wimlib.net Git - wimlib/blob - src/export_image.c

   1 /*
   2  * export_image.c
   3  */
   4
   5 /*
   6  * Copyright (C) 2012, 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.h"
  29 #include "wimlib/dentry.h"
  30 #include "wimlib/error.h"
  31 #include "wimlib/lookup_table.h"
  32 #include "wimlib/metadata.h"
  33 #include "wimlib/xml.h"
  34 #include <stdlib.h>
  35
  36 static int
  37 inode_export_streams(struct wim_inode *inode,
  38                      const struct wim_lookup_table *src_lookup_table,
  39                      struct wim_lookup_table *dest_lookup_table)
  40 {
  41         unsigned i;
  42         const u8 *hash;
  43         struct wim_lookup_table_entry *src_lte, *dest_lte;
  44
  45         inode_unresolve_ltes(inode);
  46         for (i = 0; i <= inode->i_num_ads; i++) {
  47
  48                 /* Retrieve SHA1 message digest of stream to export.  */
  49                 hash = inode_stream_hash(inode, i);
  50                 if (is_zero_hash(hash))  /* Empty stream?  */
  51                         continue;
  52
  53                 /* Search for the stream (via SHA1 message digest) in the
  54                  * destination WIM.  */
  55                 dest_lte = lookup_resource(dest_lookup_table, hash);
  56                 if (!dest_lte) {
  57                         /* Stream not yet present in destination WIM.  Search
  58                          * for it in the source WIM, then export it into the
  59                          * destination WIM.  */
  60                         src_lte = lookup_resource(src_lookup_table, hash);
  61                         if (!src_lte)
  62                                 return resource_not_found_error(inode, hash);
  63
  64                         dest_lte = clone_lookup_table_entry(src_lte);
  65                         if (!dest_lte)
  66                                 return WIMLIB_ERR_NOMEM;
  67                         dest_lte->refcnt = 0;
  68                         dest_lte->out_refcnt = 0;
  69                         lookup_table_insert(dest_lookup_table, dest_lte);
  70                 }
  71
  72                 /* Stream is present in destination WIM (either pre-existing,
  73                  * already exported, or just exported above).  Increment its
  74                  * reference count appropriately.   Note: we use 'refcnt' for
  75                  * the raw reference count, but 'out_refcnt' for references
  76                  * arising just from the export operation; this is used to roll
  77                  * back a failed export if needed.  */
  78                 dest_lte->refcnt += inode->i_nlink;
  79                 dest_lte->out_refcnt += inode->i_nlink;
  80         }
  81         return 0;
  82 }
  83
  84 static int
  85 lte_unexport(struct wim_lookup_table_entry *lte, void *_lookup_table)
  86 {
  87         struct wim_lookup_table *lookup_table = _lookup_table;
  88
  89         lte->refcnt -= lte->out_refcnt;
  90         if (lte->refcnt == 0) {
  91                 lookup_table_unlink(lookup_table, lte);
  92                 free_lookup_table_entry(lte);
  93         }
  94         return 0;
  95 }
  96
  97 /* API function documented in wimlib.h  */
  98 WIMLIBAPI int
  99 wimlib_export_image(WIMStruct *src_wim,
 100                     int src_image,
 101                     WIMStruct *dest_wim,
 102                     const tchar *dest_name,
 103                     const tchar *dest_description,
 104                     int export_flags,
 105                     wimlib_progress_func_t progress_func)
 106 {
 107         int ret;
 108         int start_image;
 109         int end_image;
 110         int image;
 111         u32 orig_dest_boot_idx;
 112         u32 orig_dest_image_count;
 113
 114         /* Check for sane parameters.  */
 115         if (src_wim == NULL || dest_wim == NULL)
 116                 return WIMLIB_ERR_INVALID_PARAM;
 117
 118         if (!wim_has_metadata(dest_wim))
 119                 return WIMLIB_ERR_METADATA_NOT_FOUND;
 120
 121         /* Destination WIM must be writable.  */
 122         ret = can_modify_wim(dest_wim);
 123         if (ret)
 124                 return ret;
 125
 126         if (src_image == WIMLIB_ALL_IMAGES) {
 127                 /* Multi-image export.  */
 128                 if ((!(export_flags & WIMLIB_EXPORT_FLAG_NO_NAMES) &&
 129                         dest_name) ||
 130                     (!(export_flags & WIMLIB_EXPORT_FLAG_NO_DESCRIPTIONS) &&
 131                         dest_description))
 132                 {
 133                         ERROR("Image name or image description was "
 134                               "specified, but we are exporting "
 135                               "multiple images");
 136                         return WIMLIB_ERR_INVALID_PARAM;
 137                 }
 138                 start_image = 1;
 139                 end_image = src_wim->hdr.image_count;
 140         } else {
 141                 start_image = src_image;
 142                 end_image = src_image;
 143         }
 144
 145         /* Stream checksums must be known before proceeding.  */
 146         ret = wim_checksum_unhashed_streams(src_wim);
 147         if (ret)
 148                 return ret;
 149         ret = wim_checksum_unhashed_streams(dest_wim);
 150         if (ret)
 151                 return ret;
 152
 153         /* Zero 'out_refcnt' in all lookup table entries in the destination WIM;
 154          * this tracks the number of references found from the source WIM
 155          * image(s).  */
 156         for_lookup_table_entry(dest_wim->lookup_table, lte_zero_out_refcnt,
