/* * 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 <linux/ratelimit.h> #include "ctree.h" #include "free-space-cache.h" #include "transaction.h" #include "disk-io.h" #include "extent_io.h" #include "inode-map.h" #define BITS_PER_BITMAP (PAGE_CACHE_SIZE * 8) #define MAX_CACHE_BYTES_PER_GIG (32 * 1024) static int link_free_space(struct btrfs_free_space_ctl *ctl, struct btrfs_free_space *info); static void unlink_free_space(struct btrfs_free_space_ctl *ctl, struct btrfs_free_space *info); static struct inode *__lookup_free_space_inode(struct btrfs_root *root, struct btrfs_path *path, u64 offset) { 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; key.objectid = BTRFS_FREE_SPACE_OBJECTID; key.offset = offset; 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(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(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); } mapping_set_gfp_mask(inode->i_mapping, mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS); return inode; } struct inode *lookup_free_space_inode(struct btrfs_root *root, struct btrfs_block_group_cache *block_group, struct btrfs_path *path) { struct inode *inode = NULL; u32 flags = BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW; spin_lock(&block_group->lock); if (block_group->inode) inode = igrab(block_group->inode); spin_unlock(&block_group->lock); if (inode) return inode; inode = __lookup_free_space_inode(root, path, block_group->key.objectid); if (IS_ERR(inode)) return inode; spin_lock(&block_group->lock); if (!((BTRFS_I(inode)->flags & flags) == flags)) { printk(KERN_INFO "Old style space inode found, converting.\n"); BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW; block_group->disk_cache_state = BTRFS_DC_CLEAR; } if (!block_group->iref) { 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_path *path, u64 ino, u64 offset) { 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 flags = BTRFS_INODE_NOCOMPRESS | BTRFS_INODE_PREALLOC; int ret; ret = btrfs_insert_empty_inode(trans, root, path, ino); if (ret) return ret; /* We inline crc's for the free disk space cache */ if (ino != BTRFS_FREE_INO_OBJECTID) flags |= BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW; 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, flags); 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, offset); btrfs_mark_buffer_dirty(leaf); btrfs_release_path(path); key.objectid = BTRFS_FREE_SPACE_OBJECTID; key.offset = offset; key.type = 0; ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(struct btrfs_free_space_header)); if (ret < 0) { btrfs_release_path(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(path); return 0; } 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) { int ret; u64 ino; ret = btrfs_find_free_objectid(root, &ino); if (ret < 0) return ret; return __create_free_space_inode(root, trans, path, ino, block_group->key.objectid); } int btrfs_truncate_free_space_cache(struct btrfs_root *root, struct btrfs_trans_handle *trans, struct btrfs_path *path, struct inode *inode) { struct btrfs_block_rsv *rsv; u64 needed_bytes; loff_t oldsize; int ret = 0; rsv = trans->block_rsv; trans->block_rsv = &root->fs_info->global_block_rsv; /* 1 for slack space, 1 for updating the inode */ needed_bytes = btrfs_calc_trunc_metadata_size(root, 1) + btrfs_calc_trans_metadata_size(root, 1); spin_lock(&trans->block_rsv->lock); if (trans->block_rsv->reserved < needed_bytes) { spin_unlock(&trans->block_rsv->lock); trans->block_rsv = rsv; return -ENOSPC; } spin_unlock(&trans->block_rsv->lock); 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) { trans->block_rsv = rsv; btrfs_abort_transaction(trans, root, ret); return ret; } ret = btrfs_update_inode(trans, root, inode); if (ret) btrfs_abort_transaction(trans, root, ret); trans->block_rsv = rsv; return ret; } 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; } struct io_ctl { void *cur, *orig; struct page *page; struct page **pages; struct btrfs_root *root; unsigned long size; int index; int num_pages; unsigned check_crcs:1; }; static int io_ctl_init(struct io_ctl *io_ctl, struct inode *inode, struct btrfs_root *root) { memset(io_ctl, 0, sizeof(struct io_ctl)); io_ctl->num_pages = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; io_ctl->pages = kzalloc(sizeof(struct page *) * io_ctl->num_pages, GFP_NOFS); if (!io_ctl->pages) return -ENOMEM; io_ctl->root = root; if (btrfs_ino(inode) != BTRFS_FREE_INO_OBJECTID) io_ctl->check_crcs = 1; return 0; } static void io_ctl_free(struct io_ctl *io_ctl) { kfree(io_ctl->pages); } static void io_ctl_unmap_page(struct io_ctl *io_ctl) { if (io_ctl->cur) { kunmap(io_ctl->page); io_ctl->cur = NULL; io_ctl->orig = NULL; } } static void io_ctl_map_page(struct io_ctl *io_ctl, int clear) { BUG_ON(io_ctl->index >= io_ctl->num_pages); io_ctl->page = io_ctl->pages[io_ctl->index++]; io_ctl->cur = kmap(io_ctl->page); io_ctl->orig = io_ctl->cur; io_ctl->size = PAGE_CACHE_SIZE; if (clear) memset(io_ctl->cur, 0, PAGE_CACHE_SIZE); } static void io_ctl_drop_pages(struct io_ctl *io_ctl) { int i; io_ctl_unmap_page(io_ctl); for (i = 0; i < io_ctl->num_pages; i++) { if (io_ctl->pages[i]) { ClearPageChecked(io_ctl->pages[i]); unlock_page(io_ctl->pages[i]); page_cache_release(io_ctl->pages[i]); } } } static int io_ctl_prepare_pages(struct io_ctl *io_ctl, struct inode *inode, int uptodate) { struct page *page; gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping); int i; for (i = 0; i < io_ctl->num_pages; i++) { page = find_or_create_page(inode->i_mapping, i, mask); if (!page) { io_ctl_drop_pages(io_ctl); return -ENOMEM; } io_ctl->pages[i] = page; if (uptodate && !PageUptodate(page)) { btrfs_readpage(NULL, page); lock_page(page); if (!PageUptodate(page)) { printk(KERN_ERR "btrfs: error reading free " "space cache\n"); io_ctl_drop_pages(io_ctl); return -EIO; } } } for (i = 0; i < io_ctl->num_pages; i++) { clear_page_dirty_for_io(io_ctl->pages[i]); set_page_extent_mapped(io_ctl->pages[i]); } return 0; } static void io_ctl_set_generation(struct io_ctl *io_ctl, u64 generation) { __le64 *val; io_ctl_map_page(io_ctl, 1); /* * Skip the csum areas. If we don't check crcs then we just have a * 64bit chunk at the front of the first page. */ if (io_ctl->check_crcs) { io_ctl->cur += (sizeof(u32) * io_ctl->num_pages); io_ctl->size -= sizeof(u64) + (sizeof(u32) * io_ctl->num_pages); } else { io_ctl->cur += sizeof(u64); io_ctl->size -= sizeof(u64) * 2; } val = io_ctl->cur; *val = cpu_to_le64(generation); io_ctl->cur += sizeof(u64); } static int io_ctl_check_generation(struct io_ctl *io_ctl, u64 generation) { __le64 *gen; /* * Skip the crc area. If we don't check crcs then we just have a 64bit * chunk at the front of the first page. */ if (io_ctl->check_crcs) { io_ctl->cur += sizeof(u32) * io_ctl->num_pages; io_ctl->size -= sizeof(u64) + (sizeof(u32) * io_ctl->num_pages); } else { io_ctl->cur += sizeof(u64); io_ctl->size -= sizeof(u64) * 2; } gen = io_ctl->cur; if (le64_to_cpu(*gen) != generation) { printk_ratelimited(KERN_ERR "btrfs: space cache generation " "(%Lu) does not match inode (%Lu)\n", *gen, generation); io_ctl_unmap_page(io_ctl); return -EIO; } io_ctl->cur += sizeof(u64); return 0; } static void io_ctl_set_crc(struct io_ctl *io_ctl, int index) { u32 *tmp; u32 crc = ~(u32)0; unsigned offset = 0; if (!io_ctl->check_crcs) { io_ctl_unmap_page(io_ctl); return; } if (index == 0) offset = sizeof(u32) * io_ctl->num_pages; crc = btrfs_csum_data(io_ctl->root, io_ctl->orig + offset, crc, PAGE_CACHE_SIZE - offset); btrfs_csum_final(crc, (char *)&crc); io_ctl_unmap_page(io_ctl); tmp = kmap(io_ctl->pages[0]); tmp += index; *tmp = crc; kunmap(io_ctl->pages[0]); } static int io_ctl_check_crc(struct io_ctl *io_ctl, int index) { u32 *tmp, val; u32 crc = ~(u32)0; unsigned offset = 0; if (!io_ctl->check_crcs) { io_ctl_map_page(io_ctl, 0); return 0; } if (index == 0) offset = sizeof(u32) * io_ctl->num_pages; tmp = kmap(io_ctl->pages[0]); tmp += index; val = *tmp; kunmap(io_ctl->pages[0]); io_ctl_map_page(io_ctl, 0); crc = btrfs_csum_data(io_ctl->root, io_ctl->orig + offset, crc, PAGE_CACHE_SIZE - offset); btrfs_csum_final(crc, (char *)&crc); if (val != crc) { printk_ratelimited(KERN_ERR "btrfs: csum mismatch on free " "space cache\n"); io_ctl_unmap_page(io_ctl); return -EIO; } return 0; } static int io_ctl_add_entry(struct io_ctl *io_ctl, u64 offset, u64 bytes, void *bitmap) { struct btrfs_free_space_entry *entry; if (!io_ctl->cur) return -ENOSPC; entry = io_ctl->cur; entry->offset = cpu_to_le64(offset); entry->bytes = cpu_to_le64(bytes); entry->type = (bitmap) ? BTRFS_FREE_SPACE_BITMAP : BTRFS_FREE_SPACE_EXTENT; io_ctl->cur += sizeof(struct btrfs_free_space_entry); io_ctl->size -= sizeof(struct btrfs_free_space_entry); if (io_ctl->size >= sizeof(struct btrfs_free_space_entry)) return 0; io_ctl_set_crc(io_ctl, io_ctl->index - 1); /* No more pages to map */ if (io_ctl->index >= io_ctl->num_pages) return 0; /* map the next page */ io_ctl_map_page(io_ctl, 1); return 0; } static int io_ctl_add_bitmap(struct io_ctl *io_ctl, void *bitmap) { if (!io_ctl->cur) return -ENOSPC; /* * If we aren't at the start of the current page, unmap this one and * map the next one if there is any left. */ if (io_ctl->cur != io_ctl->orig) { io_ctl_set_crc(io_ctl, io_ctl->index - 1); if (io_ctl->index >= io_ctl->num_pages) return -ENOSPC; io_ctl_map_page(io_ctl, 0); } memcpy(io_ctl->cur, bitmap, PAGE_CACHE_SIZE); io_ctl_set_crc(io_ctl, io_ctl->index - 1); if (io_ctl->index < io_ctl->num_pages) io_ctl_map_page(io_ctl, 0); return 0; } static void io_ctl_zero_remaining_pages(struct io_ctl *io_ctl) { /* * If we're not on the boundary we know we've modified the page and we * need to crc the page. */ if (io_ctl->cur != io_ctl->orig) io_ctl_set_crc(io_ctl, io_ctl->index - 1); else io_ctl_unmap_page(io_ctl); while (io_ctl->index < io_ctl->num_pages) { io_ctl_map_page(io_ctl, 1); io_ctl_set_crc(io_ctl, io_ctl->index - 1); } } static int io_ctl_read_entry(struct io_ctl *io_ctl, struct btrfs_free_space *entry, u8 *type) { struct btrfs_free_space_entry *e; int ret; if (!io_ctl->cur) { ret = io_ctl_check_crc(io_ctl, io_ctl->index); if (ret) return ret; } e = io_ctl->cur; entry->offset = le64_to_cpu(e->offset); entry->bytes = le64_to_cpu(e->bytes); *type = e->type; io_ctl->cur += sizeof(struct btrfs_free_space_entry); io_ctl->size -= sizeof(struct btrfs_free_space_entry); if (io_ctl->size >= sizeof(struct btrfs_free_space_entry)) return 0; io_ctl_unmap_page(io_ctl); return 0; } static int io_ctl_read_bitmap(struct io_ctl *io_ctl, struct btrfs_free_space *entry) { int ret; ret = io_ctl_check_crc(io_ctl, io_ctl->index); if (ret) return ret; memcpy(entry->bitmap, io_ctl->cur, PAGE_CACHE_SIZE); io_ctl_unmap_page(io_ctl); return 0; } /* * Since we attach pinned extents after the fact we can have contiguous sections * of free space that are split up in entries. This poses a problem with the * tree logging stuff since it could have allocated across what appears to be 2 * entries since we would have merged the entries when adding the pinned extents * back to the free space cache. So run through the space cache that we just * loaded and merge contiguous entries. This will make the log replay stuff not * blow up and it will make for nicer allocator behavior. */ static void merge_space_tree(struct btrfs_free_space_ctl *ctl) { struct btrfs_free_space *e, *prev = NULL; struct rb_node *n; again: spin_lock(&ctl->tree_lock); for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) { e = rb_entry(n, struct btrfs_free_space, offset_index); if (!prev) goto next; if (e->bitmap || prev->bitmap) goto next; if (prev->offset + prev->bytes == e->offset) { unlink_free_space(ctl, prev); unlink_free_space(ctl, e); prev->bytes += e->bytes; kmem_cache_free(btrfs_free_space_cachep, e); link_free_space(ctl, prev); prev = NULL; spin_unlock(&ctl->tree_lock); goto again; } next: prev = e; } spin_unlock(&ctl->tree_lock); } int __load_free_space_cache(struct btrfs_root *root, struct inode *inode, struct btrfs_free_space_ctl *ctl, struct btrfs_path *path, u64 offset) { struct btrfs_free_space_header *header; struct extent_buffer *leaf; struct io_ctl io_ctl; struct btrfs_key key; struct btrfs_free_space *e, *n; struct list_head bitmaps; u64 num_entries; u64 num_bitmaps; u64 generation; u8 type; int ret = 0; INIT_LIST_HEAD(&bitmaps); /* Nothing in the space cache, goodbye */ if (!i_size_read(inode)) return 0; key.objectid = BTRFS_FREE_SPACE_OBJECTID; key.offset = offset; key.type = 0; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) return 0; else if (ret > 0) { btrfs_release_path(path); return 0; } ret = -1; 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_release_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)\n", (unsigned long long)BTRFS_I(inode)->generation, (unsigned long long)generation); return 0; } if (!num_entries) return 0; ret = io_ctl_init(&io_ctl, inode, root); if (ret) return ret; ret = readahead_cache(inode); if (ret) goto out; ret = io_ctl_prepare_pages(&io_ctl, inode, 1); if (ret) goto out; ret = io_ctl_check_crc(&io_ctl, 0); if (ret) goto free_cache; ret = io_ctl_check_generation(&io_ctl, generation); if (ret) goto free_cache; while (num_entries) { e = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS); if (!e) goto free_cache; ret = io_ctl_read_entry(&io_ctl, e, &type); if (ret) { kmem_cache_free(btrfs_free_space_cachep, e); goto free_cache; } if (!e->bytes) { kmem_cache_free(btrfs_free_space_cachep, e); goto free_cache; } if (type == BTRFS_FREE_SPACE_EXTENT) { spin_lock(&ctl->tree_lock); ret = link_free_space(ctl, e); spin_unlock(&ctl->tree_lock); if (ret) { printk(KERN_ERR "Duplicate entries in " "free