external/bsd/am-utils/dist/amd/ops_cachefs.c

   1 /*      $NetBSD$        */
   2
   3 /*
   4  * Copyright (c) 1997-2009 Erez Zadok
   5  * Copyright (c) 1990 Jan-Simon Pendry
   6  * Copyright (c) 1990 Imperial College of Science, Technology & Medicine
   7  * Copyright (c) 1990 The Regents of the University of California.
   8  * All rights reserved.
   9  *
  10  * This code is derived from software contributed to Berkeley by
  11  * Jan-Simon Pendry at Imperial College, London.
  12  *
  13  * Redistribution and use in source and binary forms, with or without
  14  * modification, are permitted provided that the following conditions
  15  * are met:
  16  * 1. Redistributions of source code must retain the above copyright
  17  *    notice, this list of conditions and the following disclaimer.
  18  * 2. Redistributions in binary form must reproduce the above copyright
  19  *    notice, this list of conditions and the following disclaimer in the
  20  *    documentation and/or other materials provided with the distribution.
  21  * 3. All advertising materials mentioning features or use of this software
  22  *    must display the following acknowledgment:
  23  *      This product includes software developed by the University of
  24  *      California, Berkeley and its contributors.
  25  * 4. Neither the name of the University nor the names of its contributors
  26  *    may be used to endorse or promote products derived from this software
  27  *    without specific prior written permission.
  28  *
  29  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  30  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  31  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  32  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  33  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  34  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  35  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  36  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  37  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  38  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  39  * SUCH DAMAGE.
  40  *
  41  *
  42  * File: am-utils/amd/ops_cachefs.c
  43  *
  44  */
  45
  46 /*
  47  * Caching filesystem (Solaris 2.x)
  48  */
  49
  50 #ifdef HAVE_CONFIG_H
  51 # include <config.h>
  52 #endif /* HAVE_CONFIG_H */
  53 #include <am_defs.h>
  54 #include <amd.h>
  55
  56 /* forward declarations */
  57 static char *cachefs_match(am_opts *fo);
  58 static int cachefs_init(mntfs *mf);
  59 static int cachefs_mount(am_node *am, mntfs *mf);
  60 static int cachefs_umount(am_node *am, mntfs *mf);
  61
  62
  63 /*
  64  * Ops structure
  65  */
  66 am_ops cachefs_ops =
  67 {
  68   "cachefs",
  69   cachefs_match,
  70   cachefs_init,
  71   cachefs_mount,
  72   cachefs_umount,
  73   amfs_error_lookup_child,
  74   amfs_error_mount_child,
  75   amfs_error_readdir,
  76   0,                            /* cachefs_readlink */
  77   0,                            /* cachefs_mounted */
  78   0,                            /* cachefs_umounted */
  79   amfs_generic_find_srvr,
  80   0,                            /* cachefs_get_wchan */
  81   FS_MKMNT | FS_NOTIMEOUT | FS_UBACKGROUND | FS_AMQINFO, /* nfs_fs_flags */
  82 #ifdef HAVE_FS_AUTOFS
  83   AUTOFS_CACHEFS_FS_FLAGS,
  84 #endif /* HAVE_FS_AUTOFS */
  85 };
  86
  87
  88 /*
  89  * Check that f/s has all needed fields.
  90  * Returns: matched string if found, NULL otherwise.
  91  */
  92 static char *
  93 cachefs_match(am_opts *fo)
  94 {
  95   /* sanity check */
  96   if (!fo->opt_rfs || !fo->opt_fs || !fo->opt_cachedir) {
  97     plog(XLOG_USER, "cachefs: must specify cachedir, rfs, and fs");
  98     return NULL;
  99   }
 100
 101   dlog("CACHEFS: using cache directory \"%s\"", fo->opt_cachedir);
 102
 103   /* determine magic cookie to put in mtab */
 104   return strdup(fo->opt_cachedir);
 105 }
 106
 107
 108 /*
 109  * Initialize.
 110  * Returns: 0 if OK, non-zero (errno) if failed.
 111  */
 112 static int
 113 cachefs_init(mntfs *mf)
 114 {
 115   /*
 116    * Save cache directory name
 117    */
 118   if (!mf->mf_private) {
 119     mf->mf_private = (voidp) strdup(mf->mf_fo->opt_cachedir);
 120     mf->mf_prfree = (void (*)(voidp)) free;
 121   }
 122
 123   return 0;
 124 }
 125
 126
 127 /*
 128  * mntpt is the mount point ($fs) [XXX: was 'dir']
 129  * backdir is the mounted pathname ($rfs) [XXX: was 'fs_name']
 130  * cachedir is the cache directory ($cachedir)
 131  */
 132 static int
 133 mount_cachefs(char *mntdir, char *backdir, char *cachedir,
 134               char *opts, int on_autofs)
 135 {
 136   cachefs_args_t ca;
 137   mntent_t mnt;
 138   int flags;
 139   char *cp;
 140   MTYPE_TYPE type = MOUNT_TYPE_CACHEFS; /* F/S mount type */
 141
 142   memset((voidp) &ca, 0, sizeof(ca)); /* Paranoid */
 143
 144   /*
 145    * Fill in the mount structure
 146    */
 147   memset((voidp) &mnt, 0, sizeof(mnt));
 148   mnt.mnt_dir = mntdir;
 149   mnt.mnt_fsname = backdir;
 150   mnt.mnt_type = MNTTAB_TYPE_CACHEFS;
 151   mnt.mnt_opts = opts;
 152
 153   flags = compute_mount_flags(&mnt);
 154 #ifdef HAVE_FS_AUTOFS
 155   if (on_autofs)
 156     flags |= autofs_compute_mount_flags(&mnt);
 157 #endif /* HAVE_FS_AUTOFS */
 158
 159   /* Fill in cachefs mount arguments */
 160
 161   /*
 162    * XXX: Caveats
 163    * (1) cache directory is NOT checked for sanity beforehand, nor is it
 164    * purged.  Maybe it should be purged first?
