freebsd-nq/lib/libbe/be.c

877 lines
19 KiB
C

/*
* be.c
*
* Copyright (c) 2017 Kyle J. Kneitinger <kyle@kneit.in>
* All rights reserved.
*
* 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 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/stat.h>
#include <sys/types.h>
#include <ctype.h>
#include <kenv.h>
#include <libgen.h>
#include <libzfs_core.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
#include "be.h"
#include "be_impl.h"
/*
* Initializes the libbe context to operate in the root boot environment
* dataset, for example, zroot/ROOT.
*/
libbe_handle_t *
libbe_init(void)
{
char buf[BE_MAXPATHLEN];
struct stat sb;
dev_t root_dev, boot_dev;
libbe_handle_t *lbh;
char *pos;
// TODO: use errno here??
/* Verify that /boot and / are mounted on the same filesystem */
if (stat("/", &sb) != 0) {
return (NULL);
}
root_dev = sb.st_dev;
if (stat("/boot", &sb) != 0) {
return (NULL);
}
boot_dev = sb.st_dev;
if (root_dev != boot_dev) {
fprintf(stderr, "/ and /boot not on same device, quitting\n");
return (NULL);
}
if ((lbh = calloc(1, sizeof(libbe_handle_t))) == NULL) {
return (NULL);
}
if ((lbh->lzh = libzfs_init()) == NULL) {
free(lbh);
return (NULL);
}
/* Obtain path to active boot environment */
if ((kenv(KENV_GET, "zfs_be_active", lbh->active,
BE_MAXPATHLEN)) == -1) {
libzfs_fini(lbh->lzh);
free(lbh);
return (NULL);
}
/* Remove leading 'zfs:' if present, otherwise use value as-is */
if ((pos = strrchr(lbh->active, ':')) != NULL) {
strncpy(lbh->active, pos + sizeof(char), BE_MAXPATHLEN);
}
/* Obtain path to boot environment root */
if ((kenv(KENV_GET, "zfs_be_root", lbh->root, BE_MAXPATHLEN)) == -1) {
libzfs_fini(lbh->lzh);
free(lbh);
return (NULL);
}
/* Remove leading 'zfs:' if present, otherwise use value as-is */
if ((pos = strrchr(lbh->root, ':')) != NULL) {
strncpy(lbh->root, pos + sizeof(char), BE_MAXPATHLEN);
}
return (lbh);
}
/*
* Free memory allocated by libbe_init()
*/
void
libbe_close(libbe_handle_t *lbh)
{
libzfs_fini(lbh->lzh);
free(lbh);
}
/*
* Destroy the boot environment or snapshot specified by the name
* parameter. Options are or'd together with the possible values:
* BE_DESTROY_FORCE : forces operation on mounted datasets
* TODO: Test destroying a non active but mounted be
*/
int
be_destroy(libbe_handle_t *lbh, char *name, int options)
{
zfs_handle_t *fs;
char path[BE_MAXPATHLEN];
char *p = path;
int mounted;
int force = options & BE_DESTROY_FORCE;
int err = BE_ERR_SUCCESS;
be_root_concat(lbh, name, path);
printf("path: %s\n", path);
if (strchr(name, '@') == NULL) {
if (!zfs_dataset_exists(lbh->lzh, path, ZFS_TYPE_FILESYSTEM)) {
return (set_error(lbh, BE_ERR_NOENT));
}
if (strcmp(path, lbh->active) == 0) {
return (set_error(lbh, BE_ERR_DESTROYACT));
}
fs = zfs_open(lbh->lzh, p, ZFS_TYPE_FILESYSTEM);
} else {
if (!zfs_dataset_exists(lbh->lzh, path, ZFS_TYPE_SNAPSHOT)) {
