xref: /openbmc/qemu/qemu-img.c (revision 90bda082)
1 /*
2  * QEMU disk image utility
3  *
4  * Copyright (c) 2003-2008 Fabrice Bellard
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 #include "qapi-visit.h"
25 #include "qapi/qmp-output-visitor.h"
26 #include "qapi/qmp/qjson.h"
27 #include "qemu-common.h"
28 #include "qemu/option.h"
29 #include "qemu/error-report.h"
30 #include "qemu/osdep.h"
31 #include "sysemu/sysemu.h"
32 #include "block/block_int.h"
33 #include "block/qapi.h"
34 #include <getopt.h>
35 #include <glib.h>
36 
37 #define QEMU_IMG_VERSION "qemu-img version " QEMU_VERSION \
38                           ", Copyright (c) 2004-2008 Fabrice Bellard\n"
39 
40 typedef struct img_cmd_t {
41     const char *name;
42     int (*handler)(int argc, char **argv);
43 } img_cmd_t;
44 
45 enum {
46     OPTION_OUTPUT = 256,
47     OPTION_BACKING_CHAIN = 257,
48 };
49 
50 typedef enum OutputFormat {
51     OFORMAT_JSON,
52     OFORMAT_HUMAN,
53 } OutputFormat;
54 
55 /* Default to cache=writeback as data integrity is not important for qemu-tcg. */
56 #define BDRV_O_FLAGS BDRV_O_CACHE_WB
57 #define BDRV_DEFAULT_CACHE "writeback"
58 
59 static gint compare_data(gconstpointer a, gconstpointer b, gpointer user)
60 {
61     return g_strcmp0(a, b);
62 }
63 
64 static void print_format(gpointer data, gpointer user)
65 {
66     printf(" %s", (char *)data);
67 }
68 
69 static void add_format_to_seq(void *opaque, const char *fmt_name)
70 {
71     GSequence *seq = opaque;
72 
73     g_sequence_insert_sorted(seq, (gpointer)fmt_name,
74                              compare_data, NULL);
75 }
76 
77 static void QEMU_NORETURN GCC_FMT_ATTR(1, 2) error_exit(const char *fmt, ...)
78 {
79     va_list ap;
80 
81     error_printf("qemu-img: ");
82 
83     va_start(ap, fmt);
84     error_vprintf(fmt, ap);
85     va_end(ap);
86 
87     error_printf("\nTry 'qemu-img --help' for more information\n");
88     exit(EXIT_FAILURE);
89 }
90 
91 /* Please keep in synch with qemu-img.texi */
92 static void QEMU_NORETURN help(void)
93 {
94     const char *help_msg =
95            QEMU_IMG_VERSION
96            "usage: qemu-img command [command options]\n"
97            "QEMU disk image utility\n"
98            "\n"
99            "Command syntax:\n"
100 #define DEF(option, callback, arg_string)        \
101            "  " arg_string "\n"
102 #include "qemu-img-cmds.h"
103 #undef DEF
104 #undef GEN_DOCS
105            "\n"
106            "Command parameters:\n"
107            "  'filename' is a disk image filename\n"
108            "  'fmt' is the disk image format. It is guessed automatically in most cases\n"
109            "  'cache' is the cache mode used to write the output disk image, the valid\n"
110            "    options are: 'none', 'writeback' (default, except for convert), 'writethrough',\n"
111            "    'directsync' and 'unsafe' (default for convert)\n"
112            "  'size' is the disk image size in bytes. Optional suffixes\n"
113            "    'k' or 'K' (kilobyte, 1024), 'M' (megabyte, 1024k), 'G' (gigabyte, 1024M),\n"
114            "    'T' (terabyte, 1024G), 'P' (petabyte, 1024T) and 'E' (exabyte, 1024P)  are\n"
115            "    supported. 'b' is ignored.\n"
116            "  'output_filename' is the destination disk image filename\n"
117            "  'output_fmt' is the destination format\n"
118            "  'options' is a comma separated list of format specific options in a\n"
119            "    name=value format. Use -o ? for an overview of the options supported by the\n"
120            "    used format\n"
121            "  'snapshot_param' is param used for internal snapshot, format\n"
122            "    is 'snapshot.id=[ID],snapshot.name=[NAME]', or\n"
123            "    '[ID_OR_NAME]'\n"
124            "  'snapshot_id_or_name' is deprecated, use 'snapshot_param'\n"
125            "    instead\n"
126            "  '-c' indicates that target image must be compressed (qcow format only)\n"
127            "  '-u' enables unsafe rebasing. It is assumed that old and new backing file\n"
128            "       match exactly. The image doesn't need a working backing file before\n"
129            "       rebasing in this case (useful for renaming the backing file)\n"
130            "  '-h' with or without a command shows this help and lists the supported formats\n"
131            "  '-p' show progress of command (only certain commands)\n"
132            "  '-q' use Quiet mode - do not print any output (except errors)\n"
133            "  '-S' indicates the consecutive number of bytes (defaults to 4k) that must\n"
134            "       contain only zeros for qemu-img to create a sparse image during\n"
135            "       conversion. If the number of bytes is 0, the source will not be scanned for\n"
136            "       unallocated or zero sectors, and the destination image will always be\n"
137            "       fully allocated\n"
138            "  '--output' takes the format in which the output must be done (human or json)\n"
139            "  '-n' skips the target volume creation (useful if the volume is created\n"
140            "       prior to running qemu-img)\n"
141            "\n"
142            "Parameters to check subcommand:\n"
143            "  '-r' tries to repair any inconsistencies that are found during the check.\n"
144            "       '-r leaks' repairs only cluster leaks, whereas '-r all' fixes all\n"
145            "       kinds of errors, with a higher risk of choosing the wrong fix or\n"
146            "       hiding corruption that has already occurred.\n"
147            "\n"
148            "Parameters to snapshot subcommand:\n"
149            "  'snapshot' is the name of the snapshot to create, apply or delete\n"
150            "  '-a' applies a snapshot (revert disk to saved state)\n"
151            "  '-c' creates a snapshot\n"
152            "  '-d' deletes a snapshot\n"
153            "  '-l' lists all snapshots in the given image\n"
154            "\n"
155            "Parameters to compare subcommand:\n"
156            "  '-f' first image format\n"
157            "  '-F' second image format\n"
158            "  '-s' run in Strict mode - fail on different image size or sector allocation\n";
159     GSequence *seq;
160 
161     printf("%s\nSupported formats:", help_msg);
162     seq = g_sequence_new(NULL);
163     bdrv_iterate_format(add_format_to_seq, seq);
164     g_sequence_foreach(seq, print_format, NULL);
165     printf("\n");
166     g_sequence_free(seq);
167 
168     exit(EXIT_SUCCESS);
169 }
170 
171 static int GCC_FMT_ATTR(2, 3) qprintf(bool quiet, const char *fmt, ...)
172 {
173     int ret = 0;
174     if (!quiet) {
175         va_list args;
176         va_start(args, fmt);
177         ret = vprintf(fmt, args);
178         va_end(args);
179     }
180     return ret;
181 }
182 
183 #if defined(WIN32)
184 /* XXX: put correct support for win32 */
185 static int read_password(char *buf, int buf_size)
186 {
187     int c, i;
188 
189     printf("Password: ");
190     fflush(stdout);
191     i = 0;
192     for(;;) {
193         c = getchar();
194         if (c < 0) {
195             buf[i] = '\0';
196             return -1;
197         } else if (c == '\n') {
198             break;
199         } else if (i < (buf_size - 1)) {
200             buf[i++] = c;
201         }
202     }
203     buf[i] = '\0';
204     return 0;
205 }
206 
207 #else
208 
209 #include <termios.h>
210 
211 static struct termios oldtty;
212 
213 static void term_exit(void)
214 {
215     tcsetattr (0, TCSANOW, &oldtty);
216 }
217 
218 static void term_init(void)
219 {
220     struct termios tty;
221 
222     tcgetattr (0, &tty);
223     oldtty = tty;
224 
225     tty.c_iflag &= ~(IGNBRK|BRKINT|PARMRK|ISTRIP
226                           |INLCR|IGNCR|ICRNL|IXON);
227     tty.c_oflag |= OPOST;
228     tty.c_lflag &= ~(ECHO|ECHONL|ICANON|IEXTEN);
229     tty.c_cflag &= ~(CSIZE|PARENB);
230     tty.c_cflag |= CS8;
231     tty.c_cc[VMIN] = 1;
232     tty.c_cc[VTIME] = 0;
233 
234     tcsetattr (0, TCSANOW, &tty);
235 
236     atexit(term_exit);
237 }
238 
239 static int read_password(char *buf, int buf_size)
240 {
241     uint8_t ch;
242     int i, ret;
243 
244     printf("password: ");
245     fflush(stdout);
246     term_init();
247     i = 0;
248     for(;;) {
249         ret = read(0, &ch, 1);
250         if (ret == -1) {
251             if (errno == EAGAIN || errno == EINTR) {
252                 continue;
253             } else {
254                 break;
255             }
256         } else if (ret == 0) {
257             ret = -1;
258             break;
259         } else {
260             if (ch == '\r') {
261                 ret = 0;
262                 break;
263             }
264             if (i < (buf_size - 1))
265                 buf[i++] = ch;
266         }
267     }
268     term_exit();
269     buf[i] = '\0';
270     printf("\n");
271     return ret;
272 }
273 #endif
274 
275 static int print_block_option_help(const char *filename, const char *fmt)
276 {
277     BlockDriver *drv, *proto_drv;
278     QemuOptsList *create_opts = NULL;
279 
280     /* Find driver and parse its options */
281     drv = bdrv_find_format(fmt);
282     if (!drv) {
283         error_report("Unknown file format '%s'", fmt);
284         return 1;
285     }
286 
287     create_opts = qemu_opts_append(create_opts, drv->create_opts);
288     if (filename) {
289         proto_drv = bdrv_find_protocol(filename, true);
290         if (!proto_drv) {
291             error_report("Unknown protocol '%s'", filename);
292             qemu_opts_free(create_opts);
293             return 1;
294         }
295         create_opts = qemu_opts_append(create_opts, proto_drv->create_opts);
296     }
297 
298     qemu_opts_print_help(create_opts);
299     qemu_opts_free(create_opts);
300     return 0;
301 }
302 
303 static BlockDriverState *bdrv_new_open(const char *id,
304                                        const char *filename,
305                                        const char *fmt,
306                                        int flags,
307                                        bool require_io,
308                                        bool quiet)
309 {
310     BlockDriverState *bs;
311     BlockDriver *drv;
312     char password[256];
313     Error *local_err = NULL;
314     int ret;
315 
316     bs = bdrv_new(id, &error_abort);
317 
318     if (fmt) {
319         drv = bdrv_find_format(fmt);
320         if (!drv) {
321             error_report("Unknown file format '%s'", fmt);
322             goto fail;
323         }
324     } else {
325         drv = NULL;
326     }
327 
328     ret = bdrv_open(&bs, filename, NULL, NULL, flags, drv, &local_err);
329     if (ret < 0) {
330         error_report("Could not open '%s': %s", filename,
331                      error_get_pretty(local_err));
332         error_free(local_err);
333         goto fail;
334     }
335 
336     if (bdrv_is_encrypted(bs) && require_io) {
337         qprintf(quiet, "Disk image '%s' is encrypted.\n", filename);
338         if (read_password(password, sizeof(password)) < 0) {
339             error_report("No password given");
340             goto fail;
341         }
342         if (bdrv_set_key(bs, password) < 0) {
343             error_report("invalid password");
344             goto fail;
345         }
346     }
347     return bs;
348 fail:
349     bdrv_unref(bs);
350     return NULL;
351 }
352 
353 static int add_old_style_options(const char *fmt, QemuOpts *opts,
354                                  const char *base_filename,
355                                  const char *base_fmt)
356 {
357     if (base_filename) {
358         if (qemu_opt_set(opts, BLOCK_OPT_BACKING_FILE, base_filename)) {
359             error_report("Backing file not supported for file format '%s'",
360                          fmt);
361             return -1;
362         }
363     }
364     if (base_fmt) {
365         if (qemu_opt_set(opts, BLOCK_OPT_BACKING_FMT, base_fmt)) {
366             error_report("Backing file format not supported for file "
367                          "format '%s'", fmt);
368             return -1;
369         }
370     }
371     return 0;
372 }
373 
374 static int img_create(int argc, char **argv)
375 {
376     int c;
377     uint64_t img_size = -1;
378     const char *fmt = "raw";
379     const char *base_fmt = NULL;
380     const char *filename;
381     const char *base_filename = NULL;
382     char *options = NULL;
383     Error *local_err = NULL;
384     bool quiet = false;
385 
386     for(;;) {
387         c = getopt(argc, argv, "F:b:f:he6o:q");
388         if (c == -1) {
389             break;
390         }
391         switch(c) {
392         case '?':
393         case 'h':
394             help();
395             break;
396         case 'F':
397             base_fmt = optarg;
398             break;
399         case 'b':
400             base_filename = optarg;
401             break;
402         case 'f':
403             fmt = optarg;
404             break;
405         case 'e':
406             error_report("option -e is deprecated, please use \'-o "
407                   "encryption\' instead!");
