1 /* $NetBSD: amfs_toplvl.c,v 1.1.1.3 2015/01/17 16:34:15 christos Exp $ */ 2 3 /* 4 * Copyright (c) 1997-2014 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. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * 38 * File: am-utils/amd/amfs_toplvl.c 39 * 40 */ 41 42 /* 43 * Top-level file system 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 /**************************************************************************** 53 *** FORWARD DEFINITIONS *** 54 ****************************************************************************/ 55 static int amfs_toplvl_init(mntfs *mf); 56 57 /**************************************************************************** 58 *** OPS STRUCTURES *** 59 ****************************************************************************/ 60 am_ops amfs_toplvl_ops = 61 { 62 "toplvl", 63 amfs_generic_match, 64 amfs_toplvl_init, /* amfs_toplvl_init */ 65 amfs_toplvl_mount, 66 amfs_toplvl_umount, 67 amfs_generic_lookup_child, 68 amfs_generic_mount_child, 69 amfs_generic_readdir, 70 0, /* amfs_toplvl_readlink */ 71 amfs_generic_mounted, 72 0, /* amfs_toplvl_umounted */ 73 amfs_generic_find_srvr, 74 0, /* amfs_toplvl_get_wchan */ 75 FS_MKMNT | FS_NOTIMEOUT | FS_BACKGROUND | 76 FS_AMQINFO | FS_DIRECTORY, /* nfs_fs_flags */ 77 #ifdef HAVE_FS_AUTOFS 78 AUTOFS_TOPLVL_FS_FLAGS, 79 #endif /* HAVE_FS_AUTOFS */ 80 }; 81 82 83 /**************************************************************************** 84 *** FUNCTIONS *** 85 ****************************************************************************/ 86 87 static void 88 set_auto_attrcache_timeout(char *preopts, char *opts, size_t l) 89 { 90 91 #ifdef MNTTAB_OPT_NOAC 92 /* 93 * Don't cache attributes - they are changing under the kernel's feet. 94 * For example, IRIX5.2 will dispense with nfs lookup calls and hand stale 95 * filehandles to getattr unless we disable attribute caching on the 96 * automount points. 97 */ 98 if (gopt.auto_attrcache == 0) { 99 xsnprintf(preopts, l, ",%s", MNTTAB_OPT_NOAC); 100 xstrlcat(opts, preopts, l); 101 } 102 #endif /* MNTTAB_OPT_NOAC */ 103 104 /* 105 * XXX: note that setting these to 0 in the past resulted in an error on 106 * some systems, which is why it's better to use "noac" if possible. For 107 * now, we're setting everything possible, but if this will cause trouble, 108 * then we'll have to condition the remainder of this on OPT_NOAC. 109 */ 110 #ifdef MNTTAB_OPT_ACTIMEO 111 xsnprintf(preopts, l, ",%s=%d", MNTTAB_OPT_ACTIMEO, gopt.auto_attrcache); 112 xstrlcat(opts, preopts, l); 113 #else /* MNTTAB_OPT_ACTIMEO */ 114 # ifdef MNTTAB_OPT_ACDIRMIN 115 xsnprintf(preopts, l, ",%s=%d", MNTTAB_OPT_ACTDIRMIN, gopt.auto_attrcache); 116 xstrlcat(opts, preopts, l); 117 # endif /* MNTTAB_OPT_ACDIRMIN */ 118 # ifdef MNTTAB_OPT_ACDIRMAX 119 xsnprintf(preopts, l, ",%s=%d", MNTTAB_OPT_ACTDIRMAX, gopt.auto_attrcache); 120 xstrlcat(opts, preopts, l); 121 # endif /* MNTTAB_OPT_ACDIRMAX */ 122 # ifdef MNTTAB_OPT_ACREGMIN 123 xsnprintf(preopts, l, ",%s=%d", MNTTAB_OPT_ACTREGMIN, gopt.auto_attrcache); 124 xstrlcat(opts, preopts, l); 125 # endif /* MNTTAB_OPT_ACREGMIN */ 126 # ifdef MNTTAB_OPT_ACREGMAX 127 xsnprintf(preopts, l, ",%s=%d", MNTTAB_OPT_ACTREGMAX, gopt.auto_attrcache); 128 xstrlcat(opts, preopts, l); 129 # endif /* MNTTAB_OPT_ACREGMAX */ 130 #endif /* MNTTAB_OPT_ACTIMEO */ 131 } 132 133 134 /* 135 * Initialize a top-level mount. In our case, if the user asked for 136 * forced_unmounts, and the OS supports it, then we try forced/lazy unmounts 137 * on any previous toplvl mounts. This is useful if a previous Amd died and 138 * left behind toplvl mount points (this Amd will clean them up). 