| /* |
| * 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" |
| #include "volumes.h" |
| |
| #define BITS_PER_BITMAP (PAGE_CACHE_SIZE * 8) |
| #define MAX_CACHE_BYTES_PER_GIG (32 * 1024) |
| |
| struct btrfs_trim_range { |
| u64 start; |
| u64 bytes; |
| struct list_head list; |
| }; |
| |
| 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_constraint(inode->i_mapping, |
| ~(__GFP_FS | __GFP_HIGHMEM))); |
| |
| 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)) { |
| btrfs_info(root->fs_info, |
| "Old style space inode found, converting."); |
| 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; |
| } |
| |
| static 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_check_trunc_cache_free_space(struct btrfs_root *root, |
| struct btrfs_block_rsv *rsv) |
| { |
| u64 needed_bytes; |
| int ret; |
| |
| /* 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(&rsv->lock); |
| if (rsv->reserved < needed_bytes) |
| ret = -ENOSPC; |
| else |
| ret = 0; |
| spin_unlock(&rsv->lock); |
| return ret; |
| } |
| |
| int btrfs_truncate_free_space_cache(struct btrfs_root *root, |
| struct btrfs_trans_handle *trans, |
| struct btrfs_block_group_cache *block_group, |
| struct inode *inode) |
| { |
| int ret = 0; |
| struct btrfs_path *path = btrfs_alloc_path(); |
| bool locked = false; |
| |
| if (!path) { |
| ret = -ENOMEM; |
| goto fail; |
| } |
| |
| if (block_group) { |
| locked = true; |
| mutex_lock(&trans->transaction->cache_write_mutex); |
| if (!list_empty(&block_group->io_list)) { |
| list_del_init(&block_group->io_list); |
| |
| btrfs_wait_cache_io(root, trans, block_group, |
| &block_group->io_ctl, path, |
| block_group->key.objectid); |
| btrfs_put_block_group(block_group); |
| } |
| |
| /* |
| * now that we've truncated the cache away, its no longer |
| * setup or written |
| */ |
| spin_lock(&block_group->lock); |
| block_group->disk_cache_state = BTRFS_DC_CLEAR; |
| spin_unlock(&block_group->lock); |
| } |
| btrfs_free_path(path); |
| |
| btrfs_i_size_write(inode, 0); |
| truncate_pagecache(inode, 0); |
| |
| /* |
| * We don't need an orphan item because truncating the free space cache |
| * will never be split across transactions. |
| * We don't need to check for -EAGAIN because we're a free space |
| * cache inode |
| */ |
| ret = btrfs_truncate_inode_items(trans, root, inode, |
| 0, BTRFS_EXTENT_DATA_KEY); |
| if (ret) |
| goto fail; |
| |
| ret = btrfs_update_inode(trans, root, inode); |
| |
| fail: |
| if (locked) |
| mutex_unlock(&trans->transaction->cache_write_mutex); |
| if (ret) |
| btrfs_abort_transaction(trans, root, ret); |
| |
| 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; |
| } |
| |
| static int io_ctl_init(struct btrfs_io_ctl *io_ctl, struct inode *inode, |
| struct btrfs_root *root, int write) |
| { |
| int num_pages; |
| int check_crcs = 0; |
| |
| num_pages = DIV_ROUND_UP(i_size_read(inode), PAGE_CACHE_SIZE); |
| |
| if (btrfs_ino(inode) != BTRFS_FREE_INO_OBJECTID) |
| check_crcs = 1; |
| |
| /* Make sure we can fit our crcs into the first page */ |
| if (write && check_crcs && |
| (num_pages * sizeof(u32)) >= PAGE_CACHE_SIZE) |
| return -ENOSPC; |
| |
| memset(io_ctl, 0, sizeof(struct btrfs_io_ctl)); |
| |
| io_ctl->pages = kcalloc(num_pages, sizeof(struct page *), GFP_NOFS); |
| if (!io_ctl->pages) |
| return -ENOMEM; |
| |
| io_ctl->num_pages = num_pages; |
| io_ctl->root = root; |
| io_ctl->check_crcs = check_crcs; |
| io_ctl->inode = inode; |
| |
| return 0; |
| } |
| |
| static void io_ctl_free(struct btrfs_io_ctl *io_ctl) |
| { |
| kfree(io_ctl->pages); |
| io_ctl->pages = NULL; |
| } |
| |
| static void io_ctl_unmap_page(struct btrfs_io_ctl *io_ctl) |
| { |
| if (io_ctl->cur) { |
| io_ctl->cur = NULL; |
| io_ctl->orig = NULL; |
| } |
| } |
| |
| static void io_ctl_map_page(struct btrfs_io_ctl *io_ctl, int clear) |
| { |
| ASSERT(io_ctl->index < io_ctl->num_pages); |
| io_ctl->page = io_ctl->pages[io_ctl->index++]; |
| io_ctl->cur = page_address(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 btrfs_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 btrfs_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)) { |
