/* * write.c * * Support for writing WIM files; write a WIM file, overwrite a WIM file, write * compressed file resources, etc. */ /* * Copyright (C) 2010 Carl Thijssen * Copyright (C) 2012 Eric Biggers * * This file is part of wimlib, a library for working with WIM files. * * wimlib is free software; you can redistribute it and/or modify it under the * terms of the GNU General Public License as published by the Free * Software Foundation; either version 3 of the License, or (at your option) * any later version. * * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR * A PARTICULAR PURPOSE. See the GNU General Public License for more * details. * * You should have received a copy of the GNU General Public License * along with wimlib; if not, see http://www.gnu.org/licenses/. */ #include "config.h" #if defined(HAVE_SYS_FILE_H) && defined(HAVE_FLOCK) /* On BSD, this should be included before "list.h" so that "list.h" can * overwrite the LIST_HEAD macro. */ #include #endif #include "list.h" #include "wimlib_internal.h" #include "io.h" #include "dentry.h" #include "lookup_table.h" #include "xml.h" #include "lzx.h" #include "xpress.h" #ifdef ENABLE_MULTITHREADED_COMPRESSION #include #endif #include #include #ifdef WITH_NTFS_3G #include #include #include #include #endif #ifdef HAVE_ALLOCA_H #include #else #include #endif static int do_fflush(FILE *fp) { int ret = fflush(fp); if (ret != 0) { ERROR_WITH_ERRNO("Failed to flush data to output WIM file"); return WIMLIB_ERR_WRITE; } return 0; } static int fflush_and_ftruncate(FILE *fp, off_t size) { int ret; ret = do_fflush(fp); if (ret != 0) return ret; ret = ftruncate(fileno(fp), size); if (ret != 0) { ERROR_WITH_ERRNO("Failed to truncate output WIM file to " "%"PRIu64" bytes", size); return WIMLIB_ERR_WRITE; } return 0; } /* Chunk table that's located at the beginning of each compressed resource in * the WIM. (This is not the on-disk format; the on-disk format just has an * array of offsets.) */ struct chunk_table { off_t file_offset; u64 num_chunks; u64 original_resource_size; u64 bytes_per_chunk_entry; u64 table_disk_size; u64 cur_offset; u64 *cur_offset_p; u64 offsets[0]; }; /* * Allocates and initializes a chunk table, and reserves space for it in the * output file. */ static int begin_wim_resource_chunk_tab(const struct lookup_table_entry *lte, FILE *out_fp, off_t file_offset, struct chunk_table **chunk_tab_ret) { u64 size = wim_resource_size(lte); u64 num_chunks = (size + WIM_CHUNK_SIZE - 1) / WIM_CHUNK_SIZE; size_t alloc_size = sizeof(struct chunk_table) + num_chunks * sizeof(u64); struct chunk_table *chunk_tab = CALLOC(1, alloc_size); int ret; if (!chunk_tab) { ERROR("Failed to allocate chunk table for %"PRIu64" byte " "resource", size); ret = WIMLIB_ERR_NOMEM; goto out; } chunk_tab->file_offset = file_offset; chunk_tab->num_chunks = num_chunks; chunk_tab->original_resource_size = size; chunk_tab->bytes_per_chunk_entry = (size >= (1ULL << 32)) ? 