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 {
 115         int ret;
 116         int start_image;
 117         int end_image;
 118         int image;
 119         u32 orig_dest_boot_idx;
 120         u32 orig_dest_image_count;
 121
 122         /* Check for sane parameters.  */
 123         if (export_flags & ~(WIMLIB_EXPORT_FLAG_BOOT |
 124                              WIMLIB_EXPORT_FLAG_NO_NAMES |
 125                              WIMLIB_EXPORT_FLAG_NO_DESCRIPTIONS |
 126                              WIMLIB_EXPORT_FLAG_GIFT |
 127                              WIMLIB_EXPORT_FLAG_WIMBOOT))
 128                 return WIMLIB_ERR_INVALID_PARAM;
 129
 130         if (src_wim == NULL || dest_wim == NULL)
 131                 return WIMLIB_ERR_INVALID_PARAM;
 132
 133         if (!wim_has_metadata(dest_wim))
 134                 return WIMLIB_ERR_METADATA_NOT_FOUND;
 135
 136         /* Destination WIM must be writable.  */
 137         ret = can_modify_wim(dest_wim);
 138         if (ret)
 139                 return ret;
 140
 141         if (src_image == WIMLIB_ALL_IMAGES) {
 142                 /* Multi-image export.  */
 143                 if ((!(export_flags & WIMLIB_EXPORT_FLAG_NO_NAMES) &&
 144                         dest_name) ||
 145                     (!(export_flags & WIMLIB_EXPORT_FLAG_NO_DESCRIPTIONS) &&
 146                         dest_description))
 147                 {
 148                         ERROR("Image name or image description was "
 149                               "specified, but we are exporting "
 150                               "multiple images");
 151                         return WIMLIB_ERR_INVALID_PARAM;
 152                 }
 153                 start_image = 1;
 154                 end_image = src_wim->hdr.image_count;
 155         } else {
 156                 start_image = src_image;
 157                 end_image = src_image;
 158         }
 159
 160         /* Stream checksums must be known before proceeding.  */
 161         ret = wim_checksum_unhashed_streams(src_wim);
 162         if (ret)
 163                 return ret;
 164         ret = wim_checksum_unhashed_streams(dest_wim);
 165         if (ret)
 166                 return ret;
 167
 168         /* Zero 'out_refcnt' in all lookup table entries in the destination WIM;
 169          * this tracks the number of references found from the source WIM
 170          * image(s).  */
 171         for_lookup_table_entry(dest_wim->lookup_table, lte_zero_out_refcnt,
 172                                NULL);
 173
 174         /* Save the original count of images in the destination WIM and the boot
 175          * index (used if rollback necessary).  */
 176         orig_dest_image_count = dest_wim->hdr.image_count;
 177         orig_dest_boot_idx = dest_wim->hdr.boot_idx;
 178
 179         /* Export each requested image.  */
 180         for (image = start_image; image <= end_image; image++) {
 181                 const tchar *next_dest_name, *next_dest_description;
 182                 struct wim_image_metadata *src_imd;
 183                 struct wim_inode *inode;
 184
 185                 DEBUG("Exporting image %d from \"%"TS"\"",
 186                       image, src_wim->filename);
 187
 188                 /* Determine destination image name and description.  */
 189
 190                 if (export_flags & WIMLIB_EXPORT_FLAG_NO_NAMES) {
 191                         next_dest_name = T("");
 192                 } else if (dest_name) {
 193                         next_dest_name = dest_name;
 194                 } else {
 195                         next_dest_name = wimlib_get_image_name(src_wim,
 196                                                                image);
 197                 }
 198
 199                 DEBUG("Using name \"%"TS"\"", next_dest_name);
 200
 201                 if (export_flags & WIMLIB_EXPORT_FLAG_NO_DESCRIPTIONS) {
 202                         next_dest_description = T("");
 203                 } else if (dest_description) {
 204                         next_dest_description = dest_description;
 205                 } else {
 206                         next_dest_description = wimlib_get_image_description(
 207                                                         src_wim, image);
 208                 }
 209
 210                 DEBUG("Using description \"%"TS"\"", next_dest_description);
