xref: /qemu/qemu-img.c (revision de4905f4)
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 "qemu/osdep.h"
25 #include "qapi/error.h"
26 #include "qapi-visit.h"
27 #include "qapi/qmp-output-visitor.h"
28 #include "qapi/qmp/qerror.h"
29 #include "qapi/qmp/qjson.h"
30 #include "qemu/cutils.h"
31 #include "qemu/config-file.h"
32 #include "qemu/option.h"
33 #include "qemu/error-report.h"
34 #include "qom/object_interfaces.h"
35 #include "sysemu/sysemu.h"
36 #include "sysemu/block-backend.h"
37 #include "block/block_int.h"
38 #include "block/blockjob.h"
39 #include "block/qapi.h"
40 #include "crypto/init.h"
41 #include <getopt.h>
42 
43 #define QEMU_IMG_VERSION "qemu-img version " QEMU_VERSION QEMU_PKGVERSION \
44                           ", Copyright (c) 2004-2008 Fabrice Bellard\n"
45 
46 typedef struct img_cmd_t {
47     const char *name;
48     int (*handler)(int argc, char **argv);
49 } img_cmd_t;
50 
51 enum {
52     OPTION_OUTPUT = 256,
53     OPTION_BACKING_CHAIN = 257,
54     OPTION_OBJECT = 258,
55     OPTION_IMAGE_OPTS = 259,
56 };
57 
58 typedef enum OutputFormat {
59     OFORMAT_JSON,
60     OFORMAT_HUMAN,
61 } OutputFormat;
62 
63 /* Default to cache=writeback as data integrity is not important for qemu-img */
64 #define BDRV_DEFAULT_CACHE "writeback"
65 
66 static void format_print(void *opaque, const char *name)
67 {
68     printf(" %s", name);
69 }
70 
71 static void QEMU_NORETURN GCC_FMT_ATTR(1, 2) error_exit(const char *fmt, ...)
72 {
73     va_list ap;
74 
75     error_printf("qemu-img: ");
76 
77     va_start(ap, fmt);
78     error_vprintf(fmt, ap);
79     va_end(ap);
80 
81     error_printf("\nTry 'qemu-img --help' for more information\n");
82     exit(EXIT_FAILURE);
83 }
84 
85 /* Please keep in synch with qemu-img.texi */
86 static void QEMU_NORETURN help(void)
87 {
88     const char *help_msg =
89            QEMU_IMG_VERSION
90            "usage: qemu-img command [command options]\n"
91            "QEMU disk image utility\n"
92            "\n"
93            "Command syntax:\n"
94 #define DEF(option, callback, arg_string)        \
95            "  " arg_string "\n"
96 #include "qemu-img-cmds.h"
97 #undef DEF
98 #undef GEN_DOCS
99            "\n"
100            "Command parameters:\n"
101            "  'filename' is a disk image filename\n"
102            "  'objectdef' is a QEMU user creatable object definition. See the qemu(1)\n"
103            "    manual page for a description of the object properties. The most common\n"
104            "    object type is a 'secret', which is used to supply passwords and/or\n"
105            "    encryption keys.\n"
106            "  'fmt' is the disk image format. It is guessed automatically in most cases\n"
107            "  'cache' is the cache mode used to write the output disk image, the valid\n"
108            "    options are: 'none', 'writeback' (default, except for convert), 'writethrough',\n"
109            "    'directsync' and 'unsafe' (default for convert)\n"
110            "  'src_cache' is the cache mode used to read input disk images, the valid\n"
111            "    options are the same as for the 'cache' option\n"
112            "  'size' is the disk image size in bytes. Optional suffixes\n"
113            "    'k' or 'K' (kilobyte, 1024), 'M' (megabyte, 1024k), 'G' (gigabyte, 1024M),\n"
114            "    'T' (terabyte, 1024G), 'P' (petabyte, 1024T) and 'E' (exabyte, 1024P)  are\n"
115            "    supported. 'b' is ignored.\n"
116            "  'output_filename' is the destination disk image filename\n"
117            "  'output_fmt' is the destination format\n"
118            "  'options' is a comma separated list of format specific options in a\n"
119            "    name=value format. Use -o ? for an overview of the options supported by the\n"
120            "    used format\n"
121            "  'snapshot_param' is param used for internal snapshot, format\n"
122            "    is 'snapshot.id=[ID],snapshot.name=[NAME]', or\n"
123            "    '[ID_OR_NAME]'\n"
124            "  'snapshot_id_or_name' is deprecated, use 'snapshot_param'\n"
125            "    instead\n"
126            "  '-c' indicates that target image must be compressed (qcow format only)\n"
127            "  '-u' enables unsafe rebasing. It is assumed that old and new backing file\n"
128            "       match exactly. The image doesn't need a working backing file before\n"
129            "       rebasing in this case (useful for renaming the backing file)\n"
130            "  '-h' with or without a command shows this help and lists the supported formats\n"
131            "  '-p' show progress of command (only certain commands)\n"
132            "  '-q' use Quiet mode - do not print any output (except errors)\n"
133            "  '-S' indicates the consecutive number of bytes (defaults to 4k) that must\n"
134            "       contain only zeros for qemu-img to create a sparse image during\n"
135            "       conversion. If the number of bytes is 0, the source will not be scanned for\n"
136            "       unallocated or zero sectors, and the destination image will always be\n"
137            "       fully allocated\n"
138            "  '--output' takes the format in which the output must be done (human or json)\n"
139            "  '-n' skips the target volume creation (useful if the volume is created\n"
140            "       prior to running qemu-img)\n"
141            "\n"
142            "Parameters to check subcommand:\n"
143            "  '-r' tries to repair any inconsistencies that are found during the check.\n"
144            "       '-r leaks' repairs only cluster leaks, whereas '-r all' fixes all\n"
145            "       kinds of errors, with a higher risk of choosing the wrong fix or\n"
146            "       hiding corruption that has already occurred.\n"
147            "\n"
148            "Parameters to snapshot subcommand:\n"
149            "  'snapshot' is the name of the snapshot to create, apply or delete\n"
150            "  '-a' applies a snapshot (revert disk to saved state)\n"
151            "  '-c' creates a snapshot\n"
152            "  '-d' deletes a snapshot\n"
153            "  '-l' lists all snapshots in the given image\n"
154            "\n"
155            "Parameters to compare subcommand:\n"
156            "  '-f' first image format\n"
157            "  '-F' second image format\n"
158            "  '-s' run in Strict mode - fail on different image size or sector allocation\n";
159 
160     printf("%s\nSupported formats:", help_msg);
161     bdrv_iterate_format(format_print, NULL);
162     printf("\n");
163     exit(EXIT_SUCCESS);
164 }
165 
166 static QemuOptsList qemu_object_opts = {
167     .name = "object",
168     .implied_opt_name = "qom-type",
169     .head = QTAILQ_HEAD_INITIALIZER(qemu_object_opts.head),
170     .desc = {
171         { }
172     },
173 };
174 
175 static QemuOptsList qemu_source_opts = {
176     .name = "source",
177     .implied_opt_name = "file",
178     .head = QTAILQ_HEAD_INITIALIZER(qemu_source_opts.head),
179     .desc = {
180         { }
181     },
182 };
183 
184 static int GCC_FMT_ATTR(2, 3) qprintf(bool quiet, const char *fmt, ...)
185 {
186     int ret = 0;
187     if (!quiet) {
188         va_list args;
189         va_start(args, fmt);
190         ret = vprintf(fmt, args);
191         va_end(args);
192     }
193     return ret;
194 }
195 
196 
197 static int print_block_option_help(const char *filename, const char *fmt)
198 {
199     BlockDriver *drv, *proto_drv;
200     QemuOptsList *create_opts = NULL;
201     Error *local_err = NULL;
202 
203     /* Find driver and parse its options */
204     drv = bdrv_find_format(fmt);
205     if (!drv) {
206         error_report("Unknown file format '%s'", fmt);
207         return 1;
208     }
209 
210     create_opts = qemu_opts_append(create_opts, drv->create_opts);
211     if (filename) {
212         proto_drv = bdrv_find_protocol(filename, true, &local_err);
213         if (!proto_drv) {
214             error_report_err(local_err);
215             qemu_opts_free(create_opts);
216             return 1;
217         }
218         create_opts = qemu_opts_append(create_opts, proto_drv->create_opts);
219     }
220 
221     qemu_opts_print_help(create_opts);
222     qemu_opts_free(create_opts);
223     return 0;
224 }
225 
226 
227 static int img_open_password(BlockBackend *blk, const char *filename,
228                              int flags, bool quiet)
229 {
230     BlockDriverState *bs;
231     char password[256];
232 
233     bs = blk_bs(blk);
234     if (bdrv_is_encrypted(bs) && bdrv_key_required(bs) &&
235         !(flags & BDRV_O_NO_IO)) {
236         qprintf(quiet, "Disk image '%s' is encrypted.\n", filename);
237         if (qemu_read_password(password, sizeof(password)) < 0) {
238             error_report("No password given");
239             return -1;
240         }
241         if (bdrv_set_key(bs, password) < 0) {
242             error_report("invalid password");
243             return -1;
244         }
245     }
246     return 0;
247 }
248 
249 
250 static BlockBackend *img_open_opts(const char *optstr,
251                                    QemuOpts *opts, int flags, bool writethrough,
252                                    bool quiet)
253 {
254     QDict *options;
255     Error *local_err = NULL;
256     BlockBackend *blk;
257     options = qemu_opts_to_qdict(opts, NULL);
258     blk = blk_new_open(NULL, NULL, options, flags, &local_err);
259     if (!blk) {
260         error_reportf_err(local_err, "Could not open '%s': ", optstr);
261         return NULL;
262     }
263     blk_set_enable_write_cache(blk, !writethrough);
264 
265     if (img_open_password(blk, optstr, flags, quiet) < 0) {
266         blk_unref(blk);
267         return NULL;
268     }
269     return blk;
270 }
271 
272 static BlockBackend *img_open_file(const char *filename,
273                                    const char *fmt, int flags,
274                                    bool writethrough, bool quiet)
275 {
276     BlockBackend *blk;
277     Error *local_err = NULL;
278     QDict *options = NULL;
279 
280     if (fmt) {
281         options = qdict_new();
282         qdict_put(options, "driver", qstring_from_str(fmt));
283     }
284 
285     blk = blk_new_open(filename, NULL, options, flags, &local_err);
286     if (!blk) {
287         error_reportf_err(local_err, "Could not open '%s': ", filename);
288         return NULL;
289     }
290     blk_set_enable_write_cache(blk, !writethrough);
291 
292     if (img_open_password(blk, filename, flags, quiet) < 0) {
293         blk_unref(blk);
294         return NULL;
295     }
296     return blk;
297 }
298 
299 
300 static BlockBackend *img_open(bool image_opts,
301                               const char *filename,
302                               const char *fmt, int flags, bool writethrough,
303                               bool quiet)
304 {
305     BlockBackend *blk;
306     if (image_opts) {
307         QemuOpts *opts;
308         if (fmt) {
309             error_report("--image-opts and --format are mutually exclusive");
310             return NULL;
311         }
312         opts = qemu_opts_parse_noisily(qemu_find_opts("source"),
313                                        filename, true);
314         if (!opts) {
315             return NULL;
316         }
317         blk = img_open_opts(filename, opts, flags, writethrough, quiet);
318     } else {
319         blk = img_open_file(filename, fmt, flags, writethrough, quiet);
320     }
321     return blk;
322 }
323 
324 
325 static int add_old_style_options(const char *fmt, QemuOpts *opts,
326                                  const char *base_filename,
327                                  const char *base_fmt)
328 {
329     Error *err = NULL;
330 
331     if (base_filename) {
332         qemu_opt_set(opts, BLOCK_OPT_BACKING_FILE, base_filename, &err);
333         if (err) {
334             error_report("Backing file not supported for file format '%s'",
335                          fmt);
336             error_free(err);
337             return -1;
338         }
339     }
340     if (base_fmt) {
341         qemu_opt_set(opts, BLOCK_OPT_BACKING_FMT, base_fmt, &err);
342         if (err) {
343             error_report("Backing file format not supported for file "
344                          "format '%s'", fmt);
345             error_free(err);
346             return -1;
347         }
348     }
349     return 0;
350 }
351 
352 static int img_create(int argc, char **argv)
353 {
354     int c;
355     uint64_t img_size = -1;
356     const char *fmt = "raw";
357     const char *base_fmt = NULL;
358     const char *filename;
359     const char *base_filename = NULL;
360     char *options = NULL;
361     Error *local_err = NULL;
362     bool quiet = false;
363 
364     for(;;) {
365         static const struct option long_options[] = {
366             {"help", no_argument, 0, 'h'},
367             {"object", required_argument, 0, OPTION_OBJECT},
368             {0, 0, 0, 0}
369         };
370         c = getopt_long(argc, argv, "F:b:f:he6o:q",
371                         long_options, NULL);
372         if (c == -1) {
373             break;
374         }
375         switch(c) {
376         case '?':
377         case 'h':
378             help();
379             break;
380         case 'F':
381             base_fmt = optarg;
382             break;
383         case 'b':
384             base_filename = optarg;
385             break;
386         case 'f':
387             fmt = optarg;
388             break;
389         case 'e':
390             error_report("option -e is deprecated, please use \'-o "
391                   "encryption\' instead!");
392             goto fail;
393         case '6':
394             error_report("option -6 is deprecated, please use \'-o "
395                   "compat6\' instead!");
396             goto fail;
397         case 'o':
398             if (!is_valid_option_list(optarg)) {
399                 error_report("Invalid option list: %s", optarg);
400                 goto fail;
401             }
402             if (!options) {
403                 options = g_strdup(optarg);
404             } else {
405                 char *old_options = options;
406                 options = g_strdup_printf("%s,%s", options, optarg);
407                 g_free(old_options);
408             }
409             break;
410         case 'q':
411             quiet = true;
412             break;
413         case OPTION_OBJECT: {
414             QemuOpts *opts;
415             opts = qemu_opts_parse_noisily(&qemu_object_opts,
416                                            optarg, true);
417             if (!opts) {
418                 goto fail;
419             }
420         }   break;
421         }
422     }
423 
424     /* Get the filename */
425     filename = (optind < argc) ? argv[optind] : NULL;
426     if (options && has_help_option(options)) {
427         g_free(options);
428         return print_block_option_help(filename, fmt);
429     }
430 
431     if (optind >= argc) {
432         error_exit("Expecting image file name");
433     }
434     optind++;
435 
436     if (qemu_opts_foreach(&qemu_object_opts,
437                           user_creatable_add_opts_foreach,
438                           NULL, NULL)) {
439         goto fail;
440     }
441 
442     /* Get image size, if specified */
443     if (optind < argc) {
444         int64_t sval;
445         char *end;
446         sval = qemu_strtosz_suffix(argv[optind++], &end,
447                                    QEMU_STRTOSZ_DEFSUFFIX_B);
448         if (sval < 0 || *end) {
449             if (sval == -ERANGE) {
450                 error_report("Image size must be less than 8 EiB!");
451             } else {
452                 error_report("Invalid image size specified! You may use k, M, "
453                       "G, T, P or E suffixes for ");
454                 error_report("kilobytes, megabytes, gigabytes, terabytes, "
455                              "petabytes and exabytes.");
456             }
457             goto fail;
458         }
459         img_size = (uint64_t)sval;
460     }
461     if (optind != argc) {
462         error_exit("Unexpected argument: %s", argv[optind]);
463     }
464 
465     bdrv_img_create(filename, fmt, base_filename, base_fmt,
466                     options, img_size, 0, &local_err, quiet);