408             goto fail;
409         case '6':
410             error_report("option -6 is deprecated, please use \'-o "
411                   "compat6\' instead!");
412             goto fail;
413         case 'o':
414             if (!is_valid_option_list(optarg)) {
415                 error_report("Invalid option list: %s", optarg);
416                 goto fail;
417             }
418             if (!options) {
419                 options = g_strdup(optarg);
420             } else {
421                 char *old_options = options;
422                 options = g_strdup_printf("%s,%s", options, optarg);
423                 g_free(old_options);
424             }
425             break;
426         case 'q':
427             quiet = true;
428             break;
429         }
430     }
431 
432     /* Get the filename */
433     filename = (optind < argc) ? argv[optind] : NULL;
434     if (options && has_help_option(options)) {
435         g_free(options);
436         return print_block_option_help(filename, fmt);
437     }
438 
439     if (optind >= argc) {
440         error_exit("Expecting image file name");
441     }
442     optind++;
443 
444     /* Get image size, if specified */
445     if (optind < argc) {
446         int64_t sval;
447         char *end;
448         sval = strtosz_suffix(argv[optind++], &end, STRTOSZ_DEFSUFFIX_B);
449         if (sval < 0 || *end) {
450             if (sval == -ERANGE) {
451                 error_report("Image size must be less than 8 EiB!");
452             } else {
453                 error_report("Invalid image size specified! You may use k, M, "
454                       "G, T, P or E suffixes for ");
455                 error_report("kilobytes, megabytes, gigabytes, terabytes, "
456                              "petabytes and exabytes.");
457             }
458             goto fail;
459         }
460         img_size = (uint64_t)sval;
461     }
462     if (optind != argc) {
463         error_exit("Unexpected argument: %s", argv[optind]);
464     }
465 
466     bdrv_img_create(filename, fmt, base_filename, base_fmt,
467                     options, img_size, BDRV_O_FLAGS, &local_err, quiet);
468     if (local_err) {
469         error_report("%s: %s", filename, error_get_pretty(local_err));
470         error_free(local_err);
471         goto fail;
472     }
473 
474     g_free(options);
475     return 0;
476 
477 fail:
478     g_free(options);
479     return 1;
480 }
481 
482 static void dump_json_image_check(ImageCheck *check, bool quiet)
483 {
484     Error *local_err = NULL;
485     QString *str;
486     QmpOutputVisitor *ov = qmp_output_visitor_new();
487     QObject *obj;
488     visit_type_ImageCheck(qmp_output_get_visitor(ov),
489                           &check, NULL, &local_err);
490     obj = qmp_output_get_qobject(ov);
491     str = qobject_to_json_pretty(obj);
492     assert(str != NULL);
493     qprintf(quiet, "%s\n", qstring_get_str(str));
494     qobject_decref(obj);
495     qmp_output_visitor_cleanup(ov);
496     QDECREF(str);
497 }
498 
499 static void dump_human_image_check(ImageCheck *check, bool quiet)
500 {
501     if (!(check->corruptions || check->leaks || check->check_errors)) {
502         qprintf(quiet, "No errors were found on the image.\n");
503     } else {
504         if (check->corruptions) {
505             qprintf(quiet, "\n%" PRId64 " errors were found on the image.\n"
506                     "Data may be corrupted, or further writes to the image "
507                     "may corrupt it.\n",
508                     check->corruptions);
509         }
510 
511         if (check->leaks) {
512             qprintf(quiet,
513                     "\n%" PRId64 " leaked clusters were found on the image.\n"
514                     "This means waste of disk space, but no harm to data.\n",
515                     check->leaks);
516         }
517 
518         if (check->check_errors) {
519             qprintf(quiet,
520                     "\n%" PRId64
521                     " internal errors have occurred during the check.\n",
522                     check->check_errors);
523         }
524     }
525 
526     if (check->total_clusters != 0 && check->allocated_clusters != 0) {
527         qprintf(quiet, "%" PRId64 "/%" PRId64 " = %0.2f%% allocated, "
528                 "%0.2f%% fragmented, %0.2f%% compressed clusters\n",
529                 check->allocated_clusters, check->total_clusters,
530                 check->allocated_clusters * 100.0 / check->total_clusters,
531                 check->fragmented_clusters * 100.0 / check->allocated_clusters,
532                 check->compressed_clusters * 100.0 /
533                 check->allocated_clusters);
534     }
535 
536     if (check->image_end_offset) {
537         qprintf(quiet,
538                 "Image end offset: %" PRId64 "\n", check->image_end_offset);
539     }
540 }
541 
542 static int collect_image_check(BlockDriverState *bs,
543                    ImageCheck *check,
544                    const char *filename,
545                    const char *fmt,
546                    int fix)
547 {
548     int ret;
549     BdrvCheckResult result;
550 
551     ret = bdrv_check(bs, &result, fix);
552     if (ret < 0) {
553         return ret;
554     }
555 
556     check->filename                 = g_strdup(filename);
557     check->format                   = g_strdup(bdrv_get_format_name(bs));
558     check->check_errors             = result.check_errors;
559     check->corruptions              = result.corruptions;
560     check->has_corruptions          = result.corruptions != 0;
561     check->leaks                    = result.leaks;
562     check->has_leaks                = result.leaks != 0;
563     check->corruptions_fixed        = result.corruptions_fixed;
564     check->has_corruptions_fixed    = result.corruptions != 0;
565     check->leaks_fixed              = result.leaks_fixed;
566     check->has_leaks_fixed          = result.leaks != 0;
567     check->image_end_offset         = result.image_end_offset;
568     check->has_image_end_offset     = result.image_end_offset != 0;
569     check->total_clusters           = result.bfi.total_clusters;
570     check->has_total_clusters       = result.bfi.total_clusters != 0;
571     check->allocated_clusters       = result.bfi.allocated_clusters;
572     check->has_allocated_clusters   = result.bfi.allocated_clusters != 0;
573     check->fragmented_clusters      = result.bfi.fragmented_clusters;
574     check->has_fragmented_clusters  = result.bfi.fragmented_clusters != 0;
575     check->compressed_clusters      = result.bfi.compressed_clusters;
576     check->has_compressed_clusters  = result.bfi.compressed_clusters != 0;
577 
578     return 0;
579 }
580 
581 /*
582  * Checks an image for consistency. Exit codes:
583  *
584  *  0 - Check completed, image is good
585  *  1 - Check not completed because of internal errors
586  *  2 - Check completed, image is corrupted
587  *  3 - Check completed, image has leaked clusters, but is good otherwise
588  * 63 - Checks are not supported by the image format
589  */
590 static int img_check(int argc, char **argv)
591 {
592     int c, ret;
593     OutputFormat output_format = OFORMAT_HUMAN;
594     const char *filename, *fmt, *output;
595     BlockDriverState *bs;
596     int fix = 0;
597     int flags = BDRV_O_FLAGS | BDRV_O_CHECK;
598     ImageCheck *check;
599     bool quiet = false;
600 
601     fmt = NULL;
602     output = NULL;
603     for(;;) {
604         int option_index = 0;
605         static const struct option long_options[] = {
606             {"help", no_argument, 0, 'h'},
607             {"format", required_argument, 0, 'f'},
608             {"repair", required_argument, 0, 'r'},
609             {"output", required_argument, 0, OPTION_OUTPUT},
610             {0, 0, 0, 0}
611         };
612         c = getopt_long(argc, argv, "f:hr:q",
613                         long_options, &option_index);
614         if (c == -1) {
615             break;
616         }
617         switch(c) {
618         case '?':
619         case 'h':
620             help();
621             break;
622         case 'f':
623             fmt = optarg;
624             break;
625         case 'r':
626             flags |= BDRV_O_RDWR;
627 
628             if (!strcmp(optarg, "leaks")) {
629                 fix = BDRV_FIX_LEAKS;
630             } else if (!strcmp(optarg, "all")) {
631                 fix = BDRV_FIX_LEAKS | BDRV_FIX_ERRORS;
632             } else {
633                 error_exit("Unknown option value for -r "
634                            "(expecting 'leaks' or 'all'): %s", optarg);
635             }
636             break;
637         case OPTION_OUTPUT:
638             output = optarg;
639             break;
640         case 'q':
641             quiet = true;
642             break;
643         }
644     }
645     if (optind != argc - 1) {
646         error_exit("Expecting one image file name");
647     }
648     filename = argv[optind++];
649 
650     if (output && !strcmp(output, "json")) {
651         output_format = OFORMAT_JSON;
652     } else if (output && !strcmp(output, "human")) {
653         output_format = OFORMAT_HUMAN;
654     } else if (output) {
655         error_report("--output must be used with human or json as argument.");
656         return 1;
657     }
658 
659     bs = bdrv_new_open("image", filename, fmt, flags, true, quiet);
660     if (!bs) {
661         return 1;
662     }
663 
664     check = g_new0(ImageCheck, 1);
665     ret = collect_image_check(bs, check, filename, fmt, fix);
666 
667     if (ret == -ENOTSUP) {
668         error_report("This image format does not support checks");
669         ret = 63;
670         goto fail;
671     }
672 
673     if (check->corruptions_fixed || check->leaks_fixed) {
674         int corruptions_fixed, leaks_fixed;
675 
676         leaks_fixed         = check->leaks_fixed;
677         corruptions_fixed   = check->corruptions_fixed;
678 
679         if (output_format == OFORMAT_HUMAN) {
680             qprintf(quiet,
681                     "The following inconsistencies were found and repaired:\n\n"
682                     "    %" PRId64 " leaked clusters\n"
683                     "    %" PRId64 " corruptions\n\n"
684                     "Double checking the fixed image now...\n",
685                     check->leaks_fixed,
686                     check->corruptions_fixed);
687         }
688 
689         ret = collect_image_check(bs, check, filename, fmt, 0);
690 
691         check->leaks_fixed          = leaks_fixed;
692         check->corruptions_fixed    = corruptions_fixed;
693     }
694 
695     switch (output_format) {
696     case OFORMAT_HUMAN:
697         dump_human_image_check(check, quiet);
698         break;
699     case OFORMAT_JSON:
700         dump_json_image_check(check, quiet);
701         break;
702     }
703 
704     if (ret || check->check_errors) {
705         ret = 1;
706         goto fail;
707     }
708 
709     if (check->corruptions) {
710         ret = 2;
711     } else if (check->leaks) {
712         ret = 3;
713     } else {
714         ret = 0;
715     }
716 
717 fail:
718     qapi_free_ImageCheck(check);
719     bdrv_unref(bs);
720 
721     return ret;
722 }
723 
724 static int img_commit(int argc, char **argv)
725 {
726     int c, ret, flags;
727     const char *filename, *fmt, *cache;
728     BlockDriverState *bs;
729     bool quiet = false;
730 
731     fmt = NULL;
732     cache = BDRV_DEFAULT_CACHE;
733     for(;;) {
734         c = getopt(argc, argv, "f:ht:q");
735         if (c == -1) {
736             break;
737         }
738         switch(c) {
739         case '?':
740         case 'h':
741             help();
742             break;
743         case 'f':
744             fmt = optarg;
745             break;
746         case 't':
747             cache = optarg;
748             break;
749         case 'q':
750             quiet = true;
751             break;
752         }
753     }
754     if (optind != argc - 1) {
755         error_exit("Expecting one image file name");
756     }
757     filename = argv[optind++];
758 
759     flags = BDRV_O_RDWR;
760     ret = bdrv_parse_cache_flags(cache, &flags);
761     if (ret < 0) {
762         error_report("Invalid cache option: %s", cache);
763         return -1;
764     }
765 
766     bs = bdrv_new_open("image", filename, fmt, flags, true, quiet);
767     if (!bs) {
768         return 1;
769     }
770     ret = bdrv_commit(bs);
771     switch(ret) {
772     case 0:
773         qprintf(quiet, "Image committed.\n");
774         break;
775     case -ENOENT:
776         error_report("No disk inserted");
777         break;
778     case -EACCES:
779         error_report("Image is read-only");
780         break;
781     case -ENOTSUP:
782         error_report("Image is already committed");
783         break;
784     default:
785         error_report("Error while committing image");
786         break;
787     }
788 
789     bdrv_unref(bs);
790     if (ret) {
791         return 1;
792     }
793     return 0;
794 }
795 
796 /*
797  * Returns true iff the first sector pointed to by 'buf' contains at least
798  * a non-NUL byte.
