xref: /openbmc/qemu/qemu-img.c (revision 01c22f2c)
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 
36 typedef struct img_cmd_t {
37     const char *name;
38     int (*handler)(int argc, char **argv);
39 } img_cmd_t;
40 
41 enum {
42     OPTION_OUTPUT = 256,
43     OPTION_BACKING_CHAIN = 257,
44 };
45 
46 typedef enum OutputFormat {
47     OFORMAT_JSON,
48     OFORMAT_HUMAN,
49 } OutputFormat;
50 
51 /* Default to cache=writeback as data integrity is not important for qemu-tcg. */
52 #define BDRV_O_FLAGS BDRV_O_CACHE_WB
53 #define BDRV_DEFAULT_CACHE "writeback"
54 
55 static void format_print(void *opaque, const char *name)
56 {
57     printf(" %s", name);
58 }
59 
60 /* Please keep in synch with qemu-img.texi */
61 static void help(void)
62 {
63     const char *help_msg =
64            "qemu-img version " QEMU_VERSION ", Copyright (c) 2004-2008 Fabrice Bellard\n"
65            "usage: qemu-img command [command options]\n"
66            "QEMU disk image utility\n"
67            "\n"
68            "Command syntax:\n"
69 #define DEF(option, callback, arg_string)        \
70            "  " arg_string "\n"
71 #include "qemu-img-cmds.h"
72 #undef DEF
73 #undef GEN_DOCS
74            "\n"
75            "Command parameters:\n"
76            "  'filename' is a disk image filename\n"
77            "  'fmt' is the disk image format. It is guessed automatically in most cases\n"
78            "  'cache' is the cache mode used to write the output disk image, the valid\n"
79            "    options are: 'none', 'writeback' (default, except for convert), 'writethrough',\n"
80            "    'directsync' and 'unsafe' (default for convert)\n"
81            "  'size' is the disk image size in bytes. Optional suffixes\n"
82            "    'k' or 'K' (kilobyte, 1024), 'M' (megabyte, 1024k), 'G' (gigabyte, 1024M),\n"
83            "    'T' (terabyte, 1024G), 'P' (petabyte, 1024T) and 'E' (exabyte, 1024P)  are\n"
84            "    supported. 'b' is ignored.\n"
85            "  'output_filename' is the destination disk image filename\n"
86            "  'output_fmt' is the destination format\n"
87            "  'options' is a comma separated list of format specific options in a\n"
88            "    name=value format. Use -o ? for an overview of the options supported by the\n"
89            "    used format\n"
90            "  'snapshot_param' is param used for internal snapshot, format\n"
91            "    is 'snapshot.id=[ID],snapshot.name=[NAME]', or\n"
92            "    '[ID_OR_NAME]'\n"
93            "  'snapshot_id_or_name' is deprecated, use 'snapshot_param'\n"
94            "    instead\n"
95            "  '-c' indicates that target image must be compressed (qcow format only)\n"
96            "  '-u' enables unsafe rebasing. It is assumed that old and new backing file\n"
97            "       match exactly. The image doesn't need a working backing file before\n"
98            "       rebasing in this case (useful for renaming the backing file)\n"
99            "  '-h' with or without a command shows this help and lists the supported formats\n"
100            "  '-p' show progress of command (only certain commands)\n"
101            "  '-q' use Quiet mode - do not print any output (except errors)\n"
102            "  '-S' indicates the consecutive number of bytes (defaults to 4k) that must\n"
103            "       contain only zeros for qemu-img to create a sparse image during\n"
104            "       conversion. If the number of bytes is 0, the source will not be scanned for\n"
105            "       unallocated or zero sectors, and the destination image will always be\n"
106            "       fully allocated\n"
107            "  '--output' takes the format in which the output must be done (human or json)\n"
108            "  '-n' skips the target volume creation (useful if the volume is created\n"
109            "       prior to running qemu-img)\n"
110            "\n"
111            "Parameters to check subcommand:\n"
112            "  '-r' tries to repair any inconsistencies that are found during the check.\n"
113            "       '-r leaks' repairs only cluster leaks, whereas '-r all' fixes all\n"
114            "       kinds of errors, with a higher risk of choosing the wrong fix or\n"
115            "       hiding corruption that has already occurred.\n"
116            "\n"
117            "Parameters to snapshot subcommand:\n"
118            "  'snapshot' is the name of the snapshot to create, apply or delete\n"
119            "  '-a' applies a snapshot (revert disk to saved state)\n"
120            "  '-c' creates a snapshot\n"
121            "  '-d' deletes a snapshot\n"
122            "  '-l' lists all snapshots in the given image\n"
123            "\n"
124            "Parameters to compare subcommand:\n"
125            "  '-f' first image format\n"
126            "  '-F' second image format\n"
127            "  '-s' run in Strict mode - fail on different image size or sector allocation\n";
128 
129     printf("%s\nSupported formats:", help_msg);
130     bdrv_iterate_format(format_print, NULL);
131     printf("\n");
132     exit(1);
133 }
134 
135 static int GCC_FMT_ATTR(2, 3) qprintf(bool quiet, const char *fmt, ...)
136 {
137     int ret = 0;
138     if (!quiet) {
139         va_list args;
140         va_start(args, fmt);
141         ret = vprintf(fmt, args);
142         va_end(args);
143     }
144     return ret;
145 }
146 
147 #if defined(WIN32)
148 /* XXX: put correct support for win32 */
149 static int read_password(char *buf, int buf_size)
150 {
151     int c, i;
152     printf("Password: ");
153     fflush(stdout);
154     i = 0;
155     for(;;) {
156         c = getchar();
157         if (c == '\n')
158             break;
159         if (i < (buf_size - 1))
160             buf[i++] = c;
161     }
162     buf[i] = '\0';
163     return 0;
164 }
165 
166 #else
167 
168 #include <termios.h>
169 
170 static struct termios oldtty;
171 
172 static void term_exit(void)
173 {
174     tcsetattr (0, TCSANOW, &oldtty);
175 }
176 
177 static void term_init(void)
178 {
179     struct termios tty;
180 
181     tcgetattr (0, &tty);
182     oldtty = tty;
183 
184     tty.c_iflag &= ~(IGNBRK|BRKINT|PARMRK|ISTRIP
185                           |INLCR|IGNCR|ICRNL|IXON);
186     tty.c_oflag |= OPOST;
187     tty.c_lflag &= ~(ECHO|ECHONL|ICANON|IEXTEN);
188     tty.c_cflag &= ~(CSIZE|PARENB);
189     tty.c_cflag |= CS8;
190     tty.c_cc[VMIN] = 1;
191     tty.c_cc[VTIME] = 0;
192 
193     tcsetattr (0, TCSANOW, &tty);
194 
195     atexit(term_exit);
196 }
197 
198 static int read_password(char *buf, int buf_size)
199 {
200     uint8_t ch;
201     int i, ret;
202 
203     printf("password: ");
204     fflush(stdout);
205     term_init();
206     i = 0;
207     for(;;) {
208         ret = read(0, &ch, 1);
209         if (ret == -1) {
210             if (errno == EAGAIN || errno == EINTR) {
211                 continue;
212             } else {
213                 ret = -1;
214                 break;
215             }
216         } else if (ret == 0) {
217             ret = -1;
218             break;
219         } else {
220             if (ch == '\r') {
221                 ret = 0;
222                 break;
223             }
224             if (i < (buf_size - 1))
225                 buf[i++] = ch;
226         }
227     }
228     term_exit();
229     buf[i] = '\0';
230     printf("\n");
231     return ret;
232 }
233 #endif
234 
235 static int print_block_option_help(const char *filename, const char *fmt)
236 {
237     BlockDriver *drv, *proto_drv;
238     QEMUOptionParameter *create_options = NULL;
239 
240     /* Find driver and parse its options */
241     drv = bdrv_find_format(fmt);
242     if (!drv) {
243         error_report("Unknown file format '%s'", fmt);
244         return 1;
245     }
246 
247     create_options = append_option_parameters(create_options,
248                                               drv->create_options);
249 
250     if (filename) {
251         proto_drv = bdrv_find_protocol(filename, true);
252         if (!proto_drv) {
253             error_report("Unknown protocol '%s'", filename);
254             return 1;
255         }
256         create_options = append_option_parameters(create_options,
257                                                   proto_drv->create_options);
258     }
259 
260     print_option_help(create_options);
261     free_option_parameters(create_options);
262     return 0;
263 }
264 
265 static BlockDriverState *bdrv_new_open(const char *filename,
266                                        const char *fmt,
267                                        int flags,
268                                        bool require_io,
269                                        bool quiet)
270 {
271     BlockDriverState *bs;
272     BlockDriver *drv;
273     char password[256];
274     Error *local_err = NULL;
275     int ret;
276 
277     bs = bdrv_new("image");
278 
279     if (fmt) {
280         drv = bdrv_find_format(fmt);
281         if (!drv) {
282             error_report("Unknown file format '%s'", fmt);
283             goto fail;
284         }
285     } else {
286         drv = NULL;
287     }
288 
289     ret = bdrv_open(&bs, filename, NULL, NULL, flags, drv, &local_err);
290     if (ret < 0) {
291         error_report("Could not open '%s': %s", filename,
292                      error_get_pretty(local_err));
293         error_free(local_err);
294         goto fail;
295     }
296 
297     if (bdrv_is_encrypted(bs) && require_io) {
298         qprintf(quiet, "Disk image '%s' is encrypted.\n", filename);
299         if (read_password(password, sizeof(password)) < 0) {
300             error_report("No password given");
301             goto fail;
302         }
303         if (bdrv_set_key(bs, password) < 0) {
304             error_report("invalid password");
305             goto fail;
306         }
307     }
308     return bs;
309 fail:
310     bdrv_unref(bs);
311     return NULL;
312 }
313 
314 static int add_old_style_options(const char *fmt, QEMUOptionParameter *list,
315                                  const char *base_filename,
316                                  const char *base_fmt)
317 {
318     if (base_filename) {
319         if (set_option_parameter(list, BLOCK_OPT_BACKING_FILE, base_filename)) {
320             error_report("Backing file not supported for file format '%s'",
321                          fmt);
322             return -1;
323         }
324     }
325     if (base_fmt) {
326         if (set_option_parameter(list, BLOCK_OPT_BACKING_FMT, base_fmt)) {
327             error_report("Backing file format not supported for file "
328                          "format '%s'", fmt);
329             return -1;
330         }
331     }
332     return 0;
333 }
334 
335 static int img_create(int argc, char **argv)
336 {
337     int c;
338     uint64_t img_size = -1;
339     const char *fmt = "raw";
340     const char *base_fmt = NULL;
341     const char *filename;
342     const char *base_filename = NULL;
343     char *options = NULL;
344     Error *local_err = NULL;
345     bool quiet = false;
346 
347     for(;;) {
348         c = getopt(argc, argv, "F:b:f:he6o:q");
349         if (c == -1) {
350             break;
351         }
352         switch(c) {
353         case '?':
354         case 'h':
355             help();
356             break;
357         case 'F':
358             base_fmt = optarg;
359             break;
360         case 'b':
361             base_filename = optarg;
362             break;
363         case 'f':
364             fmt = optarg;
365             break;
366         case 'e':
367             error_report("option -e is deprecated, please use \'-o "
368                   "encryption\' instead!");
369             goto fail;
370         case '6':
371             error_report("option -6 is deprecated, please use \'-o "
372                   "compat6\' instead!");
373             goto fail;
374         case 'o':
375             if (!is_valid_option_list(optarg)) {
376                 error_report("Invalid option list: %s", optarg);
377                 goto fail;
378             }
379             if (!options) {
380                 options = g_strdup(optarg);
381             } else {
382                 char *old_options = options;
