summaryrefslogtreecommitdiffstats
path: root/fs/reiserfs/fix_node.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/reiserfs/fix_node.c
downloadlinux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.bz2
Linux-2.6.12-rc2v2.6.12-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.c2518
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 000000000000..e4f64be9e15b
--- /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);
+
+}
+
+
+
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-25 20:53:32 +0000