| /* |
| * Copyright (C) 2015 Facebook. All rights reserved. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public |
| * License v2 as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public |
| * License along with this program; if not, write to the |
| * Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
| * Boston, MA 021110-1307, USA. |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/vmalloc.h> |
| #include "ctree.h" |
| #include "disk-io.h" |
| #include "locking.h" |
| #include "free-space-tree.h" |
| #include "transaction.h" |
| |
| static int __add_block_group_free_space(struct btrfs_trans_handle *trans, |
| struct btrfs_fs_info *fs_info, |
| struct btrfs_block_group_cache *block_group, |
| struct btrfs_path *path); |
| |
| void set_free_space_tree_thresholds(struct btrfs_block_group_cache *cache) |
| { |
| u32 bitmap_range; |
| size_t bitmap_size; |
| u64 num_bitmaps, total_bitmap_size; |
| |
| /* |
| * We convert to bitmaps when the disk space required for using extents |
| * exceeds that required for using bitmaps. |
| */ |
| bitmap_range = cache->sectorsize * BTRFS_FREE_SPACE_BITMAP_BITS; |
| num_bitmaps = div_u64(cache->key.offset + bitmap_range - 1, |
| bitmap_range); |
| bitmap_size = sizeof(struct btrfs_item) + BTRFS_FREE_SPACE_BITMAP_SIZE; |
| total_bitmap_size = num_bitmaps * bitmap_size; |
| cache->bitmap_high_thresh = div_u64(total_bitmap_size, |
| sizeof(struct btrfs_item)); |
| |
| /* |
| * We allow for a small buffer between the high threshold and low |
| * threshold to avoid thrashing back and forth between the two formats. |
| */ |
| if (cache->bitmap_high_thresh > 100) |
| cache->bitmap_low_thresh = cache->bitmap_high_thresh - 100; |
| else |
| cache->bitmap_low_thresh = 0; |
| } |
| |
| static int add_new_free_space_info(struct btrfs_trans_handle *trans, |
| struct btrfs_fs_info *fs_info, |
| struct btrfs_block_group_cache *block_group, |
| struct btrfs_path *path) |
| { |
| struct btrfs_root *root = 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; |
| } |
| |
| struct btrfs_free_space_info * |
| search_free_space_info(struct btrfs_trans_handle *trans, |
| struct btrfs_fs_info *fs_info, |
| struct btrfs_block_group_cache *block_group, |
| struct btrfs_path *path, int cow) |
| { |
| struct btrfs_root *root = fs_info->free_space_root; |
| struct btrfs_key key; |
| int ret; |
| |
| key.objectid = block_group->key.objectid; |
| key.type = BTRFS_FREE_SPACE_INFO_KEY; |
| key.offset = block_group->key.offset; |
| |
| ret = btrfs_search_slot(trans, root, &key, path, 0, cow); |
| if (ret < 0) |
| return ERR_PTR(ret); |
| if (ret != 0) { |
| btrfs_warn(fs_info, "missing free space info for %llu\n", |
| block_group->key.objectid); |
| ASSERT(0); |
| return ERR_PTR(-ENOENT); |
| } |
| |
| return btrfs_item_ptr(path->nodes[0], path->slots[0], |
| struct btrfs_free_space_info); |
| } |
| |
| /* |
| * 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 inline u32 free_space_bitmap_size(u64 size, u32 sectorsize) |
| { |
| return DIV_ROUND_UP((u32)div_u64(size, sectorsize), BITS_PER_BYTE); |
| } |
| |
| static unsigned long *alloc_bitmap(u32 bitmap_size) |
| { |
| return __vmalloc(bitmap_size, GFP_NOFS | __GFP_HIGHMEM | __GFP_ZERO, |
| PAGE_KERNEL); |
| } |
| |
| int convert_free_space_to_bitmaps(struct btrfs_trans_handle *trans, |
| struct btrfs_fs_info *fs_info, |
| struct btrfs_block_group_cache *block_group, |
