X-Git-Url: https://wimlib.net/git/?a=blobdiff_plain;ds=sidebyside;f=src%2Fdentry.c;h=b2bddf2293f14f20e24280f0bb66de823d6e352a;hb=49a63aa13cdeb4c1348697ccd92207a1a65ec7b0;hp=c9a84d718eee2952197886e634cf1fcb12594335;hpb=61db93f82eca3fe9f7676355c709c58cc425a6ad;p=wimlib diff --git a/src/dentry.c b/src/dentry.c index c9a84d71..b2bddf22 100644 --- a/src/dentry.c +++ b/src/dentry.c @@ -217,7 +217,7 @@ struct wim_dentry_on_disk { * a file name and short name that take the specified numbers of bytes. This * excludes any alternate data stream entries that may follow the dentry. */ static u64 -_dentry_correct_length_unaligned(u16 file_name_nbytes, u16 short_name_nbytes) +dentry_correct_length_unaligned(u16 file_name_nbytes, u16 short_name_nbytes) { u64 length = sizeof(struct wim_dentry_on_disk); if (file_name_nbytes) @@ -232,10 +232,13 @@ _dentry_correct_length_unaligned(u16 file_name_nbytes, u16 short_name_nbytes) * ignored; also, this excludes any alternate data stream entries that may * follow the dentry. */ static u64 -dentry_correct_length_unaligned(const struct wim_dentry *dentry) +dentry_correct_length_aligned(const struct wim_dentry *dentry) { - return _dentry_correct_length_unaligned(dentry->file_name_nbytes, - dentry->short_name_nbytes); + u64 len; + + len = dentry_correct_length_unaligned(dentry->file_name_nbytes, + dentry->short_name_nbytes); + return (len + 7) & ~7; } /* Duplicates a string of system-dependent encoding into a UTF-16LE string and @@ -305,31 +308,58 @@ ads_entry_total_length(const struct wim_ads_entry *entry) return (len + 7) & ~7; } +/* + * Determine whether to include a "dummy" stream when writing a WIM dentry: + * + * Some versions of Microsoft's WIM software (the boot driver(s) in WinPE 3.0, + * for example) contain a bug where they assume the first alternate data stream + * (ADS) entry of a dentry with a nonzero ADS count specifies the unnamed + * stream, even if it has a name and the unnamed stream is already specified in + * the hash field of the dentry itself. + * + * wimlib has to work around this behavior by carefully emulating the behavior + * of (most versions of) ImageX/WIMGAPI, which move the unnamed stream reference + * into the alternate stream entries whenever there are named data streams, even + * though there is already a field in the dentry itself for the unnamed stream + * reference, which then goes to waste. + */ +static inline bool inode_needs_dummy_stream(const struct wim_inode *inode) +{ + return (inode->i_num_ads > 0 && + inode->i_num_ads < 0xffff && /* overflow check */ + inode->i_canonical_streams); /* assume the dentry is okay if it + already had an unnamed ADS entry + when it was read in */ +} -static u64 -_dentry_total_length(const struct wim_dentry *dentry, u64 length) +/* Calculate the total number of bytes that will be consumed when a WIM dentry + * is written. This includes base dentry and name fields as well as all + * alternate data stream entries and alignment bytes. */ +u64 +dentry_out_total_length(const struct wim_dentry *dentry) { + u64 length = dentry_correct_length_aligned(dentry); const struct wim_inode *inode = dentry->d_inode; + + if (inode_needs_dummy_stream(inode)) + length += ads_entry_total_length(&(struct wim_ads_entry){}); + for (u16 i = 0; i < inode->i_num_ads; i++) length += ads_entry_total_length(&inode->i_ads_entries[i]); - return (length + 7) & ~7; -} -/* Calculate the aligned *total* length of an on-disk WIM dentry. This includes - * all alternate data streams. */ -u64 -dentry_correct_total_length(const struct wim_dentry *dentry) -{ - return _dentry_total_length(dentry, - dentry_correct_length_unaligned(dentry)); + return length; } -/* Like dentry_correct_total_length(), but use the existing dentry->length field - * instead of calculating its "correct" value. */ +/* Calculate the aligned, total length of a dentry, including all alternate data + * stream entries. Uses dentry->length. */ static u64 -dentry_total_length(const struct wim_dentry *dentry) +dentry_in_total_length(const struct wim_dentry *dentry) { - return _dentry_total_length(dentry, dentry->length); + u64 length = dentry->length; + const struct wim_inode *inode = dentry->d_inode; + for (u16 i = 0; i < inode->i_num_ads; i++) + length += ads_entry_total_length(&inode->i_ads_entries[i]); + return (length + 7) & ~7; } int @@ -537,7 +567,7 @@ dentry_full_path(struct wim_dentry *dentry) static int increment_subdir_offset(struct wim_dentry *dentry, void *subdir_offset_p) { - *(u64*)subdir_offset_p += dentry_correct_total_length(dentry); + *(u64*)subdir_offset_p += dentry_out_total_length(dentry); return 0; } @@ -987,6 +1017,7 @@ new_timeless_inode(void) inode->i_nlink = 1; inode->i_next_stream_id = 1; inode->i_not_rpfixed = 1; + inode->i_canonical_streams = 1; INIT_LIST_HEAD(&inode->i_list); INIT_LIST_HEAD(&inode->i_dentry); } @@ -1086,6 +1117,19 @@ new_filler_directory(const tchar *name, struct wim_dentry **dentry_ret) return 0; } +static int +dentry_clear_inode_visited(struct wim_dentry *dentry, void *_ignore) +{ + dentry->d_inode->i_visited = 0; + return 0; +} + +void +dentry_tree_clear_inode_visited(struct wim_dentry *root) +{ + for_dentry_in_tree(root, dentry_clear_inode_visited, NULL); +} + static int init_ads_entry(struct wim_ads_entry *ads_entry, const void *name, size_t name_nbytes, bool is_utf16le) @@ -1336,7 +1380,11 @@ unlink_dentry(struct wim_dentry *dentry) /* * Returns the alternate data stream entry belonging to @inode that has the - * stream name @stream_name. + * stream name @stream_name, or NULL if the inode has no alternate data stream + * with that name. + * + * If @p stream_name is the empty string, NULL is returned --- that is, this + * function will not return "unnamed" alternate data stream entries. */ struct wim_ads_entry * inode_get_ads_entry(struct wim_inode *inode, const tchar *stream_name, @@ -1349,6 +1397,9 @@ inode_get_ads_entry(struct wim_inode *inode, const tchar *stream_name, u16 i; struct wim_ads_entry *result; + if (stream_name[0] == T('\0')) + return NULL; + #if TCHAR_IS_UTF16LE const utf16lechar *stream_name_utf16le; @@ -1395,6 +1446,8 @@ do_inode_add_ads(struct wim_inode *inode, const void *stream_name, struct wim_ads_entry *ads_entries; struct wim_ads_entry *new_entry; + wimlib_assert(stream_name_nbytes != 0); + if (inode->i_num_ads >= 0xfffe) { ERROR("Too many alternate data streams in one inode!"); return NULL; @@ -1426,8 +1479,10 @@ inode_add_ads_utf16le(struct wim_inode *inode, } /* - * Add an alternate stream entry to a WIM inode and return a pointer to it, or - * NULL if memory could not be allocated. + * Add an alternate stream entry to a WIM inode. On success, returns a pointer + * to the new entry; on failure, returns NULL. + * + * @stream_name must be a nonempty string. */ struct wim_ads_entry * inode_add_ads(struct wim_inode *inode, const tchar *stream_name) @@ -1446,7 +1501,7 @@ add_stream_from_data_buffer(const void *buffer, size_t size, struct wim_lookup_table_entry *lte, *existing_lte; sha1_buffer(buffer, size, hash); - existing_lte = __lookup_resource(lookup_table, hash); + existing_lte = lookup_resource(lookup_table, hash); if (existing_lte) { wimlib_assert(wim_resource_size(existing_lte) == size); lte = existing_lte; @@ -1721,6 +1776,9 @@ read_ads_entries(const u8 * restrict p, struct wim_inode * restrict inode, disk_entry->stream_name, cur_entry->stream_name_nbytes); cur_entry->stream_name[cur_entry->stream_name_nbytes / 2] = cpu_to_le16(0); + } else { + /* Mark inode as having weird stream entries. */ + inode->i_canonical_streams = 0; } /* It's expected that the size of every ADS entry is a multiple @@ -1901,8 +1959,8 @@ read_dentry(const u8 * restrict metadata_resource, u64 metadata_resource_len, * The calculated length here is unaligned to allow for the possibility * that the dentry->length names an unaligned length, although this * would be unexpected. */ - calculated_size = _dentry_correct_length_unaligned(file_name_nbytes, - short_name_nbytes); + calculated_size = dentry_correct_length_unaligned(file_name_nbytes, + short_name_nbytes); if (dentry->length < calculated_size) { ERROR("Unexpected end of directory entry! (Expected " @@ -2084,7 +2142,7 @@ read_dentry_tree(const u8 * restrict metadata_resource, * cur_child.length, which although it does take into account * the padding, it DOES NOT take into account alternate stream * entries. */ - cur_offset += dentry_total_length(child); + cur_offset += dentry_in_total_length(child); if (unlikely(!dentry_has_long_name(child))) { WARNING("Ignoring unnamed dentry in " @@ -2127,6 +2185,38 @@ read_dentry_tree(const u8 * restrict metadata_resource, return ret; } +/* + * Writes a WIM alternate data stream (ADS) entry to an output buffer. + * + * @ads_entry: The ADS entry structure. + * @hash: The hash field to use (instead of the one in the ADS entry). + * @p: The memory location to write the data to. + * + * Returns a pointer to the byte after the last byte written. + */ +static u8 * +write_ads_entry(const struct wim_ads_entry *ads_entry, + const u8 *hash, u8 * restrict p) +{ + struct wim_ads_entry_on_disk *disk_ads_entry = + (struct wim_ads_entry_on_disk*)p; + u8 *orig_p = p; + + disk_ads_entry->reserved = cpu_to_le64(ads_entry->reserved); + copy_hash(disk_ads_entry->hash, hash); + disk_ads_entry->stream_name_nbytes = cpu_to_le16(ads_entry->stream_name_nbytes); + p += sizeof(struct wim_ads_entry_on_disk); + if (ads_entry->stream_name_nbytes) { + p = mempcpy(p, ads_entry->stream_name, + ads_entry->stream_name_nbytes + 2); + } + /* Align to 8-byte boundary */ + while ((uintptr_t)p & 7) + *p++ = 0; + disk_ads_entry->length = cpu_to_le64(p - orig_p); + return p; +} + /* * Writes a WIM dentry to an output buffer. * @@ -2143,11 +2233,14 @@ write_dentry(const struct wim_dentry * restrict dentry, u8 * restrict p) struct wim_dentry_on_disk *disk_dentry; const u8 *orig_p; const u8 *hash; + bool use_dummy_stream; + u16 num_ads; wimlib_assert(((uintptr_t)p & 7) == 0); /* 8 byte aligned */ orig_p = p; inode = dentry->d_inode; + use_dummy_stream = inode_needs_dummy_stream(inode); disk_dentry = (struct wim_dentry_on_disk*)p; disk_dentry->attributes = cpu_to_le32(inode->i_attributes); @@ -2158,7 +2251,10 @@ write_dentry(const struct wim_dentry * restrict dentry, u8 * restrict p) disk_dentry->creation_time = cpu_to_le64(inode->i_creation_time); disk_dentry->last_access_time = cpu_to_le64(inode->i_last_access_time); disk_dentry->last_write_time = cpu_to_le64(inode->i_last_write_time); - hash = inode_stream_hash(inode, 0); + if (use_dummy_stream) + hash = zero_hash; + else + hash = inode_stream_hash(inode, 0); copy_hash(disk_dentry->unnamed_stream_hash, hash); if (inode->i_attributes & FILE_ATTRIBUTE_REPARSE_POINT) { disk_dentry->reparse.rp_unknown_1 = cpu_to_le32(inode->i_rp_unknown_1); @@ -2170,7 +2266,10 @@ write_dentry(const struct wim_dentry * restrict dentry, u8 * restrict p) disk_dentry->nonreparse.hard_link_group_id = cpu_to_le64((inode->i_nlink == 1) ? 