467     if (local_err) {
468         error_reportf_err(local_err, "%s: ", filename);
469         goto fail;
470     }
471 
472     g_free(options);
473     return 0;
474 
475 fail:
476     g_free(options);
477     return 1;
478 }
479 
480 static void dump_json_image_check(ImageCheck *check, bool quiet)
481 {
482     Error *local_err = NULL;
483     QString *str;
484     QmpOutputVisitor *ov = qmp_output_visitor_new();
485     QObject *obj;
486     visit_type_ImageCheck(qmp_output_get_visitor(ov), NULL, &check,
487                           &local_err);
488     obj = qmp_output_get_qobject(ov);
489     str = qobject_to_json_pretty(obj);
490     assert(str != NULL);
491     qprintf(quiet, "%s\n", qstring_get_str(str));
492     qobject_decref(obj);
493     qmp_output_visitor_cleanup(ov);
494     QDECREF(str);
495 }
496 
497 static void dump_human_image_check(ImageCheck *check, bool quiet)
498 {
499     if (!(check->corruptions || check->leaks || check->check_errors)) {
500         qprintf(quiet, "No errors were found on the image.\n");
501     } else {
502         if (check->corruptions) {
503             qprintf(quiet, "\n%" PRId64 " errors were found on the image.\n"
504                     "Data may be corrupted, or further writes to the image "
505                     "may corrupt it.\n",
506                     check->corruptions);
507         }
508 
509         if (check->leaks) {
510             qprintf(quiet,
511                     "\n%" PRId64 " leaked clusters were found on the image.\n"
512                     "This means waste of disk space, but no harm to data.\n",
513                     check->leaks);
514         }
515 
516         if (check->check_errors) {
517             qprintf(quiet,
518                     "\n%" PRId64
519                     " internal errors have occurred during the check.\n",
520                     check->check_errors);
521         }
522     }
523 
524     if (check->total_clusters != 0 && check->allocated_clusters != 0) {
525         qprintf(quiet, "%" PRId64 "/%" PRId64 " = %0.2f%% allocated, "
526                 "%0.2f%% fragmented, %0.2f%% compressed clusters\n",
527                 check->allocated_clusters, check->total_clusters,
528                 check->allocated_clusters * 100.0 / check->total_clusters,
529                 check->fragmented_clusters * 100.0 / check->allocated_clusters,
530                 check->compressed_clusters * 100.0 /
531                 check->allocated_clusters);
532     }
533 
534     if (check->image_end_offset) {
535         qprintf(quiet,
536                 "Image end offset: %" PRId64 "\n", check->image_end_offset);
537     }
538 }
539 
540 static int collect_image_check(BlockDriverState *bs,
541                    ImageCheck *check,
542                    const char *filename,
543                    const char *fmt,
544                    int fix)
545 {
546     int ret;
547     BdrvCheckResult result;
548 
549     ret = bdrv_check(bs, &result, fix);
550     if (ret < 0) {
551         return ret;
552     }
553 
554     check->filename                 = g_strdup(filename);
555     check->format                   = g_strdup(bdrv_get_format_name(bs));
556     check->check_errors             = result.check_errors;
557     check->corruptions              = result.corruptions;
558     check->has_corruptions          = result.corruptions != 0;
559     check->leaks                    = result.leaks;
560     check->has_leaks                = result.leaks != 0;
561     check->corruptions_fixed        = result.corruptions_fixed;
562     check->has_corruptions_fixed    = result.corruptions != 0;
563     check->leaks_fixed              = result.leaks_fixed;
564     check->has_leaks_fixed          = result.leaks != 0;
565     check->image_end_offset         = result.image_end_offset;
566     check->has_image_end_offset     = result.image_end_offset != 0;
567     check->total_clusters           = result.bfi.total_clusters;
568     check->has_total_clusters       = result.bfi.total_clusters != 0;
569     check->allocated_clusters       = result.bfi.allocated_clusters;
570     check->has_allocated_clusters   = result.bfi.allocated_clusters != 0;
571     check->fragmented_clusters      = result.bfi.fragmented_clusters;
572     check->has_fragmented_clusters  = result.bfi.fragmented_clusters != 0;
573     check->compressed_clusters      = result.bfi.compressed_clusters;
574     check->has_compressed_clusters  = result.bfi.compressed_clusters != 0;
575 
576     return 0;
577 }
578 
579 /*
580  * Checks an image for consistency. Exit codes:
581  *
582  *  0 - Check completed, image is good
583  *  1 - Check not completed because of internal errors
584  *  2 - Check completed, image is corrupted
585  *  3 - Check completed, image has leaked clusters, but is good otherwise
586  * 63 - Checks are not supported by the image format
587  */
588 static int img_check(int argc, char **argv)
589 {
590     int c, ret;
591     OutputFormat output_format = OFORMAT_HUMAN;
592     const char *filename, *fmt, *output, *cache;
593     BlockBackend *blk;
594     BlockDriverState *bs;
595     int fix = 0;
596     int flags = BDRV_O_CHECK;
597     bool writethrough;
598     ImageCheck *check;
599     bool quiet = false;
600     bool image_opts = false;
601 
602     fmt = NULL;
603     output = NULL;
604     cache = BDRV_DEFAULT_CACHE;
605 
606     for(;;) {
607         int option_index = 0;
608         static const struct option long_options[] = {
609             {"help", no_argument, 0, 'h'},
610             {"format", required_argument, 0, 'f'},
611             {"repair", required_argument, 0, 'r'},
612             {"output", required_argument, 0, OPTION_OUTPUT},
613             {"object", required_argument, 0, OPTION_OBJECT},
614             {"image-opts", no_argument, 0, OPTION_IMAGE_OPTS},
615             {0, 0, 0, 0}
616         };
617         c = getopt_long(argc, argv, "hf:r:T:q",
618                         long_options, &option_index);
619         if (c == -1) {
620             break;
621         }
622         switch(c) {
623         case '?':
624         case 'h':
625             help();
626             break;
627         case 'f':
628             fmt = optarg;
629             break;
630         case 'r':
631             flags |= BDRV_O_RDWR;
632 
633             if (!strcmp(optarg, "leaks")) {
634                 fix = BDRV_FIX_LEAKS;
635             } else if (!strcmp(optarg, "all")) {
636                 fix = BDRV_FIX_LEAKS | BDRV_FIX_ERRORS;
637             } else {
638                 error_exit("Unknown option value for -r "
639                            "(expecting 'leaks' or 'all'): %s", optarg);
640             }
641             break;
642         case OPTION_OUTPUT:
643             output = optarg;
644             break;
645         case 'T':
646             cache = optarg;
647             break;
648         case 'q':
649             quiet = true;
650             break;
651         case OPTION_OBJECT: {
652             QemuOpts *opts;
653             opts = qemu_opts_parse_noisily(&qemu_object_opts,
654                                            optarg, true);
655             if (!opts) {
656                 return 1;
657             }
658         }   break;
659         case OPTION_IMAGE_OPTS:
660             image_opts = true;
661             break;
662         }
663     }
664     if (optind != argc - 1) {
665         error_exit("Expecting one image file name");
666     }
667     filename = argv[optind++];
668 
669     if (output && !strcmp(output, "json")) {
670         output_format = OFORMAT_JSON;
671     } else if (output && !strcmp(output, "human")) {
672         output_format = OFORMAT_HUMAN;
673     } else if (output) {
674         error_report("--output must be used with human or json as argument.");
675         return 1;
676     }
677 
678     if (qemu_opts_foreach(&qemu_object_opts,
679                           user_creatable_add_opts_foreach,
680                           NULL, NULL)) {
681         return 1;
682     }
683 
684     ret = bdrv_parse_cache_mode(cache, &flags, &writethrough);
685     if (ret < 0) {
686         error_report("Invalid source cache option: %s", cache);
687         return 1;
688     }
689 
690     blk = img_open(image_opts, filename, fmt, flags, writethrough, quiet);
691     if (!blk) {
692         return 1;
693     }
694     bs = blk_bs(blk);
695 
696     check = g_new0(ImageCheck, 1);
697     ret = collect_image_check(bs, check, filename, fmt, fix);
698 
699     if (ret == -ENOTSUP) {
700         error_report("This image format does not support checks");
701         ret = 63;
702         goto fail;
703     }
704 
705     if (check->corruptions_fixed || check->leaks_fixed) {
706         int corruptions_fixed, leaks_fixed;
707 
708         leaks_fixed         = check->leaks_fixed;
709         corruptions_fixed   = check->corruptions_fixed;
710 
711         if (output_format == OFORMAT_HUMAN) {
712             qprintf(quiet,
713                     "The following inconsistencies were found and repaired:\n\n"
714                     "    %" PRId64 " leaked clusters\n"
715                     "    %" PRId64 " corruptions\n\n"
716                     "Double checking the fixed image now...\n",
717                     check->leaks_fixed,
718                     check->corruptions_fixed);
719         }
720 
721         ret = collect_image_check(bs, check, filename, fmt, 0);
722 
723         check->leaks_fixed          = leaks_fixed;
724         check->corruptions_fixed    = corruptions_fixed;
725     }
726 
727     if (!ret) {
728         switch (output_format) {
729         case OFORMAT_HUMAN:
730             dump_human_image_check(check, quiet);
731             break;
732         case OFORMAT_JSON:
733             dump_json_image_check(check, quiet);
734             break;
735         }
736     }
737 
738     if (ret || check->check_errors) {
739         if (ret) {
740             error_report("Check failed: %s", strerror(-ret));
741         } else {
742             error_report("Check failed");
743         }
744         ret = 1;
745         goto fail;
746     }
747 
748     if (check->corruptions) {
749         ret = 2;
750     } else if (check->leaks) {
751         ret = 3;
752     } else {
753         ret = 0;
754     }
755 
756 fail:
757     qapi_free_ImageCheck(check);
758     blk_unref(blk);
759     return ret;
760 }
761 
762 typedef struct CommonBlockJobCBInfo {
763     BlockDriverState *bs;
764     Error **errp;
765 } CommonBlockJobCBInfo;
766 
767 static void common_block_job_cb(void *opaque, int ret)
768 {
769     CommonBlockJobCBInfo *cbi = opaque;
770 
771     if (ret < 0) {
772         error_setg_errno(cbi->errp, -ret, "Block job failed");
773     }
774 }
775 
776 static void run_block_job(BlockJob *job, Error **errp)
777 {
778     AioContext *aio_context = bdrv_get_aio_context(job->bs);
779 
780     do {
781         aio_poll(aio_context, true);
782         qemu_progress_print(job->len ?
783                             ((float)job->offset / job->len * 100.f) : 0.0f, 0);
784     } while (!job->ready);
785 
786     block_job_complete_sync(job, errp);
787 
788     /* A block job may finish instantaneously without publishing any progress,
789      * so just signal completion here */
790     qemu_progress_print(100.f, 0);
791 }
792 
793 static int img_commit(int argc, char **argv)
794 {
795     int c, ret, flags;
796     const char *filename, *fmt, *cache, *base;
797     BlockBackend *blk;
798     BlockDriverState *bs, *base_bs;
799     bool progress = false, quiet = false, drop = false;
800     bool writethrough;
801     Error *local_err = NULL;
802     CommonBlockJobCBInfo cbi;
803     bool image_opts = false;
804 
805     fmt = NULL;
806     cache = BDRV_DEFAULT_CACHE;
807     base = NULL;
808     for(;;) {
809         static const struct option long_options[] = {
810             {"help", no_argument, 0, 'h'},
811             {"object", required_argument, 0, OPTION_OBJECT},
812             {"image-opts", no_argument, 0, OPTION_IMAGE_OPTS},
813             {0, 0, 0, 0}
814         };
815         c = getopt_long(argc, argv, "f:ht:b:dpq",
816                         long_options, NULL);
817         if (c == -1) {
818             break;
819         }
820         switch(c) {
821         case '?':
822         case 'h':
823             help();
824             break;
825         case 'f':
826             fmt = optarg;
827             break;
828         case 't':
829             cache = optarg;
830             break;
831         case 'b':
832             base = optarg;
833             /* -b implies -d */
834             drop = true;
835             break;
836         case 'd':
837             drop = true;
838             break;
839         case 'p':
840             progress = true;
841             break;
842         case 'q':
843             quiet = true;
844             break;
845         case OPTION_OBJECT: {
846             QemuOpts *opts;
847             opts = qemu_opts_parse_noisily(&qemu_object_opts,
848                                            optarg, true);
849             if (!opts) {
850                 return 1;
851             }
852         }   break;
853         case OPTION_IMAGE_OPTS:
854             image_opts = true;
855             break;
856         }
857     }
858 
859     /* Progress is not shown in Quiet mode */
860     if (quiet) {
861         progress = false;
862     }
863 
864     if (optind != argc - 1) {
865         error_exit("Expecting one image file name");
866     }
867     filename = argv[optind++];
868 
869     if (qemu_opts_foreach(&qemu_object_opts,
870                           user_creatable_add_opts_foreach,
871                           NULL, NULL)) {
872         return 1;
873     }
874 
875     flags = BDRV_O_RDWR | BDRV_O_UNMAP;
876     ret = bdrv_parse_cache_mode(cache, &flags, &writethrough);
877     if (ret < 0) {
878         error_report("Invalid cache option: %s", cache);
879         return 1;
880     }
881 
882     blk = img_open(image_opts, filename, fmt, flags, writethrough, quiet);
883     if (!blk) {
884         return 1;
885     }
886     bs = blk_bs(blk);
887 
888     qemu_progress_init(progress, 1.f);
889     qemu_progress_print(0.f, 100);
890 
891     if (base) {
892         base_bs = bdrv_find_backing_image(bs, base);
893         if (!base_bs) {
894             error_setg(&local_err, QERR_BASE_NOT_FOUND, base);
895             goto done;
896         }
897     } else {
898         /* This is different from QMP, which by default uses the deepest file in
899          * the backing chain (i.e., the very base); however, the traditional
900          * behavior of qemu-img commit is using the immediate backing file. */
901         base_bs = backing_bs(bs);
902         if (!base_bs) {
903             error_setg(&local_err, "Image does not have a backing file");
904             goto done;
905         }
906     }
907 
908     cbi = (CommonBlockJobCBInfo){
909         .errp = &local_err,
910         .bs   = bs,
911     };
912 
913     commit_active_start(bs, base_bs, 0, BLOCKDEV_ON_ERROR_REPORT,
914                         common_block_job_cb, &cbi, &local_err);
915     if (local_err) {
916         goto done;
917     }
918 
919     /* When the block job completes, the BlockBackend reference will point to
920      * the old backing file. In order to avoid that the top image is already
921      * deleted, so we can still empty it afterwards, increment the reference
922      * counter here preemptively. */
923     if (!drop) {
924         bdrv_ref(bs);
925     }
926 
927     run_block_job(bs->job, &local_err);
928     if (local_err) {
929         goto unref_backing;
930     }
931 
932     if (!drop && bs->drv->bdrv_make_empty) {
933         ret = bs->drv->bdrv_make_empty(bs);
934         if (ret) {
935             error_setg_errno(&local_err, -ret, "Could not empty %s",
936                              filename);
937             goto unref_backing;
938         }
939     }
940 
941 unref_backing:
942     if (!drop) {
943         bdrv_unref(bs);
944     }
945 
946 done:
947     qemu_progress_end();
948 
949     blk_unref(blk);
950 
951     if (local_err) {
952         error_report_err(local_err);
953         return 1;
954     }
955 
956     qprintf(quiet, "Image committed.\n");
957     return 0;
958 }
959 
960 /*
961  * Returns true iff the first sector pointed to by 'buf' contains at least
962  * a non-NUL byte.
