freebsd-dev/sys/fs/autofs/autofs.c
Edward Tomasz Napierala f5440d1a9d Fix includes.
Suggested by:	pluknet@
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
2014-08-21 15:59:25 +00:00

640 lines
17 KiB
C

/*-
* Copyright (c) 2014 The FreeBSD Foundation
* All rights reserved.
*
* This software was developed by Edward Tomasz Napierala under sponsorship
* from the FreeBSD Foundation.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
*/
/*-
* Copyright (c) 1989, 1991, 1993, 1995
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Rick Macklem at The University of Guelph.
*
* 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.
* 4. 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.
*
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/conf.h>
#include <sys/dirent.h>
#include <sys/ioccom.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/mount.h>
#include <sys/refcount.h>
#include <sys/sx.h>
#include <sys/sysctl.h>
#include <sys/syscallsubr.h>
#include <sys/vnode.h>
#include <machine/atomic.h>
#include <vm/uma.h>
#include <fs/autofs/autofs.h>
#include <fs/autofs/autofs_ioctl.h>
MALLOC_DEFINE(M_AUTOFS, "autofs", "Automounter filesystem");
uma_zone_t autofs_request_zone;
uma_zone_t autofs_node_zone;
static int autofs_open(struct cdev *dev, int flags, int fmt,
struct thread *td);
static int autofs_close(struct cdev *dev, int flag, int fmt,
struct thread *td);
static int autofs_ioctl(struct cdev *dev, u_long cmd, caddr_t arg,
int mode, struct thread *td);
static struct cdevsw autofs_cdevsw = {
.d_version = D_VERSION,
.d_open = autofs_open,
.d_close = autofs_close,
.d_ioctl = autofs_ioctl,
.d_name = "autofs",
};
/*
* List of signals that can interrupt an autofs trigger. Might be a good
* idea to keep it synchronised with list in sys/fs/nfs/nfs_commonkrpc.c.
*/
int autofs_sig_set[] = {
SIGINT,
SIGTERM,
SIGHUP,
SIGKILL,
SIGQUIT
};
struct autofs_softc *sc;
SYSCTL_NODE(_vfs, OID_AUTO, autofs, CTLFLAG_RD, 0, "Automounter filesystem");
int autofs_debug = 1;
TUNABLE_INT("vfs.autofs.debug", &autofs_debug);
SYSCTL_INT(_vfs_autofs, OID_AUTO, debug, CTLFLAG_RWTUN,
&autofs_debug, 1, "Enable debug messages");
int autofs_mount_on_stat = 0;
TUNABLE_INT("vfs.autofs.mount_on_stat", &autofs_mount_on_stat);
SYSCTL_INT(_vfs_autofs, OID_AUTO, mount_on_stat, CTLFLAG_RWTUN,
&autofs_mount_on_stat, 0, "Trigger mount on stat(2) on mountpoint");
int autofs_timeout = 30;
TUNABLE_INT("vfs.autofs.timeout", &autofs_timeout);
SYSCTL_INT(_vfs_autofs, OID_AUTO, timeout, CTLFLAG_RWTUN,
&autofs_timeout, 30, "Number of seconds to wait for automountd(8)");
int autofs_cache = 600;
TUNABLE_INT("vfs.autofs.cache", &autofs_cache);
SYSCTL_INT(_vfs_autofs, OID_AUTO, cache, CTLFLAG_RWTUN,
&autofs_cache, 600, "Number of seconds to wait before reinvoking "
"automountd(8) for any given file or directory");
int autofs_retry_attempts = 3;
TUNABLE_INT("vfs.autofs.retry_attempts", &autofs_retry_attempts);
SYSCTL_INT(_vfs_autofs, OID_AUTO, retry_attempts, CTLFLAG_RWTUN,
&autofs_retry_attempts, 3, "Number of attempts before failing mount");
int autofs_retry_delay = 1;
TUNABLE_INT("vfs.autofs.retry_delay", &autofs_retry_delay);
SYSCTL_INT(_vfs_autofs, OID_AUTO, retry_delay, CTLFLAG_RWTUN,
&autofs_retry_delay, 1, "Number of seconds before retrying");
int autofs_interruptible = 1;
TUNABLE_INT("vfs.autofs.interruptible", &autofs_interruptible);
SYSCTL_INT(_vfs_autofs, OID_AUTO, interruptible, CTLFLAG_RWTUN,
&autofs_interruptible, 1, "Allow requests to be interrupted by signal");
int
autofs_init(struct vfsconf *vfsp)
{
int error;
sc = malloc(sizeof(*sc), M_AUTOFS, M_WAITOK | M_ZERO);
autofs_request_zone = uma_zcreate("autofs_request",
sizeof(struct autofs_request), NULL, NULL, NULL, NULL,
UMA_ALIGN_PTR, 0);
autofs_node_zone = uma_zcreate("autofs_node",
sizeof(struct autofs_node), NULL, NULL, NULL, NULL,
UMA_ALIGN_PTR, 0);
TAILQ_INIT(&sc->sc_requests);
cv_init(&sc->sc_cv, "autofscv");
sx_init(&sc->sc_lock, "autofslk");
error = make_dev_p(MAKEDEV_CHECKNAME, &sc->sc_cdev, &autofs_cdevsw,
NULL, UID_ROOT, GID_WHEEL, 0600, "autofs");
if (error != 0) {
AUTOFS_WARN("failed to create device node, error %d", error);
free(sc, M_AUTOFS);
return (error);
}
sc->sc_cdev->si_drv1 = sc;
return (0);
}
int
autofs_uninit(struct vfsconf *vfsp)
{
sx_xlock(&sc->sc_lock);
if (sc->sc_dev_opened) {
sx_xunlock(&sc->sc_lock);
return (EBUSY);
}
if (sc->sc_cdev != NULL)
destroy_dev(sc->sc_cdev);
uma_zdestroy(autofs_request_zone);
uma_zdestroy(autofs_node_zone);
sx_xunlock(&sc->sc_lock);
/*
* XXX: Race with open?
