contrib/amd/amd/ops_cachefs.c

   1 /*
   2  * Copyright (c) 1997-1999 Erez Zadok
   3  * Copyright (c) 1990 Jan-Simon Pendry
   4  * Copyright (c) 1990 Imperial College of Science, Technology & Medicine
   5  * Copyright (c) 1990 The Regents of the University of California.
   6  * All rights reserved.
   7  *
   8  * This code is derived from software contributed to Berkeley by
   9  * Jan-Simon Pendry at Imperial College, London.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. All advertising materials mentioning features or use of this software
  20  *    must display the following acknowledgment:
  21  *      This product includes software developed by the University of
  22  *      California, Berkeley and its contributors.
  23  * 4. Neither the name of the University nor the names of its contributors
  24  *    may be used to endorse or promote products derived from this software
  25  *    without specific prior written permission.
  26  *
  27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  37  * SUCH DAMAGE.
  38  *
  39  *      %W% (Berkeley) %G%
  40  *
  41  * $Id: ops_cachefs.c,v 1.2 1999/01/10 21:53:49 ezk Exp $
  42  *
  43  */
  44
  45 /*
  46  * Caching filesystem (Solaris 2.x)
  47  */
  48
  49 #ifdef HAVE_CONFIG_H
  50 # include <config.h>
  51 #endif /* HAVE_CONFIG_H */
  52 #include <am_defs.h>
  53 #include <amd.h>
  54
  55 /* forward declarations */
  56 static char *cachefs_match(am_opts *fo);
  57 static int cachefs_init(mntfs *mf);
  58 static int cachefs_fmount(mntfs *mf);
  59 static int cachefs_fumount(mntfs *mf);
  60
  61
  62 /*
  63  * Ops structure
  64  */
  65 am_ops cachefs_ops =
  66 {
  67   "cachefs",
  68   cachefs_match,
  69   cachefs_init,
  70   amfs_auto_fmount,
  71   cachefs_fmount,
  72   amfs_auto_fumount,
  73   cachefs_fumount,
  74   amfs_error_lookuppn,
  75   amfs_error_readdir,
  76   0,                            /* cachefs_readlink */
  77   0,                            /* post-mount actions */
  78   0,                            /* post-umount actions */
  79   find_amfs_auto_srvr,
  80   FS_MKMNT | FS_NOTIMEOUT | FS_UBACKGROUND | FS_AMQINFO
  81 };
  82
  83
  84 /*
  85  * Check that f/s has all needed fields.
  86  * Returns: matched string if found, NULL otherwise.
  87  */
  88 static char *
  89 cachefs_match(am_opts *fo)
  90 {
  91   /* sanity check */
  92   if (!fo->opt_rfs || !fo->opt_fs || !fo->opt_cachedir) {
  93     plog(XLOG_USER, "cachefs: must specify cachedir, rfs, and fs");
  94     return NULL;
  95   }
  96
  97 #ifdef DEBUG
  98   dlog("CACHEFS: using cache directory \"%s\"", fo->opt_cachedir);
  99 #endif /* DEBUG */
 100
 101   /* determine magic cookie to put in mtab */
 102   return strdup(fo->opt_cachedir);
 103 }
 104
 105
 106 /*
 107  * Initialize.
 108  * Returns: 0 if OK, non-zero (errno) if failed.
 109  */
 110 static int
 111 cachefs_init(mntfs *mf)
 112 {
 113   /*
 114    * Save cache directory name
 115    */
 116   if (mf->mf_refc == 1) {
 117     mf->mf_private = (voidp) strdup(mf->mf_fo->opt_cachedir);
 118     mf->mf_prfree = (void (*)(voidp)) free;
 119   }
 120
 121   return 0;
 122 }
 123
 124
 125 /*
 126  * mntpt is the mount point ($fs) [XXX: was 'dir']
 127  * backdir is the mounted pathname ($rfs) [XXX: was 'fs_name']
 128  * cachedir is the cache directory ($cachedir)
 129  */
 130 static int
 131 mount_cachefs(char *mntpt, char *backdir, char *cachedir, char *opts)
 132 {
 133   cachefs_args_t ca;
 134   mntent_t mnt;
 135   int flags;
 136   char *cp;
 137   MTYPE_TYPE type = MOUNT_TYPE_CACHEFS; /* F/S mount type */
 138
 139   memset((voidp) &ca, 0, sizeof(ca)); /* Paranoid */
 140
 141   /*
 142    * Fill in the mount structure
 143    */
 144   memset((voidp) &mnt, 0, sizeof(mnt));
 145   mnt.mnt_dir = mntpt;
 146   mnt.mnt_fsname = backdir;
 147   mnt.mnt_type = MNTTAB_TYPE_CACHEFS;
 148   mnt.mnt_opts = opts;
 149
 150   flags = compute_mount_flags(&mnt);
 151
 152   /* Fill in cachefs mount arguments */
 153
 154   /*
 155    * XXX: Caveats
 156    * (1) cache directory is NOT checked for sanity beforehand, nor is it
 157    * purged.  Maybe it should be purged first?