383                 options = g_strdup_printf("%s,%s", options, optarg);
384                 g_free(old_options);
385             }
386             break;
387         case 'q':
388             quiet = true;
389             break;
390         }
391     }
392 
393     /* Get the filename */
394     filename = (optind < argc) ? argv[optind] : NULL;
395     if (options && has_help_option(options)) {
396         g_free(options);
397         return print_block_option_help(filename, fmt);
398     }
399 
400     if (optind >= argc) {
401         help();
402     }
403     optind++;
404 
405     /* Get image size, if specified */
406     if (optind < argc) {
407         int64_t sval;
408         char *end;
409         sval = strtosz_suffix(argv[optind++], &end, STRTOSZ_DEFSUFFIX_B);
410         if (sval < 0 || *end) {
411             if (sval == -ERANGE) {
412                 error_report("Image size must be less than 8 EiB!");
413             } else {
414                 error_report("Invalid image size specified! You may use k, M, "
415                       "G, T, P or E suffixes for ");
416                 error_report("kilobytes, megabytes, gigabytes, terabytes, "
417                              "petabytes and exabytes.");
418             }
419             goto fail;
420         }
421         img_size = (uint64_t)sval;
422     }
423     if (optind != argc) {
424         help();
425     }
426 
427     bdrv_img_create(filename, fmt, base_filename, base_fmt,
428                     options, img_size, BDRV_O_FLAGS, &local_err, quiet);
429     if (local_err) {
430         error_report("%s: %s", filename, error_get_pretty(local_err));
431         error_free(local_err);
432         goto fail;
433     }
434 
435     g_free(options);
436     return 0;
437 
438 fail:
439     g_free(options);
440     return 1;
441 }
442 
443 static void dump_json_image_check(ImageCheck *check, bool quiet)
444 {
445     Error *errp = NULL;
446     QString *str;
447     QmpOutputVisitor *ov = qmp_output_visitor_new();
448     QObject *obj;
449     visit_type_ImageCheck(qmp_output_get_visitor(ov),
450                           &check, NULL, &errp);
451     obj = qmp_output_get_qobject(ov);
452     str = qobject_to_json_pretty(obj);
453     assert(str != NULL);
454     qprintf(quiet, "%s\n", qstring_get_str(str));
455     qobject_decref(obj);
456     qmp_output_visitor_cleanup(ov);
457     QDECREF(str);
458 }
459 
460 static void dump_human_image_check(ImageCheck *check, bool quiet)
461 {
462     if (!(check->corruptions || check->leaks || check->check_errors)) {
463         qprintf(quiet, "No errors were found on the image.\n");
464     } else {
465         if (check->corruptions) {
466             qprintf(quiet, "\n%" PRId64 " errors were found on the image.\n"
467                     "Data may be corrupted, or further writes to the image "
468                     "may corrupt it.\n",
469                     check->corruptions);
470         }
471 
472         if (check->leaks) {
473             qprintf(quiet,
474                     "\n%" PRId64 " leaked clusters were found on the image.\n"
475                     "This means waste of disk space, but no harm to data.\n",
476                     check->leaks);
477         }
478 
479         if (check->check_errors) {
480             qprintf(quiet,
481                     "\n%" PRId64
482                     " internal errors have occurred during the check.\n",
483                     check->check_errors);
484         }
485     }
486 
487     if (check->total_clusters != 0 && check->allocated_clusters != 0) {
488         qprintf(quiet, "%" PRId64 "/%" PRId64 " = %0.2f%% allocated, "
489                 "%0.2f%% fragmented, %0.2f%% compressed clusters\n",
490                 check->allocated_clusters, check->total_clusters,
491                 check->allocated_clusters * 100.0 / check->total_clusters,
492                 check->fragmented_clusters * 100.0 / check->allocated_clusters,
493                 check->compressed_clusters * 100.0 /
494                 check->allocated_clusters);
495     }
496 
497     if (check->image_end_offset) {
498         qprintf(quiet,
499                 "Image end offset: %" PRId64 "\n", check->image_end_offset);
500     }
501 }
502 
503 static int collect_image_check(BlockDriverState *bs,
504                    ImageCheck *check,
505                    const char *filename,
506                    const char *fmt,
507                    int fix)
508 {
509     int ret;
510     BdrvCheckResult result;
511 
512     ret = bdrv_check(bs, &result, fix);
513     if (ret < 0) {
514         return ret;
515     }
516 
517     check->filename                 = g_strdup(filename);
518     check->format                   = g_strdup(bdrv_get_format_name(bs));
519     check->check_errors             = result.check_errors;
520     check->corruptions              = result.corruptions;
521     check->has_corruptions          = result.corruptions != 0;
522     check->leaks                    = result.leaks;
523     check->has_leaks                = result.leaks != 0;
524     check->corruptions_fixed        = result.corruptions_fixed;
525     check->has_corruptions_fixed    = result.corruptions != 0;
526     check->leaks_fixed              = result.leaks_fixed;
527     check->has_leaks_fixed          = result.leaks != 0;
528     check->image_end_offset         = result.image_end_offset;
529     check->has_image_end_offset     = result.image_end_offset != 0;
530     check->total_clusters           = result.bfi.total_clusters;
531     check->has_total_clusters       = result.bfi.total_clusters != 0;
532     check->allocated_clusters       = result.bfi.allocated_clusters;
533     check->has_allocated_clusters   = result.bfi.allocated_clusters != 0;
534     check->fragmented_clusters      = result.bfi.fragmented_clusters;
535     check->has_fragmented_clusters  = result.bfi.fragmented_clusters != 0;
536     check->compressed_clusters      = result.bfi.compressed_clusters;
537     check->has_compressed_clusters  = result.bfi.compressed_clusters != 0;
538 
539     return 0;
540 }
541 
542 /*
543  * Checks an image for consistency. Exit codes:
544  *
545  * 0 - Check completed, image is good
546  * 1 - Check not completed because of internal errors
547  * 2 - Check completed, image is corrupted
548  * 3 - Check completed, image has leaked clusters, but is good otherwise
549  */
550 static int img_check(int argc, char **argv)
551 {
552     int c, ret;
553     OutputFormat output_format = OFORMAT_HUMAN;
554     const char *filename, *fmt, *output;
555     BlockDriverState *bs;
556     int fix = 0;
557     int flags = BDRV_O_FLAGS | BDRV_O_CHECK;
558     ImageCheck *check;
559     bool quiet = false;
560 
561     fmt = NULL;
562     output = NULL;
563     for(;;) {
564         int option_index = 0;
565         static const struct option long_options[] = {
566             {"help", no_argument, 0, 'h'},
567             {"format", required_argument, 0, 'f'},
568             {"repair", no_argument, 0, 'r'},
569             {"output", required_argument, 0, OPTION_OUTPUT},
570             {0, 0, 0, 0}
571         };
572         c = getopt_long(argc, argv, "f:hr:q",
573                         long_options, &option_index);
574         if (c == -1) {
575             break;
576         }
577         switch(c) {
578         case '?':
579         case 'h':
580             help();
581             break;
582         case 'f':
583             fmt = optarg;
584             break;
585         case 'r':
586             flags |= BDRV_O_RDWR;
587 
588             if (!strcmp(optarg, "leaks")) {
589                 fix = BDRV_FIX_LEAKS;
590             } else if (!strcmp(optarg, "all")) {
591                 fix = BDRV_FIX_LEAKS | BDRV_FIX_ERRORS;
592             } else {
593                 help();
594             }
595             break;
596         case OPTION_OUTPUT:
597             output = optarg;
598             break;
599         case 'q':
600             quiet = true;
601             break;
602         }
603     }
604     if (optind != argc - 1) {
605         help();
606     }
607     filename = argv[optind++];
608 
609     if (output && !strcmp(output, "json")) {
610         output_format = OFORMAT_JSON;
611     } else if (output && !strcmp(output, "human")) {
612         output_format = OFORMAT_HUMAN;
613     } else if (output) {
614         error_report("--output must be used with human or json as argument.");
615         return 1;
616     }
617 
618     bs = bdrv_new_open(filename, fmt, flags, true, quiet);
619     if (!bs) {
620         return 1;
621     }
622 
623     check = g_new0(ImageCheck, 1);
624     ret = collect_image_check(bs, check, filename, fmt, fix);
625 
626     if (ret == -ENOTSUP) {
627         if (output_format == OFORMAT_HUMAN) {
628             error_report("This image format does not support checks");
629         }
630         ret = 63;
631         goto fail;
632     }
633 
634     if (check->corruptions_fixed || check->leaks_fixed) {
635         int corruptions_fixed, leaks_fixed;
636 
637         leaks_fixed         = check->leaks_fixed;
638         corruptions_fixed   = check->corruptions_fixed;
639 
640         if (output_format == OFORMAT_HUMAN) {
641             qprintf(quiet,
642                     "The following inconsistencies were found and repaired:\n\n"
643                     "    %" PRId64 " leaked clusters\n"
644                     "    %" PRId64 " corruptions\n\n"
645                     "Double checking the fixed image now...\n",
646                     check->leaks_fixed,
647                     check->corruptions_fixed);
648         }
649 
650         ret = collect_image_check(bs, check, filename, fmt, 0);
651 
652         check->leaks_fixed          = leaks_fixed;
653         check->corruptions_fixed    = corruptions_fixed;
654     }
655 
656     switch (output_format) {
657     case OFORMAT_HUMAN:
658         dump_human_image_check(check, quiet);
659         break;
660     case OFORMAT_JSON:
661         dump_json_image_check(check, quiet);
662         break;
663     }
664 
665     if (ret || check->check_errors) {
666         ret = 1;
667         goto fail;
668     }
669 
670     if (check->corruptions) {
671         ret = 2;
672     } else if (check->leaks) {
673         ret = 3;
674     } else {
675         ret = 0;
676     }
677 
678 fail:
679     qapi_free_ImageCheck(check);
680     bdrv_unref(bs);
681 
682     return ret;
683 }
684 
685 static int img_commit(int argc, char **argv)
686 {
687     int c, ret, flags;
688     const char *filename, *fmt, *cache;
689     BlockDriverState *bs;
690     bool quiet = false;
691 
692     fmt = NULL;
693     cache = BDRV_DEFAULT_CACHE;
694     for(;;) {
695         c = getopt(argc, argv, "f:ht:q");
696         if (c == -1) {
697             break;
698         }
699         switch(c) {
700         case '?':
701         case 'h':
702             help();
703             break;
704         case 'f':
705             fmt = optarg;
706             break;
707         case 't':
708             cache = optarg;
709             break;
710         case 'q':
711             quiet = true;
712             break;
713         }
714     }
715     if (optind != argc - 1) {
716         help();
717     }
718     filename = argv[optind++];
719 
720     flags = BDRV_O_RDWR;
721     ret = bdrv_parse_cache_flags(cache, &flags);
722     if (ret < 0) {
723         error_report("Invalid cache option: %s", cache);
724         return -1;
725     }
726 
727     bs = bdrv_new_open(filename, fmt, flags, true, quiet);
728     if (!bs) {
729         return 1;
730     }
731     ret = bdrv_commit(bs);
732     switch(ret) {
733     case 0:
734         qprintf(quiet, "Image committed.\n");
735         break;
736     case -ENOENT:
737         error_report("No disk inserted");
738         break;
739     case -EACCES:
740         error_report("Image is read-only");
741         break;
742     case -ENOTSUP:
743         error_report("Image is already committed");
744         break;
745     default:
746         error_report("Error while committing image");
747         break;
748     }
749 
750     bdrv_unref(bs);
751     if (ret) {
752         return 1;
753     }
754     return 0;
755 }
756 
757 /*
758  * Returns true iff the first sector pointed to by 'buf' contains at least
759  * a non-NUL byte.
