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 free software; you can redistribute it and/or modify it under
   9  * the terms of the GNU Lesser General Public License as published by the Free
  10  * Software Foundation; either version 3 of the License, or (at your option) any
  11  * later version.
  12  *
  13  * This file is distributed in the hope that it will be useful, but WITHOUT
  14  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  15  * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
  16  * details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public License
  19  * along with this file; if not, see http://www.gnu.org/licenses/.
  20  */
  21
  22 #ifdef HAVE_CONFIG_H
  23 #  include "config.h"
  24 #endif
  25
  26 #include "wimlib.h"
  27 #include "wimlib/dentry.h"
  28 #include "wimlib/error.h"
  29 #include "wimlib/inode.h"
  30 #include "wimlib/lookup_table.h"
  31 #include "wimlib/metadata.h"
  32 #include "wimlib/xml.h"
  33 #include <stdlib.h>
  34
  35 static int
  36 inode_export_streams(struct wim_inode *inode,
  37                      struct wim_lookup_table *src_lookup_table,
  38                      struct wim_lookup_table *dest_lookup_table,
  39                      bool gift)
  40 {
  41         unsigned i;
  42         const u8 *hash;
  43         struct wim_lookup_table_entry *src_lte, *dest_lte;
  44
  45         inode_unresolve_streams(inode);
  46         for (i = 0; i <= inode->i_num_ads; i++) {
  47
  48                 /* Retrieve SHA1 message digest of stream to export.  */
  49                 hash = inode_stream_hash(inode, i);
  50                 if (is_zero_hash(hash))  /* Empty stream?  */
  51                         continue;
  52
  53                 /* Search for the stream (via SHA1 message digest) in the
  54                  * destination WIM.  */
  55                 dest_lte = lookup_stream(dest_lookup_table, hash);
  56                 if (!dest_lte) {
  57                         /* Stream not yet present in destination WIM.  Search
  58                          * for it in the source WIM, then export it into the
  59                          * destination WIM.  */
  60                         src_lte = lookup_stream(src_lookup_table, hash);
  61                         if (!src_lte)
  62                                 return stream_not_found_error(inode, hash);
  63
  64                         if (gift) {
  65                                 dest_lte = src_lte;
  66                                 lookup_table_unlink(src_lookup_table, src_lte);
  67                         } else {
  68                                 dest_lte = clone_lookup_table_entry(src_lte);
  69                                 if (!dest_lte)
  70                                         return WIMLIB_ERR_NOMEM;
  71                         }
  72                         dest_lte->refcnt = 0;
  73                         dest_lte->out_refcnt = 0;
  74                         lookup_table_insert(dest_lookup_table, dest_lte);
  75                 }
  76
  77                 /* Stream is present in destination WIM (either pre-existing,
  78                  * already exported, or just exported above).  Increment its
  79                  * reference count appropriately.   Note: we use 'refcnt' for
  80                  * the raw reference count, but 'out_refcnt' for references
  81                  * arising just from the export operation; this is used to roll
  82                  * back a failed export if needed.  */
  83                 dest_lte->refcnt += inode->i_nlink;
  84                 dest_lte->out_refcnt += inode->i_nlink;
  85         }
  86         return 0;
  87 }
  88
  89 static int
  90 lte_unexport(struct wim_lookup_table_entry *lte, void *_lookup_table)
  91 {
  92         struct wim_lookup_table *lookup_table = _lookup_table;
  93
  94         if (lte->out_refcnt) {
  95                 lte->refcnt -= lte->out_refcnt;
  96                 if (lte->refcnt == 0) {
  97                         lookup_table_unlink(lookup_table, lte);
  98                         free_lookup_table_entry(lte);
  99                 }
 100         }
 101         return 0;
 102 }
 103
 104 /* API function documented in wimlib.h  */
 105 WIMLIBAPI int
 106 wimlib_export_image(WIMStruct *src_wim,
 107                     int src_image,
 108                     WIMStruct *dest_wim,
