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qemu/qemu-nbd.c
Eric Blake 0a4795455c nbd: Prepare for NBD_CMD_FLAG_FAST_ZERO 
Commit fe0480d6 and friends added BDRV_REQ_NO_FALLBACK as a way to
avoid wasting time on a preliminary write-zero request that will later
be rewritten by actual data, if it is known that the write-zero
request will use a slow fallback; but in doing so, could not optimize
for NBD.  The NBD specification is now considering an extension that
will allow passing on those semantics; this patch updates the new
protocol bits and 'qemu-nbd --list' output to recognize the bit, as
well as the new errno value possible when using the new flag; while
upcoming patches will improve the client to use the feature when
present, and the server to advertise support for it.

The NBD spec recommends (but not requires) that ENOTSUP be avoided for
all but failures of a fast zero (the only time it is mandatory to
avoid an ENOTSUP failure is when fast zero is supported but not
requested during write zeroes; the questionable use is for ENOTSUP to
other actions like a normal write request).  However, clients that get
an unexpected ENOTSUP will either already be treating it the same as
EINVAL, or may appreciate the extra bit of information.  We were
equally loose for returning EOVERFLOW in more situations than
recommended by the spec, so if it turns out to be a problem in
practice, a later patch can tighten handling for both error codes.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190823143726.27062-3-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
[eblake: tweak commit message, also handle EOPNOTSUPP]
2019-09-05 16:03:13 -05:00

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/*
* Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws>
*
* Network Block Device
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; under version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include <getopt.h>
#include <libgen.h>
#include <pthread.h>
#include "qemu-common.h"
#include "qapi/error.h"
#include "qemu/cutils.h"
#include "sysemu/block-backend.h"
#include "block/block_int.h"
#include "block/nbd.h"
#include "qemu/main-loop.h"
#include "qemu/module.h"
#include "qemu/option.h"
#include "qemu/error-report.h"
#include "qemu/config-file.h"
#include "qemu/bswap.h"
#include "qemu/log.h"
#include "qemu/systemd.h"
#include "block/snapshot.h"
#include "qapi/qmp/qdict.h"
#include "qapi/qmp/qstring.h"
#include "qom/object_interfaces.h"
#include "io/channel-socket.h"
#include "io/net-listener.h"
#include "crypto/init.h"
#include "trace/control.h"
#include "qemu-version.h"
#ifdef __linux__
#define HAVE_NBD_DEVICE 1
#else
#define HAVE_NBD_DEVICE 0
#endif
#define SOCKET_PATH "/var/lock/qemu-nbd-%s"
#define QEMU_NBD_OPT_CACHE 256
#define QEMU_NBD_OPT_AIO 257
#define QEMU_NBD_OPT_DISCARD 258
#define QEMU_NBD_OPT_DETECT_ZEROES 259
#define QEMU_NBD_OPT_OBJECT 260
#define QEMU_NBD_OPT_TLSCREDS 261
#define QEMU_NBD_OPT_IMAGE_OPTS 262
#define QEMU_NBD_OPT_FORK 263
#define QEMU_NBD_OPT_TLSAUTHZ 264
#define QEMU_NBD_OPT_PID_FILE 265
#define MBR_SIZE 512
static NBDExport *export;
static int verbose;
static char *srcpath;
static SocketAddress *saddr;
static int persistent = 0;
static enum { RUNNING, TERMINATE, TERMINATING, TERMINATED } state;
static int shared = 1;
static int nb_fds;
static QIONetListener *server;
static QCryptoTLSCreds *tlscreds;
static const char *tlsauthz;
static void usage(const char *name)
{
(printf) (
"Usage: %s [OPTIONS] FILE\n"
" or: %s -L [OPTIONS]\n"
"QEMU Disk Network Block Device Utility\n"
"\n"
" -h, --help display this help and exit\n"
" -V, --version output version information and exit\n"
"\n"
"Connection properties:\n"
