Refactor headers
[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, T('/')))) {
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 == T('/'));
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         union wimlib_progress_info progress;
184         struct wimlib_capture_config *config;
185 #ifdef WITH_NTFS_3G
186         struct _ntfs_volume *ntfs_vol = NULL;
187 #endif
188         void *extra_arg;
189         struct wim_dentry *branch;
190         bool rollback_sd = true;
191
192         wimlib_assert(add_cmd->op == WIMLIB_UPDATE_OP_ADD);
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         imd = wim->image_metadata[wim->current_image - 1];
201
202         if (add_flags & WIMLIB_ADD_FLAG_NTFS) {
203         #ifdef WITH_NTFS_3G
204                 capture_tree = build_dentry_tree_ntfs;
205                 extra_arg = &ntfs_vol;
206                 if (imd->ntfs_vol != NULL) {
207                         ERROR("NTFS volume already set");
208                         ret = WIMLIB_ERR_INVALID_PARAM;
209                         goto out;
210                 }
211         #else
212                 ret = WIMLIB_ERR_INVALID_PARAM;
213                 goto out;
214         #endif
215         } else {
216         #ifdef __WIN32__
217                 capture_tree = win32_build_dentry_tree;
218         #else
219                 capture_tree = unix_build_dentry_tree;
220         #endif
221                 extra_arg = NULL;
222         }
223
224         ret = init_inode_table(&params.inode_table, 9001);
225         if (ret)
226                 goto out;
227
228         ret = init_sd_set(&params.sd_set, imd->security_data);
229         if (ret)
230                 goto out_destroy_inode_table;
231
232         INIT_LIST_HEAD(&unhashed_streams);
233         wim->lookup_table->unhashed_streams = &unhashed_streams;
234         params.lookup_table = wim->lookup_table;
235         params.config = config;
236         params.add_flags = add_flags;
237         params.progress_func = progress_func;
238         params.extra_arg = extra_arg;
239
240         if (progress_func) {
241                 memset(&progress, 0, sizeof(progress));
242                 progress.scan.source = fs_source_path;
243                 progress.scan.wim_target_path = wim_target_path;
244                 progress_func(WIMLIB_PROGRESS_MSG_SCAN_BEGIN, &progress);
245         }
246         config->_prefix = fs_source_path;
247         config->_prefix_num_tchars = tstrlen(fs_source_path);
248
249         if (wim_target_path[0] == T('\0'))
250                 add_flags |= WIMLIB_ADD_FLAG_ROOT;
251         ret = (*capture_tree)(&branch, fs_source_path, &params);
252         if (ret) {
253                 ERROR("Failed to build dentry tree for \"%"TS"\"",
254                       fs_source_path);
255                 goto out_destroy_sd_set;
256         }
257         if (branch) {
258                 /* Use the target name, not the source name, for
259                  * the root of each branch from a capture
260                  * source.  (This will also set the root dentry
261                  * of the entire image to be unnamed.) */
262                 ret = set_dentry_name(branch,
263                                       path_basename(wim_target_path));
264                 if (ret)
265                         goto out_ntfs_umount;
266
267                 ret = attach_branch(&imd->root_dentry, branch, wim_target_path);
268                 if (ret)
269                         goto out_ntfs_umount;
270         }
271         if (progress_func)
272                 progress_func(WIMLIB_PROGRESS_MSG_SCAN_END, &progress);
273         list_splice_tail(&unhashed_streams, &imd->unhashed_streams);
274 #ifdef WITH_NTFS_3G
275         imd->ntfs_vol = ntfs_vol;
276 #endif
277         inode_table_prepare_inode_list(&params.inode_table, &imd->inode_list);
278         ret = 0;
279         rollback_sd = false;
280         if (add_flags & WIMLIB_ADD_FLAG_RPFIX)
281                 wim->hdr.flags |= WIM_HDR_FLAG_RP_FIX;
282         goto out_destroy_sd_set;
283 out_ntfs_umount:
284 #ifdef WITH_NTFS_3G
285         if (ntfs_vol)
286                 do_ntfs_umount(ntfs_vol);
287 #endif
288         free_dentry_tree(branch, wim->lookup_table);
289 out_destroy_sd_set:
290         destroy_sd_set(&params.sd_set, rollback_sd);
291 out_destroy_inode_table:
292         destroy_inode_table(&params.inode_table);
293 out:
294         return ret;
295 }
296
297 static int
298 execute_delete_command(WIMStruct *wim,
299                        const struct wimlib_update_command *delete_cmd)