*/
free(sc, M_AUTOFS);
return (0);
}
bool
autofs_ignore_thread(const struct thread *td)
{
struct proc *p;
p = td->td_proc;
if (sc->sc_dev_opened == false)
return (false);
PROC_LOCK(p);
if (p->p_session->s_sid == sc->sc_dev_sid) {
PROC_UNLOCK(p);
return (true);
}
PROC_UNLOCK(p);
return (false);
}
static char *
autofs_path(struct autofs_node *anp)
{
struct autofs_mount *amp;
char *path, *tmp;
amp = anp->an_mount;
path = strdup("", M_AUTOFS);
for (; anp->an_parent != NULL; anp = anp->an_parent) {
tmp = malloc(strlen(anp->an_name) + strlen(path) + 2,
M_AUTOFS, M_WAITOK);
strcpy(tmp, anp->an_name);
strcat(tmp, "/");
strcat(tmp, path);
free(path, M_AUTOFS);
path = tmp;
}
tmp = malloc(strlen(amp->am_mountpoint) + strlen(path) + 2,
M_AUTOFS, M_WAITOK);
strcpy(tmp, amp->am_mountpoint);
strcat(tmp, "/");
strcat(tmp, path);
free(path, M_AUTOFS);
path = tmp;
return (path);
}
static void
autofs_callout(void *context)
{
struct autofs_request *ar;
struct autofs_softc *sc;
ar = context;
sc = ar->ar_mount->am_softc;
sx_xlock(&sc->sc_lock);
AUTOFS_WARN("request %d for %s timed out after %d seconds",
ar->ar_id, ar->ar_path, autofs_timeout);
/*
* XXX: EIO perhaps?
*/
ar->ar_error = ETIMEDOUT;
ar->ar_done = true;
ar->ar_in_progress = false;
cv_broadcast(&sc->sc_cv);
sx_xunlock(&sc->sc_lock);
}
bool
autofs_cached(struct autofs_node *anp, const char *component, int componentlen)
{
int error;
struct autofs_mount *amp;
amp = anp->an_mount;
AUTOFS_ASSERT_UNLOCKED(amp);
/*
* For top-level nodes we need to request automountd(8)
* assistance even if the node is marked as cached,
* but the requested subdirectory does not exist. This
* is necessary for wildcard indirect map keys to work.
*/
if (anp->an_parent == NULL && componentlen != 0) {
AUTOFS_LOCK(amp);
error = autofs_node_find(anp, component, componentlen, NULL);
AUTOFS_UNLOCK(amp);
if (error != 0)
return (false);
}
return (anp->an_cached);
}
static void
autofs_cache_callout(void *context)
{
struct autofs_node *anp;
anp = context;
anp->an_cached = false;
}
/*
* The set/restore sigmask functions are used to (temporarily) overwrite
* the thread td_sigmask during triggering.
*/
static void
autofs_set_sigmask(sigset_t *oldset)
{
sigset_t newset;
int i;
SIGFILLSET(newset);
/* Remove the autofs set of signals from newset */
PROC_LOCK(curproc);
mtx_lock(&curproc->p_sigacts->ps_mtx);
for (i = 0 ; i < sizeof(autofs_sig_set)/sizeof(int) ; i++) {
/*
* But make sure we leave the ones already masked
* by the process, i.e. remove the signal from the
* temporary signalmask only if it wasn't already
* in p_sigmask.