" -p, --port=PORT port to listen on (default `%d')\n"
" -b, --bind=IFACE interface to bind to (default `0.0.0.0')\n"
" -k, --socket=PATH path to the unix socket\n"
" (default '"SOCKET_PATH"')\n"
" -e, --shared=NUM device can be shared by NUM clients (default '1')\n"
" -t, --persistent don't exit on the last connection\n"
" -v, --verbose display extra debugging information\n"
" -x, --export-name=NAME expose export by name (default is empty string)\n"
" -D, --description=TEXT export a human-readable description\n"
"\n"
"Exposing part of the image:\n"
" -o, --offset=OFFSET offset into the image\n"
" -P, --partition=NUM only expose partition NUM\n"
" -B, --bitmap=NAME expose a persistent dirty bitmap\n"
"\n"
"General purpose options:\n"
" -L, --list list exports available from another NBD server\n"
" --object type,id=ID,... define an object such as 'secret' for providing\n"
" passwords and/or encryption keys\n"
" --tls-creds=ID use id of an earlier --object to provide TLS\n"
" --tls-authz=ID use id of an earlier --object to provide\n"
" authorization\n"
" -T, --trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
" specify tracing options\n"
" --fork fork off the server process and exit the parent\n"
" once the server is running\n"
" --pid-file=PATH store the server's process ID in the given file\n"
#if HAVE_NBD_DEVICE
"\n"
"Kernel NBD client support:\n"
" -c, --connect=DEV connect FILE to the local NBD device DEV\n"
" -d, --disconnect disconnect the specified device\n"
#endif
"\n"
"Block device options:\n"
" -f, --format=FORMAT set image format (raw, qcow2, ...)\n"
" -r, --read-only export read-only\n"
" -s, --snapshot use FILE as an external snapshot, create a temporary\n"
" file with backing_file=FILE, redirect the write to\n"
" the temporary one\n"
" -l, --load-snapshot=SNAPSHOT_PARAM\n"
" load an internal snapshot inside FILE and export it\n"
" as an read-only device, SNAPSHOT_PARAM format is\n"
" 'snapshot.id=[ID],snapshot.name=[NAME]', or\n"
" '[ID_OR_NAME]'\n"
" -n, --nocache disable host cache\n"
" --cache=MODE set cache mode (none, writeback, ...)\n"
" --aio=MODE set AIO mode (native or threads)\n"
" --discard=MODE set discard mode (ignore, unmap)\n"
" --detect-zeroes=MODE set detect-zeroes mode (off, on, unmap)\n"
" --image-opts treat FILE as a full set of image options\n"
"\n"
QEMU_HELP_BOTTOM "\n"
, name, name, NBD_DEFAULT_PORT, "DEVICE");
}
static void version(const char *name)
{
printf(
"%s " QEMU_FULL_VERSION "\n"
"Written by Anthony Liguori.\n"
"\n"
QEMU_COPYRIGHT "\n"
"This is free software; see the source for copying conditions. There is NO\n"
"warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
, name);
}
struct partition_record
{
uint8_t bootable;
uint8_t start_head;
uint32_t start_cylinder;
uint8_t start_sector;
uint8_t system;
uint8_t end_head;
uint8_t end_cylinder;
uint8_t end_sector;
uint32_t start_sector_abs;
uint32_t nb_sectors_abs;
};
static void read_partition(uint8_t *p, struct partition_record *r)
{
r->bootable = p[0];
r->start_head = p[1];
r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300);
r->start_sector = p[2] & 0x3f;
r->system = p[4];
r->end_head = p[5];
r->end_cylinder = p[7] | ((p[6] << 2) & 0x300);
r->end_sector = p[6] & 0x3f;
r->start_sector_abs = ldl_le_p(p + 8);
r->nb_sectors_abs = ldl_le_p(p + 12);
}
static int find_partition(BlockBackend *blk, int partition,
uint64_t *offset, uint64_t *size)
{
struct partition_record mbr[4];
uint8_t data[MBR_SIZE];
int i;
int ext_partnum = 4;
int ret;
ret = blk_pread(blk, 0, data, sizeof(data));
if (ret < 0) {
error_report("error while reading: %s", strerror(-ret));
exit(EXIT_FAILURE);
}
if (data[510] != 0x55 || data[511] != 0xaa) {
return -EINVAL;
}
for (i = 0; i < 4; i++) {
