| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Josef Bacik | 9346 | 50.31% | 65 | 29.02% |
| Chris Mason | 2076 | 11.17% | 19 | 8.48% |
| Li Zefan | 2073 | 11.16% | 16 | 7.14% |
| Dennis Zhou | 2043 | 11.00% | 14 | 6.25% |
| Filipe David Borba Manana | 1051 | 5.66% | 12 | 5.36% |
| Miao Xie | 578 | 3.11% | 8 | 3.57% |
| Jeff Mahoney | 398 | 2.14% | 13 | 5.80% |
| Li Dongyang | 255 | 1.37% | 1 | 0.45% |
| David Sterba | 166 | 0.89% | 28 | 12.50% |
| David Woodhouse | 151 | 0.81% | 1 | 0.45% |
| Alexandre Oliva | 112 | 0.60% | 3 | 1.34% |
| Josef Whiter | 94 | 0.51% | 7 | 3.12% |
| Simon Kirby | 32 | 0.17% | 1 | 0.45% |
| Christophe Leroy | 28 | 0.15% | 1 | 0.45% |
| Frank Holton | 22 | 0.12% | 1 | 0.45% |
| Wang Sheng-Hui | 18 | 0.10% | 1 | 0.45% |
| Geliang Tang | 15 | 0.08% | 1 | 0.45% |
| Feifei Xu | 12 | 0.06% | 3 | 1.34% |
| Omar Sandoval | 11 | 0.06% | 2 | 0.89% |
| Wei Yongjun | 9 | 0.05% | 2 | 0.89% |
| Al Viro | 9 | 0.05% | 1 | 0.45% |
| Nikolay Borisov | 9 | 0.05% | 3 | 1.34% |
| Johannes Thumshirn | 8 | 0.04% | 1 | 0.45% |
| Liu Bo | 8 | 0.04% | 2 | 0.89% |
| Kirill A. Shutemov | 7 | 0.04% | 1 | 0.45% |
| Zhihui Zhang | 7 | 0.04% | 1 | 0.45% |
| Tsutomu Itoh | 5 | 0.03% | 1 | 0.45% |
| Eric Sandeen | 4 | 0.02% | 1 | 0.45% |
| Masami Hiramatsu | 4 | 0.02% | 2 | 0.89% |
| Gui Hecheng | 4 | 0.02% | 1 | 0.45% |
| Byongho Lee | 3 | 0.02% | 1 | 0.45% |
| Michal Hocko | 3 | 0.02% | 1 | 0.45% |
| Tejun Heo | 3 | 0.02% | 1 | 0.45% |
| Ingo Molnar | 3 | 0.02% | 1 | 0.45% |
| Eric Paris | 2 | 0.01% | 1 | 0.45% |
| Domagoj Tršan | 2 | 0.01% | 1 | 0.45% |
| Qu Wenruo | 2 | 0.01% | 1 | 0.45% |
| Su Yue | 2 | 0.01% | 1 | 0.45% |
| Stoyan Gaydarov | 1 | 0.01% | 1 | 0.45% |
| Nicholas D Steeves | 1 | 0.01% | 1 | 0.45% |
| Holger Hoffstätte | 1 | 0.01% | 1 | 0.45% |
| Total | 18578 | 224 |
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// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2008 Red Hat. All rights reserved. */ #include <linux/pagemap.h> #include <linux/sched.h> #include <linux/sched/signal.h> #include <linux/slab.h> #include <linux/math64.h> #include <linux/ratelimit.h> #include <linux/error-injection.h> #include <linux/sched/mm.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" #include "space-info.h" #include "delalloc-space.h" #include "block-group.h" #include "discard.h" #define BITS_PER_BITMAP (PAGE_SIZE * 8UL) #define MAX_CACHE_BYTES_PER_GIG SZ_64K #define FORCE_EXTENT_THRESHOLD SZ_1M struct btrfs_trim_range { u64 start; u64 bytes; struct list_head list; }; static int count_bitmap_extents(struct btrfs_free_space_ctl *ctl, struct btrfs_free_space *bitmap_info); 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 int btrfs_wait_cache_io_root(struct btrfs_root *root, struct btrfs_trans_handle *trans, struct btrfs_io_ctl *io_ctl, struct btrfs_path *path); static struct inode *__lookup_free_space_inode(struct btrfs_root *root, struct btrfs_path *path, u64 offset) { struct btrfs_fs_info *fs_info = root->fs_info; 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; unsigned nofs_flag; 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); /* * We are often under a trans handle at this point, so we need to make * sure NOFS is set to keep us from deadlocking. */ nofs_flag = memalloc_nofs_save(); inode = btrfs_iget_path(fs_info->sb, &location, root, path); btrfs_release_path(path); memalloc_nofs_restore(nofs_flag); if (IS_ERR(inode)) return inode; 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_block_group *block_group, struct btrfs_path *path) { struct btrfs_fs_info *fs_info = block_group->fs_info; 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(fs_info->tree_root, path, block_group->start); if (IS_ERR(inode)) return inode; spin_lock(&block_group->lock); if (!((BTRFS_I(inode)->flags & flags) == flags)) { btrfs_info(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]); memzero_extent_buffer(leaf, (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); memzero_extent_buffer(leaf, (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_trans_handle *trans, struct btrfs_block_group *block_group, struct btrfs_path *path) { int ret; u64 ino; ret = btrfs_find_free_objectid(trans->fs_info->tree_root, &ino); if (ret < 0) return ret; return __create_free_space_inode(trans->fs_info->tree_root, trans, path, ino, block_group->start); } int btrfs_check_trunc_cache_free_space(struct btrfs_fs_info *fs_info, struct btrfs_block_rsv *rsv) { u64 needed_bytes; int ret; /* 1 for slack space, 1 for updating the inode */ needed_bytes = btrfs_calc_insert_metadata_size(fs_info, 1) + btrfs_calc_metadata_size(fs_info, 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_trans_handle *trans, struct btrfs_block_group *block_group, struct inode *inode) { struct btrfs_root *root = BTRFS_I(inode)->root; int ret = 0; bool locked = false; if (block_group) { struct btrfs_path *path = btrfs_alloc_path(); if (!path) { ret = -ENOMEM; goto fail; } 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(trans, block_group, path); 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(BTRFS_I(inode), 0); truncate_pagecache(inode, 0); /* * We skip the throttling logic for free space cache inodes, so we don't * need to check for -EAGAIN. */ 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, ret); return ret; } static void readahead_cache(struct inode *inode) { struct file_ra_state *ra; unsigned long last_index; ra = kzalloc(sizeof(*ra), GFP_NOFS); if (!ra) return; file_ra_state_init(ra, inode->i_mapping); last_index = (i_size_read(inode) - 1) >> PAGE_SHIFT; page_cache_sync_readahead(inode->i_mapping, ra, NULL, 0, last_index); kfree(ra); } static int io_ctl_init(struct btrfs_io_ctl *io_ctl, struct inode *inode, int write) { int num_pages; int check_crcs = 0; num_pages = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE); if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FREE_INO_OBJECTID) check_crcs = 1; /* Make sure we can fit our crcs and generation into the first page */ if (write && check_crcs && (num_pages * sizeof(u32) + sizeof(u64)) > PAGE_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->fs_info = btrfs_sb(inode->i_sb); io_ctl->check_crcs = check_crcs; io_ctl->inode = inode; return 0; } ALLOW_ERROR_INJECTION(io_ctl_init, ERRNO); 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_SIZE; if (clear) clear_page(io_ctl->cur); } 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]); put_page(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 (page->mapping != inode->i_mapping) { btrfs_err(BTRFS_I(inode)->root->fs_info, "free space cache page truncated"); io_ctl_drop_pages(io_ctl); return -EIO; } 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->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_crc32c(crc, io_ctl->orig + offset, PAGE_SIZE - offset); btrfs_crc32c_final(crc, (u8 *)&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_crc32c(crc, io_ctl->orig + offset, PAGE_SIZE - offset); btrfs_crc32c_final(crc, (u8 *)&crc); if (val != crc) { btrfs_err_rl(io_ctl->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); } copy_page(io_ctl->cur, bitmap); 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; copy_page(entry->bitmap, io_ctl->cur); 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_fs_info *fs_info = root->fs_info; 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(fs_info, "the free space cache file (%llu) is invalid, skip it", offset); return 0; } if (BTRFS_I(inode)->generation != generation) { btrfs_err(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, 0); if (ret) return ret; readahead_cache(inode); 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; } /* * Sync discard ensures that the free space cache is always * trimmed. So when reading this in, the state should reflect * that. We also do this for async as a stop gap for lack of * persistence. */ if (btrfs_test_opt(fs_info, DISCARD_SYNC) || btrfs_test_opt(fs_info, DISCARD_ASYNC)) e->trim_state = BTRFS_TRIM_STATE_TRIMMED; 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(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 = kmem_cache_zalloc( btrfs_free_space_bitmap_cachep, 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(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; e->bitmap_extents = count_bitmap_extents(ctl, e); if (!btrfs_free_space_trimmed(e)) { ctl->discardable_extents[BTRFS_STAT_CURR] += e->bitmap_extents; ctl->discardable_bytes[BTRFS_STAT_CURR] += e->bytes; } } io_ctl_drop_pages(&io_ctl); merge_space_tree(ctl); ret = 1; out: btrfs_discard_update_discardable(ctl->private, ctl); 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_block_group *block_group) { struct btrfs_fs_info *fs_info = block_group->fs_info; struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; struct inode *inode; struct btrfs_path *path; int ret = 0; bool matched; u64 used = block_group->used; /* * 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; /* * We must pass a path with search_commit_root set to btrfs_iget in * order to avoid a deadlock when allocating extents for the tree root. * * When we are COWing an extent buffer from the tree root, when looking * for a free extent, at extent-tree.c:find_free_extent(), we can find * block group without its free space cache loaded. When we find one * we must load its space cache which requires reading its free space * cache's inode item from the root tree. If this inode item is located * in the same leaf that we started COWing before, then we end up in * deadlock on the extent buffer (trying to read lock it when we * previously write locked it). * * It's safe to read the inode item using the commit root because * block groups, once loaded, stay in memory forever (until they are * removed) as well as their space caches once loaded. New block groups * once created get their ->cached field set to BTRFS_CACHE_FINISHED so * we will never try to read their inode item while the fs is mounted. */ inode = lookup_free_space_inode(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->start); btrfs_free_path(path); if (ret <= 0) goto out; spin_lock(&ctl->tree_lock); matched = (ctl->free_space == (block_group->length - 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->start); 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->start); } 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 *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_DELALLOC, 0, 0, NULL); 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_DELALLOC, 0, 0, NULL); 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_block_group *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 = block_group->fs_info->pinned_extents; start = block_group->start; while (start < block_group->start + block_group->length) { 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->start + block_group->length) return 0; extent_start = max(extent_start, start); extent_end = min(block_group->start + block_group->length, 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 btrfs_free_space *entry, *next; int ret; /* Write out the bitmaps */ list_for_each_entry_safe(entry, next, bitmap_list, 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_DELALLOC, 0, 0, NULL); return ret; } static void noinline_for_stack cleanup_bitmap_list(struct list_head *bitmap_list) { struct btrfs_free_space *entry, *next; list_for_each_entry_safe(entry, next, bitmap_list, 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) { io_ctl_drop_pages(io_ctl); unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1, cached_state); } static int __btrfs_wait_cache_io(struct btrfs_root *root, struct btrfs_trans_handle *trans, struct btrfs_block_group *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; /* 