799  *
800  * 'pnum' is set to the number of sectors (including and immediately following
801  * the first one) that are known to be in the same allocated/unallocated state.
802  */
803 static int is_allocated_sectors(const uint8_t *buf, int n, int *pnum)
804 {
805     bool is_zero;
806     int i;
807 
808     if (n <= 0) {
809         *pnum = 0;
810         return 0;
811     }
812     is_zero = buffer_is_zero(buf, 512);
813     for(i = 1; i < n; i++) {
814         buf += 512;
815         if (is_zero != buffer_is_zero(buf, 512)) {
816             break;
817         }
818     }
819     *pnum = i;
820     return !is_zero;
821 }
822 
823 /*
824  * Like is_allocated_sectors, but if the buffer starts with a used sector,
825  * up to 'min' consecutive sectors containing zeros are ignored. This avoids
826  * breaking up write requests for only small sparse areas.
827  */
828 static int is_allocated_sectors_min(const uint8_t *buf, int n, int *pnum,
829     int min)
830 {
831     int ret;
832     int num_checked, num_used;
833 
834     if (n < min) {
835         min = n;
836     }
837 
838     ret = is_allocated_sectors(buf, n, pnum);
839     if (!ret) {
840         return ret;
841     }
842 
843     num_used = *pnum;
844     buf += BDRV_SECTOR_SIZE * *pnum;
845     n -= *pnum;
846     num_checked = num_used;
847 
848     while (n > 0) {
849         ret = is_allocated_sectors(buf, n, pnum);
850 
851         buf += BDRV_SECTOR_SIZE * *pnum;
852         n -= *pnum;
853         num_checked += *pnum;
854         if (ret) {
855             num_used = num_checked;
856         } else if (*pnum >= min) {
857             break;
858         }
859     }
860 
861     *pnum = num_used;
862     return 1;
863 }
864 
865 /*
866  * Compares two buffers sector by sector. Returns 0 if the first sector of both
867  * buffers matches, non-zero otherwise.
868  *
869  * pnum is set to the number of sectors (including and immediately following
870  * the first one) that are known to have the same comparison result
871  */
872 static int compare_sectors(const uint8_t *buf1, const uint8_t *buf2, int n,
873     int *pnum)
874 {
875     int res, i;
876 
877     if (n <= 0) {
878         *pnum = 0;
879         return 0;
880     }
881 
882     res = !!memcmp(buf1, buf2, 512);
883     for(i = 1; i < n; i++) {
884         buf1 += 512;
885         buf2 += 512;
886 
887         if (!!memcmp(buf1, buf2, 512) != res) {
888             break;
889         }
890     }
891 
892     *pnum = i;
893     return res;
894 }
895 
896 #define IO_BUF_SIZE (2 * 1024 * 1024)
897 
898 static int64_t sectors_to_bytes(int64_t sectors)
899 {
900     return sectors << BDRV_SECTOR_BITS;
901 }
902 
903 static int64_t sectors_to_process(int64_t total, int64_t from)
904 {
905     return MIN(total - from, IO_BUF_SIZE >> BDRV_SECTOR_BITS);
906 }
907 
908 /*
909  * Check if passed sectors are empty (not allocated or contain only 0 bytes)
910  *
911  * Returns 0 in case sectors are filled with 0, 1 if sectors contain non-zero
912  * data and negative value on error.
913  *
914  * @param bs:  Driver used for accessing file
915  * @param sect_num: Number of first sector to check
916  * @param sect_count: Number of sectors to check
917  * @param filename: Name of disk file we are checking (logging purpose)
918  * @param buffer: Allocated buffer for storing read data
919  * @param quiet: Flag for quiet mode
920  */
921 static int check_empty_sectors(BlockDriverState *bs, int64_t sect_num,
922                                int sect_count, const char *filename,
923                                uint8_t *buffer, bool quiet)
924 {
925     int pnum, ret = 0;
926     ret = bdrv_read(bs, sect_num, buffer, sect_count);
927     if (ret < 0) {
928         error_report("Error while reading offset %" PRId64 " of %s: %s",
929                      sectors_to_bytes(sect_num), filename, strerror(-ret));
930         return ret;
931     }
932     ret = is_allocated_sectors(buffer, sect_count, &pnum);
933     if (ret || pnum != sect_count) {
934         qprintf(quiet, "Content mismatch at offset %" PRId64 "!\n",
935                 sectors_to_bytes(ret ? sect_num : sect_num + pnum));
936         return 1;
937     }
938 
939     return 0;
940 }
941 
942 /*
943  * Compares two images. Exit codes:
944  *
945  * 0 - Images are identical
946  * 1 - Images differ
947  * >1 - Error occurred
948  */
949 static int img_compare(int argc, char **argv)
950 {
951     const char *fmt1 = NULL, *fmt2 = NULL, *filename1, *filename2;
952     BlockDriverState *bs1, *bs2;
953     int64_t total_sectors1, total_sectors2;
954     uint8_t *buf1 = NULL, *buf2 = NULL;
955     int pnum1, pnum2;
956     int allocated1, allocated2;
957     int ret = 0; /* return value - 0 Ident, 1 Different, >1 Error */
958     bool progress = false, quiet = false, strict = false;
959     int64_t total_sectors;
960     int64_t sector_num = 0;
961     int64_t nb_sectors;
962     int c, pnum;
963     uint64_t bs_sectors;
964     uint64_t progress_base;
965 
966     for (;;) {
967         c = getopt(argc, argv, "hpf:F:sq");
968         if (c == -1) {
969             break;
970         }
971         switch (c) {
972         case '?':
973         case 'h':
974             help();
975             break;
976         case 'f':
977             fmt1 = optarg;
978             break;
979         case 'F':
980             fmt2 = optarg;
981             break;
982         case 'p':
983             progress = true;
984             break;
985         case 'q':
986             quiet = true;
987             break;
988         case 's':
989             strict = true;
990             break;
991         }
992     }
993 
994     /* Progress is not shown in Quiet mode */
995     if (quiet) {
996         progress = false;
997     }
998 
999 
1000     if (optind != argc - 2) {
1001         error_exit("Expecting two image file names");
1002     }
1003     filename1 = argv[optind++];
1004     filename2 = argv[optind++];
1005 
1006     /* Initialize before goto out */
1007     qemu_progress_init(progress, 2.0);
1008 
1009     bs1 = bdrv_new_open("image 1", filename1, fmt1, BDRV_O_FLAGS, true, quiet);
1010     if (!bs1) {
1011         error_report("Can't open file %s", filename1);
1012         ret = 2;
1013         goto out3;
1014     }
1015 
1016     bs2 = bdrv_new_open("image 2", filename2, fmt2, BDRV_O_FLAGS, true, quiet);
1017     if (!bs2) {
1018         error_report("Can't open file %s", filename2);
1019         ret = 2;
1020         goto out2;
1021     }
1022 
1023     buf1 = qemu_blockalign(bs1, IO_BUF_SIZE);
1024     buf2 = qemu_blockalign(bs2, IO_BUF_SIZE);
1025     bdrv_get_geometry(bs1, &bs_sectors);
1026     total_sectors1 = bs_sectors;
1027     bdrv_get_geometry(bs2, &bs_sectors);
1028     total_sectors2 = bs_sectors;
1029     total_sectors = MIN(total_sectors1, total_sectors2);
1030     progress_base = MAX(total_sectors1, total_sectors2);
1031 
1032     qemu_progress_print(0, 100);
1033 
1034     if (strict && total_sectors1 != total_sectors2) {
1035         ret = 1;
1036         qprintf(quiet, "Strict mode: Image size mismatch!\n");
1037         goto out;
1038     }
1039 
1040     for (;;) {
1041         nb_sectors = sectors_to_process(total_sectors, sector_num);
1042         if (nb_sectors <= 0) {
1043             break;
1044         }
1045         allocated1 = bdrv_is_allocated_above(bs1, NULL, sector_num, nb_sectors,
1046                                              &pnum1);
1047         if (allocated1 < 0) {
1048             ret = 3;
1049             error_report("Sector allocation test failed for %s", filename1);
1050             goto out;
1051         }
1052 
1053         allocated2 = bdrv_is_allocated_above(bs2, NULL, sector_num, nb_sectors,
1054                                              &pnum2);
1055         if (allocated2 < 0) {
1056             ret = 3;
1057             error_report("Sector allocation test failed for %s", filename2);
1058             goto out;
1059         }
1060         nb_sectors = MIN(pnum1, pnum2);
1061 
1062         if (allocated1 == allocated2) {
1063             if (allocated1) {
1064                 ret = bdrv_read(bs1, sector_num, buf1, nb_sectors);
1065                 if (ret < 0) {
1066                     error_report("Error while reading offset %" PRId64 " of %s:"
1067                                  " %s", sectors_to_bytes(sector_num), filename1,
1068                                  strerror(-ret));
1069                     ret = 4;
1070                     goto out;
1071                 }
1072                 ret = bdrv_read(bs2, sector_num, buf2, nb_sectors);
1073                 if (ret < 0) {
1074                     error_report("Error while reading offset %" PRId64
1075                                  " of %s: %s", sectors_to_bytes(sector_num),
1076                                  filename2, strerror(-ret));
1077                     ret = 4;
1078                     goto out;
1079                 }
1080                 ret = compare_sectors(buf1, buf2, nb_sectors, &pnum);
1081                 if (ret || pnum != nb_sectors) {
1082                     qprintf(quiet, "Content mismatch at offset %" PRId64 "!\n",
1083                             sectors_to_bytes(
1084                                 ret ? sector_num : sector_num + pnum));
1085                     ret = 1;
1086                     goto out;
1087                 }
1088             }
1089         } else {
1090             if (strict) {
1091                 ret = 1;
1092                 qprintf(quiet, "Strict mode: Offset %" PRId64
1093                         " allocation mismatch!\n",
1094                         sectors_to_bytes(sector_num));
1095                 goto out;
1096             }
1097 
1098             if (allocated1) {
1099                 ret = check_empty_sectors(bs1, sector_num, nb_sectors,
1100                                           filename1, buf1, quiet);
1101             } else {
1102                 ret = check_empty_sectors(bs2, sector_num, nb_sectors,
1103                                           filename2, buf1, quiet);
1104             }
1105             if (ret) {
1106                 if (ret < 0) {
1107                     error_report("Error while reading offset %" PRId64 ": %s",
1108                                  sectors_to_bytes(sector_num), strerror(-ret));
1109                     ret = 4;
1110                 }
1111                 goto out;
1112             }
1113         }
1114         sector_num += nb_sectors;
1115         qemu_progress_print(((float) nb_sectors / progress_base)*100, 100);
1116     }
1117 
1118     if (total_sectors1 != total_sectors2) {
1119         BlockDriverState *bs_over;
1120         int64_t total_sectors_over;
1121         const char *filename_over;
1122 
1123         qprintf(quiet, "Warning: Image size mismatch!\n");
1124         if (total_sectors1 > total_sectors2) {
1125             total_sectors_over = total_sectors1;
1126             bs_over = bs1;
1127             filename_over = filename1;
1128         } else {
1129             total_sectors_over = total_sectors2;
1130             bs_over = bs2;
1131             filename_over = filename2;
1132         }
1133 
1134         for (;;) {
1135             nb_sectors = sectors_to_process(total_sectors_over, sector_num);
1136             if (nb_sectors <= 0) {
1137                 break;
1138             }
1139             ret = bdrv_is_allocated_above(bs_over, NULL, sector_num,
1140                                           nb_sectors, &pnum);
1141             if (ret < 0) {
1142                 ret = 3;
1143                 error_report("Sector allocation test failed for %s",
1144                              filename_over);
1145                 goto out;
1146 
1147             }
1148             nb_sectors = pnum;
1149             if (ret) {
1150                 ret = check_empty_sectors(bs_over, sector_num, nb_sectors,
1151                                           filename_over, buf1, quiet);
1152                 if (ret) {
1153                     if (ret < 0) {
1154                         error_report("Error while reading offset %" PRId64