| struct btrfs_path *path) |
| { |
| struct btrfs_root *root = fs_info->free_space_root; |
| struct btrfs_free_space_info *info; |
| struct btrfs_key key, found_key; |
| struct extent_buffer *leaf; |
| unsigned long *bitmap; |
| char *bitmap_cursor; |
| u64 start, end; |
| u64 bitmap_range, i; |
| u32 bitmap_size, flags, expected_extent_count; |
| u32 extent_count = 0; |
| int done = 0, nr; |
| int ret; |
| |
| bitmap_size = free_space_bitmap_size(block_group->key.offset, |
| block_group->sectorsize); |
| bitmap = alloc_bitmap(bitmap_size); |
| if (!bitmap) { |
| 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; |
| break; |
| } else if (found_key.type == BTRFS_FREE_SPACE_EXTENT_KEY) { |
| u64 first, last; |
| |
| ASSERT(found_key.objectid >= start); |
| ASSERT(found_key.objectid < end); |
| ASSERT(found_key.objectid + found_key.offset <= end); |
| |
| first = div_u64(found_key.objectid - start, |
| block_group->sectorsize); |
| last = div_u64(found_key.objectid + found_key.offset - start, |
| block_group->sectorsize); |
| bitmap_set(bitmap, first, last - first); |
| |
| extent_count++; |
| 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); |
| } |
| |
| info = search_free_space_info(trans, fs_info, block_group, path, 1); |
| if (IS_ERR(info)) { |
| ret = PTR_ERR(info); |
| goto out; |
| } |
| leaf = path->nodes[0]; |
| flags = btrfs_free_space_flags(leaf, info); |
| flags |= BTRFS_FREE_SPACE_USING_BITMAPS; |
| btrfs_set_free_space_flags(leaf, info, flags); |
| expected_extent_count = btrfs_free_space_extent_count(leaf, info); |
| btrfs_mark_buffer_dirty(leaf); |
| btrfs_release_path(path); |
| |
| if (extent_count != expected_extent_count) { |
| btrfs_err(fs_info, "incorrect extent count for %llu; counted %u, expected %u", |
| block_group->key.objectid, extent_count, |
| expected_extent_count); |
| ASSERT(0); |
| ret = -EIO; |
| goto out; |
| } |
| |
| bitmap_cursor = (char *)bitmap; |
| bitmap_range = block_group->sectorsize * BTRFS_FREE_SPACE_BITMAP_BITS; |
| i = start; |
| while (i < end) { |
| unsigned long ptr; |
| u64 extent_size; |
| u32 data_size; |
| |
| extent_size = min(end - i, bitmap_range); |
| data_size = free_space_bitmap_size(extent_size, |
| block_group->sectorsize); |
| |
| key.objectid = i; |
| key.type = BTRFS_FREE_SPACE_BITMAP_KEY; |
| key.offset = extent_size; |
| |
| ret = btrfs_insert_empty_item(trans, root, path, &key, |
| data_size); |
| if (ret) |
| goto out; |
| |
| leaf = path->nodes[0]; |
| ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); |
| write_extent_buffer(leaf, bitmap_cursor, ptr, |
| data_size); |
| btrfs_mark_buffer_dirty(leaf); |
| btrfs_release_path(path); |
| |
| i += extent_size; |
| bitmap_cursor += data_size; |
| } |
| |
| ret = 0; |
| out: |
| vfree(bitmap); |
| if (ret) |
| btrfs_abort_transaction(trans, root, ret); |
| return ret; |
| } |
| |
| int convert_free_space_to_extents(struct btrfs_trans_handle *trans, |
| struct btrfs_fs_info *fs_info, |
| struct btrfs_block_group_cache *block_group, |
| struct btrfs_path *path) |
| { |
| struct btrfs_root *root = fs_info->free_space_root; |
| struct btrfs_free_space_info *info; |
| struct btrfs_key key, found_key; |
| struct extent_buffer *leaf; |
| unsigned long *bitmap; |
| u64 start, end; |
| /* Initialize to silence GCC. */ |
| u64 extent_start = 0; |
| u64 offset; |
| u32 bitmap_size, flags, expected_extent_count; |
