}
}
-/* Decrements the reference count for the lookup table entry @lte. If its
- * reference count reaches 0, it is unlinked from the lookup table. If,
- * furthermore, the entry has no opened file descriptors associated with it, the
- * entry is freed. */
+/* Should this stream be retained even if it has no references? */
+static bool
+should_retain_lte(const struct wim_lookup_table_entry *lte)
+{
+ return lte->resource_location == RESOURCE_IN_WIM;
+}
+
+static void
+finalize_lte(struct wim_lookup_table_entry *lte)
+{
+ if (!should_retain_lte(lte))
+ free_lookup_table_entry(lte);
+}
+
+/*
+ * Decrements the reference count for the lookup table entry @lte, which must be
+ * inserted in the stream lookup table @table.
+ *
+ * If the reference count reaches 0, this may cause @lte to be destroyed.
+ * However, we may retain entries with 0 reference count. This does not affect
+ * correctness, but it prevents the entries for valid streams in a WIM archive,
+ * which will continue to be present after appending to the file, from being
+ * lost merely because we dropped all references to them.
+ */
void
lte_decrement_refcnt(struct wim_lookup_table_entry *lte,
struct wim_lookup_table *table)
unlink(lte->staging_file_name);
#endif
} else {
- lookup_table_unlink(table, lte);
+ if (!should_retain_lte(lte))
+ lookup_table_unlink(table, lte);
}
/* If FUSE mounts are enabled, we don't actually free the entry
#ifdef WITH_FUSE
if (lte->num_opened_fds == 0)
#endif
- free_lookup_table_entry(lte);
+ finalize_lte(lte);
}
}
wimlib_assert(lte->num_opened_fds != 0);
if (--lte->num_opened_fds == 0 && lte->refcnt == 0)
- free_lookup_table_entry(lte);
+ finalize_lte(lte);
}
#endif
#define WIM_LOOKUP_TABLE_ENTRY_DISK_SIZE 50
+static int
+cmp_streams_by_offset_in_res(const void *p1, const void *p2)
+{
+ const struct wim_lookup_table_entry *lte1, *lte2;
+
+ lte1 = *(const struct wim_lookup_table_entry**)p1;
+ lte2 = *(const struct wim_lookup_table_entry**)p2;
+
+ return cmp_u64(lte1->offset_in_res, lte2->offset_in_res);
+}
+
/* Validate the size and location of a WIM resource. */
static int
-validate_resource(const struct wim_resource_spec *rspec)
+validate_resource(struct wim_resource_spec *rspec)
{
struct wim_lookup_table_entry *lte;
- u64 cur_offset;
+ bool out_of_order;
+ u64 expected_next_offset;
+ int ret;
- /* Verify that calculating the offset of the end of the resource doesn't
- * overflow. */
+ /* Verify that the resource itself has a valid offset and size. */
if (rspec->offset_in_wim + rspec->size_in_wim < rspec->size_in_wim)
- goto invalid;
+ goto invalid_due_to_overflow;
- /* Verify that each stream in the resource has a valid offset and size,
- * and that no streams overlap, and that the streams were added in order
- * of increasing offset. */
- cur_offset = 0;
+ /* Verify that each stream in the resource has a valid offset and size.
+ */
+ expected_next_offset = 0;
+ out_of_order = false;
list_for_each_entry(lte, &rspec->stream_list, rspec_node) {
if (lte->offset_in_res + lte->size < lte->size ||
- lte->offset_in_res + lte->size > rspec->uncompressed_size ||
- lte->offset_in_res < cur_offset)
- goto invalid;
+ lte->offset_in_res + lte->size > rspec->uncompressed_size)
+ goto invalid_due_to_overflow;
+
+ if (lte->offset_in_res >= expected_next_offset)
+ expected_next_offset = lte->offset_in_res + lte->size;
+ else
+ out_of_order = true;
+ }
- cur_offset = lte->offset_in_res + lte->size;
+ /* If the streams were not located at strictly increasing positions (not
+ * allowing for overlap), sort them. Then make sure that none overlap.