139 * 140 * WARNING: Don't use forced/lazy unmounts if you have another valid Amd 141 * running, because this code WILL force those valid toplvl mount points to 142 * be detached as well! 143 */ 144 static int 145 amfs_toplvl_init(mntfs *mf) 146 { 147 int error = 0; 148 149 #if (defined(MNT2_GEN_OPT_FORCE) || defined(MNT2_GEN_OPT_DETACH)) && (defined(HAVE_UVMOUNT) || defined(HAVE_UMOUNT2)) 150 if (gopt.flags & CFM_FORCED_UNMOUNTS) { 151 plog(XLOG_INFO, "amfs_toplvl_init: trying forced/lazy unmount of %s", 152 mf->mf_mount); 153 error = umount2_fs(mf->mf_mount, AMU_UMOUNT_FORCE | AMU_UMOUNT_DETACH); 154 if (error) 155 plog(XLOG_INFO, "amfs_toplvl_init: forced/lazy unmount failed: %m"); 156 else 157 dlog("amfs_toplvl_init: forced/lazy unmount succeeded"); 158 } 159 #endif /* (MNT2_GEN_OPT_FORCE || MNT2_GEN_OPT_DETACH) && (HAVE_UVMOUNT || HAVE_UMOUNT2) */ 160 return error; 161 } 162 163 164 /* 165 * Mount the top-level 166 */ 167 int 168 amfs_toplvl_mount(am_node *mp, mntfs *mf) 169 { 170 struct stat stb; 171 char opts[SIZEOF_OPTS], preopts[SIZEOF_OPTS], toplvl_opts[40]; 172 int error; 173 174 /* 175 * Mounting the automounter. 176 * Make sure the mount directory exists, construct 177 * the mount options and call the mount_amfs_toplvl routine. 178 */ 179 180 if (stat(mp->am_path, &stb) < 0) { 181 return errno; 182 } else if ((stb.st_mode & S_IFMT) != S_IFDIR) { 183 plog(XLOG_WARNING, "%s is not a directory", mp->am_path); 184 return ENOTDIR; 185 } 186 187 /* 188 * Construct some mount options: 189 * 190 * Tack on magic map=<mapname> option in mtab to emulate 191 * SunOS automounter behavior. 192 */ 193 194 #ifdef HAVE_FS_AUTOFS 195 if (mf->mf_flags & MFF_IS_AUTOFS) { 196 autofs_get_opts(opts, sizeof(opts), mp->am_autofs_fh); 197 } else 198 #endif /* HAVE_FS_AUTOFS */ 199 { 200 preopts[0] = '\0'; 201 #ifdef MNTTAB_OPT_INTR 202 xstrlcat(preopts, MNTTAB_OPT_INTR, sizeof(preopts)); 203 xstrlcat(preopts, ",", sizeof(preopts)); 204 #endif /* MNTTAB_OPT_INTR */ 205 #ifdef MNTTAB_OPT_IGNORE 206 xstrlcat(preopts, MNTTAB_OPT_IGNORE, sizeof(preopts)); 207 xstrlcat(preopts, ",", sizeof(preopts)); 208 #endif /* MNTTAB_OPT_IGNORE */ 209 /* write most of the initial options + preopts */ 210 xsnprintf(opts, sizeof(opts), "%s%s,%s=%d,%s,map=%s", 211 preopts, 212 MNTTAB_OPT_RW, 213 MNTTAB_OPT_PORT, nfs_port, 214 mf->mf_ops->fs_type, mf->mf_info); 215 216 /* process toplvl timeo/retrans options, if any */ 217 if (gopt.amfs_auto_timeo[AMU_TYPE_TOPLVL] > 0) { 218 xsnprintf(toplvl_opts, sizeof(toplvl_opts), ",%s=%d", 219 MNTTAB_OPT_TIMEO, gopt.amfs_auto_timeo[AMU_TYPE_TOPLVL]); 220 xstrlcat(opts, toplvl_opts, sizeof(opts)); 221 } 222 if (gopt.amfs_auto_retrans[AMU_TYPE_TOPLVL] > 0) { 223 xsnprintf(toplvl_opts, sizeof(toplvl_opts), ",%s=%d", 