zfs-builds-mm/zfs-0.8.0/lib/libzfs/libzfs_mount.c

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2019-07-06 23:40:11 +02:00
/*
* 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 http://www.opensolaris.org/os/licensing.
* 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 2015 Nexenta Systems, Inc. All rights reserved.
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2014, 2017 by Delphix. All rights reserved.
* Copyright 2016 Igor Kozhukhov <ikozhukhov@gmail.com>
* Copyright 2017 RackTop Systems.
* Copyright (c) 2018 Datto Inc.
* Copyright 2018 OmniOS Community Edition (OmniOSce) Association.
*/
/*
* Routines to manage ZFS mounts. We separate all the nasty routines that have
* to deal with the OS. The following functions are the main entry points --
* they are used by mount and unmount and when changing a filesystem's
* mountpoint.
*
* zfs_is_mounted()
* zfs_mount()
* zfs_unmount()
* zfs_unmountall()
*
* This file also contains the functions used to manage sharing filesystems via
* NFS and iSCSI:
*
* zfs_is_shared()
* zfs_share()
* zfs_unshare()
*
* zfs_is_shared_nfs()
* zfs_is_shared_smb()
* zfs_share_proto()
* zfs_shareall();
* zfs_unshare_nfs()
* zfs_unshare_smb()
* zfs_unshareall_nfs()
* zfs_unshareall_smb()
* zfs_unshareall()
* zfs_unshareall_bypath()
*
* The following functions are available for pool consumers, and will
* mount/unmount and share/unshare all datasets within pool:
*
* zpool_enable_datasets()
* zpool_disable_datasets()
*/
#include <dirent.h>
#include <dlfcn.h>
#include <errno.h>
#include <fcntl.h>
#include <libgen.h>
#include <libintl.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <unistd.h>
#include <zone.h>
#include <sys/mntent.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/vfs.h>
#include <sys/dsl_crypt.h>
#include <libzfs.h>
#include "libzfs_impl.h"
#include <thread_pool.h>
#include <libshare.h>
#include <sys/systeminfo.h>
#define MAXISALEN 257 /* based on sysinfo(2) man page */
static int mount_tp_nthr = 512; /* tpool threads for multi-threaded mounting */
static void zfs_mount_task(void *);
static int zfs_share_proto(zfs_handle_t *, zfs_share_proto_t *);
zfs_share_type_t zfs_is_shared_proto(zfs_handle_t *, char **,
zfs_share_proto_t);
/*
* The share protocols table must be in the same order as the zfs_share_proto_t
* enum in libzfs_impl.h
*/
typedef struct {
zfs_prop_t p_prop;
char *p_name;
int p_share_err;
int p_unshare_err;
} proto_table_t;
proto_table_t proto_table[PROTO_END] = {
{ZFS_PROP_SHARENFS, "nfs", EZFS_SHARENFSFAILED, EZFS_UNSHARENFSFAILED},
{ZFS_PROP_SHARESMB, "smb", EZFS_SHARESMBFAILED, EZFS_UNSHARESMBFAILED},
};
zfs_share_proto_t nfs_only[] = {
PROTO_NFS,
PROTO_END
};
zfs_share_proto_t smb_only[] = {
PROTO_SMB,
PROTO_END
};
zfs_share_proto_t share_all_proto[] = {
PROTO_NFS,
PROTO_SMB,
PROTO_END
};
/*
* Search the sharetab for the given mountpoint and protocol, returning
* a zfs_share_type_t value.
*/
static zfs_share_type_t
is_shared(libzfs_handle_t *hdl, const char *mountpoint, zfs_share_proto_t proto)
{
char buf[MAXPATHLEN], *tab;
char *ptr;
if (hdl->libzfs_sharetab == NULL)
return (SHARED_NOT_SHARED);
/* Reopen ZFS_SHARETAB to prevent reading stale data from open file */
if (freopen(ZFS_SHARETAB, "r", hdl->libzfs_sharetab) == NULL)
return (SHARED_NOT_SHARED);
(void) fseek(hdl->libzfs_sharetab, 0, SEEK_SET);
while (fgets(buf, sizeof (buf), hdl->libzfs_sharetab) != NULL) {
/* the mountpoint is the first entry on each line */
if ((tab = strchr(buf, '\t')) == NULL)
continue;
*tab = '\0';
if (strcmp(buf, mountpoint) == 0) {
/*
* the protocol field is the third field
* skip over second field
*/
ptr = ++tab;
if ((tab = strchr(ptr, '\t')) == NULL)
continue;
ptr = ++tab;
if ((tab = strchr(ptr, '\t')) == NULL)
continue;
*tab = '\0';
if (strcmp(ptr,
proto_table[proto].p_name) == 0) {
switch (proto) {
case PROTO_NFS:
return (SHARED_NFS);
case PROTO_SMB:
return (SHARED_SMB);
default:
return (0);
}
}
}
}
return (SHARED_NOT_SHARED);
}
static boolean_t
dir_is_empty_stat(const char *dirname)
{
struct stat st;
/*
* We only want to return false if the given path is a non empty
* directory, all other errors are handled elsewhere.
*/
if (stat(dirname, &st) < 0 || !S_ISDIR(st.st_mode)) {
return (B_TRUE);
}
/*
* An empty directory will still have two entries in it, one
* entry for each of "." and "..".
*/
if (st.st_size > 2) {
return (B_FALSE);
}
return (B_TRUE);
}
static boolean_t
dir_is_empty_readdir(const char *dirname)
{
DIR *dirp;
struct dirent64 *dp;
int dirfd;
if ((dirfd = openat(AT_FDCWD, dirname,
O_RDONLY | O_NDELAY | O_LARGEFILE | O_CLOEXEC, 0)) < 0) {
return (B_TRUE);
}
if ((dirp = fdopendir(dirfd)) == NULL) {
(void) close(dirfd);
return (B_TRUE);
}
while ((dp = readdir64(dirp)) != NULL) {
if (strcmp(dp->d_name, ".") == 0 ||
strcmp(dp->d_name, "..") == 0)
continue;
(void) closedir(dirp);
return (B_FALSE);
}
(void) closedir(dirp);
return (B_TRUE);
}
/*
* Returns true if the specified directory is empty. If we can't open the
* directory at all, return true so that the mount can fail with a more
* informative error message.
*/
static boolean_t
dir_is_empty(const char *dirname)
{
struct statfs64 st;
/*
* If the statvfs call fails or the filesystem is not a ZFS
* filesystem, fall back to the slow path which uses readdir.