963  *
964  * 'pnum' is set to the number of sectors (including and immediately following
965  * the first one) that are known to be in the same allocated/unallocated state.
966  */
967 static int is_allocated_sectors(const uint8_t *buf, int n, int *pnum)
968 {
969     bool is_zero;
970     int i;
971 
972     if (n <= 0) {
973         *pnum = 0;
974         return 0;
975     }
976     is_zero = buffer_is_zero(buf, 512);
977     for(i = 1; i < n; i++) {
978         buf += 512;
979         if (is_zero != buffer_is_zero(buf, 512)) {
980             break;
981         }
982     }
983     *pnum = i;
984     return !is_zero;
985 }
986 
987 /*
988  * Like is_allocated_sectors, but if the buffer starts with a used sector,
989  * up to 'min' consecutive sectors containing zeros are ignored. This avoids
990  * breaking up write requests for only small sparse areas.
991  */
992 static int is_allocated_sectors_min(const uint8_t *buf, int n, int *pnum,
993     int min)
994 {
995     int ret;
996     int num_checked, num_used;
997 
998     if (n < min) {
999         min = n;
1000     }
1001 
1002     ret = is_allocated_sectors(buf, n, pnum);
1003     if (!ret) {
1004         return ret;
1005     }
1006 
1007     num_used = *pnum;
1008     buf += BDRV_SECTOR_SIZE * *pnum;
1009     n -= *pnum;
1010     num_checked = num_used;
1011 
1012     while (n > 0) {
1013         ret = is_allocated_sectors(buf, n, pnum);
1014 
1015         buf += BDRV_SECTOR_SIZE * *pnum;
1016         n -= *pnum;
1017         num_checked += *pnum;
1018         if (ret) {
1019             num_used = num_checked;
1020         } else if (*pnum >= min) {
1021             break;
1022         }
1023     }
1024 
1025     *pnum = num_used;
1026     return 1;
1027 }
1028 
1029 /*
1030  * Compares two buffers sector by sector. Returns 0 if the first sector of both
1031  * buffers matches, non-zero otherwise.
1032  *
1033  * pnum is set to the number of sectors (including and immediately following
1034  * the first one) that are known to have the same comparison result
1035  */
1036 static int compare_sectors(const uint8_t *buf1, const uint8_t *buf2, int n,
1037     int *pnum)
1038 {
1039     bool res;
1040     int i;
1041 
1042     if (n <= 0) {
1043         *pnum = 0;
1044         return 0;
1045     }
1046 
1047     res = !!memcmp(buf1, buf2, 512);
1048     for(i = 1; i < n; i++) {
1049         buf1 += 512;
1050         buf2 += 512;
1051 
1052         if (!!memcmp(buf1, buf2, 512) != res) {
1053             break;
1054         }
1055     }
1056 
1057     *pnum = i;
1058     return res;
1059 }
1060 
1061 #define IO_BUF_SIZE (2 * 1024 * 1024)
1062 
1063 static int64_t sectors_to_bytes(int64_t sectors)
1064 {
1065     return sectors << BDRV_SECTOR_BITS;
1066 }
1067 
1068 static int64_t sectors_to_process(int64_t total, int64_t from)
1069 {
1070     return MIN(total - from, IO_BUF_SIZE >> BDRV_SECTOR_BITS);
1071 }
1072 
1073 /*
1074  * Check if passed sectors are empty (not allocated or contain only 0 bytes)
1075  *
1076  * Returns 0 in case sectors are filled with 0, 1 if sectors contain non-zero
1077  * data and negative value on error.
1078  *
1079  * @param blk:  BlockBackend for the image
1080  * @param sect_num: Number of first sector to check
1081  * @param sect_count: Number of sectors to check
1082  * @param filename: Name of disk file we are checking (logging purpose)
1083  * @param buffer: Allocated buffer for storing read data
1084  * @param quiet: Flag for quiet mode
1085  */
1086 static int check_empty_sectors(BlockBackend *blk, int64_t sect_num,
1087                                int sect_count, const char *filename,
1088                                uint8_t *buffer, bool quiet)
1089 {
1090     int pnum, ret = 0;
1091     ret = blk_pread(blk, sect_num << BDRV_SECTOR_BITS, buffer,
1092                     sect_count << BDRV_SECTOR_BITS);
1093     if (ret < 0) {
1094         error_report("Error while reading offset %" PRId64 " of %s: %s",
1095                      sectors_to_bytes(sect_num), filename, strerror(-ret));
1096         return ret;
1097     }
1098     ret = is_allocated_sectors(buffer, sect_count, &pnum);
1099     if (ret || pnum != sect_count) {
1100         qprintf(quiet, "Content mismatch at offset %" PRId64 "!\n",
1101                 sectors_to_bytes(ret ? sect_num : sect_num + pnum));
1102         return 1;
1103     }
1104 
1105     return 0;
1106 }
1107 
1108 /*
1109  * Compares two images. Exit codes:
1110  *
1111  * 0 - Images are identical
1112  * 1 - Images differ
1113  * >1 - Error occurred
1114  */
1115 static int img_compare(int argc, char **argv)
1116 {
1117     const char *fmt1 = NULL, *fmt2 = NULL, *cache, *filename1, *filename2;
1118     BlockBackend *blk1, *blk2;
1119     BlockDriverState *bs1, *bs2;
1120     int64_t total_sectors1, total_sectors2;
1121     uint8_t *buf1 = NULL, *buf2 = NULL;
1122     int pnum1, pnum2;
1123     int allocated1, allocated2;
1124     int ret = 0; /* return value - 0 Ident, 1 Different, >1 Error */
1125     bool progress = false, quiet = false, strict = false;
1126     int flags;
1127     bool writethrough;
1128     int64_t total_sectors;
1129     int64_t sector_num = 0;
1130     int64_t nb_sectors;
1131     int c, pnum;
1132     uint64_t progress_base;
1133     bool image_opts = false;
1134 
1135     cache = BDRV_DEFAULT_CACHE;
1136     for (;;) {
1137         static const struct option long_options[] = {
1138             {"help", no_argument, 0, 'h'},
1139             {"object", required_argument, 0, OPTION_OBJECT},
1140             {"image-opts", no_argument, 0, OPTION_IMAGE_OPTS},
1141             {0, 0, 0, 0}
1142         };
1143         c = getopt_long(argc, argv, "hf:F:T:pqs",
1144                         long_options, NULL);
1145         if (c == -1) {
1146             break;
1147         }
1148         switch (c) {
1149         case '?':
1150         case 'h':
1151             help();
1152             break;
1153         case 'f':
1154             fmt1 = optarg;
1155             break;
1156         case 'F':
1157             fmt2 = optarg;
1158             break;
1159         case 'T':
1160             cache = optarg;
1161             break;
1162         case 'p':
1163             progress = true;
1164             break;
1165         case 'q':
1166             quiet = true;
1167             break;
1168         case 's':
1169             strict = true;
1170             break;
1171         case OPTION_OBJECT: {
1172             QemuOpts *opts;
1173             opts = qemu_opts_parse_noisily(&qemu_object_opts,
1174                                            optarg, true);
1175             if (!opts) {
1176                 ret = 2;
1177                 goto out4;
1178             }
1179         }   break;
1180         case OPTION_IMAGE_OPTS:
1181             image_opts = true;
1182             break;
1183         }
1184     }
1185 
1186     /* Progress is not shown in Quiet mode */
1187     if (quiet) {
1188         progress = false;
1189     }
1190 
1191 
1192     if (optind != argc - 2) {
1193         error_exit("Expecting two image file names");
1194     }
1195     filename1 = argv[optind++];
1196     filename2 = argv[optind++];
1197 
1198     if (qemu_opts_foreach(&qemu_object_opts,
1199                           user_creatable_add_opts_foreach,
1200                           NULL, NULL)) {
1201         ret = 2;
1202         goto out4;
1203     }
1204 
1205     /* Initialize before goto out */
1206     qemu_progress_init(progress, 2.0);
1207 
1208     flags = 0;
1209     ret = bdrv_parse_cache_mode(cache, &flags, &writethrough);
1210     if (ret < 0) {
1211         error_report("Invalid source cache option: %s", cache);
1212         ret = 2;
1213         goto out3;
1214     }
1215 
1216     blk1 = img_open(image_opts, filename1, fmt1, flags, writethrough, quiet);
1217     if (!blk1) {
1218         ret = 2;
1219         goto out3;
1220     }
1221 
1222     blk2 = img_open(image_opts, filename2, fmt2, flags, writethrough, quiet);
1223     if (!blk2) {
1224         ret = 2;
1225         goto out2;
1226     }
1227     bs1 = blk_bs(blk1);
1228     bs2 = blk_bs(blk2);
1229 
1230     buf1 = blk_blockalign(blk1, IO_BUF_SIZE);
1231     buf2 = blk_blockalign(blk2, IO_BUF_SIZE);
1232     total_sectors1 = blk_nb_sectors(blk1);
1233     if (total_sectors1 < 0) {
1234         error_report("Can't get size of %s: %s",
1235                      filename1, strerror(-total_sectors1));
1236         ret = 4;
1237         goto out;
1238     }
1239     total_sectors2 = blk_nb_sectors(blk2);
1240     if (total_sectors2 < 0) {
1241         error_report("Can't get size of %s: %s",
1242                      filename2, strerror(-total_sectors2));
1243         ret = 4;
1244         goto out;
1245     }
1246     total_sectors = MIN(total_sectors1, total_sectors2);
1247     progress_base = MAX(total_sectors1, total_sectors2);
1248 
1249     qemu_progress_print(0, 100);
1250 
1251     if (strict && total_sectors1 != total_sectors2) {
1252         ret = 1;
1253         qprintf(quiet, "Strict mode: Image size mismatch!\n");
1254         goto out;
1255     }
1256 
1257     for (;;) {
1258         int64_t status1, status2;
1259         BlockDriverState *file;
1260 
1261         nb_sectors = sectors_to_process(total_sectors, sector_num);
1262         if (nb_sectors <= 0) {
1263             break;
1264         }
1265         status1 = bdrv_get_block_status_above(bs1, NULL, sector_num,
1266                                               total_sectors1 - sector_num,
1267                                               &pnum1, &file);
1268         if (status1 < 0) {
1269             ret = 3;
1270             error_report("Sector allocation test failed for %s", filename1);
1271             goto out;
1272         }
1273         allocated1 = status1 & BDRV_BLOCK_ALLOCATED;
1274 
1275         status2 = bdrv_get_block_status_above(bs2, NULL, sector_num,
1276                                               total_sectors2 - sector_num,
1277                                               &pnum2, &file);
1278         if (status2 < 0) {
1279             ret = 3;
1280             error_report("Sector allocation test failed for %s", filename2);
1281             goto out;
1282         }
1283         allocated2 = status2 & BDRV_BLOCK_ALLOCATED;
1284         if (pnum1) {
1285             nb_sectors = MIN(nb_sectors, pnum1);
1286         }
1287         if (pnum2) {
1288             nb_sectors = MIN(nb_sectors, pnum2);
1289         }
1290 
1291         if (strict) {
1292             if ((status1 & ~BDRV_BLOCK_OFFSET_MASK) !=
1293                 (status2 & ~BDRV_BLOCK_OFFSET_MASK)) {
1294                 ret = 1;
1295                 qprintf(quiet, "Strict mode: Offset %" PRId64
1296                         " block status mismatch!\n",
1297                         sectors_to_bytes(sector_num));
1298                 goto out;
1299             }
1300         }
1301         if ((status1 & BDRV_BLOCK_ZERO) && (status2 & BDRV_BLOCK_ZERO)) {
1302             nb_sectors = MIN(pnum1, pnum2);
1303         } else if (allocated1 == allocated2) {
1304             if (allocated1) {
1305                 ret = blk_pread(blk1, sector_num << BDRV_SECTOR_BITS, buf1,
1306                                 nb_sectors << BDRV_SECTOR_BITS);
1307                 if (ret < 0) {
1308                     error_report("Error while reading offset %" PRId64 " of %s:"
1309                                  " %s", sectors_to_bytes(sector_num), filename1,
1310                                  strerror(-ret));
1311                     ret = 4;
1312                     goto out;
1313                 }
1314                 ret = blk_pread(blk2, sector_num << BDRV_SECTOR_BITS, buf2,
1315                                 nb_sectors << BDRV_SECTOR_BITS);
1316                 if (ret < 0) {
1317                     error_report("Error while reading offset %" PRId64
1318                                  " of %s: %s", sectors_to_bytes(sector_num),
1319                                  filename2, strerror(-ret));
1320                     ret = 4;
1321                     goto out;
1322                 }
1323                 ret = compare_sectors(buf1, buf2, nb_sectors, &pnum);
1324                 if (ret || pnum != nb_sectors) {
1325                     qprintf(quiet, "Content mismatch at offset %" PRId64 "!\n",
1326                             sectors_to_bytes(
1327                                 ret ? sector_num : sector_num + pnum));
1328                     ret = 1;
1329                     goto out;
1330                 }
1331             }
1332         } else {
1333 
1334             if (allocated1) {
1335                 ret = check_empty_sectors(blk1, sector_num, nb_sectors,
1336                                           filename1, buf1, quiet);
1337             } else {
1338                 ret = check_empty_sectors(blk2, sector_num, nb_sectors,
1339                                           filename2, buf1, quiet);
1340             }
1341             if (ret) {
1342                 if (ret < 0) {
1343                     error_report("Error while reading offset %" PRId64 ": %s",
1344                                  sectors_to_bytes(sector_num), strerror(-ret));
1345                     ret = 4;
1346                 }
1347                 goto out;
1348             }
1349         }
1350         sector_num += nb_sectors;
1351         qemu_progress_print(((float) nb_sectors / progress_base)*100, 100);
1352     }
1353 
1354     if (total_sectors1 != total_sectors2) {
1355         BlockBackend *blk_over;
1356         int64_t total_sectors_over;
1357         const char *filename_over;
1358 
1359         qprintf(quiet, "Warning: Image size mismatch!\n");
1360         if (total_sectors1 > total_sectors2) {
1361             total_sectors_over = total_sectors1;
1362             blk_over = blk1;
1363             filename_over = filename1;
1364         } else {
1365             total_sectors_over = total_sectors2;
1366             blk_over = blk2;
1367             filename_over = filename2;
1368         }
1369 
1370         for (;;) {
1371             nb_sectors = sectors_to_process(total_sectors_over, sector_num);
1372             if (nb_sectors <= 0) {
1373                 break;
1374             }
1375             ret = bdrv_is_allocated_above(blk_bs(blk_over), NULL, sector_num,
1376                                           nb_sectors, &pnum);
1377             if (ret < 0) {
1378                 ret = 3;
1379                 error_report("Sector allocation test failed for %s",
1380                              filename_over);
1381                 goto out;
1382 
1383             }
1384             nb_sectors = pnum;
1385             if (ret) {
