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/inode.h"
  32 #include "wimlib/lookup_table.h"
  33 #include "wimlib/metadata.h"
  34 #include "wimlib/xml.h"
  35 #include <stdlib.h>
  36
  37 static int
  38 inode_export_streams(struct wim_inode *inode,
  39                      struct wim_lookup_table *src_lookup_table,
  40                      struct wim_lookup_table *dest_lookup_table,
  41                      bool gift)
  42 {
  43         unsigned i;
  44         const u8 *hash;
  45         struct wim_lookup_table_entry *src_lte, *dest_lte;
  46
  47         inode_unresolve_streams(inode);
  48         for (i = 0; i <= inode->i_num_ads; i++) {
  49
  50                 /* Retrieve SHA1 message digest of stream to export.  */
  51                 hash = inode_stream_hash(inode, i);
  52                 if (is_zero_hash(hash))  /* Empty stream?  */
  53                         continue;
  54
  55                 /* Search for the stream (via SHA1 message digest) in the
  56                  * destination WIM.  */
  57                 dest_lte = lookup_stream(dest_lookup_table, hash);
  58                 if (!dest_lte) {
  59                         /* Stream not yet present in destination WIM.  Search
  60                          * for it in the source WIM, then export it into the
  61                          * destination WIM.  */
  62                         src_lte = lookup_stream(src_lookup_table, hash);
  63                         if (!src_lte)
  64                                 return stream_not_found_error(inode, hash);
  65
  66                         if (gift) {
  67                                 dest_lte = src_lte;
  68                                 lookup_table_unlink(src_lookup_table, src_lte);
  69                         } else {
  70                                 dest_lte = clone_lookup_table_entry(src_lte);
  71                                 if (!dest_lte)
  72                                         return WIMLIB_ERR_NOMEM;
  73                         }
  74                         dest_lte->refcnt = 0;
  75                         dest_lte->out_refcnt = 0;
  76                         lookup_table_insert(dest_lookup_table, dest_lte);
  77                 }
  78
  79                 /* Stream is present in destination WIM (either pre-existing,
  80                  * already exported, or just exported above).  Increment its
  81                  * reference count appropriately.   Note: we use 'refcnt' for
  82                  * the raw reference count, but 'out_refcnt' for references
  83                  * arising just from the export operation; this is used to roll
  84                  * back a failed export if needed.  */
  85                 dest_lte->refcnt += inode->i_nlink;
  86                 dest_lte->out_refcnt += inode->i_nlink;
  87         }
  88         return 0;
  89 }
  90
  91 static int
  92 lte_unexport(struct wim_lookup_table_entry *lte, void *_lookup_table)
  93 {
  94         struct wim_lookup_table *lookup_table = _lookup_table;
  95
  96         if (lte->out_refcnt) {
  97                 lte->refcnt -= lte->out_refcnt;
  98                 if (lte->refcnt == 0) {
  99                         lookup_table_unlink(lookup_table, lte);
 100                         free_lookup_table_entry(lte);
 101                 }
 102         }
 103         return 0;
 104 }
 105
 106 /* API function documented in wimlib.h  */
 107 WIMLIBAPI int
 108 wimlib_export_image(WIMStruct *src_wim,
 109                     int src_image,
 110                     WIMStruct *dest_wim,
 111                     const tchar *dest_name,
 112                     const tchar *dest_description,
 113                     int export_flags,
 114                     wimlib_progress_func_t progress_func)
 115 {
 116         int ret;
 117         int start_image;
 118         int end_image;
 119         int image;
 120         u32 orig_dest_boot_idx;
 121         u32 orig_dest_image_count;
 122
 123         /* Check for sane parameters.  */
 124         if (export_flags & ~(WIMLIB_EXPORT_FLAG_BOOT |
 125                              WIMLIB_EXPORT_FLAG_NO_NAMES |
 126                              WIMLIB_EXPORT_FLAG_NO_DESCRIPTIONS |
 127                              WIMLIB_EXPORT_FLAG_GIFT |
 128                              WIMLIB_EXPORT_FLAG_WIMBOOT))
 129                 return WIMLIB_ERR_INVALID_PARAM;
 130
 131         if (src_wim == NULL || dest_wim == NULL)
 132                 return WIMLIB_ERR_INVALID_PARAM;
 133
 134         if (!wim_has_metadata(dest_wim))
 135                 return WIMLIB_ERR_METADATA_NOT_FOUND;
 136
 137         /* Destination WIM must be writable.  */
 138         ret = can_modify_wim(dest_wim);
 139         if (ret)
 140                 return ret;
 141
 142         if (src_image == WIMLIB_ALL_IMAGES) {
 143                 /* Multi-image export.  */
 144                 if ((!(export_flags & WIMLIB_EXPORT_FLAG_NO_NAMES) &&
 145                         dest_name) ||
 146                     (!(export_flags & WIMLIB_EXPORT_FLAG_NO_DESCRIPTIONS) &&
 147                         dest_description))
 148                 {
 149                         ERROR("Image name or image description was "
 150                               "specified, but we are exporting "
 151                               "multiple images");
 152                         return WIMLIB_ERR_INVALID_PARAM;
 153                 }
 154                 start_image = 1;
 155                 end_image = src_wim->hdr.image_count;
 156         } else {
 157                 start_image = src_image;
 158                 end_image = src_image;
 159         }
 160
 161         /* Stream checksums must be known before proceeding.  */
 162         ret = wim_checksum_unhashed_streams(src_wim);
 163         if (ret)
 164                 return ret;
 165         ret = wim_checksum_unhashed_streams(dest_wim);
 166         if (ret)
 167                 return ret;
 168
 169         /* Zero 'out_refcnt' in all lookup table entries in the destination WIM;
 170          * this tracks the number of references found from the source WIM
 171          * image(s).  */
 172         for_lookup_table_entry(dest_wim->lookup_table, lte_zero_out_refcnt,