+ */
+ if (out_of_order) {
+ ret = sort_stream_list(&rspec->stream_list,
+ offsetof(struct wim_lookup_table_entry,
+ rspec_node),
+ cmp_streams_by_offset_in_res);
+ if (ret)
+ return ret;
+
+ expected_next_offset = 0;
+ list_for_each_entry(lte, &rspec->stream_list, rspec_node) {
+ if (lte->offset_in_res >= expected_next_offset)
+ expected_next_offset = lte->offset_in_res + lte->size;
+ else
+ goto invalid_due_to_overlap;
+ }
}
+
return 0;
-invalid:
+invalid_due_to_overflow:
+ ERROR("Invalid resource entry (offset overflow)");
+ return WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
- ERROR("Invalid resource entry!");
+invalid_due_to_overlap:
+ ERROR("Invalid resource entry (streams in packed resource overlap)");
return WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
}
+/* Validate the resource, or free it if unused. */
+static int
+finish_resource(struct wim_resource_spec *rspec)
+{
+ if (!list_empty(&rspec->stream_list)) {
+ /* This resource contains at least one stream. */
+ return validate_resource(rspec);
+ } else {
+ /* No streams are in this resource. Get rid of it. */
+ FREE(rspec);
+ return 0;
+ }
+}
+
/*
- * Reads the lookup table from a WIM file. Each entry specifies a stream that
- * the WIM file contains, along with its location and SHA1 message digest.
+ * Reads the lookup table from a WIM file. Usually, each entry specifies a
+ * stream that the WIM file contains, along with its location and SHA1 message
+ * digest.
+ *
+ * Saves lookup table entries for non-metadata streams in a hash table (set to
+ * wim->lookup_table), and saves the metadata entry for each image in a special
+ * per-image location (the wim->image_metadata array).
*
- * Saves lookup table entries for non-metadata streams in a hash table, and
- * saves the metadata entry for each image in a special per-image location (the
- * image_metadata array).
+ * This works for both version WIM_VERSION_DEFAULT (68864) and version
+ * WIM_VERSION_PACKED_STREAMS (3584) WIMs.
*
- * Return values:
+ * Possible return values:
* WIMLIB_ERR_SUCCESS (0)
* WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY
- * WIMLIB_ERR_RESOURCE_NOT_FOUND
+ * WIMLIB_ERR_NOMEM
*
- * Or an error code caused by failure to read the lookup table into memory.
+ * Or an error code caused by failure to read the lookup table from the WIM
+ * file.
*/
int
read_wim_lookup_table(WIMStruct *wim)
{
int ret;
- size_t i;
size_t num_entries;
- struct wim_lookup_table *table;
- struct wim_lookup_table_entry *cur_entry, *duplicate_entry;
- struct wim_resource_spec *cur_rspec;
- void *buf;
- bool back_to_back_pack;
+ void *buf = NULL;
+ struct wim_lookup_table *table = NULL;
+ struct wim_lookup_table_entry *cur_entry = NULL;
+ struct wim_resource_spec *cur_rspec = NULL;
+ size_t num_duplicate_entries = 0;
+ size_t num_wrong_part_entries = 0;
+ u32 image_index = 0;
DEBUG("Reading lookup table.");
BUILD_BUG_ON(sizeof(struct wim_lookup_table_entry_disk) !=
WIM_LOOKUP_TABLE_ENTRY_DISK_SIZE);
- /* Calculate number of entries in the lookup table. */
+ /* Calculate the number of entries in the lookup table. */
num_entries = wim->hdr.lookup_table_reshdr.uncompressed_size /
sizeof(struct wim_lookup_table_entry_disk);
/* Allocate a hash table to map SHA1 message digests into stream
* specifications. This is the in-memory "lookup table". */
table = new_lookup_table(num_entries * 2 + 1);
- if (table == NULL) {
- ERROR("Not enough memory to read lookup table.");
- ret = WIMLIB_ERR_NOMEM;
- goto out_free_buf;
- }
+ if (!table)
+ goto oom;
- /* Allocate and initalize stream entries from the raw lookup table
- * buffer. */
- wim->current_image = 0;
- cur_rspec = NULL;
- for (i = 0; i < num_entries; i++) {
+ /* Allocate and initalize stream entries ('struct
+ * wim_lookup_table_entry's) from the raw lookup table buffer. Each of
+ * these entries will point to a 'struct wim_resource_spec' that
+ * describes the underlying resource. In WIMs with version number
+ * WIM_VERSION_PACKED_STREAMS, a resource may contain multiple streams.