1155                                      " of %s: %s", sectors_to_bytes(sector_num),
1156                                      filename_over, strerror(-ret));
1157                         ret = 4;
1158                     }
1159                     goto out;
1160                 }
1161             }
1162             sector_num += nb_sectors;
1163             qemu_progress_print(((float) nb_sectors / progress_base)*100, 100);
1164         }
1165     }
1166 
1167     qprintf(quiet, "Images are identical.\n");
1168     ret = 0;
1169 
1170 out:
1171     bdrv_unref(bs2);
1172     qemu_vfree(buf1);
1173     qemu_vfree(buf2);
1174 out2:
1175     bdrv_unref(bs1);
1176 out3:
1177     qemu_progress_end();
1178     return ret;
1179 }
1180 
1181 static int img_convert(int argc, char **argv)
1182 {
1183     int c, n, n1, bs_n, bs_i, compress, cluster_sectors, skip_create;
1184     int64_t ret = 0;
1185     int progress = 0, flags;
1186     const char *fmt, *out_fmt, *cache, *out_baseimg, *out_filename;
1187     BlockDriver *drv, *proto_drv;
1188     BlockDriverState **bs = NULL, *out_bs = NULL;
1189     int64_t total_sectors, nb_sectors, sector_num, bs_offset;
1190     uint64_t bs_sectors;
1191     uint8_t * buf = NULL;
1192     size_t bufsectors = IO_BUF_SIZE / BDRV_SECTOR_SIZE;
1193     const uint8_t *buf1;
1194     BlockDriverInfo bdi;
1195     QemuOpts *opts = NULL;
1196     QemuOptsList *create_opts = NULL;
1197     const char *out_baseimg_param;
1198     char *options = NULL;
1199     const char *snapshot_name = NULL;
1200     int min_sparse = 8; /* Need at least 4k of zeros for sparse detection */
1201     bool quiet = false;
1202     Error *local_err = NULL;
1203     QemuOpts *sn_opts = NULL;
1204 
1205     fmt = NULL;
1206     out_fmt = "raw";
1207     cache = "unsafe";
1208     out_baseimg = NULL;
1209     compress = 0;
1210     skip_create = 0;
1211     for(;;) {
1212         c = getopt(argc, argv, "f:O:B:s:hce6o:pS:t:qnl:");
1213         if (c == -1) {
1214             break;
1215         }
1216         switch(c) {
1217         case '?':
1218         case 'h':
1219             help();
1220             break;
1221         case 'f':
1222             fmt = optarg;
1223             break;
1224         case 'O':
1225             out_fmt = optarg;
1226             break;
1227         case 'B':
1228             out_baseimg = optarg;
1229             break;
1230         case 'c':
1231             compress = 1;
1232             break;
1233         case 'e':
1234             error_report("option -e is deprecated, please use \'-o "
1235                   "encryption\' instead!");
1236             ret = -1;
1237             goto fail_getopt;
1238         case '6':
1239             error_report("option -6 is deprecated, please use \'-o "
1240                   "compat6\' instead!");
1241             ret = -1;
1242             goto fail_getopt;
1243         case 'o':
1244             if (!is_valid_option_list(optarg)) {
1245                 error_report("Invalid option list: %s", optarg);
1246                 ret = -1;
1247                 goto fail_getopt;
1248             }
1249             if (!options) {
1250                 options = g_strdup(optarg);
1251             } else {
1252                 char *old_options = options;
1253                 options = g_strdup_printf("%s,%s", options, optarg);
1254                 g_free(old_options);
1255             }
1256             break;
1257         case 's':
1258             snapshot_name = optarg;
1259             break;
1260         case 'l':
1261             if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
1262                 sn_opts = qemu_opts_parse(&internal_snapshot_opts, optarg, 0);
1263                 if (!sn_opts) {
1264                     error_report("Failed in parsing snapshot param '%s'",
1265                                  optarg);
1266                     ret = -1;
1267                     goto fail_getopt;
1268                 }
1269             } else {
1270                 snapshot_name = optarg;
1271             }
1272             break;
1273         case 'S':
1274         {
1275             int64_t sval;
1276             char *end;
1277             sval = strtosz_suffix(optarg, &end, STRTOSZ_DEFSUFFIX_B);
1278             if (sval < 0 || *end) {
1279                 error_report("Invalid minimum zero buffer size for sparse output specified");
1280                 ret = -1;
1281                 goto fail_getopt;
1282             }
1283 
1284             min_sparse = sval / BDRV_SECTOR_SIZE;
1285             break;
1286         }
1287         case 'p':
1288             progress = 1;
1289             break;
1290         case 't':
1291             cache = optarg;
1292             break;
1293         case 'q':
1294             quiet = true;
1295             break;
1296         case 'n':
1297             skip_create = 1;
1298             break;
1299         }
1300     }
1301 
1302     /* Initialize before goto out */
1303     if (quiet) {
1304         progress = 0;
1305     }
1306     qemu_progress_init(progress, 1.0);
1307 
1308 
1309     bs_n = argc - optind - 1;
1310     out_filename = bs_n >= 1 ? argv[argc - 1] : NULL;
1311 
1312     if (options && has_help_option(options)) {
1313         ret = print_block_option_help(out_filename, out_fmt);
1314         goto out;
1315     }
1316 
1317     if (bs_n < 1) {
1318         error_exit("Must specify image file name");
1319     }
1320 
1321 
1322     if (bs_n > 1 && out_baseimg) {
1323         error_report("-B makes no sense when concatenating multiple input "
1324                      "images");
1325         ret = -1;
1326         goto out;
1327     }
1328 
1329     qemu_progress_print(0, 100);
1330 
1331     bs = g_malloc0(bs_n * sizeof(BlockDriverState *));
1332 
1333     total_sectors = 0;
1334     for (bs_i = 0; bs_i < bs_n; bs_i++) {
1335         char *id = bs_n > 1 ? g_strdup_printf("source %d", bs_i)
1336                             : g_strdup("source");
1337         bs[bs_i] = bdrv_new_open(id, argv[optind + bs_i], fmt, BDRV_O_FLAGS,
1338                                  true, quiet);
1339         g_free(id);
1340         if (!bs[bs_i]) {
1341             error_report("Could not open '%s'", argv[optind + bs_i]);
1342             ret = -1;
1343             goto out;
1344         }
1345         bdrv_get_geometry(bs[bs_i], &bs_sectors);
1346         total_sectors += bs_sectors;
1347     }
1348 
1349     if (sn_opts) {
1350         ret = bdrv_snapshot_load_tmp(bs[0],
1351                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
1352                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
1353                                      &local_err);
1354     } else if (snapshot_name != NULL) {
1355         if (bs_n > 1) {
1356             error_report("No support for concatenating multiple snapshot");
1357             ret = -1;
1358             goto out;
1359         }
1360 
1361         bdrv_snapshot_load_tmp_by_id_or_name(bs[0], snapshot_name, &local_err);
1362     }
1363     if (local_err) {
1364         error_report("Failed to load snapshot: %s",
1365                      error_get_pretty(local_err));
1366         error_free(local_err);
1367         ret = -1;
1368         goto out;
1369     }
1370 
1371     /* Find driver and parse its options */
1372     drv = bdrv_find_format(out_fmt);
1373     if (!drv) {
1374         error_report("Unknown file format '%s'", out_fmt);
1375         ret = -1;
1376         goto out;
1377     }
1378 
1379     proto_drv = bdrv_find_protocol(out_filename, true);
1380     if (!proto_drv) {
1381         error_report("Unknown protocol '%s'", out_filename);
1382         ret = -1;
1383         goto out;
1384     }
1385 
1386     create_opts = qemu_opts_append(create_opts, drv->create_opts);
1387     create_opts = qemu_opts_append(create_opts, proto_drv->create_opts);
1388 
1389     opts = qemu_opts_create(create_opts, NULL, 0, &error_abort);
1390     if (options && qemu_opts_do_parse(opts, options, NULL)) {
1391         error_report("Invalid options for file format '%s'", out_fmt);
1392         ret = -1;
1393         goto out;
1394     }
1395 
1396     qemu_opt_set_number(opts, BLOCK_OPT_SIZE, total_sectors * 512);
1397     ret = add_old_style_options(out_fmt, opts, out_baseimg, NULL);
1398     if (ret < 0) {
1399         goto out;
1400     }
1401 
1402     /* Get backing file name if -o backing_file was used */
1403     out_baseimg_param = qemu_opt_get(opts, BLOCK_OPT_BACKING_FILE);
1404     if (out_baseimg_param) {
1405         out_baseimg = out_baseimg_param;
1406     }
1407 
1408     /* Check if compression is supported */
1409     if (compress) {
1410         bool encryption =
1411             qemu_opt_get_bool(opts, BLOCK_OPT_ENCRYPT, false);
1412         const char *preallocation =
1413             qemu_opt_get(opts, BLOCK_OPT_PREALLOC);
1414 
1415         if (!drv->bdrv_write_compressed) {
1416             error_report("Compression not supported for this file format");
1417             ret = -1;
1418             goto out;
1419         }
1420 
1421         if (encryption) {
1422             error_report("Compression and encryption not supported at "
1423                          "the same time");
1424             ret = -1;
1425             goto out;
1426         }
1427 
1428         if (preallocation
1429             && strcmp(preallocation, "off"))
1430         {
1431             error_report("Compression and preallocation not supported at "
1432                          "the same time");
1433             ret = -1;
1434             goto out;
1435         }
1436     }
1437 
1438     if (!skip_create) {
1439         /* Create the new image */
1440         ret = bdrv_create(drv, out_filename, opts, &local_err);
1441         if (ret < 0) {
1442             error_report("%s: error while converting %s: %s",
1443                          out_filename, out_fmt, error_get_pretty(local_err));
1444             error_free(local_err);
1445             goto out;
1446         }
1447     }
1448 
1449     flags = min_sparse ? (BDRV_O_RDWR | BDRV_O_UNMAP) : BDRV_O_RDWR;
1450     ret = bdrv_parse_cache_flags(cache, &flags);
1451     if (ret < 0) {
1452         error_report("Invalid cache option: %s", cache);
1453         goto out;
1454     }
1455 
1456     out_bs = bdrv_new_open("target", out_filename, out_fmt, flags, true, quiet);
1457     if (!out_bs) {
1458         ret = -1;
1459         goto out;
1460     }
1461 
1462     bs_i = 0;
1463     bs_offset = 0;
1464     bdrv_get_geometry(bs[0], &bs_sectors);
1465 
1466     /* increase bufsectors from the default 4096 (2M) if opt_transfer_length
1467      * or discard_alignment of the out_bs is greater. Limit to 32768 (16MB)
1468      * as maximum. */
1469     bufsectors = MIN(32768,
1470                      MAX(bufsectors, MAX(out_bs->bl.opt_transfer_length,
1471                                          out_bs->bl.discard_alignment))
1472                     );
1473 
1474     buf = qemu_blockalign(out_bs, bufsectors * BDRV_SECTOR_SIZE);
1475 
1476     if (skip_create) {
1477         int64_t output_length = bdrv_getlength(out_bs);
1478         if (output_length < 0) {
1479             error_report("unable to get output image length: %s\n",
1480                          strerror(-output_length));
1481             ret = -1;
1482             goto out;
1483         } else if (output_length < total_sectors << BDRV_SECTOR_BITS) {
1484             error_report("output file is smaller than input file");
1485             ret = -1;
1486             goto out;
1487         }
1488     }
1489 
1490     cluster_sectors = 0;
1491     ret = bdrv_get_info(out_bs, &bdi);
1492     if (ret < 0) {
1493         if (compress) {
1494             error_report("could not get block driver info");
1495             goto out;
1496         }
1497     } else {
1498         compress = compress || bdi.needs_compressed_writes;
1499         cluster_sectors = bdi.cluster_size / BDRV_SECTOR_SIZE;
1500     }
1501 
1502     if (compress) {
1503         if (cluster_sectors <= 0 || cluster_sectors > bufsectors) {
