qemu-e2k/qemu-io.c
Eric Blake 64ebf55648 qemu-io: Don't die on second open
Most callback commands in qemu-io return 0 to keep the interpreter
loop running, or 1 to quit immediately.  However, open_f() just
passed through the return value of openfile(), which has different
semantics of returning 0 if a file was opened, or 1 on any failure.

As a result of mixing the return semantics, we are forcing the
qemu-io interpreter to exit early on any failures, which is rather
annoying when some of the failures are obviously trying to give
the user a hint of how to proceed (if we didn't then kill qemu-io
out from under the user's feet):

$ qemu-io
qemu-io> open foo
qemu-io> open foo
file open already, try 'help close'
$ echo $?
0

In general, we WANT openfile() to report failures, since it is the
function used in the form 'qemu-io -c "$something" no_such_file'
for performing one or more -c options on a single file, and it is
not worth attempting $something if the file itself cannot be opened.
So the solution is to fix open_f() to always return 0 (when we are
in interactive mode, even failure to open should not end the
session), and save the return value of openfile() for command line
use in main().

Note, however, that we do have some qemu-iotests that do 'qemu-io
-c "open file" -c "$something"'; such tests will now proceed to
attempt $something whether or not the open succeeded, the same way
as if the two commands had been attempted in interactive mode.  As
such, the expected output for those tests has to be modified.  But it
also means that it is now possible to use -c close and have a single
qemu-io command line operate on more than one file even without
using interactive mode.  Although the '-c open' action is a subtle
change in behavior, remember that qemu-io is for debugging purposes,
so as long as it serves the needs of qemu-iotests while still being
reasonable for interactive use, it should not be a problem that we
are changing tests to the new behavior.

This has been awkward since at least as far back as commit
e3aff4f, in 2009.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-07-10 13:18:05 +02:00

