diff options
Diffstat (limited to 'fs/reiserfs/stree.c')
| -rw-r--r-- | fs/reiserfs/stree.c | 2280 |
1 files changed, 0 insertions, 2280 deletions
diff --git a/fs/reiserfs/stree.c b/fs/reiserfs/stree.c deleted file mode 100644 index 5faf702f8d15..000000000000 --- a/fs/reiserfs/stree.c +++ /dev/null @@ -1,2280 +0,0 @@ -/* - * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README - */ - -/* - * Written by Anatoly P. Pinchuk pap@namesys.botik.ru - * Programm System Institute - * Pereslavl-Zalessky Russia - */ - -#include <linux/time.h> -#include <linux/string.h> -#include <linux/pagemap.h> -#include <linux/bio.h> -#include "reiserfs.h" -#include <linux/buffer_head.h> -#include <linux/quotaops.h> - -/* Does the buffer contain a disk block which is in the tree. */ -inline int B_IS_IN_TREE(const struct buffer_head *bh) -{ - - RFALSE(B_LEVEL(bh) > MAX_HEIGHT, - "PAP-1010: block (%b) has too big level (%z)", bh, bh); - - return (B_LEVEL(bh) != FREE_LEVEL); -} - -/* to get item head in le form */ -inline void copy_item_head(struct item_head *to, - const struct item_head *from) -{ - memcpy(to, from, IH_SIZE); -} - -/* - * k1 is pointer to on-disk structure which is stored in little-endian - * form. k2 is pointer to cpu variable. For key of items of the same - * object this returns 0. - * Returns: -1 if key1 < key2 - * 0 if key1 == key2 - * 1 if key1 > key2 - */ -inline int comp_short_keys(const struct reiserfs_key *le_key, - const struct cpu_key *cpu_key) -{ - __u32 n; - n = le32_to_cpu(le_key->k_dir_id); - if (n < cpu_key->on_disk_key.k_dir_id) - return -1; - if (n > cpu_key->on_disk_key.k_dir_id) - return 1; - n = le32_to_cpu(le_key->k_objectid); - if (n < cpu_key->on_disk_key.k_objectid) - return -1; - if (n > cpu_key->on_disk_key.k_objectid) - return 1; - return 0; -} - -/* - * k1 is pointer to on-disk structure which is stored in little-endian - * form. k2 is pointer to cpu variable. - * Compare keys using all 4 key fields. - * Returns: -1 if key1 < key2 0 - * if key1 = key2 1 if key1 > key2 - */ -static inline int comp_keys(const struct reiserfs_key *le_key, - const struct cpu_key *cpu_key) -{ - int retval; - - retval = comp_short_keys(le_key, cpu_key); - if (retval) - return retval; - if (le_key_k_offset(le_key_version(le_key), le_key) < - cpu_key_k_offset(cpu_key)) - return -1; - if (le_key_k_offset(le_key_version(le_key), le_key) > - cpu_key_k_offset(cpu_key)) - return 1; - - if (cpu_key->key_length == 3) - return 0; - - /* this part is needed only when tail conversion is in progress */ - if (le_key_k_type(le_key_version(le_key), le_key) < - cpu_key_k_type(cpu_key)) - return -1; - - if (le_key_k_type(le_key_version(le_key), le_key) > - cpu_key_k_type(cpu_key)) - return 1; - - return 0; -} - -inline int comp_short_le_keys(const struct reiserfs_key *key1, - const struct reiserfs_key *key2) -{ - __u32 *k1_u32, *k2_u32; - int key_length = REISERFS_SHORT_KEY_LEN; - - k1_u32 = (__u32 *) key1; - k2_u32 = (__u32 *) key2; - for (; key_length--; ++k1_u32, ++k2_u32) { - if (le32_to_cpu(*k1_u32) < le32_to_cpu(*k2_u32)) - return -1; - if (le32_to_cpu(*k1_u32) > le32_to_cpu(*k2_u32)) - return 1; - } - return 0; -} - -inline void le_key2cpu_key(struct cpu_key *to, const struct reiserfs_key *from) -{ - int version; - to->on_disk_key.k_dir_id = le32_to_cpu(from->k_dir_id); - to->on_disk_key.k_objectid = le32_to_cpu(from->k_objectid); - - /* find out version of the key */ - version = le_key_version(from); - to->version = version; - to->on_disk_key.k_offset = le_key_k_offset(version, from); - to->on_disk_key.k_type = le_key_k_type(version, from); -} - -/* - * this does not say which one is bigger, it only returns 1 if keys - * are not equal, 0 otherwise - */ -inline int comp_le_keys(const struct reiserfs_key *k1, - const struct reiserfs_key *k2) -{ - return memcmp(k1, k2, sizeof(struct reiserfs_key)); -} - -/************************************************************************** - * Binary search toolkit function * - * Search for an item in the array by the item key * - * Returns: 