The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/fs/ext2fs/ext2_htree.c

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    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/11.0/sys/fs/ext2fs/ext2_htree.c 298518 2016-04-23 18:28:59Z 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_version,
   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         if (EXT2_HAS_COMPAT_FEATURE(ip->i_e2fs, EXT2F_COMPAT_DIRHASHINDEX) &&
   93             ip->i_flag & IN_E3INDEX)
   94                 return (1);
   95         else
   96                 return (0);
   97 }
   98 
   99 static int
  100 ext2_htree_check_next(struct inode *ip, uint32_t hash, const char *name,
  101                 struct ext2fs_htree_lookup_info *info)
  102 {
  103         struct vnode *vp = ITOV(ip);
  104         struct ext2fs_htree_lookup_level *level;
  105         struct buf *bp;
  106         uint32_t next_hash;
  107         int idx = info->h_levels_num - 1;
  108         int levels = 0;
  109 
  110         do {
  111                 level = &info->h_levels[idx];
  112                 level->h_entry++;
  113                 if (level->h_entry < level->h_entries +
  114                     ext2_htree_get_count(level->h_entries))
  115                         break;
  116                 if (idx == 0)
  117                         return (0);
  118                 idx--;
  119                 levels++;
  120         } while (1);
  121 
  122         next_hash = ext2_htree_get_hash(level->h_entry);
  123         if ((hash & 1) == 0) {
  124                 if (hash != (next_hash & ~1))
  125                         return (0);
  126         }
  127 
  128         while (levels > 0) {
  129                 levels--;
  130                 if (ext2_blkatoff(vp, ext2_htree_get_block(level->h_entry) *
  131                     ip->i_e2fs->e2fs_bsize, NULL, &bp) != 0)
  132                         return (0);
  133                 level = &info->h_levels[idx + 1];
  134                 brelse(level->h_bp);
  135                 level->h_bp = bp;
  136                 level->h_entry = level->h_entries =
  137                     ((struct ext2fs_htree_node *)bp->b_data)->h_entries;
  138         }
  139 
  140         return (1);
  141 }
  142 
  143 static uint32_t
  144 ext2_htree_get_block(struct ext2fs_htree_entry *ep)
  145 {
  146         return (ep->h_blk & 0x00FFFFFF);
  147 }
  148 
  149 static void
  150 ext2_htree_set_block(struct ext2fs_htree_entry *ep, uint32_t blk)
  151 {
  152         ep->h_blk = blk;
  153 }
  154 
  155 static uint16_t
  156 ext2_htree_get_count(struct ext2fs_htree_entry *ep)
  157 {
  158         return (((struct ext2fs_htree_count *)(ep))->h_entries_num);
  159 }
  160 
  161 static void
  162 ext2_htree_set_count(struct ext2fs_htree_entry *ep, uint16_t cnt)
  163 {
  164         ((struct ext2fs_htree_count *)(ep))->h_entries_num = cnt;
  165 }
  166 
  167 static uint32_t
  168 ext2_htree_get_hash(struct ext2fs_htree_entry *ep)
  169 {
  170         return (ep->h_hash);
  171 }
  172 
  173 static uint16_t
  174 ext2_htree_get_limit(struct ext2fs_htree_entry *ep)
  175 {
  176         return (((struct ext2fs_htree_count *)(ep))->h_entries_max);
  177 }
  178 
  179 static void
  180 ext2_htree_set_hash(struct ext2fs_htree_entry *ep, uint32_t hash)
  181 {
  182         ep->h_hash = hash;
  183 }
  184 
  185 static void
  186 ext2_htree_set_limit(struct ext2fs_htree_entry *ep, uint16_t limit)
  187 {
  188         ((struct ext2fs_htree_count *)(ep))->h_entries_max = limit;
  189 }
  190 
  191 static void
  192 ext2_htree_release(struct ext2fs_htree_lookup_info *info)
  193 {
  194         u_int i;
  195 
  196         for (i = 0; i < info->h_levels_num; i++) {
  197                 struct buf *bp = info->h_levels[i].h_bp;
  198                 if (bp != NULL)
  199                         brelse(bp);
  200         }
  201 }
  202 
  203 static uint32_t