*/
if ((statfs64(dirname, &st) != 0) ||
(st.f_type != ZFS_SUPER_MAGIC)) {
return (dir_is_empty_readdir(dirname));
}
/*
* At this point, we know the provided path is on a ZFS
* filesystem, so we can use stat instead of readdir to
* determine if the directory is empty or not. We try to avoid
* using readdir because that requires opening "dirname"; this
* open file descriptor can potentially end up in a child
* process if there's a concurrent fork, thus preventing the
* zfs_mount() from otherwise succeeding (the open file
* descriptor inherited by the child process will cause the
* parent's mount to fail with EBUSY). The performance
* implications of replacing the open, read, and close with a
* single stat is nice; but is not the main motivation for the
* added complexity.
*/
return (dir_is_empty_stat(dirname));
}
/*
* Checks to see if the mount is active. If the filesystem is mounted, we fill
* in 'where' with the current mountpoint, and return 1. Otherwise, we return
* 0.
*/
boolean_t
is_mounted(libzfs_handle_t *zfs_hdl, const char *special, char **where)
{
struct mnttab entry;
if (libzfs_mnttab_find(zfs_hdl, special, &entry) != 0)
return (B_FALSE);
if (where != NULL)
*where = zfs_strdup(zfs_hdl, entry.mnt_mountp);
return (B_TRUE);
}
boolean_t
zfs_is_mounted(zfs_handle_t *zhp, char **where)
{
return (is_mounted(zhp->zfs_hdl, zfs_get_name(zhp), where));
}
/*
* Returns true if the given dataset is mountable, false otherwise. Returns the
* mountpoint in 'buf'.
*/
static boolean_t
zfs_is_mountable(zfs_handle_t *zhp, char *buf, size_t buflen,
zprop_source_t *source)
{
char sourceloc[MAXNAMELEN];
zprop_source_t sourcetype;
if (!zfs_prop_valid_for_type(ZFS_PROP_MOUNTPOINT, zhp->zfs_type,
B_FALSE))
return (B_FALSE);
verify(zfs_prop_get(zhp, ZFS_PROP_MOUNTPOINT, buf, buflen,
&sourcetype, sourceloc, sizeof (sourceloc), B_FALSE) == 0);
if (strcmp(buf, ZFS_MOUNTPOINT_NONE) == 0 ||
strcmp(buf, ZFS_MOUNTPOINT_LEGACY) == 0)
return (B_FALSE);
if (zfs_prop_get_int(zhp, ZFS_PROP_CANMOUNT) == ZFS_CANMOUNT_OFF)
return (B_FALSE);
if (zfs_prop_get_int(zhp, ZFS_PROP_ZONED) &&
getzoneid() == GLOBAL_ZONEID)
return (B_FALSE);
if (source)
*source = sourcetype;
return (B_TRUE);
}
/*
* The filesystem is mounted by invoking the system mount utility rather
* than by the system call mount(2). This ensures that the /etc/mtab
* file is correctly locked for the update. Performing our own locking
* and /etc/mtab update requires making an unsafe assumption about how
* the mount utility performs its locking. Unfortunately, this also means
* in the case of a mount failure we do not have the exact errno. We must
* make due with return value from the mount process.
*
* In the long term a shared library called libmount is under development
* which provides a common API to address the locking and errno issues.
* Once the standard mount utility has been updated to use this library
* we can add an autoconf check to conditionally use it.
*
* http://www.kernel.org/pub/linux/utils/util-linux/libmount-docs/index.html
*/
static int
do_mount(const char *src, const char *mntpt, char *opts)
{
char *argv[9] = {
"/bin/mount",
"--no-canonicalize",
"-t", MNTTYPE_ZFS,
"-o", opts,
(char *)src,
(char *)mntpt,
(char *)NULL };
int rc;
/* Return only the most critical mount error */
rc = libzfs_run_process(argv[0], argv, STDOUT_VERBOSE|STDERR_VERBOSE);
if (rc) {
if (rc & MOUNT_FILEIO)
return (EIO);
if (rc & MOUNT_USER)
return (EINTR);
if (rc & MOUNT_SOFTWARE)
return (EPIPE);
if (rc & MOUNT_BUSY)
return (EBUSY);
if (rc & MOUNT_SYSERR)
return (EAGAIN);
if (rc & MOUNT_USAGE)
return (EINVAL);
return (ENXIO); /* Generic error */
}
return (0);
}
static int
do_unmount(const char *mntpt, int flags)
{
char force_opt[] = "-f";
char lazy_opt[] = "-l";
char *argv[7] = {
"/bin/umount",
"-t", MNTTYPE_ZFS,
NULL, NULL, NULL, NULL };
int rc, count = 3;
if (flags & MS_FORCE) {
argv[count] = force_opt;
count++;
}
if (flags & MS_DETACH) {
argv[count] = lazy_opt;
count++;
}
argv[count] = (char *)mntpt;
rc = libzfs_run_process(argv[0], argv, STDOUT_VERBOSE|STDERR_VERBOSE);
return (rc ? EINVAL : 0);
}
static int
zfs_add_option(zfs_handle_t *zhp, char *options, int len,
zfs_prop_t prop, char *on, char *off)
{
char *source;
uint64_t value;
/* Skip adding duplicate default options */
if ((strstr(options, on) != NULL) || (strstr(options, off) != NULL))
return (0);
/*
* zfs_prop_get_int() is not used to ensure our mount options
* are not influenced by the current /proc/self/mounts contents.
*/
value = getprop_uint64(zhp, prop, &source);
(void) strlcat(options, ",", len);
(void) strlcat(options, value ? on : off, len);
return (0);
}
static int
zfs_add_options(zfs_handle_t *zhp, char *options, int len)
{
int error = 0;
error = zfs_add_option(zhp, options, len,
ZFS_PROP_ATIME, MNTOPT_ATIME, MNTOPT_NOATIME);
/*
* don't add relatime/strictatime when atime=off, otherwise strictatime
* will force atime=on
*/
if (strstr(options, MNTOPT_NOATIME) == NULL) {
error = zfs_add_option(zhp, options, len,
ZFS_PROP_RELATIME, MNTOPT_RELATIME, MNTOPT_STRICTATIME);
}
error = error ? error : zfs_add_option(zhp, options, len,
ZFS_PROP_DEVICES, MNTOPT_DEVICES, MNTOPT_NODEVICES);
error = error ? error : zfs_add_option(zhp, options, len,
ZFS_PROP_EXEC, MNTOPT_EXEC, MNTOPT_NOEXEC);
error = error ? error : zfs_add_option(zhp, options, len,
ZFS_PROP_READONLY, MNTOPT_RO, MNTOPT_RW);
error = error ? error : zfs_add_option(zhp, options, len,
ZFS_PROP_SETUID, MNTOPT_SETUID, MNTOPT_NOSETUID);
error = error ? error : zfs_add_option(zhp, options, len,
ZFS_PROP_NBMAND, MNTOPT_NBMAND, MNTOPT_NONBMAND);
return (error);
}
/*
* Mount the given filesystem.
