The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/fs/ext2fs/ext2_htree.c

Version: -  FREEBSD  -  FREEBSD-13-STABLE  -  FREEBSD-13-0  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  l41  -  OPENBSD  -  linux-2.6  -  MK84  -  PLAN9  -  xnu-8792 
SearchContext: -  none  -  3  -  10 

    1 /*-
    2  * Copyright (c) 2010, 2012 Zheng Liu <lz@freebsd.org>
    3  * Copyright (c) 2012, Vyacheslav Matyushin
    4  * All rights reserved.
    5  *
    6  * Redistribution and use in source and binary forms, with or without
    7  * modification, are permitted provided that the following conditions
    8  * are met:
    9  * 1. Redistributions of source code must retain the above copyright
   10  *    notice, this list of conditions and the following disclaimer.
   11  * 2. Redistributions in binary form must reproduce the above copyright
   12  *    notice, this list of conditions and the following disclaimer in the
   13  *    documentation and/or other materials provided with the distribution.
   14  *
   15  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   25  * SUCH DAMAGE.
   26  *
   27  * $FreeBSD: releng/10.0/sys/fs/ext2fs/ext2_htree.c 255338 2013-09-07 02:45:51Z pfg $
   28  */
   29 
   30 #include <sys/param.h>
   31 #include <sys/endian.h>
   32 #include <sys/systm.h>
   33 #include <sys/namei.h>
   34 #include <sys/bio.h>
   35 #include <sys/buf.h>
   36 #include <sys/endian.h>
   37 #include <sys/mount.h>
   38 #include <sys/vnode.h>
   39 #include <sys/malloc.h>
   40 #include <sys/dirent.h>
   41 #include <sys/sysctl.h>
   42 
   43 #include <ufs/ufs/dir.h>
   44 
   45 #include <fs/ext2fs/inode.h>
   46 #include <fs/ext2fs/ext2_mount.h>
   47 #include <fs/ext2fs/ext2fs.h>
   48 #include <fs/ext2fs/fs.h>
   49 #include <fs/ext2fs/ext2_extern.h>
   50 #include <fs/ext2fs/ext2_dinode.h>
   51 #include <fs/ext2fs/ext2_dir.h>
   52 #include <fs/ext2fs/htree.h>
   53 
   54 static void     ext2_append_entry(char *block, uint32_t blksize,
   55                     struct ext2fs_direct_2 *last_entry,
   56                     struct ext2fs_direct_2 *new_entry);
   57 static int      ext2_htree_append_block(struct vnode *vp, char *data,
   58                     struct componentname *cnp, uint32_t blksize);
   59 static int      ext2_htree_check_next(struct inode *ip, uint32_t hash,
   60                     const char *name, struct ext2fs_htree_lookup_info *info);
   61 static int      ext2_htree_cmp_sort_entry(const void *e1, const void *e2);
   62 static int      ext2_htree_find_leaf(struct inode *ip, const char *name,
   63                     int namelen, uint32_t *hash, uint8_t *hash_verion,
   64                     struct ext2fs_htree_lookup_info *info);
   65 static uint32_t ext2_htree_get_block(struct ext2fs_htree_entry *ep);
   66 static uint16_t ext2_htree_get_count(struct ext2fs_htree_entry *ep);
   67 static uint32_t ext2_htree_get_hash(struct ext2fs_htree_entry *ep);
   68 static uint16_t ext2_htree_get_limit(struct ext2fs_htree_entry *ep);
   69 static void     ext2_htree_insert_entry_to_level(struct ext2fs_htree_lookup_level *level,
   70                     uint32_t hash, uint32_t blk);
   71 static void     ext2_htree_insert_entry(struct ext2fs_htree_lookup_info *info,
   72                     uint32_t hash, uint32_t blk);
   73 static uint32_t ext2_htree_node_limit(struct inode *ip);
   74 static void     ext2_htree_set_block(struct ext2fs_htree_entry *ep,
   75                     uint32_t blk);
   76 static void     ext2_htree_set_count(struct ext2fs_htree_entry *ep,
   77                     uint16_t cnt);
   78 static void     ext2_htree_set_hash(struct ext2fs_htree_entry *ep,
   79                     uint32_t hash);
   80 static void     ext2_htree_set_limit(struct ext2fs_htree_entry *ep,
   81                     uint16_t limit);
   82 static int      ext2_htree_split_dirblock(char *block1, char *block2,
   83                     uint32_t blksize, uint32_t *hash_seed, uint8_t hash_version,
   84                     uint32_t *split_hash, struct  ext2fs_direct_2 *entry);
   85 static void     ext2_htree_release(struct ext2fs_htree_lookup_info *info);
   86 static uint32_t ext2_htree_root_limit(struct inode *ip, int len);
   87 static int      ext2_htree_writebuf(struct ext2fs_htree_lookup_info *info);
   88 
   89 int
   90 ext2_htree_has_idx(struct inode *ip)
   91 {