+ */
+ for (size_t i = 0; i < num_entries; i++) {
const struct wim_lookup_table_entry_disk *disk_entry =
&((const struct wim_lookup_table_entry_disk*)buf)[i];
- u16 part_number;
struct wim_reshdr reshdr;
+ u16 part_number;
+ /* Get the resource header */
get_wim_reshdr(&disk_entry->reshdr, &reshdr);
DEBUG("reshdr: size_in_wim=%"PRIu64", "
"uncompressed_size=%"PRIu64", "
"offset_in_wim=%"PRIu64", "
- "flags=0x%02x",
+ "flags=0x%02x\n",
reshdr.size_in_wim, reshdr.uncompressed_size,
reshdr.offset_in_wim, reshdr.flags);
+ /* Ignore PACKED_STREAMS flag if it isn't supposed to be used in
+ * this WIM version */
if (wim->hdr.wim_version == WIM_VERSION_DEFAULT)
reshdr.flags &= ~WIM_RESHDR_FLAG_PACKED_STREAMS;
+ /* Allocate a 'struct wim_lookup_table_entry' */
cur_entry = new_lookup_table_entry();
- if (cur_entry == NULL) {
- ERROR("Not enough memory to read lookup table!");
- ret = WIMLIB_ERR_NOMEM;
- goto err;
- }
+ if (!cur_entry)
+ goto oom;
+ /* Get the part number, reference count, and hash. */
part_number = le16_to_cpu(disk_entry->part_number);
cur_entry->refcnt = le32_to_cpu(disk_entry->refcnt);
copy_hash(cur_entry->hash, disk_entry->hash);
+ /* Verify that the part number matches that of the underlying
+ * WIM file. */
if (part_number != wim->hdr.part_number) {
- WARNING("A lookup table entry in part %hu of the WIM "
- "points to part %hu (ignoring it)",
- wim->hdr.part_number, part_number);
- free_lookup_table_entry(cur_entry);
- continue;
+ num_wrong_part_entries++;
+ goto free_cur_entry_and_continue;
}
+ /* If resource is uncompressed, check for (unexpected) size
+ * mismatch. */
if (!(reshdr.flags & (WIM_RESHDR_FLAG_PACKED_STREAMS |
WIM_RESHDR_FLAG_COMPRESSED))) {
if (reshdr.uncompressed_size != reshdr.size_in_wim) {
- ERROR("Invalid resource entry!");
- ret = WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
- goto err;
+ /* So ... This is an uncompressed resource, but
+ * its uncompressed size is NOT the same as its
+ * "compressed" size (size_in_wim). What to do
+ * with it?
+ *
+ * Based on a simple test, WIMGAPI seems to
+ * handle this as follows:
+ *
+ * if (size_in_wim > uncompressed_size) {
+ * Ignore uncompressed_size; use
+ * size_in_wim instead.
+ * } else {
+ * Honor uncompressed_size, but treat the
+ * part of the file data above size_in_wim
+ * as all zeros.
+ * }
+ *
+ * So we will do the same.
+ */
+ if (reshdr.size_in_wim > reshdr.uncompressed_size)
+ reshdr.uncompressed_size = reshdr.size_in_wim;
}
}
- back_to_back_pack = false;
- if (!(reshdr.flags & WIM_RESHDR_FLAG_PACKED_STREAMS) ||
- cur_rspec == NULL ||
- (back_to_back_pack =
- ((reshdr.flags & WIM_RESHDR_FLAG_PACKED_STREAMS) &&
- reshdr.uncompressed_size == WIM_PACK_MAGIC_NUMBER &&
- cur_rspec != NULL &&
- cur_rspec->size_in_wim != 0)))
+ /*
+ * Possibly start a new resource.
+ *
+ * We need to start a new resource if:
+ *
+ * - There is no previous resource (cur_rspec).
+ *
+ * OR
+ *
+ * - The resource header did not have PACKED_STREAMS set, so it
+ * specifies a new, single-stream resource.