*/
int
zfs_mount(zfs_handle_t *zhp, const char *options, int flags)
{
struct stat buf;
char mountpoint[ZFS_MAXPROPLEN];
char mntopts[MNT_LINE_MAX];
char overlay[ZFS_MAXPROPLEN];
libzfs_handle_t *hdl = zhp->zfs_hdl;
uint64_t keystatus;
int remount = 0, rc;
if (options == NULL) {
(void) strlcpy(mntopts, MNTOPT_DEFAULTS, sizeof (mntopts));
} else {
(void) strlcpy(mntopts, options, sizeof (mntopts));
}
if (strstr(mntopts, MNTOPT_REMOUNT) != NULL)
remount = 1;
/*
* If the pool is imported read-only then all mounts must be read-only
*/
if (zpool_get_prop_int(zhp->zpool_hdl, ZPOOL_PROP_READONLY, NULL))
(void) strlcat(mntopts, "," MNTOPT_RO, sizeof (mntopts));
if (!zfs_is_mountable(zhp, mountpoint, sizeof (mountpoint), NULL))
return (0);
/*
* Append default mount options which apply to the mount point.
* This is done because under Linux (unlike Solaris) multiple mount
* points may reference a single super block. This means that just
* given a super block there is no back reference to update the per
* mount point options.
*/
rc = zfs_add_options(zhp, mntopts, sizeof (mntopts));
if (rc) {
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"default options unavailable"));
return (zfs_error_fmt(hdl, EZFS_MOUNTFAILED,
dgettext(TEXT_DOMAIN, "cannot mount '%s'"),
mountpoint));
}
/*
* If the filesystem is encrypted the key must be loaded in order to
* mount. If the key isn't loaded, the MS_CRYPT flag decides whether
* or not we attempt to load the keys. Note: we must call
* zfs_refresh_properties() here since some callers of this function
* (most notably zpool_enable_datasets()) may implicitly load our key
* by loading the parent's key first.
*/
if (zfs_prop_get_int(zhp, ZFS_PROP_ENCRYPTION) != ZIO_CRYPT_OFF) {
zfs_refresh_properties(zhp);
keystatus = zfs_prop_get_int(zhp, ZFS_PROP_KEYSTATUS);
/*
* If the key is unavailable and MS_CRYPT is set give the
* user a chance to enter the key. Otherwise just fail
* immediately.
*/
if (keystatus == ZFS_KEYSTATUS_UNAVAILABLE) {
if (flags & MS_CRYPT) {
rc = zfs_crypto_load_key(zhp, B_FALSE, NULL);
if (rc)
return (rc);
} else {
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"encryption key not loaded"));
return (zfs_error_fmt(hdl, EZFS_MOUNTFAILED,
dgettext(TEXT_DOMAIN, "cannot mount '%s'"),
mountpoint));
}
}
}
/*
* Append zfsutil option so the mount helper allow the mount
*/
strlcat(mntopts, "," MNTOPT_ZFSUTIL, sizeof (mntopts));
/* Create the directory if it doesn't already exist */
if (lstat(mountpoint, &buf) != 0) {
if (mkdirp(mountpoint, 0755) != 0) {
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"failed to create mountpoint"));
return (zfs_error_fmt(hdl, EZFS_MOUNTFAILED,
dgettext(TEXT_DOMAIN, "cannot mount '%s'"),
mountpoint));
}
}
/*
* Overlay mounts are disabled by default but may be enabled
* via the 'overlay' property or the 'zfs mount -O' option.
*/
if (!(flags & MS_OVERLAY)) {
if (zfs_prop_get(zhp, ZFS_PROP_OVERLAY, overlay,
sizeof (overlay), NULL, NULL, 0, B_FALSE) == 0) {
if (strcmp(overlay, "on") == 0) {
flags |= MS_OVERLAY;
}
}
}
/*
* Determine if the mountpoint is empty. If so, refuse to perform the
* mount. We don't perform this check if 'remount' is
* specified or if overlay option(-O) is given
*/
if ((flags & MS_OVERLAY) == 0 && !remount &&
!dir_is_empty(mountpoint)) {
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"directory is not empty"));
return (zfs_error_fmt(hdl, EZFS_MOUNTFAILED,
dgettext(TEXT_DOMAIN, "cannot mount '%s'"), mountpoint));
}
/* perform the mount */
rc = do_mount(zfs_get_name(zhp), mountpoint, mntopts);
if (rc) {
/*
* Generic errors are nasty, but there are just way too many
* from mount(), and they're well-understood. We pick a few
* common ones to improve upon.
*/
if (rc == EBUSY) {
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"mountpoint or dataset is busy"));
} else if (rc == EPERM) {
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
"Insufficient privileges"));
} else if (rc == ENOTSUP) {
char buf[256];
int spa_version;
VERIFY(zfs_spa_version(zhp, &spa_version) == 0);
(void) snprintf(buf, sizeof (buf),
dgettext(TEXT_DOMAIN, "Can't mount a version %lld "
"file system on a version %d pool. Pool must be"
" upgraded to mount this file system."),
(u_longlong_t)zfs_prop_get_int(zhp,
ZFS_PROP_VERSION), spa_version);
zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, buf));
} else {
zfs_error_aux(hdl, strerror(rc));
}
return (zfs_error_fmt(hdl, EZFS_MOUNTFAILED,
dgettext(TEXT_DOMAIN, "cannot mount '%s'"),
zhp->zfs_name));
}
/* remove the mounted entry before re-adding on remount */
if (remount)
libzfs_mnttab_remove(hdl, zhp->zfs_name);
/* add the mounted entry into our cache */
libzfs_mnttab_add(hdl, zfs_get_name(zhp), mountpoint, mntopts);
return (0);
}
/*
* Unmount a single filesystem.
*/
static int
unmount_one(libzfs_handle_t *hdl, const char *mountpoint, int flags)
{
int error;
error = do_unmount(mountpoint, flags);
if (error != 0) {
return (zfs_error_fmt(hdl, EZFS_UMOUNTFAILED,
dgettext(TEXT_DOMAIN, "cannot unmount '%s'"),
mountpoint));
}
return (0);
}
/*
* Unmount the given filesystem.
*/
int
zfs_unmount(zfs_handle_t *zhp, const char *mountpoint, int flags)
{
libzfs_handle_t *hdl = zhp->zfs_hdl;
struct mnttab entry;
char *mntpt = NULL;
/* check to see if we need to unmount the filesystem */
if (mountpoint != NULL || ((zfs_get_type(zhp) == ZFS_TYPE_FILESYSTEM) &&
libzfs_mnttab_find(hdl, zhp->zfs_name, &entry) == 0)) {
/*
* mountpoint may have come from a call to
* getmnt/getmntany if it isn't NULL. If it is NULL,
* we know it comes from libzfs_mnttab_find which can
* then get freed later. We strdup it to play it safe.
