v4.19.13 snapshot.
diff --git a/fs/reiserfs/fix_node.c b/fs/reiserfs/fix_node.c
new file mode 100644
index 0000000..6b0ddb2
--- /dev/null
+++ b/fs/reiserfs/fix_node.c
@@ -0,0 +1,2825 @@
+/*
+ * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
+ */
+
+#include <linux/time.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include "reiserfs.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.
+ */
+
+/*
+ * Takes 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 = item_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 that 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 = ih_item_body(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",
+ "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];
+ /* pointer to data which is going to be pasted */
+ vi->vi_new_data = vn->vn_data;
+ }
+ }
+
+ /* 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 == NULL,
+ "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 = internal_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(item_head(Sh, 0))
+ && ih_entry_count(item_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",
+ "rdkey %k, affected item==%d "
+ "(mode==%c) Must be %c",
+ key, vn->vn_affected_item_num,
+ vn->vn_mode, M_DELETE);
+ }
+ }
+#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
+ */
+
+ /* cannot shift even a part of the current item */
+ if (cur_free <= ih_size) {
+ 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
+ */
+
+ /* cannot shift even a part of the current item */
+ if (cur_free <= ih_size) {
+ 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 units;
+ struct virtual_node *vn = tb->tb_vn;
+ int total_node_size, max_node_size, current_item_size;
+ int needed_nodes;
+
+ /* position of item we start filling node from */
+ int start_item;
+
+ /* position of item we finish filling node by */
+ int end_item;
+
+ /*
+ * number of first bytes (entries for directory) of start_item-th item
+ * we do not include into node that is being filled
+ */
+ int start_bytes;
+
+ /*
+ * number of last bytes (entries for directory) of end_item-th item
+ * we do node include into node that is being filled
+ */
+ int end_bytes;
+
+ /*
+ * these are positions in virtual item of items, that are split
+ * between S[0] and S1new and S1new and S2new
+ */
+ int split_item_positions[2];
+
+ 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;
+ }
+
+ /*
+ * virtual item length is longer, than max size of item in
+ * a node. It is impossible for direct item
+ */
+ if (current_item_size > max_node_size) {
+ 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;
+ }
+
+ /* as we do not split items, take new node and continue */
+ if (!flow) {
+ 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);
+ /*
+ * nothing fits into current node, take new
+ * node and continue
+ */
+ if (units == -1) {
+ needed_nodes++, i--, total_node_size = 0;
+ continue;
+ }
+ }
+
+ /* something fits into the current node */
+ start_bytes += units;
+ snum012[needed_nodes - 1 + 3] = units;
+
+ if (needed_nodes > 2)
+ reiserfs_warning(tb->tb_sb, "vs-8111",
+ "split_item_position is out of range");
+ 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",
+ "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;
+}
+
+
+/*
+ * 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;
+
+ /* only for leaf level */
+ if (h == 0) {
+ if (s012 != NULL) {
+ tb->s0num = *s012++;
+ tb->snum[0] = *s012++;
+ tb->snum[1] = *s012++;
+ tb->sbytes[0] = *s012++;
+ tb->sbytes[1] = *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 if node disappears 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);
+
+ /* all content of node can be shifted to neighbors */
+ if (remain_items < 1) {
+ set_parameters(tb, 0, to_left, vn->vn_nr_item - to_left, 0,
+ NULL, -1, -1);
+ return 1;
+ }
+
+ /* S[0] is not removable */
+ if (remain_items > 1 || tb->lbytes == -1 || tb->rbytes == -1)
+ 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 = item_head(S0, 0);
+ if (tb->CFR[0]
+ && !comp_short_le_keys(&ih->ih_key,
+ internal_key(tb->CFR[0],
+ tb->rkey[0])))
+ /*
+ * 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
+ */
+ if (is_direntry_le_ih(ih)) {
+ 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 *tb)
+{
+ int i;
+
+ pathrelse(tb->tb_path);
+
+ for (i = 0; i < MAX_HEIGHT; 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]);
+
+ tb->L[i] = NULL;
+ tb->R[i] = NULL;
+ tb->FL[i] = NULL;
+ tb->FR[i] = NULL;
+ tb->CFL[i] = NULL;
+ tb->CFR[i] = 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 *tb, int h)
+{
+ struct buffer_head *new_bh, *Sh = PATH_H_PBUFFER(tb->tb_path, h);
+ b_blocknr_t *blocknr, blocknrs[MAX_AMOUNT_NEEDED] = { 0, };
+ int counter, number_of_freeblk;
+ int amount_needed; /* number of needed empty blocks */
+ int retval = CARRY_ON;
+ struct super_block *sb = 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 (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 h.