  204 ext2_htree_root_limit(struct inode *ip, int len)
  205 {
  206         uint32_t space;
  207 
  208         space = ip->i_e2fs->e2fs_bsize - EXT2_DIR_REC_LEN(1) -
  209             EXT2_DIR_REC_LEN(2) - len;
  210         return (space / sizeof(struct ext2fs_htree_entry));
  211 }
  212 
  213 static uint32_t
  214 ext2_htree_node_limit(struct inode *ip)
  215 {
  216         struct m_ext2fs *fs;
  217         uint32_t space;
  218 
  219         fs = ip->i_e2fs;
  220         space = fs->e2fs_bsize - EXT2_DIR_REC_LEN(0);
  221 
  222         return (space / sizeof(struct ext2fs_htree_entry));
  223 }
  224 
  225 static int
  226 ext2_htree_find_leaf(struct inode *ip, const char *name, int namelen,
  227                      uint32_t *hash, uint8_t *hash_ver,
  228                      struct ext2fs_htree_lookup_info *info)
  229 {
  230         struct vnode *vp;
  231         struct ext2fs *fs;
  232         struct m_ext2fs *m_fs;
  233         struct buf *bp = NULL;
  234         struct ext2fs_htree_root *rootp;
  235         struct ext2fs_htree_entry *entp, *start, *end, *middle, *found;
  236         struct ext2fs_htree_lookup_level *level_info;
  237         uint32_t hash_major = 0, hash_minor = 0;
  238         uint32_t levels, cnt;
  239         uint8_t hash_version;
  240 
  241         if (name == NULL || info == NULL)
  242                 return (-1);
  243 
  244         vp = ITOV(ip);
  245         fs = ip->i_e2fs->e2fs;
  246         m_fs = ip->i_e2fs;
  247 
  248         if (ext2_blkatoff(vp, 0, NULL, &bp) != 0)
  249                 return (-1);
  250 
  251         info->h_levels_num = 1;
  252         info->h_levels[0].h_bp = bp;
  253         rootp = (struct ext2fs_htree_root *)bp->b_data;
  254         if (rootp->h_info.h_hash_version != EXT2_HTREE_LEGACY &&
  255             rootp->h_info.h_hash_version != EXT2_HTREE_HALF_MD4 &&
  256             rootp->h_info.h_hash_version != EXT2_HTREE_TEA)
  257                 goto error;
  258 
  259         hash_version = rootp->h_info.h_hash_version;
  260         if (hash_version <= EXT2_HTREE_TEA)
  261                 hash_version += m_fs->e2fs_uhash;
  262         *hash_ver = hash_version;
  263 
  264         ext2_htree_hash(name, namelen, fs->e3fs_hash_seed,
  265             hash_version, &hash_major, &hash_minor);
  266         *hash = hash_major;
  267 
  268         if ((levels = rootp->h_info.h_ind_levels) > 1)
  269                 goto error;
  270 
  271         entp = (struct ext2fs_htree_entry *)(((char *)&rootp->h_info) +
  272             rootp->h_info.h_info_len);
  273 
  274         if (ext2_htree_get_limit(entp) !=
  275             ext2_htree_root_limit(ip, rootp->h_info.h_info_len))
  276                 goto error;
  277 
  278         while (1) {
  279                 cnt = ext2_htree_get_count(entp);
  280                 if (cnt == 0 || cnt > ext2_htree_get_limit(entp))
  281                         goto error;
  282 
  283                 start = entp + 1;
  284                 end = entp + cnt - 1;
  285                 while (start <= end) {
  286                         middle = start + (end - start) / 2;
  287                         if (ext2_htree_get_hash(middle) > hash_major)
  288                                 end = middle - 1;
  289                         else
  290                                 start = middle + 1;
  291                 }
  292                 found = start - 1;
  293 
  294                 level_info = &(info->h_levels[info->h_levels_num - 1]);
  295                 level_info->h_bp = bp;
  296                 level_info->h_entries = entp;
  297                 level_info->h_entry = found;
  298                 if (levels == 0)
  299                         return (0);
  300                 levels--;
  301                 if (ext2_blkatoff(vp,
  302                     ext2_htree_get_block(found) * m_fs->e2fs_bsize,
