xref: /openbmc/qemu/qemu-img.c (revision 4c25f365)
1 /*
2  * QEMU disk image utility
3  *
4  * Copyright (c) 2003-2008 Fabrice Bellard
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 #include "qapi-visit.h"
25 #include "qapi/qmp-output-visitor.h"
26 #include "qapi/qmp/qjson.h"
27 #include "qemu-common.h"
28 #include "qemu/option.h"
29 #include "qemu/error-report.h"
30 #include "qemu/osdep.h"
31 #include "sysemu/sysemu.h"
32 #include "block/block_int.h"
33 #include "block/qapi.h"
34 #include <getopt.h>
35 #include <stdio.h>
36 #include <stdarg.h>
37 
38 #ifdef _WIN32
39 #include <windows.h>
40 #endif
41 
42 typedef struct img_cmd_t {
43     const char *name;
44     int (*handler)(int argc, char **argv);
45 } img_cmd_t;
46 
47 enum {
48     OPTION_OUTPUT = 256,
49     OPTION_BACKING_CHAIN = 257,
50 };
51 
52 typedef enum OutputFormat {
53     OFORMAT_JSON,
54     OFORMAT_HUMAN,
55 } OutputFormat;
56 
57 /* Default to cache=writeback as data integrity is not important for qemu-tcg. */
58 #define BDRV_O_FLAGS BDRV_O_CACHE_WB
59 #define BDRV_DEFAULT_CACHE "writeback"
60 
61 static void format_print(void *opaque, const char *name)
62 {
63     printf(" %s", name);
64 }
65 
66 /* Please keep in synch with qemu-img.texi */
67 static void help(void)
68 {
69     const char *help_msg =
70            "qemu-img version " QEMU_VERSION ", Copyright (c) 2004-2008 Fabrice Bellard\n"
71            "usage: qemu-img command [command options]\n"
72            "QEMU disk image utility\n"
73            "\n"
74            "Command syntax:\n"
75 #define DEF(option, callback, arg_string)        \
76            "  " arg_string "\n"
77 #include "qemu-img-cmds.h"
78 #undef DEF
79 #undef GEN_DOCS
80            "\n"
81            "Command parameters:\n"
82            "  'filename' is a disk image filename\n"
83            "  'fmt' is the disk image format. It is guessed automatically in most cases\n"
84            "  'cache' is the cache mode used to write the output disk image, the valid\n"
85            "    options are: 'none', 'writeback' (default, except for convert), 'writethrough',\n"
86            "    'directsync' and 'unsafe' (default for convert)\n"
87            "  'size' is the disk image size in bytes. Optional suffixes\n"
88            "    'k' or 'K' (kilobyte, 1024), 'M' (megabyte, 1024k), 'G' (gigabyte, 1024M),\n"
89            "    'T' (terabyte, 1024G), 'P' (petabyte, 1024T) and 'E' (exabyte, 1024P)  are\n"
90            "    supported. 'b' is ignored.\n"
91            "  'output_filename' is the destination disk image filename\n"
92            "  'output_fmt' is the destination format\n"
93            "  'options' is a comma separated list of format specific options in a\n"
94            "    name=value format. Use -o ? for an overview of the options supported by the\n"
95            "    used format\n"
96            "  'snapshot_param' is param used for internal snapshot, format\n"
97            "    is 'snapshot.id=[ID],snapshot.name=[NAME]', or\n"
98            "    '[ID_OR_NAME]'\n"
99            "  'snapshot_id_or_name' is deprecated, use 'snapshot_param'\n"
100            "    instead\n"
101            "  '-c' indicates that target image must be compressed (qcow format only)\n"
102            "  '-u' enables unsafe rebasing. It is assumed that old and new backing file\n"
103            "       match exactly. The image doesn't need a working backing file before\n"
104            "       rebasing in this case (useful for renaming the backing file)\n"
105            "  '-h' with or without a command shows this help and lists the supported formats\n"
106            "  '-p' show progress of command (only certain commands)\n"
107            "  '-q' use Quiet mode - do not print any output (except errors)\n"
108            "  '-S' indicates the consecutive number of bytes (defaults to 4k) that must\n"
109            "       contain only zeros for qemu-img to create a sparse image during\n"
110            "       conversion. If the number of bytes is 0, the source will not be scanned for\n"
111            "       unallocated or zero sectors, and the destination image will always be\n"
112            "       fully allocated\n"
113            "  '--output' takes the format in which the output must be done (human or json)\n"
114            "  '-n' skips the target volume creation (useful if the volume is created\n"
115            "       prior to running qemu-img)\n"
116            "\n"
117            "Parameters to check subcommand:\n"
118            "  '-r' tries to repair any inconsistencies that are found during the check.\n"
119            "       '-r leaks' repairs only cluster leaks, whereas '-r all' fixes all\n"
120            "       kinds of errors, with a higher risk of choosing the wrong fix or\n"
121            "       hiding corruption that has already occurred.\n"
122            "\n"
123            "Parameters to snapshot subcommand:\n"
124            "  'snapshot' is the name of the snapshot to create, apply or delete\n"
125            "  '-a' applies a snapshot (revert disk to saved state)\n"
126            "  '-c' creates a snapshot\n"
127            "  '-d' deletes a snapshot\n"
128            "  '-l' lists all snapshots in the given image\n"
129            "\n"
130            "Parameters to compare subcommand:\n"
131            "  '-f' first image format\n"
132            "  '-F' second image format\n"
133            "  '-s' run in Strict mode - fail on different image size or sector allocation\n";
134 
135     printf("%s\nSupported formats:", help_msg);
136     bdrv_iterate_format(format_print, NULL);
137     printf("\n");
138     exit(1);
139 }
140 
141 static int GCC_FMT_ATTR(2, 3) qprintf(bool quiet, const char *fmt, ...)
142 {
143     int ret = 0;
144     if (!quiet) {
145         va_list args;
146         va_start(args, fmt);
147         ret = vprintf(fmt, args);
148         va_end(args);
149     }
150     return ret;
151 }
152 
153 #if defined(WIN32)
154 /* XXX: put correct support for win32 */
155 static int read_password(char *buf, int buf_size)
156 {
157     int c, i;
158     printf("Password: ");
159     fflush(stdout);
160     i = 0;
161     for(;;) {
162         c = getchar();
163         if (c == '\n')
164             break;
165         if (i < (buf_size - 1))
166             buf[i++] = c;
167     }
168     buf[i] = '\0';
169     return 0;
170 }
171 
172 #else
173 
174 #include <termios.h>
175 
176 static struct termios oldtty;
177 
178 static void term_exit(void)
179 {
180     tcsetattr (0, TCSANOW, &oldtty);
181 }
182 
183 static void term_init(void)
184 {
185     struct termios tty;
186 
187     tcgetattr (0, &tty);
188     oldtty = tty;
189 
190     tty.c_iflag &= ~(IGNBRK|BRKINT|PARMRK|ISTRIP
191                           |INLCR|IGNCR|ICRNL|IXON);
192     tty.c_oflag |= OPOST;
193     tty.c_lflag &= ~(ECHO|ECHONL|ICANON|IEXTEN);
194     tty.c_cflag &= ~(CSIZE|PARENB);
195     tty.c_cflag |= CS8;
196     tty.c_cc[VMIN] = 1;
197     tty.c_cc[VTIME] = 0;
198 
199     tcsetattr (0, TCSANOW, &tty);
200 
201     atexit(term_exit);
202 }
203 
204 static int read_password(char *buf, int buf_size)
205 {
206     uint8_t ch;
207     int i, ret;
208 
209     printf("password: ");
210     fflush(stdout);
211     term_init();
212     i = 0;
213     for(;;) {
214         ret = read(0, &ch, 1);
215         if (ret == -1) {
216             if (errno == EAGAIN || errno == EINTR) {
217                 continue;
218             } else {
219                 ret = -1;
220                 break;
221             }
222         } else if (ret == 0) {
223             ret = -1;
224             break;
225         } else {
226             if (ch == '\r') {
227                 ret = 0;
228                 break;
229             }
230             if (i < (buf_size - 1))
231                 buf[i++] = ch;
232         }
233     }
234     term_exit();
235     buf[i] = '\0';
236     printf("\n");
237     return ret;
238 }
239 #endif
240 
241 static int print_block_option_help(const char *filename, const char *fmt)
242 {
243     BlockDriver *drv, *proto_drv;
244     QEMUOptionParameter *create_options = NULL;
245 
246     /* Find driver and parse its options */
247     drv = bdrv_find_format(fmt);
248     if (!drv) {
249         error_report("Unknown file format '%s'", fmt);
250         return 1;
251     }
252 
253     proto_drv = bdrv_find_protocol(filename, true);
254     if (!proto_drv) {
255         error_report("Unknown protocol '%s'", filename);
256         return 1;
257     }
258 
259     create_options = append_option_parameters(create_options,
260                                               drv->create_options);
261     create_options = append_option_parameters(create_options,
262                                               proto_drv->create_options);
263     print_option_help(create_options);
264     free_option_parameters(create_options);
265     return 0;
266 }
267 
268 static BlockDriverState *bdrv_new_open(const char *filename,
269                                        const char *fmt,
270                                        int flags,
271                                        bool require_io,
272                                        bool quiet)
273 {
274     BlockDriverState *bs;
275     BlockDriver *drv;
276     char password[256];
277     Error *local_err = NULL;
278     int ret;
279 
280     bs = bdrv_new("image");
281 
282     if (fmt) {
283         drv = bdrv_find_format(fmt);
284         if (!drv) {
285             error_report("Unknown file format '%s'", fmt);
286             goto fail;
287         }
288     } else {
289         drv = NULL;
290     }
291 
292     ret = bdrv_open(bs, filename, NULL, flags, drv, &local_err);
293     if (ret < 0) {
294         error_report("Could not open '%s': %s", filename,
295                      error_get_pretty(local_err));
296         error_free(local_err);
297         goto fail;
298     }
299 
300     if (bdrv_is_encrypted(bs) && require_io) {
301         qprintf(quiet, "Disk image '%s' is encrypted.\n", filename);
302         if (read_password(password, sizeof(password)) < 0) {
303             error_report("No password given");
304             goto fail;
305         }
306         if (bdrv_set_key(bs, password) < 0) {
307             error_report("invalid password");
308             goto fail;
309         }
310     }
311     return bs;
312 fail:
313     if (bs) {
314         bdrv_unref(bs);
315     }
316     return NULL;
317 }
318 
319 static int add_old_style_options(const char *fmt, QEMUOptionParameter *list,
320                                  const char *base_filename,
321                                  const char *base_fmt)
322 {
323     if (base_filename) {
324         if (set_option_parameter(list, BLOCK_OPT_BACKING_FILE, base_filename)) {
325             error_report("Backing file not supported for file format '%s'",
326                          fmt);
327             return -1;
328         }
329     }
330     if (base_fmt) {
331         if (set_option_parameter(list, BLOCK_OPT_BACKING_FMT, base_fmt)) {
332             error_report("Backing file format not supported for file "
333                          "format '%s'", fmt);
334             return -1;
335         }
336     }
337     return 0;
338 }
339 
340 static int img_create(int argc, char **argv)
341 {
342     int c;
343     uint64_t img_size = -1;
344     const char *fmt = "raw";
345     const char *base_fmt = NULL;
346     const char *filename;
347     const char *base_filename = NULL;
348     char *options = NULL;
349     Error *local_err = NULL;
350     bool quiet = false;
351 
352     for(;;) {
353         c = getopt(argc, argv, "F:b:f:he6o:q");
354         if (c == -1) {
355             break;
356         }
357         switch(c) {
358         case '?':
359         case 'h':
360             help();
361             break;
362         case 'F':
363             base_fmt = optarg;
364             break;
365         case 'b':
366             base_filename = optarg;
367             break;
368         case 'f':
369             fmt = optarg;
370             break;
371         case 'e':
372             error_report("option -e is deprecated, please use \'-o "
373                   "encryption\' instead!");
374             return 1;
375         case '6':
