| /* |
| * Copyright (C) 2008 Red Hat. 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/pagemap.h> |
| #include <linux/sched.h> |
| #include <linux/slab.h> |
| #include <linux/math64.h> |
| #include "ctree.h" |
| #include "free-space-cache.h" |
| #include "transaction.h" |
| #include "disk-io.h" |
| |
| #define BITS_PER_BITMAP (PAGE_CACHE_SIZE * 8) |
| #define MAX_CACHE_BYTES_PER_GIG (32 * 1024) |
| |
| static void recalculate_thresholds(struct btrfs_block_group_cache |
| *block_group); |
| static int link_free_space(struct btrfs_block_group_cache *block_group, |
| struct btrfs_free_space *info); |
| |
| struct inode *lookup_free_space_inode(struct btrfs_root *root, |
| struct btrfs_block_group_cache |
| *block_group, struct btrfs_path *path) |
| { |
| struct btrfs_key key; |
| struct btrfs_key location; |
| struct btrfs_disk_key disk_key; |
| struct btrfs_free_space_header *header; |
| struct extent_buffer *leaf; |
| struct inode *inode = NULL; |
| int ret; |
| |
| spin_lock(&block_group->lock); |
| if (block_group->inode) |
| inode = igrab(block_group->inode); |
| spin_unlock(&block_group->lock); |
| if (inode) |
| return inode; |
| |
| key.objectid = BTRFS_FREE_SPACE_OBJECTID; |
| key.offset = block_group->key.objectid; |
| key.type = 0; |
| |
| ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| if (ret < 0) |
| return ERR_PTR(ret); |
| if (ret > 0) { |
| btrfs_release_path(root, path); |
| return ERR_PTR(-ENOENT); |
| } |
| |
| leaf = path->nodes[0]; |
| header = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_free_space_header); |
| btrfs_free_space_key(leaf, header, &disk_key); |
| btrfs_disk_key_to_cpu(&location, &disk_key); |
| btrfs_release_path(root, path); |
| |
| inode = btrfs_iget(root->fs_info->sb, &location, root, NULL); |
| if (!inode) |
| return ERR_PTR(-ENOENT); |
| if (IS_ERR(inode)) |
| return inode; |
| if (is_bad_inode(inode)) { |
| iput(inode); |
| return ERR_PTR(-ENOENT); |
| } |
| |
| spin_lock(&block_group->lock); |
| if (!root->fs_info->closing) { |
| block_group->inode = igrab(inode); |
| block_group->iref = 1; |
| } |
| spin_unlock(&block_group->lock); |
| |
| return inode; |
| } |
| |
| int create_free_space_inode(struct btrfs_root *root, |
| struct btrfs_trans_handle *trans, |
| struct btrfs_block_group_cache *block_group, |
| struct btrfs_path *path) |
| { |
| struct btrfs_key key; |
| struct btrfs_disk_key disk_key; |
| struct btrfs_free_space_header *header; |
| struct btrfs_inode_item *inode_item; |
| struct extent_buffer *leaf; |
| u64 objectid; |
| int ret; |
| |
| ret = btrfs_find_free_objectid(trans, root, 0, &objectid); |
| if (ret < 0) |
| return ret; |
| |
| ret = btrfs_insert_empty_inode(trans, root, path, objectid); |
| if (ret) |
| return ret; |
| |
| leaf = path->nodes[0]; |
| inode_item = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_inode_item); |
| btrfs_item_key(leaf, &disk_key, path->slots[0]); |
| memset_extent_buffer(leaf, 0, (unsigned long)inode_item, |
| sizeof(*inode_item)); |
| btrfs_set_inode_generation(leaf, inode_item, trans->transid); |
| btrfs_set_inode_size(leaf, inode_item, 0); |
| btrfs_set_inode_nbytes(leaf, inode_item, 0); |
| btrfs_set_inode_uid(leaf, inode_item, 0); |
| btrfs_set_inode_gid(leaf, inode_item, 0); |
| btrfs_set_inode_mode(leaf, inode_item, S_IFREG | 0600); |
| btrfs_set_inode_flags(leaf, inode_item, BTRFS_INODE_NOCOMPRESS | |
| BTRFS_INODE_PREALLOC | BTRFS_INODE_NODATASUM); |
| btrfs_set_inode_nlink(leaf, inode_item, 1); |
| btrfs_set_inode_transid(leaf, inode_item, trans->transid); |
| btrfs_set_inode_block_group(leaf, inode_item, |
| block_group->key.objectid); |
| btrfs_mark_buffer_dirty(leaf); |
| btrfs_release_path(root, path); |
| |
| key.objectid = BTRFS_FREE_SPACE_OBJECTID; |
| key.offset = block_group->key.objectid; |
| key.type = 0; |
| |
| ret = btrfs_insert_empty_item(trans, root, path, &key, |
| sizeof(struct btrfs_free_space_header)); |
| if (ret < 0) { |
| btrfs_release_path(root, path); |
| return ret; |
| } |
| leaf = path->nodes[0]; |
| header = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_free_space_header); |
| memset_extent_buffer(leaf, 0, (unsigned long)header, sizeof(*header)); |
| btrfs_set_free_space_key(leaf, header, &disk_key); |
| btrfs_mark_buffer_dirty(leaf); |
| btrfs_release_path(root, path); |
| |
| return 0; |
| } |
| |
| int btrfs_truncate_free_space_cache(struct btrfs_root *root, |
| struct btrfs_trans_handle *trans, |
| struct btrfs_path *path, |
| struct inode *inode) |
| { |
| loff_t oldsize; |
| int ret = 0; |
| |
| trans->block_rsv = root->orphan_block_rsv; |
| ret = btrfs_block_rsv_check(trans, root, |
| root->orphan_block_rsv, |
| 0, 5); |
| if (ret) |
| return ret; |
| |
| oldsize = i_size_read(inode); |
| btrfs_i_size_write(inode, 0); |
| truncate_pagecache(inode, oldsize, 0); |
| |
| /* |
| * We don't need an orphan item because truncating the free space cache |
| * will never be split across transactions. |
| */ |
| ret = btrfs_truncate_inode_items(trans, root, inode, |
| 0, BTRFS_EXTENT_DATA_KEY); |
| if (ret) { |
| WARN_ON(1); |
| return ret; |
| } |
| |
| return btrfs_update_inode(trans, root, inode); |
| } |
| |
| static int readahead_cache(struct inode *inode) |
| { |
| struct file_ra_state *ra; |
| unsigned long last_index; |
| |
| ra = kzalloc(sizeof(*ra), GFP_NOFS); |
| if (!ra) |
| return -ENOMEM; |
| |
| file_ra_state_init(ra, inode->i_mapping); |
| last_index = (i_size_read(inode) - 1) >> PAGE_CACHE_SHIFT; |
| |
| page_cache_sync_readahead(inode->i_mapping, ra, NULL, 0, last_index); |
| |
| kfree(ra); |
| |
| return 0; |
| } |
| |
| int load_free_space_cache(struct btrfs_fs_info *fs_info, |
| struct btrfs_block_group_cache *block_group) |
| { |
| struct btrfs_root *root = fs_info->tree_root; |
| struct inode *inode; |
| struct btrfs_free_space_header *header; |
| struct extent_buffer *leaf; |
| struct page *page; |
| struct btrfs_path *path; |
| u32 *checksums = NULL, *crc; |
| char *disk_crcs = NULL; |
| struct btrfs_key key; |
| struct list_head bitmaps; |
| u64 num_entries; |
| u64 num_bitmaps; |
| u64 generation; |
| u32 cur_crc = ~(u32)0; |
| pgoff_t index = 0; |
| unsigned long first_page_offset; |
| int num_checksums; |
| int ret = 0; |
| |
| /* |
| * If we're unmounting then just return, since this does a search on the |
| * normal root and not the commit root and we could deadlock. |
| */ |
| smp_mb(); |
| if (fs_info->closing) |
| return 0; |
| |
| /* |
| * If this block group has been marked to be cleared for one reason or |
| * another then we can't trust the on disk cache, so just return. |
| */ |
| spin_lock(&block_group->lock); |
| if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) { |
| spin_unlock(&block_group->lock); |
| return 0; |
| } |
| spin_unlock(&block_group->lock); |
| |
| INIT_LIST_HEAD(&bitmaps); |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return 0; |
| |
| inode = lookup_free_space_inode(root, block_group, path); |
| if (IS_ERR(inode)) { |
| btrfs_free_path(path); |
| return 0; |
| } |
| |
| /* Nothing in the space cache, goodbye */ |
| if (!i_size_read(inode)) { |
| btrfs_free_path(path); |
| goto out; |
| } |
| |
| key.objectid = BTRFS_FREE_SPACE_OBJECTID; |
| key.offset = block_group->key.objectid; |
| key.type = 0; |
| |
| ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| if (ret) { |
| btrfs_free_path(path); |
| goto out; |
| } |
| |
| leaf = path->nodes[0]; |
| header = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_free_space_header); |
| num_entries = btrfs_free_space_entries(leaf, header); |
| num_bitmaps = btrfs_free_space_bitmaps(leaf, header); |
| generation = btrfs_free_space_generation(leaf, header); |
| btrfs_free_path(path); |
| |
| if (BTRFS_I(inode)->generation != generation) { |
| printk(KERN_ERR "btrfs: free space inode generation (%llu) did" |
| " not match free space cache generation (%llu) for " |
| "block group %llu\n", |
| (unsigned long long)BTRFS_I(inode)->generation, |
| (unsigned long long)generation, |
| (unsigned long long)block_group->key.objectid); |
| goto free_cache; |
| } |
| |
| if (!num_entries) |
| goto out; |
| |
| /* Setup everything for doing checksumming */ |
| num_checksums = i_size_read(inode) / PAGE_CACHE_SIZE; |
| checksums = crc = kzalloc(sizeof(u32) * num_checksums, GFP_NOFS); |
| if (!checksums) |
| goto out; |
| first_page_offset = (sizeof(u32) * num_checksums) + sizeof(u64); |
| disk_crcs = kzalloc(first_page_offset, GFP_NOFS); |
| if (!disk_crcs) |
| goto out; |
| |
| ret = readahead_cache(inode); |
| if (ret) { |
| ret = 0; |
| goto out; |
| } |
| |
| while (1) { |
| struct btrfs_free_space_entry *entry; |
| struct btrfs_free_space *e; |
| void *addr; |
| unsigned long offset = 0; |
| unsigned long start_offset = 0; |
| int need_loop = 0; |
| |
| if (!num_entries && !num_bitmaps) |
| break; |
| |
| if (index == 0) { |
| start_offset = first_page_offset; |
| offset = start_offset; |
| } |
| |
| page = grab_cache_page(inode->i_mapping, index); |
| if (!page) { |
| ret = 0; |
| goto free_cache; |
| } |
| |
| if (!PageUptodate(page)) { |
| btrfs_readpage(NULL, page); |
| lock_page(page); |
| if (!PageUptodate(page)) { |
| unlock_page(page); |
| page_cache_release(page); |
| printk(KERN_ERR "btrfs: error reading free " |
| "space cache: %llu\n", |
| (unsigned long long) |
| block_group->key.objectid); |
| goto free_cache; |
| } |
| } |
| addr = kmap(page); |
| |
| if (index == 0) { |
| u64 *gen; |
| |
| memcpy(disk_crcs, addr, first_page_offset); |
| gen = addr + (sizeof(u32) * num_checksums); |
| if (*gen != BTRFS_I(inode)->generation) { |
| printk(KERN_ERR "btrfs: space cache generation" |
| " (%llu) does not match inode (%llu) " |
| "for block group %llu\n", |
| (unsigned long long)*gen, |
| (unsigned long long) |
| BTRFS_I(inode)->generation, |
| (unsigned long long) |
| block_group->key.objectid); |
| kunmap(page); |
| unlock_page(page); |
| page_cache_release(page); |
| goto free_cache; |
| } |
| crc = (u32 *)disk_crcs; |
| } |
| entry = addr + start_offset; |
| |
| /* First lets check our crc before we do anything fun */ |
| cur_crc = ~(u32)0; |
| cur_crc = btrfs_csum_data(root, addr + start_offset, cur_crc, |
| PAGE_CACHE_SIZE - start_offset); |
| btrfs_csum_final(cur_crc, (char *)&cur_crc); |
| if (cur_crc != *crc) { |
| printk(KERN_ERR "btrfs: crc mismatch for page %lu in " |
| "block group %llu\n", index, |
| (unsigned long long)block_group->key.objectid); |
| kunmap(page); |
| unlock_page(page); |
| page_cache_release(page); |
| goto free_cache; |
| } |
| crc++; |
| |
| while (1) { |
| if (!num_entries) |
| break; |
| |
| need_loop = 1; |
| e = kzalloc(sizeof(struct btrfs_free_space), GFP_NOFS); |
| if (!e) { |
| kunmap(page); |
| unlock_page(page); |
| page_cache_release(page); |
| goto free_cache; |
| } |
| |
| e->offset = le64_to_cpu(entry->offset); |
| e->bytes = le64_to_cpu(entry->bytes); |
| if (!e->bytes) { |
| kunmap(page); |
| kfree(e); |
| unlock_page(page); |
| page_cache_release(page); |
| goto free_cache; |
| } |
| |
| if (entry->type == BTRFS_FREE_SPACE_EXTENT) { |
| spin_lock(&block_group->tree_lock); |
| ret = link_free_space(block_group, e); |
| spin_unlock(&block_group->tree_lock); |
| BUG_ON(ret); |
| } else { |
| e->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS); |
| if (!e->bitmap) { |
| kunmap(page); |
| kfree(e); |
| unlock_page(page); |
| page_cache_release(page); |
| goto free_cache; |
| } |
| spin_lock(&block_group->tree_lock); |
| ret = link_free_space(block_group, e); |
| block_group->total_bitmaps++; |
| recalculate_thresholds(block_group); |
| spin_unlock(&block_group->tree_lock); |
| list_add_tail(&e->list, &bitmaps); |
| } |
| |
| num_entries--; |
| offset += sizeof(struct btrfs_free_space_entry); |
| if (offset + sizeof(struct btrfs_free_space_entry) >= |
| PAGE_CACHE_SIZE) |
| break; |
| entry++; |
| } |
| |
| /* |
| * We read an entry out of this page, we need to move on to the |
| * next page. |
| */ |
| if (need_loop) { |
| kunmap(page); |
| goto next; |
| } |
| |
| /* |
| * We add the bitmaps at the end of the entries in order that |
| * the bitmap entries are added to the cache. |
| */ |
| e = list_entry(bitmaps.next, struct btrfs_free_space, list); |
| list_del_init(&e->list); |
| memcpy(e->bitmap, addr, PAGE_CACHE_SIZE); |
| kunmap(page); |
| num_bitmaps--; |
| next: |
| unlock_page(page); |
| page_cache_release(page); |
| index++; |
| } |
| |
| ret = 1; |
| out: |
| kfree(checksums); |
| kfree(disk_crcs); |
| iput(inode); |
| return ret; |
| |
| free_cache: |
| /* This cache is bogus, make sure it gets cleared */ |
| spin_lock(&block_group->lock); |
| block_group->disk_cache_state = BTRFS_DC_CLEAR; |
| spin_unlock(&block_group->lock); |
| btrfs_remove_free_space_cache(block_group); |
| goto out; |
| } |
| |
| int btrfs_write_out_cache(struct btrfs_root *root, |
| struct btrfs_trans_handle *trans, |
| struct btrfs_block_group_cache *block_group, |
| struct btrfs_path *path) |
| { |
| struct btrfs_free_space_header *header; |
| struct extent_buffer *leaf; |
| struct inode *inode; |
| struct rb_node *node; |
| struct list_head *pos, *n; |
| struct page *page; |
| struct extent_state *cached_state = NULL; |
| struct list_head bitmap_list; |
| struct btrfs_key key; |
| u64 bytes = 0; |
| u32 *crc, *checksums; |
| pgoff_t index = 0, last_index = 0; |
| unsigned long first_page_offset; |
| int num_checksums; |
| int entries = 0; |
| int bitmaps = 0; |
| int ret = 0; |
| |
| root = root->fs_info->tree_root; |
| |
| INIT_LIST_HEAD(&bitmap_list); |
| |
| spin_lock(&block_group->lock); |
| if (block_group->disk_cache_state < BTRFS_DC_SETUP) { |
| spin_unlock(&block_group->lock); |
| return 0; |
| } |
| spin_unlock(&block_group->lock); |
| |
| inode = lookup_free_space_inode(root, block_group, path); |
| if (IS_ERR(inode)) |
| return 0; |
| |
| if (!i_size_read(inode)) { |
| iput(inode); |
| return 0; |
| } |
| |
| node = rb_first(&block_group->free_space_offset); |
| if (!node) { |
| iput(inode); |
| return 0; |
| } |
| |
| last_index = (i_size_read(inode) - 1) >> PAGE_CACHE_SHIFT; |
| filemap_write_and_wait(inode->i_mapping); |
| btrfs_wait_ordered_range(inode, inode->i_size & |
| ~(root->sectorsize - 1), (u64)-1); |
| |
| /* We need a checksum per page. */ |
| num_checksums = i_size_read(inode) / PAGE_CACHE_SIZE; |
| crc = checksums = kzalloc(sizeof(u32) * num_checksums, GFP_NOFS); |
| if (!crc) { |
| iput(inode); |
| return 0; |
| } |
| |
| /* Since the first page has all of our checksums and our generation we |