return (set_error(lbh, BE_ERR_NOENT));
}
fs = zfs_open(lbh->lzh, p, ZFS_TYPE_SNAPSHOT);
}
if (fs == NULL)
return (set_error(lbh, BE_ERR_ZFSOPEN));
/* Check if mounted, unmount if force is specified */
if (mounted = zfs_is_mounted(fs, NULL)) {
if (force) {
zfs_unmount(fs, NULL, 0);
} else {
return (set_error(lbh, BE_ERR_DESTROYMNT));
}
}
// TODO: convert this to use zfs_iter_children first for deep bes
// XXX note: errno 16 (device busy) occurs when chilren are present
if ((err = zfs_destroy(fs, false)) != 0) {
fprintf(stderr, "delete failed errno: %d\n", errno);
}
return (err);
}
int
be_snapshot(libbe_handle_t *lbh, char *source, char *snap_name,
bool recursive, char *result)
{
char buf[BE_MAXPATHLEN];
time_t rawtime;
int len, err;
be_root_concat(lbh, source, buf);
if (!be_exists(lbh, buf)) {
return (BE_ERR_NOENT);
}
if (snap_name != NULL) {
strcat(buf, "@");
strcat(buf, snap_name);
if (result != NULL) {
snprintf(result, BE_MAXPATHLEN, "%s@%s", source,
snap_name);
}
} else {
time(&rawtime);
len = strlen(buf);
strftime(buf + len, BE_MAXPATHLEN - len,
"@%F-%T", localtime(&rawtime));
if (result != NULL) {
strcpy(result, strrchr(buf, '/') + 1);
}
}
if (err = zfs_snapshot(lbh->lzh, buf, recursive, NULL) != 0) {
switch (err) {
case EZFS_INVALIDNAME:
return (set_error(lbh, BE_ERR_INVALIDNAME));
default:
// TODO: elaborate return codes
return (set_error(lbh, BE_ERR_UNKNOWN));
}
}
return (BE_ERR_SUCCESS);
}
/*
* Create the boot environment specified by the name parameter
*/
int
be_create(libbe_handle_t *lbh, char *name)
{
int err;
err = be_create_from_existing(lbh, name, (char *)be_active_path(lbh));
return (set_error(lbh, err));
}
static int
be_deep_clone_prop(int prop, void *cb)
{
int err;
struct libbe_dccb *dccb = cb;
zprop_source_t src;
char pval[BE_MAXPATHLEN];
char source[BE_MAXPATHLEN];
/* Skip some properties we don't want to touch */
switch (prop) {
case ZFS_PROP_CANMOUNT:
return (ZPROP_CONT);
break;
}
/* Don't copy readonly properties */
if (zfs_prop_readonly(prop)) {
return (ZPROP_CONT);
}
if ((err = zfs_prop_get(dccb->zhp, prop, (char *)&pval,
sizeof(pval), &src, (char *)&source, sizeof(source), false))) {
/* Just continue if we fail to read a property */
return (ZPROP_CONT);
}
/* Only copy locally defined properties */
if (src != ZPROP_SRC_LOCAL) {
return (ZPROP_CONT);
}
nvlist_add_string(dccb->props, zfs_prop_to_name(prop), (char *)pval);
return (ZPROP_CONT);
}
static int
be_deep_clone(zfs_handle_t *ds, void *data)
{
int err;
char be_path[BE_MAXPATHLEN];
char snap_path[BE_MAXPATHLEN];
char mp[BE_MAXPATHLEN];
const char *dspath;
char *dsname;
zfs_handle_t *snap_hdl;
nvlist_t *props;
struct libbe_deep_clone sdc;
struct libbe_deep_clone *isdc = (struct libbe_deep_clone *)data;
struct libbe_dccb dccb;
dspath = zfs_get_name(ds);
if ((dsname = strrchr(dspath, '/')) == NULL) {
return (BE_ERR_UNKNOWN);
}
dsname++;