376             error_report("option -6 is deprecated, please use \'-o "
377                   "compat6\' instead!");
378             return 1;
379         case 'o':
380             options = optarg;
381             break;
382         case 'q':
383             quiet = true;
384             break;
385         }
386     }
387 
388     /* Get the filename */
389     if (optind >= argc) {
390         help();
391     }
392     filename = argv[optind++];
393 
394     /* Get image size, if specified */
395     if (optind < argc) {
396         int64_t sval;
397         char *end;
398         sval = strtosz_suffix(argv[optind++], &end, STRTOSZ_DEFSUFFIX_B);
399         if (sval < 0 || *end) {
400             if (sval == -ERANGE) {
401                 error_report("Image size must be less than 8 EiB!");
402             } else {
403                 error_report("Invalid image size specified! You may use k, M, "
404                       "G, T, P or E suffixes for ");
405                 error_report("kilobytes, megabytes, gigabytes, terabytes, "
406                              "petabytes and exabytes.");
407             }
408             return 1;
409         }
410         img_size = (uint64_t)sval;
411     }
412     if (optind != argc) {
413         help();
414     }
415 
416     if (options && is_help_option(options)) {
417         return print_block_option_help(filename, fmt);
418     }
419 
420     bdrv_img_create(filename, fmt, base_filename, base_fmt,
421                     options, img_size, BDRV_O_FLAGS, &local_err, quiet);
422     if (error_is_set(&local_err)) {
423         error_report("%s: %s", filename, error_get_pretty(local_err));
424         error_free(local_err);
425         return 1;
426     }
427 
428     return 0;
429 }
430 
431 static void dump_json_image_check(ImageCheck *check, bool quiet)
432 {
433     Error *errp = NULL;
434     QString *str;
435     QmpOutputVisitor *ov = qmp_output_visitor_new();
436     QObject *obj;
437     visit_type_ImageCheck(qmp_output_get_visitor(ov),
438                           &check, NULL, &errp);
439     obj = qmp_output_get_qobject(ov);
440     str = qobject_to_json_pretty(obj);
441     assert(str != NULL);
442     qprintf(quiet, "%s\n", qstring_get_str(str));
443     qobject_decref(obj);
444     qmp_output_visitor_cleanup(ov);
445     QDECREF(str);
446 }
447 
448 static void dump_human_image_check(ImageCheck *check, bool quiet)
449 {
450     if (!(check->corruptions || check->leaks || check->check_errors)) {
451         qprintf(quiet, "No errors were found on the image.\n");
452     } else {
453         if (check->corruptions) {
454             qprintf(quiet, "\n%" PRId64 " errors were found on the image.\n"
455                     "Data may be corrupted, or further writes to the image "
456                     "may corrupt it.\n",
457                     check->corruptions);
458         }
459 
460         if (check->leaks) {
461             qprintf(quiet,
462                     "\n%" PRId64 " leaked clusters were found on the image.\n"
463                     "This means waste of disk space, but no harm to data.\n",
464                     check->leaks);
465         }
466 
467         if (check->check_errors) {
468             qprintf(quiet,
469                     "\n%" PRId64
470                     " internal errors have occurred during the check.\n",
471                     check->check_errors);
472         }
473     }
474 
475     if (check->total_clusters != 0 && check->allocated_clusters != 0) {
476         qprintf(quiet, "%" PRId64 "/%" PRId64 " = %0.2f%% allocated, "
477                 "%0.2f%% fragmented, %0.2f%% compressed clusters\n",
478                 check->allocated_clusters, check->total_clusters,
479                 check->allocated_clusters * 100.0 / check->total_clusters,
480                 check->fragmented_clusters * 100.0 / check->allocated_clusters,
481                 check->compressed_clusters * 100.0 /
482                 check->allocated_clusters);
483     }
484 
485     if (check->image_end_offset) {
486         qprintf(quiet,
487                 "Image end offset: %" PRId64 "\n", check->image_end_offset);
488     }
489 }
490 
491 static int collect_image_check(BlockDriverState *bs,
492                    ImageCheck *check,
493                    const char *filename,
494                    const char *fmt,
495                    int fix)
496 {
497     int ret;
498     BdrvCheckResult result;
499 
500     ret = bdrv_check(bs, &result, fix);
501     if (ret < 0) {
502         return ret;
503     }
504 
505     check->filename                 = g_strdup(filename);
506     check->format                   = g_strdup(bdrv_get_format_name(bs));
507     check->check_errors             = result.check_errors;
508     check->corruptions              = result.corruptions;
509     check->has_corruptions          = result.corruptions != 0;
510     check->leaks                    = result.leaks;
511     check->has_leaks                = result.leaks != 0;
512     check->corruptions_fixed        = result.corruptions_fixed;
513     check->has_corruptions_fixed    = result.corruptions != 0;
514     check->leaks_fixed              = result.leaks_fixed;
515     check->has_leaks_fixed          = result.leaks != 0;
516     check->image_end_offset         = result.image_end_offset;
517     check->has_image_end_offset     = result.image_end_offset != 0;
518     check->total_clusters           = result.bfi.total_clusters;
519     check->has_total_clusters       = result.bfi.total_clusters != 0;
520     check->allocated_clusters       = result.bfi.allocated_clusters;
521     check->has_allocated_clusters   = result.bfi.allocated_clusters != 0;
522     check->fragmented_clusters      = result.bfi.fragmented_clusters;
523     check->has_fragmented_clusters  = result.bfi.fragmented_clusters != 0;
524     check->compressed_clusters      = result.bfi.compressed_clusters;
525     check->has_compressed_clusters  = result.bfi.compressed_clusters != 0;
526 
527     return 0;
528 }
529 
530 /*
531  * Checks an image for consistency. Exit codes:
532  *
533  * 0 - Check completed, image is good
534  * 1 - Check not completed because of internal errors
535  * 2 - Check completed, image is corrupted
536  * 3 - Check completed, image has leaked clusters, but is good otherwise
537  */
538 static int img_check(int argc, char **argv)
539 {
540     int c, ret;
541     OutputFormat output_format = OFORMAT_HUMAN;
542     const char *filename, *fmt, *output;
543     BlockDriverState *bs;
544     int fix = 0;
545     int flags = BDRV_O_FLAGS | BDRV_O_CHECK;
546     ImageCheck *check;
547     bool quiet = false;
548 
549     fmt = NULL;
550     output = NULL;
551     for(;;) {
552         int option_index = 0;
553         static const struct option long_options[] = {
554             {"help", no_argument, 0, 'h'},
555             {"format", required_argument, 0, 'f'},
556             {"repair", no_argument, 0, 'r'},
557             {"output", required_argument, 0, OPTION_OUTPUT},
558             {0, 0, 0, 0}
559         };
560         c = getopt_long(argc, argv, "f:hr:q",
561                         long_options, &option_index);
562         if (c == -1) {
563             break;
564         }
565         switch(c) {
566         case '?':
567         case 'h':
568             help();
569             break;
570         case 'f':
571             fmt = optarg;
572             break;
573         case 'r':
574             flags |= BDRV_O_RDWR;
575 
576             if (!strcmp(optarg, "leaks")) {
577                 fix = BDRV_FIX_LEAKS;
578             } else if (!strcmp(optarg, "all")) {
579                 fix = BDRV_FIX_LEAKS | BDRV_FIX_ERRORS;
580             } else {
581                 help();
582             }
583             break;
584         case OPTION_OUTPUT:
585             output = optarg;
586             break;
587         case 'q':
588             quiet = true;
589             break;
590         }
591     }
592     if (optind != argc - 1) {
593         help();
594     }
595     filename = argv[optind++];
596 
597     if (output && !strcmp(output, "json")) {
598         output_format = OFORMAT_JSON;
599     } else if (output && !strcmp(output, "human")) {
600         output_format = OFORMAT_HUMAN;
601     } else if (output) {
602         error_report("--output must be used with human or json as argument.");
603         return 1;
604     }
605 
606     bs = bdrv_new_open(filename, fmt, flags, true, quiet);
607     if (!bs) {
608         return 1;
609     }
610 
611     check = g_new0(ImageCheck, 1);
612     ret = collect_image_check(bs, check, filename, fmt, fix);
613 
614     if (ret == -ENOTSUP) {
615         if (output_format == OFORMAT_HUMAN) {
616             error_report("This image format does not support checks");
617         }
618         ret = 63;
619         goto fail;
620     }
621 
622     if (check->corruptions_fixed || check->leaks_fixed) {
623         int corruptions_fixed, leaks_fixed;
624 
625         leaks_fixed         = check->leaks_fixed;
626         corruptions_fixed   = check->corruptions_fixed;
627 
628         if (output_format == OFORMAT_HUMAN) {
629             qprintf(quiet,
630                     "The following inconsistencies were found and repaired:\n\n"
631                     "    %" PRId64 " leaked clusters\n"
632                     "    %" PRId64 " corruptions\n\n"
633                     "Double checking the fixed image now...\n",
634                     check->leaks_fixed,
635                     check->corruptions_fixed);
636         }
637 
638         ret = collect_image_check(bs, check, filename, fmt, 0);
639 
640         check->leaks_fixed          = leaks_fixed;
641         check->corruptions_fixed    = corruptions_fixed;
642     }
643 
644     switch (output_format) {
645     case OFORMAT_HUMAN:
646         dump_human_image_check(check, quiet);
647         break;
648     case OFORMAT_JSON:
649         dump_json_image_check(check, quiet);
650         break;
651     }
652 
653     if (ret || check->check_errors) {
654         ret = 1;
655         goto fail;
656     }
657 
658     if (check->corruptions) {
659         ret = 2;
660     } else if (check->leaks) {
661         ret = 3;
662     } else {
663         ret = 0;
664     }
665 
666 fail:
667     qapi_free_ImageCheck(check);
668     bdrv_unref(bs);
669 
670     return ret;
671 }
672 
673 static int img_commit(int argc, char **argv)
674 {
675     int c, ret, flags;
676     const char *filename, *fmt, *cache;
677     BlockDriverState *bs;
678     bool quiet = false;
679 
680     fmt = NULL;
681     cache = BDRV_DEFAULT_CACHE;
682     for(;;) {
683         c = getopt(argc, argv, "f:ht:q");
684         if (c == -1) {
685             break;
686         }
687         switch(c) {
688         case '?':
689         case 'h':
690             help();
691             break;
692         case 'f':
693             fmt = optarg;
694             break;
695         case 't':
696             cache = optarg;
697             break;
698         case 'q':
699             quiet = true;
700             break;
701         }
702     }
703     if (optind != argc - 1) {
704         help();
705     }
706     filename = argv[optind++];
707 
708     flags = BDRV_O_RDWR;
709     ret = bdrv_parse_cache_flags(cache, &flags);
710     if (ret < 0) {
711         error_report("Invalid cache option: %s", cache);
712         return -1;
713     }
714 
715     bs = bdrv_new_open(filename, fmt, flags, true, quiet);
716     if (!bs) {
717         return 1;
718     }
719     ret = bdrv_commit(bs);
720     switch(ret) {
721     case 0:
722         qprintf(quiet, "Image committed.\n");
723         break;
724     case -ENOENT:
725         error_report("No disk inserted");
726         break;
727     case -EACCES:
728         error_report("Image is read-only");
729         break;
730     case -ENOTSUP:
731         error_report("Image is already committed");
732         break;
733     default:
734         error_report("Error while committing image");
735         break;
736     }
737 
738     bdrv_unref(bs);
739     if (ret) {
740         return 1;
741     }
742     return 0;
743 }
744 
745 /*
746  * Returns true iff the first sector pointed to by 'buf' contains at least
747  * a non-NUL byte.