   92 #ifdef EXT2FS_HTREE
   93         if (EXT2_HAS_COMPAT_FEATURE(ip->i_e2fs, EXT2F_COMPAT_DIRHASHINDEX) &&
   94             ip->i_flags & EXT4_INDEX)
   95                 return (1);
   96         else
   97 #endif
   98                 return (0);
   99 }
  100 
  101 static int
  102 ext2_htree_check_next(struct inode *ip, uint32_t hash, const char *name,
  103                 struct ext2fs_htree_lookup_info *info)
  104 {
  105         struct vnode *vp = ITOV(ip);
  106         struct ext2fs_htree_lookup_level *level;
  107         struct buf *bp;
  108         uint32_t next_hash;
  109         int idx = info->h_levels_num - 1;
  110         int levels = 0;
  111 
  112         do {
  113                 level = &info->h_levels[idx];
  114                 level->h_entry++;
  115                 if (level->h_entry < level->h_entries +
  116                     ext2_htree_get_count(level->h_entries))
  117                         break;
  118                 if (idx == 0)
  119                         return (0);
  120                 idx--;
  121                 levels++;
  122         } while (1);
  123 
  124         next_hash = ext2_htree_get_hash(level->h_entry);
  125         if ((hash & 1) == 0) {
  126                 if (hash != (next_hash & ~1))
  127                         return (0);
  128         }
  129 
  130         while (levels > 0) {
  131                 levels--;
  132                 if (ext2_blkatoff(vp, ext2_htree_get_block(level->h_entry) *
  133                     ip->i_e2fs->e2fs_bsize, NULL, &bp) != 0)
  134                         return (0);
  135                 level = &info->h_levels[idx + 1];
  136                 brelse(level->h_bp);
  137                 level->h_bp = bp;
  138                 level->h_entry = level->h_entries =
  139                     ((struct ext2fs_htree_node *)bp->b_data)->h_entries;
  140         }
  141 
  142         return (1);
  143 }
  144 
  145 static uint32_t
  146 ext2_htree_get_block(struct ext2fs_htree_entry *ep)
  147 {
  148         return (ep->h_blk & 0x00FFFFFF);
  149 }
  150 
  151 static void
  152 ext2_htree_set_block(struct ext2fs_htree_entry *ep, uint32_t blk)
  153 {
  154         ep->h_blk = blk;
  155 }
  156 
  157 static uint16_t
  158 ext2_htree_get_count(struct ext2fs_htree_entry *ep)
  159 {
  160         return (((struct ext2fs_htree_count *)(ep))->h_entries_num);
  161 }
  162 
  163 static void
  164 ext2_htree_set_count(struct ext2fs_htree_entry *ep, uint16_t cnt)
  165 {
  166         ((struct ext2fs_htree_count *)(ep))->h_entries_num = cnt;
  167 }
  168 
  169 static uint32_t
  170 ext2_htree_get_hash(struct ext2fs_htree_entry *ep)
  171 {
  172         return (ep->h_hash);
  173 }
  174 
  175 static uint16_t
  176 ext2_htree_get_limit(struct ext2fs_htree_entry *ep)
  177 {
  178         return (((struct ext2fs_htree_count *)(ep))->h_entries_max);
  179 }
  180 
  181 static void
  182 ext2_htree_set_hash(struct ext2fs_htree_entry *ep, uint32_t hash)
  183 {
  184         ep->h_hash = hash;
  185 }
  186 
  187 static void
  188 ext2_htree_set_limit(struct ext2fs_htree_entry *ep, uint16_t limit)
  189 {
  190         ((struct ext2fs_htree_count *)(ep))->h_entries_max = limit;
  191 }
  192 
  193 static void
  194 ext2_htree_release(struct ext2fs_htree_lookup_info *info)
  195 {
  196         int i;
  197 
  198         for (i = 0; i < info->h_levels_num; i++) {
  199                 struct buf *bp = info->h_levels[i].h_bp;
  200                 if (bp != NULL)
  201                         brelse(bp);
  202         }
  203 }
  204 
  205 static uint32_t
  206 ext2_htree_root_limit(struct inode *ip, int len)
  207 {
  208         uint32_t space;
  209 
  210         space = ip->i_e2fs->e2fs_bsize - EXT2_DIR_REC_LEN(1) -
  211             EXT2_DIR_REC_LEN(2) - len;
  212         return (space / sizeof(struct ext2fs_htree_entry));
  213 }
  214 
  215 static uint32_t
  216 ext2_htree_node_limit(struct inode *ip)
  217 {
  218         struct m_ext2fs *fs;
  219         uint32_t space;
  220 
  221         fs = ip->i_e2fs;
  222         space = fs->e2fs_bsize - EXT2_DIR_REC_LEN(0);
  223 
  224         return (space / sizeof(struct ext2fs_htree_entry));
  225 }
  226 
  227 static int
  228 ext2_htree_find_leaf(struct inode *ip, const char *name, int namelen,
  229                      uint32_t *hash, uint8_t *hash_ver,
