diff options
author | Jeff Mahoney <jeffm@suse.com> | 2014-04-23 14:00:36 (GMT) |
---|---|---|
committer | Jan Kara <jack@suse.cz> | 2014-05-06 20:52:19 (GMT) |
commit | 098297b27d23ad9d0fc302e3417474d9342c6c14 (patch) | |
tree | 58f2054cd9933225ef1ae9c7febedc9160041af6 /fs/reiserfs/fix_node.c | |
parent | 4cf5f7addf18ecae2ea49b11944976cbd26d5281 (diff) | |
download | linux-098297b27d23ad9d0fc302e3417474d9342c6c14.tar.xz |
reiserfs: cleanup, reformat comments to normal kernel style
This patch reformats comments in the reiserfs code to fit in 80 columns and
to follow the style rules.
There is no functional change but it helps make my eyes bleed less.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs/reiserfs/fix_node.c')
-rw-r--r-- | fs/reiserfs/fix_node.c | 967 |
1 files changed, 598 insertions, 369 deletions
diff --git a/fs/reiserfs/fix_node.c b/fs/reiserfs/fix_node.c index b6a05a7..144bd62 100644 --- a/fs/reiserfs/fix_node.c +++ b/fs/reiserfs/fix_node.c @@ -2,59 +2,32 @@ * 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/time.h> #include <linux/slab.h> #include <linux/string.h> #include "reiserfs.h" #include <linux/buffer_head.h> -/* To make any changes in the tree we find a node, that contains item - to be changed/deleted or position in the node we insert a new item - to. We call this node S. To do balancing we need to decide what we - will shift to left/right neighbor, or to a new node, where new item - will be etc. To make this analysis simpler we build virtual - node. Virtual node is an array of items, that will replace items of - node S. (For instance if we are going to delete an item, virtual - node does not contain it). Virtual node keeps information about - item sizes and types, mergeability of first and last items, sizes - of all entries in directory item. We use this array of items when - calculating what we can shift to neighbors and how many nodes we - have to have if we do not any shiftings, if we shift to left/right - neighbor or to both. */ - -/* taking item number in virtual node, returns number of item, that it has in source buffer */ +/* + * To make any changes in the tree we find a node that contains item + * to be changed/deleted or position in the node we insert a new item + * to. We call this node S. To do balancing we need to decide what we + * will shift to left/right neighbor, or to a new node, where new item + * will be etc. To make this analysis simpler we build virtual + * node. Virtual node is an array of items, that will replace items of + * node S. (For instance if we are going to delete an item, virtual + * node does not contain it). Virtual node keeps information about + * item sizes and types, mergeability of first and last items, sizes + * of all entries in directory item. We use this array of items when + * calculating what we can shift to neighbors and how many nodes we + * have to have if we do not any shiftings, if we shift to left/right + * neighbor or to both. + */ + +/* + * Takes item number in virtual node, returns number of item + * that it has in source buffer + */ static inline int old_item_num(int new_num, int affected_item_num, int mode) { if (mode == M_PASTE || mode == M_CUT || new_num < affected_item_num) @@ -112,7 +85,10 @@ static void create_virtual_node(struct tree_balance *tb, int h) && (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) */ + /* + * go through all items that remain in the virtual + * node (except for the new (inserted) one) + */ for (new_num = 0; new_num < vn->vn_nr_item; new_num++) { int j; struct virtual_item *vi = vn->vn_vi + new_num; @@ -131,8 +107,10 @@ static void create_virtual_node(struct tree_balance *tb, int h) vi->vi_item = ih_item_body(Sh, ih + j); vi->vi_uarea = vn->vn_free_ptr; - // FIXME: there is no check, that item operation did not - // consume too much memory + /* + * 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) @@ -145,7 +123,8 @@ static void create_virtual_node(struct tree_balance *tb, int h) 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 + /* pointer to data which is going to be pasted */ + vi->vi_new_data = vn->vn_data; } } @@ -164,7 +143,10 @@ static void create_virtual_node(struct tree_balance *tb, int h) tb->insert_size[0]); } - /* set right merge flag we take right delimiting key and check whether it is a mergeable item */ + /* + * 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; @@ -179,12 +161,19 @@ static void create_virtual_node(struct tree_balance *tb, int h) 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 */ + /* + * we delete last item and it could be merged + * with right neighbor's first item + */ if (! (B_NR_ITEMS(Sh) == 1 && is_direntry_le_ih(item_head(Sh, 0)) && ih_entry_count(item_head(Sh, 0)) == 1)) { - /* node contains more than 1 item, or item is not directory item, or this item contains more than 1 entry */ + /* + * node contains more than 1 item, or item + * is not directory item, or this item + * contains more than 1 entry + */ print_block(Sh, 0, -1, -1); reiserfs_panic(tb->tb_sb, "vs-8045", "rdkey %k, affected item==%d " @@ -198,8 +187,10 @@ static void create_virtual_node(struct tree_balance *tb, int h) } } -/* using virtual node check, how many items can be shifted to left - neighbor */ +/* + * 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; @@ -259,9 +250,13 @@ static void check_left(struct tree_balance *tb, int h, int cur_free) } /* 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 */ + /* + * check whether L[0] can hold ih and at least one byte + * of the item body + */ + + /* cannot shift even a part of the current item */ if (cur_free <= ih_size) { - /* cannot shift even a part of the current item */ tb->lbytes = -1; return; } @@ -278,8 +273,10 @@ static void check_left(struct tree_balance *tb, int h, int cur_free) return; } -/* using virtual node check, how many items can be shifted to right - neighbor */ +/* + * 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; @@ -338,13 +335,21 @@ static void check_right(struct tree_balance *tb, int h, int cur_free) 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 */ + /* + * check whether R[0] can hold ih and at least one + * byte of the item body + */ + + /* cannot shift even a part of the current item */ + if (cur_free <= ih_size) { tb->rbytes = -1; return; } - /* R[0] can hold the header of the item and at least one byte of its body */ + /* + * 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); @@ -361,45 +366,64 @@ static void check_right(struct tree_balance *tb, int h, int cur_free) /* * 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 */ + * 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 */ + + /* position of item we start filling node from */ + int start_item; + + /* position of item we finish filling node by */ + int end_item; + + /* + * number of first bytes (entries for directory) of start_item-th item + * we do not include into node that is being filled + */ + int start_bytes; + + /* + * number of last bytes (entries for directory) of end_item-th item + * we do node include into node that is being filled + */ + int end_bytes; + + /* + * these are positions in virtual item of items, that are split + * between S[0] and S1new and S1new and S2new + */ + int split_item_positions[2]; split_item_positions[0] = -1; split_item_positions[1] = -1; - /* We only create additional nodes if we are in insert or paste mode - or we are in replace mode at the internal level. If h is 0 and - the mode is M_REPLACE then in fix_nodes we change the mode to - paste or insert before we get here in the code. */ + /* + * 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 [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 */ @@ -416,20 +440,22 @@ static int get_num_ver(int mode, struct tree_balance *tb, int h, total_node_size = 0; cur_free = max_node_size; - // start from 'from'-th item + /* start from 'from'-th item */ start_item = from; - // skip its first 'start_bytes' units + /* skip its first 'start_bytes' units */ start_bytes = ((from_bytes != -1) ? from_bytes : 0); - // last included item is the 'end_item'-th one + /* 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 + /* 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 */ - + /* + * 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); @@ -439,7 +465,10 @@ static int get_num_ver(int mode, struct tree_balance *tb, int h, /* 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 */ + /* + * 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); @@ -455,9 +484,11 @@ static int get_num_ver(int mode, struct tree_balance *tb, int h, continue; } + /* + * virtual item length is longer, than max size of item in + * a node. It is impossible for direct item + */ if (current_item_size > max_node_size) { - /* 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", @@ -466,15 +497,18 @@ static int get_num_ver(int mode, struct tree_balance *tb, int h, flow = 1; } + /* as we do not split items, take new node and continue */ 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 + + /* + * calculate number of item units which fit into node being + * filled + */ { int free_space; @@ -482,17 +516,17 @@ static int get_num_ver(int mode, struct tree_balance *tb, int h, units = op_check_left(vi, free_space, start_bytes, skip_from_end); + /* + * nothing fits into current node, take new + * node and continue + */ if (units == -1) { - /* 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; @@ -508,9 +542,11 @@ static int get_num_ver(int mode, struct tree_balance *tb, int h, 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 + /* + * 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; @@ -527,7 +563,7 @@ static int get_num_ver(int mode, struct tree_balance *tb, int h, ((split_item_positions[0] == split_item_positions[1]) ? snum012[3] : 0); - // s2bytes + /* s2bytes */ snum012[4] = op_unit_num(&vn->vn_vi[split_item_num]) - snum012[4] - bytes_to_r - bytes_to_l - bytes_to_S1new; @@ -555,7 +591,7 @@ static int get_num_ver(int mode, struct tree_balance *tb, int h, ((split_item_positions[0] == split_item_positions[1] && snum012[4] != -1) ? snum012[4] : 0); - // s1bytes + /* s1bytes */ snum012[3] = op_unit_num(&vn->vn_vi[split_item_num]) - snum012[3] - bytes_to_r - bytes_to_l - bytes_to_S2new; @@ -565,7 +601,8 @@ static int get_num_ver(int mode, struct tree_balance *tb, int h, } -/* Set parameters for balancing. +/* + * 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: @@ -575,11 +612,12 @@ static int get_num_ver(int mode, struct tree_balance *tb, int 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) + * 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, @@ -590,7 +628,8 @@ static void set_parameters(struct tree_balance *tb, int h, int lnum, tb->rnum[h] = rnum; tb->blknum[h] = blk_num; - if (h == 0) { /* only for leaf level */ + /* only for leaf level */ + if (h == 0) { if (s012 != NULL) { tb->s0num = *s012++, tb->s1num = *s012++, tb->s2num = *s012++; @@ -607,8 +646,10 @@ static void set_parameters(struct tree_balance *tb, int h, int lnum, 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. */ +/* + * check if node disappears if we shift tb->lnum[0] items to left + * neighbor and tb->rnum[0] to the right one. + */ static int