+ */
+ /* blknum includes S[h], so we subtract 1 in this calculation */
+ for (counter = 0, number_of_freeblk = tb->cur_blknum;
+ counter < h; counter++)
+ number_of_freeblk -=
+ (tb->blknum[counter]) ? (tb->blknum[counter] -
+ 1) : 0;
+
+ /* Allocate missing empty blocks. */
+ /* if Sh == 0 then we are getting a new root */
+ amount_needed = (Sh) ? (tb->blknum[h] - 1) : 1;
+ /*
+ * Amount_needed = the amount that we need more than the
+ * amount that we have.
+ */
+ if (amount_needed > number_of_freeblk)
+ amount_needed -= 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(tb, blocknrs,
+ amount_needed) == NO_DISK_SPACE)
+ return NO_DISK_SPACE;
+
+ /* for each blocknumber we just got, get a buffer and stick it on FEB */
+ for (blocknr = blocknrs, counter = 0;
+ counter < amount_needed; blocknr++, counter++) {
+
+ RFALSE(!*blocknr,
+ "PAP-8135: reiserfs_new_blocknrs failed when got new blocks");
+
+ new_bh = sb_getblk(sb, *blocknr);
+ RFALSE(buffer_dirty(new_bh) ||
+ buffer_journaled(new_bh) ||
+ buffer_journal_dirty(new_bh),
+ "PAP-8140: journaled or dirty buffer %b for the new block",
+ new_bh);
+
+ /* Put empty buffers into the array. */
+ RFALSE(tb->FEB[tb->cur_blknum],
+ "PAP-8141: busy slot for new buffer");
+
+ set_buffer_journal_new(new_bh);
+ tb->FEB[tb->cur_blknum++] = new_bh;
+ }
+
+ if (retval == CARRY_ON && FILESYSTEM_CHANGED_TB(tb))
+ retval = REPEAT_SEARCH;
+
+ return 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)) == NULL ||
+ (l = tb->FL[h]) == NULL)
+ 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)) == NULL ||
+ (r = tb->FR[h]) == NULL)
+ 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 *tb, int h)
+{
+ struct buffer_head *father, *left;
+ struct super_block *sb = tb->tb_sb;
+ b_blocknr_t left_neighbor_blocknr;
+ int left_neighbor_position;
+
+ /* Father of the left neighbor does not exist. */
+ if (!tb->FL[h])
+ return 0;
+
+ /* Calculate father of the node to be balanced. */
+ father = PATH_H_PBUFFER(tb->tb_path, h + 1);
+
+ RFALSE(!father ||
+ !B_IS_IN_TREE(father) ||
+ !B_IS_IN_TREE(tb->FL[h]) ||
+ !buffer_uptodate(father) ||
+ !buffer_uptodate(tb->FL[h]),
+ "vs-8165: F[h] (%b) or FL[h] (%b) is invalid",
+ father, tb->FL[h]);
+
+ /*
+ * Get position of the pointer to the left neighbor
+ * into the left father.
+ */
+ left_neighbor_position = (father == tb->FL[h]) ?
+ tb->lkey[h] : B_NR_ITEMS(tb->FL[h]);
+ /* Get left neighbor block number. */
+ left_neighbor_blocknr =
+ B_N_CHILD_NUM(tb->FL[h], left_neighbor_position);
+ /* Look for the left neighbor in the cache. */
+ if ((left = sb_find_get_block(sb, 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 *key)
+{
+ /* call item specific function for this key */
+ item_ops[cpu_key_k_type(key)]->decrement_key(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 *tb,
+ int h,
+ struct buffer_head **pfather,
+ struct buffer_head **pcom_father, char c_lr_par)
+{
+ struct buffer_head *parent;
+ INITIALIZE_PATH(s_path_to_neighbor_father);
+ struct treepath *path = tb->tb_path;
+ struct cpu_key s_lr_father_key;
+ int counter,
+ position = INT_MAX,
+ first_last_position = 0,
+ path_offset = PATH_H_PATH_OFFSET(path, h);
+
+ /*
+ * Starting from F[h] go upwards in the tree, and look for the common
+ * ancestor of F[h], and its neighbor l/r, that should be obtained.
+ */
+
+ counter = path_offset;
+
+ RFALSE(counter < FIRST_PATH_ELEMENT_OFFSET,
+ "PAP-8180: invalid path length");
+
+ for (; counter > FIRST_PATH_ELEMENT_OFFSET; counter--) {
+ /*
+ * Check whether parent of the current buffer in the path
+ * is really parent in the tree.
+ */
+ if (!B_IS_IN_TREE
+ (parent = PATH_OFFSET_PBUFFER(path, counter - 1)))
+ return REPEAT_SEARCH;
+
+ /* Check whether position in the parent is correct. */
+ if ((position =
+ PATH_OFFSET_POSITION(path,
+ counter - 1)) >
+ B_NR_ITEMS(parent))
+ return REPEAT_SEARCH;
+
+ /*
+ * Check whether parent at the path really points
+ * to the child.