 109                     const tchar *dest_name,
 110                     const tchar *dest_description,
 111                     int export_flags)
 112 {
 113         int ret;
 114         int start_image;
 115         int end_image;
 116         int image;
 117         u32 orig_dest_boot_idx;
 118         u32 orig_dest_image_count;
 119
 120         /* Check for sane parameters.  */
 121         if (export_flags & ~(WIMLIB_EXPORT_FLAG_BOOT |
 122                              WIMLIB_EXPORT_FLAG_NO_NAMES |
 123                              WIMLIB_EXPORT_FLAG_NO_DESCRIPTIONS |
 124                              WIMLIB_EXPORT_FLAG_GIFT |
 125                              WIMLIB_EXPORT_FLAG_WIMBOOT))
 126                 return WIMLIB_ERR_INVALID_PARAM;
 127
 128         if (src_wim == NULL || dest_wim == NULL)
 129                 return WIMLIB_ERR_INVALID_PARAM;
 130
 131         if (!wim_has_metadata(dest_wim))
 132                 return WIMLIB_ERR_METADATA_NOT_FOUND;
 133
 134         /* Destination WIM must be writable.  */
 135         ret = can_modify_wim(dest_wim);
 136         if (ret)
 137                 return ret;
 138
 139         if (src_image == WIMLIB_ALL_IMAGES) {
 140                 /* Multi-image export.  */
 141                 if ((!(export_flags & WIMLIB_EXPORT_FLAG_NO_NAMES) &&
 142                         dest_name) ||
 143                     (!(export_flags & WIMLIB_EXPORT_FLAG_NO_DESCRIPTIONS) &&
 144                         dest_description))
 145                 {
 146                         ERROR("Image name or image description was "
 147                               "specified, but we are exporting "
 148                               "multiple images");
 149                         return WIMLIB_ERR_INVALID_PARAM;
 150                 }
 151                 start_image = 1;
 152                 end_image = src_wim->hdr.image_count;
 153         } else {
 154                 start_image = src_image;
 155                 end_image = src_image;
 156         }
 157
 158         /* Stream checksums must be known before proceeding.  */
 159         ret = wim_checksum_unhashed_streams(src_wim);
 160         if (ret)
 161                 return ret;
 162         ret = wim_checksum_unhashed_streams(dest_wim);
 163         if (ret)
 164                 return ret;
 165
 166         /* Zero 'out_refcnt' in all lookup table entries in the destination WIM;
 167          * this tracks the number of references found from the source WIM
 168          * image(s).  */
 169         for_lookup_table_entry(dest_wim->lookup_table, lte_zero_out_refcnt,
 170                                NULL);
 171
 172         /* Save the original count of images in the destination WIM and the boot
 173          * index (used if rollback necessary).  */
 174         orig_dest_image_count = dest_wim->hdr.image_count;
 175         orig_dest_boot_idx = dest_wim->hdr.boot_idx;
 176
 177         /* Export each requested image.  */
 178         for (image = start_image; image <= end_image; image++) {
 179                 const tchar *next_dest_name, *next_dest_description;
 180                 struct wim_image_metadata *src_imd;
 181                 struct wim_inode *inode;
 182
 183                 DEBUG("Exporting image %d from \"%"TS"\"",
 184                       image, src_wim->filename);
 185
 186                 /* Determine destination image name and description.  */
 187
 188                 if (export_flags & WIMLIB_EXPORT_FLAG_NO_NAMES) {
 189                         next_dest_name = T("");
 190                 } else if (dest_name) {
 191                         next_dest_name = dest_name;
 192                 } else {
 193                         next_dest_name = wimlib_get_image_name(src_wim,
 194                                                                image);
 195                 }
 196
 197                 DEBUG("Using name \"%"TS"\"", next_dest_name);
 198
 199                 if (export_flags & WIMLIB_EXPORT_FLAG_NO_DESCRIPTIONS) {
 200                         next_dest_description = T("");
 201                 } else if (dest_description) {
 202                         next_dest_description = dest_description;
 203                 } else {
 204                         next_dest_description = wimlib_get_image_description(
 205                                                         src_wim, image);
 206                 }
 207
