->fs_info->sectorsize; + + key.objectid = prev_block; + key.type = (u8)-1; + key.offset = (u64)-1; + + ret = btrfs_search_prev_slot(trans, root, &key, path, 0, 1); + if (ret) + goto out; + + prev_bit = free_space_test_bit(block_group, path, prev_block); + + /* The previous block may have been in the previous bitmap. */ + btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); + if (start >= key.objectid + key.offset) { + ret = free_space_next_bitmap(trans, root, path); + if (ret) + goto out; + } + } else { + key.objectid = start; + key.type = (u8)-1; + key.offset = (u64)-1; + + ret = btrfs_search_prev_slot(trans, root, &key, path, 0, 1); + if (ret) + goto out; + + prev_bit = -1; + } + + /* + * Iterate over all of the bitmaps overlapped by the extent of space, + * clearing/setting bits as required. + */ + cur_start = start; + cur_size = size; + while (1) { + free_space_set_bits(block_group, path, &cur_start, &cur_size, + !remove); + if (cur_size == 0) + break; + ret = free_space_next_bitmap(trans, root, path); + if (ret) + goto out; + } + + /* + * Read the bit for the block immediately after the extent of space if + * that block is within the block group. + */ + if (end < block_group->key.objectid + block_group->key.offset) { + /* The next block may be in the next bitmap. */ + btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); + if (end >= key.objectid + key.offset) { + ret = free_space_next_bitmap(trans, root, path); + if (ret) + goto out; + } + + next_bit = free_space_test_bit(block_group, path, end); + } else { + next_bit = -1; + } + + if (remove) { + new_extents = -1; + if (prev_bit == 1) { + /* Leftover on the left. */ + new_extents++; + } + if (next_bit == 1) { + /* Leftover on the right. */ + new_extents++; + } + } else { + new_extents = 1; + if (prev_bit == 1) { + /* Merging with neighbor on the left. */ + new_extents--; + } + if (next_bit == 1) { + /* Merging with neighbor on the right. */ + new_extents--; + } + } + + btrfs_release_path(path); + ret = update_free_space_extent_count(trans, block_group, path, + new_extents); + +out: + return ret; +} + +static int remove_free_space_extent(struct btrfs_trans_handle *trans, + struct btrfs_block_group_cache *block_group, + struct btrfs_path *path, + u64 start, u64 size) +{ + struct btrfs_root *root = trans->fs_info->free_space_root; + struct btrfs_key key; + u64 found_start, found_end; + u64 end = start + size; + int new_extents = -1; + int ret; + + key.objectid = start; + key.type = (u8)-1; + key.offset = (u64)-1; + + ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1); + if (ret) + goto out; + + btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); + + ASSERT(key.type == BTRFS_FREE_SPACE_EXTENT_KEY); + + found_start = key.objectid; + found_end = key.objectid + key.offset; + ASSERT(start >= found_start && end <= found_end); + + /* + * Okay, now that we've found the free space extent which contains the + * free space that we are removing, there are four cases: + * + * 1. We're using the whole extent: delete the key we found and + * decrement the free space extent count. + * 2. We are using part of the extent starting at the beginning: delete + * the key we found and insert a new key representing the leftover at + * the end. There is no net change in the number of extents. + * 3. We are using part of the extent ending at the end: delete the key + * we found and insert a new key representing the leftover at the + * beginning. There is no net change in the number of extents. + * 4. We are using part of the extent in the middle: delete the key we + * found and insert two new keys representing the leftovers on each + * side. Where we used to have one extent, we now have two, so increment + * the extent count. We may need to convert the block group to bitmaps + * as a result. + */ + + /* Delete the existing key (cases 1-4). */ + ret = btrfs_del_item(trans, root, path); + if (ret) + goto out; + + /* Add a key for leftovers at the beginning (cases 3 and 4). */ + if (start > found_start) { + key.objectid = found_start; + key.type = BTRFS_FREE_SPACE_EXTENT_KEY; + key.offset = start - found_start; + + btrfs_release_path(path); + ret = btrfs_insert_empty_item(trans, root, path, &key, 0); + if (ret) + goto out; + new_extents++; + } + + /* Add a key for leftovers at the end (cases 2 and 4). */ + if (end < found_end) { + key.objectid = end; + key.type = BTRFS_FREE_SPACE_EXTENT_KEY; + key.offset = found_end - end; + + btrfs_release_path(path); + ret = btrfs_insert_empty_item(trans, root, path, &key, 0); + if (ret) + goto out; + new_extents++; + } + + btrfs_release_path(path); + ret = update_free_space_extent_count(trans, block_group, path, + new_extents); + +out: + return ret; +} + +int __remove_from_free_space_tree(struct btrfs_trans_handle *trans, + struct btrfs_block_group_cache *block_group, + struct btrfs_path *path, u64 start, u64 size) +{ + struct btrfs_free_space_info *info; + u32 flags; + + info = search_free_space_info(NULL, trans->fs_info, block_group, path, + 0); + if (IS_ERR(info)) + return PTR_ERR(info); + flags = btrfs_free_space_flags(path->nodes[0], info); + btrfs_release_path(path); + + if (flags & BTRFS_FREE_SPACE_USING_BITMAPS) { + return modify_free_space_bitmap(trans, block_group, path, + start, size, 1); + } else { + return remove_free_space_extent(trans, block_group, path, + start, size); + } +} + +int remove_from_free_space_tree(struct btrfs_trans_handle *trans, + u64 start, u64 size) +{ + struct btrfs_block_group_cache *block_group; + struct btrfs_path *path; + int ret; + + if (!btrfs_fs_compat_ro(trans->fs_info, FREE_SPACE_TREE)) + return 0; + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto out; + } + + block_group = btrfs_lookup_block_group(trans->fs_info, start); + if (!block_group) { + ASSERT(0); + ret = -ENOENT; + goto out; + } + + ret = __remove_from_free_space_tree(trans, block_group, path, start, + size); +out: + btrfs_free_path(path); + if (ret) + btrfs_abort_transaction(trans, ret); + return ret; +} + +static int add_free_space_extent(struct btrfs_trans_handle *trans, + struct btrfs_block_group_cache *block_group, + struct btrfs_path *path, + u64 start, u64 size) +{ + struct btrfs_root *root = trans->fs_info->free_space_root; + struct btrfs_key key, new_key; + u64 found_start, found_end; + u64 end = start + size; + int new_extents = 1; + int ret; + + /* + * We are adding a new extent of free space, but we need to merge + * extents. There are four cases here: + * + * 1. The new extent does not have any immediate neighbors to merge + * with: add the new key and increment the free space extent count. We + * may need to convert the block group to bitmaps as a result. + * 2. The new extent has an immediate neighbor before it: remove the + * previous key and insert a new key combining both of them. There is no + * net change in the number of extents. + * 3. The new extent has an immediate neighbor after it: remove the next + * key and insert a new key combining both of them. There is no net + * change in the number of extents. + * 4. The new extent has immediate neighbors on both sides: remove both + * of the keys and insert a new key combining all of them. Where we used + * to have two extents, we now have one, so decrement the extent count. + */ + + new_key.objectid = start; + new_key.type = BTRFS_FREE_SPACE_EXTENT_KEY; + new_key.offset = size; + + /* Search for a neighbor on the left. */ + if (start == block_group->key.objectid) + goto right; + key.objectid = start - 1; + key.type = (u8)-1; + key.offset = (u64)-1; + + ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1); + if (ret) + goto out; + + btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); + + if (key.type != BTRFS_FREE_SPACE_EXTENT_KEY) { + ASSERT(key.type == BTRFS_FREE_SPACE_INFO_KEY); + btrfs_release_path(path); + goto right; + } + + found_start = key.objectid; + found_end = key.objectid + key.offset; + ASSERT(found_start >= block_group->key.objectid && + found_end > block_group->key.objectid); + ASSERT(found_start < start && found_end <= start); + + /* + * Delete the neighbor