| btrfs_err(BTRFS_I(inode)->root->fs_info, |
| "error reading free space cache"); |
| 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 btrfs_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 btrfs_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) { |
| btrfs_err_rl(io_ctl->root->fs_info, |
| "space cache generation (%llu) does not match inode (%llu)", |
| *gen, generation); |
| io_ctl_unmap_page(io_ctl); |
| return -EIO; |
| } |
| io_ctl->cur += sizeof(u64); |
| return 0; |
| } |
| |
| static void io_ctl_set_crc(struct btrfs_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->orig + offset, crc, |
| PAGE_CACHE_SIZE - offset); |
| btrfs_csum_final(crc, (char *)&crc); |
| io_ctl_unmap_page(io_ctl); |
| tmp = page_address(io_ctl->pages[0]); |
| tmp += index; |
| *tmp = crc; |
| } |
| |
| static int io_ctl_check_crc(struct btrfs_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 = page_address(io_ctl->pages[0]); |
| tmp += index; |
| val = *tmp; |
| |
| io_ctl_map_page(io_ctl, 0); |
| crc = btrfs_csum_data(io_ctl->orig + offset, crc, |
| PAGE_CACHE_SIZE - offset); |
| btrfs_csum_final(crc, (char *)&crc); |
| if (val != crc) { |
| btrfs_err_rl(io_ctl->root->fs_info, |
| "csum mismatch on free space cache"); |
| io_ctl_unmap_page(io_ctl); |
| return -EIO; |
| } |
| |
| return 0; |
| } |
| |
| static int io_ctl_add_entry(struct btrfs_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 btrfs_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 btrfs_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 btrfs_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 btrfs_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); |
| } |
| |
| static 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 btrfs_io_ctl io_ctl; |
| struct btrfs_key key; |
| struct btrfs_free_space *e, *n; |
| LIST_HEAD(bitmaps); |
| u64 num_entries; |
| u64 num_bitmaps; |
| u64 generation; |
| u8 type; |
| int ret = 0; |
| |
| /* 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) { |
| btrfs_info(root->fs_info, |
| "The free space cache file (%llu) is invalid. skip it\n", |
| offset); |
| return 0; |
| } |
| |
| if (BTRFS_I(inode)->generation != generation) { |
| btrfs_err(root->fs_info, |
| "free space inode generation (%llu) " |
| "did not match free space cache generation (%llu)", |
| BTRFS_I(inode)->generation, generation); |
| return 0; |
| } |
| |
| if (!num_entries) |
| return 0; |
| |
| ret = io_ctl_init(&io_ctl, inode, root, 0); |
| 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) { |
| btrfs_err(root->fs_info, |
| "Duplicate entries in free space cache, dumping"); |
| kmem_cache_free(btrfs_free_space_cachep, e); |
| goto free_cache; |
| } |
| } else { |
| ASSERT(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) { |
| btrfs_err(root->fs_info, |
| "Duplicate entries in free space cache, dumping"); |
| 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); |
| btrfs_warn(fs_info, "block group %llu has wrong amount of free space", |
| 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; |
| |
| btrfs_warn(fs_info, "failed to load free space cache for block group %llu, rebuilding it now", |
| block_group->key.objectid); |
| } |
| |
| iput(inode); |
| return ret; |
| } |
| |
| static noinline_for_stack |
| int write_cache_extent_entries(struct btrfs_io_ctl *io_ctl, |
| struct btrfs_free_space_ctl *ctl, |
| struct btrfs_block_group_cache *block_group, |
| int *entries, int *bitmaps, |
| struct list_head *bitmap_list) |
| { |
| int ret; |
| struct btrfs_free_cluster *cluster = NULL; |
| struct btrfs_free_cluster *cluster_locked = NULL; |
| struct rb_node *node = rb_first(&ctl->free_space_offset); |
| struct btrfs_trim_range *trim_entry; |
| |
| /* 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); |
| } |
| |
| if (!node && cluster) { |
| cluster_locked = cluster; |
| spin_lock(&cluster_locked->lock); |
| node = rb_first(&cluster->root); |
| cluster = NULL; |
| } |
| |
| /* Write out the extent entries */ |
| while (node) { |
| struct btrfs_free_space *e; |
| |
