wimlib: Clean up code that sends capture progress messages
[wimlib] / src / update_image.c
1 /*
2  * update_image.c - Update a WIM image.
3  */
4
5 /*
6  * Copyright (C) 2013 Eric Biggers
7  *
8  * This file is part of wimlib, a library for working with WIM files.
9  *
10  * wimlib is free software; you can redistribute it and/or modify it under the
11  * terms of the GNU General Public License as published by the Free
12  * Software Foundation; either version 3 of the License, or (at your option)
13  * any later version.
14  *
15  * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
16  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
17  * A PARTICULAR PURPOSE. See the GNU General Public License for more
18  * details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with wimlib; if not, see http://www.gnu.org/licenses/.
22  */
23
24 #ifdef HAVE_CONFIG_H
25 #  include "config.h"
26 #endif
27
28 #include "wimlib/capture.h"
29 #include "wimlib/dentry.h"
30 #include "wimlib/error.h"
31 #include "wimlib/lookup_table.h"
32 #include "wimlib/metadata.h"
33 #ifdef WITH_NTFS_3G
34 #  include "wimlib/ntfs_3g.h" /* for do_ntfs_umount() */
35 #endif
36 #include "wimlib/paths.h"
37 #include "wimlib/xml.h"
38
39 #include <errno.h>
40
41 /* Overlays @branch onto @target, both of which must be directories. */
42 static int
43 do_overlay(struct wim_dentry *target, struct wim_dentry *branch)
44 {
45         struct rb_root *rb_root;
46
47         DEBUG("Doing overlay \"%"WS"\" => \"%"WS"\"",
48               branch->file_name, target->file_name);
49
50         if (!dentry_is_directory(branch) || !dentry_is_directory(target)) {
51                 ERROR("Cannot overlay \"%"WS"\" onto existing dentry: "
52                       "is not directory-on-directory!", branch->file_name);
53                 return WIMLIB_ERR_INVALID_OVERLAY;
54         }
55
56         rb_root = &branch->d_inode->i_children;
57         LIST_HEAD(moved_children);
58         while (rb_root->rb_node) { /* While @branch has children... */
59                 struct wim_dentry *child = rbnode_dentry(rb_root->rb_node);
60                 struct wim_dentry *existing;
61
62                 /* Move @child to the directory @target */
63                 unlink_dentry(child);
64                 existing = dentry_add_child(target, child);
65
66                 /* File or directory with same name already exists */
67                 if (existing) {
68                         int ret;
69                         ret = do_overlay(existing, child);
70                         if (ret) {
71                                 /* Overlay failed.  Revert the changes. */
72                                 dentry_add_child(branch, child);
73                                 list_for_each_entry(child, &moved_children, tmp_list)
74                                 {
75                                         unlink_dentry(child);
76                                         dentry_add_child(branch, child);
77                                 }
78                                 return ret;
79                         }
80                 } else {
81                         list_add(&child->tmp_list, &moved_children);
82                 }
83         }
84         free_dentry(branch);
85         return 0;
86 }
87
88 /* Attach or overlay a branch onto the WIM image.
89  *
90  * @root_p:
91  *      Pointer to the root of the WIM image, or pointer to NULL if it has not
92  *      been created yet.
93  * @branch
94  *      Branch to add.
95  * @target_path:
96  *      Path in the WIM image to add the branch, with leading and trailing
97  *      slashes stripped.
98  */
99 static int
100 attach_branch(struct wim_dentry **root_p, struct wim_dentry *branch,
101               tchar *target_path)
102 {
103         tchar *slash;
104         struct wim_dentry *dentry, *parent, *target;
105         int ret;
106
107         DEBUG("Attaching branch \"%"WS"\" => \"%"TS"\"",
108               branch->file_name, target_path);
109
110         if (*target_path == T('\0')) {
111                 /* Target: root directory */
112                 if (*root_p) {
113                         /* Overlay on existing root */
114                         return do_overlay(*root_p, branch);
115                 } else {
116                         if (!dentry_is_directory(branch)) {
117                                 ERROR("Cannot set non-directory as root of WIM image");
118                                 return WIMLIB_ERR_NOTDIR;
119                         }
120                         /* Set as root */
121                         *root_p = branch;
122                         return 0;
123                 }
124         }
125
126         /* Adding a non-root branch.  Create root if it hasn't been created
127          * already. */
128         if (!*root_p) {
129                 ret  = new_filler_directory(T(""), root_p);
130                 if (ret)
131                         return ret;
132         }
133
134         /* Walk the path to the branch, creating filler directories as needed.