*/
if (mountpoint == NULL)
mntpt = zfs_strdup(hdl, entry.mnt_mountp);
else
mntpt = zfs_strdup(hdl, mountpoint);
/*
* Unshare and unmount the filesystem
*/
if (zfs_unshare_proto(zhp, mntpt, share_all_proto) != 0) {
free(mntpt);
return (-1);
}
if (unmount_one(hdl, mntpt, flags) != 0) {
free(mntpt);
(void) zfs_shareall(zhp);
return (-1);
}
libzfs_mnttab_remove(hdl, zhp->zfs_name);
free(mntpt);
}
return (0);
}
/*
* Unmount this filesystem and any children inheriting the mountpoint property.
* To do this, just act like we're changing the mountpoint property, but don't
* remount the filesystems afterwards.
*/
int
zfs_unmountall(zfs_handle_t *zhp, int flags)
{
prop_changelist_t *clp;
int ret;
clp = changelist_gather(zhp, ZFS_PROP_MOUNTPOINT,
CL_GATHER_ITER_MOUNTED, 0);
if (clp == NULL)
return (-1);
ret = changelist_prefix(clp);
changelist_free(clp);
return (ret);
}
boolean_t
zfs_is_shared(zfs_handle_t *zhp)
{
zfs_share_type_t rc = 0;
zfs_share_proto_t *curr_proto;
if (ZFS_IS_VOLUME(zhp))
return (B_FALSE);
for (curr_proto = share_all_proto; *curr_proto != PROTO_END;
curr_proto++)
rc |= zfs_is_shared_proto(zhp, NULL, *curr_proto);
return (rc ? B_TRUE : B_FALSE);
}
int
zfs_share(zfs_handle_t *zhp)
{
assert(!ZFS_IS_VOLUME(zhp));
return (zfs_share_proto(zhp, share_all_proto));
}
int
zfs_unshare(zfs_handle_t *zhp)
{
assert(!ZFS_IS_VOLUME(zhp));
return (zfs_unshareall(zhp));
}
/*
* Check to see if the filesystem is currently shared.
*/
zfs_share_type_t
zfs_is_shared_proto(zfs_handle_t *zhp, char **where, zfs_share_proto_t proto)
{
char *mountpoint;
zfs_share_type_t rc;
if (!zfs_is_mounted(zhp, &mountpoint))
return (SHARED_NOT_SHARED);
if ((rc = is_shared(zhp->zfs_hdl, mountpoint, proto))
!= SHARED_NOT_SHARED) {
if (where != NULL)
*where = mountpoint;
else
free(mountpoint);
return (rc);
} else {
free(mountpoint);
return (SHARED_NOT_SHARED);
}
}
boolean_t
zfs_is_shared_nfs(zfs_handle_t *zhp, char **where)
{
return (zfs_is_shared_proto(zhp, where,
PROTO_NFS) != SHARED_NOT_SHARED);
}
boolean_t
zfs_is_shared_smb(zfs_handle_t *zhp, char **where)
{
return (zfs_is_shared_proto(zhp, where,
PROTO_SMB) != SHARED_NOT_SHARED);
}
/*
* zfs_init_libshare(zhandle, service)
*
* Initialize the libshare API if it hasn't already been initialized.
* In all cases it returns 0 if it succeeded and an error if not. The
* service value is which part(s) of the API to initialize and is a
* direct map to the libshare sa_init(service) interface.
*/
int
zfs_init_libshare(libzfs_handle_t *zhandle, int service)
{
int ret = SA_OK;
if (ret == SA_OK && zhandle->libzfs_shareflags & ZFSSHARE_MISS) {
/*
* We had a cache miss. Most likely it is a new ZFS
* dataset that was just created. We want to make sure
* so check timestamps to see if a different process
* has updated any of the configuration. If there was
* some non-ZFS change, we need to re-initialize the
* internal cache.
*/
zhandle->libzfs_shareflags &= ~ZFSSHARE_MISS;
if (sa_needs_refresh(zhandle->libzfs_sharehdl)) {
zfs_uninit_libshare(zhandle);
zhandle->libzfs_sharehdl = sa_init(service);
}
}
if (ret == SA_OK && zhandle && zhandle->libzfs_sharehdl == NULL)
zhandle->libzfs_sharehdl = sa_init(service);
if (ret == SA_OK && zhandle->libzfs_sharehdl == NULL)
ret = SA_NO_MEMORY;
return (ret);
}
/*
* zfs_uninit_libshare(zhandle)
*
* Uninitialize the libshare API if it hasn't already been
* uninitialized. It is OK to call multiple times.
*/
void
zfs_uninit_libshare(libzfs_handle_t *zhandle)
{
if (zhandle != NULL && zhandle->libzfs_sharehdl != NULL) {
sa_fini(zhandle->libzfs_sharehdl);
zhandle->libzfs_sharehdl = NULL;
}
}
/*
* zfs_parse_options(options, proto)
*
* Call the legacy parse interface to get the protocol specific
* options using the NULL arg to indicate that this is a "parse" only.
*/
int
zfs_parse_options(char *options, zfs_share_proto_t proto)
{
return (sa_parse_legacy_options(NULL, options,
proto_table[proto].p_name));
}
/*
* Share the given filesystem according to the options in the specified
* protocol specific properties (sharenfs, sharesmb). We rely
* on "libshare" to do the dirty work for us.
*/
static int
zfs_share_proto(zfs_handle_t *zhp, zfs_share_proto_t *proto)
{
char mountpoint[ZFS_MAXPROPLEN];
char shareopts[ZFS_MAXPROPLEN];
char sourcestr[ZFS_MAXPROPLEN];
libzfs_handle_t *hdl = zhp->zfs_hdl;
sa_share_t share;
zfs_share_proto_t *curr_proto;
zprop_source_t sourcetype;
int ret;
if (!zfs_is_mountable(zhp, mountpoint, sizeof (mountpoint), NULL))
return (0);
for (curr_proto = proto; *curr_proto != PROTO_END; curr_proto++) {
/*
* Return success if there are no share options.
