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| author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
| commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
| tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/reiserfs/fix_node.c | |
| download | olio-linux-3.10-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz olio-linux-3.10-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip | |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'fs/reiserfs/fix_node.c')
| -rw-r--r-- | fs/reiserfs/fix_node.c | 2518 |
1 files changed, 2518 insertions, 0 deletions
diff --git a/fs/reiserfs/fix_node.c b/fs/reiserfs/fix_node.c new file mode 100644 index 00000000000..e4f64be9e15 --- /dev/null +++ b/fs/reiserfs/fix_node.c @@ -0,0 +1,2518 @@ +/* + * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README + */ + +/** + ** old_item_num + ** old_entry_num + ** set_entry_sizes + ** create_virtual_node + ** check_left + ** check_right + ** directory_part_size + ** get_num_ver + ** set_parameters + ** is_leaf_removable + ** are_leaves_removable + ** get_empty_nodes + ** get_lfree + ** get_rfree + ** is_left_neighbor_in_cache + ** decrement_key + ** get_far_parent + ** get_parents + ** can_node_be_removed + ** ip_check_balance + ** dc_check_balance_internal + ** dc_check_balance_leaf + ** dc_check_balance + ** check_balance + ** get_direct_parent + ** get_neighbors + ** fix_nodes + ** + ** + **/ + + +#include <linux/config.h> +#include <linux/time.h> +#include <linux/string.h> +#include <linux/reiserfs_fs.h> +#include <linux/buffer_head.h> + + +/* To make any changes in the tree we find a node, that contains item + to be changed/deleted or position in the node we insert a new item + to. We call this node S. To do balancing we need to decide what we + will shift to left/right neighbor, or to a new node, where new item + will be etc. To make this analysis simpler we build virtual + node. Virtual node is an array of items, that will replace items of + node S. (For instance if we are going to delete an item, virtual + node does not contain it). Virtual node keeps information about + item sizes and types, mergeability of first and last items, sizes + of all entries in directory item. We use this array of items when + calculating what we can shift to neighbors and how many nodes we + have to have if we do not any shiftings, if we shift to left/right + neighbor or to both. */ + + +/* taking item number in virtual node, returns number of item, that it has in source buffer */ +static inline int old_item_num (int new_num, int affected_item_num, int mode) +{ + if (mode == M_PASTE || mode == M_CUT || new_num < affected_item_num) + return new_num; + + if (mode == M_INSERT) { + + RFALSE( new_num == 0, + "vs-8005: for INSERT mode and item number of inserted item"); + + return new_num - 1; + } + + RFALSE( mode != M_DELETE, + "vs-8010: old_item_num: mode must be M_DELETE (mode = \'%c\'", mode); + /* delete mode */ + return new_num + 1; +} + +static void create_virtual_node (struct tree_balance * tb, int h) +{ + struct item_head * ih; + struct virtual_node * vn = tb->tb_vn; + int new_num; + struct buffer_head * Sh; /* this comes from tb->S[h] */ + + Sh = PATH_H_PBUFFER (tb->tb_path, h); + + /* size of changed node */ + vn->vn_size = MAX_CHILD_SIZE (Sh) - B_FREE_SPACE (Sh) + tb->insert_size[h]; + + /* for internal nodes array if virtual items is not created */ + if (h) { + vn->vn_nr_item = (vn->vn_size - DC_SIZE) / (DC_SIZE + KEY_SIZE); + return; + } + + /* number of items in virtual node */ + vn->vn_nr_item = B_NR_ITEMS (Sh) + ((vn->vn_mode == M_INSERT)? 1 : 0) - ((vn->vn_mode == M_DELETE)? 1 : 0); + + /* first virtual item */ + vn->vn_vi = (struct virtual_item *)(tb->tb_vn + 1); + memset (vn->vn_vi, 0, vn->vn_nr_item * sizeof (struct virtual_item)); + vn->vn_free_ptr += vn->vn_nr_item * sizeof (struct virtual_item); + + + /* first item in the node */ + ih = B_N_PITEM_HEAD (Sh, 0); + + /* define the mergeability for 0-th item (if it is not being deleted) */ + if (op_is_left_mergeable (&(ih->ih_key), Sh->b_size) && (vn->vn_mode != M_DELETE || vn->vn_affected_item_num)) + vn->vn_vi[0].vi_type |= VI_TYPE_LEFT_MERGEABLE; + + /* go through all items those remain in the virtual node (except for the new (inserted) one) */ + for (new_num = 0; new_num < vn->vn_nr_item; new_num ++) { + int j; + struct virtual_item * vi = vn->vn_vi + new_num; + int is_affected = ((new_num != vn->vn_affected_item_num) ? 0 : 1); + + + if (is_affected && vn->vn_mode == M_INSERT) + continue; + + /* get item number in source node */ + j = old_item_num (new_num, vn->vn_affected_item_num, vn->vn_mode); + + vi->vi_item_len += ih_item_len(ih + j) + IH_SIZE; + vi->vi_ih = ih + j; + vi->vi_item = B_I_PITEM (Sh, ih + j); + vi->vi_uarea = vn->vn_free_ptr; + + // FIXME: there is no check, that item operation did not + // consume too much memory + vn->vn_free_ptr += op_create_vi (vn, vi, is_affected, tb->insert_size [0]); + if (tb->vn_buf + tb->vn_buf_size < vn->vn_free_ptr) + reiserfs_panic (tb->tb_sb, "vs-8030: create_virtual_node: " + "virtual node space consumed"); + + if (!is_affected) + /* this is not being changed */ + continue; + + if (vn->vn_mode == M_PASTE || vn->vn_mode == M_CUT) { + vn->vn_vi[new_num].vi_item_len += tb->insert_size[0]; + vi->vi_new_data = vn->vn_data; // pointer to data which is going to be pasted + } + } + + + /* virtual inserted item is not defined yet */ + if (vn->vn_mode == M_INSERT) { + struct virtual_item * vi = vn->vn_vi + vn->vn_affected_item_num; + + RFALSE( vn->vn_ins_ih == 0, + "vs-8040: item header of inserted item is not specified"); + vi->vi_item_len = tb->insert_size[0]; + vi->vi_ih = vn->vn_ins_ih; + vi->vi_item = vn->vn_data; + vi->vi_uarea = vn->vn_free_ptr; + + op_create_vi (vn, vi, 0/*not pasted or cut*/, tb->insert_size [0]); + } + + /* set right merge flag we take right delimiting key and check whether it is a mergeable item */ + if (tb->CFR[0]) { + struct reiserfs_key * key; + + key = B_N_PDELIM_KEY (tb->CFR[0], tb->rkey[0]); + if (op_is_left_mergeable (key, Sh->b_size) && (vn->vn_mode != M_DELETE || + vn->vn_affected_item_num != B_NR_ITEMS (Sh) - 1)) + vn->vn_vi[vn->vn_nr_item-1].vi_type |= VI_TYPE_RIGHT_MERGEABLE; + +#ifdef CONFIG_REISERFS_CHECK + if (op_is_left_mergeable (key, Sh->b_size) && + !(vn->vn_mode != M_DELETE || vn->vn_affected_item_num != B_NR_ITEMS (Sh) - 1) ) { + /* we delete last item and it could be merged with right neighbor's first item */ + if (!(B_NR_ITEMS (Sh) == 1 && is_direntry_le_ih (B_N_PITEM_HEAD (Sh, 0)) && + I_ENTRY_COUNT (B_N_PITEM_HEAD (Sh, 0)) == 1)) { + /* node contains more than 1 item, or item is not directory item, or this item contains more than 1 entry */ + print_block (Sh, 0, -1, -1); + reiserfs_panic (tb->tb_sb, "vs-8045: create_virtual_node: rdkey %k, affected item==%d (mode==%c) Must be %c", + key, vn->vn_affected_item_num, vn->vn_mode, M_DELETE); + } else + /* we can delete directory item, that has only one directory entry in it */ + ; + } +#endif + + } +} + + +/* using virtual node check, how many items can be shifted to left + neighbor */ +static void check_left (struct tree_balance * tb, int h, int cur_free) +{ + int i; + struct virtual_node * vn = tb->tb_vn; + struct virtual_item * vi; + int d_size, ih_size; + + RFALSE( cur_free < 0, "vs-8050: cur_free (%d) < 0", cur_free); + + /* internal level */ + if (h > 0) { + tb->lnum[h] = cur_free / (DC_SIZE + KEY_SIZE); + return; + } + + /* leaf level */ + + if (!cur_free || !vn->vn_nr_item) { + /* no free space or nothing to move */ + tb->lnum[h] = 0; + tb->lbytes = -1; + return; + } + + RFALSE( !PATH_H_PPARENT (tb->tb_path, 0), + "vs-8055: parent does not exist or invalid"); + + vi = vn->vn_vi; + if ((unsigned int)cur_free >= (vn->vn_size - ((vi->vi_type & VI_TYPE_LEFT_MERGEABLE) ? IH_SIZE : 0))) { + /* all contents of S[0] fits into L[0] */ + + RFALSE( vn->vn_mode == M_INSERT || vn->vn_mode == M_PASTE, + "vs-8055: invalid mode or balance condition failed"); + + tb->lnum[0] = vn->vn_nr_item; + tb->lbytes = -1; + return; + } + + + d_size = 0, ih_size = IH_SIZE; + + /* first item may be merge with last item in left neighbor */ + if (vi->vi_type & VI_TYPE_LEFT_MERGEABLE) + d_size = -((int)IH_SIZE), ih_size = 0; + + tb->lnum[0] = 0; + for (i = 0; i < vn->vn_nr_item; i ++, ih_size = IH_SIZE, d_size = 0, vi ++) { + d_size += vi->vi_item_len; + if (cur_free >= d_size) { + /* the item can be shifted entirely */ + cur_free -= d_size; + tb->lnum[0] ++; + continue; + } + + /* the item cannot be shifted entirely, try to split it */ + /* check whether L[0] can hold ih and at least one byte of the item body */ + if (cur_free <= ih_size) { + /* cannot shift even a part of the current item */ + tb->lbytes = -1; + return; + } + cur_free -= ih_size; + + tb->lbytes = op_check_left (vi, cur_free, 0, 0); + if (tb->lbytes != -1) + /* count partially shifted item */ + tb->lnum[0] ++; + + break; + } + + return; +} + + +/* using virtual node check, how many items can be shifted to right + neighbor */ +static void check_right (struct tree_balance * tb, int h, int cur_free) +{ + int i; + struct virtual_node * vn = tb->tb_vn; + struct virtual_item * vi; + int d_size, ih_size; + + RFALSE( cur_free < 0, "vs-8070: cur_free < 0"); + + /* internal level */ + if (h > 0) { + tb->rnum[h] = cur_free / (DC_SIZE + KEY_SIZE); + return; + } + + /* leaf level */ + + if (!cur_free || !vn->vn_nr_item) { + /* no free space */ + tb->rnum[h] = 0; + tb->rbytes = -1; + return; + } + + RFALSE( !PATH_H_PPARENT (tb->tb_path, 0), + "vs-8075: parent does not exist or invalid"); + + vi = vn->vn_vi + vn->vn_nr_item - 1; + if ((unsigned int)cur_free >= (vn->vn_size - ((vi->vi_type & VI_TYPE_RIGHT_MERGEABLE) ? IH_SIZE : 0))) { + /* all contents of S[0] fits into R[0] */ + + RFALSE( vn->vn_mode == M_INSERT || vn->vn_mode == M_PASTE, + "vs-8080: invalid mode or balance condition failed"); + + tb->rnum[h] = vn->vn_nr_item; + tb->rbytes = -1; + return; + } + + d_size = 0, ih_size = IH_SIZE; + + /* last item may be merge with first item in right neighbor */ + if (vi->vi_type & VI_TYPE_RIGHT_MERGEABLE) + d_size = -(int)IH_SIZE, ih_size = 0; + + tb->rnum[0] = 0; + for (i = vn->vn_nr_item - 1; i >= 0; i --, d_size = 0, ih_size = IH_SIZE, vi --) { + d_size += vi->vi_item_len; + if (cur_free >= d_size) { + /* the item can be shifted entirely */ + cur_free -= d_size; + tb->rnum[0] ++; + continue; + } + + /* check whether R[0] can hold ih and at least one byte of the item body */ + if ( cur_free <= ih_size ) { /* cannot shift even a part of the current item */ + tb->rbytes = -1; + return; + } + + /* R[0] can hold the header of the item and at least one byte of its body */ + cur_free -= ih_size; /* cur_free is still > 0 */ + + tb->rbytes = op_check_right (vi, cur_free); + if (tb->rbytes != -1) + /* count partially shifted item */ + tb->rnum[0] ++; + + break; + } + + return; +} + + +/* + * from - number of items, which are shifted to left neighbor entirely + * to - number of item, which are shifted to right neighbor entirely + * from_bytes - number of bytes of boundary item (or directory entries) which are shifted to left neighbor + * to_bytes - number of bytes of boundary item (or directory entries) which are shifted to right neighbor */ +static int get_num_ver (int mode, struct tree_balance * tb, int h, + int from, int from_bytes, + int to, int to_bytes, + short * snum012, int flow + ) +{ + int i; + int cur_free; + // int bytes; + int units; + struct virtual_node * vn = tb->tb_vn; + // struct virtual_item * vi; + + int total_node_size, max_node_size, current_item_size; + int needed_nodes; + int start_item, /* position of item we start filling node from */ + end_item, /* position of item we finish filling node by */ + start_bytes,/* number of first bytes (entries for directory) of start_item-th item + we do not include into node that is being filled */ + end_bytes; /* number of last bytes (entries for directory) of end_item-th item + we do node include into node that is being filled */ + int split_item_positions[2]; /* these are positions in virtual item of + items, that are split between S[0] and + S1new and S1new and S2new */ + + split_item_positions[0] = -1; + split_item_positions[1] = -1; + + /* We only create additional nodes if we are in insert or paste mode + or we are in replace mode at the internal level. If h is 0 and + the mode is M_REPLACE then in fix_nodes we change the mode to + paste or insert before we get here in the code. */ + RFALSE( tb->insert_size[h] < 0 || (mode != M_INSERT && mode != M_PASTE), + "vs-8100: insert_size < 0 in overflow"); + + max_node_size = MAX_CHILD_SIZE (PATH_H_PBUFFER (tb->tb_path, h)); + + /* snum012 [0-2] - number of items, that lay + to S[0], first new node and second new node */ + snum012[3] = -1; /* s1bytes */ + snum012[4] = -1; /* s2bytes */ + + /* internal level */ + if (h > 0) { + i = ((to - from) * (KEY_SIZE + DC_SIZE) + DC_SIZE); + if (i == max_node_size) + return 1; + return (i / max_node_size + 1); + } + + /* leaf level */ + needed_nodes = 1; + total_node_size = 0; + cur_free = max_node_size; + + // start from 'from'-th item + start_item = from; + // skip its first 'start_bytes' units + start_bytes = ((from_bytes != -1) ? from_bytes : 0); + + // last included item is the 'end_item'-th one + end_item = vn->vn_nr_item - to - 1; + // do not count last 'end_bytes' units of 'end_item'-th item + end_bytes = (to_bytes != -1) ? to_bytes : 0; + + /* go through all item beginning from the start_item-th item and ending by + the end_item-th item. Do not count first 'start_bytes' units of + 'start_item'-th item and last 'end_bytes' of 'end_item'-th item */ + + for (i = start_item; i <= end_item; i ++) { + struct virtual_item * vi = vn->vn_vi + i; + int skip_from_end = ((i == end_item) ? end_bytes : 0); + + RFALSE( needed_nodes > 3, "vs-8105: too many nodes are needed"); + + /* get size of current item */ + current_item_size = vi->vi_item_len; + + /* do not take in calculation head part (from_bytes) of from-th item */ + current_item_size -= op_part_size (vi, 0/*from start*/, start_bytes); + + /* do not take in calculation tail part of last item */ + current_item_size -= op_part_size (vi, 1/*from end*/, skip_from_end); + + /* if item fits into current node entierly */ + if (total_node_size + current_item_size <= max_node_size) { + snum012[needed_nodes - 1] ++; + total_node_size += current_item_size; + start_bytes = 0; + continue; + } + + if (current_item_size > max_node_size) { + /* virtual item length is longer, than max size of item in + a node. It is impossible for direct item */ + RFALSE( is_direct_le_ih (vi->vi_ih), + "vs-8110: " + "direct item length is %d. It can not be longer than %d", + current_item_size, max_node_size); + /* we will try to split it */ + flow = 1; + } + + if (!flow) { + /* as we do not split items, take new node and continue */ + needed_nodes ++; i --; total_node_size = 0; + continue; + } + + // calculate number of item units which fit into node being + // filled + { + int free_space; + + free_space = max_node_size - total_node_size - IH_SIZE; + units = op_check_left (vi, free_space, start_bytes, skip_from_end); + if (units == -1) { + /* nothing fits into current node, take new node and continue */ + needed_nodes ++, i--, total_node_size = 0; + continue; + } + } + + /* something fits into the current node */ + //if (snum012[3] != -1 || needed_nodes != 1) + // reiserfs_panic (tb->tb_sb, "vs-8115: get_num_ver: too many nodes required"); + //snum012[needed_nodes - 1 + 3] = op_unit_num (vi) - start_bytes - units; + start_bytes += units; + snum012[needed_nodes - 1 + 3] = units; + + if (needed_nodes > 2) + reiserfs_warning (tb->tb_sb, "vs-8111: get_num_ver: " + "split_item_position is out of boundary"); + snum012[needed_nodes - 1] ++; + split_item_positions[needed_nodes - 1] = i; + needed_nodes ++; + /* continue from the same item with start_bytes != -1 */ + start_item = i; + i --; + total_node_size = 0; + } + + // sum012[4] (if it is not -1) contains number of units of which + // are to be in S1new, snum012[3] - to be in S0. They are supposed + // to be S1bytes and S2bytes correspondingly, so recalculate + if (snum012[4] > 0) { + int split_item_num; + int bytes_to_r, bytes_to_l; + int bytes_to_S1new; + + split_item_num = split_item_positions[1]; + bytes_to_l = ((from == split_item_num && from_bytes != -1) ? from_bytes : 0); + bytes_to_r = ((end_item == split_item_num && end_bytes != -1) ? end_bytes : 0); + bytes_to_S1new = ((split_item_positions[0] == split_item_positions[1]) ? snum012[3] : 0); + + // s2bytes + snum012[4] = op_unit_num (&vn->vn_vi[split_item_num]) - snum012[4] - bytes_to_r - bytes_to_l - bytes_to_S1new; + + if (vn->vn_vi[split_item_num].vi_index != TYPE_DIRENTRY && + vn->vn_vi[split_item_num].vi_index != TYPE_INDIRECT) + reiserfs_warning (tb->tb_sb, "vs-8115: get_num_ver: not " + "directory or indirect item"); + } + + /* now we know S2bytes, calculate S1bytes */ + if (snum012[3] > 0) { + int split_item_num; + int bytes_to_r, bytes_to_l; + int bytes_to_S2new; + + split_item_num = split_item_positions[0]; + bytes_to_l = ((from == split_item_num && from_bytes != -1) ? from_bytes : 0); + bytes_to_r = ((end_item == split_item_num && end_bytes != -1) ? end_bytes : 0); + bytes_to_S2new = ((split_item_positions[0] == split_item_positions[1] && snum012[4] != -1) ? snum012[4] : 0); + + // s1bytes + snum012[3] = op_unit_num (&vn->vn_vi[split_item_num]) - snum012[3] - bytes_to_r - bytes_to_l - bytes_to_S2new; + } + + return needed_nodes; +} + + +#ifdef CONFIG_REISERFS_CHECK +extern struct tree_balance * cur_tb; +#endif + + +/* Set parameters for balancing. + * Performs write of results of analysis of balancing into structure tb, + * where it will later be used by the functions that actually do the balancing. + * Parameters: + * tb tree_balance structure; + * h current level of the node; + * lnum number of items from S[h] that must be shifted to L[h]; + * rnum number of items from S[h] that must be shifted to R[h]; + * blk_num number of blocks that S[h] will be splitted into; + * s012 number of items that fall into splitted nodes. + * lbytes number of bytes which flow to the left neighbor from the item that is not + * not shifted entirely + * rbytes number of bytes which flow to the right neighbor from the item that is not + * not shifted entirely + * s1bytes number of bytes which flow to the first new node when S[0] splits (this number is contained in s012 array) + */ + +static void set_parameters (struct tree_balance * tb, int h, int lnum, + int rnum, int blk_num, short * s012, int lb, int rb) +{ + + tb->lnum[h] = lnum; + tb->rnum[h] = rnum; + tb->blknum[h] = blk_num; + + if (h == 0) + { /* only for leaf level */ + if (s012 != NULL) + { + tb->s0num = * s012 ++, + tb->s1num = * s012 ++, + tb->s2num = * s012 ++; + tb->s1bytes = * s012 ++; + tb->s2bytes = * s012; + } + tb->lbytes = lb; + tb->rbytes = rb; + } + PROC_INFO_ADD( tb -> tb_sb, lnum[ h ], lnum ); + PROC_INFO_ADD( tb -> tb_sb, rnum[ h ], rnum ); + + PROC_INFO_ADD( tb -> tb_sb, lbytes[ h ], lb ); + PROC_INFO_ADD( tb -> tb_sb, rbytes[ h ], rb ); +} + + + +/* check, does node disappear if we shift tb->lnum[0] items to left + neighbor and tb->rnum[0] to the right one. */ +static int is_leaf_removable (struct tree_balance * tb) +{ + struct virtual_node * vn = tb->tb_vn; + int to_left, to_right; + int size; + int remain_items; + + /* number of items, that will be shifted to left (right) neighbor + entirely */ + to_left = tb->lnum[0] - ((tb->lbytes != -1) ? 1 : 0); + to_right = tb->rnum[0] - ((tb->rbytes != -1) ? 