135          * */
136         parent = *root_p;
137         while ((slash = tstrchr(target_path, WIM_PATH_SEPARATOR))) {
138                 *slash = T('\0');
139                 dentry = get_dentry_child_with_name(parent, target_path);
140                 if (!dentry) {
141                         ret = new_filler_directory(target_path, &dentry);
142                         if (ret)
143                                 return ret;
144                         dentry_add_child(parent, dentry);
145                 }
146                 parent = dentry;
147                 target_path = slash;
148                 /* Skip over slashes.  Note: this cannot overrun the length of
149                  * the string because the last character cannot be a slash, as
150                  * trailing slashes were tripped.  */
151                 do {
152                         ++target_path;
153                 } while (*target_path == WIM_PATH_SEPARATOR);
154         }
155
156         /* If the target path already existed, overlay the branch onto it.
157          * Otherwise, set the branch as the target path. */
158         target = get_dentry_child_with_utf16le_name(parent, branch->file_name,
159                                                     branch->file_name_nbytes);
160         if (target) {
161                 return do_overlay(target, branch);
162         } else {
163                 dentry_add_child(parent, branch);
164                 return 0;
165         }
166 }
167
168 static int
169 execute_add_command(WIMStruct *wim,
170                     const struct wimlib_update_command *add_cmd,
171                     wimlib_progress_func_t progress_func)
172 {
173         int ret;
174         int add_flags;
175         tchar *fs_source_path;
176         tchar *wim_target_path;
177         struct wim_image_metadata *imd;
178         struct list_head unhashed_streams;
179         struct add_image_params params;
180         int (*capture_tree)(struct wim_dentry **,
181                             const tchar *,
182                             struct add_image_params *);
183         struct wimlib_capture_config *config;
184 #ifdef WITH_NTFS_3G
185         struct _ntfs_volume *ntfs_vol = NULL;
186 #endif
187         void *extra_arg;
188         struct wim_dentry *branch;
189         bool rollback_sd = true;
190
191         wimlib_assert(add_cmd->op == WIMLIB_UPDATE_OP_ADD);
192
193         add_flags = add_cmd->add.add_flags;
194         fs_source_path = add_cmd->add.fs_source_path;
195         wim_target_path = add_cmd->add.wim_target_path;
196         config = add_cmd->add.config;
197         DEBUG("fs_source_path=\"%"TS"\", wim_target_path=\"%"TS"\", add_flags=%#x",
198               fs_source_path, wim_target_path, add_flags);
199
200         memset(&params, 0, sizeof(params));
201
202         imd = wim->image_metadata[wim->current_image - 1];
203
204         if (add_flags & WIMLIB_ADD_FLAG_NTFS) {
205         #ifdef WITH_NTFS_3G
206                 capture_tree = build_dentry_tree_ntfs;
207                 extra_arg = &ntfs_vol;
208                 if (imd->ntfs_vol != NULL) {
209                         ERROR("NTFS volume already set");
210                         ret = WIMLIB_ERR_INVALID_PARAM;
211                         goto out;
212                 }
213         #else
214                 ret = WIMLIB_ERR_INVALID_PARAM;
215                 goto out;
216         #endif
217         } else {
218         #ifdef __WIN32__
219                 capture_tree = win32_build_dentry_tree;
220         #else
221                 capture_tree = unix_build_dentry_tree;
222         #endif
223                 extra_arg = NULL;
224         }
225
226
227         ret = init_inode_table(&params.inode_table, 9001);
228         if (ret)
229                 goto out;
230
231         ret = init_sd_set(&params.sd_set, imd->security_data);
232         if (ret)
233                 goto out_destroy_inode_table;
234
235         INIT_LIST_HEAD(&unhashed_streams);
236         wim->lookup_table->unhashed_streams = &unhashed_streams;
237         params.lookup_table = wim->lookup_table;
238         params.config = config;
239         params.add_flags = add_flags;
240         params.extra_arg = extra_arg;
241
242         params.progress_func = progress_func;