1 if found, 0 if not found; * - * *pos = number of the searched element if found, else the * - * number of the first element that is larger than key. * - **************************************************************************/ -/* - * For those not familiar with binary search: lbound is the leftmost item - * that it could be, rbound the rightmost item that it could be. We examine - * the item halfway between lbound and rbound, and that tells us either - * that we can increase lbound, or decrease rbound, or that we have found it, - * or if lbound <= rbound that there are no possible items, and we have not - * found it. With each examination we cut the number of possible items it - * could be by one more than half rounded down, or we find it. - */ -static inline int bin_search(const void *key, /* Key to search for. */ - const void *base, /* First item in the array. */ - int num, /* Number of items in the array. */ - /* - * Item size in the array. searched. Lest the - * reader be confused, note that this is crafted - * as a general function, and when it is applied - * specifically to the array of item headers in a - * node, width is actually the item header size - * not the item size. - */ - int width, - int *pos /* Number of the searched for element. */ - ) -{ - int rbound, lbound, j; - - for (j = ((rbound = num - 1) + (lbound = 0)) / 2; - lbound <= rbound; j = (rbound + lbound) / 2) - switch (comp_keys - ((struct reiserfs_key *)((char *)base + j * width), - (struct cpu_key *)key)) { - case -1: - lbound = j + 1; - continue; - case 1: - rbound = j - 1; - continue; - case 0: - *pos = j; - return ITEM_FOUND; /* Key found in the array. */ - } - - /* - * bin_search did not find given key, it returns position of key, - * that is minimal and greater than the given one. - */ - *pos = lbound; - return ITEM_NOT_FOUND; -} - - -/* Minimal possible key. It is never in the tree. */ -const struct reiserfs_key MIN_KEY = { 0, 0, {{0, 0},} }; - -/* Maximal possible key. It is never in the tree. */ -static const struct reiserfs_key MAX_KEY = { - cpu_to_le32(0xffffffff), - cpu_to_le32(0xffffffff), - {{cpu_to_le32(0xffffffff), - cpu_to_le32(0xffffffff)},} -}; - -/* - * Get delimiting key of the buffer by looking for it in the buffers in the - * path, starting from the bottom of the path, and going upwards. We must - * check the path's validity at each step. If the key is not in the path, - * there is no delimiting key in the tree (buffer is first or last buffer - * in tree), and in this case we return a special key, either MIN_KEY or - * MAX_KEY. - */ -static inline const struct reiserfs_key *get_lkey(const struct treepath *chk_path, - const struct super_block *sb) -{ - int position, path_offset = chk_path->path_length; - struct buffer_head *parent; - - RFALSE(path_offset < FIRST_PATH_ELEMENT_OFFSET, - "PAP-5010: invalid offset in the path"); - - /* While not higher in path than first element. */ - while (path_offset-- > FIRST_PATH_ELEMENT_OFFSET) { - - RFALSE(!buffer_uptodate - (PATH_OFFSET_PBUFFER(chk_path, path_offset)), - "PAP-5020: parent is not uptodate"); - - /* Parent at the path is not in the tree now. */ - if (!B_IS_IN_TREE - (parent = - PATH_OFFSET_PBUFFER(chk_path, path_offset))) - return &MAX_KEY; - /* Check whether position in the parent is correct. */ - if ((position = - PATH_OFFSET_POSITION(chk_path, - path_offset)) > - B_NR_ITEMS(parent)) - return &MAX_KEY; - /* Check whether parent at the path really points to the child. */ - if (B_N_CHILD_NUM(parent, position) != - PATH_OFFSET_PBUFFER(chk_path, - path_offset + 1)->b_blocknr) - return &MAX_KEY; - /* - * Return delimiting key if position in the parent - * is not equal to zero. - */ - if (position) - return internal_key(parent, position - 1); - } - /* Return MIN_KEY if we are in the root of the buffer tree. */ - if (PATH_OFFSET_PBUFFER(chk_path, FIRST_PATH_ELEMENT_OFFSET)-> - b_blocknr == SB_ROOT_BLOCK(sb)) - return &MIN_KEY; - return &MAX_KEY; -} - -/* Get delimiting key of the buffer at the path and its right neighbor. */ -inline const struct reiserfs_key *get_rkey(const struct treepath *chk_path, - const struct super_block *sb) -{ - int position, path_offset = chk_path->path_length; - struct buffer_head *parent; - - RFALSE(path_offset < FIRST_PATH_ELEMENT_OFFSET, - "PAP-5030: invalid offset in the path"); - - while (path_offset-- > FIRST_PATH_ELEMENT_OFFSET) { - - RFALSE(!buffer_uptodate - (PATH_OFFSET_PBUFFER(chk_path, path_offset)), - "PAP-5040: parent is not uptodate"); - - /* Parent at the path is not in the tree now. */ - if (!B_IS_IN_TREE - (parent = - PATH_OFFSET_PBUFFER(chk_path, path_offset))) - return &MIN_KEY; - /* Check whether position in the parent is correct. */ - if ((position = - PATH_OFFSET_POSITION(chk_path, - path_offset)) > - B_NR_ITEMS(parent)) - return &MIN_KEY; - /* - * Check whether parent at the path really points - * to the child. - */ - if (B_N_CHILD_NUM(parent, position) != - PATH_OFFSET_PBUFFER(chk_path, - path_offset + 1)->b_blocknr) - return &MIN_KEY; - - /* - * Return delimiting key if position in the parent - * is not the last one. - */ - if (position != B_NR_ITEMS(parent)) - return internal_key(parent, position); - } - - /* Return MAX_KEY if we are in the root of the buffer tree. */ - if (PATH_OFFSET_PBUFFER(chk_path, FIRST_PATH_ELEMENT_OFFSET)-> - b_blocknr == SB_ROOT_BLOCK(sb)) - return &MAX_KEY; - return &MIN_KEY; -} - -/* - * Check whether a key is contained in the tree rooted from a buffer at a path. - * This works by looking at the left and right delimiting keys for the buffer - * in the last path_element in the path. These delimiting keys are stored - * at least one level above that buffer in the tree. If the buffer is the - * first or last node in the tree order then one of the delimiting keys may - * be absent, and in this case get_lkey and get_rkey return a special key - * which is MIN_KEY or MAX_KEY. - */ -static inline int key_in_buffer( - /* Path which should be checked. */ - struct treepath *chk_path, - /* Key which should be checked. */ - const struct cpu_key *key, - struct super_block *sb - ) -{ - - RFALSE(!key || chk_path->path_length < FIRST_PATH_ELEMENT_OFFSET - || chk_path->path_length > MAX_HEIGHT, - "PAP-5050: pointer to the key(%p) is NULL or invalid path length(%d)", - key, chk_path->path_length); - RFALSE(!PATH_PLAST_BUFFER(chk_path)->b_bdev, - "PAP-5060: device must not be NODEV"); - - if (comp_keys(get_lkey(chk_path, sb), key) == 1) - /* left delimiting key is bigger, that the key we look for */ - return 0; - /* if ( comp_keys(key, get_rkey(chk_path, sb)) != -1 ) */ - if (comp_keys(get_rkey(chk_path, sb), key) != 1) - /* key must be less than right delimitiing key */ - return 0; - return 1; -} - -int reiserfs_check_path(struct treepath *p) -{ - RFALSE(p->path_length != ILLEGAL_PATH_ELEMENT_OFFSET, - "path not properly relsed"); - return 0; -} - -/* - * Drop the reference to each buffer in a path and restore - * dirty bits clean when preparing the buffer for the log. - * This version should only be called from fix_nodes() - */ -void pathrelse_and_restore(struct super_block *sb, - struct treepath *search_path) -{ - int path_offset = search_path->path_length; - - RFALSE(path_offset < ILLEGAL_PATH_ELEMENT_OFFSET, - "clm-4000: invalid path offset"); - - while (path_offset > ILLEGAL_PATH_ELEMENT_OFFSET) { - struct buffer_head *bh; - bh = PATH_OFFSET_PBUFFER(search_path, path_offset--); - reiserfs_restore_prepared_buffer(sb, bh); - brelse(bh); - } - search_path->path_length = ILLEGAL_PATH_ELEMENT_OFFSET; -} - -/* Drop the reference to each buffer in a path */ -void pathrelse(struct treepath *search_path) -{ - int path_offset = search_path->path_length; - - RFALSE(path_offset < ILLEGAL_PATH_ELEMENT_OFFSET, - "PAP-5090: invalid path offset"); - - while (path_offset > ILLEGAL_PATH_ELEMENT_OFFSET) - brelse(PATH_OFFSET_PBUFFER(search_path, path_offset--)); - - search_path->path_length = ILLEGAL_PATH_ELEMENT_OFFSET; -} - -static int has_valid_deh_location(struct buffer_head *bh, struct item_head *ih) -{ - struct reiserfs_de_head *deh; - int