| e = rb_entry(node, struct btrfs_free_space, offset_index); |
| *entries += 1; |
| |
| ret = io_ctl_add_entry(io_ctl, e->offset, e->bytes, |
| e->bitmap); |
| if (ret) |
| goto fail; |
| |
| if (e->bitmap) { |
| list_add_tail(&e->list, bitmap_list); |
| *bitmaps += 1; |
| } |
| node = rb_next(node); |
| if (!node && cluster) { |
| node = rb_first(&cluster->root); |
| cluster_locked = cluster; |
| spin_lock(&cluster_locked->lock); |
| cluster = NULL; |
| } |
| } |
| if (cluster_locked) { |
| spin_unlock(&cluster_locked->lock); |
| cluster_locked = NULL; |
| } |
| |
| /* |
| * Make sure we don't miss any range that was removed from our rbtree |
| * because trimming is running. Otherwise after a umount+mount (or crash |
| * after committing the transaction) we would leak free space and get |
| * an inconsistent free space cache report from fsck. |
| */ |
| list_for_each_entry(trim_entry, &ctl->trimming_ranges, list) { |
| ret = io_ctl_add_entry(io_ctl, trim_entry->start, |
| trim_entry->bytes, NULL); |
| if (ret) |
| goto fail; |
| *entries += 1; |
| } |
| |
| return 0; |
| fail: |
| if (cluster_locked) |
| spin_unlock(&cluster_locked->lock); |
| return -ENOSPC; |
| } |
| |
| static noinline_for_stack int |
| update_cache_item(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct inode *inode, |
| struct btrfs_path *path, u64 offset, |
| int entries, int bitmaps) |
| { |
| struct btrfs_key key; |
| struct btrfs_free_space_header *header; |
| struct extent_buffer *leaf; |
| int ret; |
| |
| 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 fail; |
| } |
| leaf = path->nodes[0]; |
| if (ret > 0) { |
| struct btrfs_key found_key; |
| ASSERT(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 fail; |
| } |
| } |
| |
| 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); |
| |
| return 0; |
| |
| fail: |
| return -1; |
| } |
| |
| static noinline_for_stack int |
| write_pinned_extent_entries(struct btrfs_root *root, |
| struct btrfs_block_group_cache *block_group, |
| struct btrfs_io_ctl *io_ctl, |
| int *entries) |
| { |
| u64 start, extent_start, extent_end, len; |
| struct extent_io_tree *unpin = NULL; |
| int ret; |
| |
| if (!block_group) |
| return 0; |
| |
| /* |
| * 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; |
| |
| start = block_group->key.objectid; |
| |
| while (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) |
| return 0; |
| |
| /* This pinned extent is out of our range */ |
| if (extent_start >= block_group->key.objectid + |
| block_group->key.offset) |
| return 0; |
| |
| 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 += 1; |
| ret = io_ctl_add_entry(io_ctl, extent_start, len, NULL); |
| if (ret) |
| return -ENOSPC; |
| |
| start = extent_end; |
| } |
| |
| return 0; |
| } |
| |
| static noinline_for_stack int |
| write_bitmap_entries(struct btrfs_io_ctl *io_ctl, struct list_head *bitmap_list) |
| { |
| struct list_head *pos, *n; |
| int ret; |
| |
| /* 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) |
| return -ENOSPC; |
| list_del_init(&entry->list); |
| } |
| |
| return 0; |
| } |
| |
| static int flush_dirty_cache(struct inode *inode) |
| { |
| int ret; |
| |
| ret = btrfs_wait_ordered_range(inode, 0, (u64)-1); |
| if (ret) |
| clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1, |
| EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, NULL, |
| GFP_NOFS); |
| |
| return ret; |
| } |
| |
| static void noinline_for_stack |
| cleanup_bitmap_list(struct list_head *bitmap_list) |
| { |
| struct list_head *pos, *n; |
| |
| 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); |
| } |
| } |
| |
| static void noinline_for_stack |
| cleanup_write_cache_enospc(struct inode *inode, |
| struct btrfs_io_ctl *io_ctl, |
| struct extent_state **cached_state, |
| struct list_head *bitmap_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); |
| } |
| |
| int btrfs_wait_cache_io(struct btrfs_root *root, |
| struct btrfs_trans_handle *trans, |
| struct btrfs_block_group_cache *block_group, |
| struct btrfs_io_ctl *io_ctl, |
| struct btrfs_path *path, u64 offset) |
| { |
| int ret; |