243         params.progress.scan.source = fs_source_path;
244         params.progress.scan.wim_target_path = wim_target_path;
245         if (progress_func)
246                 progress_func(WIMLIB_PROGRESS_MSG_SCAN_BEGIN, &params.progress);
247         if (config) {
248                 config->_prefix = fs_source_path;
249                 config->_prefix_num_tchars = tstrlen(fs_source_path);
250         }
251
252         if (wim_target_path[0] == T('\0'))
253                 params.add_flags |= WIMLIB_ADD_FLAG_ROOT;
254         ret = (*capture_tree)(&branch, fs_source_path, &params);
255         if (ret) {
256                 ERROR("Failed to build dentry tree for \"%"TS"\"",
257                       fs_source_path);
258                 goto out_destroy_sd_set;
259         }
260         if (branch) {
261                 /* Use the target name, not the source name, for
262                  * the root of each branch from a capture
263                  * source.  (This will also set the root dentry
264                  * of the entire image to be unnamed.) */
265                 ret = set_dentry_name(branch,
266                                       path_basename(wim_target_path));
267                 if (ret)
268                         goto out_ntfs_umount;
269
270                 ret = attach_branch(&imd->root_dentry, branch, wim_target_path);
271                 if (ret)
272                         goto out_ntfs_umount;
273         }
274         if (progress_func)
275                 progress_func(WIMLIB_PROGRESS_MSG_SCAN_END, &params.progress);
276         list_splice_tail(&unhashed_streams, &imd->unhashed_streams);
277 #ifdef WITH_NTFS_3G
278         imd->ntfs_vol = ntfs_vol;
279 #endif
280         inode_table_prepare_inode_list(&params.inode_table, &imd->inode_list);
281         ret = 0;
282         rollback_sd = false;
283         if (add_flags & WIMLIB_ADD_FLAG_RPFIX)
284                 wim->hdr.flags |= WIM_HDR_FLAG_RP_FIX;
285         goto out_destroy_sd_set;
286 out_ntfs_umount:
287 #ifdef WITH_NTFS_3G
288         if (ntfs_vol)
289                 do_ntfs_umount(ntfs_vol);
290 #endif
291         free_dentry_tree(branch, wim->lookup_table);
292 out_destroy_sd_set:
293         destroy_sd_set(&params.sd_set, rollback_sd);
294 out_destroy_inode_table:
295         destroy_inode_table(&params.inode_table);
296 out:
297         return ret;
298 }
299
300 static int
301 execute_delete_command(WIMStruct *wim,
302                        const struct wimlib_update_command *delete_cmd)
303 {
304         int flags;
305         const tchar *wim_path;
306         struct wim_dentry *tree;
307         bool is_root;
308
309         wimlib_assert(delete_cmd->op == WIMLIB_UPDATE_OP_DELETE);
310         flags = delete_cmd->delete.delete_flags;
311         wim_path = delete_cmd->delete.wim_path;
312
313         DEBUG("Deleting WIM path \"%"TS"\" (flags=%#x)", wim_path, flags);
314
315         tree = get_dentry(wim, wim_path);
316         if (!tree) {
317                 /* Path to delete does not exist in the WIM. */
318                 if (flags & WIMLIB_DELETE_FLAG_FORCE) {
319                         return 0;
320                 } else {
321                         ERROR("Path \"%"TS"\" does not exist in WIM image %d",
322                               wim_path, wim->current_image);
323                         return WIMLIB_ERR_PATH_DOES_NOT_EXIST;
324                 }
325         }
326
327         if (dentry_is_directory(tree) && !(flags & WIMLIB_DELETE_FLAG_RECURSIVE)) {
328                 ERROR("Path \"%"TS"\" in WIM image %d is a directory "
329                       "but a recursive delete was not requested",
330                       wim_path, wim->current_image);
331                 return WIMLIB_ERR_IS_DIRECTORY;
332         }
333
334         is_root = dentry_is_root(tree);
335         unlink_dentry(tree);
336         free_dentry_tree(tree, wim->lookup_table);
337         if (is_root)
338                 wim->image_metadata[wim->current_image - 1]->root_dentry = NULL;
339         return 0;
340 }
341
342 static int
343 free_dentry_full_path(struct wim_dentry *dentry, void *_ignore)
344 {
345         FREE(dentry->_full_path);
346         dentry->_full_path = NULL;
347         return 0;
348 }
349
350 /*
351  * Rename a file or directory in the WIM.
