external/bsd/am-utils/dist/amd/mntfs.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/mntfs.c
  43  *
  44  */
  45
  46 #ifdef HAVE_CONFIG_H
  47 # include <config.h>
  48 #endif /* HAVE_CONFIG_H */
  49 #include <am_defs.h>
  50 #include <amd.h>
  51
  52 qelem mfhead = {&mfhead, &mfhead};
  53
  54 int mntfs_allocated;
  55
  56
  57 mntfs *
  58 dup_mntfs(mntfs *mf)
  59 {
  60   if (mf->mf_refc == 0) {
  61     if (mf->mf_cid)
  62       untimeout(mf->mf_cid);
  63     mf->mf_cid = 0;
  64   }
  65   mf->mf_refc++;
  66
  67   return mf;
  68 }
  69
  70
  71 static void
  72 init_mntfs(mntfs *mf, am_ops *ops, am_opts *mo, char *mp, char *info, char *auto_opts, char *mopts, char *remopts)
  73 {
  74   mf->mf_ops = ops;
  75   mf->mf_fsflags = ops->nfs_fs_flags;
  76   mf->mf_fo = mo;
  77   mf->mf_mount = strdup(mp);
  78   mf->mf_info = strdup(info);
  79   mf->mf_auto = strdup(auto_opts);
  80   mf->mf_mopts = strdup(mopts);
  81   mf->mf_remopts = strdup(remopts);
  82   mf->mf_loopdev = NULL;
  83   mf->mf_refc = 1;
  84   mf->mf_flags = 0;
  85   mf->mf_error = -1;
  86   mf->mf_cid = 0;
  87   mf->mf_private = NULL;
  88   mf->mf_prfree = NULL;
  89
  90   if (ops->ffserver)
  91     mf->mf_server = (*ops->ffserver) (mf);
  92   else
  93     mf->mf_server = NULL;
  94 }
  95
  96
  97 static mntfs *
  98 alloc_mntfs(am_ops *ops, am_opts *mo, char *mp, char *info, char *auto_opts, char *mopts, char *remopts)
  99 {
 100   mntfs *mf = ALLOC(struct mntfs);
 101
 102   init_mntfs(mf, ops, mo, mp, info, auto_opts, mopts, remopts);
 103   ins_que(&mf->mf_q, &mfhead);
 104   mntfs_allocated++;
 105
 106   return mf;
 107 }
 108
 109
 110 /* find a matching mntfs in our list */
 111 mntfs *
 112 locate_mntfs(am_ops *ops, am_opts *mo, char *mp, char *info, char *auto_opts, char *mopts, char *remopts)
 113 {
 114   mntfs *mf;
 115
 116   dlog("Locating mntfs reference to (%s,%s)", mp, info);
 117
 118   ITER(mf, mntfs, &mfhead) {
 119     /*
 120      * For backwards compatibility purposes, we treat already-mounted
 121      * filesystems differently and only require a match of their mount point,
 122      * not of their server info. After all, there is little we can do if
 123      * the user asks us to mount two different things onto the same mount: one
 124      * will always cover the other one.
 125      */
 126     if (STREQ(mf->mf_mount, mp) &&
 127         ((mf->mf_flags & MFF_MOUNTED && !(mf->mf_fsflags & FS_DIRECT))
 128          || (STREQ(mf->mf_info, info) && mf->mf_ops == ops))) {
 129       /*
 130        * Handle cases where error ops are involved
 131        */
 132       if (ops == &amfs_error_ops) {
 133         /*
 134          * If the existing ops are not amfs_error_ops
 135          * then continue...
 136          */
 137         if (mf->mf_ops != &amfs_error_ops)
 138           continue;
 139         return dup_mntfs(mf);
 140       }
 141
 142       dlog("mf->mf_flags = %#x", mf->mf_flags);
 143       mf->mf_fo = mo;
 144       if ((mf->mf_flags & MFF_RESTART) && amd_state < Finishing) {
 145         /*
 146          * Restart a previously mounted filesystem.
 147          */
 148         dlog("Restarting filesystem %s", mf->mf_mount);
 149
 150         /*
 151          * If we are restarting an amd internal filesystem,
 152          * we need to initialize it a bit.
