ufsread.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) 2002 McAfee, Inc.
    3  * All rights reserved.
    4  *
    5  * This software was developed for the FreeBSD Project by Marshall
    6  * Kirk McKusick and McAfee Research,, the Security Research Division of
    7  * McAfee, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as
    8  * part of the DARPA CHATS research program
    9  *
   10  * Redistribution and use in source and binary forms, with or without
   11  * modification, are permitted provided that the following conditions
   12  * are met:
   13  * 1. Redistributions of source code must retain the above copyright
   14  *    notice, this list of conditions and the following disclaimer.
   15  * 2. Redistributions in binary form must reproduce the above copyright
   16  *    notice, this list of conditions and the following disclaimer in the
   17  *    documentation and/or other materials provided with the distribution.
   18  *
   19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   29  * SUCH DAMAGE.
   30  */
   31 /*-
   32  * Copyright (c) 1998 Robert Nordier
   33  * All rights reserved.
   34  *
   35  * Redistribution and use in source and binary forms are freely
   36  * permitted provided that the above copyright notice and this
   37  * paragraph and the following disclaimer are duplicated in all
   38  * such forms.
   39  *
   40  * This software is provided "AS IS" and without any express or
   41  * implied warranties, including, without limitation, the implied
   42  * warranties of merchantability and fitness for a particular
   43  * purpose.
   44  */
   45 
   46 #include <sys/cdefs.h>
   47 __FBSDID("$FreeBSD$");
   48 
   49 #include <ufs/ufs/dinode.h>
   50 #include <ufs/ffs/fs.h>
   51 #ifdef UFS_SMALL_CGBASE
   52 /* XXX: Revert to old (broken for over 1.5Tb filesystems) version of cgbase
   53    (see sys/ufs/ffs/fs.h rev 1.39) so that small boot loaders (e.g. boot2) can
   54    support both UFS1 and UFS2. */
   55 #undef cgbase
   56 #define cgbase(fs, c)   ((ufs2_daddr_t)((fs)->fs_fpg * (c)))
   57 #endif
   58 
   59 /*
   60  * We use 4k `virtual' blocks for filesystem data, whatever the actual
   61  * filesystem block size. FFS blocks are always a multiple of 4k.
   62  */
   63 #define VBLKSHIFT       12
   64 #define VBLKSIZE        (1 << VBLKSHIFT)
   65 #define VBLKMASK        (VBLKSIZE - 1)
   66 #define DBPERVBLK       (VBLKSIZE / DEV_BSIZE)
   67 #define INDIRPERVBLK(fs) (NINDIR(fs) / ((fs)->fs_bsize >> VBLKSHIFT))
   68 #define IPERVBLK(fs)    (INOPB(fs) / ((fs)->fs_bsize >> VBLKSHIFT))
   69 #define INO_TO_VBA(fs, ipervblk, x) \
   70     (fsbtodb(fs, cgimin(fs, ino_to_cg(fs, x))) + \
   71     (((x) % (fs)->fs_ipg) / (ipervblk) * DBPERVBLK))
   72 #define INO_TO_VBO(ipervblk, x) ((x) % ipervblk)
   73 #define FS_TO_VBA(fs, fsb, off) (fsbtodb(fs, fsb) + \
   74     ((off) / VBLKSIZE) * DBPERVBLK)
   75 #define FS_TO_VBO(fs, fsb, off) ((off) & VBLKMASK)
   76 
   77 /* Buffers that must not span a 64k boundary. */
   78 struct dmadat {
   79         char blkbuf[VBLKSIZE];  /* filesystem blocks */
   80         char indbuf[VBLKSIZE];  /* indir blocks */
   81         char sbbuf[SBLOCKSIZE]; /* superblock */
   82         char secbuf[DEV_BSIZE]; /* for MBR/disklabel */
   83 };
   84 static struct dmadat *dmadat;
   85 
   86 static ino_t lookup(const char *);
   87 static ssize_t fsread(ino_t, void *, size_t);
   88 
   89 static int ls, dsk_meta;
   90 static uint32_t fs_off;
   91 
   92 static __inline int
   93 fsfind(const char *name, ino_t * ino)
   94 {
   95         char buf[DEV_BSIZE];
   96         struct dirent *d;
   97         char *s;
   98         ssize_t n;
   99 
  100         fs_off = 0;
  101         while ((n = fsread(*ino, buf, DEV_BSIZE)) > 0)