760  *
761  * 'pnum' is set to the number of sectors (including and immediately following
762  * the first one) that are known to be in the same allocated/unallocated state.
763  */
764 static int is_allocated_sectors(const uint8_t *buf, int n, int *pnum)
765 {
766     bool is_zero;
767     int i;
768 
769     if (n <= 0) {
770         *pnum = 0;
771         return 0;
772     }
773     is_zero = buffer_is_zero(buf, 512);
774     for(i = 1; i < n; i++) {
775         buf += 512;
776         if (is_zero != buffer_is_zero(buf, 512)) {
777             break;
778         }
779     }
780     *pnum = i;
781     return !is_zero;
782 }
783 
784 /*
785  * Like is_allocated_sectors, but if the buffer starts with a used sector,
786  * up to 'min' consecutive sectors containing zeros are ignored. This avoids
787  * breaking up write requests for only small sparse areas.
788  */
789 static int is_allocated_sectors_min(const uint8_t *buf, int n, int *pnum,
790     int min)
791 {
792     int ret;
793     int num_checked, num_used;
794 
795     if (n < min) {
796         min = n;
797     }
798 
799     ret = is_allocated_sectors(buf, n, pnum);
800     if (!ret) {
801         return ret;
802     }
803 
804     num_used = *pnum;
805     buf += BDRV_SECTOR_SIZE * *pnum;
806     n -= *pnum;
807     num_checked = num_used;
808 
809     while (n > 0) {
810         ret = is_allocated_sectors(buf, n, pnum);
811 
812         buf += BDRV_SECTOR_SIZE * *pnum;
813         n -= *pnum;
814         num_checked += *pnum;
815         if (ret) {
816             num_used = num_checked;
817         } else if (*pnum >= min) {
818             break;
819         }
820     }
821 
822     *pnum = num_used;
823     return 1;
824 }
825 
826 /*
827  * Compares two buffers sector by sector. Returns 0 if the first sector of both
828  * buffers matches, non-zero otherwise.
829  *
830  * pnum is set to the number of sectors (including and immediately following
831  * the first one) that are known to have the same comparison result
832  */
833 static int compare_sectors(const uint8_t *buf1, const uint8_t *buf2, int n,
834     int *pnum)
835 {
836     int res, i;
837 
838     if (n <= 0) {
839         *pnum = 0;
840         return 0;
841     }
842 
843     res = !!memcmp(buf1, buf2, 512);
844     for(i = 1; i < n; i++) {
845         buf1 += 512;
846         buf2 += 512;
847 
848         if (!!memcmp(buf1, buf2, 512) != res) {
849             break;
850         }
851     }
852 
853     *pnum = i;
854     return res;
855 }
856 
857 #define IO_BUF_SIZE (2 * 1024 * 1024)
858 
859 static int64_t sectors_to_bytes(int64_t sectors)
860 {
861     return sectors << BDRV_SECTOR_BITS;
862 }
863 
864 static int64_t sectors_to_process(int64_t total, int64_t from)
865 {
866     return MIN(total - from, IO_BUF_SIZE >> BDRV_SECTOR_BITS);
867 }
868 
869 /*
870  * Check if passed sectors are empty (not allocated or contain only 0 bytes)
871  *
872  * Returns 0 in case sectors are filled with 0, 1 if sectors contain non-zero
873  * data and negative value on error.
874  *
875  * @param bs:  Driver used for accessing file
876  * @param sect_num: Number of first sector to check
877  * @param sect_count: Number of sectors to check
878  * @param filename: Name of disk file we are checking (logging purpose)
879  * @param buffer: Allocated buffer for storing read data
880  * @param quiet: Flag for quiet mode
881  */
882 static int check_empty_sectors(BlockDriverState *bs, int64_t sect_num,
883                                int sect_count, const char *filename,
884                                uint8_t *buffer, bool quiet)
885 {
886     int pnum, ret = 0;
887     ret = bdrv_read(bs, sect_num, buffer, sect_count);
888     if (ret < 0) {
889         error_report("Error while reading offset %" PRId64 " of %s: %s",
890                      sectors_to_bytes(sect_num), filename, strerror(-ret));
891         return ret;
892     }
893     ret = is_allocated_sectors(buffer, sect_count, &pnum);
894     if (ret || pnum != sect_count) {
895         qprintf(quiet, "Content mismatch at offset %" PRId64 "!\n",
896                 sectors_to_bytes(ret ? sect_num : sect_num + pnum));
897         return 1;
898     }
899 
900     return 0;
901 }
902 
903 /*
904  * Compares two images. Exit codes:
905  *
906  * 0 - Images are identical
907  * 1 - Images differ
908  * >1 - Error occurred
909  */
910 static int img_compare(int argc, char **argv)
911 {
912     const char *fmt1 = NULL, *fmt2 = NULL, *filename1, *filename2;
913     BlockDriverState *bs1, *bs2;
914     int64_t total_sectors1, total_sectors2;
915     uint8_t *buf1 = NULL, *buf2 = NULL;
916     int pnum1, pnum2;
917     int allocated1, allocated2;
918     int ret = 0; /* return value - 0 Ident, 1 Different, >1 Error */
919     bool progress = false, quiet = false, strict = false;
920     int64_t total_sectors;
921     int64_t sector_num = 0;
922     int64_t nb_sectors;
923     int c, pnum;
924     uint64_t bs_sectors;
925     uint64_t progress_base;
926 
927     for (;;) {
928         c = getopt(argc, argv, "hpf:F:sq");
929         if (c == -1) {
930             break;
931         }
932         switch (c) {
933         case '?':
934         case 'h':
935             help();
936             break;
937         case 'f':
938             fmt1 = optarg;
939             break;
940         case 'F':
941             fmt2 = optarg;
942             break;
943         case 'p':
944             progress = true;
945             break;
946         case 'q':
947             quiet = true;
948             break;
949         case 's':
950             strict = true;
951             break;
952         }
953     }
954 
955     /* Progress is not shown in Quiet mode */
956     if (quiet) {
957         progress = false;
958     }
959 
960 
961     if (optind != argc - 2) {
962         help();
963     }
964     filename1 = argv[optind++];
965     filename2 = argv[optind++];
966 
967     /* Initialize before goto out */
968     qemu_progress_init(progress, 2.0);
969 
970     bs1 = bdrv_new_open(filename1, fmt1, BDRV_O_FLAGS, true, quiet);
971     if (!bs1) {
972         error_report("Can't open file %s", filename1);
973         ret = 2;
974         goto out3;
975     }
976 
977     bs2 = bdrv_new_open(filename2, fmt2, BDRV_O_FLAGS, true, quiet);
978     if (!bs2) {
979         error_report("Can't open file %s", filename2);
980         ret = 2;
981         goto out2;
982     }
983 
984     buf1 = qemu_blockalign(bs1, IO_BUF_SIZE);
985     buf2 = qemu_blockalign(bs2, IO_BUF_SIZE);
986     bdrv_get_geometry(bs1, &bs_sectors);
987     total_sectors1 = bs_sectors;
988     bdrv_get_geometry(bs2, &bs_sectors);
989     total_sectors2 = bs_sectors;
990     total_sectors = MIN(total_sectors1, total_sectors2);
991     progress_base = MAX(total_sectors1, total_sectors2);
992 
993     qemu_progress_print(0, 100);
994 
995     if (strict && total_sectors1 != total_sectors2) {
996         ret = 1;
997         qprintf(quiet, "Strict mode: Image size mismatch!\n");
998         goto out;
999     }
1000 
1001     for (;;) {
1002         nb_sectors = sectors_to_process(total_sectors, sector_num);
1003         if (nb_sectors <= 0) {
1004             break;
1005         }
1006         allocated1 = bdrv_is_allocated_above(bs1, NULL, sector_num, nb_sectors,
1007                                              &pnum1);
1008         if (allocated1 < 0) {
1009             ret = 3;
1010             error_report("Sector allocation test failed for %s", filename1);
1011             goto out;
1012         }
1013 
1014         allocated2 = bdrv_is_allocated_above(bs2, NULL, sector_num, nb_sectors,
1015                                              &pnum2);
1016         if (allocated2 < 0) {
1017             ret = 3;
1018             error_report("Sector allocation test failed for %s", filename2);
1019             goto out;
1020         }
1021         nb_sectors = MIN(pnum1, pnum2);
1022 
1023         if (allocated1 == allocated2) {
1024             if (allocated1) {
1025                 ret = bdrv_read(bs1, sector_num, buf1, nb_sectors);
1026                 if (ret < 0) {
1027                     error_report("Error while reading offset %" PRId64 " of %s:"
1028                                  " %s", sectors_to_bytes(sector_num), filename1,
1029                                  strerror(-ret));
1030                     ret = 4;
1031                     goto out;
1032                 }
1033                 ret = bdrv_read(bs2, sector_num, buf2, nb_sectors);
1034                 if (ret < 0) {
1035                     error_report("Error while reading offset %" PRId64
1036                                  " of %s: %s", sectors_to_bytes(sector_num),
1037                                  filename2, strerror(-ret));
1038                     ret = 4;
1039                     goto out;
1040                 }
1041                 ret = compare_sectors(buf1, buf2, nb_sectors, &pnum);
1042                 if (ret || pnum != nb_sectors) {
1043                     qprintf(quiet, "Content mismatch at offset %" PRId64 "!\n",
1044                             sectors_to_bytes(
1045                                 ret ? sector_num : sector_num + pnum));
1046                     ret = 1;
1047                     goto out;
1048                 }
1049             }
1050         } else {
1051             if (strict) {
1052                 ret = 1;
1053                 qprintf(quiet, "Strict mode: Offset %" PRId64
1054                         " allocation mismatch!\n",
1055                         sectors_to_bytes(sector_num));
1056                 goto out;
1057             }
1058 
1059             if (allocated1) {
1060                 ret = check_empty_sectors(bs1, sector_num, nb_sectors,
1061                                           filename1, buf1, quiet);
1062             } else {
1063                 ret = check_empty_sectors(bs2, sector_num, nb_sectors,
1064                                           filename2, buf1, quiet);
1065             }
1066             if (ret) {
1067                 if (ret < 0) {
1068                     error_report("Error while reading offset %" PRId64 ": %s",
1069                                  sectors_to_bytes(sector_num), strerror(-ret));
1070                     ret = 4;
1071                 }
1072                 goto out;
1073             }
1074         }
1075         sector_num += nb_sectors;
1076         qemu_progress_print(((float) nb_sectors / progress_base)*100, 100);
1077     }
1078 
1079     if (total_sectors1 != total_sectors2) {
1080         BlockDriverState *bs_over;
1081         int64_t total_sectors_over;
1082         const char *filename_over;
1083 
1084         qprintf(quiet, "Warning: Image size mismatch!\n");
1085         if (total_sectors1 > total_sectors2) {
1086             total_sectors_over = total_sectors1;
1087             bs_over = bs1;
1088             filename_over = filename1;
1089         } else {
1090             total_sectors_over = total_sectors2;
1091             bs_over = bs2;
1092             filename_over = filename2;
1093         }
1094 
1095         for (;;) {
1096             nb_sectors = sectors_to_process(total_sectors_over, sector_num);
1097             if (nb_sectors <= 0) {
1098                 break;
1099             }
1100             ret = bdrv_is_allocated_above(bs_over, NULL, sector_num,
1101                                           nb_sectors, &pnum);
1102             if (ret < 0) {
1103                 ret = 3;
1104                 error_report("Sector allocation test failed for %s",
1105                              filename_over);
1106                 goto out;
1107 
1108             }
1109             nb_sectors = pnum;
1110             if (ret) {
1111                 ret = check_empty_sectors(bs_over, sector_num, nb_sectors,
1112                                           filename_over, buf1, quiet);
1113                 if (ret) {
1114                     if (ret < 0) {
1115                         error_report("Error while reading offset %" PRId64
1116                                      " of %s: %s", sectors_to_bytes(sector_num),