748  *
749  * 'pnum' is set to the number of sectors (including and immediately following
750  * the first one) that are known to be in the same allocated/unallocated state.
751  */
752 static int is_allocated_sectors(const uint8_t *buf, int n, int *pnum)
753 {
754     bool is_zero;
755     int i;
756 
757     if (n <= 0) {
758         *pnum = 0;
759         return 0;
760     }
761     is_zero = buffer_is_zero(buf, 512);
762     for(i = 1; i < n; i++) {
763         buf += 512;
764         if (is_zero != buffer_is_zero(buf, 512)) {
765             break;
766         }
767     }
768     *pnum = i;
769     return !is_zero;
770 }
771 
772 /*
773  * Like is_allocated_sectors, but if the buffer starts with a used sector,
774  * up to 'min' consecutive sectors containing zeros are ignored. This avoids
775  * breaking up write requests for only small sparse areas.
776  */
777 static int is_allocated_sectors_min(const uint8_t *buf, int n, int *pnum,
778     int min)
779 {
780     int ret;
781     int num_checked, num_used;
782 
783     if (n < min) {
784         min = n;
785     }
786 
787     ret = is_allocated_sectors(buf, n, pnum);
788     if (!ret) {
789         return ret;
790     }
791 
792     num_used = *pnum;
793     buf += BDRV_SECTOR_SIZE * *pnum;
794     n -= *pnum;
795     num_checked = num_used;
796 
797     while (n > 0) {
798         ret = is_allocated_sectors(buf, n, pnum);
799 
800         buf += BDRV_SECTOR_SIZE * *pnum;
801         n -= *pnum;
802         num_checked += *pnum;
803         if (ret) {
804             num_used = num_checked;
805         } else if (*pnum >= min) {
806             break;
807         }
808     }
809 
810     *pnum = num_used;
811     return 1;
812 }
813 
814 /*
815  * Compares two buffers sector by sector. Returns 0 if the first sector of both
816  * buffers matches, non-zero otherwise.
817  *
818  * pnum is set to the number of sectors (including and immediately following
819  * the first one) that are known to have the same comparison result
820  */
821 static int compare_sectors(const uint8_t *buf1, const uint8_t *buf2, int n,
822     int *pnum)
823 {
824     int res, i;
825 
826     if (n <= 0) {
827         *pnum = 0;
828         return 0;
829     }
830 
831     res = !!memcmp(buf1, buf2, 512);
832     for(i = 1; i < n; i++) {
833         buf1 += 512;
834         buf2 += 512;
835 
836         if (!!memcmp(buf1, buf2, 512) != res) {
837             break;
838         }
839     }
840 
841     *pnum = i;
842     return res;
843 }
844 
845 #define IO_BUF_SIZE (2 * 1024 * 1024)
846 
847 static int64_t sectors_to_bytes(int64_t sectors)
848 {
849     return sectors << BDRV_SECTOR_BITS;
850 }
851 
852 static int64_t sectors_to_process(int64_t total, int64_t from)
853 {
854     return MIN(total - from, IO_BUF_SIZE >> BDRV_SECTOR_BITS);
855 }
856 
857 /*
858  * Check if passed sectors are empty (not allocated or contain only 0 bytes)
859  *
860  * Returns 0 in case sectors are filled with 0, 1 if sectors contain non-zero
861  * data and negative value on error.
862  *
863  * @param bs:  Driver used for accessing file
864  * @param sect_num: Number of first sector to check
865  * @param sect_count: Number of sectors to check
866  * @param filename: Name of disk file we are checking (logging purpose)
867  * @param buffer: Allocated buffer for storing read data
868  * @param quiet: Flag for quiet mode
869  */
870 static int check_empty_sectors(BlockDriverState *bs, int64_t sect_num,
871                                int sect_count, const char *filename,
872                                uint8_t *buffer, bool quiet)
873 {
874     int pnum, ret = 0;
875     ret = bdrv_read(bs, sect_num, buffer, sect_count);
876     if (ret < 0) {
877         error_report("Error while reading offset %" PRId64 " of %s: %s",
878                      sectors_to_bytes(sect_num), filename, strerror(-ret));
879         return ret;
880     }
881     ret = is_allocated_sectors(buffer, sect_count, &pnum);
882     if (ret || pnum != sect_count) {
883         qprintf(quiet, "Content mismatch at offset %" PRId64 "!\n",
884                 sectors_to_bytes(ret ? sect_num : sect_num + pnum));
885         return 1;
886     }
887 
888     return 0;
889 }
890 
891 /*
892  * Compares two images. Exit codes:
893  *
894  * 0 - Images are identical
895  * 1 - Images differ
896  * >1 - Error occurred
897  */
898 static int img_compare(int argc, char **argv)
899 {
900     const char *fmt1 = NULL, *fmt2 = NULL, *filename1, *filename2;
901     BlockDriverState *bs1, *bs2;
902     int64_t total_sectors1, total_sectors2;
903     uint8_t *buf1 = NULL, *buf2 = NULL;
904     int pnum1, pnum2;
905     int allocated1, allocated2;
906     int ret = 0; /* return value - 0 Ident, 1 Different, >1 Error */
907     bool progress = false, quiet = false, strict = false;
908     int64_t total_sectors;
909     int64_t sector_num = 0;
910     int64_t nb_sectors;
911     int c, pnum;
912     uint64_t bs_sectors;
913     uint64_t progress_base;
914 
915     for (;;) {
916         c = getopt(argc, argv, "hpf:F:sq");
917         if (c == -1) {
918             break;
919         }
920         switch (c) {
921         case '?':
922         case 'h':
923             help();
924             break;
925         case 'f':
926             fmt1 = optarg;
927             break;
928         case 'F':
929             fmt2 = optarg;
930             break;
931         case 'p':
932             progress = true;
933             break;
934         case 'q':
935             quiet = true;
936             break;
937         case 's':
938             strict = true;
939             break;
940         }
941     }
942 
943     /* Progress is not shown in Quiet mode */
944     if (quiet) {
945         progress = false;
946     }
947 
948 
949     if (optind != argc - 2) {
950         help();
951     }
952     filename1 = argv[optind++];
953     filename2 = argv[optind++];
954 
955     /* Initialize before goto out */
956     qemu_progress_init(progress, 2.0);
957 
958     bs1 = bdrv_new_open(filename1, fmt1, BDRV_O_FLAGS, true, quiet);
959     if (!bs1) {
960         error_report("Can't open file %s", filename1);
961         ret = 2;
962         goto out3;
963     }
964 
965     bs2 = bdrv_new_open(filename2, fmt2, BDRV_O_FLAGS, true, quiet);
966     if (!bs2) {
967         error_report("Can't open file %s", filename2);
968         ret = 2;
969         goto out2;
970     }
971 
972     buf1 = qemu_blockalign(bs1, IO_BUF_SIZE);
973     buf2 = qemu_blockalign(bs2, IO_BUF_SIZE);
974     bdrv_get_geometry(bs1, &bs_sectors);
975     total_sectors1 = bs_sectors;
976     bdrv_get_geometry(bs2, &bs_sectors);
977     total_sectors2 = bs_sectors;
978     total_sectors = MIN(total_sectors1, total_sectors2);
979     progress_base = MAX(total_sectors1, total_sectors2);
980 
981     qemu_progress_print(0, 100);
982 
983     if (strict && total_sectors1 != total_sectors2) {
984         ret = 1;
985         qprintf(quiet, "Strict mode: Image size mismatch!\n");
986         goto out;
987     }
988 
989     for (;;) {
990         nb_sectors = sectors_to_process(total_sectors, sector_num);
991         if (nb_sectors <= 0) {
992             break;
993         }
994         allocated1 = bdrv_is_allocated_above(bs1, NULL, sector_num, nb_sectors,
995                                              &pnum1);
996         if (allocated1 < 0) {
997             ret = 3;
998             error_report("Sector allocation test failed for %s", filename1);
999             goto out;
1000         }
1001 
1002         allocated2 = bdrv_is_allocated_above(bs2, NULL, sector_num, nb_sectors,
1003                                              &pnum2);
1004         if (allocated2 < 0) {
1005             ret = 3;
1006             error_report("Sector allocation test failed for %s", filename2);
1007             goto out;
1008         }
1009         nb_sectors = MIN(pnum1, pnum2);
1010 
1011         if (allocated1 == allocated2) {
1012             if (allocated1) {
1013                 ret = bdrv_read(bs1, sector_num, buf1, nb_sectors);
1014                 if (ret < 0) {
1015                     error_report("Error while reading offset %" PRId64 " of %s:"
1016                                  " %s", sectors_to_bytes(sector_num), filename1,
1017                                  strerror(-ret));
1018                     ret = 4;
1019                     goto out;
1020                 }
1021                 ret = bdrv_read(bs2, sector_num, buf2, nb_sectors);
1022                 if (ret < 0) {
1023                     error_report("Error while reading offset %" PRId64
1024                                  " of %s: %s", sectors_to_bytes(sector_num),
1025                                  filename2, strerror(-ret));
1026                     ret = 4;
1027                     goto out;
1028                 }
1029                 ret = compare_sectors(buf1, buf2, nb_sectors, &pnum);
1030                 if (ret || pnum != nb_sectors) {
1031                     qprintf(quiet, "Content mismatch at offset %" PRId64 "!\n",
1032                             sectors_to_bytes(
1033                                 ret ? sector_num : sector_num + pnum));
1034                     ret = 1;
1035                     goto out;
1036                 }
1037             }
1038         } else {
1039             if (strict) {
1040                 ret = 1;
1041                 qprintf(quiet, "Strict mode: Offset %" PRId64
1042                         " allocation mismatch!\n",
1043                         sectors_to_bytes(sector_num));
1044                 goto out;
1045             }
1046 
1047             if (allocated1) {
1048                 ret = check_empty_sectors(bs1, sector_num, nb_sectors,
1049                                           filename1, buf1, quiet);
1050             } else {
1051                 ret = check_empty_sectors(bs2, sector_num, nb_sectors,
1052                                           filename2, buf1, quiet);
1053             }
1054             if (ret) {
1055                 if (ret < 0) {
1056                     error_report("Error while reading offset %" PRId64 ": %s",
1057                                  sectors_to_bytes(sector_num), strerror(-ret));
1058                     ret = 4;
1059                 }
1060                 goto out;
1061             }
1062         }
1063         sector_num += nb_sectors;
1064         qemu_progress_print(((float) nb_sectors / progress_base)*100, 100);
1065     }
1066 
1067     if (total_sectors1 != total_sectors2) {
1068         BlockDriverState *bs_over;
1069         int64_t total_sectors_over;
1070         const char *filename_over;
1071 
1072         qprintf(quiet, "Warning: Image size mismatch!\n");
1073         if (total_sectors1 > total_sectors2) {
1074             total_sectors_over = total_sectors1;
1075             bs_over = bs1;
1076             filename_over = filename1;
1077         } else {
1078             total_sectors_over = total_sectors2;
1079             bs_over = bs2;
1080             filename_over = filename2;
1081         }
1082 
1083         for (;;) {
1084             nb_sectors = sectors_to_process(total_sectors_over, sector_num);
1085             if (nb_sectors <= 0) {
1086                 break;
1087             }
1088             ret = bdrv_is_allocated_above(bs_over, NULL, sector_num,
1089                                           nb_sectors, &pnum);
1090             if (ret < 0) {
1091                 ret = 3;
1092                 error_report("Sector allocation test failed for %s",
1093                              filename_over);
1094                 goto out;
1095 
1096             }