+ */
+ if (B_N_CHILD_NUM(parent, position) !=
+ PATH_OFFSET_PBUFFER(path, 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)
+ first_last_position = B_NR_ITEMS(parent);
+ if (position != first_last_position) {
+ *pcom_father = parent;
+ get_bh(*pcom_father);
+ /*(*pcom_father = parent)->b_count++; */
+ break;
+ }
+ }
+
+ /* if we are in the root of the tree, then there is no common father */
+ if (counter == FIRST_PATH_ELEMENT_OFFSET) {
+ /*
+ * Check whether first buffer in the path is the
+ * root of the tree.
+ */
+ if (PATH_OFFSET_PBUFFER
+ (tb->tb_path,
+ FIRST_PATH_ELEMENT_OFFSET)->b_blocknr ==
+ SB_ROOT_BLOCK(tb->tb_sb)) {
+ *pfather = *pcom_father = NULL;
+ return CARRY_ON;
+ }
+ return REPEAT_SEARCH;
+ }
+
+ RFALSE(B_LEVEL(*pcom_father) <= DISK_LEAF_NODE_LEVEL,
+ "PAP-8185: (%b %z) level too small",
+ *pcom_father, *pcom_father);
+
+ /* Check whether the common parent is locked. */
+
+ if (buffer_locked(*pcom_father)) {
+
+ /* Release the write lock while the buffer is busy */
+ int depth = reiserfs_write_unlock_nested(tb->tb_sb);
+ __wait_on_buffer(*pcom_father);
+ reiserfs_write_lock_nested(tb->tb_sb, depth);
+ if (FILESYSTEM_CHANGED_TB(tb)) {
+ brelse(*pcom_father);
+ return REPEAT_SEARCH;
+ }
+ }
+
+ /*
+ * So, we got common parent of the current node and its
+ * left/right neighbor. Now we are getting the parent of the
+ * left/right neighbor.
+ */
+
+ /* Form key to get parent of the left/right neighbor. */
+ le_key2cpu_key(&s_lr_father_key,
+ internal_key(*pcom_father,
+ (c_lr_par ==
+ LEFT_PARENTS) ? (tb->lkey[h - 1] =
+ position -
+ 1) : (tb->rkey[h -
+ 1] =
+ position)));
+
+ if (c_lr_par == LEFT_PARENTS)
+ decrement_key(&s_lr_father_key);
+
+ if (search_by_key
+ (tb->tb_sb, &s_lr_father_key, &s_path_to_neighbor_father,
+ h + 1) == IO_ERROR)
+ /* path is released */
+ return IO_ERROR;
+
+ if (FILESYSTEM_CHANGED_TB(tb)) {
+ pathrelse(&s_path_to_neighbor_father);
+ brelse(*pcom_father);
+ return REPEAT_SEARCH;
+ }
+
+ *pfather = PATH_PLAST_BUFFER(&s_path_to_neighbor_father);
+
+ RFALSE(B_LEVEL(*pfather) != h + 1,
+ "PAP-8190: (%b %z) level too small", *pfather, *pfather);
+ 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--;
+ pathrelse(&s_path_to_neighbor_father);
+ return CARRY_ON;
+}
+
+/*
+ * Get parents of neighbors of node in the path(S[path_offset]) and
+ * common parents of S[path_offset] and L[path_offset]/R[path_offset]:
+ * F[path_offset], FL[path_offset], FR[path_offset], CFL[path_offset],
+ * CFR[path_offset].
+ * Calculate numbers of left and right delimiting keys position:
+ * lkey[path_offset], rkey[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 *tb, int h)
+{
+ struct treepath *path = tb->tb_path;
+ int position,
+ ret,
+ path_offset = PATH_H_PATH_OFFSET(tb->tb_path, h);
+ struct buffer_head *curf, *curcf;
+
+ /* Current node is the root of the tree or will be root of the tree */
+ if (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.
+ */
+ brelse(tb->FL[h]);
+ brelse(tb->CFL[h]);
+ brelse(tb->FR[h]);
+ brelse(tb->CFR[h]);
+ tb->FL[h] = NULL;
+ tb->CFL[h] = NULL;
+ tb->FR[h] = NULL;
+ tb->CFR[h] = NULL;
+ return CARRY_ON;
+ }
+
+ /* Get parent FL[path_offset] of L[path_offset]. */
+ position = PATH_OFFSET_POSITION(path, path_offset - 1);
+ if (position) {
+ /* Current node is not the first child of its parent. */
+ curf = PATH_OFFSET_PBUFFER(path, path_offset - 1);
+ curcf = PATH_OFFSET_PBUFFER(path, path_offset - 1);
+ get_bh(curf);
+ get_bh(curf);
+ tb->lkey[h] = position - 1;
+ } else {
+ /*
+ * Calculate current parent of L[path_offset], which is the
+ * left neighbor of the current node. Calculate current
+ * common parent of L[path_offset] and the current node.
