// SPDX-License-Identifier: GPL-2.0+ /* * btree.c - NILFS B-tree. * * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. * * Written by Koji Sato. */ #include <linux/slab.h> #include <linux/string.h> #include <linux/errno.h> #include <linux/pagevec.h> #include "nilfs.h" #include "page.h" #include "btnode.h" #include "btree.h" #include "alloc.h" #include "dat.h" static void __nilfs_btree_init(struct nilfs_bmap *bmap); static struct nilfs_btree_path *nilfs_btree_alloc_path(void) { struct nilfs_btree_path *path; int level = NILFS_BTREE_LEVEL_DATA; path = kmem_cache_alloc(nilfs_btree_path_cache, GFP_NOFS); if (path == NULL) goto out; for (; level < NILFS_BTREE_LEVEL_MAX; level++) { path[level].bp_bh = NULL; path[level].bp_sib_bh = NULL; path[level].bp_index = 0; path[level].bp_oldreq.bpr_ptr = NILFS_BMAP_INVALID_PTR; path[level].bp_newreq.bpr_ptr = NILFS_BMAP_INVALID_PTR; path[level].bp_op = NULL; } out: return path; } static void nilfs_btree_free_path(struct nilfs_btree_path *path) { int level = NILFS_BTREE_LEVEL_DATA; for (; level < NILFS_BTREE_LEVEL_MAX; level++) brelse(path[level].bp_bh); kmem_cache_free(nilfs_btree_path_cache, path); } /* * B-tree node operations */ static int nilfs_btree_get_new_block(const struct nilfs_bmap *btree, __u64 ptr, struct buffer_head **bhp) { struct address_space *btnc = &NILFS_BMAP_I(btree)->i_btnode_cache; struct buffer_head *bh; bh = nilfs_btnode_create_block(btnc, ptr); if (!bh) return -ENOMEM; set_buffer_nilfs_volatile(bh); *bhp = bh; return 0; } static int nilfs_btree_node_get_flags(const struct nilfs_btree_node *node) { return node->bn_flags; } static void nilfs_btree_node_set_flags(struct nilfs_btree_node *node, int flags) { node->bn_flags = flags; } static int nilfs_btree_node_root(const struct nilfs_btree_node *node) { return nilfs_btree_node_get_flags(node) & NILFS_BTREE_NODE_ROOT; } static int nilfs_btree_node_get_level(const struct nilfs_btree_node *node) { return node->bn_level; } static void nilfs_btree_node_set_level(struct nilfs_btree_node *node, int level) { node->bn_level = level; } static int nilfs_btree_node_get_nchildren(const struct nilfs_btree_node *node) { return le16_to_cpu(node->bn_nchildren); } static void nilfs_btree_node_set_nchildren(struct nilfs_btree_node *node, int nchildren) { node->bn_nchildren = cpu_to_le16(nchildren); } static int nilfs_btree_node_size(const struct nilfs_bmap *btree) { return i_blocksize(btree->b_inode); } static int nilfs_btree_nchildren_per_block(const struct nilfs_bmap *btree) { return btree->b_nchildren_per_block; } static __le64 * nilfs_btree_node_dkeys(const struct nilfs_btree_node *node) { return (__le64 *)((char *)(node + 1) + (nilfs_btree_node_root(node) ? 0 : NILFS_BTREE_NODE_EXTRA_PAD_SIZE)); } static __le64 * nilfs_btree_node_dptrs(const struct nilfs_btree_node *node, int ncmax) { return (__le64 *)(nilfs_btree_node_dkeys(node) + ncmax); } static __u64 nilfs_btree_node_get_key(const struct nilfs_btree_node *node, int index) { return le64_to_cpu(*(nilfs_btree_node_dkeys(node) + index)); } static void nilfs_btree_node_set_key(struct nilfs_btree_node *node, int index, __u64 key) { *(nilfs_btree_node_dkeys(node) + index) = cpu_to_le64(key); } static __u64 nilfs_btree_node_get_ptr(const struct nilfs_btree_node *node, int index, int ncmax) { return le64_to_cpu(*(nilfs_btree_node_dptrs(node, ncmax) + index)); } static void nilfs_btree_node_set_ptr(struct nilfs_btree_node *node, int index, __u64 ptr, int ncmax) { *(nilfs_btree_node_dptrs(node, ncmax) + index) = cpu_to_le64(ptr); } static void nilfs_btree_node_init(struct nilfs_btree_node *node, int flags, int level, int nchildren, int ncmax, const __u64 *keys, const __u64 *ptrs) { __le64 *dkeys; __le64 *dptrs; int i; nilfs_btree_node_set_flags(node, flags); nilfs_btree_node_set_level(node, level); nilfs_btree_node_set_nchildren(node, nchildren); dkeys = nilfs_btree_node_dkeys(node); dptrs = nilfs_btree_node_dptrs(node, ncmax); for (i = 0; i < nchildren; i++) { dkeys[i] = cpu_to_le64(keys[i]); dptrs[i] = cpu_to_le64(ptrs[i]); } } /* Assume the buffer heads corresponding to left and right are locked. */ static void nilfs_btree_node_move_left(struct nilfs_btree_node *left, struct nilfs_btree_node *right, int n, int lncmax, int rncmax) { __le64 *ldkeys, *rdkeys; __le64 *ldptrs, *rdptrs; int lnchildren, rnchildren; ldkeys = nilfs_btree_node_dkeys(left); ldptrs = nilfs_btree_node_dptrs(left, lncmax); lnchildren = nilfs_btree_node_get_nchildren(left); rdkeys = nilfs_btree_node_dkeys(right); rdptrs = nilfs_btree_node_dptrs(right, rncmax); rnchildren = nilfs_btree_node_get_nchildren(right); memcpy(ldkeys + lnchildren, rdkeys, n * sizeof(*rdkeys)); memcpy(ldptrs + lnchildren, rdptrs, n * sizeof(*rdptrs)); memmove(rdkeys, rdkeys + n, (rnchildren - n) * sizeof(*rdkeys)); memmove(rdptrs, rdptrs + n, (rnchildren - n) * sizeof(*rdptrs)); lnchildren += n; rnchildren -= n; nilfs_btree_node_set_nchildren(left, lnchildren); nilfs_btree_node_set_nchildren(right, rnchildren); } /* Assume that the buffer heads corresponding to left and right are locked. */ static void nilfs_btree_node_move_right(struct nilfs_btree_node *left, struct nilfs_btree_node *right, int n, int lncmax, int rncmax) { __le64 *ldkeys, *rdkeys; __le64 *ldptrs, *rdptrs; int lnchildren, rnchildren; ldkeys = nilfs_btree_node_dkeys(left); ldptrs = nilfs_btree_node_dptrs(left, lncmax); lnchildren = nilfs_btree_node_get_nchildren(left); rdkeys = nilfs_btree_node_dkeys(right); rdptrs = nilfs_btree_node_dptrs(right, rncmax); rnchildren = nilfs_btree_node_get_nchildren(right); memmove(rdkeys + n, rdkeys, rnchildren * sizeof(*rdkeys)); memmove(rdptrs + n, rdptrs, rnchildren * sizeof(*rdptrs)); memcpy(rdkeys, ldkeys + lnchildren - n, n * sizeof(*rdkeys)); memcpy(rdptrs, ldptrs + lnchildren - n, n * sizeof(*rdptrs)); lnchildren -= n; rnchildren += n; nilfs_btree_node_set_nchildren(left, lnchildren); nilfs_btree_node_set_nchildren(right, rnchildren); } /* Assume that the buffer head corresponding to node is locked. */ static void nilfs_btree_node_insert(struct nilfs_btree_node *node, int index, __u64 key, __u64 ptr, int ncmax) { __le64 *dkeys; __le64 *dptrs; int nchildren; dkeys = nilfs_btree_node_dkeys(node); dptrs = nilfs_btree_node_dptrs(node, ncmax); nchildren = nilfs_btree_node_get_nchildren(node); if (index < nchildren) { memmove(dkeys + index + 1, dkeys + index, (nchildren - index) * sizeof(*dkeys)); memmove(dptrs + index + 1, dptrs + index, (nchildren - index) * sizeof(*dptrs)); } dkeys[index] = cpu_to_le64(key); dptrs[index] = cpu_to_le64(ptr); nchildren++; nilfs_btree_node_set_nchildren(node, nchildren); } /* Assume that the buffer head corresponding to node is locked. */ static void nilfs_btree_node_delete(struct nilfs_btree_node *node, int index, __u64 *keyp, __u64 *ptrp, int ncmax) { __u64 key; __u64 ptr; __le64 *dkeys; __le64 *dptrs; int nchildren; dkeys = nilfs_btree_node_dkeys(node); dptrs = nilfs_btree_node_dptrs(node, ncmax); key = le64_to_cpu(dkeys[index]); ptr = le64_to_cpu(dptrs[index]); nchildren = nilfs_btree_node_get_nchildren(node); if (keyp != NULL) *keyp = key; if (ptrp != NULL) *ptrp = ptr; if (index < nchildren - 1) { memmove(dkeys + index, dkeys + index + 1, (nchildren - index - 1) * sizeof(*dkeys)); memmove(dptrs + index, dptrs + index + 1, (nchildren - index - 1) * sizeof(*dptrs)); } nchildren--; nilfs_btree_node_set_nchildren(node, nchildren); } static int