8 : 4; chunk_tab->table_disk_size = chunk_tab->bytes_per_chunk_entry * (num_chunks - 1); chunk_tab->cur_offset = 0; chunk_tab->cur_offset_p = chunk_tab->offsets; if (fwrite(chunk_tab, 1, chunk_tab->table_disk_size, out_fp) != chunk_tab->table_disk_size) { ERROR_WITH_ERRNO("Failed to write chunk table in compressed " "file resource"); ret = WIMLIB_ERR_WRITE; goto out; } ret = 0; out: *chunk_tab_ret = chunk_tab; return ret; } /* * Pointer to function to compresses a chunk of a WIM resource. * * @chunk: Uncompressed data of the chunk. * @chunk_size: Size of the uncompressed chunk in bytes. * @compressed_chunk: Pointer to output buffer of size at least * (@chunk_size - 1) bytes. * @compressed_chunk_len_ret: Pointer to an unsigned int into which the size * of the compressed chunk will be * returned. * * Returns zero if compressed succeeded, and nonzero if the chunk could not be * compressed to any smaller than @chunk_size. This function cannot fail for * any other reasons. */ typedef int (*compress_func_t)(const void *, unsigned, void *, unsigned *); compress_func_t get_compress_func(int out_ctype) { if (out_ctype == WIMLIB_COMPRESSION_TYPE_LZX) return lzx_compress; else return xpress_compress; } /* * Writes a chunk of a WIM resource to an output file. * * @chunk: Uncompressed data of the chunk. * @chunk_size: Size of the chunk (<= WIM_CHUNK_SIZE) * @out_fp: FILE * to write tho chunk to. * @out_ctype: Compression type to use when writing the chunk (ignored if no * chunk table provided) * @chunk_tab: Pointer to chunk table being created. It is updated with the * offset of the chunk we write. * * Returns 0 on success; nonzero on failure. */ static int write_wim_resource_chunk(const u8 chunk[], unsigned chunk_size, FILE *out_fp, compress_func_t compress, struct chunk_table *chunk_tab) { const u8 *out_chunk; unsigned out_chunk_size; if (chunk_tab) { u8 *compressed_chunk = alloca(chunk_size); int ret; ret = compress(chunk, chunk_size, compressed_chunk, &out_chunk_size); if (ret == 0) { out_chunk = compressed_chunk; } else { out_chunk = chunk; out_chunk_size = chunk_size; } *chunk_tab->cur_offset_p++ = chunk_tab->cur_offset; chunk_tab->cur_offset += out_chunk_size; } else { out_chunk = chunk; out_chunk_size = chunk_size; } if (fwrite(out_chunk, 1, out_chunk_size, out_fp) != out_chunk_size) { ERROR_WITH_ERRNO("Failed to write WIM resource chunk"); return WIMLIB_ERR_WRITE; } return 0; } /* * Finishes a WIM chunk tale and writes it to the output file at the correct * offset. * * The final size of the full compressed resource is returned in the * @compressed_size_p. */ static int finish_wim_resource_chunk_tab(struct chunk_table *chunk_tab, FILE *out_fp, u64 *compressed_size_p) { size_t bytes_written; if (fseeko(out_fp, chunk_tab->file_offset, SEEK_SET) != 0) { ERROR_WITH_ERRNO("Failed to seek to byte %"PRIu64" of output " "WIM file", chunk_tab->file_offset); return WIMLIB_ERR_WRITE; } if (chunk_tab->bytes_per_chunk_entry == 8) { array_cpu_to_le64(chunk_tab->offsets, chunk_tab->num_chunks); } else { for (u64 i = 0; i < chunk_tab->num_chunks; i++) ((u32*)chunk_tab->offsets)[i] = cpu_to_le32(chunk_tab->offsets[i]); } bytes_written = fwrite((u8*)chunk_tab->offsets + chunk_tab->bytes_per_chunk_entry, 1, chunk_tab->table_disk_size, out_fp); if (bytes_written != chunk_tab->table_disk_size) { ERROR_WITH_ERRNO("Failed to write chunk table in compressed " "file resource"); return WIMLIB_ERR_WRITE; } if (fseeko(out_fp, 0, SEEK_END) != 0) { ERROR_WITH_ERRNO("Failed to seek to end of output WIM file"); return WIMLIB_ERR_WRITE; } *compressed_size_p = chunk_tab->cur_offset + chunk_tab->table_disk_size; return 0; } /* Prepare for multiple reads to a resource by caching a FILE * or NTFS * attribute pointer in the lookup table entry. */ static int prepare_resource_for_read(struct lookup_table_entry *lte #ifdef WITH_NTFS_3G , ntfs_inode **ni_ret #endif ) { if (lte->resource_location == RESOURCE_IN_FILE_ON_DISK && !lte->file_on_disk_fp) { wimlib_assert(lte->file_on_disk); lte->file_on_disk_fp = fopen(lte->file_on_disk, "rb"); if (!lte->file_on_disk_fp) { ERROR_WITH_ERRNO("Failed to open the file `%s' for " "reading", lte->file_on_disk); return WIMLIB_ERR_OPEN; } } #ifdef WITH_NTFS_3G else if (lte->resource_location == RESOURCE_IN_NTFS_VOLUME && !lte->attr) { struct ntfs_location *loc = lte->ntfs_loc; ntfs_inode *ni; wimlib_assert(loc); ni = ntfs_pathname_to_inode(*loc->ntfs_vol_p, NULL, loc->path_utf8); if (!ni) { ERROR_WITH_ERRNO("Failed to open inode `%s' in NTFS " "volume", loc->path_utf8); return WIMLIB_ERR_NTFS_3G; } lte->attr = ntfs_attr_open(ni, loc->is_reparse_point ? AT_REPARSE_POINT : AT_DATA, (ntfschar*)loc->stream_name_utf16, loc->stream_name_utf16_num_chars); if (!lte->attr) { ERROR_WITH_ERRNO("Failed to open attribute of `%s' in " "NTFS volume", loc->path_utf8); ntfs_inode_close(ni); return WIMLIB_ERR_NTFS_3G; } *ni_ret = ni; } #endif return 0; } /* Undo prepare_resource_for_read() by closing the cached FILE * or NTFS * attribute. */ static void end_wim_resource_read(struct lookup_table_entry *lte #ifdef WITH_NTFS_3G , ntfs_inode *ni #endif ) { if (lte->resource_location == RESOURCE_IN_FILE_ON_DISK && lte->file_on_disk_fp) { fclose(lte->file_on_disk_fp); lte->file_on_disk_fp = NULL; } #ifdef WITH_NTFS_3G else if (lte->resource_location == RESOURCE_IN_NTFS_VOLUME) { if (lte->attr) { ntfs_attr_close(lte->attr); lte->attr = NULL; } if (ni) ntfs_inode_close(ni); } #endif } /* * Writes a WIM resource to a FILE * opened for writing. The resource may be * written uncompressed or compressed depending on the @out_ctype parameter. * * If by chance the resource compresses to more than the original size (this may * happen with random data or files than are pre-compressed), the resource is * instead written uncompressed (and this is reflected in the @out_res_entry by * removing the WIM_RESHDR_FLAG_COMPRESSED flag). * * @lte: The lookup table entry for the WIM resource. * @out_fp: The FILE * to write the resource to. * @out_ctype: The compression type of the resource to write. Note: if this is * the same as the compression type of the WIM resource we * need to read, we simply copy the data (i.e. we do not * uncompress it, then compress it again). * @out_res_entry: If non-NULL, a resource entry that is filled in with the * offset, original size, compressed size, and compression flag * of the output resource. * * Returns 0 on success; nonzero on failure. */ int write_wim_resource(struct lookup_table_entry *lte, FILE *out_fp, int out_ctype, struct resource_entry *out_res_entry, int flags) { u64 bytes_remaining; u64 original_size; u64 old_compressed_size; u64 new_compressed_size; u64 offset; int ret; struct chunk_table *chunk_tab = NULL; bool raw; off_t file_offset; compress_func_t compress = NULL; #ifdef WITH_NTFS_3G ntfs_inode *ni = NULL; #endif wimlib_assert(lte); /* Original size of the resource */ original_size = wim_resource_size(lte); /* Compressed size of the resource (as it exists now) */ old_compressed_size = wim_resource_compressed_size(lte); /* Current offset in output file */ file_offset = ftello(out_fp); if (file_offset == -1) { ERROR_WITH_ERRNO("Failed to get offset in output " "stream"); return WIMLIB_ERR_WRITE; } /* Are the compression types the same? If so, do a raw copy (copy * without decompressing and recompressing the data). */ raw = (wim_resource_compression_type(lte) == out_ctype && out_ctype != WIMLIB_COMPRESSION_TYPE_NONE && !