1386                 ret = check_empty_sectors(blk_over, sector_num, nb_sectors,
1387                                           filename_over, buf1, quiet);
1388                 if (ret) {
1389                     if (ret < 0) {
1390                         error_report("Error while reading offset %" PRId64
1391                                      " of %s: %s", sectors_to_bytes(sector_num),
1392                                      filename_over, strerror(-ret));
1393                         ret = 4;
1394                     }
1395                     goto out;
1396                 }
1397             }
1398             sector_num += nb_sectors;
1399             qemu_progress_print(((float) nb_sectors / progress_base)*100, 100);
1400         }
1401     }
1402 
1403     qprintf(quiet, "Images are identical.\n");
1404     ret = 0;
1405 
1406 out:
1407     qemu_vfree(buf1);
1408     qemu_vfree(buf2);
1409     blk_unref(blk2);
1410 out2:
1411     blk_unref(blk1);
1412 out3:
1413     qemu_progress_end();
1414 out4:
1415     return ret;
1416 }
1417 
1418 enum ImgConvertBlockStatus {
1419     BLK_DATA,
1420     BLK_ZERO,
1421     BLK_BACKING_FILE,
1422 };
1423 
1424 typedef struct ImgConvertState {
1425     BlockBackend **src;
1426     int64_t *src_sectors;
1427     int src_cur, src_num;
1428     int64_t src_cur_offset;
1429     int64_t total_sectors;
1430     int64_t allocated_sectors;
1431     enum ImgConvertBlockStatus status;
1432     int64_t sector_next_status;
1433     BlockBackend *target;
1434     bool has_zero_init;
1435     bool compressed;
1436     bool target_has_backing;
1437     int min_sparse;
1438     size_t cluster_sectors;
1439     size_t buf_sectors;
1440 } ImgConvertState;
1441 
1442 static void convert_select_part(ImgConvertState *s, int64_t sector_num)
1443 {
1444     assert(sector_num >= s->src_cur_offset);
1445     while (sector_num - s->src_cur_offset >= s->src_sectors[s->src_cur]) {
1446         s->src_cur_offset += s->src_sectors[s->src_cur];
1447         s->src_cur++;
1448         assert(s->src_cur < s->src_num);
1449     }
1450 }
1451 
1452 static int convert_iteration_sectors(ImgConvertState *s, int64_t sector_num)
1453 {
1454     int64_t ret;
1455     int n;
1456 
1457     convert_select_part(s, sector_num);
1458 
1459     assert(s->total_sectors > sector_num);
1460     n = MIN(s->total_sectors - sector_num, BDRV_REQUEST_MAX_SECTORS);
1461 
1462     if (s->sector_next_status <= sector_num) {
1463         BlockDriverState *file;
1464         ret = bdrv_get_block_status(blk_bs(s->src[s->src_cur]),
1465                                     sector_num - s->src_cur_offset,
1466                                     n, &n, &file);
1467         if (ret < 0) {
1468             return ret;
1469         }
1470 
1471         if (ret & BDRV_BLOCK_ZERO) {
1472             s->status = BLK_ZERO;
1473         } else if (ret & BDRV_BLOCK_DATA) {
1474             s->status = BLK_DATA;
1475         } else if (!s->target_has_backing) {
1476             /* Without a target backing file we must copy over the contents of
1477              * the backing file as well. */
1478             /* Check block status of the backing file chain to avoid
1479              * needlessly reading zeroes and limiting the iteration to the
1480              * buffer size */
1481             ret = bdrv_get_block_status_above(blk_bs(s->src[s->src_cur]), NULL,
1482                                               sector_num - s->src_cur_offset,
1483                                               n, &n, &file);
1484             if (ret < 0) {
1485                 return ret;
1486             }
1487 
1488             if (ret & BDRV_BLOCK_ZERO) {
1489                 s->status = BLK_ZERO;
1490             } else {
1491                 s->status = BLK_DATA;
1492             }
1493         } else {
1494             s->status = BLK_BACKING_FILE;
1495         }
1496 
1497         s->sector_next_status = sector_num + n;
1498     }
1499 
1500     n = MIN(n, s->sector_next_status - sector_num);
1501     if (s->status == BLK_DATA) {
1502         n = MIN(n, s->buf_sectors);
1503     }
1504 
1505     /* We need to write complete clusters for compressed images, so if an
1506      * unallocated area is shorter than that, we must consider the whole
1507      * cluster allocated. */
1508     if (s->compressed) {
1509         if (n < s->cluster_sectors) {
1510             n = MIN(s->cluster_sectors, s->total_sectors - sector_num);
1511             s->status = BLK_DATA;
1512         } else {
1513             n = QEMU_ALIGN_DOWN(n, s->cluster_sectors);
1514         }
1515     }
1516 
1517     return n;
1518 }
1519 
1520 static int convert_read(ImgConvertState *s, int64_t sector_num, int nb_sectors,
1521                         uint8_t *buf)
1522 {
1523     int n;
1524     int ret;
1525 
1526     assert(nb_sectors <= s->buf_sectors);
1527     while (nb_sectors > 0) {
1528         BlockBackend *blk;
1529         int64_t bs_sectors;
1530 
1531         /* In the case of compression with multiple source files, we can get a
1532          * nb_sectors that spreads into the next part. So we must be able to
1533          * read across multiple BDSes for one convert_read() call. */
1534         convert_select_part(s, sector_num);
1535         blk = s->src[s->src_cur];
1536         bs_sectors = s->src_sectors[s->src_cur];
1537 
1538         n = MIN(nb_sectors, bs_sectors - (sector_num - s->src_cur_offset));
1539         ret = blk_pread(blk,
1540                         (sector_num - s->src_cur_offset) << BDRV_SECTOR_BITS,
1541                         buf, n << BDRV_SECTOR_BITS);
1542         if (ret < 0) {
1543             return ret;
1544         }
1545 
1546         sector_num += n;
1547         nb_sectors -= n;
1548         buf += n * BDRV_SECTOR_SIZE;
1549     }
1550 
1551     return 0;
1552 }
1553 
1554 static int convert_write(ImgConvertState *s, int64_t sector_num, int nb_sectors,
1555                          const uint8_t *buf)
1556 {
1557     int ret;
1558 
1559     while (nb_sectors > 0) {
1560         int n = nb_sectors;
1561 
1562         switch (s->status) {
1563         case BLK_BACKING_FILE:
1564             /* If we have a backing file, leave clusters unallocated that are
1565              * unallocated in the source image, so that the backing file is
1566              * visible at the respective offset. */
1567             assert(s->target_has_backing);
1568             break;
1569 
1570         case BLK_DATA:
1571             /* We must always write compressed clusters as a whole, so don't
1572              * try to find zeroed parts in the buffer. We can only save the
1573              * write if the buffer is completely zeroed and we're allowed to
1574              * keep the target sparse. */
1575             if (s->compressed) {
1576                 if (s->has_zero_init && s->min_sparse &&
1577                     buffer_is_zero(buf, n * BDRV_SECTOR_SIZE))
1578                 {
1579                     assert(!s->target_has_backing);
1580                     break;
1581                 }
1582 
1583                 ret = blk_write_compressed(s->target, sector_num, buf, n);
1584                 if (ret < 0) {
1585                     return ret;
1586                 }
1587                 break;
1588             }
1589 
1590             /* If there is real non-zero data or we're told to keep the target
1591              * fully allocated (-S 0), we must write it. Otherwise we can treat
1592              * it as zero sectors. */
1593             if (!s->min_sparse ||
1594                 is_allocated_sectors_min(buf, n, &n, s->min_sparse))
1595             {
1596                 ret = blk_pwrite(s->target, sector_num << BDRV_SECTOR_BITS,
1597                                  buf, n << BDRV_SECTOR_BITS, 0);
1598                 if (ret < 0) {
1599                     return ret;
1600                 }
1601                 break;
1602             }
1603             /* fall-through */
1604 
1605         case BLK_ZERO:
1606             if (s->has_zero_init) {
1607                 break;
1608             }
1609             ret = blk_write_zeroes(s->target, sector_num << BDRV_SECTOR_BITS,
1610                                    n << BDRV_SECTOR_BITS, 0);
1611             if (ret < 0) {
1612                 return ret;
1613             }
1614             break;
1615         }
1616 
1617         sector_num += n;
1618         nb_sectors -= n;
1619         buf += n * BDRV_SECTOR_SIZE;
1620     }
1621 
1622     return 0;
1623 }
1624 
1625 static int convert_do_copy(ImgConvertState *s)
1626 {
1627     uint8_t *buf = NULL;
1628     int64_t sector_num, allocated_done;
1629     int ret;
1630     int n;
1631 
1632     /* Check whether we have zero initialisation or can get it efficiently */
1633     s->has_zero_init = s->min_sparse && !s->target_has_backing
1634                      ? bdrv_has_zero_init(blk_bs(s->target))
1635                      : false;
1636 
1637     if (!s->has_zero_init && !s->target_has_backing &&
1638         bdrv_can_write_zeroes_with_unmap(blk_bs(s->target)))
1639     {
1640         ret = bdrv_make_zero(blk_bs(s->target), BDRV_REQ_MAY_UNMAP);
1641         if (ret == 0) {
1642             s->has_zero_init = true;
1643         }
1644     }
1645 
1646     /* Allocate buffer for copied data. For compressed images, only one cluster
1647      * can be copied at a time. */
1648     if (s->compressed) {
1649         if (s->cluster_sectors <= 0 || s->cluster_sectors > s->buf_sectors) {
1650             error_report("invalid cluster size");
1651             ret = -EINVAL;
1652             goto fail;
1653         }
1654         s->buf_sectors = s->cluster_sectors;
1655     }
1656     buf = blk_blockalign(s->target, s->buf_sectors * BDRV_SECTOR_SIZE);
1657 
1658     /* Calculate allocated sectors for progress */
1659     s->allocated_sectors = 0;
1660     sector_num = 0;
1661     while (sector_num < s->total_sectors) {
1662         n = convert_iteration_sectors(s, sector_num);
1663         if (n < 0) {
1664             ret = n;
1665             goto fail;
1666         }
1667         if (s->status == BLK_DATA || (!s->min_sparse && s->status == BLK_ZERO))
1668         {
1669             s->allocated_sectors += n;
1670         }
1671         sector_num += n;
1672     }
1673 
1674     /* Do the copy */
1675     s->src_cur = 0;
1676     s->src_cur_offset = 0;
1677     s->sector_next_status = 0;
1678 
1679     sector_num = 0;
1680     allocated_done = 0;
1681 
1682     while (sector_num < s->total_sectors) {
1683         n = convert_iteration_sectors(s, sector_num);
1684         if (n < 0) {
1685             ret = n;
1686             goto fail;
1687         }
1688         if (s->status == BLK_DATA || (!s->min_sparse && s->status == BLK_ZERO))
1689         {
1690             allocated_done += n;
1691             qemu_progress_print(100.0 * allocated_done / s->allocated_sectors,
1692                                 0);
1693         }
1694 
1695         if (s->status == BLK_DATA) {
1696             ret = convert_read(s, sector_num, n, buf);
1697             if (ret < 0) {
1698                 error_report("error while reading sector %" PRId64
1699                              ": %s", sector_num, strerror(-ret));
1700                 goto fail;
1701             }
1702         } else if (!s->min_sparse && s->status == BLK_ZERO) {
1703             n = MIN(n, s->buf_sectors);
1704             memset(buf, 0, n * BDRV_SECTOR_SIZE);
1705             s->status = BLK_DATA;
1706         }
1707 
1708         ret = convert_write(s, sector_num, n, buf);
1709         if (ret < 0) {
1710             error_report("error while writing sector %" PRId64
1711                          ": %s", sector_num, strerror(-ret));
1712             goto fail;
1713         }
1714 
1715         sector_num += n;
1716     }
1717 
1718     if (s->compressed) {
1719         /* signal EOF to align */
1720         ret = blk_write_compressed(s->target, 0, NULL, 0);
1721         if (ret < 0) {
1722             goto fail;
1723         }
1724     }
1725 
1726     ret = 0;
1727 fail:
1728     qemu_vfree(buf);
1729     return ret;
1730 }
1731 
1732 static int img_convert(int argc, char **argv)
1733 {
1734     int c, bs_n, bs_i, compress, cluster_sectors, skip_create;
1735     int64_t ret = 0;
1736     int progress = 0, flags, src_flags;
1737     bool writethrough, src_writethrough;
1738     const char *fmt, *out_fmt, *cache, *src_cache, *out_baseimg, *out_filename;
1739     BlockDriver *drv, *proto_drv;
1740     BlockBackend **blk = NULL, *out_blk = NULL;
1741     BlockDriverState **bs = NULL, *out_bs = NULL;
1742     int64_t total_sectors;
1743     int64_t *bs_sectors = NULL;
1744     size_t bufsectors = IO_BUF_SIZE / BDRV_SECTOR_SIZE;
1745     BlockDriverInfo bdi;
1746     QemuOpts *opts = NULL;
1747     QemuOptsList *create_opts = NULL;
1748     const char *out_baseimg_param;
1749     char *options = NULL;
1750     const char *snapshot_name = NULL;
1751     int min_sparse = 8; /* Need at least 4k of zeros for sparse detection */
1752     bool quiet = false;
1753     Error *local_err = NULL;
1754     QemuOpts *sn_opts = NULL;
1755     ImgConvertState state;
1756     bool image_opts = false;
1757 
1758     fmt = NULL;
1759     out_fmt = "raw";
1760     cache = "unsafe";
1761     src_cache = BDRV_DEFAULT_CACHE;
1762     out_baseimg = NULL;
1763     compress = 0;
1764     skip_create = 0;
1765     for(;;) {
1766         static const struct option long_options[] = {
1767             {"help", no_argument, 0, 'h'},
1768             {"object", required_argument, 0, OPTION_OBJECT},
1769             {"image-opts", no_argument, 0, OPTION_IMAGE_OPTS},
1770             {0, 0, 0, 0}
1771         };
1772         c = getopt_long(argc, argv, "hf:O:B:ce6o:s:l:S:pt:T:qn",
1773                         long_options, NULL);
1774         if (c == -1) {
1775             break;
1776         }
1777         switch(c) {
1778         case '?':
1779         case 'h':
1780             help();
1781             break;
1782         case 'f':
1783             fmt = optarg;
1784             break;
1785         case 'O':
1786             out_fmt = optarg;
1787             break;
1788         case 'B':
1789             out_baseimg = optarg;
1790             break;
1791         case 'c':
1792             compress = 1;
1793             break;
1794         case 'e':
1795             error_report("option -e is deprecated, please use \'-o "
1796                   "encryption\' instead!");
1797             ret = -1;
1798             goto fail_getopt;
1799         case '6':
1800             error_report("option -6 is deprecated, please use \'-o "
1801                   "compat6\' instead!");
1802             ret = -1;
1803             goto fail_getopt;
1804         case 'o':