nilfs_btree_node_lookup(const struct nilfs_btree_node *node, __u64 key, int *indexp) { __u64 nkey; int index, low, high, s; /* binary search */ low = 0; high = nilfs_btree_node_get_nchildren(node) - 1; index = 0; s = 0; while (low <= high) { index = (low + high) / 2; nkey = nilfs_btree_node_get_key(node, index); if (nkey == key) { s = 0; goto out; } else if (nkey < key) { low = index + 1; s = -1; } else { high = index - 1; s = 1; } } /* adjust index */ if (nilfs_btree_node_get_level(node) > NILFS_BTREE_LEVEL_NODE_MIN) { if (s > 0 && index > 0) index--; } else if (s < 0) index++; out: *indexp = index; return s == 0; } /** * nilfs_btree_node_broken - verify consistency of btree node * @node: btree node block to be examined * @size: node size (in bytes) * @inode: host inode of btree * @blocknr: block number * * Return Value: If node is broken, 1 is returned. Otherwise, 0 is returned. */ static int nilfs_btree_node_broken(const struct nilfs_btree_node *node, size_t size, struct inode *inode, sector_t blocknr) { int level, flags, nchildren; int ret = 0; level = nilfs_btree_node_get_level(node); flags = nilfs_btree_node_get_flags(node); nchildren = nilfs_btree_node_get_nchildren(node); if (unlikely(level < NILFS_BTREE_LEVEL_NODE_MIN || level >= NILFS_BTREE_LEVEL_MAX || (flags & NILFS_BTREE_NODE_ROOT) || nchildren < 0 || nchildren > NILFS_BTREE_NODE_NCHILDREN_MAX(size))) { nilfs_crit(inode->i_sb, "bad btree node (ino=%lu, blocknr=%llu): level = %d, flags = 0x%x, nchildren = %d", inode->i_ino, (unsigned long long)blocknr, level, flags, nchildren); ret = 1; } return ret; } /** * nilfs_btree_root_broken - verify consistency of btree root node * @node: btree root node to be examined * @inode: host inode of btree * * Return Value: If node is broken, 1 is returned. Otherwise, 0 is returned. */ static int nilfs_btree_root_broken(const struct nilfs_btree_node *node, struct inode *inode) { int level, flags, nchildren; int ret = 0; level = nilfs_btree_node_get_level(node); flags = nilfs_btree_node_get_flags(node); nchildren = nilfs_btree_node_get_nchildren(node); if (unlikely(level < NILFS_BTREE_LEVEL_NODE_MIN || level >= NILFS_BTREE_LEVEL_MAX || nchildren < 0 || nchildren > NILFS_BTREE_ROOT_NCHILDREN_MAX)) { nilfs_crit(inode->i_sb, "bad btree root (ino=%lu): level = %d, flags = 0x%x, nchildren = %d", inode->i_ino, level, flags, nchildren); ret = 1; } return ret; } int nilfs_btree_broken_node_block(struct buffer_head *bh) { struct inode *inode; int ret; if (buffer_nilfs_checked(bh)) return 0; inode = bh->b_page->mapping->host; ret = nilfs_btree_node_broken((struct nilfs_btree_node *)bh->b_data, bh->b_size, inode, bh->b_blocknr); if (likely(!ret)) set_buffer_nilfs_checked(bh); return ret; } static struct nilfs_btree_node * nilfs_btree_get_root(const struct nilfs_bmap *btree) { return (struct nilfs_btree_node *)btree->b_u.u_data; } static struct nilfs_btree_node * nilfs_btree_get_nonroot_node(const struct nilfs_btree_path *path, int level) { return (struct nilfs_btree_node *)path[level].bp_bh->b_data; } static struct nilfs_btree_node * nilfs_btree_get_sib_node(const struct nilfs_btree_path *path, int level) { return (struct nilfs_btree_node *)path[level].bp_sib_bh->b_data; } static int nilfs_btree_height(const struct nilfs_bmap *btree) { return nilfs_btree_node_get_level(nilfs_btree_get_root(btree)) + 1; } static struct nilfs_btree_node * nilfs_btree_get_node(const struct nilfs_bmap *btree, const struct nilfs_btree_path *path, int level, int *ncmaxp) { struct nilfs_btree_node *node; if (level == nilfs_btree_height(btree) - 1) { node = nilfs_btree_get_root(btree); *ncmaxp = NILFS_BTREE_ROOT_NCHILDREN_MAX; } else { node = nilfs_btree_get_nonroot_node(path, level); *ncmaxp = nilfs_btree_nchildren_per_block(btree); } return node; } static int nilfs_btree_bad_node(const struct nilfs_bmap *btree, struct nilfs_btree_node *node, int level) { if (unlikely(nilfs_btree_node_get_level(node) != level)) { dump_stack(); nilfs_crit(btree->b_inode->i_sb, "btree level mismatch (ino=%lu): %d != %d", btree->b_inode->i_ino, nilfs_btree_node_get_level(node), level); return 1; } return 0; } struct nilfs_btree_readahead_info { struct nilfs_btree_node *node; /* parent node */ int max_ra_blocks; /* max nof blocks to read ahead */ int index; /* current index on the parent node */ int ncmax; /* nof children in the parent node */ }; static int __nilfs_btree_get_block(const struct nilfs_bmap *btree, __u64 ptr, struct buffer_head **bhp, const struct nilfs_btree_readahead_info *ra) { struct address_space *btnc = &NILFS_BMAP_I(btree)->i_btnode_cache; struct buffer_head *bh, *ra_bh; sector_t submit_ptr = 0; int ret; ret = nilfs_btnode_submit_block(btnc, ptr, 0, REQ_OP_READ, 0, &bh, &submit_ptr); if (ret) { if (ret != -EEXIST) return ret; goto out_check; } if (ra) { int i, n; __u64 ptr2; /* read ahead sibling nodes */ for (n = ra->max_ra_blocks, i = ra->index + 1; n > 0 && i < ra->ncmax; n--, i++) { ptr2 = nilfs_btree_node_get_ptr(ra->node, i, ra->ncmax); ret = nilfs_btnode_submit_block(btnc, ptr2, 0, REQ_OP_READ, REQ_RAHEAD, &ra_bh, &submit_ptr); if (likely(!ret || ret == -EEXIST)) brelse(ra_bh); else if (ret != -EBUSY) break; if (!buffer_locked(bh)) goto out_no_wait; } } wait_on_buffer(bh); out_no_wait: if (!buffer_uptodate(bh)) { nilfs_err(btree->b_inode->i_sb, "I/O error reading b-tree node block (ino=%lu, blocknr=%llu)", btree->b_inode->i_ino, (unsigned long long)ptr); brelse(bh); return -EIO; } out_check: if (nilfs_btree_broken_node_block(bh)) { clear_buffer_uptodate(bh); brelse(bh); return -EINVAL; } *bhp = bh; return 0; } static int nilfs_btree_get_block(const struct nilfs_bmap *btree, __u64 ptr, struct buffer_head **bhp) { return __nilfs_btree_get_block(btree, ptr, bhp, NULL); } static int nilfs_btree_do_lookup(const struct nilfs_bmap *btree, struct nilfs_btree_path *path, __u64 key, __u64 *ptrp, int minlevel, int readahead) { struct nilfs_btree_node *node; struct nilfs_btree_readahead_info p, *ra; __u64 ptr; int level, index, found, ncmax, ret; node = nilfs_btree_get_root(btree); level = nilfs_btree_node_get_level(node); if (level < minlevel || nilfs_btree_node_get_nchildren(node) <= 0) return -ENOENT; found = nilfs_btree_node_lookup(node, key, &index); ptr = nilfs_btree_node_get_ptr(node, index, NILFS_BTREE_ROOT_NCHILDREN_MAX); path[level].bp_bh = NULL; path[level].bp_index = index; ncmax = nilfs_btree_nchildren_per_block(btree); while (--level >= minlevel) { ra = NULL; if (level == NILFS_BTREE_LEVEL_NODE_MIN && readahead) { p.node = nilfs_btree_get_node(btree, path, level + 1, &p.ncmax); p.index = index; p.max_ra_blocks = 7; ra = &p; } ret = __nilfs_btree_get_block(btree, ptr, &path[level].bp_bh, ra); if (ret < 0) return ret; node = nilfs_btree_get_nonroot_node(path, level); if (nilfs_btree_bad_node(btree, node, level)) return -EINVAL; if (!found) found = nilfs_btree_node_lookup(node, key, &index); else index = 0; if (index < ncmax) { ptr = nilfs_btree_node_get_ptr(node, index, ncmax); } else { WARN_ON(found || level != NILFS_BTREE_LEVEL_NODE_MIN); /* insert */ ptr = NILFS_BMAP_INVALID_PTR; } path[level].bp_index = index; } if (!found) return -ENOENT; if (ptrp != NULL) *ptrp = ptr; return 0; } static int nilfs_btree_do_lookup_last(const struct nilfs_bmap *btree, struct nilfs_btree_path *path, __u64 *keyp, __u64 *ptrp) { struct nilfs_btree_node *node; __u64 ptr; int index, level, ncmax, ret; node = nilfs_btree_get_root(btree); index = nilfs_btree_node_get_nchildren(node) - 1; if (index < 0) return -ENOENT; level = nilfs_btree_node_get_level(node); ptr = nilfs_btree_node_get_ptr(node, index, NILFS_BTREE_ROOT_NCHILDREN_MAX); path[level].bp_bh = NULL; path[level].bp_index = index; ncmax = nilfs_btree_nchildren_per_block(btree); for (level--; level > 0; level--) { ret = nilfs_btree_get_block(btree, ptr, &path[level].bp_bh); if (ret < 0) return ret; node = nilfs_btree_get_nonroot_node(path, level); if (nilfs_btree_bad_node(btree, node, level)) return -EINVAL; index = nilfs_btree_node_get_nchildren(node) - 1; ptr = nilfs_btree_node_get_ptr(node, index, ncmax); path[level].bp_index = index; } if (keyp != NULL) *keyp = nilfs_btree_node_get_key(node, index); if (ptrp != NULL) *ptrp = ptr; return 0; } /** * nilfs_btree_get_next_key - get next valid key from btree path array * @btree: bmap struct of btree * @path: array of nilfs_btree_path struct * @minlevel: start level * @nextkey: place to store the next valid key * * Return Value: If a next key was found, 0 is returned. Otherwise, * -ENOENT is returned. */ static int nilfs_btree_get_next_key(const struct nilfs_bmap *btree, const struct nilfs_btree_path *path, int minlevel, __u64 *nextkey) { struct nilfs_btree_node *node; int maxlevel = nilfs_btree_height(btree) - 1; int index, next_adj, level; /* Next index is already set to bp_index for leaf nodes. */ next_adj = 0; for (level = minlevel; level <= maxlevel; level++) { if (level == maxlevel) node = nilfs_btree_get_root(btree); else node = nilfs_btree_get_nonroot_node(path, level); index = path[level].bp_index + next_adj; if (index < nilfs_btree_node_get_nchildren(node)) { /* Next key is in this node */ *nextkey = nilfs_btree_node_get_key(node, index); return 0; } /* For non-leaf nodes, next index is stored at bp_index + 1. */ next_adj = 1; } return -ENOENT; } static int nilfs_btree_lookup(const struct nilfs_bmap *btree, __u64 key, int level, __u64 *ptrp) { struct nilfs_btree_path *path; int ret; path = nilfs_btree_alloc_path(); if (path == NULL) return -ENOMEM; ret = nilfs_btree_do_lookup(btree, path, key, ptrp, level, 0); nilfs_btree_free_path(path); return ret; } static int nilfs_btree_lookup_contig(const struct nilfs_bmap *btree, __u64 key, __u64 *ptrp, unsigned int maxblocks) { struct nilfs_btree_path *path; struct nilfs_btree_node *node; struct inode *dat = NULL; __u64 ptr, ptr2; sector_t blocknr; int level = NILFS_BTREE_LEVEL_NODE_MIN; int ret, cnt, index, maxlevel, ncmax; struct nilfs_btree_readahead_info p; path = nilfs_btree_alloc_path(); if (path == NULL) return -ENOMEM; ret = nilfs_btree_do_lookup(btree, path, key, &ptr, level, 1); if (ret < 0) goto out; if (NILFS_BMAP_USE_VBN(btree)) { dat = nilfs_bmap_get_dat(btree); ret = nilfs_dat_translate(dat, ptr, &blocknr); if (ret < 0) goto out; ptr = blocknr; } cnt = 1; if (cnt == maxblocks) goto end; maxlevel = nilfs_btree_height(btree) - 1; node = nilfs_btree_get_node(btree, path, level, &ncmax); index = path[level].bp_index + 1; for (;;) { while (index < nilfs_btree_node_get_nchildren(node)) { if (nilfs_btree_node_get_key(node, index) != key + cnt) goto end; ptr2 = nilfs_btree_node_get_ptr(node, index, ncmax); if (dat) { ret = nilfs_dat_translate(dat, ptr2, &blocknr); if (ret < 0) goto out; ptr2 = blocknr; } if (ptr2 != ptr + cnt || ++cnt == maxblocks) goto end; index++; continue; } if (level == maxlevel) break; /* look-up right sibling node */ p.node = nilfs_btree_get_node(btree, path, level + 1, &p.ncmax); p.index = path[level + 1].bp_index + 1; p.max_ra_blocks = 7; if (p.index >= nilfs_btree_node_get_nchildren(p.node) || nilfs_btree_node_get_key(p.node, p.index) != key + cnt) break; ptr2 = nilfs_btree_node_get_ptr(p.node, p.index, p.ncmax); path[level + 1].bp_index = p.index; brelse(path[level].bp_bh); path[level].bp_bh = NULL; ret = __nilfs_btree_get_block(btree, ptr2, &path[level].bp_bh, &p); if (ret < 0) goto out; node = nilfs_btree_get_nonroot_node(path, level); ncmax = nilfs_btree_nchildren_per_block(btree); index = 0; path[level].bp_index = index; } end: *ptrp = ptr; ret = cnt; out: nilfs_btree_free_path(path); return ret; } static void nilfs_btree_promote_key(struct nilfs_bmap *btree, struct nilfs_btree_path *path, int level, __u64 key) { if (level < nilfs_btree_height(btree) - 1) { do { nilfs_btree_node_set_key( nilfs_btree_get_nonroot_node(path, level), path[level].bp_index, key); if (!buffer_dirty(path[level].bp_bh)) mark_buffer_dirty(path[level].bp_bh); } while ((path[level].bp_index == 0) && (++level < nilfs_btree_height(btree) - 1)); } /* root */ if (level == nilfs_btree_height(btree) - 1) { nilfs_btree_node_set_key(nilfs_btree_get_root(btree), path[level].bp_index, key); } } static void nilfs_btree_do_insert(struct nilfs_bmap *btree, struct nilfs_btree_path *path, int level, __u64 *keyp, __u64 *ptrp) { struct nilfs_btree_node *node; int ncblk; if (level < nilfs_btree_height(btree) - 1) { node = nilfs_btree_get_nonroot_node(path, level); ncblk = nilfs_btree_nchildren_per_block(btree); nilfs_btree_node_insert(node, path[level].bp_index, *keyp, *ptrp, ncblk); if (!buffer_dirty(path[level].bp_bh)) mark_buffer_dirty(path[level].bp_bh); if (path[level].bp_index == 0) nilfs_btree_promote_key(btree, path, level + 1, nilfs_btree_node_get_key(node, 0)); } else { node = nilfs_btree_get_root(btree); nilfs_btree_node_insert(node, path[level].bp_index, *keyp, *ptrp, NILFS_BTREE_ROOT_NCHILDREN_MAX); } } static void nilfs_btree_carry_left(struct nilfs_bmap *btree, struct nilfs_btree_path *path, int level, __u64 *keyp, __u64 *ptrp) { struct nilfs_btree_node *node, *left; int nchildren, lnchildren, n, move, ncblk; node = nilfs_btree_get_nonroot_node(path, level); left = nilfs_btree_get_sib_node(path, level); nchildren = nilfs_btree_node_get_nchildren(node); lnchildren = nilfs_btree_node_get_nchildren(left); ncblk = nilfs_btree_nchildren_per_block(btree); move = 0; n = (nchildren + lnchildren + 1) / 2 - lnchildren; if (n > path[level].bp_index) { /* move insert point */ n--; move = 1; } nilfs_btree_node_move_left(left, node, n, ncblk, ncblk); if (!buffer_dirty(path[level].bp_bh)) mark_buffer_dirty(path[level].bp_bh); if (!buffer_dirty(path[level].bp_sib_bh)) mark_buffer_dirty(path[level].bp_sib_bh); nilfs_btree_promote_key(btree, path, level + 1, nilfs_btree_node_get_key(node, 0)); if (move) { brelse(path[level].bp_bh); path[level].bp_bh = path[level].bp_sib_bh; path[level].bp_sib_bh = NULL; path[level].bp_index += lnchildren; path[level + 1].bp_index--; } else { brelse(path[level].bp_sib_bh); path[level].bp_sib_bh = NULL; path[level].bp_index -= n; } nilfs_btree_do_insert(btree, path, level, keyp, ptrp); } static void nilfs_btree_carry_right(struct nilfs_bmap *btree, struct nilfs_btree_path *path, int level, __u64 *keyp, __u64 *ptrp) { struct nilfs_btree_node *node, *right; int nchildren, rnchildren, n, move, ncblk; node = nilfs_btree_get_nonroot_node(path, level); right = nilfs_btree_get_sib_node(path, level); nchildren = nilfs_btree_node_get_nchildren(node); rnchildren = nilfs_btree_node_get_nchildren(right); ncblk = nilfs_btree_nchildren_per_block(btree); move = 0; n = (nchildren + rnchildren + 1) / 2 - rnchildren; if (n > nchildren - path[level].bp_index) { /* move insert point */ n--; move = 1; } nilfs_btree_node_move_right(node, right, n, ncblk, ncblk); if (!buffer_dirty(path[level].bp_bh)) mark_buffer_dirty(path[level].bp_bh); if (!buffer_dirty(path[level].bp_sib_bh)) mark_buffer_dirty(path[level].bp_sib_bh); path[level + 1].bp_index++; nilfs_btree_promote_key(btree, path, level + 1, nilfs_btree_node_get_key(right, 0)); path[level + 1].bp_index--; if (move) { brelse(path[level].bp_bh); path[level].bp_bh = path[level].bp_sib_bh; path[level].bp_sib_bh = NULL; path[level].bp_index -= nilfs_btree_node_get_nchildren(node); path[level + 1].bp_index++; } else { brelse(path[level].bp_sib_bh); path[level].bp_sib_bh = NULL; } nilfs_btree_do_insert(btree, path, level, keyp, ptrp); } static void nilfs_btree_split(struct nilfs_bmap *btree, struct nilfs_btree_path *path, int level, __u64 *keyp, __u64 *ptrp) { struct nilfs_btree_node *node, *right; int nchildren, n, move, ncblk; node = nilfs_btree_get_nonroot_node(path, level); right = nilfs_btree_get_sib_node(path, level); nchildren = nilfs_btree_node_get_nchildren(node); ncblk = nilfs_btree_nchildren_per_block(btree); move = 0; n = (nchildren + 1) / 2; if (n > nchildren - path[level].bp_index) { n--; move = 1; } nilfs_btree_node_move_right(node, right, n, ncblk, ncblk); if (!buffer_dirty(path[level].bp_bh)) mark_buffer_dirty(path[level].bp_bh); if (!buffer_dirty(path[level].bp_sib_bh)) mark_buffer_dirty(path[level].bp_sib_bh); if (move) { path[level].bp_index -= nilfs_btree_node_get_nchildren(node); nilfs_btree_node_insert(right, path[level].bp_index, *keyp, *ptrp, ncblk); *keyp = nilfs_btree_node_get_key(right, 0); *ptrp = path[level].bp_newreq.bpr_ptr; brelse(path[level].bp_bh); path[level].bp_bh = path[level].bp_sib_bh; path[level].bp_sib_bh = NULL; } else { nilfs_btree_do_insert(btree, path, level, keyp, ptrp); *keyp = nilfs_btree_node_get_key(right, 0); *ptrp = path[level].bp_newreq.bpr_ptr; brelse(path[level].bp_sib_bh); path[level].bp_sib_bh = NULL; } path[level + 1].bp_index++; } static void nilfs_btree_grow(struct nilfs_bmap *btree, struct nilfs_btree_path *path, int level, __u64 *keyp, __u64 *ptrp) { struct nilfs_btree_node *root, *child; int n, ncblk; root = nilfs_btree_get_root(btree); child = nilfs_btree_get_sib_node(path, level); ncblk = nilfs_btree_nchildren_per_block(btree); n = nilfs_btree_node_get_nchildren(root); nilfs_btree_node_move_right(root, child, n, NILFS_BTREE_ROOT_NCHILDREN_MAX, ncblk); nilfs_btree_node_set_level(root, level + 1); if (!buffer_dirty(path[level].bp_sib_bh)) mark_buffer_dirty(path[level].bp_sib_bh); path[level].bp_bh = path[level].bp_sib_bh; path[level].bp_sib_bh = NULL; nilfs_btree_do_insert(btree, path, level, keyp, ptrp); *keyp = nilfs_btree_node_get_key(child, 0); *ptrp = path[level].bp_newreq.bpr_ptr; } static __u64 nilfs_btree_find_near(const struct nilfs_bmap *btree, const struct nilfs_btree_path *path) { struct nilfs_btree_node *node; int level, ncmax; if (path == NULL) return NILFS_BMAP_INVALID_PTR; /* left sibling */ level = NILFS_BTREE_LEVEL_NODE_MIN; if (path[level].bp_index > 0) { node = nilfs_btree_get_node(btree, path, level, &ncmax); return nilfs_btree_node_get_ptr(node, path[level].bp_index - 1, ncmax); } /* parent */ level = NILFS_BTREE_LEVEL_NODE_MIN + 1; if (level <= nilfs_btree_height(btree) - 1) { node = nilfs_btree_get_node(btree, path, level, &ncmax); return nilfs_btree_node_get_ptr(node, path[level].bp_index, ncmax); } return NILFS_BMAP_INVALID_PTR; } static __u64 nilfs_btree_find_target_v(const struct nilfs_bmap *btree, const struct nilfs_btree_path *path, __u64 key) { __u64 ptr; ptr = nilfs_bmap_find_target_seq(btree, key); if (ptr != NILFS_BMAP_INVALID_PTR) /* sequential access */ return ptr; ptr = nilfs_btree_find_near(btree, path); if (ptr != NILFS_BMAP_INVALID_PTR) /* near */ return ptr; /* block group */ return nilfs_bmap_find_target_in_group(btree); } static int nilfs_btree_prepare_insert(struct nilfs_bmap *btree, struct nilfs_btree_path *path, int *levelp, __u64 key, __u64 ptr, struct nilfs_bmap_stats *stats) { struct buffer_head *bh; struct nilfs_btree_node *node, *parent, *sib; __u64 sibptr; int pindex, level, ncmax, ncblk, ret; struct inode *dat = NULL; stats->bs_nblocks = 0; level = NILFS_BTREE_LEVEL_DATA; /* allocate a new ptr for data block */ if (NILFS_BMAP_USE_VBN(btree)) { path[level].bp_newreq.bpr_ptr = nilfs_btree_find_target_v(btree, path, key); dat = nilfs_bmap_get_dat(btree); } ret = nilfs_bmap_prepare_alloc_ptr(btree, &path[level].bp_newreq, dat); if (ret < 0) goto err_out_data; ncblk = nilfs_btree_nchildren_per_block(btree); for (level = NILFS_BTREE_LEVEL_NODE_MIN; level < nilfs_btree_height(btree) - 1; level++) { node = nilfs_btree_get_nonroot_node(path, level); if (nilfs_btree_node_get_nchildren(node) < ncblk) { path[level].bp_op = nilfs_btree_do_insert; stats->bs_nblocks++; goto out; } parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax); pindex = path[level + 1].bp_index; /* left sibling */ if (pindex > 0) { sibptr = nilfs_btree_node_get_ptr(parent, pindex - 1, ncmax); ret = nilfs_btree_get_block(btree, sibptr, &bh); if (ret < 0) goto err_out_child_node; sib = (struct nilfs_btree_node *)bh->b_data; if (nilfs_btree_node_get_nchildren(sib) < ncblk) { path[level].bp_sib_bh = bh; path[level].bp_op = nilfs_btree_carry_left; stats->bs_nblocks++; goto out; } else { brelse(bh); } } /* right sibling */ if (pindex < nilfs_btree_node_get_nchildren(parent) - 1) { sibptr = nilfs_btree_node_get_ptr(parent, pindex + 1, ncmax); ret = nilfs_btree_get_block(btree, sibptr, &bh); if (ret < 0) goto err_out_child_node; sib = (struct nilfs_btree_node *)bh->b_data; if (nilfs_btree_node_get_nchildren(sib) < ncblk) { path[level].bp_sib_bh = bh; path[level].bp_op = nilfs_btree_carry_right; stats->bs_nblocks++; goto out; } else { brelse(bh); } } /* split */ path[level].bp_newreq.bpr_ptr = path[level - 1].bp_newreq.bpr_ptr + 1; ret = nilfs_bmap_prepare_alloc_ptr(btree, &path[level].bp_newreq, dat); if (ret < 0) goto err_out_child_node; ret = nilfs_btree_get_new_block(btree, path[level].bp_newreq.bpr_ptr, &bh); if (ret < 0) goto err_out_curr_node; stats->bs_nblocks++; sib = (struct nilfs_btree_node *)bh->b_data; nilfs_btree_node_init(sib, 0, level, 0, ncblk, NULL, NULL); path[level].bp_sib_bh = bh; path[level].bp_op = nilfs_btree_split; } /* root */ node = nilfs_btree_get_root(btree); if (nilfs_btree_node_get_nchildren(node) < NILFS_BTREE_ROOT_NCHILDREN_MAX) { path[level].bp_op = nilfs_btree_do_insert; stats->bs_nblocks++; goto out; } /* grow */ path[level].bp_newreq.bpr_ptr = path[level - 1].bp_newreq.bpr_ptr + 1; ret = nilfs_bmap_prepare_alloc_ptr(btree, &path[level].bp_newreq, dat); if (ret < 0) goto err_out_child_node; ret = nilfs_btree_get_new_block(btree, path[level].bp_newreq.bpr_ptr, &bh); if (ret < 0) goto err_out_curr_node; nilfs_btree_node_init((struct nilfs_btree_node *)bh->b_data, 0, level, 0, ncblk, NULL, NULL); path[level].bp_sib_bh = bh; path[level].bp_op = nilfs_btree_grow; level++; path[level].bp_op = nilfs_btree_do_insert; /* a newly-created node block and a data block are added */ stats->bs_nblocks += 2; /* success */ out: *levelp = level; return ret; /* error */ err_out_curr_node: nilfs_bmap_abort_alloc_ptr(btree, &path[level].bp_newreq, dat); err_out_child_node: for (level--; level > NILFS_BTREE_LEVEL_DATA; level--) { nilfs_btnode_delete(path[level].bp_sib_bh); nilfs_bmap_abort_alloc_ptr(btree, &path[level].bp_newreq, dat); } nilfs_bmap_abort_alloc_ptr(btree, &path[level].bp_newreq, dat); err_out_data: *levelp = level; stats->bs_nblocks = 0; return ret; } static void nilfs_btree_commit_insert(struct