 153          *
 154          * We know it's internal because it is marked as toplvl.
 155          */
 156         if (mf->mf_ops == &amfs_toplvl_ops) {
 157           mf->mf_ops = ops;
 158           mf->mf_info = strealloc(mf->mf_info, info);
 159           ops->mounted(mf);     /* XXX: not right, but will do for now */
 160         }
 161
 162         return mf;
 163       }
 164
 165       if (!(mf->mf_flags & (MFF_MOUNTED | MFF_MOUNTING | MFF_UNMOUNTING))) {
 166         fserver *fs;
 167         mf->mf_flags &= ~MFF_ERROR;
 168         mf->mf_error = -1;
 169         mf->mf_auto = strealloc(mf->mf_auto, auto_opts);
 170         mf->mf_mopts = strealloc(mf->mf_mopts, mopts);
 171         mf->mf_remopts = strealloc(mf->mf_remopts, remopts);
 172         mf->mf_info = strealloc(mf->mf_info, info);
 173
 174         if (mf->mf_private && mf->mf_prfree) {
 175           mf->mf_prfree(mf->mf_private);
 176           mf->mf_private = NULL;
 177         }
 178
 179         fs = ops->ffserver ? (*ops->ffserver) (mf) : (fserver *) NULL;
 180         if (mf->mf_server)
 181           free_srvr(mf->mf_server);
 182         mf->mf_server = fs;
 183       }
 184       return dup_mntfs(mf);
 185     } /* end of "if (STREQ(mf-> ..." */
 186   } /* end of ITER */
 187
 188   return 0;
 189 }
 190
 191
 192 /* find a matching mntfs in our list, create a new one if none is found */
 193 mntfs *
 194 find_mntfs(am_ops *ops, am_opts *mo, char *mp, char *info, char *auto_opts, char *mopts, char *remopts)
 195 {
 196   mntfs *mf = locate_mntfs(ops, mo, mp, info, auto_opts, mopts, remopts);
 197   if (mf)
 198     return mf;
 199
 200   return alloc_mntfs(ops, mo, mp, info, auto_opts, mopts, remopts);
 201 }
 202
 203
 204 mntfs *
 205 new_mntfs(void)
 206 {
 207   return alloc_mntfs(&amfs_error_ops, (am_opts *) NULL, "//nil//", ".", "", "", "");
 208 }
 209
 210
 211 static void
 212 uninit_mntfs(mntfs *mf)
 213 {
 214   if (mf->mf_auto)
 215     XFREE(mf->mf_auto);
 216   if (mf->mf_mopts)
 217     XFREE(mf->mf_mopts);
 218   if (mf->mf_remopts)
 219     XFREE(mf->mf_remopts);
 220   if (mf->mf_info)
 221     XFREE(mf->mf_info);
 222   if (mf->mf_private && mf->mf_prfree)
 223     (*mf->mf_prfree) (mf->mf_private);
 224
 225   if (mf->mf_mount)
 226     XFREE(mf->mf_mount);
 227
 228   /*
 229    * Clean up the file server
 230    */
 231   if (mf->mf_server)
 232     free_srvr(mf->mf_server);
 233
 234   /*
 235    * Don't do a callback on this mount
 236    */
 237   if (mf->mf_cid) {
 238     untimeout(mf->mf_cid);
 239     mf->mf_cid = 0;
 240   }
 241 }
 242
 243
 244 static void
 245 discard_mntfs(voidp v)
 246 {
 247   mntfs *mf = v;
 248
 249   rem_que(&mf->mf_q);
 250
 251   /*
 252    * Free memory
 253    */
 254   uninit_mntfs(mf);
 255   XFREE(mf);
 256
 257   --mntfs_allocated;
 258 }
 259
 260
 261 void
 262 flush_mntfs(void)
 263 {
 264   mntfs *mf;
 265
 266   mf = AM_FIRST(mntfs, &mfhead);
 267   while (mf != HEAD(mntfs, &mfhead)) {
 268     mntfs *mf2 = mf;
 269     mf = NEXT(mntfs, mf);
 270     if (mf2->mf_refc == 0 && mf2->mf_cid)
 271       discard_mntfs(mf2);
 272   }
 273 }
 274
 275
 276 void
 277 free_mntfs(opaque_t arg)
 278 {
 279   mntfs *mf = (mntfs *) arg;
 280
 281   dlog("free_mntfs <%s> type %s mf_refc %d flags %x",
 282        mf->mf_mount, mf->mf_ops->fs_type, mf->mf_refc, mf->mf_flags);
 283
 284   /*
 285    * We shouldn't ever be called to free something that has
 286    * a non-positive refcount.  Something is badly wrong if
 287    * we have been!  Ignore the request for now...