space cache, dumping\n"); kmem_cache_free(btrfs_free_space_cachep, e); goto free_cache; } } else { BUG_ON(!num_bitmaps); num_bitmaps--; e->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS); if (!e->bitmap) { kmem_cache_free( btrfs_free_space_cachep, e); goto free_cache; } spin_lock(&ctl->tree_lock); ret = link_free_space(ctl, e); ctl->total_bitmaps++; ctl->op->recalc_thresholds(ctl); spin_unlock(&ctl->tree_lock); if (ret) { printk(KERN_ERR "Duplicate entries in " "free space cache, dumping\n"); kmem_cache_free(btrfs_free_space_cachep, e); goto free_cache; } list_add_tail(&e->list, &bitmaps); } num_entries--; } io_ctl_unmap_page(&io_ctl); /* * We add the bitmaps at the end of the entries in order that * the bitmap entries are added to the cache. */ list_for_each_entry_safe(e, n, &bitmaps, list) { list_del_init(&e->list); ret = io_ctl_read_bitmap(&io_ctl, e); if (ret) goto free_cache; } io_ctl_drop_pages(&io_ctl); merge_space_tree(ctl); ret = 1; out: io_ctl_free(&io_ctl); return ret; free_cache: io_ctl_drop_pages(&io_ctl); __btrfs_remove_free_space_cache(ctl); goto out; } int load_free_space_cache(struct btrfs_fs_info *fs_info, struct btrfs_block_group_cache *block_group) { struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; struct btrfs_root *root = fs_info->tree_root; struct inode *inode; struct btrfs_path *path; int ret = 0; bool matched; u64 used = btrfs_block_group_used(&block_group->item); /* * 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); path = btrfs_alloc_path(); if (!path) return 0; path->search_commit_root = 1; path->skip_locking = 1; inode = lookup_free_space_inode(root, block_group, path); if (IS_ERR(inode)) { btrfs_free_path(path); return 0; } /* We may have converted the inode and made the cache invalid. */ spin_lock(&block_group->lock); if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) { spin_unlock(&block_group->lock); btrfs_free_path(path); goto out; } spin_unlock(&block_group->lock); ret = __load_free_space_cache(fs_info->tree_root, inode, ctl, path, block_group->key.objectid); btrfs_free_path(path); if (ret <= 0) goto out; spin_lock(&ctl->tree_lock); matched = (ctl->free_space == (block_group->key.offset - used - block_group->bytes_super)); spin_unlock(&ctl->tree_lock); if (!matched) { __btrfs_remove_free_space_cache(ctl); printk(KERN_ERR "block group %llu has an wrong amount of free " "space\n", block_group->key.objectid); ret = -1; } out: if (ret < 0) { /* 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); ret = 0; printk(KERN_ERR "btrfs: failed to load free space cache " "for block group %llu\n", block_group->key.objectid); } iput(inode); return ret; } /** * __btrfs_write_out_cache - write out cached info to an inode * @root - the root the inode belongs to * @ctl - the free space cache we are going to write out * @block_group - the block_group for this cache if it belongs to a block_group * @trans - the trans handle * @path - the path to use * @offset - the offset for the key we'll insert * * This function writes out a free space cache struct to disk for quick recovery * on mount. This will return 0 if it was successfull in writing the cache out, * and -1 if it was not. */ int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode, struct btrfs_free_space_ctl *ctl, struct btrfs_block_group_cache *block_group, struct btrfs_trans_handle *trans, struct btrfs_path *path, u64 offset) { struct btrfs_free_space_header *header; struct extent_buffer *leaf; struct rb_node *node; struct list_head *pos, *n; struct extent_state *cached_state = NULL; struct btrfs_free_cluster *cluster = NULL; struct extent_io_tree *unpin = NULL; struct io_ctl io_ctl; struct list_head bitmap_list; struct btrfs_key key; u64 start, extent_start, extent_end, len; int entries = 0; int bitmaps = 0; int ret; int err = -1; INIT_LIST_HEAD(&bitmap_list); if (!i_size_read(inode)) return -1; ret = io_ctl_init(&io_ctl, inode, root); if (ret) return -1; /* Get the cluster for this block_group if it exists */ if (block_group && !list_empty(&block_group->cluster_list)) cluster = list_entry(block_group->cluster_list.next, struct btrfs_free_cluster, block_group_list); /* Lock all pages first so we can lock the extent safely. */ io_ctl_prepare_pages(&io_ctl, inode, 0); lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1, 0, &cached_state); node = rb_first(&ctl->free_space_offset); if (!node && cluster) { node = rb_first(&cluster->root); cluster = NULL; } /* Make sure we can fit our crcs into the first page */ if (io_ctl.check_crcs && (io_ctl.num_pages * sizeof(u32)) >= PAGE_CACHE_SIZE) { WARN_ON(1); goto out_nospc; } io_ctl_set_generation(&io_ctl, trans->transid); /* Write out the extent entries */ while (node) { struct btrfs_free_space *e; e = rb_entry(node, struct btrfs_free_space, offset_index); entries++; ret = io_ctl_add_entry(&io_ctl, e->offset, e->bytes, e->bitmap); if (ret) goto out_nospc; if (e->bitmap) { list_add_tail(&e->list, &bitmap_list); bitmaps++; } node = rb_next(node); if (!node && cluster) { node = rb_first(&cluster->root); cluster = NULL; } } /* * We want to add any pinned extents to our free space cache * so we don't leak the space */ /* * We shouldn't have switched the pinned extents yet so this is the * right one */ unpin = root->fs_info->pinned_extents; if (block_group) start = block_group->key.objectid; while (block_group && (start < block_group->key.objectid + block_group->key.offset)) { ret = find_first_extent_bit(unpin, start, &extent_start, &extent_end, EXTENT_DIRTY, NULL); if (ret) { ret = 0; break; } /* This pinned extent is out of our range */ if (extent_start >= block_group->key.objectid + block_group->key.offset) break; extent_start = max(extent_start, start); extent_end = min(block_group->key.objectid + block_group->key.offset, extent_end + 1); len = extent_end - extent_start; entries++; ret = io_ctl_add_entry(&io_ctl, extent_start, len, NULL); if (ret) goto out_nospc; start = extent_end; } /* Write out the bitmaps */ list_for_each_safe(pos, n, &bitmap_list) { struct btrfs_free_space *entry = list_entry(pos, struct btrfs_free_space, list); ret = io_ctl_add_bitmap(&io_ctl, entry->bitmap); if (ret) goto out_nospc; list_del_init(&entry->list); } /* Zero out the rest of the pages just to make sure */ io_ctl_zero_remaining_pages(&io_ctl); ret = btrfs_dirty_pages(root, inode, io_ctl.pages, io_ctl.num_pages, 0, i_size_read(inode), &cached_state); io_ctl_drop_pages(&io_ctl); unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1, &cached_state, GFP_NOFS); if (ret) goto out; btrfs_wait_ordered_range(inode, 0, (u64)-1); key.objectid = BTRFS_FREE_SPACE_OBJECTID; key.offset = offset; key.type = 0; ret = btrfs_search_slot(trans, root, &key, path, 0, 1); if (ret < 0) { clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1, EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, NULL, GFP_NOFS); goto