nilfs_bmap *btree, struct nilfs_btree_path *path, int maxlevel, __u64 key, __u64 ptr) { struct inode *dat = NULL; int level; set_buffer_nilfs_volatile((struct buffer_head *)((unsigned long)ptr)); ptr = path[NILFS_BTREE_LEVEL_DATA].bp_newreq.bpr_ptr; if (NILFS_BMAP_USE_VBN(btree)) { nilfs_bmap_set_target_v(btree, key, ptr); dat = nilfs_bmap_get_dat(btree); } for (level = NILFS_BTREE_LEVEL_NODE_MIN; level <= maxlevel; level++) { nilfs_bmap_commit_alloc_ptr(btree, &path[level - 1].bp_newreq, dat); path[level].bp_op(btree, path, level, &key, &ptr); } if (!nilfs_bmap_dirty(btree)) nilfs_bmap_set_dirty(btree); } static int nilfs_btree_insert(struct nilfs_bmap *btree, __u64 key, __u64 ptr) { struct nilfs_btree_path *path; struct nilfs_bmap_stats stats; int level, ret; path = nilfs_btree_alloc_path(); if (path == NULL) return -ENOMEM; ret = nilfs_btree_do_lookup(btree, path, key, NULL, NILFS_BTREE_LEVEL_NODE_MIN, 0); if (ret != -ENOENT) { if (ret == 0) ret = -EEXIST; goto out; } ret = nilfs_btree_prepare_insert(btree, path, &level, key, ptr, &stats); if (ret < 0) goto out; nilfs_btree_commit_insert(btree, path, level, key, ptr); nilfs_inode_add_blocks(btree->b_inode, stats.bs_nblocks); out: nilfs_btree_free_path(path); return ret; } static void nilfs_btree_do_delete(struct nilfs_bmap *btree, struct nilfs_btree_path *path, int level, __u64 *keyp, __u64 *ptrp) { struct nilfs_btree_node *node; int ncblk; if (level < nilfs_btree_height(btree) - 1) { node = nilfs_btree_get_nonroot_node(path, level); ncblk = nilfs_btree_nchildren_per_block(btree); nilfs_btree_node_delete(node, path[level].bp_index, keyp, ptrp, ncblk); if (!buffer_dirty(path[level].bp_bh)) mark_buffer_dirty(path[level].bp_bh); if (path[level].bp_index == 0) nilfs_btree_promote_key(btree, path, level + 1, nilfs_btree_node_get_key(node, 0)); } else { node = nilfs_btree_get_root(btree); nilfs_btree_node_delete(node, path[level].bp_index, keyp, ptrp, NILFS_BTREE_ROOT_NCHILDREN_MAX); } } static void nilfs_btree_borrow_left(struct nilfs_bmap *btree, struct nilfs_btree_path *path, int level, __u64 *keyp, __u64 *ptrp) { struct nilfs_btree_node *node, *left; int nchildren, lnchildren, n, ncblk; nilfs_btree_do_delete(btree, path, level, keyp, ptrp); node = nilfs_btree_get_nonroot_node(path, level); left = nilfs_btree_get_sib_node(path, level); nchildren = nilfs_btree_node_get_nchildren(node); lnchildren = nilfs_btree_node_get_nchildren(left); ncblk = nilfs_btree_nchildren_per_block(btree); n = (nchildren + lnchildren) / 2 - nchildren; nilfs_btree_node_move_right(left, node, n, ncblk, ncblk); if (!buffer_dirty(path[level].bp_bh)) mark_buffer_dirty(path[level].bp_bh); if (!buffer_dirty(path[level].bp_sib_bh)) mark_buffer_dirty(path[level].bp_sib_bh); nilfs_btree_promote_key(btree, path, level + 1, nilfs_btree_node_get_key(node, 0)); brelse(path[level].bp_sib_bh); path[level].bp_sib_bh = NULL; path[level].bp_index += n; } static void nilfs_btree_borrow_right(struct nilfs_bmap *btree, struct nilfs_btree_path *path, int level, __u64 *keyp, __u64 *ptrp) { struct nilfs_btree_node *node, *right; int nchildren, rnchildren, n, ncblk; nilfs_btree_do_delete(btree, path, level, keyp, ptrp); node = nilfs_btree_get_nonroot_node(path, level); right = nilfs_btree_get_sib_node(path, level); nchildren = nilfs_btree_node_get_nchildren(node); rnchildren = nilfs_btree_node_get_nchildren(right); ncblk = nilfs_btree_nchildren_per_block(btree); n = (nchildren + rnchildren) / 2 - nchildren; nilfs_btree_node_move_left(node, right, n, ncblk, ncblk); if (!buffer_dirty(path[level].bp_bh)) mark_buffer_dirty(path[level].bp_bh); if (!buffer_dirty(path[level].bp_sib_bh)) mark_buffer_dirty(path[level].bp_sib_bh); path[level + 1].bp_index++; nilfs_btree_promote_key(btree, path, level + 1, nilfs_btree_node_get_key(right, 0)); path[level + 1].bp_index--; brelse(path[level].bp_sib_bh); path[level].bp_sib_bh = NULL; } static void nilfs_btree_concat_left(struct nilfs_bmap *btree, struct nilfs_btree_path *path, int level, __u64 *keyp, __u64 *ptrp) { struct nilfs_btree_node *node, *left; int n, ncblk; nilfs_btree_do_delete(btree, path, level, keyp, ptrp); node = nilfs_btree_get_nonroot_node(path, level); left = nilfs_btree_get_sib_node(path, level); ncblk = nilfs_btree_nchildren_per_block(btree); n = nilfs_btree_node_get_nchildren(node); nilfs_btree_node_move_left(left, node, n, ncblk, ncblk); if (!buffer_dirty(path[level].bp_sib_bh)) mark_buffer_dirty(path[level].bp_sib_bh); nilfs_btnode_delete(path[level].bp_bh); path[level].bp_bh = path[level].bp_sib_bh; path[level].bp_sib_bh = NULL; path[level].bp_index += nilfs_btree_node_get_nchildren(left); } static void nilfs_btree_concat_right(struct nilfs_bmap *btree, struct nilfs_btree_path *path, int level, __u64 *keyp, __u64 *ptrp) { struct nilfs_btree_node *node, *right; int n, ncblk; nilfs_btree_do_delete(btree, path, level, keyp, ptrp); node = nilfs_btree_get_nonroot_node(path, level); right = nilfs_btree_get_sib_node(path, level); ncblk = nilfs_btree_nchildren_per_block(btree); n = nilfs_btree_node_get_nchildren(right); nilfs_btree_node_move_left(node, right, n, ncblk, ncblk); if (!buffer_dirty(path[level].bp_bh)) mark_buffer_dirty(path[level].bp_bh); nilfs_btnode_delete(path[level].bp_sib_bh); path[level].bp_sib_bh = NULL; path[level + 1].bp_index++; } static void nilfs_btree_shrink(struct nilfs_bmap *btree, struct nilfs_btree_path *path, int level, __u64 *keyp, __u64 *ptrp) { struct nilfs_btree_node *root, *child; int n, ncblk; nilfs_btree_do_delete(btree, path, level, keyp, ptrp); root = nilfs_btree_get_root(btree); child = nilfs_btree_get_nonroot_node(path, level); ncblk = nilfs_btree_nchildren_per_block(btree); nilfs_btree_node_delete(root, 0, NULL, NULL, NILFS_BTREE_ROOT_NCHILDREN_MAX); nilfs_btree_node_set_level(root, level); n = nilfs_btree_node_get_nchildren(child); nilfs_btree_node_move_left(root, child, n, NILFS_BTREE_ROOT_NCHILDREN_MAX, ncblk); nilfs_btnode_delete(path[level].bp_bh); path[level].bp_bh = NULL; } static void nilfs_btree_nop(struct nilfs_bmap *btree, struct nilfs_btree_path *path, int level, __u64 *keyp, __u64 *ptrp) { } static int nilfs_btree_prepare_delete(struct nilfs_bmap *btree, struct nilfs_btree_path *path, int *levelp, struct nilfs_bmap_stats *stats, struct inode *dat) { struct buffer_head *bh; struct nilfs_btree_node *node, *parent, *sib; __u64 sibptr; int pindex, dindex, level, ncmin, ncmax, ncblk, ret; ret = 0; stats->bs_nblocks = 0; ncmin = NILFS_BTREE_NODE_NCHILDREN_MIN(nilfs_btree_node_size(btree)); ncblk = nilfs_btree_nchildren_per_block(btree); for (level = NILFS_BTREE_LEVEL_NODE_MIN, dindex = path[level].bp_index; level < nilfs_btree_height(btree) - 1; level++) { node = nilfs_btree_get_nonroot_node(path, level); path[level].bp_oldreq.bpr_ptr = nilfs_btree_node_get_ptr(node, dindex, ncblk); ret = nilfs_bmap_prepare_end_ptr(btree, &path[level].bp_oldreq, dat); if (ret < 0) goto err_out_child_node; if (nilfs_btree_node_get_nchildren(node) > ncmin) { path[level].bp_op = nilfs_btree_do_delete; stats->bs_nblocks++; goto out; } parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax); pindex = path[level + 1].bp_index; dindex = pindex; if (pindex > 0) { /* left sibling */ sibptr = nilfs_btree_node_get_ptr(parent, pindex - 1, ncmax); ret = nilfs_btree_get_block(btree, sibptr, &bh); if (ret < 0) goto err_out_curr_node; sib = (struct nilfs_btree_node *)bh->b_data; if (nilfs_btree_node_get_nchildren(sib) > ncmin) { path[level].bp_sib_bh = bh; path[level].bp_op = nilfs_btree_borrow_left; stats->bs_nblocks++; goto out; } else { path[level].bp_sib_bh = bh; path[level].bp_op = nilfs_btree_concat_left; stats->bs_nblocks++; /* continue; */ } } else if (pindex < nilfs_btree_node_get_nchildren(parent) - 1) { /* right sibling */ sibptr = nilfs_btree_node_get_ptr(parent, pindex + 1, ncmax); ret = nilfs_btree_get_block(btree, sibptr, &bh); if (ret < 0) goto err_out_curr_node; sib = (struct nilfs_btree_node *)bh->b_data; if (nilfs_btree_node_get_nchildren(sib) > ncmin) { path[level].bp_sib_bh = bh; path[level].bp_op = nilfs_btree_borrow_right; stats->bs_nblocks++; goto out; } else { path[level].bp_sib_bh = bh; path[level].bp_op = nilfs_btree_concat_right; stats->bs_nblocks++; /* * When merging right sibling node * into the current node, pointer to * the right sibling node must be * terminated instead. The adjustment * below is required for that. */ dindex = pindex + 1; /* continue; */ } } else { /* no siblings */ /* the only child of the root node */ WARN_ON(level != nilfs_btree_height(btree) - 2); if (nilfs_btree_node_get_nchildren(node) - 1 <= NILFS_BTREE_ROOT_NCHILDREN_MAX) { path[level].bp_op = nilfs_btree_shrink; stats->bs_nblocks += 2; level++; path[level].bp_op = nilfs_btree_nop; goto shrink_root_child; } else { path[level].bp_op = nilfs_btree_do_delete; stats->bs_nblocks++; goto out; } } } /* child of the root node is deleted */ path[level].bp_op = nilfs_btree_do_delete; stats->bs_nblocks++; shrink_root_child: node = nilfs_btree_get_root(btree); path[level].bp_oldreq.bpr_ptr = nilfs_btree_node_get_ptr(node, dindex, NILFS_BTREE_ROOT_NCHILDREN_MAX); ret = nilfs_bmap_prepare_end_ptr(btree, &path[level].bp_oldreq, dat); if (ret < 0) goto err_out_child_node; /* success */ out: *levelp = level; return ret; /* error */ err_out_curr_node: nilfs_bmap_abort_end_ptr(btree, &path[level].bp_oldreq, dat); err_out_child_node: for (level--; level >= NILFS_BTREE_LEVEL_NODE_MIN; level--) { brelse(path[level].bp_sib_bh); nilfs_bmap_abort_end_ptr(btree, &path[level].bp_oldreq, dat); } *levelp = level; stats->bs_nblocks = 0; return ret; } static void nilfs_btree_commit_delete(struct nilfs_bmap *btree, struct nilfs_btree_path *path, int maxlevel, struct inode *dat) { int level; for (level = NILFS_BTREE_LEVEL_NODE_MIN; level <= maxlevel; level++) { nilfs_bmap_commit_end_ptr(btree, &path[level].bp_oldreq, dat); path[level].bp_op(btree, path, level, NULL, NULL); } if (!nilfs_bmap_dirty(btree)) nilfs_bmap_set_dirty(btree); } static int nilfs_btree_delete(struct nilfs_bmap *btree, __u64 key) { struct nilfs_btree_path *path; struct nilfs_bmap_stats stats; struct inode *dat; int level, ret; path = nilfs_btree_alloc_path(); if (path == NULL) return -ENOMEM; ret = nilfs_btree_do_lookup(btree, path, key, NULL, NILFS_BTREE_LEVEL_NODE_MIN, 0); if (ret < 0) goto out; dat = NILFS_BMAP_USE_VBN(btree) ? nilfs_bmap_get_dat(btree) : NULL; ret = nilfs_btree_prepare_delete(btree, path, &level, &stats, dat); if (ret < 0) goto out; nilfs_btree_commit_delete(btree, path, level, dat); nilfs_inode_sub_blocks(btree->b_inode, stats.bs_nblocks); out: nilfs_btree_free_path(path); return ret; } static int nilfs_btree_seek_key(const struct nilfs_bmap *btree, __u64 start, __u64 *keyp) { struct nilfs_btree_path *path; const int minlevel = NILFS_BTREE_LEVEL_NODE_MIN; int ret; path = nilfs_btree_alloc_path(); if (!path) return -ENOMEM; ret = nilfs_btree_do_lookup(btree, path, start, NULL, minlevel, 0); if (!ret) *keyp = start; else if (ret == -ENOENT) ret = nilfs_btree_get_next_key(btree, path, minlevel, keyp); nilfs_btree_free_path(path); return ret; } static int nilfs_btree_last_key(const struct nilfs_bmap *btree, __u64 *keyp) { struct nilfs_btree_path *path; int ret; path = nilfs_btree_alloc_path(); if (path == NULL) return -ENOMEM; ret = nilfs_btree_do_lookup_last(btree, path, keyp, NULL); nilfs_btree_free_path(path); return ret; } static int nilfs_btree_check_delete(struct nilfs_bmap *btree, __u64 key) { struct buffer_head *bh; struct nilfs_btree_node *root, *node; __u64 maxkey, nextmaxkey; __u64 ptr; int nchildren, ret; root = nilfs_btree_get_root(btree); switch (nilfs_btree_height(btree)) { case 2: bh = NULL; node = root; break; case 3: nchildren = nilfs_btree_node_get_nchildren(root); if (nchildren > 1) return 0; ptr = nilfs_btree_node_get_ptr(root, nchildren - 1, NILFS_BTREE_ROOT_NCHILDREN_MAX); ret = nilfs_btree_get_block(btree, ptr, &bh); if (ret < 0) return ret; node = (struct nilfs_btree_node *)bh->b_data; break; default: return 0; } nchildren = nilfs_btree_node_get_nchildren(node); maxkey = nilfs_btree_node_get_key(node, nchildren - 1); nextmaxkey = (nchildren > 1) ? nilfs_btree_node_get_key(node, nchildren - 2) : 0; if (bh != NULL) brelse(bh); return (maxkey == key) && (nextmaxkey < NILFS_BMAP_LARGE_LOW); } static int nilfs_btree_gather_data(struct nilfs_bmap *btree, __u64 *keys, __u64 *ptrs, int nitems) { struct buffer_head *bh; struct nilfs_btree_node *node, *root; __le64 *dkeys; __le64 *dptrs; __u64 ptr; int nchildren, ncmax, i, ret; root = nilfs_btree_get_root(btree); switch (nilfs_btree_height(btree)) { case 2: bh = NULL; node = root; ncmax = NILFS_BTREE_ROOT_NCHILDREN_MAX; break; case 3: nchildren = nilfs_btree_node_get_nchildren(root); WARN_ON(nchildren > 1); ptr = nilfs_btree_node_get_ptr(root, nchildren - 1, NILFS_BTREE_ROOT_NCHILDREN_MAX); ret = nilfs_btree_get_block(btree, ptr, &bh); if (ret < 0) return ret; node = (struct nilfs_btree_node *)bh->b_data; ncmax = nilfs_btree_nchildren_per_block(btree); break; default: node = NULL; return -EINVAL; } nchildren = nilfs_btree_node_get_nchildren(node); if (nchildren < nitems) nitems = nchildren; dkeys = nilfs_btree_node_dkeys(node); dptrs = nilfs_btree_node_dptrs(node, ncmax); for (i = 0; i < nitems; i++) { keys[i] = le64_to_cpu(dkeys[i]); ptrs[i] = le64_to_cpu(dptrs[i]); } if (bh != NULL) brelse(bh); return nitems; } static int nilfs_btree_prepare_convert_and_insert(struct nilfs_bmap *btree, __u64 key, union nilfs_bmap_ptr_req *dreq, union nilfs_bmap_ptr_req *nreq, struct buffer_head **bhp, struct nilfs_bmap_stats *stats) { struct buffer_head *bh; struct inode *dat = NULL; int ret; stats->bs_nblocks = 0; /* for data */ /* cannot find near ptr */ if (NILFS_BMAP_USE_VBN(btree)) { dreq->bpr_ptr = nilfs_btree_find_target_v(btree, NULL, key); dat = nilfs_bmap_get_dat(btree); } ret = nilfs_bmap_prepare_alloc_ptr(btree, dreq, dat); if (ret < 0) return ret; *bhp = NULL; stats->bs_nblocks++; if (nreq != NULL) { nreq->bpr_ptr = dreq->bpr_ptr + 1; ret = nilfs_bmap_prepare_alloc_ptr(btree, nreq, dat); if (ret < 0) goto err_out_dreq; ret = nilfs_btree_get_new_block(btree, nreq->bpr_ptr, &bh); if (ret < 0) goto err_out_nreq; *bhp = bh; stats->bs_nblocks++; } /* success */ return 0; /* error */ err_out_nreq: nilfs_bmap_abort_alloc_ptr(btree, nreq, dat); err_out_dreq: nilfs_bmap_abort_alloc_ptr(btree, dreq, dat); stats->bs_nblocks = 0; return ret; } static void nilfs_btree_commit_convert_and_insert(struct nilfs_bmap *btree, __u64 key, __u64 ptr, const __u64 *keys, const __u64 *ptrs, int n, union nilfs_bmap_ptr_req *dreq, union nilfs_bmap_ptr_req *nreq, struct buffer_head *bh) { struct nilfs_btree_node *node; struct inode *dat; __u64 tmpptr; int ncblk; /* free resources */ if (btree->b_ops->bop_clear != NULL) btree->b_ops->bop_clear(btree); /* ptr must be a