*/
if (zfs_prop_get(zhp, proto_table[*curr_proto].p_prop,
shareopts, sizeof (shareopts), &sourcetype, sourcestr,
ZFS_MAXPROPLEN, B_FALSE) != 0 ||
strcmp(shareopts, "off") == 0)
continue;
ret = zfs_init_libshare(hdl, SA_INIT_SHARE_API);
if (ret != SA_OK) {
(void) zfs_error_fmt(hdl, EZFS_SHARENFSFAILED,
dgettext(TEXT_DOMAIN, "cannot share '%s': %s"),
zfs_get_name(zhp), sa_errorstr(ret));
return (-1);
}
/*
* If the 'zoned' property is set, then zfs_is_mountable()
* will have already bailed out if we are in the global zone.
* But local zones cannot be NFS servers, so we ignore it for
* local zones as well.
*/
if (zfs_prop_get_int(zhp, ZFS_PROP_ZONED))
continue;
share = sa_find_share(hdl->libzfs_sharehdl, mountpoint);
if (share == NULL) {
/*
* This may be a new file system that was just
* created so isn't in the internal cache
* (second time through). Rather than
* reloading the entire configuration, we can
* assume ZFS has done the checking and it is
* safe to add this to the internal
* configuration.
*/
if (sa_zfs_process_share(hdl->libzfs_sharehdl,
NULL, NULL, mountpoint,
proto_table[*curr_proto].p_name, sourcetype,
shareopts, sourcestr, zhp->zfs_name) != SA_OK) {
(void) zfs_error_fmt(hdl,
proto_table[*curr_proto].p_share_err,
dgettext(TEXT_DOMAIN, "cannot share '%s'"),
zfs_get_name(zhp));
return (-1);
}
hdl->libzfs_shareflags |= ZFSSHARE_MISS;
share = sa_find_share(hdl->libzfs_sharehdl,
mountpoint);
}
if (share != NULL) {
int err;
err = sa_enable_share(share,
proto_table[*curr_proto].p_name);
if (err != SA_OK) {
(void) zfs_error_fmt(hdl,
proto_table[*curr_proto].p_share_err,
dgettext(TEXT_DOMAIN, "cannot share '%s'"),
zfs_get_name(zhp));
return (-1);
}
} else {
(void) zfs_error_fmt(hdl,
proto_table[*curr_proto].p_share_err,
dgettext(TEXT_DOMAIN, "cannot share '%s'"),
zfs_get_name(zhp));
return (-1);
}
}
return (0);
}
int
zfs_share_nfs(zfs_handle_t *zhp)
{
return (zfs_share_proto(zhp, nfs_only));
}
int
zfs_share_smb(zfs_handle_t *zhp)
{
return (zfs_share_proto(zhp, smb_only));
}
int
zfs_shareall(zfs_handle_t *zhp)
{
return (zfs_share_proto(zhp, share_all_proto));
}
/*
* Unshare a filesystem by mountpoint.
*/
static int
unshare_one(libzfs_handle_t *hdl, const char *name, const char *mountpoint,
zfs_share_proto_t proto)
{
sa_share_t share;
int err;
char *mntpt;
/*
* Mountpoint could get trashed if libshare calls getmntany
* which it does during API initialization, so strdup the
* value.
*/
mntpt = zfs_strdup(hdl, mountpoint);
/* make sure libshare initialized */
if ((err = zfs_init_libshare(hdl, SA_INIT_SHARE_API)) != SA_OK) {
free(mntpt); /* don't need the copy anymore */
return (zfs_error_fmt(hdl, proto_table[proto].p_unshare_err,
dgettext(TEXT_DOMAIN, "cannot unshare '%s': %s"),
name, sa_errorstr(err)));
}
share = sa_find_share(hdl->libzfs_sharehdl, mntpt);
free(mntpt); /* don't need the copy anymore */
if (share != NULL) {
err = sa_disable_share(share, proto_table[proto].p_name);
if (err != SA_OK) {
return (zfs_error_fmt(hdl,
proto_table[proto].p_unshare_err,
dgettext(TEXT_DOMAIN, "cannot unshare '%s': %s"),
name, sa_errorstr(err)));
}
} else {
return (zfs_error_fmt(hdl, proto_table[proto].p_unshare_err,
dgettext(TEXT_DOMAIN, "cannot unshare '%s': not found"),
name));
}
return (0);
}
/*
* Unshare the given filesystem.
*/
int
zfs_unshare_proto(zfs_handle_t *zhp, const char *mountpoint,
zfs_share_proto_t *proto)
{
libzfs_handle_t *hdl = zhp->zfs_hdl;
struct mnttab entry;
char *mntpt = NULL;
/* check to see if need to unmount the filesystem */
if (mountpoint != NULL)
mntpt = zfs_strdup(hdl, mountpoint);
if (mountpoint != NULL || ((zfs_get_type(zhp) == ZFS_TYPE_FILESYSTEM) &&
libzfs_mnttab_find(hdl, zfs_get_name(zhp), &entry) == 0)) {
zfs_share_proto_t *curr_proto;
if (mountpoint == NULL)
mntpt = zfs_strdup(zhp->zfs_hdl, entry.mnt_mountp);
for (curr_proto = proto; *curr_proto != PROTO_END;
curr_proto++) {
if (is_shared(hdl, mntpt, *curr_proto) &&
unshare_one(hdl, zhp->zfs_name,
mntpt, *curr_proto) != 0) {
if (mntpt != NULL)
free(mntpt);
return (-1);
}
}
}
if (mntpt != NULL)
free(mntpt);
return (0);
}
int
zfs_unshare_nfs(zfs_handle_t *zhp, const char *mountpoint)
{
return (zfs_unshare_proto(zhp, mountpoint, nfs_only));
}
int
zfs_unshare_smb(zfs_handle_t *zhp, const char *mountpoint)
{
return (zfs_unshare_proto(zhp, mountpoint, smb_only));
}
/*
* Same as zfs_unmountall(), but for NFS and SMB unshares.
*/
int
zfs_unshareall_proto(zfs_handle_t *zhp, zfs_share_proto_t *proto)
{
prop_changelist_t *clp;
int ret;
clp = changelist_gather(zhp, ZFS_PROP_SHARENFS, 0, 0);
if (clp == NULL)
return (-1);
ret = changelist_unshare(clp, proto);
changelist_free(clp);
return (ret);
}
int
zfs_unshareall_nfs(zfs_handle_t *zhp)
{
return (zfs_unshareall_proto(zhp, nfs_only));
}
int
zfs_unshareall_smb(zfs_handle_t *zhp)
{
return (zfs_unshareall_proto(zhp, smb_only));
}
int
zfs_unshareall(zfs_handle_t *zhp)
{
return (zfs_unshareall_proto(zhp, share_all_proto));
}
int
zfs_unshareall_bypath(zfs_handle_t *zhp, const char *mountpoint)
{
return (zfs_unshare_proto(zhp, mountpoint, share_all_proto));
}
int
zfs_unshareall_bytype(zfs_handle_t *zhp, const char *mountpoint,
const char *proto)
{
if (proto == NULL)
return (zfs_unshare_proto(zhp, mountpoint, share_all_proto));
if (strcmp(proto, "nfs") == 0)
return (zfs_unshare_proto(zhp, mountpoint, nfs_only));
else if (strcmp(proto, "smb") == 0)
return (zfs_unshare_proto(zhp, mountpoint, smb_only));
else
return (1);
}
/*
* Remove the mountpoint associated with the current dataset, if necessary.