| struct inode *inode = io_ctl->inode; |
| |
| if (!inode) |
| return 0; |
| |
| if (block_group) |
| root = root->fs_info->tree_root; |
| |
| /* Flush the dirty pages in the cache file. */ |
| ret = flush_dirty_cache(inode); |
| if (ret) |
| goto out; |
| |
| /* Update the cache item to tell everyone this cache file is valid. */ |
| ret = update_cache_item(trans, root, inode, path, offset, |
| io_ctl->entries, io_ctl->bitmaps); |
| out: |
| io_ctl_free(io_ctl); |
| if (ret) { |
| invalidate_inode_pages2(inode->i_mapping); |
| BTRFS_I(inode)->generation = 0; |
| if (block_group) { |
| #ifdef DEBUG |
| btrfs_err(root->fs_info, |
| "failed to write free space cache for block group %llu", |
| block_group->key.objectid); |
| #endif |
| } |
| } |
| btrfs_update_inode(trans, root, inode); |
| |
| if (block_group) { |
| /* the dirty list is protected by the dirty_bgs_lock */ |
| spin_lock(&trans->transaction->dirty_bgs_lock); |
| |
| /* the disk_cache_state is protected by the block group lock */ |
| spin_lock(&block_group->lock); |
| |
| /* |
| * only mark this as written if we didn't get put back on |
| * the dirty list while waiting for IO. Otherwise our |
| * cache state won't be right, and we won't get written again |
| */ |
| if (!ret && list_empty(&block_group->dirty_list)) |
| block_group->disk_cache_state = BTRFS_DC_WRITTEN; |
| else if (ret) |
| block_group->disk_cache_state = BTRFS_DC_ERROR; |
| |
| spin_unlock(&block_group->lock); |
| spin_unlock(&trans->transaction->dirty_bgs_lock); |
| io_ctl->inode = NULL; |
| 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 successful in writing the cache out, |
| * or an errno if it was not. |
| */ |
| static 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_io_ctl *io_ctl, |
| struct btrfs_trans_handle *trans, |
| struct btrfs_path *path, u64 offset) |
| { |
| struct extent_state *cached_state = NULL; |
| LIST_HEAD(bitmap_list); |
| int entries = 0; |
| int bitmaps = 0; |
| int ret; |
| int must_iput = 0; |
| |
| if (!i_size_read(inode)) |
| return -EIO; |
| |
| WARN_ON(io_ctl->pages); |
| ret = io_ctl_init(io_ctl, inode, root, 1); |
| if (ret) |
| return ret; |
| |
| if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA)) { |
| down_write(&block_group->data_rwsem); |
| spin_lock(&block_group->lock); |
| if (block_group->delalloc_bytes) { |
| block_group->disk_cache_state = BTRFS_DC_WRITTEN; |
| spin_unlock(&block_group->lock); |
| up_write(&block_group->data_rwsem); |
| BTRFS_I(inode)->generation = 0; |
| ret = 0; |
| must_iput = 1; |
| goto out; |
| } |
| spin_unlock(&block_group->lock); |
| } |
| |
| /* Lock all pages first so we can lock the extent safely. */ |
| ret = io_ctl_prepare_pages(io_ctl, inode, 0); |
| if (ret) |
| goto out; |
| |
| lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1, |
| 0, &cached_state); |
| |
| io_ctl_set_generation(io_ctl, trans->transid); |
| |
| mutex_lock(&ctl->cache_writeout_mutex); |
| /* Write out the extent entries in the free space cache */ |
| spin_lock(&ctl->tree_lock); |
| ret = write_cache_extent_entries(io_ctl, ctl, |
| block_group, &entries, &bitmaps, |
| &bitmap_list); |
| if (ret) |
| goto out_nospc_locked; |
| |
| /* |
| * Some spaces that are freed in the current transaction are pinned, |
| * they will be added into free space cache after the transaction is |
| * committed, we shouldn't lose them. |
| * |
| * If this changes while we are working we'll get added back to |
| * the dirty list and redo it. No locking needed |
| */ |
| ret = write_pinned_extent_entries(root, block_group, io_ctl, &entries); |
| if (ret) |
| goto out_nospc_locked; |
| |
| /* |
| * At last, we write out all the bitmaps and keep cache_writeout_mutex |
| * locked while doing it because a concurrent trim can be manipulating |
| * or freeing the bitmap. |
| */ |
| ret = write_bitmap_entries(io_ctl, &bitmap_list); |
| spin_unlock(&ctl->tree_lock); |
| mutex_unlock(&ctl->cache_writeout_mutex); |
| if (ret) |
| goto out_nospc; |
| |
| /* Zero out the rest of the pages just to make sure */ |
| io_ctl_zero_remaining_pages(io_ctl); |
| |