1117                                      filename_over, strerror(-ret));
1118                         ret = 4;
1119                     }
1120                     goto out;
1121                 }
1122             }
1123             sector_num += nb_sectors;
1124             qemu_progress_print(((float) nb_sectors / progress_base)*100, 100);
1125         }
1126     }
1127 
1128     qprintf(quiet, "Images are identical.\n");
1129     ret = 0;
1130 
1131 out:
1132     bdrv_unref(bs2);
1133     qemu_vfree(buf1);
1134     qemu_vfree(buf2);
1135 out2:
1136     bdrv_unref(bs1);
1137 out3:
1138     qemu_progress_end();
1139     return ret;
1140 }
1141 
1142 static int img_convert(int argc, char **argv)
1143 {
1144     int c, n, n1, bs_n, bs_i, compress, cluster_sectors, skip_create;
1145     int64_t ret = 0;
1146     int progress = 0, flags;
1147     const char *fmt, *out_fmt, *cache, *out_baseimg, *out_filename;
1148     BlockDriver *drv, *proto_drv;
1149     BlockDriverState **bs = NULL, *out_bs = NULL;
1150     int64_t total_sectors, nb_sectors, sector_num, bs_offset;
1151     uint64_t bs_sectors;
1152     uint8_t * buf = NULL;
1153     size_t bufsectors = IO_BUF_SIZE / BDRV_SECTOR_SIZE;
1154     const uint8_t *buf1;
1155     BlockDriverInfo bdi;
1156     QEMUOptionParameter *param = NULL, *create_options = NULL;
1157     QEMUOptionParameter *out_baseimg_param;
1158     char *options = NULL;
1159     const char *snapshot_name = NULL;
1160     int min_sparse = 8; /* Need at least 4k of zeros for sparse detection */
1161     bool quiet = false;
1162     Error *local_err = NULL;
1163     QemuOpts *sn_opts = NULL;
1164 
1165     fmt = NULL;
1166     out_fmt = "raw";
1167     cache = "unsafe";
1168     out_baseimg = NULL;
1169     compress = 0;
1170     skip_create = 0;
1171     for(;;) {
1172         c = getopt(argc, argv, "f:O:B:s:hce6o:pS:t:qnl:");
1173         if (c == -1) {
1174             break;
1175         }
1176         switch(c) {
1177         case '?':
1178         case 'h':
1179             help();
1180             break;
1181         case 'f':
1182             fmt = optarg;
1183             break;
1184         case 'O':
1185             out_fmt = optarg;
1186             break;
1187         case 'B':
1188             out_baseimg = optarg;
1189             break;
1190         case 'c':
1191             compress = 1;
1192             break;
1193         case 'e':
1194             error_report("option -e is deprecated, please use \'-o "
1195                   "encryption\' instead!");
1196             ret = -1;
1197             goto fail_getopt;
1198         case '6':
1199             error_report("option -6 is deprecated, please use \'-o "
1200                   "compat6\' instead!");
1201             ret = -1;
1202             goto fail_getopt;
1203         case 'o':
1204             if (!is_valid_option_list(optarg)) {
1205                 error_report("Invalid option list: %s", optarg);
1206                 ret = -1;
1207                 goto fail_getopt;
1208             }
1209             if (!options) {
1210                 options = g_strdup(optarg);
1211             } else {
1212                 char *old_options = options;
1213                 options = g_strdup_printf("%s,%s", options, optarg);
1214                 g_free(old_options);
1215             }
1216             break;
1217         case 's':
1218             snapshot_name = optarg;
1219             break;
1220         case 'l':
1221             if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
1222                 sn_opts = qemu_opts_parse(&internal_snapshot_opts, optarg, 0);
1223                 if (!sn_opts) {
1224                     error_report("Failed in parsing snapshot param '%s'",
1225                                  optarg);
1226                     ret = -1;
1227                     goto fail_getopt;
1228                 }
1229             } else {
1230                 snapshot_name = optarg;
1231             }
1232             break;
1233         case 'S':
1234         {
1235             int64_t sval;
1236             char *end;
1237             sval = strtosz_suffix(optarg, &end, STRTOSZ_DEFSUFFIX_B);
1238             if (sval < 0 || *end) {
1239                 error_report("Invalid minimum zero buffer size for sparse output specified");
1240                 ret = -1;
1241                 goto fail_getopt;
1242             }
1243 
1244             min_sparse = sval / BDRV_SECTOR_SIZE;
1245             break;
1246         }
1247         case 'p':
1248             progress = 1;
1249             break;
1250         case 't':
1251             cache = optarg;
1252             break;
1253         case 'q':
1254             quiet = true;
1255             break;
1256         case 'n':
1257             skip_create = 1;
1258             break;
1259         }
1260     }
1261 
1262     /* Initialize before goto out */
1263     if (quiet) {
1264         progress = 0;
1265     }
1266     qemu_progress_init(progress, 1.0);
1267 
1268 
1269     bs_n = argc - optind - 1;
1270     out_filename = bs_n >= 1 ? argv[argc - 1] : NULL;
1271 
1272     if (options && has_help_option(options)) {
1273         ret = print_block_option_help(out_filename, out_fmt);
1274         goto out;
1275     }
1276 
1277     if (bs_n < 1) {
1278         help();
1279     }
1280 
1281 
1282     if (bs_n > 1 && out_baseimg) {
1283         error_report("-B makes no sense when concatenating multiple input "
1284                      "images");
1285         ret = -1;
1286         goto out;
1287     }
1288 
1289     qemu_progress_print(0, 100);
1290 
1291     bs = g_malloc0(bs_n * sizeof(BlockDriverState *));
1292 
1293     total_sectors = 0;
1294     for (bs_i = 0; bs_i < bs_n; bs_i++) {
1295         bs[bs_i] = bdrv_new_open(argv[optind + bs_i], fmt, BDRV_O_FLAGS, true,
1296                                  quiet);
1297         if (!bs[bs_i]) {
1298             error_report("Could not open '%s'", argv[optind + bs_i]);
1299             ret = -1;
1300             goto out;
1301         }
1302         bdrv_get_geometry(bs[bs_i], &bs_sectors);
1303         total_sectors += bs_sectors;
1304     }
1305 
1306     if (sn_opts) {
1307         ret = bdrv_snapshot_load_tmp(bs[0],
1308                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
1309                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
1310                                      &local_err);
1311     } else if (snapshot_name != NULL) {
1312         if (bs_n > 1) {
1313             error_report("No support for concatenating multiple snapshot");
1314             ret = -1;
1315             goto out;
1316         }
1317 
1318         bdrv_snapshot_load_tmp_by_id_or_name(bs[0], snapshot_name, &local_err);
1319     }
1320     if (local_err) {
1321         error_report("Failed to load snapshot: %s",
1322                      error_get_pretty(local_err));
1323         error_free(local_err);
1324         ret = -1;
1325         goto out;
1326     }
1327 
1328     /* Find driver and parse its options */
1329     drv = bdrv_find_format(out_fmt);
1330     if (!drv) {
1331         error_report("Unknown file format '%s'", out_fmt);
1332         ret = -1;
1333         goto out;
1334     }
1335 
1336     proto_drv = bdrv_find_protocol(out_filename, true);
1337     if (!proto_drv) {
1338         error_report("Unknown protocol '%s'", out_filename);
1339         ret = -1;
1340         goto out;
1341     }
1342 
1343     create_options = append_option_parameters(create_options,
1344                                               drv->create_options);
1345     create_options = append_option_parameters(create_options,
1346                                               proto_drv->create_options);
1347 
1348     if (options) {
1349         param = parse_option_parameters(options, create_options, param);
1350         if (param == NULL) {
1351             error_report("Invalid options for file format '%s'.", out_fmt);
1352             ret = -1;
1353             goto out;
1354         }
1355     } else {
1356         param = parse_option_parameters("", create_options, param);
1357     }
1358 
1359     set_option_parameter_int(param, BLOCK_OPT_SIZE, total_sectors * 512);
1360     ret = add_old_style_options(out_fmt, param, out_baseimg, NULL);
1361     if (ret < 0) {
1362         goto out;
1363     }
1364 
1365     /* Get backing file name if -o backing_file was used */
1366     out_baseimg_param = get_option_parameter(param, BLOCK_OPT_BACKING_FILE);
1367     if (out_baseimg_param) {
1368         out_baseimg = out_baseimg_param->value.s;
1369     }
1370 
1371     /* Check if compression is supported */
1372     if (compress) {
1373         QEMUOptionParameter *encryption =
1374             get_option_parameter(param, BLOCK_OPT_ENCRYPT);
1375         QEMUOptionParameter *preallocation =
1376             get_option_parameter(param, BLOCK_OPT_PREALLOC);
1377 
1378         if (!drv->bdrv_write_compressed) {
1379             error_report("Compression not supported for this file format");
1380             ret = -1;
1381             goto out;
1382         }
1383 
1384         if (encryption && encryption->value.n) {
1385             error_report("Compression and encryption not supported at "
1386                          "the same time");
1387             ret = -1;
1388             goto out;
1389         }
1390 
1391         if (preallocation && preallocation->value.s
1392             && strcmp(preallocation->value.s, "off"))
1393         {
1394             error_report("Compression and preallocation not supported at "
1395                          "the same time");
1396             ret = -1;
1397             goto out;
1398         }
1399     }
1400 
1401     if (!skip_create) {
1402         /* Create the new image */
1403         ret = bdrv_create(drv, out_filename, param, &local_err);
1404         if (ret < 0) {
1405             error_report("%s: error while converting %s: %s",
1406                          out_filename, out_fmt, error_get_pretty(local_err));
1407             error_free(local_err);
1408             goto out;
1409         }
1410     }
1411 
1412     flags = min_sparse ? (BDRV_O_RDWR | BDRV_O_UNMAP) : BDRV_O_RDWR;
1413     ret = bdrv_parse_cache_flags(cache, &flags);
1414     if (ret < 0) {
1415         error_report("Invalid cache option: %s", cache);
1416         return -1;
1417     }
1418 
1419     out_bs = bdrv_new_open(out_filename, out_fmt, flags, true, quiet);
1420     if (!out_bs) {
1421         ret = -1;
1422         goto out;
1423     }
1424 
1425     bs_i = 0;
1426     bs_offset = 0;
1427     bdrv_get_geometry(bs[0], &bs_sectors);
1428 
1429     /* increase bufsectors from the default 4096 (2M) if opt_transfer_length
1430      * or discard_alignment of the out_bs is greater. Limit to 32768 (16MB)
1431      * as maximum. */
1432     bufsectors = MIN(32768,
1433                      MAX(bufsectors, MAX(out_bs->bl.opt_transfer_length,
1434                                          out_bs->bl.discard_alignment))
1435                     );
1436 
1437     buf = qemu_blockalign(out_bs, bufsectors * BDRV_SECTOR_SIZE);
1438 
1439     if (skip_create) {
1440         int64_t output_length = bdrv_getlength(out_bs);
1441         if (output_length < 0) {
1442             error_report("unable to get output image length: %s\n",
1443                          strerror(-output_length));
1444             ret = -1;
1445             goto out;
1446         } else if (output_length < total_sectors << BDRV_SECTOR_BITS) {
1447             error_report("output file is smaller than input file");
1448             ret = -1;
1449             goto out;
1450         }
1451     }
1452 
1453     cluster_sectors = 0;
1454     ret = bdrv_get_info(out_bs, &bdi);
1455     if (ret < 0) {
1456         if (compress) {
1457             error_report("could not get block driver info");
1458             goto out;
1459         }
1460     } else {
1461         cluster_sectors = bdi.cluster_size / BDRV_SECTOR_SIZE;
1462     }
1463 
1464     if (compress) {
1465         if (cluster_sectors <= 0 || cluster_sectors > bufsectors) {