i; - - deh = B_I_DEH(bh, ih); - for (i = 0; i < ih_entry_count(ih); i++) { - if (deh_location(&deh[i]) > ih_item_len(ih)) { - reiserfs_warning(NULL, "reiserfs-5094", - "directory entry location seems wrong %h", - &deh[i]); - return 0; - } - } - - return 1; -} - -static int is_leaf(char *buf, int blocksize, struct buffer_head *bh) -{ - struct block_head *blkh; - struct item_head *ih; - int used_space; - int prev_location; - int i; - int nr; - - blkh = (struct block_head *)buf; - if (blkh_level(blkh) != DISK_LEAF_NODE_LEVEL) { - reiserfs_warning(NULL, "reiserfs-5080", - "this should be caught earlier"); - return 0; - } - - nr = blkh_nr_item(blkh); - if (nr < 1 || nr > ((blocksize - BLKH_SIZE) / (IH_SIZE + MIN_ITEM_LEN))) { - /* item number is too big or too small */ - reiserfs_warning(NULL, "reiserfs-5081", - "nr_item seems wrong: %z", bh); - return 0; - } - ih = (struct item_head *)(buf + BLKH_SIZE) + nr - 1; - used_space = BLKH_SIZE + IH_SIZE * nr + (blocksize - ih_location(ih)); - - /* free space does not match to calculated amount of use space */ - if (used_space != blocksize - blkh_free_space(blkh)) { - reiserfs_warning(NULL, "reiserfs-5082", - "free space seems wrong: %z", bh); - return 0; - } - /* - * FIXME: it is_leaf will hit performance too much - we may have - * return 1 here - */ - - /* check tables of item heads */ - ih = (struct item_head *)(buf + BLKH_SIZE); - prev_location = blocksize; - for (i = 0; i < nr; i++, ih++) { - if (le_ih_k_type(ih) == TYPE_ANY) { - reiserfs_warning(NULL, "reiserfs-5083", - "wrong item type for item %h", - ih); - return 0; - } - if (ih_location(ih) >= blocksize - || ih_location(ih) < IH_SIZE * nr) { - reiserfs_warning(NULL, "reiserfs-5084", - "item location seems wrong: %h", - ih); - return 0; - } - if (ih_item_len(ih) < 1 - || ih_item_len(ih) > MAX_ITEM_LEN(blocksize)) { - reiserfs_warning(NULL, "reiserfs-5085", - "item length seems wrong: %h", - ih); - return 0; - } - if (prev_location - ih_location(ih) != ih_item_len(ih)) { - reiserfs_warning(NULL, "reiserfs-5086", - "item location seems wrong " - "(second one): %h", ih); - return 0; - } - if (is_direntry_le_ih(ih)) { - if (ih_item_len(ih) < (ih_entry_count(ih) * IH_SIZE)) { - reiserfs_warning(NULL, "reiserfs-5093", - "item entry count seems wrong %h", - ih); - return 0; - } - return has_valid_deh_location(bh, ih); - } - prev_location = ih_location(ih); - } - - /* one may imagine many more checks */ - return 1; -} - -/* returns 1 if buf looks like an internal node, 0 otherwise */ -static int is_internal(char *buf, int blocksize, struct buffer_head *bh) -{ - struct block_head *blkh; - int nr; - int used_space; - - blkh = (struct block_head *)buf; - nr = blkh_level(blkh); - if (nr <= DISK_LEAF_NODE_LEVEL || nr > MAX_HEIGHT) { - /* this level is not possible for internal nodes */ - reiserfs_warning(NULL, "reiserfs-5087", - "this should be caught earlier"); - return 0; - } - - nr = blkh_nr_item(blkh); - /* for internal which is not root we might check min number of keys */ - if (nr > (blocksize - BLKH_SIZE - DC_SIZE) / (KEY_SIZE + DC_SIZE)) { - reiserfs_warning(NULL, "reiserfs-5088", - "number of key seems wrong: %z", bh); - return 0; - } - - used_space = BLKH_SIZE + KEY_SIZE * nr + DC_SIZE * (nr + 1); - if (used_space != blocksize - blkh_free_space(blkh)) { - reiserfs_warning(NULL, "reiserfs-5089", - "free space seems wrong: %z", bh); - return 0; - } - - /* one may imagine many more checks */ - return 1; -} - -/* - * make sure that bh contains formatted node of reiserfs tree of - * 'level'-th level - */ -static int is_tree_node(struct buffer_head *bh, int level) -{ - if (B_LEVEL(bh) != level) { - reiserfs_warning(NULL, "reiserfs-5090", "node level %d does " - "not match to the expected one %d", - B_LEVEL(bh), level); - return 0; - } - if (level == DISK_LEAF_NODE_LEVEL) - return is_leaf(bh->b_data, bh->b_size, bh); - - return is_internal(bh->b_data, bh->b_size, bh); -} - -#define SEARCH_BY_KEY_READA 16 - -/* - * The function is NOT SCHEDULE-SAFE! - * It might unlock the write