/* $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 <config.h>
#endif /* HAVE_CONFIG_H */
#include <am_defs.h>
#include <amd.h>
/****************************************************************************
*** 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=<mapname> 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;
}