  303                     NULL, &bp) != 0)
  304                         goto error;
  305                 entp = ((struct ext2fs_htree_node *)bp->b_data)->h_entries;
  306                 info->h_levels_num++;
  307                 info->h_levels[info->h_levels_num - 1].h_bp = bp;
  308         }
  309 
  310 error:
  311         ext2_htree_release(info);
  312         return (-1);
  313 }
  314 
  315 /*
  316  * Try to lookup a directory entry in HTree index
  317  */
  318 int
  319 ext2_htree_lookup(struct inode *ip, const char *name, int namelen,
  320                   struct buf **bpp, int *entryoffp, doff_t *offp,
  321                   doff_t *prevoffp, doff_t *endusefulp,
  322                   struct ext2fs_searchslot *ss)
  323 {
  324         struct vnode *vp;
  325         struct ext2fs_htree_lookup_info info;
  326         struct ext2fs_htree_entry *leaf_node;
  327         struct m_ext2fs *m_fs;
  328         struct buf *bp;
  329         uint32_t blk;
  330         uint32_t dirhash;
  331         uint32_t bsize;
  332         uint8_t hash_version;
  333         int search_next;
  334         int found = 0;
  335 
  336         m_fs = ip->i_e2fs;
  337         bsize = m_fs->e2fs_bsize;
  338         vp = ITOV(ip);
  339 
  340         /* TODO: print error msg because we don't lookup '.' and '..' */
  341 
  342         memset(&info, 0, sizeof(info));
  343         if (ext2_htree_find_leaf(ip, name, namelen, &dirhash,
  344             &hash_version, &info))
  345                 return (-1);
  346 
  347         do {
  348                 leaf_node = info.h_levels[info.h_levels_num - 1].h_entry;
  349                 blk = ext2_htree_get_block(leaf_node);
  350                 if (ext2_blkatoff(vp, blk * bsize, NULL, &bp) != 0) {
  351                         ext2_htree_release(&info);
  352                         return (-1);
  353                 }
  354 
  355                 *offp = blk * bsize;
  356                 *entryoffp = 0;
  357                 *prevoffp = blk * bsize;
  358                 *endusefulp = blk * bsize;
  359 
  360                 if (ss->slotstatus == NONE) {
  361                         ss->slotoffset = -1;
  362                         ss->slotfreespace = 0;
  363                 }
  364 
  365                 if (ext2_search_dirblock(ip, bp->b_data, &found,
  366                     name, namelen, entryoffp, offp, prevoffp,
  367                     endusefulp, ss) != 0) {
  368                         brelse(bp);
  369                         ext2_htree_release(&info);
  370                         return (-1);
  371                 }
  372 
  373                 if (found) {
  374                         *bpp = bp;
  375                         ext2_htree_release(&info);
  376                         return (0);
  377                 }
  378 
  379                 brelse(bp);
  380                 search_next = ext2_htree_check_next(ip, dirhash, name, &info);
  381         } while (search_next);
  382 
  383         ext2_htree_release(&info);
  384         return (ENOENT);
  385 }
  386 
  387 static int
  388 ext2_htree_append_block(struct vnode *vp, char *data,
  389                         struct componentname *cnp, uint32_t blksize)
  390 {
  391         struct iovec aiov;
  392         struct uio auio;
  393         struct inode *dp = VTOI(vp);
  394         uint64_t cursize, newsize;
  395         int error;
  396 
  397         cursize = roundup(dp->i_size, blksize);
  398         newsize = cursize + blksize;
  399 
  400         auio.uio_offset = cursize;
  401         auio.uio_resid = blksize;
  402         aiov.iov_len = blksize;
  403         aiov.iov_base = data;
  404         auio.uio_iov = &aiov;
  405         auio.uio_iovcnt = 1;
  406         auio.uio_rw = UIO_WRITE;
  407         auio.uio_segflg = UIO_SYSSPACE;
  408         error = VOP_WRITE(vp, &auio, IO_SYNC, cnp->cn_cred);
  409         if (!error)