out; } 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 != offset) { clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1, EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, NULL, GFP_NOFS); btrfs_release_path(path); goto out; } } BTRFS_I(inode)->generation = trans->transid; 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(path); err = 0; out: io_ctl_free(&io_ctl); if (err) { invalidate_inode_pages2(inode->i_mapping); BTRFS_I(inode)->generation = 0; } btrfs_update_inode(trans, root, inode); return err; out_nospc: list_for_each_safe(pos, n, &bitmap_list) { struct btrfs_free_space *entry = list_entry(pos, struct btrfs_free_space, list); list_del_init(&entry->list); } io_ctl_drop_pages(&io_ctl); unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1, &cached_state, GFP_NOFS); 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_ctl *ctl = block_group->free_space_ctl; struct inode *inode; int ret = 0; root = root->fs_info->tree_root; 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; ret = __btrfs_write_out_cache(root, inode, ctl, block_group, trans, path, block_group->key.objectid); if (ret) { spin_lock(&block_group->lock); block_group->disk_cache_state = BTRFS_DC_ERROR; spin_unlock(&block_group->lock); ret = 0; #ifdef DEBUG printk(KERN_ERR "btrfs: failed to write free space cache " "for block group %llu\n", block_group->key.objectid); #endif } iput(inode); return ret; } static inline unsigned long offset_to_bit(u64 bitmap_start, u32 unit, u64 offset) { BUG_ON(offset < bitmap_start); offset -= bitmap_start; return (unsigned long)(div_u64(offset, unit)); } static inline unsigned long bytes_to_bits(u64 bytes, u32 unit) { return (unsigned long)(div_u64(bytes, unit)); } static inline u64 offset_to_bitmap(struct btrfs_free_space_ctl *ctl, u64 offset) { u64 bitmap_start; u64 bytes_per_bitmap; bytes_per_bitmap = BITS_PER_BITMAP * ctl->unit; bitmap_start = offset - ctl->start; bitmap_start = div64_u64(bitmap_start, bytes_per_bitmap); bitmap_start *= bytes_per_bitmap; bitmap_start += ctl->start; 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) { if (info->bitmap) { WARN_ON_ONCE(1); return -EEXIST; } p = &(*p)->rb_right; } else { if (!info->bitmap) { WARN_ON_ONCE(1); return -EEXIST; } 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_free_space_ctl *ctl, u64 offset, int bitmap_only, int fuzzy) { struct rb_node *n = ctl->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 = rb_prev(&entry->offset_index); if (n) { prev = rb_entry(n, struct btrfs_free_space, offset_index); if (!prev->bitmap && prev->offset + prev->bytes > offset) entry = prev; } } 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 = rb_prev(&entry->offset_index); if (n) { prev = rb_entry(n, struct btrfs_free_space, offset_index); if (!prev->bitmap && prev->offset + prev->bytes > offset) return prev; } if (entry->offset + BITS_PER_BITMAP * ctl->unit > 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 * ctl->unit > 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 inline void __unlink_free_space(struct btrfs_free_space_ctl *ctl, struct btrfs_free_space *info) { rb_erase(&info->offset_index, &ctl->free_space_offset); ctl->free_extents--; } static void unlink_free_space(struct btrfs_free_space_ctl *ctl, struct btrfs_free_space *info) { __unlink_free_space(ctl, info); ctl->free_space -= info->bytes; } static int link_free_space(struct btrfs_free_space_ctl *ctl, struct btrfs_free_space *info) { int ret = 0; BUG_ON(!info->bitmap && !info->bytes); ret = tree_insert_offset(&ctl->free_space_offset, info->offset, &info->offset_index, (info->bitmap != NULL)); if (ret) return ret; ctl->free_space += info->bytes; ctl->free_extents++; return ret; } static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl) { struct btrfs_block_group_cache *block_group = ctl->private; u64 max_bytes; u64 bitmap_bytes; u64 extent_bytes; u64 size = block_group->key.offset; u64 bytes_per_bg = BITS_PER_BITMAP * ctl->unit; int max_bitmaps = div64_u64(size + bytes_per_bg - 1, bytes_per_bg); BUG_ON(ctl->total_bitmaps > max_bitmaps); /* * 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 = (ctl->total_bitmaps + 1) * PAGE_CACHE_SIZE; if (bitmap_bytes >= max_bytes) { ctl->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)); ctl->extents_thresh = div64_u64(extent_bytes, (sizeof(struct btrfs_free_space))); } static inline void __bitmap_clear_bits(struct btrfs_free_space_ctl *ctl, struct btrfs_free_space *info, u64 offset, u64 bytes) { unsigned long start, count; start = offset_to_bit(info->offset, ctl->unit, offset); count = bytes_to_bits(bytes, ctl->unit); BUG_ON(start + count > BITS_PER_BITMAP); bitmap_clear(info->bitmap, start, count); info->bytes -= bytes; } static void bitmap_clear_bits(struct btrfs_free_space_ctl *ctl, struct btrfs_free_space *info, u64 offset, u64 bytes) { __bitmap_clear_bits(ctl, info, offset, bytes); ctl->free_space -= bytes; } static void bitmap_set_bits(struct btrfs_free_space_ctl *ctl, struct btrfs_free_space *info, u64 offset, u64 bytes) { unsigned long start, count; start = offset_to_bit(info->offset, ctl->unit, offset); count = bytes_to_bits(bytes, ctl->unit); BUG_ON(start + count > BITS_PER_BITMAP); bitmap_set(info->bitmap, start, count); info->bytes += bytes; ctl->free_space += bytes; } static int search_bitmap(struct btrfs_free_space_ctl *ctl, 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, ctl->unit, max_t(u64, *offset, bitmap_info->offset)); bits = bytes_to_bits(*bytes, ctl->unit); for_each_set_bit_from(i, bitmap_info->bitmap, BITS_PER_BITMAP) { 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 * ctl->unit) + bitmap_info->offset; *bytes = (u64)(found_bits) * ctl->unit; return 0; } return -1; } static struct btrfs_free_space * find_free_space(struct btrfs_free_space_ctl *ctl, u64 *offset, u64 *bytes) { struct btrfs_free_space *entry; struct rb_node *node; int ret; if (!ctl->free_space_offset.rb_node) return NULL; entry = tree_search_offset(ctl, offset_to_bitmap(ctl, *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(ctl, 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_free_space_ctl *ctl, struct btrfs_free_space *info, u64 offset) { info->offset = offset_to_bitmap(ctl, offset); info->bytes = 0; INIT_LIST_HEAD(&info->list); link_free_space(ctl, info); ctl->total_bitmaps++; ctl->op->recalc_thresholds(ctl); } static void free_bitmap(struct btrfs_free_space_ctl *ctl, struct btrfs_free_space *bitmap_info) { unlink_free_space(ctl, bitmap_info); kfree(bitmap_info->bitmap); kmem_cache_free(btrfs_free_space_cachep, bitmap_info); ctl->total_bitmaps--; ctl->op->recalc_thresholds(ctl); } static noinline int remove_from_bitmap(struct btrfs_free_space_ctl *ctl, 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 * ctl->unit) - 1; /* * We need to search for bits in