| int prev_bit = 0, bit, bitnr; |
| u32 extent_count = 0; |
| int done = 0, nr; |
| int ret; |
| |
| bitmap_size = free_space_bitmap_size(block_group->key.offset, |
| block_group->sectorsize); |
| bitmap = alloc_bitmap(bitmap_size); |
| if (!bitmap) { |
| 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; |
| break; |
| } else if (found_key.type == BTRFS_FREE_SPACE_BITMAP_KEY) { |
| unsigned long ptr; |
| char *bitmap_cursor; |
| u32 bitmap_pos, data_size; |
| |
| ASSERT(found_key.objectid >= start); |
| ASSERT(found_key.objectid < end); |
| ASSERT(found_key.objectid + found_key.offset <= end); |
| |
| bitmap_pos = div_u64(found_key.objectid - start, |
| block_group->sectorsize * |
| BITS_PER_BYTE); |
| bitmap_cursor = ((char *)bitmap) + bitmap_pos; |
| data_size = free_space_bitmap_size(found_key.offset, |
| block_group->sectorsize); |
| |
| ptr = btrfs_item_ptr_offset(leaf, path->slots[0] - 1); |
| read_extent_buffer(leaf, bitmap_cursor, ptr, |
| data_size); |
| |
| 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); |
| } |
| |
| info = search_free_space_info(trans, fs_info, block_group, path, 1); |
| if (IS_ERR(info)) { |
| ret = PTR_ERR(info); |
| goto out; |
| } |
| leaf = path->nodes[0]; |
| flags = btrfs_free_space_flags(leaf, info); |
| flags &= ~BTRFS_FREE_SPACE_USING_BITMAPS; |
| btrfs_set_free_space_flags(leaf, info, flags); |
| expected_extent_count = btrfs_free_space_extent_count(leaf, info); |
| btrfs_mark_buffer_dirty(leaf); |
| btrfs_release_path(path); |
| |
| offset = start; |
| bitnr = 0; |
| while (offset < end) { |
| bit = !!test_bit(bitnr, bitmap); |
| if (prev_bit == 0 && bit == 1) { |
| extent_start = offset; |
| } else if (prev_bit == 1 && bit == 0) { |
| key.objectid = extent_start; |
| key.type = BTRFS_FREE_SPACE_EXTENT_KEY; |
| key.offset = offset - extent_start; |
| |
| ret = btrfs_insert_empty_item(trans, root, path, &key, 0); |
| if (ret) |
| goto out; |
| btrfs_release_path(path); |
| |
| extent_count++; |
| } |
| prev_bit = bit; |
| offset += block_group->sectorsize; |
| bitnr++; |
| } |
| if (prev_bit == 1) { |
| key.objectid = extent_start; |
| key.type = BTRFS_FREE_SPACE_EXTENT_KEY; |
| key.offset = end - extent_start; |
| |
| ret = btrfs_insert_empty_item(trans, root, path, &key, 0); |
| if (ret) |
| goto out; |
| btrfs_release_path(path); |
| |
| extent_count++; |
| } |
| |
| if (extent_count != expected_extent_count) { |
| btrfs_err(fs_info, "incorrect extent count for %llu; counted %u, expected %u", |
| block_group->key.objectid, extent_count, |
| expected_extent_count); |
| ASSERT(0); |
| ret = -EIO; |
| goto out; |
| } |
| |
| ret = 0; |
| out: |
| vfree(bitmap); |
| if (ret) |
| btrfs_abort_transaction(trans, root, ret); |
| return ret; |
| } |
| |
| static int update_free_space_extent_count(struct btrfs_trans_handle *trans, |
| struct btrfs_fs_info *fs_info, |
| struct btrfs_block_group_cache *block_group, |
| struct btrfs_path *path, |
| int new_extents) |
| { |
| struct btrfs_free_space_info *info; |
| u32 flags; |
| u32 extent_count; |
| int ret = 0; |
| |
| if (new_extents == 0) |
| return 0; |
| |
| info = search_free_space_info(trans, fs_info, block_group, path, 1); |
| if (IS_ERR(info)) { |
| ret = PTR_ERR(info); |
| goto out; |
| } |
| flags = btrfs_free_space_flags(path->nodes[0], info); |
| 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); |
| |