649 lines
17 KiB
C

/*
* Command line utility to exercise the QEMU I/O path.
*
* Copyright (C) 2009 Red Hat, Inc.
* Copyright (c) 2003-2005 Silicon Graphics, Inc.
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include <getopt.h>
#include <libgen.h>
#include "qapi/error.h"
#include "qemu-io.h"
#include "qemu/error-report.h"
#include "qemu/main-loop.h"
#include "qemu/option.h"
#include "qemu/config-file.h"
#include "qemu/readline.h"
#include "qemu/log.h"
#include "qapi/qmp/qstring.h"
#include "qapi/qmp/qbool.h"
#include "qom/object_interfaces.h"
#include "sysemu/block-backend.h"
#include "block/block_int.h"
#include "trace/control.h"
#include "crypto/init.h"
#define CMD_NOFILE_OK 0x01
static char *progname;
static BlockBackend *qemuio_blk;
/* qemu-io commands passed using -c */
static int ncmdline;
static char **cmdline;
static bool imageOpts;
static ReadLineState *readline_state;
static int close_f(BlockBackend *blk, int argc, char **argv)
{
blk_unref(qemuio_blk);
qemuio_blk = NULL;
return 0;
}
static const cmdinfo_t close_cmd = {
.name = "close",
.altname = "c",
.cfunc = close_f,
.oneline = "close the current open file",
};
static int openfile(char *name, int flags, bool writethrough, bool force_share,
QDict *opts)
{
Error *local_err = NULL;
BlockDriverState *bs;
if (qemuio_blk) {
error_report("file open already, try 'help close'");
QDECREF(opts);
return 1;
}
if (force_share) {
if (!opts) {
opts = qdict_new();
}
if (qdict_haskey(opts, BDRV_OPT_FORCE_SHARE)
&& !qdict_get_bool(opts, BDRV_OPT_FORCE_SHARE)) {
error_report("-U conflicts with image options");
QDECREF(opts);
return 1;
}
qdict_put_bool(opts, BDRV_OPT_FORCE_SHARE, true);
}
qemuio_blk = blk_new_open(name, NULL, opts, flags, &local_err);
if (!qemuio_blk) {
error_reportf_err(local_err, "can't open%s%s: ",
name ? " device " : "", name ?: "");
return 1;
}
bs = blk_bs(qemuio_blk);
if (bdrv_is_encrypted(bs) && bdrv_key_required(bs)) {
char password[256];
printf("Disk image '%s' is encrypted.\n", name);
if (qemu_read_password(password, sizeof(password)) < 0) {
error_report("No password given");
goto error;
}
if (bdrv_set_key(bs, password) < 0) {
error_report("invalid password");
goto error;
}
}
blk_set_enable_write_cache(qemuio_blk, !writethrough);
return 0;
error:
blk_unref(qemuio_blk);
qemuio_blk = NULL;
return 1;
}
static void open_help(void)
{
printf(
"\n"
" opens a new file in the requested mode\n"
"\n"
" Example:\n"
" 'open -n -o driver=raw /tmp/data' - opens raw data file read-write, uncached\n"
"\n"
" Opens a file for subsequent use by all of the other qemu-io commands.\n"
" -r, -- open file read-only\n"
" -s, -- use snapshot file\n"
" -n, -- disable host cache, short for -t none\n"
" -U, -- force shared permissions\n"
" -k, -- use kernel AIO implementation (on Linux only)\n"
" -t, -- use the given cache mode for the image\n"
" -d, -- use the given discard mode for the image\n"
" -o, -- options to be given to the block driver"
"\n");
}
static int open_f(BlockBackend *blk, int argc, char **argv);
static const cmdinfo_t open_cmd = {
.name = "open",
.altname = "o",
.cfunc = open_f,
.argmin = 1,
.argmax = -1,
.flags = CMD_NOFILE_OK,
.args = "[-rsnkU] [-t cache] [-d discard] [-o options] [path]",
.oneline = "open the file specified by path",
.help = open_help,
};
static QemuOptsList empty_opts = {
.name = "drive",
.merge_lists = true,
.head = QTAILQ_HEAD_INITIALIZER(empty_opts.head),
.desc = {
/* no elements => accept any params */
{ /* end of list */ }
},
};
static int open_f(BlockBackend *blk, int argc, char **argv)
{
int flags = BDRV_O_UNMAP;
int readonly = 0;
bool writethrough = true;
int c;
QemuOpts *qopts;
QDict *opts;
bool force_share = false;
while ((c = getopt(argc, argv, "snro:kt:d:U")) != -1) {
switch (c) {
case 's':
flags |= BDRV_O_SNAPSHOT;
break;
case 'n':
flags |= BDRV_O_NOCACHE;
writethrough = false;
break;
case 'r':
readonly = 1;
break;
case 'k':
flags |= BDRV_O_NATIVE_AIO;
break;
case 't':
if (bdrv_parse_cache_mode(optarg, &flags, &writethrough) < 0) {
error_report("Invalid cache option: %s", optarg);
qemu_opts_reset(&empty_opts);
return 0;
}
break;
case 'd':
if (bdrv_parse_discard_flags(optarg, &flags) < 0) {
error_report("Invalid discard option: %s", optarg);
qemu_opts_reset(&empty_opts);
return 0;
}
break;
case 'o':
if (imageOpts) {
printf("--image-opts and 'open -o' are mutually exclusive\n");
qemu_opts_reset(&empty_opts);
return 0;