lock if we needed to wait for a block - * to be read. Note that in this case it won't recover the lock to avoid - * high contention resulting from too much lock requests, especially - * the caller (search_by_key) will perform other schedule-unsafe - * operations just after calling this function. - * - * @return depth of lock to be restored after read completes - */ -static int search_by_key_reada(struct super_block *s, - struct buffer_head **bh, - b_blocknr_t *b, int num) -{ - int i, j; - int depth = -1; - - for (i = 0; i < num; i++) { - bh[i] = sb_getblk(s, b[i]); - } - /* - * We are going to read some blocks on which we - * have a reference. It's safe, though we might be - * reading blocks concurrently changed if we release - * the lock. But it's still fine because we check later - * if the tree changed - */ - for (j = 0; j < i; j++) { - /* - * note, this needs attention if we are getting rid of the BKL - * you have to make sure the prepared bit isn't set on this - * buffer - */ - if (!buffer_uptodate(bh[j])) { - if (depth == -1) - depth = reiserfs_write_unlock_nested(s); - bh_readahead(bh[j], REQ_RAHEAD); - } - brelse(bh[j]); - } - return depth; -} - -/* - * This function fills up the path from the root to the leaf as it - * descends the tree looking for the key. It uses reiserfs_bread to - * try to find buffers in the cache given their block number. If it - * does not find them in the cache it reads them from disk. For each - * node search_by_key finds using reiserfs_bread it then uses - * bin_search to look through that node. bin_search will find the - * position of the block_number of the next node if it is looking - * through an internal node. If it is looking through a leaf node - * bin_search will find the position of the item which has key either - * equal to given key, or which is the maximal key less than the given - * key. search_by_key returns a path that must be checked for the - * correctness of the top of the path but need not be checked for the - * correctness of the bottom of the path - */ -/* - * search_by_key - search for key (and item) in stree - * @sb: superblock - * @key: pointer to key to search for - * @search_path: Allocated and initialized struct treepath; Returned filled - * on success. - * @stop_level: How far down the tree to search, Use DISK_LEAF_NODE_LEVEL to - * stop at leaf level. - * - * The function is NOT SCHEDULE-SAFE! - */ -int search_by_key(struct super_block *sb, const struct cpu_key *key, - struct treepath *search_path, int stop_level) -{ - b_blocknr_t block_number; - int expected_level; - struct buffer_head *bh; - struct path_element *last_element; - int node_level, retval; - int fs_gen; - struct buffer_head *reada_bh[SEARCH_BY_KEY_READA]; - b_blocknr_t reada_blocks[SEARCH_BY_KEY_READA]; - int reada_count = 0; - -#ifdef CONFIG_REISERFS_CHECK - int repeat_counter = 0; -#endif - - PROC_INFO_INC(sb, search_by_key); - - /* - * As we add each node to a path we increase its count. This means - * that we must be careful to release all nodes in a path before we - * either discard the path struct or re-use the path struct, as we - * do here. - */ - - pathrelse(search_path); - - /* - * With each iteration of this loop we search through the items in the - * current node, and calculate the next current node(next path element) - * for the next iteration of this loop.. - */ - block_number = SB_ROOT_BLOCK(sb); - expected_level = -1; - while (1) { - -#ifdef CONFIG_REISERFS_CHECK - if (!