  410                 dp->i_size = newsize;
  411 
  412         return (error);
  413 }
  414 
  415 static int
  416 ext2_htree_writebuf(struct ext2fs_htree_lookup_info *info)
  417 {
  418         int i, error;
  419 
  420         for (i = 0; i < info->h_levels_num; i++) {
  421                 struct buf *bp = info->h_levels[i].h_bp;
  422                 error = bwrite(bp);
  423                 if (error)
  424                         return (error);
  425         }
  426 
  427         return (0);
  428 }
  429 
  430 static void
  431 ext2_htree_insert_entry_to_level(struct ext2fs_htree_lookup_level *level,
  432                                  uint32_t hash, uint32_t blk)
  433 {
  434         struct ext2fs_htree_entry *target;
  435         int entries_num;
  436 
  437         target = level->h_entry + 1;
  438         entries_num = ext2_htree_get_count(level->h_entries);
  439 
  440         memmove(target + 1, target, (char *)(level->h_entries + entries_num) -
  441             (char *)target);
  442         ext2_htree_set_block(target, blk);
  443         ext2_htree_set_hash(target, hash);
  444         ext2_htree_set_count(level->h_entries, entries_num + 1);
  445 }
  446 
  447 /*
  448  * Insert an index entry to the index node.
  449  */
  450 static void
  451 ext2_htree_insert_entry(struct ext2fs_htree_lookup_info *info,
  452                         uint32_t hash, uint32_t blk)
  453 {
  454         struct ext2fs_htree_lookup_level *level;
  455 
  456         level = &info->h_levels[info->h_levels_num - 1];
  457         ext2_htree_insert_entry_to_level(level, hash, blk);
  458 }
  459 
  460 /*
  461  * Compare two entry sort descriptors by name hash value.
  462  * This is used together with qsort.
  463  */
  464 static int
  465 ext2_htree_cmp_sort_entry(const void *e1, const void *e2)
  466 {
  467         const struct ext2fs_htree_sort_entry *entry1, *entry2;
  468 
  469         entry1 = (const struct ext2fs_htree_sort_entry *)e1;
  470         entry2 = (const struct ext2fs_htree_sort_entry *)e2;
  471 
  472         if (entry1->h_hash < entry2->h_hash)
  473                 return (-1);
  474         if (entry1->h_hash > entry2->h_hash)
  475                 return (1);
  476         return (0);
  477 }
  478 
  479 /*
  480  * Append an entry to the end of the directory block.
  481  */
  482 static void
  483 ext2_append_entry(char *block, uint32_t blksize,
  484                   struct ext2fs_direct_2 *last_entry,
  485                   struct ext2fs_direct_2 *new_entry)
  486 {
  487         uint16_t entry_len;
  488 
  489         entry_len = EXT2_DIR_REC_LEN(last_entry->e2d_namlen);
  490         last_entry->e2d_reclen = entry_len;
  491         last_entry = (struct ext2fs_direct_2 *)((char *)last_entry + entry_len);
  492         new_entry->e2d_reclen = block + blksize - (char *)last_entry;
  493         memcpy(last_entry, new_entry, EXT2_DIR_REC_LEN(new_entry->e2d_namlen));
  494 }
  495 
  496 /*
  497  * Move half of entries from the old directory block to the new one.
  498  */
  499 static int
  500 ext2_htree_split_dirblock(char *block1, char *block2, uint32_t blksize,
  501                           uint32_t *hash_seed, uint8_t hash_version,
  502                           uint32_t *split_hash, struct ext2fs_direct_2 *entry)
  503 {
  504         int entry_cnt = 0;
  505         int size = 0;
  506         int i, k;
  507         uint32_t offset;
  508         uint16_t entry_len = 0;
  509         uint32_t entry_hash;
  510         struct ext2fs_direct_2 *ep, *last;
  511         char *dest;
  512         struct ext2fs_htree_sort_entry *sort_info;
  513 
  514         ep = (struct ext2fs_direct_2 *)block1;
  515         dest = block2;
  516         sort_info = (struct ext2fs_htree_sort_entry *)
  517             ((char *)block2 + blksize);
  518 
  519         /*
  520          * Calculate name hash value for the entry which is to be added.