  230                      struct ext2fs_htree_lookup_info *info)
  231 {
  232         struct vnode *vp;
  233         struct ext2fs *fs;
  234         struct m_ext2fs *m_fs;
  235         struct buf *bp = NULL;
  236         struct ext2fs_htree_root *rootp;
  237         struct ext2fs_htree_entry *entp, *start, *end, *middle, *found;
  238         struct ext2fs_htree_lookup_level *level_info;
  239         uint32_t hash_major = 0, hash_minor = 0;
  240         uint32_t levels, cnt;
  241         uint8_t hash_version;
  242 
  243         if (name == NULL || info == NULL)
  244                 return (-1);
  245 
  246         vp = ITOV(ip);
  247         fs = ip->i_e2fs->e2fs;
  248         m_fs = ip->i_e2fs;
  249 
  250         if (ext2_blkatoff(vp, 0, NULL, &bp) != 0)
  251                 return (-1);
  252 
  253         info->h_levels_num = 1;
  254         info->h_levels[0].h_bp = bp;
  255         rootp = (struct ext2fs_htree_root *)bp->b_data;
  256         if (rootp->h_info.h_hash_version != EXT2_HTREE_LEGACY &&
  257             rootp->h_info.h_hash_version != EXT2_HTREE_HALF_MD4 &&
  258             rootp->h_info.h_hash_version != EXT2_HTREE_TEA)
  259                 goto error;
  260 
  261         hash_version = rootp->h_info.h_hash_version;
  262         if (hash_version <= EXT2_HTREE_TEA)
  263                 hash_version += m_fs->e2fs_uhash;
  264         *hash_ver = hash_version;
  265 
  266         ext2_htree_hash(name, namelen, fs->e3fs_hash_seed,
  267             hash_version, &hash_major, &hash_minor);
  268         *hash = hash_major;
  269 
  270         if ((levels = rootp->h_info.h_ind_levels) > 1)
  271                 goto error;
  272 
  273         entp = (struct ext2fs_htree_entry *)(((char *)&rootp->h_info) +
  274             rootp->h_info.h_info_len);
  275 
  276         if (ext2_htree_get_limit(entp) !=
  277             ext2_htree_root_limit(ip, rootp->h_info.h_info_len))
  278                 goto error;
  279 
  280         while (1) {
  281                 cnt = ext2_htree_get_count(entp);
  282                 if (cnt == 0 || cnt > ext2_htree_get_limit(entp))
  283                         goto error;
  284 
  285                 start = entp + 1;
  286                 end = entp + cnt - 1;
  287                 while (start <= end) {
  288                         middle = start + (end - start) / 2;
  289                         if (ext2_htree_get_hash(middle) > hash_major)
  290                                 end = middle - 1;
  291                         else
  292                                 start = middle + 1;
  293                 }
  294                 found = start - 1;
  295 
  296                 level_info = &(info->h_levels[info->h_levels_num - 1]);
  297                 level_info->h_bp = bp;
  298                 level_info->h_entries = entp;
  299                 level_info->h_entry = found;
  300                 if (levels == 0)
  301                         return (0);
  302                 levels--;
  303                 if (ext2_blkatoff(vp,
  304                     ext2_htree_get_block(found) * m_fs->e2fs_bsize,
  305                     NULL, &bp) != 0)
  306                         goto error;
  307                 entp = ((struct ext2fs_htree_node *)bp->b_data)->h_entries;
  308                 info->h_levels_num++;
  309                 info->h_levels[info->h_levels_num - 1].h_bp = bp;
  310         }
  311 
  312 error:
  313         ext2_htree_release(info);
  314         return (-1);
  315 }
  316 
  317 /*
  318  * Try to lookup a directory entry in HTree index
  319  */
  320 int
  321 ext2_htree_lookup(struct inode *ip, const char *name, int namelen,
  322                   struct buf **bpp, int *entryoffp, doff_t *offp,
  323                   doff_t *prevoffp, doff_t *endusefulp,
  324                   struct ext2fs_searchslot *ss)
  325 {
  326         struct vnode *vp;
  327         struct ext2fs_htree_lookup_info info;
  328         struct ext2fs_htree_entry *leaf_node;
  329         struct m_ext2fs *m_fs;
  330         struct buf *bp;
  331         uint32_t blk;
  332         uint32_t dirhash;
  333         uint32_t bsize;
  334         uint8_t hash_version;
  335         int search_next;
  336         int found = 0;
  337 
  338         m_fs = ip->i_e2fs;
  339         bsize = m_fs->e2fs_bsize;
  340         vp = ITOV(ip);
  341 
