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