  521          */
  522         ext2_htree_hash(entry->e2d_name, entry->e2d_namlen, hash_seed,
  523             hash_version, &entry_hash, NULL);
  524 
  525         /*
  526          * Fill in directory entry sort descriptors.
  527          */
  528         while ((char *)ep < block1 + blksize) {
  529                 if (ep->e2d_ino && ep->e2d_namlen) {
  530                         entry_cnt++;
  531                         sort_info--;
  532                         sort_info->h_size = ep->e2d_reclen;
  533                         sort_info->h_offset = (char *)ep - block1;
  534                         ext2_htree_hash(ep->e2d_name, ep->e2d_namlen,
  535                             hash_seed, hash_version,
  536                             &sort_info->h_hash, NULL);
  537                 }
  538                 ep = (struct ext2fs_direct_2 *)
  539                     ((char *)ep + ep->e2d_reclen);
  540         }
  541 
  542         /*
  543          * Sort directory entry descriptors by name hash value.
  544          */
  545         qsort(sort_info, entry_cnt, sizeof(struct ext2fs_htree_sort_entry),
  546             ext2_htree_cmp_sort_entry);
  547 
  548         /*
  549          * Count the number of entries to move to directory block 2.
  550          */
  551         for (i = entry_cnt - 1; i >= 0; i--) {
  552                 if (sort_info[i].h_size + size > blksize / 2)
  553                         break;
  554                 size += sort_info[i].h_size;
  555         }
  556 
  557         *split_hash = sort_info[i + 1].h_hash;
  558 
  559         /*
  560          * Set collision bit.
  561          */
  562         if (*split_hash == sort_info[i].h_hash)
  563                 *split_hash += 1;
  564 
  565         /*
  566          * Move half of directory entries from block 1 to block 2.
  567          */
  568         for (k = i + 1; k < entry_cnt; k++) {
  569                 ep = (struct ext2fs_direct_2 *)((char *)block1 +
  570                     sort_info[k].h_offset);
  571                 entry_len = EXT2_DIR_REC_LEN(ep->e2d_namlen);
  572                 memcpy(dest, ep, entry_len);
  573                 ((struct ext2fs_direct_2 *)dest)->e2d_reclen = entry_len;
  574                 /* Mark directory entry as unused. */
  575                 ep->e2d_ino = 0;
  576                 dest += entry_len;
  577         }
  578         dest -= entry_len;
  579 
  580         /* Shrink directory entries in block 1. */
  581         last = (struct ext2fs_direct_2 *)block1;
  582         entry_len = 0;
  583         for (offset = 0; offset < blksize; ) {
  584                 ep = (struct ext2fs_direct_2 *)(block1 + offset);
  585                 offset += ep->e2d_reclen;
  586                 if (ep->e2d_ino) {
  587                         last = (struct ext2fs_direct_2 *)
  588                            ((char *)last + entry_len);
  589                         entry_len = EXT2_DIR_REC_LEN(ep->e2d_namlen);
  590                         memcpy((void *)last, (void *)ep, entry_len);
  591                         last->e2d_reclen = entry_len;
  592                 }
  593         }
  594 
  595         if (entry_hash >= *split_hash) {
  596                 /* Add entry to block 2. */
  597                 ext2_append_entry(block2, blksize,
  598                     (struct ext2fs_direct_2 *)dest, entry);
  599 
  600                 /* Adjust length field of last entry of block 1. */
  601                 last->e2d_reclen = block1 + blksize - (char *)last;
  602         } else {
  603                 /* Add entry to block 1. */
  604                 ext2_append_entry(block1, blksize, last, entry);
  605 
  606                 /* Adjust length field of last entry of block 2. */
  607                 ((struct ext2fs_direct_2 *)dest)->e2d_reclen =
  608                     block2 + blksize - dest;
  609         }
  610 
  611         return (0);
  612 }
  613 
  614 /*