300 {
301         int flags;
302         const tchar *wim_path;
303         struct wim_dentry *tree;
304         bool is_root;
305
306         wimlib_assert(delete_cmd->op == WIMLIB_UPDATE_OP_DELETE);
307         flags = delete_cmd->delete.delete_flags;
308         wim_path = delete_cmd->delete.wim_path;
309
310         DEBUG("Deleting WIM path \"%"TS"\" (flags=%#x)", wim_path, flags);
311
312         tree = get_dentry(wim, wim_path);
313         if (!tree) {
314                 /* Path to delete does not exist in the WIM. */
315                 if (flags & WIMLIB_DELETE_FLAG_FORCE) {
316                         return 0;
317                 } else {
318                         ERROR("Path \"%"TS"\" does not exist in WIM image %d",
319                               wim_path, wim->current_image);
320                         return WIMLIB_ERR_PATH_DOES_NOT_EXIST;
321                 }
322         }
323
324         if (dentry_is_directory(tree) && !(flags & WIMLIB_DELETE_FLAG_RECURSIVE)) {
325                 ERROR("Path \"%"TS"\" in WIM image %d is a directory "
326                       "but a recursive delete was not requested",
327                       wim_path, wim->current_image);
328                 return WIMLIB_ERR_IS_DIRECTORY;
329         }
330
331         is_root = dentry_is_root(tree);
332         unlink_dentry(tree);
333         free_dentry_tree(tree, wim->lookup_table);
334         if (is_root)
335                 wim->image_metadata[wim->current_image - 1]->root_dentry = NULL;
336         return 0;
337 }
338
339 static int
340 free_dentry_full_path(struct wim_dentry *dentry, void *_ignore)
341 {
342         FREE(dentry->_full_path);
343         dentry->_full_path = NULL;
344         return 0;
345 }
346
347 /*
348  * Rename a file or directory in the WIM.
349  *
350  * This is also called from wimfs_rename() in the FUSE mount code.
351  */
352 int
353 rename_wim_path(WIMStruct *wim, const tchar *from, const tchar *to)
354 {
355         struct wim_dentry *src;
356         struct wim_dentry *dst;
357         struct wim_dentry *parent_of_dst;
358         int ret;
359
360         /* This rename() implementation currently only supports actual files
361          * (not alternate data streams) */
362
363         src = get_dentry(wim, from);
364         if (!src)
365                 return -errno;
366
367         dst = get_dentry(wim, to);
368
369         if (dst) {
370                 /* Destination file exists */
371
372                 if (src == dst) /* Same file */
373                         return 0;
374
375                 if (!dentry_is_directory(src)) {
376                         /* Cannot rename non-directory to directory. */
377                         if (dentry_is_directory(dst))
378                                 return -EISDIR;
379                 } else {
380                         /* Cannot rename directory to a non-directory or a non-empty
381                          * directory */
382                         if (!dentry_is_directory(dst))
383                                 return -ENOTDIR;
384                         if (inode_has_children(dst->d_inode))
385                                 return -ENOTEMPTY;
386                 }
387                 parent_of_dst = dst->parent;
388         } else {
389                 /* Destination does not exist */
390                 parent_of_dst = get_parent_dentry(wim, to);
391                 if (!parent_of_dst)
392                         return -errno;
393
394                 if (!dentry_is_directory(parent_of_dst))
395                         return -ENOTDIR;
396         }
397
398         ret = set_dentry_name(src, path_basename(to));
399         if (ret)
400                 return -ENOMEM;
401         if (dst) {
402                 unlink_dentry(dst);
403                 free_dentry_tree(dst, wim->lookup_table);
404         }
405         unlink_dentry(src);
406         dentry_add_child(parent_of_dst, src);
407         if (src->_full_path)
408                 for_dentry_in_tree(src, free_dentry_full_path, NULL);
409         return 0;
410 }
411
412
413 static int
414 execute_rename_command(WIMStruct *wim,
415                        const struct wimlib_update_command *rename_cmd)
416 {
417         int ret;
418
419         wimlib_assert(rename_cmd->op == WIMLIB_UPDATE_OP_RENAME);
420
421         ret = rename_wim_path(wim, rename_cmd->rename.wim_source_path,
422                               rename_cmd->rename.wim_target_path);
423         if (ret) {
424                 ret = -ret;
