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         if (lte->out_refcnt) {
  91                 lte->refcnt -= lte->out_refcnt;
  92                 if (lte->refcnt == 0) {
  93                         lookup_table_unlink(lookup_table, lte);
  94                         free_lookup_table_entry(lte);
  95                 }
  96         }
  97         return 0;
  98 }
  99
 100 /* API function documented in wimlib.h  */
 101 WIMLIBAPI int
 102 wimlib_export_image(WIMStruct *src_wim,
 103                     int src_image,
 104                     WIMStruct *dest_wim,
 105                     const tchar *dest_name,
 106                     const tchar *dest_description,
 107                     int export_flags,
 108                     wimlib_progress_func_t progress_func)
 109 {
 110         int ret;
 111         int start_image;
 112         int end_image;
 113         int image;
 114         u32 orig_dest_boot_idx;
 115         u32 orig_dest_image_count;
 116
 117         /* Check for sane parameters.  */
 118         if (export_flags & ~(WIMLIB_EXPORT_FLAG_BOOT |
 119                              WIMLIB_EXPORT_FLAG_NO_NAMES |
 120                              WIMLIB_EXPORT_FLAG_NO_DESCRIPTIONS))
 121                 return WIMLIB_ERR_INVALID_PARAM;
 122
 123         if (src_wim == NULL || dest_wim == NULL)
 124                 return WIMLIB_ERR_INVALID_PARAM;
 125
 126         if (!wim_has_metadata(dest_wim))
 127                 return WIMLIB_ERR_METADATA_NOT_FOUND;
 128
 129         /* Destination WIM must be writable.  */
 130         ret = can_modify_wim(dest_wim);
 131         if (ret)
 132                 return ret;
 133
 134         if (src_image == WIMLIB_ALL_IMAGES) {
 135                 /* Multi-image export.  */
 136                 if ((!(export_flags & WIMLIB_EXPORT_FLAG_NO_NAMES) &&
 137                         dest_name) ||
 138                     (!(export_flags & WIMLIB_EXPORT_FLAG_NO_DESCRIPTIONS) &&
 139                         dest_description))
 140                 {
 141                         ERROR("Image name or image description was "
 142                               "specified, but we are exporting "
 143                               "multiple images");
 144                         return WIMLIB_ERR_INVALID_PARAM;
 145                 }
 146                 start_image = 1;
 147                 end_image = src_wim->hdr.image_count;
 148         } else {
 149                 start_image = src_image;
 150                 end_image = src_image;
 151         }
 152
 153         /* Stream checksums must be known before proceeding.  */
 154         ret = wim_checksum_unhashed_streams(src_wim);
 155         if (ret)
 156                 return ret;
 157         ret = wim_checksum_unhashed_streams(dest_wim);
 158         if (ret)
 159                 return ret;
 160
 161         /* Zero 'out_refcnt' in all lookup table entries in the destination WIM;
 162          * this tracks the number of references found from the source WIM
 163          * image(s).  */
 164         for_lookup_table_entry(dest_wim->lookup_table, lte_zero_out_refcnt,
 165                                NULL);
 166
 167         /* Save the original count of images in the destination WIM and the boot
 168          * index (used if rollback necessary).  */
 169         orig_dest_image_count = dest_wim->hdr.image_count;
 170         orig_dest_boot_idx = dest_wim->hdr.boot_idx;
 171
 172         /* Export each requested image.  */
 173         for (image = start_image; image <= end_image; image++) {
 174                 const tchar *next_dest_name, *next_dest_description;
 175                 struct wim_image_metadata *src_imd;
 176                 struct wim_inode *inode;
 177
 178                 DEBUG("Exporting image %d from \"%"TS"\"",
 179                       image, src_wim->filename);
 180
 181                 /* Determine destination image name and description.  */
 182
 183                 if (export_flags & WIMLIB_EXPORT_FLAG_NO_NAMES) {
 184                         next_dest_name = T("");
 185                 } else if (dest_name) {
 186                         next_dest_name = dest_name;
 187                 } else {
 188                         next_dest_name = wimlib_get_image_name(src_wim,
 189                                                                image);