  615  * Create an HTree index for a directory
  616  */
  617 int
  618 ext2_htree_create_index(struct vnode *vp, struct componentname *cnp,
  619                         struct ext2fs_direct_2 *new_entry)
  620 {
  621         struct buf *bp = NULL;
  622         struct inode *dp;
  623         struct ext2fs *fs;
  624         struct m_ext2fs *m_fs;
  625         struct ext2fs_direct_2 *ep, *dotdot;
  626         struct ext2fs_htree_root *root;
  627         struct ext2fs_htree_lookup_info info;
  628         uint32_t blksize, dirlen, split_hash;
  629         uint8_t hash_version;
  630         char *buf1 = NULL;
  631         char *buf2 = NULL;
  632         int error = 0;
  633 
  634         dp = VTOI(vp);
  635         fs = dp->i_e2fs->e2fs;
  636         m_fs = dp->i_e2fs;
  637         blksize = m_fs->e2fs_bsize;
  638 
  639         buf1 = malloc(blksize, M_TEMP, M_WAITOK | M_ZERO);
  640         buf2 = malloc(blksize, M_TEMP, M_WAITOK | M_ZERO);
  641 
  642         if ((error = ext2_blkatoff(vp, 0, NULL, &bp)) != 0)
  643                 goto out;
  644 
  645         root = (struct ext2fs_htree_root *)bp->b_data;
  646         dotdot = (struct ext2fs_direct_2 *)((char *)&(root->h_dotdot));
  647         ep = (struct ext2fs_direct_2 *)((char *)dotdot + dotdot->e2d_reclen);
  648         dirlen = (char *)root + blksize - (char *)ep;
  649         memcpy(buf1, ep, dirlen);
  650         ep = (struct ext2fs_direct_2 *)buf1;
  651         while ((char *)ep < buf1 + dirlen)
  652                 ep = (struct ext2fs_direct_2 *)
  653                     ((char *)ep + ep->e2d_reclen);
  654         ep->e2d_reclen = buf1 + blksize - (char *)ep;
  655 
  656         dp->i_flag |= IN_E3INDEX;
  657 
  658         /*
  659          * Initialize index root.
  660          */
  661         dotdot->e2d_reclen = blksize - EXT2_DIR_REC_LEN(1);
  662         memset(&root->h_info, 0, sizeof(root->h_info));
  663         root->h_info.h_hash_version = fs->e3fs_def_hash_version;
  664         root->h_info.h_info_len = sizeof(root->h_info);
  665         ext2_htree_set_block(root->h_entries, 1);
  666         ext2_htree_set_count(root->h_entries, 1);
  667         ext2_htree_set_limit(root->h_entries,
  668             ext2_htree_root_limit(dp, sizeof(root->h_info)));
  669 
  670         memset(&info, 0, sizeof(info));
  671         info.h_levels_num = 1;
  672         info.h_levels[0].h_entries = root->h_entries;
  673         info.h_levels[0].h_entry = root->h_entries;
  674 
  675         hash_version = root->h_info.h_hash_version;
  676         if (hash_version <= EXT2_HTREE_TEA)
  677                 hash_version += m_fs->e2fs_uhash;
  678         ext2_htree_split_dirblock(buf1, buf2, blksize, fs->e3fs_hash_seed,
  679             hash_version, &split_hash, new_entry);
  680         ext2_htree_insert_entry(&info, split_hash, 2);
  681 
  682         /*
  683          * Write directory block 0.
  684          */
  685         if (DOINGASYNC(vp)) {
  686                 bdwrite(bp);
  687                 error = 0;
  688         } else {
  689                 error = bwrite(bp);
  690         }
  691         dp->i_flag |= IN_CHANGE | IN_UPDATE;
  692         if (error)
  693                 goto out;
  694 
  695         /*
  696          * Write directory block 1.
  697          */
  698         error = ext2_htree_append_block(vp, buf1, cnp, blksize);
  699         if (error)
  700                 goto out1;
  701 
  702         /*
  703          * Write directory block 2.
  704          */
  705         error = ext2_htree_append_block(vp, buf2, cnp, blksize);
  706 
  707         free(buf1, M_TEMP);
  708         free(buf2, M_TEMP);
  709         return (error);
  710 out:
  711         if (bp != NULL)
  712                 brelse(bp);
  713 out1:
  714         free(buf1, M_TEMP);
  715         free(buf2, M_TEMP);
  716         return (error);
  717 }
  718 
  719 /*
  720  * Add an entry to the directory using htree index.