+ * Note that CFL[path_offset] not equal FL[path_offset] and
+ * CFL[path_offset] not equal F[path_offset].
+ * Calculate lkey[path_offset].
+ */
+ if ((ret = get_far_parent(tb, h + 1, &curf,
+ &curcf,
+ LEFT_PARENTS)) != CARRY_ON)
+ return ret;
+ }
+
+ brelse(tb->FL[h]);
+ tb->FL[h] = curf; /* New initialization of FL[h]. */
+ brelse(tb->CFL[h]);
+ tb->CFL[h] = curcf; /* New initialization of CFL[h]. */
+
+ RFALSE((curf && !B_IS_IN_TREE(curf)) ||
+ (curcf && !B_IS_IN_TREE(curcf)),
+ "PAP-8195: FL (%b) or CFL (%b) is invalid", curf, curcf);
+
+ /* Get parent FR[h] of R[h]. */
+
+ /* Current node is the last child of F[h]. FR[h] != F[h]. */
+ if (position == B_NR_ITEMS(PATH_H_PBUFFER(path, h + 1))) {
+ /*
+ * Calculate current parent of R[h], which is the right
+ * neighbor of F[h]. Calculate current common parent of
+ * R[h] and current node. Note that CFR[h] not equal
+ * FR[path_offset] and CFR[h] not equal F[h].
+ */
+ if ((ret =
+ get_far_parent(tb, h + 1, &curf, &curcf,
+ RIGHT_PARENTS)) != CARRY_ON)
+ return ret;
+ } else {
+ /* Current node is not the last child of its parent F[h]. */
+ curf = PATH_OFFSET_PBUFFER(path, path_offset - 1);
+ curcf = PATH_OFFSET_PBUFFER(path, path_offset - 1);
+ get_bh(curf);
+ get_bh(curf);
+ tb->rkey[h] = position;
+ }
+
+ brelse(tb->FR[h]);
+ /* New initialization of FR[path_offset]. */
+ tb->FR[h] = curf;
+
+ brelse(tb->CFR[h]);
+ /* New initialization of CFR[path_offset]. */
+ tb->CFR[h] = curcf;
+
+ RFALSE((curf && !B_IS_IN_TREE(curf)) ||
+ (curcf && !B_IS_IN_TREE(curcf)),
+ "PAP-8205: FR (%b) or CFR (%b) is invalid", curf, 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 = item_head(Sh, 0);
+ if (tb->CFR[h])
+ r_key = internal_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;
+ /*
+ * 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.
+ */
+ int levbytes;
+ int ret;
+
+ 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
+ *
+ * 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)
+ */
+ short snum012[40] = { 0, };
+
+ /* 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",
+ "S[0] can not be 0");
+ switch (ret = get_empty_nodes(tb, h)) {
+ /* no balancing for higher levels needed */
+ case CARRY_ON:
+ set_parameters(tb, h, 0, 0, 1, NULL, -1, -1);
+ return NO_BALANCING_NEEDED;
+
+ case NO_DISK_SPACE:
+ case REPEAT_SEARCH:
+ return ret;
+ default:
+ reiserfs_panic(tb->tb_sb, "vs-8215", "incorrect "
+ "return value of get_empty_nodes");
+ }
+ }
+
+ /* get parents of S[h] neighbors. */
+ ret = get_parents(tb, h);
+ if (ret != CARRY_ON)
+ return ret;
+
+ sfree = B_FREE_SPACE(Sh);
+
+ /* get free space of neighbors */
+ rfree = get_rfree(tb, h);
+ lfree = get_lfree(tb, h);
+
+ /* and new item fits into node S[h] without any shifting */
+ if (can_node_be_removed(vn->vn_mode, lfree, sfree, rfree, tb, h) ==
+ NO_BALANCING_NEEDED)
+ 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
+ */
+
+ /* new item fits into node S[h] without any shifting */
+ if (sfree >= levbytes) {
+ 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 of 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, ret;
+ 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. */
+ /* no balancing for higher levels needed */
+ if (vn->vn_nr_item > 0) {
+ set_parameters(tb, h, 0, 0, 1, NULL, -1, -1);
+ return NO_BALANCING_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 ((ret = get_parents(tb, h)) != CARRY_ON)
+ return ret;