| * need to calculate the offset into the page that we can start writing |
| * our entries. |
| */ |
| first_page_offset = (sizeof(u32) * num_checksums) + sizeof(u64); |
| |
| /* |
| * Lock all pages first so we can lock the extent safely. |
| * |
| * NOTE: Because we hold the ref the entire time we're going to write to |
| * the page find_get_page should never fail, so we don't do a check |
| * after find_get_page at this point. Just putting this here so people |
| * know and don't freak out. |
| */ |
| while (index <= last_index) { |
| page = grab_cache_page(inode->i_mapping, index); |
| if (!page) { |
| pgoff_t i = 0; |
| |
| while (i < index) { |
| page = find_get_page(inode->i_mapping, i); |
| unlock_page(page); |
| page_cache_release(page); |
| page_cache_release(page); |
| i++; |
| } |
| goto out_free; |
| } |
| index++; |
| } |
| |
| index = 0; |
| lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1, |
| 0, &cached_state, GFP_NOFS); |
| |
| /* Write out the extent entries */ |
| do { |
| struct btrfs_free_space_entry *entry; |
| void *addr; |
| unsigned long offset = 0; |
| unsigned long start_offset = 0; |
| |
| if (index == 0) { |
| start_offset = first_page_offset; |
| offset = start_offset; |
| } |
| |
| page = find_get_page(inode->i_mapping, index); |
| |
| addr = kmap(page); |
| entry = addr + start_offset; |
| |
| memset(addr, 0, PAGE_CACHE_SIZE); |
| while (1) { |
| struct btrfs_free_space *e; |
| |
| e = rb_entry(node, struct btrfs_free_space, offset_index); |
| entries++; |
| |
| entry->offset = cpu_to_le64(e->offset); |
| entry->bytes = cpu_to_le64(e->bytes); |
| if (e->bitmap) { |
| entry->type = BTRFS_FREE_SPACE_BITMAP; |
| list_add_tail(&e->list, &bitmap_list); |
| bitmaps++; |
| } else { |
| entry->type = BTRFS_FREE_SPACE_EXTENT; |
| } |
| node = rb_next(node); |
| if (!node) |
| break; |
| offset += sizeof(struct btrfs_free_space_entry); |
| if (offset + sizeof(struct btrfs_free_space_entry) >= |
| PAGE_CACHE_SIZE) |
| break; |
| entry++; |
| } |
| *crc = ~(u32)0; |
| *crc = btrfs_csum_data(root, addr + start_offset, *crc, |
| PAGE_CACHE_SIZE - start_offset); |
| kunmap(page); |
| |
| btrfs_csum_final(*crc, (char *)crc); |
| crc++; |
| |
| bytes += PAGE_CACHE_SIZE; |
| |
| ClearPageChecked(page); |
| set_page_extent_mapped(page); |
| SetPageUptodate(page); |
| set_page_dirty(page); |
| |
| /* |
| * We need to release our reference we got for grab_cache_page, |
| * except for the first page which will hold our checksums, we |
| * do that below. |
| */ |
| if (index != 0) { |
| unlock_page(page); |
| page_cache_release(page); |
| } |
| |
| page_cache_release(page); |
| |
| index++; |
| } while (node); |
| |
| /* Write out the bitmaps */ |
| list_for_each_safe(pos, n, &bitmap_list) { |
| void *addr; |
| struct btrfs_free_space *entry = |
| list_entry(pos, struct btrfs_free_space, list); |
| |
| page = find_get_page(inode->i_mapping, index); |
| |
| addr = kmap(page); |
| memcpy(addr, entry->bitmap, PAGE_CACHE_SIZE); |
| *crc = ~(u32)0; |
| *crc = btrfs_csum_data(root, addr, *crc, PAGE_CACHE_SIZE); |
| kunmap(page); |
| btrfs_csum_final(*crc, (char *)crc); |
| crc++; |
| bytes += PAGE_CACHE_SIZE; |
| |
| ClearPageChecked(page); |
| set_page_extent_mapped(page); |
| SetPageUptodate(page); |
| set_page_dirty(page); |
| unlock_page(page); |
| page_cache_release(page); |
| page_cache_release(page); |
| list_del_init(&entry->list); |
| index++; |
| } |
| |
| /* Zero out the rest of the pages just to make sure */ |
| while (index <= last_index) { |
| void *addr; |
| |
| page = find_get_page(inode->i_mapping, index); |
| |
| addr = kmap(page); |
| memset(addr, 0, PAGE_CACHE_SIZE); |
| kunmap(page); |
| ClearPageChecked(page); |
| set_page_extent_mapped(page); |
| SetPageUptodate(page); |
| set_page_dirty(page); |
| unlock_page(page); |
| page_cache_release(page); |
| page_cache_release(page); |
| bytes += PAGE_CACHE_SIZE; |
| index++; |
| } |
| |
| btrfs_set_extent_delalloc(inode, 0, bytes - 1, &cached_state); |
| |
| /* Write the checksums and trans id to the first page */ |
| { |
| void *addr; |
| u64 *gen; |
| |
| page = find_get_page(inode->i_mapping, 0); |
| |
| addr = kmap(page); |
| memcpy(addr, checksums, sizeof(u32) * num_checksums); |
| gen = addr + (sizeof(u32) * num_checksums); |
| *gen = trans->transid; |
| kunmap(page); |
| ClearPageChecked(page); |
| set_page_extent_mapped(page); |
| SetPageUptodate(page); |
| set_page_dirty(page); |
| unlock_page(page); |
| page_cache_release(page); |
| page_cache_release(page); |
| } |
| BTRFS_I(inode)->generation = trans->transid; |
| |
| unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0, |
| i_size_read(inode) - 1, &cached_state, GFP_NOFS); |
| |
| filemap_write_and_wait(inode->i_mapping); |
| |
| key.objectid = BTRFS_FREE_SPACE_OBJECTID; |
| key.offset = block_group->key.objectid; |
| key.type = 0; |
| |
| ret = btrfs_search_slot(trans, root, &key, path, 1, 1); |
| if (ret < 0) { |
| ret = 0; |
| clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, bytes - 1, |
| EXTENT_DIRTY | EXTENT_DELALLOC | |
| EXTENT_DO_ACCOUNTING, 0, 0, NULL, GFP_NOFS); |
| goto out_free; |
| } |
| leaf = path->nodes[0]; |
| if (ret > 0) { |
| struct btrfs_key found_key; |
| BUG_ON(!path->slots[0]); |
| path->slots[0]--; |
| btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
| if (found_key.objectid != BTRFS_FREE_SPACE_OBJECTID || |
| found_key.offset != block_group->key.objectid) { |
| ret = 0; |
| clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, bytes - 1, |
| EXTENT_DIRTY | EXTENT_DELALLOC | |
| EXTENT_DO_ACCOUNTING, 0, 0, NULL, |
| GFP_NOFS); |
| btrfs_release_path(root, path); |
| goto out_free; |
| } |
| } |
| header = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_free_space_header); |
| btrfs_set_free_space_entries(leaf, header, entries); |
| btrfs_set_free_space_bitmaps(leaf, header, bitmaps); |
| btrfs_set_free_space_generation(leaf, header, trans->transid); |
| btrfs_mark_buffer_dirty(leaf); |
| btrfs_release_path(root, path); |
| |
| ret = 1; |
| |
| out_free: |
| if (ret == 0) { |
| invalidate_inode_pages2_range(inode->i_mapping, 0, index); |
| spin_lock(&block_group->lock); |
| block_group->disk_cache_state = BTRFS_DC_ERROR; |
| spin_unlock(&block_group->lock); |
| BTRFS_I(inode)->generation = 0; |
| } |
| kfree(checksums); |
| btrfs_update_inode(trans, root, inode); |
| iput(inode); |
| return ret; |
| } |
| |
| static inline unsigned long offset_to_bit(u64 bitmap_start, u64 sectorsize, |
| u64 offset) |
| { |
| BUG_ON(offset < bitmap_start); |
| offset -= bitmap_start; |
| return (unsigned long)(div64_u64(offset, sectorsize)); |
| } |
| |
| static inline unsigned long bytes_to_bits(u64 bytes, u64 sectorsize) |
| { |
| return (unsigned long)(div64_u64(bytes, sectorsize)); |
| } |
| |
| static inline u64 offset_to_bitmap(struct btrfs_block_group_cache *block_group, |
| u64 offset) |
| { |
| u64 bitmap_start; |
| u64 bytes_per_bitmap; |
| |
| bytes_per_bitmap = BITS_PER_BITMAP * block_group->sectorsize; |
| bitmap_start = offset - block_group->key.objectid; |
| bitmap_start = div64_u64(bitmap_start, bytes_per_bitmap); |
| bitmap_start *= bytes_per_bitmap; |
| bitmap_start += block_group->key.objectid; |
| |
| return bitmap_start; |
| } |
| |
| static int tree_insert_offset(struct rb_root *root, u64 offset, |