1805             if (!is_valid_option_list(optarg)) {
1806                 error_report("Invalid option list: %s", optarg);
1807                 ret = -1;
1808                 goto fail_getopt;
1809             }
1810             if (!options) {
1811                 options = g_strdup(optarg);
1812             } else {
1813                 char *old_options = options;
1814                 options = g_strdup_printf("%s,%s", options, optarg);
1815                 g_free(old_options);
1816             }
1817             break;
1818         case 's':
1819             snapshot_name = optarg;
1820             break;
1821         case 'l':
1822             if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
1823                 sn_opts = qemu_opts_parse_noisily(&internal_snapshot_opts,
1824                                                   optarg, false);
1825                 if (!sn_opts) {
1826                     error_report("Failed in parsing snapshot param '%s'",
1827                                  optarg);
1828                     ret = -1;
1829                     goto fail_getopt;
1830                 }
1831             } else {
1832                 snapshot_name = optarg;
1833             }
1834             break;
1835         case 'S':
1836         {
1837             int64_t sval;
1838             char *end;
1839             sval = qemu_strtosz_suffix(optarg, &end, QEMU_STRTOSZ_DEFSUFFIX_B);
1840             if (sval < 0 || *end) {
1841                 error_report("Invalid minimum zero buffer size for sparse output specified");
1842                 ret = -1;
1843                 goto fail_getopt;
1844             }
1845 
1846             min_sparse = sval / BDRV_SECTOR_SIZE;
1847             break;
1848         }
1849         case 'p':
1850             progress = 1;
1851             break;
1852         case 't':
1853             cache = optarg;
1854             break;
1855         case 'T':
1856             src_cache = optarg;
1857             break;
1858         case 'q':
1859             quiet = true;
1860             break;
1861         case 'n':
1862             skip_create = 1;
1863             break;
1864         case OPTION_OBJECT:
1865             opts = qemu_opts_parse_noisily(&qemu_object_opts,
1866                                            optarg, true);
1867             if (!opts) {
1868                 goto fail_getopt;
1869             }
1870             break;
1871         case OPTION_IMAGE_OPTS:
1872             image_opts = true;
1873             break;
1874         }
1875     }
1876 
1877     if (qemu_opts_foreach(&qemu_object_opts,
1878                           user_creatable_add_opts_foreach,
1879                           NULL, NULL)) {
1880         goto fail_getopt;
1881     }
1882 
1883     /* Initialize before goto out */
1884     if (quiet) {
1885         progress = 0;
1886     }
1887     qemu_progress_init(progress, 1.0);
1888 
1889     bs_n = argc - optind - 1;
1890     out_filename = bs_n >= 1 ? argv[argc - 1] : NULL;
1891 
1892     if (options && has_help_option(options)) {
1893         ret = print_block_option_help(out_filename, out_fmt);
1894         goto out;
1895     }
1896 
1897     if (bs_n < 1) {
1898         error_exit("Must specify image file name");
1899     }
1900 
1901 
1902     if (bs_n > 1 && out_baseimg) {
1903         error_report("-B makes no sense when concatenating multiple input "
1904                      "images");
1905         ret = -1;
1906         goto out;
1907     }
1908 
1909     src_flags = 0;
1910     ret = bdrv_parse_cache_mode(src_cache, &src_flags, &src_writethrough);
1911     if (ret < 0) {
1912         error_report("Invalid source cache option: %s", src_cache);
1913         goto out;
1914     }
1915 
1916     qemu_progress_print(0, 100);
1917 
1918     blk = g_new0(BlockBackend *, bs_n);
1919     bs = g_new0(BlockDriverState *, bs_n);
1920     bs_sectors = g_new(int64_t, bs_n);
1921 
1922     total_sectors = 0;
1923     for (bs_i = 0; bs_i < bs_n; bs_i++) {
1924         blk[bs_i] = img_open(image_opts, argv[optind + bs_i],
1925                              fmt, src_flags, src_writethrough, quiet);
1926         if (!blk[bs_i]) {
1927             ret = -1;
1928             goto out;
1929         }
1930         bs[bs_i] = blk_bs(blk[bs_i]);
1931         bs_sectors[bs_i] = blk_nb_sectors(blk[bs_i]);
1932         if (bs_sectors[bs_i] < 0) {
1933             error_report("Could not get size of %s: %s",
1934                          argv[optind + bs_i], strerror(-bs_sectors[bs_i]));
1935             ret = -1;
1936             goto out;
1937         }
1938         total_sectors += bs_sectors[bs_i];
1939     }
1940 
1941     if (sn_opts) {
1942         ret = bdrv_snapshot_load_tmp(bs[0],
1943                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
1944                                      qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
1945                                      &local_err);
1946     } else if (snapshot_name != NULL) {
1947         if (bs_n > 1) {
1948             error_report("No support for concatenating multiple snapshot");
1949             ret = -1;
1950             goto out;
1951         }
1952 
1953         bdrv_snapshot_load_tmp_by_id_or_name(bs[0], snapshot_name, &local_err);
1954     }
1955     if (local_err) {
1956         error_reportf_err(local_err, "Failed to load snapshot: ");
1957         ret = -1;
1958         goto out;
1959     }
1960 
1961     /* Find driver and parse its options */
1962     drv = bdrv_find_format(out_fmt);
1963     if (!drv) {
1964         error_report("Unknown file format '%s'", out_fmt);
1965         ret = -1;
1966         goto out;
1967     }
1968 
1969     proto_drv = bdrv_find_protocol(out_filename, true, &local_err);
1970     if (!proto_drv) {
1971         error_report_err(local_err);
1972         ret = -1;
1973         goto out;
1974     }
1975 
1976     if (!skip_create) {
1977         if (!drv->create_opts) {
1978             error_report("Format driver '%s' does not support image creation",
1979                          drv->format_name);
1980             ret = -1;
1981             goto out;
1982         }
1983 
1984         if (!proto_drv->create_opts) {
1985             error_report("Protocol driver '%s' does not support image creation",
1986                          proto_drv->format_name);
1987             ret = -1;
1988             goto out;
1989         }
1990 
1991         create_opts = qemu_opts_append(create_opts, drv->create_opts);
1992         create_opts = qemu_opts_append(create_opts, proto_drv->create_opts);
1993 
1994         opts = qemu_opts_create(create_opts, NULL, 0, &error_abort);
1995         if (options) {
1996             qemu_opts_do_parse(opts, options, NULL, &local_err);
1997             if (local_err) {
1998                 error_report_err(local_err);
1999                 ret = -1;
2000                 goto out;
2001             }
2002         }
2003 
2004         qemu_opt_set_number(opts, BLOCK_OPT_SIZE, total_sectors * 512,
2005                             &error_abort);
2006         ret = add_old_style_options(out_fmt, opts, out_baseimg, NULL);
2007         if (ret < 0) {
2008             goto out;
2009         }
2010     }
2011 
2012     /* Get backing file name if -o backing_file was used */
2013     out_baseimg_param = qemu_opt_get(opts, BLOCK_OPT_BACKING_FILE);
2014     if (out_baseimg_param) {
2015         out_baseimg = out_baseimg_param;
2016     }
2017 
2018     /* Check if compression is supported */
2019     if (compress) {
2020         bool encryption =
2021             qemu_opt_get_bool(opts, BLOCK_OPT_ENCRYPT, false);
2022         const char *preallocation =
2023             qemu_opt_get(opts, BLOCK_OPT_PREALLOC);
2024 
2025         if (!drv->bdrv_write_compressed) {
2026             error_report("Compression not supported for this file format");
2027             ret = -1;
2028             goto out;
2029         }
2030 
2031         if (encryption) {
2032             error_report("Compression and encryption not supported at "
2033                          "the same time");
2034             ret = -1;
2035             goto out;
2036         }
2037 
2038         if (preallocation
2039             && strcmp(preallocation, "off"))
2040         {
2041             error_report("Compression and preallocation not supported at "
2042                          "the same time");
2043             ret = -1;
2044             goto out;
2045         }
2046     }
2047 
2048     if (!skip_create) {
2049         /* Create the new image */
2050         ret = bdrv_create(drv, out_filename, opts, &local_err);
2051         if (ret < 0) {
2052             error_reportf_err(local_err, "%s: error while converting %s: ",
2053                               out_filename, out_fmt);
2054             goto out;
2055         }
2056     }
2057 
2058     flags = min_sparse ? (BDRV_O_RDWR | BDRV_O_UNMAP) : BDRV_O_RDWR;
2059     ret = bdrv_parse_cache_mode(cache, &flags, &writethrough);
2060     if (ret < 0) {
2061         error_report("Invalid cache option: %s", cache);
2062         goto out;
2063     }
2064 
2065     /* XXX we should allow --image-opts to trigger use of
2066      * img_open() here, but then we have trouble with
2067      * the bdrv_create() call which takes different params.
2068      * Not critical right now, so fix can wait...
2069      */
2070     out_blk = img_open_file(out_filename, out_fmt, flags, writethrough, quiet);
2071     if (!out_blk) {
2072         ret = -1;
2073         goto out;
2074     }
2075     out_bs = blk_bs(out_blk);
2076 
2077     /* increase bufsectors from the default 4096 (2M) if opt_transfer_length
2078      * or discard_alignment of the out_bs is greater. Limit to 32768 (16MB)
2079      * as maximum. */
2080     bufsectors = MIN(32768,
2081                      MAX(bufsectors, MAX(out_bs->bl.opt_transfer_length,
2082                                          out_bs->bl.discard_alignment))
2083                     );
2084 
2085     if (skip_create) {
2086         int64_t output_sectors = blk_nb_sectors(out_blk);
2087         if (output_sectors < 0) {
2088             error_report("unable to get output image length: %s",
2089                          strerror(-output_sectors));
2090             ret = -1;
2091             goto out;
2092         } else if (output_sectors < total_sectors) {
2093             error_report("output file is smaller than input file");
2094             ret = -1;
2095             goto out;
2096         }
2097     }
2098 
2099     cluster_sectors = 0;
2100     ret = bdrv_get_info(out_bs, &bdi);
2101     if (ret < 0) {
2102         if (compress) {
2103             error_report("could not get block driver info");
2104             goto out;
2105         }
2106     } else {
2107         compress = compress || bdi.needs_compressed_writes;
2108         cluster_sectors = bdi.cluster_size / BDRV_SECTOR_SIZE;
2109     }
2110 
2111     state = (ImgConvertState) {
2112         .src                = blk,
2113         .src_sectors        = bs_sectors,
2114         .src_num            = bs_n,
2115         .total_sectors      = total_sectors,
2116         .target             = out_blk,
2117         .compressed         = compress,
2118         .target_has_backing = (bool) out_baseimg,
2119         .min_sparse         = min_sparse,
2120         .cluster_sectors    = cluster_sectors,
2121         .buf_sectors        = bufsectors,
2122     };
2123     ret = convert_do_copy(&state);
2124 
2125 out:
2126     if (!ret) {
2127         qemu_progress_print(100, 0);
2128     }
2129     qemu_progress_end();
2130     qemu_opts_del(opts);
2131     qemu_opts_free(create_opts);
2132     qemu_opts_del(sn_opts);
2133     blk_unref(out_blk);
2134     g_free(bs);
2135     if (blk) {
2136         for (bs_i = 0; bs_i < bs_n; bs_i++) {
2137             blk_unref(blk[bs_i]);
2138         }
2139         g_free(blk);
2140     }
2141     g_free(bs_sectors);
2142 fail_getopt:
2143     g_free(options);
2144 
2145     if (ret) {
2146         return 1;
2147     }
2148     return 0;
2149 }
2150 
2151 
2152 static void dump_snapshots(BlockDriverState *bs)
2153 {
2154     QEMUSnapshotInfo *sn_tab, *sn;
2155     int nb_sns, i;
2156 
2157     nb_sns = bdrv_snapshot_list(bs, &sn_tab);
2158     if (nb_sns <= 0)
2159         return;
2160     printf("Snapshot list:\n");
2161     bdrv_snapshot_dump(fprintf, stdout, NULL);
2162     printf("\n");
2163     for(i = 0; i < nb_sns; i++) {
2164         sn = &sn_tab[i];
2165         bdrv_snapshot_dump(fprintf, stdout, sn);
2166         printf("\n");
2167     }
2168     g_free(sn_tab);
2169 }
2170 
2171 static void dump_json_image_info_list(ImageInfoList *list)
2172 {
2173     Error *local_err = NULL;
2174     QString *str;
2175     QmpOutputVisitor *ov = qmp_output_visitor_new();
2176     QObject *obj;
2177     visit_type_ImageInfoList(qmp_output_get_visitor(ov), NULL, &list,
2178                              &local_err);
2179     obj = qmp_output_get_qobject(ov);
2180     str = qobject_to_json_pretty(obj);
2181     assert(str != NULL);
2182     printf("%s\n", qstring_get_str(str));
2183     qobject_decref(obj);
2184     qmp_output_visitor_cleanup(ov);
2185     QDECREF(str);
2186 }
2187 
2188 static void dump_json_image_info(ImageInfo *info)
2189 {
2190     Error *local_err = NULL;
2191     QString *str;
2192     QmpOutputVisitor *ov = qmp_output_visitor_new();
2193     QObject *obj;
2194     visit_type_ImageInfo(qmp_output_get_visitor(ov), NULL, &info, &local_err);
2195     obj = qmp_output_get_qobject(ov);
2196     str = qobject_to_json_pretty(obj);
2197     assert(str != NULL);
2198     printf("%s\n", qstring_get_str(str));
2199     qobject_decref(obj);
2200     qmp_output_visitor_cleanup(ov);
2201     QDECREF(str);
2202 }
2203 
2204 static void dump_human_image_info_list(ImageInfoList *list)
2205 {
2206     ImageInfoList *elem;
2207     bool delim = false;
2208 
2209     for (elem = list; elem; elem = elem->next) {
2210         if (delim) {
2211             printf("\n");
2212         }
2213         delim = true;
2214 
2215         bdrv_image_info_dump(fprintf, stdout, elem->value);
2216     }
2217 }
2218 
2219 static gboolean str_equal_func(gconstpointer a, gconstpointer b)
2220 {
2221     return strcmp(a, b) == 0;
2222 }
2223 
2224 /**
2225  * Open an image file chain and return an ImageInfoList
2226  *
2227  * @filename: topmost image filename
2228  * @fmt: topmost image format (may be NULL to autodetect)
2229  * @chain: true  - enumerate entire backing file chain
2230  *         false - only topmost image file
2231  *
2232  * Returns a list of ImageInfo objects or NULL if there was an error opening an
2233  * image file.  If there was an error a message will have been printed to
2234  * stderr.