 165    * (2) cache directory is NOT locked.  Should we?
 166    */
 167
 168   /* mount flags */
 169   ca.cfs_options.opt_flags = CFS_WRITE_AROUND | CFS_ACCESS_BACKFS;
 170   /* cache population size */
 171   ca.cfs_options.opt_popsize = DEF_POP_SIZE; /* default: 64K */
 172   /* filegrp size */
 173   ca.cfs_options.opt_fgsize = DEF_FILEGRP_SIZE; /* default: 256 */
 174
 175   /* CFS ID for file system (must be unique) */
 176   ca.cfs_fsid = cachedir;
 177
 178   /* CFS fscdir name */
 179   memset(ca.cfs_cacheid, 0, sizeof(ca.cfs_cacheid));
 180   /*
 181    * Append cacheid and mountpoint.
 182    * sizeof(cfs_cacheid) should be C_MAX_MOUNT_FSCDIRNAME as per
 183    * <sys/fs/cachefs_fs.h> (checked on Solaris 8).
 184    */
 185   xsnprintf(ca.cfs_cacheid, sizeof(ca.cfs_cacheid),
 186             "%s:%s", ca.cfs_fsid, mntdir);
 187   /* convert '/' to '_' (Solaris does that...) */
 188   cp = ca.cfs_cacheid;
 189   while ((cp = strpbrk(cp, "/")) != NULL)
 190     *cp = '_';
 191
 192   /* path for this cache dir */
 193   ca.cfs_cachedir = cachedir;
 194
 195   /* back filesystem dir */
 196   ca.cfs_backfs = backdir;
 197
 198   /* same as nfs values (XXX: need to handle these options) */
 199   ca.cfs_acregmin = 0;
 200   ca.cfs_acregmax = 0;
 201   ca.cfs_acdirmin = 0;
 202   ca.cfs_acdirmax = 0;
 203
 204   /*
 205    * Call generic mount routine
 206    */
 207   return mount_fs(&mnt, flags, (caddr_t) &ca, 0, type, 0, NULL, mnttab_file_name, on_autofs);
 208 }
 209
 210
 211 static int
 212 cachefs_mount(am_node *am, mntfs *mf)
 213 {
 214   int on_autofs = mf->mf_flags & MFF_ON_AUTOFS;
 215   int error;
 216
 217   error = mount_cachefs(mf->mf_mount,
 218                         mf->mf_fo->opt_rfs,
 219                         mf->mf_fo->opt_cachedir,
 220                         mf->mf_mopts,
 221                         on_autofs);
 222   if (error) {
 223     errno = error;
 224     /* according to Solaris, if errno==ESRCH, "options to not match" */
 225     if (error == ESRCH)
 226       plog(XLOG_ERROR, "mount_cachefs: options to no match: %m");
 227     else
 228       plog(XLOG_ERROR, "mount_cachefs: %m");
 229     return error;
 230   }
 231
 232   return 0;
 233 }
 234
 235
 236 static int
 237 cachefs_umount(am_node *am, mntfs *mf)
 238 {
 239   int unmount_flags = (mf->mf_flags & MFF_ON_AUTOFS) ? AMU_UMOUNT_AUTOFS : 0;
 240   int error;
 241
 242   error = UMOUNT_FS(mf->mf_mount, mnttab_file_name, unmount_flags);
 243
 244   /*
 245    * In the case of cachefs, we must fsck the cache directory.  Otherwise,
 246    * it will remain inconsistent, and the next cachefs mount will fail
 247    * with the error "no space left on device" (ENOSPC).
 248    *
 249    * XXX: this is hacky! use fork/exec/wait instead...
 250    */
 251   if (!error) {
 252     char *cachedir = NULL;
 253     char cmd[128];
 254
 255     cachedir = (char *) mf->mf_private;
 256     plog(XLOG_INFO, "running fsck on cache directory \"%s\"", cachedir);
 257     xsnprintf(cmd, sizeof(cmd), "fsck -F cachefs %s", cachedir);
 258     system(cmd);
 259   }
 260
 261   return error;
 262 }