1097             nb_sectors = pnum;
1098             if (ret) {
1099                 ret = check_empty_sectors(bs_over, sector_num, nb_sectors,
1100                                           filename_over, buf1, quiet);
1101                 if (ret) {
1102                     if (ret < 0) {
1103                         error_report("Error while reading offset %" PRId64
1104                                      " of %s: %s", sectors_to_bytes(sector_num),
1105                                      filename_over, strerror(-ret));
1106                         ret = 4;
1107                     }
1108                     goto out;
1109                 }
1110             }
1111             sector_num += nb_sectors;
1112             qemu_progress_print(((float) nb_sectors / progress_base)*100, 100);
1113         }
1114     }
1115 
1116     qprintf(quiet, "Images are identical.\n");
1117     ret = 0;
1118 
1119 out:
1120     bdrv_unref(bs2);
1121     qemu_vfree(buf1);
1122     qemu_vfree(buf2);
1123 out2:
1124     bdrv_unref(bs1);
1125 out3:
1126     qemu_progress_end();
1127     return ret;
1128 }
1129 
1130 static int img_convert(int argc, char **argv)
1131 {
1132     int c, n, n1, bs_n, bs_i, compress, cluster_sectors, skip_create;
1133     int64_t ret = 0;
1134     int progress = 0, flags;
1135     const char *fmt, *out_fmt, *cache, *out_baseimg, *out_filename;
1136     BlockDriver *drv, *proto_drv;
1137     BlockDriverState **bs = NULL, *out_bs = NULL;
1138     int64_t total_sectors, nb_sectors, sector_num, bs_offset,
1139             sector_num_next_status = 0;
1140     uint64_t bs_sectors;
1141     uint8_t * buf = NULL;
1142     size_t bufsectors = IO_BUF_SIZE / BDRV_SECTOR_SIZE;
1143     const uint8_t *buf1;
1144     BlockDriverInfo bdi;
1145     QEMUOptionParameter *param = NULL, *create_options = NULL;
1146     QEMUOptionParameter *out_baseimg_param;
1147     char *options = NULL;
1148     const char *snapshot_name = NULL;
1149     int min_sparse = 8; /* Need at least 4k of zeros for sparse detection */
1150     bool quiet = false;
1151     Error *local_err = NULL;
1152     QemuOpts *sn_opts = NULL;
1153 
1154     fmt = NULL;
1155     out_fmt = "raw";
1156     cache = "unsafe";
1157     out_baseimg = NULL;
1158     compress = 0;
1159     skip_create = 0;
1160     for(;;) {
1161         c = getopt(argc, argv, "f:O:B:s:hce6o:pS:t:qnl:");
1162         if (c == -1) {
1163             break;
1164         }
1165         switch(c) {
1166         case '?':
1167         case 'h':
1168             help();
1169             break;
1170         case 'f':
1171             fmt = optarg;
1172             break;
1173         case 'O':
1174             out_fmt = optarg;
1175             break;
1176         case 'B':
1177             out_baseimg = optarg;
1178             break;
1179         case 'c':
1180             compress = 1;
1181             break;
1182         case 'e':
1183             error_report("option -e is deprecated, please use \'-o "
1184                   "encryption\' instead!");
1185             return 1;
1186         case '6':
1187             error_report("option -6 is deprecated, please use \'-o "
1188                   "compat6\' instead!");
1189             return 1;
1190         case 'o':
1191             options = optarg;
1192             break;
1193         case 's':
1194             snapshot_name = optarg;
1195             break;
1196         case 'l':
1197             if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
1198                 sn_opts = qemu_opts_parse(&internal_snapshot_opts, optarg, 0);
1199                 if (!sn_opts) {
1200                     error_report("Failed in parsing snapshot param '%s'",
1201                                  optarg);
1202                     return 1;
1203                 }
1204             } else {
1205                 snapshot_name = optarg;
1206             }
1207             break;
1208         case 'S':
1209         {
1210             int64_t sval;
1211             char *end;
1212             sval = strtosz_suffix(optarg, &end, STRTOSZ_DEFSUFFIX_B);
1213             if (sval < 0 || *end) {
1214                 error_report("Invalid minimum zero buffer size for sparse output specified");
1215                 return 1;
1216             }
1217 
1218             min_sparse = sval / BDRV_SECTOR_SIZE;
1219             break;
1220         }
1221         case 'p':
1222             progress = 1;
1223             break;
1224         case 't':
1225             cache = optarg;
1226             break;
1227         case 'q':
1228             quiet = true;
1229             break;
1230         case 'n':
1231             skip_create = 1;
1232             break;
1233         }
1234     }
1235 
1236     if (quiet) {
1237         progress = 0;
1238     }
1239 
1240     bs_n = argc - optind - 1;
1241     if (bs_n < 1) {
1242         help();
1243     }
1244 
1245     out_filename = argv[argc - 1];
1246 
1247     /* Initialize before goto out */
1248     qemu_progress_init(progress, 1.0);
1249 
1250     if (options && is_help_option(options)) {
1251         ret = print_block_option_help(out_filename, out_fmt);
1252         goto out;
1253     }
1254 
1255     if (bs_n > 1 && out_baseimg) {
1256         error_report("-B makes no sense when concatenating multiple input "
1257                      "images");
1258         ret = -1;
1259         goto out;
1260     }
1261 
1262     qemu_progress_print(0, 100);
1263 
1264     bs = g_malloc0(bs_n * sizeof(BlockDriverState *));
1265 
1266     total_sectors = 0;
1267     for (bs_i = 0; bs_i < bs_n; bs_i++) {
1268         bs[bs_i] = bdrv_new_open(argv[optind + bs_i], fmt, BDRV_O_FLAGS, true,
1269                                  quiet);
1270         if (!bs[bs_i]) {
1271             error_report("Could not open '%s'", argv[optind + bs_i]);
1272             ret = -1;
1273             goto out;
1274         }
1275         bdrv_get_geometry(bs[bs_i], &bs_sectors);
1276         total_sectors += bs_sectors;
1277     }
1278 
1279     if (sn_opts) {
1280         ret = bdrv_snapshot_load_tmp(bs[0],
1281                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
1282                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
1283                                      &local_err);
1284     } else if (snapshot_name != NULL) {
1285         if (bs_n > 1) {
1286             error_report("No support for concatenating multiple snapshot");
1287             ret = -1;
1288             goto out;
1289         }
1290 
1291         bdrv_snapshot_load_tmp_by_id_or_name(bs[0], snapshot_name, &local_err);
1292     }
1293     if (error_is_set(&local_err)) {
1294         error_report("Failed to load snapshot: %s",
1295                      error_get_pretty(local_err));
1296         error_free(local_err);
1297         ret = -1;
1298         goto out;
1299     }
1300 
1301     /* Find driver and parse its options */
1302     drv = bdrv_find_format(out_fmt);
1303     if (!drv) {
1304         error_report("Unknown file format '%s'", out_fmt);
1305         ret = -1;
1306         goto out;
1307     }
1308 
1309     proto_drv = bdrv_find_protocol(out_filename, true);
1310     if (!proto_drv) {
1311         error_report("Unknown protocol '%s'", out_filename);
1312         ret = -1;
1313         goto out;
1314     }
1315 
1316     create_options = append_option_parameters(create_options,
1317                                               drv->create_options);
1318     create_options = append_option_parameters(create_options,
1319                                               proto_drv->create_options);
1320 
1321     if (options) {
1322         param = parse_option_parameters(options, create_options, param);
1323         if (param == NULL) {
1324             error_report("Invalid options for file format '%s'.", out_fmt);
1325             ret = -1;
1326             goto out;
1327         }
1328     } else {
1329         param = parse_option_parameters("", create_options, param);
1330     }
1331 
1332     set_option_parameter_int(param, BLOCK_OPT_SIZE, total_sectors * 512);
1333     ret = add_old_style_options(out_fmt, param, out_baseimg, NULL);
1334     if (ret < 0) {
1335         goto out;
1336     }
1337 
1338     /* Get backing file name if -o backing_file was used */
1339     out_baseimg_param = get_option_parameter(param, BLOCK_OPT_BACKING_FILE);
1340     if (out_baseimg_param) {
1341         out_baseimg = out_baseimg_param->value.s;
1342     }
1343 
1344     /* Check if compression is supported */
1345     if (compress) {
1346         QEMUOptionParameter *encryption =
1347             get_option_parameter(param, BLOCK_OPT_ENCRYPT);
1348         QEMUOptionParameter *preallocation =
1349             get_option_parameter(param, BLOCK_OPT_PREALLOC);
1350 
1351         if (!drv->bdrv_write_compressed) {
1352             error_report("Compression not supported for this file format");
1353             ret = -1;
1354             goto out;
1355         }
1356 
1357         if (encryption && encryption->value.n) {
1358             error_report("Compression and encryption not supported at "
1359                          "the same time");
1360             ret = -1;
1361             goto out;
1362         }
1363 
1364         if (preallocation && preallocation->value.s
1365             && strcmp(preallocation->value.s, "off"))
1366         {
1367             error_report("Compression and preallocation not supported at "
1368                          "the same time");
1369             ret = -1;
1370             goto out;
1371         }
1372     }
1373 
1374     if (!skip_create) {
1375         /* Create the new image */
1376         ret = bdrv_create(drv, out_filename, param, &local_err);
1377         if (ret < 0) {
1378             error_report("%s: error while converting %s: %s",
1379                          out_filename, out_fmt, error_get_pretty(local_err));
1380             error_free(local_err);
1381             goto out;
1382         }
1383     }
1384 
1385     flags = min_sparse ? (BDRV_O_RDWR | BDRV_O_UNMAP) : BDRV_O_RDWR;
1386     ret = bdrv_parse_cache_flags(cache, &flags);
1387     if (ret < 0) {
1388         error_report("Invalid cache option: %s", cache);
1389         return -1;
1390     }
1391 
1392     out_bs = bdrv_new_open(out_filename, out_fmt, flags, true, quiet);
1393     if (!out_bs) {
1394         ret = -1;
1395         goto out;
1396     }
1397 
1398     bs_i = 0;
1399     bs_offset = 0;
1400     bdrv_get_geometry(bs[0], &bs_sectors);
1401 
1402     /* increase bufsectors from the default 4096 (2M) if opt_transfer_length
1403      * or discard_alignment of the out_bs is greater. Limit to 32768 (16MB)
1404      * as maximum. */
1405     bufsectors = MIN(32768,
1406                      MAX(bufsectors, MAX(out_bs->bl.opt_transfer_length,
1407                                          out_bs->bl.discard_alignment))
1408                     );
1409 
1410     buf = qemu_blockalign(out_bs, bufsectors * BDRV_SECTOR_SIZE);
1411 
1412     if (skip_create) {
1413         int64_t output_length = bdrv_getlength(out_bs);
1414         if (output_length < 0) {
1415             error_report("unable to get output image length: %s\n",
1416                          strerror(-output_length));
1417             ret = -1;
1418             goto out;
1419         } else if (output_length < total_sectors << BDRV_SECTOR_BITS) {
1420             error_report("output file is smaller than input file");
1421             ret = -1;
1422             goto out;
1423         }
1424     }
1425 
1426     cluster_sectors = 0;
1427     ret = bdrv_get_info(out_bs, &bdi);
1428     if (ret < 0) {
1429         if (compress) {
