2 * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
12 ** directory_part_size
16 ** are_leaves_removable
20 ** is_left_neighbor_in_cache
24 ** can_node_be_removed
26 ** dc_check_balance_internal
27 ** dc_check_balance_leaf
37 #include <linux/time.h>
38 #include <linux/string.h>
39 #include <linux/reiserfs_fs.h>
40 #include <linux/buffer_head.h>
42 /* To make any changes in the tree we find a node, that contains item
43 to be changed/deleted or position in the node we insert a new item
44 to. We call this node S. To do balancing we need to decide what we
45 will shift to left/right neighbor, or to a new node, where new item
46 will be etc. To make this analysis simpler we build virtual
47 node. Virtual node is an array of items, that will replace items of
48 node S. (For instance if we are going to delete an item, virtual
49 node does not contain it). Virtual node keeps information about
50 item sizes and types, mergeability of first and last items, sizes
51 of all entries in directory item. We use this array of items when
52 calculating what we can shift to neighbors and how many nodes we
53 have to have if we do not any shiftings, if we shift to left/right
54 neighbor or to both. */
56 /* taking item number in virtual node, returns number of item, that it has in source buffer */
57 static inline int old_item_num(int new_num, int affected_item_num, int mode)
59 if (mode == M_PASTE || mode == M_CUT || new_num < affected_item_num)
62 if (mode == M_INSERT) {
65 "vs-8005: for INSERT mode and item number of inserted item");
70 RFALSE(mode != M_DELETE,
71 "vs-8010: old_item_num: mode must be M_DELETE (mode = \'%c\'",
77 static void create_virtual_node(struct tree_balance *tb, int h)
80 struct virtual_node *vn = tb->tb_vn;
82 struct buffer_head *Sh; /* this comes from tb->S[h] */
84 Sh = PATH_H_PBUFFER(tb->tb_path, h);
86 /* size of changed node */
88 MAX_CHILD_SIZE(Sh) - B_FREE_SPACE(Sh) + tb->insert_size[h];
90 /* for internal nodes array if virtual items is not created */
92 vn->vn_nr_item = (vn->vn_size - DC_SIZE) / (DC_SIZE + KEY_SIZE);
96 /* number of items in virtual node */
98 B_NR_ITEMS(Sh) + ((vn->vn_mode == M_INSERT) ? 1 : 0) -
99 ((vn->vn_mode == M_DELETE) ? 1 : 0);
101 /* first virtual item */
102 vn->vn_vi = (struct virtual_item *)(tb->tb_vn + 1);
103 memset(vn->vn_vi, 0, vn->vn_nr_item * sizeof(struct virtual_item));
104 vn->vn_free_ptr += vn->vn_nr_item * sizeof(struct virtual_item);
106 /* first item in the node */
107 ih = B_N_PITEM_HEAD(Sh, 0);
109 /* define the mergeability for 0-th item (if it is not being deleted) */
110 if (op_is_left_mergeable(&(ih->ih_key), Sh->b_size)
111 && (vn->vn_mode != M_DELETE || vn->vn_affected_item_num))
112 vn->vn_vi[0].vi_type |= VI_TYPE_LEFT_MERGEABLE;
114 /* go through all items those remain in the virtual node (except for the new (inserted) one) */
115 for (new_num = 0; new_num < vn->vn_nr_item; new_num++) {
117 struct virtual_item *vi = vn->vn_vi + new_num;
119 ((new_num != vn->vn_affected_item_num) ? 0 : 1);
121 if (is_affected && vn->vn_mode == M_INSERT)
124 /* get item number in source node */
125 j = old_item_num(new_num, vn->vn_affected_item_num,
128 vi->vi_item_len += ih_item_len(ih + j) + IH_SIZE;
130 vi->vi_item = B_I_PITEM(Sh, ih + j);
131 vi->vi_uarea = vn->vn_free_ptr;
133 // FIXME: there is no check, that item operation did not
134 // consume too much memory
136 op_create_vi(vn, vi, is_affected, tb->insert_size[0]);
137 if (tb->vn_buf + tb->vn_buf_size < vn->vn_free_ptr)
138 reiserfs_panic(tb->tb_sb, "vs-8030",
139 "virtual node space consumed");
142 /* this is not being changed */
145 if (vn->vn_mode == M_PASTE || vn->vn_mode == M_CUT) {
146 vn->vn_vi[new_num].vi_item_len += tb->insert_size[0];
147 vi->vi_new_data = vn->vn_data; // pointer to data which is going to be pasted
151 /* virtual inserted item is not defined yet */
152 if (vn->vn_mode == M_INSERT) {
153 struct virtual_item *vi = vn->vn_vi + vn->vn_affected_item_num;
155 RFALSE(vn->vn_ins_ih == NULL,
156 "vs-8040: item header of inserted item is not specified");
157 vi->vi_item_len = tb->insert_size[0];
158 vi->vi_ih = vn->vn_ins_ih;
159 vi->vi_item = vn->vn_data;
160 vi->vi_uarea = vn->vn_free_ptr;
162 op_create_vi(vn, vi, 0 /*not pasted or cut */ ,
166 /* set right merge flag we take right delimiting key and check whether it is a mergeable item */
168 struct reiserfs_key *key;
170 key = B_N_PDELIM_KEY(tb->CFR[0], tb->rkey[0]);
171 if (op_is_left_mergeable(key, Sh->b_size)
172 && (vn->vn_mode != M_DELETE
173 || vn->vn_affected_item_num != B_NR_ITEMS(Sh) - 1))
174 vn->vn_vi[vn->vn_nr_item - 1].vi_type |=
175 VI_TYPE_RIGHT_MERGEABLE;
177 #ifdef CONFIG_REISERFS_CHECK
178 if (op_is_left_mergeable(key, Sh->b_size) &&
179 !(vn->vn_mode != M_DELETE
180 || vn->vn_affected_item_num != B_NR_ITEMS(Sh) - 1)) {
181 /* we delete last item and it could be merged with right neighbor's first item */
184 && is_direntry_le_ih(B_N_PITEM_HEAD(Sh, 0))
185 && I_ENTRY_COUNT(B_N_PITEM_HEAD(Sh, 0)) == 1)) {
186 /* node contains more than 1 item, or item is not directory item, or this item contains more than 1 entry */
187 print_block(Sh, 0, -1, -1);
188 reiserfs_panic(tb->tb_sb, "vs-8045",
189 "rdkey %k, affected item==%d "
190 "(mode==%c) Must be %c",
191 key, vn->vn_affected_item_num,
192 vn->vn_mode, M_DELETE);
200 /* using virtual node check, how many items can be shifted to left
202 static void check_left(struct tree_balance *tb, int h, int cur_free)
205 struct virtual_node *vn = tb->tb_vn;
206 struct virtual_item *vi;
209 RFALSE(cur_free < 0, "vs-8050: cur_free (%d) < 0", cur_free);
213 tb->lnum[h] = cur_free / (DC_SIZE + KEY_SIZE);
219 if (!cur_free || !vn->vn_nr_item) {
220 /* no free space or nothing to move */
226 RFALSE(!PATH_H_PPARENT(tb->tb_path, 0),
227 "vs-8055: parent does not exist or invalid");
230 if ((unsigned int)cur_free >=
232 ((vi->vi_type & VI_TYPE_LEFT_MERGEABLE) ? IH_SIZE : 0))) {
233 /* all contents of S[0] fits into L[0] */
235 RFALSE(vn->vn_mode == M_INSERT || vn->vn_mode == M_PASTE,
236 "vs-8055: invalid mode or balance condition failed");
238 tb->lnum[0] = vn->vn_nr_item;
243 d_size = 0, ih_size = IH_SIZE;
245 /* first item may be merge with last item in left neighbor */
246 if (vi->vi_type & VI_TYPE_LEFT_MERGEABLE)
247 d_size = -((int)IH_SIZE), ih_size = 0;
250 for (i = 0; i < vn->vn_nr_item;
251 i++, ih_size = IH_SIZE, d_size = 0, vi++) {
252 d_size += vi->vi_item_len;
253 if (cur_free >= d_size) {
254 /* the item can be shifted entirely */
260 /* the item cannot be shifted entirely, try to split it */
261 /* check whether L[0] can hold ih and at least one byte of the item body */
262 if (cur_free <= ih_size) {
263 /* cannot shift even a part of the current item */
269 tb->lbytes = op_check_left(vi, cur_free, 0, 0);
270 if (tb->lbytes != -1)
271 /* count partially shifted item */
280 /* using virtual node check, how many items can be shifted to right
282 static void check_right(struct tree_balance *tb, int h, int cur_free)
285 struct virtual_node *vn = tb->tb_vn;
286 struct virtual_item *vi;
289 RFALSE(cur_free < 0, "vs-8070: cur_free < 0");
293 tb->rnum[h] = cur_free / (DC_SIZE + KEY_SIZE);
299 if (!cur_free || !vn->vn_nr_item) {
306 RFALSE(!PATH_H_PPARENT(tb->tb_path, 0),
307 "vs-8075: parent does not exist or invalid");
309 vi = vn->vn_vi + vn->vn_nr_item - 1;
310 if ((unsigned int)cur_free >=
312 ((vi->vi_type & VI_TYPE_RIGHT_MERGEABLE) ? IH_SIZE : 0))) {
313 /* all contents of S[0] fits into R[0] */
315 RFALSE(vn->vn_mode == M_INSERT || vn->vn_mode == M_PASTE,
316 "vs-8080: invalid mode or balance condition failed");
318 tb->rnum[h] = vn->vn_nr_item;
323 d_size = 0, ih_size = IH_SIZE;
325 /* last item may be merge with first item in right neighbor */
326 if (vi->vi_type & VI_TYPE_RIGHT_MERGEABLE)
327 d_size = -(int)IH_SIZE, ih_size = 0;
330 for (i = vn->vn_nr_item - 1; i >= 0;
331 i--, d_size = 0, ih_size = IH_SIZE, vi--) {
332 d_size += vi->vi_item_len;
333 if (cur_free >= d_size) {
334 /* the item can be shifted entirely */
340 /* check whether R[0] can hold ih and at least one byte of the item body */
341 if (cur_free <= ih_size) { /* cannot shift even a part of the current item */
346 /* R[0] can hold the header of the item and at least one byte of its body */
347 cur_free -= ih_size; /* cur_free is still > 0 */
349 tb->rbytes = op_check_right(vi, cur_free);
350 if (tb->rbytes != -1)
351 /* count partially shifted item */
361 * from - number of items, which are shifted to left neighbor entirely
362 * to - number of item, which are shifted to right neighbor entirely
363 * from_bytes - number of bytes of boundary item (or directory entries) which are shifted to left neighbor