this bitmap. We could only cover some * of the extent in this bitmap thanks to how we add space, so we need * to search for as much as it as we can and clear that amount, and then * go searching for the next bit. */ search_start = *offset; search_bytes = ctl->unit; search_bytes = min(search_bytes, end - search_start + 1); ret = search_bitmap(ctl, bitmap_info, &search_start, &search_bytes); BUG_ON(ret < 0 || search_start != *offset); /* We may have found more bits than what we need */ search_bytes = min(search_bytes, *bytes); /* Cannot clear past the end of the bitmap */ search_bytes = min(search_bytes, end - search_start + 1); bitmap_clear_bits(ctl, bitmap_info, search_start, search_bytes); *offset += search_bytes; *bytes -= search_bytes; if (*bytes) { struct rb_node *next = rb_next(&bitmap_info->offset_index); if (!bitmap_info->bytes) free_bitmap(ctl, 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 = ctl->unit; ret = search_bitmap(ctl, bitmap_info, &search_start, &search_bytes); if (ret < 0 || search_start != *offset) return -EAGAIN; goto again; } else if (!bitmap_info->bytes) free_bitmap(ctl, bitmap_info); return 0; } static u64 add_bytes_to_bitmap(struct btrfs_free_space_ctl *ctl, struct btrfs_free_space *info, u64 offset, u64 bytes) { u64 bytes_to_set = 0; u64 end; end = info->offset + (u64)(BITS_PER_BITMAP * ctl->unit); bytes_to_set = min(end - offset, bytes); bitmap_set_bits(ctl, info, offset, bytes_to_set); return bytes_to_set; } static bool use_bitmap(struct btrfs_free_space_ctl *ctl, struct btrfs_free_space *info) { struct btrfs_block_group_cache *block_group = ctl->private; /* * 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 (ctl->free_extents < ctl->extents_thresh) { /* * If this block group has some small extents we don't want to * use up all of our free slots in the cache with them, we want * to reserve them to larger extents, however if we have plent * of cache left then go ahead an dadd them, no sense in adding * the overhead of a bitmap if we don't have to. */ if (info->bytes <= block_group->sectorsize * 4) { if (ctl->free_extents * 2 <= ctl->extents_thresh) return false; } else { return false; } } /* * 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 * ctl->unit > block_group->key.offset) return false; return true; } static struct btrfs_free_space_op free_space_op = { .recalc_thresholds = recalculate_thresholds, .use_bitmap = use_bitmap, }; static int insert_into_bitmap(struct btrfs_free_space_ctl *ctl, struct btrfs_free_space *info) { struct btrfs_free_space *bitmap_info; struct btrfs_block_group_cache *block_group = NULL; int added = 0; u64 bytes, offset, bytes_added; int ret; bytes = info->bytes; offset = info->offset; if (!ctl->op->use_bitmap(ctl, info)) return 0; if (ctl->op == &free_space_op) block_group = ctl->private; again: /* * Since we link bitmaps right into the cluster we need to see if we * have a cluster here, and if so and it has our bitmap we need to add * the free space to that bitmap. */ if (block_group && !list_empty(&block_group->cluster_list)) { struct btrfs_free_cluster *cluster; struct rb_node *node; struct btrfs_free_space *entry; cluster = list_entry(block_group->cluster_list.next, struct btrfs_free_cluster, block_group_list); spin_lock(&cluster->lock); node = rb_first(&cluster->root); if (!node) { spin_unlock(&cluster->lock); goto no_cluster_bitmap; } entry = rb_entry(node, struct btrfs_free_space, offset_index); if (!entry->bitmap) { spin_unlock(&cluster->lock); goto no_cluster_bitmap; } if (entry->offset == offset_to_bitmap(ctl, offset)) { bytes_added = add_bytes_to_bitmap(ctl, entry, offset, bytes); bytes -= bytes_added; offset += bytes_added; } spin_unlock(&cluster->lock); if (!bytes) { ret = 1; goto out; } } no_cluster_bitmap: bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset), 1, 0); if (!bitmap_info) { BUG_ON(added); goto new_bitmap; } bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes); bytes -= bytes_added; offset += bytes_added; added = 0; if (!bytes) { ret = 1; goto out; } else goto again; new_bitmap: if (info && info->bitmap) { add_new_bitmap(ctl, info, offset); added = 1; info = NULL; goto again; } else { spin_unlock(&ctl->tree_lock); /* no pre-allocated info, allocate a new one */ if (!info) { info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS); if (!info) { spin_lock(&ctl->tree_lock); ret = -ENOMEM; goto out; } } /* allocate the bitmap */ info->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS); spin_lock(&ctl->tree_lock); if (!info->bitmap) { ret = -ENOMEM; goto out; } goto again; } out: if (info) { if (info->bitmap) kfree(info->bitmap); kmem_cache_free(btrfs_free_space_cachep, info); } return ret; } static bool try_merge_free_space(struct btrfs_free_space_ctl *ctl, struct btrfs_free_space *info, bool update_stat) { 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(ctl, 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(ctl, offset - 1, 0, 0); if (right_info && !right_info->bitmap) { if (update_stat) unlink_free_space(ctl, right_info); else __unlink_free_space(ctl, right_info); info->bytes += right_info->bytes; kmem_cache_free(btrfs_free_space_cachep, right_info); merged = true; } if (left_info && !left_info->bitmap && left_info->offset + left_info->bytes == offset) { if (update_stat) unlink_free_space(ctl, left_info); else __unlink_free_space(ctl, left_info); info->offset = left_info->offset; info->bytes += left_info->bytes; kmem_cache_free(btrfs_free_space_cachep, left_info); merged = true; } return merged; } int __btrfs_add_free_space(struct btrfs_free_space_ctl *ctl, u64 offset, u64 bytes) { struct btrfs_free_space *info; int ret = 0; info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS); if (!info) return -ENOMEM; info->offset = offset; info->bytes = bytes; spin_lock(&ctl->tree_lock); if (try_merge_free_space(ctl, info, true)) 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(ctl, info); if (ret < 0) { goto out; } else if (ret) { ret = 0; goto out; } link: ret = link_free_space(ctl, info); if (ret) kmem_cache_free(btrfs_free_space_cachep, info); out: spin_unlock(&ctl->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_ctl *ctl = block_group->free_space_ctl; struct btrfs_free_space *info; int ret = 0; spin_lock(&ctl->tree_lock); again: if (!bytes) goto out_lock; info = tree_search_offset(ctl, 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(ctl, offset_to_bitmap(ctl, offset), 1, 0); if (!info) { /* the tree logging code might be calling us before we * have fully loaded the free space rbtree for this * block group. So it is possible the entry won't * be in the rbtree yet at all. The caching code * will make sure not to put it in the rbtree if * the logging code has pinned it. */ goto out_lock; } } if (!info->bitmap) { unlink_free_space(ctl, info); if (offset == info->offset) { u64 