read_partition(&data[446 + 16 * i], &mbr[i]);
if (!mbr[i].system || !mbr[i].nb_sectors_abs) {
continue;
}
if (mbr[i].system == 0xF || mbr[i].system == 0x5) {
struct partition_record ext[4];
uint8_t data1[MBR_SIZE];
int j;
ret = blk_pread(blk, mbr[i].start_sector_abs * MBR_SIZE,
data1, sizeof(data1));
if (ret < 0) {
error_report("error while reading: %s", strerror(-ret));
exit(EXIT_FAILURE);
}
for (j = 0; j < 4; j++) {
read_partition(&data1[446 + 16 * j], &ext[j]);
if (!ext[j].system || !ext[j].nb_sectors_abs) {
continue;
}
if ((ext_partnum + j + 1) == partition) {
*offset = (uint64_t)ext[j].start_sector_abs << 9;
*size = (uint64_t)ext[j].nb_sectors_abs << 9;
return 0;
}
}
ext_partnum += 4;
} else if ((i + 1) == partition) {
*offset = (uint64_t)mbr[i].start_sector_abs << 9;
*size = (uint64_t)mbr[i].nb_sectors_abs << 9;
return 0;
}
}
return -ENOENT;
}
static void termsig_handler(int signum)
{
atomic_cmpxchg(&state, RUNNING, TERMINATE);
qemu_notify_event();
}
static int qemu_nbd_client_list(SocketAddress *saddr, QCryptoTLSCreds *tls,
const char *hostname)
{
int ret = EXIT_FAILURE;
int rc;
Error *err = NULL;
QIOChannelSocket *sioc;
NBDExportInfo *list;
int i, j;
sioc = qio_channel_socket_new();
if (qio_channel_socket_connect_sync(sioc, saddr, &err) < 0) {
error_report_err(err);
return EXIT_FAILURE;
}
rc = nbd_receive_export_list(QIO_CHANNEL(sioc), tls, hostname, &list,
&err);
if (rc < 0) {
if (err) {
error_report_err(err);
}
goto out;
}
printf("exports available: %d\n", rc);
for (i = 0; i < rc; i++) {
printf(" export: '%s'\n", list[i].name);
if (list[i].description && *list[i].description) {
printf(" description: %s\n", list[i].description);
}
if (list[i].flags & NBD_FLAG_HAS_FLAGS) {
static const char *const flag_names[] = {
[NBD_FLAG_READ_ONLY_BIT] = "readonly",
[NBD_FLAG_SEND_FLUSH_BIT] = "flush",
[NBD_FLAG_SEND_FUA_BIT] = "fua",
[NBD_FLAG_ROTATIONAL_BIT] = "rotational",
[NBD_FLAG_SEND_TRIM_BIT] = "trim",
[NBD_FLAG_SEND_WRITE_ZEROES_BIT] = "zeroes",
[NBD_FLAG_SEND_DF_BIT] = "df",
[NBD_FLAG_CAN_MULTI_CONN_BIT] = "multi",
[NBD_FLAG_SEND_RESIZE_BIT] = "resize",
[NBD_FLAG_SEND_CACHE_BIT] = "cache",
[NBD_FLAG_SEND_FAST_ZERO_BIT] = "fast-zero",
};
printf(" size: %" PRIu64 "\n", list[i].size);
printf(" flags: 0x%x (", list[i].flags);
for (size_t bit = 0; bit < ARRAY_SIZE(flag_names); bit++) {
if (flag_names[bit] && (list[i].flags & (1 << bit))) {
printf(" %s", flag_names[bit]);
}
}
printf(" )\n");
}
if (list[i].min_block) {
printf(" min block: %u\n", list[i].min_block);
printf(" opt block: %u\n", list[i].opt_block);
printf(" max block: %u\n", list[i].max_block);
}
if (list[i].n_contexts) {
printf(" available meta contexts: %d\n", list[i].n_contexts);
for (j = 0; j < list[i].n_contexts; j++) {
printf(" %s\n", list[i].contexts[j]);
}
}
}
nbd_free_export_list(list, rc);
ret = EXIT_SUCCESS;
out:
object_unref(OBJECT(sioc));
return ret;
}
#if HAVE_NBD_DEVICE
static void *show_parts(void *arg)
{
char *device = arg;
int nbd;
/* linux just needs an open() to trigger
* the partition table update
* but remember to load the module with max_part != 0 :
* modprobe nbd max_part=63
*/
nbd = open(device, O_RDWR);
if (nbd >= 0) {
close(nbd);
}
return NULL;
}
static void *nbd_client_thread(void *arg)
{
char *device = arg;
NBDExportInfo info = { .request_sizes = false, .name = g_strdup("") };
QIOChannelSocket *sioc;
int fd;
int ret;
pthread_t show_parts_thread;
Error *local_error = NULL;
sioc = qio_channel_socket_new();
if (qio_channel_socket_connect_sync(sioc,
saddr,
&local_error) < 0) {
error_report_err(local_error);
goto out;
}
ret = nbd_receive_negotiate(NULL, QIO_CHANNEL(sioc),
NULL, NULL, NULL, &info, &local_error);
if (ret < 0) {
if (local_error) {
error_report_err(local_error);