| struct rb_node *node, int bitmap) |
| { |
| struct rb_node **p = &root->rb_node; |
| struct rb_node *parent = NULL; |
| struct btrfs_free_space *info; |
| |
| while (*p) { |
| parent = *p; |
| info = rb_entry(parent, struct btrfs_free_space, offset_index); |
| |
| if (offset < info->offset) { |
| p = &(*p)->rb_left; |
| } else if (offset > info->offset) { |
| p = &(*p)->rb_right; |
| } else { |
| /* |
| * we could have a bitmap entry and an extent entry |
| * share the same offset. If this is the case, we want |
| * the extent entry to always be found first if we do a |
| * linear search through the tree, since we want to have |
| * the quickest allocation time, and allocating from an |
| * extent is faster than allocating from a bitmap. So |
| * if we're inserting a bitmap and we find an entry at |
| * this offset, we want to go right, or after this entry |
| * logically. If we are inserting an extent and we've |
| * found a bitmap, we want to go left, or before |
| * logically. |
| */ |
| if (bitmap) { |
| WARN_ON(info->bitmap); |
| p = &(*p)->rb_right; |
| } else { |
| WARN_ON(!info->bitmap); |
| p = &(*p)->rb_left; |
| } |
| } |
| } |
| |
| rb_link_node(node, parent, p); |
| rb_insert_color(node, root); |
| |
| return 0; |
| } |
| |
| /* |
| * searches the tree for the given offset. |
| * |
| * fuzzy - If this is set, then we are trying to make an allocation, and we just |
| * want a section that has at least bytes size and comes at or after the given |
| * offset. |
| */ |
| static struct btrfs_free_space * |
| tree_search_offset(struct btrfs_block_group_cache *block_group, |
| u64 offset, int bitmap_only, int fuzzy) |
| { |
| struct rb_node *n = block_group->free_space_offset.rb_node; |
| struct btrfs_free_space *entry, *prev = NULL; |
| |
| /* find entry that is closest to the 'offset' */ |
| while (1) { |
| if (!n) { |
| entry = NULL; |
| break; |
| } |
| |
| entry = rb_entry(n, struct btrfs_free_space, offset_index); |
| prev = entry; |
| |
| if (offset < entry->offset) |
| n = n->rb_left; |
| else if (offset > entry->offset) |
| n = n->rb_right; |
| else |
| break; |
| } |
| |
| if (bitmap_only) { |
| if (!entry) |
| return NULL; |
| if (entry->bitmap) |
| return entry; |
| |
| /* |
| * bitmap entry and extent entry may share same offset, |
| * in that case, bitmap entry comes after extent entry. |
| */ |
| n = rb_next(n); |
| if (!n) |
| return NULL; |
| entry = rb_entry(n, struct btrfs_free_space, offset_index); |
| if (entry->offset != offset) |
| return NULL; |
| |
| WARN_ON(!entry->bitmap); |
| return entry; |
| } else if (entry) { |
| if (entry->bitmap) { |
| /* |
| * if previous extent entry covers the offset, |
| * we should return it instead of the bitmap entry |
| */ |
| n = &entry->offset_index; |
| while (1) { |
| n = rb_prev(n); |
| if (!n) |
| break; |
| prev = rb_entry(n, struct btrfs_free_space, |
| offset_index); |
| if (!prev->bitmap) { |
| if (prev->offset + prev->bytes > offset) |
| entry = prev; |
| break; |
| } |
| } |
| } |
| return entry; |
| } |
| |
| if (!prev) |
| return NULL; |
| |
| /* find last entry before the 'offset' */ |
| entry = prev; |
| if (entry->offset > offset) { |
| n = rb_prev(&entry->offset_index); |
| if (n) { |
| entry = rb_entry(n, struct btrfs_free_space, |
| offset_index); |
| BUG_ON(entry->offset > offset); |
| } else { |
| if (fuzzy) |
| return entry; |
| else |
| return NULL; |
| } |
| } |
| |
| if (entry->bitmap) { |
| n = &entry->offset_index; |
| while (1) { |
| n = rb_prev(n); |
| if (!n) |
| break; |
| prev = rb_entry(n, struct btrfs_free_space, |
| offset_index); |
| if (!prev->bitmap) { |
| if (prev->offset + prev->bytes > offset) |
| return prev; |
| break; |
| } |
| } |
| if (entry->offset + BITS_PER_BITMAP * |
| block_group->sectorsize > offset) |
| return entry; |
| } else if (entry->offset + entry->bytes > offset) |
| return entry; |
| |
| if (!fuzzy) |
| return NULL; |
| |
| while (1) { |
| if (entry->bitmap) { |
| if (entry->offset + BITS_PER_BITMAP * |
| block_group->sectorsize > offset) |
| break; |
| } else { |
| if (entry->offset + entry->bytes > offset) |
| break; |
| } |
| |
| n = rb_next(&entry->offset_index); |
| if (!n) |
| return NULL; |
| entry = rb_entry(n, struct btrfs_free_space, offset_index); |
| } |
| return entry; |
| } |
| |
| static void unlink_free_space(struct btrfs_block_group_cache *block_group, |
| struct btrfs_free_space *info) |
| { |
| rb_erase(&info->offset_index, &block_group->free_space_offset); |
| block_group->free_extents--; |
| block_group->free_space -= info->bytes; |
| } |
| |
| static int link_free_space(struct btrfs_block_group_cache *block_group, |
| struct btrfs_free_space *info) |
| { |
| int ret = 0; |
| |
| BUG_ON(!info->bitmap && !info->bytes); |
| ret = tree_insert_offset(&block_group->free_space_offset, info->offset, |
| &info->offset_index, (info->bitmap != NULL)); |
| if (ret) |
| return ret; |
| |
| block_group->free_space += info->bytes; |
| block_group->free_extents++; |
| return ret; |
| } |
| |
| static void recalculate_thresholds(struct btrfs_block_group_cache *block_group) |
| { |
| u64 max_bytes; |
| u64 bitmap_bytes; |
| u64 extent_bytes; |
| u64 size = block_group->key.offset; |
| |
| /* |
| * The goal is to keep the total amount of memory used per 1gb of space |
| * at or below 32k, so we need to adjust how much memory we allow to be |
| * used by extent based free space tracking |
| */ |
| if (size < 1024 * 1024 * 1024) |
| max_bytes = MAX_CACHE_BYTES_PER_GIG; |
| else |
| max_bytes = MAX_CACHE_BYTES_PER_GIG * |
| div64_u64(size, 1024 * 1024 * 1024); |
| |
| /* |
| * we want to account for 1 more bitmap than what we have so we can make |
| * sure we don't go over our overall goal of MAX_CACHE_BYTES_PER_GIG as |
| * we add more bitmaps. |
| */ |
| bitmap_bytes = (block_group->total_bitmaps + 1) * PAGE_CACHE_SIZE; |
| |
| if (bitmap_bytes >= max_bytes) { |
| block_group->extents_thresh = 0; |
| return; |
| } |
| |
| /* |
| * we want the extent entry threshold to always be at most 1/2 the maxw |
| * bytes we can have, or whatever is less than that. |
| */ |
| extent_bytes = max_bytes - bitmap_bytes; |
| extent_bytes = min_t(u64, extent_bytes, div64_u64(max_bytes, 2)); |
| |
| block_group->extents_thresh = |
| div64_u64(extent_bytes, (sizeof(struct btrfs_free_space))); |
| } |
| |
| static void bitmap_clear_bits(struct btrfs_block_group_cache *block_group, |
| struct btrfs_free_space *info, u64 offset, |
| u64 bytes) |
| { |
| unsigned long start, end; |
| unsigned long i; |
| |
| start = offset_to_bit(info->offset, block_group->sectorsize, offset); |
| end = start + bytes_to_bits(bytes, block_group->sectorsize); |
| BUG_ON(end > BITS_PER_BITMAP); |
| |
| for (i = start; i < end; i++) |
| clear_bit(i, info->bitmap); |
| |
| info->bytes -= bytes; |
| block_group->free_space -= bytes; |
| } |
| |
| static void bitmap_set_bits(struct btrfs_block_group_cache *block_group, |
| struct btrfs_free_space *info, u64 offset, |
| u64 bytes) |
| { |
| unsigned long start, end; |
| unsigned long i; |
| |
| start = offset_to_bit(info->offset, block_group->sectorsize, offset); |
| end = start + bytes_to_bits(bytes, block_group->sectorsize); |
| BUG_ON(end > BITS_PER_BITMAP); |
| |