1466             error_report("invalid cluster size");
1467             ret = -1;
1468             goto out;
1469         }
1470         sector_num = 0;
1471 
1472         nb_sectors = total_sectors;
1473 
1474         for(;;) {
1475             int64_t bs_num;
1476             int remainder;
1477             uint8_t *buf2;
1478 
1479             nb_sectors = total_sectors - sector_num;
1480             if (nb_sectors <= 0)
1481                 break;
1482             if (nb_sectors >= cluster_sectors)
1483                 n = cluster_sectors;
1484             else
1485                 n = nb_sectors;
1486 
1487             bs_num = sector_num - bs_offset;
1488             assert (bs_num >= 0);
1489             remainder = n;
1490             buf2 = buf;
1491             while (remainder > 0) {
1492                 int nlow;
1493                 while (bs_num == bs_sectors) {
1494                     bs_i++;
1495                     assert (bs_i < bs_n);
1496                     bs_offset += bs_sectors;
1497                     bdrv_get_geometry(bs[bs_i], &bs_sectors);
1498                     bs_num = 0;
1499                     /* printf("changing part: sector_num=%" PRId64 ", "
1500                        "bs_i=%d, bs_offset=%" PRId64 ", bs_sectors=%" PRId64
1501                        "\n", sector_num, bs_i, bs_offset, bs_sectors); */
1502                 }
1503                 assert (bs_num < bs_sectors);
1504 
1505                 nlow = (remainder > bs_sectors - bs_num) ? bs_sectors - bs_num : remainder;
1506 
1507                 ret = bdrv_read(bs[bs_i], bs_num, buf2, nlow);
1508                 if (ret < 0) {
1509                     error_report("error while reading sector %" PRId64 ": %s",
1510                                  bs_num, strerror(-ret));
1511                     goto out;
1512                 }
1513 
1514                 buf2 += nlow * 512;
1515                 bs_num += nlow;
1516 
1517                 remainder -= nlow;
1518             }
1519             assert (remainder == 0);
1520 
1521             if (!buffer_is_zero(buf, n * BDRV_SECTOR_SIZE)) {
1522                 ret = bdrv_write_compressed(out_bs, sector_num, buf, n);
1523                 if (ret != 0) {
1524                     error_report("error while compressing sector %" PRId64
1525                                  ": %s", sector_num, strerror(-ret));
1526                     goto out;
1527                 }
1528             }
1529             sector_num += n;
1530             qemu_progress_print(100.0 * sector_num / total_sectors, 0);
1531         }
1532         /* signal EOF to align */
1533         bdrv_write_compressed(out_bs, 0, NULL, 0);
1534     } else {
1535         int64_t sectors_to_read, sectors_read, sector_num_next_status;
1536         bool count_allocated_sectors;
1537         int has_zero_init = min_sparse ? bdrv_has_zero_init(out_bs) : 0;
1538 
1539         if (!has_zero_init && bdrv_can_write_zeroes_with_unmap(out_bs)) {
1540             ret = bdrv_make_zero(out_bs, BDRV_REQ_MAY_UNMAP);
1541             if (ret < 0) {
1542                 goto out;
1543             }
1544             has_zero_init = 1;
1545         }
1546 
1547         sectors_to_read = total_sectors;
1548         count_allocated_sectors = progress && (out_baseimg || has_zero_init);
1549 restart:
1550         sector_num = 0; // total number of sectors converted so far
1551         sectors_read = 0;
1552         sector_num_next_status = 0;
1553 
1554         for(;;) {
1555             nb_sectors = total_sectors - sector_num;
1556             if (nb_sectors <= 0) {
1557                 if (count_allocated_sectors) {
1558                     sectors_to_read = sectors_read;
1559                     count_allocated_sectors = false;
1560                     goto restart;
1561                 }
1562                 ret = 0;
1563                 break;
1564             }
1565 
1566             while (sector_num - bs_offset >= bs_sectors) {
1567                 bs_i ++;
1568                 assert (bs_i < bs_n);
1569                 bs_offset += bs_sectors;
1570                 bdrv_get_geometry(bs[bs_i], &bs_sectors);
1571                 /* printf("changing part: sector_num=%" PRId64 ", bs_i=%d, "
1572                   "bs_offset=%" PRId64 ", bs_sectors=%" PRId64 "\n",
1573                    sector_num, bs_i, bs_offset, bs_sectors); */
1574             }
1575 
1576             if ((out_baseimg || has_zero_init) &&
1577                 sector_num >= sector_num_next_status) {
1578                 n = nb_sectors > INT_MAX ? INT_MAX : nb_sectors;
1579                 ret = bdrv_get_block_status(bs[bs_i], sector_num - bs_offset,
1580                                             n, &n1);
1581                 if (ret < 0) {
1582                     error_report("error while reading block status of sector %"
1583                                  PRId64 ": %s", sector_num - bs_offset,
1584                                  strerror(-ret));
1585                     goto out;
1586                 }
1587                 /* If the output image is zero initialized, we are not working
1588                  * on a shared base and the input is zero we can skip the next
1589                  * n1 sectors */
1590                 if (has_zero_init && !out_baseimg && (ret & BDRV_BLOCK_ZERO)) {
1591                     sector_num += n1;
1592                     continue;
1593                 }
1594                 /* If the output image is being created as a copy on write
1595                  * image, assume that sectors which are unallocated in the
1596                  * input image are present in both the output's and input's
1597                  * base images (no need to copy them). */
1598                 if (out_baseimg) {
1599                     if (!(ret & BDRV_BLOCK_DATA)) {
1600                         sector_num += n1;
1601                         continue;
1602                     }
1603                     /* The next 'n1' sectors are allocated in the input image.
1604                      * Copy only those as they may be followed by unallocated
1605                      * sectors. */
1606                     nb_sectors = n1;
1607                 }
1608                 /* avoid redundant callouts to get_block_status */
1609                 sector_num_next_status = sector_num + n1;
1610             }
1611 
1612             n = MIN(nb_sectors, bufsectors);
1613 
1614             /* round down request length to an aligned sector, but
1615              * do not bother doing this on short requests. They happen
1616              * when we found an all-zero area, and the next sector to
1617              * write will not be sector_num + n. */
1618             if (cluster_sectors > 0 && n >= cluster_sectors) {
1619                 int64_t next_aligned_sector = (sector_num + n);
1620                 next_aligned_sector -= next_aligned_sector % cluster_sectors;
1621                 if (sector_num + n > next_aligned_sector) {
1622                     n = next_aligned_sector - sector_num;
1623                 }
1624             }
1625 
1626             n = MIN(n, bs_sectors - (sector_num - bs_offset));
1627 
1628             sectors_read += n;
1629             if (count_allocated_sectors) {
1630                 sector_num += n;
1631                 continue;
1632             }
1633 
1634             n1 = n;
1635             ret = bdrv_read(bs[bs_i], sector_num - bs_offset, buf, n);
1636             if (ret < 0) {
1637                 error_report("error while reading sector %" PRId64 ": %s",
1638                              sector_num - bs_offset, strerror(-ret));
1639                 goto out;
1640             }
1641             /* NOTE: at the same time we convert, we do not write zero
1642                sectors to have a chance to compress the image. Ideally, we
1643                should add a specific call to have the info to go faster */
1644             buf1 = buf;
1645             while (n > 0) {
1646                 if (!has_zero_init ||
1647                     is_allocated_sectors_min(buf1, n, &n1, min_sparse)) {
1648                     ret = bdrv_write(out_bs, sector_num, buf1, n1);
1649                     if (ret < 0) {
1650                         error_report("error while writing sector %" PRId64
1651                                      ": %s", sector_num, strerror(-ret));
1652                         goto out;
1653                     }
1654                 }
1655                 sector_num += n1;
1656                 n -= n1;
1657                 buf1 += n1 * 512;
1658             }
1659             qemu_progress_print(100.0 * sectors_read / sectors_to_read, 0);
1660         }
1661     }
1662 out:
1663     if (!ret) {
1664         qemu_progress_print(100, 0);
1665     }
1666     qemu_progress_end();
1667     free_option_parameters(create_options);
1668     free_option_parameters(param);
1669     qemu_vfree(buf);
1670     if (sn_opts) {
1671         qemu_opts_del(sn_opts);
1672     }
1673     if (out_bs) {
1674         bdrv_unref(out_bs);
1675     }
1676     if (bs) {
1677         for (bs_i = 0; bs_i < bs_n; bs_i++) {
1678             if (bs[bs_i]) {
1679                 bdrv_unref(bs[bs_i]);
1680             }
1681         }
1682         g_free(bs);
1683     }
1684 fail_getopt:
1685     g_free(options);
1686 
1687     if (ret) {
1688         return 1;
1689     }
1690     return 0;
1691 }
1692 
1693 
1694 static void dump_snapshots(BlockDriverState *bs)
1695 {
1696     QEMUSnapshotInfo *sn_tab, *sn;
1697     int nb_sns, i;
1698 
1699     nb_sns = bdrv_snapshot_list(bs, &sn_tab);
1700     if (nb_sns <= 0)
1701         return;
1702     printf("Snapshot list:\n");
1703     bdrv_snapshot_dump(fprintf, stdout, NULL);
1704     printf("\n");
1705     for(i = 0; i < nb_sns; i++) {
1706         sn = &sn_tab[i];
1707         bdrv_snapshot_dump(fprintf, stdout, sn);
1708         printf("\n");
1709     }
1710     g_free(sn_tab);
1711 }
1712 
1713 static void dump_json_image_info_list(ImageInfoList *list)
1714 {
1715     Error *errp = NULL;
1716     QString *str;
1717     QmpOutputVisitor *ov = qmp_output_visitor_new();
1718     QObject *obj;
1719     visit_type_ImageInfoList(qmp_output_get_visitor(ov),
1720                              &list, NULL, &errp);
1721     obj = qmp_output_get_qobject(ov);
1722     str = qobject_to_json_pretty(obj);
1723     assert(str != NULL);
1724     printf("%s\n", qstring_get_str(str));
1725     qobject_decref(obj);
1726     qmp_output_visitor_cleanup(ov);
1727     QDECREF(str);
1728 }
1729 
1730 static void dump_json_image_info(ImageInfo *info)
1731 {
1732     Error *errp = NULL;
1733     QString *str;
1734     QmpOutputVisitor *ov = qmp_output_visitor_new();
1735     QObject *obj;
1736     visit_type_ImageInfo(qmp_output_get_visitor(ov),
1737                          &info, NULL, &errp);
1738     obj = qmp_output_get_qobject(ov);
1739     str = qobject_to_json_pretty(obj);
1740     assert(str != NULL);
1741     printf("%s\n", qstring_get_str(str));
1742     qobject_decref(obj);
1743     qmp_output_visitor_cleanup(ov);
1744     QDECREF(str);
1745 }
1746 
1747 static void dump_human_image_info_list(ImageInfoList *list)
1748 {
1749     ImageInfoList *elem;
1750     bool delim = false;
1751 
1752     for (elem = list; elem; elem = elem->next) {
1753         if (delim) {
1754             printf("\n");
1755         }
1756         delim = true;
1757 
1758         bdrv_image_info_dump(fprintf, stdout, elem->value);
1759     }
1760 }
1761 
1762 static gboolean str_equal_func(gconstpointer a, gconstpointer b)
1763 {
1764     return strcmp(a, b) == 0;
1765 }
1766 
1767 /**
1768  * Open an image file chain and return an ImageInfoList
1769  *
1770  * @filename: topmost image filename
1771  * @fmt: topmost image format (may be NULL to autodetect)
1772  * @chain: true  - enumerate entire backing file chain
1773  *         false - only topmost image file
1774  *
1775  * Returns a list of ImageInfo objects or NULL if there was an error opening an
1776  * image file.  If there was an error a message will have been printed to
1777  * stderr.
