sys/arch/x68k/stand/boot_ufs/readufs_ffs.c

   1 /*      $NetBSD: readufs_ffs.c,v 1.11 2009/03/14 15:36:15 dsl Exp $     */
   2 /*      from Id: readufs_ffs.c,v 1.6 2003/04/08 09:19:32 itohy Exp      */
   3
   4 /*
   5  * FS specific support for 4.2BSD Fast Filesystem
   6  *
   7  * Written in 1999, 2002, 2003 by ITOH Yasufumi (itohy@NetBSD.org).
   8  * Public domain.
   9  *
  10  * Intended to be used for boot programs (first stage).
  11  * DON'T ADD ANY FANCY FEATURE.  THIS SHALL BE COMPACT.
  12  */
  13
  14 #include "readufs.h"
  15
  16 #include <ufs/ffs/fs.h>
  17
  18 static int get_ffs_inode(ino32_t ino, union ufs_dinode *dibuf);
  19
  20 #define fsi     (*ufsinfo)
  21 #define fsi_ffs fsi.fs_u.u_ffs
  22
  23 /*
  24  * Read and check superblock.
  25  * If it is an FFS, save information from the superblock.
  26  */
  27 int
  28 try_ffs(void)
  29 {
  30         union {
  31                 struct fs       sblk;
  32                 unsigned char   pad[SBLOCKSIZE];
  33         } buf;
  34         struct ufs_info *ufsinfo = &ufs_info;
  35         static const int sblocs[] = SBLOCKSEARCH;
  36         const int *sbl;
  37         int magic;
  38
  39 #ifdef DEBUG_WITH_STDIO
  40         printf("trying FFS\n");
  41 #endif
  42         /* read FFS superblock */
  43         for (sbl = sblocs; ; sbl++) {
  44                 if (*sbl == -1)
  45                         return 1;
  46
  47                 RAW_READ(&buf, (daddr_t) btodb(*sbl), SBLOCKSIZE);
  48
  49                 magic = buf.sblk.fs_magic;
  50 #ifdef DEBUG_WITH_STDIO
  51                 printf("FFS: sblk: pos %d magic 0x%x\n", btodb(*sbl), magic);
  52 #endif
  53 #ifdef USE_UFS1
  54                 if (magic == FS_UFS1_MAGIC
  55                     && !(buf.sblk.fs_old_flags & FS_FLAGS_UPDATED)) {
  56                         if (*sbl == SBLOCK_UFS2)
  57                                 /* might be an alternate suberblock */
  58                                 continue;
  59                         break;
  60                 }
  61 #endif
  62                 if (*sbl != buf.sblk.fs_sblockloc)
  63                         /* must be an alternate suberblock */
  64                         continue;
  65
  66 #ifdef USE_UFS1
  67                 if (magic == FS_UFS1_MAGIC) {
  68                         break;
  69                 }
  70 #endif
  71 #ifdef USE_UFS2
  72                 if (magic == FS_UFS2_MAGIC) {
  73 #ifdef USE_UFS1
  74                         fsi.ufstype = UFSTYPE_UFS2;
  75 #endif
  76                         break;
  77                 }
  78 #endif
  79         }
  80
  81         /*
  82          * XXX <ufs/ffs/fs.h> always uses fs_magic
  83          * (UFS1 only or UFS2 only is impossible)
  84          */
  85         fsi_ffs.magic = magic;
  86 #ifdef DEBUG_WITH_STDIO
  87         printf("FFS: detected UFS%d format\n", (magic == FS_UFS2_MAGIC) + 1);
  88 #endif
  89
  90         /* This partition looks like an FFS. */
  91         fsi.fstype = UFSTYPE_FFS;
  92         fsi.get_inode = get_ffs_inode;
  93
  94         /* Get information from the superblock. */
  95         fsi.bsize = buf.sblk.fs_bsize;
  96         fsi.fsbtodb = buf.sblk.fs_fsbtodb;
  97         fsi.nindir = buf.sblk.fs_nindir;
  98
  99         fsi_ffs.iblkno = buf.sblk.fs_iblkno;
 100         fsi_ffs.old_cgoffset = buf.sblk.fs_old_cgoffset;
 101         fsi_ffs.old_cgmask = buf.sblk.fs_old_cgmask;
 102         fsi_ffs.fragshift = buf.sblk.fs_fragshift;
 103         fsi_ffs.inopb = buf.sblk.fs_inopb;
 104         fsi_ffs.ipg = buf.sblk.fs_ipg;
 105         fsi_ffs.fpg = buf.sblk.fs_fpg;
 106
 107         return 0;
 108 }
 109
 110 /* for inode macros */
 111 #define fs_ipg          fs_u.u_ffs.ipg
 112 #define fs_iblkno       fs_u.u_ffs.iblkno
 113 #define fs_old_cgoffset fs_u.u_ffs.old_cgoffset
 114 #define fs_old_cgmask   fs_u.u_ffs.old_cgmask
 115 #define fs_fpg          fs_u.u_ffs.fpg
 116 #define fs_magic        fs_u.u_ffs.magic
 117 #define fs_inopb        fs_u.u_ffs.inopb
 118 #define fs_fragshift    fs_u.u_ffs.fragshift
 119 #define fs_fsbtodb      fsbtodb
 120
 121 /*
 122  * Get inode from disk.
 123  */
 124 static int
 125 get_ffs_inode(ino32_t ino, union ufs_dinode *dibuf)
 126 {
 127         struct ufs_info *ufsinfo = &ufs_info;
 128         union ufs_dinode *buf = alloca((size_t) fsi.bsize);
 129         union ufs_dinode *di;
 130         unsigned ioff;
 131
 132         RAW_READ(buf, fsbtodb(&fsi, ino_to_fsba(&fsi, ino)),
 133                         (size_t) fsi.bsize);
 134
 135         ioff = ino_to_fsbo(&fsi, ino);
 136
 137 #if defined(USE_UFS1) && defined(USE_UFS2)
 138         if (ufsinfo->ufstype == UFSTYPE_UFS1)
 139                 di = (void *) &(&buf->di1)[ioff];
 140         else {
 141                 di = (void *) &(&buf->di2)[ioff];
 142
 143                 /* XXX for DI_SIZE() macro */
 144                 di->di1.di_size = di->di2.di_size;
 145         }
 146 #else
 147         di = &buf[ioff];
 148 #endif
 149
 150 #ifdef DEBUG_WITH_STDIO
 151         printf("FFS: dinode(%d): mode 0%o, nlink %d, size %u\n",
 152                 ino, di->di_common.di_mode, di->di_common.di_nlink,
 153                 (unsigned) DI_SIZE(di));
 154 #endif
 155
 156         if (di->di_common.di_mode == 0)
 157                 return 1;       /* unused inode (file is not found) */
 158
 159         *dibuf = *di;
 160
 161         return 0;
 162 }