+
+ /* 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);
+
+ /*
+ * 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 (vn->vn_nr_item == MIN_NR_KEY(Sh)) {
+ /* All contents of S[h] can be moved to L[h]. */
+ if (tb->lnum[h] >= vn->vn_nr_item + 1) {
+ 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;
+ }
+
+ /* All contents of S[h] can be moved to R[h]. */
+ 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;
+ }
+
+ /* 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, ret;
+
+ /*
+ * 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 ((ret = get_parents(tb, h)) != CARRY_ON)
+ return ret;
+
+ /* 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");
+
+ /* Calculate balance parameters when size of node is increasing. */
+ if (tb->insert_size[h] > 0)
+ 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 *tb, int h)
+{
+ struct buffer_head *bh;
+ struct treepath *path = tb->tb_path;
+ int position,
+ path_offset = PATH_H_PATH_OFFSET(tb->tb_path, h);
+
+ /* We are in the root or in the new root. */
+ if (path_offset <= FIRST_PATH_ELEMENT_OFFSET) {
+
+ RFALSE(path_offset < FIRST_PATH_ELEMENT_OFFSET - 1,
+ "PAP-8260: invalid offset in the path");
+
+ if (PATH_OFFSET_PBUFFER(path, FIRST_PATH_ELEMENT_OFFSET)->
+ b_blocknr == SB_ROOT_BLOCK(tb->tb_sb)) {
+ /* Root is not changed. */
+ PATH_OFFSET_PBUFFER(path, path_offset - 1) = NULL;
+ PATH_OFFSET_POSITION(path, path_offset - 1) = 0;
+ return CARRY_ON;
+ }
+ /* Root is changed and we must recalculate the path. */
+ return REPEAT_SEARCH;
+ }
+
+ /* Parent in the path is not in the tree. */
+ if (!B_IS_IN_TREE
+ (bh = PATH_OFFSET_PBUFFER(path, path_offset - 1)))
+ return REPEAT_SEARCH;
+
+ if ((position =
+ PATH_OFFSET_POSITION(path,
+ path_offset - 1)) > B_NR_ITEMS(bh))
+ return REPEAT_SEARCH;
+
+ /* Parent in the path is not parent of the current node in the tree. */
+ if (B_N_CHILD_NUM(bh, position) !=
+ PATH_OFFSET_PBUFFER(path, path_offset)->b_blocknr)
+ return REPEAT_SEARCH;
+
+ if (buffer_locked(bh)) {
+ int depth = reiserfs_write_unlock_nested(tb->tb_sb);
+ __wait_on_buffer(bh);
+ reiserfs_write_lock_nested(tb->tb_sb, depth);
+ if (FILESYSTEM_CHANGED_TB(tb))
+ return REPEAT_SEARCH;
+ }
+
+ /*
+ * Parent in the path is unlocked and really parent
+ * of the current node.
+ */
+ return CARRY_ON;
+}
+
+/*
+ * Using lnum[h] and rnum[h] we should determine what neighbors
+ * of S[h] we
+ * need in order to balance S[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 *tb, int h)
+{
+ int child_position,
+ path_offset = PATH_H_PATH_OFFSET(tb->tb_path, h + 1);
+ unsigned long son_number;
+ struct super_block *sb = tb->tb_sb;
+ struct buffer_head *bh;
+ int depth;
+
+ PROC_INFO_INC(sb, get_neighbors[h]);
+
+ if (tb->lnum[h]) {
+ /* We need left neighbor to balance S[h]. */
+ PROC_INFO_INC(sb, need_l_neighbor[h]);
+ bh = PATH_OFFSET_PBUFFER(tb->tb_path, path_offset);
+
+ RFALSE(bh == tb->FL[h] &&
+ !PATH_OFFSET_POSITION(tb->tb_path, path_offset),
+ "PAP-8270: invalid position in the parent");
+
+ child_position =
+ (bh ==
+ tb->FL[h]) ? tb->lkey[h] : B_NR_ITEMS(tb->
+ FL[h]);
+ son_number = B_N_CHILD_NUM(tb->FL[h], child_position);
+ depth = reiserfs_write_unlock_nested(tb->tb_sb);
+ bh = sb_bread(sb, son_number);
+ reiserfs_write_lock_nested(tb->tb_sb, depth);
+ if (!bh)
+ return IO_ERROR;
+ if (FILESYSTEM_CHANGED_TB(tb)) {
+ brelse(bh);
+ PROC_INFO_INC(sb, get_neighbors_restart[h]);