| if (!(flags & BTRFS_FREE_SPACE_USING_BITMAPS) && |
| extent_count > block_group->bitmap_high_thresh) { |
| ret = convert_free_space_to_bitmaps(trans, fs_info, block_group, |
| path); |
| } else if ((flags & BTRFS_FREE_SPACE_USING_BITMAPS) && |
| extent_count < block_group->bitmap_low_thresh) { |
| ret = convert_free_space_to_extents(trans, fs_info, block_group, |
| path); |
| } |
| |
| out: |
| return ret; |
| } |
| |
| int free_space_test_bit(struct btrfs_block_group_cache *block_group, |
| struct btrfs_path *path, u64 offset) |
| { |
| struct extent_buffer *leaf; |
| struct btrfs_key key; |
| u64 found_start, found_end; |
| unsigned long ptr, i; |
| |
| leaf = path->nodes[0]; |
| 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(offset >= found_start && offset < found_end); |
| |
| ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); |
| i = div_u64(offset - found_start, block_group->sectorsize); |
| return !!extent_buffer_test_bit(leaf, ptr, i); |
| } |
| |
| 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; |
| struct btrfs_key key; |
| u64 end = *start + *size; |
| u64 found_start, found_end; |
| unsigned long ptr, first, last; |
| |
| leaf = path->nodes[0]; |
| 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 = div_u64(*start - found_start, block_group->sectorsize); |
| last = div_u64(end - found_start, block_group->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_fs_info *fs_info, |
| struct btrfs_block_group_cache *block_group, |
| struct btrfs_path *path, |
| u64 start, u64 size, int remove) |
| { |
| struct btrfs_root *root = 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 - block_group->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, fs_info, block_group, path, |
| new_extents); |
| |
| out: |
| return ret; |
| } |
| |
| static int remove_free_space_extent(struct btrfs_trans_handle *trans, |
| struct btrfs_fs_info *fs_info, |
| struct btrfs_block_group_cache *block_group, |
| struct btrfs_path *path, |
| u64 start, u64 size) |
| { |
| struct btrfs_root *root = 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, fs_info, block_group, path, |
| new_extents); |
| |
| out: |
| return ret; |
| } |
| |
| int __remove_from_free_space_tree(struct btrfs_trans_handle *trans, |
| struct btrfs_fs_info *fs_info, |
| struct btrfs_block_group_cache *block_group, |
| struct btrfs_path *path, u64 start, u64 size) |
| { |
| struct btrfs_free_space_info *info; |
| u32 flags; |
| int ret; |
| |
| if (block_group->needs_free_space) { |
| ret = __add_block_group_free_space(trans, fs_info, block_group, |
| path); |
| if (ret) |
| return ret; |
| } |
| |
| 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, fs_info, block_group, |
| path, start, size, 1); |
| } else { |
| return remove_free_space_extent(trans, fs_info, block_group, |
| path, start, size); |
| } |
| } |
| |
| int remove_from_free_space_tree(struct btrfs_trans_handle *trans, |
| struct btrfs_fs_info *fs_info, |
| u64 start, u64 size) |
| { |
| struct btrfs_block_group_cache *block_group; |
| struct btrfs_path *path; |
| int ret; |
| |
| if (!btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) |
| return 0; |
| |
| path = btrfs_alloc_path(); |
| if (!path) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| block_group = btrfs_lookup_block_group(fs_info, start); |
| if (!block_group) { |
| ASSERT(0); |
| ret = -ENOENT; |
| goto out; |
| } |
| |