* We only remove the underlying directory if:
*
* - The mountpoint is not 'none' or 'legacy'
* - The mountpoint is non-empty
* - The mountpoint is the default or inherited
* - The 'zoned' property is set, or we're in a local zone
*
* Any other directories we leave alone.
*/
void
remove_mountpoint(zfs_handle_t *zhp)
{
char mountpoint[ZFS_MAXPROPLEN];
zprop_source_t source;
if (!zfs_is_mountable(zhp, mountpoint, sizeof (mountpoint),
&source))
return;
if (source == ZPROP_SRC_DEFAULT ||
source == ZPROP_SRC_INHERITED) {
/*
* Try to remove the directory, silently ignoring any errors.
* The filesystem may have since been removed or moved around,
* and this error isn't really useful to the administrator in
* any way.
*/
(void) rmdir(mountpoint);
}
}
/*
* Add the given zfs handle to the cb_handles array, dynamically reallocating
* the array if it is out of space.
*/
void
libzfs_add_handle(get_all_cb_t *cbp, zfs_handle_t *zhp)
{
if (cbp->cb_alloc == cbp->cb_used) {
size_t newsz;
zfs_handle_t **newhandles;
newsz = cbp->cb_alloc != 0 ? cbp->cb_alloc * 2 : 64;
newhandles = zfs_realloc(zhp->zfs_hdl,
cbp->cb_handles, cbp->cb_alloc * sizeof (zfs_handle_t *),
newsz * sizeof (zfs_handle_t *));
cbp->cb_handles = newhandles;
cbp->cb_alloc = newsz;
}
cbp->cb_handles[cbp->cb_used++] = zhp;
}
/*
* Recursive helper function used during file system enumeration
*/
static int
zfs_iter_cb(zfs_handle_t *zhp, void *data)
{
get_all_cb_t *cbp = data;
if (!(zfs_get_type(zhp) & ZFS_TYPE_FILESYSTEM)) {
zfs_close(zhp);
return (0);
}
if (zfs_prop_get_int(zhp, ZFS_PROP_CANMOUNT) == ZFS_CANMOUNT_NOAUTO) {
zfs_close(zhp);
return (0);
}
if (zfs_prop_get_int(zhp, ZFS_PROP_KEYSTATUS) ==
ZFS_KEYSTATUS_UNAVAILABLE) {
zfs_close(zhp);
return (0);
}
/*
* If this filesystem is inconsistent and has a receive resume
* token, we can not mount it.
*/
if (zfs_prop_get_int(zhp, ZFS_PROP_INCONSISTENT) &&
zfs_prop_get(zhp, ZFS_PROP_RECEIVE_RESUME_TOKEN,
NULL, 0, NULL, NULL, 0, B_TRUE) == 0) {
zfs_close(zhp);
return (0);
}
libzfs_add_handle(cbp, zhp);
if (zfs_iter_filesystems(zhp, zfs_iter_cb, cbp) != 0) {
zfs_close(zhp);
return (-1);
}
return (0);
}
/*
* Sort comparator that compares two mountpoint paths. We sort these paths so
* that subdirectories immediately follow their parents. This means that we
* effectively treat the '/' character as the lowest value non-nul char.
* Since filesystems from non-global zones can have the same mountpoint
* as other filesystems, the comparator sorts global zone filesystems to
* the top of the list. This means that the global zone will traverse the
* filesystem list in the correct order and can stop when it sees the
* first zoned filesystem. In a non-global zone, only the delegated
* filesystems are seen.
*
* An example sorted list using this comparator would look like:
*
* /foo
* /foo/bar
* /foo/bar/baz
* /foo/baz
* /foo.bar
* /foo (NGZ1)
* /foo (NGZ2)
*
* The mounting code depends on this ordering to deterministically iterate
* over filesystems in order to spawn parallel mount tasks.
*/
static int
mountpoint_cmp(const void *arga, const void *argb)
{
zfs_handle_t *const *zap = arga;
zfs_handle_t *za = *zap;
zfs_handle_t *const *zbp = argb;
zfs_handle_t *zb = *zbp;
char mounta[MAXPATHLEN];
char mountb[MAXPATHLEN];
const char *a = mounta;
const char *b = mountb;
boolean_t gota, gotb;
uint64_t zoneda, zonedb;
zoneda = zfs_prop_get_int(za, ZFS_PROP_ZONED);
zonedb = zfs_prop_get_int(zb, ZFS_PROP_ZONED);
if (zoneda && !zonedb)
return (1);
if (!zoneda && zonedb)
return (-1);
gota = (zfs_get_type(za) == ZFS_TYPE_FILESYSTEM);
if (gota) {
verify(zfs_prop_get(za, ZFS_PROP_MOUNTPOINT, mounta,
sizeof (mounta), NULL, NULL, 0, B_FALSE) == 0);
}
gotb = (zfs_get_type(zb) == ZFS_TYPE_FILESYSTEM);
if (gotb) {
verify(zfs_prop_get(zb, ZFS_PROP_MOUNTPOINT, mountb,
sizeof (mountb), NULL, NULL, 0, B_FALSE) == 0);
}
if (gota && gotb) {
while (*a != '\0' && (*a == *b)) {
a++;
b++;
}
if (*a == *b)
return (0);
if (*a == '\0')
return (-1);
if (*b == '\0')
return (1);
if (*a == '/')
return (-1);
if (*b == '/')
return (1);
return (*a < *b ? -1 : *a > *b);
}
if (gota)
return (-1);
if (gotb)
return (1);
/*
* If neither filesystem has a mountpoint, revert to sorting by
* dataset name.
*/
return (strcmp(zfs_get_name(za), zfs_get_name(zb)));
}
/*
* Return true if path2 is a child of path1.
*/
static boolean_t
libzfs_path_contains(const char *path1, const char *path2)
{
return (strstr(path2, path1) == path2 && path2[strlen(path1)] == '/');
}
/*
* Given a mountpoint specified by idx in the handles array, find the first
* non-descendent of that mountpoint and return its index. Descendant paths
* start with the parent's path. This function relies on the ordering
* enforced by mountpoint_cmp().