+ *
+ * OR
+ *
+ * - The resource header had PACKED_STREAMS set, and it's a
+ * special entry that specifies the resource itself as opposed
+ * to a stream, and we already encountered one such entry in
+ * the current resource. We will interpret this as the
+ * beginning of a new packed resource. (However, note that
+ * wimlib does not currently allow create WIMs with multiple
+ * packed resources, as to remain compatible with WIMGAPI.)
+ */
+ if (likely(!(reshdr.flags & WIM_RESHDR_FLAG_PACKED_STREAMS))
+ || !cur_rspec
+ || (reshdr.uncompressed_size == WIM_PACK_MAGIC_NUMBER &&
+ cur_rspec->size_in_wim != 0))
{
- /* Starting new run of streams that share the same WIM
- * resource. */
- struct wim_lookup_table_entry *prev_entry = NULL;
-
- if (back_to_back_pack &&
- !list_empty(&cur_rspec->stream_list))
- {
- prev_entry = list_entry(cur_rspec->stream_list.prev,
- struct wim_lookup_table_entry,
- rspec_node);
- lte_unbind_wim_resource_spec(prev_entry);
- }
- if (cur_rspec != NULL) {
- ret = validate_resource(cur_rspec);
+ /* Finish previous resource (if existent) */
+ if (cur_rspec) {
+ ret = finish_resource(cur_rspec);
+ cur_rspec = NULL;
if (ret)
- goto err;
+ goto out;
}
/* Allocate the resource specification and initialize it
* with values from the current stream entry. */
cur_rspec = MALLOC(sizeof(*cur_rspec));
- if (cur_rspec == NULL) {
- ERROR("Not enough memory to read lookup table!");
- ret = WIMLIB_ERR_NOMEM;
- goto err;
- }
+ if (!cur_rspec)
+ goto oom;
+
wim_res_hdr_to_spec(&reshdr, wim, cur_rspec);
/* If this is a packed run, the current stream entry may
* specify a stream within the resource, and not the
* resource itself. Zero possibly irrelevant data until
- * it is read for certain. (Note that the computation
- * of 'back_to_back_pack' tests if 'size_in_wim' is
- * nonzero to see if the resource info has been read;
- * hence we need to set it to 0 here.) */
+ * it is read for certain. */
if (reshdr.flags & WIM_RESHDR_FLAG_PACKED_STREAMS) {
cur_rspec->size_in_wim = 0;
cur_rspec->uncompressed_size = 0;
cur_rspec->offset_in_wim = 0;
}
-
- if (prev_entry)
- lte_bind_wim_resource_spec(prev_entry, cur_rspec);
}
- if ((reshdr.flags & WIM_RESHDR_FLAG_PACKED_STREAMS) &&
- reshdr.uncompressed_size == WIM_PACK_MAGIC_NUMBER)
+ /* Now cur_rspec != NULL. */
+
+ /* Checked for packed resource specification. */
+ if (unlikely((reshdr.flags & WIM_RESHDR_FLAG_PACKED_STREAMS) &&
+ reshdr.uncompressed_size == WIM_PACK_MAGIC_NUMBER))
{
/* Found the specification for the packed resource.
* Transfer the values to the `struct
* wim_resource_spec', and discard the current stream
* since this lookup table entry did not, in fact,
- * correspond to a "stream".
- */
+ * correspond to a "stream". */
- /* Uncompressed size of the resource pack is actually
- * stored in the header of the resource itself. Read
- * it, and also grab the chunk size and compression type
- * (which are not necessarily the defaults from the WIM
- * header). */
+ /* The uncompressed size of the packed resource is
+ * actually stored in the header of the resource itself.