| mutex_lock(&block_group->free_space_lock); |
| ret = __remove_from_free_space_tree(trans, fs_info, block_group, path, |
| start, size); |
| mutex_unlock(&block_group->free_space_lock); |
| |
| btrfs_put_block_group(block_group); |
| out: |
| btrfs_free_path(path); |
| if (ret) |
| btrfs_abort_transaction(trans, fs_info->free_space_root, ret); |
| return ret; |
| } |
| |
| static int add_free_space_extent(struct btrfs_trans_handle *trans, |
| struct btrfs_fs_info *fs_info, |
| struct btrfs_block_group_cache *block_group, |
| struct btrfs_path *path, |
| u64 start, u64 size) |
| { |
| struct btrfs_root *root = 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, fs_info, block_group, path, |
| new_extents); |
| |
| out: |
| return ret; |
| } |
| |
| int __add_to_free_space_tree(struct btrfs_trans_handle *trans, |
| struct btrfs_fs_info *fs_info, |
| struct btrfs_block_group_cache *block_group, |
| struct btrfs_path *path, u64 start, u64 size) |
| { |
| struct btrfs_free_space_info *info; |
| u32 flags; |
| int ret; |
| |
| if (block_group->needs_free_space) { |
| ret = __add_block_group_free_space(trans, fs_info, block_group, |
| path); |
| if (ret) |
| return ret; |
| } |
| |
| 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, fs_info, block_group, |
| path, start, size, 0); |
| } else { |
| return add_free_space_extent(trans, fs_info, block_group, path, |
| start, size); |
| } |
| } |
| |
| int add_to_free_space_tree(struct btrfs_trans_handle *trans, |
| struct btrfs_fs_info *fs_info, |
| u64 start, u64 size) |
| { |
| struct btrfs_block_group_cache *block_group; |
| struct btrfs_path *path; |
| int ret; |
| |
| if (!btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) |
| return 0; |
| |
| path = btrfs_alloc_path(); |
| if (!path) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| block_group = btrfs_lookup_block_group(fs_info, start); |
| if (!block_group) { |
| ASSERT(0); |
| ret = -ENOENT; |
| goto out; |
| } |
| |
| mutex_lock(&block_group->free_space_lock); |
| ret = __add_to_free_space_tree(trans, fs_info, block_group, path, start, |
| size); |
| mutex_unlock(&block_group->free_space_lock); |
| |
| btrfs_put_block_group(block_group); |
| out: |
| btrfs_free_path(path); |
| if (ret) |
| btrfs_abort_transaction(trans, fs_info->free_space_root, ret); |
| return ret; |
| } |
| |
| /* |
| * Populate the free space tree by walking the extent tree. Operations on the |
| * extent tree that happen as a result of writes to the free space tree will go |
| * through the normal add/remove hooks. |
| */ |
| static int populate_free_space_tree(struct btrfs_trans_handle *trans, |
| struct btrfs_fs_info *fs_info, |
| struct btrfs_block_group_cache *block_group) |
| { |
| struct btrfs_root *extent_root = 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 = 1; |
| |
| path2 = btrfs_alloc_path(); |
| if (!path2) { |
| btrfs_free_path(path); |
| return -ENOMEM; |
| } |
| |
| ret = add_new_free_space_info(trans, fs_info, block_group, path2); |
| if (ret) |
| goto out; |
| |
| mutex_lock(&block_group->free_space_lock); |
| |
| /* |
| * 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_locked; |
| 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, fs_info, |
| block_group, |
| path2, start, |
| key.objectid - |
| start); |
| if (ret) |
| goto out_locked; |
| } |
| start = key.objectid; |
| if (key.type == BTRFS_METADATA_ITEM_KEY) |