(flags & WIMLIB_RESOURCE_FLAG_RECOMPRESS)); if (raw) { flags |= WIMLIB_RESOURCE_FLAG_RAW; bytes_remaining = old_compressed_size; } else { flags &= ~WIMLIB_RESOURCE_FLAG_RAW; bytes_remaining = original_size; } /* Empty resource; nothing needs to be done, so just return success. */ if (bytes_remaining == 0) return 0; /* Buffer for reading chunks for the resource */ u8 buf[min(WIM_CHUNK_SIZE, bytes_remaining)]; /* If we are writing a compressed resource and not doing a raw copy, we * need to initialize the chunk table */ if (out_ctype != WIMLIB_COMPRESSION_TYPE_NONE && !raw) { ret = begin_wim_resource_chunk_tab(lte, out_fp, file_offset, &chunk_tab); if (ret != 0) goto out; } /* If the WIM resource is in an external file, open a FILE * to it so we * don't have to open a temporary one in read_wim_resource() for each * chunk. */ #ifdef WITH_NTFS_3G ret = prepare_resource_for_read(lte, &ni); #else ret = prepare_resource_for_read(lte); #endif if (ret != 0) goto out; /* If we aren't doing a raw copy, we will compute the SHA1 message * digest of the resource as we read it, and verify it's the same as the * hash given in the lookup table entry once we've finished reading the * resource. */ SHA_CTX ctx; if (!raw) { sha1_init(&ctx); compress = get_compress_func(out_ctype); } offset = 0; /* While there are still bytes remaining in the WIM resource, read a * chunk of the resource, update SHA1, then write that chunk using the * desired compression type. */ do { u64 to_read = min(bytes_remaining, WIM_CHUNK_SIZE); ret = read_wim_resource(lte, buf, to_read, offset, flags); if (ret != 0) goto out_fclose; if (!raw) sha1_update(&ctx, buf, to_read); ret = write_wim_resource_chunk(buf, to_read, out_fp, compress, chunk_tab); if (ret != 0) goto out_fclose; bytes_remaining -= to_read; offset += to_read; } while (bytes_remaining); /* Raw copy: The new compressed size is the same as the old compressed * size * * Using WIMLIB_COMPRESSION_TYPE_NONE: The new compressed size is the * original size * * Using a different compression type: Call * finish_wim_resource_chunk_tab() and it will provide the new * compressed size. */ if (raw) { new_compressed_size = old_compressed_size; } else { if (out_ctype == WIMLIB_COMPRESSION_TYPE_NONE) new_compressed_size = original_size; else { ret = finish_wim_resource_chunk_tab(chunk_tab, out_fp, &new_compressed_size); if (ret != 0) goto out_fclose; } } /* Verify SHA1 message digest of the resource, unless we are doing a raw * write (in which case we never even saw the uncompressed data). Or, * if the hash we had before is all 0's, just re-set it to be the new * hash. */ if (!raw) { u8 md[SHA1_HASH_SIZE]; sha1_final(md, &ctx); if (is_zero_hash(lte->hash)) { copy_hash(lte->hash, md); } else if (!hashes_equal(md, lte->hash)) { ERROR("WIM resource has incorrect hash!"); if (lte->resource_location == RESOURCE_IN_FILE_ON_DISK) { ERROR("We were reading it from `%s'; maybe it changed " "while we were reading it.", lte->file_on_disk); } ret = WIMLIB_ERR_INVALID_RESOURCE_HASH; goto out_fclose; } } if (!raw && new_compressed_size >= original_size && out_ctype != WIMLIB_COMPRESSION_TYPE_NONE) { /* Oops! We compressed the resource to larger than the original * size. Write the resource uncompressed instead. */ if (fseeko(out_fp, file_offset, SEEK_SET) != 0) { ERROR_WITH_ERRNO("Failed to seek to byte %"PRIu64" " "of