1778  */
1779 static ImageInfoList *collect_image_info_list(const char *filename,
1780                                               const char *fmt,
1781                                               bool chain)
1782 {
1783     ImageInfoList *head = NULL;
1784     ImageInfoList **last = &head;
1785     GHashTable *filenames;
1786     Error *err = NULL;
1787 
1788     filenames = g_hash_table_new_full(g_str_hash, str_equal_func, NULL, NULL);
1789 
1790     while (filename) {
1791         BlockDriverState *bs;
1792         ImageInfo *info;
1793         ImageInfoList *elem;
1794 
1795         if (g_hash_table_lookup_extended(filenames, filename, NULL, NULL)) {
1796             error_report("Backing file '%s' creates an infinite loop.",
1797                          filename);
1798             goto err;
1799         }
1800         g_hash_table_insert(filenames, (gpointer)filename, NULL);
1801 
1802         bs = bdrv_new_open(filename, fmt, BDRV_O_FLAGS | BDRV_O_NO_BACKING,
1803                            false, false);
1804         if (!bs) {
1805             goto err;
1806         }
1807 
1808         bdrv_query_image_info(bs, &info, &err);
1809         if (err) {
1810             error_report("%s", error_get_pretty(err));
1811             error_free(err);
1812             goto err;
1813         }
1814 
1815         elem = g_new0(ImageInfoList, 1);
1816         elem->value = info;
1817         *last = elem;
1818         last = &elem->next;
1819 
1820         bdrv_unref(bs);
1821 
1822         filename = fmt = NULL;
1823         if (chain) {
1824             if (info->has_full_backing_filename) {
1825                 filename = info->full_backing_filename;
1826             } else if (info->has_backing_filename) {
1827                 filename = info->backing_filename;
1828             }
1829             if (info->has_backing_filename_format) {
1830                 fmt = info->backing_filename_format;
1831             }
1832         }
1833     }
1834     g_hash_table_destroy(filenames);
1835     return head;
1836 
1837 err:
1838     qapi_free_ImageInfoList(head);
1839     g_hash_table_destroy(filenames);
1840     return NULL;
1841 }
1842 
1843 static int img_info(int argc, char **argv)
1844 {
1845     int c;
1846     OutputFormat output_format = OFORMAT_HUMAN;
1847     bool chain = false;
1848     const char *filename, *fmt, *output;
1849     ImageInfoList *list;
1850 
1851     fmt = NULL;
1852     output = NULL;
1853     for(;;) {
1854         int option_index = 0;
1855         static const struct option long_options[] = {
1856             {"help", no_argument, 0, 'h'},
1857             {"format", required_argument, 0, 'f'},
1858             {"output", required_argument, 0, OPTION_OUTPUT},
1859             {"backing-chain", no_argument, 0, OPTION_BACKING_CHAIN},
1860             {0, 0, 0, 0}
1861         };
1862         c = getopt_long(argc, argv, "f:h",
1863                         long_options, &option_index);
1864         if (c == -1) {
1865             break;
1866         }
1867         switch(c) {
1868         case '?':
1869         case 'h':
1870             help();
1871             break;
1872         case 'f':
1873             fmt = optarg;
1874             break;
1875         case OPTION_OUTPUT:
1876             output = optarg;
1877             break;
1878         case OPTION_BACKING_CHAIN:
1879             chain = true;
1880             break;
1881         }
1882     }
1883     if (optind != argc - 1) {
1884         help();
1885     }
1886     filename = argv[optind++];
1887 
1888     if (output && !strcmp(output, "json")) {
1889         output_format = OFORMAT_JSON;
1890     } else if (output && !strcmp(output, "human")) {
1891         output_format = OFORMAT_HUMAN;
1892     } else if (output) {
1893         error_report("--output must be used with human or json as argument.");
1894         return 1;
1895     }
1896 
1897     list = collect_image_info_list(filename, fmt, chain);
1898     if (!list) {
1899         return 1;
1900     }
1901 
1902     switch (output_format) {
1903     case OFORMAT_HUMAN:
1904         dump_human_image_info_list(list);
1905         break;
1906     case OFORMAT_JSON:
1907         if (chain) {
1908             dump_json_image_info_list(list);
1909         } else {
1910             dump_json_image_info(list->value);
1911         }
1912         break;
1913     }
1914 
1915     qapi_free_ImageInfoList(list);
1916     return 0;
1917 }
1918 
1919 
1920 typedef struct MapEntry {
1921     int flags;
1922     int depth;
1923     int64_t start;
1924     int64_t length;
1925     int64_t offset;
1926     BlockDriverState *bs;
1927 } MapEntry;
1928 
1929 static void dump_map_entry(OutputFormat output_format, MapEntry *e,
1930                            MapEntry *next)
1931 {
1932     switch (output_format) {
1933     case OFORMAT_HUMAN:
1934         if ((e->flags & BDRV_BLOCK_DATA) &&
1935             !(e->flags & BDRV_BLOCK_OFFSET_VALID)) {
1936             error_report("File contains external, encrypted or compressed clusters.");
1937             exit(1);
1938         }
1939         if ((e->flags & (BDRV_BLOCK_DATA|BDRV_BLOCK_ZERO)) == BDRV_BLOCK_DATA) {
1940             printf("%#-16"PRIx64"%#-16"PRIx64"%#-16"PRIx64"%s\n",
1941                    e->start, e->length, e->offset, e->bs->filename);
1942         }
1943         /* This format ignores the distinction between 0, ZERO and ZERO|DATA.
1944          * Modify the flags here to allow more coalescing.
1945          */
1946         if (next &&
1947             (next->flags & (BDRV_BLOCK_DATA|BDRV_BLOCK_ZERO)) != BDRV_BLOCK_DATA) {
1948             next->flags &= ~BDRV_BLOCK_DATA;
1949             next->flags |= BDRV_BLOCK_ZERO;
1950         }
1951         break;
1952     case OFORMAT_JSON:
1953         printf("%s{ \"start\": %"PRId64", \"length\": %"PRId64", \"depth\": %d,"
1954                " \"zero\": %s, \"data\": %s",
1955                (e->start == 0 ? "[" : ",\n"),
1956                e->start, e->length, e->depth,
1957                (e->flags & BDRV_BLOCK_ZERO) ? "true" : "false",
1958                (e->flags & BDRV_BLOCK_DATA) ? "true" : "false");
1959         if (e->flags & BDRV_BLOCK_OFFSET_VALID) {
1960             printf(", \"offset\": %"PRId64"", e->offset);
1961         }
1962         putchar('}');
1963 
1964         if (!next) {
1965             printf("]\n");
1966         }
1967         break;
1968     }
1969 }
1970 
1971 static int get_block_status(BlockDriverState *bs, int64_t sector_num,
1972                             int nb_sectors, MapEntry *e)
1973 {
1974     int64_t ret;
1975     int depth;
1976 
1977     /* As an optimization, we could cache the current range of unallocated
1978      * clusters in each file of the chain, and avoid querying the same
1979      * range repeatedly.