  342         /* TODO: print error msg because we don't lookup '.' and '..' */
  343 
  344         memset(&info, 0, sizeof(info));
  345         if (ext2_htree_find_leaf(ip, name, namelen, &dirhash,
  346             &hash_version, &info))
  347                 return (-1);
  348 
  349         do {
  350                 leaf_node = info.h_levels[info.h_levels_num - 1].h_entry;
  351                 blk = ext2_htree_get_block(leaf_node);
  352                 if (ext2_blkatoff(vp, blk * bsize, NULL, &bp) != 0) {
  353                         ext2_htree_release(&info);
  354                         return (-1);
  355                 }
  356 
  357                 *offp = blk * bsize;
  358                 *entryoffp = 0;
  359                 *prevoffp = blk * bsize;
  360                 *endusefulp = blk * bsize;
  361 
  362                 if (ss->slotstatus == NONE) {
  363                         ss->slotoffset = -1;
  364                         ss->slotfreespace = 0;
  365                 }
  366 
  367                 if (ext2_search_dirblock(ip, bp->b_data, &found,
  368                     name, namelen, entryoffp, offp, prevoffp,
  369                     endusefulp, ss) != 0) {
  370                         brelse(bp);
  371                         ext2_htree_release(&info);
  372                         return (-1);
  373                 }
  374 
  375                 if (found) {
  376                         *bpp = bp;
  377                         ext2_htree_release(&info);
  378                         return (0);
  379                 }
  380 
  381                 brelse(bp);
  382                 search_next = ext2_htree_check_next(ip, dirhash, name, &info);
  383         } while (search_next);
  384 
  385         ext2_htree_release(&info);
  386         return (ENOENT);
  387 }
  388 
  389 static int
  390 ext2_htree_append_block(struct vnode *vp, char *data,
  391                         struct componentname *cnp, uint32_t blksize)
  392 {
  393         struct iovec aiov;
  394         struct uio auio;
  395         struct inode *dp = VTOI(vp);
  396         uint64_t cursize, newsize;
  397         int error;
  398 
  399         cursize = roundup(dp->i_size, blksize);
  400         newsize = roundup(dp->i_size, blksize) + blksize;
  401 
  402         auio.uio_offset = cursize;
  403         auio.uio_resid = blksize;
  404         aiov.iov_len = blksize;
  405         aiov.iov_base = data;
  406         auio.uio_iov = &aiov;
  407         auio.uio_iovcnt = 1;
  408         auio.uio_rw = UIO_WRITE;
  409         auio.uio_segflg = UIO_SYSSPACE;
  410         error = VOP_WRITE(vp, &auio, IO_SYNC, cnp->cn_cred);
  411         if (!error)
  412                 dp->i_size = newsize;
  413 
  414         return (error);
  415 }
  416 
  417 static int
  418 ext2_htree_writebuf(struct ext2fs_htree_lookup_info *info)
  419 {
  420         int i, error;
  421 
  422         for (i = 0; i < info->h_levels_num; i++) {
  423                 struct buf *bp = info->h_levels[i].h_bp;
  424                 error = bwrite(bp);
  425                 if (error)
  426                         return (error);
  427         }
  428 
  429         return (0);
  430 }
  431 
  432 static void
  433 ext2_htree_insert_entry_to_level(struct ext2fs_htree_lookup_level *level,
  434                                  uint32_t hash, uint32_t blk)
  435 {
  436         struct ext2fs_htree_entry *target;
  437         int entries_num;
  438 
  439         target = level->h_entry + 1;
  440         entries_num = ext2_htree_get_count(level->h_entries);
  441 
  442         memmove(target + 1, target, (char *)(level->h_entries + entries_num) -
  443             (char *)target);
  444         ext2_htree_set_block(target, blk);
  445         ext2_htree_set_hash(target, hash);
  446         ext2_htree_set_count(level->h_entries, entries_num + 1);
  447 }
  448 
  449 /*
  450  * Insert an index entry to the index node.
  451  */
  452 static void
  453 ext2_htree_insert_entry(struct ext2fs_htree_lookup_info *info,
  454                         uint32_t hash, uint32_t blk)
  455 {
  456         struct ext2fs_htree_lookup_level *level;
  457 
  458         level = &info->h_levels[info->h_levels_num - 1];
  459         ext2_htree_insert_entry_to_level(level, hash, blk);
  460 }
  461 
  462 /*
  463  * Compare two entry sort descriptors by name hash value.