is_leaf_removable(struct tree_balance *tb) { struct virtual_node *vn = tb->tb_vn; @@ -616,8 +657,10 @@ static int is_leaf_removable(struct tree_balance *tb) int size; int remain_items; - /* number of items, that will be shifted to left (right) neighbor - entirely */ + /* + * 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; @@ -625,18 +668,18 @@ static int is_leaf_removable(struct tree_balance *tb) /* how many items remain in S[0] after shiftings to neighbors */ remain_items -= (to_left + to_right); + /* all content of node can be shifted to neighbors */ if (remain_items < 1) { - /* 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; } + /* S[0] is not removable */ 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 */ + /* 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])); @@ -680,18 +723,23 @@ static int are_leaves_removable(struct tree_balance *tb, int lfree, int rfree) && !comp_short_le_keys(&(ih->ih_key), internal_key(tb->CFR[0], tb->rkey[0]))) + /* + * Directory must be in correct state here: that is + * somewhere at the left side should exist first + * directory item. But the item being deleted can + * not be that first one because its right neighbor + * is item of the same directory. (But first item + * always gets deleted in last turn). So, neighbors + * of deleted item can be merged, so we can save + * ih_size + */ if (is_direntry_le_ih(ih)) { - /* 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 */ + /* + * 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"); } @@ -770,7 +818,8 @@ static void free_buffers_in_tb(struct tree_balance *tb) } } -/* Get new buffers for storing new nodes that are created while balancing. +/* + * 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. @@ -778,28 +827,33 @@ static void free_buffers_in_tb(struct tree_balance *tb) /* The function is NOT SCHEDULE-SAFE! */ static int get_empty_nodes(struct tree_balance *tb, int h) { - struct buffer_head *new_bh, - *Sh = PATH_H_PBUFFER(tb->tb_path, h); + struct buffer_head *new_bh, *Sh = PATH_H_PBUFFER(tb->tb_path, h); b_blocknr_t *blocknr, blocknrs[MAX_AMOUNT_NEEDED] = { 0, }; - int counter, number_of_freeblk, amount_needed, /* number of needed empty blocks */ - retval = CARRY_ON; + int counter, number_of_freeblk; + int amount_needed; /* number of needed empty blocks */ + int retval = CARRY_ON; struct super_block *sb = tb->tb_sb; - /* number_of_freeblk is the number of empty blocks which have been - acquired for use by the balancing algorithm minus the number of - empty blocks used in the previous levels of the analysis, - number_of_freeblk = tb->cur_blknum can be non-zero if a schedule occurs - after empty blocks are acquired, and the balancing analysis is - then restarted, amount_needed is the number needed by this level - (h) of the balancing analysis. - - Note that for systems with many processes writing, it would be - more layout optimal to calculate the total number needed by all - levels and then to run reiserfs_new_blocks to get all of them at once. */ - - /* Initiate number_of_freeblk to the amount acquired prior to the restart of - the analysis or 0 if not restarted, then subtract the amount needed - by all of the levels of the tree below h. */ + /* + * number_of_freeblk is the number of empty blocks which have been + * acquired for use by the balancing algorithm minus the number of + * empty blocks used in the previous levels of the analysis, + * number_of_freeblk = tb->cur_blknum can be non-zero if a schedule + * occurs after empty blocks are acquired, and the balancing analysis + * is then restarted, amount_needed is the number needed by this + * level (h) of the balancing analysis. + * + * Note that for systems with many processes writing, it would be + * more layout optimal to calculate the total number needed by all + * levels and then to run reiserfs_new_blocks to get all of them at + * once. + */ + + /* + * Initiate number_of_freeblk to the amount acquired prior to the + * restart of the analysis or 0 if not restarted, then subtract the + * amount needed by all of the levels of the tree below h. + */ /* blknum includes S[h], so we subtract 1 in this calculation */ for (counter = 0, number_of_freeblk = tb->cur_blknum; counter < h; counter++) @@ -810,13 +864,19 @@ static int get_empty_nodes(struct tree_balance *tb, int h) /* Allocate missing empty blocks. */ /* if Sh == 0 then we are getting a new root */ amount_needed = (Sh) ? (tb->blknum[h] - 1) : 1; - /* Amount_needed = the amount that we need more than the amount that we have. */ + /* + * Amount_needed = the amount that we need more than the + * amount that we have. + */ if (amount_needed > number_of_freeblk) amount_needed -= number_of_freeblk; - else /* If we have enough already then there is nothing to do. */ + 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 */ + /* + * No need to check quota - is not allocated for blocks used + * for formatted nodes + */ if (reiserfs_new_form_blocknrs(tb, blocknrs, amount_needed) == NO_DISK_SPACE) return NO_DISK_SPACE; @@ -849,8 +909,10 @@ static int get_empty_nodes(struct tree_balance *tb, int h) return retval; } -/* Get free space of the left neighbor, which is stored in the parent - * node of the left neighbor. */ +/* + * 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; @@ -870,7 +932,8 @@ static int get_lfree(struct tree_balance *tb, int h) return (MAX_CHILD_SIZE(f) - dc_size(B_N_CHILD(f, order))); } -/* Get free space of the right neighbor, +/* + * 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) @@ -916,7 +979,10 @@ static int is_left_neighbor_in_cache(struct tree_balance *tb, int