2235  */
2236 static ImageInfoList *collect_image_info_list(bool image_opts,
2237                                               const char *filename,
2238                                               const char *fmt,
2239                                               bool chain)
2240 {
2241     ImageInfoList *head = NULL;
2242     ImageInfoList **last = &head;
2243     GHashTable *filenames;
2244     Error *err = NULL;
2245 
2246     filenames = g_hash_table_new_full(g_str_hash, str_equal_func, NULL, NULL);
2247 
2248     while (filename) {
2249         BlockBackend *blk;
2250         BlockDriverState *bs;
2251         ImageInfo *info;
2252         ImageInfoList *elem;
2253 
2254         if (g_hash_table_lookup_extended(filenames, filename, NULL, NULL)) {
2255             error_report("Backing file '%s' creates an infinite loop.",
2256                          filename);
2257             goto err;
2258         }
2259         g_hash_table_insert(filenames, (gpointer)filename, NULL);
2260 
2261         blk = img_open(image_opts, filename, fmt,
2262                        BDRV_O_NO_BACKING | BDRV_O_NO_IO, false, false);
2263         if (!blk) {
2264             goto err;
2265         }
2266         bs = blk_bs(blk);
2267 
2268         bdrv_query_image_info(bs, &info, &err);
2269         if (err) {
2270             error_report_err(err);
2271             blk_unref(blk);
2272             goto err;
2273         }
2274 
2275         elem = g_new0(ImageInfoList, 1);
2276         elem->value = info;
2277         *last = elem;
2278         last = &elem->next;
2279 
2280         blk_unref(blk);
2281 
2282         filename = fmt = NULL;
2283         if (chain) {
2284             if (info->has_full_backing_filename) {
2285                 filename = info->full_backing_filename;
2286             } else if (info->has_backing_filename) {
2287                 error_report("Could not determine absolute backing filename,"
2288                              " but backing filename '%s' present",
2289                              info->backing_filename);
2290                 goto err;
2291             }
2292             if (info->has_backing_filename_format) {
2293                 fmt = info->backing_filename_format;
2294             }
2295         }
2296     }
2297     g_hash_table_destroy(filenames);
2298     return head;
2299 
2300 err:
2301     qapi_free_ImageInfoList(head);
2302     g_hash_table_destroy(filenames);
2303     return NULL;
2304 }
2305 
2306 static int img_info(int argc, char **argv)
2307 {
2308     int c;
2309     OutputFormat output_format = OFORMAT_HUMAN;
2310     bool chain = false;
2311     const char *filename, *fmt, *output;
2312     ImageInfoList *list;
2313     bool image_opts = false;
2314 
2315     fmt = NULL;
2316     output = NULL;
2317     for(;;) {
2318         int option_index = 0;
2319         static const struct option long_options[] = {
2320             {"help", no_argument, 0, 'h'},
2321             {"format", required_argument, 0, 'f'},
2322             {"output", required_argument, 0, OPTION_OUTPUT},
2323             {"backing-chain", no_argument, 0, OPTION_BACKING_CHAIN},
2324             {"object", required_argument, 0, OPTION_OBJECT},
2325             {"image-opts", no_argument, 0, OPTION_IMAGE_OPTS},
2326             {0, 0, 0, 0}
2327         };
2328         c = getopt_long(argc, argv, "f:h",
2329                         long_options, &option_index);
2330         if (c == -1) {
2331             break;
2332         }
2333         switch(c) {
2334         case '?':
2335         case 'h':
2336             help();
2337             break;
2338         case 'f':
2339             fmt = optarg;
2340             break;
2341         case OPTION_OUTPUT:
2342             output = optarg;
2343             break;
2344         case OPTION_BACKING_CHAIN:
2345             chain = true;
2346             break;
2347         case OPTION_OBJECT: {
2348             QemuOpts *opts;
2349             opts = qemu_opts_parse_noisily(&qemu_object_opts,
2350                                            optarg, true);
2351             if (!opts) {
2352                 return 1;
2353             }
2354         }   break;
2355         case OPTION_IMAGE_OPTS:
2356             image_opts = true;
2357             break;
2358         }
2359     }
2360     if (optind != argc - 1) {
2361         error_exit("Expecting one image file name");
2362     }
2363     filename = argv[optind++];
2364 
2365     if (output && !strcmp(output, "json")) {
2366         output_format = OFORMAT_JSON;
2367     } else if (output && !strcmp(output, "human")) {
2368         output_format = OFORMAT_HUMAN;
2369     } else if (output) {
2370         error_report("--output must be used with human or json as argument.");
2371         return 1;
2372     }
2373 
2374     if (qemu_opts_foreach(&qemu_object_opts,
2375                           user_creatable_add_opts_foreach,
2376                           NULL, NULL)) {
2377         return 1;
2378     }
2379 
2380     list = collect_image_info_list(image_opts, filename, fmt, chain);
2381     if (!list) {
2382         return 1;
2383     }
2384 
2385     switch (output_format) {
2386     case OFORMAT_HUMAN:
2387         dump_human_image_info_list(list);
2388         break;
2389     case OFORMAT_JSON:
2390         if (chain) {
2391             dump_json_image_info_list(list);
2392         } else {
2393             dump_json_image_info(list->value);
2394         }
2395         break;
2396     }
2397 
2398     qapi_free_ImageInfoList(list);
2399     return 0;
2400 }
2401 
2402 static void dump_map_entry(OutputFormat output_format, MapEntry *e,
2403                            MapEntry *next)
2404 {
2405     switch (output_format) {
2406     case OFORMAT_HUMAN:
2407         if (e->data && !e->has_offset) {
2408             error_report("File contains external, encrypted or compressed clusters.");
2409             exit(1);
2410         }
2411         if (e->data && !e->zero) {
2412             printf("%#-16"PRIx64"%#-16"PRIx64"%#-16"PRIx64"%s\n",
2413                    e->start, e->length,
2414                    e->has_offset ? e->offset : 0,
2415                    e->has_filename ? e->filename : "");
2416         }
2417         /* This format ignores the distinction between 0, ZERO and ZERO|DATA.
2418          * Modify the flags here to allow more coalescing.
2419          */
2420         if (next && (!next->data || next->zero)) {
2421             next->data = false;
2422             next->zero = true;
2423         }
2424         break;
2425     case OFORMAT_JSON:
2426         printf("%s{ \"start\": %"PRId64", \"length\": %"PRId64","
2427                " \"depth\": %"PRId64", \"zero\": %s, \"data\": %s",
2428                (e->start == 0 ? "[" : ",\n"),
2429                e->start, e->length, e->depth,
2430                e->zero ? "true" : "false",
2431                e->data ? "true" : "false");
2432         if (e->has_offset) {
2433             printf(", \"offset\": %"PRId64"", e->offset);
2434         }
2435         putchar('}');
2436 
2437         if (!next) {
2438             printf("]\n");
2439         }
2440         break;
2441     }
2442 }
2443 
2444 static int get_block_status(BlockDriverState *bs, int64_t sector_num,
2445                             int nb_sectors, MapEntry *e)
2446 {
2447     int64_t ret;
2448     int depth;
2449     BlockDriverState *file;
2450     bool has_offset;
2451 
2452     /* As an optimization, we could cache the current range of unallocated
2453      * clusters in each file of the chain, and avoid querying the same
2454      * range repeatedly.
2455      */
2456 
2457     depth = 0;
2458     for (;;) {
2459         ret = bdrv_get_block_status(bs, sector_num, nb_sectors, &nb_sectors,
2460                                     &file);
2461         if (ret < 0) {
2462             return ret;
2463         }
2464         assert(nb_sectors);
2465         if (ret & (BDRV_BLOCK_ZERO|BDRV_BLOCK_DATA)) {
2466             break;
2467         }
2468         bs = backing_bs(bs);
2469         if (bs == NULL) {
2470             ret = 0;
2471             break;
2472         }
2473 
2474         depth++;
2475     }
2476 
2477     has_offset = !!(ret & BDRV_BLOCK_OFFSET_VALID);
2478 
2479     *e = (MapEntry) {
2480         .start = sector_num * BDRV_SECTOR_SIZE,
2481         .length = nb_sectors * BDRV_SECTOR_SIZE,
2482         .data = !!(ret & BDRV_BLOCK_DATA),
2483         .zero = !!(ret & BDRV_BLOCK_ZERO),
2484         .offset = ret & BDRV_BLOCK_OFFSET_MASK,
2485         .has_offset = has_offset,
2486         .depth = depth,
2487         .has_filename = file && has_offset,
2488         .filename = file && has_offset ? file->filename : NULL,
2489     };
2490 
2491     return 0;
2492 }
2493 
2494 static inline bool entry_mergeable(const MapEntry *curr, const MapEntry *next)
2495 {
2496     if (curr->length == 0) {
2497         return false;
2498     }
2499     if (curr->zero != next->zero ||
2500         curr->data != next->data ||
2501         curr->depth != next->depth ||
2502         curr->has_filename != next->has_filename ||
2503         curr->has_offset != next->has_offset) {
2504         return false;
2505     }
2506     if (curr->has_filename && strcmp(curr->filename, next->filename)) {
2507         return false;
2508     }
2509     if (curr->has_offset && curr->offset + curr->length != next->offset) {
2510         return false;
2511     }
2512     return true;
2513 }
2514 
2515 static int img_map(int argc, char **argv)
2516 {
2517     int c;
2518     OutputFormat output_format = OFORMAT_HUMAN;
2519     BlockBackend *blk;
2520     BlockDriverState *bs;
2521     const char *filename, *fmt, *output;
2522     int64_t length;
2523     MapEntry curr = { .length = 0 }, next;
2524     int ret = 0;
2525     bool image_opts = false;
2526 
2527     fmt = NULL;
2528     output = NULL;
2529     for (;;) {
2530         int option_index = 0;
2531         static const struct option long_options[] = {
2532             {"help", no_argument, 0, 'h'},
2533             {"format", required_argument, 0, 'f'},
2534             {"output", required_argument, 0, OPTION_OUTPUT},
2535             {"object", required_argument, 0, OPTION_OBJECT},
2536             {"image-opts", no_argument, 0, OPTION_IMAGE_OPTS},
2537             {0, 0, 0, 0}
2538         };
2539         c = getopt_long(argc, argv, "f:h",
2540                         long_options, &option_index);
2541         if (c == -1) {
2542             break;
2543         }
2544         switch (c) {
2545         case '?':
2546         case 'h':
2547             help();
2548             break;
2549         case 'f':
2550             fmt = optarg;
2551             break;
2552         case OPTION_OUTPUT:
2553             output = optarg;
2554             break;
2555         case OPTION_OBJECT: {
2556             QemuOpts *opts;
2557             opts = qemu_opts_parse_noisily(&qemu_object_opts,
2558                                            optarg, true);
2559             if (!opts) {
2560                 return 1;
2561             }
2562         }   break;
2563         case OPTION_IMAGE_OPTS:
2564             image_opts = true;
2565             break;
2566         }
2567     }
2568     if (optind != argc - 1) {
2569         error_exit("Expecting one image file name");
2570     }
2571     filename = argv[optind];
2572 
2573     if (output && !strcmp(output, "json")) {
2574         output_format = OFORMAT_JSON;
2575     } else if (output && !strcmp(output, "human")) {
2576         output_format = OFORMAT_HUMAN;
2577     } else if (output) {
2578         error_report("--output must be used with human or json as argument.");
2579         return 1;
2580     }
2581 
2582     if (qemu_opts_foreach(&qemu_object_opts,
2583                           user_creatable_add_opts_foreach,
2584                           NULL, NULL)) {
2585         return 1;
2586     }
2587 
2588     blk = img_open(image_opts, filename, fmt, 0, false, false);
2589     if (!blk) {
2590         return 1;
2591     }
2592     bs = blk_bs(blk);
2593 
2594     if (output_format == OFORMAT_HUMAN) {
2595         printf("%-16s%-16s%-16s%s\n", "Offset", "Length", "Mapped to", "File");
2596     }
2597 
2598     length = blk_getlength(blk);
2599     while (curr.start + curr.length < length) {
2600         int64_t nsectors_left;
2601         int64_t sector_num;
2602         int n;
2603 
2604         sector_num = (curr.start + curr.length) >> BDRV_SECTOR_BITS;
2605 
2606         /* Probe up to 1 GiB at a time.  */
2607         nsectors_left = DIV_ROUND_UP(length, BDRV_SECTOR_SIZE) - sector_num;
2608         n = MIN(1 << (30 - BDRV_SECTOR_BITS), nsectors_left);
2609         ret = get_block_status(bs, sector_num, n, &next);
2610 
2611         if (ret < 0) {
2612             error_report("Could not read file metadata: %s", strerror(-ret));
2613             goto out;
2614         }
2615 
2616         if (entry_mergeable(&curr, &next)) {
2617             curr.length += next.length;
2618             continue;
2619         }
2620 
2621         if (curr.length > 0) {
2622             dump_map_entry(output_format, &curr, &next);
2623         }
2624         curr = next;
2625     }
2626 
2627     dump_map_entry(output_format, &curr, NULL);
2628 
2629 out:
2630     blk_unref(blk);
2631     return ret < 0;
2632 }
2633 
2634 #define SNAPSHOT_LIST   1
2635 #define SNAPSHOT_CREATE 2
2636 #define SNAPSHOT_APPLY  3
2637 #define SNAPSHOT_DELETE 4
2638 
2639 static int img_snapshot(int argc, char **argv)
2640 {
2641     BlockBackend *blk;
2642     BlockDriverState *bs;
2643     QEMUSnapshotInfo sn;
2644     char *filename, *snapshot_name = NULL;