(++repeat_counter % 50000)) - reiserfs_warning(sb, "PAP-5100", - "%s: there were %d iterations of " - "while loop looking for key %K", - current->comm, repeat_counter, - key); -#endif - - /* prep path to have another element added to it. */ - last_element = - PATH_OFFSET_PELEMENT(search_path, - ++search_path->path_length); - fs_gen = get_generation(sb); - - /* - * Read the next tree node, and set the last element - * in the path to have a pointer to it. - */ - if ((bh = last_element->pe_buffer = - sb_getblk(sb, block_number))) { - - /* - * We'll need to drop the lock if we encounter any - * buffers that need to be read. If all of them are - * already up to date, we don't need to drop the lock. - */ - int depth = -1; - - if (!buffer_uptodate(bh) && reada_count > 1) - depth = search_by_key_reada(sb, reada_bh, - reada_blocks, reada_count); - - if (!buffer_uptodate(bh) && depth == -1) - depth = reiserfs_write_unlock_nested(sb); - - bh_read_nowait(bh, 0); - wait_on_buffer(bh); - - if (depth != -1) - reiserfs_write_lock_nested(sb, depth); - if (!buffer_uptodate(bh)) - goto io_error; - } else { -io_error: - search_path->path_length--; - pathrelse(search_path); - return IO_ERROR; - } - reada_count = 0; - if (expected_level == -1) - expected_level = SB_TREE_HEIGHT(sb); - expected_level--; - - /* - * It is possible that schedule occurred. We must check - * whether the key to search is still in the tree rooted - * from the current buffer. If not then repeat search - * from the root. - */ - if (fs_changed(fs_gen, sb) && - (!B_IS_IN_TREE(bh) || - B_LEVEL(bh) != expected_level || - !key_in_buffer(search_path, key, sb))) { - PROC_INFO_INC(sb, search_by_key_fs_changed); - PROC_INFO_INC(sb, search_by_key_restarted); - PROC_INFO_INC(sb, - sbk_restarted[expected_level - 1]); - pathrelse(search_path); - - /* - * Get the root block number so that we can - * repeat the search starting from the root. - */ - block_number = SB_ROOT_BLOCK(sb); - expected_level = -1; - - /* repeat search from the root */ - continue; - } - - /* - * only check that the key is in the buffer if key is not - * equal to the MAX_KEY. Latter case is only possible in - * "finish_unfinished()" processing during mount. - */ - RFALSE(comp_keys(&MAX_KEY, key) && - !key_in_buffer(search_path, key, sb), - "PAP-5130: key is not in the buffer"); -#ifdef CONFIG_REISERFS_CHECK - if (REISERFS_SB(sb)->cur_tb) { - print_cur_tb("5140"); - reiserfs_panic(sb, "PAP-5140", - "schedule occurred in do_balance!"); - } -#endif - - /* - * make sure, that the node contents look like a node of - * certain level - */ - if (!is_tree_node(bh, expected_level)) { - reiserfs_error(sb, "vs-5150", - "invalid format found in block %ld. " - "Fsck?", bh->b_blocknr); - pathrelse(search_path); - return IO_ERROR; - } - - /* ok, we have acquired next formatted node in the tree */ - node_level = B_LEVEL(bh); - - PROC_INFO_BH_STAT(sb, bh, node_level - 1); - - RFALSE(node_level < stop_level, - "vs-5152: tree level (%d) is less than stop level (%d)", - node_level, stop_level); - - retval = bin_search(key, item_head(bh, 0), - B_NR_ITEMS(bh), - (node_level == - DISK_LEAF_NODE_LEVEL) ? IH_SIZE : - KEY_SIZE, - &last_element->pe_position); - if (node_level == stop_level) { - return retval; - } - - /* we are not in the stop level */ - /* - * item has been found, so we choose the pointer which - * is to the right of the found one - */ - if (retval == ITEM_FOUND) - last_element->pe_position++; - - /* - * if item was not found we choose the position which is to - * the left of the found item. This requires no code, - * bin_search did it already. - */ - - /* - * So we have chosen a position in the current node which is - * an internal node. Now we calculate child block number by - * position in the node. - */ - block_number = - B_N_CHILD_NUM(bh, last_element->pe_position); - - /* - * if we are going to read leaf nodes, try for read - * ahead as well - */ - if ((search_path->reada & PATH_READA) && - node_level == DISK_LEAF_NODE_LEVEL + 1) { - int pos = last_element->pe_position; - int limit = B_NR_ITEMS(bh); - struct reiserfs_key *le_key; - - if (search_path->reada & PATH_READA_BACK) - limit = 0; - while (reada_count < SEARCH_BY_KEY_READA) { - if (pos == limit) - break; - reada_blocks[reada_count++] = - B_N_CHILD_NUM(bh, pos); - if (search_path->reada & PATH_READA_BACK) - pos--; - else - pos++; - - /* - * check to make sure we're in the same object - */ - le_key = internal_key(bh, pos); - if (le32_to_cpu(le_key->k_objectid) != - key->on_disk_key.k_objectid) { - break; - } - } - } - } -} - -/* - * Form the path to an item and position