if (isdc->bename == NULL) {
snprintf(be_path, sizeof(be_path), "%s/%s", isdc->be_root, dsname);
} else {
snprintf(be_path, sizeof(be_path), "%s/%s", isdc->be_root, isdc->bename);
}
snprintf(snap_path, sizeof(snap_path), "%s@%s", dspath, isdc->snapname);
if (zfs_dataset_exists(isdc->lbh->lzh, be_path, ZFS_TYPE_DATASET)) {
return (set_error(isdc->lbh, BE_ERR_EXISTS));
}
if ((snap_hdl =
zfs_open(isdc->lbh->lzh, snap_path, ZFS_TYPE_SNAPSHOT)) == NULL) {
return (set_error(isdc->lbh, BE_ERR_ZFSOPEN));
}
nvlist_alloc(&props, NV_UNIQUE_NAME, KM_SLEEP);
nvlist_add_string(props, "canmount", "noauto");
dccb.zhp = ds;
dccb.props = props;
if (zprop_iter(be_deep_clone_prop, &dccb, B_FALSE, B_FALSE,
ZFS_TYPE_FILESYSTEM) == ZPROP_INVAL) {
return (-1);
}
if (err = zfs_clone(snap_hdl, be_path, props)) {
switch (err) {
case EZFS_SUCCESS:
err = BE_ERR_SUCCESS;
break;
default:
err = BE_ERR_ZFSCLONE;
break;
}
}
nvlist_free(props);
zfs_close(snap_hdl);
sdc.lbh = isdc->lbh;
sdc.bename = NULL;
sdc.snapname = isdc->snapname;
sdc.be_root = (char *)&be_path;
err = zfs_iter_filesystems(ds, be_deep_clone, &sdc);
return (err);
}
/*
* Create the boot environment from pre-existing snapshot
*/
int
be_create_from_existing_snap(libbe_handle_t *lbh, char *name, char *snap)
{
int err;
char be_path[BE_MAXPATHLEN];
char snap_path[BE_MAXPATHLEN];
char *parentname, *bename, *snapname;
zfs_handle_t *parent_hdl;
struct libbe_deep_clone sdc;
if (err = be_validate_name(lbh, name)) {
return (set_error(lbh, err));
}
if (err = be_root_concat(lbh, snap, snap_path)) {
return (set_error(lbh, err));
}
if (err = be_validate_snap(lbh, snap_path)) {
return (set_error(lbh, err));
}
if (err = be_root_concat(lbh, name, be_path)) {
return (set_error(lbh, err));
}
if ((bename = strrchr(name, '/')) == NULL) {
bename = name;
} else {
bename++;
}
if ((parentname = strdup(snap_path)) == NULL) {
err = BE_ERR_UNKNOWN;
return (set_error(lbh, err));
}
snapname = strchr(parentname, '@');
if (snapname == NULL) {
err = BE_ERR_UNKNOWN;
return (set_error(lbh, err));
}
*snapname = '\0';
snapname++;
sdc.lbh = lbh;
sdc.bename = bename;
sdc.snapname = snapname;
sdc.be_root = lbh->root;
parent_hdl = zfs_open(lbh->lzh, parentname, ZFS_TYPE_DATASET);
err = be_deep_clone(parent_hdl, &sdc);
return (set_error(lbh, err));
}
/*
* Create a boot environment from an existing boot environment
*/
int
be_create_from_existing(libbe_handle_t *lbh, char *name, char *old)
{
int err;
char buf[BE_MAXPATHLEN];
if ((err = be_snapshot(lbh, old, NULL, true, (char *)&buf))) {
return (set_error(lbh, err));
}
err = be_create_from_existing_snap(lbh, name, (char *)buf);
return (set_error(lbh, err));
}
/*
* Verifies that a snapshot has a valid name, exists, and has a mountpoint of
* '/'. Returns BE_ERR_SUCCESS (0), upon success, or the relevant BE_ERR_* upon
* failure. Does not set the internal library error state.