364 * to_bytes - number of bytes of boundary item (or directory entries) which are shifted to right neighbor */
365 static int get_num_ver(int mode, struct tree_balance *tb, int h,
366 int from, int from_bytes,
367 int to, int to_bytes, short *snum012, int flow)
373 struct virtual_node *vn = tb->tb_vn;
374 // struct virtual_item * vi;
376 int total_node_size, max_node_size, current_item_size;
378 int start_item, /* position of item we start filling node from */
379 end_item, /* position of item we finish filling node by */
380 start_bytes, /* number of first bytes (entries for directory) of start_item-th item
381 we do not include into node that is being filled */
382 end_bytes; /* number of last bytes (entries for directory) of end_item-th item
383 we do node include into node that is being filled */
384 int split_item_positions[2]; /* these are positions in virtual item of
385 items, that are split between S[0] and
386 S1new and S1new and S2new */
388 split_item_positions[0] = -1;
389 split_item_positions[1] = -1;
391 /* We only create additional nodes if we are in insert or paste mode
392 or we are in replace mode at the internal level. If h is 0 and
393 the mode is M_REPLACE then in fix_nodes we change the mode to
394 paste or insert before we get here in the code. */
395 RFALSE(tb->insert_size[h] < 0 || (mode != M_INSERT && mode != M_PASTE),
396 "vs-8100: insert_size < 0 in overflow");
398 max_node_size = MAX_CHILD_SIZE(PATH_H_PBUFFER(tb->tb_path, h));
400 /* snum012 [0-2] - number of items, that lay
401 to S[0], first new node and second new node */
402 snum012[3] = -1; /* s1bytes */
403 snum012[4] = -1; /* s2bytes */
407 i = ((to - from) * (KEY_SIZE + DC_SIZE) + DC_SIZE);
408 if (i == max_node_size)
410 return (i / max_node_size + 1);
416 cur_free = max_node_size;
418 // start from 'from'-th item
420 // skip its first 'start_bytes' units
421 start_bytes = ((from_bytes != -1) ? from_bytes : 0);
423 // last included item is the 'end_item'-th one
424 end_item = vn->vn_nr_item - to - 1;
425 // do not count last 'end_bytes' units of 'end_item'-th item
426 end_bytes = (to_bytes != -1) ? to_bytes : 0;
428 /* go through all item beginning from the start_item-th item and ending by
429 the end_item-th item. Do not count first 'start_bytes' units of
430 'start_item'-th item and last 'end_bytes' of 'end_item'-th item */
432 for (i = start_item; i <= end_item; i++) {
433 struct virtual_item *vi = vn->vn_vi + i;
434 int skip_from_end = ((i == end_item) ? end_bytes : 0);
436 RFALSE(needed_nodes > 3, "vs-8105: too many nodes are needed");
438 /* get size of current item */
439 current_item_size = vi->vi_item_len;
441 /* do not take in calculation head part (from_bytes) of from-th item */
443 op_part_size(vi, 0 /*from start */ , start_bytes);
445 /* do not take in calculation tail part of last item */
447 op_part_size(vi, 1 /*from end */ , skip_from_end);
449 /* if item fits into current node entierly */
450 if (total_node_size + current_item_size <= max_node_size) {
451 snum012[needed_nodes - 1]++;
452 total_node_size += current_item_size;
457 if (current_item_size > max_node_size) {
458 /* virtual item length is longer, than max size of item in
459 a node. It is impossible for direct item */
460 RFALSE(is_direct_le_ih(vi->vi_ih),
462 "direct item length is %d. It can not be longer than %d",
463 current_item_size, max_node_size);
464 /* we will try to split it */
469 /* as we do not split items, take new node and continue */
475 // calculate number of item units which fit into node being
480 free_space = max_node_size - total_node_size - IH_SIZE;
482 op_check_left(vi, free_space, start_bytes,
485 /* nothing fits into current node, take new node and continue */
486 needed_nodes++, i--, total_node_size = 0;
491 /* something fits into the current node */
492 //if (snum012[3] != -1 || needed_nodes != 1)
493 // reiserfs_panic (tb->tb_sb, "vs-8115: get_num_ver: too many nodes required");
494 //snum012[needed_nodes - 1 + 3] = op_unit_num (vi) - start_bytes - units;
495 start_bytes += units;
496 snum012[needed_nodes - 1 + 3] = units;
498 if (needed_nodes > 2)
499 reiserfs_warning(tb->tb_sb, "vs-8111",
500 "split_item_position is out of range");
501 snum012[needed_nodes - 1]++;
502 split_item_positions[needed_nodes - 1] = i;
504 /* continue from the same item with start_bytes != -1 */
510 // sum012[4] (if it is not -1) contains number of units of which
511 // are to be in S1new, snum012[3] - to be in S0. They are supposed
512 // to be S1bytes and S2bytes correspondingly, so recalculate
513 if (snum012[4] > 0) {
515 int bytes_to_r, bytes_to_l;
518 split_item_num = split_item_positions[1];
520 ((from == split_item_num
521 && from_bytes != -1) ? from_bytes : 0);
523 ((end_item == split_item_num
524 && end_bytes != -1) ? end_bytes : 0);
526 ((split_item_positions[0] ==
527 split_item_positions[1]) ? snum012[3] : 0);
531 op_unit_num(&vn->vn_vi[split_item_num]) - snum012[4] -
532 bytes_to_r - bytes_to_l - bytes_to_S1new;
534 if (vn->vn_vi[split_item_num].vi_index != TYPE_DIRENTRY &&
535 vn->vn_vi[split_item_num].vi_index != TYPE_INDIRECT)
536 reiserfs_warning(tb->tb_sb, "vs-8115",
537 "not directory or indirect item");
540 /* now we know S2bytes, calculate S1bytes */
541 if (snum012[3] > 0) {
543 int bytes_to_r, bytes_to_l;
546 split_item_num = split_item_positions[0];
548 ((from == split_item_num
549 && from_bytes != -1) ? from_bytes : 0);
551 ((end_item == split_item_num
552 && end_bytes != -1) ? end_bytes : 0);
554 ((split_item_positions[0] == split_item_positions[1]
555 && snum012[4] != -1) ? snum012[4] : 0);
559 op_unit_num(&vn->vn_vi[split_item_num]) - snum012[3] -
560 bytes_to_r - bytes_to_l - bytes_to_S2new;
566 #ifdef CONFIG_REISERFS_CHECK
567 extern struct tree_balance *cur_tb;
570 /* Set parameters for balancing.
571 * Performs write of results of analysis of balancing into structure tb,
572 * where it will later be used by the functions that actually do the balancing.
574 * tb tree_balance structure;
575 * h current level of the node;
576 * lnum number of items from S[h] that must be shifted to L[h];
577 * rnum number of items from S[h] that must be shifted to R[h];
578 * blk_num number of blocks that S[h] will be splitted into;
579 * s012 number of items that fall into splitted nodes.
580 * lbytes number of bytes which flow to the left neighbor from the item that is not
581 * not shifted entirely
582 * rbytes number of bytes which flow to the right neighbor from the item that is not
583 * not shifted entirely
584 * s1bytes number of bytes which flow to the first new node when S[0] splits (this number is contained in s012 array)
587 static void set_parameters(struct tree_balance *tb, int h, int lnum,
588 int rnum, int blk_num, short *s012, int lb, int rb)
593 tb->blknum[h] = blk_num;
595 if (h == 0) { /* only for leaf level */
598 tb->s1num = *s012++, tb->s2num = *s012++;
599 tb->s1bytes = *s012++;
605 PROC_INFO_ADD(tb->tb_sb, lnum[h], lnum);
606 PROC_INFO_ADD(tb->tb_sb, rnum[h], rnum);
608 PROC_INFO_ADD(tb->tb_sb, lbytes[h], lb);
609 PROC_INFO_ADD(tb->tb_sb, rbytes[h], rb);
612 /* check, does node disappear if we shift tb->lnum[0] items to left
613 neighbor and tb->rnum[0] to the right one. */
614 static int is_leaf_removable(struct tree_balance *tb)
616 struct virtual_node *vn = tb->tb_vn;
617 int to_left, to_right;
621 /* number of items, that will be shifted to left (right) neighbor
623 to_left = tb->lnum[0] - ((tb->lbytes != -1) ? 1 : 0);
624 to_right = tb->rnum[0] - ((tb->rbytes != -1) ? 1 : 0);
625 remain_items = vn->vn_nr_item;
627 /* how many items remain in S[0] after shiftings to neighbors */
628 remain_items -= (to_left + to_right);
630 if (remain_items < 1) {
631 /* all content of node can be shifted to neighbors */
632 set_parameters(tb, 0, to_left, vn->vn_nr_item - to_left, 0,
637 if (remain_items > 1 || tb->lbytes == -1 || tb->rbytes == -1)
638 /* S[0] is not removable */
641 /* check, whether we can divide 1 remaining item between neighbors */
643 /* get size of remaining item (in item units) */
644 size = op_unit_num(&(vn->vn_vi[to_left]));
646 if (tb->lbytes + tb->rbytes >= size) {
647 set_parameters(tb, 0, to_left + 1, to_right + 1, 0, NULL,
655 /* check whether L, S, R can be joined in one node */
656 static int are_leaves_removable(struct tree_balance *tb, int lfree, int rfree)
658 struct virtual_node *vn = tb->tb_vn;
660 struct buffer_head *S0;
662 S0 = PATH_H_PBUFFER(tb->tb_path, 0);
665 if (vn->vn_nr_item) {
666 if (vn->vn_vi[0].vi_type & VI_TYPE_LEFT_MERGEABLE)
669 if (vn->vn_vi[vn->vn_nr_item - 1].