1 : 0); + remain_items = vn->vn_nr_item; + + /* how many items remain in S[0] after shiftings to neighbors */ + remain_items -= (to_left + to_right); + + if (remain_items < 1) { + /* all content of node can be shifted to neighbors */ + set_parameters (tb, 0, to_left, vn->vn_nr_item - to_left, 0, NULL, -1, -1); + return 1; + } + + if (remain_items > 1 || tb->lbytes == -1 || tb->rbytes == -1) + /* S[0] is not removable */ + return 0; + + /* check, whether we can divide 1 remaining item between neighbors */ + + /* get size of remaining item (in item units) */ + size = op_unit_num (&(vn->vn_vi[to_left])); + + if (tb->lbytes + tb->rbytes >= size) { + set_parameters (tb, 0, to_left + 1, to_right + 1, 0, NULL, tb->lbytes, -1); + return 1; + } + + return 0; +} + + +/* check whether L, S, R can be joined in one node */ +static int are_leaves_removable (struct tree_balance * tb, int lfree, int rfree) +{ + struct virtual_node * vn = tb->tb_vn; + int ih_size; + struct buffer_head *S0; + + S0 = PATH_H_PBUFFER (tb->tb_path, 0); + + ih_size = 0; + if (vn->vn_nr_item) { + if (vn->vn_vi[0].vi_type & VI_TYPE_LEFT_MERGEABLE) + ih_size += IH_SIZE; + + if (vn->vn_vi[vn->vn_nr_item-1].vi_type & VI_TYPE_RIGHT_MERGEABLE) + ih_size += IH_SIZE; + } else { + /* there was only one item and it will be deleted */ + struct item_head * ih; + + RFALSE( B_NR_ITEMS (S0) != 1, + "vs-8125: item number must be 1: it is %d", B_NR_ITEMS(S0)); + + ih = B_N_PITEM_HEAD (S0, 0); + if (tb->CFR[0] && !comp_short_le_keys (&(ih->ih_key), B_N_PDELIM_KEY (tb->CFR[0], tb->rkey[0]))) + if (is_direntry_le_ih (ih)) { + /* Directory must be in correct state here: that is + somewhere at the left side should exist first directory + item. But the item being deleted can not be that first + one because its right neighbor is item of the same + directory. (But first item always gets deleted in last + turn). So, neighbors of deleted item can be merged, so + we can save ih_size */ + ih_size = IH_SIZE; + + /* we might check that left neighbor exists and is of the + same directory */ + RFALSE(le_ih_k_offset (ih) == DOT_OFFSET, + "vs-8130: first directory item can not be removed until directory is not empty"); + } + + } + + if (MAX_CHILD_SIZE (S0) + vn->vn_size <= rfree + lfree + ih_size) { + set_parameters (tb, 0, -1, -1, -1, NULL, -1, -1); + PROC_INFO_INC( tb -> tb_sb, leaves_removable ); + return 1; + } + return 0; + +} + + + +/* when we do not split item, lnum and rnum are numbers of entire items */ +#define SET_PAR_SHIFT_LEFT \ +if (h)\ +{\ + int to_l;\ + \ + to_l = (MAX_NR_KEY(Sh)+1 - lpar + vn->vn_nr_item + 1) / 2 -\ + (MAX_NR_KEY(Sh) + 1 - lpar);\ + \ + set_parameters (tb, h, to_l, 0, lnver, NULL, -1, -1);\ +}\ +else \ +{\ + if (lset==LEFT_SHIFT_FLOW)\ + set_parameters (tb, h, lpar, 0, lnver, snum012+lset,\ + tb->lbytes, -1);\ + else\ + set_parameters (tb, h, lpar - (tb->lbytes!=-1), 0, lnver, snum012+lset,\ + -1, -1);\ +} + + +#define SET_PAR_SHIFT_RIGHT \ +if (h)\ +{\ + int to_r;\ + \ + to_r = (MAX_NR_KEY(Sh)+1 - rpar + vn->vn_nr_item + 1) / 2 - (MAX_NR_KEY(Sh) + 1 - rpar);\ + \ + set_parameters (tb, h, 0, to_r, rnver, NULL, -1, -1);\ +}\ +else \ +{\ + if (rset==RIGHT_SHIFT_FLOW)\ + set_parameters (tb, h, 0, rpar, rnver, snum012+rset,\ + -1, tb->rbytes);\ + else\ + set_parameters (tb, h, 0, rpar - (tb->rbytes!=-1), rnver, snum012+rset,\ + -1, -1);\ +} + + +static void free_buffers_in_tb ( + struct tree_balance * p_s_tb + ) { + int n_counter; + + decrement_counters_in_path(p_s_tb->tb_path); + + for ( n_counter = 0; n_counter < MAX_HEIGHT; n_counter++ ) { + decrement_bcount(p_s_tb->L[n_counter]); + p_s_tb->L[n_counter] = NULL; + decrement_bcount(p_s_tb->R[n_counter]); + p_s_tb->R[n_counter] = NULL; + decrement_bcount(p_s_tb->FL[n_counter]); + p_s_tb->FL[n_counter] = NULL; + decrement_bcount(p_s_tb->FR[n_counter]); + p_s_tb->FR[n_counter] = NULL; + decrement_bcount(p_s_tb->CFL[n_counter]); + p_s_tb->CFL[n_counter] = NULL; + decrement_bcount(p_s_tb->CFR[n_counter]); + p_s_tb->CFR[n_counter] = NULL; + } +} + + +/* Get new buffers for storing new nodes that are created while balancing. + * Returns: SCHEDULE_OCCURRED - schedule occurred while the function worked; + * CARRY_ON - schedule didn't occur while the function worked; + * NO_DISK_SPACE - no disk space. + */ +/* The function is NOT SCHEDULE-SAFE! */ +static int get_empty_nodes( + struct tree_balance * p_s_tb, + int n_h + ) { + struct buffer_head * p_s_new_bh, + * p_s_Sh = PATH_H_PBUFFER (p_s_tb->tb_path, n_h); + b_blocknr_t * p_n_blocknr, + a_n_blocknrs[MAX_AMOUNT_NEEDED] = {0, }; + int n_counter, + n_number_of_freeblk, + n_amount_needed,/* number of needed empty blocks */ + n_retval = CARRY_ON; + struct super_block * p_s_sb = p_s_tb->tb_sb; + + + /* number_of_freeblk is the number of empty blocks which have been + acquired for use by the balancing algorithm minus the number of + empty blocks used in the previous levels of the analysis, + number_of_freeblk = tb->cur_blknum can be non-zero if a schedule occurs + after empty blocks are acquired, and the balancing analysis is + then restarted, amount_needed is the number needed by this level + (n_h) of the balancing analysis. + + Note that for systems with many processes writing, it would be + more layout optimal to calculate the total number needed by all + levels and then to run reiserfs_new_blocks to get all of them at once. */ + + /* Initiate number_of_freeblk to the amount acquired prior to the restart of + the analysis or 0 if not restarted, then subtract the amount needed + by all of the levels of the tree below n_h. */ + /* blknum includes S[n_h], so we subtract 1 in this calculation */ + for ( n_counter = 0, n_number_of_freeblk = p_s_tb->cur_blknum; n_counter < n_h; n_counter++ ) + n_number_of_freeblk -= ( p_s_tb->blknum[n_counter] ) ? (p_s_tb->blknum[n_counter] - 1) : 0; + + /* Allocate missing empty blocks. */ + /* if p_s_Sh == 0 then we are getting a new root */ + n_amount_needed = ( p_s_Sh ) ? (p_s_tb->blknum[n_h] - 1) : 1; + /* Amount_needed = the amount that we need more than the amount that we have. */ + if ( n_amount_needed > n_number_of_freeblk ) + n_amount_needed -= n_number_of_freeblk; + else /* If we have enough already then there is nothing to do. */ + return CARRY_ON; + + /* No need to check quota - is not allocated for blocks used for formatted nodes */ + if (reiserfs_new_form_blocknrs (p_s_tb, a_n_blocknrs, + n_amount_needed) == NO_DISK_SPACE) + return NO_DISK_SPACE; + + /* for each blocknumber we just got, get a buffer and stick it on FEB */ + for ( p_n_blocknr = a_n_blocknrs, n_counter = 0; n_counter < n_amount_needed; + p_n_blocknr++, n_counter++ ) { + + RFALSE( ! *p_n_blocknr, + "PAP-8135: reiserfs_new_blocknrs failed when got new blocks"); + + p_s_new_bh = sb_getblk(p_s_sb, *p_n_blocknr); + RFALSE (buffer_dirty (p_s_new_bh) || + buffer_journaled (p_s_new_bh) || + buffer_journal_dirty (p_s_new_bh), + "PAP-8140: journlaled or dirty buffer %b for the new block", + p_s_new_bh); + + /* Put empty buffers into the array. */ + RFALSE (p_s_tb->FEB[p_s_tb->cur_blknum], + "PAP-8141: busy slot for new buffer"); + + set_buffer_journal_new (p_s_new_bh); + p_s_tb->FEB[p_s_tb->cur_blknum++] = p_s_new_bh; + } + + if ( n_retval == CARRY_ON && FILESYSTEM_CHANGED_TB (p_s_tb) ) + n_retval = REPEAT_SEARCH ; + + return n_retval; +} + + +/* Get free space of the left neighbor, which is stored in the parent + * node of the left neighbor. */ +static int get_lfree (struct tree_balance * tb, int h) +{ + struct buffer_head * l, * f; + int order; + + if ((f = PATH_H_PPARENT (tb->tb_path, h)) == 0 || (l = tb->FL[h]) == 0) + return 0; + + if (f == l) + order = PATH_H_B_ITEM_ORDER (tb->tb_path, h) - 1; + else { + order = B_NR_ITEMS (l); + f = l; + } + + return (MAX_CHILD_SIZE(f) - dc_size(B_N_CHILD(f,order))); +} + + +/* Get free space of the right neighbor, + * which is stored in the parent node of the right neighbor. + */ +static int get_rfree (struct tree_balance * tb, int h) +{ + struct buffer_head * r, * f; + int order; + + if ((f = PATH_H_PPARENT (tb->tb_path, h)) == 0 || (r = tb->FR[h]) == 0) + return 0; + + if (f == r) + order = PATH_H_B_ITEM_ORDER (tb->tb_path, h) + 1; + else { + order = 0; + f = r; + } + + return (MAX_CHILD_SIZE(f) - dc_size( B_N_CHILD(f,order))); + +} + + +/* Check whether left neighbor is in memory. */ +static int is_left_neighbor_in_cache( + struct tree_balance * p_s_tb, + int n_h + ) { + struct buffer_head * p_s_father, * left; + struct super_block * p_s_sb = p_s_tb->tb_sb; + b_blocknr_t n_left_neighbor_blocknr; + int n_left_neighbor_position; + + if ( ! p_s_tb->FL[n_h] ) /* Father of the left neighbor does not exist. */ + return 0; + + /* Calculate father of the node to be balanced. */ + p_s_father = PATH_H_PBUFFER(p_s_tb->tb_path, n_h + 1); + + RFALSE( ! p_s_father || + ! B_IS_IN_TREE (p_s_father) || + ! B_IS_IN_TREE (p_s_tb->FL[n_h]) || + ! buffer_uptodate (p_s_father) || + ! buffer_uptodate (p_s_tb->FL[n_h]), + "vs-8165: F[h] (%b) or FL[h] (%b) is invalid", + p_s_father, p_s_tb->FL[n_h]); + + + /* Get position of the pointer to the left neighbor into the left father. */ + n_left_neighbor_position = ( p_s_father == p_s_tb->FL[n_h] ) ? + p_s_tb->lkey[n_h] : B_NR_ITEMS (p_s_tb->FL[n_h]); + /* Get left neighbor block number. */ + n_left_neighbor_blocknr = B_N_CHILD_NUM(p_s_tb->FL[n_h], n_left_neighbor_position); + /* Look for the left neighbor in the cache. */ + if ( (left = sb_find_get_block(p_s_sb, n_left_neighbor_blocknr)) ) { + + RFALSE( buffer_uptodate (left) && ! B_IS_IN_TREE(left), + "vs-8170: left neighbor (%b %z) is not in the tree", left, left); + put_bh(left) ; + return 1; + } + + return 0; +} + + +#define LEFT_PARENTS 'l' +#define RIGHT_PARENTS 'r' + + +static void decrement_key (struct cpu_key * p_s_key) +{ + // call item specific function for this key + item_ops[cpu_key_k_type (p_s_key)]->decrement_key (p_s_key); +} + + + + +/* Calculate far left/right parent of the left/right neighbor of the current node, that + * is calculate the left/right (FL[h]/FR[h]) neighbor of the parent F[h]. + * Calculate left/right common parent of the current node and L[h]/R[h]. + * Calculate left/right delimiting key position. + * Returns: PATH_INCORRECT - path in the tree is not correct; + SCHEDULE_OCCURRED - schedule occurred while the function worked; + * CARRY_ON - schedule didn't occur while the function worked; + */ +static int get_far_parent (struct tree_balance * p_s_tb, + int n_h, + struct buffer_head ** pp_s_father, + struct buffer_head ** pp_s_com_father, + char c_lr_par) +{ + struct buffer_head * p_s_parent; + INITIALIZE_PATH (s_path_to_neighbor_father); + struct path * p_s_path = p_s_tb->tb_path; + struct cpu_key s_lr_father_key; + int n_counter, + n_position = INT_MAX, + n_first_last_position = 0, + n_path_offset = PATH_H_PATH_OFFSET(p_s_path, n_h); + + /* Starting from F[n_h] go upwards in the tree, and look for the common + ancestor of F[n_h], and its neighbor l/r, that should be obtained. */ + + n_counter = n_path_offset; + + RFALSE( n_counter < FIRST_PATH_ELEMENT_OFFSET, + "PAP-8180: invalid path length"); + + + for ( ; n_counter > FIRST_PATH_ELEMENT_OFFSET; n_counter-- ) { + /* Check whether parent of the current buffer in the path is really parent in the tree. */ + if ( ! B_IS_IN_TREE(p_s_parent = PATH_OFFSET_PBUFFER(p_s_path, n_counter - 1)) ) + return REPEAT_SEARCH; + /* Check whether position in the parent is correct. */ + if ( (n_position = PATH_OFFSET_POSITION(p_s_path, n_counter - 1)) > B_NR_ITEMS(p_s_parent) ) + return REPEAT_SEARCH; + /* Check whether parent at the path really points to the child. */ + if ( B_N_CHILD_NUM(p_s_parent, n_position) != + PATH_OFFSET_PBUFFER(p_s_path, n_counter)->b_blocknr ) + return REPEAT_SEARCH; + /* Return delimiting key if position in the parent is not equal to first/last one. */ + if ( c_lr_par == RIGHT_PARENTS ) + n_first_last_position = B_NR_ITEMS (p_s_parent); + if ( n_position != n_first_last_position ) { + *pp_s_com_father = p_s_parent; + get_bh(*pp_s_com_father) ; + /*(*pp_s_com_father = p_s_parent)->b_count++;*/ + break; + } + } + + /* if we are in the root of the tree, then there is no common father */ + if ( n_counter == FIRST_PATH_ELEMENT_OFFSET ) { + /* Check whether first buffer in the path is the root of the tree. */ + if ( PATH_OFFSET_PBUFFER(p_s_tb->tb_path, FIRST_PATH_ELEMENT_OFFSET)->b_blocknr == + SB_ROOT_BLOCK (p_s_tb->tb_sb) ) { + *pp_s_father = *pp_s_com_father = NULL; + return CARRY_ON; + } + return REPEAT_SEARCH; + } + + RFALSE( B_LEVEL (*pp_s_com_father) <= DISK_LEAF_NODE_LEVEL, + "PAP-8185: (%b %z) level too small", + *pp_s_com_father, *pp_s_com_father); + + /* Check whether the common parent is locked. */ + + if ( buffer_locked (*pp_s_com_father) ) { + __wait_on_buffer(*pp_s_com_father); + if ( FILESYSTEM_CHANGED_TB (p_s_tb) ) { + decrement_bcount(*pp_s_com_father); + return REPEAT_SEARCH; + } + } + + /* So, we got common parent of the current node and its left/right neighbor. + Now we are geting the parent of the left/right neighbor. */ + + /* Form key to get parent of the left/right neighbor. */ + le_key2cpu_key (&s_lr_father_key, B_N_PDELIM_KEY(*pp_s_com_father, ( c_lr_par == LEFT_PARENTS ) ? + (p_s_tb->lkey[n_h - 1] = n_position - 1) : (p_s_tb->rkey[n_h - 1] = n_position))); + + + if ( c_lr_par == LEFT_PARENTS ) + decrement_key(&s_lr_father_key); + + if (search_by_key(p_s_tb->tb_sb, &s_lr_father_key, &s_path_to_neighbor_father, n_h + 1) == IO_ERROR) + // path is released + return IO_ERROR; + + if ( FILESYSTEM_CHANGED_TB (p_s_tb) ) { + decrement_counters_in_path(&s_path_to_neighbor_father); + decrement_bcount(*pp_s_com_father); + return REPEAT_SEARCH; + } + + *pp_s_father = PATH_PLAST_BUFFER(&s_path_to_neighbor_father); + + RFALSE( B_LEVEL (*pp_s_father) != n_h + 1, + "PAP-8190: (%b %z) level too small", *pp_s_father, *pp_s_father); + RFALSE( s_path_to_neighbor_father.path_length < FIRST_PATH_ELEMENT_OFFSET, + "PAP-8192: path length is too small"); + + s_path_to_neighbor_father.path_length--; + decrement_counters_in_path(&s_path_to_neighbor_father); + return CARRY_ON; +} + + +/* Get parents of neighbors of node in the path(S[n_path_offset]) and common parents of + * S[n_path_offset] and L[n_path_offset]/R[n_path_offset]: F[n_path_offset], FL[n_path_offset], + * FR[n_path_offset], CFL[n_path_offset], CFR[n_path_offset]. + * Calculate numbers of left and right delimiting keys position: lkey[n_path_offset], rkey[n_path_offset]. + * Returns: SCHEDULE_OCCURRED - schedule occurred while the function worked; + * CARRY_ON - schedule didn't occur while the function worked; + */ +static int get_parents (struct tree_balance * p_s_tb, int n_h) +{ + struct path * p_s_path = p_s_tb->tb_path; + int n_position, + n_ret_value, + n_path_offset = PATH_H_PATH_OFFSET(p_s_tb->tb_path, n_h); + struct buffer_head * p_s_curf, + * p_s_curcf; + + /* Current node is the root of the tree or will be root of the tree */ + if ( n_path_offset <= FIRST_PATH_ELEMENT_OFFSET ) { + /* The root can not have parents. + Release nodes which previously were obtained as parents of the current node neighbors. */ + decrement_bcount(p_s_tb->FL[n_h]); + decrement_bcount(p_s_tb->CFL[n_h]); + decrement_bcount(p_s_tb->FR[n_h]); + decrement_bcount(p_s_tb->CFR[n_h]); + p_s_tb->FL[n_h] = p_s_tb->CFL[n_h] = p_s_tb->FR[n_h] = p_s_tb->CFR[n_h] = NULL; + return CARRY_ON; + } + + /* Get parent FL[n_path_offset] of L[n_path_offset]. */ + if ( (n_position = PATH_OFFSET_POSITION(p_s_path, n_path_offset - 1)) ) { + /* Current node is not the first child of its parent. */ + /*(p_s_curf = p_s_curcf = PATH_OFFSET_PBUFFER(p_s_path, n_path_offset - 1))->b_count += 2;*/ + p_s_curf = p_s_curcf = PATH_OFFSET_PBUFFER(p_s_path, n_path_offset - 1); + get_bh(p_s_curf) ; + get_bh(p_s_curf) ; + p_s_tb->lkey[n_h] = n_position - 1; + } + else { + /* Calculate current parent of L[n_path_offset], which is the left neighbor of the current node. + Calculate current common parent of L[n_path_offset] and the current node. Note that + CFL[n_path_offset] not equal FL[n_path_offset] and CFL[n_path_offset] not equal F[n_path_offset]. + Calculate lkey[n_path_offset]. */ + if ( (n_ret_value = get_far_parent(p_s_tb, n_h + 1, &p_s_curf, + &p_s_curcf, LEFT_PARENTS)) != CARRY_ON ) + return n_ret_value; + } + + decrement_bcount(p_s_tb->FL[n_h]); + p_s_tb->FL[n_h] = p_s_curf; /* New initialization of FL[n_h]. */ + decrement_bcount(p_s_tb->CFL[n_h]); + p_s_tb->CFL[n_h] = p_s_curcf; /* New initialization of CFL[n_h]. */ + + RFALSE( (p_s_curf && !B_IS_IN_TREE (p_s_curf)) || + (p_s_curcf && !B_IS_IN_TREE (p_s_curcf)), + "PAP-8195: FL (%b) or CFL (%b) is invalid", p_s_curf, p_s_curcf); + +/* Get parent FR[n_h] of R[n_h]. */ + +/* Current node is the last child of F[n_h]. FR[n_h] != F[n_h]. */ + if ( n_position == B_NR_ITEMS (PATH_H_PBUFFER(p_s_path, n_h + 1)) ) { +/* Calculate current parent of R[n_h], which is the right neighbor of F[n_h]. + Calculate current common parent of R[n_h] and current node. Note that CFR[n_h] + not equal FR[n_path_offset] and CFR[n_h] not equal F[n_h]. */ + if ( (n_ret_value = get_far_parent(p_s_tb, n_h + 1, &p_s_curf, &p_s_curcf, RIGHT_PARENTS)) != CARRY_ON ) + return n_ret_value; + } + else { +/* Current node is not the last child of its parent F[n_h]. */ + /*(p_s_curf = p_s_curcf = PATH_OFFSET_PBUFFER(p_s_path, n_path_offset - 1))->b_count += 2;*/ + p_s_curf = p_s_curcf = PATH_OFFSET_PBUFFER(p_s_path, n_path_offset - 1); + get_bh(p_s_curf) ; + get_bh(p_s_curf) ; + p_s_tb->rkey[n_h] = n_position; + } + + decrement_bcount(p_s_tb->FR[n_h]); + p_s_tb->FR[n_h] = p_s_curf; /* New initialization of FR[n_path_offset]. */ + + decrement_bcount(p_s_tb->CFR[n_h]); + p_s_tb->CFR[n_h] = p_s_curcf; /* New initialization of CFR[n_path_offset]. */ + + RFALSE( (p_s_curf && !B_IS_IN_TREE (p_s_curf)) || + (p_s_curcf && !B_IS_IN_TREE (p_s_curcf)), + "PAP-8205: FR (%b) or CFR (%b) is invalid", p_s_curf, p_s_curcf); + + return CARRY_ON; +} + + +/* it is possible to remove node as result of shiftings to + neighbors even when we insert or paste item. */ +static inline int can_node_be_removed (int mode, int lfree, int sfree, int rfree, struct tree_balance * tb, int h) +{ + struct buffer_head * Sh = PATH_H_PBUFFER (tb->tb_path, h); + int levbytes = tb->insert_size[h]; + struct item_head * ih; + struct reiserfs_key * r_key = NULL; + + ih = B_N_PITEM_HEAD (Sh, 0); + if ( tb->CFR[h] ) + r_key = B_N_PDELIM_KEY(tb->CFR[h],tb->rkey[h]); + + if ( + lfree + rfree + sfree < MAX_CHILD_SIZE(Sh) + levbytes + /* shifting may merge items which might save space */ + - (( ! h && op_is_left_mergeable (&(ih->ih_key), Sh->b_size) ) ? IH_SIZE : 0) + - (( ! h && r_key && op_is_left_mergeable (r_key, Sh->b_size) ) ? IH_SIZE : 0) + + (( h ) ? KEY_SIZE : 0)) + { + /* node can not be removed */ + if (sfree >= levbytes ) { /* new item fits into node S[h] without any shifting */ + if ( ! h ) + tb->s0num = B_NR_ITEMS(Sh) + ((mode == M_INSERT ) ? 1 : 0); + set_parameters (tb, h, 0, 0, 1, NULL, -1, -1); + return NO_BALANCING_NEEDED; + } + } + PROC_INFO_INC( tb -> tb_sb, can_node_be_removed[ h ] ); + return !NO_BALANCING_NEEDED; +} + + + +/* Check whether current node S[h] is balanced when increasing its size by + * Inserting or Pasting. + * Calculate parameters for balancing for current level h. + * Parameters: + * tb tree_balance structure; + * h current level of the node; + * inum item number in S[h]; + * mode i - insert, p - paste; + * Returns: 1 - schedule occurred; + * 0 - balancing for higher levels needed; + * -1 - no balancing for higher levels needed; + * -2 - no disk space. + */ +/* ip means Inserting or Pasting */ +static int ip_check_balance (struct tree_balance * tb, int h) +{ + struct virtual_node * vn = tb->tb_vn; + int levbytes, /* Number of bytes that must be inserted into (value + is negative if bytes are deleted) buffer which + contains node being balanced. The mnemonic is + that the attempted change in node space used level + is levbytes bytes. */ + n_ret_value; + + int lfree, sfree, rfree /* free space in L, S and R */; + + /* nver is short for number of vertixes, and lnver is the number if + we shift to the left, rnver is the number if we shift to the + right, and lrnver is the number if we shift in both directions. + The goal is to minimize first the number of vertixes, and second, + the number of vertixes whose contents are changed by shifting, + and third the number of uncached vertixes whose contents are + changed by shifting and must be read from disk. */ + int nver, lnver, rnver, lrnver; + + /* used at leaf level only, S0 = S[0] is the node being balanced, + sInum [ I = 0,1,2 ] is the number of items that will + remain in node SI after balancing. S1 and S2 are new + nodes that might be created. */ + + /* we perform 8 calls to get_num_ver(). For each call we calculate five parameters. + where 4th parameter is s1bytes and 5th - s2bytes + */ + short snum012[40] = {0,}; /* s0num, s1num, s2num for 8 cases + 0,1 - do not shift and do not shift but bottle + 2 - shift only whole item to left + 3 - shift to left and bottle as much as possible + 4,5 - shift to right (whole items and as much as possible + 6,7 - shift to both directions (whole items and as much as possible) + */ + + /* Sh