  102                 for (s = buf; s < buf + DEV_BSIZE;) {
  103                         d = (void *)s;
  104                         if (ls)
  105                                 printf("%s ", d->d_name);
  106                         else if (!strcmp(name, d->d_name)) {
  107                                 *ino = d->d_fileno;
  108                                 return d->d_type;
  109                         }
  110                         s += d->d_reclen;
  111                 }
  112         if (n != -1 && ls)
  113                 printf("\n");
  114         return 0;
  115 }
  116 
  117 static ino_t
  118 lookup(const char *path)
  119 {
  120         char name[MAXNAMLEN + 1];
  121         const char *s;
  122         ino_t ino;
  123         ssize_t n;
  124         int dt;
  125 
  126         ino = ROOTINO;
  127         dt = DT_DIR;
  128         name[0] = '/';
  129         name[1] = '\0';
  130         for (;;) {
  131                 if (*path == '/')
  132                         path++;
  133                 if (!*path)
  134                         break;
  135                 for (s = path; *s && *s != '/'; s++);
  136                 if ((n = s - path) > MAXNAMLEN)
  137                         return 0;
  138                 ls = *path == '?' && n == 1 && !*s;
  139                 memcpy(name, path, n);
  140                 name[n] = 0;
  141                 if (dt != DT_DIR) {
  142                         printf("%s: not a directory.\n", name);
  143                         return (0);
  144                 }
  145                 if ((dt = fsfind(name, &ino)) <= 0)
  146                         break;
  147                 path = s;
  148         }
  149         return dt == DT_REG ? ino : 0;
  150 }
  151 
  152 /*
  153  * Possible superblock locations ordered from most to least likely.
  154  */
  155 static int sblock_try[] = SBLOCKSEARCH;
  156 
  157 #if defined(UFS2_ONLY)
  158 #define DIP(field) dp2.field
  159 #elif defined(UFS1_ONLY)
  160 #define DIP(field) dp1.field
  161 #else
  162 #define DIP(field) fs->fs_magic == FS_UFS1_MAGIC ? dp1.field : dp2.field
  163 #endif
  164 
  165 static ssize_t
  166 fsread(ino_t inode, void *buf, size_t nbyte)
  167 {
  168 #ifndef UFS2_ONLY
  169         static struct ufs1_dinode dp1;
  170 #endif
  171 #ifndef UFS1_ONLY
  172         static struct ufs2_dinode dp2;
  173 #endif
  174         static ino_t inomap;
  175         char *blkbuf;
  176         void *indbuf;
  177         struct fs *fs;
  178         char *s;
  179         size_t n, nb, size, off, vboff;
  180         ufs_lbn_t lbn;
  181         ufs2_daddr_t addr, vbaddr;
  182         static ufs2_daddr_t blkmap, indmap;
  183         u_int u;
  184 
  185 
  186         blkbuf = dmadat->blkbuf;
  187         indbuf = dmadat->indbuf;
  188         fs = (struct fs *)dmadat->sbbuf;
  189         if (!dsk_meta) {
  190                 inomap = 0;
  191                 for (n = 0; sblock_try[n] != -1; n++) {
  192                         if (dskread(fs, sblock_try[n] / DEV_BSIZE,
  193                             SBLOCKSIZE / DEV_BSIZE))
  194                                 return -1;
  195                         if ((
  196 #if defined(UFS1_ONLY)
  197                              fs->fs_magic == FS_UFS1_MAGIC
  198 #elif defined(UFS2_ONLY)
  199                             (fs->fs_magic == FS_UFS2_MAGIC &&
  200                             fs->fs_sblockloc == sblock_try[n])
  201 #else
  202                              fs->fs_magic == FS_UFS1_MAGIC ||
  203                             (fs->fs_magic == FS_UFS2_MAGIC &&
  204                             fs->fs_sblockloc == sblock_try[n])
  205 #endif
  206                             ) &&
  207                             fs->fs_bsize <= MAXBSIZE &&
  208                             fs->fs_bsize >= sizeof(struct fs))