| for (i = start; i < end; i++) |
| set_bit(i, info->bitmap); |
| |
| info->bytes += bytes; |
| block_group->free_space += bytes; |
| } |
| |
| static int search_bitmap(struct btrfs_block_group_cache *block_group, |
| struct btrfs_free_space *bitmap_info, u64 *offset, |
| u64 *bytes) |
| { |
| unsigned long found_bits = 0; |
| unsigned long bits, i; |
| unsigned long next_zero; |
| |
| i = offset_to_bit(bitmap_info->offset, block_group->sectorsize, |
| max_t(u64, *offset, bitmap_info->offset)); |
| bits = bytes_to_bits(*bytes, block_group->sectorsize); |
| |
| for (i = find_next_bit(bitmap_info->bitmap, BITS_PER_BITMAP, i); |
| i < BITS_PER_BITMAP; |
| i = find_next_bit(bitmap_info->bitmap, BITS_PER_BITMAP, i + 1)) { |
| next_zero = find_next_zero_bit(bitmap_info->bitmap, |
| BITS_PER_BITMAP, i); |
| if ((next_zero - i) >= bits) { |
| found_bits = next_zero - i; |
| break; |
| } |
| i = next_zero; |
| } |
| |
| if (found_bits) { |
| *offset = (u64)(i * block_group->sectorsize) + |
| bitmap_info->offset; |
| *bytes = (u64)(found_bits) * block_group->sectorsize; |
| return 0; |
| } |
| |
| return -1; |
| } |
| |
| static struct btrfs_free_space *find_free_space(struct btrfs_block_group_cache |
| *block_group, u64 *offset, |
| u64 *bytes, int debug) |
| { |
| struct btrfs_free_space *entry; |
| struct rb_node *node; |
| int ret; |
| |
| if (!block_group->free_space_offset.rb_node) |
| return NULL; |
| |
| entry = tree_search_offset(block_group, |
| offset_to_bitmap(block_group, *offset), |
| 0, 1); |
| if (!entry) |
| return NULL; |
| |
| for (node = &entry->offset_index; node; node = rb_next(node)) { |
| entry = rb_entry(node, struct btrfs_free_space, offset_index); |
| if (entry->bytes < *bytes) |
| continue; |
| |
| if (entry->bitmap) { |
| ret = search_bitmap(block_group, entry, offset, bytes); |
| if (!ret) |
| return entry; |
| continue; |
| } |
| |
| *offset = entry->offset; |
| *bytes = entry->bytes; |
| return entry; |
| } |
| |
| return NULL; |
| } |
| |
| static void add_new_bitmap(struct btrfs_block_group_cache *block_group, |
| struct btrfs_free_space *info, u64 offset) |
| { |
| u64 bytes_per_bg = BITS_PER_BITMAP * block_group->sectorsize; |
| int max_bitmaps = (int)div64_u64(block_group->key.offset + |
| bytes_per_bg - 1, bytes_per_bg); |
| BUG_ON(block_group->total_bitmaps >= max_bitmaps); |
| |
| info->offset = offset_to_bitmap(block_group, offset); |
| info->bytes = 0; |
| link_free_space(block_group, info); |
| block_group->total_bitmaps++; |
| |
| recalculate_thresholds(block_group); |
| } |
| |
| static void free_bitmap(struct btrfs_block_group_cache *block_group, |
| struct btrfs_free_space *bitmap_info) |
| { |
| unlink_free_space(block_group, bitmap_info); |
| kfree(bitmap_info->bitmap); |
| kfree(bitmap_info); |
| block_group->total_bitmaps--; |
| recalculate_thresholds(block_group); |
| } |
| |
| static noinline int remove_from_bitmap(struct btrfs_block_group_cache *block_group, |
| struct btrfs_free_space *bitmap_info, |
| u64 *offset, u64 *bytes) |
| { |
| u64 end; |
| u64 search_start, search_bytes; |
| int ret; |
| |
| again: |
| end = bitmap_info->offset + |
| (u64)(BITS_PER_BITMAP * block_group->sectorsize) - 1; |
| |
| /* |
| * XXX - this can go away after a few releases. |
| * |
| * since the only user of btrfs_remove_free_space is the tree logging |
| * stuff, and the only way to test that is under crash conditions, we |
| * want to have this debug stuff here just in case somethings not |
| * working. Search the bitmap for the space we are trying to use to |
| * make sure its actually there. If its not there then we need to stop |
| * because something has gone wrong. |
| */ |
| search_start = *offset; |
| search_bytes = *bytes; |
| ret = search_bitmap(block_group, bitmap_info, &search_start, |
| &search_bytes); |
| BUG_ON(ret < 0 || search_start != *offset); |
| |
| if (*offset > bitmap_info->offset && *offset + *bytes > end) { |
| bitmap_clear_bits(block_group, bitmap_info, *offset, |
| end - *offset + 1); |
| *bytes -= end - *offset + 1; |
| *offset = end + 1; |
| } else if (*offset >= bitmap_info->offset && *offset + *bytes <= end) { |
| bitmap_clear_bits(block_group, bitmap_info, *offset, *bytes); |
| *bytes = 0; |
| } |
| |
| if (*bytes) { |
| struct rb_node *next = rb_next(&bitmap_info->offset_index); |
| if (!bitmap_info->bytes) |
| free_bitmap(block_group, bitmap_info); |
| |
| /* |
| * no entry after this bitmap, but we still have bytes to |
| * remove, so something has gone wrong. |
| */ |
| if (!next) |
| return -EINVAL; |
| |
| bitmap_info = rb_entry(next, struct btrfs_free_space, |
| offset_index); |
| |
| /* |
| * if the next entry isn't a bitmap we need to return to let the |
| * extent stuff do its work. |
| */ |
| if (!bitmap_info->bitmap) |
| return -EAGAIN; |
| |
| /* |
| * Ok the next item is a bitmap, but it may not actually hold |
| * the information for the rest of this free space stuff, so |
| * look for it, and if we don't find it return so we can try |
| * everything over again. |
| */ |
| search_start = *offset; |
| search_bytes = *bytes; |
| ret = search_bitmap(block_group, bitmap_info, &search_start, |
| &search_bytes); |
| if (ret < 0 || search_start != *offset) |
| return -EAGAIN; |
| |
| goto again; |
| } else if (!bitmap_info->bytes) |
| free_bitmap(block_group, bitmap_info); |
| |
| return 0; |
| } |
| |
| static int insert_into_bitmap(struct btrfs_block_group_cache *block_group, |
| struct btrfs_free_space *info) |
| { |
| struct btrfs_free_space *bitmap_info; |
| int added = 0; |
| u64 bytes, offset, end; |
| int ret; |
| |
| /* |
| * If we are below the extents threshold then we can add this as an |
| * extent, and don't have to deal with the bitmap |
| */ |
| if (block_group->free_extents < block_group->extents_thresh && |
| info->bytes > block_group->sectorsize * 4) |
| return 0; |
| |
| /* |
| * some block groups are so tiny they can't be enveloped by a bitmap, so |
| * don't even bother to create a bitmap for this |
| */ |
| if (BITS_PER_BITMAP * block_group->sectorsize > |
| block_group->key.offset) |
| return 0; |
| |
| bytes = info->bytes; |
| offset = info->offset; |
| |
| again: |
| bitmap_info = tree_search_offset(block_group, |
| offset_to_bitmap(block_group, offset), |
| 1, 0); |
| if (!bitmap_info) { |
| BUG_ON(added); |
| goto new_bitmap; |
| } |
| |
| end = bitmap_info->offset + |
| (u64)(BITS_PER_BITMAP * block_group->sectorsize); |
| |
| if (offset >= bitmap_info->offset && offset + bytes > end) { |
| bitmap_set_bits(block_group, bitmap_info, offset, |
| end - offset); |
| bytes -= end - offset; |
| offset = end; |
| added = 0; |
| } else if (offset >= bitmap_info->offset && offset + bytes <= end) { |
| bitmap_set_bits(block_group, bitmap_info, offset, bytes); |
| bytes = 0; |
| } else { |
| BUG(); |
| } |
| |
| if (!bytes) { |
| ret = 1; |
| goto out; |
| } else |
| goto again; |
| |
| new_bitmap: |
| if (info && info->bitmap) { |
| add_new_bitmap(block_group, info, offset); |
| added = 1; |
| info = NULL; |
| goto again; |
| } else { |
| spin_unlock(&block_group->tree_lock); |
| |
| /* no pre-allocated info, allocate a new one */ |
| if (!info) { |
| info = kzalloc(sizeof(struct btrfs_free_space), |
| GFP_NOFS); |
| if (!info) { |
| spin_lock(&block_group->tree_lock); |