2645     int c, ret = 0, bdrv_oflags;
2646     int action = 0;
2647     qemu_timeval tv;
2648     bool quiet = false;
2649     Error *err = NULL;
2650     bool image_opts = false;
2651 
2652     bdrv_oflags = BDRV_O_RDWR;
2653     /* Parse commandline parameters */
2654     for(;;) {
2655         static const struct option long_options[] = {
2656             {"help", no_argument, 0, 'h'},
2657             {"object", required_argument, 0, OPTION_OBJECT},
2658             {"image-opts", no_argument, 0, OPTION_IMAGE_OPTS},
2659             {0, 0, 0, 0}
2660         };
2661         c = getopt_long(argc, argv, "la:c:d:hq",
2662                         long_options, NULL);
2663         if (c == -1) {
2664             break;
2665         }
2666         switch(c) {
2667         case '?':
2668         case 'h':
2669             help();
2670             return 0;
2671         case 'l':
2672             if (action) {
2673                 error_exit("Cannot mix '-l', '-a', '-c', '-d'");
2674                 return 0;
2675             }
2676             action = SNAPSHOT_LIST;
2677             bdrv_oflags &= ~BDRV_O_RDWR; /* no need for RW */
2678             break;
2679         case 'a':
2680             if (action) {
2681                 error_exit("Cannot mix '-l', '-a', '-c', '-d'");
2682                 return 0;
2683             }
2684             action = SNAPSHOT_APPLY;
2685             snapshot_name = optarg;
2686             break;
2687         case 'c':
2688             if (action) {
2689                 error_exit("Cannot mix '-l', '-a', '-c', '-d'");
2690                 return 0;
2691             }
2692             action = SNAPSHOT_CREATE;
2693             snapshot_name = optarg;
2694             break;
2695         case 'd':
2696             if (action) {
2697                 error_exit("Cannot mix '-l', '-a', '-c', '-d'");
2698                 return 0;
2699             }
2700             action = SNAPSHOT_DELETE;
2701             snapshot_name = optarg;
2702             break;
2703         case 'q':
2704             quiet = true;
2705             break;
2706         case OPTION_OBJECT: {
2707             QemuOpts *opts;
2708             opts = qemu_opts_parse_noisily(&qemu_object_opts,
2709                                            optarg, true);
2710             if (!opts) {
2711                 return 1;
2712             }
2713         }   break;
2714         case OPTION_IMAGE_OPTS:
2715             image_opts = true;
2716             break;
2717         }
2718     }
2719 
2720     if (optind != argc - 1) {
2721         error_exit("Expecting one image file name");
2722     }
2723     filename = argv[optind++];
2724 
2725     if (qemu_opts_foreach(&qemu_object_opts,
2726                           user_creatable_add_opts_foreach,
2727                           NULL, NULL)) {
2728         return 1;
2729     }
2730 
2731     /* Open the image */
2732     blk = img_open(image_opts, filename, NULL, bdrv_oflags, false, quiet);
2733     if (!blk) {
2734         return 1;
2735     }
2736     bs = blk_bs(blk);
2737 
2738     /* Perform the requested action */
2739     switch(action) {
2740     case SNAPSHOT_LIST:
2741         dump_snapshots(bs);
2742         break;
2743 
2744     case SNAPSHOT_CREATE:
2745         memset(&sn, 0, sizeof(sn));
2746         pstrcpy(sn.name, sizeof(sn.name), snapshot_name);
2747 
2748         qemu_gettimeofday(&tv);
2749         sn.date_sec = tv.tv_sec;
2750         sn.date_nsec = tv.tv_usec * 1000;
2751 
2752         ret = bdrv_snapshot_create(bs, &sn);
2753         if (ret) {
2754             error_report("Could not create snapshot '%s': %d (%s)",
2755                 snapshot_name, ret, strerror(-ret));
2756         }
2757         break;
2758 
2759     case SNAPSHOT_APPLY:
2760         ret = bdrv_snapshot_goto(bs, snapshot_name);
2761         if (ret) {
2762             error_report("Could not apply snapshot '%s': %d (%s)",
2763                 snapshot_name, ret, strerror(-ret));
2764         }
2765         break;
2766 
2767     case SNAPSHOT_DELETE:
2768         bdrv_snapshot_delete_by_id_or_name(bs, snapshot_name, &err);
2769         if (err) {
2770             error_reportf_err(err, "Could not delete snapshot '%s': ",
2771                               snapshot_name);
2772             ret = 1;
2773         }
2774         break;
2775     }
2776 
2777     /* Cleanup */
2778     blk_unref(blk);
2779     if (ret) {
2780         return 1;
2781     }
2782     return 0;
2783 }
2784 
2785 static int img_rebase(int argc, char **argv)
2786 {
2787     BlockBackend *blk = NULL, *blk_old_backing = NULL, *blk_new_backing = NULL;
2788     uint8_t *buf_old = NULL;
2789     uint8_t *buf_new = NULL;
2790     BlockDriverState *bs = NULL;
2791     char *filename;
2792     const char *fmt, *cache, *src_cache, *out_basefmt, *out_baseimg;
2793     int c, flags, src_flags, ret;
2794     bool writethrough, src_writethrough;
2795     int unsafe = 0;
2796     int progress = 0;
2797     bool quiet = false;
2798     Error *local_err = NULL;
2799     bool image_opts = false;
2800 
2801     /* Parse commandline parameters */
2802     fmt = NULL;
2803     cache = BDRV_DEFAULT_CACHE;
2804     src_cache = BDRV_DEFAULT_CACHE;
2805     out_baseimg = NULL;
2806     out_basefmt = NULL;
2807     for(;;) {
2808         static const struct option long_options[] = {
2809             {"help", no_argument, 0, 'h'},
2810             {"object", required_argument, 0, OPTION_OBJECT},
2811             {"image-opts", no_argument, 0, OPTION_IMAGE_OPTS},
2812             {0, 0, 0, 0}
2813         };
2814         c = getopt_long(argc, argv, "hf:F:b:upt:T:q",
2815                         long_options, NULL);
2816         if (c == -1) {
2817             break;
2818         }
2819         switch(c) {
2820         case '?':
2821         case 'h':
2822             help();
2823             return 0;
2824         case 'f':
2825             fmt = optarg;
2826             break;
2827         case 'F':
2828             out_basefmt = optarg;
2829             break;
2830         case 'b':
2831             out_baseimg = optarg;
2832             break;
2833         case 'u':
2834             unsafe = 1;
2835             break;
2836         case 'p':
2837             progress = 1;
2838             break;
2839         case 't':
2840             cache = optarg;
2841             break;
2842         case 'T':
2843             src_cache = optarg;
2844             break;
2845         case 'q':
2846             quiet = true;
2847             break;
2848         case OPTION_OBJECT: {
2849             QemuOpts *opts;
2850             opts = qemu_opts_parse_noisily(&qemu_object_opts,
2851                                            optarg, true);
2852             if (!opts) {
2853                 return 1;
2854             }
2855         }   break;
2856         case OPTION_IMAGE_OPTS:
2857             image_opts = true;
2858             break;
2859         }
2860     }
2861 
2862     if (quiet) {
2863         progress = 0;
2864     }
2865 
2866     if (optind != argc - 1) {
2867         error_exit("Expecting one image file name");
2868     }
2869     if (!unsafe && !out_baseimg) {
2870         error_exit("Must specify backing file (-b) or use unsafe mode (-u)");
2871     }
2872     filename = argv[optind++];
2873 
2874     if (qemu_opts_foreach(&qemu_object_opts,
2875                           user_creatable_add_opts_foreach,
2876                           NULL, NULL)) {
2877         return 1;
2878     }
2879 
2880     qemu_progress_init(progress, 2.0);
2881     qemu_progress_print(0, 100);
2882 
2883     flags = BDRV_O_RDWR | (unsafe ? BDRV_O_NO_BACKING : 0);
2884     ret = bdrv_parse_cache_mode(cache, &flags, &writethrough);
2885     if (ret < 0) {
2886         error_report("Invalid cache option: %s", cache);
2887         goto out;
2888     }
2889 
2890     src_flags = 0;
2891     ret = bdrv_parse_cache_mode(src_cache, &src_flags, &src_writethrough);
2892     if (ret < 0) {
2893         error_report("Invalid source cache option: %s", src_cache);
2894         goto out;
2895     }
2896 
2897     /* The source files are opened read-only, don't care about WCE */
2898     assert((src_flags & BDRV_O_RDWR) == 0);
2899     (void) src_writethrough;
2900 
2901     /*
2902      * Open the images.
2903      *
2904      * Ignore the old backing file for unsafe rebase in case we want to correct
2905      * the reference to a renamed or moved backing file.
2906      */
2907     blk = img_open(image_opts, filename, fmt, flags, writethrough, quiet);
2908     if (!blk) {
2909         ret = -1;
2910         goto out;
2911     }
2912     bs = blk_bs(blk);
2913 
2914     if (out_basefmt != NULL) {
2915         if (bdrv_find_format(out_basefmt) == NULL) {
2916             error_report("Invalid format name: '%s'", out_basefmt);
2917             ret = -1;
2918             goto out;
2919         }
2920     }
2921 
2922     /* For safe rebasing we need to compare old and new backing file */
2923     if (!unsafe) {
2924         char backing_name[PATH_MAX];
2925         QDict *options = NULL;
2926 
2927         if (bs->backing_format[0] != '\0') {
2928             options = qdict_new();
2929             qdict_put(options, "driver", qstring_from_str(bs->backing_format));
2930         }
2931 
2932         bdrv_get_backing_filename(bs, backing_name, sizeof(backing_name));
2933         blk_old_backing = blk_new_open(backing_name, NULL,
2934                                        options, src_flags, &local_err);
2935         if (!blk_old_backing) {
2936             error_reportf_err(local_err,
2937                               "Could not open old backing file '%s': ",
2938                               backing_name);
2939             goto out;
2940         }
2941 
2942         if (out_baseimg[0]) {
2943             if (out_basefmt) {
2944                 options = qdict_new();
2945                 qdict_put(options, "driver", qstring_from_str(out_basefmt));
2946             } else {
2947                 options = NULL;
2948             }
2949 
2950             blk_new_backing = blk_new_open(out_baseimg, NULL,
2951                                            options, src_flags, &local_err);
2952             if (!blk_new_backing) {
2953                 error_reportf_err(local_err,
2954                                   "Could not open new backing file '%s': ",
2955                                   out_baseimg);
2956                 goto out;
2957             }
2958         }
2959     }
2960 
2961     /*
2962      * Check each unallocated cluster in the COW file. If it is unallocated,
2963      * accesses go to the backing file. We must therefore compare this cluster
2964      * in the old and new backing file, and if they differ we need to copy it
2965      * from the old backing file into the COW file.
2966      *
2967      * If qemu-img crashes during this step, no harm is done. The content of
2968      * the image is the same as the original one at any time.
2969      */
2970     if (!unsafe) {
2971         int64_t num_sectors;
2972         int64_t old_backing_num_sectors;
2973         int64_t new_backing_num_sectors = 0;
2974         uint64_t sector;
2975         int n;
2976         float local_progress = 0;
2977 
2978         buf_old = blk_blockalign(blk, IO_BUF_SIZE);
2979         buf_new = blk_blockalign(blk, IO_BUF_SIZE);
2980 
2981         num_sectors = blk_nb_sectors(blk);
2982         if (num_sectors < 0) {
2983             error_report("Could not get size of '%s': %s",
2984                          filename, strerror(-num_sectors));
2985             ret = -1;
2986             goto out;
2987         }
2988         old_backing_num_sectors = blk_nb_sectors(blk_old_backing);
2989         if (old_backing_num_sectors < 0) {
2990             char backing_name[PATH_MAX];
2991 
2992             bdrv_get_backing_filename(bs, backing_name, sizeof(backing_name));
2993             error_report("Could not get size of '%s': %s",
2994                          backing_name, strerror(-old_backing_num_sectors));
2995             ret = -1;
2996             goto out;
2997         }
2998         if (blk_new_backing) {
2999             new_backing_num_sectors = blk_nb_sectors(blk_new_backing);
3000             if (new_backing_num_sectors < 0) {
3001                 error_report("Could not get size of '%s': %s",
3002                              out_baseimg, strerror(-new_backing_num_sectors));
3003                 ret = -1;
3004                 goto out;
3005             }
3006         }
3007 
3008         if (num_sectors != 0) {
3009             local_progress = (float)100 /
3010                 (num_sectors / MIN(num_sectors, IO_BUF_SIZE / 512));
3011         }
3012 
3013         for (sector = 0; sector < num_sectors; sector += n) {
3014 
3015             /* How many sectors can we handle with the next read? */
3016             if (sector + (IO_BUF_SIZE / 512) <= num_sectors) {
3017                 n = (IO_BUF_SIZE / 512);
3018             } else {
3019                 n = num_sectors - sector;
3020             }
3021 
3022             /* If the cluster is allocated, we don't need to take action */
3023             ret = bdrv_is_allocated(bs, sector, n, &n);
3024             if (ret < 0) {
3025                 error_report("error while reading image metadata: %s",
3026                              strerror(-ret));
3027                 goto out;
3028             }
3029             if (ret) {
3030                 continue;
3031             }
3032 
3033             /*
3034              * Read old and new backing file and take into consideration that
3035              * backing files may be smaller than the COW image.