  209                                 break;
  210                 }
  211                 if (sblock_try[n] == -1) {
  212                         printf("Not ufs\n");
  213                         return -1;
  214                 }
  215                 dsk_meta++;
  216         }
  217         if (!inode)
  218                 return 0;
  219         if (inomap != inode) {
  220                 n = IPERVBLK(fs);
  221                 if (dskread(blkbuf, INO_TO_VBA(fs, n, inode), DBPERVBLK))
  222                         return -1;
  223                 n = INO_TO_VBO(n, inode);
  224 #if defined(UFS1_ONLY)
  225                 dp1 = ((struct ufs1_dinode *)blkbuf)[n];
  226 #elif defined(UFS2_ONLY)
  227                 dp2 = ((struct ufs2_dinode *)blkbuf)[n];
  228 #else
  229                 if (fs->fs_magic == FS_UFS1_MAGIC)
  230                         dp1 = ((struct ufs1_dinode *)blkbuf)[n];
  231                 else
  232                         dp2 = ((struct ufs2_dinode *)blkbuf)[n];
  233 #endif
  234                 inomap = inode;
  235                 fs_off = 0;
  236                 blkmap = indmap = 0;
  237         }
  238         s = buf;
  239         size = DIP(di_size);
  240         n = size - fs_off;
  241         if (nbyte > n)
  242                 nbyte = n;
  243         nb = nbyte;
  244         while (nb) {
  245                 lbn = lblkno(fs, fs_off);
  246                 off = blkoff(fs, fs_off);
  247                 if (lbn < NDADDR) {
  248                         addr = DIP(di_db[lbn]);
  249                 } else if (lbn < NDADDR + NINDIR(fs)) {
  250                         n = INDIRPERVBLK(fs);
  251                         addr = DIP(di_ib[0]);
  252                         u = (u_int)(lbn - NDADDR) / n * DBPERVBLK;
  253                         vbaddr = fsbtodb(fs, addr) + u;
  254                         if (indmap != vbaddr) {
  255                                 if (dskread(indbuf, vbaddr, DBPERVBLK))
  256                                         return -1;
  257                                 indmap = vbaddr;
  258                         }
  259                         n = (lbn - NDADDR) & (n - 1);
  260 #if defined(UFS1_ONLY)
  261                         addr = ((ufs1_daddr_t *)indbuf)[n];
  262 #elif defined(UFS2_ONLY)
  263                         addr = ((ufs2_daddr_t *)indbuf)[n];
  264 #else
  265                         if (fs->fs_magic == FS_UFS1_MAGIC)
  266                                 addr = ((ufs1_daddr_t *)indbuf)[n];
  267                         else
  268                                 addr = ((ufs2_daddr_t *)indbuf)[n];
  269 #endif
  270                 } else {
  271                         return -1;
  272                 }
  273                 vbaddr = fsbtodb(fs, addr) + (off >> VBLKSHIFT) * DBPERVBLK;
  274                 vboff = off & VBLKMASK;
  275                 n = sblksize(fs, size, lbn) - (off & ~VBLKMASK);
  276                 if (n > VBLKSIZE)
  277                         n = VBLKSIZE;
  278                 if (blkmap != vbaddr) {
  279                         if (dskread(blkbuf, vbaddr, n >> DEV_BSHIFT))
  280                                 return -1;
  281                         blkmap = vbaddr;
  282                 }
  283                 n -= vboff;
  284                 if (n > nb)
  285                         n = nb;
  286                 memcpy(s, blkbuf + vboff, n);
  287                 s += n;
  288                 fs_off += n;
  289                 nb -= n;
  290         }
  291         return nbyte;
  292 }
Cache object: fdfb584fa326bb9c4c6b2dff9770bad3
[ 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.
FreeBSD/Linux Kernel Cross Reference sys/boot/common/ufsread.c

FreeBSD/Linux Kernel Cross Reference
sys/boot/common/ufsread.c