}
if (!qemu_opts_parse_noisily(&empty_opts, optarg, false)) {
qemu_opts_reset(&empty_opts);
return 0;
}
break;
case 'U':
force_share = true;
break;
default:
qemu_opts_reset(&empty_opts);
return qemuio_command_usage(&open_cmd);
}
}
if (!readonly) {
flags |= BDRV_O_RDWR;
}
if (imageOpts && (optind == argc - 1)) {
if (!qemu_opts_parse_noisily(&empty_opts, argv[optind], false)) {
qemu_opts_reset(&empty_opts);
return 0;
}
optind++;
}
qopts = qemu_opts_find(&empty_opts, NULL);
opts = qopts ? qemu_opts_to_qdict(qopts, NULL) : NULL;
qemu_opts_reset(&empty_opts);
if (optind == argc - 1) {
openfile(argv[optind], flags, writethrough, force_share, opts);
} else if (optind == argc) {
openfile(NULL, flags, writethrough, force_share, opts);
} else {
QDECREF(opts);
qemuio_command_usage(&open_cmd);
}
return 0;
}
static int quit_f(BlockBackend *blk, int argc, char **argv)
{
return 1;
}
static const cmdinfo_t quit_cmd = {
.name = "quit",
.altname = "q",
.cfunc = quit_f,
.argmin = -1,
.argmax = -1,
.flags = CMD_FLAG_GLOBAL,
.oneline = "exit the program",
};
static void usage(const char *name)
{
printf(
"Usage: %s [OPTIONS]... [-c STRING]... [file]\n"
"QEMU Disk exerciser\n"
"\n"
" --object OBJECTDEF define an object such as 'secret' for\n"
" passwords and/or encryption keys\n"
" --image-opts treat file as option string\n"
" -c, --cmd STRING execute command with its arguments\n"
" from the given string\n"
" -f, --format FMT specifies the block driver to use\n"
" -r, --read-only export read-only\n"
" -s, --snapshot use snapshot file\n"
" -n, --nocache disable host cache, short for -t none\n"
" -m, --misalign misalign allocations for O_DIRECT\n"
" -k, --native-aio use kernel AIO implementation (on Linux only)\n"
" -t, --cache=MODE use the given cache mode for the image\n"
" -d, --discard=MODE use the given discard mode for the image\n"
" -T, --trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
" specify tracing options\n"
" see qemu-img(1) man page for full description\n"
" -U, --force-share force shared permissions\n"
" -h, --help display this help and exit\n"
" -V, --version output version information and exit\n"
"\n"
"See '%s -c help' for information on available commands."
"\n",
name, name);
}
static char *get_prompt(void)
{
static char prompt[FILENAME_MAX + 2 /*"> "*/ + 1 /*"\0"*/ ];
if (!prompt[0]) {
snprintf(prompt, sizeof(prompt), "%s> ", progname);
}
return prompt;
}
static void GCC_FMT_ATTR(2, 3) readline_printf_func(void *opaque,
const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
vprintf(fmt, ap);
va_end(ap);
}
static void readline_flush_func(void *opaque)
{
fflush(stdout);
}
static void readline_func(void *opaque, const char *str, void *readline_opaque)
{
char **line = readline_opaque;
*line = g_strdup(str);
}
static void completion_match(const char *cmd, void *opaque)
{
readline_add_completion(readline_state, cmd);
}
static void readline_completion_func(void *opaque, const char *str)
{
readline_set_completion_index(readline_state, strlen(str));
qemuio_complete_command(str, completion_match, NULL);
}
static char *fetchline_readline(void)
{
char *line = NULL;
readline_start(readline_state, get_prompt(), 0, readline_func, &line);
while (!line) {
int ch = getchar();
if (ch == EOF) {
break;
}
readline_handle_byte(readline_state, ch);
}
return line;
}
#define MAXREADLINESZ 1024
static char *fetchline_fgets(void)
{
char *p, *line = g_malloc(MAXREADLINESZ);
if (!fgets(line, MAXREADLINESZ, stdin)) {
g_free(line);
return NULL;
}
p = line + strlen(line);
if (p != line && p[-1] == '\n') {
p[-1] = '\0';
}
return line;
}
static char *fetchline(void)
{
if (readline_state) {
return fetchline_readline();
} else {
return fetchline_fgets();
}
}
static void prep_fetchline(void *opaque)
{
int *fetchable = opaque;
qemu_set_fd_handler(STDIN_FILENO, NULL, NULL, NULL);
*fetchable= 1;
}
static void command_loop(void)
{
int i, done = 0, fetchable = 0, prompted = 0;
char *input;
for (i = 0; !done && i < ncmdline; i++) {
done = qemuio_command(qemuio_blk, cmdline[i]);
}
if (cmdline) {
g_free(cmdline);
return;
}
while (!done) {
if (!prompted) {
printf("%s", get_prompt());
fflush(stdout);
qemu_set_fd_handler(STDIN_FILENO, prep_fetchline, NULL, &fetchable);
prompted = 1;
}
main_loop_wait(false);
if (!fetchable) {
continue;
}
input = fetchline();
if (input == NULL) {
break;
}
done = qemuio_command(qemuio_blk, input);
g_free(input);