| /* Everything is written out, now we dirty the pages in the file. */ |
| ret = btrfs_dirty_pages(root, inode, io_ctl->pages, io_ctl->num_pages, |
| 0, i_size_read(inode), &cached_state); |
| if (ret) |
| goto out_nospc; |
| |
| if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA)) |
| up_write(&block_group->data_rwsem); |
| /* |
| * Release the pages and unlock the extent, we will flush |
| * them out later |
| */ |
| io_ctl_drop_pages(io_ctl); |
| |
| unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0, |
| i_size_read(inode) - 1, &cached_state, GFP_NOFS); |
| |
| /* |
| * at this point the pages are under IO and we're happy, |
| * The caller is responsible for waiting on them and updating the |
| * the cache and the inode |
| */ |
| io_ctl->entries = entries; |
| io_ctl->bitmaps = bitmaps; |
| |
| ret = btrfs_fdatawrite_range(inode, 0, (u64)-1); |
| if (ret) |
| goto out; |
| |
| return 0; |
| |
| out: |
| io_ctl->inode = NULL; |
| io_ctl_free(io_ctl); |
| if (ret) { |
| invalidate_inode_pages2(inode->i_mapping); |
| BTRFS_I(inode)->generation = 0; |
| } |
| btrfs_update_inode(trans, root, inode); |
| if (must_iput) |
| iput(inode); |
| return ret; |
| |
| out_nospc_locked: |
| cleanup_bitmap_list(&bitmap_list); |
| spin_unlock(&ctl->tree_lock); |
| mutex_unlock(&ctl->cache_writeout_mutex); |
| |
| out_nospc: |
| cleanup_write_cache_enospc(inode, io_ctl, &cached_state, &bitmap_list); |
| |
| if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA)) |
| up_write(&block_group->data_rwsem); |
| |
| 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, |
| &block_group->io_ctl, trans, |
| path, block_group->key.objectid); |
| if (ret) { |
| #ifdef DEBUG |
| btrfs_err(root->fs_info, |
| "failed to write free space cache for block group %llu", |
| block_group->key.objectid); |
| #endif |
| spin_lock(&block_group->lock); |
| block_group->disk_cache_state = BTRFS_DC_ERROR; |
| spin_unlock(&block_group->lock); |
| |
| block_group->io_ctl.inode = NULL; |
| iput(inode); |
| } |
| |
| /* |
| * if ret == 0 the caller is expected to call btrfs_wait_cache_io |
| * to wait for IO and put the inode |
| */ |
| |
| return ret; |
| } |
| |
| static inline unsigned long offset_to_bit(u64 bitmap_start, u32 unit, |
| u64 offset) |
| { |
| ASSERT(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; |
| u32 bytes_per_bitmap; |
| |
| bytes_per_bitmap = BITS_PER_BITMAP * ctl->unit; |
| bitmap_start = offset - ctl->start; |
| bitmap_start = div_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); |
| ASSERT(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; |
| |
| ASSERT(info->bytes || info->bitmap); |
| 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; |
| u32 bytes_per_bg = BITS_PER_BITMAP * ctl->unit; |
| u32 max_bitmaps = div_u64(size + bytes_per_bg - 1, bytes_per_bg); |
| |
| max_bitmaps = max_t(u32, max_bitmaps, 1); |
| |
| ASSERT(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 * |
| div_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 max |
| * bytes we can have, or whatever is less than that. |
| */ |
| extent_bytes = max_bytes - bitmap_bytes; |
| extent_bytes = min_t(u64, extent_bytes, max_bytes >> 1); |
| |
| ctl->extents_thresh = |
| div_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); |
| ASSERT(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); |
| ASSERT(start + count <= BITS_PER_BITMAP); |
| |
| bitmap_set(info->bitmap, start, count); |
| |
| info->bytes += bytes; |
| ctl->free_space += bytes; |
| } |
| |
| /* |
| * If we can not find suitable extent, we will use bytes to record |
| * the size of the max extent. |
| */ |
| static int search_bitmap(struct btrfs_free_space_ctl *ctl, |
| struct btrfs_free_space *bitmap_info, u64 *offset, |
| u64 *bytes, bool for_alloc) |
| { |
| unsigned long found_bits = 0; |
| unsigned long max_bits = 0; |
| unsigned long bits, i; |
| unsigned long next_zero; |
| unsigned long extent_bits; |
| |
| /* |
| * Skip searching the bitmap if we don't have a contiguous section that |
| * is large enough for this allocation. |
| */ |
| if (for_alloc && |
| bitmap_info->max_extent_size && |