224 MNTTAB_OPT_RETRANS, gopt.amfs_auto_retrans[AMU_TYPE_TOPLVL]); 225 xstrlcat(opts, toplvl_opts, sizeof(opts)); 226 } 227 228 #ifdef MNTTAB_OPT_NOLOCK 229 xstrlcat(opts, ",", sizeof(opts)); 230 xstrlcat(opts, MNTTAB_OPT_NOLOCK, sizeof(opts)); 231 #endif /* MNTTAB_OPT_NOLOCK */ 232 233 #ifdef MNTTAB_OPT_NOAC 234 if (gopt.auto_attrcache == 0) { 235 xstrlcat(opts, ",", sizeof(opts)); 236 xstrlcat(opts, MNTTAB_OPT_NOAC, sizeof(opts)); 237 } else 238 #endif /* MNTTAB_OPT_NOAC */ 239 set_auto_attrcache_timeout(preopts, opts, sizeof(preopts)); 240 } 241 242 /* now do the mount */ 243 error = amfs_mount(mp, mf, opts); 244 if (error) { 245 errno = error; 246 plog(XLOG_FATAL, "amfs_toplvl_mount: amfs_mount failed: %m"); 247 return error; 248 } 249 return 0; 250 } 251 252 253 /* 254 * Unmount a top-level automount node 255 */ 256 int 257 amfs_toplvl_umount(am_node *mp, mntfs *mf) 258 { 259 struct stat stb; 260 int unmount_flags = (mf->mf_flags & MFF_ON_AUTOFS) ? AMU_UMOUNT_AUTOFS : 0; 261 int error; 262 int count = 0; /* how many times did we try to unmount? */ 263 264 again: 265 /* 266 * The lstat is needed if this mount is type=direct. 267 * When that happens, the kernel cache gets confused 268 * between the underlying type (dir) and the mounted 269 * type (link) and so needs to be re-synced before 270 * the unmount. This is all because the unmount system 271 * call follows links and so can't actually unmount 272 * a link (stupid!). It was noted that doing an ls -ld 273 * of the mount point to see why things were not working 274 * actually fixed the problem - so simulate an ls -ld here. 275 */ 276 if (lstat(mp->am_path, &stb) < 0) { 277 error = errno; 278 dlog("lstat(%s): %m", mp->am_path); 279 goto out; 280 } 281 if ((stb.st_mode & S_IFMT) != S_IFDIR) { 282 plog(XLOG_ERROR, "amfs_toplvl_umount: %s is not a directory, aborting.", mp->am_path); 283 error = ENOTDIR; 284 goto out; 285 } 286 287 error = UMOUNT_FS(mp->am_path, mnttab_file_name, unmount_flags); 288 if (error == EBUSY) { 289 #ifdef HAVE_FS_AUTOFS 290 /* 291 * autofs mounts are "in place", so it is possible 292 * that we can't just unmount our mount points and go away. 293 * If that's the case, just give up. 294 */ 295 if (mf->mf_flags & MFF_IS_AUTOFS) 296 return error; 297 #endif /* HAVE_FS_AUTOFS */ 298 plog(XLOG_WARNING, "amfs_toplvl_unmount retrying %s in 1s", mp->am_path); 299 count++; 300 sleep(1); 301 /* 302 * If user wants forced/lazy unmount semantics, then set those flags, 303 * but only after we've tried normal lstat/umount a few times -- 304 * otherwise forced unmounts may hang this very same Amd (by preventing 305 * it from achieving a clean unmount). 306 */ 307 if (gopt.flags & CFM_FORCED_UNMOUNTS) { 308 if (count == 5) { /* after 5 seconds, try MNT_FORCE */ 309 dlog("enabling forced unmounts for toplvl node %s", mp->am_path); 310 unmount_flags |= AMU_UMOUNT_FORCE; 311 } 312 if (count == 10) { /* after 10 seconds, try MNT_DETACH */ 313 dlog("enabling detached unmounts for toplvl node %s", mp->am_path); 314 unmount_flags |= AMU_UMOUNT_DETACH; 315 } 316 } 317 goto again; 318 } 319 out: 320 return error; 321 } 322
Indexes created Wed Jul 01 00:25:26 UTC 2026