1504             error_report("invalid cluster size");
1505             ret = -1;
1506             goto out;
1507         }
1508         sector_num = 0;
1509 
1510         nb_sectors = total_sectors;
1511 
1512         for(;;) {
1513             int64_t bs_num;
1514             int remainder;
1515             uint8_t *buf2;
1516 
1517             nb_sectors = total_sectors - sector_num;
1518             if (nb_sectors <= 0)
1519                 break;
1520             if (nb_sectors >= cluster_sectors)
1521                 n = cluster_sectors;
1522             else
1523                 n = nb_sectors;
1524 
1525             bs_num = sector_num - bs_offset;
1526             assert (bs_num >= 0);
1527             remainder = n;
1528             buf2 = buf;
1529             while (remainder > 0) {
1530                 int nlow;
1531                 while (bs_num == bs_sectors) {
1532                     bs_i++;
1533                     assert (bs_i < bs_n);
1534                     bs_offset += bs_sectors;
1535                     bdrv_get_geometry(bs[bs_i], &bs_sectors);
1536                     bs_num = 0;
1537                     /* printf("changing part: sector_num=%" PRId64 ", "
1538                        "bs_i=%d, bs_offset=%" PRId64 ", bs_sectors=%" PRId64
1539                        "\n", sector_num, bs_i, bs_offset, bs_sectors); */
1540                 }
1541                 assert (bs_num < bs_sectors);
1542 
1543                 nlow = (remainder > bs_sectors - bs_num) ? bs_sectors - bs_num : remainder;
1544 
1545                 ret = bdrv_read(bs[bs_i], bs_num, buf2, nlow);
1546                 if (ret < 0) {
1547                     error_report("error while reading sector %" PRId64 ": %s",
1548                                  bs_num, strerror(-ret));
1549                     goto out;
1550                 }
1551 
1552                 buf2 += nlow * 512;
1553                 bs_num += nlow;
1554 
1555                 remainder -= nlow;
1556             }
1557             assert (remainder == 0);
1558 
1559             if (!buffer_is_zero(buf, n * BDRV_SECTOR_SIZE)) {
1560                 ret = bdrv_write_compressed(out_bs, sector_num, buf, n);
1561                 if (ret != 0) {
1562                     error_report("error while compressing sector %" PRId64
1563                                  ": %s", sector_num, strerror(-ret));
1564                     goto out;
1565                 }
1566             }
1567             sector_num += n;
1568             qemu_progress_print(100.0 * sector_num / total_sectors, 0);
1569         }
1570         /* signal EOF to align */
1571         bdrv_write_compressed(out_bs, 0, NULL, 0);
1572     } else {
1573         int64_t sectors_to_read, sectors_read, sector_num_next_status;
1574         bool count_allocated_sectors;
1575         int has_zero_init = min_sparse ? bdrv_has_zero_init(out_bs) : 0;
1576 
1577         if (!has_zero_init && bdrv_can_write_zeroes_with_unmap(out_bs)) {
1578             ret = bdrv_make_zero(out_bs, BDRV_REQ_MAY_UNMAP);
1579             if (ret < 0) {
1580                 goto out;
1581             }
1582             has_zero_init = 1;
1583         }
1584 
1585         sectors_to_read = total_sectors;
1586         count_allocated_sectors = progress && (out_baseimg || has_zero_init);
1587 restart:
1588         sector_num = 0; // total number of sectors converted so far
1589         sectors_read = 0;
1590         sector_num_next_status = 0;
1591 
1592         for(;;) {
1593             nb_sectors = total_sectors - sector_num;
1594             if (nb_sectors <= 0) {
1595                 if (count_allocated_sectors) {
1596                     sectors_to_read = sectors_read;
1597                     count_allocated_sectors = false;
1598                     goto restart;
1599                 }
1600                 ret = 0;
1601                 break;
1602             }
1603 
1604             while (sector_num - bs_offset >= bs_sectors) {
1605                 bs_i ++;
1606                 assert (bs_i < bs_n);
1607                 bs_offset += bs_sectors;
1608                 bdrv_get_geometry(bs[bs_i], &bs_sectors);
1609                 /* printf("changing part: sector_num=%" PRId64 ", bs_i=%d, "
1610                   "bs_offset=%" PRId64 ", bs_sectors=%" PRId64 "\n",
1611                    sector_num, bs_i, bs_offset, bs_sectors); */
1612             }
1613 
1614             if ((out_baseimg || has_zero_init) &&
1615                 sector_num >= sector_num_next_status) {
1616                 n = nb_sectors > INT_MAX ? INT_MAX : nb_sectors;
1617                 ret = bdrv_get_block_status(bs[bs_i], sector_num - bs_offset,
1618                                             n, &n1);
1619                 if (ret < 0) {
1620                     error_report("error while reading block status of sector %"
1621                                  PRId64 ": %s", sector_num - bs_offset,
1622                                  strerror(-ret));
1623                     goto out;
1624                 }
1625                 /* If the output image is zero initialized, we are not working
1626                  * on a shared base and the input is zero we can skip the next
1627                  * n1 sectors */
1628                 if (has_zero_init && !out_baseimg && (ret & BDRV_BLOCK_ZERO)) {
1629                     sector_num += n1;
1630                     continue;
1631                 }
1632                 /* If the output image is being created as a copy on write
1633                  * image, assume that sectors which are unallocated in the
1634                  * input image are present in both the output's and input's
1635                  * base images (no need to copy them). */
1636                 if (out_baseimg) {
1637                     if (!(ret & BDRV_BLOCK_DATA)) {
1638                         sector_num += n1;
1639                         continue;
1640                     }
1641                     /* The next 'n1' sectors are allocated in the input image.
1642                      * Copy only those as they may be followed by unallocated
1643                      * sectors. */
1644                     nb_sectors = n1;
1645                 }
1646                 /* avoid redundant callouts to get_block_status */
1647                 sector_num_next_status = sector_num + n1;
1648             }
1649 
1650             n = MIN(nb_sectors, bufsectors);
1651 
1652             /* round down request length to an aligned sector, but
1653              * do not bother doing this on short requests. They happen
1654              * when we found an all-zero area, and the next sector to
1655              * write will not be sector_num + n. */
1656             if (cluster_sectors > 0 && n >= cluster_sectors) {
1657                 int64_t next_aligned_sector = (sector_num + n);
1658                 next_aligned_sector -= next_aligned_sector % cluster_sectors;
1659                 if (sector_num + n > next_aligned_sector) {
1660                     n = next_aligned_sector - sector_num;
1661                 }
1662             }
1663 
1664             n = MIN(n, bs_sectors - (sector_num - bs_offset));
1665 
1666             sectors_read += n;
1667             if (count_allocated_sectors) {
1668                 sector_num += n;
1669                 continue;
1670             }
1671 
1672             n1 = n;
1673             ret = bdrv_read(bs[bs_i], sector_num - bs_offset, buf, n);
1674             if (ret < 0) {
1675                 error_report("error while reading sector %" PRId64 ": %s",
1676                              sector_num - bs_offset, strerror(-ret));
1677                 goto out;
1678             }
1679             /* NOTE: at the same time we convert, we do not write zero
1680                sectors to have a chance to compress the image. Ideally, we
1681                should add a specific call to have the info to go faster */
1682             buf1 = buf;
1683             while (n > 0) {
1684                 if (!has_zero_init ||
1685                     is_allocated_sectors_min(buf1, n, &n1, min_sparse)) {
1686                     ret = bdrv_write(out_bs, sector_num, buf1, n1);
1687                     if (ret < 0) {
1688                         error_report("error while writing sector %" PRId64
1689                                      ": %s", sector_num, strerror(-ret));
1690                         goto out;
1691                     }
1692                 }
1693                 sector_num += n1;
1694                 n -= n1;
1695                 buf1 += n1 * 512;
1696             }
1697             qemu_progress_print(100.0 * sectors_read / sectors_to_read, 0);
1698         }
1699     }
1700 out:
1701     if (!ret) {
1702         qemu_progress_print(100, 0);
1703     }
1704     qemu_progress_end();
1705     qemu_opts_del(opts);
1706     qemu_opts_free(create_opts);
1707     qemu_vfree(buf);
1708     if (sn_opts) {
1709         qemu_opts_del(sn_opts);
1710     }
1711     if (out_bs) {
1712         bdrv_unref(out_bs);
1713     }
1714     if (bs) {
1715         for (bs_i = 0; bs_i < bs_n; bs_i++) {
1716             if (bs[bs_i]) {
1717                 bdrv_unref(bs[bs_i]);
1718             }
1719         }
1720         g_free(bs);
1721     }
1722 fail_getopt:
1723     g_free(options);
1724 
1725     if (ret) {
1726         return 1;
1727     }
1728     return 0;
1729 }
1730 
1731 
1732 static void dump_snapshots(BlockDriverState *bs)
1733 {
1734     QEMUSnapshotInfo *sn_tab, *sn;
1735     int nb_sns, i;
1736 
1737     nb_sns = bdrv_snapshot_list(bs, &sn_tab);
1738     if (nb_sns <= 0)
1739         return;
1740     printf("Snapshot list:\n");
1741     bdrv_snapshot_dump(fprintf, stdout, NULL);
1742     printf("\n");
1743     for(i = 0; i < nb_sns; i++) {
1744         sn = &sn_tab[i];
1745         bdrv_snapshot_dump(fprintf, stdout, sn);
1746         printf("\n");
1747     }
1748     g_free(sn_tab);
1749 }
1750 
1751 static void dump_json_image_info_list(ImageInfoList *list)
1752 {
1753     Error *local_err = NULL;
1754     QString *str;
1755     QmpOutputVisitor *ov = qmp_output_visitor_new();
1756     QObject *obj;
1757     visit_type_ImageInfoList(qmp_output_get_visitor(ov),
1758                              &list, NULL, &local_err);
1759     obj = qmp_output_get_qobject(ov);
1760     str = qobject_to_json_pretty(obj);
1761     assert(str != NULL);
1762     printf("%s\n", qstring_get_str(str));
1763     qobject_decref(obj);
1764     qmp_output_visitor_cleanup(ov);
1765     QDECREF(str);
1766 }
1767 
1768 static void dump_json_image_info(ImageInfo *info)
1769 {
1770     Error *local_err = NULL;
1771     QString *str;
1772     QmpOutputVisitor *ov = qmp_output_visitor_new();
1773     QObject *obj;
1774     visit_type_ImageInfo(qmp_output_get_visitor(ov),
1775                          &info, NULL, &local_err);
1776     obj = qmp_output_get_qobject(ov);
1777     str = qobject_to_json_pretty(obj);
1778     assert(str != NULL);
1779     printf("%s\n", qstring_get_str(str));
1780     qobject_decref(obj);
1781     qmp_output_visitor_cleanup(ov);
1782     QDECREF(str);
1783 }
1784 
1785 static void dump_human_image_info_list(ImageInfoList *list)
1786 {
1787     ImageInfoList *elem;
1788     bool delim = false;
1789 
1790     for (elem = list; elem; elem = elem->next) {
1791         if (delim) {
1792             printf("\n");
1793         }
1794         delim = true;
1795 
1796         bdrv_image_info_dump(fprintf, stdout, elem->value);
1797     }
1798 }
1799 
1800 static gboolean str_equal_func(gconstpointer a, gconstpointer b)
1801 {
1802     return strcmp(a, b) == 0;
1803 }
1804 
1805 /**
1806  * Open an image file chain and return an ImageInfoList
1807  *
1808  * @filename: topmost image filename
1809  * @fmt: topmost image format (may be NULL to autodetect)
1810  * @chain: true  - enumerate entire backing file chain
1811  *         false - only topmost image file
1812  *
1813  * Returns a list of ImageInfo objects or NULL if there was an error opening an
1814  * image file.  If there was an error a message will have been printed to
1815  * stderr.