+ return REPEAT_SEARCH;
+ }
+
+ RFALSE(!B_IS_IN_TREE(tb->FL[h]) ||
+ child_position > B_NR_ITEMS(tb->FL[h]) ||
+ B_N_CHILD_NUM(tb->FL[h], child_position) !=
+ bh->b_blocknr, "PAP-8275: invalid parent");
+ RFALSE(!B_IS_IN_TREE(bh), "PAP-8280: invalid child");
+ RFALSE(!h &&
+ B_FREE_SPACE(bh) !=
+ MAX_CHILD_SIZE(bh) -
+ dc_size(B_N_CHILD(tb->FL[0], child_position)),
+ "PAP-8290: invalid child size of left neighbor");
+
+ brelse(tb->L[h]);
+ tb->L[h] = bh;
+ }
+
+ /* We need right neighbor to balance S[path_offset]. */
+ if (tb->rnum[h]) {
+ PROC_INFO_INC(sb, need_r_neighbor[h]);
+ bh = PATH_OFFSET_PBUFFER(tb->tb_path, path_offset);
+
+ RFALSE(bh == tb->FR[h] &&
+ PATH_OFFSET_POSITION(tb->tb_path,
+ path_offset) >=
+ B_NR_ITEMS(bh),
+ "PAP-8295: invalid position in the parent");
+
+ child_position =
+ (bh == tb->FR[h]) ? tb->rkey[h] + 1 : 0;
+ son_number = B_N_CHILD_NUM(tb->FR[h], child_position);
+ depth = reiserfs_write_unlock_nested(tb->tb_sb);
+ bh = sb_bread(sb, son_number);
+ reiserfs_write_lock_nested(tb->tb_sb, depth);
+ if (!bh)
+ return IO_ERROR;
+ if (FILESYSTEM_CHANGED_TB(tb)) {
+ brelse(bh);
+ PROC_INFO_INC(sb, get_neighbors_restart[h]);
+ return REPEAT_SEARCH;
+ }
+ brelse(tb->R[h]);
+ tb->R[h] = bh;
+
+ RFALSE(!h
+ && B_FREE_SPACE(bh) !=
+ MAX_CHILD_SIZE(bh) -
+ dc_size(B_N_CHILD(tb->FR[0], child_position)),
+ "PAP-8300: invalid child size of right neighbor (%d != %d - %d)",
+ B_FREE_SPACE(bh), MAX_CHILD_SIZE(bh),
+ dc_size(B_N_CHILD(tb->FR[0], child_position)));
+
+ }
+ return CARRY_ON;
+}
+
+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));
+
+ /* we have to allocate more memory for virtual node */
+ if (size > tb->vn_buf_size) {
+ if (tb->vn_buf) {
+ /* free memory allocated before */
+ kfree(tb->vn_buf);
+ /* 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 = kmalloc(size, GFP_ATOMIC | __GFP_NOWARN);
+ 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 = kmalloc(size, GFP_NOFS);
+ if (!buf) {
+ 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 *sb,
+ struct buffer_head *bh,
+ const char *descr, int level)
+{
+ if (bh) {
+ if (atomic_read(&(bh->b_count)) <= 0)
+
+ reiserfs_panic(sb, "jmacd-1", "negative or zero "
+ "reference counter for buffer %s[%d] "
+ "(%b)", descr, level, bh);
+
+ if (!buffer_uptodate(bh))
+ reiserfs_panic(sb, "jmacd-2", "buffer is not up "
+ "to date %s[%d] (%b)",
+ descr, level, bh);
+
+ if (!B_IS_IN_TREE(bh))
+ reiserfs_panic(sb, "jmacd-3", "buffer is not "
+ "in tree %s[%d] (%b)",
+ descr, level, bh);
+
+ if (bh->b_bdev != sb->s_bdev)
+ reiserfs_panic(sb, "jmacd-4", "buffer has wrong "
+ "device %s[%d] (%b)",
+ descr, level, bh);
+
+ if (bh->b_size != sb->s_blocksize)
+ reiserfs_panic(sb, "jmacd-5", "buffer has wrong "
+ "blocksize %s[%d] (%b)",
+ descr, level, bh);
+
+ if (bh->b_blocknr > SB_BLOCK_COUNT(sb))
+ reiserfs_panic(sb, "jmacd-6", "buffer block "
+ "number too high %s[%d] (%b)",
+ descr, level, bh);
+ }
+}
+#else
+static void tb_buffer_sanity_check(struct super_block *sb,
+ struct buffer_head *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 *tb)
+{
+ struct buffer_head *locked;
+#ifdef CONFIG_REISERFS_CHECK
+ int repeat_counter = 0;
+#endif
+ int i;
+
+ do {
+
+ locked = NULL;
+
+ for (i = tb->tb_path->path_length;
+ !locked && i > ILLEGAL_PATH_ELEMENT_OFFSET; i--) {
+ if (PATH_OFFSET_PBUFFER(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(tb->tb_path) ==