0 : inode->i_ino); } - disk_dentry->num_alternate_data_streams = cpu_to_le16(inode->i_num_ads); + num_ads = inode->i_num_ads; + if (use_dummy_stream) + num_ads++; + disk_dentry->num_alternate_data_streams = cpu_to_le16(num_ads); disk_dentry->short_name_nbytes = cpu_to_le16(dentry->short_name_nbytes); disk_dentry->file_name_nbytes = cpu_to_le16(dentry->file_name_nbytes); p += sizeof(struct wim_dentry_on_disk); @@ -2194,29 +2293,17 @@ write_dentry(const struct wim_dentry * restrict dentry, u8 * restrict p) * have been renamed, thus changing its needed length. */ disk_dentry->length = cpu_to_le64(p - orig_p); + if (use_dummy_stream) { + hash = inode_unnamed_stream_hash(inode); + p = write_ads_entry(&(struct wim_ads_entry){}, hash, p); + } + /* Write the alternate data streams entries, if any. */ for (u16 i = 0; i < inode->i_num_ads; i++) { - const struct wim_ads_entry *ads_entry = - &inode->i_ads_entries[i]; - struct wim_ads_entry_on_disk *disk_ads_entry = - (struct wim_ads_entry_on_disk*)p; - orig_p = p; - - disk_ads_entry->reserved = cpu_to_le64(ads_entry->reserved); - hash = inode_stream_hash(inode, i + 1); - copy_hash(disk_ads_entry->hash, hash); - disk_ads_entry->stream_name_nbytes = cpu_to_le16(ads_entry->stream_name_nbytes); - p += sizeof(struct wim_ads_entry_on_disk); - if (ads_entry->stream_name_nbytes) { - p = mempcpy(p, ads_entry->stream_name, - ads_entry->stream_name_nbytes + 2); - } - /* Align to 8-byte boundary */ - while ((uintptr_t)p & 7) - *p++ = 0; - disk_ads_entry->length = cpu_to_le64(p - orig_p); + p = write_ads_entry(&inode->i_ads_entries[i], hash, p); } + return p; } @@ -2295,12 +2382,14 @@ write_dentry_tree(const struct wim_dentry * restrict root, u8 * restrict p) static int init_wimlib_dentry(struct wimlib_dir_entry *wdentry, struct wim_dentry *dentry, - const WIMStruct *wim) + const WIMStruct *wim, + int flags) { int ret; size_t dummy; const struct wim_inode *inode = dentry->d_inode; struct wim_lookup_table_entry *lte; + const u8 *hash; #if TCHAR_IS_UTF16LE wdentry->filename = dentry->file_name; @@ -2345,17 +2434,30 @@ init_wimlib_dentry(struct wimlib_dir_entry *wdentry, wdentry->last_access_time = wim_timestamp_to_timespec(inode->i_last_access_time); lte = inode_unnamed_lte(inode, wim->lookup_table); - if (lte) + if (lte) { lte_to_wimlib_resource_entry(lte, &wdentry->streams[0].resource); + } else if (!is_zero_hash(hash = inode_unnamed_stream_hash(inode))) { + if (flags & WIMLIB_ITERATE_DIR_TREE_FLAG_RESOURCES_NEEDED) + return resource_not_found_error(inode, hash); + copy_hash(wdentry->streams[0].resource.sha1_hash, hash); + wdentry->streams[0].resource.is_missing = 1; + } for (unsigned i = 0; i < inode->i_num_ads; i++) { - if (inode->i_ads_entries[i].stream_name == NULL) + if (!ads_entry_is_named_stream(&inode->i_ads_entries[i])) continue; lte = inode_stream_lte(inode, i + 1, wim->lookup_table); wdentry->num_named_streams++; if (lte) { lte_to_wimlib_resource_entry(lte, &wdentry->streams[ wdentry->num_named_streams].resource); + } else if (!is_zero_hash(hash = inode_stream_hash(inode, i + 1))) { + if (flags & WIMLIB_ITERATE_DIR_TREE_FLAG_RESOURCES_NEEDED) + return resource_not_found_error(inode, hash); + copy_hash(wdentry->streams[ + wdentry->num_named_streams].resource.sha1_hash, hash); + wdentry->streams[ + wdentry->num_named_streams].resource.is_missing = 1; } #if TCHAR_IS_UTF16LE wdentry->streams[wdentry->num_named_streams].stream_name = @@ -2424,7 +2526,7 @@ do_iterate_dir_tree(WIMStruct *wim, if (!wdentry) goto out; - ret = init_wimlib_dentry(wdentry, dentry, wim); + ret = init_wimlib_dentry(wdentry, dentry, wim, flags); if (ret) goto out_free_wimlib_dentry; @@ -2486,3 +2588,211 @@ wimlib_iterate_dir_tree(WIMStruct *wim, int image, const tchar *path, wim->private = &ctx; return for_image(wim, image, image_do_iterate_dir_tree); } + +/* Returns %true iff the metadata of @inode and @template_inode are reasonably + * consistent with them being the same, unmodified file. */ +static bool +inode_metadata_consistent(const struct wim_inode *inode, + const struct wim_inode *template_inode, + const struct wim_lookup_table *template_lookup_table) +{ + /* Must have exact same creation time and last write time. */ + if (inode->i_creation_time != template_inode->i_creation_time || + inode->i_last_write_time != template_inode->i_last_write_time) + return false; + + /* Last access time may have stayed the same or increased, but certainly + * shouldn't have decreased. */ + if (inode->i_last_access_time < template_inode->i_last_access_time) + return false; + + /* Must have same number of alternate data stream entries. */ + if (inode->i_num_ads != template_inode->i_num_ads) + return false; + + /* If the stream entries for the inode are for some reason not resolved, + * then the hashes are already available and the point of this function + * is defeated. */ + if (!inode->i_resolved) + return false; + + /* Iterate through each stream and do some more checks. */ + for (unsigned i = 0; i <= inode->i_num_ads; i++) { + const struct wim_lookup_table_entry *lte, *template_lte; + + lte = inode_stream_lte_resolved(inode, i); + template_lte = inode_stream_lte(template_inode, i, + template_lookup_table); + + /* Compare stream sizes. */ + if (lte && template_lte) { + if (wim_resource_size(lte) != wim_resource_size(template_lte)) + return false; + + /* If hash happens to be available, compare with template. */ + if (!lte->unhashed && !template_lte->unhashed && + !hashes_equal(lte->hash, template_lte->hash)) + return false; + + } else if (lte && wim_resource_size(lte)) { + return false; + } else if (template_lte && wim_resource_size(template_lte)) { + return false; + } + } + + /* All right, barring a full checksum and given that the inodes share a + * path and the user isn't trying to trick us, these inodes most likely + * refer to the same file. */ + return true; +} + +/** + * Given an inode @inode that has been determined to be "the same" as another + * inode @template_inode in either the same WIM or another WIM, retrieve some + * useful stream information (e.g. checksums) from @template_inode. + * + * This assumes that the streams for @inode have been resolved (to point + * directly to the appropriate `struct wim_lookup_table_entry's) but do not + * necessarily have checksum information filled in. + */ +static int +inode_copy_checksums(struct wim_inode *inode, + struct wim_inode *template_inode, + WIMStruct *wim, + WIMStruct *template_wim) +{ + for (unsigned i = 0; i <= inode->i_num_ads; i++) { + struct wim_lookup_table_entry *lte, *template_lte; + struct wim_lookup_table_entry *replace_lte; + + lte = inode_stream_lte_resolved(inode, i); + template_lte = inode_stream_lte(template_inode, i, + template_wim->lookup_table); + + /* Only take action if both entries exist, the entry for @inode + * has no checksum calculated, but the entry for @template_inode + * does. */ + if (!lte || !template_lte || + !lte->unhashed || template_lte->unhashed) + continue; + + wimlib_assert(lte->refcnt == inode->i_nlink); + + /* If the WIM of the template image is the same as the WIM of + * the new image, then @template_lte can be used directly. + * + * Otherwise, look for a stream with the same hash in the WIM of + * the new image. If found, use it; otherwise re-use the entry + * being discarded, filling in the hash. */ + + if (wim == template_wim) + replace_lte = template_lte; + else + replace_lte = lookup_resource(wim->lookup_table, + template_lte->hash); + + list_del(<e->unhashed_list); + if (replace_lte) { + free_lookup_table_entry(lte); + } else { + copy_hash(lte->hash, template_lte->hash); + lte->unhashed = 0; + lookup_table_insert(wim->lookup_table, lte); + lte->refcnt = 0; + replace_lte = lte; + } + + if (i == 0) + inode->i_lte = replace_lte; + else + inode->i_ads_entries[i - 1].lte = replace_lte; + + replace_lte->refcnt += inode->i_nlink; + } + return 0; +} + +struct reference_template_args { + WIMStruct *wim; + WIMStruct *template_wim; +}; + +static int +dentry_reference_template(struct wim_dentry *dentry, void *_args) +{ + int ret; + struct wim_dentry *template_dentry; + struct wim_inode *inode, *template_inode; + struct reference_template_args *args = _args; + WIMStruct *wim = args->wim; + WIMStruct *template_wim = args->template_wim; + + if (dentry->d_inode->i_visited) + return 0; + + ret = calculate_dentry_full_path(dentry); + if (ret) + return ret; + + template_dentry = get_dentry(template_wim, dentry->_full_path); + if (!template_dentry) { + DEBUG("\"%"TS"\": newly added file", dentry->_full_path); + return 0; + } + + inode = dentry->d_inode; + template_inode = template_dentry->d_inode; + + if (inode_metadata_consistent(inode, template_inode, + template_wim->lookup_table)) { + /*DEBUG("\"%"TS"\": No change detected", dentry->_full_path);*/ + ret = inode_copy_checksums(inode, template_inode, + wim, template_wim); + inode->i_visited = 1; + } else { + DEBUG("\"%"TS"\": change detected!", dentry->_full_path); + ret = 0; + } + return ret; +} + +/* API function documented in wimlib.h */ +WIMLIBAPI int +wimlib_reference_template_image(WIMStruct *wim, int new_image, + WIMStruct *template_wim, int template_image, + int flags, wimlib_progress_func_t progress_func) +{ + int ret; + struct wim_image_metadata *new_imd; + + if (wim == NULL || template_wim == NULL) + return WIMLIB_ERR_INVALID_PARAM; + + if (wim == template_wim && new_image == template_image) + return WIMLIB_ERR_INVALID_PARAM; + + if (new_image < 1 || new_image > wim->hdr.image_count) + return WIMLIB_ERR_INVALID_IMAGE; + + if (!wim_has_metadata(wim)) + return WIMLIB_ERR_METADATA_NOT_FOUND; + + new_imd = wim->image_metadata[new_image - 1]; + if (!new_imd->modified) + return WIMLIB_ERR_INVALID_PARAM; + + ret = select_wim_image(template_wim, template_image); + if (ret) + return ret; + + struct reference_template_args args = { + .wim = wim, + .template_wim = template_wim, + }; + + ret = for_dentry_in_tree(new_imd->root_dentry, + dentry_reference_template, &args); + dentry_tree_clear_inode_visited(new_imd->root_dentry); + return ret; +}