| start += fs_info->tree_root->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_locked; |
| if (ret) |
| break; |
| } |
| if (start < end) { |
| ret = __add_to_free_space_tree(trans, fs_info, block_group, |
| path2, start, end - start); |
| if (ret) |
| goto out_locked; |
| } |
| |
| ret = 0; |
| out_locked: |
| mutex_unlock(&block_group->free_space_lock); |
| out: |
| btrfs_free_path(path2); |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| 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; |
| struct rb_node *node; |
| int ret; |
| |
| trans = btrfs_start_transaction(tree_root, 0); |
| if (IS_ERR(trans)) |
| return PTR_ERR(trans); |
| |
| fs_info->creating_free_space_tree = 1; |
| 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; |
| |
| node = rb_first(&fs_info->block_group_cache_tree); |
| while (node) { |
| block_group = rb_entry(node, struct btrfs_block_group_cache, |
| cache_node); |
| ret = populate_free_space_tree(trans, fs_info, block_group); |
| if (ret) |
| goto abort; |
| node = rb_next(node); |
| } |
| |
| btrfs_set_fs_compat_ro(fs_info, FREE_SPACE_TREE); |
| fs_info->creating_free_space_tree = 0; |
| |
| ret = btrfs_commit_transaction(trans, tree_root); |
| if (ret) |
| return ret; |
| |
| return 0; |
| |
| abort: |
| fs_info->creating_free_space_tree = 0; |
| btrfs_abort_transaction(trans, tree_root, ret); |
| btrfs_end_transaction(trans, tree_root); |
| return ret; |
| } |
| |
| static int clear_free_space_tree(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root) |
| { |
| struct btrfs_path *path; |
| struct btrfs_key key; |
| int nr; |
| int ret; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| path->leave_spinning = 1; |
| |
| key.objectid = 0; |
| key.type = 0; |
| key.offset = 0; |
| |
| while (1) { |
| ret = btrfs_search_slot(trans, root, &key, path, -1, 1); |
| if (ret < 0) |
| goto out; |
| |
| nr = btrfs_header_nritems(path->nodes[0]); |
| if (!nr) |
| break; |
| |
| path->slots[0] = 0; |
| ret = btrfs_del_items(trans, root, path, 0, nr); |
| if (ret) |
| goto out; |
| |
| btrfs_release_path(path); |
| } |
| |
| ret = 0; |
| out: |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| int btrfs_clear_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 = fs_info->free_space_root; |
| int ret; |
| |
| trans = btrfs_start_transaction(tree_root, 0); |
| if (IS_ERR(trans)) |
| return PTR_ERR(trans); |
| |
| btrfs_clear_fs_compat_ro(fs_info, FREE_SPACE_TREE); |
| fs_info->free_space_root = NULL; |
| |
| ret = clear_free_space_tree(trans, free_space_root); |
| if (ret) |
| goto abort; |
| |
| ret = btrfs_del_root(trans, tree_root, &free_space_root->root_key); |
| if (ret) |
| goto abort; |
| |
| list_del(&free_space_root->dirty_list); |
| |
| btrfs_tree_lock(free_space_root->node); |
| clean_tree_block(trans, tree_root->fs_info, free_space_root->node); |
| btrfs_tree_unlock(free_space_root->node); |
| btrfs_free_tree_block(trans, free_space_root, free_space_root->node, |
| 0, 1); |
| |
| free_extent_buffer(free_space_root->node); |
| free_extent_buffer(free_space_root->commit_root); |
| kfree(free_space_root); |
| |
| ret = btrfs_commit_transaction(trans, tree_root); |
| if (ret) |
| return ret; |
| |
| return 0; |
| |
| abort: |
| btrfs_abort_transaction(trans, tree_root, ret); |
| btrfs_end_transaction(trans, tree_root); |
| return ret; |
| } |
| |
| static int __add_block_group_free_space(struct btrfs_trans_handle *trans, |