+ PATH_OFFSET_PBUFFER(tb->tb_path, i))
+ tb_buffer_sanity_check(tb->tb_sb,
+ PATH_OFFSET_PBUFFER
+ (tb->tb_path,
+ i), "S",
+ tb->tb_path->
+ path_length - i);
+#endif
+ if (!clear_all_dirty_bits(tb->tb_sb,
+ PATH_OFFSET_PBUFFER
+ (tb->tb_path,
+ i))) {
+ locked =
+ PATH_OFFSET_PBUFFER(tb->tb_path,
+ i);
+ }
+ }
+ }
+
+ for (i = 0; !locked && i < MAX_HEIGHT && tb->insert_size[i];
+ i++) {
+
+ if (tb->lnum[i]) {
+
+ if (tb->L[i]) {
+ tb_buffer_sanity_check(tb->tb_sb,
+ tb->L[i],
+ "L", i);
+ if (!clear_all_dirty_bits
+ (tb->tb_sb, tb->L[i]))
+ locked = tb->L[i];
+ }
+
+ if (!locked && tb->FL[i]) {
+ tb_buffer_sanity_check(tb->tb_sb,
+ tb->FL[i],
+ "FL", i);
+ if (!clear_all_dirty_bits
+ (tb->tb_sb, tb->FL[i]))
+ locked = tb->FL[i];
+ }
+
+ if (!locked && tb->CFL[i]) {
+ tb_buffer_sanity_check(tb->tb_sb,
+ tb->CFL[i],
+ "CFL", i);
+ if (!clear_all_dirty_bits
+ (tb->tb_sb, tb->CFL[i]))
+ locked = tb->CFL[i];
+ }
+
+ }
+
+ if (!locked && (tb->rnum[i])) {
+
+ if (tb->R[i]) {
+ tb_buffer_sanity_check(tb->tb_sb,
+ tb->R[i],
+ "R", i);
+ if (!clear_all_dirty_bits
+ (tb->tb_sb, tb->R[i]))
+ locked = tb->R[i];
+ }
+
+ if (!locked && tb->FR[i]) {
+ tb_buffer_sanity_check(tb->tb_sb,
+ tb->FR[i],
+ "FR", i);
+ if (!clear_all_dirty_bits
+ (tb->tb_sb, tb->FR[i]))
+ locked = tb->FR[i];
+ }
+
+ if (!locked && tb->CFR[i]) {
+ tb_buffer_sanity_check(tb->tb_sb,
+ tb->CFR[i],
+ "CFR", i);
+ if (!clear_all_dirty_bits
+ (tb->tb_sb, tb->CFR[i]))
+ locked = 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 (tb->FEB[i]) {
+ if (!clear_all_dirty_bits
+ (tb->tb_sb, tb->FEB[i]))
+ locked = tb->FEB[i];
+ }
+ }
+
+ if (locked) {
+ int depth;
+#ifdef CONFIG_REISERFS_CHECK
+ repeat_counter++;
+ if ((repeat_counter % 10000) == 0) {
+ reiserfs_warning(tb->tb_sb, "reiserfs-8200",
+ "too many iterations waiting "
+ "for buffer to unlock "
+ "(%b)", locked);
+
+ /* Don't loop forever. Try to recover from possible error. */
+
+ return (FILESYSTEM_CHANGED_TB(tb)) ?
+ REPEAT_SEARCH : CARRY_ON;
+ }
+#endif
+ depth = reiserfs_write_unlock_nested(tb->tb_sb);
+ __wait_on_buffer(locked);
+ reiserfs_write_lock_nested(tb->tb_sb, depth);
+ if (FILESYSTEM_CHANGED_TB(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 item head of item being inserted
+ * data inserted item or data to be pasted
+ * 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 op_mode, struct tree_balance *tb,
+ struct item_head *ins_ih, const void *data)
+{
+ int ret, h, item_num = PATH_LAST_POSITION(tb->tb_path);
+ int 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 *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
+
+ ++REISERFS_SB(tb->tb_sb)->s_fix_nodes;
+
+ pos_in_item = tb->tb_path->pos_in_item;
+
+ tb->fs_gen = get_generation(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(tb->tb_sb,
+ SB_BUFFER_WITH_SB(tb->tb_sb), 1);
+ journal_mark_dirty(tb->transaction_handle,
+ SB_BUFFER_WITH_SB(tb->tb_sb));
+ if (FILESYSTEM_CHANGED_TB(tb))
+ return REPEAT_SEARCH;
+
+ /* if it possible in indirect_to_direct conversion */
+ if (buffer_locked(tbS0)) {
+ int depth = reiserfs_write_unlock_nested(tb->tb_sb);
+ __wait_on_buffer(tbS0);
+ reiserfs_write_lock_nested(tb->tb_sb, depth);
+ if (FILESYSTEM_CHANGED_TB(tb))
+ return REPEAT_SEARCH;
+ }
+#ifdef CONFIG_REISERFS_CHECK
+ if (REISERFS_SB(tb->tb_sb)->cur_tb) {
+ print_cur_tb("fix_nodes");
+ reiserfs_panic(tb->tb_sb, "PAP-8305",
+ "there is pending do_balance");
+ }
+