1980      */
1981 
1982     depth = 0;
1983     for (;;) {
1984         ret = bdrv_get_block_status(bs, sector_num, nb_sectors, &nb_sectors);
1985         if (ret < 0) {
1986             return ret;
1987         }
1988         assert(nb_sectors);
1989         if (ret & (BDRV_BLOCK_ZERO|BDRV_BLOCK_DATA)) {
1990             break;
1991         }
1992         bs = bs->backing_hd;
1993         if (bs == NULL) {
1994             ret = 0;
1995             break;
1996         }
1997 
1998         depth++;
1999     }
2000 
2001     e->start = sector_num * BDRV_SECTOR_SIZE;
2002     e->length = nb_sectors * BDRV_SECTOR_SIZE;
2003     e->flags = ret & ~BDRV_BLOCK_OFFSET_MASK;
2004     e->offset = ret & BDRV_BLOCK_OFFSET_MASK;
2005     e->depth = depth;
2006     e->bs = bs;
2007     return 0;
2008 }
2009 
2010 static int img_map(int argc, char **argv)
2011 {
2012     int c;
2013     OutputFormat output_format = OFORMAT_HUMAN;
2014     BlockDriverState *bs;
2015     const char *filename, *fmt, *output;
2016     int64_t length;
2017     MapEntry curr = { .length = 0 }, next;
2018     int ret = 0;
2019 
2020     fmt = NULL;
2021     output = NULL;
2022     for (;;) {
2023         int option_index = 0;
2024         static const struct option long_options[] = {
2025             {"help", no_argument, 0, 'h'},
2026             {"format", required_argument, 0, 'f'},
2027             {"output", required_argument, 0, OPTION_OUTPUT},
2028             {0, 0, 0, 0}
2029         };
2030         c = getopt_long(argc, argv, "f:h",
2031                         long_options, &option_index);
2032         if (c == -1) {
2033             break;
2034         }
2035         switch (c) {
2036         case '?':
2037         case 'h':
2038             help();
2039             break;
2040         case 'f':
2041             fmt = optarg;
2042             break;
2043         case OPTION_OUTPUT:
2044             output = optarg;
2045             break;
2046         }
2047     }
2048     if (optind >= argc) {
2049         help();
2050     }
2051     filename = argv[optind++];
2052 
2053     if (output && !strcmp(output, "json")) {
2054         output_format = OFORMAT_JSON;
2055     } else if (output && !strcmp(output, "human")) {
2056         output_format = OFORMAT_HUMAN;
2057     } else if (output) {
2058         error_report("--output must be used with human or json as argument.");
2059         return 1;
2060     }
2061 
2062     bs = bdrv_new_open(filename, fmt, BDRV_O_FLAGS, true, false);
2063     if (!bs) {
2064         return 1;
2065     }
2066 
2067     if (output_format == OFORMAT_HUMAN) {
2068         printf("%-16s%-16s%-16s%s\n", "Offset", "Length", "Mapped to", "File");
2069     }
2070 
2071     length = bdrv_getlength(bs);
2072     while (curr.start + curr.length < length) {
2073         int64_t nsectors_left;
2074         int64_t sector_num;
2075         int n;
2076 
2077         sector_num = (curr.start + curr.length) >> BDRV_SECTOR_BITS;
2078 
2079         /* Probe up to 1 GiB at a time.  */
2080         nsectors_left = DIV_ROUND_UP(length, BDRV_SECTOR_SIZE) - sector_num;
2081         n = MIN(1 << (30 - BDRV_SECTOR_BITS), nsectors_left);
2082         ret = get_block_status(bs, sector_num, n, &next);
2083 
2084         if (ret < 0) {
2085             error_report("Could not read file metadata: %s", strerror(-ret));
2086             goto out;
2087         }
2088 
2089         if (curr.length != 0 && curr.flags == next.flags &&
2090             curr.depth == next.depth &&
2091             ((curr.flags & BDRV_BLOCK_OFFSET_VALID) == 0 ||
2092              curr.offset + curr.length == next.offset)) {
2093             curr.length += next.length;
2094             continue;
2095         }
2096 
2097         if (curr.length > 0) {
2098             dump_map_entry(output_format, &curr, &next);
2099         }
2100         curr = next;
2101     }
2102 
2103     dump_map_entry(output_format, &curr, NULL);
2104 
2105 out:
2106     bdrv_unref(bs);
2107     return ret < 0;
2108 }
2109 
2110 #define SNAPSHOT_LIST   1
2111 #define SNAPSHOT_CREATE 2
2112 #define SNAPSHOT_APPLY  3
2113 #define SNAPSHOT_DELETE 4
2114 
2115 static int img_snapshot(int argc, char **argv)
2116 {
2117     BlockDriverState *bs;
2118     QEMUSnapshotInfo sn;
2119     char *filename, *snapshot_name = NULL;
2120     int c, ret = 0, bdrv_oflags;
2121     int action = 0;
2122     qemu_timeval tv;
2123     bool quiet = false;
2124     Error *err = NULL;
2125 
2126     bdrv_oflags = BDRV_O_FLAGS | BDRV_O_RDWR;
2127     /* Parse commandline parameters */
2128     for(;;) {
2129         c = getopt(argc, argv, "la:c:d:hq");
2130         if (c == -1) {
2131             break;
2132         }
2133         switch(c) {
2134         case '?':
2135         case 'h':
2136             help();
2137             return 0;
2138         case 'l':
2139             if (action) {
2140                 help();
2141                 return 0;
2142             }
2143             action = SNAPSHOT_LIST;
2144             bdrv_oflags &= ~BDRV_O_RDWR; /* no need for RW */
2145             break;
2146         case 'a':
2147             if (action) {
2148                 help();
2149                 return 0;
2150             }
2151             action = SNAPSHOT_APPLY;
2152             snapshot_name = optarg;
2153             break;
2154         case 'c':
2155             if (action) {
2156                 help();
2157                 return 0;
2158             }
2159             action = SNAPSHOT_CREATE;
2160             snapshot_name = optarg;
2161             break;
2162         case 'd':
2163             if (action) {
2164                 help();
2165                 return 0;
2166             }
2167             action = SNAPSHOT_DELETE;
2168             snapshot_name = optarg;
2169             break;
2170         case 'q':
2171             quiet = true;
2172             break;
2173         }
2174     }
2175 
2176     if (optind != argc - 1) {
2177         help();
2178     }
2179     filename = argv[optind++];
2180 
2181     /* Open the image */
2182     bs = bdrv_new_open(filename, NULL, bdrv_oflags, true, quiet);
2183     if (!bs) {
2184         return 1;
2185     }
2186 
2187     /* Perform the requested action */
2188     switch(action) {
2189     case SNAPSHOT_LIST:
2190         dump_snapshots(bs);
2191         break;
2192 
2193     case SNAPSHOT_CREATE:
2194         memset(&sn, 0, sizeof(sn));
2195         pstrcpy(sn.name, sizeof(sn.name), snapshot_name);
2196 
2197         qemu_gettimeofday(&tv);
2198         sn.date_sec = tv.tv_sec;
2199         sn.date_nsec = tv.tv_usec * 1000;
2200 
2201         ret = bdrv_snapshot_create(bs, &sn);
2202         if (ret) {
2203             error_report("Could not create snapshot '%s': %d (%s)",
2204                 snapshot_name, ret, strerror(-ret));
2205         }
2206         break;
2207 
2208     case SNAPSHOT_APPLY:
2209         ret = bdrv_snapshot_goto(bs, snapshot_name);
2210         if (ret) {
2211             error_report("Could not apply snapshot '%s': %d (%s)",
2212                 snapshot_name, ret, strerror(-ret));
2213         }
2214         break;
2215 
2216     case SNAPSHOT_DELETE:
2217         bdrv_snapshot_delete_by_id_or_name(bs, snapshot_name, &err);
2218         if (err) {
2219             error_report("Could not delete snapshot '%s': (%s)",
2220                          snapshot_name, error_get_pretty(err));
2221             error_free(err);
2222             ret = 1;
2223         }
2224         break;
2225     }
2226 
2227     /* Cleanup */
2228     bdrv_unref(bs);
2229     if (ret) {
2230         return 1;
2231     }
2232     return 0;
2233 }
2234 
2235 static int img_rebase(int argc, char **argv)
2236 {
2237     BlockDriverState *bs, *bs_old_backing = NULL, *bs_new_backing = NULL;
2238     BlockDriver *old_backing_drv, *new_backing_drv;
2239     char *filename;
2240     const char *fmt, *cache, *out_basefmt, *out_baseimg;
2241     int c, flags, ret;
2242     int unsafe = 0;
2243     int progress = 0;
2244     bool quiet = false;
2245     Error *local_err = NULL;
2246 
2247     /* Parse commandline parameters */
2248     fmt = NULL;
2249     cache = BDRV_DEFAULT_CACHE;
2250     out_baseimg = NULL;
2251     out_basefmt = NULL;
2252     for(;;) {
2253         c = getopt(argc, argv, "uhf:F:b:pt:q");
2254         if (c == -1) {
2255             break;
2256         }
2257         switch(c) {
2258         case '?':
2259         case 'h':
2260             help();
2261             return 0;
2262         case 'f':
2263             fmt = optarg;
2264             break;
2265         case 'F':
2266             out_basefmt = optarg;
2267             break;
2268         case 'b':
2269             out_baseimg = optarg;
2270             break;
2271         case 'u':
2272             unsafe = 1;
2273             break;
2274         case 'p':
2275             progress = 1;
2276             break;
2277         case 't':
2278             cache = optarg;
2279             break;
2280         case 'q':
2281             quiet = true;
2282             break;
2283         }
2284     }
2285 
2286     if (quiet) {
2287         progress = 0;
2288     }
2289 
2290     if ((optind != argc - 1) || (!unsafe && !out_baseimg)) {
2291         help();
2292     }
2293     filename = argv[optind++];
2294 
2295     qemu_progress_init(progress, 2.0);
2296     qemu_progress_print(0, 100);
2297 
2298     flags = BDRV_O_RDWR | (unsafe ? BDRV_O_NO_BACKING : 0);
2299     ret = bdrv_parse_cache_flags(cache, &flags);
2300     if (ret < 0) {
2301         error_report("Invalid cache option: %s", cache);
2302         return -1;
2303     }
2304 
2305     /*
2306      * Open the images.
2307      *
2308      * Ignore the old backing file for unsafe rebase in case we want to correct
2309      * the reference to a renamed or moved backing file.
2310      */
2311     bs = bdrv_new_open(filename, fmt, flags, true, quiet);
2312     if (!bs) {
2313         return 1;
2314     }
2315 
2316     /* Find the right drivers for the backing files */
2317     old_backing_drv = NULL;
2318     new_backing_drv = NULL;
2319 
2320     if (!unsafe && bs->backing_format[0] != '\0') {
2321         old_backing_drv = bdrv_find_format(bs->backing_format);
2322         if (old_backing_drv == NULL) {
2323             error_report("Invalid format name: '%s'", bs->backing_format);
2324             ret = -1;
2325             goto out;
2326         }
2327     }
2328 
2329     if (out_basefmt != NULL) {
2330         new_backing_drv = bdrv_find_format(out_basefmt);
2331         if (new_backing_drv == NULL) {
2332             error_report("Invalid format name: '%s'", out_basefmt);
2333             ret = -1;
2334             goto out;
2335         }
2336     }
2337 
2338     /* For safe rebasing we need to compare old and new backing file */
2339     if (unsafe) {
2340         /* Make the compiler happy */
2341         bs_old_backing = NULL;
2342         bs_new_backing = NULL;
2343     } else {
2344         char backing_name[1024];
2345 
2346         bs_old_backing = bdrv_new("old_backing");
2347         bdrv_get_backing_filename(bs, backing_name, sizeof(backing_name));
2348         ret = bdrv_open(&bs_old_backing, backing_name, NULL, NULL, BDRV_O_FLAGS,
2349                         old_backing_drv, &local_err);
2350         if (ret) {
2351             error_report("Could not open old backing file '%s': %s",
2352                          backing_name, error_get_pretty(local_err));
2353             error_free(local_err);
2354             goto out;
2355         }
2356         if (out_baseimg[0]) {
2357             bs_new_backing = bdrv_new("new_backing");
2358             ret = bdrv_open(&bs_new_backing, out_baseimg, NULL, NULL,
2359                             BDRV_O_FLAGS, new_backing_drv, &local_err);
2360             if (ret) {
2361                 error_report("Could not open new backing file '%s': %s",
2362                              out_baseimg, error_get_pretty(local_err));
2363                 error_free(local_err);
2364                 goto out;
2365             }
2366         }
2367     }
2368 
2369     /*
2370      * Check each unallocated cluster in the COW file. If it is unallocated,
2371      * accesses go to the backing file. We must therefore compare this cluster
2372      * in the old and new backing file, and if they differ we need to copy it
2373      * from the old backing file into the COW file.
2374      *
2375      * If qemu-img crashes during this step, no harm is done. The content of
2376      * the image is the same as the original one at any time.
2377      */
2378     if (!unsafe) {
2379         uint64_t num_sectors;
2380         uint64_t old_backing_num_sectors;
2381         uint64_t new_backing_num_sectors = 0;
2382         uint64_t sector;
2383         int n;
2384         uint8_t * buf_old;
2385         uint8_t * buf_new;
2386         float local_progress = 0;
2387 
2388         buf_old = qemu_blockalign(bs, IO_BUF_SIZE);
2389         buf_new = qemu_blockalign(bs, IO_BUF_SIZE);
2390 
2391         bdrv_get_geometry(bs, &num_sectors);
2392         bdrv_get_geometry(bs_old_backing, &old_backing_num_sectors);
2393         if (bs_new_backing) {
2394             bdrv_get_geometry(bs_new_backing, &new_backing_num_sectors);
2395         }
2396 
2397         if (num_sectors != 0) {
2398             local_progress = (float)100 /
2399                 (num_sectors / MIN(num_sectors, IO_BUF_SIZE / 512));
2400         }
2401 
2402         for (sector = 0; sector < num_sectors; sector += n) {
2403 
2404             /* How many sectors can we handle with the next read? */
2405             if (sector + (IO_BUF_SIZE / 512) <= num_sectors) {
2406                 n = (IO_BUF_SIZE / 512);
2407             } else {
2408                 n = num_sectors - sector;
2409             }
2410 
2411             /* If the cluster is allocated, we don't need to take action */
2412             ret = bdrv_is_allocated(bs, sector, n, &n);
2413             if (ret < 0) {
2414                 error_report("error while reading image metadata: %s",
2415                              strerror(-ret));
2416                 goto out;
2417             }
2418             if (ret) {
2419                 continue;
2420             }
2421 
2422             /*
2423              * Read old and new backing file and take into consideration that
2424              * backing files may be smaller than the COW image.