 208                 DEBUG("Using description \"%"TS"\"", next_dest_description);
 209
 210                 /* Check for name conflict.  */
 211                 if (wimlib_image_name_in_use(dest_wim, next_dest_name)) {
 212                         ERROR("There is already an image named \"%"TS"\" "
 213                               "in the destination WIM", next_dest_name);
 214                         ret = WIMLIB_ERR_IMAGE_NAME_COLLISION;
 215                         goto out_rollback;
 216                 }
 217
 218                 /* Load metadata for source image into memory.  */
 219                 ret = select_wim_image(src_wim, image);
 220                 if (ret)
 221                         goto out_rollback;
 222
 223                 src_imd = wim_get_current_image_metadata(src_wim);
 224
 225                 /* Iterate through inodes in the source image and export their
 226                  * streams into the destination WIM.  */
 227                 image_for_each_inode(inode, src_imd) {
 228                         ret = inode_export_streams(inode,
 229                                                    src_wim->lookup_table,
 230                                                    dest_wim->lookup_table,
 231                                                    export_flags & WIMLIB_EXPORT_FLAG_GIFT);
 232                         if (ret)
 233                                 goto out_rollback;
 234                 }
 235
 236                 /* Export XML information into the destination WIM.  */
 237                 ret = xml_export_image(src_wim->wim_info, image,
 238                                        &dest_wim->wim_info, next_dest_name,
 239                                        next_dest_description);
 240                 if (ret)
 241                         goto out_rollback;
 242
 243                 /* Reference the source image metadata from the destination WIM.
 244                  */
 245                 ret = append_image_metadata(dest_wim, src_imd);
 246                 if (ret)
 247                         goto out_rollback;
 248                 src_imd->refcnt++;
 249
 250                 /* Lock the metadata into memory.  XXX: need better solution for
 251                  * this.  */
 252                 src_imd->modified = 1;
 253
 254                 /* Set boot index in destination WIM.  */
 255                 if ((export_flags & WIMLIB_EXPORT_FLAG_BOOT) &&
 256                     (src_image != WIMLIB_ALL_IMAGES ||
 257                      image == src_wim->hdr.boot_idx))
 258                 {
 259                         DEBUG("Marking destination image %u as bootable.",
 260                               dest_wim->hdr.image_count);
 261                         dest_wim->hdr.boot_idx = dest_wim->hdr.image_count;
 262                 }
 263
 264                 /* Possibly set WIMBoot flag  */
 265                 if (export_flags & WIMLIB_EXPORT_FLAG_WIMBOOT) {
 266                         wim_info_set_wimboot(dest_wim->wim_info,
 267                                              dest_wim->hdr.image_count,
 268                                              true);
 269                 }
 270
 271         }
 272         /* Set the reparse point fixup flag on the destination WIM if the flag
 273          * is set on the source WIM. */
 274         if (src_wim->hdr.flags & WIM_HDR_FLAG_RP_FIX)
 275                 dest_wim->hdr.flags |= WIM_HDR_FLAG_RP_FIX;
 276
 277         if (export_flags & WIMLIB_EXPORT_FLAG_GIFT) {
 278                 free_lookup_table(src_wim->lookup_table);
 279                 src_wim->lookup_table = NULL;
 280         }
 281         DEBUG("Export operation successful.");
 282         return 0;
 283
 284 out_rollback:
 285         while ((image = wim_info_get_num_images(dest_wim->wim_info))
 286                > orig_dest_image_count)
 287         {
 288                 xml_delete_image(&dest_wim->wim_info, image);
 289         }
 290         while (dest_wim->hdr.image_count > orig_dest_image_count)
 291         {
 292                 put_image_metadata(dest_wim->image_metadata[
 293                                         --dest_wim->hdr.image_count], NULL);
 294         }
 295         for_lookup_table_entry(dest_wim->lookup_table, lte_unexport,
 296                                dest_wim->lookup_table);
 297         dest_wim->hdr.boot_idx = orig_dest_boot_idx;
 298         return ret;
 299 }