1816  */
1817 static ImageInfoList *collect_image_info_list(const char *filename,
1818                                               const char *fmt,
1819                                               bool chain)
1820 {
1821     ImageInfoList *head = NULL;
1822     ImageInfoList **last = &head;
1823     GHashTable *filenames;
1824     Error *err = NULL;
1825 
1826     filenames = g_hash_table_new_full(g_str_hash, str_equal_func, NULL, NULL);
1827 
1828     while (filename) {
1829         BlockDriverState *bs;
1830         ImageInfo *info;
1831         ImageInfoList *elem;
1832 
1833         if (g_hash_table_lookup_extended(filenames, filename, NULL, NULL)) {
1834             error_report("Backing file '%s' creates an infinite loop.",
1835                          filename);
1836             goto err;
1837         }
1838         g_hash_table_insert(filenames, (gpointer)filename, NULL);
1839 
1840         bs = bdrv_new_open("image", filename, fmt,
1841                            BDRV_O_FLAGS | BDRV_O_NO_BACKING, false, false);
1842         if (!bs) {
1843             goto err;
1844         }
1845 
1846         bdrv_query_image_info(bs, &info, &err);
1847         if (err) {
1848             error_report("%s", error_get_pretty(err));
1849             error_free(err);
1850             bdrv_unref(bs);
1851             goto err;
1852         }
1853 
1854         elem = g_new0(ImageInfoList, 1);
1855         elem->value = info;
1856         *last = elem;
1857         last = &elem->next;
1858 
1859         bdrv_unref(bs);
1860 
1861         filename = fmt = NULL;
1862         if (chain) {
1863             if (info->has_full_backing_filename) {
1864                 filename = info->full_backing_filename;
1865             } else if (info->has_backing_filename) {
1866                 filename = info->backing_filename;
1867             }
1868             if (info->has_backing_filename_format) {
1869                 fmt = info->backing_filename_format;
1870             }
1871         }
1872     }
1873     g_hash_table_destroy(filenames);
1874     return head;
1875 
1876 err:
1877     qapi_free_ImageInfoList(head);
1878     g_hash_table_destroy(filenames);
1879     return NULL;
1880 }
1881 
1882 static int img_info(int argc, char **argv)
1883 {
1884     int c;
1885     OutputFormat output_format = OFORMAT_HUMAN;
1886     bool chain = false;
1887     const char *filename, *fmt, *output;
1888     ImageInfoList *list;
1889 
1890     fmt = NULL;
1891     output = NULL;
1892     for(;;) {
1893         int option_index = 0;
1894         static const struct option long_options[] = {
1895             {"help", no_argument, 0, 'h'},
1896             {"format", required_argument, 0, 'f'},
1897             {"output", required_argument, 0, OPTION_OUTPUT},
1898             {"backing-chain", no_argument, 0, OPTION_BACKING_CHAIN},
1899             {0, 0, 0, 0}
1900         };
1901         c = getopt_long(argc, argv, "f:h",
1902                         long_options, &option_index);
1903         if (c == -1) {
1904             break;
1905         }
1906         switch(c) {
1907         case '?':
1908         case 'h':
1909             help();
1910             break;
1911         case 'f':
1912             fmt = optarg;
1913             break;
1914         case OPTION_OUTPUT:
1915             output = optarg;
1916             break;
1917         case OPTION_BACKING_CHAIN:
1918             chain = true;
1919             break;
1920         }
1921     }
1922     if (optind != argc - 1) {
1923         error_exit("Expecting one image file name");
1924     }
1925     filename = argv[optind++];
1926 
1927     if (output && !strcmp(output, "json")) {
1928         output_format = OFORMAT_JSON;
1929     } else if (output && !strcmp(output, "human")) {
1930         output_format = OFORMAT_HUMAN;
1931     } else if (output) {
1932         error_report("--output must be used with human or json as argument.");
1933         return 1;
1934     }
1935 
1936     list = collect_image_info_list(filename, fmt, chain);
1937     if (!list) {
1938         return 1;
1939     }
1940 
1941     switch (output_format) {
1942     case OFORMAT_HUMAN:
1943         dump_human_image_info_list(list);
1944         break;
1945     case OFORMAT_JSON:
1946         if (chain) {
1947             dump_json_image_info_list(list);
1948         } else {
1949             dump_json_image_info(list->value);
1950         }
1951         break;
1952     }
1953 
1954     qapi_free_ImageInfoList(list);
1955     return 0;
1956 }
1957 
1958 
1959 typedef struct MapEntry {
1960     int flags;
1961     int depth;
1962     int64_t start;
1963     int64_t length;
1964     int64_t offset;
1965     BlockDriverState *bs;
1966 } MapEntry;
1967 
1968 static void dump_map_entry(OutputFormat output_format, MapEntry *e,
1969                            MapEntry *next)
1970 {
1971     switch (output_format) {
1972     case OFORMAT_HUMAN:
1973         if ((e->flags & BDRV_BLOCK_DATA) &&
1974             !(e->flags & BDRV_BLOCK_OFFSET_VALID)) {
1975             error_report("File contains external, encrypted or compressed clusters.");
1976             exit(1);
1977         }
1978         if ((e->flags & (BDRV_BLOCK_DATA|BDRV_BLOCK_ZERO)) == BDRV_BLOCK_DATA) {
1979             printf("%#-16"PRIx64"%#-16"PRIx64"%#-16"PRIx64"%s\n",
1980                    e->start, e->length, e->offset, e->bs->filename);
1981         }
1982         /* This format ignores the distinction between 0, ZERO and ZERO|DATA.
1983          * Modify the flags here to allow more coalescing.
1984          */
1985         if (next &&
1986             (next->flags & (BDRV_BLOCK_DATA|BDRV_BLOCK_ZERO)) != BDRV_BLOCK_DATA) {
1987             next->flags &= ~BDRV_BLOCK_DATA;
1988             next->flags |= BDRV_BLOCK_ZERO;
1989         }
1990         break;
1991     case OFORMAT_JSON:
1992         printf("%s{ \"start\": %"PRId64", \"length\": %"PRId64", \"depth\": %d,"
1993                " \"zero\": %s, \"data\": %s",
1994                (e->start == 0 ? "[" : ",\n"),
1995                e->start, e->length, e->depth,
1996                (e->flags & BDRV_BLOCK_ZERO) ? "true" : "false",
1997                (e->flags & BDRV_BLOCK_DATA) ? "true" : "false");
1998         if (e->flags & BDRV_BLOCK_OFFSET_VALID) {
1999             printf(", \"offset\": %"PRId64"", e->offset);
2000         }
2001         putchar('}');
2002 
2003         if (!next) {
2004             printf("]\n");
2005         }
2006         break;
2007     }
2008 }
2009 
2010 static int get_block_status(BlockDriverState *bs, int64_t sector_num,
2011                             int nb_sectors, MapEntry *e)
2012 {
2013     int64_t ret;
2014     int depth;
2015 
2016     /* As an optimization, we could cache the current range of unallocated
2017      * clusters in each file of the chain, and avoid querying the same
2018      * range repeatedly.
