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