670 vi_type & VI_TYPE_RIGHT_MERGEABLE)
673 /* there was only one item and it will be deleted */
674 struct item_head *ih;
676 RFALSE(B_NR_ITEMS(S0) != 1,
677 "vs-8125: item number must be 1: it is %d",
680 ih = B_N_PITEM_HEAD(S0, 0);
682 && !comp_short_le_keys(&(ih->ih_key),
683 B_N_PDELIM_KEY(tb->CFR[0],
685 if (is_direntry_le_ih(ih)) {
686 /* Directory must be in correct state here: that is
687 somewhere at the left side should exist first directory
688 item. But the item being deleted can not be that first
689 one because its right neighbor is item of the same
690 directory. (But first item always gets deleted in last
691 turn). So, neighbors of deleted item can be merged, so
692 we can save ih_size */
695 /* we might check that left neighbor exists and is of the
697 RFALSE(le_ih_k_offset(ih) == DOT_OFFSET,
698 "vs-8130: first directory item can not be removed until directory is not empty");
703 if (MAX_CHILD_SIZE(S0) + vn->vn_size <= rfree + lfree + ih_size) {
704 set_parameters(tb, 0, -1, -1, -1, NULL, -1, -1);
705 PROC_INFO_INC(tb->tb_sb, leaves_removable);
712 /* when we do not split item, lnum and rnum are numbers of entire items */
713 #define SET_PAR_SHIFT_LEFT \
718 to_l = (MAX_NR_KEY(Sh)+1 - lpar + vn->vn_nr_item + 1) / 2 -\
719 (MAX_NR_KEY(Sh) + 1 - lpar);\
721 set_parameters (tb, h, to_l, 0, lnver, NULL, -1, -1);\
725 if (lset==LEFT_SHIFT_FLOW)\
726 set_parameters (tb, h, lpar, 0, lnver, snum012+lset,\
729 set_parameters (tb, h, lpar - (tb->lbytes!=-1), 0, lnver, snum012+lset,\
733 #define SET_PAR_SHIFT_RIGHT \
738 to_r = (MAX_NR_KEY(Sh)+1 - rpar + vn->vn_nr_item + 1) / 2 - (MAX_NR_KEY(Sh) + 1 - rpar);\
740 set_parameters (tb, h, 0, to_r, rnver, NULL, -1, -1);\
744 if (rset==RIGHT_SHIFT_FLOW)\
745 set_parameters (tb, h, 0, rpar, rnver, snum012+rset,\
748 set_parameters (tb, h, 0, rpar - (tb->rbytes!=-1), rnver, snum012+rset,\
752 static void free_buffers_in_tb(struct tree_balance *tb)
756 pathrelse(tb->tb_path);
758 for (i = 0; i < MAX_HEIGHT; i++) {
775 /* Get new buffers for storing new nodes that are created while balancing.
776 * Returns: SCHEDULE_OCCURRED - schedule occurred while the function worked;
777 * CARRY_ON - schedule didn't occur while the function worked;
778 * NO_DISK_SPACE - no disk space.
780 /* The function is NOT SCHEDULE-SAFE! */
781 static int get_empty_nodes(struct tree_balance *tb, int h)
783 struct buffer_head *new_bh,
784 *Sh = PATH_H_PBUFFER(tb->tb_path, h);
785 b_blocknr_t *blocknr, blocknrs[MAX_AMOUNT_NEEDED] = { 0, };
786 int counter, number_of_freeblk, amount_needed, /* number of needed empty blocks */
788 struct super_block *sb = tb->tb_sb;
790 /* number_of_freeblk is the number of empty blocks which have been
791 acquired for use by the balancing algorithm minus the number of
792 empty blocks used in the previous levels of the analysis,
793 number_of_freeblk = tb->cur_blknum can be non-zero if a schedule occurs
794 after empty blocks are acquired, and the balancing analysis is
795 then restarted, amount_needed is the number needed by this level
796 (h) of the balancing analysis.
798 Note that for systems with many processes writing, it would be
799 more layout optimal to calculate the total number needed by all
800 levels and then to run reiserfs_new_blocks to get all of them at once. */
802 /* Initiate number_of_freeblk to the amount acquired prior to the restart of
803 the analysis or 0 if not restarted, then subtract the amount needed
804 by all of the levels of the tree below h. */
805 /* blknum includes S[h], so we subtract 1 in this calculation */
806 for (counter = 0, number_of_freeblk = tb->cur_blknum;
807 counter < h; counter++)
809 (tb->blknum[counter]) ? (tb->blknum[counter] -
812 /* Allocate missing empty blocks. */
813 /* if Sh == 0 then we are getting a new root */
814 amount_needed = (Sh) ? (tb->blknum[h] - 1) : 1;
815 /* Amount_needed = the amount that we need more than the amount that we have. */
816 if (amount_needed > number_of_freeblk)
817 amount_needed -= number_of_freeblk;
818 else /* If we have enough already then there is nothing to do. */
821 /* No need to check quota - is not allocated for blocks used for formatted nodes */
822 if (reiserfs_new_form_blocknrs(tb, blocknrs,
823 amount_needed) == NO_DISK_SPACE)
824 return NO_DISK_SPACE;
826 /* for each blocknumber we just got, get a buffer and stick it on FEB */
827 for (blocknr = blocknrs, counter = 0;
828 counter < amount_needed; blocknr++, counter++) {
831 "PAP-8135: reiserfs_new_blocknrs failed when got new blocks");
833 new_bh = sb_getblk(sb, *blocknr);
834 RFALSE(buffer_dirty(new_bh) ||
835 buffer_journaled(new_bh) ||
836 buffer_journal_dirty(new_bh),
837 "PAP-8140: journlaled or dirty buffer %b for the new block",
840 /* Put empty buffers into the array. */
841 RFALSE(tb->FEB[tb->cur_blknum],
842 "PAP-8141: busy slot for new buffer");
844 set_buffer_journal_new(new_bh);
845 tb->FEB[tb->cur_blknum++] = new_bh;
848 if (retval == CARRY_ON && FILESYSTEM_CHANGED_TB(tb))
849 retval = REPEAT_SEARCH;
854 /* Get free space of the left neighbor, which is stored in the parent
855 * node of the left neighbor. */
856 static int get_lfree(struct tree_balance *tb, int h)
858 struct buffer_head *l, *f;
861 if ((f = PATH_H_PPARENT(tb->tb_path, h)) == NULL ||
862 (l = tb->FL[h]) == NULL)
866 order = PATH_H_B_ITEM_ORDER(tb->tb_path, h) - 1;
868 order = B_NR_ITEMS(l);
872 return (MAX_CHILD_SIZE(f) - dc_size(B_N_CHILD(f, order)));
875 /* Get free space of the right neighbor,
876 * which is stored in the parent node of the right neighbor.
878 static int get_rfree(struct tree_balance *tb, int h)
880 struct buffer_head *r, *f;
883 if ((f = PATH_H_PPARENT(tb->tb_path, h)) == NULL ||
884 (r = tb->FR[h]) == NULL)
888 order = PATH_H_B_ITEM_ORDER(tb->tb_path, h) + 1;
894 return (MAX_CHILD_SIZE(f) - dc_size(B_N_CHILD(f, order)));
898 /* Check whether left neighbor is in memory. */
899 static int is_left_neighbor_in_cache(struct tree_balance *tb, int h)
901 struct buffer_head *father, *left;
902 struct super_block *sb = tb->tb_sb;
903 b_blocknr_t left_neighbor_blocknr;
904 int left_neighbor_position;
906 /* Father of the left neighbor does not exist. */
910 /* Calculate father of the node to be balanced. */
911 father = PATH_H_PBUFFER(tb->tb_path, h + 1);
914 !B_IS_IN_TREE(father) ||
915 !B_IS_IN_TREE(tb->FL[h]) ||
916 !buffer_uptodate(father) ||
917 !buffer_uptodate(tb->FL[h]),
918 "vs-8165: F[h] (%b) or FL[h] (%b) is invalid",
921 /* Get position of the pointer to the left neighbor into the left father. */
922 left_neighbor_position = (father == tb->FL[h]) ?
923 tb->lkey[h] : B_NR_ITEMS(tb->FL[h]);
924 /* Get left neighbor block number. */
925 left_neighbor_blocknr =
926 B_N_CHILD_NUM(tb->FL[h], left_neighbor_position);
927 /* Look for the left neighbor in the cache. */
928 if ((left = sb_find_get_block(sb, left_neighbor_blocknr))) {
930 RFALSE(buffer_uptodate(left) && !B_IS_IN_TREE(left),
931 "vs-8170: left neighbor (%b %z) is not in the tree",
940 #define LEFT_PARENTS 'l'
941 #define RIGHT_PARENTS 'r'
943 static void decrement_key(struct cpu_key *key)
945 // call item specific function for this key
946 item_ops[cpu_key_k_type(key)]->decrement_key(key);
949 /* Calculate far left/right parent of the left/right neighbor of the current node, that
950 * is calculate the left/right (FL[h]/FR[h]) neighbor of the parent F[h].
951 * Calculate left/right common parent of the current node and L[h]/R[h].
952 * Calculate left/right delimiting key position.
953 * Returns: PATH_INCORRECT - path in the tree is not correct;
954 SCHEDULE_OCCURRED - schedule occurred while the function worked;
955 * CARRY_ON - schedule didn't occur while the function worked;
957 static int get_far_parent(struct tree_balance *tb,
959 struct buffer_head **pfather,
960 struct buffer_head **pcom_father, char c_lr_par)
962 struct buffer_head *parent;
963 INITIALIZE_PATH(s_path_to_neighbor_father);
964 struct treepath *path = tb->tb_path;
965 struct cpu_key s_lr_father_key;
968 first_last_position = 0,
969 path_offset = PATH_H_PATH_OFFSET(path, h);
971 /* Starting from F[h] go upwards in the tree, and look for the common
972 ancestor of F[h], and its neighbor l/r, that should be obtained. */
974 counter = path_offset;
976 RFALSE(counter < FIRST_PATH_ELEMENT_OFFSET,
977 "PAP-8180: invalid path length");
979 for (; counter > FIRST_PATH_ELEMENT_OFFSET; counter--) {
980 /* Check whether parent of the current buffer in the path is really parent in the tree. */
982 (parent = PATH_OFFSET_PBUFFER(path, counter - 1)))
983 return REPEAT_SEARCH;
984 /* Check whether position in the parent is correct. */
986 PATH_OFFSET_POSITION(path,
989 return REPEAT_SEARCH;
990 /* Check whether parent at the path really points to the child. */
991 if (B_N_CHILD_NUM(parent, position) !=
992 PATH_OFFSET_PBUFFER(path, counter)->b_blocknr)
993 return REPEAT_SEARCH;
994 /* Return delimiting key if position in the parent is not equal to first/last one. */
995 if (c_lr_par == RIGHT_PARENTS)
996 first_last_position = B_NR_ITEMS(parent);
997 if (position != first_last_position) {
998 *pcom_father = parent;
999 get_bh(*pcom_father);
1000 /*(*pcom_father = parent)->b_count++; */
1005 /* if we are in the root of the tree, then there is no common father */
1006 if (counter == FIRST_PATH_ELEMENT_OFFSET) {
1007 /* Check whether first buffer in the path is the root of the tree. */
1008 if (PATH_OFFSET_PBUFFER
1010 FIRST_PATH_ELEMENT_OFFSET)->b_blocknr ==
1011 SB_ROOT_BLOCK(tb->tb_sb)) {
1012 *pfather = *pcom_father = NULL;
1015 return REPEAT_SEARCH;
1018 RFALSE(B_LEVEL(*pcom_father) <= DISK_LEAF_NODE_LEVEL,
1019 "PAP-8185: (%b %z) level too small",
1020 *pcom_father, *pcom_father);
1022 /* Check whether the common parent is locked. */
1024 if (buffer_locked(*pcom_father)) {
1025 __wait_on_buffer(*pcom_father);
1026 if (FILESYSTEM_CHANGED_TB(tb)) {
1027 brelse(*pcom_father);
1028 return REPEAT_SEARCH;
1032 /* So, we got common parent of the current node and its left/right neighbor.