352  *
353  * This is also called from wimfs_rename() in the FUSE mount code.
354  */
355 int
356 rename_wim_path(WIMStruct *wim, const tchar *from, const tchar *to)
357 {
358         struct wim_dentry *src;
359         struct wim_dentry *dst;
360         struct wim_dentry *parent_of_dst;
361         int ret;
362
363         /* This rename() implementation currently only supports actual files
364          * (not alternate data streams) */
365
366         src = get_dentry(wim, from);
367         if (!src)
368                 return -errno;
369
370         dst = get_dentry(wim, to);
371
372         if (dst) {
373                 /* Destination file exists */
374
375                 if (src == dst) /* Same file */
376                         return 0;
377
378                 if (!dentry_is_directory(src)) {
379                         /* Cannot rename non-directory to directory. */
380                         if (dentry_is_directory(dst))
381                                 return -EISDIR;
382                 } else {
383                         /* Cannot rename directory to a non-directory or a non-empty
384                          * directory */
385                         if (!dentry_is_directory(dst))
386                                 return -ENOTDIR;
387                         if (inode_has_children(dst->d_inode))
388                                 return -ENOTEMPTY;
389                 }
390                 parent_of_dst = dst->parent;
391         } else {
392                 /* Destination does not exist */
393                 parent_of_dst = get_parent_dentry(wim, to);
394                 if (!parent_of_dst)
395                         return -errno;
396
397                 if (!dentry_is_directory(parent_of_dst))
398                         return -ENOTDIR;
399         }
400
401         ret = set_dentry_name(src, path_basename(to));
402         if (ret)
403                 return -ENOMEM;
404         if (dst) {
405                 unlink_dentry(dst);
406                 free_dentry_tree(dst, wim->lookup_table);
407         }
408         unlink_dentry(src);
409         dentry_add_child(parent_of_dst, src);
410         if (src->_full_path)
411                 for_dentry_in_tree(src, free_dentry_full_path, NULL);
412         return 0;
413 }
414
415
416 static int
417 execute_rename_command(WIMStruct *wim,
418                        const struct wimlib_update_command *rename_cmd)
419 {
420         int ret;
421
422         wimlib_assert(rename_cmd->op == WIMLIB_UPDATE_OP_RENAME);
423
424         ret = rename_wim_path(wim, rename_cmd->rename.wim_source_path,
425                               rename_cmd->rename.wim_target_path);
426         if (ret) {
427                 ret = -ret;
428                 errno = ret;
429                 ERROR_WITH_ERRNO("Can't rename \"%"TS"\" to \"%"TS"\"",
430                                  rename_cmd->rename.wim_source_path,
431                                  rename_cmd->rename.wim_target_path);
432                 switch (ret) {
433                 case ENOMEM:
434                         ret = WIMLIB_ERR_NOMEM;
435                         break;
436                 case ENOTDIR:
437                         ret = WIMLIB_ERR_NOTDIR;
438                         break;
439                 case ENOTEMPTY:
440                         ret = WIMLIB_ERR_NOTEMPTY;
441                         break;
442                 case EISDIR:
443                         ret = WIMLIB_ERR_IS_DIRECTORY;
444                         break;
445                 case ENOENT:
446                 default:
447                         ret = WIMLIB_ERR_PATH_DOES_NOT_EXIST;
448                         break;
449                 }
450         }
451         return ret;
452 }
453
454 static inline const tchar *
455 update_op_to_str(int op)
456 {
457         switch (op) {
458         case WIMLIB_UPDATE_OP_ADD:
459                 return T("add");
460         case WIMLIB_UPDATE_OP_DELETE:
461                 return T("delete");
462         case WIMLIB_UPDATE_OP_RENAME:
463                 return T("rename");
464         default:
465                 wimlib_assert(0);
466                 return NULL;
467         }
468 }
469
470 static int
471 execute_update_commands(WIMStruct *wim,
472                         const struct wimlib_update_command *cmds,
473                         size_t num_cmds,