| ret = -ENOMEM; |
| goto out; |
| } |
| } |
| |
| /* allocate the bitmap */ |
| info->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS); |
| spin_lock(&block_group->tree_lock); |
| if (!info->bitmap) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| goto again; |
| } |
| |
| out: |
| if (info) { |
| if (info->bitmap) |
| kfree(info->bitmap); |
| kfree(info); |
| } |
| |
| return ret; |
| } |
| |
| bool try_merge_free_space(struct btrfs_block_group_cache *block_group, |
| struct btrfs_free_space *info) |
| { |
| struct btrfs_free_space *left_info; |
| struct btrfs_free_space *right_info; |
| bool merged = false; |
| u64 offset = info->offset; |
| u64 bytes = info->bytes; |
| |
| /* |
| * first we want to see if there is free space adjacent to the range we |
| * are adding, if there is remove that struct and add a new one to |
| * cover the entire range |
| */ |
| right_info = tree_search_offset(block_group, offset + bytes, 0, 0); |
| if (right_info && rb_prev(&right_info->offset_index)) |
| left_info = rb_entry(rb_prev(&right_info->offset_index), |
| struct btrfs_free_space, offset_index); |
| else |
| left_info = tree_search_offset(block_group, offset - 1, 0, 0); |
| |
| if (right_info && !right_info->bitmap) { |
| unlink_free_space(block_group, right_info); |
| info->bytes += right_info->bytes; |
| kfree(right_info); |
| merged = true; |
| } |
| |
| if (left_info && !left_info->bitmap && |
| left_info->offset + left_info->bytes == offset) { |
| unlink_free_space(block_group, left_info); |
| info->offset = left_info->offset; |
| info->bytes += left_info->bytes; |
| kfree(left_info); |
| merged = true; |
| } |
| |
| return merged; |
| } |
| |
| int btrfs_add_free_space(struct btrfs_block_group_cache *block_group, |
| u64 offset, u64 bytes) |
| { |
| struct btrfs_free_space *info; |
| int ret = 0; |
| |
| info = kzalloc(sizeof(struct btrfs_free_space), GFP_NOFS); |
| if (!info) |
| return -ENOMEM; |
| |
| info->offset = offset; |
| info->bytes = bytes; |
| |
| spin_lock(&block_group->tree_lock); |
| |
| if (try_merge_free_space(block_group, info)) |
| goto link; |
| |
| /* |
| * There was no extent directly to the left or right of this new |
| * extent then we know we're going to have to allocate a new extent, so |
| * before we do that see if we need to drop this into a bitmap |
| */ |
| ret = insert_into_bitmap(block_group, info); |
| if (ret < 0) { |
| goto out; |
| } else if (ret) { |
| ret = 0; |
| goto out; |
| } |
| link: |
| ret = link_free_space(block_group, info); |
| if (ret) |
| kfree(info); |
| out: |
| spin_unlock(&block_group->tree_lock); |
| |
| if (ret) { |
| printk(KERN_CRIT "btrfs: unable to add free space :%d\n", ret); |
| BUG_ON(ret == -EEXIST); |
| } |
| |
| return ret; |
| } |
| |
| int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group, |
| u64 offset, u64 bytes) |
| { |
| struct btrfs_free_space *info; |
| struct btrfs_free_space *next_info = NULL; |
| int ret = 0; |
| |
| spin_lock(&block_group->tree_lock); |
| |
| again: |
| info = tree_search_offset(block_group, offset, 0, 0); |
| if (!info) { |
| /* |
| * oops didn't find an extent that matched the space we wanted |
| * to remove, look for a bitmap instead |
| */ |
| info = tree_search_offset(block_group, |
| offset_to_bitmap(block_group, offset), |
| 1, 0); |
| if (!info) { |
| WARN_ON(1); |
| goto out_lock; |
| } |
| } |
| |
| if (info->bytes < bytes && rb_next(&info->offset_index)) { |
| u64 end; |
| next_info = rb_entry(rb_next(&info->offset_index), |
| struct btrfs_free_space, |
| offset_index); |
| |
| if (next_info->bitmap) |
| end = next_info->offset + BITS_PER_BITMAP * |
| block_group->sectorsize - 1; |
| else |
| end = next_info->offset + next_info->bytes; |
| |
| if (next_info->bytes < bytes || |
| next_info->offset > offset || offset > end) { |
| printk(KERN_CRIT "Found free space at %llu, size %llu," |
| " trying to use %llu\n", |
| (unsigned long long)info->offset, |
| (unsigned long long)info->bytes, |
| (unsigned long long)bytes); |
| WARN_ON(1); |
| ret = -EINVAL; |
| goto out_lock; |
| } |
| |
| info = next_info; |
| } |
| |
| if (info->bytes == bytes) { |
| unlink_free_space(block_group, info); |
| if (info->bitmap) { |
| kfree(info->bitmap); |
| block_group->total_bitmaps--; |
| } |
| kfree(info); |
| goto out_lock; |
| } |
| |
| if (!info->bitmap && info->offset == offset) { |
| unlink_free_space(block_group, info); |
| info->offset += bytes; |
| info->bytes -= bytes; |
| link_free_space(block_group, info); |
| goto out_lock; |
| } |
| |
| if (!info->bitmap && info->offset <= offset && |
| info->offset + info->bytes >= offset + bytes) { |
| u64 old_start = info->offset; |
| /* |
| * we're freeing space in the middle of the info, |
| * this can happen during tree log replay |
| * |
| * first unlink the old info and then |
| * insert it again after the hole we're creating |
| */ |
| unlink_free_space(block_group, info); |
| if (offset + bytes < info->offset + info->bytes) { |
| u64 old_end = info->offset + info->bytes; |
| |
| info->offset = offset + bytes; |
| info->bytes = old_end - info->offset; |
| ret = link_free_space(block_group, info); |
| WARN_ON(ret); |
| if (ret) |
| goto out_lock; |
| } else { |
| /* the hole we're creating ends at the end |
| * of the info struct, just free the info |
| */ |
| kfree(info); |
| } |
| spin_unlock(&block_group->tree_lock); |
| |
| /* step two, insert a new info struct to cover |
| * anything before the hole |
| */ |
| ret = btrfs_add_free_space(block_group, old_start, |
| offset - old_start); |
| WARN_ON(ret); |
| goto out; |
| } |
| |
| ret = remove_from_bitmap(block_group, info, &offset, &bytes); |
| if (ret == -EAGAIN) |
| goto again; |
| BUG_ON(ret); |
| out_lock: |
| spin_unlock(&block_group->tree_lock); |
| out: |
| return ret; |
| } |
| |
| void btrfs_dump_free_space(struct btrfs_block_group_cache *block_group, |
| u64 bytes) |
| { |
| struct btrfs_free_space *info; |
| struct rb_node *n; |
| int count = 0; |
| |
| for (n = rb_first(&block_group->free_space_offset); n; n = rb_next(n)) { |
| info = rb_entry(n, struct btrfs_free_space, offset_index); |
| if (info->bytes >= bytes) |
| count++; |
| printk(KERN_CRIT "entry offset %llu, bytes %llu, bitmap %s\n", |
| (unsigned long long)info->offset, |
| (unsigned long long)info->bytes, |
| (info->bitmap) ? "yes" : "no"); |
| } |
| printk(KERN_INFO "block group has cluster?: %s\n", |
| list_empty(&block_group->cluster_list) ? "no" : "yes"); |
| printk(KERN_INFO "%d blocks of free space at or bigger than bytes is" |
| "\n", count); |
| } |
| |
| u64 btrfs_block_group_free_space(struct btrfs_block_group_cache *block_group) |
| { |
| struct btrfs_free_space *info; |
| struct rb_node *n; |
| u64 ret = 0; |
| |
| for (n = rb_first(&block_group->free_space_offset); n; |
| n = rb_next(n)) { |
| info = rb_entry(n, struct btrfs_free_space, offset_index); |
| ret += info->bytes; |
| } |
| |
| return ret; |
| } |
| |
| /* |
| * for a given cluster, put all of its extents back into the free |
| * space cache. If the block group passed doesn't match the block group |
| * pointed to by the cluster, someone else raced in and freed the |
| * cluster already. In that case, we just return without changing anything |
| */ |
| static int |