1033 Now we are geting the parent of the left/right neighbor. */
1035 /* Form key to get parent of the left/right neighbor. */
1036 le_key2cpu_key(&s_lr_father_key,
1037 B_N_PDELIM_KEY(*pcom_father,
1039 LEFT_PARENTS) ? (tb->lkey[h - 1] =
1045 if (c_lr_par == LEFT_PARENTS)
1046 decrement_key(&s_lr_father_key);
1049 (tb->tb_sb, &s_lr_father_key, &s_path_to_neighbor_father,
1054 if (FILESYSTEM_CHANGED_TB(tb)) {
1055 pathrelse(&s_path_to_neighbor_father);
1056 brelse(*pcom_father);
1057 return REPEAT_SEARCH;
1060 *pfather = PATH_PLAST_BUFFER(&s_path_to_neighbor_father);
1062 RFALSE(B_LEVEL(*pfather) != h + 1,
1063 "PAP-8190: (%b %z) level too small", *pfather, *pfather);
1064 RFALSE(s_path_to_neighbor_father.path_length <
1065 FIRST_PATH_ELEMENT_OFFSET, "PAP-8192: path length is too small");
1067 s_path_to_neighbor_father.path_length--;
1068 pathrelse(&s_path_to_neighbor_father);
1072 /* Get parents of neighbors of node in the path(S[path_offset]) and common parents of
1073 * S[path_offset] and L[path_offset]/R[path_offset]: F[path_offset], FL[path_offset],
1074 * FR[path_offset], CFL[path_offset], CFR[path_offset].
1075 * Calculate numbers of left and right delimiting keys position: lkey[path_offset], rkey[path_offset].
1076 * Returns: SCHEDULE_OCCURRED - schedule occurred while the function worked;
1077 * CARRY_ON - schedule didn't occur while the function worked;
1079 static int get_parents(struct tree_balance *tb, int h)
1081 struct treepath *path = tb->tb_path;
1084 path_offset = PATH_H_PATH_OFFSET(tb->tb_path, h);
1085 struct buffer_head *curf, *curcf;
1087 /* Current node is the root of the tree or will be root of the tree */
1088 if (path_offset <= FIRST_PATH_ELEMENT_OFFSET) {
1089 /* The root can not have parents.
1090 Release nodes which previously were obtained as parents of the current node neighbors. */
1102 /* Get parent FL[path_offset] of L[path_offset]. */
1103 position = PATH_OFFSET_POSITION(path, path_offset - 1);
1105 /* Current node is not the first child of its parent. */
1106 curf = PATH_OFFSET_PBUFFER(path, path_offset - 1);
1107 curcf = PATH_OFFSET_PBUFFER(path, path_offset - 1);
1110 tb->lkey[h] = position - 1;
1112 /* Calculate current parent of L[path_offset], which is the left neighbor of the current node.
1113 Calculate current common parent of L[path_offset] and the current node. Note that
1114 CFL[path_offset] not equal FL[path_offset] and CFL[path_offset] not equal F[path_offset].
1115 Calculate lkey[path_offset]. */
1116 if ((ret = get_far_parent(tb, h + 1, &curf,
1118 LEFT_PARENTS)) != CARRY_ON)
1123 tb->FL[h] = curf; /* New initialization of FL[h]. */
1125 tb->CFL[h] = curcf; /* New initialization of CFL[h]. */
1127 RFALSE((curf && !B_IS_IN_TREE(curf)) ||
1128 (curcf && !B_IS_IN_TREE(curcf)),
1129 "PAP-8195: FL (%b) or CFL (%b) is invalid", curf, curcf);
1131 /* Get parent FR[h] of R[h]. */
1133 /* Current node is the last child of F[h]. FR[h] != F[h]. */
1134 if (position == B_NR_ITEMS(PATH_H_PBUFFER(path, h + 1))) {
1135 /* Calculate current parent of R[h], which is the right neighbor of F[h].
1136 Calculate current common parent of R[h] and current node. Note that CFR[h]
1137 not equal FR[path_offset] and CFR[h] not equal F[h]. */
1139 get_far_parent(tb, h + 1, &curf, &curcf,
1140 RIGHT_PARENTS)) != CARRY_ON)
1143 /* Current node is not the last child of its parent F[h]. */
1144 curf = PATH_OFFSET_PBUFFER(path, path_offset - 1);
1145 curcf = PATH_OFFSET_PBUFFER(path, path_offset - 1);
1148 tb->rkey[h] = position;
1152 /* New initialization of FR[path_offset]. */
1156 /* New initialization of CFR[path_offset]. */
1159 RFALSE((curf && !B_IS_IN_TREE(curf)) ||
1160 (curcf && !B_IS_IN_TREE(curcf)),
1161 "PAP-8205: FR (%b) or CFR (%b) is invalid", curf, curcf);
1166 /* it is possible to remove node as result of shiftings to
1167 neighbors even when we insert or paste item. */
1168 static inline int can_node_be_removed(int mode, int lfree, int sfree, int rfree,
1169 struct tree_balance *tb, int h)
1171 struct buffer_head *Sh = PATH_H_PBUFFER(tb->tb_path, h);
1172 int levbytes = tb->insert_size[h];
1173 struct item_head *ih;
1174 struct reiserfs_key *r_key = NULL;
1176 ih = B_N_PITEM_HEAD(Sh, 0);
1178 r_key = B_N_PDELIM_KEY(tb->CFR[h], tb->rkey[h]);
1180 if (lfree + rfree + sfree < MAX_CHILD_SIZE(Sh) + levbytes
1181 /* shifting may merge items which might save space */
1184 && op_is_left_mergeable(&(ih->ih_key), Sh->b_size)) ? IH_SIZE : 0)
1187 && op_is_left_mergeable(r_key, Sh->b_size)) ? IH_SIZE : 0)
1188 + ((h) ? KEY_SIZE : 0)) {
1189 /* node can not be removed */
1190 if (sfree >= levbytes) { /* new item fits into node S[h] without any shifting */
1194 ((mode == M_INSERT) ? 1 : 0);
1195 set_parameters(tb, h, 0, 0, 1, NULL, -1, -1);
1196 return NO_BALANCING_NEEDED;
1199 PROC_INFO_INC(tb->tb_sb, can_node_be_removed[h]);
1200 return !NO_BALANCING_NEEDED;
1203 /* Check whether current node S[h] is balanced when increasing its size by
1204 * Inserting or Pasting.
1205 * Calculate parameters for balancing for current level h.
1207 * tb tree_balance structure;
1208 * h current level of the node;
1209 * inum item number in S[h];
1210 * mode i - insert, p - paste;
1211 * Returns: 1 - schedule occurred;
1212 * 0 - balancing for higher levels needed;
1213 * -1 - no balancing for higher levels needed;
1214 * -2 - no disk space.
1216 /* ip means Inserting or Pasting */
1217 static int ip_check_balance(struct tree_balance *tb, int h)
1219 struct virtual_node *vn = tb->tb_vn;
1220 int levbytes, /* Number of bytes that must be inserted into (value
1221 is negative if bytes are deleted) buffer which
1222 contains node being balanced. The mnemonic is
1223 that the attempted change in node space used level
1224 is levbytes bytes. */
1227 int lfree, sfree, rfree /* free space in L, S and R */ ;
1229 /* nver is short for number of vertixes, and lnver is the number if
1230 we shift to the left, rnver is the number if we shift to the
1231 right, and lrnver is the number if we shift in both directions.
1232 The goal is to minimize first the number of vertixes, and second,
1233 the number of vertixes whose contents are changed by shifting,
1234 and third the number of uncached vertixes whose contents are
1235 changed by shifting and must be read from disk. */
1236 int nver, lnver, rnver, lrnver;
1238 /* used at leaf level only, S0 = S[0] is the node being balanced,
1239 sInum [ I = 0,1,2 ] is the number of items that will
1240 remain in node SI after balancing. S1 and S2 are new
1241 nodes that might be created. */
1243 /* we perform 8 calls to get_num_ver(). For each call we calculate five parameters.
1244 where 4th parameter is s1bytes and 5th - s2bytes
1246 short snum012[40] = { 0, }; /* s0num, s1num, s2num for 8 cases
1247 0,1 - do not shift and do not shift but bottle
1248 2 - shift only whole item to left
1249 3 - shift to left and bottle as much as possible
1250 4,5 - shift to right (whole items and as much as possible
1251 6,7 - shift to both directions (whole items and as much as possible)
1254 /* Sh is the node whose balance is currently being checked */
1255 struct buffer_head *Sh;
1257 Sh = PATH_H_PBUFFER(tb->tb_path, h);
1258 levbytes = tb->insert_size[h];
1260 /* Calculate balance parameters for creating new root. */
1263 reiserfs_panic(tb->tb_sb, "vs-8210",
1264 "S[0] can not be 0");
1265 switch (ret = get_empty_nodes(tb, h)) {
1267 set_parameters(tb, h, 0, 0, 1, NULL, -1, -1);
1268 return NO_BALANCING_NEEDED; /* no balancing for higher levels needed */
1274 reiserfs_panic(tb->tb_sb, "vs-8215", "incorrect "
1275 "return value of get_empty_nodes");
1279 if ((ret = get_parents(tb, h)) != CARRY_ON) /* get parents of S[h] neighbors. */
1282 sfree = B_FREE_SPACE(Sh);
1284 /* get free space of neighbors */
1285 rfree = get_rfree(tb, h);
1286 lfree = get_lfree(tb, h);
1288 if (can_node_be_removed(vn->vn_mode, lfree, sfree, rfree, tb, h) ==
1289 NO_BALANCING_NEEDED)
1290 /* and new item fits into node S[h] without any shifting */
1291 return NO_BALANCING_NEEDED;
1293 create_virtual_node(tb, h);
1296 determine maximal number of items we can shift to the left neighbor (in tb structure)
1297 and the maximal number of bytes that can flow to the left neighbor
1298 from the left most liquid item that cannot be shifted from S[0] entirely (returned value)
1300 check_left(tb, h, lfree);
1303 determine maximal number of items we can shift to the right neighbor (in tb structure)
1304 and the maximal number of bytes that can flow to the right neighbor
1305 from the right most liquid item that cannot be shifted from S[0] entirely (returned value)
1307 check_right(tb, h, rfree);
1309 /* all contents of internal node S[h] can be moved into its
1310 neighbors, S[h] will be removed after balancing */
1311 if (h && (tb->rnum[h] + tb->lnum[h] >= vn->vn_nr_item + 1)) {
1314 /* Since we are working on internal nodes, and our internal
1315 nodes have fixed size entries, then we can balance by the
1316 number of items rather than the space they consume. In this
1317 routine we set the left node equal to the right node,
1318 allowing a difference of less than or equal to 1 child
1321 ((MAX_NR_KEY(Sh) << 1) + 2 - tb->lnum[h] - tb->rnum[h] +
1322 vn->vn_nr_item + 1) / 2 - (MAX_NR_KEY(Sh) + 1 -
1324 set_parameters(tb, h, vn->vn_nr_item + 1 - to_r, to_r, 0, NULL,
1329 /* this checks balance condition, that any two neighboring nodes can not fit in one node */
1331 (tb->lnum[h] >= vn->vn_nr_item + 1 ||
1332 tb->rnum[h] >= vn->vn_nr_item + 1),
1333 "vs-8220: tree is not balanced on internal level");
1334 RFALSE(!h && ((tb->lnum[h] >= vn->vn_nr_item && (tb->lbytes == -1)) ||
1335 (tb->rnum[h] >= vn->vn_nr_item && (tb->rbytes == -1))),
1336 "vs-8225: tree is not balanced on leaf level");
1338 /* all contents of S[0] can be moved into its neighbors
1339 S[0] will be removed after balancing. */
1340 if (!h && is_leaf_removable(tb))
1343 /* why do we perform this check here rather than earlier??
