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

   1 /*
   2  * export_image.c
   3  */
   4
   5 /*
   6  * Copyright (C) 2012, 2013, 2014 Eric Biggers
   7  *
   8  * This file is free software; you can redistribute it and/or modify it under
   9  * the terms of the GNU Lesser General Public License as published by the Free
  10  * Software Foundation; either version 3 of the License, or (at your option) any
  11  * later version.
  12  *
  13  * This file is distributed in the hope that it will be useful, but WITHOUT
  14  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  15  * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
  16  * details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public License
  19  * along with this file; if not, see http://www.gnu.org/licenses/.
  20  */
  21
  22 #ifdef HAVE_CONFIG_H
  23 #  include "config.h"
  24 #endif
  25
  26 #include "wimlib.h"
  27 #include "wimlib/error.h"
  28 #include "wimlib/inode.h"
  29 #include "wimlib/lookup_table.h"
  30 #include "wimlib/metadata.h"
  31 #include "wimlib/xml.h"
  32
  33 static int
  34 lte_set_not_exported(struct wim_lookup_table_entry *lte, void *_ignore)
  35 {
  36         lte->out_refcnt = 0;
  37         lte->was_exported = 0;
  38         return 0;
  39 }
  40
  41 static int
  42 lte_rollback_export(struct wim_lookup_table_entry *lte, void *_lookup_table)
  43 {
  44         struct wim_lookup_table *lookup_table = _lookup_table;
  45
  46         lte->refcnt -= lte->out_refcnt;
  47         if (lte->was_exported) {
  48                 lookup_table_unlink(lookup_table, lte);
  49                 free_lookup_table_entry(lte);
  50         }
  51         return 0;
  52 }
  53
  54 static int
  55 inode_export_streams(struct wim_inode *inode,
  56                      struct wim_lookup_table *src_lookup_table,
  57                      struct wim_lookup_table *dest_lookup_table,
  58                      bool gift)
  59 {
  60         unsigned i;
  61         const u8 *hash;
  62         struct wim_lookup_table_entry *src_lte, *dest_lte;
  63
  64         inode_unresolve_streams(inode);
  65         for (i = 0; i <= inode->i_num_ads; i++) {
  66
  67                 /* Retrieve SHA1 message digest of stream to export.  */
  68                 hash = inode_stream_hash(inode, i);
  69                 if (is_zero_hash(hash))  /* Empty stream?  */
  70                         continue;
  71
  72                 /* Search for the stream (via SHA1 message digest) in the
  73                  * destination WIM.  */
  74                 dest_lte = lookup_stream(dest_lookup_table, hash);
  75                 if (!dest_lte) {
  76                         /* Stream not yet present in destination WIM.  Search
  77                          * for it in the source WIM, then export it into the
  78                          * destination WIM.  */
  79                         src_lte = lookup_stream(src_lookup_table, hash);
  80                         if (!src_lte)
  81                                 return stream_not_found_error(inode, hash);
  82
  83                         if (gift) {
  84                                 dest_lte = src_lte;
  85                                 lookup_table_unlink(src_lookup_table, src_lte);
  86                         } else {
  87                                 dest_lte = clone_lookup_table_entry(src_lte);
  88                                 if (!dest_lte)
  89                                         return WIMLIB_ERR_NOMEM;
  90                         }
  91                         dest_lte->refcnt = 0;
  92                         dest_lte->out_refcnt = 0;
  93                         dest_lte->was_exported = 1;
  94                         lookup_table_insert(dest_lookup_table, dest_lte);
  95                 }
  96
  97                 /* Stream is present in destination WIM (either pre-existing,
  98                  * already exported, or just exported above).  Increment its
  99                  * reference count appropriately.   Note: we use 'refcnt' for
 100                  * the raw reference count, but 'out_refcnt' for references
 101                  * arising just from the export operation; this is used to roll
 102                  * back a failed export if needed.  */
 103                 dest_lte->refcnt += inode->i_nlink;
 104                 dest_lte->out_refcnt += inode->i_nlink;
 105         }
 106         return 0;
 107 }
 108
 109 /* API function documented in wimlib.h  */
 110 WIMLIBAPI int
 111 wimlib_export_image(WIMStruct *src_wim,
 112                     int src_image,
 113                     WIMStruct *dest_wim,
 114                     const tchar *dest_name,
 115                     const tchar *dest_description,
 116                     int export_flags)
 117 {
 118         int ret;
 119         int start_src_image;
 120         int end_src_image;
 121         int orig_dest_image_count;
 122         int image;
 123         bool all_images = (src_image == WIMLIB_ALL_IMAGES);
 124
 125         /* Check for sane parameters.  */
 126         if (export_flags & ~(WIMLIB_EXPORT_FLAG_BOOT |
 127                              WIMLIB_EXPORT_FLAG_NO_NAMES |
 128                              WIMLIB_EXPORT_FLAG_NO_DESCRIPTIONS |
 129                              WIMLIB_EXPORT_FLAG_GIFT |
 130                              WIMLIB_EXPORT_FLAG_WIMBOOT))
 131                 return WIMLIB_ERR_INVALID_PARAM;
 132
 133         if (src_wim == NULL || dest_wim == NULL)
 134                 return WIMLIB_ERR_INVALID_PARAM;
 135
 136         if (!wim_has_metadata(src_wim) || !wim_has_metadata(dest_wim))
 137                 return WIMLIB_ERR_METADATA_NOT_FOUND;
 138
 139         if (all_images) {
 140                 /* Multi-image export.  */
 141                 if ((!(export_flags & WIMLIB_EXPORT_FLAG_NO_NAMES) &&
 142                         dest_name) ||
 143                     (!(export_flags & WIMLIB_EXPORT_FLAG_NO_DESCRIPTIONS) &&
 144                         dest_description))
 145                 {
 146                         ERROR("Image name or image description was "