3036              */
3037             if (sector >= old_backing_num_sectors) {
3038                 memset(buf_old, 0, n * BDRV_SECTOR_SIZE);
3039             } else {
3040                 if (sector + n > old_backing_num_sectors) {
3041                     n = old_backing_num_sectors - sector;
3042                 }
3043 
3044                 ret = blk_pread(blk_old_backing, sector << BDRV_SECTOR_BITS,
3045                                 buf_old, n << BDRV_SECTOR_BITS);
3046                 if (ret < 0) {
3047                     error_report("error while reading from old backing file");
3048                     goto out;
3049                 }
3050             }
3051 
3052             if (sector >= new_backing_num_sectors || !blk_new_backing) {
3053                 memset(buf_new, 0, n * BDRV_SECTOR_SIZE);
3054             } else {
3055                 if (sector + n > new_backing_num_sectors) {
3056                     n = new_backing_num_sectors - sector;
3057                 }
3058 
3059                 ret = blk_pread(blk_new_backing, sector << BDRV_SECTOR_BITS,
3060                                 buf_new, n << BDRV_SECTOR_BITS);
3061                 if (ret < 0) {
3062                     error_report("error while reading from new backing file");
3063                     goto out;
3064                 }
3065             }
3066 
3067             /* If they differ, we need to write to the COW file */
3068             uint64_t written = 0;
3069 
3070             while (written < n) {
3071                 int pnum;
3072 
3073                 if (compare_sectors(buf_old + written * 512,
3074                     buf_new + written * 512, n - written, &pnum))
3075                 {
3076                     ret = blk_pwrite(blk,
3077                                      (sector + written) << BDRV_SECTOR_BITS,
3078                                      buf_old + written * 512,
3079                                      pnum << BDRV_SECTOR_BITS, 0);
3080                     if (ret < 0) {
3081                         error_report("Error while writing to COW image: %s",
3082                             strerror(-ret));
3083                         goto out;
3084                     }
3085                 }
3086 
3087                 written += pnum;
3088             }
3089             qemu_progress_print(local_progress, 100);
3090         }
3091     }
3092 
3093     /*
3094      * Change the backing file. All clusters that are different from the old
3095      * backing file are overwritten in the COW file now, so the visible content
3096      * doesn't change when we switch the backing file.
3097      */
3098     if (out_baseimg && *out_baseimg) {
3099         ret = bdrv_change_backing_file(bs, out_baseimg, out_basefmt);
3100     } else {
3101         ret = bdrv_change_backing_file(bs, NULL, NULL);
3102     }
3103 
3104     if (ret == -ENOSPC) {
3105         error_report("Could not change the backing file to '%s': No "
3106                      "space left in the file header", out_baseimg);
3107     } else if (ret < 0) {
3108         error_report("Could not change the backing file to '%s': %s",
3109             out_baseimg, strerror(-ret));
3110     }
3111 
3112     qemu_progress_print(100, 0);
3113     /*
3114      * TODO At this point it is possible to check if any clusters that are
3115      * allocated in the COW file are the same in the backing file. If so, they
3116      * could be dropped from the COW file. Don't do this before switching the
3117      * backing file, in case of a crash this would lead to corruption.
3118      */
3119 out:
3120     qemu_progress_end();
3121     /* Cleanup */
3122     if (!unsafe) {
3123         blk_unref(blk_old_backing);
3124         blk_unref(blk_new_backing);
3125     }
3126     qemu_vfree(buf_old);
3127     qemu_vfree(buf_new);
3128 
3129     blk_unref(blk);
3130     if (ret) {
3131         return 1;
3132     }
3133     return 0;
3134 }
3135 
3136 static int img_resize(int argc, char **argv)
3137 {
3138     Error *err = NULL;
3139     int c, ret, relative;
3140     const char *filename, *fmt, *size;
3141     int64_t n, total_size;
3142     bool quiet = false;
3143     BlockBackend *blk = NULL;
3144     QemuOpts *param;
3145 
3146     static QemuOptsList resize_options = {
3147         .name = "resize_options",
3148         .head = QTAILQ_HEAD_INITIALIZER(resize_options.head),
3149         .desc = {
3150             {
3151                 .name = BLOCK_OPT_SIZE,
3152                 .type = QEMU_OPT_SIZE,
3153                 .help = "Virtual disk size"
3154             }, {
3155                 /* end of list */
3156             }
3157         },
3158     };
3159     bool image_opts = false;
3160 
3161     /* Remove size from argv manually so that negative numbers are not treated
3162      * as options by getopt. */
3163     if (argc < 3) {
3164         error_exit("Not enough arguments");
3165         return 1;
3166     }
3167 
3168     size = argv[--argc];
3169 
3170     /* Parse getopt arguments */
3171     fmt = NULL;
3172     for(;;) {
3173         static const struct option long_options[] = {
3174             {"help", no_argument, 0, 'h'},
3175             {"object", required_argument, 0, OPTION_OBJECT},
3176             {"image-opts", no_argument, 0, OPTION_IMAGE_OPTS},
3177             {0, 0, 0, 0}
3178         };
3179         c = getopt_long(argc, argv, "f:hq",
3180                         long_options, NULL);
3181         if (c == -1) {
3182             break;
3183         }
3184         switch(c) {
3185         case '?':
3186         case 'h':
3187             help();
3188             break;
3189         case 'f':
3190             fmt = optarg;
3191             break;
3192         case 'q':
3193             quiet = true;
3194             break;
3195         case OPTION_OBJECT: {
3196             QemuOpts *opts;
3197             opts = qemu_opts_parse_noisily(&qemu_object_opts,
3198                                            optarg, true);
3199             if (!opts) {
3200                 return 1;
3201             }
3202         }   break;
3203         case OPTION_IMAGE_OPTS:
3204             image_opts = true;
3205             break;
3206         }
3207     }
3208     if (optind != argc - 1) {
3209         error_exit("Expecting one image file name");
3210     }
3211     filename = argv[optind++];
3212 
3213     if (qemu_opts_foreach(&qemu_object_opts,
3214                           user_creatable_add_opts_foreach,
3215                           NULL, NULL)) {
3216         return 1;
3217     }
3218 
3219     /* Choose grow, shrink, or absolute resize mode */
3220     switch (size[0]) {
3221     case '+':
3222         relative = 1;
3223         size++;
3224         break;
3225     case '-':
3226         relative = -1;
3227         size++;
3228         break;
3229     default:
3230         relative = 0;
3231         break;
3232     }
3233 
3234     /* Parse size */
3235     param = qemu_opts_create(&resize_options, NULL, 0, &error_abort);
3236     qemu_opt_set(param, BLOCK_OPT_SIZE, size, &err);
3237     if (err) {
3238         error_report_err(err);
3239         ret = -1;
3240         qemu_opts_del(param);
3241         goto out;
3242     }
3243     n = qemu_opt_get_size(param, BLOCK_OPT_SIZE, 0);
3244     qemu_opts_del(param);
3245 
3246     blk = img_open(image_opts, filename, fmt,
3247                    BDRV_O_RDWR, false, quiet);
3248     if (!blk) {
3249         ret = -1;
3250         goto out;
3251     }
3252 
3253     if (relative) {
3254         total_size = blk_getlength(blk) + n * relative;
3255     } else {
3256         total_size = n;
3257     }
3258     if (total_size <= 0) {
3259         error_report("New image size must be positive");
3260         ret = -1;
3261         goto out;
3262     }
3263 
3264     ret = blk_truncate(blk, total_size);
3265     switch (ret) {
3266     case 0:
3267         qprintf(quiet, "Image resized.\n");
3268         break;
3269     case -ENOTSUP:
3270         error_report("This image does not support resize");
3271         break;
3272     case -EACCES:
3273         error_report("Image is read-only");
3274         break;
3275     default:
3276         error_report("Error resizing image (%d)", -ret);
3277         break;
3278     }
3279 out:
3280     blk_unref(blk);
3281     if (ret) {
3282         return 1;
3283     }
3284     return 0;
3285 }
3286 
3287 static void amend_status_cb(BlockDriverState *bs,
3288                             int64_t offset, int64_t total_work_size,
3289                             void *opaque)
3290 {
3291     qemu_progress_print(100.f * offset / total_work_size, 0);
3292 }
3293 
3294 static int img_amend(int argc, char **argv)
3295 {
3296     Error *err = NULL;
3297     int c, ret = 0;
3298     char *options = NULL;
3299     QemuOptsList *create_opts = NULL;
3300     QemuOpts *opts = NULL;
3301     const char *fmt = NULL, *filename, *cache;
3302     int flags;
3303     bool writethrough;
3304     bool quiet = false, progress = false;
3305     BlockBackend *blk = NULL;
3306     BlockDriverState *bs = NULL;
3307     bool image_opts = false;
3308 
3309     cache = BDRV_DEFAULT_CACHE;
3310     for (;;) {
3311         static const struct option long_options[] = {
3312             {"help", no_argument, 0, 'h'},
3313             {"object", required_argument, 0, OPTION_OBJECT},
3314             {"image-opts", no_argument, 0, OPTION_IMAGE_OPTS},
3315             {0, 0, 0, 0}
3316         };
3317         c = getopt_long(argc, argv, "ho:f:t:pq",
3318                         long_options, NULL);
3319         if (c == -1) {
3320             break;
3321         }
3322 
3323         switch (c) {
3324             case 'h':
3325             case '?':
3326                 help();
3327                 break;
3328             case 'o':
3329                 if (!is_valid_option_list(optarg)) {
3330                     error_report("Invalid option list: %s", optarg);
3331                     ret = -1;
3332                     goto out_no_progress;
3333                 }
3334                 if (!options) {
3335                     options = g_strdup(optarg);
3336                 } else {
3337                     char *old_options = options;
3338                     options = g_strdup_printf("%s,%s", options, optarg);
3339                     g_free(old_options);
3340                 }
3341                 break;
3342             case 'f':
3343                 fmt = optarg;
3344                 break;
3345             case 't':
3346                 cache = optarg;
3347                 break;
3348             case 'p':
3349                 progress = true;
3350                 break;
3351             case 'q':
3352                 quiet = true;
3353                 break;
3354             case OPTION_OBJECT:
3355                 opts = qemu_opts_parse_noisily(&qemu_object_opts,
3356                                                optarg, true);
3357                 if (!opts) {
3358                     ret = -1;
3359                     goto out_no_progress;
3360                 }
3361                 break;
3362             case OPTION_IMAGE_OPTS:
3363                 image_opts = true;
3364                 break;
3365         }
3366     }
3367 
3368     if (!options) {
3369         error_exit("Must specify options (-o)");
3370     }
3371 
3372     if (qemu_opts_foreach(&qemu_object_opts,
3373                           user_creatable_add_opts_foreach,
3374                           NULL, NULL)) {
3375         ret = -1;
3376         goto out_no_progress;
3377     }
3378 
3379     if (quiet) {
3380         progress = false;
3381     }
3382     qemu_progress_init(progress, 1.0);
3383 
3384     filename = (optind == argc - 1) ? argv[argc - 1] : NULL;
3385     if (fmt && has_help_option(options)) {
3386         /* If a format is explicitly specified (and possibly no filename is
3387          * given), print option help here */
3388         ret = print_block_option_help(filename, fmt);
3389         goto out;
3390     }
3391 
3392     if (optind != argc - 1) {
3393         error_report("Expecting one image file name");
3394         ret = -1;
3395         goto out;
3396     }
3397 
3398     flags = BDRV_O_RDWR;
3399     ret = bdrv_parse_cache_mode(cache, &flags, &writethrough);
3400     if (ret < 0) {
3401         error_report("Invalid cache option: %s", cache);
3402         goto out;
3403     }
3404 
3405     blk = img_open(image_opts, filename, fmt, flags, writethrough, quiet);
3406     if (!blk) {
3407         ret = -1;
3408         goto out;
3409     }
3410     bs = blk_bs(blk);
3411 
3412     fmt = bs->drv->format_name;
3413 
3414     if (has_help_option(options)) {
3415         /* If the format was auto-detected, print option help here */
3416         ret = print_block_option_help(filename, fmt);
3417         goto out;
3418     }
3419 
3420     if (!bs->drv->create_opts) {
3421         error_report("Format driver '%s' does not support any options to amend",
3422                      fmt);
3423         ret = -1;
3424         goto out;
3425     }
3426 
3427     create_opts = qemu_opts_append(create_opts, bs->drv->create_opts);
3428     opts = qemu_opts_create(create_opts, NULL, 0, &error_abort);
3429     if (options) {
3430         qemu_opts_do_parse(opts, options, NULL, &err);
3431         if (err) {
3432             error_report_err(err);
3433             ret = -1;
3434             goto out;
3435         }
3436     }
3437 
3438     /* In case the driver does not call amend_status_cb() */
3439     qemu_progress_print(0.f, 0);
3440     ret = bdrv_amend_options(bs, opts, &amend_status_cb, NULL);
3441     qemu_progress_print(100.f, 0);
3442     if (ret < 0) {
3443         error_report("Error while amending options: %s", strerror(-ret));
3444         goto out;
3445     }
3446 
3447 out:
3448     qemu_progress_end();
3449 
3450 out_no_progress:
3451     blk_unref(blk);
3452     qemu_opts_del(opts);
3453     qemu_opts_free(create_opts);
3454     g_free(options);
3455 
3456     if (ret) {
3457         return 1;
3458     }
3459     return 0;
3460 }
3461 
3462 static const img_cmd_t img_cmds[] = {
3463 #define DEF(option, callback, arg_string)        \
3464     { option, callback },
3465 #include "qemu-img-cmds.h"
3466 #undef DEF
3467 #undef GEN_DOCS
3468     { NULL, NULL, },
3469 };
3470 
3471 int main(int argc, char **argv)
3472 {
3473     const img_cmd_t *cmd;
3474     const char *cmdname;
3475     Error *local_error = NULL;
3476     int c;
3477     static const struct option long_options[] = {
3478         {"help", no_argument, 0, 'h'},
3479         {"version", no_argument, 0, 'v'},
3480         {0, 0, 0, 0}
3481     };
3482 
3483 #ifdef CONFIG_POSIX
3484     signal(SIGPIPE, SIG_IGN);
3485 #endif
3486 
3487     error_set_progname(argv[0]);
3488     qemu_init_exec_dir(argv[0]);
3489 
3490     if (qemu_init_main_loop(&local_error)) {
3491         error_report_err(local_error);
3492         exit(EXIT_FAILURE);
3493     }
3494 
3495     if (qcrypto_init(&local_error) < 0) {
3496         error_reportf_err(local_error, "cannot initialize crypto: ");
3497         exit(1);
3498     }
3499 
3500     module_call_init(MODULE_INIT_QOM);
3501     bdrv_init();
3502     if (argc < 2) {
3503         error_exit("Not enough arguments");
3504     }
3505     cmdname = argv[1];
3506 
3507     qemu_add_opts(&qemu_object_opts);
3508     qemu_add_opts(&qemu_source_opts);
3509 
3510     /* find the command */
3511     for (cmd = img_cmds; cmd->name != NULL; cmd++) {
3512         if (!strcmp(cmdname, cmd->name)) {
3513             return cmd->handler(argc - 1, argv + 1);
3514         }
3515     }
3516 
3517     c = getopt_long(argc, argv, "h", long_options, NULL);
3518 
3519     if (c == 'h') {
3520         help();
3521     }
3522     if (c == 'v') {
3523         printf(QEMU_IMG_VERSION);
3524         return 0;
3525     }
3526 
3527     /* not found */
3528     error_exit("Command not found: %s", cmdname);
3529 }
3530