1344 Answer: we can win 1 node in some cases above. Moreover we
1345 checked it above, when we checked, that S[0] is not removable
1347 if (sfree >= levbytes) { /* new item fits into node S[h] without any shifting */
1349 tb->s0num = vn->vn_nr_item;
1350 set_parameters(tb, h, 0, 0, 1, NULL, -1, -1);
1351 return NO_BALANCING_NEEDED;
1355 int lpar, rpar, nset, lset, rset, lrset;
1357 * regular overflowing of the node
1360 /* get_num_ver works in 2 modes (FLOW & NO_FLOW)
1361 lpar, rpar - number of items we can shift to left/right neighbor (including splitting item)
1362 nset, lset, rset, lrset - shows, whether flowing items give better packing
1365 #define NO_FLOW 0 /* do not any splitting */
1367 /* we choose one the following */
1368 #define NOTHING_SHIFT_NO_FLOW 0
1369 #define NOTHING_SHIFT_FLOW 5
1370 #define LEFT_SHIFT_NO_FLOW 10
1371 #define LEFT_SHIFT_FLOW 15
1372 #define RIGHT_SHIFT_NO_FLOW 20
1373 #define RIGHT_SHIFT_FLOW 25
1374 #define LR_SHIFT_NO_FLOW 30
1375 #define LR_SHIFT_FLOW 35
1380 /* calculate number of blocks S[h] must be split into when
1381 nothing is shifted to the neighbors,
1382 as well as number of items in each part of the split node (s012 numbers),
1383 and number of bytes (s1bytes) of the shared drop which flow to S1 if any */
1384 nset = NOTHING_SHIFT_NO_FLOW;
1385 nver = get_num_ver(vn->vn_mode, tb, h,
1386 0, -1, h ? vn->vn_nr_item : 0, -1,
1392 /* note, that in this case we try to bottle between S[0] and S1 (S1 - the first new node) */
1393 nver1 = get_num_ver(vn->vn_mode, tb, h,
1395 snum012 + NOTHING_SHIFT_FLOW, FLOW);
1397 nset = NOTHING_SHIFT_FLOW, nver = nver1;
1400 /* calculate number of blocks S[h] must be split into when
1401 l_shift_num first items and l_shift_bytes of the right most
1402 liquid item to be shifted are shifted to the left neighbor,
1403 as well as number of items in each part of the splitted node (s012 numbers),
1404 and number of bytes (s1bytes) of the shared drop which flow to S1 if any
1406 lset = LEFT_SHIFT_NO_FLOW;
1407 lnver = get_num_ver(vn->vn_mode, tb, h,
1408 lpar - ((h || tb->lbytes == -1) ? 0 : 1),
1409 -1, h ? vn->vn_nr_item : 0, -1,
1410 snum012 + LEFT_SHIFT_NO_FLOW, NO_FLOW);
1414 lnver1 = get_num_ver(vn->vn_mode, tb, h,
1416 ((tb->lbytes != -1) ? 1 : 0),
1418 snum012 + LEFT_SHIFT_FLOW, FLOW);
1420 lset = LEFT_SHIFT_FLOW, lnver = lnver1;
1423 /* calculate number of blocks S[h] must be split into when
1424 r_shift_num first items and r_shift_bytes of the left most
1425 liquid item to be shifted are shifted to the right neighbor,
1426 as well as number of items in each part of the splitted node (s012 numbers),
1427 and number of bytes (s1bytes) of the shared drop which flow to S1 if any
1429 rset = RIGHT_SHIFT_NO_FLOW;
1430 rnver = get_num_ver(vn->vn_mode, tb, h,
1432 h ? (vn->vn_nr_item - rpar) : (rpar -
1437 snum012 + RIGHT_SHIFT_NO_FLOW, NO_FLOW);
1441 rnver1 = get_num_ver(vn->vn_mode, tb, h,
1444 ((tb->rbytes != -1) ? 1 : 0)),
1446 snum012 + RIGHT_SHIFT_FLOW, FLOW);
1449 rset = RIGHT_SHIFT_FLOW, rnver = rnver1;
1452 /* calculate number of blocks S[h] must be split into when
1453 items are shifted in both directions,
1454 as well as number of items in each part of the splitted node (s012 numbers),
1455 and number of bytes (s1bytes) of the shared drop which flow to S1 if any
1457 lrset = LR_SHIFT_NO_FLOW;
1458 lrnver = get_num_ver(vn->vn_mode, tb, h,
1459 lpar - ((h || tb->lbytes == -1) ? 0 : 1),
1461 h ? (vn->vn_nr_item - rpar) : (rpar -
1466 snum012 + LR_SHIFT_NO_FLOW, NO_FLOW);
1470 lrnver1 = get_num_ver(vn->vn_mode, tb, h,
1472 ((tb->lbytes != -1) ? 1 : 0),
1475 ((tb->rbytes != -1) ? 1 : 0)),
1477 snum012 + LR_SHIFT_FLOW, FLOW);
1478 if (lrnver > lrnver1)
1479 lrset = LR_SHIFT_FLOW, lrnver = lrnver1;
1482 /* Our general shifting strategy is:
1483 1) to minimized number of new nodes;
1484 2) to minimized number of neighbors involved in shifting;
1485 3) to minimized number of disk reads; */
1487 /* we can win TWO or ONE nodes by shifting in both directions */
1488 if (lrnver < lnver && lrnver < rnver) {
1490 (tb->lnum[h] != 1 ||
1492 lrnver != 1 || rnver != 2 || lnver != 2
1493 || h != 1), "vs-8230: bad h");
1494 if (lrset == LR_SHIFT_FLOW)
1495 set_parameters(tb, h, tb->lnum[h], tb->rnum[h],
1496 lrnver, snum012 + lrset,
1497 tb->lbytes, tb->rbytes);
1499 set_parameters(tb, h,
1501 ((tb->lbytes == -1) ? 0 : 1),
1503 ((tb->rbytes == -1) ? 0 : 1),
1504 lrnver, snum012 + lrset, -1, -1);
1509 /* if shifting doesn't lead to better packing then don't shift */
1510 if (nver == lrnver) {
1511 set_parameters(tb, h, 0, 0, nver, snum012 + nset, -1,
1516 /* now we know that for better packing shifting in only one
1517 direction either to the left or to the right is required */
1519 /* if shifting to the left is better than shifting to the right */
1520 if (lnver < rnver) {
1525 /* if shifting to the right is better than shifting to the left */
1526 if (lnver > rnver) {
1527 SET_PAR_SHIFT_RIGHT;
1531 /* now shifting in either direction gives the same number
1532 of nodes and we can make use of the cached neighbors */
1533 if (is_left_neighbor_in_cache(tb, h)) {
1538 /* shift to the right independently on whether the right neighbor in cache or not */
1539 SET_PAR_SHIFT_RIGHT;
1544 /* Check whether current node S[h] is balanced when Decreasing its size by
1545 * Deleting or Cutting for INTERNAL node of S+tree.
1546 * Calculate parameters for balancing for current level h.
1548 * tb tree_balance structure;
1549 * h current level of the node;
1550 * inum item number in S[h];
1551 * mode i - insert, p - paste;
1552 * Returns: 1 - schedule occurred;
1553 * 0 - balancing for higher levels needed;
1554 * -1 - no balancing for higher levels needed;
1555 * -2 - no disk space.
1557 * Note: Items of internal nodes have fixed size, so the balance condition for
1558 * the internal part of S+tree is as for the B-trees.
1560 static int dc_check_balance_internal(struct tree_balance *tb, int h)
1562 struct virtual_node *vn = tb->tb_vn;
1564 /* Sh is the node whose balance is currently being checked,
1565 and Fh is its father. */
1566 struct buffer_head *Sh, *Fh;
1568 int lfree, rfree /* free space in L and R */ ;
1570 Sh = PATH_H_PBUFFER(tb->tb_path, h);
1571 Fh = PATH_H_PPARENT(tb->tb_path, h);
1573 maxsize = MAX_CHILD_SIZE(Sh);
1575 /* using tb->insert_size[h], which is negative in this case, create_virtual_node calculates: */
1576 /* new_nr_item = number of items node would have if operation is */
1577 /* performed without balancing (new_nr_item); */
1578 create_virtual_node(tb, h);
1580 if (!Fh) { /* S[h] is the root. */
1581 if (vn->vn_nr_item > 0) {
1582 set_parameters(tb, h, 0, 0, 1, NULL, -1, -1);
1583 return NO_BALANCING_NEEDED; /* no balancing for higher levels needed */
1585 /* new_nr_item == 0.
1586 * Current root will be deleted resulting in
1587 * decrementing the tree height. */
1588 set_parameters(tb, h, 0, 0, 0, NULL, -1, -1);
1592 if ((ret = get_parents(tb, h)) != CARRY_ON)
1595 /* get free space of neighbors */
1596 rfree = get_rfree(tb, h);
1597 lfree = get_lfree(tb, h);
1599 /* determine maximal number of items we can fit into neighbors */
1600 check_left(tb, h, lfree);
1601 check_right(tb, h, rfree);
1603 if (vn->vn_nr_item >= MIN_NR_KEY(Sh)) { /* Balance condition for the internal node is valid.