 158    * (2) cache directory is NOT locked.  Should we?
 159    */
 160
 161   /* mount flags */
 162   ca.cfs_options.opt_flags = CFS_WRITE_AROUND | CFS_ACCESS_BACKFS;
 163   /* cache population size */
 164   ca.cfs_options.opt_popsize = DEF_POP_SIZE; /* default: 64K */
 165   /* filegrp size */
 166   ca.cfs_options.opt_fgsize = DEF_FILEGRP_SIZE; /* default: 256 */
 167
 168   /* CFS ID for file system (must be unique) */
 169   ca.cfs_fsid = cachedir;
 170
 171   /* CFS fscdir name */
 172   memset(ca.cfs_cacheid, 0, sizeof(ca.cfs_cacheid));
 173   /* append cacheid and mountpoint */
 174   sprintf(ca.cfs_cacheid, "%s:%s", ca.cfs_fsid, mntpt);
 175   /* convert '/' to '_' (Solaris does that...) */
 176   cp = ca.cfs_cacheid;
 177   while ((cp = strpbrk(cp, "/")) != NULL)
 178     *cp = '_';
 179
 180   /* path for this cache dir */
 181   ca.cfs_cachedir = cachedir;
 182
 183   /* back filesystem dir */
 184   ca.cfs_backfs = backdir;
 185
 186   /* same as nfs values (XXX: need to handle these options) */
 187   ca.cfs_acregmin = 0;
 188   ca.cfs_acregmax = 0;
 189   ca.cfs_acdirmin = 0;
 190   ca.cfs_acdirmax = 0;
 191
 192   /*
 193    * Call generic mount routine
 194    */
 195   return mount_fs(&mnt, flags, (caddr_t) &ca, 0, type, 0, NULL, mnttab_file_name);
 196 }
 197
 198
 199 static int
 200 cachefs_fmount(mntfs *mf)
 201 {
 202   int error;
 203
 204   error = mount_cachefs(mf->mf_mount,
 205                         mf->mf_fo->opt_rfs,
 206                         mf->mf_fo->opt_cachedir,
 207                         mf->mf_mopts);
 208   if (error) {
 209     errno = error;
 210     /* according to Solaris, if errno==ESRCH, "options to not match" */
 211     if (error == ESRCH)
 212       plog(XLOG_ERROR, "mount_cachefs: options to no match: %m");
 213     else
 214       plog(XLOG_ERROR, "mount_cachefs: %m");
 215     return error;
 216   }
 217
 218   return 0;
 219 }
 220
 221
 222 static int
 223 cachefs_fumount(mntfs *mf)
 224 {
 225   int error;
 226
 227   error = UMOUNT_FS(mf->mf_mount, mnttab_file_name);
 228
 229   /*
 230    * In the case of cachefs, we must fsck the cache directory.  Otherwise,
 231    * it will remain inconsistent, and the next cachefs mount will fail
 232    * with the error "no space left on device" (ENOSPC).
 233    *
 234    * XXX: this is hacky! use fork/exec/wait instead...
 235    */
 236   if (!error) {
 237     char *cachedir = NULL;
 238     char cmd[128];
 239
 240     cachedir = (char *) mf->mf_private;
 241     plog(XLOG_INFO, "running fsck on cache directory \"%s\"", cachedir);
 242     sprintf(cmd, "fsck -F cachefs %s", cachedir);
 243     system(cmd);
 244   }
 245
 246   return error;
 247 }