in this item which contains - * file byte defined by key. If there is no such item - * corresponding to the key, we point the path to the item with - * maximal key less than key, and *pos_in_item is set to one - * past the last entry/byte in the item. If searching for entry in a - * directory item, and it is not found, *pos_in_item is set to one - * entry more than the entry with maximal key which is less than the - * sought key. - * - * Note that if there is no entry in this same node which is one more, - * then we point to an imaginary entry. for direct items, the - * position is in units of bytes, for indirect items the position is - * in units of blocknr entries, for directory items the position is in - * units of directory entries. - */ -/* The function is NOT SCHEDULE-SAFE! */ -int search_for_position_by_key(struct super_block *sb, - /* Key to search (cpu variable) */ - const struct cpu_key *p_cpu_key, - /* Filled up by this function. */ - struct treepath *search_path) -{ - struct item_head *p_le_ih; /* pointer to on-disk structure */ - int blk_size; - loff_t item_offset, offset; - struct reiserfs_dir_entry de; - int retval; - - /* If searching for directory entry. */ - if (is_direntry_cpu_key(p_cpu_key)) - return search_by_entry_key(sb, p_cpu_key, search_path, - &de); - - /* If not searching for directory entry. */ - - /* If item is found. */ - retval = search_item(sb, p_cpu_key, search_path); - if (retval == IO_ERROR) - return retval; - if (retval == ITEM_FOUND) { - - RFALSE(!ih_item_len - (item_head - (PATH_PLAST_BUFFER(search_path), - PATH_LAST_POSITION(search_path))), - "PAP-5165: item length equals zero"); - - pos_in_item(search_path) = 0; - return POSITION_FOUND; - } - - RFALSE(!PATH_LAST_POSITION(search_path), - "PAP-5170: position equals zero"); - - /* Item is not found. Set path to the previous item. */ - p_le_ih = - item_head(PATH_PLAST_BUFFER(search_path), - --PATH_LAST_POSITION(search_path)); - blk_size = sb->s_blocksize; - - if (comp_short_keys(&p_le_ih->ih_key, p_cpu_key)) - return FILE_NOT_FOUND; - - /* FIXME: quite ugly this far */ - - item_offset = le_ih_k_offset(p_le_ih); - offset = cpu_key_k_offset(p_cpu_key); - - /* Needed byte is contained in the item pointed to by the path. */ - if (item_offset <= offset && - item_offset + op_bytes_number(p_le_ih, blk_size) > offset) { - pos_in_item(search_path) = offset - item_offset; - if (is_indirect_le_ih(p_le_ih)) { - pos_in_item(search_path) /= blk_size; - } - return POSITION_FOUND; - } - - /* - * Needed byte is not contained in the item pointed to by the - * path. Set pos_in_item out of the item. - */ - if (is_indirect_le_ih(p_le_ih)) - pos_in_item(search_path) = - ih_item_len(p_le_ih) / UNFM_P_SIZE; - else - pos_in_item(search_path) = ih_item_len(p_le_ih); - - return POSITION_NOT_FOUND; -} - -/* Compare given item and item pointed to by the path. */ -int comp_items(const struct item_head *stored_ih, const struct treepath *path) -{ - struct buffer_head *bh = PATH_PLAST_BUFFER(path); - struct item_head *ih; - - /* Last buffer at the path is not in the tree. */ - if (!B_IS_IN_TREE(bh)) - return 1; - - /* Last path position is invalid. */ - if (PATH_LAST_POSITION(path) >= B_NR_ITEMS(bh)) - return 1; - - /* we need only to know, whether it is the same item */ - ih = tp_item_head(path); - return memcmp(stored_ih, ih, IH_SIZE); -} - -/* prepare for delete or cut of direct item */ -static inline int prepare_for_direct_item(struct treepath *path, - struct item_head *le_ih, - struct inode *inode, - loff_t new_file_length, int *cut_size) -{ - loff_t round_len; - - if (new_file_length == max_reiserfs_offset(inode)) { - /* item has to be deleted */ - *cut_size = -(IH_SIZE + ih_item_len(le_ih)); - return M_DELETE; - } - /* new file gets truncated */ - if (get_inode_item_key_version(inode) == KEY_FORMAT_3_6) { - round_len = ROUND_UP(new_file_length); - /* this was new_file_length < le_ih ... */ - if (round_len < le_ih_k_offset(le_ih)) { - *cut_size = -(IH_SIZE + ih_item_len(le_ih)); - return M_DELETE; /* Delete