1430             error_report("could not get block driver info");
1431             goto out;
1432         }
1433     } else {
1434         cluster_sectors = bdi.cluster_size / BDRV_SECTOR_SIZE;
1435     }
1436 
1437     if (compress) {
1438         if (cluster_sectors <= 0 || cluster_sectors > bufsectors) {
1439             error_report("invalid cluster size");
1440             ret = -1;
1441             goto out;
1442         }
1443         sector_num = 0;
1444 
1445         nb_sectors = total_sectors;
1446 
1447         for(;;) {
1448             int64_t bs_num;
1449             int remainder;
1450             uint8_t *buf2;
1451 
1452             nb_sectors = total_sectors - sector_num;
1453             if (nb_sectors <= 0)
1454                 break;
1455             if (nb_sectors >= cluster_sectors)
1456                 n = cluster_sectors;
1457             else
1458                 n = nb_sectors;
1459 
1460             bs_num = sector_num - bs_offset;
1461             assert (bs_num >= 0);
1462             remainder = n;
1463             buf2 = buf;
1464             while (remainder > 0) {
1465                 int nlow;
1466                 while (bs_num == bs_sectors) {
1467                     bs_i++;
1468                     assert (bs_i < bs_n);
1469                     bs_offset += bs_sectors;
1470                     bdrv_get_geometry(bs[bs_i], &bs_sectors);
1471                     bs_num = 0;
1472                     /* printf("changing part: sector_num=%" PRId64 ", "
1473                        "bs_i=%d, bs_offset=%" PRId64 ", bs_sectors=%" PRId64
1474                        "\n", sector_num, bs_i, bs_offset, bs_sectors); */
1475                 }
1476                 assert (bs_num < bs_sectors);
1477 
1478                 nlow = (remainder > bs_sectors - bs_num) ? bs_sectors - bs_num : remainder;
1479 
1480                 ret = bdrv_read(bs[bs_i], bs_num, buf2, nlow);
1481                 if (ret < 0) {
1482                     error_report("error while reading sector %" PRId64 ": %s",
1483                                  bs_num, strerror(-ret));
1484                     goto out;
1485                 }
1486 
1487                 buf2 += nlow * 512;
1488                 bs_num += nlow;
1489 
1490                 remainder -= nlow;
1491             }
1492             assert (remainder == 0);
1493 
1494             if (!buffer_is_zero(buf, n * BDRV_SECTOR_SIZE)) {
1495                 ret = bdrv_write_compressed(out_bs, sector_num, buf, n);
1496                 if (ret != 0) {
1497                     error_report("error while compressing sector %" PRId64
1498                                  ": %s", sector_num, strerror(-ret));
1499                     goto out;
1500                 }
1501             }
1502             sector_num += n;
1503             qemu_progress_print(100.0 * sector_num / total_sectors, 0);
1504         }
1505         /* signal EOF to align */
1506         bdrv_write_compressed(out_bs, 0, NULL, 0);
1507     } else {
1508         int has_zero_init = min_sparse ? bdrv_has_zero_init(out_bs) : 0;
1509 
1510         if (!has_zero_init && bdrv_can_write_zeroes_with_unmap(out_bs)) {
1511             ret = bdrv_make_zero(out_bs, BDRV_REQ_MAY_UNMAP);
1512             if (ret < 0) {
1513                 goto out;
1514             }
1515             has_zero_init = 1;
1516         }
1517 
1518         sector_num = 0; // total number of sectors converted so far
1519         nb_sectors = total_sectors - sector_num;
1520 
1521         for(;;) {
1522             nb_sectors = total_sectors - sector_num;
1523             if (nb_sectors <= 0) {
1524                 ret = 0;
1525                 break;
1526             }
1527 
1528             while (sector_num - bs_offset >= bs_sectors) {
1529                 bs_i ++;
1530                 assert (bs_i < bs_n);
1531                 bs_offset += bs_sectors;
1532                 bdrv_get_geometry(bs[bs_i], &bs_sectors);
1533                 /* printf("changing part: sector_num=%" PRId64 ", bs_i=%d, "
1534                   "bs_offset=%" PRId64 ", bs_sectors=%" PRId64 "\n",
1535                    sector_num, bs_i, bs_offset, bs_sectors); */
1536             }
1537 
1538             if ((out_baseimg || has_zero_init) &&
1539                 sector_num >= sector_num_next_status) {
1540                 n = nb_sectors > INT_MAX ? INT_MAX : nb_sectors;
1541                 ret = bdrv_get_block_status(bs[bs_i], sector_num - bs_offset,
1542                                             n, &n1);
1543                 if (ret < 0) {
1544                     error_report("error while reading block status of sector %"
1545                                  PRId64 ": %s", sector_num - bs_offset,
1546                                  strerror(-ret));
1547                     goto out;
1548                 }
1549                 /* If the output image is zero initialized, we are not working
1550                  * on a shared base and the input is zero we can skip the next
1551                  * n1 sectors */
1552                 if (has_zero_init && !out_baseimg && (ret & BDRV_BLOCK_ZERO)) {
1553                     sector_num += n1;
1554                     continue;
1555                 }
1556                 /* If the output image is being created as a copy on write
1557                  * image, assume that sectors which are unallocated in the
1558                  * input image are present in both the output's and input's
1559                  * base images (no need to copy them). */
1560                 if (out_baseimg) {
1561                     if (!(ret & BDRV_BLOCK_DATA)) {
1562                         sector_num += n1;
1563                         continue;
1564                     }
1565                     /* The next 'n1' sectors are allocated in the input image.
1566                      * Copy only those as they may be followed by unallocated
1567                      * sectors. */
1568                     nb_sectors = n1;
1569                 }
1570                 /* avoid redundant callouts to get_block_status */
1571                 sector_num_next_status = sector_num + n1;
1572             }
1573 
1574             n = MIN(nb_sectors, bufsectors);
1575 
1576             /* round down request length to an aligned sector, but
1577              * do not bother doing this on short requests. They happen
1578              * when we found an all-zero area, and the next sector to
1579              * write will not be sector_num + n. */
1580             if (cluster_sectors > 0 && n >= cluster_sectors) {
1581                 int64_t next_aligned_sector = (sector_num + n);
1582                 next_aligned_sector -= next_aligned_sector % cluster_sectors;
1583                 if (sector_num + n > next_aligned_sector) {
1584                     n = next_aligned_sector - sector_num;
1585                 }
1586             }
1587 
1588             n = MIN(n, bs_sectors - (sector_num - bs_offset));
1589             n1 = n;
1590 
1591             ret = bdrv_read(bs[bs_i], sector_num - bs_offset, buf, n);
1592             if (ret < 0) {
1593                 error_report("error while reading sector %" PRId64 ": %s",
1594                              sector_num - bs_offset, strerror(-ret));
1595                 goto out;
1596             }
1597             /* NOTE: at the same time we convert, we do not write zero
1598                sectors to have a chance to compress the image. Ideally, we
1599                should add a specific call to have the info to go faster */
1600             buf1 = buf;
1601             while (n > 0) {
1602                 if (!has_zero_init ||
1603                     is_allocated_sectors_min(buf1, n, &n1, min_sparse)) {
1604                     ret = bdrv_write(out_bs, sector_num, buf1, n1);
1605                     if (ret < 0) {
1606                         error_report("error while writing sector %" PRId64
1607                                      ": %s", sector_num, strerror(-ret));
1608                         goto out;
1609                     }
1610                 }
1611                 sector_num += n1;
1612                 n -= n1;
1613                 buf1 += n1 * 512;
1614             }
1615             qemu_progress_print(100.0 * sector_num / total_sectors, 0);
1616         }
1617     }
1618 out:
1619     if (!ret) {
1620         qemu_progress_print(100, 0);
1621     }
1622     qemu_progress_end();
1623     free_option_parameters(create_options);
1624     free_option_parameters(param);
1625     qemu_vfree(buf);
1626     if (sn_opts) {
1627         qemu_opts_del(sn_opts);
1628     }
1629     if (out_bs) {
1630         bdrv_unref(out_bs);
1631     }
1632     if (bs) {
1633         for (bs_i = 0; bs_i < bs_n; bs_i++) {
1634             if (bs[bs_i]) {
1635                 bdrv_unref(bs[bs_i]);
1636             }
1637         }
1638         g_free(bs);
1639     }
1640     if (ret) {
1641         return 1;
1642     }
1643     return 0;
1644 }
1645 
1646 
1647 static void dump_snapshots(BlockDriverState *bs)
1648 {
1649     QEMUSnapshotInfo *sn_tab, *sn;
1650     int nb_sns, i;
1651 
1652     nb_sns = bdrv_snapshot_list(bs, &sn_tab);
1653     if (nb_sns <= 0)
1654         return;
1655     printf("Snapshot list:\n");
1656     bdrv_snapshot_dump(fprintf, stdout, NULL);
1657     printf("\n");
1658     for(i = 0; i < nb_sns; i++) {
1659         sn = &sn_tab[i];
1660         bdrv_snapshot_dump(fprintf, stdout, sn);
1661         printf("\n");
1662     }
1663     g_free(sn_tab);
1664 }
1665 
1666 static void dump_json_image_info_list(ImageInfoList *list)
1667 {
1668     Error *errp = NULL;
1669     QString *str;
1670     QmpOutputVisitor *ov = qmp_output_visitor_new();
1671     QObject *obj;
1672     visit_type_ImageInfoList(qmp_output_get_visitor(ov),
1673                              &list, NULL, &errp);
1674     obj = qmp_output_get_qobject(ov);
1675     str = qobject_to_json_pretty(obj);
1676     assert(str != NULL);
1677     printf("%s\n", qstring_get_str(str));
1678     qobject_decref(obj);
1679     qmp_output_visitor_cleanup(ov);
1680     QDECREF(str);
1681 }
1682 
1683 static void dump_json_image_info(ImageInfo *info)
1684 {
1685     Error *errp = NULL;
1686     QString *str;
1687     QmpOutputVisitor *ov = qmp_output_visitor_new();
1688     QObject *obj;
1689     visit_type_ImageInfo(qmp_output_get_visitor(ov),
1690                          &info, NULL, &errp);
1691     obj = qmp_output_get_qobject(ov);
1692     str = qobject_to_json_pretty(obj);
1693     assert(str != NULL);
1694     printf("%s\n", qstring_get_str(str));
1695     qobject_decref(obj);
1696     qmp_output_visitor_cleanup(ov);
1697     QDECREF(str);
1698 }
1699 
1700 static void dump_human_image_info_list(ImageInfoList *list)
1701 {
1702     ImageInfoList *elem;
1703     bool delim = false;
1704 
1705     for (elem = list; elem; elem = elem->next) {
1706         if (delim) {
1707             printf("\n");
1708         }
1709         delim = true;
1710 
1711         bdrv_image_info_dump(fprintf, stdout, elem->value);
1712     }
1713 }
1714 
1715 static gboolean str_equal_func(gconstpointer a, gconstpointer b)
1716 {
1717     return strcmp(a, b) == 0;
1718 }
1719 
1720 /**
1721  * Open an image file chain and return an ImageInfoList
1722  *
1723  * @filename: topmost image filename
1724  * @fmt: topmost image format (may be NULL to autodetect)
1725  * @chain: true  - enumerate entire backing file chain
1726  *         false - only topmost image file
1727  *
1728  * Returns a list of ImageInfo objects or NULL if there was an error opening an
1729  * image file.  If there was an error a message will have been printed to
1730  * stderr.