*/
int
be_validate_snap(libbe_handle_t *lbh, char *snap_name)
{
zfs_handle_t *zfs_hdl;
char buf[BE_MAXPATHLEN];
char *delim_pos;
char *mountpoint;
int err = BE_ERR_SUCCESS;
if (strlen(snap_name) >= BE_MAXPATHLEN) {
return (BE_ERR_PATHLEN);
}
if (!zfs_dataset_exists(lbh->lzh, snap_name,
ZFS_TYPE_SNAPSHOT)) {
return (BE_ERR_NOENT);
}
strncpy(buf, snap_name, BE_MAXPATHLEN);
/* Find the base filesystem of the snapshot */
if ((delim_pos = strchr(buf, '@')) == NULL) {
return (BE_ERR_INVALIDNAME);
}
*delim_pos = '\0';
if ((zfs_hdl =
zfs_open(lbh->lzh, buf, ZFS_TYPE_DATASET)) == NULL) {
return (BE_ERR_NOORIGIN);
}
if (err =
zfs_prop_get(zfs_hdl, ZFS_PROP_MOUNTPOINT, buf,
BE_MAXPATHLEN,
NULL, NULL, 0, 1)) {
err = BE_ERR_INVORIGIN;
}
if ((err != 0) && (strncmp(buf, "/", BE_MAXPATHLEN) != 0)) {
err = BE_ERR_INVORIGIN;
}
zfs_close(zfs_hdl);
return (err);
}
/*
* Idempotently appends the name argument to the root boot environment path
* and copies the resulting string into the result buffer (which is assumed
* to be at least BE_MAXPATHLEN characters long. Returns BE_ERR_SUCCESS upon
* success, BE_ERR_PATHLEN if the resulting path is longer than BE_MAXPATHLEN,
* or BE_ERR_INVALIDNAME if the name is a path that does not begin with
* zfs_be_root. Does not set internal library error state.
*/
int
be_root_concat(libbe_handle_t *lbh, char *name, char *result)
{
size_t name_len, root_len;
name_len = strlen(name);
root_len = strlen(lbh->root);
/* Act idempotently; return be name if it is already a full path */
if (strrchr(name, '/') != NULL) {
if (strstr(name, lbh->root) != name) {
return (BE_ERR_INVALIDNAME);
}
if (name_len >= BE_MAXPATHLEN) {
return (BE_ERR_PATHLEN);
}
strncpy(result, name, BE_MAXPATHLEN);
return (BE_ERR_SUCCESS);
} else if (name_len + root_len + 1 < BE_MAXPATHLEN) {
snprintf(result, BE_MAXPATHLEN, "%s/%s", lbh->root,
name);
return (BE_ERR_SUCCESS);
}
return (BE_ERR_PATHLEN);
}
/*
* Verifies the validity of a boot environment name (A-Za-z0-9-_.). Returns
* BE_ERR_SUCCESS (0) if name is valid, otherwise returns BE_ERR_INVALIDNAME.
* Does not set internal library error state.
*/
int
be_validate_name(libbe_handle_t *lbh, char *name)
{
for (int i = 0; *name; i++) {
char c = *(name++);
if (isalnum(c) || (c == '-') || (c == '_') ||
(c == '.')) {
continue;
}
return (BE_ERR_INVALIDNAME);
}
return (BE_ERR_SUCCESS);
}
/*
* usage
*/
int
be_rename(libbe_handle_t *lbh, char *old, char *new)
{
char full_old[BE_MAXPATHLEN];
char full_new[BE_MAXPATHLEN];
zfs_handle_t *zfs_hdl;
int err;
if (err = be_root_concat(lbh, old, full_old)) {
return (set_error(lbh, err));
}
if (err = be_root_concat(lbh, new, full_new)) {
return (set_error(lbh, err));
}
if (be_validate_name(lbh, new)) {
return (BE_ERR_UNKNOWN);
// TODO set and return correct error
}
// check if old is active be
if (strcmp(full_new, be_active_path(lbh)) == 0) {
return (BE_ERR_UNKNOWN);
// TODO set and return correct error
}
if (!zfs_dataset_exists(lbh->lzh, full_old, ZFS_TYPE_DATASET)) {
return (BE_ERR_UNKNOWN);
// TODO set and return correct error
}
if (zfs_dataset_exists(lbh->lzh, full_new, ZFS_TYPE_DATASET)) {
return (BE_ERR_UNKNOWN);
// TODO set and return correct error
}
// TODO: what about mounted bes?