}
goto out_socket;
}
fd = open(device, O_RDWR);
if (fd < 0) {
/* Linux-only, we can use %m in printf. */
error_report("Failed to open %s: %m", device);
goto out_socket;
}
ret = nbd_init(fd, sioc, &info, &local_error);
if (ret < 0) {
error_report_err(local_error);
goto out_fd;
}
/* update partition table */
pthread_create(&show_parts_thread, NULL, show_parts, device);
if (verbose) {
fprintf(stderr, "NBD device %s is now connected to %s\n",
device, srcpath);
} else {
/* Close stderr so that the qemu-nbd process exits. */
dup2(STDOUT_FILENO, STDERR_FILENO);
}
ret = nbd_client(fd);
if (ret) {
goto out_fd;
}
close(fd);
object_unref(OBJECT(sioc));
g_free(info.name);
kill(getpid(), SIGTERM);
return (void *) EXIT_SUCCESS;
out_fd:
close(fd);
out_socket:
object_unref(OBJECT(sioc));
out:
g_free(info.name);
kill(getpid(), SIGTERM);
return (void *) EXIT_FAILURE;
}
#endif /* HAVE_NBD_DEVICE */
static int nbd_can_accept(void)
{
return state == RUNNING && nb_fds < shared;
}
static void nbd_export_closed(NBDExport *export)
{
assert(state == TERMINATING);
state = TERMINATED;
}
static void nbd_update_server_watch(void);
static void nbd_client_closed(NBDClient *client, bool negotiated)
{
nb_fds--;
if (negotiated && nb_fds == 0 && !persistent && state == RUNNING) {
state = TERMINATE;
}
nbd_update_server_watch();
nbd_client_put(client);
}
static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc,
gpointer opaque)
{
if (state >= TERMINATE) {
return;
}
nb_fds++;
nbd_update_server_watch();
nbd_client_new(cioc, tlscreds, tlsauthz, nbd_client_closed);
}
static void nbd_update_server_watch(void)
{
if (nbd_can_accept()) {
qio_net_listener_set_client_func(server, nbd_accept, NULL, NULL);
} else {
qio_net_listener_set_client_func(server, NULL, NULL, NULL);
}
}
static SocketAddress *nbd_build_socket_address(const char *sockpath,
const char *bindto,
const char *port)
{
SocketAddress *saddr;
saddr = g_new0(SocketAddress, 1);
if (sockpath) {
saddr->type = SOCKET_ADDRESS_TYPE_UNIX;
saddr->u.q_unix.path = g_strdup(sockpath);
} else {
InetSocketAddress *inet;
saddr->type = SOCKET_ADDRESS_TYPE_INET;
inet = &saddr->u.inet;
inet->host = g_strdup(bindto);
if (port) {
inet->port = g_strdup(port);
} else {
inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);
}
}
return saddr;
}
static QemuOptsList file_opts = {
.name = "file",
.implied_opt_name = "file",
.head = QTAILQ_HEAD_INITIALIZER(file_opts.head),
.desc = {
/* no elements => accept any params */
{ /* end of list */ }
},
};
static QemuOptsList qemu_object_opts = {
.name = "object",
.implied_opt_name = "qom-type",
.head = QTAILQ_HEAD_INITIALIZER(qemu_object_opts.head),
.desc = {
{ }
},
};
static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, bool list,
Error **errp)
{
Object *obj;
QCryptoTLSCreds *creds;
obj = object_resolve_path_component(
object_get_objects_root(), id);
if (!obj) {
error_setg(errp, "No TLS credentials with id '%s'",
id);
return NULL;
}
creds = (QCryptoTLSCreds *)
object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
if (!creds) {
error_setg(errp, "Object with id '%s' is not TLS credentials",
id);
return NULL;
}
if (list) {
if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT) {
error_setg(errp,
"Expecting TLS credentials with a client endpoint");
return NULL;
}
} else {
if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
error_setg(errp,
"Expecting TLS credentials with a server endpoint");
return NULL;
}
}
object_ref(obj);
return creds;
}
static void setup_address_and_port(const char **address, const char **port)
{
if (*address == NULL) {
*address = "0.0.0.0";
}
if (*port == NULL) {
*port = stringify(NBD_DEFAULT_PORT);
}
}
/*
* Check socket parameters compatibility when socket activation is used.