1731  */
1732 static ImageInfoList *collect_image_info_list(const char *filename,
1733                                               const char *fmt,
1734                                               bool chain)
1735 {
1736     ImageInfoList *head = NULL;
1737     ImageInfoList **last = &head;
1738     GHashTable *filenames;
1739     Error *err = NULL;
1740 
1741     filenames = g_hash_table_new_full(g_str_hash, str_equal_func, NULL, NULL);
1742 
1743     while (filename) {
1744         BlockDriverState *bs;
1745         ImageInfo *info;
1746         ImageInfoList *elem;
1747 
1748         if (g_hash_table_lookup_extended(filenames, filename, NULL, NULL)) {
1749             error_report("Backing file '%s' creates an infinite loop.",
1750                          filename);
1751             goto err;
1752         }
1753         g_hash_table_insert(filenames, (gpointer)filename, NULL);
1754 
1755         bs = bdrv_new_open(filename, fmt, BDRV_O_FLAGS | BDRV_O_NO_BACKING,
1756                            false, false);
1757         if (!bs) {
1758             goto err;
1759         }
1760 
1761         bdrv_query_image_info(bs, &info, &err);
1762         if (error_is_set(&err)) {
1763             error_report("%s", error_get_pretty(err));
1764             error_free(err);
1765             goto err;
1766         }
1767 
1768         elem = g_new0(ImageInfoList, 1);
1769         elem->value = info;
1770         *last = elem;
1771         last = &elem->next;
1772 
1773         bdrv_unref(bs);
1774 
1775         filename = fmt = NULL;
1776         if (chain) {
1777             if (info->has_full_backing_filename) {
1778                 filename = info->full_backing_filename;
1779             } else if (info->has_backing_filename) {
1780                 filename = info->backing_filename;
1781             }
1782             if (info->has_backing_filename_format) {
1783                 fmt = info->backing_filename_format;
1784             }
1785         }
1786     }
1787     g_hash_table_destroy(filenames);
1788     return head;
1789 
1790 err:
1791     qapi_free_ImageInfoList(head);
1792     g_hash_table_destroy(filenames);
1793     return NULL;
1794 }
1795 
1796 static int img_info(int argc, char **argv)
1797 {
1798     int c;
1799     OutputFormat output_format = OFORMAT_HUMAN;
1800     bool chain = false;
1801     const char *filename, *fmt, *output;
1802     ImageInfoList *list;
1803 
1804     fmt = NULL;
1805     output = NULL;
1806     for(;;) {
1807         int option_index = 0;
1808         static const struct option long_options[] = {
1809             {"help", no_argument, 0, 'h'},
1810             {"format", required_argument, 0, 'f'},
1811             {"output", required_argument, 0, OPTION_OUTPUT},
1812             {"backing-chain", no_argument, 0, OPTION_BACKING_CHAIN},
1813             {0, 0, 0, 0}
1814         };
1815         c = getopt_long(argc, argv, "f:h",
1816                         long_options, &option_index);
1817         if (c == -1) {
1818             break;
1819         }
1820         switch(c) {
1821         case '?':
1822         case 'h':
1823             help();
1824             break;
1825         case 'f':
1826             fmt = optarg;
1827             break;
1828         case OPTION_OUTPUT:
1829             output = optarg;
1830             break;
1831         case OPTION_BACKING_CHAIN:
1832             chain = true;
1833             break;
1834         }
1835     }
1836     if (optind != argc - 1) {
1837         help();
1838     }
1839     filename = argv[optind++];
1840 
1841     if (output && !strcmp(output, "json")) {
1842         output_format = OFORMAT_JSON;
1843     } else if (output && !strcmp(output, "human")) {
1844         output_format = OFORMAT_HUMAN;
1845     } else if (output) {
1846         error_report("--output must be used with human or json as argument.");
1847         return 1;
1848     }
1849 
1850     list = collect_image_info_list(filename, fmt, chain);
1851     if (!list) {
1852         return 1;
1853     }
1854 
1855     switch (output_format) {
1856     case OFORMAT_HUMAN:
1857         dump_human_image_info_list(list);
1858         break;
1859     case OFORMAT_JSON:
1860         if (chain) {
1861             dump_json_image_info_list(list);
1862         } else {
1863             dump_json_image_info(list->value);
1864         }
1865         break;
1866     }
1867 
1868     qapi_free_ImageInfoList(list);
1869     return 0;
1870 }
1871 
1872 
1873 typedef struct MapEntry {
1874     int flags;
1875     int depth;
1876     int64_t start;
1877     int64_t length;
1878     int64_t offset;
1879     BlockDriverState *bs;
1880 } MapEntry;
1881 
1882 static void dump_map_entry(OutputFormat output_format, MapEntry *e,
1883                            MapEntry *next)
1884 {
1885     switch (output_format) {
1886     case OFORMAT_HUMAN:
1887         if ((e->flags & BDRV_BLOCK_DATA) &&
1888             !(e->flags & BDRV_BLOCK_OFFSET_VALID)) {
1889             error_report("File contains external, encrypted or compressed clusters.");
1890             exit(1);
1891         }
1892         if ((e->flags & (BDRV_BLOCK_DATA|BDRV_BLOCK_ZERO)) == BDRV_BLOCK_DATA) {
1893             printf("%#-16"PRIx64"%#-16"PRIx64"%#-16"PRIx64"%s\n",
1894                    e->start, e->length, e->offset, e->bs->filename);
1895         }
1896         /* This format ignores the distinction between 0, ZERO and ZERO|DATA.
1897          * Modify the flags here to allow more coalescing.
1898          */
1899         if (next &&
1900             (next->flags & (BDRV_BLOCK_DATA|BDRV_BLOCK_ZERO)) != BDRV_BLOCK_DATA) {
1901             next->flags &= ~BDRV_BLOCK_DATA;
1902             next->flags |= BDRV_BLOCK_ZERO;
1903         }
1904         break;
1905     case OFORMAT_JSON:
1906         printf("%s{ \"start\": %"PRId64", \"length\": %"PRId64", \"depth\": %d,"
1907                " \"zero\": %s, \"data\": %s",
1908                (e->start == 0 ? "[" : ",\n"),
1909                e->start, e->length, e->depth,
1910                (e->flags & BDRV_BLOCK_ZERO) ? "true" : "false",
1911                (e->flags & BDRV_BLOCK_DATA) ? "true" : "false");
1912         if (e->flags & BDRV_BLOCK_OFFSET_VALID) {
1913             printf(", \"offset\": %"PRId64"", e->offset);
1914         }
1915         putchar('}');
1916 
1917         if (!next) {
1918             printf("]\n");
1919         }
1920         break;
1921     }
1922 }
1923 
1924 static int get_block_status(BlockDriverState *bs, int64_t sector_num,
1925                             int nb_sectors, MapEntry *e)
1926 {
1927     int64_t ret;
1928     int depth;
1929 
1930     /* As an optimization, we could cache the current range of unallocated
1931      * clusters in each file of the chain, and avoid querying the same
1932      * range repeatedly.