| bitmap_info->max_extent_size < *bytes) { |
| *bytes = bitmap_info->max_extent_size; |
| return -1; |
| } |
| |
| 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) { |
| if (for_alloc && bits == 1) { |
| found_bits = 1; |
| break; |
| } |
| next_zero = find_next_zero_bit(bitmap_info->bitmap, |
| BITS_PER_BITMAP, i); |
| extent_bits = next_zero - i; |
| if (extent_bits >= bits) { |
| found_bits = extent_bits; |
| break; |
| } else if (extent_bits > max_bits) { |
| max_bits = extent_bits; |
| } |
| i = next_zero; |
| } |
| |
| if (found_bits) { |
| *offset = (u64)(i * ctl->unit) + bitmap_info->offset; |
| *bytes = (u64)(found_bits) * ctl->unit; |
| return 0; |
| } |
| |
| *bytes = (u64)(max_bits) * ctl->unit; |
| bitmap_info->max_extent_size = *bytes; |
| return -1; |
| } |
| |
| /* Cache the size of the max extent in bytes */ |
| static struct btrfs_free_space * |
| find_free_space(struct btrfs_free_space_ctl *ctl, u64 *offset, u64 *bytes, |
| unsigned long align, u64 *max_extent_size) |
| { |
| struct btrfs_free_space *entry; |
| struct rb_node *node; |
| u64 tmp; |
| u64 align_off; |
| int ret; |
| |
| if (!ctl->free_space_offset.rb_node) |
| goto out; |
| |
| entry = tree_search_offset(ctl, offset_to_bitmap(ctl, *offset), 0, 1); |
| if (!entry) |
| goto out; |
| |
| for (node = &entry->offset_index; node; node = rb_next(node)) { |
| entry = rb_entry(node, struct btrfs_free_space, offset_index); |
| if (entry->bytes < *bytes) { |
| if (entry->bytes > *max_extent_size) |
| *max_extent_size = entry->bytes; |
| continue; |
| } |
| |
| /* make sure the space returned is big enough |
| * to match our requested alignment |
| */ |
| if (*bytes >= align) { |
| tmp = entry->offset - ctl->start + align - 1; |
| tmp = div64_u64(tmp, align); |
| tmp = tmp * align + ctl->start; |
| align_off = tmp - entry->offset; |
| } else { |
| align_off = 0; |
| tmp = entry->offset; |
| } |
| |
| if (entry->bytes < *bytes + align_off) { |
| if (entry->bytes > *max_extent_size) |
| *max_extent_size = entry->bytes; |
| continue; |
| } |
| |
| if (entry->bitmap) { |
| u64 size = *bytes; |
| |
| ret = search_bitmap(ctl, entry, &tmp, &size, true); |
| if (!ret) { |
| *offset = tmp; |
| *bytes = size; |
| return entry; |
| } else if (size > *max_extent_size) { |
| *max_extent_size = size; |
| } |
| continue; |
| } |
| |
| *offset = tmp; |
| *bytes = entry->bytes - align_off; |
| return entry; |
| } |
| out: |
| 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, |
| false); |
| if (ret < 0 || search_start != *offset) |
| return -EINVAL; |
| |
| /* 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, false); |
| 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); |
| |
| /* |
| * We set some bytes, we have no idea what the max extent size is |
| * anymore. |
| */ |
| info->max_extent_size = 0; |
| |
| 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; |
| bool forced = false; |
| |
| #ifdef CONFIG_BTRFS_DEBUG |
| if (btrfs_should_fragment_free_space(block_group->fs_info->extent_root, |
| block_group)) |
| forced = true; |
| #endif |
| |
| /* |
| * 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 (!forced && 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; |
| } |
| } |
| |
| /* |
| * The original block groups from mkfs can be really small, like 8 |
| * megabytes, so don't bother with a bitmap for those entries. However |
| * some block groups can be smaller than what a bitmap would cover but |
| * are still large enough that they could overflow the 32k memory limit, |
| * so allow those block groups to still be allowed to have a bitmap |
| * entry. |
| */ |
| if (((BITS_PER_BITMAP * ctl->unit) >> 1) > 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) { |
| ASSERT(added == 0); |
| 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; |
| } |
| |
| static bool steal_from_bitmap_to_end(struct btrfs_free_space_ctl *ctl, |
| struct btrfs_free_space *info, |
| bool update_stat) |
| { |
| struct btrfs_free_space *bitmap; |
| unsigned long i; |
| unsigned long j; |
| const u64 end = info->offset + info->bytes; |