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->start); #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; } static int btrfs_wait_cache_io_root(struct btrfs_root *root, struct btrfs_trans_handle *trans, struct btrfs_io_ctl *io_ctl, struct btrfs_path *path) { return __btrfs_wait_cache_io(root, trans, NULL, io_ctl, path, 0); } int btrfs_wait_cache_io(struct btrfs_trans_handle *trans, struct btrfs_block_group *block_group, struct btrfs_path *path) { return __btrfs_wait_cache_io(block_group->fs_info->tree_root, trans, block_group, &block_group->io_ctl, path, block_group->start); } /** * __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 * * 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 *block_group, struct btrfs_io_ctl *io_ctl, struct btrfs_trans_handle *trans) { 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, 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_unlock; lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1, &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(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(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); /* * 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); out_unlock: 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_trans_handle *trans, struct btrfs_block_group *block_group, struct btrfs_path *path) { struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; struct inode *inode; int ret = 0; 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(block_group, path); if (IS_ERR(inode)) return 0; ret = __btrfs_write_out_cache(fs_info->tree_root, inode, ctl, block_group, &block_group->io_ctl, trans); if (ret) { #ifdef DEBUG btrfs_err(fs_info, "failed to write free space cache for block group %llu", block_group->start); #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; 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); 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--; if (!info->bitmap && !btrfs_free_space_trimmed(info)) { ctl->discardable_extents[BTRFS_STAT_CURR]--; ctl->discardable_bytes[BTRFS_STAT_CURR] -= info->bytes; } } 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; if (!info->bitmap && !btrfs_free_space_trimmed(info)) { ctl->discardable_extents[BTRFS_STAT_CURR]++; ctl->discardable_bytes[BTRFS_STAT_CURR] += info->bytes; } ctl->free_space += info->bytes; ctl->free_extents++; return ret; } static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl) { struct btrfs_block_group *block_group = ctl->private; u64 max_bytes; u64 bitmap_bytes; u64 extent_bytes; u64 size = block_group->length; u64 bytes_per_bg = BITS_PER_BITMAP * ctl->unit; u64 max_bitmaps = div64_u64(size + bytes_per_bg - 1, bytes_per_bg); max_bitmaps = max_t(u64, max_bitmaps, 1); ASSERT(ctl->total_bitmaps <= max_bitmaps); /* * We are trying to keep the total amount of memory used per 1GiB of * space to be MAX_CACHE_BYTES_PER_GIG. However, with a reclamation * mechanism of pulling extents >= FORCE_EXTENT_THRESHOLD out of * bitmaps, we may end up using more memory than this. */ if (size < SZ_1G) max_bytes = MAX_CACHE_BYTES_PER_GIG; else max_bytes = MAX_CACHE_BYTES_PER_GIG * div_u64(size, SZ_1G); bitmap_bytes = ctl->total_bitmaps * ctl->unit; /* * 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, end; int extent_delta = -1; start = offset_to_bit(info->offset, ctl->unit, offset); count = bytes_to_bits(bytes, ctl->unit); end = start + count; ASSERT(end <= BITS_PER_BITMAP); bitmap_clear(info->bitmap, start, count); info->bytes -= bytes; if (info->max_extent_size > ctl->unit) info->max_extent_size = 0; if (start && test_bit(start - 1, info->bitmap)) extent_delta++; if (end < BITS_PER_BITMAP && test_bit(end, info->bitmap)) extent_delta++; info->bitmap_extents += extent_delta; if (!btrfs_free_space_trimmed(info)) { ctl->discardable_extents[BTRFS_STAT_CURR] += extent_delta; ctl->discardable_bytes[BTRFS_STAT_CURR] -= 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, end; int extent_delta = 1; start = offset_to_bit(info->offset, ctl->unit, offset); count = bytes_to_bits(bytes, ctl->unit); end = start + count; ASSERT(end <= BITS_PER_BITMAP); bitmap_set(info->bitmap, start, count); info->bytes += bytes; ctl->free_space += bytes; if (start && test_bit(start - 1, info->bitmap)) extent_delta--; if (end < BITS_PER_BITMAP && test_bit(end, info->bitmap)) extent_delta--; info->bitmap_extents += extent_delta; if (!btrfs_free_space_trimmed(info)) { ctl->discardable_extents[BTRFS_STAT_CURR] += extent_delta; ctl->discardable_bytes[BTRFS_STAT_CURR] += 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; } static inline u64 get_max_extent_size(struct btrfs_free_space *entry) { if (entry->bitmap) return entry->max_extent_size; return entry->bytes; } /* 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) { *max_extent_size = max(get_max_extent_size(entry), *max_extent_size); 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) { *max_extent_size = max(get_max_extent_size(entry), *max_extent_size); continue; } if (entry->bitmap) { u64 size = *bytes; ret = search_bitmap(ctl, entry, &tmp, &size, true); if (!ret) { *offset = tmp; *bytes = size; return entry; } else { *max_extent_size = max(get_max_extent_size(entry), *max_extent_size); } continue; } *offset = tmp; *bytes = entry->bytes - align_off; return entry; } out: return NULL; } static int count_bitmap_extents(struct btrfs_free_space_ctl *ctl, struct btrfs_free_space *bitmap_info) { struct btrfs_block_group *block_group = ctl->private; u64 bytes = bitmap_info->bytes; unsigned int rs, re; int count = 0; if (!block_group || !bytes) return count; bitmap_for_each_set_region(bitmap_info->bitmap, rs, re, 0, BITS_PER_BITMAP) { bytes -= (rs - re) * ctl->unit; count++; if (!bytes) break; } return count; } 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; info->bitmap_extents = 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) { /* * Normally when this is