on the left and absorb it into the new key (cases + * 2 and 4). + */ + if (found_end == start) { + ret = btrfs_del_item(trans, root, path); + if (ret) + goto out; + new_key.objectid = found_start; + new_key.offset += key.offset; + new_extents--; + } + btrfs_release_path(path); +right: + /* Search for a neighbor on the right. */ + if (end == block_group->key.objectid + block_group->key.offset) + goto insert; + key.objectid = end; + key.type = (u8)-1; + key.offset = (u64)-1; + + ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1); + if (ret) + goto out; + + btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); + + if (key.type != BTRFS_FREE_SPACE_EXTENT_KEY) { + ASSERT(key.type == BTRFS_FREE_SPACE_INFO_KEY); + btrfs_release_path(path); + goto insert; + } + + found_start = key.objectid; + found_end = key.objectid + key.offset; + ASSERT(found_start >= block_group->key.objectid && + found_end > block_group->key.objectid); + ASSERT((found_start < start && found_end <= start) || + (found_start >= end && found_end > end)); + + /* + * Delete the neighbor on the right and absorb it into the new key + * (cases 3 and 4). + */ + if (found_start == end) { + ret = btrfs_del_item(trans, root, path); + if (ret) + goto out; + new_key.offset += key.offset; + new_extents--; + } + btrfs_release_path(path); + +insert: + /* Insert the new key (cases 1-4). */ + ret = btrfs_insert_empty_item(trans, root, path, &new_key, 0); + if (ret) + goto out; + + btrfs_release_path(path); + ret = update_free_space_extent_count(trans, block_group, path, + new_extents); + +out: + return ret; +} + +int __add_to_free_space_tree(struct btrfs_trans_handle *trans, + struct btrfs_block_group_cache *block_group, + struct btrfs_path *path, u64 start, u64 size) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_free_space_info *info; + u32 flags; + + info = search_free_space_info(NULL, fs_info, block_group, path, 0); + if (IS_ERR(info)) + return PTR_ERR(info); + flags = btrfs_free_space_flags(path->nodes[0], info); + btrfs_release_path(path); + + if (flags & BTRFS_FREE_SPACE_USING_BITMAPS) { + return modify_free_space_bitmap(trans, block_group, path, + start, size, 0); + } else { + return add_free_space_extent(trans, block_group, path, start, + size); + } +} + + +int add_to_free_space_tree(struct btrfs_trans_handle *trans, + u64 start, u64 size) +{ + struct btrfs_block_group_cache *block_group; + struct btrfs_path *path; + int ret; + + if (!btrfs_fs_compat_ro(trans->fs_info, FREE_SPACE_TREE)) + return 0; + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto out; + } + + block_group = btrfs_lookup_block_group(trans->fs_info, start); + if (!block_group) { + ASSERT(0); + ret = -ENOENT; + goto out; + } + + ret = __add_to_free_space_tree(trans, block_group, path, start, size); +out: + btrfs_free_path(path); + if (ret) + btrfs_abort_transaction(trans, ret); + return ret; +} + +int populate_free_space_tree(struct btrfs_trans_handle *trans, + struct btrfs_block_group_cache *block_group) +{ + struct btrfs_root *extent_root = trans->fs_info->extent_root; + struct btrfs_path *path, *path2; + struct btrfs_key key; + u64 start, end; + int ret; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + path->reada = READA_FORWARD; + + path2 = btrfs_alloc_path(); + if (!path2) { + btrfs_free_path(path); + return -ENOMEM; + } + + ret = add_new_free_space_info(trans, block_group, path2); + if (ret) + goto out; + + /* + * Iterate through all of the extent and metadata items in this block + * group, adding the free space between them and the free space at the + * end. Note that EXTENT_ITEM and METADATA_ITEM are less than + * BLOCK_GROUP_ITEM, so an extent may precede the block group that it's + * contained in. + */ + key.objectid = block_group->key.objectid; + key.type = BTRFS_EXTENT_ITEM_KEY; + key.offset = 0; + + ret = btrfs_search_slot_for_read(extent_root, &key, path, 1, 0); + if (ret < 0) + goto out; + ASSERT(ret == 0); + + start = block_group->key.objectid; + end = block_group->key.objectid + block_group->key.offset; + while (1) { + btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); + + if (key.type == BTRFS_EXTENT_ITEM_KEY || + key.type == BTRFS_METADATA_ITEM_KEY) { + if (key.objectid >= end) + break; + + if (start < key.objectid) { + ret = __add_to_free_space_tree(trans, + block_group, + path2, start, + key.objectid - + start); + if (ret) + goto out; + } + start = key.objectid; + if (key.type == BTRFS_METADATA_ITEM_KEY) + start += trans->fs_info->nodesize; + else + start += key.offset; + } else if (key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) { + if (key.objectid != block_group->key.objectid) + break; + } + + ret = btrfs_next_item(extent_root, path); + if (ret < 0) + goto out; + if (ret) + break; + } + if (start < end) { + ret = __add_to_free_space_tree(trans, block_group, path2, + start, end - start); + if (ret) + goto out; + } + + ret = 0; +out: + btrfs_free_path(path2); + btrfs_free_path(path); + return ret; +} + +int remove_block_group_free_space(struct btrfs_trans_handle *trans, + struct btrfs_block_group_cache *block_group) +{ + struct btrfs_root *root = trans->fs_info->free_space_root; + struct btrfs_path *path; + struct btrfs_key key, found_key; + struct extent_buffer *leaf; + u64 start, end; + int done = 0, nr; + int ret; + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto out; + } + + start = block_group->key.objectid; + end = block_group->key.objectid + block_group->key.offset; + + key.objectid = end - 1; + key.type = (u8)-1; + key.offset = (u64)-1; + + while (!done) { + ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1); + if (ret) + goto out; + + leaf = path->nodes[0]; + nr = 0; + path->slots[0]++; + while (path->slots[0] > 0) { + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0] - 1); + + if (found_key.type == BTRFS_FREE_SPACE_INFO_KEY) { + ASSERT(found_key.objectid == block_group->key.objectid); + ASSERT(found_key.offset == block_group->key.offset); + done = 1; + nr++; + path->slots[0]--; + break; + } else if (found_key.type == BTRFS_FREE_SPACE_EXTENT_KEY || + found_key.type == BTRFS_FREE_SPACE_BITMAP_KEY) { + ASSERT(found_key.objectid >= start); + ASSERT(found_key.objectid < end); + ASSERT(found_key.objectid + found_key.offset <= end); + nr++; + path->slots[0]--; + } else { + ASSERT(0); + } + } + + ret = btrfs_del_items(trans, root, path, path->slots[0], nr); + if (ret) + goto out; + btrfs_release_path(path); + } + + ret = 0; +out: + btrfs_free_path(path); + if (ret) + btrfs_abort_transaction(trans, ret); + return ret; +} static int clear_free_space_tree(struct btrfs_trans_handle *trans, struct btrfs_root *root) { @@ -204,8 +949,8 @@ static int load_free_space_bitmaps(struct btrfs_fs_info *fs_info, offset = key.objectid; while (offset < key.objectid + key.offset) { - bit = free_space_test_bit(block_group, path, offset, - fs_info->sectorsize); + bit = free_space_test_bit(block_group, path, offset); + if (prev_bit == 0 && bit == 1) { extent_start = offset; } else if (prev_bit == 1 && bit == 0) { @@ -320,6 +1065,142 @@ static int load_free_space_extents(struct btrfs_fs_info *fs_info, return ret; } +struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans, + struct btrfs_fs_info *fs_info, + u64 objectid) +{ + struct extent_buffer *leaf; + struct btrfs_root *tree_root = fs_info->tree_root; + struct btrfs_root *root; + struct btrfs_key key; + int ret = 0; + + root = kzalloc(sizeof(*root), GFP_KERNEL); + if (!root) + return ERR_PTR(-ENOMEM); + + btrfs_setup_root(root, fs_info, objectid); + root->root_key.objectid = objectid; + root->root_key.type = BTRFS_ROOT_ITEM_KEY; + root->root_key.offset = 0; + + leaf = btrfs_alloc_free_block(trans, root, fs_info->nodesize, objectid, NULL, 0, 0, 0); + if (IS_ERR(leaf)) { + ret = PTR_ERR(leaf); + leaf = NULL; + goto fail; + } + + memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header)); + btrfs_set_header_bytenr(leaf, leaf->start); + btrfs_set_header_generation(leaf, trans->transid); + btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV); + btrfs_set_header_owner(leaf, objectid); + root->node = leaf; + write_extent_buffer(leaf, fs_info->fsid, btrfs_header_fsid(), BTRFS_FSID_SIZE); + write_extent_buffer(leaf, fs_info->chunk_tree_uuid, + btrfs_header_chunk_tree_uuid(leaf), + BTRFS_UUID_SIZE); + btrfs_mark_buffer_dirty(leaf); + + extent_buffer_get(root->node); + root->commit_root = root->node; + root->track_dirty = 1; + + root->root_item.flags = 0; + root->root_item.byte_limit = 0; + btrfs_set_root_bytenr(&root->root_item, leaf->start); + btrfs_set_root_generation(&root->root_item, trans->transid); + btrfs_set_root_level(&root->root_item, 0); + btrfs_set_root_refs(&root->root_item, 1); + btrfs_set_root_used(&root->root_item, leaf->len); + btrfs_set_root_last_snapshot(&root->root_item, 0); + btrfs_set_root_dirid(&root->root_item, 0); + memset(root->root_item.uuid, 0, BTRFS_UUID_SIZE); + root->root_item.drop_level = 0; + + key.objectid = objectid; + key.type = BTRFS_ROOT_ITEM_KEY; + key.offset = 0; + ret = btrfs_insert_root(trans, tree_root, &key, &root->root_item); + if (ret) + goto fail; + + return root; + +fail: + if (leaf) + free_extent_buffer(leaf); + + kfree(root); + return ERR_PTR(ret); +} + +#define btrfs_set_fs_compat_ro(__fs_info, opt) \ + __btrfs_set_fs_compat_ro((__fs_info), BTRFS_FEATURE_COMPAT_RO_##opt) + +static inline void __btrfs_set_fs_compat_ro(struct btrfs_fs_info *fs_info, + u64 flag) +{ + struct btrfs_super_block *disk_super; + u64 features; + + disk_super = fs_info->super_copy; + features = btrfs_super_compat_ro_flags(disk_super); + if (!(features & flag)) { + features = btrfs_super_compat_ro_flags(disk_super); + if (!(features & flag)) { + features |= flag; + btrfs_set_super_compat_ro_flags(disk_super, features); + } + } +} + +int btrfs_create_free_space_tree(struct btrfs_fs_info *fs_info) +{ + struct btrfs_trans_handle *trans; + struct btrfs_root *tree_root = fs_info->tree_root; + struct btrfs_root *free_space_root; + struct btrfs_block_group_cache *block_group; + u64 start = BTRFS_SUPER_INFO_OFFSET + BTRFS_SUPER_INFO_SIZE; + int ret; + + trans = btrfs_start_transaction(tree_root, 0); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + free_space_root = btrfs_create_tree(trans, fs_info, + BTRFS_FREE_SPACE_TREE_OBJECTID); + if (IS_ERR(free_space_root)) { + ret = PTR_ERR(free_space_root); + goto abort; + } + fs_info->free_space_root = free_space_root; + + do { + block_group = btrfs_lookup_first_block_group(fs_info, start); + if (!block_group) + break; + start = block_group->key.objectid + block_group->key.offset; + ret = populate_free_space_tree(trans, block_group); + if (ret) + goto abort; + } while (block_group); + + btrfs_set_fs_compat_ro(fs_info, FREE_SPACE_TREE); + btrfs_set_fs_compat_ro(fs_info, FREE_SPACE_TREE_VALID); + + ret = btrfs_commit_transaction(trans, tree_root); + if (ret) + return ret; + + return 0; + +abort: + btrfs_abort_transaction(trans, ret); + return ret; +} + int load_free_space_tree(struct btrfs_fs_info *fs_info, struct btrfs_block_group_cache *block_group) { @@ -332,7 +1213,7 @@ int load_free_space_tree(struct btrfs_fs_info *fs_info, path = btrfs_alloc_path(); if (!path) return -ENOMEM; - path->reada = 1; + path->reada = READA_BACK; info = search_free_space_info(NULL, fs_info, block_group, path, 0); if (IS_ERR(info)) { diff --git a/free-space-tree.h b/free-space-tree.h index 4845f13e6808..0509e9ae21ae 100644 --- a/free-space-tree.h +++ b/free-space-tree.h @@ -22,5 +22,13 @@ int btrfs_clear_free_space_tree(struct btrfs_fs_info *fs_info); int load_free_space_tree(struct btrfs_fs_info *fs_info, struct btrfs_block_group_cache *block_group); - +int populate_free_space_tree(struct btrfs_trans_handle *trans, + struct btrfs_block_group_cache *block_group); +int remove_block_group_free_space(struct btrfs_trans_handle *trans, + struct btrfs_block_group_cache *block_group); +int add_to_free_space_tree(struct btrfs_trans_handle *trans, u64 start, + u64 size); +int remove_from_free_space_tree(struct btrfs_trans_handle *trans, u64 start, + u64 size); +int btrfs_create_free_space_tree(struct btrfs_fs_info *info); #endif -- 2.7.4