1604 * In this case we balance only if it leads to better packing. */
1605 if (vn->vn_nr_item == MIN_NR_KEY(Sh)) { /* Here we join S[h] with one of its neighbors,
1606 * which is impossible with greater values of new_nr_item. */
1607 if (tb->lnum[h] >= vn->vn_nr_item + 1) {
1608 /* All contents of S[h] can be moved to L[h]. */
1614 PATH_H_B_ITEM_ORDER(tb->tb_path,
1616 0) ? B_NR_ITEMS(tb->FL[h]) : n - 1;
1617 n = dc_size(B_N_CHILD(tb->FL[h], order_L)) /
1618 (DC_SIZE + KEY_SIZE);
1619 set_parameters(tb, h, -n - 1, 0, 0, NULL, -1,
1624 if (tb->rnum[h] >= vn->vn_nr_item + 1) {
1625 /* All contents of S[h] can be moved to R[h]. */
1631 PATH_H_B_ITEM_ORDER(tb->tb_path,
1633 B_NR_ITEMS(Fh)) ? 0 : n + 1;
1634 n = dc_size(B_N_CHILD(tb->FR[h], order_R)) /
1635 (DC_SIZE + KEY_SIZE);
1636 set_parameters(tb, h, 0, -n - 1, 0, NULL, -1,
1642 if (tb->rnum[h] + tb->lnum[h] >= vn->vn_nr_item + 1) {
1643 /* All contents of S[h] can be moved to the neighbors (L[h] & R[h]). */
1647 ((MAX_NR_KEY(Sh) << 1) + 2 - tb->lnum[h] -
1648 tb->rnum[h] + vn->vn_nr_item + 1) / 2 -
1649 (MAX_NR_KEY(Sh) + 1 - tb->rnum[h]);
1650 set_parameters(tb, h, vn->vn_nr_item + 1 - to_r, to_r,
1655 /* Balancing does not lead to better packing. */
1656 set_parameters(tb, h, 0, 0, 1, NULL, -1, -1);
1657 return NO_BALANCING_NEEDED;
1660 /* Current node contain insufficient number of items. Balancing is required. */
1661 /* Check whether we can merge S[h] with left neighbor. */
1662 if (tb->lnum[h] >= vn->vn_nr_item + 1)
1663 if (is_left_neighbor_in_cache(tb, h)
1664 || tb->rnum[h] < vn->vn_nr_item + 1 || !tb->FR[h]) {
1670 PATH_H_B_ITEM_ORDER(tb->tb_path,
1672 0) ? B_NR_ITEMS(tb->FL[h]) : n - 1;
1673 n = dc_size(B_N_CHILD(tb->FL[h], order_L)) / (DC_SIZE +
1675 set_parameters(tb, h, -n - 1, 0, 0, NULL, -1, -1);
1679 /* Check whether we can merge S[h] with right neighbor. */
1680 if (tb->rnum[h] >= vn->vn_nr_item + 1) {
1686 PATH_H_B_ITEM_ORDER(tb->tb_path,
1687 h)) == B_NR_ITEMS(Fh)) ? 0 : (n + 1);
1688 n = dc_size(B_N_CHILD(tb->FR[h], order_R)) / (DC_SIZE +
1690 set_parameters(tb, h, 0, -n - 1, 0, NULL, -1, -1);
1694 /* All contents of S[h] can be moved to the neighbors (L[h] & R[h]). */
1695 if (tb->rnum[h] + tb->lnum[h] >= vn->vn_nr_item + 1) {
1699 ((MAX_NR_KEY(Sh) << 1) + 2 - tb->lnum[h] - tb->rnum[h] +
1700 vn->vn_nr_item + 1) / 2 - (MAX_NR_KEY(Sh) + 1 -
1702 set_parameters(tb, h, vn->vn_nr_item + 1 - to_r, to_r, 0, NULL,
1707 /* For internal nodes try to borrow item from a neighbor */
1708 RFALSE(!tb->FL[h] && !tb->FR[h], "vs-8235: trying to borrow for root");
1710 /* Borrow one or two items from caching neighbor */
1711 if (is_left_neighbor_in_cache(tb, h) || !tb->FR[h]) {
1715 (MAX_NR_KEY(Sh) + 1 - tb->lnum[h] + vn->vn_nr_item +
1716 1) / 2 - (vn->vn_nr_item + 1);
1717 set_parameters(tb, h, -from_l, 0, 1, NULL, -1, -1);
1721 set_parameters(tb, h, 0,
1722 -((MAX_NR_KEY(Sh) + 1 - tb->rnum[h] + vn->vn_nr_item +
1723 1) / 2 - (vn->vn_nr_item + 1)), 1, NULL, -1, -1);
1727 /* Check whether current node S[h] is balanced when Decreasing its size by
1728 * Deleting or Truncating for LEAF node of S+tree.
1729 * Calculate parameters for balancing for current level h.
1731 * tb tree_balance structure;
1732 * h current level of the node;
1733 * inum item number in S[h];
1734 * mode i - insert, p - paste;
1735 * Returns: 1 - schedule occurred;
1736 * 0 - balancing for higher levels needed;
1737 * -1 - no balancing for higher levels needed;
1738 * -2 - no disk space.
1740 static int dc_check_balance_leaf(struct tree_balance *tb, int h)
1742 struct virtual_node *vn = tb->tb_vn;
1744 /* Number of bytes that must be deleted from
1745 (value is negative if bytes are deleted) buffer which
1746 contains node being balanced. The mnemonic is that the
1747 attempted change in node space used level is levbytes bytes. */
1749 /* the maximal item size */
1751 /* S0 is the node whose balance is currently being checked,
1752 and F0 is its father. */
1753 struct buffer_head *S0, *F0;
1754 int lfree, rfree /* free space in L and R */ ;
1756 S0 = PATH_H_PBUFFER(tb->tb_path, 0);
1757 F0 = PATH_H_PPARENT(tb->tb_path, 0);
1759 levbytes = tb->insert_size[h];
1761 maxsize = MAX_CHILD_SIZE(S0); /* maximal possible size of an item */
1763 if (!F0) { /* S[0] is the root now. */
1765 RFALSE(-levbytes >= maxsize - B_FREE_SPACE(S0),
1766 "vs-8240: attempt to create empty buffer tree");
1768 set_parameters(tb, h, 0, 0, 1, NULL, -1, -1);
1769 return NO_BALANCING_NEEDED;
1772 if ((ret = get_parents(tb, h)) != CARRY_ON)
1775 /* get free space of neighbors */
1776 rfree = get_rfree(tb, h);
1777 lfree = get_lfree(tb, h);
1779 create_virtual_node(tb, h);
1781 /* if 3 leaves can be merge to one, set parameters and return */
1782 if (are_leaves_removable(tb, lfree, rfree))
1785 /* determine maximal number of items we can shift to the left/right neighbor
1786 and the maximal number of bytes that can flow to the left/right neighbor
1787 from the left/right most liquid item that cannot be shifted from S[0] entirely
1789 check_left(tb, h, lfree);
1790 check_right(tb, h, rfree);
1792 /* check whether we can merge S with left neighbor. */
1793 if (tb->lnum[0] >= vn->vn_nr_item && tb->lbytes == -1)
1794 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 */
1798 "vs-8245: dc_check_balance_leaf: FL[h] must exist");
1800 /* set parameter to merge S[0] with its left neighbor */
1801 set_parameters(tb, h, -1, 0, 0, NULL, -1, -1);
1805 /* check whether we can merge S[0] with right neighbor. */
1806 if (tb->rnum[0] >= vn->vn_nr_item && tb->rbytes == -1) {
1807 set_parameters(tb, h, 0, -1, 0, NULL, -1, -1);
1811 /* All contents of S[0] can be moved to the neighbors (L[0] & R[0]). Set parameters and return */
1812 if (is_leaf_removable(tb))
1815 /* Balancing is not required. */
1816 tb->s0num = vn->vn_nr_item;
1817 set_parameters(tb, h, 0, 0, 1, NULL, -1, -1);
1818 return NO_BALANCING_NEEDED;
1821 /* Check whether current node S[h] is balanced when Decreasing its size by
1822 * Deleting or Cutting.
1823 * Calculate parameters for balancing for current level h.
1825 * tb tree_balance structure;
1826 * h current level of the node;
1827 * inum item number in S[h];
1828 * mode d - delete, c - cut.
1829 * Returns: 1 - schedule occurred;
1830 * 0 - balancing for higher levels needed;
1831 * -1 - no balancing for higher levels needed;
1832 * -2 - no disk space.
1834 static int dc_check_balance(struct tree_balance *tb, int h)
1836 RFALSE(!(PATH_H_PBUFFER(tb->tb_path, h)),
1837 "vs-8250: S is not initialized");
1840 return dc_check_balance_internal(tb, h);
1842 return dc_check_balance_leaf(tb, h);
1845 /* Check whether current node S[h] is balanced.
1846 * Calculate parameters for balancing for current level h.
1849 * tb tree_balance structure:
1851 * tb is a large structure that must be read about in the header file
1852 * at the same time as this procedure if the reader is to successfully
1853 * understand this procedure
1855 * h current level of the node;
1856 * inum item number in S[h];
1857 * mode i - insert, p - paste, d - delete, c - cut.
1858 * Returns: 1 - schedule occurred;
1859 * 0 - balancing for higher levels needed;
1860 * -1 - no balancing for higher levels needed;
1861 * -2 - no disk space.
1863 static int check_balance(int mode,
1864 struct tree_balance *tb,
1868 struct item_head *ins_ih, const void *data)
1870 struct virtual_node *vn;
1872 vn = tb->tb_vn = (struct virtual_node *)(tb->vn_buf);
1873 vn->vn_free_ptr = (char *)(tb->tb_vn + 1);
1875 vn->vn_affected_item_num = inum;
1876 vn->vn_pos_in_item = pos_in_item;
1877 vn->vn_ins_ih = ins_ih;
1880 RFALSE(mode == M_INSERT && !vn->vn_ins_ih,
1881 "vs-8255: ins_ih can not be 0 in insert mode");
1883 if (tb->insert_size[h] > 0)
1884 /* Calculate balance parameters when size of node is increasing. */
1885 return ip_check_balance(tb, h);
1887 /* Calculate balance parameters when size of node is decreasing. */
1888 return dc_check_balance(tb, h);
1891 /* Check whether parent at the path is the really parent of the current node.*/
1892 static int get_direct_parent(struct tree_balance *tb, int h)
1894 struct buffer_head *bh;
1895 struct treepath *path = tb->tb_path;
1897 path_offset = PATH_H_PATH_OFFSET(tb->tb_path, h);
1899 /* We are in the root or in the new root. */
1900 if (path_offset <= FIRST_PATH_ELEMENT_OFFSET) {
1902 RFALSE(path_offset < FIRST_PATH_ELEMENT_OFFSET - 1,
1903 "PAP-8260: invalid offset in the path");
1905 if (PATH_OFFSET_PBUFFER(path, FIRST_PATH_ELEMENT_OFFSET)->
1906 b_blocknr == SB_ROOT_BLOCK(tb->tb_sb)) {
1907 /* Root is not changed. */
1908 PATH_OFFSET_PBUFFER(path, path_offset - 1) = NULL;
1909 PATH_OFFSET_POSITION(path, path_offset - 1) = 0;
1912 return REPEAT_SEARCH; /* Root is changed and we must recalculate the path. */
1916 (bh = PATH_OFFSET_PBUFFER(path, path_offset - 1)))
1917 return REPEAT_SEARCH; /* Parent in the path is not in the tree. */
1920 PATH_OFFSET_POSITION(path,
1921 path_offset - 1)) > B_NR_ITEMS(bh))
1922 return REPEAT_SEARCH;
1924 if (B_N_CHILD_NUM(bh, position) !=
1925 PATH_OFFSET_PBUFFER(path, path_offset)->b_blocknr)
1926 /* Parent in the path is not parent of the current node in the tree. */
1927 return REPEAT_SEARCH;
1929 if (buffer_locked(bh)) {
1930 __wait_on_buffer(bh);
1931 if (FILESYSTEM_CHANGED_TB(tb))
1932 return REPEAT_SEARCH;
1935 return CARRY_ON; /* Parent in the path is unlocked and really parent of the current node. */
1938 /* Using lnum[h] and rnum[h] we should determine what neighbors
1940 * need in order to balance S[h], and get them if necessary.
