amfs_toplvl.c revision 310490
1162271Srwatson/* 2162271Srwatson * Copyright (c) 1997-2014 Erez Zadok 3172106Srwatson * Copyright (c) 1990 Jan-Simon Pendry 4162271Srwatson * Copyright (c) 1990 Imperial College of Science, Technology & Medicine 5162271Srwatson * Copyright (c) 1990 The Regents of the University of California. 6162271Srwatson * All rights reserved. 7162271Srwatson * 8162271Srwatson * This code is derived from software contributed to Berkeley by 9162271Srwatson * Jan-Simon Pendry at Imperial College, London. 10162271Srwatson * 11162271Srwatson * Redistribution and use in source and binary forms, with or without 12162271Srwatson * modification, are permitted provided that the following conditions 13162271Srwatson * are met: 14162271Srwatson * 1. Redistributions of source code must retain the above copyright 15162271Srwatson * notice, this list of conditions and the following disclaimer. 16162271Srwatson * 2. Redistributions in binary form must reproduce the above copyright 17162271Srwatson * notice, this list of conditions and the following disclaimer in the 18162271Srwatson * documentation and/or other materials provided with the distribution. 19162271Srwatson * 3. Neither the name of the University nor the names of its contributors 20162271Srwatson * may be used to endorse or promote products derived from this software 21162271Srwatson * without specific prior written permission. 22162271Srwatson * 23162271Srwatson * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24162271Srwatson * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25162271Srwatson * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26162271Srwatson * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27162271Srwatson * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28162271Srwatson * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29162271Srwatson * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30162271Srwatson * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31162271Srwatson * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32162271Srwatson * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33162271Srwatson * SUCH DAMAGE. 34172106Srwatson * 35162271Srwatson * 36162271Srwatson * File: am-utils/amd/amfs_toplvl.c 37162271Srwatson * 38162271Srwatson */ 39162271Srwatson 40162271Srwatson/* 41162271Srwatson * Top-level file system 42162271Srwatson */ 43162271Srwatson 44162271Srwatson#ifdef HAVE_CONFIG_H 45162271Srwatson# include <config.h> 46172106Srwatson#endif /* HAVE_CONFIG_H */ 47172106Srwatson#include <am_defs.h> 48172106Srwatson#include <amd.h> 49172106Srwatson 50172106Srwatson/**************************************************************************** 51172106Srwatson *** FORWARD DEFINITIONS *** 52172106Srwatson ****************************************************************************/ 53162271Srwatsonstatic int amfs_toplvl_init(mntfs *mf); 54172106Srwatson 55162271Srwatson/**************************************************************************** 56162271Srwatson *** OPS STRUCTURES *** 57162271Srwatson ****************************************************************************/ 58162271Srwatsonam_ops amfs_toplvl_ops = 59172106Srwatson{ 60172106Srwatson "toplvl", 61172106Srwatson amfs_generic_match, 62172106Srwatson amfs_toplvl_init, /* amfs_toplvl_init */ 63172106Srwatson amfs_toplvl_mount, 64172106Srwatson amfs_toplvl_umount, 65172106Srwatson amfs_generic_lookup_child, 66172106Srwatson amfs_generic_mount_child, 67172106Srwatson amfs_generic_readdir, 68172106Srwatson 0, /* amfs_toplvl_readlink */ 69172106Srwatson amfs_generic_mounted, 70172106Srwatson 0, /* amfs_toplvl_umounted */ 71162271Srwatson amfs_generic_find_srvr, 72172106Srwatson 0, /* amfs_toplvl_get_wchan */ 73172106Srwatson FS_MKMNT | FS_NOTIMEOUT | FS_BACKGROUND | 74172106Srwatson FS_AMQINFO | FS_DIRECTORY, /* nfs_fs_flags */ 75162271Srwatson#ifdef HAVE_FS_AUTOFS 76162271Srwatson AUTOFS_TOPLVL_FS_FLAGS, 77#endif /* HAVE_FS_AUTOFS */ 78}; 79 80 81/**************************************************************************** 82 *** FUNCTIONS *** 83 ****************************************************************************/ 84 85static void 86set_auto_attrcache_timeout(char *preopts, char *opts, size_t l) 87{ 88 89#ifdef MNTTAB_OPT_NOAC 90 /* 91 * Don't cache attributes - they are changing under the kernel's feet. 92 * For example, IRIX5.2 will dispense with nfs lookup calls and hand stale 93 * filehandles to getattr unless we disable attribute caching on the 94 * automount points. 