 157                                NULL);
 158
 159         /* Save the original count of images in the destination WIM and the boot
 160          * index (used if rollback necessary).  */
 161         orig_dest_image_count = dest_wim->hdr.image_count;
 162         orig_dest_boot_idx = dest_wim->hdr.boot_idx;
 163
 164         /* Export each requested image.  */
 165         for (image = start_image; image <= end_image; image++) {
 166                 const tchar *next_dest_name, *next_dest_description;
 167                 struct wim_image_metadata *src_imd;
 168                 struct wim_inode *inode;
 169
 170                 DEBUG("Exporting image %d from \"%"TS"\"",
 171                       image, src_wim->filename);
 172
 173                 /* Determine destination image name and description.  */
 174
 175                 if (export_flags & WIMLIB_EXPORT_FLAG_NO_NAMES) {
 176                         next_dest_name = NULL;
 177                 } else if (dest_name) {
 178                         next_dest_name = dest_name;
 179                 } else {
 180                         next_dest_name = wimlib_get_image_name(src_wim,
 181                                                                image);
 182                 }
 183
 184                 DEBUG("Using name \"%"TS"\"", next_dest_name);
 185
 186                 if (export_flags & WIMLIB_EXPORT_FLAG_NO_DESCRIPTIONS) {
 187                         next_dest_description = NULL;
 188                 } if (dest_description) {
 189                         next_dest_description = dest_description;
 190                 } else {
 191                         next_dest_description = wimlib_get_image_description(
 192                                                         src_wim, image);
 193                 }
 194
 195                 DEBUG("Using description \"%"TS"\"", next_dest_description);
 196
 197                 /* Check for name conflict.  */
 198                 if (wimlib_image_name_in_use(dest_wim, next_dest_name)) {
 199                         ERROR("There is already an image named \"%"TS"\" "
 200                               "in the destination WIM", next_dest_name);
 201                         ret = WIMLIB_ERR_IMAGE_NAME_COLLISION;
 202                         goto out_rollback;
 203                 }
 204
 205                 /* Load metadata for source image into memory.  */
 206                 ret = select_wim_image(src_wim, image);
 207                 if (ret)
 208                         goto out_rollback;
 209
 210                 src_imd = wim_get_current_image_metadata(src_wim);
 211
 212                 /* Iterate through inodes in the source image and export their
 213                  * streams into the destination WIM.  */
 214                 image_for_each_inode(inode, src_imd) {
 215                         ret = inode_export_streams(inode,
 216                                                    src_wim->lookup_table,
 217                                                    dest_wim->lookup_table);
 218                         if (ret)
 219                                 goto out_rollback;
 220                 }
 221
 222                 /* Export XML information into the destination WIM.  */
 223                 ret = xml_export_image(src_wim->wim_info, image,
 224                                        &dest_wim->wim_info, next_dest_name,
 225                                        next_dest_description);
 226                 if (ret)
 227                         goto out_rollback;
 228
 229                 /* Reference the source image metadata from the destination WIM.
 230                  */
 231                 ret = append_image_metadata(dest_wim, src_imd);
 232                 if (ret)
 233                         goto out_rollback;
 234                 src_imd->refcnt++;
 235
 236                 /* Lock the metadata into memory.  XXX: need better solution for
 237                  * this.  */
 238                 src_imd->modified = 1;
 239
 240                 /* Set boot index in destination WIM.  */
 241                 if ((export_flags & WIMLIB_EXPORT_FLAG_BOOT) &&
 242                     (src_image != WIMLIB_ALL_IMAGES ||
 243                      image == src_wim->hdr.boot_idx))
 244                 {
 245                         DEBUG("Marking destination image %u as bootable.",
 246                               dest_wim->hdr.image_count);
 247                         dest_wim->hdr.boot_idx = dest_wim->hdr.image_count;
 248                 }
 249
 250         }
 251         /* Set the reparse point fixup flag on the destination WIM if the flag
 252          * is set on the source WIM. */
 253         if (src_wim->hdr.flags & WIM_HDR_FLAG_RP_FIX)
 254                 dest_wim->hdr.flags |= WIM_HDR_FLAG_RP_FIX;
 255         DEBUG("Export operation successful.");
 256         return 0;
 257
 258 out_rollback:
 259         while ((image = wim_info_get_num_images(dest_wim->wim_info))
 260                > orig_dest_image_count)
 261         {
 262                 xml_delete_image(&dest_wim->wim_info, image);
 263         }
 264         while (dest_wim->hdr.image_count > orig_dest_image_count)
 265         {
 266                 put_image_metadata(dest_wim->image_metadata[
 267                                         --dest_wim->hdr.image_count], NULL);
 268         }
 269         for_lookup_table_entry(dest_wim->lookup_table, lte_unexport,
 270                                dest_wim->lookup_table);
 271         dest_wim->hdr.boot_idx = orig_dest_boot_idx;
 272         return ret;
 273 }