*/
if (!SIGISMEMBER(curthread->td_sigmask, autofs_sig_set[i]) &&
!SIGISMEMBER(curproc->p_sigacts->ps_sigignore,
autofs_sig_set[i])) {
SIGDELSET(newset, autofs_sig_set[i]);
}
}
mtx_unlock(&curproc->p_sigacts->ps_mtx);
kern_sigprocmask(curthread, SIG_SETMASK, &newset, oldset,
SIGPROCMASK_PROC_LOCKED);
PROC_UNLOCK(curproc);
}
static void
autofs_restore_sigmask(sigset_t *set)
{
kern_sigprocmask(curthread, SIG_SETMASK, set, NULL, 0);
}
static int
autofs_trigger_one(struct autofs_node *anp,
const char *component, int componentlen)
{
sigset_t oldset;
struct autofs_mount *amp;
struct autofs_softc *sc;
struct autofs_node *firstanp;
struct autofs_request *ar;
char *key, *path;
int error = 0, request_error, last;
amp = VFSTOAUTOFS(anp->an_vnode->v_mount);
sc = amp->am_softc;
sx_assert(&sc->sc_lock, SA_XLOCKED);
if (anp->an_parent == NULL) {
key = strndup(component, componentlen, M_AUTOFS);
} else {
for (firstanp = anp; firstanp->an_parent->an_parent != NULL;
firstanp = firstanp->an_parent)
continue;
key = strdup(firstanp->an_name, M_AUTOFS);
}
path = autofs_path(anp);
TAILQ_FOREACH(ar, &sc->sc_requests, ar_next) {
if (strcmp(ar->ar_path, path) != 0)
continue;
if (strcmp(ar->ar_key, key) != 0)
continue;
KASSERT(strcmp(ar->ar_from, amp->am_from) == 0,
("from changed; %s != %s", ar->ar_from, amp->am_from));
KASSERT(strcmp(ar->ar_prefix, amp->am_prefix) == 0,
("prefix changed; %s != %s",
ar->ar_prefix, amp->am_prefix));
KASSERT(strcmp(ar->ar_options, amp->am_options) == 0,
("options changed; %s != %s",
ar->ar_options, amp->am_options));
break;
}
if (ar != NULL) {
refcount_acquire(&ar->ar_refcount);
} else {
ar = uma_zalloc(autofs_request_zone, M_WAITOK | M_ZERO);
ar->ar_mount = amp;
ar->ar_id = atomic_fetchadd_int(&sc->sc_last_request_id, 1);
strlcpy(ar->ar_from, amp->am_from, sizeof(ar->ar_from));
strlcpy(ar->ar_path, path, sizeof(ar->ar_path));
strlcpy(ar->ar_prefix, amp->am_prefix, sizeof(ar->ar_prefix));
strlcpy(ar->ar_key, key, sizeof(ar->ar_key));
strlcpy(ar->ar_options,
amp->am_options, sizeof(ar->ar_options));
callout_init(&ar->ar_callout, 1);
callout_reset(&ar->ar_callout,
autofs_timeout * hz, autofs_callout, ar);
refcount_init(&ar->ar_refcount, 1);
TAILQ_INSERT_TAIL(&sc->sc_requests, ar, ar_next);
}
cv_broadcast(&sc->sc_cv);
while (ar->ar_done == false) {
if (autofs_interruptible != 0) {
autofs_set_sigmask(&oldset);
error = cv_wait_sig(&sc->sc_cv, &sc->sc_lock);
autofs_restore_sigmask(&oldset);
if (error != 0) {
/*
* XXX: For some reson this returns -1
* instead of EINTR, wtf?!
*/
error = EINTR;
AUTOFS_WARN("cv_wait_sig for %s failed "
"with error %d", ar->ar_path, error);
break;
}
} else {
cv_wait(&sc->sc_cv, &sc->sc_lock);
}
}
request_error = ar->ar_error;
if (request_error != 0) {
AUTOFS_WARN("request for %s completed with error %d",
ar->ar_path, request_error);
}
last = refcount_release(&ar->ar_refcount);
if (last) {
TAILQ_REMOVE(&sc->sc_requests, ar, ar_next);
/*
* XXX: Is it safe?
*/
sx_xunlock(&sc->sc_lock);
callout_drain(&ar->ar_callout);
sx_xlock(&sc->sc_lock);
uma_zfree(autofs_request_zone, ar);
}
/*
* Note that we do not do negative caching on purpose. This
* way the user can retry access at any time, e.g. after fixing
* the failure reason, without waiting for cache timer to expire.