425                 errno = ret;
426                 ERROR_WITH_ERRNO("Can't rename \"%"TS"\" to \"%"TS"\"",
427                                  rename_cmd->rename.wim_source_path,
428                                  rename_cmd->rename.wim_target_path);
429                 switch (ret) {
430                 case ENOMEM:
431                         ret = WIMLIB_ERR_NOMEM;
432                         break;
433                 case ENOTDIR:
434                         ret = WIMLIB_ERR_NOTDIR;
435                         break;
436                 case ENOTEMPTY:
437                         ret = WIMLIB_ERR_NOTEMPTY;
438                         break;
439                 case EISDIR:
440                         ret = WIMLIB_ERR_IS_DIRECTORY;
441                         break;
442                 case ENOENT:
443                 default:
444                         ret = WIMLIB_ERR_PATH_DOES_NOT_EXIST;
445                         break;
446                 }
447         }
448         return ret;
449 }
450
451 static inline const tchar *
452 update_op_to_str(int op)
453 {
454         switch (op) {
455         case WIMLIB_UPDATE_OP_ADD:
456                 return T("add");
457         case WIMLIB_UPDATE_OP_DELETE:
458                 return T("delete");
459         case WIMLIB_UPDATE_OP_RENAME:
460                 return T("rename");
461         default:
462                 wimlib_assert(0);
463                 return NULL;
464         }
465 }
466
467 static int
468 execute_update_commands(WIMStruct *wim,
469                         const struct wimlib_update_command *cmds,
470                         size_t num_cmds,
471                         wimlib_progress_func_t progress_func)
472 {
473         int ret = 0;
474         for (size_t i = 0; i < num_cmds; i++) {
475                 DEBUG("Executing update command %zu of %zu (op=%"TS")",
476                       i + 1, num_cmds, update_op_to_str(cmds[i].op));
477                 switch (cmds[i].op) {
478                 case WIMLIB_UPDATE_OP_ADD:
479                         ret = execute_add_command(wim, &cmds[i], progress_func);
480                         break;
481                 case WIMLIB_UPDATE_OP_DELETE:
482                         ret = execute_delete_command(wim, &cmds[i]);
483                         break;
484                 case WIMLIB_UPDATE_OP_RENAME:
485                         ret = execute_rename_command(wim, &cmds[i]);
486                         break;
487                 default:
488                         wimlib_assert(0);
489                 }
490                 if (ret)
491                         break;
492         }
493         return ret;
494 }
495
496 static int
497 check_add_command(struct wimlib_update_command *cmd,
498                   const struct wim_header *hdr)
499 {
500         int add_flags = cmd->add.add_flags;
501
502         /* Are we adding the entire image or not?  An empty wim_target_path
503          * indicates that the tree we're adding is to be placed in the root of
504          * the image.  We consider this to be capturing the entire image,
505          * although it could potentially be an overlay on an existing root as
506          * well. */
507         bool is_entire_image = cmd->add.wim_target_path[0] == T('\0');
508
509 #ifdef __WIN32__
510         /* Check for flags not supported on Windows */
511         if (add_flags & WIMLIB_ADD_FLAG_NTFS) {
512                 ERROR("wimlib was compiled without support for NTFS-3g, so");
513                 ERROR("we cannot capture a WIM image directly from a NTFS volume");
514                 return WIMLIB_ERR_UNSUPPORTED;
515         }
516         if (add_flags & WIMLIB_ADD_FLAG_UNIX_DATA) {
517                 ERROR("Capturing UNIX-specific data is not supported on Windows");
518                 return WIMLIB_ERR_UNSUPPORTED;
519         }
520         if (add_flags & WIMLIB_ADD_FLAG_DEREFERENCE) {
521                 ERROR("Dereferencing symbolic links is not supported on Windows");
522                 return WIMLIB_ERR_UNSUPPORTED;
523         }
524 #endif
525
526         /* VERBOSE implies EXCLUDE_VERBOSE */
527         if (add_flags & WIMLIB_ADD_FLAG_VERBOSE)
528                 add_flags |= WIMLIB_ADD_FLAG_EXCLUDE_VERBOSE;
529
530         /* Check for contradictory reparse point fixup flags */
531         if ((add_flags & (WIMLIB_ADD_FLAG_RPFIX |
532                           WIMLIB_ADD_FLAG_NORPFIX)) ==
533                 (WIMLIB_ADD_FLAG_RPFIX |
534                  WIMLIB_ADD_FLAG_NORPFIX))
535         {
536                 ERROR("Cannot specify RPFIX and NORPFIX flags "