 147                               "specified, but we are exporting "
 148                               "multiple images");
 149                         return WIMLIB_ERR_INVALID_PARAM;
 150                 }
 151                 start_src_image = 1;
 152                 end_src_image = src_wim->hdr.image_count;
 153         } else {
 154                 start_src_image = src_image;
 155                 end_src_image = src_image;
 156         }
 157         orig_dest_image_count = dest_wim->hdr.image_count;
 158
 159         /* Stream checksums must be known before proceeding.  */
 160         ret = wim_checksum_unhashed_streams(src_wim);
 161         if (ret)
 162                 return ret;
 163         ret = wim_checksum_unhashed_streams(dest_wim);
 164         if (ret)
 165                 return ret;
 166
 167         /* Enable rollbacks  */
 168         for_lookup_table_entry(dest_wim->lookup_table, lte_set_not_exported, NULL);
 169
 170         /* Export each requested image.  */
 171         for (src_image = start_src_image;
 172              src_image <= end_src_image;
 173              src_image++)
 174         {
 175                 const tchar *next_dest_name, *next_dest_description;
 176                 struct wim_image_metadata *src_imd;
 177                 struct wim_inode *inode;
 178
 179                 /* Determine destination image name and description.  */
 180
 181                 if (export_flags & WIMLIB_EXPORT_FLAG_NO_NAMES)
 182                         next_dest_name = T("");
 183                 else if (dest_name)
 184                         next_dest_name = dest_name;
 185                 else
 186                         next_dest_name = wimlib_get_image_name(src_wim, src_image);
 187
 188                 if (export_flags & WIMLIB_EXPORT_FLAG_NO_DESCRIPTIONS)
 189                         next_dest_description = T("");
 190                 else if (dest_description)
 191                         next_dest_description = dest_description;
 192                 else
 193                         next_dest_description = wimlib_get_image_description(src_wim, src_image);
 194
 195                 /* Check for name conflict.  */
 196                 if (wimlib_image_name_in_use(dest_wim, next_dest_name)) {
 197                         ERROR("There is already an image named \"%"TS"\" "
 198                               "in the destination WIM", next_dest_name);
 199                         ret = WIMLIB_ERR_IMAGE_NAME_COLLISION;
 200                         goto out_rollback;
 201                 }
 202
 203                 /* Load metadata for source image into memory.  */
 204                 ret = select_wim_image(src_wim, src_image);
 205                 if (ret)
 206                         goto out_rollback;
 207
 208                 src_imd = wim_get_current_image_metadata(src_wim);
 209
 210                 /* Iterate through inodes in the source image and export their
 211                  * streams into the destination WIM.  */
 212                 image_for_each_inode(inode, src_imd) {
 213                         ret = inode_export_streams(inode,
 214                                                    src_wim->lookup_table,
 215                                                    dest_wim->lookup_table,
 216                                                    export_flags & WIMLIB_EXPORT_FLAG_GIFT);
 217                         if (ret)
 218                                 goto out_rollback;
 219                 }
 220
 221                 /* Export XML information into the destination WIM.  */
 222                 ret = xml_export_image(src_wim->wim_info, src_image,
 223                                        &dest_wim->wim_info, next_dest_name,
 224                                        next_dest_description);
 225                 if (ret)
 226                         goto out_rollback;
 227
 228                 /* Reference the source image metadata from the destination WIM.
 229                  */
 230                 ret = append_image_metadata(dest_wim, src_imd);
 231                 if (ret)
 232                         goto out_rollback;
 233                 src_imd->refcnt++;
 234
 235                 /* Lock the metadata into memory.  XXX: need better solution for
 236                  * this.  */
 237                 src_imd->modified = 1;
 238
 239         }
 240
 241         /* Image export complete.  Finish by setting any needed special metadata
 242          * on the destination WIM.  */
 243
 244         if (src_wim->hdr.flags & WIM_HDR_FLAG_RP_FIX)
 245                 dest_wim->hdr.flags |= WIM_HDR_FLAG_RP_FIX;
 246
 247         for (src_image = start_src_image;
 248              src_image <= end_src_image;
 249              src_image++)
 250         {
 251                 int dst_image = orig_dest_image_count + 1 +
 252                                 (src_image - start_src_image);
 253
 254                 if (export_flags & WIMLIB_EXPORT_FLAG_WIMBOOT)
 255                         wim_info_set_wimboot(dest_wim->wim_info, dst_image, true);
 256
 257                 if ((export_flags & WIMLIB_EXPORT_FLAG_BOOT) &&
 258                     (!all_images || src_image == src_wim->hdr.boot_idx))
 259                         dest_wim->hdr.boot_idx = dst_image;
 260         }
 261
 262         if (export_flags & WIMLIB_EXPORT_FLAG_GIFT) {
 263                 free_lookup_table(src_wim->lookup_table);
 264                 src_wim->lookup_table = NULL;
 265         }
 266         return 0;
 267
 268 out_rollback:
 269         while ((image = wim_info_get_num_images(dest_wim->wim_info))
 270                > orig_dest_image_count)
 271         {
 272                 xml_delete_image(&dest_wim->wim_info, image);
 273         }
 274         while (dest_wim->hdr.image_count > orig_dest_image_count)
 275         {
 276                 put_image_metadata(dest_wim->image_metadata[
 277                                         --dest_wim->hdr.image_count], NULL);
 278         }
 279         for_lookup_table_entry(dest_wim->lookup_table, lte_rollback_export,
 280                                dest_wim->lookup_table);
 281         return ret;
 282 }