h) "vs-8165: F[h] (%b) or FL[h] (%b) is invalid", father, tb->FL[h]); - /* Get position of the pointer to the left neighbor into the left father. */ + /* + * Get position of the pointer to the left neighbor + * into the left father. + */ left_neighbor_position = (father == tb->FL[h]) ? tb->lkey[h] : B_NR_ITEMS(tb->FL[h]); /* Get left neighbor block number. */ @@ -940,17 +1006,20 @@ static int is_left_neighbor_in_cache(struct tree_balance *tb, int h) static void decrement_key(struct cpu_key *key) { - // call item specific function for this key + /* call item specific function for this key */ item_ops[cpu_key_k_type(key)]->decrement_key(key); } -/* Calculate far left/right parent of the left/right neighbor of the current node, that - * is calculate the left/right (FL[h]/FR[h]) neighbor of the parent F[h]. +/* + * Calculate 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; + * Returns: PATH_INCORRECT - path in the tree is not correct + * SCHEDULE_OCCURRED - schedule occurred while the function worked + * CARRY_ON - schedule didn't occur while the function + * worked */ static int get_far_parent(struct tree_balance *tb, int h, @@ -966,8 +1035,10 @@ static int get_far_parent(struct tree_balance *tb, first_last_position = 0, path_offset = PATH_H_PATH_OFFSET(path, h); - /* Starting from F[h] go upwards in the tree, and look for the common - ancestor of F[h], and its neighbor l/r, that should be obtained. */ + /* + * Starting from F[h] go upwards in the tree, and look for the common + * ancestor of F[h], and its neighbor l/r, that should be obtained. + */ counter = path_offset; @@ -975,21 +1046,33 @@ static int get_far_parent(struct tree_balance *tb, "PAP-8180: invalid path length"); for (; counter > FIRST_PATH_ELEMENT_OFFSET; counter--) { - /* Check whether parent of the current buffer in the path is really parent in the tree. */ + /* + * Check whether parent of the current buffer in the path + * is really parent in the tree. + */ if (!B_IS_IN_TREE (parent = PATH_OFFSET_PBUFFER(path, counter - 1))) return REPEAT_SEARCH; + /* Check whether position in the parent is correct. */ if ((position = PATH_OFFSET_POSITION(path, counter - 1)) > B_NR_ITEMS(parent)) return REPEAT_SEARCH; - /* Check whether parent at the path really points to the child. */ + + /* + * Check whether parent at the path really points + * to the child. + */ if (B_N_CHILD_NUM(parent, position) != PATH_OFFSET_PBUFFER(path, counter)->b_blocknr) return REPEAT_SEARCH; - /* Return delimiting key if position in the parent is not equal to first/last one. */ + + /* + * Return delimiting key if position in the parent is not + * equal to first/last one. + */ if (c_lr_par == RIGHT_PARENTS) first_last_position = B_NR_ITEMS(parent); if (position != first_last_position) { @@ -1002,7 +1085,10 @@ static int get_far_parent(struct tree_balance *tb, /* if we are in the root of the tree, then there is no common father */ if (counter == FIRST_PATH_ELEMENT_OFFSET) { - /* Check whether first buffer in the path is the root of the tree. */ + /* + * Check whether first buffer in the path is the + * root of the tree. + */ if (PATH_OFFSET_PBUFFER (tb->tb_path, FIRST_PATH_ELEMENT_OFFSET)->b_blocknr == @@ -1031,8 +1117,11 @@ static int get_far_parent(struct tree_balance *tb, } } - /* 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. */ + /* + * So, we got common parent of the current node and its + * left/right neighbor. Now we are getting the parent of the + * left/right neighbor. + */ /* Form key to get parent of the left/right neighbor. */ le_key2cpu_key(&s_lr_father_key, @@ -1050,7 +1139,7 @@ static int get_far_parent(struct tree_balance *tb, if (search_by_key (tb->tb_sb, &s_lr_father_key, &s_path_to_neighbor_father, h + 1) == IO_ERROR) - // path is released + /* path is released */ return IO_ERROR; if (FILESYSTEM_CHANGED_TB(tb)) { @@ -1071,12 +1160,15 @@ static int get_far_parent(struct tree_balance *tb, return CARRY_ON; } -/* Get parents of neighbors of node in the path(S[path_offset]) and common parents of - * S[path_offset] and L[path_offset]/R[path_offset]: F[path_offset], FL[path_offset], - * FR[path_offset], CFL[path_offset], CFR[path_offset]. - * Calculate numbers of left and right delimiting keys position: lkey[path_offset], rkey[path_offset]. - * Returns: SCHEDULE_OCCURRED - schedule occurred while the function worked; - * CARRY_ON - schedule didn't occur while the function worked; +/* + * Get parents of neighbors of node in the path(S[path_offset]) and + * common parents of S[path_offset] and L[path_offset]/R[path_offset]: + * F[path_offset], FL[path_offset], FR[path_offset], CFL[path_offset], + * CFR[path_offset]. + * Calculate numbers of left and right delimiting keys position: + * lkey[path_offset], rkey[path_offset]. + * Returns: SCHEDULE_OCCURRED - schedule occurred while the function worked + * CARRY_ON - schedule didn't occur while the function worked */ static int get_parents(struct tree_balance *tb, int h) { @@ -1088,8 +1180,11 @@ static int get_parents(struct tree_balance *tb, int h) /* Current node is the root of the tree or will be root of the tree */ if (path_offset <= FIRST_PATH_ELEMENT_OFFSET) { - /* The root can not have parents. - Release nodes which previously were obtained as parents of the current node neighbors. */ + /* + * The root can not have parents. + * Release nodes which previously were obtained as + * parents of the current node neighbors. + */ brelse(tb->FL[h]); brelse(tb->CFL[h]); brelse(tb->FR[h]); @@ -1111,10 +1206,14 @@ static int get_parents(struct tree_balance *tb, int h) get_bh(curf); tb->lkey[h] = position - 1; } else { - /* Calculate current parent of L[path_offset], which is the left neighbor of the current node. - Calculate current common parent of L[path_offset] and the current node. Note that - CFL[path_offset] not equal FL[path_offset] and CFL[path_offset] not equal F[path_offset]. - Calculate lkey[path_offset]. */ + /* + * Calculate current parent of L[path_offset], which is the + * left neighbor of the current node. Calculate current + * common parent of L[path_offset] and the current node. + * Note that CFL[path_offset] not equal FL[path_offset] and + * CFL[path_offset] not equal F[path_offset]. + * Calculate lkey[path_offset]. + */ if ((ret = get_far_parent(tb, h + 1, &curf, &curcf, LEFT_PARENTS)) != CARRY_ON) @@ -1130,19 +1229,22 @@ static int get_parents(struct tree_balance *tb, int h) (curcf && !B_IS_IN_TREE(curcf)), "PAP-8195: FL (%b) or CFL (%b) is invalid", curf, curcf); -/* Get parent FR[h] of R[h]. */ + /* Get parent FR[h] of R[h]. */ -/* Current node is the last child of F[h]. FR[h] != F[h]. */ + /* Current node is the last child of F[h]. FR[h] != F[h]. */ if (position == B_NR_ITEMS(PATH_H_PBUFFER(path, h + 1))) { -/* Calculate current parent of R[h], which is the right neighbor of F[h]. - Calculate current common parent of R[h] and current node. Note that CFR[h] - not equal FR[path_offset] and CFR[h] not equal F[h]. */ + /* + * Calculate current parent of R[h], which is the right + * neighbor of F[h]. Calculate current common parent of + * R[h] and current node. Note that CFR[h] not equal + * FR[path_offset] and CFR[h] not equal F[h]. + */ if ((ret = get_far_parent(tb, h + 1, &curf, &curcf, RIGHT_PARENTS)) != CARRY_ON) return ret; } else { -/* Current node is not the last child of its parent F[h]. */ + /* Current node is not the last child of its parent F[h]. */ curf = PATH_OFFSET_PBUFFER(path, path_offset - 1); curcf = PATH_OFFSET_PBUFFER(path, path_offset - 1); get_bh(curf); @@ -1165,8 +1267,10 @@ static int get_parents(struct tree_balance *tb, int h) return CARRY_ON; } -/* it is possible to remove node as result of shiftings to - neighbors even when we insert or paste item. */ +/* + * 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) { @@ -1189,7 +1293,8 @@ static inline int can_node_be_removed(int mode, int lfree, int sfree, int rfree, && 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 (sfree >= levbytes) { + /* new item fits into node S[h] without any shifting */ if (!h) tb->s0num = B_NR_ITEMS(Sh) + @@ -1202,7 +1307,8 @@ static inline int can_node_be_removed(int mode, int lfree, int sfree, int rfree, return !NO_BALANCING_NEEDED; } -/* Check whether current node S[h] is balanced when increasing its size by +/* + * 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: @@ -1219,39 +1325,48 @@ static inline int can_node_be_removed(int mode, int lfree, int sfree, int rfree, 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. */ - ret; + /* + * Number of bytes that must be inserted into (value is negative + * if bytes are deleted) buffer which contains node being balanced. + * The mnemonic is that the attempted change in node space used + * level is levbytes bytes. + */ + int levbytes; + int ret; int lfree, sfree, rfree /* free space in L, S and R */ ; - /* nver is short for number of vertixes, and lnver is the number if - we shift to the left, rnver is the number if we shift to the - right, and lrnver is the number if we shift in both directions. - The goal is to minimize first the number of vertixes, and second, - the number of vertixes whose contents are changed by shifting, - and third the number of uncached vertixes whose contents are - changed by shifting and must be read from disk. */ + /* + * 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. */ + /* + * 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 + /* + * we perform 8 calls to get_num_ver(). For each call we + * calculate five parameters. where 4th parameter is s1bytes + * and 5th - s2bytes + * + * s0num, s1num, s2num for 8 cases + * 0,1 - do not shift and do not shift but bottle + * 2 - shift only whole item to left + * 3 - shift to left and bottle as much as possible + * 4,5 - shift to right (whole items and as much as possible + * 6,7 - shift to both directions (whole items and as much as possible) */ - short snum012[40] = { 0, }; /* s0num, s1num, s2num for 8 cases - 0,1 - do not shift and do not shift but bottle - 2 - shift only whole item to left - 3 - shift to left and bottle as much as possible - 4,5 - shift to right (whole items and as much as possible - 6,7 - shift to both directions (whole items and as much as possible) - */ + short snum012[40] = { 0, }; /* Sh is the node whose balance is currently being checked */ struct buffer_head *Sh; @@ -1265,9 +1380,10 @@ static int ip_check_balance(struct tree_balance *tb, int h) reiserfs_panic(tb->tb_sb, "vs-8210", "S[0] can not be 0"); switch (ret = get_empty_nodes(tb, h)) { + /* no balancing for higher levels needed */ case CARRY_ON: set_parameters(tb, h, 0, 0, 1, NULL, -1, -1); - return NO_BALANCING_NEEDED; /* no balancing for higher levels needed */ + return NO_BALANCING_NEEDED; case NO_DISK_SPACE: case REPEAT_SEARCH: @@ -1278,7 +1394,9 @@ static int ip_check_balance(struct tree_balance *tb, int h) } } - if ((ret = get_parents(tb, h)) != CARRY_ON) /* get parents of S[h] neighbors. */ + /* get parents of S[h] neighbors. */ + ret = get_parents(tb, h); + if (ret != CARRY_ON) return ret; sfree = B_FREE_SPACE(Sh); @@ -1287,38 +1405,44 @@ static int ip_check_balance(struct tree_balance *tb, int h) rfree = get_rfree(tb, h); lfree = get_lfree(tb, h); + /* and new item fits into