| struct btrfs_fs_info *fs_info, |
| struct btrfs_block_group_cache *block_group, |
| struct btrfs_path *path) |
| { |
| u64 start, end; |
| int ret; |
| |
| start = block_group->key.objectid; |
| end = block_group->key.objectid + block_group->key.offset; |
| |
| block_group->needs_free_space = 0; |
| |
| ret = add_new_free_space_info(trans, fs_info, block_group, path); |
| if (ret) |
| return ret; |
| |
| return __add_to_free_space_tree(trans, fs_info, block_group, path, |
| block_group->key.objectid, |
| block_group->key.offset); |
| } |
| |
| int add_block_group_free_space(struct btrfs_trans_handle *trans, |
| struct btrfs_fs_info *fs_info, |
| struct btrfs_block_group_cache *block_group) |
| { |
| struct btrfs_path *path = NULL; |
| int ret = 0; |
| |
| if (!btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) |
| return 0; |
| |
| mutex_lock(&block_group->free_space_lock); |
| if (!block_group->needs_free_space) |
| goto out; |
| |
| path = btrfs_alloc_path(); |
| if (!path) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| ret = __add_block_group_free_space(trans, fs_info, block_group, path); |
| |
| out: |
| btrfs_free_path(path); |
| mutex_unlock(&block_group->free_space_lock); |
| if (ret) |
| btrfs_abort_transaction(trans, fs_info->free_space_root, ret); |
| return ret; |
| } |
| |
| int remove_block_group_free_space(struct btrfs_trans_handle *trans, |
| struct btrfs_fs_info *fs_info, |
| struct btrfs_block_group_cache *block_group) |
| { |
| struct btrfs_root *root = 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; |
| |
| if (!btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) |
| return 0; |
| |
| if (block_group->needs_free_space) { |
| /* We never added this block group to the free space tree. */ |
| return 0; |
| } |
| |
| 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, root, ret); |
| return ret; |
| } |
| |
| static int load_free_space_bitmaps(struct btrfs_caching_control *caching_ctl, |
| struct btrfs_path *path, |
| u32 expected_extent_count) |
| { |
| struct btrfs_block_group_cache *block_group; |
| struct btrfs_fs_info *fs_info; |
| struct btrfs_root *root; |
| struct btrfs_key key; |
| int prev_bit = 0, bit; |
| /* Initialize to silence GCC. */ |
| u64 extent_start = 0; |
| u64 end, offset; |
| u64 total_found = 0; |
| u32 extent_count = 0; |
| int ret; |
| |
| block_group = caching_ctl->block_group; |
| fs_info = block_group->fs_info; |
| root = fs_info->free_space_root; |
| |
| end = block_group->key.objectid + block_group->key.offset; |
| |
| while (1) { |
| ret = btrfs_next_item(root, path); |
| if (ret < 0) |
| goto out; |
| if (ret) |
| break; |
| |
| btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); |
| |
| if (key.type == BTRFS_FREE_SPACE_INFO_KEY) |
| break; |
| |
| ASSERT(key.type == BTRFS_FREE_SPACE_BITMAP_KEY); |
| ASSERT(key.objectid < end && key.objectid + key.offset <= end); |
| |
| caching_ctl->progress = key.objectid; |
| |
| offset = key.objectid; |
| while (offset < key.objectid + key.offset) { |
| 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) { |
| total_found += add_new_free_space(block_group, |
| fs_info, |
| extent_start, |
| offset); |
| if (total_found > CACHING_CTL_WAKE_UP) { |
| total_found = 0; |
| wake_up(&caching_ctl->wait); |
| } |
| extent_count++; |
| } |
| prev_bit = bit; |
| offset += block_group->sectorsize; |