474                         int update_flags,
475                         wimlib_progress_func_t progress_func)
476 {
477         int ret = 0;
478         union wimlib_progress_info info;
479         info.update.completed_commands = 0;
480         info.update.total_commands = num_cmds;
481         for (size_t i = 0; i < num_cmds; i++) {
482                 DEBUG("Executing update command %zu of %zu (op=%"TS")",
483                       i + 1, num_cmds, update_op_to_str(cmds[i].op));
484                 if (update_flags & WIMLIB_UPDATE_FLAG_SEND_PROGRESS &&
485                     progress_func)
486                 {
487                         info.update.command = &cmds[i];
488                         (*progress_func)(WIMLIB_PROGRESS_MSG_UPDATE_BEGIN_COMMAND,
489                                          &info);
490                 }
491                 switch (cmds[i].op) {
492                 case WIMLIB_UPDATE_OP_ADD:
493                         ret = execute_add_command(wim, &cmds[i], progress_func);
494                         break;
495                 case WIMLIB_UPDATE_OP_DELETE:
496                         ret = execute_delete_command(wim, &cmds[i]);
497                         break;
498                 case WIMLIB_UPDATE_OP_RENAME:
499                         ret = execute_rename_command(wim, &cmds[i]);
500                         break;
501                 default:
502                         wimlib_assert(0);
503                 }
504                 if (ret)
505                         break;
506                 info.update.completed_commands++;
507                 if (update_flags & WIMLIB_UPDATE_FLAG_SEND_PROGRESS &&
508                     progress_func)
509                 {
510                         (*progress_func)(WIMLIB_PROGRESS_MSG_UPDATE_END_COMMAND,
511                                          &info);
512                 }
513         }
514         return ret;
515 }
516
517 static int
518 check_add_command(struct wimlib_update_command *cmd,
519                   const struct wim_header *hdr)
520 {
521         int add_flags = cmd->add.add_flags;
522
523         /* Are we adding the entire image or not?  An empty wim_target_path
524          * indicates that the tree we're adding is to be placed in the root of
525          * the image.  We consider this to be capturing the entire image,
526          * although it could potentially be an overlay on an existing root as
527          * well. */
528         bool is_entire_image = cmd->add.wim_target_path[0] == T('\0');
529
530 #ifdef __WIN32__
531         /* Check for flags not supported on Windows */
532         if (add_flags & WIMLIB_ADD_FLAG_NTFS) {
533                 ERROR("wimlib was compiled without support for NTFS-3g, so");
534                 ERROR("we cannot capture a WIM image directly from a NTFS volume");
535                 return WIMLIB_ERR_UNSUPPORTED;
536         }
537         if (add_flags & WIMLIB_ADD_FLAG_UNIX_DATA) {
538                 ERROR("Capturing UNIX-specific data is not supported on Windows");
539                 return WIMLIB_ERR_UNSUPPORTED;
540         }
541         if (add_flags & WIMLIB_ADD_FLAG_DEREFERENCE) {
542                 ERROR("Dereferencing symbolic links is not supported on Windows");
543                 return WIMLIB_ERR_UNSUPPORTED;
544         }
545 #endif
546
547         /* VERBOSE implies EXCLUDE_VERBOSE */
548         if (add_flags & WIMLIB_ADD_FLAG_VERBOSE)
549                 add_flags |= WIMLIB_ADD_FLAG_EXCLUDE_VERBOSE;
550
551         /* Check for contradictory reparse point fixup flags */
552         if ((add_flags & (WIMLIB_ADD_FLAG_RPFIX |
553                           WIMLIB_ADD_FLAG_NORPFIX)) ==
554                 (WIMLIB_ADD_FLAG_RPFIX |
555                  WIMLIB_ADD_FLAG_NORPFIX))
556         {
557                 ERROR("Cannot specify RPFIX and NORPFIX flags "
558                       "at the same time!");
559                 return WIMLIB_ERR_INVALID_PARAM;
560         }
561
562         /* Set default behavior on reparse point fixups if requested */
563         if ((add_flags & (WIMLIB_ADD_FLAG_RPFIX |
564                           WIMLIB_ADD_FLAG_NORPFIX)) == 0)
565         {
566                 /* Do reparse-point fixups by default if we are capturing an
567                  * entire image and either the header flag is set from previous
568                  * images, or if this is the first image being added. */