2425              */
2426             if (sector >= old_backing_num_sectors) {
2427                 memset(buf_old, 0, n * BDRV_SECTOR_SIZE);
2428             } else {
2429                 if (sector + n > old_backing_num_sectors) {
2430                     n = old_backing_num_sectors - sector;
2431                 }
2432 
2433                 ret = bdrv_read(bs_old_backing, sector, buf_old, n);
2434                 if (ret < 0) {
2435                     error_report("error while reading from old backing file");
2436                     goto out;
2437                 }
2438             }
2439 
2440             if (sector >= new_backing_num_sectors || !bs_new_backing) {
2441                 memset(buf_new, 0, n * BDRV_SECTOR_SIZE);
2442             } else {
2443                 if (sector + n > new_backing_num_sectors) {
2444                     n = new_backing_num_sectors - sector;
2445                 }
2446 
2447                 ret = bdrv_read(bs_new_backing, sector, buf_new, n);
2448                 if (ret < 0) {
2449                     error_report("error while reading from new backing file");
2450                     goto out;
2451                 }
2452             }
2453 
2454             /* If they differ, we need to write to the COW file */
2455             uint64_t written = 0;
2456 
2457             while (written < n) {
2458                 int pnum;
2459 
2460                 if (compare_sectors(buf_old + written * 512,
2461                     buf_new + written * 512, n - written, &pnum))
2462                 {
2463                     ret = bdrv_write(bs, sector + written,
2464                         buf_old + written * 512, pnum);
2465                     if (ret < 0) {
2466                         error_report("Error while writing to COW image: %s",
2467                             strerror(-ret));
2468                         goto out;
2469                     }
2470                 }
2471 
2472                 written += pnum;
2473             }
2474             qemu_progress_print(local_progress, 100);
2475         }
2476 
2477         qemu_vfree(buf_old);
2478         qemu_vfree(buf_new);
2479     }
2480 
2481     /*
2482      * Change the backing file. All clusters that are different from the old
2483      * backing file are overwritten in the COW file now, so the visible content
2484      * doesn't change when we switch the backing file.
2485      */
2486     if (out_baseimg && *out_baseimg) {
2487         ret = bdrv_change_backing_file(bs, out_baseimg, out_basefmt);
2488     } else {
2489         ret = bdrv_change_backing_file(bs, NULL, NULL);
2490     }
2491 
2492     if (ret == -ENOSPC) {
2493         error_report("Could not change the backing file to '%s': No "
2494                      "space left in the file header", out_baseimg);
2495     } else if (ret < 0) {
2496         error_report("Could not change the backing file to '%s': %s",
2497             out_baseimg, strerror(-ret));
2498     }
2499 
2500     qemu_progress_print(100, 0);
2501     /*
2502      * TODO At this point it is possible to check if any clusters that are
2503      * allocated in the COW file are the same in the backing file. If so, they
2504      * could be dropped from the COW file. Don't do this before switching the
2505      * backing file, in case of a crash this would lead to corruption.
2506      */
2507 out:
2508     qemu_progress_end();
2509     /* Cleanup */
2510     if (!unsafe) {
2511         if (bs_old_backing != NULL) {
2512             bdrv_unref(bs_old_backing);
2513         }
2514         if (bs_new_backing != NULL) {
2515             bdrv_unref(bs_new_backing);
2516         }
2517     }
2518 
2519     bdrv_unref(bs);
2520     if (ret) {
2521         return 1;
2522     }
2523     return 0;
2524 }
2525 
2526 static int img_resize(int argc, char **argv)
2527 {
2528     int c, ret, relative;
2529     const char *filename, *fmt, *size;
2530     int64_t n, total_size;
2531     bool quiet = false;
2532     BlockDriverState *bs = NULL;
2533     QemuOpts *param;
2534     static QemuOptsList resize_options = {
2535         .name = "resize_options",
2536         .head = QTAILQ_HEAD_INITIALIZER(resize_options.head),
2537         .desc = {
2538             {
2539                 .name = BLOCK_OPT_SIZE,
2540                 .type = QEMU_OPT_SIZE,
2541                 .help = "Virtual disk size"
2542             }, {
2543                 /* end of list */
2544             }
2545         },
2546     };
2547 
2548     /* Remove size from argv manually so that negative numbers are not treated
2549      * as options by getopt. */
2550     if (argc < 3) {
2551         help();
2552         return 1;
2553     }
2554 
2555     size = argv[--argc];
2556 
2557     /* Parse getopt arguments */
2558     fmt = NULL;
2559     for(;;) {
2560         c = getopt(argc, argv, "f:hq");
2561         if (c == -1) {
2562             break;
2563         }
2564         switch(c) {
2565         case '?':
2566         case 'h':
2567             help();
2568             break;
2569         case 'f':
2570             fmt = optarg;
2571             break;
2572         case 'q':
2573             quiet = true;
2574             break;
2575         }
2576     }
2577     if (optind != argc - 1) {
2578         help();
2579     }
2580     filename = argv[optind++];
2581 
2582     /* Choose grow, shrink, or absolute resize mode */
2583     switch (size[0]) {
2584     case '+':
2585         relative = 1;
2586         size++;
2587         break;
2588     case '-':
2589         relative = -1;
2590         size++;
2591         break;
2592     default:
2593         relative = 0;
2594         break;
2595     }
2596 
2597     /* Parse size */
2598     param = qemu_opts_create(&resize_options, NULL, 0, &error_abort);
2599     if (qemu_opt_set(param, BLOCK_OPT_SIZE, size)) {
2600         /* Error message already printed when size parsing fails */
2601         ret = -1;
2602         qemu_opts_del(param);
2603         goto out;
2604     }
2605     n = qemu_opt_get_size(param, BLOCK_OPT_SIZE, 0);
2606     qemu_opts_del(param);
2607 
2608     bs = bdrv_new_open(filename, fmt, BDRV_O_FLAGS | BDRV_O_RDWR, true, quiet);
2609     if (!bs) {
2610         ret = -1;
2611         goto out;
2612     }
2613 
2614     if (relative) {
2615         total_size = bdrv_getlength(bs) + n * relative;
2616     } else {
2617         total_size = n;
2618     }
2619     if (total_size <= 0) {
2620         error_report("New image size must be positive");
2621         ret = -1;
2622         goto out;
2623     }
2624 
2625     ret = bdrv_truncate(bs, total_size);
2626     switch (ret) {
2627     case 0:
2628         qprintf(quiet, "Image resized.\n");
2629         break;
2630     case -ENOTSUP:
2631         error_report("This image does not support resize");
2632         break;
2633     case -EACCES:
2634         error_report("Image is read-only");
2635         break;
2636     default:
2637         error_report("Error resizing image (%d)", -ret);
2638         break;
2639     }
2640 out:
2641     if (bs) {
2642         bdrv_unref(bs);
2643     }
2644     if (ret) {
2645         return 1;
2646     }
2647     return 0;
2648 }
2649 
2650 static int img_amend(int argc, char **argv)
2651 {
2652     int c, ret = 0;
2653     char *options = NULL;
2654     QEMUOptionParameter *create_options = NULL, *options_param = NULL;
2655     const char *fmt = NULL, *filename;
2656     bool quiet = false;
2657     BlockDriverState *bs = NULL;
2658 
2659     for (;;) {
2660         c = getopt(argc, argv, "hqf:o:");
2661         if (c == -1) {
2662             break;
2663         }
2664 
2665         switch (c) {
2666             case 'h':
2667             case '?':
2668                 help();
2669                 break;
2670             case 'o':
2671                 if (!is_valid_option_list(optarg)) {
2672                     error_report("Invalid option list: %s", optarg);
2673                     ret = -1;
2674                     goto out;
2675                 }
2676                 if (!options) {
2677                     options = g_strdup(optarg);
2678                 } else {
2679                     char *old_options = options;
2680                     options = g_strdup_printf("%s,%s", options, optarg);
2681                     g_free(old_options);
2682                 }
2683                 break;
2684             case 'f':
2685                 fmt = optarg;
2686                 break;
2687             case 'q':
2688                 quiet = true;
2689                 break;
2690         }
2691     }
2692 
2693     if (!options) {
2694         help();
2695     }
2696 
2697     filename = (optind == argc - 1) ? argv[argc - 1] : NULL;
2698     if (fmt && has_help_option(options)) {
2699         /* If a format is explicitly specified (and possibly no filename is
2700          * given), print option help here */
2701         ret = print_block_option_help(filename, fmt);
2702         goto out;
2703     }
2704 
2705     if (optind != argc - 1) {
2706         help();
2707     }
2708 
2709     bs = bdrv_new_open(filename, fmt, BDRV_O_FLAGS | BDRV_O_RDWR, true, quiet);
2710     if (!bs) {
2711         error_report("Could not open image '%s'", filename);
2712         ret = -1;
2713         goto out;
2714     }
2715 
2716     fmt = bs->drv->format_name;
2717 
2718     if (has_help_option(options)) {
2719         /* If the format was auto-detected, print option help here */
2720         ret = print_block_option_help(filename, fmt);
2721         goto out;
2722     }
2723 
2724     create_options = append_option_parameters(create_options,
2725             bs->drv->create_options);
2726     options_param = parse_option_parameters(options, create_options,
2727             options_param);
2728     if (options_param == NULL) {
2729         error_report("Invalid options for file format '%s'", fmt);
2730         ret = -1;
2731         goto out;
2732     }
2733 
2734     ret = bdrv_amend_options(bs, options_param);
2735     if (ret < 0) {
2736         error_report("Error while amending options: %s", strerror(-ret));
2737         goto out;
2738     }
2739 
2740 out:
2741     if (bs) {
2742         bdrv_unref(bs);
2743     }
2744     free_option_parameters(create_options);
2745     free_option_parameters(options_param);
2746     g_free(options);
2747 
2748     if (ret) {
2749         return 1;
2750     }
2751     return 0;
2752 }
2753 
2754 static const img_cmd_t img_cmds[] = {
2755 #define DEF(option, callback, arg_string)        \
2756     { option, callback },
2757 #include "qemu-img-cmds.h"
2758 #undef DEF
2759 #undef GEN_DOCS
2760     { NULL, NULL, },
2761 };
2762 
2763 int main(int argc, char **argv)
2764 {
2765     const img_cmd_t *cmd;
2766     const char *cmdname;
2767 
2768 #ifdef CONFIG_POSIX
2769     signal(SIGPIPE, SIG_IGN);
2770 #endif
2771 
2772     error_set_progname(argv[0]);
2773     qemu_init_exec_dir(argv[0]);
2774 
2775     qemu_init_main_loop();
2776     bdrv_init();
2777     if (argc < 2)
2778         help();
2779     cmdname = argv[1];
2780     argc--; argv++;
2781 
2782     /* find the command */
2783     for(cmd = img_cmds; cmd->name != NULL; cmd++) {
2784         if (!strcmp(cmdname, cmd->name)) {
2785             return cmd->handler(argc, argv);
2786         }
2787     }
2788 
2789     /* not found */
2790     help();
2791     return 0;
2792 }
2793