is the node whose balance is currently being checked */ + struct buffer_head * Sh; + + Sh = PATH_H_PBUFFER (tb->tb_path, h); + levbytes = tb->insert_size[h]; + + /* Calculate balance parameters for creating new root. */ + if ( ! Sh ) { + if ( ! h ) + reiserfs_panic (tb->tb_sb, "vs-8210: ip_check_balance: S[0] can not be 0"); + switch ( n_ret_value = get_empty_nodes (tb, h) ) { + case CARRY_ON: + set_parameters (tb, h, 0, 0, 1, NULL, -1, -1); + return NO_BALANCING_NEEDED; /* no balancing for higher levels needed */ + + case NO_DISK_SPACE: + case REPEAT_SEARCH: + return n_ret_value; + default: + reiserfs_panic(tb->tb_sb, "vs-8215: ip_check_balance: incorrect return value of get_empty_nodes"); + } + } + + if ( (n_ret_value = get_parents (tb, h)) != CARRY_ON ) /* get parents of S[h] neighbors. */ + return n_ret_value; + + sfree = B_FREE_SPACE (Sh); + + /* get free space of neighbors */ + rfree = get_rfree (tb, h); + lfree = get_lfree (tb, h); + + if (can_node_be_removed (vn->vn_mode, lfree, sfree, rfree, tb, h) == NO_BALANCING_NEEDED) + /* and new item fits into node S[h] without any shifting */ + return NO_BALANCING_NEEDED; + + create_virtual_node (tb, h); + + /* + determine maximal number of items we can shift to the left neighbor (in tb structure) + and the maximal number of bytes that can flow to the left neighbor + from the left most liquid item that cannot be shifted from S[0] entirely (returned value) + */ + check_left (tb, h, lfree); + + /* + determine maximal number of items we can shift to the right neighbor (in tb structure) + and the maximal number of bytes that can flow to the right neighbor + from the right most liquid item that cannot be shifted from S[0] entirely (returned value) + */ + check_right (tb, h, rfree); + + + /* all contents of internal node S[h] can be moved into its + neighbors, S[h] will be removed after balancing */ + if (h && (tb->rnum[h] + tb->lnum[h] >= vn->vn_nr_item + 1)) { + int to_r; + + /* Since we are working on internal nodes, and our internal + nodes have fixed size entries, then we can balance by the + number of items rather than the space they consume. In this + routine we set the left node equal to the right node, + allowing a difference of less than or equal to 1 child + pointer. */ + to_r = ((MAX_NR_KEY(Sh)<<1)+2-tb->lnum[h]-tb->rnum[h]+vn->vn_nr_item+1)/2 - + (MAX_NR_KEY(Sh) + 1 - tb->rnum[h]); + set_parameters (tb, h, vn->vn_nr_item + 1 - to_r, to_r, 0, NULL, -1, -1); + return CARRY_ON; + } + + /* this checks balance condition, that any two neighboring nodes can not fit in one node */ + RFALSE( h && + ( tb->lnum[h] >= vn->vn_nr_item + 1 || + tb->rnum[h] >= vn->vn_nr_item + 1), + "vs-8220: tree is not balanced on internal level"); + RFALSE( ! h && ((tb->lnum[h] >= vn->vn_nr_item && (tb->lbytes == -1)) || + (tb->rnum[h] >= vn->vn_nr_item && (tb->rbytes == -1)) ), + "vs-8225: tree is not balanced on leaf level"); + + /* all contents of S[0] can be moved into its neighbors + S[0] will be removed after balancing. */ + if (!h && is_leaf_removable (tb)) + return CARRY_ON; + + + /* why do we perform this check here rather than earlier?? + Answer: we can win 1 node in some cases above. Moreover we + checked it above, when we checked, that S[0] is not removable + in principle */ + if (sfree >= levbytes) { /* new item fits into node S[h] without any shifting */ + if ( ! h ) + tb->s0num = vn->vn_nr_item; + set_parameters (tb, h, 0, 0, 1, NULL, -1, -1); + return NO_BALANCING_NEEDED; + } + + + { + int lpar, rpar, nset, lset, rset, lrset; + /* + * regular overflowing of the node + */ + + /* get_num_ver works in 2 modes (FLOW & NO_FLOW) + lpar, rpar - number of items we can shift to left/right neighbor (including splitting item) + nset, lset, rset, lrset - shows, whether flowing items give better packing + */ +#define FLOW 1 +#define NO_FLOW 0 /* do not any splitting */ + + /* we choose one the following */ +#define NOTHING_SHIFT_NO_FLOW 0 +#define NOTHING_SHIFT_FLOW 5 +#define LEFT_SHIFT_NO_FLOW 10 +#define LEFT_SHIFT_FLOW 15 +#define RIGHT_SHIFT_NO_FLOW 20 +#define RIGHT_SHIFT_FLOW 25 +#define LR_SHIFT_NO_FLOW 30 +#define LR_SHIFT_FLOW 35 + + + lpar = tb->lnum[h]; + rpar = tb->rnum[h]; + + + /* calculate number of blocks S[h] must be split into when + nothing is shifted to the neighbors, + as well as number of items in each part of the split node (s012 numbers), + and number of bytes (s1bytes) of the shared drop which flow to S1 if any */ + nset = NOTHING_SHIFT_NO_FLOW; + nver = get_num_ver (vn->vn_mode, tb, h, + 0, -1, h?vn->vn_nr_item:0, -1, + snum012, NO_FLOW); + + if (!h) + { + int nver1; + + /* note, that in this case we try to bottle between S[0] and S1 (S1 - the first new node) */ + nver1 = get_num_ver (vn->vn_mode, tb, h, + 0, -1, 0, -1, + snum012 + NOTHING_SHIFT_FLOW, FLOW); + if (nver > nver1) + nset = NOTHING_SHIFT_FLOW, nver = nver1; + } + + + /* calculate number of blocks S[h] must be split into when + l_shift_num first items and l_shift_bytes of the right most + liquid item to be shifted are shifted to the left neighbor, + as well as number of items in each part of the splitted node (s012 numbers), + and number of bytes (s1bytes) of the shared drop which flow to S1 if any + */ + lset = LEFT_SHIFT_NO_FLOW; + lnver = get_num_ver (vn->vn_mode, tb, h, + lpar - (( h || tb->lbytes == -1 ) ? 0 : 1), -1, h ? vn->vn_nr_item:0, -1, + snum012 + LEFT_SHIFT_NO_FLOW, NO_FLOW); + if (!h) + { + int lnver1; + + lnver1 = get_num_ver (vn->vn_mode, tb, h, + lpar - ((tb->lbytes != -1) ? 1 : 0), tb->lbytes, 0, -1, + snum012 + LEFT_SHIFT_FLOW, FLOW); + if (lnver > lnver1) + lset = LEFT_SHIFT_FLOW, lnver = lnver1; + } + + + /* calculate number of blocks S[h] must be split into when + r_shift_num first items and r_shift_bytes of the left most + liquid item to be shifted are shifted to the right neighbor, + as well as number of items in each part of the splitted node (s012 numbers), + and number of bytes (s1bytes) of the shared drop which flow to S1 if any + */ + rset = RIGHT_SHIFT_NO_FLOW; + rnver = get_num_ver (vn->vn_mode, tb, h, + 0, -1, h ? (vn->vn_nr_item-rpar) : (rpar - (( tb->rbytes != -1 ) ? 1 : 0)), -1, + snum012 + RIGHT_SHIFT_NO_FLOW, NO_FLOW); + if (!h) + { + int rnver1; + + rnver1 = get_num_ver (vn->vn_mode, tb, h, + 0, -1, (rpar - ((tb->rbytes != -1) ? 1 : 0)), tb->rbytes, + snum012 + RIGHT_SHIFT_FLOW, FLOW); + + if (rnver > rnver1) + rset = RIGHT_SHIFT_FLOW, rnver = rnver1; + } + + + /* calculate number of blocks S[h] must be split into when + items are shifted in both directions, + as well as number of items in each part of the splitted node (s012 numbers), + and number of bytes (s1bytes) of the shared drop which flow to S1 if any + */ + lrset = LR_SHIFT_NO_FLOW; + lrnver = get_num_ver (vn->vn_mode, tb, h, + lpar - ((h || tb->lbytes == -1) ? 0 : 1), -1, h ? (vn->vn_nr_item-rpar):(rpar - ((tb->rbytes != -1) ? 1 : 0)), -1, + snum012 + LR_SHIFT_NO_FLOW, NO_FLOW); + if (!h) + { + int lrnver1; + + lrnver1 = get_num_ver (vn->vn_mode, tb, h, + lpar - ((tb->lbytes != -1) ? 1 : 0), tb->lbytes, (rpar - ((tb->rbytes != -1) ? 1 : 0)), tb->rbytes, + snum012 + LR_SHIFT_FLOW, FLOW); + if (lrnver > lrnver1) + lrset = LR_SHIFT_FLOW, lrnver = lrnver1; + } + + + + /* Our general shifting strategy is: + 1) to minimized number of new nodes; + 2) to minimized number of neighbors involved in shifting; + 3) to minimized number of disk reads; */ + + /* we can win TWO or ONE nodes by shifting in both directions */ + if (lrnver < lnver && lrnver < rnver) + { + RFALSE( h && + (tb->lnum[h] != 1 || + tb->rnum[h] != 1 || + lrnver != 1 || rnver != 2 || lnver != 2 || h != 1), + "vs-8230: bad h"); + if (lrset == LR_SHIFT_FLOW) + set_parameters (tb, h, tb->lnum[h], tb->rnum[h], lrnver, snum012 + lrset, + tb->lbytes, tb->rbytes); + else + set_parameters (tb, h, tb->lnum[h] - ((tb->lbytes == -1) ? 0 : 1), + tb->rnum[h] - ((tb->rbytes == -1) ? 0 : 1), lrnver, snum012 + lrset, -1, -1); + + return CARRY_ON; + } + + /* if shifting doesn't lead to better packing then don't shift */ + if (nver == lrnver) + { + set_parameters (tb, h, 0, 0, nver, snum012 + nset, -1, -1); + return CARRY_ON; + } + + + /* now we know that for better packing shifting in only one + direction either to the left or to the right is required */ + + /* if shifting to the left is better than shifting to the right */ + if (lnver < rnver) + { + SET_PAR_SHIFT_LEFT; + return CARRY_ON; + } + + /* if shifting to the right is better than shifting to the left */ + if (lnver > rnver) + { + SET_PAR_SHIFT_RIGHT; + return CARRY_ON; + } + + + /* now shifting in either direction gives the same number + of nodes and we can make use of the cached neighbors */ + if (is_left_neighbor_in_cache (tb,h)) + { + SET_PAR_SHIFT_LEFT; + return CARRY_ON; + } + + /* shift to the right independently on whether the right neighbor in cache or not */ + SET_PAR_SHIFT_RIGHT; + return CARRY_ON; + } +} + + +/* Check whether current node S[h] is balanced when Decreasing its size by + * Deleting or Cutting for INTERNAL node of S+tree. + * Calculate parameters for balancing for current level h. + * Parameters: + * tb tree_balance structure; + * h current level of the node; + * inum item number in S[h]; + * mode i - insert, p - paste; + * Returns: 1 - schedule occurred; + * 0 - balancing for higher levels needed; + * -1 - no balancing for higher levels needed; + * -2 - no disk space. + * + * Note: Items of internal nodes have fixed size, so the balance condition for + * the internal part of S+tree is as for the B-trees. + */ +static int dc_check_balance_internal (struct tree_balance * tb, int h) +{ + struct virtual_node * vn = tb->tb_vn; + + /* Sh is the node whose balance is currently being checked, + and Fh is its father. */ + struct buffer_head * Sh, * Fh; + int maxsize, + n_ret_value; + int lfree, rfree /* free space in L and R */; + + Sh = PATH_H_PBUFFER (tb->tb_path, h); + Fh = PATH_H_PPARENT (tb->tb_path, h); + + maxsize = MAX_CHILD_SIZE(Sh); + +/* using tb->insert_size[h], which is negative in this case, create_virtual_node calculates: */ +/* new_nr_item = number of items node would have if operation is */ +/* performed without balancing (new_nr_item); */ + create_virtual_node (tb, h); + + if ( ! Fh ) + { /* S[h] is the root. */ + if ( vn->vn_nr_item > 0 ) + { + set_parameters (tb, h, 0, 0, 1, NULL, -1, -1); + return NO_BALANCING_NEEDED; /* no balancing for higher levels needed */ + } + /* new_nr_item == 0. + * Current root will be deleted resulting in + * decrementing the tree height. */ + set_parameters (tb, h, 0, 0, 0, NULL, -1, -1); + return CARRY_ON; + } + + if ( (n_ret_value = get_parents(tb,h)) != CARRY_ON ) + return n_ret_value; + + + /* get free space of neighbors */ + rfree = get_rfree (tb, h); + lfree = get_lfree (tb, h); + + /* determine maximal number of items we can fit into neighbors */ + check_left (tb, h, lfree); + check_right (tb, h, rfree); + + + if ( vn->vn_nr_item >= MIN_NR_KEY(Sh) ) + { /* Balance condition for the internal node is valid. + * In this case we balance only if it leads to better packing. */ + if ( vn->vn_nr_item == MIN_NR_KEY(Sh) ) + { /* Here we join S[h] with one of its neighbors, + * which is impossible with greater values of new_nr_item. */ + if ( tb->lnum[h] >= vn->vn_nr_item + 1 ) + { + /* All contents of S[h] can be moved to L[h]. */ + int n; + int order_L; + + order_L = ((n=PATH_H_B_ITEM_ORDER(tb->tb_path, h))==0) ? B_NR_ITEMS(tb->FL[h]) : n - 1; + n = dc_size(B_N_CHILD(tb->FL[h],order_L)) / (DC_SIZE + KEY_SIZE); + set_parameters (tb, h, -n-1, 0, 0, NULL, -1, -1); + return CARRY_ON; + } + + if ( tb->rnum[h] >= vn->vn_nr_item + 1 ) + { + /* All contents of S[h] can be moved to R[h]. */ + int n; + int order_R; + + order_R = ((n=PATH_H_B_ITEM_ORDER(tb->tb_path, h))==B_NR_ITEMS(Fh)) ? 0 : n + 1; + n = dc_size(B_N_CHILD(tb->FR[h],order_R)) / (DC_SIZE + KEY_SIZE); + set_parameters (tb, h, 0, -n-1, 0, NULL, -1, -1); + return CARRY_ON; + } + } + + if (tb->rnum[h] + tb->lnum[h] >= vn->vn_nr_item + 1) + { + /* All contents of S[h] can be moved to the neighbors (L[h] & R[h]). */ + int to_r; + + to_r = ((MAX_NR_KEY(Sh)<<1)+2-tb->lnum[h]-tb->rnum[h]+vn->vn_nr_item+1)/2 - + (MAX_NR_KEY(Sh) + 1 - tb->rnum[h]); + set_parameters (tb, h, vn->vn_nr_item + 1 - to_r, to_r, 0, NULL, -1, -1); + return CARRY_ON; + } + + /* Balancing does not lead to better packing. */ + set_parameters (tb, h, 0, 0, 1, NULL, -1, -1); + return NO_BALANCING_NEEDED; + } + + /* Current node contain insufficient number of items. Balancing is required. */ + /* Check whether we can merge S[h] with left neighbor. */ + if (tb->lnum[h] >= vn->vn_nr_item + 1) + if (is_left_neighbor_in_cache (tb,h) || tb->rnum[h] < vn->vn_nr_item + 1 || !tb->FR[h]) + { + int n; + int order_L; + + order_L = ((n=PATH_H_B_ITEM_ORDER(tb->tb_path, h))==0) ? B_NR_ITEMS(tb->FL[h]) : n - 1; + n = dc_size(B_N_CHILD(tb->FL[h],order_L)) / (DC_SIZE + KEY_SIZE); + set_parameters (tb, h, -n-1, 0, 0, NULL, -1, -1); + return CARRY_ON; + } + + /* Check whether we can merge S[h] with right neighbor. */ + if (tb->rnum[h] >= vn->vn_nr_item + 1) + { + int n; + int order_R; + + order_R = ((n=PATH_H_B_ITEM_ORDER(tb->tb_path, h))==B_NR_ITEMS(Fh)) ? 0 : (n + 1); + n = dc_size(B_N_CHILD(tb->FR[h],order_R)) / (DC_SIZE + KEY_SIZE); + set_parameters (tb, h, 0, -n-1, 0, NULL, -1, -1); + return CARRY_ON; + } + + /* All contents of S[h] can be moved to the neighbors (L[h] & R[h]). */ + if (tb->rnum[h] + tb->lnum[h] >= vn->vn_nr_item + 1) + { + int to_r; + + to_r = ((MAX_NR_KEY(Sh)<<1)+2-tb->lnum[h]-tb->rnum[h]+vn->vn_nr_item+1)/2 - + (MAX_NR_KEY(Sh) + 1 - tb->rnum[h]); + set_parameters (tb, h, vn->vn_nr_item + 1 - to_r, to_r, 0, NULL, -1, -1); + return CARRY_ON; + } + + /* For internal nodes try to borrow item from a neighbor */ + RFALSE( !tb->FL[h] && !tb->FR[h], "vs-8235: trying to borrow for root"); + + /* Borrow one or two items from caching neighbor */ + if (is_left_neighbor_in_cache (tb,h) || !tb->FR[h]) + { + int from_l; + + from_l = (MAX_NR_KEY(Sh) + 1 - tb->lnum[h] + vn->vn_nr_item + 1) / 2 - (vn->vn_nr_item + 1); + set_parameters (tb, h, -from_l, 0, 1, NULL, -1, -1); + return CARRY_ON; + } + + set_parameters (tb, h, 0, -((MAX_NR_KEY(Sh)+1-tb->rnum[h]+vn->vn_nr_item+1)/2-(vn->vn_nr_item+1)), 1, + NULL, -1, -1); + return CARRY_ON; +} + + +/* Check whether current node S[h] is balanced when Decreasing its size by + * Deleting or Truncating for LEAF node of S+tree. + * Calculate parameters for balancing for current level h. + * Parameters: + * tb tree_balance structure; + * h current level of the node; + * inum item number in S[h]; + * mode i - insert, p - paste; + * Returns: 1 - schedule occurred; + * 0 - balancing for higher levels needed; + * -1 - no balancing for higher levels needed; + * -2 - no disk space. + */ +static int dc_check_balance_leaf (struct tree_balance * tb, int h) +{ + struct virtual_node * vn = tb->tb_vn; + + /* Number of bytes that must be deleted from + (value is negative if bytes are deleted) buffer which + contains node being balanced. The mnemonic is that the + attempted change in node space used level is levbytes bytes. */ + int levbytes; + /* the maximal item size */ + int maxsize, + n_ret_value; + /* S0 is the node whose balance is currently being checked, + and F0 is its father. */ + struct buffer_head * S0, * F0; + int lfree, rfree /* free space in L and R */; + + S0 = PATH_H_PBUFFER (tb->tb_path, 0); + F0 = PATH_H_PPARENT (tb->tb_path, 0); + + levbytes = tb->insert_size[h]; + + maxsize = MAX_CHILD_SIZE(S0); /* maximal possible size of an item */ + + if ( ! F0 ) + { /* S[0] is the root now. */ + + RFALSE( -levbytes >= maxsize - B_FREE_SPACE (S0), + "vs-8240: attempt to create empty buffer tree"); + + set_parameters (tb, h, 0, 0, 1, NULL, -1, -1); + return NO_BALANCING_NEEDED; + } + + if ( (n_ret_value = get_parents(tb,h)) != CARRY_ON ) + return n_ret_value; + + /* get free space of neighbors */ + rfree = get_rfree (tb, h); + lfree = get_lfree (tb, h); + + create_virtual_node (tb, h); + + /* if 3 leaves can be merge to one, set parameters and return */ + if (are_leaves_removable (tb, lfree, rfree)) + return CARRY_ON; + + /* determine maximal number of items we can shift to the left/right neighbor + and the maximal number of bytes that can flow to the left/right neighbor + from the left/right most liquid item that cannot be shifted from S[0] entirely + */ + check_left (tb, h, lfree); + check_right (tb, h, rfree); + + /* check whether we can merge S with left neighbor. */ + if (tb->lnum[0] >= vn->vn_nr_item && tb->lbytes == -1) + if (is_left_neighbor_in_cache (tb,h) || + ((tb->rnum[0] - ((tb->rbytes == -1) ? 0 : 1)) < vn->vn_nr_item) || /* S can not be merged with R */ + !tb->FR[h]) { + + RFALSE( !tb->FL[h], "vs-8245: dc_check_balance_leaf: FL[h] must exist"); + + /* set parameter to merge S[0] with its left neighbor */ + set_parameters (tb, h, -1, 0, 0, NULL, -1, -1); + return CARRY_ON; + } + + /* check whether we can merge S[0] with right neighbor. */ + if (tb->rnum[0] >= vn->vn_nr_item && tb->rbytes == -1) { + set_parameters (tb, h, 0, -1, 0, NULL, -1, -1); + return CARRY_ON; + } + + /* All contents of S[0] can be moved to the neighbors (L[0] & R[0]). Set parameters and return */ + if (is_leaf_removable (tb)) + return CARRY_ON; + + /* Balancing is not required. */ + tb->s0num = vn->vn_nr_item; + set_parameters (tb, h, 0, 0, 1, NULL, -1, -1); + return NO_BALANCING_NEEDED; +} + + + +/* Check whether current node S[h] is balanced when Decreasing its size by + * Deleting or Cutting. + * Calculate parameters for balancing for current level h. + * Parameters: + * tb tree_balance structure; + * h current level of the node; + * inum item number in S[h]; + * mode d - delete, c - cut. + * Returns: 1 - schedule occurred; + * 0 - balancing for higher levels needed; + * -1 - no balancing for higher levels needed; + * -2 - no disk space. + */ +static int dc_check_balance (struct tree_balance * tb, int h) +{ + RFALSE( ! (PATH_H_PBUFFER (tb->tb_path, h)), "vs-8250: S is not initialized"); + + if ( h ) + return dc_check_balance_internal (tb, h); + else + return dc_check_balance_leaf (tb, h); +} + + + +/* Check whether current node S[h] is balanced. + * Calculate parameters for balancing for current level h. + * Parameters: + * + * tb tree_balance structure: + * + * tb is a large structure that must be read about in the header file + * at the same time as this procedure if the reader is to successfully + * understand this procedure + * + * h current level of the node; + * inum item number in S[h]; + * mode i - insert, p - paste, d - delete, c - cut. + * Returns: 1 - schedule occurred; + * 0 - balancing for higher levels needed; + * -1 - no balancing for higher levels needed; + * -2 - no disk space. + */ +static int check_balance (int mode, + struct tree_balance * tb, + int h, + int inum, + int pos_in_item, + struct item_head * ins_ih, + const void * data + ) +{ + struct virtual_node * vn; + + vn = tb->tb_vn = (struct virtual_node *)(tb->vn_buf); + vn->vn_free_ptr = (char *)(tb->tb_vn + 1); + vn->vn_mode = mode; + vn->vn_affected_item_num = inum; + vn->vn_pos_in_item = pos_in_item; + vn->vn_ins_ih = ins_ih; + vn->vn_data = data; + + RFALSE( mode == M_INSERT && !vn->vn_ins_ih, + "vs-8255: ins_ih can not be 0 in insert mode"); + + if ( tb->insert_size[h] > 0 ) + /* Calculate balance parameters when size of node is increasing. */ + return ip_check_balance (tb, h); + + /* Calculate balance parameters when size of node is decreasing. */ + return dc_check_balance (tb, h); +} + + + +/* Check whether parent at the path is the really parent of the current node.