sys/geom/geom_vol_ffs.c

   1 /*-
   2  * Copyright (c) 2002, 2003 Gordon Tetlow
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  */
  26
  27 #include <sys/cdefs.h>
  28 __FBSDID("$FreeBSD$");
  29
  30 #include <sys/param.h>
  31 #include <sys/errno.h>
  32 #include <sys/systm.h>
  33 #include <sys/sysctl.h>
  34 #include <sys/kernel.h>
  35 #include <sys/malloc.h>
  36 #include <sys/bio.h>
  37 #include <sys/lock.h>
  38 #include <sys/mutex.h>
  39
  40 #include <ufs/ufs/dinode.h>
  41 #include <ufs/ffs/fs.h>
  42
  43 #include <geom/geom.h>
  44 #include <geom/geom_slice.h>
  45
  46 FEATURE(geom_vol, "GEOM support for volume names from UFS superblock");
  47
  48 #define VOL_FFS_CLASS_NAME "VOL_FFS"
  49
  50 static int superblocks[] = SBLOCKSEARCH;
  51
  52 struct g_vol_ffs_softc {
  53         char *  vol;
  54 };
  55
  56 static int
  57 g_vol_ffs_start(struct bio *bp __unused)
  58 {
  59         return(0);
  60 }
  61
  62 static struct g_geom *
  63 g_vol_ffs_taste(struct g_class *mp, struct g_provider *pp, int flags)
  64 {
  65         struct g_geom *gp;
  66         struct g_consumer *cp;
  67         struct g_vol_ffs_softc *ms;
  68         int sb, superblock;
  69         struct fs *fs;
  70
  71         g_trace(G_T_TOPOLOGY, "vol_taste(%s,%s)", mp->name, pp->name);
  72         g_topology_assert();
  73
  74         /*
  75          * XXX This is a really weak way to make sure we don't recurse.
  76          * Probably ought to use BIO_GETATTR to check for this.
  77          */
  78         if (flags == G_TF_NORMAL &&
  79             !strcmp(pp->geom->class->name, VOL_FFS_CLASS_NAME))
  80                 return (NULL);
  81
  82         gp = g_slice_new(mp, 1, pp, &cp, &ms, sizeof(*ms), g_vol_ffs_start);
  83         if (gp == NULL)
  84                 return (NULL);
  85         g_topology_unlock();
  86         /*
  87          * Walk through the standard places that superblocks hide and look
  88          * for UFS magic. If we find magic, then check that the size in the
  89          * superblock corresponds to the size of the underlying provider.
  90          * Finally, look for a volume label and create an appropriate
  91          * provider based on that.
  92          */
  93         for (sb=0; (superblock = superblocks[sb]) != -1; sb++) {
  94                 /*
  95                  * Take care not to issue an invalid I/O request.  The
  96                  * offset and size of the superblock candidate must be
  97                  * multiples of the provider's sector size, otherwise an
  98                  * FFS can't exist on the provider anyway.
  99                  */
 100                 if (superblock % cp->provider->sectorsize != 0 ||
 101                     SBLOCKSIZE % cp->provider->sectorsize != 0)
 102                         continue;
 103
 104                 fs = (struct fs *) g_read_data(cp, superblock,
 105                         SBLOCKSIZE, NULL);
 106                 if (fs == NULL)
 107                         continue;
 108                 /* Check for magic and make sure things are the right size */
 109                 if (fs->fs_magic == FS_UFS1_MAGIC) {
 110                         if (fs->fs_old_size * fs->fs_fsize !=
 111                             (int32_t) pp->mediasize) {
 112                                 g_free(fs);
 113                                 continue;
 114                         }
 115                 } else if (fs->fs_magic == FS_UFS2_MAGIC) {
 116                         if (fs->fs_size * fs->fs_fsize !=
 117                             (int64_t) pp->mediasize) {
 118                                 g_free(fs);
 119                                 continue;
 120                         }
 121                 } else {
 122                         g_free(fs);
 123                         continue;
 124                 }
 125                 /* Check for volume label */
 126                 if (fs->fs_volname[0] == '\0') {
 127                         g_free(fs);
 128                         continue;
 129                 }
 130                 /* XXX We need to check for namespace conflicts. */
 131                 /* XXX How do you handle a mirror set? */
 132                 /* XXX We don't validate the volume name. */
 133                 g_topology_lock();
 134                 /* Alright, we have a label and a volume name, reconfig. */
 135                 g_slice_config(gp, 0, G_SLICE_CONFIG_SET, (off_t) 0,
 136                     pp->mediasize, pp->sectorsize, "vol/%s",
 137                     fs->fs_volname);
 138                 g_free(fs);
 139                 g_topology_unlock();
 140                 break;
 141         }
 142         g_topology_lock();
 143         g_access(cp, -1, 0, 0);
 144         if (LIST_EMPTY(&gp->provider)) {
 145                 g_slice_spoiled(cp);
 146                 return (NULL);
 147         }
 148         return (gp);
 149 }
 150
 151 static struct g_class g_vol_ffs_class   = {
 152         .name = VOL_FFS_CLASS_NAME,
 153         .version = G_VERSION,
 154         .taste = g_vol_ffs_taste,
 155 };
 156
 157 DECLARE_GEOM_CLASS(g_vol_ffs_class, g_vol_ffs);