*/
static const char *socket_activation_validate_opts(const char *device,
const char *sockpath,
const char *address,
const char *port,
bool list)
{
if (device != NULL) {
return "NBD device can't be set when using socket activation";
}
if (sockpath != NULL) {
return "Unix socket can't be set when using socket activation";
}
if (address != NULL) {
return "The interface can't be set when using socket activation";
}
if (port != NULL) {
return "TCP port number can't be set when using socket activation";
}
if (list) {
return "List mode is incompatible with socket activation";
}
return NULL;
}
static void qemu_nbd_shutdown(void)
{
job_cancel_sync_all();
bdrv_close_all();
}
int main(int argc, char **argv)
{
BlockBackend *blk;
BlockDriverState *bs;
uint64_t dev_offset = 0;
bool readonly = false;
bool disconnect = false;
const char *bindto = NULL;
const char *port = NULL;
char *sockpath = NULL;
char *device = NULL;
int64_t fd_size;
QemuOpts *sn_opts = NULL;
const char *sn_id_or_name = NULL;
const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:T:D:B:L";
struct option lopt[] = {
{ "help", no_argument, NULL, 'h' },
{ "version", no_argument, NULL, 'V' },
{ "bind", required_argument, NULL, 'b' },
{ "port", required_argument, NULL, 'p' },
{ "socket", required_argument, NULL, 'k' },
{ "offset", required_argument, NULL, 'o' },
{ "read-only", no_argument, NULL, 'r' },
{ "partition", required_argument, NULL, 'P' },
{ "bitmap", required_argument, NULL, 'B' },
{ "connect", required_argument, NULL, 'c' },
{ "disconnect", no_argument, NULL, 'd' },
{ "list", no_argument, NULL, 'L' },
{ "snapshot", no_argument, NULL, 's' },
{ "load-snapshot", required_argument, NULL, 'l' },
{ "nocache", no_argument, NULL, 'n' },
{ "cache", required_argument, NULL, QEMU_NBD_OPT_CACHE },
{ "aio", required_argument, NULL, QEMU_NBD_OPT_AIO },
{ "discard", required_argument, NULL, QEMU_NBD_OPT_DISCARD },
{ "detect-zeroes", required_argument, NULL,
QEMU_NBD_OPT_DETECT_ZEROES },
{ "shared", required_argument, NULL, 'e' },
{ "format", required_argument, NULL, 'f' },
{ "persistent", no_argument, NULL, 't' },
{ "verbose", no_argument, NULL, 'v' },
{ "object", required_argument, NULL, QEMU_NBD_OPT_OBJECT },
{ "export-name", required_argument, NULL, 'x' },
{ "description", required_argument, NULL, 'D' },
{ "tls-creds", required_argument, NULL, QEMU_NBD_OPT_TLSCREDS },
{ "tls-authz", required_argument, NULL, QEMU_NBD_OPT_TLSAUTHZ },
{ "image-opts", no_argument, NULL, QEMU_NBD_OPT_IMAGE_OPTS },
{ "trace", required_argument, NULL, 'T' },
{ "fork", no_argument, NULL, QEMU_NBD_OPT_FORK },
{ "pid-file", required_argument, NULL, QEMU_NBD_OPT_PID_FILE },
{ NULL, 0, NULL, 0 }
};
int ch;
int opt_ind = 0;
int flags = BDRV_O_RDWR;
int partition = 0;
int ret = 0;
bool seen_cache = false;
bool seen_discard = false;
bool seen_aio = false;
pthread_t client_thread;
const char *fmt = NULL;
Error *local_err = NULL;
BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
QDict *options = NULL;
const char *export_name = NULL; /* defaults to "" later for server mode */
const char *export_description = NULL;
const char *bitmap = NULL;
const char *tlscredsid = NULL;
bool imageOpts = false;
bool writethrough = true;
char *trace_file = NULL;
bool fork_process = false;
bool list = false;
int old_stderr = -1;
unsigned socket_activation;
const char *pid_file_name = NULL;
/* The client thread uses SIGTERM to interrupt the server. A signal
* handler ensures that "qemu-nbd -v -c" exits with a nice status code.
*/
struct sigaction sa_sigterm;
memset(&sa_sigterm, 0, sizeof(sa_sigterm));
sa_sigterm.sa_handler = termsig_handler;
sigaction(SIGTERM, &sa_sigterm, NULL);
#ifdef CONFIG_POSIX
signal(SIGPIPE, SIG_IGN);
#endif
error_init(argv[0]);
module_call_init(MODULE_INIT_TRACE);
qcrypto_init(&error_fatal);
module_call_init(MODULE_INIT_QOM);
