/* * fs/f2fs/node.c * * Copyright (c) 2012 Samsung Electronics Co., Ltd. * http://www.samsung.com/ * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/fs.h> #include <linux/f2fs_fs.h> #include <linux/mpage.h> #include <linux/backing-dev.h> #include <linux/blkdev.h> #include <linux/pagevec.h> #include <linux/swap.h> #include "f2fs.h" #include "node.h" #include "segment.h" static struct kmem_cache *nat_entry_slab; static struct kmem_cache *free_nid_slab; static void clear_node_page_dirty(struct page *page) { struct address_space *mapping = page->mapping; struct f2fs_sb_info *sbi = F2FS_SB(mapping->host->i_sb); unsigned int long flags; if (PageDirty(page)) { spin_lock_irqsave(&mapping->tree_lock, flags); radix_tree_tag_clear(&mapping->page_tree, page_index(page), PAGECACHE_TAG_DIRTY); spin_unlock_irqrestore(&mapping->tree_lock, flags); clear_page_dirty_for_io(page); dec_page_count(sbi, F2FS_DIRTY_NODES); } ClearPageUptodate(page); } static struct page *get_current_nat_page(struct f2fs_sb_info *sbi, nid_t nid) { pgoff_t index = current_nat_addr(sbi, nid); return get_meta_page(sbi, index); } static struct page *get_next_nat_page(struct f2fs_sb_info *sbi, nid_t nid) { struct page *src_page; struct page *dst_page; pgoff_t src_off; pgoff_t dst_off; void *src_addr; void *dst_addr; struct f2fs_nm_info *nm_i = NM_I(sbi); src_off = current_nat_addr(sbi, nid); dst_off = next_nat_addr(sbi, src_off); /* get current nat block page with lock */ src_page = get_meta_page(sbi, src_off); /* Dirty src_page means that it is already the new target NAT page. */ if (PageDirty(src_page)) return src_page; dst_page = grab_meta_page(sbi, dst_off); src_addr = page_address(src_page); dst_addr = page_address(dst_page); memcpy(dst_addr, src_addr, PAGE_CACHE_SIZE); set_page_dirty(dst_page); f2fs_put_page(src_page, 1); set_to_next_nat(nm_i, nid); return dst_page; } /* * Readahead NAT pages */ static void ra_nat_pages(struct f2fs_sb_info *sbi, int nid) { struct address_space *mapping = sbi->meta_inode->i_mapping; struct f2fs_nm_info *nm_i = NM_I(sbi); struct page *page; pgoff_t index; int i; for (i = 0; i < FREE_NID_PAGES; i++, nid += NAT_ENTRY_PER_BLOCK) { if (nid >= nm_i->max_nid) nid = 0; index = current_nat_addr(sbi, nid); page = grab_cache_page(mapping, index); if (!page) continue; if (f2fs_readpage(sbi, page, index, READ)) { f2fs_put_page(page, 1); continue; } page_cache_release(page); } } static struct nat_entry *__lookup_nat_cache(struct f2fs_nm_info *nm_i, nid_t n) { return radix_tree_lookup(&nm_i->nat_root, n); } static unsigned int __gang_lookup_nat_cache(struct f2fs_nm_info *nm_i, nid_t start, unsigned int nr, struct nat_entry **ep) { return radix_tree_gang_lookup(&nm_i->nat_root, (void **)ep, start, nr); } static void __del_from_nat_cache(struct f2fs_nm_info *nm_i, struct nat_entry *e) { list_del(&e->list); radix_tree_delete(&nm_i->nat_root, nat_get_nid(e)); nm_i->nat_cnt--; kmem_cache_free(nat_entry_slab, e); } int is_checkpointed_node(struct f2fs_sb_info *sbi, nid_t nid) { struct f2fs_nm_info *nm_i = NM_I(sbi); struct nat_entry *e; int is_cp = 1; read_lock(&nm_i->nat_tree_lock); e = __lookup_nat_cache(nm_i, nid); if (e && !e->checkpointed) is_cp = 0; read_unlock(&nm_i->nat_tree_lock); return is_cp; } static struct nat_entry *grab_nat_entry(struct f2fs_nm_info *nm_i, nid_t nid) { struct nat_entry *new; new = kmem_cache_alloc(nat_entry_slab, GFP_ATOMIC); if (!new) return NULL; if (radix_tree_insert(&nm_i->nat_root, nid, new)) { kmem_cache_free(nat_entry_slab, new); return NULL; } memset(new, 0, sizeof(struct nat_entry)); nat_set_nid(new, nid); list_add_tail(&new->list, &nm_i->nat_entries); nm_i->nat_cnt++; return new; } static void cache_nat_entry(struct f2fs_nm_info *nm_i, nid_t nid, struct f2fs_nat_entry *ne) { struct nat_entry *e; retry: write_lock(&nm_i->nat_tree_lock); e = __lookup_nat_cache(nm_i, nid); if (!e) { e = grab_nat_entry(nm_i, nid); if (!e) { write_unlock(&nm_i->nat_tree_lock); goto retry; } nat_set_blkaddr(e, le32_to_cpu(ne->block_addr)); nat_set_ino(e, le32_to_cpu(ne->ino)); nat_set_version(e, ne->version); e->checkpointed = true; } write_unlock(&nm_i->nat_tree_lock); } static void set_node_addr(struct f2fs_sb_info *sbi, struct node_info *ni, block_t new_blkaddr) { struct f2fs_nm_info *nm_i = NM_I(sbi); struct nat_entry *e; retry: write_lock(&nm_i->nat_tree_lock); e = __lookup_nat_cache(nm_i, ni->nid); if (!e) { e = grab_nat_entry(nm_i, ni->nid); if (!e) { write_unlock(&nm_i->nat_tree_lock); goto retry; } e->ni = *ni; e->checkpointed = true; BUG_ON(ni->blk_addr == NEW_ADDR); } else if (new_blkaddr == NEW_ADDR) { /* * when nid is reallocated, * previous nat entry can be remained in nat cache. * So, reinitialize it with new information. */ e->ni = *ni; BUG_ON(ni->blk_addr != NULL_ADDR); } if (new_blkaddr == NEW_ADDR) e->checkpointed = false; /* sanity check */ BUG_ON(nat_get_blkaddr(e) != ni->blk_addr); BUG_ON(nat_get_blkaddr(e) == NULL_ADDR && new_blkaddr == NULL_ADDR); BUG_ON(nat_get_blkaddr(e) == NEW_ADDR && new_blkaddr == NEW_ADDR); BUG_ON(nat_get_blkaddr(e) != NEW_ADDR && nat_get_blkaddr(e) != NULL_ADDR && new_blkaddr == NEW_ADDR); /* increament version no as node is removed */ if (nat_get_blkaddr(e) != NEW_ADDR && new_blkaddr == NULL_ADDR) { unsigned char version = nat_get_version(e); nat_set_version(e, inc_node_version(version)); } /* change address */ nat_set_blkaddr(e, new_blkaddr); __set_nat_cache_dirty(nm_i, e); write_unlock(&nm_i->nat_tree_lock); } static int try_to_free_nats(struct f2fs_sb_info *sbi, int nr_shrink) { struct f2fs_nm_info *nm_i = NM_I(sbi); if (nm_i->nat_cnt < 2 * NM_WOUT_THRESHOLD) return 0; write_lock(&nm_i->nat_tree_lock); while (nr_shrink && !list_empty(&nm_i->nat_entries)) { struct nat_entry *ne; ne = list_first_entry(&nm_i->nat_entries, struct nat_entry, list); __del_from_nat_cache(nm_i, ne); nr_shrink--; } write_unlock(&nm_i->nat_tree_lock); return nr_shrink; } /* * This function returns always success */ void get_node_info(struct f2fs_sb_info *sbi, nid_t nid, struct node_info *ni) { struct f2fs_nm_info *nm_i = NM_I(sbi); struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA); struct f2fs_summary_block *sum = curseg->sum_blk; nid_t start_nid = START_NID(nid); struct f2fs_nat_block *nat_blk; struct page *page = NULL; struct f2fs_nat_entry ne; struct nat_entry *e; int i; memset(&ne, 0, sizeof(struct f2fs_nat_entry)); ni->nid = nid; /* Check nat cache */ read_lock(&nm_i->nat_tree_lock); e = __lookup_nat_cache(nm_i, nid); if (e) { ni->ino = nat_get_ino(e); ni->blk_addr = nat_get_blkaddr(e); ni->version = nat_get_version(e); } read_unlock(&nm_i->nat_tree_lock); if (e) return; /* Check current segment summary */ mutex_lock(&curseg->curseg_mutex); i = lookup_journal_in_cursum(sum, NAT_JOURNAL, nid, 0); if (i >= 0) { ne = nat_in_journal(sum, i); node_info_from_raw_nat(ni, &ne); } mutex_unlock(&curseg->curseg_mutex); if (i >= 0) goto cache; /* Fill node_info from nat page */ page = get_current_nat_page(sbi, start_nid); nat_blk = (struct f2fs_nat_block *)page_address(page); ne = nat_blk->entries[nid - start_nid]; node_info_from_raw_nat(ni, &ne); f2fs_put_page(page, 1); cache: /* cache nat entry */ cache_nat_entry(NM_I(sbi), nid, &ne); } /* * The maximum depth is four. * Offset[0] will have raw inode offset. */ static int get_node_path(long block, int offset[4], unsigned int noffset[4]) { const long direct_index = ADDRS_PER_INODE; const long direct_blks = ADDRS_PER_BLOCK; const long dptrs_per_blk = NIDS_PER_BLOCK; const long indirect_blks = ADDRS_PER_BLOCK * NIDS_PER_BLOCK; const long dindirect_blks = indirect_blks * NIDS_PER_BLOCK; int n = 0; int level = 0; noffset[0] = 0; if (block < direct_index) { offset[n++] = block; level = 0; goto got; } block -= direct_index; if (block < direct_blks) { offset[n++] = NODE_DIR1_BLOCK; noffset[n] = 1; offset[n++] = block; level = 1; goto got; } block -= direct_blks; if (block < direct_blks) { offset[n++] = NODE_DIR2_BLOCK; noffset[n] = 2; offset[n++] = block; level = 1; goto got; } block -= direct_blks; if (block < indirect_blks) { offset[n++] = NODE_IND1_BLOCK; noffset[n] = 3; offset[n++] = block / direct_blks; noffset[n] = 4 + offset[n - 1]; offset[n++] = block % direct_blks; level = 2; goto got; } block -= indirect_blks; if (block < indirect_blks) { offset[n++] = NODE_IND2_BLOCK; noffset[n] = 4 + dptrs_per_blk; offset[n++] = block / direct_blks; noffset[n] = 5 + dptrs_per_blk + offset[n - 1]; offset[n++] = block % direct_blks; level = 2; goto got; } block -= indirect_blks; if (block < dindirect_blks) { offset[n++] = NODE_DIND_BLOCK; noffset[n] = 5 + (dptrs_per_blk * 2); offset[n++] = block / indirect_blks; noffset[n] = 6 + (dptrs_per_blk * 2) + offset[n - 1] * (dptrs_per_blk + 1); offset[n++] = (block / direct_blks) % dptrs_per_blk; noffset[n] = 7 + (dptrs_per_blk * 2) + offset[n - 2] * (dptrs_per_blk + 1) + offset[n - 1]; offset[n++] = block % direct_blks; level = 3; goto got; } else { BUG(); } got: return level; } /* * Caller should call f2fs_put_dnode(dn). */ int get_dnode_of_data(struct dnode_of_data *dn, pgoff_t index, int ro) { struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb); struct page *npage[4]; struct page *parent; int offset[4]; unsigned int noffset[4]; nid_t nids[4]; int level, i; int err = 0; level = get_node_path(index, offset, noffset); nids[0] = dn->inode->i_ino; npage[0] = get_node_page(sbi, nids[0]); if (IS_ERR(npage[0])) return PTR_ERR(npage[0]); parent = npage[0]; nids[1] = get_nid(parent, offset[0], true); dn->inode_page = npage[0]; dn->inode_page_locked = true; /* get indirect or direct nodes */ for (i = 1; i <= level; i++) { bool done = false; if (!nids[i] && !ro) { mutex_lock_op(sbi, NODE_NEW); /* alloc new node */ if (!alloc_nid(sbi, &(nids[i]))) { mutex_unlock_op(sbi, NODE_NEW); err = -ENOSPC; goto release_pages; } dn->nid = nids[i]; npage[i] = new_node_page(dn, noffset[i]); if (IS_ERR(npage[i])) { alloc_nid_failed(sbi, nids[i]); mutex_unlock_op(sbi, NODE_NEW); err = PTR_ERR(npage[i]); goto release_pages; } set_nid(parent, offset[i - 1], nids[i], i == 1); alloc_nid_done(sbi, nids[i]); mutex_unlock_op(sbi, NODE_NEW); done = true; } else if (ro && i == level && level > 1) { npage[i] = get_node_page_ra(parent, offset[i - 1]); if (IS_ERR(npage[i])) { err = PTR_ERR(npage[i]); goto release_pages; } done = true; } if (i == 1) { dn->inode_page_locked = false; unlock_page(parent); } else { f2fs_put_page(parent, 1); } if (!done) { npage[i] = get_node_page(sbi, nids[i]); if (IS_ERR(npage[i])) { err = PTR_ERR(npage[i]); f2fs_put_page(npage[0], 0); goto release_out; } } if (i < level) { parent = npage[i]; nids[i + 1] = get_nid(parent, offset[i], false); } } dn->nid = nids[level]; dn->ofs_in_node = offset[level]; dn->node_page = npage[level]; dn->data_blkaddr = datablock_addr(dn->node_page, dn->ofs_in_node); return 0; release_pages: f2fs_put_page(parent, 1); if (i > 1) f2fs_put_page(npage[0], 0); release_out: dn->inode_page = NULL; dn->node_page = NULL; return err; } static void truncate_node(struct dnode_of_data *dn) { struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb); struct node_info ni; get_node_info(sbi, dn->nid, &ni); if (dn->inode->i_blocks == 0) { BUG_ON(ni.blk_addr != NULL_ADDR); goto invalidate; } BUG_ON(ni.blk_addr == NULL_ADDR); /* Deallocate node address */ invalidate_blocks(sbi, ni.blk_addr); dec_valid_node_count(sbi, dn->inode, 1); set_node_addr(sbi, &ni, NULL_ADDR); if (dn->nid == dn->inode->i_ino) { remove_orphan_inode(sbi, dn->nid); dec_valid_inode_count(sbi); } else { sync_inode_page(dn); } invalidate: clear_node_page_dirty(dn->node_page); F2FS_SET_SB_DIRT(sbi); f2fs_put_page(dn->node_page, 1); dn->node_page = NULL; } static int truncate_dnode(struct dnode_of_data *dn) { struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb); struct page *page; if (dn->nid == 0) return 1; /* get direct node */ page = get_node_page(sbi, dn->nid); if (IS_ERR(page) && PTR_ERR(page) == -ENOENT) return 1; else if (IS_ERR(page)) return PTR_ERR(page); /* Make dnode_of_data for parameter */ dn->node_page = page; dn->ofs_in_node = 0; truncate_data_blocks(dn); truncate_node(dn); return 1; } static int truncate_nodes(struct dnode_of_data *dn, unsigned int nofs, int ofs, int depth) { struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb); struct dnode_of_data rdn = *dn; struct page *page; struct f2fs_node *rn; nid_t child_nid; unsigned int child_nofs; int freed = 0; int i, ret; if (dn->nid == 0) return NIDS_PER_BLOCK + 1; page = get_node_page(sbi, dn->nid); if (IS_ERR(page)) return PTR_ERR(page); rn = (struct f2fs_node *)page_address(page); if (depth < 3) { for (i = ofs; i < NIDS_PER_BLOCK; i++, freed++) { child_nid = le32_to_cpu(rn->in.nid[i]); if (child_nid == 0) continue; rdn.nid = child_nid; ret = truncate_dnode(&rdn); if (ret < 0) goto out_err; set_nid(page, i, 0, false); } } else { child_nofs = nofs + ofs * (NIDS_PER_BLOCK + 1) + 1; for (i = ofs; i < NIDS_PER_BLOCK; i++) { child_nid = le32_to_cpu(rn->in.nid[i]); if (child_nid == 0) { child_nofs += NIDS_PER_BLOCK + 1; continue; } rdn.nid = child_nid; ret = truncate_nodes(&rdn, child_nofs, 0, depth - 1); if (ret == (NIDS_PER_BLOCK + 1)) { set_nid(page, i, 0, false); child_nofs += ret; } else if (ret < 0 && ret != -ENOENT) { goto out_err; } } freed = child_nofs; } if (!ofs) { /* remove current indirect node */ dn->node_page = page; truncate_node(dn); freed++; } else { f2fs_put_page(page, 1); } return freed; out_err: f2fs_put_page(page, 1); return ret; } static int truncate_partial_nodes(struct dnode_of_data *dn, struct f2fs_inode *ri, int *offset, int depth) { struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb); struct page *pages[2]; nid_t nid[3]; nid_t child_nid; int err = 0; int i; int idx = depth - 2; nid[0] = le32_to_cpu(ri->i_nid[offset[0] - NODE_DIR1_BLOCK]); if (!nid[0]) return 0; /* get indirect nodes in the path */ for (i = 0; i < depth - 1; i++) { /* refernece count'll be increased */ pages[i] = get_node_page(sbi, nid[i]); if (IS_ERR(pages[i])) { depth = i + 1; err = PTR_ERR(pages[i]); goto fail; } nid[i + 1] = get_nid(pages[i], offset[i + 1], false); } /* free direct nodes linked to a partial indirect node */ for (i = offset[depth - 1]; i < NIDS_PER_BLOCK; i++) { child_nid = get_nid(pages[idx], i, false); if (!child_nid) continue; dn->nid = child_nid; err = truncate_dnode(dn); if (err < 0) goto fail; set_nid(pages[idx], i, 0, false); } if (offset[depth - 1] == 0) { dn->node_page = pages[idx]; dn->nid = nid[idx]; truncate_node(dn); } else { f2fs_put_page(pages[idx], 1); } offset[idx]++; offset[depth - 1] = 0; fail: for (i = depth - 3; i >= 0; i--) f2fs_put_page(pages[i], 1); return err; } /* * All the block addresses of data and nodes should be nullified. */ int truncate_inode_blocks(struct inode *inode, pgoff_t from) { struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); int err = 0, cont = 1; int level, offset[4], noffset[4]; unsigned int nofs; struct f2fs_node *rn; struct dnode_of_data dn; struct page *page; level = get_node_path(from, offset, noffset); page = get_node_page(sbi, inode->i_ino); if (IS_ERR(page)) return PTR_ERR(page); set_new_dnode(&dn, inode, page, NULL, 0); unlock_page(page); rn = page_address(page); switch (level) { case 0: case 1: nofs = noffset[1]; break; case 2: nofs = noffset[1]; if (!offset[level - 1]) goto skip_partial; err = truncate_partial_nodes(&dn, &rn->i, offset, level); if (err < 0 && err != -ENOENT) goto fail; nofs += 1 + NIDS_PER_BLOCK; break; case 3: nofs = 5 + 2 * NIDS_PER_BLOCK; if (!offset[level - 1]) goto skip_partial; err = truncate_partial_nodes(&dn, &rn->i, offset, level); if (err < 0 && err != -ENOENT) goto fail; break; default: BUG(); } skip_partial: while (cont) { dn.nid = le32_to_cpu(rn->i.i_nid[offset[0] - NODE_DIR1_BLOCK]); switch (offset[0]) { case NODE_DIR1_BLOCK: case NODE_DIR2_BLOCK: err = truncate_dnode(&dn); break; case NODE_IND1_BLOCK: case NODE_IND2_BLOCK: err = truncate_nodes(&dn, nofs, offset[1], 2); break; case NODE_DIND_BLOCK: err = truncate_nodes(&dn, nofs, offset[1], 3); cont = 0; break; default: BUG(); } if (err < 0 && err != -ENOENT) goto fail; if (offset[1] == 0 && rn->i.i_nid[offset[0] - NODE_DIR1_BLOCK]) { lock_page(page); wait_on_page_writeback(page); rn->i.i_nid[offset[0] - NODE_DIR1_BLOCK] = 0; set_page_dirty(page); unlock_page(page); } offset[1] = 0; offset[0]++; nofs += err; } fail: f2fs_put_page(page, 0); return err > 0 ? 0 : err; } int remove_inode_page(struct inode *inode) { struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); struct page *page; nid_t ino = inode->i_ino; struct dnode_of_data dn; mutex_lock_op(sbi, NODE_TRUNC); page = get_node_page(sbi, ino); if (IS_ERR(page)) { mutex_unlock_op(sbi, NODE_TRUNC); return PTR_ERR(page); } if (F2FS_I(inode)->i_xattr_nid) { nid_t nid = F2FS_I(inode)->i_xattr_nid; struct page *npage = get_node_page(sbi, nid); if (IS_ERR(npage)) { mutex_unlock_op(sbi, NODE_TRUNC); return PTR_ERR(npage); } F2FS_I(inode)->i_xattr_nid = 0; set_new_dnode(&dn, inode, page, npage, nid); dn.inode_page_locked = 1; truncate_node(&dn); } /* 0 is possible, after f2fs_new_inode() is failed */ BUG_ON(inode->i_blocks != 0 && inode->i_blocks != 1); set_new_dnode(&dn, inode, page, page, ino); truncate_node(&dn); mutex_unlock_op(sbi, NODE_TRUNC); return 0; } int new_inode_page(struct inode *inode, struct dentry *dentry) { struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); struct page *page; struct dnode_of_data dn; /* allocate inode page for new inode */ set_new_dnode(&dn, inode, NULL, NULL, inode->i_ino); mutex_lock_op(sbi, NODE_NEW); page = new_node_page(&dn, 0); init_dent_inode(dentry, page); mutex_unlock_op(sbi, NODE_NEW); if (IS_ERR(page)) return PTR_ERR(page); f2fs_put_page(page, 1); return 0; } struct page *new_node_page(struct dnode_of_data *dn, unsigned int ofs) { struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb); struct address_space *mapping = sbi->node_inode->i_mapping; struct node_info old_ni, new_ni; struct page *page; int err; if (is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)) return ERR_PTR(-EPERM); page = grab_cache_page(mapping, dn->nid); if (!page) return ERR_PTR(-ENOMEM); get_node_info(sbi, dn->nid, &old_ni); SetPageUptodate(page); fill_node_footer(page, dn->nid, dn->inode->i_ino, ofs, true); /* Reinitialize old_ni with new node page */ BUG_ON(old_ni.blk_addr != NULL_ADDR); new_ni = old_ni; new_ni.ino = dn->inode->i_ino; if (!inc_valid_node_count(sbi, dn->inode, 1)) { err = -ENOSPC; goto fail; } set_node_addr(sbi, &new_ni, NEW_ADDR); set_cold_node(dn->inode, page); dn->node_page = page; sync_inode_page(dn); set_page_dirty(page); if (ofs == 0) inc_valid_inode_count(sbi); return page; fail: clear_node_page_dirty(page); f2fs_put_page(page, 1); return ERR_PTR(err); } static int read_node_page(struct page *page, int type) { struct f2fs_sb_info *sbi = F2FS_SB(page->mapping->host->i_sb); struct node_info ni; get_node_info(sbi, page->index, &ni); if (ni.blk_addr == NULL_ADDR) return -ENOENT; return f2fs_readpage(sbi, page, ni.blk_addr, type); } /* * Readahead a node page */ void ra_node_page(struct f2fs_sb_info *sbi, nid_t nid) { struct address_space *mapping = sbi->node_inode->i_mapping; struct page *apage; apage = find_get_page(mapping, nid); if (apage && PageUptodate(apage)) goto release_out; f2fs_put_page(apage, 0); apage = grab_cache_page(mapping, nid); if (!apage) return; if (read_node_page(apage, READA)) goto unlock_out; page_cache_release(apage); return; unlock_out: unlock_page(apage); release_out: page_cache_release(apage); } struct page *get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid) { int err; struct page *page; struct address_space *mapping = sbi->node_inode->i_mapping; page = grab_cache_page(mapping, nid); if (!page) return ERR_PTR(-ENOMEM); err = read_node_page(page, READ_SYNC); if (err) { f2fs_put_page(page, 1); return ERR_PTR(err); } BUG_ON(nid != nid_of_node(page)); mark_page_accessed(page); return page; } /* * Return a locked page for the desired node page. * And, readahead MAX_RA_NODE number of node pages. */ struct page *get_node_page_ra(struct page *parent, int start) { struct f2fs_sb_info *sbi = F2FS_SB(parent->mapping->host->i_sb); struct address_space *mapping = sbi->node_inode->i_mapping; int i, end; int err = 0; nid_t nid; struct page *page; /* First, try getting the desired direct node. */ nid = get_nid(parent, start, false); if (!nid) return ERR_PTR(-ENOENT); page = find_get_page(mapping, nid); if (page && PageUptodate(page)) goto page_hit; f2fs_put_page(page, 0); repeat: page = grab_cache_page(mapping, nid); if (!page) return ERR_PTR(-ENOMEM); err = read_node_page(page, READA); if (err) { f2fs_put_page(page, 1); return ERR_PTR(err); } /* Then, try readahead for siblings of the desired node */ end = start + MAX_RA_NODE; end = min(end, NIDS_PER_BLOCK); for (i = start + 1; i < end; i++) { nid = get_nid(parent, i, false); if (!nid) continue; ra_node_page(sbi, nid); } page_hit: lock_page(page); if (PageError(page)) { f2fs_put_page(page, 1); return ERR_PTR(-EIO); } /* Has the page been truncated? */ if (page->mapping != mapping) { f2fs_put_page(page, 1); goto repeat; } return page; } void sync_inode_page(struct dnode_of_data *dn) { if (IS_INODE(dn->node_page) || dn->inode_page == dn->node_page) { update_inode(dn->inode, dn->node_page); } else if (dn->inode_page) { if (!dn->inode_page_locked) lock_page(dn->inode_page); update_inode(dn->inode, dn->inode_page); if (!dn->inode_page_locked) unlock_page(dn->inode_page); } else { f2fs_write_inode(dn->inode, NULL); } } int sync_node_pages(struct f2fs_sb_info *sbi, nid_t ino, struct writeback_control *wbc) { struct address_space *mapping = sbi->node_inode->i_mapping; pgoff_t index, end; struct pagevec pvec; int step = ino ? 2 : 0; int nwritten = 0, wrote = 0; pagevec_init(&pvec, 0); next_step: index = 0; end = LONG_MAX; while (index <= end) { int i, nr_pages; nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY, min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1); if (nr_pages == 0) break; for (i = 0; i < nr_pages; i++) { struct page *page = pvec.pages[i]; /* * flushing sequence with step: * 0. indirect nodes * 1. dentry dnodes * 2. file dnodes */ if (step == 0 && IS_DNODE(page)) continue; if (step == 1 && (!IS_DNODE(page) || is_cold_node(page))) continue; if (step == 2 && (!IS_DNODE(page) || !is_cold_node(page))) continue; /* * If an fsync mode, * we should not skip writing node pages. */ if (ino && ino_of_node(page) == ino) lock_page(page); else if (!trylock_page(page)) continue; if (unlikely(page->mapping != mapping)) { continue_unlock: unlock_page(page); continue; } if (ino && ino_of_node(page) != ino) goto continue_unlock; if (!PageDirty(page)) { /* someone wrote it for us */ goto continue_unlock; } if (!clear_page_dirty_for_io(page)) goto continue_unlock; /* called by fsync() */ if (ino && IS_DNODE(page)) { int mark = !is_checkpointed_node(sbi, ino); set_fsync_mark(page, 1); if (IS_INODE(page)) set_dentry_mark(page, mark); nwritten++; } else { set_fsync_mark(page, 0); set_dentry_mark(page, 0); } mapping->a_ops->writepage(page, wbc); wrote++; if (--wbc->nr_to_write == 0) break; } pagevec_release(&pvec); cond_resched(); if (wbc->nr_to_write == 0) { step = 2; break; } } if (step < 2) { step++; goto next_step; } if (wrote) f2fs_submit_bio(sbi, NODE, wbc->sync_mode == WB_SYNC_ALL); return nwritten; } static int f2fs_write_node_page(struct page *page, struct writeback_control *wbc) { struct f2fs_sb_info *sbi = F2FS_SB(page->mapping->host->i_sb); nid_t nid; block_t new_addr; struct node_info ni; if (wbc->for_reclaim) { dec_page_count(sbi, F2FS_DIRTY_NODES); wbc->pages_skipped++; set_page_dirty(page); return AOP_WRITEPAGE_ACTIVATE; } wait_on_page_writeback(page); mutex_lock_op(sbi, NODE_WRITE); /* get old block addr of this node page */ nid = nid_of_node(page); BUG_ON(page->index != nid); get_node_info(sbi, nid, &ni); /* This page is already truncated */ if (ni.blk_addr == NULL_ADDR) return 0; set_page_writeback(page); /* insert node offset */ write_node_page(sbi, page, nid, ni.blk_addr, &new_addr); set_node_addr(sbi, &ni, new_addr); dec_page_count(sbi, F2FS_DIRTY_NODES); mutex_unlock_op(sbi, NODE_WRITE); unlock_page(page); return 0; } /* * It is very important to gather dirty pages and write at once, so that we can * submit a big bio without interfering other data writes. * Be default, 512 pages (2MB), a segment size, is quite reasonable. */ #define COLLECT_DIRTY_NODES 512 static int f2fs_write_node_pages(struct address_space *mapping, struct writeback_control *wbc) { struct f2fs_sb_info *sbi = F2FS_SB(mapping->host->i_sb); struct block_device *bdev = sbi->sb->s_bdev; long nr_to_write = wbc->nr_to_write; /* First check balancing cached NAT entries */ if (try_to_free_nats(sbi, NAT_ENTRY_PER_BLOCK)) { write_checkpoint(sbi, false, false); return 0; } /* collect a number of dirty node pages and write together */ if (get_pages(sbi, F2FS_DIRTY_NODES) < COLLECT_DIRTY_NODES) return 0; /* if mounting is failed, skip writing node pages */ wbc->nr_to_write = bio_get_nr_vecs(bdev); sync_node_pages(sbi, 0, wbc); wbc->nr_to_write = nr_to_write - (bio_get_nr_vecs(bdev) - wbc->nr_to_write); return 0; } static int f2fs_set_node_page_dirty(struct page *page) { struct address_space *mapping = page->mapping; struct f2fs_sb_info *sbi = F2FS_SB(mapping->host->i_sb); SetPageUptodate(page); if (!PageDirty(page)) { __set_page_dirty_nobuffers(page); inc_page_count(sbi, F2FS_DIRTY_NODES); SetPagePrivate(page); return 1; } return 0; } static void f2fs_invalidate_node_page(struct page *page, unsigned long offset) { struct inode *inode = page->mapping->host; struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); if (PageDirty(page)) dec_page_count(sbi, F2FS_DIRTY_NODES); ClearPagePrivate(page); } static int f2fs_release_node_page(struct page *page, gfp_t wait) { ClearPagePrivate(page); return 0; } /* * Structure of the f2fs node operations */ const struct address_space_operations f2fs_node_aops = { .writepage = f2fs_write_node_page, .writepages = f2fs_write_node_pages, .set_page_dirty = f2fs_set_node_page_dirty, .invalidatepage = f2fs_invalidate_node_page, .releasepage = f2fs_release_node_page, }; static struct free_nid *__lookup_free_nid_list(nid_t n, struct list_head *head) { struct list_head *this; struct free_nid *i = NULL; list_for_each(this, head) { i = list_entry(this, struct free_nid, list); if (i->nid == n) break; i = NULL; } return i; } static void __del_from_free_nid_list(struct free_nid *i) { list_del(&i->list); kmem_cache_free(free_nid_slab, i); } static int add_free_nid(struct f2fs_nm_info *nm_i, nid_t nid) { struct free_nid *i; if (nm_i->fcnt > 2 * MAX_FREE_NIDS) return 0; retry: i = kmem_cache_alloc(free_nid_slab, GFP_NOFS); if (!i) { cond_resched(); goto retry; } i->nid = nid; i->state = NID_NEW; spin_lock(&nm_i->free_nid_list_lock); if (__lookup_free_nid_list(nid, &nm_i->free_nid_list)) { spin_unlock(&nm_i->free_nid_list_lock); kmem_cache_free(free_nid_slab, i); return 0; } list_add_tail(&i->list, &nm_i->free_nid_list); nm_i->fcnt++; spin_unlock(&nm_i->free_nid_list_lock); return 1; } static void remove_free_nid(struct f2fs_nm_info *nm_i, nid_t nid) { struct free_nid *i; spin_lock(&nm_i->free_nid_list_lock); i = __lookup_free_nid_list(nid, &nm_i->free_nid_list); if (i && i->state == NID_NEW) { __del_from_free_nid_list(i); nm_i->fcnt--; } spin_unlock(&nm_i->free_nid_list_lock); } static int scan_nat_page(struct f2fs_nm_info *nm_i, struct page *nat_page, nid_t start_nid) { struct f2fs_nat_block *nat_blk = page_address(nat_page); block_t blk_addr; int fcnt = 0; int i; /* 0 nid should not be used */ if (start_nid == 0) ++start_nid; i = start_nid % NAT_ENTRY_PER_BLOCK; for (; i < NAT_ENTRY_PER_BLOCK; i++, start_nid++) { blk_addr = le32_to_cpu(nat_blk->entries[i].block_addr); BUG_ON(blk_addr == NEW_ADDR); if (blk_addr == NULL_ADDR) fcnt += add_free_nid(nm_i, start_nid); } return fcnt; } static void build_free_nids(struct f2fs_sb_info *sbi) { struct free_nid *fnid, *next_fnid; struct f2fs_nm_info *nm_i = NM_I(sbi); struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA); struct f2fs_summary_block *sum = curseg->sum_blk; nid_t nid = 0; bool is_cycled = false; int fcnt = 0; int i; nid = nm_i->next_scan_nid; nm_i->init_scan_nid = nid; ra_nat_pages(sbi, nid); while (1) { struct page *page = get_current_nat_page(sbi, nid); fcnt += scan_nat_page(nm_i, page, nid); f2fs_put_page(page, 1); nid += (NAT_ENTRY_PER_BLOCK - (nid % NAT_ENTRY_PER_BLOCK)); if (nid >= nm_i->max_nid) { nid = 0; is_cycled = true; } if (fcnt > MAX_FREE_NIDS) break; if (is_cycled && nm_i->init_scan_nid <= nid) break; } nm_i->next_scan_nid = nid; /* find free nids from current sum_pages */ mutex_lock(&curseg->curseg_mutex); for (i = 0; i < nats_in_cursum(sum); i++) { block_t addr = le32_to_cpu(nat_in_journal(sum, i).block_addr); nid = le32_to_cpu(nid_in_journal(sum, i)); if (addr == NULL_ADDR) add_free_nid(nm_i, nid); else remove_free_nid(nm_i, nid); } mutex_unlock(&curseg->curseg_mutex); /* remove the free nids from current allocated nids */ list_for_each_entry_safe(fnid, next_fnid, &nm_i->free_nid_list, list) { struct nat_entry *ne; read_lock(&nm_i->nat_tree_lock); ne = __lookup_nat_cache(nm_i, fnid->nid); if (ne && nat_get_blkaddr(ne) != NULL_ADDR) remove_free_nid(nm_i, fnid->nid); read_unlock(&nm_i->nat_tree_lock); } } /* * If this function returns success, caller can obtain a new nid * from second parameter of this function. * The returned nid could be used ino as well as