*/
static int
non_descendant_idx(zfs_handle_t **handles, size_t num_handles, int idx)
{
char parent[ZFS_MAXPROPLEN];
char child[ZFS_MAXPROPLEN];
int i;
verify(zfs_prop_get(handles[idx], ZFS_PROP_MOUNTPOINT, parent,
sizeof (parent), NULL, NULL, 0, B_FALSE) == 0);
for (i = idx + 1; i < num_handles; i++) {
verify(zfs_prop_get(handles[i], ZFS_PROP_MOUNTPOINT, child,
sizeof (child), NULL, NULL, 0, B_FALSE) == 0);
if (!libzfs_path_contains(parent, child))
break;
}
return (i);
}
typedef struct mnt_param {
libzfs_handle_t *mnt_hdl;
tpool_t *mnt_tp;
zfs_handle_t **mnt_zhps; /* filesystems to mount */
size_t mnt_num_handles;
int mnt_idx; /* Index of selected entry to mount */
zfs_iter_f mnt_func;
void *mnt_data;
} mnt_param_t;
/*
* Allocate and populate the parameter struct for mount function, and
* schedule mounting of the entry selected by idx.
*/
static void
zfs_dispatch_mount(libzfs_handle_t *hdl, zfs_handle_t **handles,
size_t num_handles, int idx, zfs_iter_f func, void *data, tpool_t *tp)
{
mnt_param_t *mnt_param = zfs_alloc(hdl, sizeof (mnt_param_t));
mnt_param->mnt_hdl = hdl;
mnt_param->mnt_tp = tp;
mnt_param->mnt_zhps = handles;
mnt_param->mnt_num_handles = num_handles;
mnt_param->mnt_idx = idx;
mnt_param->mnt_func = func;
mnt_param->mnt_data = data;
(void) tpool_dispatch(tp, zfs_mount_task, (void*)mnt_param);
}
/*
* This is the structure used to keep state of mounting or sharing operations
* during a call to zpool_enable_datasets().
*/
typedef struct mount_state {
/*
* ms_mntstatus is set to -1 if any mount fails. While multiple threads
* could update this variable concurrently, no synchronization is
* needed as it's only ever set to -1.
*/
int ms_mntstatus;
int ms_mntflags;
const char *ms_mntopts;
} mount_state_t;
static int
zfs_mount_one(zfs_handle_t *zhp, void *arg)
{
mount_state_t *ms = arg;
int ret = 0;
/*
* don't attempt to mount encrypted datasets with
* unloaded keys
*/
if (zfs_prop_get_int(zhp, ZFS_PROP_KEYSTATUS) ==
ZFS_KEYSTATUS_UNAVAILABLE)
return (0);
if (zfs_mount(zhp, ms->ms_mntopts, ms->ms_mntflags) != 0)
ret = ms->ms_mntstatus = -1;
return (ret);
}
static int
zfs_share_one(zfs_handle_t *zhp, void *arg)
{
mount_state_t *ms = arg;
int ret = 0;
if (zfs_share(zhp) != 0)
ret = ms->ms_mntstatus = -1;
return (ret);
}
/*
* Thread pool function to mount one file system. On completion, it finds and
* schedules its children to be mounted. This depends on the sorting done in
* zfs_foreach_mountpoint(). Note that the degenerate case (chain of entries
* each descending from the previous) will have no parallelism since we always
* have to wait for the parent to finish mounting before we can schedule
* its children.
*/
static void
zfs_mount_task(void *arg)
{
mnt_param_t *mp = arg;
int idx = mp->mnt_idx;
zfs_handle_t **handles = mp->mnt_zhps;
size_t num_handles = mp->mnt_num_handles;
char mountpoint[ZFS_MAXPROPLEN];
verify(zfs_prop_get(handles[idx], ZFS_PROP_MOUNTPOINT, mountpoint,
sizeof (mountpoint), NULL, NULL, 0, B_FALSE) == 0);
if (mp->mnt_func(handles[idx], mp->mnt_data) != 0)
return;
/*
* We dispatch tasks to mount filesystems with mountpoints underneath
* this one. We do this by dispatching the next filesystem with a
* descendant mountpoint of the one we just mounted, then skip all of
* its descendants, dispatch the next descendant mountpoint, and so on.
* The non_descendant_idx() function skips over filesystems that are
* descendants of the filesystem we just dispatched.
*/
for (int i = idx + 1; i < num_handles;
i = non_descendant_idx(handles, num_handles, i)) {
char child[ZFS_MAXPROPLEN];
verify(zfs_prop_get(handles[i], ZFS_PROP_MOUNTPOINT,
child, sizeof (child), NULL, NULL, 0, B_FALSE) == 0);
if (!libzfs_path_contains(mountpoint, child))
break; /* not a descendant, return */
zfs_dispatch_mount(mp->mnt_hdl, handles, num_handles, i,
mp->mnt_func, mp->mnt_data, mp->mnt_tp);
}
free(mp);
}
/*
* Issue the func callback for each ZFS handle contained in the handles
* array. This function is used to mount all datasets, and so this function
* guarantees that filesystems for parent mountpoints are called before their
* children. As such, before issuing any callbacks, we first sort the array
* of handles by mountpoint.
*
* Callbacks are issued in one of two ways:
*
* 1. Sequentially: If the parallel argument is B_FALSE or the ZFS_SERIAL_MOUNT
* environment variable is set, then we issue callbacks sequentially.
*
* 2. In parallel: If the parallel argument is B_TRUE and the ZFS_SERIAL_MOUNT
* environment variable is not set, then we use a tpool to dispatch threads
* to mount filesystems in parallel. This function dispatches tasks to mount
* the filesystems at the top-level mountpoints, and these tasks in turn
* are responsible for recursively mounting filesystems in their children
* mountpoints.
*/
void
zfs_foreach_mountpoint(libzfs_handle_t *hdl, zfs_handle_t **handles,
size_t num_handles, zfs_iter_f func, void *data, boolean_t parallel)
{
zoneid_t zoneid = getzoneid();
/*
* The ZFS_SERIAL_MOUNT environment variable is an undocumented
* variable that can be used as a convenience to do a/b comparison
* of serial vs. parallel mounting.
*/
boolean_t serial_mount = !parallel ||
(getenv("ZFS_SERIAL_MOUNT") != NULL);
/*
* Sort the datasets by mountpoint. See mountpoint_cmp for details
* of how these are sorted.
*/
qsort(handles, num_handles, sizeof (zfs_handle_t *), mountpoint_cmp);
if (serial_mount) {
for (int i = 0; i < num_handles; i++) {
func(handles[i], data);
}
return;
}
/*
* Issue the callback function for each dataset using a parallel
* algorithm that uses a thread pool to manage threads.