| const u64 bitmap_offset = offset_to_bitmap(ctl, end); |
| u64 bytes; |
| |
| bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0); |
| if (!bitmap) |
| return false; |
| |
| i = offset_to_bit(bitmap->offset, ctl->unit, end); |
| j = find_next_zero_bit(bitmap->bitmap, BITS_PER_BITMAP, i); |
| if (j == i) |
| return false; |
| bytes = (j - i) * ctl->unit; |
| info->bytes += bytes; |
| |
| if (update_stat) |
| bitmap_clear_bits(ctl, bitmap, end, bytes); |
| else |
| __bitmap_clear_bits(ctl, bitmap, end, bytes); |
| |
| if (!bitmap->bytes) |
| free_bitmap(ctl, bitmap); |
| |
| return true; |
| } |
| |
| static bool steal_from_bitmap_to_front(struct btrfs_free_space_ctl *ctl, |
| struct btrfs_free_space *info, |
| bool update_stat) |
| { |
| struct btrfs_free_space *bitmap; |
| u64 bitmap_offset; |
| unsigned long i; |
| unsigned long j; |
| unsigned long prev_j; |
| u64 bytes; |
| |
| bitmap_offset = offset_to_bitmap(ctl, info->offset); |
| /* If we're on a boundary, try the previous logical bitmap. */ |
| if (bitmap_offset == info->offset) { |
| if (info->offset == 0) |
| return false; |
| bitmap_offset = offset_to_bitmap(ctl, info->offset - 1); |
| } |
| |
| bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0); |
| if (!bitmap) |
| return false; |
| |
| i = offset_to_bit(bitmap->offset, ctl->unit, info->offset) - 1; |
| j = 0; |
| prev_j = (unsigned long)-1; |
| for_each_clear_bit_from(j, bitmap->bitmap, BITS_PER_BITMAP) { |
| if (j > i) |
| break; |
| prev_j = j; |
| } |
| if (prev_j == i) |
| return false; |
| |
| if (prev_j == (unsigned long)-1) |
| bytes = (i + 1) * ctl->unit; |
| else |
| bytes = (i - prev_j) * ctl->unit; |
| |
| info->offset -= bytes; |
| info->bytes += bytes; |
| |
| if (update_stat) |
| bitmap_clear_bits(ctl, bitmap, info->offset, bytes); |
| else |
| __bitmap_clear_bits(ctl, bitmap, info->offset, bytes); |
| |
| if (!bitmap->bytes) |
| free_bitmap(ctl, bitmap); |
| |
| return true; |
| } |
| |
| /* |
| * We prefer always to allocate from extent entries, both for clustered and |
| * non-clustered allocation requests. So when attempting to add a new extent |
| * entry, try to see if there's adjacent free space in bitmap entries, and if |
| * there is, migrate that space from the bitmaps to the extent. |
| * Like this we get better chances of satisfying space allocation requests |
| * because we attempt to satisfy them based on a single cache entry, and never |
| * on 2 or more entries - even if the entries represent a contiguous free space |
| * region (e.g. 1 extent entry + 1 bitmap entry starting where the extent entry |
| * ends). |
| */ |
| static void steal_from_bitmap(struct btrfs_free_space_ctl *ctl, |
| struct btrfs_free_space *info, |
| bool update_stat) |
| { |
| /* |
| * Only work with disconnected entries, as we can change their offset, |
| * and must be extent entries. |
| */ |
| ASSERT(!info->bitmap); |
| ASSERT(RB_EMPTY_NODE(&info->offset_index)); |
| |
| if (ctl->total_bitmaps > 0) { |
| bool stole_end; |
| bool stole_front = false; |
| |
| stole_end = steal_from_bitmap_to_end(ctl, info, update_stat); |
| if (ctl->total_bitmaps > 0) |
| stole_front = steal_from_bitmap_to_front(ctl, info, |
| update_stat); |
| |
| if (stole_end || stole_front) |
| try_merge_free_space(ctl, info, update_stat); |
| } |
| } |
| |
| 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; |
| RB_CLEAR_NODE(&info->offset_index); |
| |
| 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: |
| /* |
| * Only steal free space from adjacent bitmaps if we're sure we're not |
| * going to add the new free space to existing bitmap entries - because |
| * that would mean unnecessary work that would be reverted. Therefore |
| * attempt to steal space from bitmaps if we're adding an extent entry. |
| */ |
| steal_from_bitmap(ctl, info, true); |
| |
| 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); |
| ASSERT(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; |
| bool re_search = false; |
| |
| spin_lock(&ctl->tree_lock); |
| |
| again: |
| ret = 0; |
| 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) { |
| /* |