nid when inode is created. */ bool alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid) { struct f2fs_nm_info *nm_i = NM_I(sbi); struct free_nid *i = NULL; struct list_head *this; retry: mutex_lock(&nm_i->build_lock); if (!nm_i->fcnt) { /* scan NAT in order to build free nid list */ build_free_nids(sbi); if (!nm_i->fcnt) { mutex_unlock(&nm_i->build_lock); return false; } } mutex_unlock(&nm_i->build_lock); /* * We check fcnt again since previous check is racy as * we didn't hold free_nid_list_lock. So other thread * could consume all of free nids. */ spin_lock(&nm_i->free_nid_list_lock); if (!nm_i->fcnt) { spin_unlock(&nm_i->free_nid_list_lock); goto retry; } BUG_ON(list_empty(&nm_i->free_nid_list)); list_for_each(this, &nm_i->free_nid_list) { i = list_entry(this, struct free_nid, list); if (i->state == NID_NEW) break; } BUG_ON(i->state != NID_NEW); *nid = i->nid; i->state = NID_ALLOC; nm_i->fcnt--; spin_unlock(&nm_i->free_nid_list_lock); return true; } /* * alloc_nid() should be called prior to this function. */ void alloc_nid_done(struct f2fs_sb_info *sbi, nid_t nid) { struct f2fs_nm_info *nm_i = NM_I(sbi); struct free_nid *i; spin_lock(&nm_i->free_nid_list_lock); i = __lookup_free_nid_list(nid, &nm_i->free_nid_list); if (i) { BUG_ON(i->state != NID_ALLOC); __del_from_free_nid_list(i); } spin_unlock(&nm_i->free_nid_list_lock); } /* * alloc_nid() should be called prior to this function. */ void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid) { alloc_nid_done(sbi, nid); add_free_nid(NM_I(sbi), nid); } void recover_node_page(struct f2fs_sb_info *sbi, struct page *page, struct f2fs_summary *sum, struct node_info *ni, block_t new_blkaddr) { rewrite_node_page(sbi, page, sum, ni->blk_addr, new_blkaddr); set_node_addr(sbi, ni, new_blkaddr); clear_node_page_dirty(page); } int recover_inode_page(struct f2fs_sb_info *sbi, struct page *page) { struct address_space *mapping = sbi->node_inode->i_mapping; struct f2fs_node *src, *dst; nid_t ino = ino_of_node(page); struct node_info old_ni, new_ni; struct page *ipage; ipage = grab_cache_page(mapping, ino); if (!ipage) return -ENOMEM; /* Should not use this inode from free nid list */ remove_free_nid(NM_I(sbi), ino); get_node_info(sbi, ino, &old_ni); SetPageUptodate(ipage); fill_node_footer(ipage, ino, ino, 0, true); src = (struct f2fs_node *)page_address(page); dst = (struct f2fs_node *)page_address(ipage); memcpy(dst, src, (unsigned long)&src->i.i_ext - (unsigned long)&src->i); dst->i.i_size = 0; dst->i.i_blocks = cpu_to_le64(1); dst->i.i_links = cpu_to_le32(1); dst->i.i_xattr_nid = 0; new_ni = old_ni; new_ni.ino = ino; set_node_addr(sbi, &new_ni, NEW_ADDR); inc_valid_inode_count(sbi); f2fs_put_page(ipage, 1); return 0; } int restore_node_summary(struct f2fs_sb_info *sbi, unsigned int segno, struct f2fs_summary_block *sum) { struct f2fs_node *rn; struct f2fs_summary *sum_entry; struct page *page; block_t addr; int i, last_offset; /* alloc temporal page for read node */ page = alloc_page(GFP_NOFS | __GFP_ZERO); if (IS_ERR(page)) return PTR_ERR(page); lock_page(page); /* scan the node segment */ last_offset = sbi->blocks_per_seg; addr = START_BLOCK(sbi, segno); sum_entry = &sum->entries[0]; for (i = 0; i < last_offset; i++, sum_entry++) { if (f2fs_readpage(sbi, page, addr, READ_SYNC)) goto out; rn = (struct f2fs_node *)page_address(page); sum_entry->nid = rn->footer.nid; sum_entry->version = 0; sum_entry->ofs_in_node = 0; addr++; /* * In order to read next node page, * we must clear PageUptodate flag. */ ClearPageUptodate(page); } out: unlock_page(page); __free_pages(page, 0); return 0; } static bool flush_nats_in_journal(struct f2fs_sb_info *sbi) { struct f2fs_nm_info *nm_i = NM_I(sbi); struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA); struct f2fs_summary_block *sum = curseg->sum_blk; int i; mutex_lock(&curseg->curseg_mutex); if (nats_in_cursum(sum) < NAT_JOURNAL_ENTRIES) { mutex_unlock(&curseg->curseg_mutex); return false; } for (i = 0; i < nats_in_cursum(sum); i++) { struct nat_entry *ne; struct f2fs_nat_entry raw_ne; nid_t nid = le32_to_cpu(nid_in_journal(sum, i)); raw_ne = nat_in_journal(sum, i); retry: write_lock(&nm_i->nat_tree_lock); ne = __lookup_nat_cache(nm_i, nid); if (ne) { __set_nat_cache_dirty(nm_i, ne); write_unlock(&nm_i->nat_tree_lock); continue; } ne = grab_nat_entry(nm_i, nid); if (!ne) { write_unlock(&nm_i->nat_tree_lock); goto retry; } nat_set_blkaddr(ne, le32_to_cpu(raw_ne.block_addr)); nat_set_ino(ne, le32_to_cpu(raw_ne.ino)); nat_set_version(ne, raw_ne.version); __set_nat_cache_dirty(nm_i, ne); write_unlock(&nm_i->nat_tree_lock); } update_nats_in_cursum(sum, -i); mutex_unlock(&curseg->curseg_mutex); return true; } /* * This function is called during the checkpointing process. */ void flush_nat_entries(struct f2fs_sb_info *sbi) { struct f2fs_nm_info *nm_i = NM_I(sbi); struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA); struct f2fs_summary_block *sum = curseg->sum_blk; struct list_head *cur, *n; struct page *page = NULL; struct f2fs_nat_block *nat_blk = NULL; nid_t start_nid = 0, end_nid = 0; bool flushed; flushed = flush_nats_in_journal(sbi); if (!flushed) mutex_lock(&curseg->curseg_mutex); /* 1) flush dirty nat caches */ list_for_each_safe(cur, n, &nm_i->dirty_nat_entries) { struct nat_entry *ne; nid_t nid; struct f2fs_nat_entry raw_ne; int offset = -1; block_t new_blkaddr; ne = list_entry(cur, struct nat_entry, list); nid = nat_get_nid(ne); if (nat_get_blkaddr(ne) == NEW_ADDR) continue; if (flushed) goto to_nat_page; /* if there is room for nat enries in curseg->sumpage */ offset = lookup_journal_in_cursum(sum, NAT_JOURNAL, nid, 1); if (offset >= 0) { raw_ne = nat_in_journal(sum, offset); goto flush_now; } to_nat_page: if (!page || (start_nid > nid || nid > end_nid)) { if (page) { f2fs_put_page(page, 1); page = NULL; } start_nid = START_NID(nid); end_nid = start_nid + NAT_ENTRY_PER_BLOCK - 1; /* * get nat block with dirty flag, increased reference * count, mapped and lock */ page = get_next_nat_page(sbi, start_nid); nat_blk = page_address(page); } BUG_ON(!nat_blk); raw_ne = nat_blk->entries[nid - start_nid]; flush_now: new_blkaddr = nat_get_blkaddr(ne); raw_ne.ino = cpu_to_le32(nat_get_ino(ne)); raw_ne.block_addr = cpu_to_le32(new_blkaddr); raw_ne.version = nat_get_version(ne); if (offset < 0) { nat_blk->entries[nid - start_nid] = raw_ne; } else { nat_in_journal(sum, offset) = raw_ne; nid_in_journal(sum, offset) = cpu_to_le32(nid); } if (nat_get_blkaddr(ne) == NULL_ADDR) { write_lock(&nm_i->nat_tree_lock); __del_from_nat_cache(nm_i, ne); write_unlock(&nm_i->nat_tree_lock); /* We can reuse this freed nid at this point */ add_free_nid(NM_I(sbi), nid); } else { write_lock(&nm_i->nat_tree_lock); __clear_nat_cache_dirty(nm_i, ne); ne->checkpointed = true; write_unlock(&nm_i->nat_tree_lock); } } if (!flushed) mutex_unlock(&curseg->curseg_mutex); f2fs_put_page(page, 1); /* 2) shrink nat caches if necessary */ try_to_free_nats(sbi, nm_i->nat_cnt - NM_WOUT_THRESHOLD); } static int init_node_manager(struct f2fs_sb_info *sbi) { struct f2fs_super_block *sb_raw = F2FS_RAW_SUPER(sbi); struct f2fs_nm_info *nm_i = NM_I(sbi); unsigned char *version_bitmap; unsigned int nat_segs, nat_blocks; nm_i->nat_blkaddr = le32_to_cpu(sb_raw->nat_blkaddr); /* segment_count_nat includes pair segment so divide to 2. */ nat_segs = le32_to_cpu(sb_raw->segment_count_nat) >> 1; nat_blocks = nat_segs << le32_to_cpu(sb_raw->log_blocks_per_seg); nm_i->max_nid = NAT_ENTRY_PER_BLOCK * nat_blocks; nm_i->fcnt = 0; nm_i->nat_cnt = 0; INIT_LIST_HEAD(&nm_i->free_nid_list); INIT_RADIX_TREE(&nm_i->nat_root, GFP_ATOMIC); INIT_LIST_HEAD(&nm_i->nat_entries); INIT_LIST_HEAD(&nm_i->dirty_nat_entries); mutex_init(&nm_i->build_lock); spin_lock_init(&nm_i->free_nid_list_lock); rwlock_init(&nm_i->nat_tree_lock); nm_i->bitmap_size = __bitmap_size(sbi, NAT_BITMAP); nm_i->init_scan_nid = le32_to_cpu(sbi->ckpt->next_free_nid); nm_i->next_scan_nid = le32_to_cpu(sbi->ckpt->next_free_nid); nm_i->nat_bitmap = kzalloc(nm_i->bitmap_size, GFP_KERNEL); if (!nm_i->nat_bitmap) return -ENOMEM; version_bitmap = __bitmap_ptr(sbi, NAT_BITMAP); if (!version_bitmap) return -EFAULT; /* copy version bitmap */ memcpy(nm_i->nat_bitmap, version_bitmap, nm_i->bitmap_size); return 0; } int build_node_manager(struct f2fs_sb_info *sbi) { int err; sbi->nm_info = kzalloc(sizeof(struct f2fs_nm_info), GFP_KERNEL); if (!sbi->nm_info) return -ENOMEM; err = init_node_manager(sbi); if (err) return err; build_free_nids(sbi); return 0; } void destroy_node_manager(struct f2fs_sb_info *sbi) { struct f2fs_nm_info *nm_i = NM_I(sbi); struct free_nid *i, *next_i; struct nat_entry *natvec[NATVEC_SIZE]; nid_t nid = 0; unsigned int found; if (!nm_i) return; /* destroy free nid list */ spin_lock(&nm_i->free_nid_list_lock); list_for_each_entry_safe(i, next_i, &nm_i->free_nid_list, list) { BUG_ON(i->state == NID_ALLOC); __del_from_free_nid_list(i); nm_i->fcnt--; } BUG_ON(nm_i->fcnt); spin_unlock(&nm_i->free_nid_list_lock); /* destroy nat cache */ write_lock(&nm_i->nat_tree_lock); while ((found = __gang_lookup_nat_cache(nm_i, nid, NATVEC_SIZE, natvec))) { unsigned idx; for (idx = 0; idx < found; idx++) { struct nat_entry *e = natvec[idx]; nid = nat_get_nid(e) + 1; __del_from_nat_cache(nm_i, e); } } BUG_ON(nm_i->nat_cnt); write_unlock(&nm_i->nat_tree_lock); kfree(nm_i->nat_bitmap); sbi->nm_info = NULL; kfree(nm_i); } int __init create_node_manager_caches(void) { nat_entry_slab = f2fs_kmem_cache_create("nat_entry", sizeof(struct nat_entry), NULL); if (!nat_entry_slab) return -ENOMEM; free_nid_slab = f2fs_kmem_cache_create("free_nid", sizeof(struct free_nid), NULL); if (!free_nid_slab) { kmem_cache_destroy(nat_entry_slab); return -ENOMEM; } return 0; } void destroy_node_manager_caches(void) { kmem_cache_destroy(free_nid_slab); kmem_cache_destroy(nat_entry_slab); }