// - if mounted error out unless a force flag is set?
if ((zfs_hdl = zfs_open(lbh->lzh, full_old,
ZFS_TYPE_FILESYSTEM)) == NULL) {
return (BE_ERR_UNKNOWN);
// TODO set and return correct error
}
// recurse, nounmount, forceunmount
struct renameflags flags = { 0, 0, 0 };
// TODO: error log on this call
err = zfs_rename(zfs_hdl, NULL, full_new, flags);
zfs_close(zfs_hdl);
return (set_error(lbh, err));
}
int
be_export(libbe_handle_t *lbh, char *bootenv, int fd)
{
char snap_name[BE_MAXPATHLEN];
char buf[BE_MAXPATHLEN];
zfs_handle_t *zfs;
int err;
if (err = be_snapshot(lbh, bootenv, NULL, true, snap_name)) {
// TODO error handle
return (-1);
}
be_root_concat(lbh, snap_name, buf);
if ((zfs = zfs_open(lbh->lzh, buf, ZFS_TYPE_DATASET)) == NULL) {
return (BE_ERR_ZFSOPEN);
}
err = zfs_send_one(zfs, NULL, fd, 0);
return (err);
}
int
be_import(libbe_handle_t *lbh, char *bootenv, int fd)
{
char buf[BE_MAXPATHLEN];
time_t rawtime;
nvlist_t *props;
zfs_handle_t *zfs;
int err, len;
// TODO: this is a very likely name for someone to already have used
if (err = be_root_concat(lbh, "be_import_temp", buf)) {
// TODO error handle
return (-1);
}
time(&rawtime);
len = strlen(buf);
strftime(buf + len, BE_MAXPATHLEN - len,
"@%F-%T", localtime(&rawtime));
// lzc_receive(SNAPNAME, PROPS, ORIGIN, FORCE, fd)) {
if (err = lzc_receive(buf, NULL, NULL, false, fd)) {
/* TODO: go through libzfs_core's recv_impl and find returned
* errors and set appropriate BE_ERR
* edit: errors are not in libzfs_core, my assumption is
* that they use libzfs errors
* note: 17 is err for dataset already existing */
return (err);
}
if ((zfs = zfs_open(lbh->lzh, buf, ZFS_TYPE_SNAPSHOT)) == NULL) {
// TODO correct error
return (-1);
}
nvlist_alloc(&props, NV_UNIQUE_NAME, KM_SLEEP);
nvlist_add_string(props, "canmount", "noauto");
nvlist_add_string(props, "mountpoint", "/");
be_root_concat(lbh, bootenv, buf);
err = zfs_clone(zfs, buf, props);
zfs_close(zfs);
nvlist_free(props);
// TODO: recursively delete be_import_temp dataset
return (err);
}
int
be_add_child(libbe_handle_t *lbh, char *child_path, bool cp_if_exists)
{
char active[BE_MAXPATHLEN];
char buf[BE_MAXPATHLEN];
nvlist_t *props;
zfs_handle_t *zfs;
struct stat sb;
int err;
/* Require absolute paths */
if (*child_path != '/') {
/* TODO: create appropriate error */
return (-1);
}
strncpy(active, be_active_path(lbh), BE_MAXPATHLEN);
strcpy(buf, active);
/* Create non-mountable parent dataset(s) */
char *s = child_path;
for (char *p; (p = strchr(s+1, '/')) != NULL; s = p) {
size_t len = p - s;
strncat(buf, s, len);
nvlist_alloc(&props, NV_UNIQUE_NAME, KM_SLEEP);
nvlist_add_string(props, "canmount", "off");
nvlist_add_string(props, "mountpoint", "none");
zfs_create(lbh->lzh, buf, ZFS_TYPE_DATASET, props);
nvlist_free(props);
}
/* Path does not exist as a descendent of / yet */
int pos = strlen(active);