 190                 }
 191
 192                 DEBUG("Using name \"%"TS"\"", next_dest_name);
 193
 194                 if (export_flags & WIMLIB_EXPORT_FLAG_NO_DESCRIPTIONS) {
 195                         next_dest_description = T("");
 196                 } else if (dest_description) {
 197                         next_dest_description = dest_description;
 198                 } else {
 199                         next_dest_description = wimlib_get_image_description(
 200                                                         src_wim, image);
 201                 }
 202
 203                 DEBUG("Using description \"%"TS"\"", next_dest_description);
 204
 205                 /* Check for name conflict.  */
 206                 if (wimlib_image_name_in_use(dest_wim, next_dest_name)) {
 207                         ERROR("There is already an image named \"%"TS"\" "
 208                               "in the destination WIM", next_dest_name);
 209                         ret = WIMLIB_ERR_IMAGE_NAME_COLLISION;
 210                         goto out_rollback;
 211                 }
 212
 213                 /* Load metadata for source image into memory.  */
 214                 ret = select_wim_image(src_wim, image);
 215                 if (ret)
 216                         goto out_rollback;
 217
 218                 src_imd = wim_get_current_image_metadata(src_wim);
 219
 220                 /* Iterate through inodes in the source image and export their
 221                  * streams into the destination WIM.  */
 222                 image_for_each_inode(inode, src_imd) {
 223                         ret = inode_export_streams(inode,
 224                                                    src_wim->lookup_table,
 225                                                    dest_wim->lookup_table);
 226                         if (ret)
 227                                 goto out_rollback;
 228                 }
 229
 230                 /* Export XML information into the destination WIM.  */
 231                 ret = xml_export_image(src_wim->wim_info, image,
 232                                        &dest_wim->wim_info, next_dest_name,
 233                                        next_dest_description);
 234                 if (ret)
 235                         goto out_rollback;
 236
 237                 /* Reference the source image metadata from the destination WIM.
 238                  */
 239                 ret = append_image_metadata(dest_wim, src_imd);
 240                 if (ret)
 241                         goto out_rollback;
 242                 src_imd->refcnt++;
 243
 244                 /* Lock the metadata into memory.  XXX: need better solution for
 245                  * this.  */
 246                 src_imd->modified = 1;
 247
 248                 /* Set boot index in destination WIM.  */
 249                 if ((export_flags & WIMLIB_EXPORT_FLAG_BOOT) &&
 250                     (src_image != WIMLIB_ALL_IMAGES ||
 251                      image == src_wim->hdr.boot_idx))
 252                 {
 253                         DEBUG("Marking destination image %u as bootable.",
 254                               dest_wim->hdr.image_count);
 255                         dest_wim->hdr.boot_idx = dest_wim->hdr.image_count;
 256                 }
 257
 258         }
 259         /* Set the reparse point fixup flag on the destination WIM if the flag
 260          * is set on the source WIM. */
 261         if (src_wim->hdr.flags & WIM_HDR_FLAG_RP_FIX)
 262                 dest_wim->hdr.flags |= WIM_HDR_FLAG_RP_FIX;
 263         DEBUG("Export operation successful.");
 264         return 0;
 265
 266 out_rollback:
 267         while ((image = wim_info_get_num_images(dest_wim->wim_info))
 268                > orig_dest_image_count)
 269         {
 270                 xml_delete_image(&dest_wim->wim_info, image);
 271         }
 272         while (dest_wim->hdr.image_count > orig_dest_image_count)
 273         {
 274                 put_image_metadata(dest_wim->image_metadata[
 275                                         --dest_wim->hdr.image_count], NULL);
 276         }
 277         for_lookup_table_entry(dest_wim->lookup_table, lte_unexport,
 278                                dest_wim->lookup_table);
 279         dest_wim->hdr.boot_idx = orig_dest_boot_idx;
 280         return ret;
 281 }