+ if (!buffer_uptodate(tbS0) || !B_IS_IN_TREE(tbS0))
+ reiserfs_panic(tb->tb_sb, "PAP-8320", "S[0] (%b %z) is "
+ "not uptodate at the beginning of fix_nodes "
+ "or not in tree (mode %c)",
+ tbS0, tbS0, op_mode);
+
+ /* Check parameters. */
+ switch (op_mode) {
+ case M_INSERT:
+ if (item_num <= 0 || item_num > B_NR_ITEMS(tbS0))
+ reiserfs_panic(tb->tb_sb, "PAP-8330", "Incorrect "
+ "item number %d (in S0 - %d) in case "
+ "of insert", item_num,
+ B_NR_ITEMS(tbS0));
+ break;
+ case M_PASTE:
+ case M_DELETE:
+ case M_CUT:
+ if (item_num < 0 || item_num >= B_NR_ITEMS(tbS0)) {
+ print_block(tbS0, 0, -1, -1);
+ reiserfs_panic(tb->tb_sb, "PAP-8335", "Incorrect "
+ "item number(%d); mode = %c "
+ "insert_size = %d",
+ item_num, op_mode,
+ tb->insert_size[0]);
+ }
+ break;
+ default:
+ reiserfs_panic(tb->tb_sb, "PAP-8340", "Incorrect mode "
+ "of operation");
+ }
+#endif
+
+ if (get_mem_for_virtual_node(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 h of the tree. */
+ for (h = 0; h < MAX_HEIGHT && tb->insert_size[h]; h++) {
+ ret = get_direct_parent(tb, h);
+ if (ret != CARRY_ON)
+ goto repeat;
+
+ ret = check_balance(op_mode, tb, h, item_num,
+ pos_in_item, ins_ih, data);
+ if (ret != CARRY_ON) {
+ if (ret == NO_BALANCING_NEEDED) {
+ /* No balancing for higher levels needed. */
+ ret = get_neighbors(tb, h);
+ if (ret != CARRY_ON)
+ goto repeat;
+ if (h != MAX_HEIGHT - 1)
+ tb->insert_size[h + 1] = 0;
+ /*
+ * ok, analysis and resource gathering
+ * are complete
+ */
+ break;
+ }
+ goto repeat;
+ }
+
+ ret = get_neighbors(tb, h);
+ if (ret != CARRY_ON)
+ goto repeat;
+
+ /*
+ * No disk space, or schedule occurred and analysis may be
+ * invalid and needs to be redone.
+ */
+ ret = get_empty_nodes(tb, h);
+ if (ret != CARRY_ON)
+ goto repeat;
+
+ /*
+ * We have a positive insert size but no nodes exist on this
+ * level, this means that we are creating a new root.
+ */
+ if (!PATH_H_PBUFFER(tb->tb_path, h)) {
+
+ RFALSE(tb->blknum[h] != 1,
+ "PAP-8350: creating new empty root");
+
+ if (h < MAX_HEIGHT - 1)
+ tb->insert_size[h + 1] = 0;
+ } else if (!PATH_H_PBUFFER(tb->tb_path, h + 1)) {
+ /*
+ * The tree needs to be grown, so this node S[h]
+ * which is the root node is split into two nodes,
+ * and a new node (S[h+1]) will be created to
+ * become the root node.
+ */
+ if (tb->blknum[h] > 1) {
+
+ RFALSE(h == MAX_HEIGHT - 1,
+ "PAP-8355: attempt to create too high of a tree");
+
+ tb->insert_size[h + 1] =
+ (DC_SIZE +
+ KEY_SIZE) * (tb->blknum[h] - 1) +
+ DC_SIZE;
+ } else if (h < MAX_HEIGHT - 1)
+ tb->insert_size[h + 1] = 0;
+ } else
+ tb->insert_size[h + 1] =
+ (DC_SIZE + KEY_SIZE) * (tb->blknum[h] - 1);
+ }
+
+ ret = wait_tb_buffers_until_unlocked(tb);
+ if (ret == CARRY_ON) {
+ if (FILESYSTEM_CHANGED_TB(tb)) {
+ wait_tb_buffers_run = 1;
+ ret = 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(tb->tb_sb, tb->tb_path);
+ } else {
+ pathrelse(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(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]);
+
+ tb->L[i] = NULL;
+ tb->R[i] = NULL;
+ tb->FL[i] = NULL;
+ tb->FR[i] = NULL;
+ tb->CFL[i] = NULL;
+ tb->CFR[i] = NULL;
+ }
+
+ if (wait_tb_buffers_run) {
+ for (i = 0; i < MAX_FEB_SIZE; i++) {
+ if (tb->FEB[i])
+ reiserfs_restore_prepared_buffer
+ (tb->tb_sb, tb->FEB[i]);
+ }
+ }
+ return ret;
+ }
+
+}
+
+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]);
+ }
+ }
+
+ kfree(tb->vn_buf);
+
+}