/* $NetBSD: amfs_toplvl.c,v 1.1.1.3 2015/01/17 16:34:15 christos Exp $ */ /* * Copyright (c) 1997-2014 Erez Zadok * Copyright (c) 1990 Jan-Simon Pendry * Copyright (c) 1990 Imperial College of Science, Technology & Medicine * Copyright (c) 1990 The Regents of the University of California. * All rights reserved. * * This code is derived from software contributed to Berkeley by * Jan-Simon Pendry at Imperial College, London. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * * File: am-utils/amd/amfs_toplvl.c * */ /* * Top-level file system */ #ifdef HAVE_CONFIG_H # include #endif /* HAVE_CONFIG_H */ #include #include /**************************************************************************** *** FORWARD DEFINITIONS *** ****************************************************************************/ static int amfs_toplvl_init(mntfs *mf); /**************************************************************************** *** OPS STRUCTURES *** ****************************************************************************/ am_ops amfs_toplvl_ops = { "toplvl", amfs_generic_match, amfs_toplvl_init, /* amfs_toplvl_init */ amfs_toplvl_mount, amfs_toplvl_umount, amfs_generic_lookup_child, amfs_generic_mount_child, amfs_generic_readdir, 0, /* amfs_toplvl_readlink */ amfs_generic_mounted, 0, /* amfs_toplvl_umounted */ amfs_generic_find_srvr, 0, /* amfs_toplvl_get_wchan */ FS_MKMNT | FS_NOTIMEOUT | FS_BACKGROUND | FS_AMQINFO | FS_DIRECTORY, /* nfs_fs_flags */ #ifdef HAVE_FS_AUTOFS AUTOFS_TOPLVL_FS_FLAGS, #endif /* HAVE_FS_AUTOFS */ }; /**************************************************************************** *** FUNCTIONS *** ****************************************************************************/ static void set_auto_attrcache_timeout(char *preopts, char *opts, size_t l) { #ifdef MNTTAB_OPT_NOAC /* * Don't cache attributes - they are changing under the kernel's feet. * For example, IRIX5.2 will dispense with nfs lookup calls and hand stale * filehandles to getattr unless we disable attribute caching on the * automount points. */ if (gopt.auto_attrcache == 0) { xsnprintf(preopts, l, ",%s", MNTTAB_OPT_NOAC); xstrlcat(opts, preopts, l); } #endif /* MNTTAB_OPT_NOAC */ /* * XXX: note that setting these to 0 in the past resulted in an error on * some systems, which is why it's better to use "noac" if possible. For * now, we're setting everything possible, but if this will cause trouble, * then we'll have to condition the remainder of this on OPT_NOAC. */ #ifdef MNTTAB_OPT_ACTIMEO xsnprintf(preopts, l, ",%s=%d", MNTTAB_OPT_ACTIMEO, gopt.auto_attrcache); xstrlcat(opts, preopts, l); #else /* MNTTAB_OPT_ACTIMEO */ # ifdef MNTTAB_OPT_ACDIRMIN xsnprintf(preopts, l, ",%s=%d", MNTTAB_OPT_ACTDIRMIN, gopt.auto_attrcache); xstrlcat(opts, preopts, l); # endif /* MNTTAB_OPT_ACDIRMIN */ # ifdef MNTTAB_OPT_ACDIRMAX xsnprintf(preopts, l, ",%s=%d", MNTTAB_OPT_ACTDIRMAX, gopt.auto_attrcache); xstrlcat(opts, preopts, l); # endif /* MNTTAB_OPT_ACDIRMAX */ # ifdef MNTTAB_OPT_ACREGMIN xsnprintf(preopts, l, ",%s=%d", MNTTAB_OPT_ACTREGMIN, gopt.auto_attrcache); xstrlcat(opts, preopts, l); # endif /* MNTTAB_OPT_ACREGMIN */ # ifdef MNTTAB_OPT_ACREGMAX xsnprintf(preopts, l, ",%s=%d", MNTTAB_OPT_ACTREGMAX, gopt.auto_attrcache); xstrlcat(opts, preopts, l); # endif /* MNTTAB_OPT_ACREGMAX */ #endif /* MNTTAB_OPT_ACTIMEO */ } /* * Initialize a top-level mount. In our case, if the user asked for * forced_unmounts, and the OS supports it, then we try forced/lazy unmounts * on any previous toplvl mounts. This is useful if a previous Amd died and * left behind toplvl mount points (this Amd will clean them up). * * WARNING: Don't use forced/lazy unmounts if you have another valid Amd * running, because this code WILL force those valid toplvl mount points to * be detached as well! */ static int amfs_toplvl_init(mntfs *mf) { int error = 0; #if (defined(MNT2_GEN_OPT_FORCE) || defined(MNT2_GEN_OPT_DETACH)) && (defined(HAVE_UVMOUNT) || defined(HAVE_UMOUNT2)) if (gopt.flags & CFM_FORCED_UNMOUNTS) { plog(XLOG_INFO, "amfs_toplvl_init: trying forced/lazy unmount of %s", mf->mf_mount); error = umount2_fs(mf->mf_mount, AMU_UMOUNT_FORCE | AMU_UMOUNT_DETACH); if (error) plog(XLOG_INFO, "amfs_toplvl_init: forced/lazy unmount failed: %m"); else dlog("amfs_toplvl_init: forced/lazy unmount succeeded"); } #endif /* (MNT2_GEN_OPT_FORCE || MNT2_GEN_OPT_DETACH) && (HAVE_UVMOUNT || HAVE_UMOUNT2) */ return error; } /* * Mount the top-level */ int amfs_toplvl_mount(am_node *mp, mntfs *mf) { struct stat stb; char opts[SIZEOF_OPTS], preopts[SIZEOF_OPTS], toplvl_opts[40]; int error; /* * Mounting the automounter. * Make sure the mount directory exists, construct * the mount options and call the mount_amfs_toplvl routine. */ if (stat(mp->am_path, &stb) < 0) { return errno; } else if ((stb.st_mode & S_IFMT) != S_IFDIR) { plog(XLOG_WARNING, "%s is not a directory", mp->am_path); return ENOTDIR; } /* * Construct some mount options: * * Tack on magic map= option in mtab to emulate * SunOS automounter behavior. */ #ifdef HAVE_FS_AUTOFS if (mf->mf_flags & MFF_IS_AUTOFS) { autofs_get_opts(opts, sizeof(opts), mp->am_autofs_fh); } else #endif /* HAVE_FS_AUTOFS */ { preopts[0] = '\0'; #ifdef MNTTAB_OPT_INTR xstrlcat(preopts, MNTTAB_OPT_INTR, sizeof(preopts)); xstrlcat(preopts, ",", sizeof(preopts)); #endif /* MNTTAB_OPT_INTR */ #ifdef MNTTAB_OPT_IGNORE xstrlcat(preopts, MNTTAB_OPT_IGNORE, sizeof(preopts)); xstrlcat(preopts, ",", sizeof(preopts)); #endif /* MNTTAB_OPT_IGNORE */ /* write most of the initial options + preopts */ xsnprintf(opts, sizeof(opts), "%s%s,%s=%d,%s,map=%s", preopts, MNTTAB_OPT_RW, MNTTAB_OPT_PORT, nfs_port, mf->mf_ops->fs_type, mf->mf_info); /* process toplvl timeo/retrans options, if any */ if (gopt.amfs_auto_timeo[AMU_TYPE_TOPLVL] > 0) { xsnprintf(toplvl_opts, sizeof(toplvl_opts), ",%s=%d", MNTTAB_OPT_TIMEO, gopt.amfs_auto_timeo[AMU_TYPE_TOPLVL]); xstrlcat(opts, toplvl_opts, sizeof(opts)); } if (gopt.amfs_auto_retrans[AMU_TYPE_TOPLVL] > 0) { xsnprintf(toplvl_opts, sizeof(toplvl_opts), ",%s=%d", MNTTAB_OPT_RETRANS, gopt.amfs_auto_retrans[AMU_TYPE_TOPLVL]); xstrlcat(opts, toplvl_opts, sizeof(opts)); } #ifdef MNTTAB_OPT_NOLOCK xstrlcat(opts, ",", sizeof(opts)); xstrlcat(opts, MNTTAB_OPT_NOLOCK, sizeof(opts)); #endif /* MNTTAB_OPT_NOLOCK */ #ifdef MNTTAB_OPT_NOAC if (gopt.auto_attrcache == 0) { xstrlcat(opts, ",", sizeof(opts)); xstrlcat(opts, MNTTAB_OPT_NOAC, sizeof(opts)); } else #endif /* MNTTAB_OPT_NOAC */ set_auto_attrcache_timeout(preopts, opts, sizeof(preopts)); } /* now do the mount */ error = amfs_mount(mp, mf, opts); if (error) { errno = error; plog(XLOG_FATAL, "amfs_toplvl_mount: amfs_mount failed: %m"); return error; } return 0; } /* * Unmount a top-level automount node */ int amfs_toplvl_umount(am_node *mp, mntfs *mf) { struct stat stb; int unmount_flags = (mf->mf_flags & MFF_ON_AUTOFS) ? AMU_UMOUNT_AUTOFS : 0; int error; int count = 0; /* how many times did we try to unmount? */ again: /* * The lstat is needed if this mount is type=direct. * When that happens, the kernel cache gets confused * between the underlying type (dir) and the mounted * type (link) and so needs to be re-synced before * the unmount. This is all because the unmount system * call follows links and so can't actually unmount * a link (stupid!). It was noted that doing an ls -ld * of the mount point to see why things were not working * actually fixed the problem - so simulate an ls -ld here. */ if (lstat(mp->am_path, &stb) < 0) { error = errno; dlog("lstat(%s): %m", mp->am_path); goto out; } if ((stb.st_mode & S_IFMT) != S_IFDIR) { plog(XLOG_ERROR, "amfs_toplvl_umount: %s is not a directory, aborting.", mp->am_path); error = ENOTDIR; goto out; } error = UMOUNT_FS(mp->am_path, mnttab_file_name, unmount_flags); if (error == EBUSY) { #ifdef HAVE_FS_AUTOFS /* * autofs mounts are "in place", so it is possible * that we can't just unmount our mount points and go away. * If that's the case, just give up. */ if (mf->mf_flags & MFF_IS_AUTOFS) return error; #endif /* HAVE_FS_AUTOFS */ plog(XLOG_WARNING, "amfs_toplvl_unmount retrying %s in 1s", mp->am_path); count++; sleep(1); /* * If user wants forced/lazy unmount semantics, then set those flags, * but only after we've tried normal lstat/umount a few times -- * otherwise forced unmounts may hang this very same Amd (by preventing * it from achieving a clean unmount). */ if (gopt.flags & CFM_FORCED_UNMOUNTS) { if (count == 5) { /* after 5 seconds, try MNT_FORCE */ dlog("enabling forced unmounts for toplvl node %s", mp->am_path); unmount_flags |= AMU_UMOUNT_FORCE; } if (count == 10) { /* after 10 seconds, try MNT_DETACH */ dlog("enabling detached unmounts for toplvl node %s", mp->am_path); unmount_flags |= AMU_UMOUNT_DETACH; } } goto again; } out: return error; }