  721  */
  722 int
  723 ext2_htree_add_entry(struct vnode *dvp, struct ext2fs_direct_2 *entry,
  724                      struct componentname *cnp)
  725 {
  726         struct ext2fs_htree_entry *entries, *leaf_node;
  727         struct ext2fs_htree_lookup_info info;
  728         struct buf *bp = NULL;
  729         struct ext2fs *fs;
  730         struct m_ext2fs *m_fs;
  731         struct inode *ip;
  732         uint16_t ent_num;
  733         uint32_t dirhash, split_hash;
  734         uint32_t blksize, blknum;
  735         uint64_t cursize, dirsize;
  736         uint8_t hash_version;
  737         char *newdirblock = NULL;
  738         char *newidxblock = NULL;
  739         struct ext2fs_htree_node *dst_node;
  740         struct ext2fs_htree_entry *dst_entries;
  741         struct ext2fs_htree_entry *root_entires;
  742         struct buf *dst_bp = NULL;
  743         int error, write_bp = 0, write_dst_bp = 0, write_info = 0;
  744 
  745         ip = VTOI(dvp);
  746         m_fs = ip->i_e2fs;
  747         fs = m_fs->e2fs;
  748         blksize = m_fs->e2fs_bsize;
  749 
  750         if (ip->i_count != 0) 
  751                 return ext2_add_entry(dvp, entry);
  752 
  753         /* Target directory block is full, split it */
  754         memset(&info, 0, sizeof(info));
  755         error = ext2_htree_find_leaf(ip, entry->e2d_name, entry->e2d_namlen,
  756             &dirhash, &hash_version, &info);
  757         if (error)
  758                 return (error);
  759 
  760         entries = info.h_levels[info.h_levels_num - 1].h_entries;
  761         ent_num = ext2_htree_get_count(entries);
  762         if (ent_num == ext2_htree_get_limit(entries)) {
  763                 /* Split the index node. */
  764                 root_entires = info.h_levels[0].h_entries;
  765                 newidxblock = malloc(blksize, M_TEMP, M_WAITOK | M_ZERO);
  766                 dst_node = (struct ext2fs_htree_node *)newidxblock;
  767                 dst_entries = dst_node->h_entries;
  768                 memset(&dst_node->h_fake_dirent, 0,
  769                     sizeof(dst_node->h_fake_dirent));
  770                 dst_node->h_fake_dirent.e2d_reclen = blksize;
  771 
  772                 cursize = roundup(ip->i_size, blksize);
  773                 dirsize = cursize + blksize;
  774                 blknum = dirsize / blksize - 1;
  775 
  776                 error = ext2_htree_append_block(dvp, newidxblock,
  777                     cnp, blksize);
  778                 if (error)
  779                         goto finish;
  780                 error = ext2_blkatoff(dvp, cursize, NULL, &dst_bp);
  781                 if (error)
  782                         goto finish;
  783                 dst_node = (struct ext2fs_htree_node *)dst_bp->b_data;
  784                 dst_entries = dst_node->h_entries;
  785 
  786                 if (info.h_levels_num == 2) {
  787                         uint16_t src_ent_num, dst_ent_num;
  788 
  789                         if (ext2_htree_get_count(root_entires) ==
  790                             ext2_htree_get_limit(root_entires)) {
  791                                 /* Directory index is full */
  792                                 error = EIO;
  793                                 goto finish;
  794                         }
  795 
  796                         src_ent_num = ent_num / 2;
  797                         dst_ent_num = ent_num - src_ent_num;
  798                         split_hash = ext2_htree_get_hash(entries + src_ent_num);
  799 
  800                         /* Move half of index entries to the new index node */
  801                         memcpy(dst_entries, entries + src_ent_num,
  802                             dst_ent_num * sizeof(struct ext2fs_htree_entry));
  803                         ext2_htree_set_count(entries, src_ent_num);
  804                         ext2_htree_set_count(dst_entries, dst_ent_num);
  805                         ext2_htree_set_limit(dst_entries,
  806                             ext2_htree_node_limit(ip));
  807 
  808                         if (info.h_levels[1].h_entry >= entries + src_ent_num) {
  809                                 struct buf *tmp = info.h_levels[1].h_bp;