  464  * This is used together with qsort.
  465  */
  466 static int
  467 ext2_htree_cmp_sort_entry(const void *e1, const void *e2)
  468 {
  469         const struct ext2fs_htree_sort_entry *entry1, *entry2;
  470 
  471         entry1 = (const struct ext2fs_htree_sort_entry *)e1;
  472         entry2 = (const struct ext2fs_htree_sort_entry *)e2;
  473 
  474         if (entry1->h_hash < entry2->h_hash)
  475                 return (-1);
  476         if (entry2->h_hash > entry2->h_hash)
  477                 return (1);
  478         return (0);
  479 }
  480 
  481 /*
  482  * Append an entry to the end of the directory block.
  483  */
  484 static void
  485 ext2_append_entry(char *block, uint32_t blksize,
  486                   struct ext2fs_direct_2 *last_entry,
  487                   struct ext2fs_direct_2 *new_entry)
  488 {
  489         uint16_t entry_len;
  490 
  491         entry_len = EXT2_DIR_REC_LEN(last_entry->e2d_namlen);
  492         last_entry->e2d_reclen = entry_len;
  493         last_entry = (struct ext2fs_direct_2 *)((char *)last_entry + entry_len);
  494         new_entry->e2d_reclen = block + blksize - (char *)last_entry;
  495         memcpy(last_entry, new_entry, EXT2_DIR_REC_LEN(new_entry->e2d_namlen));
  496 }
  497 
  498 /*
  499  * Move half of entries from the old directory block to the new one.
  500  */
  501 static int
  502 ext2_htree_split_dirblock(char *block1, char *block2, uint32_t blksize,
  503                           uint32_t *hash_seed, uint8_t hash_version,
  504                           uint32_t *split_hash, struct ext2fs_direct_2 *entry)
  505 {
  506         int entry_cnt = 0;
  507         int size = 0;
  508         int i, k;
  509         uint32_t offset;
  510         uint16_t entry_len = 0;
  511         uint32_t entry_hash;
  512         struct ext2fs_direct_2 *ep, *last;
  513         char *dest;
  514         struct ext2fs_htree_sort_entry *sort_info;
  515 
  516         ep = (struct ext2fs_direct_2 *)block1;
  517         dest = block2;
  518         sort_info = (struct ext2fs_htree_sort_entry *)
  519             ((char *)block2 + blksize);
  520 
  521         /*
  522          * Calculate name hash value for the entry which is to be added.
  523          */
  524         ext2_htree_hash(entry->e2d_name, entry->e2d_namlen, hash_seed,
  525             hash_version, &entry_hash, NULL);
  526 
  527         /*
  528          * Fill in directory entry sort descriptors.
  529          */
  530         while ((char *)ep < block1 + blksize) {
  531                 if (ep->e2d_ino && ep->e2d_namlen) {
  532                         entry_cnt++;
  533                         sort_info--;
  534                         sort_info->h_size = ep->e2d_reclen;
  535                         sort_info->h_offset = (char *)ep - block1;
  536                         ext2_htree_hash(ep->e2d_name, ep->e2d_namlen,
  537                             hash_seed, hash_version,
  538                             &sort_info->h_hash, NULL);
  539                 }
  540                 ep = (struct ext2fs_direct_2 *)
  541                     ((char *)ep + ep->e2d_reclen);
  542         }
  543 
  544         /*
  545          * Sort directory entry descriptors by name hash value.
  546          */
  547         qsort(sort_info, entry_cnt, sizeof(struct ext2fs_htree_sort_entry),
  548             ext2_htree_cmp_sort_entry);
  549 
  550         /*
  551          * Count the number of entries to move to directory block 2.
  552          */
  553         for (i = entry_cnt - 1; i >= 0; i--) {
  554                 if (sort_info[i].h_size + size > blksize / 2)
  555                         break;
  556                 size += sort_info[i].h_size;
  557         }
  558 
  559         *split_hash = sort_info[i + 1].h_hash;
  560 
  561         /*
  562          * Set collision bit.
  563          */
  564         if (*split_hash == sort_info[i].h_hash)
  565                 *split_hash += 1;
  566 
  567         /*
  568          * Move half of directory entries from block 1 to block 2.
