zfs/lib/libzfs/os/linux/libzfs_util_os.c

281 lines
7.1 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or https://opensource.org/licenses/CDDL-1.0.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2021 Klara, Inc.
*/
#include <alloca.h>
#include <errno.h>
#include <fcntl.h>
#include <libintl.h>
#include <math.h>
#include <poll.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <sys/inotify.h>
#include <sys/mntent.h>
#include <sys/mnttab.h>
#include <sys/stat.h>
#include <sys/timerfd.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <libzfs.h>
#include <libzfs_core.h>
#include "../../libzfs_impl.h"
#include "zfs_prop.h"
#include <libzutil.h>
#include <sys/zfs_sysfs.h>
#define ZDIFF_SHARESDIR "/.zfs/shares/"
int
zfs_ioctl(libzfs_handle_t *hdl, int request, zfs_cmd_t *zc)
{
return (ioctl(hdl->libzfs_fd, request, zc));
}
const char *
libzfs_error_init(int error)
{
switch (error) {
case ENXIO:
return (dgettext(TEXT_DOMAIN, "The ZFS modules are not "
"loaded.\nTry running 'modprobe zfs' as root "
"to load them."));
case ENOENT:
return (dgettext(TEXT_DOMAIN, "/dev/zfs and /proc/self/mounts "
"are required.\nTry running 'udevadm trigger' and 'mount "
"-t proc proc /proc' as root."));
case ENOEXEC:
return (dgettext(TEXT_DOMAIN, "The ZFS modules cannot be "
"auto-loaded.\nTry running 'modprobe zfs' as "
"root to manually load them."));
case EACCES:
return (dgettext(TEXT_DOMAIN, "Permission denied the "
"ZFS utilities must be run as root."));
default:
return (dgettext(TEXT_DOMAIN, "Failed to initialize the "
"libzfs library."));
}
}
/*
* zfs(4) is loaded by udev if there's a fstype=zfs device present,
* but if there isn't, load them automatically;
* always wait for ZFS_DEV to appear via udev.
*
* Environment variables:
* - ZFS_MODULE_TIMEOUT="<seconds>" - Seconds to wait for ZFS_DEV,
* defaults to 10, max. 10 min.
*/
int
libzfs_load_module(void)
{
if (access(ZFS_DEV, F_OK) == 0)
return (0);
if (access(ZFS_SYSFS_DIR, F_OK) != 0) {
char *argv[] = {(char *)"modprobe", (char *)"zfs", NULL};
if (libzfs_run_process("modprobe", argv, 0))
return (ENOEXEC);
if (access(ZFS_SYSFS_DIR, F_OK) != 0)
return (ENXIO);
}
const char *timeout_str = getenv("ZFS_MODULE_TIMEOUT");
int seconds = 10;
if (timeout_str)
seconds = MIN(strtol(timeout_str, NULL, 0), 600);
struct itimerspec timeout = {.it_value.tv_sec = MAX(seconds, 0)};
int ino = inotify_init1(IN_CLOEXEC);
if (ino == -1)
return (ENOENT);
inotify_add_watch(ino, ZFS_DEVDIR, IN_CREATE);
if (access(ZFS_DEV, F_OK) == 0) {
close(ino);
return (0);
} else if (seconds == 0) {
close(ino);
return (ENOENT);
}
size_t evsz = sizeof (struct inotify_event) + NAME_MAX + 1;
struct inotify_event *ev = alloca(evsz);
int tout = timerfd_create(CLOCK_MONOTONIC, TFD_CLOEXEC);
if (tout == -1) {
close(ino);
return (ENOENT);
}
timerfd_settime(tout, 0, &timeout, NULL);
int ret = ENOENT;
struct pollfd pfds[] = {
{.fd = ino, .events = POLLIN},
{.fd = tout, .events = POLLIN},
};
while (poll(pfds, ARRAY_SIZE(pfds), -1) != -1) {
if (pfds[0].revents & POLLIN) {
verify(read(ino, ev, evsz) >
sizeof (struct inotify_event));