to_free = min(bytes, info->bytes); info->bytes -= to_free; info->offset += to_free; if (info->bytes) { ret = link_free_space(ctl, info); WARN_ON(ret); } else { kmem_cache_free(btrfs_free_space_cachep, info); } offset += to_free; bytes -= to_free; goto again; } else { u64 old_end = info->bytes + info->offset; info->bytes = offset - info->offset; ret = link_free_space(ctl, info); WARN_ON(ret); if (ret) goto out_lock; /* Not enough bytes in this entry to satisfy us */ if (old_end < offset + bytes) { bytes -= old_end - offset; offset = old_end; goto again; } else if (old_end == offset + bytes) { /* all done */ goto out_lock; } spin_unlock(&ctl->tree_lock); ret = btrfs_add_free_space(block_group, offset + bytes, old_end - (offset + bytes)); WARN_ON(ret); goto out; } } ret = remove_from_bitmap(ctl, info, &offset, &bytes); if (ret == -EAGAIN) goto again; BUG_ON(ret); /* logic error */ out_lock: spin_unlock(&ctl->tree_lock); out: return ret; } void btrfs_dump_free_space(struct btrfs_block_group_cache *block_group, u64 bytes) { struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; struct btrfs_free_space *info; struct rb_node *n; int count = 0; for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) { info = rb_entry(n, struct btrfs_free_space, offset_index); if (info->bytes >= bytes && !block_group->ro) 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); } void btrfs_init_free_space_ctl(struct btrfs_block_group_cache *block_group) { struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; spin_lock_init(&ctl->tree_lock); ctl->unit = block_group->sectorsize; ctl->start = block_group->key.objectid; ctl->private = block_group; ctl->op = &free_space_op; /* * we only want to have 32k of ram per block group for keeping * track of free space, and if we pass 1/2 of that we want to * start converting things over to using bitmaps */ ctl->extents_thresh = ((1024 * 32) / 2) / sizeof(struct btrfs_free_space); } /* * 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_ctl *ctl = block_group->free_space_ctl; struct btrfs_free_space *entry; struct rb_node *node; spin_lock(&cluster->lock); if (cluster->block_group != block_group) goto out; cluster->block_group = NULL; cluster->window_start = 0; list_del_init(&cluster->block_group_list); node = rb_first(&cluster->root); while (node) { bool bitmap; entry = rb_entry(node, struct btrfs_free_space, offset_index); node = rb_next(&entry->offset_index); rb_erase(&entry->offset_index, &cluster->root); bitmap = (entry->bitmap != NULL); if (!bitmap) try_merge_free_space(ctl, entry, false); tree_insert_offset(&ctl->free_space_offset, entry->offset, &entry->offset_index, bitmap); } cluster->root = RB_ROOT; out: spin_unlock(&cluster->lock); btrfs_put_block_group(block_group); return 0; } void __btrfs_remove_free_space_cache_locked(struct btrfs_free_space_ctl *ctl) { struct btrfs_free_space *info; struct rb_node *node; while ((node = rb_last(&ctl->free_space_offset)) != NULL) { info = rb_entry(node, struct btrfs_free_space, offset_index); if (!info->bitmap) { unlink_free_space(ctl, info); kmem_cache_free(btrfs_free_space_cachep, info); } else { free_bitmap(ctl, info); } if (need_resched()) { spin_unlock(&ctl->tree_lock); cond_resched(); spin_lock(&ctl->tree_lock); } } } void __btrfs_remove_free_space_cache(struct btrfs_free_space_ctl *ctl) { spin_lock(&ctl->tree_lock); __btrfs_remove_free_space_cache_locked(ctl); spin_unlock(&ctl->tree_lock); } void btrfs_remove_free_space_cache(struct btrfs_block_group_cache *block_group) { struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; struct btrfs_free_cluster *cluster; struct list_head *head; spin_lock(&ctl->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(&ctl->tree_lock); cond_resched(); spin_lock(&ctl->tree_lock); } } __btrfs_remove_free_space_cache_locked(ctl); spin_unlock(&ctl->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_ctl *ctl = block_group->free_space_ctl; struct btrfs_free_space *entry = NULL; u64 bytes_search = bytes + empty_size; u64 ret = 0; spin_lock(&ctl->tree_lock); entry = find_free_space(ctl, &offset, &bytes_search); if (!entry) goto out; ret = offset; if (entry->bitmap) { bitmap_clear_bits(ctl, entry, offset, bytes); if (!entry->bytes) free_bitmap(ctl, entry); } else { unlink_free_space(ctl, entry); entry->offset += bytes; entry->bytes -= bytes; if (!entry->bytes) kmem_cache_free(btrfs_free_space_cachep, entry); else link_free_space(ctl, entry); } out: spin_unlock(&ctl->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) { struct btrfs_free_space_ctl *ctl; 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); ctl = block_group->free_space_ctl; /* now return any extents the cluster had on it */ spin_lock(&ctl->tree_lock); ret = __btrfs_return_cluster_to_free_space(block_group, cluster); spin_unlock(&ctl->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, struct btrfs_free_space *entry, u64 bytes, u64 min_start) { struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; int err; u64 search_start = cluster->window_start; u64 search_bytes = bytes; u64 ret = 0; search_start = min_start; search_bytes = bytes; err = search_bitmap(ctl, entry, &search_start, &search_bytes); if (err) return 0; ret = search_start; __bitmap_clear_bits(ctl, entry, ret, bytes); 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_ctl *ctl = block_group->free_space_ctl; struct btrfs_free_space *entry = NULL; struct rb_node *node; u64 ret = 0; 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->bitmap && entry->offset < min_start)) { node = rb_next(&entry->offset_index); if (!node) break; entry = rb_entry(node, struct btrfs_free_space, offset_index); continue; } if (entry->bitmap) { ret = btrfs_alloc_from_bitmap(block_group, cluster, entry, bytes, cluster->window_start); if (ret == 0) { node = rb_next(&entry->offset_index); if (!node) break; entry = rb_entry(node, struct btrfs_free_space, offset_index); continue; } cluster->window_start += bytes; } else { 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(&ctl->tree_lock); ctl->free_space -= bytes; if (entry->bytes == 0) { ctl->free_extents--; if (entry->bitmap) { kfree(entry->bitmap); ctl->total_bitmaps--; ctl->op->recalc_thresholds(ctl); } kmem_cache_free(btrfs_free_space_cachep, entry); } spin_unlock(&ctl->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 cont1_bytes, u64 min_bytes) { struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; unsigned long next_zero; unsigned long i; unsigned long want_bits; unsigned long min_bits; unsigned long found_bits; unsigned long start = 0; unsigned long total_found = 0; int ret; i = offset_to_bit(entry->offset, ctl->unit, max_t(u64, offset, entry->offset)); want_bits = bytes_to_bits(bytes, ctl->unit); min_bits = bytes_to_bits(min_bytes, ctl->unit); again: found_bits = 0; for_each_set_bit_from(i, entry->bitmap, BITS_PER_BITMAP) { next_zero = find_next_zero_bit(entry->bitmap, BITS_PER_BITMAP, i); if (next_zero - i >= min_bits) { found_bits = next_zero - i; break; } i = next_zero; } if (!found_bits) return -ENOSPC; if (!total_found) { start = i; cluster->max_size = 0; } total_found += found_bits; if (cluster->max_size < found_bits * ctl->unit) cluster->max_size = found_bits * ctl->unit; if (total_found < want_bits || cluster->max_size < cont1_bytes) { i = next_zero + 1; goto again; } cluster->window_start = start * ctl->unit + entry->offset; rb_erase(&entry->offset_index, &ctl->free_space_offset); ret = tree_insert_offset(&cluster->root, entry->offset, &entry->offset_index, 1); BUG_ON(ret); /* -EEXIST; Logic error */ trace_btrfs_setup_cluster(block_group, cluster, total_found * ctl->unit, 1); return 0; } /* * This searches the block group for just extents to fill the cluster with. * Try to find a cluster with at least bytes total bytes, at least one * extent of cont1_bytes, and other clusters of at least min_bytes. */ static noinline int setup_cluster_no_bitmap(struct btrfs_block_group_cache *block_group, struct btrfs_free_cluster *cluster, struct list_head *bitmaps, u64 offset, u64 bytes, u64 cont1_bytes, u64 min_bytes) { struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; struct btrfs_free_space *first = NULL; struct btrfs_free_space *entry = NULL; struct btrfs_free_space *last; struct rb_node *node; u64 window_start; u64 window_free; u64 max_extent; u64 total_size = 0; entry = tree_search_offset(ctl, offset, 0, 1); if (!entry) return -ENOSPC; /* * We don't want bitmaps, so just move along until we find a normal * extent entry. */ while (entry->bitmap || entry->bytes < min_bytes) { if (entry->bitmap && list_empty(&entry->list)) list_add_tail(&entry->list, bitmaps); node = rb_next(&entry->offset_index); if (!node) return -ENOSPC; entry = rb_entry(node, struct btrfs_free_space, offset_index); } window_start = entry->offset; window_free = entry->bytes; max_extent = entry->bytes; first = entry; last = entry; for (node = rb_next(&entry->offset_index); node; node = rb_next(&entry->offset_index)) { entry = rb_entry(node, struct btrfs_free_space, offset_index); if (entry->bitmap) { if (list_empty(&entry->list)) list_add_tail(&entry->list, bitmaps); continue; } if (entry->bytes < min_bytes) continue; last = entry; window_free += entry->bytes; if (entry->bytes > max_extent) max_extent = entry->bytes; } if (window_free < bytes || max_extent < cont1_bytes) return -ENOSPC; cluster->window_start = first->offset; node = &first->offset_index; /* * now we've found our entries, pull them out of the free space * cache and put them into the cluster rbtree */ do { int ret; entry = rb_entry(node, struct btrfs_free_space, offset_index); node = rb_next(&entry->offset_index); if (entry->bitmap || entry->bytes < min_bytes) continue; rb_erase(&entry->offset_index, &ctl->free_space_offset); ret = tree_insert_offset(&cluster->root, entry->offset, &entry->offset_index, 0); total_size += entry->bytes; BUG_ON(ret); /* -EEXIST; Logic error */ } while (node && entry != last); cluster->max_size = max_extent; trace_btrfs_setup_cluster(block_group, cluster, total_size, 0); return 0; } /* * This specifically looks for bitmaps that may work in the cluster, we assume * that we have already failed to find extents that will work. */ static noinline int setup_cluster_bitmap(struct btrfs_block_group_cache *block_group, struct btrfs_free_cluster *cluster, struct list_head *bitmaps, u64 offset, u64 bytes, u64 cont1_bytes, u64 min_bytes) { struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; struct btrfs_free_space *entry; int ret = -ENOSPC; u64 bitmap_offset = offset_to_bitmap(ctl, offset); if (ctl->total_bitmaps == 0) return -ENOSPC; /* * The bitmap that covers offset won't be in the list unless offset * is just its start offset. */ entry = list_first_entry(bitmaps, struct btrfs_free_space, list); if (entry->offset != bitmap_offset) { entry = tree_search_offset(ctl, bitmap_offset, 1, 0); if (entry && list_empty(&entry->list)) list_add(&entry->list, bitmaps); } list_for_each_entry(entry, bitmaps, list) { if (entry->bytes < bytes) continue; ret = btrfs_bitmap_cluster(block_group, entry, cluster, offset, bytes, cont1_bytes, min_bytes); if (!ret) return 0; } /* * The bitmaps list has all the bitmaps that record free space * starting after offset, so no more search is required. */ return -ENOSPC; } /* * here we try to find a cluster of blocks in a block group. The goal * is to find at least bytes+empty_size. * 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_ctl *ctl = block_group->free_space_ctl; struct btrfs_free_space *entry, *tmp; LIST_HEAD(bitmaps); u64 min_bytes; u64 cont1_bytes; int ret; /* * Choose the minimum extent size we'll require for this * cluster. For SSD_SPREAD, don't allow any fragmentation. * For metadata, allow allocates with smaller extents. For * data, keep it dense. */ if (btrfs_test_opt(root, SSD_SPREAD)) { cont1_bytes = min_bytes = bytes + empty_size; } else if (block_group->flags & BTRFS_BLOCK_GROUP_METADATA) { cont1_bytes = bytes; min_bytes = block_group->sectorsize; } else { cont1_bytes = max(bytes, (bytes + empty_size) >> 2); min_bytes = block_group->sectorsize; } spin_lock(&ctl->tree_lock); /* * If we know we don't have enough space to make a cluster don't even * bother doing all the work to try and find one. */ if (ctl->free_space < bytes) { spin_unlock(&ctl->tree_lock); return -ENOSPC; } spin_lock(&cluster->lock); /* someone already found a cluster, hooray */ if (cluster->block_group) { ret = 0; goto out; } trace_btrfs_find_cluster(block_group, offset, bytes, empty_size, min_bytes); INIT_LIST_HEAD(&bitmaps); ret = setup_cluster_no_bitmap(block_group, cluster, &bitmaps, offset, bytes + empty_size, cont1_bytes, min_bytes); if (ret) ret = setup_cluster_bitmap(block_group, cluster, &bitmaps, offset, bytes + empty_size, cont1_bytes, min_bytes); /* Clear our temporary list */ list_for_each_entry_safe(entry, tmp, &bitmaps, list) list_del_init(&entry->list); if (!ret) { atomic_inc(&block_group->count); list_add_tail(&cluster->block_group_list, &block_group->cluster_list); cluster->block_group = block_group; } else { trace_btrfs_failed_cluster_setup(block_group); } out: spin_unlock(&cluster->lock); spin_unlock(&ctl->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; INIT_LIST_HEAD(&cluster->block_group_list); cluster->block_group = NULL; } static int do_trimming(struct btrfs_block_group_cache *block_group, u64 *total_trimmed, u64 start, u64 bytes, u64 reserved_start, u64 reserved_bytes) { struct btrfs_space_info *space_info = block_group->space_info; struct btrfs_fs_info *fs_info = block_group->fs_info; int ret; int update = 0; u64 trimmed = 0; spin_lock(&space_info->lock); spin_lock(&block_group->lock); if (!block_group->ro) { block_group->reserved += reserved_bytes; space_info->bytes_reserved += reserved_bytes; update = 1; } spin_unlock(&block_group->lock); spin_unlock(&space_info->lock); ret = btrfs_error_discard_extent(fs_info->extent_root, start, bytes, &trimmed); if (!ret) *total_trimmed += trimmed; btrfs_add_free_space(block_group, reserved_start, reserved_bytes); if (update) { spin_lock(&space_info->lock); spin_lock(&block_group->lock); if (block_group->ro) space_info->bytes_readonly += reserved_bytes; block_group->reserved -= reserved_bytes; space_info->bytes_reserved -= reserved_bytes; spin_unlock(&space_info->lock); spin_unlock(&block_group->lock); } return ret; } static int trim_no_bitmap(struct btrfs_block_group_cache *block_group, u64 *total_trimmed, u64 start, u64 end, u64 minlen) { struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; struct btrfs_free_space *entry; struct rb_node *node; int ret = 0; u64 extent_start; u64 extent_bytes; u64 bytes; while (start < end) { spin_lock(&ctl->tree_lock); if (ctl->free_space < minlen) { spin_unlock(&ctl->tree_lock); break; } entry = tree_search_offset(ctl, start, 0, 1); if (!entry) { spin_unlock(&ctl->tree_lock); break; } /* skip bitmaps */ while (entry->bitmap) { node = rb_next(&entry->offset_index); if (!node) { spin_unlock(&ctl->tree_lock); goto out; } entry = rb_entry(node, struct btrfs_free_space, offset_index); } if (entry->offset >= end) { spin_unlock(&ctl->tree_lock); break; } extent_start = entry->offset; extent_bytes = entry->bytes; start = max(start, extent_start); bytes = min(extent_start + extent_bytes, end) - start; if (bytes < minlen) { spin_unlock(&ctl->tree_lock); goto next; } unlink_free_space(ctl, entry); kmem_cache_free(btrfs_free_space_cachep, entry); spin_unlock(&ctl->tree_lock); ret = do_trimming(block_group, total_trimmed, start, bytes, extent_start, extent_bytes); if (ret) break; next: start += bytes; if (fatal_signal_pending(current)) { ret = -ERESTARTSYS; break; } cond_resched(); } out: return ret; } static int trim_bitmaps(struct btrfs_block_group_cache *block_group, u64 *total_trimmed, u64 start, u64 end, u64 minlen) { struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; struct btrfs_free_space *entry; int ret = 0; int ret2; u64 bytes; u64 offset = offset_to_bitmap(ctl, start); while (offset < end) { bool next_bitmap = false; spin_lock(&ctl->tree_lock); if (ctl->free_space < minlen) { spin_unlock(&ctl->tree_lock); break; } entry = tree_search_offset(ctl, offset, 1, 0); if (!entry) { spin_unlock(&ctl->tree_lock); next_bitmap = true; goto next; } bytes = minlen; ret2 = search_bitmap(ctl, entry, &start, &bytes); if (ret2 || start >= end) { spin_unlock(&ctl->tree_lock); next_bitmap = true; goto next; } bytes = min(bytes, end - start); if (bytes < minlen) { spin_unlock(&ctl->tree_lock); goto next; } bitmap_clear_bits(ctl, entry, start, bytes); if (entry->bytes == 0) free_bitmap(ctl, entry); spin_unlock(&ctl->tree_lock); ret = do_trimming(block_group, total_trimmed, start, bytes, start, bytes); if (ret) break; next: if (next_bitmap) { offset += BITS_PER_BITMAP * ctl->unit; } else { start += bytes; if (start >= offset + BITS_PER_BITMAP * ctl->unit) offset += BITS_PER_BITMAP * ctl->unit; } if (fatal_signal_pending(current)) { ret = -ERESTARTSYS; break; } cond_resched(); } return ret; } int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group, u64 *trimmed, u64 start, u64 end, u64 minlen) { int ret; *trimmed = 0; ret = trim_no_bitmap(block_group, trimmed, start, end, minlen); if (ret) return ret; ret = trim_bitmaps(block_group, trimmed, start, end, minlen); return ret; } /* * Find the left-most item in the cache tree, and then return the * smallest inode number in the item. * * Note: the returned inode number may not be the smallest one in * the tree, if the left-most item is a bitmap. */ u64 btrfs_find_ino_for_alloc(struct btrfs_root *fs_root) { struct btrfs_free_space_ctl *ctl = fs_root->free_ino_ctl; struct btrfs_free_space *entry = NULL; u64 ino = 0; spin_lock(&ctl->tree_lock); if (RB_EMPTY_ROOT(&ctl->free_space_offset)) goto out; entry = rb_entry(rb_first(&ctl->free_space_offset), struct btrfs_free_space, offset_index); if (!entry->bitmap) { ino = entry->offset; unlink_free_space(ctl, entry); entry->offset++; entry->bytes--; if (!entry->bytes) kmem_cache_free(btrfs_free_space_cachep, entry); else link_free_space(ctl, entry); } else { u64 offset = 0; u64 count = 1; int ret; ret = search_bitmap(ctl, entry, &offset, &count); /* Logic error; Should be empty if it can't find anything */ BUG_ON(ret); ino = offset; bitmap_clear_bits(ctl, entry, offset, 1); if (entry->bytes == 0) free_bitmap(ctl, entry); } out: spin_unlock(&ctl->tree_lock); return ino; } struct inode *lookup_free_ino_inode(struct btrfs_root *root, struct btrfs_path *path) { struct inode *inode = NULL; spin_lock(&root->cache_lock); if (root->cache_inode) inode = igrab(root->cache_inode); spin_unlock(&root->cache_lock); if (inode) return inode; inode = __lookup_free_space_inode(root, path, 0); if (IS_ERR(inode)) return inode; spin_lock(&root->cache_lock); if (!btrfs_fs_closing(root->fs_info)) root->cache_inode = igrab(inode); spin_unlock(&root->cache_lock); return inode; } int create_free_ino_inode(struct btrfs_root *root, struct btrfs_trans_handle *trans, struct btrfs_path *path) { return __create_free_space_inode(root, trans, path, BTRFS_FREE_INO_OBJECTID, 0); } int load_free_ino_cache(struct btrfs_fs_info *fs_info, struct btrfs_root *root) { struct btrfs_free_space_ctl *ctl = root->free_ino_ctl; struct btrfs_path *path; struct inode *inode; int ret = 0; u64 root_gen = btrfs_root_generation(&root->root_item); if (!btrfs_test_opt(root, INODE_MAP_CACHE)) return 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. */ if (btrfs_fs_closing(fs_info)) return 0; path = btrfs_alloc_path(); if (!path) return 0; inode = lookup_free_ino_inode(root, path); if (IS_ERR(inode)) goto out; if (root_gen != BTRFS_I(inode)->generation) goto out_put; ret = __load_free_space_cache(root, inode, ctl, path, 0); if (ret < 0) printk(KERN_ERR "btrfs: failed to load free ino cache for " "root %llu\n", root->root_key.objectid); out_put: iput(inode); out: btrfs_free_path(path); return ret; } int btrfs_write_out_ino_cache(struct btrfs_root *root, struct btrfs_trans_handle *trans, struct btrfs_path *path) { struct btrfs_free_space_ctl *ctl = root->free_ino_ctl; struct inode *inode; int ret; if (!btrfs_test_opt(root, INODE_MAP_CACHE)) return 0; inode = lookup_free_ino_inode(root, path); if (IS_ERR(inode)) return 0; ret = __btrfs_write_out_cache(root, inode, ctl, NULL, trans, path, 0); if (ret) { btrfs_delalloc_release_metadata(inode, inode->i_size); #ifdef DEBUG printk(KERN_ERR "btrfs: failed to write free ino cache " "for root %llu\n", root->root_key.objectid); #endif } iput(inode); return ret; }