| __btrfs_return_cluster_to_free_space( |
| struct btrfs_block_group_cache *block_group, |
| struct btrfs_free_cluster *cluster) |
| { |
| struct btrfs_free_space *entry; |
| struct rb_node *node; |
| bool bitmap; |
| |
| spin_lock(&cluster->lock); |
| if (cluster->block_group != block_group) |
| goto out; |
| |
| bitmap = cluster->points_to_bitmap; |
| cluster->block_group = NULL; |
| cluster->window_start = 0; |
| list_del_init(&cluster->block_group_list); |
| cluster->points_to_bitmap = false; |
| |
| if (bitmap) |
| goto out; |
| |
| node = rb_first(&cluster->root); |
| while (node) { |
| entry = rb_entry(node, struct btrfs_free_space, offset_index); |
| node = rb_next(&entry->offset_index); |
| rb_erase(&entry->offset_index, &cluster->root); |
| BUG_ON(entry->bitmap); |
| tree_insert_offset(&block_group->free_space_offset, |
| entry->offset, &entry->offset_index, 0); |
| } |
| cluster->root = RB_ROOT; |
| |
| out: |
| spin_unlock(&cluster->lock); |
| btrfs_put_block_group(block_group); |
| return 0; |
| } |
| |
| void btrfs_remove_free_space_cache(struct btrfs_block_group_cache *block_group) |
| { |
| struct btrfs_free_space *info; |
| struct rb_node *node; |
| struct btrfs_free_cluster *cluster; |
| struct list_head *head; |
| |
| spin_lock(&block_group->tree_lock); |
| while ((head = block_group->cluster_list.next) != |
| &block_group->cluster_list) { |
| cluster = list_entry(head, struct btrfs_free_cluster, |
| block_group_list); |
| |
| WARN_ON(cluster->block_group != block_group); |
| __btrfs_return_cluster_to_free_space(block_group, cluster); |
| if (need_resched()) { |
| spin_unlock(&block_group->tree_lock); |
| cond_resched(); |
| spin_lock(&block_group->tree_lock); |
| } |
| } |
| |
| while ((node = rb_last(&block_group->free_space_offset)) != NULL) { |
| info = rb_entry(node, struct btrfs_free_space, offset_index); |
| unlink_free_space(block_group, info); |
| if (info->bitmap) |
| kfree(info->bitmap); |
| kfree(info); |
| if (need_resched()) { |
| spin_unlock(&block_group->tree_lock); |
| cond_resched(); |
| spin_lock(&block_group->tree_lock); |
| } |
| } |
| |
| spin_unlock(&block_group->tree_lock); |
| } |
| |
| u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group, |
| u64 offset, u64 bytes, u64 empty_size) |
| { |
| struct btrfs_free_space *entry = NULL; |
| u64 bytes_search = bytes + empty_size; |
| u64 ret = 0; |
| |
| spin_lock(&block_group->tree_lock); |
| entry = find_free_space(block_group, &offset, &bytes_search, 0); |
| if (!entry) |
| goto out; |
| |
| ret = offset; |
| if (entry->bitmap) { |
| bitmap_clear_bits(block_group, entry, offset, bytes); |
| if (!entry->bytes) |
| free_bitmap(block_group, entry); |
| } else { |
| unlink_free_space(block_group, entry); |
| entry->offset += bytes; |
| entry->bytes -= bytes; |
| if (!entry->bytes) |
| kfree(entry); |
| else |
| link_free_space(block_group, entry); |
| } |
| |
| out: |
| spin_unlock(&block_group->tree_lock); |
| |
| return ret; |
| } |
| |
| /* |
| * given a cluster, put all of its extents back into the free space |
| * cache. If a block group is passed, this function will only free |
| * a cluster that belongs to the passed block group. |
| * |
| * Otherwise, it'll get a reference on the block group pointed to by the |
| * cluster and remove the cluster from it. |
| */ |
| int btrfs_return_cluster_to_free_space( |
| struct btrfs_block_group_cache *block_group, |
| struct btrfs_free_cluster *cluster) |
| { |
| int ret; |
| |
| /* first, get a safe pointer to the block group */ |
| spin_lock(&cluster->lock); |
| if (!block_group) { |
| block_group = cluster->block_group; |
| if (!block_group) { |
| spin_unlock(&cluster->lock); |
| return 0; |
| } |
| } else if (cluster->block_group != block_group) { |
| /* someone else has already freed it don't redo their work */ |
| spin_unlock(&cluster->lock); |
| return 0; |
| } |
| atomic_inc(&block_group->count); |
| spin_unlock(&cluster->lock); |
| |
| /* now return any extents the cluster had on it */ |
| spin_lock(&block_group->tree_lock); |
| ret = __btrfs_return_cluster_to_free_space(block_group, cluster); |
| spin_unlock(&block_group->tree_lock); |
| |
| /* finally drop our ref */ |
| btrfs_put_block_group(block_group); |
| return ret; |
| } |
| |
| static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group_cache *block_group, |
| struct btrfs_free_cluster *cluster, |
| u64 bytes, u64 min_start) |
| { |
| struct btrfs_free_space *entry; |
| int err; |
| u64 search_start = cluster->window_start; |
| u64 search_bytes = bytes; |
| u64 ret = 0; |
| |
| spin_lock(&block_group->tree_lock); |
| spin_lock(&cluster->lock); |
| |
| if (!cluster->points_to_bitmap) |
| goto out; |
| |
| if (cluster->block_group != block_group) |
| goto out; |
| |
| /* |
| * search_start is the beginning of the bitmap, but at some point it may |
| * be a good idea to point to the actual start of the free area in the |
| * bitmap, so do the offset_to_bitmap trick anyway, and set bitmap_only |
| * to 1 to make sure we get the bitmap entry |
| */ |
| entry = tree_search_offset(block_group, |
| offset_to_bitmap(block_group, search_start), |
| 1, 0); |
| if (!entry || !entry->bitmap) |
| goto out; |
| |
| search_start = min_start; |
| search_bytes = bytes; |
| |
| err = search_bitmap(block_group, entry, &search_start, |
| &search_bytes); |
| if (err) |
| goto out; |
| |
| ret = search_start; |
| bitmap_clear_bits(block_group, entry, ret, bytes); |
| if (entry->bytes == 0) |
| free_bitmap(block_group, entry); |
| out: |
| spin_unlock(&cluster->lock); |
| spin_unlock(&block_group->tree_lock); |
| |
| return ret; |
| } |
| |
| /* |
| * given a cluster, try to allocate 'bytes' from it, returns 0 |
| * if it couldn't find anything suitably large, or a logical disk offset |
| * if things worked out |
| */ |
| u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group, |
| struct btrfs_free_cluster *cluster, u64 bytes, |
| u64 min_start) |
| { |
| struct btrfs_free_space *entry = NULL; |
| struct rb_node *node; |
| u64 ret = 0; |
| |
| if (cluster->points_to_bitmap) |
| return btrfs_alloc_from_bitmap(block_group, cluster, bytes, |
| min_start); |
| |
| spin_lock(&cluster->lock); |
| if (bytes > cluster->max_size) |
| goto out; |
| |
| if (cluster->block_group != block_group) |
| goto out; |
| |
| node = rb_first(&cluster->root); |
| if (!node) |
| goto out; |
| |
| entry = rb_entry(node, struct btrfs_free_space, offset_index); |
| |
| while(1) { |
| if (entry->bytes < bytes || entry->offset < min_start) { |
| struct rb_node *node; |
| |
| node = rb_next(&entry->offset_index); |
| if (!node) |
| break; |
| entry = rb_entry(node, struct btrfs_free_space, |
| offset_index); |
| continue; |
| } |
| ret = entry->offset; |
| |
| entry->offset += bytes; |
| entry->bytes -= bytes; |
| |
| if (entry->bytes == 0) |
| rb_erase(&entry->offset_index, &cluster->root); |
| break; |
| } |
| out: |
| spin_unlock(&cluster->lock); |
| |
| if (!ret) |
| return 0; |
| |
| spin_lock(&block_group->tree_lock); |
| |
| block_group->free_space -= bytes; |
| if (entry->bytes == 0) { |
| block_group->free_extents--; |
| kfree(entry); |
| } |
| |
| spin_unlock(&block_group->tree_lock); |
| |
| return ret; |
| } |
| |
| static int btrfs_bitmap_cluster(struct btrfs_block_group_cache *block_group, |