537                       "at the same time!");
538                 return WIMLIB_ERR_INVALID_PARAM;
539         }
540
541         /* Set default behavior on reparse point fixups if requested */
542         if ((add_flags & (WIMLIB_ADD_FLAG_RPFIX |
543                           WIMLIB_ADD_FLAG_NORPFIX)) == 0)
544         {
545                 /* Do reparse-point fixups by default if we are capturing an
546                  * entire image and either the header flag is set from previous
547                  * images, or if this is the first image being added. */
548                 if (is_entire_image &&
549                     ((hdr->flags & WIM_HDR_FLAG_RP_FIX) || hdr->image_count == 1))
550                         add_flags |= WIMLIB_ADD_FLAG_RPFIX;
551         }
552
553         if (!is_entire_image) {
554                 if (add_flags & WIMLIB_ADD_FLAG_NTFS) {
555                         ERROR("Cannot add directly from a NTFS volume "
556                               "when not capturing a full image!");
557                         return WIMLIB_ERR_INVALID_PARAM;
558                 }
559
560                 if (add_flags & WIMLIB_ADD_FLAG_RPFIX) {
561                         ERROR("Cannot do reparse point fixups when "
562                               "not capturing a full image!");
563                         return WIMLIB_ERR_INVALID_PARAM;
564                 }
565         }
566         /* We may have modified the add flags. */
567         cmd->add.add_flags = add_flags;
568         return 0;
569 }
570
571 static int
572 check_update_command(struct wimlib_update_command *cmd,
573                      const struct wim_header *hdr)
574 {
575         switch (cmd->op) {
576         case WIMLIB_UPDATE_OP_ADD:
577                 return check_add_command(cmd, hdr);
578         case WIMLIB_UPDATE_OP_DELETE:
579         case WIMLIB_UPDATE_OP_RENAME:
580                 break;
581         }
582         return 0;
583 }
584
585 static int
586 check_update_commands(struct wimlib_update_command *cmds, size_t num_cmds,
587                       const struct wim_header *hdr)
588 {
589         int ret = 0;
590         for (size_t i = 0; i < num_cmds; i++) {
591                 ret = check_update_command(&cmds[i], hdr);
592                 if (ret)
593                         break;
594         }
595         return ret;
596 }
597
598
599 static void
600 free_update_commands(struct wimlib_update_command *cmds, size_t num_cmds)
601 {
602         if (cmds) {
603                 for (size_t i = 0; i < num_cmds; i++) {
604                         switch (cmds[i].op) {
605                         case WIMLIB_UPDATE_OP_ADD:
606                                 FREE(cmds[i].add.fs_source_path);
607                                 FREE(cmds[i].add.wim_target_path);
608                                 free_capture_config(cmds[i].add.config);
609                                 break;
610                         case WIMLIB_UPDATE_OP_DELETE:
611                                 FREE(cmds[i].delete.wim_path);
612                                 break;
613                         case WIMLIB_UPDATE_OP_RENAME:
614                                 FREE(cmds[i].rename.wim_source_path);
615                                 FREE(cmds[i].rename.wim_target_path);
616                                 break;
617                         }
618                 }
619                 FREE(cmds);
620         }
621 }
622
623 static int
624 copy_update_commands(const struct wimlib_update_command *cmds,
625                      size_t num_cmds,
626                      struct wimlib_update_command **cmds_copy_ret)
627 {
628         int ret;
629         struct wimlib_update_command *cmds_copy;
630
631         cmds_copy = CALLOC(num_cmds, sizeof(cmds[0]));
632         if (!cmds_copy)
633                 goto oom;
634
635         for (size_t i = 0; i < num_cmds; i++) {
636                 cmds_copy[i].op = cmds[i].op;
637                 switch (cmds[i].op) {
638                 case WIMLIB_UPDATE_OP_ADD:
639                         cmds_copy[i].add.fs_source_path =
640                                 canonicalize_fs_path(cmds[i].add.fs_source_path);
641                         cmds_copy[i].add.wim_target_path =
642                                 canonicalize_wim_path(cmds[i].add.wim_target_path);
643                         if (!cmds_copy[i].add.fs_source_path ||
644                             !cmds_copy[i].add.wim_target_path)
645                                 goto oom;
646                         if (cmds[i].add.config) {