qemu_add_opts(&qemu_object_opts);
qemu_add_opts(&qemu_trace_opts);
qemu_init_exec_dir(argv[0]);
while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
switch (ch) {
case 's':
flags |= BDRV_O_SNAPSHOT;
break;
case 'n':
optarg = (char *) "none";
/* fallthrough */
case QEMU_NBD_OPT_CACHE:
if (seen_cache) {
error_report("-n and --cache can only be specified once");
exit(EXIT_FAILURE);
}
seen_cache = true;
if (bdrv_parse_cache_mode(optarg, &flags, &writethrough) == -1) {
error_report("Invalid cache mode `%s'", optarg);
exit(EXIT_FAILURE);
}
break;
case QEMU_NBD_OPT_AIO:
if (seen_aio) {
error_report("--aio can only be specified once");
exit(EXIT_FAILURE);
}
seen_aio = true;
if (!strcmp(optarg, "native")) {
flags |= BDRV_O_NATIVE_AIO;
} else if (!strcmp(optarg, "threads")) {
/* this is the default */
} else {
error_report("invalid aio mode `%s'", optarg);
exit(EXIT_FAILURE);
}
break;
case QEMU_NBD_OPT_DISCARD:
if (seen_discard) {
error_report("--discard can only be specified once");
exit(EXIT_FAILURE);
}
seen_discard = true;
if (bdrv_parse_discard_flags(optarg, &flags) == -1) {
error_report("Invalid discard mode `%s'", optarg);
exit(EXIT_FAILURE);
}
break;
case QEMU_NBD_OPT_DETECT_ZEROES:
detect_zeroes =
qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup,
optarg,
BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
&local_err);
if (local_err) {
error_reportf_err(local_err,
"Failed to parse detect_zeroes mode: ");
exit(EXIT_FAILURE);
}
if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
!(flags & BDRV_O_UNMAP)) {
error_report("setting detect-zeroes to unmap is not allowed "
"without setting discard operation to unmap");
exit(EXIT_FAILURE);
}
break;
case 'b':
bindto = optarg;
break;
case 'p':
port = optarg;
break;
case 'o':
if (qemu_strtou64(optarg, NULL, 0, &dev_offset) < 0) {
error_report("Invalid offset '%s'", optarg);
exit(EXIT_FAILURE);
}
break;
case 'l':
if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
sn_opts = qemu_opts_parse_noisily(&internal_snapshot_opts,
optarg, false);
if (!sn_opts) {
error_report("Failed in parsing snapshot param `%s'",
optarg);
exit(EXIT_FAILURE);
}
} else {
sn_id_or_name = optarg;
}
/* fall through */
case 'r':
readonly = true;
flags &= ~BDRV_O_RDWR;
break;
case 'P':
warn_report("The '-P' option is deprecated; use --image-opts with "
"a raw device wrapper for subset exports instead");
if (qemu_strtoi(optarg, NULL, 0, &partition) < 0 ||
partition < 1 || partition > 8) {
error_report("Invalid partition '%s'", optarg);
exit(EXIT_FAILURE);
}
break;
case 'B':
bitmap = optarg;
break;
case 'k':
sockpath = optarg;
if (sockpath[0] != '/') {
error_report("socket path must be absolute");
exit(EXIT_FAILURE);
}
break;
case 'd':
disconnect = true;
break;
case 'c':
device = optarg;
break;
case 'e':
if (qemu_strtoi(optarg, NULL, 0, &shared) < 0 ||
shared < 1) {
error_report("Invalid shared device number '%s'", optarg);
exit(EXIT_FAILURE);
}
break;
case 'f':
fmt = optarg;
break;
case 't':
persistent = 1;
break;
case 'x':
export_name = optarg;
break;
case 'D':
export_description = optarg;
break;
case 'v':
verbose = 1;
break;
case 'V':
version(argv[0]);
exit(0);
break;
case 'h':
usage(argv[0]);
exit(0);
break;
case '?':
error_report("Try `%s --help' for more information.", argv[0]);
exit(EXIT_FAILURE);
case QEMU_NBD_OPT_OBJECT: {
QemuOpts *opts;
opts = qemu_opts_parse_noisily(&qemu_object_opts,
optarg, true);
if (!opts) {
exit(EXIT_FAILURE);
}
} break;
case QEMU_NBD_OPT_TLSCREDS:
tlscredsid = optarg;
break;
case QEMU_NBD_OPT_IMAGE_OPTS:
imageOpts = true;
break;
case 'T':
g_free(trace_file);
trace_file = trace_opt_parse(optarg);
break;
case QEMU_NBD_OPT_TLSAUTHZ:
tlsauthz = optarg;
break;
case QEMU_NBD_OPT_FORK:
fork_process = true;
break;
case 'L':
list = true;
break;
case QEMU_NBD_OPT_PID_FILE:
pid_file_name = optarg;
break;
}
}
if (list) {
if (argc != optind) {