| struct btrfs_free_space *entry, |
| struct btrfs_free_cluster *cluster, |
| u64 offset, u64 bytes, u64 min_bytes) |
| { |
| unsigned long next_zero; |
| unsigned long i; |
| unsigned long search_bits; |
| unsigned long total_bits; |
| unsigned long found_bits; |
| unsigned long start = 0; |
| unsigned long total_found = 0; |
| bool found = false; |
| |
| i = offset_to_bit(entry->offset, block_group->sectorsize, |
| max_t(u64, offset, entry->offset)); |
| search_bits = bytes_to_bits(min_bytes, block_group->sectorsize); |
| total_bits = bytes_to_bits(bytes, block_group->sectorsize); |
| |
| again: |
| found_bits = 0; |
| for (i = find_next_bit(entry->bitmap, BITS_PER_BITMAP, i); |
| i < BITS_PER_BITMAP; |
| i = find_next_bit(entry->bitmap, BITS_PER_BITMAP, i + 1)) { |
| next_zero = find_next_zero_bit(entry->bitmap, |
| BITS_PER_BITMAP, i); |
| if (next_zero - i >= search_bits) { |
| found_bits = next_zero - i; |
| break; |
| } |
| i = next_zero; |
| } |
| |
| if (!found_bits) |
| return -1; |
| |
| if (!found) { |
| start = i; |
| found = true; |
| } |
| |
| total_found += found_bits; |
| |
| if (cluster->max_size < found_bits * block_group->sectorsize) |
| cluster->max_size = found_bits * block_group->sectorsize; |
| |
| if (total_found < total_bits) { |
| i = find_next_bit(entry->bitmap, BITS_PER_BITMAP, next_zero); |
| if (i - start > total_bits * 2) { |
| total_found = 0; |
| cluster->max_size = 0; |
| found = false; |
| } |
| goto again; |
| } |
| |
| cluster->window_start = start * block_group->sectorsize + |
| entry->offset; |
| cluster->points_to_bitmap = true; |
| |
| return 0; |
| } |
| |
| /* |
| * here we try to find a cluster of blocks in a block group. The goal |
| * is to find at least bytes free and up to empty_size + bytes free. |
| * We might not find them all in one contiguous area. |
| * |
| * returns zero and sets up cluster if things worked out, otherwise |
| * it returns -enospc |
| */ |
| int btrfs_find_space_cluster(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_block_group_cache *block_group, |
| struct btrfs_free_cluster *cluster, |
| u64 offset, u64 bytes, u64 empty_size) |
| { |
| struct btrfs_free_space *entry = NULL; |
| struct rb_node *node; |
| struct btrfs_free_space *next; |
| struct btrfs_free_space *last = NULL; |
| u64 min_bytes; |
| u64 window_start; |
| u64 window_free; |
| u64 max_extent = 0; |
| bool found_bitmap = false; |
| int ret; |
| |
| /* for metadata, allow allocates with more holes */ |
| if (btrfs_test_opt(root, SSD_SPREAD)) { |
| min_bytes = bytes + empty_size; |
| } else if (block_group->flags & BTRFS_BLOCK_GROUP_METADATA) { |
| /* |
| * we want to do larger allocations when we are |
| * flushing out the delayed refs, it helps prevent |
| * making more work as we go along. |
| */ |
| if (trans->transaction->delayed_refs.flushing) |
| min_bytes = max(bytes, (bytes + empty_size) >> 1); |
| else |
| min_bytes = max(bytes, (bytes + empty_size) >> 4); |
| } else |
| min_bytes = max(bytes, (bytes + empty_size) >> 2); |
| |
| spin_lock(&block_group->tree_lock); |
| spin_lock(&cluster->lock); |
| |
| /* someone already found a cluster, hooray */ |
| if (cluster->block_group) { |
| ret = 0; |
| goto out; |
| } |
| again: |
| entry = tree_search_offset(block_group, offset, found_bitmap, 1); |
| if (!entry) { |
| ret = -ENOSPC; |
| goto out; |
| } |
| |
| /* |
| * If found_bitmap is true, we exhausted our search for extent entries, |
| * and we just want to search all of the bitmaps that we can find, and |
| * ignore any extent entries we find. |
| */ |
| while (entry->bitmap || found_bitmap || |
| (!entry->bitmap && entry->bytes < min_bytes)) { |
| struct rb_node *node = rb_next(&entry->offset_index); |
| |
| if (entry->bitmap && entry->bytes > bytes + empty_size) { |
| ret = btrfs_bitmap_cluster(block_group, entry, cluster, |
| offset, bytes + empty_size, |
| min_bytes); |
| if (!ret) |
| goto got_it; |
| } |
| |
| if (!node) { |
| ret = -ENOSPC; |
| goto out; |
| } |
| entry = rb_entry(node, struct btrfs_free_space, offset_index); |
| } |
| |
| /* |
| * We already searched all the extent entries from the passed in offset |
| * to the end and didn't find enough space for the cluster, and we also |
| * didn't find any bitmaps that met our criteria, just go ahead and exit |
| */ |
| if (found_bitmap) { |
| ret = -ENOSPC; |
| goto out; |
| } |
| |
| cluster->points_to_bitmap = false; |
| window_start = entry->offset; |
| window_free = entry->bytes; |
| last = entry; |
| max_extent = entry->bytes; |
| |
| while (1) { |
| /* out window is just right, lets fill it */ |
| if (window_free >= bytes + empty_size) |
| break; |
| |
| node = rb_next(&last->offset_index); |
| if (!node) { |
| if (found_bitmap) |
| goto again; |
| ret = -ENOSPC; |
| goto out; |
| } |
| next = rb_entry(node, struct btrfs_free_space, offset_index); |
| |
| /* |
| * we found a bitmap, so if this search doesn't result in a |
| * cluster, we know to go and search again for the bitmaps and |
| * start looking for space there |
| */ |
| if (next->bitmap) { |
| if (!found_bitmap) |
| offset = next->offset; |
| found_bitmap = true; |
| last = next; |
| continue; |
| } |
| |
| /* |
| * we haven't filled the empty size and the window is |
| * very large. reset and try again |
| */ |
| if (next->offset - (last->offset + last->bytes) > 128 * 1024 || |
| next->offset - window_start > (bytes + empty_size) * 2) { |
| entry = next; |
| window_start = entry->offset; |
| window_free = entry->bytes; |
| last = entry; |
| max_extent = entry->bytes; |
| } else { |
| last = next; |
| window_free += next->bytes; |
| if (entry->bytes > max_extent) |
| max_extent = entry->bytes; |
| } |
| } |
| |
| cluster->window_start = entry->offset; |
| |
| /* |
| * now we've found our entries, pull them out of the free space |
| * cache and put them into the cluster rbtree |
| * |
| * The cluster includes an rbtree, but only uses the offset index |
| * of each free space cache entry. |
| */ |
| while (1) { |
| node = rb_next(&entry->offset_index); |
| if (entry->bitmap && node) { |
| entry = rb_entry(node, struct btrfs_free_space, |
| offset_index); |
| continue; |
| } else if (entry->bitmap && !node) { |
| break; |
| } |
| |
| rb_erase(&entry->offset_index, &block_group->free_space_offset); |
| ret = tree_insert_offset(&cluster->root, entry->offset, |
| &entry->offset_index, 0); |
| BUG_ON(ret); |
| |
| if (!node || entry == last) |
| break; |
| |
| entry = rb_entry(node, struct btrfs_free_space, offset_index); |
| } |
| |
| cluster->max_size = max_extent; |
| got_it: |
| ret = 0; |
| atomic_inc(&block_group->count); |
| list_add_tail(&cluster->block_group_list, &block_group->cluster_list); |
| cluster->block_group = block_group; |
| out: |
| spin_unlock(&cluster->lock); |
| spin_unlock(&block_group->tree_lock); |
| |
| return ret; |
| } |
| |
| /* |
| * simple code to zero out a cluster |
| */ |
| void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster) |
| { |
| spin_lock_init(&cluster->lock); |
| spin_lock_init(&cluster->refill_lock); |
| cluster->root = RB_ROOT; |
| cluster->max_size = 0; |
| cluster->points_to_bitmap = false; |
| INIT_LIST_HEAD(&cluster->block_group_list); |
| cluster->block_group = NULL; |
| } |
| |