+ * Read it, and also grab the chunk size and compression
+ * type (which are not necessarily the defaults from the
+ * WIM header). */
struct alt_chunk_table_header_disk hdr;
ret = full_pread(&wim->in_fd, &hdr,
sizeof(hdr), reshdr.offset_in_wim);
if (ret)
- goto err;
+ goto out;
cur_rspec->uncompressed_size = le64_to_cpu(hdr.res_usize);
cur_rspec->offset_in_wim = reshdr.offset_in_wim;
cur_rspec->size_in_wim,
cur_rspec->offset_in_wim,
cur_rspec->flags);
- free_lookup_table_entry(cur_entry);
- continue;
+ goto free_cur_entry_and_continue;
}
- if (is_zero_hash(cur_entry->hash)) {
- free_lookup_table_entry(cur_entry);
- continue;
- }
+ /* Ignore entries with all zeroes in the hash field. */
+ if (is_zero_hash(cur_entry->hash))
+ goto free_cur_entry_and_continue;
- if (reshdr.flags & WIM_RESHDR_FLAG_PACKED_STREAMS) {
- /* Continuing the pack with another stream. */
- DEBUG("Continuing pack with stream: "
- "%"PRIu64" uncompressed bytes @ "
- "resource offset %"PRIu64")",
- reshdr.size_in_wim, reshdr.offset_in_wim);
- }
-
- lte_bind_wim_resource_spec(cur_entry, cur_rspec);
- if (reshdr.flags & WIM_RESHDR_FLAG_PACKED_STREAMS) {
- /* In packed runs, the offset field is used for
- * in-resource offset, not the in-WIM offset, and the
- * size field is used for the uncompressed size, not the
- * compressed size. */
- cur_entry->offset_in_res = reshdr.offset_in_wim;
- cur_entry->size = reshdr.size_in_wim;
- cur_entry->flags = reshdr.flags;
- } else {
- /* Normal case: The stream corresponds one-to-one with
- * the resource entry. */
- cur_entry->offset_in_res = 0;
- cur_entry->size = reshdr.uncompressed_size;
- cur_entry->flags = reshdr.flags;
- cur_rspec = NULL;
- }
+ if (reshdr.flags & WIM_RESHDR_FLAG_METADATA) {
- if (cur_entry->flags & WIM_RESHDR_FLAG_METADATA) {
- /* Lookup table entry for a metadata resource */
+ /* Lookup table entry for a metadata resource. */
- /* Metadata entries with no references must be ignored;
- * see for example the WinPE WIMs from the WAIK v2.1.
- * */
- if (cur_entry->refcnt == 0) {
- free_lookup_table_entry(cur_entry);
- continue;
- }
+ /* Metadata entries with no references must be ignored.
+ * See, for example, the WinPE WIMs from the WAIK v2.1.
+ */
+ if (cur_entry->refcnt == 0)
+ goto free_cur_entry_and_continue;
if (cur_entry->refcnt != 1) {
+ /* We don't currently support this case due to
+ * the complications of multiple images sharing
+ * the same metadata resource or a metadata
+ * resource also being referenced by files.
+ */
ERROR("Found metadata resource with refcnt != 1");
ret = WIMLIB_ERR_INVALID_LOOKUP_TABLE_ENTRY;
- goto err;
+ goto out;
}
if (wim->hdr.part_number != 1) {
WARNING("Ignoring metadata resource found in a "
"non-first part of the split WIM");
- free_lookup_table_entry(cur_entry);
- continue;
+ goto free_cur_entry_and_continue;
}
- if (wim->current_image == wim->hdr.image_count) {
- WARNING("The WIM header says there are %u images "
- "in the WIM, but we found more metadata "
- "resources than this (ignoring the extra)",
- wim->hdr.image_count);
- free_lookup_table_entry(cur_entry);
- continue;
+
+ /* The number of entries in the lookup table with
+ * WIM_RESHDR_FLAG_METADATA set should be the same as
+ * the image_count field in the WIM header. */
+ if (image_index == wim->hdr.image_count) {
+ WARNING("Found more metadata resources than images");
+ goto free_cur_entry_and_continue;
}
/* Notice very carefully: We are assigning the metadata
- * resources in the exact order mirrored by their lookup
- * table entries on disk, which is the behavior of
- * Microsoft's software. In particular, this overrides
- * the actual locations of the metadata resources
- * themselves in the WIM file as well as any information
- * written in the XML data. */
- DEBUG("Found metadata resource for image %u at "
+ * resources to images in the same order in which their
+ * lookup table entries occur on disk. (This is also