pointer to a buffer head. */ set_buffer_nilfs_volatile((struct buffer_head *)((unsigned long)ptr)); /* convert and insert */ dat = NILFS_BMAP_USE_VBN(btree) ? nilfs_bmap_get_dat(btree) : NULL; __nilfs_btree_init(btree); if (nreq != NULL) { nilfs_bmap_commit_alloc_ptr(btree, dreq, dat); nilfs_bmap_commit_alloc_ptr(btree, nreq, dat); /* create child node at level 1 */ node = (struct nilfs_btree_node *)bh->b_data; ncblk = nilfs_btree_nchildren_per_block(btree); nilfs_btree_node_init(node, 0, 1, n, ncblk, keys, ptrs); nilfs_btree_node_insert(node, n, key, dreq->bpr_ptr, ncblk); if (!buffer_dirty(bh)) mark_buffer_dirty(bh); if (!nilfs_bmap_dirty(btree)) nilfs_bmap_set_dirty(btree); brelse(bh); /* create root node at level 2 */ node = nilfs_btree_get_root(btree); tmpptr = nreq->bpr_ptr; nilfs_btree_node_init(node, NILFS_BTREE_NODE_ROOT, 2, 1, NILFS_BTREE_ROOT_NCHILDREN_MAX, &keys[0], &tmpptr); } else { nilfs_bmap_commit_alloc_ptr(btree, dreq, dat); /* create root node at level 1 */ node = nilfs_btree_get_root(btree); nilfs_btree_node_init(node, NILFS_BTREE_NODE_ROOT, 1, n, NILFS_BTREE_ROOT_NCHILDREN_MAX, keys, ptrs); nilfs_btree_node_insert(node, n, key, dreq->bpr_ptr, NILFS_BTREE_ROOT_NCHILDREN_MAX); if (!nilfs_bmap_dirty(btree)) nilfs_bmap_set_dirty(btree); } if (NILFS_BMAP_USE_VBN(btree)) nilfs_bmap_set_target_v(btree, key, dreq->bpr_ptr); } /** * nilfs_btree_convert_and_insert - * @bmap: * @key: * @ptr: * @keys: * @ptrs: * @n: */ int nilfs_btree_convert_and_insert(struct nilfs_bmap *btree, __u64 key, __u64 ptr, const __u64 *keys, const __u64 *ptrs, int n) { struct buffer_head *bh = NULL; union nilfs_bmap_ptr_req dreq, nreq, *di, *ni; struct nilfs_bmap_stats stats; int ret; if (n + 1 <= NILFS_BTREE_ROOT_NCHILDREN_MAX) { di = &dreq; ni = NULL; } else if ((n + 1) <= NILFS_BTREE_NODE_NCHILDREN_MAX( nilfs_btree_node_size(btree))) { di = &dreq; ni = &nreq; } else { di = NULL; ni = NULL; BUG(); } ret = nilfs_btree_prepare_convert_and_insert(btree, key, di, ni, &bh, &stats); if (ret < 0) return ret; nilfs_btree_commit_convert_and_insert(btree, key, ptr, keys, ptrs, n, di, ni, bh); nilfs_inode_add_blocks(btree->b_inode, stats.bs_nblocks); return 0; } static int nilfs_btree_propagate_p(struct nilfs_bmap *btree, struct nilfs_btree_path *path, int level, struct buffer_head *bh) { while ((++level < nilfs_btree_height(btree) - 1) && !buffer_dirty(path[level].bp_bh)) mark_buffer_dirty(path[level].bp_bh); return 0; } static int nilfs_btree_prepare_update_v(struct nilfs_bmap *btree, struct nilfs_btree_path *path, int level, struct inode *dat) { struct nilfs_btree_node *parent; int ncmax, ret; parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax); path[level].bp_oldreq.bpr_ptr = nilfs_btree_node_get_ptr(parent, path[level + 1].bp_index, ncmax); path[level].bp_newreq.bpr_ptr = path[level].bp_oldreq.bpr_ptr + 1; ret = nilfs_dat_prepare_update(dat, &path[level].bp_oldreq.bpr_req, &path[level].bp_newreq.bpr_req); if (ret < 0) return ret; if (buffer_nilfs_node(path[level].bp_bh)) { path[level].bp_ctxt.oldkey = path[level].bp_oldreq.bpr_ptr; path[level].bp_ctxt.newkey = path[level].bp_newreq.bpr_ptr; path[level].bp_ctxt.bh = path[level].bp_bh; ret = nilfs_btnode_prepare_change_key( &NILFS_BMAP_I(btree)->i_btnode_cache, &path[level].bp_ctxt); if (ret < 0) { nilfs_dat_abort_update(dat, &path[level].bp_oldreq.bpr_req, &path[level].bp_newreq.bpr_req); return ret; } } return 0; } static void nilfs_btree_commit_update_v(struct nilfs_bmap *btree, struct nilfs_btree_path *path, int level, struct inode *dat) { struct nilfs_btree_node *parent; int ncmax; nilfs_dat_commit_update(dat, &path[level].bp_oldreq.bpr_req, &path[level].bp_newreq.bpr_req, btree->b_ptr_type == NILFS_BMAP_PTR_VS); if (buffer_nilfs_node(path[level].bp_bh)) { nilfs_btnode_commit_change_key( &NILFS_BMAP_I(btree)->i_btnode_cache, &path[level].bp_ctxt); path[level].bp_bh = path[level].bp_ctxt.bh; } set_buffer_nilfs_volatile(path[level].bp_bh); parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax); nilfs_btree_node_set_ptr(parent, path[level + 1].bp_index, path[level].bp_newreq.bpr_ptr, ncmax); } static void nilfs_btree_abort_update_v(struct nilfs_bmap *btree, struct nilfs_btree_path *path, int level, struct inode *dat) { nilfs_dat_abort_update(dat, &path[level].bp_oldreq.bpr_req, &path[level].bp_newreq.bpr_req); if (buffer_nilfs_node(path[level].bp_bh)) nilfs_btnode_abort_change_key( &NILFS_BMAP_I(btree)->i_btnode_cache, &path[level].bp_ctxt); } static int nilfs_btree_prepare_propagate_v(struct nilfs_bmap *btree, struct nilfs_btree_path *path, int minlevel, int *maxlevelp, struct inode *dat) { int level, ret; level = minlevel; if (!buffer_nilfs_volatile(path[level].bp_bh)) { ret = nilfs_btree_prepare_update_v(btree, path, level, dat); if (ret < 0) return ret; } while ((++level < nilfs_btree_height(btree) - 1) && !buffer_dirty(path[level].bp_bh)) { WARN_ON(buffer_nilfs_volatile(path[level].bp_bh)); ret = nilfs_btree_prepare_update_v(btree, path, level, dat); if (ret < 0) goto out; } /* success */ *maxlevelp = level - 1; return 0; /* error */ out: while (--level > minlevel) nilfs_btree_abort_update_v(btree, path, level, dat); if (!buffer_nilfs_volatile(path[level].bp_bh)) nilfs_btree_abort_update_v(btree, path, level, dat); return ret; } static void nilfs_btree_commit_propagate_v(struct nilfs_bmap *btree, struct nilfs_btree_path *path, int minlevel, int maxlevel, struct buffer_head *bh, struct inode *dat) { int level; if (!buffer_nilfs_volatile(path[minlevel].bp_bh)) nilfs_btree_commit_update_v(btree, path, minlevel, dat); for (level = minlevel + 1; level <= maxlevel; level++) nilfs_btree_commit_update_v(btree, path, level, dat); } static int nilfs_btree_propagate_v(struct nilfs_bmap *btree, struct nilfs_btree_path *path, int level, struct buffer_head *bh) { int maxlevel = 0, ret; struct nilfs_btree_node *parent; struct inode *dat = nilfs_bmap_get_dat(btree); __u64 ptr; int ncmax; get_bh(bh); path[level].bp_bh = bh; ret = nilfs_btree_prepare_propagate_v(btree, path, level, &maxlevel, dat); if (ret < 0) goto out; if (buffer_nilfs_volatile(path[level].bp_bh)) { parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax); ptr = nilfs_btree_node_get_ptr(parent, path[level + 1].bp_index, ncmax); ret = nilfs_dat_mark_dirty(dat, ptr); if (ret < 0) goto out; } nilfs_btree_commit_propagate_v(btree, path, level, maxlevel, bh, dat); out: brelse(path[level].bp_bh); path[level].bp_bh = NULL; return ret; } static int nilfs_btree_propagate(struct nilfs_bmap *btree, struct buffer_head *bh) { struct nilfs_btree_path *path; struct nilfs_btree_node *node; __u64 key; int level, ret; WARN_ON(!buffer_dirty(bh)); path = nilfs_btree_alloc_path(); if (path == NULL) return -ENOMEM; if (buffer_nilfs_node(bh)) { node = (struct nilfs_btree_node *)bh->b_data; key = nilfs_btree_node_get_key(node, 0); level = nilfs_btree_node_get_level(node); } else { key = nilfs_bmap_data_get_key(btree, bh); level = NILFS_BTREE_LEVEL_DATA; } ret = nilfs_btree_do_lookup(btree, path, key, NULL, level + 1, 0); if (ret < 0) { if (unlikely(ret == -ENOENT)) nilfs_crit(btree->b_inode->i_sb, "writing node/leaf block does not appear in b-tree (ino=%lu) at key=%llu, level=%d", btree->b_inode->i_ino, (unsigned long long)key, level); goto out; } ret = NILFS_BMAP_USE_VBN(btree) ? nilfs_btree_propagate_v(btree, path, level, bh) : nilfs_btree_propagate_p(btree, path, level, bh); out: nilfs_btree_free_path(path); return ret; } static int nilfs_btree_propagate_gc(struct nilfs_bmap *btree, struct buffer_head *bh) { return nilfs_dat_mark_dirty(nilfs_bmap_get_dat(btree), bh->b_blocknr); } static void nilfs_btree_add_dirty_buffer(struct nilfs_bmap *btree, struct list_head *lists, struct buffer_head *bh) { struct list_head *head; struct buffer_head *cbh; struct nilfs_btree_node *node, *cnode; __u64 key, ckey; int level; get_bh(bh); node = (struct nilfs_btree_node *)bh->b_data; key = nilfs_btree_node_get_key(node, 0); level = nilfs_btree_node_get_level(node); if (level < NILFS_BTREE_LEVEL_NODE_MIN || level >= NILFS_BTREE_LEVEL_MAX) { dump_stack(); nilfs_warn(btree->b_inode->i_sb, "invalid btree level: %d (key=%llu, ino=%lu, blocknr=%llu)", level, (unsigned long long)key, btree->b_inode->i_ino, (unsigned long long)bh->b_blocknr); return; } list_for_each(head, &lists[level]) { cbh = list_entry(head, struct buffer_head, b_assoc_buffers); cnode = (struct nilfs_btree_node *)cbh->b_data; ckey = nilfs_btree_node_get_key(cnode, 0); if (key < ckey) break; } list_add_tail(&bh->b_assoc_buffers, head); } static void nilfs_btree_lookup_dirty_buffers(struct nilfs_bmap *btree, struct list_head *listp) { struct address_space *btcache = &NILFS_BMAP_I(btree)->i_btnode_cache; struct list_head lists[NILFS_BTREE_LEVEL_MAX]; struct pagevec pvec; struct buffer_head *bh, *head; pgoff_t index = 0; int level, i; for (level = NILFS_BTREE_LEVEL_NODE_MIN; level < NILFS_BTREE_LEVEL_MAX; level++) INIT_LIST_HEAD(&lists[level]); pagevec_init(&pvec); while (pagevec_lookup_tag(&pvec, btcache, &index, PAGECACHE_TAG_DIRTY)) { for (i = 0; i < pagevec_count(&pvec); i++) { bh = head = page_buffers(pvec.pages[i]); do { if (buffer_dirty(bh)) nilfs_btree_add_dirty_buffer(btree, lists, bh); } while ((bh = bh->b_this_page) != head); } pagevec_release(&pvec); cond_resched(); } for (level = NILFS_BTREE_LEVEL_NODE_MIN; level < NILFS_BTREE_LEVEL_MAX; level++) list_splice_tail(&lists[level], listp); } static int nilfs_btree_assign_p(struct nilfs_bmap *btree, struct nilfs_btree_path *path, int level, struct buffer_head **bh, sector_t blocknr, union nilfs_binfo *binfo) { struct nilfs_btree_node *parent; __u64 key; __u64 ptr; int ncmax, ret; parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax); ptr = nilfs_btree_node_get_ptr(parent, path[level + 1].bp_index, ncmax); if (buffer_nilfs_node(*bh)) { path[level].bp_ctxt.oldkey = ptr; path[level].bp_ctxt.newkey = blocknr; path[level].bp_ctxt.bh = *bh; ret = nilfs_btnode_prepare_change_key( &NILFS_BMAP_I(btree)->i_btnode_cache, &path[level].bp_ctxt); if (ret < 0) return ret; nilfs_btnode_commit_change_key( &NILFS_BMAP_I(btree)->i_btnode_cache, &path[level].bp_ctxt); *bh = path[level].bp_ctxt.bh; } nilfs_btree_node_set_ptr(parent, path[level + 1].bp_index, blocknr, ncmax); key = nilfs_btree_node_get_key(parent, path[level + 1].bp_index); /* on-disk format */ binfo->bi_dat.bi_blkoff = cpu_to_le64(key); binfo->bi_dat.bi_level = level; return 0; } static int nilfs_btree_assign_v(struct nilfs_bmap *btree, struct nilfs_btree_path *path, int level, struct buffer_head **bh, sector_t blocknr, union nilfs_binfo *binfo) { struct nilfs_btree_node *parent; struct inode *dat = nilfs_bmap_get_dat(btree); __u64 key; __u64 ptr; union nilfs_bmap_ptr_req req; int ncmax, ret; parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax); ptr = nilfs_btree_node_get_ptr(parent, path[level + 1].bp_index, ncmax); req.bpr_ptr = ptr; ret = nilfs_dat_prepare_start(dat, &req.bpr_req); if (ret < 0) return ret; nilfs_dat_commit_start(dat, &req.bpr_req, blocknr); key = nilfs_btree_node_get_key(parent, path[level + 1].bp_index); /* on-disk format */ binfo->bi_v.bi_vblocknr = cpu_to_le64(ptr); binfo->bi_v.bi_blkoff = cpu_to_le64(key); return 0; } static int nilfs_btree_assign(struct nilfs_bmap *btree, struct buffer_head **bh, sector_t blocknr, union nilfs_binfo *binfo) { struct nilfs_btree_path *path; struct nilfs_btree_node *node; __u64 key; int level, ret; path = nilfs_btree_alloc_path(); if (path == NULL) return -ENOMEM; if (buffer_nilfs_node(*bh)) { node = (struct nilfs_btree_node *)(*bh)->b_data; key = nilfs_btree_node_get_key(node, 0); level = nilfs_btree_node_get_level(node); } else { key = nilfs_bmap_data_get_key(btree, *bh); level = NILFS_BTREE_LEVEL_DATA; } ret = nilfs_btree_do_lookup(btree, path, key, NULL, level + 1, 0); if (ret < 0) { WARN_ON(ret == -ENOENT); goto out; } ret = NILFS_BMAP_USE_VBN(btree) ? nilfs_btree_assign_v(btree, path, level, bh, blocknr, binfo) : nilfs_btree_assign_p(btree, path, level, bh, blocknr, binfo); out: nilfs_btree_free_path(path); return ret; } static int nilfs_btree_assign_gc(struct nilfs_bmap *btree, struct buffer_head **bh, sector_t blocknr, union nilfs_binfo *binfo) { struct nilfs_btree_node *node; __u64 key; int ret; ret = nilfs_dat_move(nilfs_bmap_get_dat(btree), (*bh)->b_blocknr, blocknr); if (ret < 0) return ret; if (buffer_nilfs_node(*bh)) { node = (struct nilfs_btree_node *)(*bh)->b_data; key = nilfs_btree_node_get_key(node, 0); } else key = nilfs_bmap_data_get_key(btree, *bh); /* on-disk format */ binfo->bi_v.bi_vblocknr = cpu_to_le64((*bh)->b_blocknr); binfo->bi_v.bi_blkoff = cpu_to_le64(key); return 0; } static int nilfs_btree_mark(struct nilfs_bmap *btree, __u64 key, int level) { struct buffer_head *bh; struct nilfs_btree_path *path; __u64 ptr; int ret; path = nilfs_btree_alloc_path(); if (path == NULL) return -ENOMEM; ret = nilfs_btree_do_lookup(btree, path, key, &ptr, level + 1, 0); if (ret < 0) { WARN_ON(ret == -ENOENT); goto out; } ret = nilfs_btree_get_block(btree, ptr, &bh); if (ret < 0) { WARN_ON(ret == -ENOENT); goto out; } if (!buffer_dirty(bh)) mark_buffer_dirty(bh); brelse(bh); if (!nilfs_bmap_dirty(btree)) nilfs_bmap_set_dirty(btree); out: nilfs_btree_free_path(path); return ret; } static const struct nilfs_bmap_operations nilfs_btree_ops = { .bop_lookup = nilfs_btree_lookup, .bop_lookup_contig = nilfs_btree_lookup_contig, .bop_insert = nilfs_btree_insert, .bop_delete = nilfs_btree_delete, .bop_clear = NULL, .bop_propagate = nilfs_btree_propagate, .bop_lookup_dirty_buffers = nilfs_btree_lookup_dirty_buffers, .bop_assign = nilfs_btree_assign, .bop_mark = nilfs_btree_mark, .bop_seek_key = nilfs_btree_seek_key, .bop_last_key = nilfs_btree_last_key, .bop_check_insert = NULL, .bop_check_delete = nilfs_btree_check_delete, .bop_gather_data = nilfs_btree_gather_data, }; static const struct nilfs_bmap_operations nilfs_btree_ops_gc = { .bop_lookup = NULL, .bop_lookup_contig = NULL, .bop_insert = NULL, .bop_delete = NULL, .bop_clear = NULL, .bop_propagate = nilfs_btree_propagate_gc, .bop_lookup_dirty_buffers = nilfs_btree_lookup_dirty_buffers, .bop_assign = nilfs_btree_assign_gc, .bop_mark = NULL, .bop_seek_key = NULL, .bop_last_key = NULL, .bop_check_insert = NULL, .bop_check_delete = NULL, .bop_gather_data = NULL, }; static void __nilfs_btree_init(struct nilfs_bmap *bmap) { bmap->b_ops = &nilfs_btree_ops; bmap->b_nchildren_per_block = NILFS_BTREE_NODE_NCHILDREN_MAX(nilfs_btree_node_size(bmap)); } int nilfs_btree_init(struct nilfs_bmap *bmap) { int ret = 0; __nilfs_btree_init(bmap); if (nilfs_btree_root_broken(nilfs_btree_get_root(bmap), bmap->b_inode)) ret = -EIO; return ret; } void nilfs_btree_init_gc(struct nilfs_bmap *bmap) { bmap->b_ops = &nilfs_btree_ops_gc; bmap->b_nchildren_per_block = NILFS_BTREE_NODE_NCHILDREN_MAX(nilfs_btree_node_size(bmap)); }