647                                 ret = copy_and_canonicalize_capture_config(cmds[i].add.config,
648                                                                            &cmds_copy[i].add.config);
649                                 if (ret)
650                                         goto err;
651                         }
652                         cmds_copy[i].add.add_flags = cmds[i].add.add_flags;
653                         break;
654                 case WIMLIB_UPDATE_OP_DELETE:
655                         cmds_copy[i].delete.wim_path =
656                                 canonicalize_wim_path(cmds[i].delete.wim_path);
657                         if (!cmds_copy[i].delete.wim_path)
658                                 goto oom;
659                         cmds_copy[i].delete.delete_flags = cmds[i].delete.delete_flags;
660                         break;
661                 case WIMLIB_UPDATE_OP_RENAME:
662                         cmds_copy[i].rename.wim_source_path =
663                                 canonicalize_wim_path(cmds[i].rename.wim_source_path);
664                         cmds_copy[i].rename.wim_target_path =
665                                 canonicalize_wim_path(cmds[i].rename.wim_target_path);
666                         if (!cmds_copy[i].rename.wim_source_path ||
667                             !cmds_copy[i].rename.wim_target_path)
668                                 goto oom;
669                         break;
670                 default:
671                         ERROR("Unknown update operation %u", cmds[i].op);
672                         ret = WIMLIB_ERR_INVALID_PARAM;
673                         goto err;
674                 }
675         }
676         *cmds_copy_ret = cmds_copy;
677         ret = 0;
678 out:
679         return ret;
680 oom:
681         ret = WIMLIB_ERR_NOMEM;
682 err:
683         free_update_commands(cmds_copy, num_cmds);
684         goto out;
685 }
686
687 /*
688  * Entry point for making a series of updates to a WIM image.
689  */
690 WIMLIBAPI int
691 wimlib_update_image(WIMStruct *wim,
692                     int image,
693                     const struct wimlib_update_command *cmds,
694                     size_t num_cmds,
695                     int update_flags,
696                     wimlib_progress_func_t progress_func)
697 {
698         int ret;
699         struct wimlib_update_command *cmds_copy;
700
701         DEBUG("Updating image %d with %zu commands", image, num_cmds);
702
703         /* Refuse to update a split WIM. */
704         if (wim->hdr.total_parts != 1) {
705                 ERROR("Cannot update a split WIM!");
706                 ret = WIMLIB_ERR_SPLIT_UNSUPPORTED;
707                 goto out;
708         }
709
710         /* Load the metadata for the image to modify (if not loaded already) */
711         ret = select_wim_image(wim, image);
712         if (ret)
713                 goto out;
714
715         /* Short circuit a successful return if no commands were specified.
716          * Avoids problems with trying to allocate 0 bytes of memory. */
717         if (num_cmds == 0)
718                 goto out;
719
720         DEBUG("Preparing %zu update commands", num_cmds);
721
722         /* Make a copy of the update commands, in the process doing certain
723          * canonicalizations on paths (e.g. translating backslashes to forward
724          * slashes).  This is done to avoid modifying the caller's copy of the
725          * commands. */
726         ret = copy_update_commands(cmds, num_cmds, &cmds_copy);
727         if (ret)
728                 goto out;
729
730         /* Perform additional checks on the update commands before we execute
731          * them. */
732         ret = check_update_commands(cmds_copy, num_cmds, &wim->hdr);
733         if (ret)
734                 goto out_free_cmds_copy;
735
736         /* Actually execute the update commands. */
737         DEBUG("Executing %zu update commands", num_cmds);
738         ret = execute_update_commands(wim, cmds_copy, num_cmds, progress_func);
739         if (ret)
740                 goto out_free_cmds_copy;
741
742         wim->image_metadata[image - 1]->modified = 1;
743
744         /* Statistics about the WIM image, such as the numbers of files and
745          * directories, may have changed.  Call xml_update_image_info() to
746          * recalculate these statistics. */
747         xml_update_image_info(wim, image);
748 out_free_cmds_copy:
749         free_update_commands(cmds_copy, num_cmds);
750 out:
751         return ret;
752 }