node S[h] without any shifting */ if (can_node_be_removed(vn->vn_mode, lfree, sfree, rfree, tb, h) == NO_BALANCING_NEEDED) - /* 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) + * 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) + * 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 */ + /* + * 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. */ + /* + * 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 - @@ -1328,7 +1452,10 @@ static int ip_check_balance(struct tree_balance *tb, int h) return CARRY_ON; } - /* this checks balance condition, that any two neighboring nodes can not fit in one node */ + /* + * 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), @@ -1337,16 +1464,22 @@ static int ip_check_balance(struct tree_balance *tb, int h) (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. */ + /* + * 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 */ + /* + * why do we perform this check here rather than earlier?? + * Answer: we can win 1 node in some cases above. Moreover we + * checked it above, when we checked, that S[0] is not removable + * in principle + */ + + /* new item fits into node S[h] without any shifting */ + if (sfree >= levbytes) { if (!h) tb->s0num = vn->vn_nr_item; set_parameters(tb, h, 0, 0, 1, NULL, -1, -1); @@ -1355,18 +1488,19 @@ static int ip_check_balance(struct tree_balance *tb, int h) { int lpar, rpar, nset, lset, rset, lrset; - /* - * regular overflowing of the node - */ + /* 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 + /* + * 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 */ + /* we choose one of the following */ #define NOTHING_SHIFT_NO_FLOW 0 #define NOTHING_SHIFT_FLOW 5 #define LEFT_SHIFT_NO_FLOW 10 @@ -1379,10 +1513,13 @@ static int ip_check_balance(struct tree_balance *tb, int h) 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 */ + /* + * 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, @@ -1391,7 +1528,10 @@ static int ip_check_balance(struct tree_balance *tb, int h) if (!h) { int nver1; - /* note, that in this case we try to bottle between S[0] and S1 (S1 - the first new node) */ + /* + * 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); @@ -1399,11 +1539,13 @@ static int ip_check_balance(struct tree_balance *tb, int h) 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 + /* + * 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, @@ -1422,11 +1564,13 @@ static int ip_check_balance(struct tree_balance *tb, int h) 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 + /* + * 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, @@ -1451,10 +1595,12 @@ static int ip_check_balance(struct tree_balance *tb, int h) 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 + /* + * 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, @@ -1481,10 +1627,12 @@ static int ip_check_balance(struct tree_balance *tb, int h) 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; */ + /* + * 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) { @@ -1508,42 +1656,59 @@ static int ip_check_balance(struct tree_balance *tb, int h) return CARRY_ON; } - /* if shifting doesn't lead to better packing then don't shift */ + /* + * 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 */ + /* + * 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 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 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 */ + /* + * 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 */ + /* + * 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 +/* + * 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: @@ -1563,8 +1728,10 @@ 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. */ + /* + * Sh is the node whose balance is currently being checked, + * and Fh is its father. + */ struct buffer_head *Sh, *Fh; int maxsize, ret; int lfree, rfree /* free space in L and R */ ; @@ -1574,19 +1741,25 @@ static int dc_check_balance_internal(struct tree_balance *tb, int 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); */ + /* + * using tb->insert_size[h], which is negative in this case, + * create_virtual_node calculates: + * new_nr_item = number of items node would have if operation is + * performed without balancing (new_nr_item); + */ create_virtual_node(tb, h); if (!Fh) { /* S[h] is the root. */ + /* no balancing for higher levels needed */ if (vn->vn_nr_item > 0) { set_parameters(tb, h, 0, 0, 1, NULL, -1, -1); - return NO_BALANCING_NEEDED; /* no balancing for higher levels needed */ + return NO_BALANCING_NEEDED; } - /* new_nr_item == 0. + /* + * new_nr_item == 0. * Current root will be deleted resulting in - * decrementing the tree height. */ + * decrementing the tree height. + */ set_parameters(tb, h, 0, 0, 0, NULL, -1, -1); return CARRY_ON; } @@ -1602,12 +1775,18 @@ static int dc_check_balance_internal(struct tree_balance *tb, int h) 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. */ + /* + * Balance condition for the internal node is valid. + * In this case we balance only if it leads to better packing. + */ + if (vn->vn_nr_item >= MIN_NR_KEY(Sh)) { + /* + * Here we join S[h] with one of its neighbors, + * which is impossible with greater values of new_nr_item. + */ + if (vn->vn_nr_item == MIN_NR_KEY(Sh)) { + /* All contents of S[h] can be moved to L[h]. */ if (tb->lnum[h] >= vn->vn_nr_item + 1) { - /* All contents of S[h] can be moved to L[h]. */ int n; int order_L; @@ -1623,8 +1802,8 @@ static int dc_check_balance_internal(struct tree_balance *tb, int h) return CARRY_ON; } + /* All contents of S[h] can be moved to R[h]. */ 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; @@ -1641,8 +1820,11 @@ static int dc_check_balance_internal(struct tree_balance *tb, int h) } } + /* + * 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) { - /* All contents of S[h] can be moved to the neighbors (L[h] & R[h]). */ int to_r; to_r = @@ -1659,7 +1841,10 @@ static int dc_check_balance_internal(struct tree_balance *tb, int h) return NO_BALANCING_NEEDED; } - /* Current node contain insufficient number of items. Balancing is required. */ + /* + * 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) @@ -1726,7 +1911,8 @@ static int dc_check_balance_internal(struct tree_balance *tb, int h) return CARRY_ON; } -/* Check whether current node S[h] is balanced when Decreasing its size by +/* + * 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: @@ -1743,15 +1929,21 @@ 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. */ + /* + * Number of bytes that must be deleted from + * (value is negative if bytes are deleted) buffer which + * contains node being balanced. The mnemonic is that the + * attempted change in node space used level is levbytes bytes. + */ int levbytes; + /* the maximal item size */ int maxsize, ret; - /* S0 is the node whose balance is currently being checked, - and F0 is its father. */ + + /* + * 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 */ ; @@ -1784,9 +1976,11 @@ static int dc_check_balance_leaf(struct tree_balance *tb, int h) 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 + /* + * 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); @@ -1810,7 +2004,10 @@ static int dc_check_balance_leaf(struct tree_balance *tb, int h) return CARRY_ON; } - /* All contents of S[0] can be moved to the neighbors (L[0] & R[0]). Set parameters and return */ + /* + * 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; @@ -1820,7 +2017,8 @@ static int dc_check_balance_leaf(struct tree_balance *tb, int h) return NO_BALANCING_NEEDED; } -/* Check whether current node S[h] is balanced when Decreasing its size by +/* + * 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: @@ -1844,15 +2042,16 @@ static int dc_check_balance(struct tree_balance *tb, int h) return dc_check_balance_leaf(tb, h); } -/* Check whether current node S[h] is balanced. +/* + * 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 + * 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]; @@ -1882,8 +2081,8 @@ static int check_balance(int mode, RFALSE(mode == M_INSERT && !vn->vn_ins_ih, "vs-8255: ins_ih can not be 0 in insert mode"); + /* Calculate balance parameters when size of node is increasing. */ if (tb->insert_size[h] > 0) - /* Calculate balance parameters when size of node is increasing. */ return ip_check_balance(tb, h); /* Calculate balance parameters when size of node is decreasing. */ @@ -1911,21 +2110,23 @@ static int get_direct_parent(struct tree_balance *tb, int h) PATH_OFFSET_POSITION(path, path_offset - 1) = 0; return CARRY_ON; } - return REPEAT_SEARCH; /* Root is changed and we must recalculate the path. */ + /* Root is changed and we must recalculate the path. */ + return REPEAT_SEARCH; } + /* Parent in the path is not in the tree. */ if (!B_IS_IN_TREE (bh = PATH_OFFSET_PBUFFER(path, path_offset - 1))) - return REPEAT_SEARCH; /* Parent in the path is not in the tree. */ + return REPEAT_SEARCH; if ((position = PATH_OFFSET_POSITION(path, path_offset - 1)) > B_NR_ITEMS(bh)) return REPEAT_SEARCH; + /* Parent in the path is not parent of the current node in the tree. */ if (B_N_CHILD_NUM(bh, position) != PATH_OFFSET_PBUFFER(path, path_offset)->b_blocknr) - /* Parent in the path is not parent of the current node in the tree. */ return REPEAT_SEARCH; if (buffer_locked(bh)) { @@ -1936,10 +2137,15 @@ static int get_direct_parent(struct tree_balance *tb, int h) return REPEAT_SEARCH; } - return CARRY_ON; /* Parent in the path is unlocked and really parent of the current node. */ + /* + * Parent in the path is unlocked and really parent + * of the current node. + */ + return CARRY_ON; } -/* Using lnum[h] and rnum[h] we should determine what neighbors +/* + * Using lnum[h] and rnum[h] we should determine what neighbors * of S[h] we * need in order to balance S[h], and get them if necessary. * Returns: SCHEDULE_OCCURRED - schedule occurred while the function worked; @@ -1997,7 +2203,7 @@ static int get_neighbors(struct tree_balance *tb, int h) } /* We need right neighbor to balance S[path_offset]. */ - if (tb->rnum[h]) { /* We need right neighbor to balance S[path_offset]. */ + if (tb->rnum[h]) { PROC_INFO_INC(sb, need_r_neighbor[h]); bh = PATH_OFFSET_PBUFFER(tb->tb_path, path_offset); @@ -2053,9 +2259,11 @@ static int get_virtual_node_size(struct super_block *sb, struct buffer_head *bh) (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 */ +/* + * 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; @@ -2064,8 +2272,8 @@ static int get_mem_for_virtual_node(struct tree_balance *tb) size = get_virtual_node_size(tb->tb_sb, PATH_PLAST_BUFFER(tb->tb_path)); + /* we have to allocate more memory for virtual node */ if (size > tb->vn_buf_size) { - /* we have to allocate more memory for virtual node */ if (tb->vn_buf) { /* free memory allocated before */ kfree(tb->vn_buf); @@ -2079,10 +2287,12 @@ static int get_mem_for_virtual_node(struct tree_balance *tb) /* get memory for virtual item */ buf = kmalloc(size, GFP_ATOMIC | __GFP_NOWARN); if (!buf) { - /* getting memory with GFP_KERNEL priority may involve - balancing now (due to indirect_to_direct conversion on - dcache shrinking). So, release path and collected - resources here */ + /* + * getting memory with GFP_KERNEL priority may involve + * balancing now (due to indirect_to_direct conversion + * on dcache shrinking). So, release path and collected + * resources here + */ free_buffers_in_tb(tb); buf = kmalloc(size, GFP_NOFS); if (!buf) { @@ -2168,8 +2378,10 @@ static int wait_tb_buffers_until_unlocked(struct tree_balance *tb) for (i = tb->tb_path->path_length; !locked && i > ILLEGAL_PATH_ELEMENT_OFFSET; i--) { if (PATH_OFFSET_PBUFFER(tb->tb_path, i)) { - /* if I understand correctly, we can only be sure the last buffer - ** in the path is in the tree --clm + /* + * if I understand correctly, we can only + * be sure the last buffer in the path is + * in the tree --clm */ #ifdef CONFIG_REISERFS_CHECK if (PATH_PLAST_BUFFER(tb->tb_path) == @@ -2256,13 +2468,15 @@ static int wait_tb_buffers_until_unlocked(struct tree_balance *tb) } } } - /* 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 + + /* + * as far as I can tell, this is not required. The FEB list + * seems to be full of newly allocated nodes, which will + * never be locked, dirty, or anything else. + * To be safe, I'm putting in the checks and waits in. + * For the moment, they are needed to keep the code in + * journal.c from complaining about the buffer. + * That code is inside CONFIG_REISERFS_CHECK as well. --clm */ for (i = 0; !locked && i < MAX_FEB_SIZE; i++) { if (tb->FEB[i]) { @@ -2300,7 +2514,8 @@ static int wait_tb_buffers_until_unlocked(struct tree_balance *tb) return CARRY_ON; } -/* Prepare for balancing, that is +/* + * Prepare for balancing, that is * get all necessary parents, and neighbors; * analyze what and where should be moved; * get sufficient number of new nodes; @@ -2309,13 +2524,14 @@ static int wait_tb_buffers_until_unlocked(struct tree_balance *tb) * 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 + * 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 + * 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) @@ -2335,8 +2551,9 @@ int fix_nodes(int op_mode, struct tree_balance *tb, int ret, h, item_num = PATH_LAST_POSITION(tb->tb_path); int pos_in_item; - /* we set wait_tb_buffers_run when we have to restore any dirty bits cleared - ** during wait_tb_buffers_run + /* + * we set wait_tb_buffers_run when we have to restore any dirty + * bits cleared during wait_tb_buffers_run */ int wait_tb_buffers_run = 0; struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path); @@ -2347,10 +2564,11 @@ int fix_nodes(int op_mode, struct tree_balance *tb, tb->fs_gen = get_generation(tb->tb_sb); - /* we prepare and log the super here so it will already be in the - ** transaction when do_balance needs to change it. - ** This way do_balance won't have to schedule when trying to prepare - ** the super for logging + /* + * we prepare and log the super here so it will already be in the + * transaction when do_balance needs to change it. + * This way do_balance won't have to schedule when trying to prepare + * the super for logging */ reiserfs_prepare_for_journal(tb->tb_sb, SB_BUFFER_WITH_SB(tb->tb_sb), 1); @@ -2408,7 +2626,7 @@ int fix_nodes(int op_mode, struct tree_balance *tb, #endif if (get_mem_for_virtual_node(tb) == REPEAT_SEARCH) - // FIXME: maybe -ENOMEM when tb->vn_buf == 0? Now just repeat + /* FIXME: maybe -ENOMEM when tb->vn_buf == 0? Now just repeat */ return REPEAT_SEARCH; /* Starting from the leaf level; for all levels h of the tree. */ @@ -2427,7 +2645,10 @@ int fix_nodes(int op_mode, struct tree_balance *tb, goto repeat; if (h != MAX_HEIGHT - 1) tb->insert_size[h + 1] = 0; - /* ok, analysis and resource gathering are complete */ + /* + * ok, analysis and resource gathering + * are complete + */ break; } goto repeat; @@ -2437,15 +2658,19 @@ int fix_nodes(int op_mode, struct tree_balance *tb, if (ret != CARRY_ON) goto repeat; - /* No disk space, or schedule occurred and analysis may be - * invalid and needs to be redone. */ + /* + * No disk space, or schedule occurred and analysis may be + * invalid and needs to be redone. + */ ret = get_empty_nodes(tb, h); if (ret != CARRY_ON) goto repeat; + /* + * We have a positive insert size but no nodes exist on this + * level, this means that we are creating a new root. + */ if (!PATH_H_PBUFFER(tb->tb_path, h)) { - /* We have a positive insert size but no nodes exist on this - level, this means that we are creating a new root. */ RFALSE(tb->blknum[h] != 1, "PAP-8350: creating new empty root"); @@ -2453,11 +2678,13 @@ int fix_nodes(int op_mode, struct tree_balance *tb, if (h < MAX_HEIGHT - 1) tb->insert_size[h + 1] = 0; } else if (!PATH_H_PBUFFER(tb->tb_path, h + 1)) { + /* + * The tree needs to be grown, so this node S[h] + * which is the root node is split into two nodes, + * and a new node (S[h+1]) will be created to + * become the root node. + */ if (tb->blknum[h] > 1) { - /* The tree needs to be grown, so this node S[h] - which is the root node is split into two nodes, - and a new node (S[h+1]) will be created to - become the root node. */ RFALSE(h == MAX_HEIGHT - 1, "PAP-8355: attempt to create too high of a tree"); @@ -2488,11 +2715,13 @@ int fix_nodes(int op_mode, struct tree_balance *tb, } 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 + /* + * 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; @@ -2548,8 +2777,6 @@ int fix_nodes(int op_mode, struct tree_balance *tb, } -/* Anatoly will probably forgive me renaming tb to tb. I just - wanted to make lines shorter */ void unfix_nodes(struct tree_balance *tb) { int i; @@ -2578,8 +2805,10 @@ void unfix_nodes(struct tree_balance *tb) 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 */ + /* + * 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); |