called, the bitmap is completely empty. However, * if we are blowing up the free space cache for one reason or another * via __btrfs_remove_free_space_cache(), then it may not be freed and * we may leave stats on the table. */ if (bitmap_info->bytes && !btrfs_free_space_trimmed(bitmap_info)) { ctl->discardable_extents[BTRFS_STAT_CURR] -= bitmap_info->bitmap_extents; ctl->discardable_bytes[BTRFS_STAT_CURR] -= bitmap_info->bytes; } unlink_free_space(ctl, bitmap_info); kmem_cache_free(btrfs_free_space_bitmap_cachep, 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, enum btrfs_trim_state trim_state) { u64 bytes_to_set = 0; u64 end; /* * This is a tradeoff to make bitmap trim state minimal. We mark the * whole bitmap untrimmed if at any point we add untrimmed regions. */ if (trim_state == BTRFS_TRIM_STATE_UNTRIMMED) { if (btrfs_free_space_trimmed(info)) { ctl->discardable_extents[BTRFS_STAT_CURR] += info->bitmap_extents; ctl->discardable_bytes[BTRFS_STAT_CURR] += info->bytes; } info->trim_state = BTRFS_TRIM_STATE_UNTRIMMED; } 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 *block_group = ctl->private; struct btrfs_fs_info *fs_info = block_group->fs_info; bool forced = false; #ifdef CONFIG_BTRFS_DEBUG if (btrfs_should_fragment_free_space(block_group)) forced = true; #endif /* This is a way to reclaim large regions from the bitmaps. */ if (!forced && info->bytes >= FORCE_EXTENT_THRESHOLD) return false; /* * 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 plenty * 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 <= fs_info->sectorsize * 8) { if (ctl->free_extents * 3 <= 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->length) return false; return true; } static const 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 *block_group = NULL; int added = 0; u64 bytes, offset, bytes_added; enum btrfs_trim_state trim_state; int ret; bytes = info->bytes; offset = info->offset; trim_state = info->trim_state; 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, trim_state); 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, trim_state); 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 = kmem_cache_zalloc(btrfs_free_space_bitmap_cachep, GFP_NOFS); info->trim_state = BTRFS_TRIM_STATE_TRIMMED; spin_lock(&ctl->tree_lock); if (!info->bitmap) { ret = -ENOMEM; goto out; } goto again; } out: if (info) { if (info->bitmap) kmem_cache_free(btrfs_free_space_bitmap_cachep, info->bitmap); kmem_cache_free(btrfs_free_space_cachep, info); } return ret; } /* * Free space merging rules: * 1) Merge trimmed areas together * 2) Let untrimmed areas coalesce with trimmed areas * 3) Always pull neighboring regions from bitmaps * * The above rules are for when we merge free space based on btrfs_trim_state. * Rules 2 and 3 are subtle because they are suboptimal, but are done for the * same reason: to promote larger extent regions which makes life easier for * find_free_extent(). Rule 2 enables coalescing based on the common path * being returning free space from btrfs_finish_extent_commit(). So when free * space is trimmed, it will prevent aggregating trimmed new region and * untrimmed regions in the rb_tree. Rule 3 is purely to obtain larger extents * and provide find_free_extent() with the largest extents possible hoping for * the reuse path. */ 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; const bool is_trimmed = btrfs_free_space_trimmed(info); /* * 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); /* See try_merge_free_space() comment. */ if (right_info && !right_info->bitmap && (!is_trimmed || btrfs_free_space_trimmed(right_info))) { 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; } /* See try_merge_free_space() comment. */ if (left_info && !left_info->bitmap && left_info->offset + left_info->bytes == offset && (!is_trimmed || btrfs_free_space_trimmed(left_info))) { 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; /* See try_merge_free_space() comment. */ if (!btrfs_free_space_trimmed(bitmap)) info->trim_state = BTRFS_TRIM_STATE_UNTRIMMED; 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; /* See try_merge_free_space() comment. */ if (!btrfs_free_space_trimmed(bitmap)) info->trim_state = BTRFS_TRIM_STATE_UNTRIMMED; 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_fs_info *fs_info, struct btrfs_free_space_ctl *ctl, u64 offset, u64 bytes, enum btrfs_trim_state trim_state) { struct btrfs_block_group *block_group = ctl->private; struct btrfs_free_space *info; int ret = 0; u64 filter_bytes = bytes; info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS); if (!info) return -ENOMEM; info->offset = offset; info->bytes = bytes; info->trim_state = trim_state; 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); filter_bytes = max(filter_bytes, info->bytes); ret = link_free_space(ctl, info); if (ret) kmem_cache_free(btrfs_free_space_cachep, info); out: btrfs_discard_update_discardable(block_group, ctl); spin_unlock(&ctl->tree_lock); if (ret) { btrfs_crit(fs_info, "unable to add free space :%d", ret); ASSERT(ret != -EEXIST); } if (trim_state != BTRFS_TRIM_STATE_TRIMMED) { btrfs_discard_check_filter(block_group, filter_bytes); btrfs_discard_queue_work(&fs_info->discard_ctl, block_group); } return ret; } int btrfs_add_free_space(struct btrfs_block_group *block_group, u64 bytenr, u64 size) { enum btrfs_trim_state trim_state = BTRFS_TRIM_STATE_UNTRIMMED; if (btrfs_test_opt(block_group->fs_info, DISCARD_SYNC)) trim_state = BTRFS_TRIM_STATE_TRIMMED; return __btrfs_add_free_space(block_group->fs_info, block_group->free_space_ctl, bytenr, size, trim_state); } /* * This is a subtle distinction because when adding free space back in general, * we want it to be added as untrimmed for async. But in the case where we add * it on loading of a block group, we want to consider it trimmed. */ int btrfs_add_free_space_async_trimmed(struct btrfs_block_group *block_group, u64 bytenr, u64 size) { enum btrfs_trim_state trim_state = BTRFS_TRIM_STATE_UNTRIMMED; if (btrfs_test_opt(block_group->fs_info, DISCARD_SYNC) || btrfs_test_opt(block_group->fs_info, DISCARD_ASYNC)) trim_state = BTRFS_TRIM_STATE_TRIMMED; return __btrfs_add_free_space(block_group->fs_info, block_group->free_space_ctl, bytenr, size, trim_state); } int btrfs_remove_free_space(struct btrfs_block_group *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->fs_info, ctl, offset + bytes, old_end - (offset + bytes), info->trim_state); WARN_ON(ret); goto out; } } ret = remove_from_bitmap(ctl, info, &offset, &bytes); if (ret == -EAGAIN) { re_search = true; goto again; } out_lock: btrfs_discard_update_discardable(block_group, ctl); spin_unlock(&ctl->tree_lock); out: return ret; } void btrfs_dump_free_space(struct btrfs_block_group *block_group, u64 bytes) { struct btrfs_fs_info *fs_info = block_group->fs_info; struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; struct btrfs_free_space *info; struct rb_node *n; int count = 0; spin_lock(&ctl->tree_lock); 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(fs_info, "entry offset %llu, bytes %llu, bitmap %s", info->offset, info->bytes, (info->bitmap) ? "yes" : "no"); } spin_unlock(&ctl->tree_lock); btrfs_info(fs_info, "block group has cluster?: %s", list_empty(&block_group->cluster_list) ? "no" : "yes"); btrfs_info(fs_info, "%d blocks of free space at or bigger than bytes is", count); } void btrfs_init_free_space_ctl(struct btrfs_block_group *block_group) { struct btrfs_fs_info *fs_info = block_group->fs_info; struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; spin_lock_init(&ctl->tree_lock); ctl->unit = fs_info->sectorsize; ctl->start = block_group->start; 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 = (SZ_32K / 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 *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) { /* Merging treats extents as if they were new */ if (!btrfs_free_space_trimmed(entry)) { ctl->discardable_extents[BTRFS_STAT_CURR]--; ctl->discardable_bytes[BTRFS_STAT_CURR] -= entry->bytes; } try_merge_free_space(ctl, entry, false); steal_from_bitmap(ctl, entry, false); /* As we insert directly, update these statistics */ if (!btrfs_free_space_trimmed(entry)) { ctl->discardable_extents[BTRFS_STAT_CURR]++; ctl->discardable_bytes[BTRFS_STAT_CURR] += entry->bytes; } } 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); if (ctl->private) btrfs_discard_update_discardable(ctl->private, ctl); spin_unlock(&ctl->tree_lock); } void btrfs_remove_free_space_cache(struct btrfs_block_group *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); btrfs_discard_update_discardable(block_group, ctl); spin_unlock(&ctl->tree_lock); } /** * btrfs_is_free_space_trimmed - see if everything is trimmed * @block_group: block_group of interest * * Walk @block_group's free space rb_tree to determine if everything is trimmed. */ bool btrfs_is_free_space_trimmed(struct btrfs_block_group *block_group) { struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; struct btrfs_free_space *info; struct rb_node *node; bool ret = true; spin_lock(&ctl->tree_lock); node = rb_first(&ctl->free_space_offset); while (node) { info = rb_entry(node, struct btrfs_free_space, offset_index); if (!btrfs_free_space_trimmed(info)) { ret = false; break; } node = rb_next(node); } spin_unlock(&ctl->tree_lock); return ret; } u64 btrfs_find_space_for_alloc(struct btrfs_block_group *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_discard_ctl *discard_ctl = &block_group->fs_info->discard_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; enum btrfs_trim_state align_gap_trim_state = BTRFS_TRIM_STATE_UNTRIMMED; 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 (!btrfs_free_space_trimmed(entry)) atomic64_add(bytes, &discard_ctl->discard_bytes_saved); if (!entry->bytes) free_bitmap(ctl, entry); } else { unlink_free_space(ctl, entry); align_gap_len = offset - entry->offset; align_gap = entry->offset; align_gap_trim_state = entry->trim_state; if (!btrfs_free_space_trimmed(entry)) atomic64_add(bytes, &discard_ctl->discard_bytes_saved); 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: btrfs_discard_update_discardable(block_group, ctl); spin_unlock(&ctl->tree_lock); if (align_gap_len) __btrfs_add_free_space(block_group->fs_info, ctl, align_gap, align_gap_len, align_gap_trim_state); 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 *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); btrfs_discard_queue_work(&block_group->fs_info->discard_ctl, block_group); /* finally drop our ref */ btrfs_put_block_group(block_group); return ret; } static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group *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) { *max_extent_size = max(get_max_extent_size(entry), *max_extent_size); 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 *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_discard_ctl *discard_ctl = &block_group->fs_info->discard_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) *max_extent_size = max(get_max_extent_size(entry), *max_extent_size); 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); if (!btrfs_free_space_trimmed(entry)) atomic64_add(bytes, &discard_ctl->discard_bytes_saved); ctl->free_space -= bytes; if (!entry->bitmap && !btrfs_free_space_trimmed(entry)) ctl->discardable_bytes[BTRFS_STAT_CURR] -= bytes; if (entry->bytes == 0) { ctl->free_extents--; if (entry->bitmap) { kmem_cache_free(btrfs_free_space_bitmap_cachep, entry->bitmap); ctl->total_bitmaps--; ctl->op->recalc_thresholds(ctl); } else if (!btrfs_free_space_trimmed(entry)) { ctl->discardable_extents[BTRFS_STAT_CURR]--; } kmem_cache_free(btrfs_free_space_cachep, entry); } spin_unlock(&ctl->tree_lock); return ret; } static int btrfs_bitmap_cluster(struct btrfs_block_group *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 *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 *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_block_group *block_group, struct btrfs_free_cluster *cluster, u64 offset, u64 bytes, u64 empty_size) { struct btrfs_fs_info *fs_info = block_group->fs_info; 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(fs_info, SSD_SPREAD)) { cont1_bytes = min_bytes = bytes + empty_size; } else if (block_group->flags & BTRFS_BLOCK_GROUP_METADATA) { cont1_bytes = bytes; min_bytes = fs_info->sectorsize; } else { cont1_bytes = max(bytes, (bytes + empty_size) >> 2); min_bytes = fs_info->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->lock); spin_lock_init(&cluster->refill_lock); cluster->root = RB_ROOT; cluster->max_size = 0; cluster->fragmented = false; INIT_LIST_HEAD(&cluster->block_group_list); cluster->block_group = NULL; } static int do_trimming(struct btrfs_block_group *block_group, u64 *total_trimmed, u64 start, u64 bytes, u64 reserved_start, u64 reserved_bytes, enum btrfs_trim_state reserved_trim_state, struct btrfs_trim_range *trim_entry) { struct btrfs_space_info *space_info = block_group->space_info; struct btrfs_fs_info *fs_info = block_group->fs_info; struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; int ret; int update = 0; const u64 end = start + bytes; const u64 reserved_end = reserved_start + reserved_bytes; enum btrfs_trim_state trim_state = BTRFS_TRIM_STATE_UNTRIMMED; 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_discard_extent(fs_info, start, bytes, &trimmed); if (!ret) { *total_trimmed += trimmed; trim_state = BTRFS_TRIM_STATE_TRIMMED; } mutex_lock(&ctl->cache_writeout_mutex); if (reserved_start < start) __btrfs_add_free_space(fs_info, ctl, reserved_start, start - reserved_start, reserved_trim_state); if (start + bytes < reserved_start + reserved_bytes) __btrfs_add_free_space(fs_info, ctl, end, reserved_end - end, reserved_trim_state); __btrfs_add_free_space(fs_info, ctl, start, bytes, trim_state); list_del(&trim_entry->list); mutex_unlock(&ctl->cache_writeout_mutex); 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(&block_group->lock); spin_unlock(&space_info->lock); } return ret; } /* * If @async is set, then we will trim 1 region and return. */ static int trim_no_bitmap(struct btrfs_block_group *block_group, u64 *total_trimmed, u64 start, u64 end, u64 minlen, bool async) { struct btrfs_discard_ctl *discard_ctl = &block_group->fs_info->discard_ctl; 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; enum btrfs_trim_state extent_trim_state; u64 bytes; const u64 max_discard_size = READ_ONCE(discard_ctl->max_discard_size); while (start < end) { struct btrfs_trim_range trim_entry; mutex_lock(&ctl->cache_writeout_mutex); spin_lock(&ctl->tree_lock); if (ctl->free_space < minlen) goto out_unlock; entry = tree_search_offset(ctl, start, 0, 1); if (!entry) goto out_unlock; /* Skip bitmaps and if async, already trimmed entries */ while (entry->bitmap || (async && btrfs_free_space_trimmed(entry))) { node = rb_next(&entry->offset_index); if (!node) goto out_unlock; entry = rb_entry(node, struct btrfs_free_space, offset_index); } if (entry->offset >= end) goto out_unlock; extent_start = entry->offset; extent_bytes = entry->bytes; extent_trim_state = entry->trim_state; if (async) { start = entry->offset; bytes = entry->bytes; if (bytes < minlen) { spin_unlock(&ctl->tree_lock); mutex_unlock(&ctl->cache_writeout_mutex); goto next; } unlink_free_space(ctl, entry); /* * Let bytes = BTRFS_MAX_DISCARD_SIZE + X. * If X < BTRFS_ASYNC_DISCARD_MIN_FILTER, we won't trim * X when we come back around. So trim it now. */ if (max_discard_size && bytes >= (max_discard_size + BTRFS_ASYNC_DISCARD_MIN_FILTER)) { bytes = max_discard_size; extent_bytes = max_discard_size; entry->offset += max_discard_size; entry->bytes -= max_discard_size; link_free_space(ctl, entry); } else { kmem_cache_free(btrfs_free_space_cachep, entry); } } else { start = max(start, extent_start); bytes = min(extent_start + extent_bytes, end) - start; if (bytes < minlen) { spin_unlock(&ctl->tree_lock); mutex_unlock(&ctl->cache_writeout_mutex); goto next; } unlink_free_space(ctl, entry); kmem_cache_free(btrfs_free_space_cachep, entry); } spin_unlock(&ctl->tree_lock); trim_entry.start = extent_start; trim_entry.bytes = extent_bytes; list_add_tail(&trim_entry.list, &ctl->trimming_ranges); mutex_unlock(&ctl->cache_writeout_mutex); ret = do_trimming(block_group, total_trimmed, start, bytes, extent_start, extent_bytes, extent_trim_state, &trim_entry); if (ret) { block_group->discard_cursor = start + bytes; break; } next: start += bytes; block_group->discard_cursor = start; if (async && *total_trimmed) break; if (fatal_signal_pending(current)) { ret = -ERESTARTSYS; break; } cond_resched(); } return ret; out_unlock: block_group->discard_cursor = btrfs_block_group_end(block_group); spin_unlock(&ctl->tree_lock); mutex_unlock(&ctl->cache_writeout_mutex); return ret; } /* * If we break out of trimming a bitmap prematurely, we should reset the * trimming bit. In a rather contrieved case, it's possible to race here so * reset the state to BTRFS_TRIM_STATE_UNTRIMMED. * * start = start of bitmap * end = near end of bitmap * * Thread 1: Thread 2: * trim_bitmaps(start) * trim_bitmaps(end) * end_trimming_bitmap() * reset_trimming_bitmap() */ static void reset_trimming_bitmap(struct btrfs_free_space_ctl *ctl, u64 offset) { struct btrfs_free_space *entry; spin_lock(&ctl->tree_lock); entry = tree_search_offset(ctl, offset, 1, 0); if (entry) { if (btrfs_free_space_trimmed(entry)) { ctl->discardable_extents[BTRFS_STAT_CURR] += entry->bitmap_extents; ctl->discardable_bytes[BTRFS_STAT_CURR] += entry->bytes; } entry->trim_state = BTRFS_TRIM_STATE_UNTRIMMED; } spin_unlock(&ctl->tree_lock); } static void end_trimming_bitmap(struct btrfs_free_space_ctl *ctl, struct