| } |
| } |
| if (prev_bit == 1) { |
| total_found += add_new_free_space(block_group, fs_info, |
| extent_start, end); |
| extent_count++; |
| } |
| |
| if (extent_count != expected_extent_count) { |
| btrfs_err(fs_info, "incorrect extent count for %llu; counted %u, expected %u", |
| block_group->key.objectid, extent_count, |
| expected_extent_count); |
| ASSERT(0); |
| ret = -EIO; |
| goto out; |
| } |
| |
| caching_ctl->progress = (u64)-1; |
| |
| ret = 0; |
| out: |
| return ret; |
| } |
| |
| static int load_free_space_extents(struct btrfs_caching_control *caching_ctl, |
| struct btrfs_path *path, |
| u32 expected_extent_count) |
| { |
| struct btrfs_block_group_cache *block_group; |
| struct btrfs_fs_info *fs_info; |
| struct btrfs_root *root; |
| struct btrfs_key key; |
| u64 end; |
| u64 total_found = 0; |
| u32 extent_count = 0; |
| int ret; |
| |
| block_group = caching_ctl->block_group; |
| fs_info = block_group->fs_info; |
| root = fs_info->free_space_root; |
| |
| end = block_group->key.objectid + block_group->key.offset; |
| |
| while (1) { |
| ret = btrfs_next_item(root, path); |
| if (ret < 0) |
| goto out; |
| if (ret) |
| break; |
| |
| btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); |
| |
| if (key.type == BTRFS_FREE_SPACE_INFO_KEY) |
| break; |
| |
| ASSERT(key.type == BTRFS_FREE_SPACE_EXTENT_KEY); |
| ASSERT(key.objectid < end && key.objectid + key.offset <= end); |
| |
| caching_ctl->progress = key.objectid; |
| |
| total_found += add_new_free_space(block_group, fs_info, |
| key.objectid, |
| key.objectid + key.offset); |
| if (total_found > CACHING_CTL_WAKE_UP) { |
| total_found = 0; |
| wake_up(&caching_ctl->wait); |
| } |
| extent_count++; |
| } |
| |
| if (extent_count != expected_extent_count) { |
| btrfs_err(fs_info, "incorrect extent count for %llu; counted %u, expected %u", |
| block_group->key.objectid, extent_count, |
| expected_extent_count); |
| ASSERT(0); |
| ret = -EIO; |
| goto out; |
| } |
| |
| caching_ctl->progress = (u64)-1; |
| |
| ret = 0; |
| out: |
| return ret; |
| } |
| |
| int load_free_space_tree(struct btrfs_caching_control *caching_ctl) |
| { |
| struct btrfs_block_group_cache *block_group; |
| struct btrfs_fs_info *fs_info; |
| struct btrfs_free_space_info *info; |
| struct btrfs_path *path; |
| u32 extent_count, flags; |
| int ret; |
| |
| block_group = caching_ctl->block_group; |
| fs_info = block_group->fs_info; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| /* |
| * Just like caching_thread() doesn't want to deadlock on the extent |
| * tree, we don't want to deadlock on the free space tree. |
| */ |
| path->skip_locking = 1; |
| path->search_commit_root = 1; |
| path->reada = 1; |
| |
| info = search_free_space_info(NULL, fs_info, block_group, path, 0); |
| if (IS_ERR(info)) { |
| ret = PTR_ERR(info); |
| goto out; |
| } |
| extent_count = btrfs_free_space_extent_count(path->nodes[0], info); |
| flags = btrfs_free_space_flags(path->nodes[0], info); |
| |
| /* |
| * We left path pointing to the free space info item, so now |
| * load_free_space_foo can just iterate through the free space tree from |
| * there. |
| */ |
| if (flags & BTRFS_FREE_SPACE_USING_BITMAPS) |
| ret = load_free_space_bitmaps(caching_ctl, path, extent_count); |
| else |
| ret = load_free_space_extents(caching_ctl, path, extent_count); |
| |
| out: |
| btrfs_free_path(path); |
| return ret; |
| } |