error_report("List mode is incompatible with a file name");
exit(EXIT_FAILURE);
}
if (export_name || export_description || dev_offset || partition ||
device || disconnect || fmt || sn_id_or_name || bitmap ||
seen_aio || seen_discard || seen_cache) {
error_report("List mode is incompatible with per-device settings");
exit(EXIT_FAILURE);
}
if (fork_process) {
error_report("List mode is incompatible with forking");
exit(EXIT_FAILURE);
}
} else if ((argc - optind) != 1) {
error_report("Invalid number of arguments");
error_printf("Try `%s --help' for more information.\n", argv[0]);
exit(EXIT_FAILURE);
} else if (!export_name) {
export_name = "";
}
qemu_opts_foreach(&qemu_object_opts,
user_creatable_add_opts_foreach,
NULL, &error_fatal);
if (!trace_init_backends()) {
exit(1);
}
trace_init_file(trace_file);
qemu_set_log(LOG_TRACE);
socket_activation = check_socket_activation();
if (socket_activation == 0) {
setup_address_and_port(&bindto, &port);
} else {
/* Using socket activation - check user didn't use -p etc. */
const char *err_msg = socket_activation_validate_opts(device, sockpath,
bindto, port,
list);
if (err_msg != NULL) {
error_report("%s", err_msg);
exit(EXIT_FAILURE);
}
/* qemu-nbd can only listen on a single socket. */
if (socket_activation > 1) {
error_report("qemu-nbd does not support socket activation with %s > 1",
"LISTEN_FDS");
exit(EXIT_FAILURE);
}
}
if (tlscredsid) {
if (sockpath) {
error_report("TLS is only supported with IPv4/IPv6");
exit(EXIT_FAILURE);
}
if (device) {
error_report("TLS is not supported with a host device");
exit(EXIT_FAILURE);
}
if (tlsauthz && list) {
error_report("TLS authorization is incompatible with export list");
exit(EXIT_FAILURE);
}
tlscreds = nbd_get_tls_creds(tlscredsid, list, &local_err);
if (local_err) {
error_report("Failed to get TLS creds %s",
error_get_pretty(local_err));
exit(EXIT_FAILURE);
}
} else {
if (tlsauthz) {
error_report("--tls-authz is not permitted without --tls-creds");
exit(EXIT_FAILURE);
}
}
if (list) {
saddr = nbd_build_socket_address(sockpath, bindto, port);
return qemu_nbd_client_list(saddr, tlscreds, bindto);
}
#if !HAVE_NBD_DEVICE
if (disconnect || device) {
error_report("Kernel /dev/nbdN support not available");
exit(EXIT_FAILURE);
}
#else /* HAVE_NBD_DEVICE */
if (disconnect) {
int nbdfd = open(argv[optind], O_RDWR);
if (nbdfd < 0) {
error_report("Cannot open %s: %s", argv[optind],
strerror(errno));
exit(EXIT_FAILURE);
}
nbd_disconnect(nbdfd);
close(nbdfd);
printf("%s disconnected\n", argv[optind]);
return 0;
}
#endif
if ((device && !verbose) || fork_process) {
int stderr_fd[2];
pid_t pid;
int ret;
if (qemu_pipe(stderr_fd) < 0) {
error_report("Error setting up communication pipe: %s",
strerror(errno));
exit(EXIT_FAILURE);
}
/* Now daemonize, but keep a communication channel open to
* print errors and exit with the proper status code.
*/
pid = fork();
if (pid < 0) {
error_report("Failed to fork: %s", strerror(errno));
exit(EXIT_FAILURE);
} else if (pid == 0) {
close(stderr_fd[0]);
old_stderr = dup(STDERR_FILENO);
ret = qemu_daemon(1, 0);
/* Temporarily redirect stderr to the parent's pipe... */
dup2(stderr_fd[1], STDERR_FILENO);
if (ret < 0) {
error_report("Failed to daemonize: %s", strerror(errno));
exit(EXIT_FAILURE);
}
/* ... close the descriptor we inherited and go on. */
close(stderr_fd[1]);
} else {
bool errors = false;
char *buf;
/* In the parent. Print error messages from the child until
* it closes the pipe.
*/
close(stderr_fd[1]);
buf = g_malloc(1024);
while ((ret = read(stderr_fd[0], buf, 1024)) > 0) {
errors = true;
ret = qemu_write_full(STDERR_FILENO, buf, ret);
if (ret < 0) {
exit(EXIT_FAILURE);
}
}
if (ret < 0) {
error_report("Cannot read from daemon: %s",
strerror(errno));
exit(EXIT_FAILURE);
}
/* Usually the daemon should not print any message.
* Exit with zero status in that case.