*/
if (error == 0 && request_error == 0 && autofs_cache > 0) {
anp->an_cached = true;
callout_reset(&anp->an_callout, autofs_cache * hz,
autofs_cache_callout, anp);
}
free(key, M_AUTOFS);
free(path, M_AUTOFS);
if (error != 0)
return (error);
return (request_error);
}
/*
* Send request to automountd(8) and wait for completion.
*/
int
autofs_trigger(struct autofs_node *anp,
const char *component, int componentlen)
{
int error;
for (;;) {
error = autofs_trigger_one(anp, component, componentlen);
if (error == 0) {
anp->an_retries = 0;
return (0);
}
if (error == EINTR) {
AUTOFS_DEBUG("trigger interrupted by signal, "
"not retrying");
anp->an_retries = 0;
return (error);
}
anp->an_retries++;
if (anp->an_retries >= autofs_retry_attempts) {
AUTOFS_DEBUG("trigger failed %d times; returning "
"error %d", anp->an_retries, error);
anp->an_retries = 0;
return (error);
}
AUTOFS_DEBUG("trigger failed with error %d; will retry in "
"%d seconds, %d attempts left", error, autofs_retry_delay,
autofs_retry_attempts - anp->an_retries);
sx_xunlock(&sc->sc_lock);
pause("autofs_retry", autofs_retry_delay * hz);
sx_xlock(&sc->sc_lock);
}
}
static int
autofs_ioctl_request(struct autofs_softc *sc, struct autofs_daemon_request *adr)
{
struct autofs_request *ar;
int error;
sx_xlock(&sc->sc_lock);
for (;;) {
TAILQ_FOREACH(ar, &sc->sc_requests, ar_next) {
if (ar->ar_done)
continue;
if (ar->ar_in_progress)
continue;
break;
}
if (ar != NULL)
break;
error = cv_wait_sig(&sc->sc_cv, &sc->sc_lock);
if (error != 0) {
/*
* XXX: For some reson this returns -1 instead
* of EINTR, wtf?!
*/
error = EINTR;
sx_xunlock(&sc->sc_lock);
AUTOFS_DEBUG("failed with error %d", error);
return (error);
}
}
ar->ar_in_progress = true;
sx_xunlock(&sc->sc_lock);
adr->adr_id = ar->ar_id;
strlcpy(adr->adr_from, ar->ar_from, sizeof(adr->adr_from));
strlcpy(adr->adr_path, ar->ar_path, sizeof(adr->adr_path));
strlcpy(adr->adr_prefix, ar->ar_prefix, sizeof(adr->adr_prefix));
strlcpy(adr->adr_key, ar->ar_key, sizeof(adr->adr_key));
strlcpy(adr->adr_options, ar->ar_options, sizeof(adr->adr_options));
PROC_LOCK(curproc);
sc->sc_dev_sid = curproc->p_session->s_sid;
PROC_UNLOCK(curproc);
return (0);
}
static int
autofs_ioctl_done(struct autofs_softc *sc, struct autofs_daemon_done *add)
{
struct autofs_request *ar;
sx_xlock(&sc->sc_lock);
TAILQ_FOREACH(ar, &sc->sc_requests, ar_next) {
if (ar->ar_id == add->add_id)
break;
}
if (ar == NULL) {
sx_xunlock(&sc->sc_lock);
AUTOFS_DEBUG("id %d not found", add->add_id);
return (ESRCH);
}
ar->ar_error = add->add_error;
ar->ar_done = true;
ar->ar_in_progress = false;
cv_broadcast(&sc->sc_cv);
sx_xunlock(&sc->sc_lock);
return (0);
}
static int
autofs_open(struct cdev *dev, int flags, int fmt, struct thread *td)
{
sx_xlock(&sc->sc_lock);
if (sc->sc_dev_opened) {
sx_xunlock(&sc->sc_lock);
return (EBUSY);
}
sc->sc_dev_opened = true;
sx_xunlock(&sc->sc_lock);
return (0);
}
static int
autofs_close(struct cdev *dev, int flag, int fmt, struct thread *td)
{
sx_xlock(&sc->sc_lock);
KASSERT(sc->sc_dev_opened, ("not opened?"));
sc->sc_dev_opened = false;
sx_xunlock(&sc->sc_lock);
return (0);
}
static int
autofs_ioctl(struct cdev *dev, u_long cmd, caddr_t arg, int mode,
struct thread *td)
{
KASSERT(sc->sc_dev_opened, ("not opened?"));
switch (cmd) {
case AUTOFSREQUEST:
return (autofs_ioctl_request(sc,
(struct autofs_daemon_request *)arg));
case AUTOFSDONE:
return (autofs_ioctl_done(sc,
(struct autofs_daemon_done *)arg));
default:
AUTOFS_DEBUG("invalid cmd %lx", cmd);
return (EINVAL);
}
}