1933      */
1934 
1935     depth = 0;
1936     for (;;) {
1937         ret = bdrv_get_block_status(bs, sector_num, nb_sectors, &nb_sectors);
1938         if (ret < 0) {
1939             return ret;
1940         }
1941         assert(nb_sectors);
1942         if (ret & (BDRV_BLOCK_ZERO|BDRV_BLOCK_DATA)) {
1943             break;
1944         }
1945         bs = bs->backing_hd;
1946         if (bs == NULL) {
1947             ret = 0;
1948             break;
1949         }
1950 
1951         depth++;
1952     }
1953 
1954     e->start = sector_num * BDRV_SECTOR_SIZE;
1955     e->length = nb_sectors * BDRV_SECTOR_SIZE;
1956     e->flags = ret & ~BDRV_BLOCK_OFFSET_MASK;
1957     e->offset = ret & BDRV_BLOCK_OFFSET_MASK;
1958     e->depth = depth;
1959     e->bs = bs;
1960     return 0;
1961 }
1962 
1963 static int img_map(int argc, char **argv)
1964 {
1965     int c;
1966     OutputFormat output_format = OFORMAT_HUMAN;
1967     BlockDriverState *bs;
1968     const char *filename, *fmt, *output;
1969     int64_t length;
1970     MapEntry curr = { .length = 0 }, next;
1971     int ret = 0;
1972 
1973     fmt = NULL;
1974     output = NULL;
1975     for (;;) {
1976         int option_index = 0;
1977         static const struct option long_options[] = {
1978             {"help", no_argument, 0, 'h'},
1979             {"format", required_argument, 0, 'f'},
1980             {"output", required_argument, 0, OPTION_OUTPUT},
1981             {0, 0, 0, 0}
1982         };
1983         c = getopt_long(argc, argv, "f:h",
1984                         long_options, &option_index);
1985         if (c == -1) {
1986             break;
1987         }
1988         switch (c) {
1989         case '?':
1990         case 'h':
1991             help();
1992             break;
1993         case 'f':
1994             fmt = optarg;
1995             break;
1996         case OPTION_OUTPUT:
1997             output = optarg;
1998             break;
1999         }
2000     }
2001     if (optind >= argc) {
2002         help();
2003     }
2004     filename = argv[optind++];
2005 
2006     if (output && !strcmp(output, "json")) {
2007         output_format = OFORMAT_JSON;
2008     } else if (output && !strcmp(output, "human")) {
2009         output_format = OFORMAT_HUMAN;
2010     } else if (output) {
2011         error_report("--output must be used with human or json as argument.");
2012         return 1;
2013     }
2014 
2015     bs = bdrv_new_open(filename, fmt, BDRV_O_FLAGS, true, false);
2016     if (!bs) {
2017         return 1;
2018     }
2019 
2020     if (output_format == OFORMAT_HUMAN) {
2021         printf("%-16s%-16s%-16s%s\n", "Offset", "Length", "Mapped to", "File");
2022     }
2023 
2024     length = bdrv_getlength(bs);
2025     while (curr.start + curr.length < length) {
2026         int64_t nsectors_left;
2027         int64_t sector_num;
2028         int n;
2029 
2030         sector_num = (curr.start + curr.length) >> BDRV_SECTOR_BITS;
2031 
2032         /* Probe up to 1 GiB at a time.  */
2033         nsectors_left = DIV_ROUND_UP(length, BDRV_SECTOR_SIZE) - sector_num;
2034         n = MIN(1 << (30 - BDRV_SECTOR_BITS), nsectors_left);
2035         ret = get_block_status(bs, sector_num, n, &next);
2036 
2037         if (ret < 0) {
2038             error_report("Could not read file metadata: %s", strerror(-ret));
2039             goto out;
2040         }
2041 
2042         if (curr.length != 0 && curr.flags == next.flags &&
2043             curr.depth == next.depth &&
2044             ((curr.flags & BDRV_BLOCK_OFFSET_VALID) == 0 ||
2045              curr.offset + curr.length == next.offset)) {
2046             curr.length += next.length;
2047             continue;
2048         }
2049 
2050         if (curr.length > 0) {
2051             dump_map_entry(output_format, &curr, &next);
2052         }
2053         curr = next;
2054     }
2055 
2056     dump_map_entry(output_format, &curr, NULL);
2057 
2058 out:
2059     bdrv_unref(bs);
2060     return ret < 0;
2061 }
2062 
2063 #define SNAPSHOT_LIST   1
2064 #define SNAPSHOT_CREATE 2
2065 #define SNAPSHOT_APPLY  3
2066 #define SNAPSHOT_DELETE 4
2067 
2068 static int img_snapshot(int argc, char **argv)
2069 {
2070     BlockDriverState *bs;
2071     QEMUSnapshotInfo sn;
2072     char *filename, *snapshot_name = NULL;
2073     int c, ret = 0, bdrv_oflags;
2074     int action = 0;
2075     qemu_timeval tv;
2076     bool quiet = false;
2077     Error *err = NULL;
2078 
2079     bdrv_oflags = BDRV_O_FLAGS | BDRV_O_RDWR;
2080     /* Parse commandline parameters */
2081     for(;;) {
2082         c = getopt(argc, argv, "la:c:d:hq");
2083         if (c == -1) {
2084             break;
2085         }
2086         switch(c) {
2087         case '?':
2088         case 'h':
2089             help();
2090             return 0;
2091         case 'l':
2092             if (action) {
2093                 help();
2094                 return 0;
2095             }
2096             action = SNAPSHOT_LIST;
2097             bdrv_oflags &= ~BDRV_O_RDWR; /* no need for RW */
2098             break;
2099         case 'a':
2100             if (action) {
2101                 help();
2102                 return 0;
2103             }
2104             action = SNAPSHOT_APPLY;
2105             snapshot_name = optarg;
2106             break;
2107         case 'c':
2108             if (action) {
2109                 help();
2110                 return 0;
2111             }
2112             action = SNAPSHOT_CREATE;
2113             snapshot_name = optarg;
2114             break;
2115         case 'd':
2116             if (action) {
2117                 help();
2118                 return 0;
2119             }
2120             action = SNAPSHOT_DELETE;
2121             snapshot_name = optarg;
2122             break;
2123         case 'q':
2124             quiet = true;
2125             break;
2126         }
2127     }
2128 
2129     if (optind != argc - 1) {
2130         help();
2131     }
2132     filename = argv[optind++];
2133 
2134     /* Open the image */
2135     bs = bdrv_new_open(filename, NULL, bdrv_oflags, true, quiet);
2136     if (!bs) {
2137         return 1;
2138     }
2139 
2140     /* Perform the requested action */
2141     switch(action) {
2142     case SNAPSHOT_LIST:
2143         dump_snapshots(bs);
2144         break;
2145 
2146     case SNAPSHOT_CREATE:
2147         memset(&sn, 0, sizeof(sn));
2148         pstrcpy(sn.name, sizeof(sn.name), snapshot_name);
2149 
2150         qemu_gettimeofday(&tv);
2151         sn.date_sec = tv.tv_sec;
2152         sn.date_nsec = tv.tv_usec * 1000;
2153 
2154         ret = bdrv_snapshot_create(bs, &sn);
2155         if (ret) {
2156             error_report("Could not create snapshot '%s': %d (%s)",
2157                 snapshot_name, ret, strerror(-ret));
2158         }
2159         break;
2160 
2161     case SNAPSHOT_APPLY:
2162         ret = bdrv_snapshot_goto(bs, snapshot_name);
2163         if (ret) {
2164             error_report("Could not apply snapshot '%s': %d (%s)",
2165                 snapshot_name, ret, strerror(-ret));
2166         }
2167         break;
2168 
2169     case SNAPSHOT_DELETE:
2170         bdrv_snapshot_delete_by_id_or_name(bs, snapshot_name, &err);
2171         if (error_is_set(&err)) {
2172             error_report("Could not delete snapshot '%s': (%s)",
2173                          snapshot_name, error_get_pretty(err));
2174             error_free(err);
2175             ret = 1;
2176         }
2177         break;
2178     }
2179 
2180     /* Cleanup */
2181     bdrv_unref(bs);
2182     if (ret) {
2183         return 1;
2184     }
2185     return 0;
2186 }
2187 
2188 static int img_rebase(int argc, char **argv)
2189 {
2190     BlockDriverState *bs, *bs_old_backing = NULL, *bs_new_backing = NULL;
2191     BlockDriver *old_backing_drv, *new_backing_drv;
2192     char *filename;
2193     const char *fmt, *cache, *out_basefmt, *out_baseimg;
2194     int c, flags, ret;
2195     int unsafe = 0;
2196     int progress = 0;
2197     bool quiet = false;
2198     Error *local_err = NULL;
2199 
2200     /* Parse commandline parameters */
2201     fmt = NULL;
2202     cache = BDRV_DEFAULT_CACHE;
2203     out_baseimg = NULL;
2204     out_basefmt = NULL;
2205     for(;;) {
2206         c = getopt(argc, argv, "uhf:F:b:pt:q");
2207         if (c == -1) {
2208             break;
2209         }
2210         switch(c) {
2211         case '?':
2212         case 'h':
2213             help();
2214             return 0;
2215         case 'f':
2216             fmt = optarg;
2217             break;
2218         case 'F':
2219             out_basefmt = optarg;
2220             break;
2221         case 'b':
2222             out_baseimg = optarg;
2223             break;
2224         case 'u':
2225             unsafe = 1;
2226             break;
2227         case 'p':
2228             progress = 1;
2229             break;
2230         case 't':
2231             cache = optarg;
2232             break;
2233         case 'q':
2234             quiet = true;
2235             break;
2236         }
2237     }
2238 
2239     if (quiet) {
2240         progress = 0;
2241     }
2242 
2243     if ((optind != argc - 1) || (!unsafe && !out_baseimg)) {
2244         help();
2245     }
2246     filename = argv[optind++];
2247 
2248     qemu_progress_init(progress, 2.0);
2249     qemu_progress_print(0, 100);
2250 
2251     flags = BDRV_O_RDWR | (unsafe ? BDRV_O_NO_BACKING : 0);
2252     ret = bdrv_parse_cache_flags(cache, &flags);
2253     if (ret < 0) {
2254         error_report("Invalid cache option: %s", cache);
2255         return -1;
2256     }
2257 
2258     /*
2259      * Open the images.
2260      *
2261      * Ignore the old backing file for unsafe rebase in case we want to correct
2262      * the reference to a renamed or moved backing file.
2263      */
2264     bs = bdrv_new_open(filename, fmt, flags, true, quiet);
2265     if (!bs) {
2266         return 1;
2267     }
2268 
2269     /* Find the right drivers for the backing files */
2270     old_backing_drv = NULL;
2271     new_backing_drv = NULL;
2272 
2273     if (!unsafe && bs->backing_format[0] != '\0') {
2274         old_backing_drv = bdrv_find_format(bs->backing_format);
2275         if (old_backing_drv == NULL) {
2276             error_report("Invalid format name: '%s'", bs->backing_format);
2277             ret = -1;
2278             goto out;
2279         }
2280     }
2281 
2282     if (out_basefmt != NULL) {
2283         new_backing_drv = bdrv_find_format(out_basefmt);
2284         if (new_backing_drv == NULL) {
2285             error_report("Invalid format name: '%s'", out_basefmt);
2286             ret = -1;
2287             goto out;
2288         }
2289     }
2290 
2291     /* For safe rebasing we need to compare old and new backing file */
2292     if (unsafe) {
2293         /* Make the compiler happy */
2294         bs_old_backing = NULL;
2295         bs_new_backing = NULL;
2296     } else {
2297         char backing_name[1024];
2298 
2299         bs_old_backing = bdrv_new("old_backing");
2300         bdrv_get_backing_filename(bs, backing_name, sizeof(backing_name));
2301         ret = bdrv_open(bs_old_backing, backing_name, NULL, BDRV_O_FLAGS,
2302                         old_backing_drv, &local_err);
2303         if (ret) {
2304             error_report("Could not open old backing file '%s': %s",
2305                          backing_name, error_get_pretty(local_err));
2306             error_free(local_err);
2307             goto out;
2308         }
2309         if (out_baseimg[0]) {
2310             bs_new_backing = bdrv_new("new_backing");
2311             ret = bdrv_open(bs_new_backing, out_baseimg, NULL, BDRV_O_FLAGS,
2312                         new_backing_drv, &local_err);
2313             if (ret) {
2314                 error_report("Could not open new backing file '%s': %s",
2315                              out_baseimg, error_get_pretty(local_err));
2316                 error_free(local_err);
2317                 goto out;
2318             }
2319         }
2320     }
2321 
2322     /*
2323      * Check each unallocated cluster in the COW file. If it is unallocated,
2324      * accesses go to the backing file. We must therefore compare this cluster
2325      * in the old and new backing file, and if they differ we need to copy it
2326      * from the old backing file into the COW file.
2327      *
2328      * If qemu-img crashes during this step, no harm is done. The content of
2329      * the image is the same as the original one at any time.
