wimlib.net Git - wimlib/blob - src/export_image.c

   1 /*
   2  * export_image.c
   3  */
   4
   5 /*
   6  * Copyright (C) 2012, 2013, 2014 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/blob_table.h"
  28 #include "wimlib/error.h"
  29 #include "wimlib/inode.h"
  30 #include "wimlib/metadata.h"
  31 #include "wimlib/xml.h"
  32
  33 static int
  34 blob_set_not_exported(struct blob_descriptor *blob, void *_ignore)
  35 {
  36         blob->out_refcnt = 0;
  37         blob->was_exported = 0;
  38         return 0;
  39 }
  40
  41 static int
  42 blob_rollback_export(struct blob_descriptor *blob, void *_blob_table)
  43 {
  44         struct blob_table *blob_table = _blob_table;
  45
  46         blob->refcnt -= blob->out_refcnt;
  47         if (blob->was_exported) {
  48                 blob_table_unlink(blob_table, blob);
  49                 free_blob_descriptor(blob);
  50         }
  51         return 0;
  52 }
  53
  54 static int
  55 inode_export_blobs(struct wim_inode *inode, struct blob_table *src_blob_table,
  56                    struct blob_table *dest_blob_table, bool gift)
  57 {
  58         unsigned i;
  59         const u8 *hash;
  60         struct blob_descriptor *src_blob, *dest_blob;
  61
  62         inode_unresolve_streams(inode);
  63
  64         for (i = 0; i < inode->i_num_streams; i++) {
  65
  66                 /* Retrieve SHA-1 message digest of blob to export.  */
  67                 hash = stream_hash(&inode->i_streams[i]);
  68                 if (is_zero_hash(hash))  /* Empty blob?  */
  69                         continue;
  70
  71                 /* Search for the blob (via SHA-1 message digest) in the
  72                  * destination WIM.  */
  73                 dest_blob = lookup_blob(dest_blob_table, hash);
  74                 if (!dest_blob) {
  75                         /* Blob not yet present in destination WIM.  Search for
  76                          * it in the source WIM, then export it into the
  77                          * destination WIM.  */
  78                         src_blob = lookup_blob(src_blob_table, hash);
  79                         if (!src_blob)
  80                                 return blob_not_found_error(inode, hash);
  81
  82                         if (gift) {
  83                                 dest_blob = src_blob;
  84                                 blob_table_unlink(src_blob_table, src_blob);
  85                         } else {
  86                                 dest_blob = clone_blob_descriptor(src_blob);
  87                                 if (!dest_blob)
  88                                         return WIMLIB_ERR_NOMEM;
  89                         }
  90                         dest_blob->refcnt = 0;
  91                         dest_blob->out_refcnt = 0;
  92                         dest_blob->was_exported = 1;
  93                         blob_table_insert(dest_blob_table, dest_blob);
  94                 }
  95
  96                 /* Blob is present in destination WIM (either pre-existing,
  97                  * already exported, or just exported above).  Increment its
  98                  * reference count appropriately.   Note: we use 'refcnt' for
  99                  * the raw reference count, but 'out_refcnt' for references
 100                  * arising just from the export operation; this is used to roll
 101                  * back a failed export if needed.  */
 102                 dest_blob->refcnt += inode->i_nlink;
 103                 dest_blob->out_refcnt += inode->i_nlink;
 104         }
 105         return 0;
 106 }
 107
 108 /* API function documented in wimlib.h  */
 109 WIMLIBAPI int
 110 wimlib_export_image(WIMStruct *src_wim,
 111                     int src_image,
 112                     WIMStruct *dest_wim,
 113                     const tchar *dest_name,
 114                     const tchar *dest_description,
 115                     int export_flags)
 116 {
 117         int ret;
 118         int start_src_image;
 119         int end_src_image;
 120         int orig_dest_image_count;
 121         int image;
 122         bool all_images = (src_image == WIMLIB_ALL_IMAGES);
 123
 124         /* Check for sane parameters.  */
 125         if (export_flags & ~(WIMLIB_EXPORT_FLAG_BOOT |
 126                              WIMLIB_EXPORT_FLAG_NO_NAMES |
 127                              WIMLIB_EXPORT_FLAG_NO_DESCRIPTIONS |
 128                              WIMLIB_EXPORT_FLAG_GIFT |
 129                              WIMLIB_EXPORT_FLAG_WIMBOOT))
 130                 return WIMLIB_ERR_INVALID_PARAM;
 131
 132         if (src_wim == NULL || dest_wim == NULL)
 133                 return WIMLIB_ERR_INVALID_PARAM;
 134
 135         if (!wim_has_metadata(src_wim) || !wim_has_metadata(dest_wim))
 136                 return WIMLIB_ERR_METADATA_NOT_FOUND;
 137
 138         if (all_images) {
 139                 /* Multi-image export.  */
 140                 if ((!(export_flags & WIMLIB_EXPORT_FLAG_NO_NAMES) &&
 141                         dest_name) ||
 142                     (!(export_flags & WIMLIB_EXPORT_FLAG_NO_DESCRIPTIONS) &&
 143                         dest_description))
 144                 {
 145                         ERROR("Image name and description must be "
 146                               "left NULL for multi-image export");
 147                         return WIMLIB_ERR_INVALID_PARAM;
 148                 }