 211
 212                 /* Check for name conflict.  */
 213                 if (wimlib_image_name_in_use(dest_wim, next_dest_name)) {
 214                         ERROR("There is already an image named \"%"TS"\" "
 215                               "in the destination WIM", next_dest_name);
 216                         ret = WIMLIB_ERR_IMAGE_NAME_COLLISION;
 217                         goto out_rollback;
 218                 }
 219
 220                 /* Load metadata for source image into memory.  */
 221                 ret = select_wim_image(src_wim, image);
 222                 if (ret)
 223                         goto out_rollback;
 224
 225                 src_imd = wim_get_current_image_metadata(src_wim);
 226
 227                 /* Iterate through inodes in the source image and export their
 228                  * streams into the destination WIM.  */
 229                 image_for_each_inode(inode, src_imd) {
 230                         ret = inode_export_streams(inode,
 231                                                    src_wim->lookup_table,
 232                                                    dest_wim->lookup_table,
 233                                                    export_flags & WIMLIB_EXPORT_FLAG_GIFT);
 234                         if (ret)
 235                                 goto out_rollback;
 236                 }
 237
 238                 /* Export XML information into the destination WIM.  */
 239                 ret = xml_export_image(src_wim->wim_info, image,
 240                                        &dest_wim->wim_info, next_dest_name,
 241                                        next_dest_description);
 242                 if (ret)
 243                         goto out_rollback;
 244
 245                 /* Reference the source image metadata from the destination WIM.
 246                  */
 247                 ret = append_image_metadata(dest_wim, src_imd);
 248                 if (ret)
 249                         goto out_rollback;
 250                 src_imd->refcnt++;
 251
 252                 /* Lock the metadata into memory.  XXX: need better solution for
 253                  * this.  */
 254                 src_imd->modified = 1;
 255
 256                 /* Set boot index in destination WIM.  */
 257                 if ((export_flags & WIMLIB_EXPORT_FLAG_BOOT) &&
 258                     (src_image != WIMLIB_ALL_IMAGES ||
 259                      image == src_wim->hdr.boot_idx))
 260                 {
 261                         DEBUG("Marking destination image %u as bootable.",
 262                               dest_wim->hdr.image_count);
 263                         dest_wim->hdr.boot_idx = dest_wim->hdr.image_count;
 264                 }
 265
 266                 /* Possibly set WIMBoot flag  */
 267                 if (export_flags & WIMLIB_EXPORT_FLAG_WIMBOOT) {
 268                         wim_info_set_wimboot(dest_wim->wim_info,
 269                                              dest_wim->hdr.image_count,
 270                                              true);
 271                 }
 272
 273         }
 274         /* Set the reparse point fixup flag on the destination WIM if the flag
 275          * is set on the source WIM. */
 276         if (src_wim->hdr.flags & WIM_HDR_FLAG_RP_FIX)
 277                 dest_wim->hdr.flags |= WIM_HDR_FLAG_RP_FIX;
 278
 279         if (export_flags & WIMLIB_EXPORT_FLAG_GIFT) {
 280                 free_lookup_table(src_wim->lookup_table);
 281                 src_wim->lookup_table = NULL;
 282         }
 283         DEBUG("Export operation successful.");
 284         return 0;
 285
 286 out_rollback:
 287         while ((image = wim_info_get_num_images(dest_wim->wim_info))
 288                > orig_dest_image_count)
 289         {
 290                 xml_delete_image(&dest_wim->wim_info, image);
 291         }
 292         while (dest_wim->hdr.image_count > orig_dest_image_count)
 293         {
 294                 put_image_metadata(dest_wim->image_metadata[
 295                                         --dest_wim->hdr.image_count], NULL);
 296         }
 297         for_lookup_table_entry(dest_wim->lookup_table, lte_unexport,
 298                                dest_wim->lookup_table);
 299         dest_wim->hdr.boot_idx = orig_dest_boot_idx;
 300         return ret;
 301 }