this item. */ - } - /* Calculate first position and size for cutting from item. */ - pos_in_item(path) = round_len - (le_ih_k_offset(le_ih) - 1); - *cut_size = -(ih_item_len(le_ih) - pos_in_item(path)); - - return M_CUT; /* Cut from this item. */ - } - - /* old file: items may have any length */ - - if (new_file_length < le_ih_k_offset(le_ih)) { - *cut_size = -(IH_SIZE + ih_item_len(le_ih)); - return M_DELETE; /* Delete this item. */ - } - - /* Calculate first position and size for cutting from item. */ - *cut_size = -(ih_item_len(le_ih) - - (pos_in_item(path) = - new_file_length + 1 - le_ih_k_offset(le_ih))); - return M_CUT; /* Cut from this item. */ -} - -static inline int prepare_for_direntry_item(struct treepath *path, - struct item_head *le_ih, - struct inode *inode, - loff_t new_file_length, - int *cut_size) -{ - if (le_ih_k_offset(le_ih) == DOT_OFFSET && - new_file_length == max_reiserfs_offset(inode)) { - RFALSE(ih_entry_count(le_ih) != 2, - "PAP-5220: incorrect empty directory item (%h)", le_ih); - *cut_size = -(IH_SIZE + ih_item_len(le_ih)); - /* Delete the directory item containing "." and ".." entry. */ - return M_DELETE; - } - - if (ih_entry_count(le_ih) == 1) { - /* - * Delete the directory item such as there is one record only - * in this item - */ - *cut_size = -(IH_SIZE + ih_item_len(le_ih)); - return M_DELETE; - } - - /* Cut one record from the directory item. */ - *cut_size = - -(DEH_SIZE + - entry_length(get_last_bh(path), le_ih, pos_in_item(path))); - return M_CUT; -} - -#define JOURNAL_FOR_FREE_BLOCK_AND_UPDATE_SD (2 * JOURNAL_PER_BALANCE_CNT + 1) - -/* - * If the path points to a directory or direct item, calculate mode - * and the size cut, for balance. - * If the path points to an indirect item, remove some number of its - * unformatted nodes. - * In case of file truncate calculate whether this item must be - * deleted/truncated or last unformatted node of this item will be - * converted to a direct item. - * This function returns a determination of what balance mode the - * calling function should employ. - */ -static char prepare_for_delete_or_cut(struct reiserfs_transaction_handle *th, - struct inode *inode, - struct treepath *path, - const struct cpu_key *item_key, - /* - * Number of unformatted nodes - * which were removed from end - * of the file. - */ - int *removed, - int *cut_size, - /* MAX_KEY_OFFSET in case of delete. */ - unsigned long long new_file_length - ) -{ - struct super_block *sb = inode->i_sb; - struct item_head *p_le_ih = tp_item_head(path); - struct buffer_head *bh = PATH_PLAST_BUFFER(path); - - BUG_ON(!th->t_trans_id); - - /* Stat_data item. */ - if (is_statdata_le_ih(p_le_ih)) { - - RFALSE(new_file_length != max_reiserfs_offset(inode), - "PAP-5210: mode must be M_DELETE"); - - *cut_size = -(IH_SIZE + ih_item_len(p_le_ih)); - return M_DELETE; - } - - /* Directory item. */ - if (is_direntry_le_ih(p_le_ih)) - return prepare_for_direntry_item(path, p_le_ih, inode, - new_file_length, - cut_size); - - /* Direct item. */ - if (is_direct_le_ih(p_le_ih)) - return prepare_for_direct_item(path, p_le_ih, inode, - new_file_length, cut_size); - - /* Case of an indirect item. */ - { - int blk_size = sb->s_blocksize; - struct item_head s_ih; - int need_re_search; - int delete = 0; - int result = M_CUT; - int pos = 0; - - if ( new_file_length == max_reiserfs_offset (inode) ) { - /* - * prepare_for_delete_or_cut() is called by - * reiserfs_delete_item() - */ - new_file_length = 0; - delete = 1; - } - - do { - need_re_search = 0; - *cut_size = 0; - bh = PATH_PLAST_BUFFER(path); - copy_item_head(&s_ih, tp_item_head(path)); - pos = I_UNFM_NUM(&s_ih); - - while (le_ih_k_offset (&s_ih) + (pos - 1) * blk_size > new_file_length) { - __le32 *unfm; - __u32 block; - - /* - * Each unformatted block deletion may involve - * one additional bitmap block into the transaction, - * thereby the initial journal space reservation - * might not be enough. - */ - if (!delete && (*cut_size) != 0 && - reiserfs_transaction_free_space(th) < JOURNAL_FOR_FREE_BLOCK_ |