*/
exit(errors);
}
}
if (device != NULL && sockpath == NULL) {
sockpath = g_malloc(128);
snprintf(sockpath, 128, SOCKET_PATH, basename(device));
}
server = qio_net_listener_new();
if (socket_activation == 0) {
saddr = nbd_build_socket_address(sockpath, bindto, port);
if (qio_net_listener_open_sync(server, saddr, 1, &local_err) < 0) {
object_unref(OBJECT(server));
error_report_err(local_err);
exit(EXIT_FAILURE);
}
} else {
size_t i;
/* See comment in check_socket_activation above. */
for (i = 0; i < socket_activation; i++) {
QIOChannelSocket *sioc;
sioc = qio_channel_socket_new_fd(FIRST_SOCKET_ACTIVATION_FD + i,
&local_err);
if (sioc == NULL) {
object_unref(OBJECT(server));
error_report("Failed to use socket activation: %s",
error_get_pretty(local_err));
exit(EXIT_FAILURE);
}
qio_net_listener_add(server, sioc);
object_unref(OBJECT(sioc));
}
}
if (qemu_init_main_loop(&local_err)) {
error_report_err(local_err);
exit(EXIT_FAILURE);
}
bdrv_init();
atexit(qemu_nbd_shutdown);
srcpath = argv[optind];
if (imageOpts) {
QemuOpts *opts;
if (fmt) {
error_report("--image-opts and -f are mutually exclusive");
exit(EXIT_FAILURE);
}
opts = qemu_opts_parse_noisily(&file_opts, srcpath, true);
if (!opts) {
qemu_opts_reset(&file_opts);
exit(EXIT_FAILURE);
}
options = qemu_opts_to_qdict(opts, NULL);
qemu_opts_reset(&file_opts);
blk = blk_new_open(NULL, NULL, options, flags, &local_err);
} else {
if (fmt) {
options = qdict_new();
qdict_put_str(options, "driver", fmt);
}
blk = blk_new_open(srcpath, NULL, options, flags, &local_err);
}
if (!blk) {
error_reportf_err(local_err, "Failed to blk_new_open '%s': ",
argv[optind]);
exit(EXIT_FAILURE);
}
bs = blk_bs(blk);
blk_set_enable_write_cache(blk, !writethrough);
if (sn_opts) {
ret = bdrv_snapshot_load_tmp(bs,
qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
&local_err);
} else if (sn_id_or_name) {
ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name,
&local_err);
}
if (ret < 0) {
error_reportf_err(local_err, "Failed to load snapshot: ");
exit(EXIT_FAILURE);
}
bs->detect_zeroes = detect_zeroes;
fd_size = blk_getlength(blk);
if (fd_size < 0) {
error_report("Failed to determine the image length: %s",
strerror(-fd_size));
exit(EXIT_FAILURE);
}
if (dev_offset >= fd_size) {
error_report("Offset (%" PRIu64 ") has to be smaller than the image "
"size (%" PRId64 ")", dev_offset, fd_size);
exit(EXIT_FAILURE);
}
fd_size -= dev_offset;
if (partition) {
uint64_t limit;
if (dev_offset) {
error_report("Cannot request partition and offset together");
exit(EXIT_FAILURE);
}
ret = find_partition(blk, partition, &dev_offset, &limit);
if (ret < 0) {
error_report("Could not find partition %d: %s", partition,
strerror(-ret));
exit(EXIT_FAILURE);
}
/*
* MBR partition limits are (32-bit << 9); this assert lets
* the compiler know that we can't overflow 64 bits.
*/
assert(dev_offset + limit >= dev_offset);
if (dev_offset + limit > fd_size) {
error_report("Discovered partition %d at offset %" PRIu64
" size %" PRIu64 ", but size exceeds file length %"
PRId64, partition, dev_offset, limit, fd_size);
exit(EXIT_FAILURE);
}
fd_size = limit;
}
export = nbd_export_new(bs, dev_offset, fd_size, export_name,
export_description, bitmap, readonly, shared > 1,
nbd_export_closed, writethrough, NULL,
&error_fatal);
if (device) {
#if HAVE_NBD_DEVICE
int ret;
ret = pthread_create(&client_thread, NULL, nbd_client_thread, device);
if (ret != 0) {
error_report("Failed to create client thread: %s", strerror(ret));
exit(EXIT_FAILURE);
}
#endif
} else {
/* Shut up GCC warnings. */
memset(&client_thread, 0, sizeof(client_thread));
}
nbd_update_server_watch();
if (pid_file_name) {
qemu_write_pidfile(pid_file_name, &error_fatal);
}
/* now when the initialization is (almost) complete, chdir("/")
* to free any busy filesystems */
if (chdir("/") < 0) {
error_report("Could not chdir to root directory: %s",
strerror(errno));
exit(EXIT_FAILURE);
}
if (fork_process) {
dup2(old_stderr, STDERR_FILENO);
close(old_stderr);
}
state = RUNNING;
do {
main_loop_wait(false);
if (state == TERMINATE) {
state = TERMINATING;
nbd_export_close(export);
nbd_export_put(export);
export = NULL;
}
} while (state != TERMINATED);
blk_unref(blk);
if (sockpath) {
unlink(sockpath);
}
qemu_opts_del(sn_opts);
if (device) {
void *ret;
pthread_join(client_thread, &ret);
exit(ret != NULL);
} else {
exit(EXIT_SUCCESS);
}
}
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