| * If we found a partial bit of our free space in a |
| * bitmap but then couldn't find the other part this may |
| * be a problem, so WARN about it. |
| */ |
| WARN_ON(re_search); |
| goto out_lock; |
| } |
| } |
| |
| re_search = false; |
| 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) { |
| re_search = true; |
| goto again; |
| } |
| 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++; |
| btrfs_crit(block_group->fs_info, |
| "entry offset %llu, bytes %llu, bitmap %s", |
| info->offset, info->bytes, |
| (info->bitmap) ? "yes" : "no"); |
| } |
| btrfs_info(block_group->fs_info, "block group has cluster?: %s", |
| list_empty(&block_group->cluster_list) ? "no" : "yes"); |
| btrfs_info(block_group->fs_info, |
| "%d blocks of free space at or bigger than bytes is", 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; |
| INIT_LIST_HEAD(&ctl->trimming_ranges); |
| mutex_init(&ctl->cache_writeout_mutex); |
| |
| /* |
| * 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); |
| RB_CLEAR_NODE(&entry->offset_index); |
| |
| bitmap = (entry->bitmap != NULL); |
| if (!bitmap) { |
| try_merge_free_space(ctl, entry, false); |
| steal_from_bitmap(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; |
| } |
| |
| static 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); |
| } |
| |
| cond_resched_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); |
| |
| cond_resched_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, |
| u64 *max_extent_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; |
| u64 align_gap = 0; |
| u64 align_gap_len = 0; |
| |
| spin_lock(&ctl->tree_lock); |
| entry = find_free_space(ctl, &offset, &bytes_search, |
| block_group->full_stripe_len, max_extent_size); |
| 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); |
| align_gap_len = offset - entry->offset; |
| align_gap = entry->offset; |
| |
| entry->offset = offset + bytes; |
| WARN_ON(entry->bytes < bytes + align_gap_len); |
| |
| entry->bytes -= bytes + align_gap_len; |
| if (!entry->bytes) |
| kmem_cache_free(btrfs_free_space_cachep, entry); |
| else |
| link_free_space(ctl, entry); |
| } |
| out: |
| spin_unlock(&ctl->tree_lock); |
| |
| if (align_gap_len) |
| __btrfs_add_free_space(ctl, align_gap, align_gap_len); |
| 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, |
| u64 *max_extent_size) |
| { |
| 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, true); |
| if (err) { |
| if (search_bytes > *max_extent_size) |
| *max_extent_size = search_bytes; |
| 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, u64 *max_extent_size) |
| { |
| 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->bytes > *max_extent_size) |
| *max_extent_size = entry->bytes; |
| |
| 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, |
| max_extent_size); |
| 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 max_bits = 0; |
| 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); |
| |
| /* |
| * Don't bother looking for a cluster in this bitmap if it's heavily |
| * fragmented. |
| */ |
| if (entry->max_extent_size && |
| entry->max_extent_size < cont1_bytes) |
| return -ENOSPC; |
| 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; |
| if (found_bits > max_bits) |
| max_bits = found_bits; |
| break; |
| } |
| if (next_zero - i > max_bits) |
| max_bits = next_zero - i; |
| i = next_zero; |
| } |
| |
| if (!found_bits) { |
| entry->max_extent_size = (u64)max_bits * ctl->unit; |
| 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); |
| ASSERT(!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_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_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; |
| ASSERT(!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 = NULL; |
| 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. |
| */ |
| if (!list_empty(bitmaps)) |
| entry = list_first_entry(bitmaps, struct btrfs_free_space, list); |
| |
| if (!entry || 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_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); |
| |
| 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 |