 149                 start_src_image = 1;
 150                 end_src_image = src_wim->hdr.image_count;
 151         } else {
 152                 start_src_image = src_image;
 153                 end_src_image = src_image;
 154         }
 155         orig_dest_image_count = dest_wim->hdr.image_count;
 156
 157         /* Blob checksums must be known before proceeding.  */
 158         ret = wim_checksum_unhashed_blobs(src_wim);
 159         if (ret)
 160                 return ret;
 161         ret = wim_checksum_unhashed_blobs(dest_wim);
 162         if (ret)
 163                 return ret;
 164
 165         /* Enable rollbacks  */
 166         for_blob_in_table(dest_wim->blob_table, blob_set_not_exported, NULL);
 167
 168         /* Export each requested image.  */
 169         for (src_image = start_src_image;
 170              src_image <= end_src_image;
 171              src_image++)
 172         {
 173                 const tchar *next_dest_name, *next_dest_description;
 174                 struct wim_image_metadata *src_imd;
 175                 struct wim_inode *inode;
 176
 177                 /* Determine destination image name and description.  */
 178
 179                 if (export_flags & WIMLIB_EXPORT_FLAG_NO_NAMES)
 180                         next_dest_name = T("");
 181                 else if (dest_name)
 182                         next_dest_name = dest_name;
 183                 else
 184                         next_dest_name = wimlib_get_image_name(src_wim, src_image);
 185
 186                 if (export_flags & WIMLIB_EXPORT_FLAG_NO_DESCRIPTIONS)
 187                         next_dest_description = T("");
 188                 else if (dest_description)
 189                         next_dest_description = dest_description;
 190                 else
 191                         next_dest_description = wimlib_get_image_description(src_wim, src_image);
 192
 193                 /* Check for name conflict.  */
 194                 if (wimlib_image_name_in_use(dest_wim, next_dest_name)) {
 195                         ERROR("There is already an image named \"%"TS"\" "
 196                               "in the destination WIM", next_dest_name);
 197                         ret = WIMLIB_ERR_IMAGE_NAME_COLLISION;
 198                         goto out_rollback;
 199                 }
 200
 201                 /* Load metadata for source image into memory.  */
 202                 ret = select_wim_image(src_wim, src_image);
 203                 if (ret)
 204                         goto out_rollback;
 205
 206                 src_imd = wim_get_current_image_metadata(src_wim);
 207
 208                 /* Iterate through inodes in the source image and export their
 209                  * blobs into the destination WIM.  */
 210                 image_for_each_inode(inode, src_imd) {
 211                         ret = inode_export_blobs(inode,
 212                                                  src_wim->blob_table,
 213                                                  dest_wim->blob_table,
 214                                                  export_flags & WIMLIB_EXPORT_FLAG_GIFT);
 215                         if (ret)
 216                                 goto out_rollback;
 217                 }
 218
 219                 /* Export XML information into the destination WIM.  */
 220                 ret = xml_export_image(src_wim->wim_info, src_image,
 221                                        &dest_wim->wim_info, next_dest_name,
 222                                        next_dest_description);
 223                 if (ret)
 224                         goto out_rollback;
 225
 226                 /* Reference the source image metadata from the destination WIM.
 227                  */
 228                 ret = append_image_metadata(dest_wim, src_imd);
 229                 if (ret)
 230                         goto out_rollback;
 231                 src_imd->refcnt++;
 232
 233                 /* Lock the metadata into memory.  XXX: need better solution for
 234                  * this.  */
 235                 src_imd->modified = 1;
 236
 237         }
 238
 239         /* Image export complete.  Finish by setting any needed special metadata
 240          * on the destination WIM.  */
 241
 242         if (src_wim->hdr.flags & WIM_HDR_FLAG_RP_FIX)
 243                 dest_wim->hdr.flags |= WIM_HDR_FLAG_RP_FIX;
 244
 245         for (src_image = start_src_image;
 246              src_image <= end_src_image;
 247              src_image++)
 248         {
 249                 int dst_image = orig_dest_image_count + 1 +
 250                                 (src_image - start_src_image);
 251
 252                 if (export_flags & WIMLIB_EXPORT_FLAG_WIMBOOT)
 253                         wim_info_set_wimboot(dest_wim->wim_info, dst_image, true);
 254
 255                 if ((export_flags & WIMLIB_EXPORT_FLAG_BOOT) &&
 256                     (!all_images || src_image == src_wim->hdr.boot_idx))
 257                         dest_wim->hdr.boot_idx = dst_image;
 258         }
 259
 260         if (export_flags & WIMLIB_EXPORT_FLAG_GIFT) {
 261                 free_blob_table(src_wim->blob_table);
 262                 src_wim->blob_table = NULL;
 263         }
 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_blob_in_table(dest_wim->blob_table, blob_rollback_export,
 278                           dest_wim->blob_table);
 279         return ret;
 280 }