569                 if (is_entire_image &&
570                     ((hdr->flags & WIM_HDR_FLAG_RP_FIX) || hdr->image_count == 1))
571                         add_flags |= WIMLIB_ADD_FLAG_RPFIX;
572         }
573
574         if (!is_entire_image) {
575                 if (add_flags & WIMLIB_ADD_FLAG_NTFS) {
576                         ERROR("Cannot add directly from a NTFS volume "
577                               "when not capturing a full image!");
578                         return WIMLIB_ERR_INVALID_PARAM;
579                 }
580
581                 if (add_flags & WIMLIB_ADD_FLAG_RPFIX) {
582                         ERROR("Cannot do reparse point fixups when "
583                               "not capturing a full image!");
584                         return WIMLIB_ERR_INVALID_PARAM;
585                 }
586         }
587         /* We may have modified the add flags. */
588         cmd->add.add_flags = add_flags;
589         return 0;
590 }
591
592 static int
593 check_update_command(struct wimlib_update_command *cmd,
594                      const struct wim_header *hdr)
595 {
596         switch (cmd->op) {
597         case WIMLIB_UPDATE_OP_ADD:
598                 return check_add_command(cmd, hdr);
599         case WIMLIB_UPDATE_OP_DELETE:
600         case WIMLIB_UPDATE_OP_RENAME:
601                 break;
602         }
603         return 0;
604 }
605
606 static int
607 check_update_commands(struct wimlib_update_command *cmds, size_t num_cmds,
608                       const struct wim_header *hdr)
609 {
610         int ret = 0;
611         for (size_t i = 0; i < num_cmds; i++) {
612                 ret = check_update_command(&cmds[i], hdr);
613                 if (ret)
614                         break;
615         }
616         return ret;
617 }
618
619
620 static void
621 free_update_commands(struct wimlib_update_command *cmds, size_t num_cmds)
622 {
623         if (cmds) {
624                 for (size_t i = 0; i < num_cmds; i++) {
625                         switch (cmds[i].op) {
626                         case WIMLIB_UPDATE_OP_ADD:
627                                 FREE(cmds[i].add.fs_source_path);
628                                 FREE(cmds[i].add.wim_target_path);
629                                 free_capture_config(cmds[i].add.config);
630                                 break;
631                         case WIMLIB_UPDATE_OP_DELETE:
632                                 FREE(cmds[i].delete.wim_path);
633                                 break;
634                         case WIMLIB_UPDATE_OP_RENAME:
635                                 FREE(cmds[i].rename.wim_source_path);
636                                 FREE(cmds[i].rename.wim_target_path);
637                                 break;
638                         }
639                 }
640                 FREE(cmds);
641         }
642 }
643
644 static int
645 copy_update_commands(const struct wimlib_update_command *cmds,
646                      size_t num_cmds,
647                      struct wimlib_update_command **cmds_copy_ret)
648 {
649         int ret;
650         struct wimlib_update_command *cmds_copy;
651
652         cmds_copy = CALLOC(num_cmds, sizeof(cmds[0]));
653         if (!cmds_copy)
654                 goto oom;
655
656         for (size_t i = 0; i < num_cmds; i++) {
657                 cmds_copy[i].op = cmds[i].op;
658                 switch (cmds[i].op) {
659                 case WIMLIB_UPDATE_OP_ADD:
660                         cmds_copy[i].add.fs_source_path =
661                                 canonicalize_fs_path(cmds[i].add.fs_source_path);
662                         cmds_copy[i].add.wim_target_path =
663                                 canonicalize_wim_path(cmds[i].add.wim_target_path);
664                         if (!cmds_copy[i].add.fs_source_path ||
665                             !cmds_copy[i].add.wim_target_path)
666                                 goto oom;
667                         if (cmds[i].add.config) {
668                                 ret = copy_and_canonicalize_capture_config(cmds[i].add.config,
669                                                                            &cmds_copy[i].add.config);
670                                 if (ret)
671                                         goto err;
672                         }