2019      */
2020 
2021     depth = 0;
2022     for (;;) {
2023         ret = bdrv_get_block_status(bs, sector_num, nb_sectors, &nb_sectors);
2024         if (ret < 0) {
2025             return ret;
2026         }
2027         assert(nb_sectors);
2028         if (ret & (BDRV_BLOCK_ZERO|BDRV_BLOCK_DATA)) {
2029             break;
2030         }
2031         bs = bs->backing_hd;
2032         if (bs == NULL) {
2033             ret = 0;
2034             break;
2035         }
2036 
2037         depth++;
2038     }
2039 
2040     e->start = sector_num * BDRV_SECTOR_SIZE;
2041     e->length = nb_sectors * BDRV_SECTOR_SIZE;
2042     e->flags = ret & ~BDRV_BLOCK_OFFSET_MASK;
2043     e->offset = ret & BDRV_BLOCK_OFFSET_MASK;
2044     e->depth = depth;
2045     e->bs = bs;
2046     return 0;
2047 }
2048 
2049 static int img_map(int argc, char **argv)
2050 {
2051     int c;
2052     OutputFormat output_format = OFORMAT_HUMAN;
2053     BlockDriverState *bs;
2054     const char *filename, *fmt, *output;
2055     int64_t length;
2056     MapEntry curr = { .length = 0 }, next;
2057     int ret = 0;
2058 
2059     fmt = NULL;
2060     output = NULL;
2061     for (;;) {
2062         int option_index = 0;
2063         static const struct option long_options[] = {
2064             {"help", no_argument, 0, 'h'},
2065             {"format", required_argument, 0, 'f'},
2066             {"output", required_argument, 0, OPTION_OUTPUT},
2067             {0, 0, 0, 0}
2068         };
2069         c = getopt_long(argc, argv, "f:h",
2070                         long_options, &option_index);
2071         if (c == -1) {
2072             break;
2073         }
2074         switch (c) {
2075         case '?':
2076         case 'h':
2077             help();
2078             break;
2079         case 'f':
2080             fmt = optarg;
2081             break;
2082         case OPTION_OUTPUT:
2083             output = optarg;
2084             break;
2085         }
2086     }
2087     if (optind != argc - 1) {
2088         error_exit("Expecting one image file name");
2089     }
2090     filename = argv[optind];
2091 
2092     if (output && !strcmp(output, "json")) {
2093         output_format = OFORMAT_JSON;
2094     } else if (output && !strcmp(output, "human")) {
2095         output_format = OFORMAT_HUMAN;
2096     } else if (output) {
2097         error_report("--output must be used with human or json as argument.");
2098         return 1;
2099     }
2100 
2101     bs = bdrv_new_open("image", filename, fmt, BDRV_O_FLAGS, true, false);
2102     if (!bs) {
2103         return 1;
2104     }
2105 
2106     if (output_format == OFORMAT_HUMAN) {
2107         printf("%-16s%-16s%-16s%s\n", "Offset", "Length", "Mapped to", "File");
2108     }
2109 
2110     length = bdrv_getlength(bs);
2111     while (curr.start + curr.length < length) {
2112         int64_t nsectors_left;
2113         int64_t sector_num;
2114         int n;
2115 
2116         sector_num = (curr.start + curr.length) >> BDRV_SECTOR_BITS;
2117 
2118         /* Probe up to 1 GiB at a time.  */
2119         nsectors_left = DIV_ROUND_UP(length, BDRV_SECTOR_SIZE) - sector_num;
2120         n = MIN(1 << (30 - BDRV_SECTOR_BITS), nsectors_left);
2121         ret = get_block_status(bs, sector_num, n, &next);
2122 
2123         if (ret < 0) {
2124             error_report("Could not read file metadata: %s", strerror(-ret));
2125             goto out;
2126         }
2127 
2128         if (curr.length != 0 && curr.flags == next.flags &&
2129             curr.depth == next.depth &&
2130             ((curr.flags & BDRV_BLOCK_OFFSET_VALID) == 0 ||
2131              curr.offset + curr.length == next.offset)) {
2132             curr.length += next.length;
2133             continue;
2134         }
2135 
2136         if (curr.length > 0) {
2137             dump_map_entry(output_format, &curr, &next);
2138         }
2139         curr = next;
2140     }
2141 
2142     dump_map_entry(output_format, &curr, NULL);
2143 
2144 out:
2145     bdrv_unref(bs);
2146     return ret < 0;
2147 }
2148 
2149 #define SNAPSHOT_LIST   1
2150 #define SNAPSHOT_CREATE 2
2151 #define SNAPSHOT_APPLY  3
2152 #define SNAPSHOT_DELETE 4
2153 
2154 static int img_snapshot(int argc, char **argv)
2155 {
2156     BlockDriverState *bs;
2157     QEMUSnapshotInfo sn;
2158     char *filename, *snapshot_name = NULL;
2159     int c, ret = 0, bdrv_oflags;
2160     int action = 0;
2161     qemu_timeval tv;
2162     bool quiet = false;
2163     Error *err = NULL;
2164 
2165     bdrv_oflags = BDRV_O_FLAGS | BDRV_O_RDWR;
2166     /* Parse commandline parameters */
2167     for(;;) {
2168         c = getopt(argc, argv, "la:c:d:hq");
2169         if (c == -1) {
2170             break;
2171         }
2172         switch(c) {
2173         case '?':
2174         case 'h':
2175             help();
2176             return 0;
2177         case 'l':
2178             if (action) {
2179                 error_exit("Cannot mix '-l', '-a', '-c', '-d'");
2180                 return 0;
2181             }
2182             action = SNAPSHOT_LIST;
2183             bdrv_oflags &= ~BDRV_O_RDWR; /* no need for RW */
2184             break;
2185         case 'a':
2186             if (action) {
2187                 error_exit("Cannot mix '-l', '-a', '-c', '-d'");
2188                 return 0;
2189             }
2190             action = SNAPSHOT_APPLY;
2191             snapshot_name = optarg;
2192             break;
2193         case 'c':
2194             if (action) {
2195                 error_exit("Cannot mix '-l', '-a', '-c', '-d'");
2196                 return 0;
2197             }
2198             action = SNAPSHOT_CREATE;
2199             snapshot_name = optarg;
2200             break;
2201         case 'd':
2202             if (action) {
2203                 error_exit("Cannot mix '-l', '-a', '-c', '-d'");
2204                 return 0;
2205             }
2206             action = SNAPSHOT_DELETE;
2207             snapshot_name = optarg;
2208             break;
2209         case 'q':
2210             quiet = true;
2211             break;
2212         }
2213     }
2214 
2215     if (optind != argc - 1) {
2216         error_exit("Expecting one image file name");
2217     }
2218     filename = argv[optind++];
2219 
2220     /* Open the image */
2221     bs = bdrv_new_open("image", filename, NULL, bdrv_oflags, true, quiet);
2222     if (!bs) {
2223         return 1;
2224     }
2225 
2226     /* Perform the requested action */
2227     switch(action) {
2228     case SNAPSHOT_LIST:
2229         dump_snapshots(bs);
2230         break;
2231 
2232     case SNAPSHOT_CREATE:
2233         memset(&sn, 0, sizeof(sn));
2234         pstrcpy(sn.name, sizeof(sn.name), snapshot_name);
2235 
2236         qemu_gettimeofday(&tv);
2237         sn.date_sec = tv.tv_sec;
2238         sn.date_nsec = tv.tv_usec * 1000;
2239 
2240         ret = bdrv_snapshot_create(bs, &sn);
2241         if (ret) {
2242             error_report("Could not create snapshot '%s': %d (%s)",
2243                 snapshot_name, ret, strerror(-ret));
2244         }
2245         break;
2246 
2247     case SNAPSHOT_APPLY:
2248         ret = bdrv_snapshot_goto(bs, snapshot_name);
2249         if (ret) {
2250             error_report("Could not apply snapshot '%s': %d (%s)",
2251                 snapshot_name, ret, strerror(-ret));
2252         }
2253         break;
2254 
2255     case SNAPSHOT_DELETE:
2256         bdrv_snapshot_delete_by_id_or_name(bs, snapshot_name, &err);
2257         if (err) {
2258             error_report("Could not delete snapshot '%s': (%s)",
2259                          snapshot_name, error_get_pretty(err));
2260             error_free(err);
2261             ret = 1;
2262         }
2263         break;
2264     }
2265 
2266     /* Cleanup */
2267     bdrv_unref(bs);
2268     if (ret) {
2269         return 1;
2270     }
2271     return 0;
2272 }
2273 
2274 static int img_rebase(int argc, char **argv)
2275 {
2276     BlockDriverState *bs, *bs_old_backing = NULL, *bs_new_backing = NULL;
2277     BlockDriver *old_backing_drv, *new_backing_drv;
2278     char *filename;
2279     const char *fmt, *cache, *out_basefmt, *out_baseimg;
2280     int c, flags, ret;
2281     int unsafe = 0;
2282     int progress = 0;
2283     bool quiet = false;
2284     Error *local_err = NULL;
2285 
2286     /* Parse commandline parameters */
2287     fmt = NULL;
2288     cache = BDRV_DEFAULT_CACHE;
2289     out_baseimg = NULL;
2290     out_basefmt = NULL;
2291     for(;;) {
2292         c = getopt(argc, argv, "uhf:F:b:pt:q");
2293         if (c == -1) {
2294             break;
2295         }
2296         switch(c) {
2297         case '?':
2298         case 'h':
2299             help();
2300             return 0;
2301         case 'f':
2302             fmt = optarg;
2303             break;
2304         case 'F':
2305             out_basefmt = optarg;
2306             break;
2307         case 'b':
2308             out_baseimg = optarg;
2309             break;
2310         case 'u':
2311             unsafe = 1;
2312             break;
2313         case 'p':
2314             progress = 1;
2315             break;
2316         case 't':
2317             cache = optarg;
2318             break;
2319         case 'q':
2320             quiet = true;
2321             break;
2322         }
2323     }
2324 
2325     if (quiet) {
2326         progress = 0;
2327     }
2328 
2329     if (optind != argc - 1) {
2330         error_exit("Expecting one image file name");
2331     }
2332     if (!unsafe && !out_baseimg) {
2333         error_exit("Must specify backing file (-b) or use unsafe mode (-u)");
2334     }
2335     filename = argv[optind++];
2336 
2337     qemu_progress_init(progress, 2.0);
2338     qemu_progress_print(0, 100);
2339 
2340     flags = BDRV_O_RDWR | (unsafe ? BDRV_O_NO_BACKING : 0);
2341     ret = bdrv_parse_cache_flags(cache, &flags);
2342     if (ret < 0) {
2343         error_report("Invalid cache option: %s", cache);
2344         return -1;
2345     }
2346 
2347     /*
2348      * Open the images.
2349      *
2350      * Ignore the old backing file for unsafe rebase in case we want to correct
2351      * the reference to a renamed or moved backing file.
2352      */
2353     bs = bdrv_new_open("image", filename, fmt, flags, true, quiet);
2354     if (!bs) {
2355         return 1;
2356     }
2357 
2358     /* Find the right drivers for the backing files */
2359     old_backing_drv = NULL;
2360     new_backing_drv = NULL;
2361 
2362     if (!unsafe && bs->backing_format[0] != '\0') {
2363         old_backing_drv = bdrv_find_format(bs->backing_format);
2364         if (old_backing_drv == NULL) {
2365             error_report("Invalid format name: '%s'", bs->backing_format);
2366             ret = -1;
2367             goto out;
2368         }
2369     }
2370 
2371     if (out_basefmt != NULL) {
2372         new_backing_drv = bdrv_find_format(out_basefmt);
2373         if (new_backing_drv == NULL) {
2374             error_report("Invalid format name: '%s'", out_basefmt);
2375             ret = -1;
2376             goto out;
2377         }
2378     }
2379 
2380     /* For safe rebasing we need to compare old and new backing file */
2381     if (unsafe) {
2382         /* Make the compiler happy */
2383         bs_old_backing = NULL;
2384         bs_new_backing = NULL;
2385     } else {
2386         char backing_name[1024];
2387 
2388         bs_old_backing = bdrv_new("old_backing", &error_abort);
2389         bdrv_get_backing_filename(bs, backing_name, sizeof(backing_name));
2390         ret = bdrv_open(&bs_old_backing, backing_name, NULL, NULL, BDRV_O_FLAGS,
2391                         old_backing_drv, &local_err);
2392         if (ret) {
2393             error_report("Could not open old backing file '%s': %s",
2394                          backing_name, error_get_pretty(local_err));
2395             error_free(local_err);
2396             goto out;
2397         }
2398         if (out_baseimg[0]) {
2399             bs_new_backing = bdrv_new("new_backing", &error_abort);
2400             ret = bdrv_open(&bs_new_backing, out_baseimg, NULL, NULL,
2401                             BDRV_O_FLAGS, new_backing_drv, &local_err);
2402             if (ret) {
2403                 error_report("Could not open new backing file '%s': %s",
2404                              out_baseimg, error_get_pretty(local_err));
2405                 error_free(local_err);
2406                 goto out;
2407             }
2408         }
2409     }
2410 
2411     /*
2412      * Check each unallocated cluster in the COW file. If it is unallocated,
2413      * accesses go to the backing file. We must therefore compare this cluster
2414      * in the old and new backing file, and if they differ we need to copy it
2415      * from the old backing file into the COW file.
2416      *
2417      * If qemu-img crashes during this step, no harm is done. The content of
2418      * the image is the same as the original one at any time.
2419      */
2420     if (!unsafe) {
2421         uint64_t num_sectors;
2422         uint64_t old_backing_num_sectors;
2423         uint64_t new_backing_num_sectors = 0;
2424         uint64_t sector;
2425         int n;
2426         uint8_t * buf_old;
2427         uint8_t * buf_new;
2428         float local_progress = 0;
2429 
2430         buf_old = qemu_blockalign(bs, IO_BUF_SIZE);
2431         buf_new = qemu_blockalign(bs, IO_BUF_SIZE);
2432 
2433         bdrv_get_geometry(bs, &num_sectors);
2434         bdrv_get_geometry(bs_old_backing, &old_backing_num_sectors);
2435         if (bs_new_backing) {
2436             bdrv_get_geometry(bs_new_backing, &new_backing_num_sectors);
2437         }
2438 
2439         if (num_sectors != 0) {
2440             local_progress = (float)100 /
2441                 (num_sectors / MIN(num_sectors, IO_BUF_SIZE / 512));
2442         }
2443 
2444         for (sector = 0; sector < num_sectors; sector += n) {
2445 
2446             /* How many sectors can we handle with the next read? */
2447             if (sector + (IO_BUF_SIZE / 512) <= num_sectors) {
2448                 n = (IO_BUF_SIZE / 512);
2449             } else {
2450                 n = num_sectors - sector;
2451             }
2452 
2453             /* If the cluster is allocated, we don't need to take action */
2454             ret = bdrv_is_allocated(bs, sector, n, &n);
2455             if (ret < 0) {
2456                 error_report("error while reading image metadata: %s",
2457                              strerror(-ret));
2458                 goto out;
2459             }
2460             if (ret) {
2461                 continue;
2462             }
2463 
2464             /*
2465              * Read old and new backing file and take into consideration that
2466              * backing files may be smaller than the COW image.