btrfs_free_space *entry) { if (btrfs_free_space_trimming_bitmap(entry)) { entry->trim_state = BTRFS_TRIM_STATE_TRIMMED; ctl->discardable_extents[BTRFS_STAT_CURR] -= entry->bitmap_extents; ctl->discardable_bytes[BTRFS_STAT_CURR] -= entry->bytes; } } /* * If @async is set, then we will trim 1 region and return. */ static int trim_bitmaps(struct btrfs_block_group *block_group, u64 *total_trimmed, u64 start, u64 end, u64 minlen, u64 maxlen, bool async) { struct btrfs_discard_ctl *discard_ctl = &block_group->fs_info->discard_ctl; 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); const u64 max_discard_size = READ_ONCE(discard_ctl->max_discard_size); while (offset < end) { bool next_bitmap = false; struct btrfs_trim_range trim_entry; mutex_lock(&ctl->cache_writeout_mutex); spin_lock(&ctl->tree_lock); if (ctl->free_space < minlen) { block_group->discard_cursor = btrfs_block_group_end(block_group); spin_unlock(&ctl->tree_lock); mutex_unlock(&ctl->cache_writeout_mutex); break; } entry = tree_search_offset(ctl, offset, 1, 0); /* * Bitmaps are marked trimmed lossily now to prevent constant * discarding of the same bitmap (the reason why we are bound * by the filters). So, retrim the block group bitmaps when we * are preparing to punt to the unused_bgs list. This uses * @minlen to determine if we are in BTRFS_DISCARD_INDEX_UNUSED * which is the only discard index which sets minlen to 0. */ if (!entry || (async && minlen && start == offset && btrfs_free_space_trimmed(entry))) { spin_unlock(&ctl->tree_lock); mutex_unlock(&ctl->cache_writeout_mutex); next_bitmap = true; goto next; } /* * Async discard bitmap trimming begins at by setting the start * to be key.objectid and the offset_to_bitmap() aligns to the * start of the bitmap. This lets us know we are fully * scanning the bitmap rather than only some portion of it. */ if (start == offset) entry->trim_state = BTRFS_TRIM_STATE_TRIMMING; bytes = minlen; ret2 = search_bitmap(ctl, entry, &start, &bytes, false); if (ret2 || start >= end) { /* * We lossily consider a bitmap trimmed if we only skip * over regions <= BTRFS_ASYNC_DISCARD_MIN_FILTER. */ if (ret2 && minlen <= BTRFS_ASYNC_DISCARD_MIN_FILTER) end_trimming_bitmap(ctl, entry); else entry->trim_state = BTRFS_TRIM_STATE_UNTRIMMED; spin_unlock(&ctl->tree_lock); mutex_unlock(&ctl->cache_writeout_mutex); next_bitmap = true; goto next; } /* * We already trimmed a region, but are using the locking above * to reset the trim_state. */ if (async && *total_trimmed) { spin_unlock(&ctl->tree_lock); mutex_unlock(&ctl->cache_writeout_mutex); goto out; } bytes = min(bytes, end - start); if (bytes < minlen || (async && maxlen && bytes > maxlen)) { spin_unlock(&ctl->tree_lock); mutex_unlock(&ctl->cache_writeout_mutex); goto next; } /* * Let bytes = BTRFS_MAX_DISCARD_SIZE + X. * If X < @minlen, we won't trim X when we come back around. * So trim it now. We differ here from trimming extents as we * don't keep individual state per bit. */ if (async && max_discard_size && bytes > (max_discard_size + minlen)) bytes = max_discard_size; bitmap_clear_bits(ctl, entry, start, bytes); if (entry->bytes == 0) free_bitmap(ctl, entry); spin_unlock(&ctl->tree_lock); trim_entry.start = start; trim_entry.bytes = bytes; list_add_tail(&trim_entry.list, &ctl->trimming_ranges); mutex_unlock(&ctl->cache_writeout_mutex); ret = do_trimming(block_group, total_trimmed, start, bytes, start, bytes, 0, &trim_entry); if (ret) { reset_trimming_bitmap(ctl, offset); block_group->discard_cursor = btrfs_block_group_end(block_group); break; } next: if (next_bitmap) { offset += BITS_PER_BITMAP * ctl->unit; start = offset; } else { start += bytes; } block_group->discard_cursor = start; if (fatal_signal_pending(current)) { if (start != offset) reset_trimming_bitmap(ctl, offset); ret = -ERESTARTSYS; break; } cond_resched(); } if (offset >= end) block_group->discard_cursor = end; out: return ret; } void btrfs_get_block_group_trimming(struct btrfs_block_group *cache) { atomic_inc(&cache->trimming); } void btrfs_put_block_group_trimming(struct btrfs_block_group *block_group) { struct btrfs_fs_info *fs_info = block_group->fs_info; struct extent_map_tree *em_tree; struct extent_map *em; bool cleanup; spin_lock(&block_group->lock); cleanup = (atomic_dec_and_test(&block_group->trimming) && block_group->removed); spin_unlock(&block_group->lock); if (cleanup) { mutex_lock(&fs_info->chunk_mutex); em_tree = &fs_info->mapping_tree; write_lock(&em_tree->lock); em = lookup_extent_mapping(em_tree, block_group->start, 1); BUG_ON(!em); /* logic error, can't happen */ remove_extent_mapping(em_tree, em); write_unlock(&em_tree->lock); mutex_unlock(&fs_info->chunk_mutex); /* once for us and once for the tree */ free_extent_map(em); free_extent_map(em); /* * We've left one free space entry and other tasks trimming * this block group have left 1 entry each one. Free them. */ __btrfs_remove_free_space_cache(block_group->free_space_ctl); } } int btrfs_trim_block_group(struct btrfs_block_group *block_group, u64 *trimmed, u64 start, u64 end, u64 minlen) { struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; int ret; u64 rem = 0; *trimmed = 0; spin_lock(&block_group->lock); if (block_group->removed) { spin_unlock(&block_group->lock); return 0; } btrfs_get_block_group_trimming(block_group); spin_unlock(&block_group->lock); ret = trim_no_bitmap(block_group, trimmed, start, end, minlen, false); if (ret) goto out; ret = trim_bitmaps(block_group, trimmed, start, end, minlen, 0, false); div64_u64_rem(end, BITS_PER_BITMAP * ctl->unit, &rem); /* If we ended in the middle of a bitmap, reset the trimming flag */ if (rem) reset_trimming_bitmap(ctl, offset_to_bitmap(ctl, end)); out: btrfs_put_block_group_trimming(block_group); return ret; } int btrfs_trim_block_group_extents(struct btrfs_block_group *block_group, u64 *trimmed, u64 start, u64 end, u64 minlen, bool