95 */ 96 if (gopt.auto_attrcache == 0) { 97 xsnprintf(preopts, l, ",%s", MNTTAB_OPT_NOAC); 98 xstrlcat(opts, preopts, l); 99 } 100#endif /* MNTTAB_OPT_NOAC */ 101 102 /* 103 * XXX: note that setting these to 0 in the past resulted in an error on 104 * some systems, which is why it's better to use "noac" if possible. For 105 * now, we're setting everything possible, but if this will cause trouble, 106 * then we'll have to condition the remainder of this on OPT_NOAC. 107 */ 108#ifdef MNTTAB_OPT_ACTIMEO 109 xsnprintf(preopts, l, ",%s=%d", MNTTAB_OPT_ACTIMEO, gopt.auto_attrcache); 110 xstrlcat(opts, preopts, l); 111#else /* MNTTAB_OPT_ACTIMEO */ 112# ifdef MNTTAB_OPT_ACDIRMIN 113 xsnprintf(preopts, l, ",%s=%d", MNTTAB_OPT_ACTDIRMIN, gopt.auto_attrcache); 114 xstrlcat(opts, preopts, l); 115# endif /* MNTTAB_OPT_ACDIRMIN */ 116# ifdef MNTTAB_OPT_ACDIRMAX 117 xsnprintf(preopts, l, ",%s=%d", MNTTAB_OPT_ACTDIRMAX, gopt.auto_attrcache); 118 xstrlcat(opts, preopts, l); 119# endif /* MNTTAB_OPT_ACDIRMAX */ 120# ifdef MNTTAB_OPT_ACREGMIN 121 xsnprintf(preopts, l, ",%s=%d", MNTTAB_OPT_ACTREGMIN, gopt.auto_attrcache); 122 xstrlcat(opts, preopts, l); 123# endif /* MNTTAB_OPT_ACREGMIN */ 124# ifdef MNTTAB_OPT_ACREGMAX 125 xsnprintf(preopts, l, ",%s=%d", MNTTAB_OPT_ACTREGMAX, gopt.auto_attrcache); 126 xstrlcat(opts, preopts, l); 127# endif /* MNTTAB_OPT_ACREGMAX */ 128#endif /* MNTTAB_OPT_ACTIMEO */ 129} 130 131 132/* 133 * Initialize a top-level mount. In our case, if the user asked for 134 * forced_unmounts, and the OS supports it, then we try forced/lazy unmounts 135 * on any previous toplvl mounts. This is useful if a previous Amd died and 136 * left behind toplvl mount points (this Amd will clean them up). 137 * 138 * WARNING: Don't use forced/lazy unmounts if you have another valid Amd 139 * running, because this code WILL force those valid toplvl mount points to 140 * be detached as well! 141 */ 142static int 143amfs_toplvl_init(mntfs *mf) 144{ 145 int error = 0; 146 147#if (defined(MNT2_GEN_OPT_FORCE) || defined(MNT2_GEN_OPT_DETACH)) && (defined(HAVE_UVMOUNT) || defined(HAVE_UMOUNT2)) 148 if (gopt.flags & CFM_FORCED_UNMOUNTS) { 149 plog(XLOG_INFO, "amfs_toplvl_init: trying forced/lazy unmount of %s", 150 mf->mf_mount); 151 error = umount2_fs(mf->mf_mount, AMU_UMOUNT_FORCE | AMU_UMOUNT_DETACH); 152 if (error) 153 plog(XLOG_INFO, "amfs_toplvl_init: forced/lazy unmount failed: %m"); 154 else 155 dlog("amfs_toplvl_init: forced/lazy unmount succeeded"); 156 } 157#endif /* (MNT2_GEN_OPT_FORCE || MNT2_GEN_OPT_DETACH) && (HAVE_UVMOUNT || HAVE_UMOUNT2) */ 158 return error; 159} 160 161 162/* 163 * Mount the top-level 164 */ 165int 166amfs_toplvl_mount(am_node *mp, mntfs *mf) 167{ 168 struct stat stb; 169 char opts[SIZEOF_OPTS], preopts[SIZEOF_OPTS], toplvl_opts[40]; 170 int error; 171 172 /* 173 * Mounting the automounter. 174 * Make sure the mount directory exists, construct 175 * the mount options and call the mount_amfs_toplvl routine. 176 */ 177 178 if (stat(mp->am_path, &stb) < 0) { 179 return errno; 180 } else if ((stb.st_mode & S_IFMT) != S_IFDIR) { 181 plog(XLOG_WARNING, "%s is not a directory", mp->am_path); 182 return ENOTDIR; 183 } 184 185 /* 186 * Construct some mount options: 187 * 188 * Tack on magic map=<mapname> option in mtab to emulate 189 * SunOS automounter behavior. 