prompted = 0;
fetchable = 0;
}
qemu_set_fd_handler(STDIN_FILENO, NULL, NULL, NULL);
}
static void add_user_command(char *optarg)
{
cmdline = g_renew(char *, cmdline, ++ncmdline);
cmdline[ncmdline-1] = optarg;
}
static void reenable_tty_echo(void)
{
qemu_set_tty_echo(STDIN_FILENO, true);
}
enum {
OPTION_OBJECT = 256,
OPTION_IMAGE_OPTS = 257,
};
static QemuOptsList qemu_object_opts = {
.name = "object",
.implied_opt_name = "qom-type",
.head = QTAILQ_HEAD_INITIALIZER(qemu_object_opts.head),
.desc = {
{ }
},
};
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 */ }
},
};
int main(int argc, char **argv)
{
int readonly = 0;
const char *sopt = "hVc:d:f:rsnmkt:T:U";
const struct option lopt[] = {
{ "help", no_argument, NULL, 'h' },
{ "version", no_argument, NULL, 'V' },
{ "cmd", required_argument, NULL, 'c' },
{ "format", required_argument, NULL, 'f' },
{ "read-only", no_argument, NULL, 'r' },
{ "snapshot", no_argument, NULL, 's' },
{ "nocache", no_argument, NULL, 'n' },
{ "misalign", no_argument, NULL, 'm' },
{ "native-aio", no_argument, NULL, 'k' },
{ "discard", required_argument, NULL, 'd' },
{ "cache", required_argument, NULL, 't' },
{ "trace", required_argument, NULL, 'T' },
{ "object", required_argument, NULL, OPTION_OBJECT },
{ "image-opts", no_argument, NULL, OPTION_IMAGE_OPTS },
{ "force-share", no_argument, 0, 'U'},
{ NULL, 0, NULL, 0 }
};
int c;
int opt_index = 0;
int flags = BDRV_O_UNMAP;
bool writethrough = true;
Error *local_error = NULL;
QDict *opts = NULL;
const char *format = NULL;
char *trace_file = NULL;
bool force_share = false;
#ifdef CONFIG_POSIX
signal(SIGPIPE, SIG_IGN);
#endif
module_call_init(MODULE_INIT_TRACE);
progname = basename(argv[0]);
qemu_init_exec_dir(argv[0]);
qcrypto_init(&error_fatal);
module_call_init(MODULE_INIT_QOM);
qemu_add_opts(&qemu_object_opts);
qemu_add_opts(&qemu_trace_opts);
bdrv_init();
while ((c = getopt_long(argc, argv, sopt, lopt, &opt_index)) != -1) {
switch (c) {
case 's':
flags |= BDRV_O_SNAPSHOT;
break;
case 'n':
flags |= BDRV_O_NOCACHE;
writethrough = false;
break;
case 'd':
if (bdrv_parse_discard_flags(optarg, &flags) < 0) {
error_report("Invalid discard option: %s", optarg);
exit(1);
}
break;
case 'f':
format = optarg;
break;
case 'c':
add_user_command(optarg);
break;
case 'r':
readonly = 1;
break;
case 'm':
qemuio_misalign = true;
break;
case 'k':
flags |= BDRV_O_NATIVE_AIO;
break;
case 't':
if (bdrv_parse_cache_mode(optarg, &flags, &writethrough) < 0) {
error_report("Invalid cache option: %s", optarg);
exit(1);
}
break;
case 'T':
g_free(trace_file);
trace_file = trace_opt_parse(optarg);
break;
case 'V':
printf("%s version %s\n", progname, QEMU_VERSION);
exit(0);
case 'h':
usage(progname);
exit(0);
case 'U':
force_share = true;
break;
case OPTION_OBJECT: {
QemuOpts *qopts;
qopts = qemu_opts_parse_noisily(&qemu_object_opts,
optarg, true);
if (!qopts) {
exit(1);
}
} break;
case OPTION_IMAGE_OPTS:
imageOpts = true;
break;
default:
usage(progname);
exit(1);
}
}
if ((argc - optind) > 1) {
usage(progname);
exit(1);
}
if (format && imageOpts) {
error_report("--image-opts and -f are mutually exclusive");
exit(1);
}
if (qemu_init_main_loop(&local_error)) {
error_report_err(local_error);
exit(1);
}
if (qemu_opts_foreach(&qemu_object_opts,
user_creatable_add_opts_foreach,
NULL, NULL)) {
exit(1);
}
if (!trace_init_backends()) {
exit(1);
}
trace_init_file(trace_file);
qemu_set_log(LOG_TRACE);
/* initialize commands */
qemuio_add_command(&quit_cmd);
qemuio_add_command(&open_cmd);
qemuio_add_command(&close_cmd);
if (isatty(STDIN_FILENO)) {
readline_state = readline_init(readline_printf_func,
readline_flush_func,
NULL,
readline_completion_func);
qemu_set_tty_echo(STDIN_FILENO, false);
atexit(reenable_tty_echo);
}
/* open the device */
if (!readonly) {
flags |= BDRV_O_RDWR;
}
if ((argc - optind) == 1) {
if (imageOpts) {
QemuOpts *qopts = NULL;
qopts = qemu_opts_parse_noisily(&file_opts, argv[optind], false);
if (!qopts) {
exit(1);
}
opts = qemu_opts_to_qdict(qopts, NULL);
if (openfile(NULL, flags, writethrough, force_share, opts)) {
exit(1);
}
} else {
if (format) {
opts = qdict_new();
qdict_put_str(opts, "driver", format);
}
if (openfile(argv[optind], flags, writethrough,
force_share, opts)) {
exit(1);
}
}
}
command_loop();
/*
* Make sure all outstanding requests complete before the program exits.
*/
bdrv_drain_all();
blk_unref(qemuio_blk);
g_free(readline_state);
return 0;
}