if (strncmp(ev->name, &ZFS_DEV[sizeof (ZFS_DEVDIR)],
ev->len) == 0) {
ret = 0;
break;
}
}
if (pfds[1].revents & POLLIN)
break;
}
close(tout);
close(ino);
return (ret);
}
int
find_shares_object(differ_info_t *di)
{
char fullpath[MAXPATHLEN];
struct stat64 sb = { 0 };
(void) strlcpy(fullpath, di->dsmnt, MAXPATHLEN);
(void) strlcat(fullpath, ZDIFF_SHARESDIR, MAXPATHLEN);
if (stat64(fullpath, &sb) != 0) {
(void) snprintf(di->errbuf, sizeof (di->errbuf),
dgettext(TEXT_DOMAIN, "Cannot stat %s"), fullpath);
return (zfs_error(di->zhp->zfs_hdl, EZFS_DIFF, di->errbuf));
}
di->shares = (uint64_t)sb.st_ino;
return (0);
}
int
zfs_destroy_snaps_nvl_os(libzfs_handle_t *hdl, nvlist_t *snaps)
{
(void) hdl, (void) snaps;
return (0);
}
/*
* Return allocated loaded module version, or NULL on error (with errno set)
*/
char *
zfs_version_kernel(void)
{
FILE *f = fopen(ZFS_SYSFS_DIR "/version", "re");
if (f == NULL)
return (NULL);
char *ret = NULL;
size_t l;
ssize_t read;
if ((read = getline(&ret, &l, f)) == -1) {
int err = errno;
fclose(f);
errno = err;
return (NULL);
}
fclose(f);
if (ret[read - 1] == '\n')
ret[read - 1] = '\0';
return (ret);
}
/*
* Add or delete the given filesystem to/from the given user namespace.
*/
int
zfs_userns(zfs_handle_t *zhp, const char *nspath, int attach)
{
libzfs_handle_t *hdl = zhp->zfs_hdl;
zfs_cmd_t zc = {"\0"};
char errbuf[1024];
unsigned long cmd;
int ret;
if (attach) {
(void) snprintf(errbuf, sizeof (errbuf),
dgettext(TEXT_DOMAIN, "cannot add '%s' to namespace"),
zhp->zfs_name);
} else {
(void) snprintf(errbuf, sizeof (errbuf),
dgettext(TEXT_DOMAIN, "cannot remove '%s' from namespace"),
zhp->zfs_name);
}
switch (zhp->zfs_type) {
case ZFS_TYPE_VOLUME:
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"volumes can not be namespaced"));
return (zfs_error(hdl, EZFS_BADTYPE, errbuf));
case ZFS_TYPE_SNAPSHOT:
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"snapshots can not be namespaced"));
return (zfs_error(hdl, EZFS_BADTYPE, errbuf));
case ZFS_TYPE_BOOKMARK:
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"bookmarks can not be namespaced"));
return (zfs_error(hdl, EZFS_BADTYPE, errbuf));
case ZFS_TYPE_VDEV:
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"vdevs can not be namespaced"));
return (zfs_error(hdl, EZFS_BADTYPE, errbuf));
case ZFS_TYPE_INVALID:
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"invalid zfs_type_t: ZFS_TYPE_INVALID"));
return (zfs_error(hdl, EZFS_BADTYPE, errbuf));
case ZFS_TYPE_POOL:
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"pools can not be namespaced"));
return (zfs_error(hdl, EZFS_BADTYPE, errbuf));
case ZFS_TYPE_FILESYSTEM:
break;
}
assert(zhp->zfs_type == ZFS_TYPE_FILESYSTEM);
(void) strlcpy(zc.zc_name, zhp->zfs_name, sizeof (zc.zc_name));
zc.zc_objset_type = DMU_OST_ZFS;
zc.zc_cleanup_fd = open(nspath, O_RDONLY);
if (zc.zc_cleanup_fd < 0) {
return (zfs_error(hdl, EZFS_NOT_USER_NAMESPACE, errbuf));
}
cmd = attach ? ZFS_IOC_USERNS_ATTACH : ZFS_IOC_USERNS_DETACH;
if ((ret = zfs_ioctl(hdl, cmd, &zc)) != 0)
zfs_standard_error(hdl, errno, errbuf);
(void) close(zc.zc_cleanup_fd);
return (ret);
}