  810                                 info.h_levels[1].h_bp = dst_bp;
  811                                 dst_bp = tmp;
  812 
  813                                 info.h_levels[1].h_entry =
  814                                     info.h_levels[1].h_entry -
  815                                     (entries + src_ent_num) +
  816                                     dst_entries;
  817                                 info.h_levels[1].h_entries = dst_entries;
  818                         }
  819                         ext2_htree_insert_entry_to_level(&info.h_levels[0],
  820                             split_hash, blknum);
  821 
  822                         /* Write new index node to disk */
  823                         error = bwrite(dst_bp);
  824                         ip->i_flag |= IN_CHANGE | IN_UPDATE;
  825                         if (error)
  826                                 goto finish;
  827                         write_dst_bp = 1;
  828                 } else {
  829                         /* Create second level for htree index */
  830                         struct ext2fs_htree_root *idx_root;
  831 
  832                         memcpy(dst_entries, entries,
  833                             ent_num * sizeof(struct ext2fs_htree_entry));
  834                         ext2_htree_set_limit(dst_entries,
  835                             ext2_htree_node_limit(ip));
  836 
  837                         idx_root = (struct ext2fs_htree_root *)
  838                             info.h_levels[0].h_bp->b_data;
  839                         idx_root->h_info.h_ind_levels = 1;
  840 
  841                         ext2_htree_set_count(entries, 1);
  842                         ext2_htree_set_block(entries, blknum);
  843 
  844                         info.h_levels_num = 2;
  845                         info.h_levels[1].h_entries = dst_entries;
  846                         info.h_levels[1].h_entry = info.h_levels[0].h_entry -
  847                             info.h_levels[0].h_entries + dst_entries;
  848                         info.h_levels[1].h_bp = dst_bp;
  849                         dst_bp = NULL;
  850                 }
  851         }
  852 
  853         leaf_node = info.h_levels[info.h_levels_num - 1].h_entry;
  854         blknum = ext2_htree_get_block(leaf_node);
  855         error = ext2_blkatoff(dvp, blknum * blksize, NULL, &bp);
  856         if (error)
  857                 goto finish;
  858 
  859         /* Split target directory block */
  860         newdirblock = malloc(blksize, M_TEMP, M_WAITOK | M_ZERO);
  861         ext2_htree_split_dirblock((char *)bp->b_data, newdirblock, blksize,
  862             fs->e3fs_hash_seed, hash_version, &split_hash, entry);
  863         cursize = roundup(ip->i_size, blksize);
  864         dirsize = cursize + blksize;
  865         blknum = dirsize / blksize - 1;
  866 
  867         /* Add index entry for the new directory block */
  868         ext2_htree_insert_entry(&info, split_hash, blknum);
  869 
  870         /* Write the new directory block to the end of the directory */
  871         error = ext2_htree_append_block(dvp, newdirblock, cnp, blksize);
  872         if (error)
  873                 goto finish;
  874 
  875         /* Write the target directory block */
  876         error = bwrite(bp);
  877         ip->i_flag |= IN_CHANGE | IN_UPDATE;
  878         if (error)
  879                 goto finish;
  880         write_bp = 1;
  881 
  882         /* Write the index block */
  883         error = ext2_htree_writebuf(&info);
  884         if (!error)
  885                 write_info = 1;
  886 
  887 finish:
  888         if (dst_bp != NULL && !write_dst_bp)
  889                 brelse(dst_bp);
  890         if (bp != NULL && !write_bp)
  891                 brelse(bp);
  892         if (newdirblock != NULL)
  893                 free(newdirblock, M_TEMP);
  894         if (newidxblock != NULL)
  895                 free(newidxblock, M_TEMP);
  896         if (!write_info)
  897                 ext2_htree_release(&info);
  898         return (error);
  899 }

Cache object: f41fe5c040c919aa4ca4348c54dbd1ac


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