+ * the behavior of Microsoft's software.) In
+ * particular, this overrides the actual locations of
+ * the metadata resources themselves in the WIM file as
+ * well as any information written in the XML data. */
+ DEBUG("Found metadata resource for image %"PRIu32" at "
"offset %"PRIu64".",
- wim->current_image + 1,
- cur_entry->rspec->offset_in_wim);
- wim->image_metadata[
- wim->current_image++]->metadata_lte = cur_entry;
- continue;
+ image_index + 1,
+ reshdr.offset_in_wim);
+
+ wim->image_metadata[image_index++]->metadata_lte = cur_entry;
+ } else {
+ /* Lookup table entry for a non-metadata stream. */
+
+ /* Ignore this stream if it's a duplicate. */
+ if (lookup_stream(table, cur_entry->hash)) {
+ num_duplicate_entries++;
+ goto free_cur_entry_and_continue;
+ }
+
+ /* Insert the stream into the in-memory lookup table,
+ * keyed by its SHA1 message digest. */
+ lookup_table_insert(table, cur_entry);
}
- /* Lookup table entry for a stream that is not a metadata
- * resource. */
- duplicate_entry = lookup_stream(table, cur_entry->hash);
- if (duplicate_entry) {
- WARNING("The WIM lookup table contains two entries "
- "with the same SHA1 message digest!");
- free_lookup_table_entry(cur_entry);
- continue;
+ /* Add the stream to the current resource specification. */
+ lte_bind_wim_resource_spec(cur_entry, cur_rspec);
+ if (reshdr.flags & WIM_RESHDR_FLAG_PACKED_STREAMS) {
+ /* In packed runs, the offset field is used for
+ * in-resource offset, not the in-WIM offset, and the
+ * size field is used for the uncompressed size, not the
+ * compressed size. */
+ cur_entry->offset_in_res = reshdr.offset_in_wim;
+ cur_entry->size = reshdr.size_in_wim;
+ cur_entry->flags = reshdr.flags;
+ /* cur_rspec stays the same */
+
+ } else {
+ /* Normal case: The stream corresponds one-to-one with
+ * the resource entry. */
+ cur_entry->offset_in_res = 0;
+ cur_entry->size = reshdr.uncompressed_size;
+ cur_entry->flags = reshdr.flags;
}
+ continue;
- /* Finally, insert the stream into the lookup table, keyed by
- * its SHA1 message digest. */
- lookup_table_insert(table, cur_entry);
+ free_cur_entry_and_continue:
+ free_lookup_table_entry(cur_entry);
}
cur_entry = NULL;
/* Validate the last resource. */
- if (cur_rspec != NULL) {
- ret = validate_resource(cur_rspec);
+ if (cur_rspec) {
+ ret = finish_resource(cur_rspec);
+ cur_rspec = NULL;
if (ret)
- goto err;
+ goto out;
}
- if (wim->hdr.part_number == 1 && wim->current_image != wim->hdr.image_count) {
- WARNING("The header of \"%"TS"\" says there are %u images in\n"
- " the WIM, but we only found %d metadata resources! Acting as if\n"
- " the header specified only %d images instead.",
- wim->filename, wim->hdr.image_count,
- wim->current_image, wim->current_image);
- for (int i = wim->current_image; i < wim->hdr.image_count; i++)
+ if (wim->hdr.part_number == 1 && image_index != wim->hdr.image_count) {
+ WARNING("Could not find metadata resources for all images");
+ for (u32 i = image_index; i < wim->hdr.image_count; i++)
put_image_metadata(wim->image_metadata[i], NULL);
- wim->hdr.image_count = wim->current_image;
+ wim->hdr.image_count = image_index;
}
+
+ if (num_duplicate_entries > 0) {
+ WARNING("Ignoring %zu duplicate streams in the WIM lookup table",
+ num_duplicate_entries);
+ }
+
+ if (num_wrong_part_entries > 0) {
+ WARNING("Ignoring %zu streams with wrong part number",
+ num_wrong_part_entries);
+ }
+
DEBUG("Done reading lookup table.");
wim->lookup_table = table;
+ table = NULL;
ret = 0;
- goto out_free_buf;
-
-err:
+ goto out;
+oom:
+ ERROR("Not enough memory to read lookup table!");
+ ret = WIMLIB_ERR_NOMEM;
+out:
if (cur_rspec && list_empty(&cur_rspec->stream_list))
FREE(cur_rspec);
free_lookup_table_entry(cur_entry);
free_lookup_table(table);
-out_free_buf:
FREE(buf);
-out:
- wim->current_image = 0;
return ret;
}
git://wimlib.net / wimlib / blobdiff