  569          */
  570         for (k = i + 1; k < entry_cnt; k++) {
  571                 ep = (struct ext2fs_direct_2 *)((char *)block1 +
  572                     sort_info[k].h_offset);
  573                 entry_len = EXT2_DIR_REC_LEN(ep->e2d_namlen);
  574                 memcpy(dest, ep, entry_len);
  575                 ((struct ext2fs_direct_2 *)dest)->e2d_reclen = entry_len;
  576                 /* Mark directory entry as unused. */
  577                 ep->e2d_ino = 0;
  578                 dest += entry_len;
  579         }
  580         dest -= entry_len;
  581 
  582         /* Shrink directory entries in block 1. */
  583         last = (struct ext2fs_direct_2 *)block1;
  584         entry_len = EXT2_DIR_REC_LEN(last->e2d_namlen);
  585         for (offset = last->e2d_reclen; offset < blksize; ) {
  586                 ep = (struct ext2fs_direct_2 *)(block1 + offset);
  587                 offset += ep->e2d_reclen;
  588                 if (last->e2d_ino) {
  589                         /* Trim the existing slot */
  590                         last->e2d_reclen = entry_len;
  591                         last = (struct ext2fs_direct_2 *)
  592                            ((char *)last + entry_len);
  593                 }
  594                 entry_len = EXT2_DIR_REC_LEN(ep->e2d_namlen);
  595                 memcpy((void *)last, (void *)ep, entry_len);
  596         }
  597 
  598         if (entry_hash >= *split_hash) {
  599                 /* Add entry to block 2. */
  600                 ext2_append_entry(block2, blksize,
  601                     (struct ext2fs_direct_2 *)dest, entry);
  602 
  603                 /* Adjust length field of last entry of block 1. */
  604                 last->e2d_reclen = block1 + blksize - (char *)last;
  605         } else {
  606                 /* Add entry to block 1. */
  607                 ext2_append_entry(block1, blksize, last, entry);
  608 
  609                 /* Adjust length field of last entry of block 2. */
  610                 ((struct ext2fs_direct_2 *)dest)->e2d_reclen =
  611                     block2 + blksize - dest;
  612         }
  613 
  614         return (0);
  615 }
  616 
  617 /*
  618  * Create an HTree index for a directory
  619  */
  620 int
  621 ext2_htree_create_index(struct vnode *vp, struct componentname *cnp,
  622                         struct ext2fs_direct_2 *new_entry)
  623 {
  624         struct buf *bp = NULL;
  625         struct inode *dp;
  626         struct ext2fs *fs;
  627         struct m_ext2fs *m_fs;
  628         struct ext2fs_direct_2 *ep, *dotdot;
  629         struct ext2fs_htree_root *root;
  630         struct ext2fs_htree_lookup_info info;
  631         uint32_t blksize, dirlen, split_hash;
  632         uint8_t hash_version;
  633         char *buf1 = NULL;
  634         char *buf2 = NULL;
  635         int error = 0;
  636 
  637         dp = VTOI(vp);
  638         fs = dp->i_e2fs->e2fs;
  639         m_fs = dp->i_e2fs;
  640         blksize = m_fs->e2fs_bsize;
  641 
  642         buf1 = malloc(blksize, M_TEMP, M_WAITOK | M_ZERO);
  643         buf2 = malloc(blksize, M_TEMP, M_WAITOK | M_ZERO);
  644 
  645         if ((error = ext2_blkatoff(vp, 0, NULL, &bp)) != 0)
  646                 goto out;
  647 
  648         root = (struct ext2fs_htree_root *)bp->b_data;
  649         dotdot = (struct ext2fs_direct_2 *)((char *)&(root->h_dotdot));
  650         ep = (struct ext2fs_direct_2 *)((char *)dotdot + dotdot->e2d_reclen);
  651         dirlen = (char *)root + blksize - (char *)ep;
  652         memcpy(buf1, ep, dirlen);
  653         ep = (struct ext2fs_direct_2 *)buf1;
  654         while ((char *)ep < buf1 + dirlen)
  655                 ep = (struct ext2fs_direct_2 *)
  656                     ((char *)ep + ep->e2d_reclen);
  657         ep->e2d_reclen = buf1 + blksize - (char *)ep;
  658 
  659         dp->i_flags |= EXT4_INDEX;
  660 
  661         /*
  662          * Initialize index root.
  663          */
  664         dotdot->e2d_reclen = blksize - EXT2_DIR_REC_LEN(1);
  665         memset(&root->h_info, 0, sizeof(root->h_info));
  666         root->h_info.h_hash_version = fs->e3fs_def_hash_version;
  667         root->h_info.h_info_len = sizeof(root->h_info);
  668         ext2_htree_set_block(root->h_entries, 1);
  669         ext2_htree_set_count(root->h_entries, 1);
  670         ext2_htree_set_limit(root->h_entries,
  671             ext2_htree_root_limit(dp, sizeof(root->h_info)));
  672 
  673         memset(&info, 0, sizeof(info));
  674         info.h_levels_num = 1;
  675         info.h_levels[0].h_entries = root->h_entries;
  676         info.h_levels[0].h_entry = root->h_entries;
  677 
  678         hash_version = root->h_info.h_hash_version;
  679         if (hash_version <= EXT2_HTREE_TEA)
  680                 hash_version += m_fs->e2fs_uhash;
  681         ext2_htree_split_dirblock(buf1, buf2, blksize, fs->e3fs_hash_seed,
  682             hash_version, &split_hash, new_entry);
  683         ext2_htree_insert_entry(&info, split_hash, 2);
  684 
  685         /*
  686          * Write directory block 0.