673                         cmds_copy[i].add.add_flags = cmds[i].add.add_flags;
674                         break;
675                 case WIMLIB_UPDATE_OP_DELETE:
676                         cmds_copy[i].delete.wim_path =
677                                 canonicalize_wim_path(cmds[i].delete.wim_path);
678                         if (!cmds_copy[i].delete.wim_path)
679                                 goto oom;
680                         cmds_copy[i].delete.delete_flags = cmds[i].delete.delete_flags;
681                         break;
682                 case WIMLIB_UPDATE_OP_RENAME:
683                         cmds_copy[i].rename.wim_source_path =
684                                 canonicalize_wim_path(cmds[i].rename.wim_source_path);
685                         cmds_copy[i].rename.wim_target_path =
686                                 canonicalize_wim_path(cmds[i].rename.wim_target_path);
687                         if (!cmds_copy[i].rename.wim_source_path ||
688                             !cmds_copy[i].rename.wim_target_path)
689                                 goto oom;
690                         break;
691                 default:
692                         ERROR("Unknown update operation %u", cmds[i].op);
693                         ret = WIMLIB_ERR_INVALID_PARAM;
694                         goto err;
695                 }
696         }
697         *cmds_copy_ret = cmds_copy;
698         ret = 0;
699 out:
700         return ret;
701 oom:
702         ret = WIMLIB_ERR_NOMEM;
703 err:
704         free_update_commands(cmds_copy, num_cmds);
705         goto out;
706 }
707
708 /* API function documented in wimlib.h  */
709 WIMLIBAPI int
710 wimlib_update_image(WIMStruct *wim,
711                     int image,
712                     const struct wimlib_update_command *cmds,
713                     size_t num_cmds,
714                     int update_flags,
715                     wimlib_progress_func_t progress_func)
716 {
717         int ret;
718         struct wimlib_update_command *cmds_copy;
719         bool deletion_requested = false;
720
721         DEBUG("Updating image %d with %zu commands", image, num_cmds);
722
723         for (size_t i = 0; i < num_cmds; i++)
724                 if (cmds[i].op == WIMLIB_UPDATE_OP_DELETE)
725                         deletion_requested = true;
726
727         if (deletion_requested)
728                 ret = can_delete_from_wim(wim);
729         else
730                 ret = can_modify_wim(wim);
731
732         if (ret)
733                 goto out;
734
735         /* Load the metadata for the image to modify (if not loaded already) */
736         ret = select_wim_image(wim, image);
737         if (ret)
738                 goto out;
739
740         /* Short circuit a successful return if no commands were specified.
741          * Avoids problems with trying to allocate 0 bytes of memory. */
742         if (num_cmds == 0)
743                 goto out;
744
745         DEBUG("Preparing %zu update commands", num_cmds);
746
747         /* Make a copy of the update commands, in the process doing certain
748          * canonicalizations on paths (e.g. translating backslashes to forward
749          * slashes).  This is done to avoid modifying the caller's copy of the
750          * commands. */
751         ret = copy_update_commands(cmds, num_cmds, &cmds_copy);
752         if (ret)
753                 goto out;
754
755         /* Perform additional checks on the update commands before we execute
756          * them. */
757         ret = check_update_commands(cmds_copy, num_cmds, &wim->hdr);
758         if (ret)
759                 goto out_free_cmds_copy;
760
761         /* Actually execute the update commands. */
762         DEBUG("Executing %zu update commands", num_cmds);
763         ret = execute_update_commands(wim, cmds_copy, num_cmds, update_flags,
764                                       progress_func);
765         if (ret)
766                 goto out_free_cmds_copy;
767
768         wim->image_metadata[image - 1]->modified = 1;
769
770         /* Statistics about the WIM image, such as the numbers of files and
771          * directories, may have changed.  Call xml_update_image_info() to
772          * recalculate these statistics. */
773         xml_update_image_info(wim, image);
774 out_free_cmds_copy:
775         free_update_commands(cmds_copy, num_cmds);
776 out:
777         return ret;
778 }