190 */ 191 192#ifdef HAVE_FS_AUTOFS 193 if (mf->mf_flags & MFF_IS_AUTOFS) { 194 autofs_get_opts(opts, sizeof(opts), mp->am_autofs_fh); 195 } else 196#endif /* HAVE_FS_AUTOFS */ 197 { 198 preopts[0] = '\0'; 199#ifdef MNTTAB_OPT_INTR 200 xstrlcat(preopts, MNTTAB_OPT_INTR, sizeof(preopts)); 201 xstrlcat(preopts, ",", sizeof(preopts)); 202#endif /* MNTTAB_OPT_INTR */ 203#ifdef MNTTAB_OPT_IGNORE 204 xstrlcat(preopts, MNTTAB_OPT_IGNORE, sizeof(preopts)); 205 xstrlcat(preopts, ",", sizeof(preopts)); 206#endif /* MNTTAB_OPT_IGNORE */ 207 /* write most of the initial options + preopts */ 208 xsnprintf(opts, sizeof(opts), "%s%s,%s=%d,%s,map=%s", 209 preopts, 210 MNTTAB_OPT_RW, 211 MNTTAB_OPT_PORT, nfs_port, 212 mf->mf_ops->fs_type, mf->mf_info); 213 214 /* process toplvl timeo/retrans options, if any */ 215 if (gopt.amfs_auto_timeo[AMU_TYPE_TOPLVL] > 0) { 216 xsnprintf(toplvl_opts, sizeof(toplvl_opts), ",%s=%d", 217 MNTTAB_OPT_TIMEO, gopt.amfs_auto_timeo[AMU_TYPE_TOPLVL]); 218 xstrlcat(opts, toplvl_opts, sizeof(opts)); 219 } 220 if (gopt.amfs_auto_retrans[AMU_TYPE_TOPLVL] > 0) { 221 xsnprintf(toplvl_opts, sizeof(toplvl_opts), ",%s=%d", 222 MNTTAB_OPT_RETRANS, gopt.amfs_auto_retrans[AMU_TYPE_TOPLVL]); 223 xstrlcat(opts, toplvl_opts, sizeof(opts)); 224 } 225 226#ifdef MNTTAB_OPT_NOLOCK 227 xstrlcat(opts, ",", sizeof(opts)); 228 xstrlcat(opts, MNTTAB_OPT_NOLOCK, sizeof(opts)); 229#endif /* MNTTAB_OPT_NOLOCK */ 230 231#ifdef MNTTAB_OPT_NOAC 232 if (gopt.auto_attrcache == 0) { 233 xstrlcat(opts, ",", sizeof(opts)); 234 xstrlcat(opts, MNTTAB_OPT_NOAC, sizeof(opts)); 235 } else 236#endif /* MNTTAB_OPT_NOAC */ 237 set_auto_attrcache_timeout(preopts, opts, sizeof(preopts)); 238 } 239 240 /* now do the mount */ 241 error = amfs_mount(mp, mf, opts); 242 if (error) { 243 errno = error; 244 plog(XLOG_FATAL, "amfs_toplvl_mount: amfs_mount failed: %m"); 245 return error; 246 } 247 return 0; 248} 249 250 251/* 252 * Unmount a top-level automount node 253 */ 254int 255amfs_toplvl_umount(am_node *mp, mntfs *mf) 256{ 257 struct stat stb; 258 int unmount_flags = (mf->mf_flags & MFF_ON_AUTOFS) ? AMU_UMOUNT_AUTOFS : 0; 259 int error; 260 int count = 0; /* how many times did we try to unmount? */ 261 262again: 263 /* 264 * The lstat is needed if this mount is type=direct. 265 * When that happens, the kernel cache gets confused 266 * between the underlying type (dir) and the mounted 267 * type (link) and so needs to be re-synced before 268 * the unmount. This is all because the unmount system 269 * call follows links and so can't actually unmount 270 * a link (stupid!). It was noted that doing an ls -ld 271 * of the mount point to see why things were not working 272 * actually fixed the problem - so simulate an ls -ld here. 273 */ 274 if (lstat(mp->am_path, &stb) < 0) { 275 error = errno; 276 dlog("lstat(%s): %m", mp->am_path); 277 goto out; 278 } 279 if ((stb.st_mode & S_IFMT) != S_IFDIR) { 280 plog(XLOG_ERROR, "amfs_toplvl_umount: %s is not a directory, aborting.", mp->am_path); 281 error = ENOTDIR; 282 goto out; 283 } 284 285 error = UMOUNT_FS(mp->am_path, mnttab_file_name, unmount_flags); 286 if (error == EBUSY) { 287#ifdef HAVE_FS_AUTOFS 288 /* 289 * autofs mounts are "in place", so it is possible 290 * that we can't just unmount our mount points and go away. 291 * If that's the case, just give up. 292 */ 293 if (mf->mf_flags & MFF_IS_AUTOFS) 294 return error; 295#endif /* HAVE_FS_AUTOFS */ 296 plog(XLOG_WARNING, "amfs_toplvl_unmount retrying %s in 1s", mp->am_path); 297 count++; 298 sleep(1); 299 /* 300 * If user wants forced/lazy unmount semantics, then set those flags, 301 * but only after we've tried normal lstat/umount a few times -- 302 * otherwise forced unmounts may hang this very same Amd (by preventing 303 * it from achieving a clean unmount). 304 */ 305 if (gopt.flags & CFM_FORCED_UNMOUNTS) { 306 if (count == 5) { /* after 5 seconds, try MNT_FORCE */ 307 dlog("enabling forced unmounts for toplvl node %s", mp->am_path); 308 unmount_flags |= AMU_UMOUNT_FORCE; 309 } 310 if (count == 10) { /* after 10 seconds, try MNT_DETACH */ 311 dlog("enabling detached unmounts for toplvl node %s", mp->am_path); 312 unmount_flags |= AMU_UMOUNT_DETACH; 313 } 314 } 315 goto again; 316 } 317out: 318 return error; 319} 320