/* TODO: Verify that resulting str is less than BE_MAXPATHLEN */
strncpy(&active[pos], child_path, BE_MAXPATHLEN-pos);
if (stat(child_path, &sb) != 0) {
/* Verify that error is ENOENT */
if (errno != 2) {
/* TODO: create appropriate error */
return (-1);
}
nvlist_alloc(&props, NV_UNIQUE_NAME, KM_SLEEP);
nvlist_add_string(props, "canmount", "noauto");
nvlist_add_string(props, "mountpoint", child_path);
// create
if (err =
zfs_create(lbh->lzh, active, ZFS_TYPE_DATASET, props)) {
/* TODO handle error */
return (-1);
}
nvlist_free(props);
if ((zfs =
zfs_open(lbh->lzh, active, ZFS_TYPE_DATASET)) == NULL) {
/* TODO handle error */
return (-1);
}
// set props
if (err = zfs_prop_set(zfs, "canmount", "noauto")) {
/* TODO handle error */
return (-1);
}
} else if (cp_if_exists) {
/* Path is already a descendent of / and should be copied */
// TODO
/*
* Establish if the existing path is a zfs dataset or just
* the subdirectory of one
*/
// TODO: use mktemp
long int snap_name = random();
snprintf(buf, BE_MAXPATHLEN, "%s@%ld", child_path, snap_name);
if (err = zfs_snapshot(lbh->lzh, buf, false, NULL)) {
// TODO correct error
return (-1);
}
// clone
if ((zfs =
zfs_open(lbh->lzh, buf, ZFS_TYPE_SNAPSHOT)) == NULL) {
// TODO correct error
return (-1);
}
if (err = zfs_clone(zfs, active, NULL)) {
// TODO correct error
return (-1);
}
// set props
} else {
/* TODO: error code for exists, but not cp? */
return (-1);
}
return (BE_ERR_SUCCESS);
}
int
be_activate(libbe_handle_t *lbh, char *bootenv, bool temporary)
{
char be_path[BE_MAXPATHLEN];
char buf[BE_MAXPATHLEN];
zpool_handle_t *zph;
uint64_t pool_guid;
uint64_t vdev_guid;
int zfs_fd;
int len;
int err;
be_root_concat(lbh, bootenv, be_path);
/* Note: be_exists fails if mountpoint is not / */
if (!be_exists(lbh, be_path)) {
return (BE_ERR_NOENT);
}
if (temporary) {
// TODO: give proper attribution to author(s) of zfsbootcfg
// for this snippet
if (kenv(KENV_GET, "vfs.zfs.boot.primary_pool", buf,
sizeof(buf)) <= 0) {
return (1);
}
pool_guid = strtoumax(buf, NULL, 10);
if (pool_guid == 0) {
return (1);
}
if (kenv(KENV_GET, "vfs.zfs.boot.primary_vdev", buf,
sizeof(buf)) <= 0) {
return (1);
}
vdev_guid = strtoumax(buf, NULL, 10);
if (vdev_guid == 0) {
return (1);
}
/* Expected format according to zfsbootcfg(8) man */
strcpy(buf, "zfs:");
strcat(buf, be_path);
strcat(buf, ":");
if (zpool_nextboot(lbh->lzh, pool_guid, vdev_guid, buf) != 0) {
perror("ZFS_IOC_NEXTBOOT failed");
return (1);
}
return (BE_ERR_SUCCESS);
} else {
/* Obtain bootenv zpool */
strncpy(buf, be_path, BE_MAXPATHLEN);
*(strchr(buf, '/')) = '\0';
if ((zph = zpool_open(lbh->lzh, buf)) == NULL) {
// TODO: create error for this
return (-1);
}
printf("asdf\n");
err = zpool_set_prop(zph, "bootfs", be_path);
zpool_close(zph);
switch (err) {
case 0:
return (BE_ERR_SUCCESS);
default:
// TODO correct errors
return (-1);
}
}
}