async) { int ret; *trimmed = 0; spin_lock(&block_group->lock); if (block_group->removed) { spin_unlock(&block_group->lock); return 0; } btrfs_get_block_group_trimming(block_group); spin_unlock(&block_group->lock); ret = trim_no_bitmap(block_group, trimmed, start, end, minlen, async); btrfs_put_block_group_trimming(block_group); return ret; } int btrfs_trim_block_group_bitmaps(struct btrfs_block_group *block_group, u64 *trimmed, u64 start, u64 end, u64 minlen, u64 maxlen, bool async) { int ret; *trimmed = 0; spin_lock(&block_group->lock); if (block_group->removed) { spin_unlock(&block_group->lock); return 0; } btrfs_get_block_group_trimming(block_group); spin_unlock(&block_group->lock); ret = trim_bitmaps(block_group, trimmed, start, end, minlen, maxlen, async); btrfs_put_block_group_trimming(block_group); 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, true); /* Logic error; Should be empty if it can't find anything */ ASSERT(!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->ino_cache_lock); if (root->ino_cache_inode) inode = igrab(root->ino_cache_inode); spin_unlock(&root->ino_cache_lock); if (inode) return inode; inode = __lookup_free_space_inode(root, path, 0); if (IS_ERR(inode)) return inode; spin_lock(&root->ino_cache_lock); if (!btrfs_fs_closing(root->fs_info)) root->ino_cache_inode = igrab(inode); spin_unlock(&root->ino_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(fs_info, 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) btrfs_err(fs_info, "failed to load free ino cache for root %llu", 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 inode *inode) { struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_free_space_ctl *ctl = root->free_ino_ctl; int ret; struct btrfs_io_ctl io_ctl; bool release_metadata = true; if (!btrfs_test_opt(fs_info, INODE_MAP_CACHE)) return 0; memset(&io_ctl, 0, sizeof(io_ctl)); ret = __btrfs_write_out_cache(root, inode, ctl, NULL, &io_ctl, trans); if (!ret) { /* * At this point writepages() didn't error out, so our metadata * reservation is released when the writeback finishes, at * inode.c:btrfs_finish_ordered_io(), regardless of it finishing * with or without an error. */ release_metadata = false; ret = btrfs_wait_cache_io_root(root, trans, &io_ctl, path); } if (ret) { if (release_metadata) btrfs_delalloc_release_metadata(BTRFS_I(inode), inode->i_size, true); #ifdef DEBUG btrfs_err(fs_info, "failed to write free ino cache for root %llu", root->root_key.objectid); #endif } return ret; } #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS /* * Use this if you need to make a bitmap or extent entry specifically, it * doesn't do any of the merging that add_free_space does, this acts a lot like * how the free space cache loading stuff works, so you can get really weird * configurations. */ int test_add_free_space_entry(struct btrfs_block_group *cache, u64 offset, u64 bytes, bool bitmap) { struct btrfs_free_space_ctl *ctl = cache->free_space_ctl; struct btrfs_free_space *info = NULL, *bitmap_info; void *map = NULL; enum btrfs_trim_state trim_state = BTRFS_TRIM_STATE_TRIMMED; u64 bytes_added; int ret; again: if (!info) { info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS); if (!info) return -ENOMEM; } if (!bitmap) { spin_lock(&ctl->tree_lock); info->offset = offset; info->bytes = bytes; info->max_extent_size = 0; ret = link_free_space(ctl, info); spin_unlock(&ctl->tree_lock); if (ret) kmem_cache_free(btrfs_free_space_cachep, info); return ret; } if (!map) { map = kmem_cache_zalloc(btrfs_free_space_bitmap_cachep, GFP_NOFS); if (!map) { kmem_cache_free(btrfs_free_space_cachep, info); return -ENOMEM; } } spin_lock(&ctl->tree_lock); bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset), 1, 0); if (!bitmap_info) { info->bitmap = map; map = NULL; add_new_bitmap(ctl, info, offset); bitmap_info = info; info = NULL; } bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes, trim_state); bytes -= bytes_added; offset += bytes_added; spin_unlock(&ctl->tree_lock); if (bytes) goto again; if (info) kmem_cache_free(btrfs_free_space_cachep, info); if (map) kmem_cache_free(btrfs_free_space_bitmap_cachep, map); return 0; } /* * Checks to see if the given range is in the free space cache. This is really * just used to check the absence of space, so if there is free space in the * range at all we will return 1. */ int test_check_exists(struct btrfs_block_group *cache, u64 offset, u64 bytes) { struct btrfs_free_space_ctl *ctl = cache->free_space_ctl; struct btrfs_free_space *info; int ret = 0; spin_lock(&ctl->tree_lock); info = tree_search_offset(ctl, offset, 0, 0); if (!info) { info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset), 1, 0); if (!info) goto out; } have_info: if (info->bitmap) { u64 bit_off, bit_bytes; struct rb_node *n; struct btrfs_free_space *tmp; bit_off = offset; bit_bytes = ctl->unit; ret = search_bitmap(ctl, info, &bit_off, &bit_bytes, false); if (!ret) { if (bit_off == offset) { ret = 1; goto out; } else if (bit_off > offset && offset + bytes > bit_off) { ret = 1; goto out; } } n = rb_prev(&info->offset_index); while (n) { tmp = rb_entry(n, struct btrfs_free_space, offset_index); if (tmp->offset + tmp->bytes < offset) break; if (offset + bytes < tmp->offset) { n = rb_prev(&tmp->offset_index); continue; } info = tmp; goto have_info; } n = rb_next(&info->offset_index); while (n) { tmp = rb_entry(n, struct btrfs_free_space, offset_index); if (offset + bytes < tmp->offset) break; if (tmp->offset + tmp->bytes < offset) { n = rb_next(&tmp->offset_index); continue; } info = tmp; goto have_info; } ret = 0; goto out; } if (info->offset == offset) { ret = 1; goto out; } if (offset > info->offset && offset < info->offset + info->bytes) ret = 1; out: spin_unlock(&ctl->tree_lock); return ret; } #endif /* CONFIG_BTRFS_FS_RUN_SANITY_TESTS */
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