 173                                NULL);
 174
 175         /* Save the original count of images in the destination WIM and the boot
 176          * index (used if rollback necessary).  */
 177         orig_dest_image_count = dest_wim->hdr.image_count;
 178         orig_dest_boot_idx = dest_wim->hdr.boot_idx;
 179
 180         /* Export each requested image.  */
 181         for (image = start_image; image <= end_image; image++) {
 182                 const tchar *next_dest_name, *next_dest_description;
 183                 struct wim_image_metadata *src_imd;
 184                 struct wim_inode *inode;
 185
 186                 DEBUG("Exporting image %d from \"%"TS"\"",
 187                       image, src_wim->filename);
 188
 189                 /* Determine destination image name and description.  */
 190
 191                 if (export_flags & WIMLIB_EXPORT_FLAG_NO_NAMES) {
 192                         next_dest_name = T("");
 193                 } else if (dest_name) {
 194                         next_dest_name = dest_name;
 195                 } else {
 196                         next_dest_name = wimlib_get_image_name(src_wim,
 197                                                                image);
 198                 }
 199
 200                 DEBUG("Using name \"%"TS"\"", next_dest_name);
 201
 202                 if (export_flags & WIMLIB_EXPORT_FLAG_NO_DESCRIPTIONS) {
 203                         next_dest_description = T("");
 204                 } else if (dest_description) {
 205                         next_dest_description = dest_description;
 206                 } else {
 207                         next_dest_description = wimlib_get_image_description(
 208                                                         src_wim, image);
 209                 }
 210
 211                 DEBUG("Using description \"%"TS"\"", next_dest_description);
 212
 213                 /* Check for name conflict.  */
 214                 if (wimlib_image_name_in_use(dest_wim, next_dest_name)) {
 215                         ERROR("There is already an image named \"%"TS"\" "
 216                               "in the destination WIM", next_dest_name);
 217                         ret = WIMLIB_ERR_IMAGE_NAME_COLLISION;
 218                         goto out_rollback;
 219                 }
 220
 221                 /* Load metadata for source image into memory.  */
 222                 ret = select_wim_image(src_wim, image);
 223                 if (ret)
 224                         goto out_rollback;
 225
 226                 src_imd = wim_get_current_image_metadata(src_wim);
 227
 228                 /* Iterate through inodes in the source image and export their
 229                  * streams into the destination WIM.  */
 230                 image_for_each_inode(inode, src_imd) {
 231                         ret = inode_export_streams(inode,
 232                                                    src_wim->lookup_table,
 233                                                    dest_wim->lookup_table,
 234                                                    export_flags & WIMLIB_EXPORT_FLAG_GIFT);
 235                         if (ret)
 236                                 goto out_rollback;
 237                 }
 238
 239                 /* Export XML information into the destination WIM.  */
 240                 ret = xml_export_image(src_wim->wim_info, image,
 241                                        &dest_wim->wim_info, next_dest_name,
 242                                        next_dest_description);
 243                 if (ret)
 244                         goto out_rollback;
 245
 246                 /* Reference the source image metadata from the destination WIM.
 247                  */
 248                 ret = append_image_metadata(dest_wim, src_imd);
 249                 if (ret)
 250                         goto out_rollback;
 251                 src_imd->refcnt++;
 252
 253                 /* Lock the metadata into memory.  XXX: need better solution for
 254                  * this.  */
 255                 src_imd->modified = 1;
 256
 257                 /* Set boot index in destination WIM.  */
 258                 if ((export_flags & WIMLIB_EXPORT_FLAG_BOOT) &&
 259                     (src_image != WIMLIB_ALL_IMAGES ||
 260                      image == src_wim->hdr.boot_idx))
 261                 {
 262                         DEBUG("Marking destination image %u as bootable.",
 263                               dest_wim->hdr.image_count);
 264                         dest_wim->hdr.boot_idx = dest_wim->hdr.image_count;
 265                 }
 266
 267                 /* Possibly set WIMBoot flag  */
 268                 if (export_flags & WIMLIB_EXPORT_FLAG_WIMBOOT) {
 269                         wim_info_set_wimboot(dest_wim->wim_info,
 270                                              dest_wim->hdr.image_count,
 271                                              true);
 272                 }
 273
 274         }
 275         /* Set the reparse point fixup flag on the destination WIM if the flag
 276          * is set on the source WIM. */
 277         if (src_wim->hdr.flags & WIM_HDR_FLAG_RP_FIX)
 278                 dest_wim->hdr.flags |= WIM_HDR_FLAG_RP_FIX;
 279
 280         if (export_flags & WIMLIB_EXPORT_FLAG_GIFT) {
 281                 free_lookup_table(src_wim->lookup_table);
 282                 src_wim->lookup_table = NULL;
 283         }
 284         DEBUG("Export operation successful.");
 285         return 0;
 286
 287 out_rollback:
 288         while ((image = wim_info_get_num_images(dest_wim->wim_info))
 289                > orig_dest_image_count)
 290         {
 291                 xml_delete_image(&dest_wim->wim_info, image);
 292         }
 293         while (dest_wim->hdr.image_count > orig_dest_image_count)
 294         {
 295                 put_image_metadata(dest_wim->image_metadata[
 296                                         --dest_wim->hdr.image_count], NULL);
 297         }
 298         for_lookup_table_entry(dest_wim->lookup_table, lte_unexport,
 299                                dest_wim->lookup_table);
 300         dest_wim->hdr.boot_idx = orig_dest_boot_idx;
 301         return ret;
 302 }