1941 * Returns: SCHEDULE_OCCURRED - schedule occurred while the function worked;
1942 * CARRY_ON - schedule didn't occur while the function worked;
1944 static int get_neighbors(struct tree_balance *tb, int h)
1947 path_offset = PATH_H_PATH_OFFSET(tb->tb_path, h + 1);
1948 unsigned long son_number;
1949 struct super_block *sb = tb->tb_sb;
1950 struct buffer_head *bh;
1952 PROC_INFO_INC(sb, get_neighbors[h]);
1955 /* We need left neighbor to balance S[h]. */
1956 PROC_INFO_INC(sb, need_l_neighbor[h]);
1957 bh = PATH_OFFSET_PBUFFER(tb->tb_path, path_offset);
1959 RFALSE(bh == tb->FL[h] &&
1960 !PATH_OFFSET_POSITION(tb->tb_path, path_offset),
1961 "PAP-8270: invalid position in the parent");
1965 tb->FL[h]) ? tb->lkey[h] : B_NR_ITEMS(tb->
1967 son_number = B_N_CHILD_NUM(tb->FL[h], child_position);
1968 bh = sb_bread(sb, son_number);
1971 if (FILESYSTEM_CHANGED_TB(tb)) {
1973 PROC_INFO_INC(sb, get_neighbors_restart[h]);
1974 return REPEAT_SEARCH;
1977 RFALSE(!B_IS_IN_TREE(tb->FL[h]) ||
1978 child_position > B_NR_ITEMS(tb->FL[h]) ||
1979 B_N_CHILD_NUM(tb->FL[h], child_position) !=
1980 bh->b_blocknr, "PAP-8275: invalid parent");
1981 RFALSE(!B_IS_IN_TREE(bh), "PAP-8280: invalid child");
1984 MAX_CHILD_SIZE(bh) -
1985 dc_size(B_N_CHILD(tb->FL[0], child_position)),
1986 "PAP-8290: invalid child size of left neighbor");
1992 /* We need right neighbor to balance S[path_offset]. */
1993 if (tb->rnum[h]) { /* We need right neighbor to balance S[path_offset]. */
1994 PROC_INFO_INC(sb, need_r_neighbor[h]);
1995 bh = PATH_OFFSET_PBUFFER(tb->tb_path, path_offset);
1997 RFALSE(bh == tb->FR[h] &&
1998 PATH_OFFSET_POSITION(tb->tb_path,
2001 "PAP-8295: invalid position in the parent");
2004 (bh == tb->FR[h]) ? tb->rkey[h] + 1 : 0;
2005 son_number = B_N_CHILD_NUM(tb->FR[h], child_position);
2006 bh = sb_bread(sb, son_number);
2009 if (FILESYSTEM_CHANGED_TB(tb)) {
2011 PROC_INFO_INC(sb, get_neighbors_restart[h]);
2012 return REPEAT_SEARCH;
2018 && B_FREE_SPACE(bh) !=
2019 MAX_CHILD_SIZE(bh) -
2020 dc_size(B_N_CHILD(tb->FR[0], child_position)),
2021 "PAP-8300: invalid child size of right neighbor (%d != %d - %d)",
2022 B_FREE_SPACE(bh), MAX_CHILD_SIZE(bh),
2023 dc_size(B_N_CHILD(tb->FR[0], child_position)));
2029 static int get_virtual_node_size(struct super_block *sb, struct buffer_head *bh)
2031 int max_num_of_items;
2032 int max_num_of_entries;
2033 unsigned long blocksize = sb->s_blocksize;
2035 #define MIN_NAME_LEN 1
2037 max_num_of_items = (blocksize - BLKH_SIZE) / (IH_SIZE + MIN_ITEM_LEN);
2038 max_num_of_entries = (blocksize - BLKH_SIZE - IH_SIZE) /
2039 (DEH_SIZE + MIN_NAME_LEN);
2041 return sizeof(struct virtual_node) +
2042 max(max_num_of_items * sizeof(struct virtual_item),
2043 sizeof(struct virtual_item) + sizeof(struct direntry_uarea) +
2044 (max_num_of_entries - 1) * sizeof(__u16));
2047 /* maybe we should fail balancing we are going to perform when kmalloc
2048 fails several times. But now it will loop until kmalloc gets
2050 static int get_mem_for_virtual_node(struct tree_balance *tb)
2056 size = get_virtual_node_size(tb->tb_sb, PATH_PLAST_BUFFER(tb->tb_path));
2058 if (size > tb->vn_buf_size) {
2059 /* we have to allocate more memory for virtual node */
2061 /* free memory allocated before */
2063 /* this is not needed if kfree is atomic */
2067 /* virtual node requires now more memory */
2068 tb->vn_buf_size = size;
2070 /* get memory for virtual item */
2071 buf = kmalloc(size, GFP_ATOMIC | __GFP_NOWARN);
2073 /* getting memory with GFP_KERNEL priority may involve
2074 balancing now (due to indirect_to_direct conversion on
2075 dcache shrinking). So, release path and collected
2077 free_buffers_in_tb(tb);
2078 buf = kmalloc(size, GFP_NOFS);
2080 tb->vn_buf_size = 0;
2084 return REPEAT_SEARCH;
2090 if (check_fs && FILESYSTEM_CHANGED_TB(tb))
2091 return REPEAT_SEARCH;
2096 #ifdef CONFIG_REISERFS_CHECK
2097 static void tb_buffer_sanity_check(struct super_block *sb,
2098 struct buffer_head *bh,
2099 const char *descr, int level)
2102 if (atomic_read(&(bh->b_count)) <= 0)
2104 reiserfs_panic(sb, "jmacd-1", "negative or zero "
2105 "reference counter for buffer %s[%d] "
2106 "(%b)", descr, level, bh);
2108 if (!buffer_uptodate(bh))
2109 reiserfs_panic(sb, "jmacd-2", "buffer is not up "
2110 "to date %s[%d] (%b)",
2113 if (!B_IS_IN_TREE(bh))
2114 reiserfs_panic(sb, "jmacd-3", "buffer is not "
2115 "in tree %s[%d] (%b)",
2118 if (bh->b_bdev != sb->s_bdev)
2119 reiserfs_panic(sb, "jmacd-4", "buffer has wrong "
2120 "device %s[%d] (%b)",
2123 if (bh->b_size != sb->s_blocksize)
2124 reiserfs_panic(sb, "jmacd-5", "buffer has wrong "
2125 "blocksize %s[%d] (%b)",
2128 if (bh->b_blocknr > SB_BLOCK_COUNT(sb))
2129 reiserfs_panic(sb, "jmacd-6", "buffer block "
2130 "number too high %s[%d] (%b)",
2135 static void tb_buffer_sanity_check(struct super_block *sb,
2136 struct buffer_head *bh,
2137 const char *descr, int level)
2142 static int clear_all_dirty_bits(struct super_block *s, struct buffer_head *bh)
2144 return reiserfs_prepare_for_journal(s, bh, 0);
2147 static int wait_tb_buffers_until_unlocked(struct tree_balance *tb)
2149 struct buffer_head *locked;
2150 #ifdef CONFIG_REISERFS_CHECK
2151 int repeat_counter = 0;
2159 for (i = tb->tb_path->path_length;
2160 !locked && i > ILLEGAL_PATH_ELEMENT_OFFSET; i--) {
2161 if (PATH_OFFSET_PBUFFER(tb->tb_path, i)) {
2162 /* if I understand correctly, we can only be sure the last buffer
2163 ** in the path is in the tree --clm
2165 #ifdef CONFIG_REISERFS_CHECK
2166 if (PATH_PLAST_BUFFER(tb->tb_path) ==
2167 PATH_OFFSET_PBUFFER(tb->tb_path, i))
2168 tb_buffer_sanity_check(tb->tb_sb,
2175 if (!clear_all_dirty_bits(tb->tb_sb,
2180 PATH_OFFSET_PBUFFER(tb->tb_path,
2186 for (i = 0; !locked && i < MAX_HEIGHT && tb->insert_size[i];
2192 tb_buffer_sanity_check(tb->tb_sb,
2195 if (!clear_all_dirty_bits
2196 (tb->tb_sb, tb->L[i]))
2200 if (!locked && tb->FL[i]) {
2201 tb_buffer_sanity_check(tb->tb_sb,
2204 if (!clear_all_dirty_bits
2205 (tb->tb_sb, tb->FL[i]))
2209 if (!locked && tb->CFL[i]) {
2210 tb_buffer_sanity_check(tb->tb_sb,
2213 if (!clear_all_dirty_bits
2214 (tb->tb_sb, tb->CFL[i]))
2215 locked = tb->CFL[i];
2220 if (!locked && (tb->rnum[i])) {
2223 tb_buffer_sanity_check(tb->tb_sb,
2226 if (!clear_all_dirty_bits
2227 (tb->tb_sb, tb->R[i]))
2231 if (!locked && tb->FR[i]) {
2232 tb_buffer_sanity_check(tb->tb_sb,
2235 if (!clear_all_dirty_bits
2236 (tb->tb_sb, tb->FR[i]))
2240 if (!locked && tb->CFR[i]) {
2241 tb_buffer_sanity_check(tb->tb_sb,
2244 if (!clear_all_dirty_bits
2245 (tb->tb_sb, tb->CFR[i]))
2246 locked = tb->CFR[i];
2250 /* as far as I can tell, this is not required. The FEB list seems
2251 ** to be full of newly allocated nodes, which will never be locked,
2252 ** dirty, or anything else.