2330      */
2331     if (!unsafe) {
2332         uint64_t num_sectors;
2333         uint64_t old_backing_num_sectors;
2334         uint64_t new_backing_num_sectors = 0;
2335         uint64_t sector;
2336         int n;
2337         uint8_t * buf_old;
2338         uint8_t * buf_new;
2339         float local_progress = 0;
2340 
2341         buf_old = qemu_blockalign(bs, IO_BUF_SIZE);
2342         buf_new = qemu_blockalign(bs, IO_BUF_SIZE);
2343 
2344         bdrv_get_geometry(bs, &num_sectors);
2345         bdrv_get_geometry(bs_old_backing, &old_backing_num_sectors);
2346         if (bs_new_backing) {
2347             bdrv_get_geometry(bs_new_backing, &new_backing_num_sectors);
2348         }
2349 
2350         if (num_sectors != 0) {
2351             local_progress = (float)100 /
2352                 (num_sectors / MIN(num_sectors, IO_BUF_SIZE / 512));
2353         }
2354 
2355         for (sector = 0; sector < num_sectors; sector += n) {
2356 
2357             /* How many sectors can we handle with the next read? */
2358             if (sector + (IO_BUF_SIZE / 512) <= num_sectors) {
2359                 n = (IO_BUF_SIZE / 512);
2360             } else {
2361                 n = num_sectors - sector;
2362             }
2363 
2364             /* If the cluster is allocated, we don't need to take action */
2365             ret = bdrv_is_allocated(bs, sector, n, &n);
2366             if (ret < 0) {
2367                 error_report("error while reading image metadata: %s",
2368                              strerror(-ret));
2369                 goto out;
2370             }
2371             if (ret) {
2372                 continue;
2373             }
2374 
2375             /*
2376              * Read old and new backing file and take into consideration that
2377              * backing files may be smaller than the COW image.
2378              */
2379             if (sector >= old_backing_num_sectors) {
2380                 memset(buf_old, 0, n * BDRV_SECTOR_SIZE);
2381             } else {
2382                 if (sector + n > old_backing_num_sectors) {
2383                     n = old_backing_num_sectors - sector;
2384                 }
2385 
2386                 ret = bdrv_read(bs_old_backing, sector, buf_old, n);
2387                 if (ret < 0) {
2388                     error_report("error while reading from old backing file");
2389                     goto out;
2390                 }
2391             }
2392 
2393             if (sector >= new_backing_num_sectors || !bs_new_backing) {
2394                 memset(buf_new, 0, n * BDRV_SECTOR_SIZE);
2395             } else {
2396                 if (sector + n > new_backing_num_sectors) {
2397                     n = new_backing_num_sectors - sector;
2398                 }
2399 
2400                 ret = bdrv_read(bs_new_backing, sector, buf_new, n);
2401                 if (ret < 0) {
2402                     error_report("error while reading from new backing file");
2403                     goto out;
2404                 }
2405             }
2406 
2407             /* If they differ, we need to write to the COW file */
2408             uint64_t written = 0;
2409 
2410             while (written < n) {
2411                 int pnum;
2412 
2413                 if (compare_sectors(buf_old + written * 512,
2414                     buf_new + written * 512, n - written, &pnum))
2415                 {
2416                     ret = bdrv_write(bs, sector + written,
2417                         buf_old + written * 512, pnum);
2418                     if (ret < 0) {
2419                         error_report("Error while writing to COW image: %s",
2420                             strerror(-ret));
2421                         goto out;
2422                     }
2423                 }
2424 
2425                 written += pnum;
2426             }
2427             qemu_progress_print(local_progress, 100);
2428         }
2429 
2430         qemu_vfree(buf_old);
2431         qemu_vfree(buf_new);
2432     }
2433 
2434     /*
2435      * Change the backing file. All clusters that are different from the old
2436      * backing file are overwritten in the COW file now, so the visible content
2437      * doesn't change when we switch the backing file.
2438      */
2439     if (out_baseimg && *out_baseimg) {
2440         ret = bdrv_change_backing_file(bs, out_baseimg, out_basefmt);
2441     } else {
2442         ret = bdrv_change_backing_file(bs, NULL, NULL);
2443     }
2444 
2445     if (ret == -ENOSPC) {
2446         error_report("Could not change the backing file to '%s': No "
2447                      "space left in the file header", out_baseimg);
2448     } else if (ret < 0) {
2449         error_report("Could not change the backing file to '%s': %s",
2450             out_baseimg, strerror(-ret));
2451     }
2452 
2453     qemu_progress_print(100, 0);
2454     /*
2455      * TODO At this point it is possible to check if any clusters that are
2456      * allocated in the COW file are the same in the backing file. If so, they
2457      * could be dropped from the COW file. Don't do this before switching the
2458      * backing file, in case of a crash this would lead to corruption.
2459      */
2460 out:
2461     qemu_progress_end();
2462     /* Cleanup */
2463     if (!unsafe) {
2464         if (bs_old_backing != NULL) {
2465             bdrv_unref(bs_old_backing);
2466         }
2467         if (bs_new_backing != NULL) {
2468             bdrv_unref(bs_new_backing);
2469         }
2470     }
2471 
2472     bdrv_unref(bs);
2473     if (ret) {
2474         return 1;
2475     }
2476     return 0;
2477 }
2478 
2479 static int img_resize(int argc, char **argv)
2480 {
2481     int c, ret, relative;
2482     const char *filename, *fmt, *size;
2483     int64_t n, total_size;
2484     bool quiet = false;
2485     BlockDriverState *bs = NULL;
2486     QemuOpts *param;
2487     static QemuOptsList resize_options = {
2488         .name = "resize_options",
2489         .head = QTAILQ_HEAD_INITIALIZER(resize_options.head),
2490         .desc = {
2491             {
2492                 .name = BLOCK_OPT_SIZE,
2493                 .type = QEMU_OPT_SIZE,
2494                 .help = "Virtual disk size"
2495             }, {
2496                 /* end of list */
2497             }
2498         },
2499     };
2500 
2501     /* Remove size from argv manually so that negative numbers are not treated
2502      * as options by getopt. */
2503     if (argc < 3) {
2504         help();
2505         return 1;
2506     }
2507 
2508     size = argv[--argc];
2509 
2510     /* Parse getopt arguments */
2511     fmt = NULL;
2512     for(;;) {
2513         c = getopt(argc, argv, "f:hq");
2514         if (c == -1) {
2515             break;
2516         }
2517         switch(c) {
2518         case '?':
2519         case 'h':
2520             help();
2521             break;
2522         case 'f':
2523             fmt = optarg;
2524             break;
2525         case 'q':
2526             quiet = true;
2527             break;
2528         }
2529     }
2530     if (optind != argc - 1) {
2531         help();
2532     }
2533     filename = argv[optind++];
2534 
2535     /* Choose grow, shrink, or absolute resize mode */
2536     switch (size[0]) {
2537     case '+':
2538         relative = 1;
2539         size++;
2540         break;
2541     case '-':
2542         relative = -1;
2543         size++;
2544         break;
2545     default:
2546         relative = 0;
2547         break;
2548     }
2549 
2550     /* Parse size */
2551     param = qemu_opts_create_nofail(&resize_options);
2552     if (qemu_opt_set(param, BLOCK_OPT_SIZE, size)) {
2553         /* Error message already printed when size parsing fails */
2554         ret = -1;
2555         qemu_opts_del(param);
2556         goto out;
2557     }
2558     n = qemu_opt_get_size(param, BLOCK_OPT_SIZE, 0);
2559     qemu_opts_del(param);
2560 
2561     bs = bdrv_new_open(filename, fmt, BDRV_O_FLAGS | BDRV_O_RDWR, true, quiet);
2562     if (!bs) {
2563         ret = -1;
2564         goto out;
2565     }
2566 
2567     if (relative) {
2568         total_size = bdrv_getlength(bs) + n * relative;
2569     } else {
2570         total_size = n;
2571     }
2572     if (total_size <= 0) {
2573         error_report("New image size must be positive");
2574         ret = -1;
2575         goto out;
2576     }
2577 
2578     ret = bdrv_truncate(bs, total_size);
2579     switch (ret) {
2580     case 0:
2581         qprintf(quiet, "Image resized.\n");
2582         break;
2583     case -ENOTSUP:
2584         error_report("This image does not support resize");
2585         break;
2586     case -EACCES:
2587         error_report("Image is read-only");
2588         break;
2589     default:
2590         error_report("Error resizing image (%d)", -ret);
2591         break;
2592     }
2593 out:
2594     if (bs) {
2595         bdrv_unref(bs);
2596     }
2597     if (ret) {
2598         return 1;
2599     }
2600     return 0;
2601 }
2602 
2603 static int img_amend(int argc, char **argv)
2604 {
2605     int c, ret = 0;
2606     char *options = NULL;
2607     QEMUOptionParameter *create_options = NULL, *options_param = NULL;
2608     const char *fmt = NULL, *filename;
2609     bool quiet = false;
2610     BlockDriverState *bs = NULL;
2611 
2612     for (;;) {
2613         c = getopt(argc, argv, "hqf:o:");
2614         if (c == -1) {
2615             break;
2616         }
2617 
2618         switch (c) {
2619             case 'h':
2620             case '?':
2621                 help();
2622                 break;
2623             case 'o':
2624                 options = optarg;
2625                 break;
2626             case 'f':
2627                 fmt = optarg;
2628                 break;
2629             case 'q':
2630                 quiet = true;
2631                 break;
2632         }
2633     }
2634 
2635     if (optind != argc - 1) {
2636         help();
2637     }
2638 
2639     if (!options) {
2640         help();
2641     }
2642 
2643     filename = argv[argc - 1];
2644 
2645     bs = bdrv_new_open(filename, fmt, BDRV_O_FLAGS | BDRV_O_RDWR, true, quiet);
2646     if (!bs) {
2647         error_report("Could not open image '%s'", filename);
2648         ret = -1;
2649         goto out;
2650     }
2651 
2652     fmt = bs->drv->format_name;
2653 
2654     if (is_help_option(options)) {
2655         ret = print_block_option_help(filename, fmt);
2656         goto out;
2657     }
2658 
2659     create_options = append_option_parameters(create_options,
2660             bs->drv->create_options);
2661     options_param = parse_option_parameters(options, create_options,
2662             options_param);
2663     if (options_param == NULL) {
2664         error_report("Invalid options for file format '%s'", fmt);
2665         ret = -1;
2666         goto out;
2667     }
2668 
2669     ret = bdrv_amend_options(bs, options_param);
2670     if (ret < 0) {
2671         error_report("Error while amending options: %s", strerror(-ret));
2672         goto out;
2673     }
2674 
2675 out:
2676     if (bs) {
2677         bdrv_unref(bs);
2678     }
2679     free_option_parameters(create_options);
2680     free_option_parameters(options_param);
2681     if (ret) {
2682         return 1;
2683     }
2684     return 0;
2685 }
2686 
2687 static const img_cmd_t img_cmds[] = {
2688 #define DEF(option, callback, arg_string)        \
2689     { option, callback },
2690 #include "qemu-img-cmds.h"
2691 #undef DEF
2692 #undef GEN_DOCS
2693     { NULL, NULL, },
2694 };
2695 
2696 int main(int argc, char **argv)
2697 {
2698     const img_cmd_t *cmd;
2699     const char *cmdname;
2700 
2701 #ifdef CONFIG_POSIX
2702     signal(SIGPIPE, SIG_IGN);
2703 #endif
2704 
2705     error_set_progname(argv[0]);
2706 
2707     qemu_init_main_loop();
2708     bdrv_init();
2709     if (argc < 2)
2710         help();
2711     cmdname = argv[1];
2712     argc--; argv++;
2713 
2714     /* find the command */
2715     for(cmd = img_cmds; cmd->name != NULL; cmd++) {
2716         if (!strcmp(cmdname, cmd->name)) {
2717             return cmd->handler(argc, argv);
2718         }
2719     }
2720 
2721     /* not found */
2722     help();
2723     return 0;
2724 }
2725