*/ +static int get_direct_parent( + struct tree_balance * p_s_tb, + int n_h + ) { + struct buffer_head * p_s_bh; + struct path * p_s_path = p_s_tb->tb_path; + int n_position, + n_path_offset = PATH_H_PATH_OFFSET(p_s_tb->tb_path, n_h); + + /* We are in the root or in the new root. */ + if ( n_path_offset <= FIRST_PATH_ELEMENT_OFFSET ) { + + RFALSE( n_path_offset < FIRST_PATH_ELEMENT_OFFSET - 1, + "PAP-8260: invalid offset in the path"); + + if ( PATH_OFFSET_PBUFFER(p_s_path, FIRST_PATH_ELEMENT_OFFSET)->b_blocknr == + SB_ROOT_BLOCK (p_s_tb->tb_sb) ) { + /* Root is not changed. */ + PATH_OFFSET_PBUFFER(p_s_path, n_path_offset - 1) = NULL; + PATH_OFFSET_POSITION(p_s_path, n_path_offset - 1) = 0; + return CARRY_ON; + } + return REPEAT_SEARCH; /* Root is changed and we must recalculate the path. */ + } + + if ( ! B_IS_IN_TREE(p_s_bh = PATH_OFFSET_PBUFFER(p_s_path, n_path_offset - 1)) ) + return REPEAT_SEARCH; /* Parent in the path is not in the tree. */ + + if ( (n_position = PATH_OFFSET_POSITION(p_s_path, n_path_offset - 1)) > B_NR_ITEMS(p_s_bh) ) + return REPEAT_SEARCH; + + if ( B_N_CHILD_NUM(p_s_bh, n_position) != PATH_OFFSET_PBUFFER(p_s_path, n_path_offset)->b_blocknr ) + /* Parent in the path is not parent of the current node in the tree. */ + return REPEAT_SEARCH; + + if ( buffer_locked(p_s_bh) ) { + __wait_on_buffer(p_s_bh); + if ( FILESYSTEM_CHANGED_TB (p_s_tb) ) + return REPEAT_SEARCH; + } + + return CARRY_ON; /* Parent in the path is unlocked and really parent of the current node. */ +} + + +/* Using lnum[n_h] and rnum[n_h] we should determine what neighbors + * of S[n_h] we + * need in order to balance S[n_h], and get them if necessary. + * Returns: SCHEDULE_OCCURRED - schedule occurred while the function worked; + * CARRY_ON - schedule didn't occur while the function worked; + */ +static int get_neighbors( + struct tree_balance * p_s_tb, + int n_h + ) { + int n_child_position, + n_path_offset = PATH_H_PATH_OFFSET(p_s_tb->tb_path, n_h + 1); + unsigned long n_son_number; + struct super_block * p_s_sb = p_s_tb->tb_sb; + struct buffer_head * p_s_bh; + + + PROC_INFO_INC( p_s_sb, get_neighbors[ n_h ] ); + + if ( p_s_tb->lnum[n_h] ) { + /* We need left neighbor to balance S[n_h]. */ + PROC_INFO_INC( p_s_sb, need_l_neighbor[ n_h ] ); + p_s_bh = PATH_OFFSET_PBUFFER(p_s_tb->tb_path, n_path_offset); + + RFALSE( p_s_bh == p_s_tb->FL[n_h] && + ! PATH_OFFSET_POSITION(p_s_tb->tb_path, n_path_offset), + "PAP-8270: invalid position in the parent"); + + n_child_position = ( p_s_bh == p_s_tb->FL[n_h] ) ? p_s_tb->lkey[n_h] : B_NR_ITEMS (p_s_tb->FL[n_h]); + n_son_number = B_N_CHILD_NUM(p_s_tb->FL[n_h], n_child_position); + p_s_bh = sb_bread(p_s_sb, n_son_number); + if (!p_s_bh) + return IO_ERROR; + if ( FILESYSTEM_CHANGED_TB (p_s_tb) ) { + decrement_bcount(p_s_bh); + PROC_INFO_INC( p_s_sb, get_neighbors_restart[ n_h ] ); + return REPEAT_SEARCH; + } + + RFALSE( ! B_IS_IN_TREE(p_s_tb->FL[n_h]) || + n_child_position > B_NR_ITEMS(p_s_tb->FL[n_h]) || + B_N_CHILD_NUM(p_s_tb->FL[n_h], n_child_position) != + p_s_bh->b_blocknr, "PAP-8275: invalid parent"); + RFALSE( ! B_IS_IN_TREE(p_s_bh), "PAP-8280: invalid child"); + RFALSE( ! n_h && + B_FREE_SPACE (p_s_bh) != MAX_CHILD_SIZE (p_s_bh) - dc_size(B_N_CHILD (p_s_tb->FL[0],n_child_position)), + "PAP-8290: invalid child size of left neighbor"); + + decrement_bcount(p_s_tb->L[n_h]); + p_s_tb->L[n_h] = p_s_bh; + } + + + if ( p_s_tb->rnum[n_h] ) { /* We need right neighbor to balance S[n_path_offset]. */ + PROC_INFO_INC( p_s_sb, need_r_neighbor[ n_h ] ); + p_s_bh = PATH_OFFSET_PBUFFER(p_s_tb->tb_path, n_path_offset); + + RFALSE( p_s_bh == p_s_tb->FR[n_h] && + PATH_OFFSET_POSITION(p_s_tb->tb_path, n_path_offset) >= B_NR_ITEMS(p_s_bh), + "PAP-8295: invalid position in the parent"); + + n_child_position = ( p_s_bh == p_s_tb->FR[n_h] ) ? p_s_tb->rkey[n_h] + 1 : 0; + n_son_number = B_N_CHILD_NUM(p_s_tb->FR[n_h], n_child_position); + p_s_bh = sb_bread(p_s_sb, n_son_number); + if (!p_s_bh) + return IO_ERROR; + if ( FILESYSTEM_CHANGED_TB (p_s_tb) ) { + decrement_bcount(p_s_bh); + PROC_INFO_INC( p_s_sb, get_neighbors_restart[ n_h ] ); + return REPEAT_SEARCH; + } + decrement_bcount(p_s_tb->R[n_h]); + p_s_tb->R[n_h] = p_s_bh; + + RFALSE( ! n_h && B_FREE_SPACE (p_s_bh) != MAX_CHILD_SIZE (p_s_bh) - dc_size(B_N_CHILD (p_s_tb->FR[0],n_child_position)), + "PAP-8300: invalid child size of right neighbor (%d != %d - %d)", + B_FREE_SPACE (p_s_bh), MAX_CHILD_SIZE (p_s_bh), + dc_size(B_N_CHILD (p_s_tb->FR[0],n_child_position))); + + } + return CARRY_ON; +} + +#ifdef CONFIG_REISERFS_CHECK +void * reiserfs_kmalloc (size_t size, int flags, struct super_block * s) +{ + void * vp; + static size_t malloced; + + + vp = kmalloc (size, flags); + if (vp) { + REISERFS_SB(s)->s_kmallocs += size; + if (REISERFS_SB(s)->s_kmallocs > malloced + 200000) { + reiserfs_warning (s, + "vs-8301: reiserfs_kmalloc: allocated memory %d", + REISERFS_SB(s)->s_kmallocs); + malloced = REISERFS_SB(s)->s_kmallocs; + } + } + return vp; +} + +void reiserfs_kfree (const void * vp, size_t size, struct super_block * s) +{ + kfree (vp); + + REISERFS_SB(s)->s_kmallocs -= size; + if (REISERFS_SB(s)->s_kmallocs < 0) + reiserfs_warning (s, "vs-8302: reiserfs_kfree: allocated memory %d", + REISERFS_SB(s)->s_kmallocs); + +} +#endif + + +static int get_virtual_node_size (struct super_block * sb, struct buffer_head * bh) +{ + int max_num_of_items; + int max_num_of_entries; + unsigned long blocksize = sb->s_blocksize; + +#define MIN_NAME_LEN 1 + + max_num_of_items = (blocksize - BLKH_SIZE) / (IH_SIZE + MIN_ITEM_LEN); + max_num_of_entries = (blocksize - BLKH_SIZE - IH_SIZE) / + (DEH_SIZE + MIN_NAME_LEN); + + return sizeof(struct virtual_node) + + max(max_num_of_items * sizeof (struct virtual_item), + sizeof (struct virtual_item) + sizeof(struct direntry_uarea) + + (max_num_of_entries - 1) * sizeof (__u16)); +} + + + +/* maybe we should fail balancing we are going to perform when kmalloc + fails several times. But now it will loop until kmalloc gets + required memory */ +static int get_mem_for_virtual_node (struct tree_balance * tb) +{ + int check_fs = 0; + int size; + char * buf; + + size = get_virtual_node_size (tb->tb_sb, PATH_PLAST_BUFFER (tb->tb_path)); + + if (size > tb->vn_buf_size) { + /* we have to allocate more memory for virtual node */ + if (tb->vn_buf) { + /* free memory allocated before */ + reiserfs_kfree (tb->vn_buf, tb->vn_buf_size, tb->tb_sb); + /* this is not needed if kfree is atomic */ + check_fs = 1; + } + + /* virtual node requires now more memory */ + tb->vn_buf_size = size; + + /* get memory for virtual item */ + buf = reiserfs_kmalloc(size, GFP_ATOMIC | __GFP_NOWARN, tb->tb_sb); + if ( ! buf ) { + /* getting memory with GFP_KERNEL priority may involve + balancing now (due to indirect_to_direct conversion on + dcache shrinking). So, release path and collected + resources here */ + free_buffers_in_tb (tb); + buf = reiserfs_kmalloc(size, GFP_NOFS, tb->tb_sb); + if ( !buf ) { +#ifdef CONFIG_REISERFS_CHECK + reiserfs_warning (tb->tb_sb, + "vs-8345: get_mem_for_virtual_node: " + "kmalloc failed. reiserfs kmalloced %d bytes", + REISERFS_SB(tb->tb_sb)->s_kmallocs); +#endif + tb->vn_buf_size = 0; + } + tb->vn_buf = buf; + schedule() ; + return REPEAT_SEARCH; + } + + tb->vn_buf = buf; + } + + if ( check_fs && FILESYSTEM_CHANGED_TB (tb) ) + return REPEAT_SEARCH; + + return CARRY_ON; +} + + +#ifdef CONFIG_REISERFS_CHECK +static void tb_buffer_sanity_check (struct super_block * p_s_sb, + struct buffer_head * p_s_bh, + const char *descr, int level) { + if (p_s_bh) { + if (atomic_read (&(p_s_bh->b_count)) <= 0) { + + reiserfs_panic (p_s_sb, "jmacd-1: tb_buffer_sanity_check(): negative or zero reference counter for buffer %s[%d] (%b)\n", descr, level, p_s_bh); + } + + if ( ! buffer_uptodate (p_s_bh) ) { + reiserfs_panic (p_s_sb, "jmacd-2: tb_buffer_sanity_check(): buffer is not up to date %s[%d] (%b)\n", descr, level, p_s_bh); + } + + if ( ! B_IS_IN_TREE (p_s_bh) ) { + reiserfs_panic (p_s_sb, "jmacd-3: tb_buffer_sanity_check(): buffer is not in tree %s[%d] (%b)\n", descr, level, p_s_bh); + } + + if (p_s_bh->b_bdev != p_s_sb->s_bdev) { + reiserfs_panic (p_s_sb, "jmacd-4: tb_buffer_sanity_check(): buffer has wrong device %s[%d] (%b)\n", descr, level, p_s_bh); + } + + if (p_s_bh->b_size != p_s_sb->s_blocksize) { + reiserfs_panic (p_s_sb, "jmacd-5: tb_buffer_sanity_check(): buffer has wrong blocksize %s[%d] (%b)\n", descr, level, p_s_bh); + } + + if (p_s_bh->b_blocknr > SB_BLOCK_COUNT(p_s_sb)) { + reiserfs_panic (p_s_sb, "jmacd-6: tb_buffer_sanity_check(): buffer block number too high %s[%d] (%b)\n", descr, level, p_s_bh); + } + } +} +#else +static void tb_buffer_sanity_check (struct super_block * p_s_sb, + struct buffer_head * p_s_bh, + const char *descr, int level) +{;} +#endif + +static int clear_all_dirty_bits(struct super_block *s, + struct buffer_head *bh) { + return reiserfs_prepare_for_journal(s, bh, 0) ; +} + +static int wait_tb_buffers_until_unlocked (struct tree_balance * p_s_tb) +{ + struct buffer_head * locked; +#ifdef CONFIG_REISERFS_CHECK + int repeat_counter = 0; +#endif + int i; + + do { + + locked = NULL; + + for ( i = p_s_tb->tb_path->path_length; !locked && i > ILLEGAL_PATH_ELEMENT_OFFSET; i-- ) { + if ( PATH_OFFSET_PBUFFER (p_s_tb->tb_path, i) ) { + /* if I understand correctly, we can only be sure the last buffer + ** in the path is in the tree --clm + */ +#ifdef CONFIG_REISERFS_CHECK + if (PATH_PLAST_BUFFER(p_s_tb->tb_path) == + PATH_OFFSET_PBUFFER(p_s_tb->tb_path, i)) { + tb_buffer_sanity_check (p_s_tb->tb_sb, + PATH_OFFSET_PBUFFER (p_s_tb->tb_path, i), + "S", + p_s_tb->tb_path->path_length - i); + } +#endif + if (!clear_all_dirty_bits(p_s_tb->tb_sb, + PATH_OFFSET_PBUFFER (p_s_tb->tb_path, i))) + { + locked = PATH_OFFSET_PBUFFER (p_s_tb->tb_path, i); + } + } + } + + for ( i = 0; !locked && i < MAX_HEIGHT && p_s_tb->insert_size[i]; i++ ) { + + if (p_s_tb->lnum[i] ) { + + if ( p_s_tb->L[i] ) { + tb_buffer_sanity_check (p_s_tb->tb_sb, p_s_tb->L[i], "L", i); + if (!clear_all_dirty_bits(p_s_tb->tb_sb, p_s_tb->L[i])) + locked = p_s_tb->L[i]; + } + + if ( !locked && p_s_tb->FL[i] ) { + tb_buffer_sanity_check (p_s_tb->tb_sb, p_s_tb->FL[i], "FL", i); + if (!clear_all_dirty_bits(p_s_tb->tb_sb, p_s_tb->FL[i])) + locked = p_s_tb->FL[i]; + } + + if ( !locked && p_s_tb->CFL[i] ) { + tb_buffer_sanity_check (p_s_tb->tb_sb, p_s_tb->CFL[i], "CFL", i); + if (!clear_all_dirty_bits(p_s_tb->tb_sb, p_s_tb->CFL[i])) + locked = p_s_tb->CFL[i]; + } + + } + + if ( !locked && (p_s_tb->rnum[i]) ) { + + if ( p_s_tb->R[i] ) { + tb_buffer_sanity_check (p_s_tb->tb_sb, p_s_tb->R[i], "R", i); + if (!clear_all_dirty_bits(p_s_tb->tb_sb, p_s_tb->R[i])) + locked = p_s_tb->R[i]; + } + + + if ( !locked && p_s_tb->FR[i] ) { + tb_buffer_sanity_check (p_s_tb->tb_sb, p_s_tb->FR[i], "FR", i); + if (!clear_all_dirty_bits(p_s_tb->tb_sb, p_s_tb->FR[i])) + locked = p_s_tb->FR[i]; + } + + if ( !locked && p_s_tb->CFR[i] ) { + tb_buffer_sanity_check (p_s_tb->tb_sb, p_s_tb->CFR[i], "CFR", i); + if (!clear_all_dirty_bits(p_s_tb->tb_sb, p_s_tb->CFR[i])) + locked = p_s_tb->CFR[i]; + } + } + } + /* as far as I can tell, this is not required. The FEB list seems + ** to be full of newly allocated nodes, which will never be locked, + ** dirty, or anything else. + ** To be safe, I'm putting in the checks and waits in. For the moment, + ** they are needed to keep the code in journal.c from complaining + ** about the buffer. That code is inside CONFIG_REISERFS_CHECK as well. + ** --clm + */ + for ( i = 0; !locked && i < MAX_FEB_SIZE; i++ ) { + if ( p_s_tb->FEB[i] ) { + if (!clear_all_dirty_bits(p_s_tb->tb_sb, p_s_tb->FEB[i])) + locked = p_s_tb->FEB[i] ; + } + } + + if (locked) { +#ifdef CONFIG_REISERFS_CHECK + repeat_counter++; + if ( (repeat_counter % 10000) == 0) { + reiserfs_warning (p_s_tb->tb_sb, + "wait_tb_buffers_until_released(): too many " + "iterations waiting for buffer to unlock " + "(%b)", locked); + + /* Don't loop forever. Try to recover from possible error. */ + + return ( FILESYSTEM_CHANGED_TB (p_s_tb) ) ? REPEAT_SEARCH : CARRY_ON; + } +#endif + __wait_on_buffer (locked); + if ( FILESYSTEM_CHANGED_TB (p_s_tb) ) { + return REPEAT_SEARCH; + } + } + + } while (locked); + + return CARRY_ON; +} + + +/* Prepare for balancing, that is + * get all necessary parents, and neighbors; + * analyze what and where should be moved; + * get sufficient number of new nodes; + * Balancing will start only after all resources will be collected at a time. + * + * When ported to SMP kernels, only at the last moment after all needed nodes + * are collected in cache, will the resources be locked using the usual + * textbook ordered lock acquisition algorithms. Note that ensuring that + * this code neither write locks what it does not need to write lock nor locks out of order + * will be a pain in the butt that could have been avoided. Grumble grumble. -Hans + * + * fix is meant in the sense of render unchanging + * + * Latency might be improved by first gathering a list of what buffers are needed + * and then getting as many of them in parallel as possible? -Hans + * + * Parameters: + * op_mode i - insert, d - delete, c - cut (truncate), p - paste (append) + * tb tree_balance structure; + * inum item number in S[h]; + * pos_in_item - comment this if you can + * ins_ih & ins_sd are used when inserting + * Returns: 1 - schedule occurred while the function worked; + * 0 - schedule didn't occur while the function worked; + * -1 - if no_disk_space + */ + + +int fix_nodes (int n_op_mode, + struct tree_balance * p_s_tb, + struct item_head * p_s_ins_ih, // item head of item being inserted + const void * data // inserted item or data to be pasted + ) { + int n_ret_value, + n_h, + n_item_num = PATH_LAST_POSITION(p_s_tb->tb_path); + int n_pos_in_item; + + /* we set wait_tb_buffers_run when we have to restore any dirty bits cleared + ** during wait_tb_buffers_run + */ + int wait_tb_buffers_run = 0 ; + struct buffer_head * p_s_tbS0 = PATH_PLAST_BUFFER(p_s_tb->tb_path); + + ++ REISERFS_SB(p_s_tb -> tb_sb) -> s_fix_nodes; + + n_pos_in_item = p_s_tb->tb_path->pos_in_item; + + + p_s_tb->fs_gen = get_generation (p_s_tb->tb_sb); + + /* we prepare and log the super here so it will already be in the + ** transaction when do_balance needs to change it. + ** This way do_balance won't have to schedule when trying to prepare + ** the super for logging + */ + reiserfs_prepare_for_journal(p_s_tb->tb_sb, + SB_BUFFER_WITH_SB(p_s_tb->tb_sb), 1) ; + journal_mark_dirty(p_s_tb->transaction_handle, p_s_tb->tb_sb, + SB_BUFFER_WITH_SB(p_s_tb->tb_sb)) ; + if ( FILESYSTEM_CHANGED_TB (p_s_tb) ) + return REPEAT_SEARCH; + + /* if it possible in indirect_to_direct conversion */ + if (buffer_locked (p_s_tbS0)) { + __wait_on_buffer (p_s_tbS0); + if ( FILESYSTEM_CHANGED_TB (p_s_tb) ) + return REPEAT_SEARCH; + } + +#ifdef CONFIG_REISERFS_CHECK + if ( cur_tb ) { + print_cur_tb ("fix_nodes"); + reiserfs_panic(p_s_tb->tb_sb,"PAP-8305: fix_nodes: there is pending do_balance"); + } + + if (!buffer_uptodate (p_s_tbS0) || !B_IS_IN_TREE (p_s_tbS0)) { + reiserfs_panic (p_s_tb->tb_sb, "PAP-8320: fix_nodes: S[0] (%b %z) is not uptodate " + "at the beginning of fix_nodes or not in tree (mode %c)", p_s_tbS0, p_s_tbS0, n_op_mode); + } + + /* Check parameters. */ + switch (n_op_mode) { + case M_INSERT: + if ( n_item_num <= 0 || n_item_num > B_NR_ITEMS(p_s_tbS0) ) + reiserfs_panic(p_s_tb->tb_sb,"PAP-8330: fix_nodes: Incorrect item number %d (in S0 - %d) in case of insert", + n_item_num, B_NR_ITEMS(p_s_tbS0)); + break; + case M_PASTE: + case M_DELETE: + case M_CUT: + if ( n_item_num < 0 || n_item_num >= B_NR_ITEMS(p_s_tbS0) ) { + print_block (p_s_tbS0, 0, -1, -1); + reiserfs_panic(p_s_tb->tb_sb,"PAP-8335: fix_nodes: Incorrect item number(%d); mode = %c insert_size = %d\n", n_item_num, n_op_mode, p_s_tb->insert_size[0]); + } + break; + default: + reiserfs_panic(p_s_tb->tb_sb,"PAP-8340: fix_nodes: Incorrect mode of operation"); + } +#endif + + if (get_mem_for_virtual_node (p_s_tb) == REPEAT_SEARCH) + // FIXME: maybe -ENOMEM when tb->vn_buf == 0? Now just repeat + return REPEAT_SEARCH; + + + /* Starting from the leaf level; for all levels n_h of the tree. */ + for ( n_h = 0; n_h < MAX_HEIGHT && p_s_tb->insert_size[n_h]; n_h++ ) { + if ( (n_ret_value = get_direct_parent(p_s_tb, n_h)) != CARRY_ON ) { + goto repeat; + } + + if ( (n_ret_value = check_balance (n_op_mode, p_s_tb, n_h, n_item_num, + n_pos_in_item, p_s_ins_ih, data)) != CARRY_ON ) { + if ( n_ret_value == NO_BALANCING_NEEDED ) { + /* No balancing for higher levels needed. */ + if ( (n_ret_value = get_neighbors(p_s_tb, n_h)) != CARRY_ON ) { + goto repeat; + } + if ( n_h != MAX_HEIGHT - 1 ) + p_s_tb->insert_size[n_h + 1] = 0; + /* ok, analysis and resource gathering are complete */ + break; + } + goto repeat; + } + + if ( (n_ret_value = get_neighbors(p_s_tb, n_h)) != CARRY_ON ) { + goto repeat; + } + + if ( (n_ret_value = get_empty_nodes(p_s_tb, n_h)) != CARRY_ON ) { + goto repeat; /* No disk space, or schedule occurred and + analysis may be invalid and needs to be redone. */ + } + + if ( ! PATH_H_PBUFFER(p_s_tb->tb_path, n_h) ) { + /* We have a positive insert size but no nodes exist on this + level, this means that we are creating a new root. */ + + RFALSE( p_s_tb->blknum[n_h] != 1, + "PAP-8350: creating new empty root"); + + if ( n_h < MAX_HEIGHT - 1 ) + p_s_tb->insert_size[n_h + 1] = 0; + } + else + if ( ! PATH_H_PBUFFER(p_s_tb->tb_path, n_h + 1) ) { + if ( p_s_tb->blknum[n_h] > 1 ) { + /* The tree needs to be grown, so this node S[n_h] + which is the root node is split into two nodes, + and a new node (S[n_h+1]) will be created to + become the root node. */ + + RFALSE( n_h == MAX_HEIGHT - 1, + "PAP-8355: attempt to create too high of a tree"); + + p_s_tb->insert_size[n_h + 1] = (DC_SIZE + KEY_SIZE) * (p_s_tb->blknum[n_h] - 1) + DC_SIZE; + } + else + if ( n_h < MAX_HEIGHT - 1 ) + p_s_tb->insert_size[n_h + 1] = 0; + } + else + p_s_tb->insert_size[n_h + 1] = (DC_SIZE + KEY_SIZE) * (p_s_tb->blknum[n_h] - 1); + } + + if ((n_ret_value = wait_tb_buffers_until_unlocked (p_s_tb)) == CARRY_ON) { + if (FILESYSTEM_CHANGED_TB(p_s_tb)) { + wait_tb_buffers_run = 1 ; + n_ret_value = REPEAT_SEARCH ; + goto repeat; + } else { + return CARRY_ON; + } + } else { + wait_tb_buffers_run = 1 ; + goto repeat; + } + + repeat: + // fix_nodes was unable to perform its calculation due to + // filesystem got changed under us, lack of free disk space or i/o + // failure. If the first is the case - the search will be + // repeated. For now - free all resources acquired so far except + // for the new allocated nodes + { + int i; + + /* Release path buffers. */ + if (wait_tb_buffers_run) { + pathrelse_and_restore(p_s_tb->tb_sb, p_s_tb->tb_path) ; + } else { + pathrelse (p_s_tb->tb_path); + } + /* brelse all resources collected for balancing */ + for ( i = 0; i < MAX_HEIGHT; i++ ) { + if (wait_tb_buffers_run) { + reiserfs_restore_prepared_buffer(p_s_tb->tb_sb, p_s_tb->L[i]); + reiserfs_restore_prepared_buffer(p_s_tb->tb_sb, p_s_tb->R[i]); + reiserfs_restore_prepared_buffer(p_s_tb->tb_sb, p_s_tb->FL[i]); + reiserfs_restore_prepared_buffer(p_s_tb->tb_sb, p_s_tb->FR[i]); + reiserfs_restore_prepared_buffer(p_s_tb->tb_sb, p_s_tb->CFL[i]); + reiserfs_restore_prepared_buffer(p_s_tb->tb_sb, p_s_tb->CFR[i]); + } + + brelse (p_s_tb->L[i]);p_s_tb->L[i] = NULL; + brelse (p_s_tb->R[i]);p_s_tb->R[i] = NULL; + brelse (p_s_tb->FL[i]);p_s_tb->FL[i] = NULL; + brelse (p_s_tb->FR[i]);p_s_tb->FR[i] = NULL; + brelse (p_s_tb->CFL[i]);p_s_tb->CFL[i] = NULL; + brelse (p_s_tb->CFR[i]);p_s_tb->CFR[i] = NULL; + } + + if (wait_tb_buffers_run) { + for ( i = 0; i < MAX_FEB_SIZE; i++ ) { + if ( p_s_tb->FEB[i] ) { + reiserfs_restore_prepared_buffer(p_s_tb->tb_sb, + p_s_tb->FEB[i]) ; + } + } + } + return n_ret_value; + } + +} + + +/* Anatoly will probably forgive me renaming p_s_tb to tb. I just + wanted to make lines shorter */ +void unfix_nodes (struct tree_balance * tb) +{ + int i; + + /* Release path buffers. */ + pathrelse_and_restore (tb->tb_sb, tb->tb_path); + + /* brelse all resources collected for balancing */ + for ( i = 0; i < MAX_HEIGHT; i++ ) { + reiserfs_restore_prepared_buffer (tb->tb_sb, tb->L[i]); + reiserfs_restore_prepared_buffer (tb->tb_sb, tb->R[i]); + reiserfs_restore_prepared_buffer (tb->tb_sb, tb->FL[i]); + reiserfs_restore_prepared_buffer (tb->tb_sb, tb->FR[i]); + reiserfs_restore_prepared_buffer (tb->tb_sb, tb->CFL[i]); + reiserfs_restore_prepared_buffer (tb->tb_sb, tb->CFR[i]); + + brelse (tb->L[i]); + brelse (tb->R[i]); + brelse (tb->FL[i]); + brelse (tb->FR[i]); + brelse (tb->CFL[i]); + brelse (tb->CFR[i]); + } + + /* deal with list of allocated (used and unused) nodes */ + for ( i = 0; i < MAX_FEB_SIZE; i++ ) { + if ( tb->FEB[i] ) { + b_blocknr_t blocknr = tb->FEB[i]->b_blocknr ; + /* de-allocated block which was not used by balancing and + bforget about buffer for it */ + brelse (tb->FEB[i]); + reiserfs_free_block (tb->transaction_handle, NULL, blocknr, 0); + } + if (tb->used[i]) { + /* release used as new nodes including a new root */ + brelse (tb->used[i]); + } + } + + if (tb->vn_buf) + reiserfs_kfree (tb->vn_buf, tb->vn_buf_size, tb->tb_sb); + +} + + + |