2253 ** To be safe, I'm putting in the checks and waits in. For the moment,
2254 ** they are needed to keep the code in journal.c from complaining
2255 ** about the buffer. That code is inside CONFIG_REISERFS_CHECK as well.
2258 for (i = 0; !locked && i < MAX_FEB_SIZE; i++) {
2260 if (!clear_all_dirty_bits
2261 (tb->tb_sb, tb->FEB[i]))
2262 locked = tb->FEB[i];
2267 #ifdef CONFIG_REISERFS_CHECK
2269 if ((repeat_counter % 10000) == 0) {
2270 reiserfs_warning(tb->tb_sb, "reiserfs-8200",
2271 "too many iterations waiting "
2272 "for buffer to unlock "
2275 /* Don't loop forever. Try to recover from possible error. */
2277 return (FILESYSTEM_CHANGED_TB(tb)) ?
2278 REPEAT_SEARCH : CARRY_ON;
2281 __wait_on_buffer(locked);
2282 if (FILESYSTEM_CHANGED_TB(tb))
2283 return REPEAT_SEARCH;
2291 /* Prepare for balancing, that is
2292 * get all necessary parents, and neighbors;
2293 * analyze what and where should be moved;
2294 * get sufficient number of new nodes;
2295 * Balancing will start only after all resources will be collected at a time.
2297 * When ported to SMP kernels, only at the last moment after all needed nodes
2298 * are collected in cache, will the resources be locked using the usual
2299 * textbook ordered lock acquisition algorithms. Note that ensuring that
2300 * this code neither write locks what it does not need to write lock nor locks out of order
2301 * will be a pain in the butt that could have been avoided. Grumble grumble. -Hans
2303 * fix is meant in the sense of render unchanging
2305 * Latency might be improved by first gathering a list of what buffers are needed
2306 * and then getting as many of them in parallel as possible? -Hans
2309 * op_mode i - insert, d - delete, c - cut (truncate), p - paste (append)
2310 * tb tree_balance structure;
2311 * inum item number in S[h];
2312 * pos_in_item - comment this if you can
2313 * ins_ih item head of item being inserted
2314 * data inserted item or data to be pasted
2315 * Returns: 1 - schedule occurred while the function worked;
2316 * 0 - schedule didn't occur while the function worked;
2317 * -1 - if no_disk_space
2320 int fix_nodes(int op_mode, struct tree_balance *tb,
2321 struct item_head *ins_ih, const void *data)
2323 int ret, h, item_num = PATH_LAST_POSITION(tb->tb_path);
2326 /* we set wait_tb_buffers_run when we have to restore any dirty bits cleared
2327 ** during wait_tb_buffers_run
2329 int wait_tb_buffers_run = 0;
2330 struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
2332 ++REISERFS_SB(tb->tb_sb)->s_fix_nodes;
2334 pos_in_item = tb->tb_path->pos_in_item;
2336 tb->fs_gen = get_generation(tb->tb_sb);
2338 /* we prepare and log the super here so it will already be in the
2339 ** transaction when do_balance needs to change it.
2340 ** This way do_balance won't have to schedule when trying to prepare
2341 ** the super for logging
2343 reiserfs_prepare_for_journal(tb->tb_sb,
2344 SB_BUFFER_WITH_SB(tb->tb_sb), 1);
2345 journal_mark_dirty(tb->transaction_handle, tb->tb_sb,
2346 SB_BUFFER_WITH_SB(tb->tb_sb));
2347 if (FILESYSTEM_CHANGED_TB(tb))
2348 return REPEAT_SEARCH;
2350 /* if it possible in indirect_to_direct conversion */
2351 if (buffer_locked(tbS0)) {
2352 __wait_on_buffer(tbS0);
2353 if (FILESYSTEM_CHANGED_TB(tb))
2354 return REPEAT_SEARCH;
2356 #ifdef CONFIG_REISERFS_CHECK
2358 print_cur_tb("fix_nodes");
2359 reiserfs_panic(tb->tb_sb, "PAP-8305",
2360 "there is pending do_balance");
2363 if (!buffer_uptodate(tbS0) || !B_IS_IN_TREE(tbS0))
2364 reiserfs_panic(tb->tb_sb, "PAP-8320", "S[0] (%b %z) is "
2365 "not uptodate at the beginning of fix_nodes "
2366 "or not in tree (mode %c)",
2367 tbS0, tbS0, op_mode);
2369 /* Check parameters. */
2372 if (item_num <= 0 || item_num > B_NR_ITEMS(tbS0))
2373 reiserfs_panic(tb->tb_sb, "PAP-8330", "Incorrect "
2374 "item number %d (in S0 - %d) in case "
2375 "of insert", item_num,
2381 if (item_num < 0 || item_num >= B_NR_ITEMS(tbS0)) {
2382 print_block(tbS0, 0, -1, -1);
2383 reiserfs_panic(tb->tb_sb, "PAP-8335", "Incorrect "
2384 "item number(%d); mode = %c "
2387 tb->insert_size[0]);
2391 reiserfs_panic(tb->tb_sb, "PAP-8340", "Incorrect mode "
2396 if (get_mem_for_virtual_node(tb) == REPEAT_SEARCH)
2397 // FIXME: maybe -ENOMEM when tb->vn_buf == 0? Now just repeat
2398 return REPEAT_SEARCH;
2400 /* Starting from the leaf level; for all levels h of the tree. */
2401 for (h = 0; h < MAX_HEIGHT && tb->insert_size[h]; h++) {
2402 ret = get_direct_parent(tb, h);
2403 if (ret != CARRY_ON)
2406 ret = check_balance(op_mode, tb, h, item_num,
2407 pos_in_item, ins_ih, data);
2408 if (ret != CARRY_ON) {
2409 if (ret == NO_BALANCING_NEEDED) {
2410 /* No balancing for higher levels needed. */
2411 ret = get_neighbors(tb, h);
2412 if (ret != CARRY_ON)
2414 if (h != MAX_HEIGHT - 1)
2415 tb->insert_size[h + 1] = 0;
2416 /* ok, analysis and resource gathering are complete */
2422 ret = get_neighbors(tb, h);
2423 if (ret != CARRY_ON)
2426 /* No disk space, or schedule occurred and analysis may be
2427 * invalid and needs to be redone. */
2428 ret = get_empty_nodes(tb, h);
2429 if (ret != CARRY_ON)
2432 if (!PATH_H_PBUFFER(tb->tb_path, h)) {
2433 /* We have a positive insert size but no nodes exist on this
2434 level, this means that we are creating a new root. */
2436 RFALSE(tb->blknum[h] != 1,
2437 "PAP-8350: creating new empty root");
2439 if (h < MAX_HEIGHT - 1)
2440 tb->insert_size[h + 1] = 0;
2441 } else if (!PATH_H_PBUFFER(tb->tb_path, h + 1)) {
2442 if (tb->blknum[h] > 1) {
2443 /* The tree needs to be grown, so this node S[h]
2444 which is the root node is split into two nodes,
2445 and a new node (S[h+1]) will be created to
2446 become the root node. */
2448 RFALSE(h == MAX_HEIGHT - 1,
2449 "PAP-8355: attempt to create too high of a tree");
2451 tb->insert_size[h + 1] =
2453 KEY_SIZE) * (tb->blknum[h] - 1) +
2455 } else if (h < MAX_HEIGHT - 1)
2456 tb->insert_size[h + 1] = 0;
2458 tb->insert_size[h + 1] =
2459 (DC_SIZE + KEY_SIZE) * (tb->blknum[h] - 1);
2462 ret = wait_tb_buffers_until_unlocked(tb);
2463 if (ret == CARRY_ON) {
2464 if (FILESYSTEM_CHANGED_TB(tb)) {
2465 wait_tb_buffers_run = 1;
2466 ret = REPEAT_SEARCH;
2472 wait_tb_buffers_run = 1;
2477 // fix_nodes was unable to perform its calculation due to
2478 // filesystem got changed under us, lack of free disk space or i/o
2479 // failure. If the first is the case - the search will be
2480 // repeated. For now - free all resources acquired so far except
2481 // for the new allocated nodes
2485 /* Release path buffers. */
2486 if (wait_tb_buffers_run) {
2487 pathrelse_and_restore(tb->tb_sb, tb->tb_path);
2489 pathrelse(tb->tb_path);
2491 /* brelse all resources collected for balancing */
2492 for (i = 0; i < MAX_HEIGHT; i++) {
2493 if (wait_tb_buffers_run) {
2494 reiserfs_restore_prepared_buffer(tb->tb_sb,
2496 reiserfs_restore_prepared_buffer(tb->tb_sb,
2498 reiserfs_restore_prepared_buffer(tb->tb_sb,
2500 reiserfs_restore_prepared_buffer(tb->tb_sb,
2502 reiserfs_restore_prepared_buffer(tb->tb_sb,
2505 reiserfs_restore_prepared_buffer(tb->tb_sb,
2525 if (wait_tb_buffers_run) {
2526 for (i = 0; i < MAX_FEB_SIZE; i++) {
2528 reiserfs_restore_prepared_buffer
2529 (tb->tb_sb, tb->FEB[i]);
2537 /* Anatoly will probably forgive me renaming tb to tb. I just
2538 wanted to make lines shorter */
2539 void unfix_nodes(struct tree_balance *tb)
2543 /* Release path buffers. */
2544 pathrelse_and_restore(tb->tb_sb, tb->tb_path);
2546 /* brelse all resources collected for balancing */
2547 for (i = 0; i < MAX_HEIGHT; i++) {
2548 reiserfs_restore_prepared_buffer(tb->tb_sb, tb->L[i]);
2549 reiserfs_restore_prepared_buffer(tb->tb_sb, tb->R[i]);
2550 reiserfs_restore_prepared_buffer(tb->tb_sb, tb->FL[i]);
2551 reiserfs_restore_prepared_buffer(tb->tb_sb, tb->FR[i]);
2552 reiserfs_restore_prepared_buffer(tb->tb_sb, tb->CFL[i]);
2553 reiserfs_restore_prepared_buffer(tb->tb_sb, tb->CFR[i]);
2563 /* deal with list of allocated (used and unused) nodes */
2564 for (i = 0; i < MAX_FEB_SIZE; i++) {
2566 b_blocknr_t blocknr = tb->FEB[i]->b_blocknr;
2567 /* de-allocated block which was not used by balancing and
2568 bforget about buffer for it */
2570 reiserfs_free_block(tb->transaction_handle, NULL,
2574 /* release used as new nodes including a new root */
2575 brelse(tb->used[i]);