 288    */
 289   if (mf->mf_refc <= 0) {
 290     plog(XLOG_ERROR, "IGNORING free_mntfs for <%s>: refc %d, flags %x (bug?)",
 291          mf->mf_mount, mf->mf_refc, mf->mf_flags);
 292     return;
 293   }
 294
 295   /* don't discard last reference of a restarted/kept mntfs */
 296   if (mf->mf_refc == 1 && mf->mf_flags & MFF_RSTKEEP) {
 297     plog(XLOG_ERROR, "IGNORING free_mntfs for <%s>: refc %d, flags %x (restarted)",
 298          mf->mf_mount, mf->mf_refc, mf->mf_flags);
 299     return;
 300   }
 301
 302   if (--mf->mf_refc == 0) {
 303     if (mf->mf_flags & MFF_MOUNTED) {
 304       int quoted;
 305       mf->mf_flags &= ~MFF_MOUNTED;
 306
 307       /*
 308        * Record for posterity
 309        */
 310       quoted = strchr(mf->mf_info, ' ') != 0;   /* cheap */
 311       plog(XLOG_INFO, "%s%s%s %sed fstype %s from %s",
 312            quoted ? "\"" : "",
 313            mf->mf_info,
 314            quoted ? "\"" : "",
 315            mf->mf_error ? "discard" : "unmount",
 316            mf->mf_ops->fs_type, mf->mf_mount);
 317     }
 318
 319     if (mf->mf_fsflags & FS_DISCARD) {
 320       dlog("Immediately discarding mntfs for %s", mf->mf_mount);
 321       discard_mntfs(mf);
 322
 323     } else {
 324
 325       if (mf->mf_flags & MFF_RESTART) {
 326         dlog("Discarding remount hook for %s", mf->mf_mount);
 327       } else {
 328         dlog("Discarding last mntfs reference to %s fstype %s",
 329              mf->mf_mount, mf->mf_ops->fs_type);
 330       }
 331       if (mf->mf_flags & (MFF_MOUNTED | MFF_MOUNTING | MFF_UNMOUNTING))
 332         dlog("mntfs reference for %s still active", mf->mf_mount);
 333       mf->mf_cid = timeout(ALLOWED_MOUNT_TIME, discard_mntfs, (voidp) mf);
 334     }
 335   }
 336 }
 337
 338
 339 mntfs *
 340 realloc_mntfs(mntfs *mf, am_ops *ops, am_opts *mo, char *mp, char *info, char *auto_opts, char *mopts, char *remopts)
 341 {
 342   mntfs *mf2;
 343
 344   if (mf->mf_refc == 1 &&
 345       mf->mf_flags & MFF_RESTART &&
 346       STREQ(mf->mf_mount, mp)) {
 347     /*
 348      * If we are inheriting then just return
 349      * the same node...
 350      */
 351     return mf;
 352   }
 353
 354   /*
 355    * Re-use the existing mntfs if it is mounted.
 356    * This traps a race in nfsx.
 357    */
 358   if (mf->mf_ops != &amfs_error_ops &&
 359       (mf->mf_flags & MFF_MOUNTED) &&
 360       !FSRV_ISDOWN(mf->mf_server)) {
 361     mf->mf_fo = mo;
 362     return mf;
 363   }
 364
 365   mf2 = find_mntfs(ops, mo, mp, info, auto_opts, mopts, remopts);
 366   free_mntfs(mf);
 367   return mf2;
 368 }