2467              */
2468             if (sector >= old_backing_num_sectors) {
2469                 memset(buf_old, 0, n * BDRV_SECTOR_SIZE);
2470             } else {
2471                 if (sector + n > old_backing_num_sectors) {
2472                     n = old_backing_num_sectors - sector;
2473                 }
2474 
2475                 ret = bdrv_read(bs_old_backing, sector, buf_old, n);
2476                 if (ret < 0) {
2477                     error_report("error while reading from old backing file");
2478                     goto out;
2479                 }
2480             }
2481 
2482             if (sector >= new_backing_num_sectors || !bs_new_backing) {
2483                 memset(buf_new, 0, n * BDRV_SECTOR_SIZE);
2484             } else {
2485                 if (sector + n > new_backing_num_sectors) {
2486                     n = new_backing_num_sectors - sector;
2487                 }
2488 
2489                 ret = bdrv_read(bs_new_backing, sector, buf_new, n);
2490                 if (ret < 0) {
2491                     error_report("error while reading from new backing file");
2492                     goto out;
2493                 }
2494             }
2495 
2496             /* If they differ, we need to write to the COW file */
2497             uint64_t written = 0;
2498 
2499             while (written < n) {
2500                 int pnum;
2501 
2502                 if (compare_sectors(buf_old + written * 512,
2503                     buf_new + written * 512, n - written, &pnum))
2504                 {
2505                     ret = bdrv_write(bs, sector + written,
2506                         buf_old + written * 512, pnum);
2507                     if (ret < 0) {
2508                         error_report("Error while writing to COW image: %s",
2509                             strerror(-ret));
2510                         goto out;
2511                     }
2512                 }
2513 
2514                 written += pnum;
2515             }
2516             qemu_progress_print(local_progress, 100);
2517         }
2518 
2519         qemu_vfree(buf_old);
2520         qemu_vfree(buf_new);
2521     }
2522 
2523     /*
2524      * Change the backing file. All clusters that are different from the old
2525      * backing file are overwritten in the COW file now, so the visible content
2526      * doesn't change when we switch the backing file.
2527      */
2528     if (out_baseimg && *out_baseimg) {
2529         ret = bdrv_change_backing_file(bs, out_baseimg, out_basefmt);
2530     } else {
2531         ret = bdrv_change_backing_file(bs, NULL, NULL);
2532     }
2533 
2534     if (ret == -ENOSPC) {
2535         error_report("Could not change the backing file to '%s': No "
2536                      "space left in the file header", out_baseimg);
2537     } else if (ret < 0) {
2538         error_report("Could not change the backing file to '%s': %s",
2539             out_baseimg, strerror(-ret));
2540     }
2541 
2542     qemu_progress_print(100, 0);
2543     /*
2544      * TODO At this point it is possible to check if any clusters that are
2545      * allocated in the COW file are the same in the backing file. If so, they
2546      * could be dropped from the COW file. Don't do this before switching the
2547      * backing file, in case of a crash this would lead to corruption.
2548      */
2549 out:
2550     qemu_progress_end();
2551     /* Cleanup */
2552     if (!unsafe) {
2553         if (bs_old_backing != NULL) {
2554             bdrv_unref(bs_old_backing);
2555         }
2556         if (bs_new_backing != NULL) {
2557             bdrv_unref(bs_new_backing);
2558         }
2559     }
2560 
2561     bdrv_unref(bs);
2562     if (ret) {
2563         return 1;
2564     }
2565     return 0;
2566 }
2567 
2568 static int img_resize(int argc, char **argv)
2569 {
2570     int c, ret, relative;
2571     const char *filename, *fmt, *size;
2572     int64_t n, total_size;
2573     bool quiet = false;
2574     BlockDriverState *bs = NULL;
2575     QemuOpts *param;
2576     static QemuOptsList resize_options = {
2577         .name = "resize_options",
2578         .head = QTAILQ_HEAD_INITIALIZER(resize_options.head),
2579         .desc = {
2580             {
2581                 .name = BLOCK_OPT_SIZE,
2582                 .type = QEMU_OPT_SIZE,
2583                 .help = "Virtual disk size"
2584             }, {
2585                 /* end of list */
2586             }
2587         },
2588     };
2589 
2590     /* Remove size from argv manually so that negative numbers are not treated
2591      * as options by getopt. */
2592     if (argc < 3) {
2593         error_exit("Not enough arguments");
2594         return 1;
2595     }
2596 
2597     size = argv[--argc];
2598 
2599     /* Parse getopt arguments */
2600     fmt = NULL;
2601     for(;;) {
2602         c = getopt(argc, argv, "f:hq");
2603         if (c == -1) {
2604             break;
2605         }
2606         switch(c) {
2607         case '?':
2608         case 'h':
2609             help();
2610             break;
2611         case 'f':
2612             fmt = optarg;
2613             break;
2614         case 'q':
2615             quiet = true;
2616             break;
2617         }
2618     }
2619     if (optind != argc - 1) {
2620         error_exit("Expecting one image file name");
2621     }
2622     filename = argv[optind++];
2623 
2624     /* Choose grow, shrink, or absolute resize mode */
2625     switch (size[0]) {
2626     case '+':
2627         relative = 1;
2628         size++;
2629         break;
2630     case '-':
2631         relative = -1;
2632         size++;
2633         break;
2634     default:
2635         relative = 0;
2636         break;
2637     }
2638 
2639     /* Parse size */
2640     param = qemu_opts_create(&resize_options, NULL, 0, &error_abort);
2641     if (qemu_opt_set(param, BLOCK_OPT_SIZE, size)) {
2642         /* Error message already printed when size parsing fails */
2643         ret = -1;
2644         qemu_opts_del(param);
2645         goto out;
2646     }
2647     n = qemu_opt_get_size(param, BLOCK_OPT_SIZE, 0);
2648     qemu_opts_del(param);
2649 
2650     bs = bdrv_new_open("image", filename, fmt, BDRV_O_FLAGS | BDRV_O_RDWR,
2651                        true, quiet);
2652     if (!bs) {
2653         ret = -1;
2654         goto out;
2655     }
2656 
2657     if (relative) {
2658         total_size = bdrv_getlength(bs) + n * relative;
2659     } else {
2660         total_size = n;
2661     }
2662     if (total_size <= 0) {
2663         error_report("New image size must be positive");
2664         ret = -1;
2665         goto out;
2666     }
2667 
2668     ret = bdrv_truncate(bs, total_size);
2669     switch (ret) {
2670     case 0:
2671         qprintf(quiet, "Image resized.\n");
2672         break;
2673     case -ENOTSUP:
2674         error_report("This image does not support resize");
2675         break;
2676     case -EACCES:
2677         error_report("Image is read-only");
2678         break;
2679     default:
2680         error_report("Error resizing image (%d)", -ret);
2681         break;
2682     }
2683 out:
2684     if (bs) {
2685         bdrv_unref(bs);
2686     }
2687     if (ret) {
2688         return 1;
2689     }
2690     return 0;
2691 }
2692 
2693 static int img_amend(int argc, char **argv)
2694 {
2695     int c, ret = 0;
2696     char *options = NULL;
2697     QemuOptsList *create_opts = NULL;
2698     QemuOpts *opts = NULL;
2699     const char *fmt = NULL, *filename;
2700     bool quiet = false;
2701     BlockDriverState *bs = NULL;
2702 
2703     for (;;) {
2704         c = getopt(argc, argv, "hqf:o:");
2705         if (c == -1) {
2706             break;
2707         }
2708 
2709         switch (c) {
2710             case 'h':
2711             case '?':
2712                 help();
2713                 break;
2714             case 'o':
2715                 if (!is_valid_option_list(optarg)) {
2716                     error_report("Invalid option list: %s", optarg);
2717                     ret = -1;
2718                     goto out;
2719                 }
2720                 if (!options) {
2721                     options = g_strdup(optarg);
2722                 } else {
2723                     char *old_options = options;
2724                     options = g_strdup_printf("%s,%s", options, optarg);
2725                     g_free(old_options);
2726                 }
2727                 break;
2728             case 'f':
2729                 fmt = optarg;
2730                 break;
2731             case 'q':
2732                 quiet = true;
2733                 break;
2734         }
2735     }
2736 
2737     if (!options) {
2738         error_exit("Must specify options (-o)");
2739     }
2740 
2741     filename = (optind == argc - 1) ? argv[argc - 1] : NULL;
2742     if (fmt && has_help_option(options)) {
2743         /* If a format is explicitly specified (and possibly no filename is
2744          * given), print option help here */
2745         ret = print_block_option_help(filename, fmt);
2746         goto out;
2747     }
2748 
2749     if (optind != argc - 1) {
2750         error_exit("Expecting one image file name");
2751     }
2752 
2753     bs = bdrv_new_open("image", filename, fmt,
2754                        BDRV_O_FLAGS | BDRV_O_RDWR, true, quiet);
2755     if (!bs) {
2756         error_report("Could not open image '%s'", filename);
2757         ret = -1;
2758         goto out;
2759     }
2760 
2761     fmt = bs->drv->format_name;
2762 
2763     if (has_help_option(options)) {
2764         /* If the format was auto-detected, print option help here */
2765         ret = print_block_option_help(filename, fmt);
2766         goto out;
2767     }
2768 
2769     create_opts = qemu_opts_append(create_opts, bs->drv->create_opts);
2770     opts = qemu_opts_create(create_opts, NULL, 0, &error_abort);
2771     if (options && qemu_opts_do_parse(opts, options, NULL)) {
2772         error_report("Invalid options for file format '%s'", fmt);
2773         ret = -1;
2774         goto out;
2775     }
2776 
2777     ret = bdrv_amend_options(bs, opts);
2778     if (ret < 0) {
2779         error_report("Error while amending options: %s", strerror(-ret));
2780         goto out;
2781     }
2782 
2783 out:
2784     if (bs) {
2785         bdrv_unref(bs);
2786     }
2787     qemu_opts_del(opts);
2788     qemu_opts_free(create_opts);
2789     g_free(options);
2790 
2791     if (ret) {
2792         return 1;
2793     }
2794     return 0;
2795 }
2796 
2797 static const img_cmd_t img_cmds[] = {
2798 #define DEF(option, callback, arg_string)        \
2799     { option, callback },
2800 #include "qemu-img-cmds.h"
2801 #undef DEF
2802 #undef GEN_DOCS
2803     { NULL, NULL, },
2804 };
2805 
2806 int main(int argc, char **argv)
2807 {
2808     const img_cmd_t *cmd;
2809     const char *cmdname;
2810     int c;
2811     static const struct option long_options[] = {
2812         {"help", no_argument, 0, 'h'},
2813         {"version", no_argument, 0, 'v'},
2814         {0, 0, 0, 0}
2815     };
2816 
2817 #ifdef CONFIG_POSIX
2818     signal(SIGPIPE, SIG_IGN);
2819 #endif
2820 
2821     error_set_progname(argv[0]);
2822     qemu_init_exec_dir(argv[0]);
2823 
2824     qemu_init_main_loop();
2825     bdrv_init();
2826     if (argc < 2) {
2827         error_exit("Not enough arguments");
2828     }
2829     cmdname = argv[1];
2830 
2831     /* find the command */
2832     for (cmd = img_cmds; cmd->name != NULL; cmd++) {
2833         if (!strcmp(cmdname, cmd->name)) {
2834             return cmd->handler(argc - 1, argv + 1);
2835         }
2836     }
2837 
2838     c = getopt_long(argc, argv, "h", long_options, NULL);
2839 
2840     if (c == 'h') {
2841         help();
2842     }
2843     if (c == 'v') {
2844         printf(QEMU_IMG_VERSION);
2845         return 0;
2846     }
2847 
2848     /* not found */
2849     error_exit("Command not found: %s", cmdname);
2850 }
2851