  687          */
  688         if (DOINGASYNC(vp)) {
  689                 bdwrite(bp);
  690                 error = 0;
  691         } else {
  692                 error = bwrite(bp);
  693         }
  694         dp->i_flag |= IN_CHANGE | IN_UPDATE;
  695         if (error)
  696                 goto out;
  697 
  698         /*
  699          * Write directory block 1.
  700          */
  701         error = ext2_htree_append_block(vp, buf1, cnp, blksize);
  702         if (error)
  703                 goto out1;
  704 
  705         /*
  706          * Write directory block 2.
  707          */
  708         error = ext2_htree_append_block(vp, buf2, cnp, blksize);
  709 
  710         free(buf1, M_TEMP);
  711         free(buf2, M_TEMP);
  712         return (error);
  713 out:
  714         if (bp != NULL)
  715                 brelse(bp);
  716 out1:
  717         free(buf1, M_TEMP);
  718         free(buf2, M_TEMP);
  719         return (error);
  720 }
  721 
  722 /*
  723  * Add an entry to the directory using htree index.
  724  */
  725 int
  726 ext2_htree_add_entry(struct vnode *dvp, struct ext2fs_direct_2 *entry,
  727                      struct componentname *cnp)
  728 {
  729         struct ext2fs_htree_entry *entries, *leaf_node;
  730         struct ext2fs_htree_lookup_info info;
  731         struct buf *bp = NULL;
  732         struct ext2fs *fs;
  733         struct m_ext2fs *m_fs;
  734         struct inode *ip;
  735         uint16_t ent_num;
  736         uint32_t dirhash, split_hash;
  737         uint32_t blksize, blknum;
  738         uint64_t cursize, dirsize;
  739         uint8_t hash_version;
  740         char *newdirblock = NULL;
  741         char *newidxblock = NULL;
  742         struct ext2fs_htree_node *dst_node;
  743         struct ext2fs_htree_entry *dst_entries;
  744         struct ext2fs_htree_entry *root_entires;
  745         struct buf *dst_bp = NULL;
  746         int error, write_bp = 0, write_dst_bp = 0, write_info = 0;
  747 
  748         ip = VTOI(dvp);
  749         m_fs = ip->i_e2fs;
  750         fs = m_fs->e2fs;
  751         blksize = m_fs->e2fs_bsize;
  752 
  753         if (ip->i_count != 0) 
  754                 return ext2_add_entry(dvp, entry);
  755 
  756         /* Target directory block is full, split it */
  757         memset(&info, 0, sizeof(info));
  758         error = ext2_htree_find_leaf(ip, entry->e2d_name, entry->e2d_namlen,
  759             &dirhash, &hash_version, &info);
  760         if (error)
  761                 return (error);
  762 
  763         entries = info.h_levels[info.h_levels_num - 1].h_entries;
  764         ent_num = ext2_htree_get_count(entries);
  765         if (ent_num == ext2_htree_get_limit(entries)) {
  766                 /* Split the index node. */
  767                 root_entires = info.h_levels[0].h_entries;
  768                 newidxblock = malloc(blksize, M_TEMP, M_WAITOK | M_ZERO);
  769                 dst_node = (struct ext2fs_htree_node *)newidxblock;
  770                 dst_entries = dst_node->h_entries;
  771                 memset(&dst_node->h_fake_dirent, 0,
  772                     sizeof(dst_node->h_fake_dirent));
  773                 dst_node->h_fake_dirent.e2d_reclen = blksize;
  774 
  775                 cursize = roundup(ip->i_size, blksize);
  776                 dirsize = roundup(ip->i_size, blksize) + blksize;
  777                 blknum = dirsize / blksize - 1;
  778 
  779                 error = ext2_htree_append_block(dvp, newidxblock,
  780                     cnp, blksize);
  781                 if (error)
  782                         goto finish;
  783                 error = ext2_blkatoff(dvp, cursize, NULL, &dst_bp);
  784                 if (error)
  785                         goto finish;
  786                 dst_node = (struct ext2fs_htree_node *)dst_bp->b_data;
  787                 dst_entries = dst_node->h_entries;
  788 
  789                 if (info.h_levels_num == 2) {
  790                         uint16_t src_ent_num, dst_ent_num;
  791 
  792                         if (ext2_htree_get_count(root_entires) ==
  793                             ext2_htree_get_limit(root_entires)) {
  794                                 /* Directory index is full */
  795                                 error = EIO;
  796                                 goto finish;
  797                         }
  798 
  799                         src_ent_num = ent_num / 2;
  800                         dst_ent_num = ent_num - src_ent_num;
  801                         split_hash = ext2_htree_get_hash(entries + src_ent_num);
  802 
  803                         /* Move half of index entries to the new index node */
  804                         memcpy(dst_entries, entries + src_ent_num,