*/
tpool_t *tp = tpool_create(1, mount_tp_nthr, 0, NULL);
/*
* There may be multiple "top level" mountpoints outside of the pool's
* root mountpoint, e.g.: /foo /bar. Dispatch a mount task for each of
* these.
*/
for (int i = 0; i < num_handles;
i = non_descendant_idx(handles, num_handles, i)) {
/*
* Since the mountpoints have been sorted so that the zoned
* filesystems are at the end, a zoned filesystem seen from
* the global zone means that we're done.
*/
if (zoneid == GLOBAL_ZONEID &&
zfs_prop_get_int(handles[i], ZFS_PROP_ZONED))
break;
zfs_dispatch_mount(hdl, handles, num_handles, i, func, data,
tp);
}
tpool_wait(tp); /* wait for all scheduled mounts to complete */
tpool_destroy(tp);
}
/*
* Mount and share all datasets within the given pool. This assumes that no
* datasets within the pool are currently mounted.
*/
#pragma weak zpool_mount_datasets = zpool_enable_datasets
int
zpool_enable_datasets(zpool_handle_t *zhp, const char *mntopts, int flags)
{
get_all_cb_t cb = { 0 };
mount_state_t ms = { 0 };
zfs_handle_t *zfsp;
int ret = 0;
if ((zfsp = zfs_open(zhp->zpool_hdl, zhp->zpool_name,
ZFS_TYPE_DATASET)) == NULL)
goto out;
/*
* Gather all non-snapshot datasets within the pool. Start by adding
* the root filesystem for this pool to the list, and then iterate
* over all child filesystems.
*/
libzfs_add_handle(&cb, zfsp);
if (zfs_iter_filesystems(zfsp, zfs_iter_cb, &cb) != 0)
goto out;
/*
* Mount all filesystems
*/
ms.ms_mntopts = mntopts;
ms.ms_mntflags = flags;
zfs_foreach_mountpoint(zhp->zpool_hdl, cb.cb_handles, cb.cb_used,
zfs_mount_one, &ms, B_TRUE);
if (ms.ms_mntstatus != 0)
ret = ms.ms_mntstatus;
/*
* Share all filesystems that need to be shared. This needs to be
* a separate pass because libshare is not mt-safe, and so we need
* to share serially.
*/
ms.ms_mntstatus = 0;
zfs_foreach_mountpoint(zhp->zpool_hdl, cb.cb_handles, cb.cb_used,
zfs_share_one, &ms, B_FALSE);
if (ms.ms_mntstatus != 0)
ret = ms.ms_mntstatus;
out:
for (int i = 0; i < cb.cb_used; i++)
zfs_close(cb.cb_handles[i]);
free(cb.cb_handles);
return (ret);
}
static int
mountpoint_compare(const void *a, const void *b)
{
const char *mounta = *((char **)a);
const char *mountb = *((char **)b);
return (strcmp(mountb, mounta));
}
/* alias for 2002/240 */
#pragma weak zpool_unmount_datasets = zpool_disable_datasets
/*
* Unshare and unmount all datasets within the given pool. We don't want to
* rely on traversing the DSL to discover the filesystems within the pool,
* because this may be expensive (if not all of them are mounted), and can fail
* arbitrarily (on I/O error, for example). Instead, we walk /proc/self/mounts
* and gather all the filesystems that are currently mounted.
*/
int
zpool_disable_datasets(zpool_handle_t *zhp, boolean_t force)
{
int used, alloc;
struct mnttab entry;
size_t namelen;
char **mountpoints = NULL;
zfs_handle_t **datasets = NULL;
libzfs_handle_t *hdl = zhp->zpool_hdl;
int i;
int ret = -1;
int flags = (force ? MS_FORCE : 0);
namelen = strlen(zhp->zpool_name);
/* Reopen MNTTAB to prevent reading stale data from open file */
if (freopen(MNTTAB, "r", hdl->libzfs_mnttab) == NULL)
return (ENOENT);
used = alloc = 0;
while (getmntent(hdl->libzfs_mnttab, &entry) == 0) {
/*
* Ignore non-ZFS entries.
*/
if (entry.mnt_fstype == NULL ||
strcmp(entry.mnt_fstype, MNTTYPE_ZFS) != 0)
continue;
/*
* Ignore filesystems not within this pool.
*/
if (entry.mnt_mountp == NULL ||
strncmp(entry.mnt_special, zhp->zpool_name, namelen) != 0 ||
(entry.mnt_special[namelen] != '/' &&
entry.mnt_special[namelen] != '\0'))
continue;
/*
* At this point we've found a filesystem within our pool. Add
* it to our growing list.
*/
if (used == alloc) {
if (alloc == 0) {
if ((mountpoints = zfs_alloc(hdl,
8 * sizeof (void *))) == NULL)
goto out;
if ((datasets = zfs_alloc(hdl,
8 * sizeof (void *))) == NULL)
goto out;
alloc = 8;
} else {
void *ptr;
if ((ptr = zfs_realloc(hdl, mountpoints,
alloc * sizeof (void *),
alloc * 2 * sizeof (void *))) == NULL)
goto out;
mountpoints = ptr;
if ((ptr = zfs_realloc(hdl, datasets,
alloc * sizeof (void *),
alloc * 2 * sizeof (void *))) == NULL)
goto out;
datasets = ptr;
alloc *= 2;
}
}
if ((mountpoints[used] = zfs_strdup(hdl,
entry.mnt_mountp)) == NULL)
goto out;
/*
* This is allowed to fail, in case there is some I/O error. It
* is only used to determine if we need to remove the underlying
* mountpoint, so failure is not fatal.
*/
datasets[used] = make_dataset_handle(hdl, entry.mnt_special);
used++;
}
/*
* At this point, we have the entire list of filesystems, so sort it by
* mountpoint.
*/
qsort(mountpoints, used, sizeof (char *), mountpoint_compare);
/*
* Walk through and first unshare everything.
*/
for (i = 0; i < used; i++) {
zfs_share_proto_t *curr_proto;
for (curr_proto = share_all_proto; *curr_proto != PROTO_END;
curr_proto++) {
if (is_shared(hdl, mountpoints[i], *curr_proto) &&
unshare_one(hdl, mountpoints[i],
mountpoints[i], *curr_proto) != 0)
goto out;
}
}
/*
* Now unmount everything, removing the underlying directories as
* appropriate.
*/
for (i = 0; i < used; i++) {
if (unmount_one(hdl, mountpoints[i], flags) != 0)
goto out;
}
for (i = 0; i < used; i++) {
if (datasets[i])
remove_mountpoint(datasets[i]);
}
ret = 0;
out:
for (i = 0; i < used; i++) {
if (datasets[i])
zfs_close(datasets[i]);
free(mountpoints[i]);
}
free(datasets);
free(mountpoints);
return (ret);
}