  805                             dst_ent_num * sizeof(struct ext2fs_htree_entry));
  806                         ext2_htree_set_count(entries, src_ent_num);
  807                         ext2_htree_set_count(dst_entries, dst_ent_num);
  808                         ext2_htree_set_limit(dst_entries,
  809                             ext2_htree_node_limit(ip));
  810 
  811                         if (info.h_levels[1].h_entry >= entries + src_ent_num) {
  812                                 struct buf *tmp = info.h_levels[1].h_bp;
  813                                 info.h_levels[1].h_bp = dst_bp;
  814                                 dst_bp = tmp;
  815 
  816                                 info.h_levels[1].h_entry =
  817                                     info.h_levels[1].h_entry -
  818                                     (entries + src_ent_num) +
  819                                     dst_entries;
  820                                 info.h_levels[1].h_entries = dst_entries;
  821                         }
  822                         ext2_htree_insert_entry_to_level(&info.h_levels[0],
  823                             split_hash, blknum);
  824 
  825                         /* Write new index node to disk */
  826                         error = bwrite(dst_bp);
  827                         ip->i_flag |= IN_CHANGE | IN_UPDATE;
  828                         if (error)
  829                                 goto finish;
  830                         write_dst_bp = 1;
  831                 } else {
  832                         /* Create second level for htree index */
  833                         struct ext2fs_htree_root *idx_root;
  834 
  835                         memcpy(dst_entries, entries,
  836                             ent_num * sizeof(struct ext2fs_htree_entry));
  837                         ext2_htree_set_limit(dst_entries,
  838                             ext2_htree_node_limit(ip));
  839 
  840                         idx_root = (struct ext2fs_htree_root *)
  841                             info.h_levels[0].h_bp->b_data;
  842                         idx_root->h_info.h_ind_levels = 1;
  843 
  844                         ext2_htree_set_count(entries, 1);
  845                         ext2_htree_set_block(entries, blknum);
  846 
  847                         info.h_levels_num = 2;
  848                         info.h_levels[1].h_entries = dst_entries;
  849                         info.h_levels[1].h_entry = info.h_levels[0].h_entry -
  850                             info.h_levels[0].h_entries + dst_entries;
  851                         info.h_levels[1].h_bp = dst_bp;
  852                 }
  853         }
  854 
  855         leaf_node = info.h_levels[info.h_levels_num - 1].h_entry;
  856         blknum = ext2_htree_get_block(leaf_node);
  857         error = ext2_blkatoff(dvp, blknum * blksize, NULL, &bp);
  858         if (error)
  859                 goto finish;
  860 
  861         /* Split target directory block */
  862         newdirblock = malloc(blksize, M_TEMP, M_WAITOK | M_ZERO);
  863         ext2_htree_split_dirblock((char *)bp->b_data, newdirblock, blksize,
  864             fs->e3fs_hash_seed, hash_version, &split_hash, entry);
  865         cursize = roundup(ip->i_size, blksize);
  866         dirsize = roundup(ip->i_size, blksize) + blksize;
  867         blknum = dirsize / blksize - 1;
  868 
  869         /* Add index entry for the new directory block */
  870         ext2_htree_insert_entry(&info, split_hash, blknum);
  871 
  872         /* Write the new directory block to the end of the directory */
  873         error = ext2_htree_append_block(dvp, newdirblock, cnp, blksize);
  874         if (error)
  875                 goto finish;
  876 
  877         /* Write the target directory block */
  878         error = bwrite(bp);
  879         ip->i_flag |= IN_CHANGE | IN_UPDATE;
  880         if (error)
  881                 goto finish;
  882         write_bp = 1;
  883 
  884         /* Write the index block */
  885         error = ext2_htree_writebuf(&info);
  886         if (!error)
  887                 write_info = 1;
  888 
  889 finish:
  890         if (dst_bp != NULL && !write_dst_bp)
  891                 brelse(dst_bp);
  892         if (bp != NULL && !write_bp)
  893                 brelse(bp);
  894         if (newdirblock != NULL)
  895                 free(newdirblock, M_TEMP);
  896         if (newidxblock != NULL)
  897                 free(newidxblock, M_TEMP);
  898         if (!write_info)
  899                 ext2_htree_release(&info);
  900         return (error);
  901 }

Cache object: 6bd2d56c346a56897053651b5af95f4e


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.