output WIM file", file_offset); ret = WIMLIB_ERR_WRITE; goto out_fclose; } ret = write_wim_resource(lte, out_fp, WIMLIB_COMPRESSION_TYPE_NONE, out_res_entry, flags); if (ret != 0) goto out_fclose; ret = fflush_and_ftruncate(out_fp, file_offset + out_res_entry->size); if (ret != 0) goto out_fclose; } else { if (out_res_entry) { out_res_entry->size = new_compressed_size; out_res_entry->original_size = original_size; out_res_entry->offset = file_offset; out_res_entry->flags = lte->resource_entry.flags & ~WIM_RESHDR_FLAG_COMPRESSED; if (out_ctype != WIMLIB_COMPRESSION_TYPE_NONE) out_res_entry->flags |= WIM_RESHDR_FLAG_COMPRESSED; } } ret = 0; out_fclose: #ifdef WITH_NTFS_3G end_wim_resource_read(lte, ni); #else end_wim_resource_read(lte); #endif out: FREE(chunk_tab); return ret; } #ifdef ENABLE_MULTITHREADED_COMPRESSION struct shared_queue { unsigned size; unsigned front; unsigned back; unsigned filled_slots; void **array; pthread_mutex_t lock; pthread_cond_t msg_avail_cond; pthread_cond_t space_avail_cond; }; static int shared_queue_init(struct shared_queue *q, unsigned size) { q->array = CALLOC(sizeof(q->array[0]), size); if (!q->array) return WIMLIB_ERR_NOMEM; q->filled_slots = 0; q->front = 0; q->back = size - 1; q->size = size; pthread_mutex_init(&q->lock, NULL); pthread_cond_init(&q->msg_avail_cond, NULL); pthread_cond_init(&q->space_avail_cond, NULL); return 0; } static void shared_queue_destroy(struct shared_queue *q) { FREE(q->array); pthread_mutex_destroy(&q->lock); pthread_cond_destroy(&q->msg_avail_cond); pthread_cond_destroy(&q->space_avail_cond); } static void shared_queue_put(struct shared_queue *q, void *obj) { pthread_mutex_lock(&q->lock); while (q->filled_slots == q->size) pthread_cond_wait(&q->space_avail_cond, &q->lock); q->back = (q->back + 1) % q->size; q->array[q->back] = obj; q->filled_slots++; pthread_cond_broadcast(&q->msg_avail_cond); pthread_mutex_unlock(&q->lock); } static void *shared_queue_get(struct shared_queue *q) { void *obj; pthread_mutex_lock(&q->lock); while (q->filled_slots == 0) pthread_cond_wait(&q->msg_avail_cond, &q->lock); obj = q->array[q->front]; q->array[q->front] = NULL; q->front = (q->front + 1) % q->size; q->filled_slots--; pthread_cond_broadcast(&q->space_avail_cond); pthread_mutex_unlock(&q->lock); return obj; } struct compressor_thread_params { struct shared_queue *res_to_compress_queue; struct shared_queue *compressed_res_queue; compress_func_t compress; }; #define MAX_CHUNKS_PER_MSG 2 struct message { struct lookup_table_entry *lte; u8 *uncompressed_chunks[MAX_CHUNKS_PER_MSG]; u8 *out_compressed_chunks[MAX_CHUNKS_PER_MSG]; u8 *compressed_chunks[MAX_CHUNKS_PER_MSG]; unsigned uncompressed_chunk_sizes[MAX_CHUNKS_PER_MSG]; unsigned compressed_chunk_sizes[MAX_CHUNKS_PER_MSG]; unsigned num_chunks; struct list_head list; bool complete; u64 begin_chunk; }; static void compress_chunks(struct message *msg, compress_func_t compress) { for (unsigned i = 0; i < msg->num_chunks; i++) { DEBUG2("compress chunk %u of %u", i, msg->num_chunks); int ret = compress(msg->uncompressed_chunks[i], msg->uncompressed_chunk_sizes[i], msg->compressed_chunks[i], &msg->compressed_chunk_sizes[i]); if (ret == 0) { msg->out_compressed_chunks[i] = msg->compressed_chunks[i]; } else { msg->out_compressed_chunks[i] = msg->uncompressed_chunks[i]; msg->compressed_chunk_sizes[i] = msg->uncompressed_chunk_sizes[i]; } } } static void *compressor_thread_proc(void *arg) { struct compressor_thread_params *params = arg; struct shared_queue *res_to_compress_queue = params->res_to_compress_queue; struct shared_queue *compressed_res_queue = params->compressed_res_queue; compress_func_t compress = params->compress; struct message *msg; DEBUG("Compressor thread ready"); while ((msg = shared_queue_get(res_to_compress_queue)) != NULL) { compress_chunks(msg, compress); shared_queue_put(compressed_res_queue, msg); } DEBUG("Compressor thread terminating"); return NULL; } #endif static int do_write_stream_list(struct list_head *my_resources, FILE *out_fp, int out_ctype, wimlib_progress_func_t progress_func, union wimlib_progress_info *progress, int write_resource_flags) { int ret; struct lookup_table_entry *lte, *tmp; list_for_each_entry_safe(lte, tmp, my_resources, staging_list) { ret = write_wim_resource(lte, out_fp, out_ctype, <e->output_resource_entry, write_resource_flags); if (ret != 0) return ret; list_del(<e->staging_list); progress->write_streams.completed_bytes += wim_resource_size(lte); progress->write_streams.completed_streams++; if (progress_func) { progress_func(WIMLIB_PROGRESS_MSG_WRITE_STREAMS, progress); } } return 0; } static int write_stream_list_serial(struct list_head *stream_list, FILE *out_fp, int out_ctype, int write_flags, wimlib_progress_func_t progress_func, union wimlib_progress_info *progress) { int write_resource_flags; if (write_flags & WIMLIB_WRITE_FLAG_RECOMPRESS) write_resource_flags = WIMLIB_RESOURCE_FLAG_RECOMPRESS; else write_resource_flags = 0; progress->write_streams.num_threads = 1; if (progress_func) progress_func(WIMLIB_PROGRESS_MSG_WRITE_STREAMS, progress); return do_write_stream_list(stream_list, out_fp, out_ctype, progress_func, progress, write_resource_flags); } #ifdef ENABLE_MULTITHREADED_COMPRESSION static int write_wim_chunks(struct message *msg, FILE *out_fp, struct chunk_table *chunk_tab) { for (unsigned i = 0; i < msg->num_chunks; i++) { unsigned chunk_csize = msg->compressed_chunk_sizes[i]; DEBUG2("Write wim chunk %u of %u (csize = %u)", i, msg->num_chunks, chunk_csize); if (fwrite(msg->out_compressed_chunks[i], 1, chunk_csize, out_fp) != chunk_csize) { ERROR_WITH_ERRNO("Failed to write WIM chunk"); return WIMLIB_ERR_WRITE; } *chunk_tab->cur_offset_p++ = chunk_tab->cur_offset; chunk_tab->cur_offset += chunk_csize; } return 0; } /* * This function is executed by the main thread when the resources are being * compressed in parallel. The main thread is in change of all reading of the * uncompressed data and writing of the compressed data. The compressor threads * *only* do compression from/to in-memory buffers. * * Each unit of work given to a compressor thread is up to MAX_CHUNKS_PER_MSG * chunks of compressed data to compress, represented in a `struct message'. * Each message is passed from the main thread to a worker thread through the * res_to_compress_queue, and it is passed back through the * compressed_res_queue. */ static int main_writer_thread_proc(struct list_head *stream_list, FILE *out_fp, int out_ctype, struct shared_queue *res_to_compress_queue, struct shared_queue *compressed_res_queue, size_t queue_size, int write_flags, wimlib_progress_func_t progress_func, union wimlib_progress_info *progress) { int ret; struct message msgs[queue_size]; ZERO_ARRAY(msgs); // Initially, all the messages are available to use. LIST_HEAD(available_msgs); for (size_t i = 0; i < ARRAY_LEN(msgs); i++) list_add(&msgs[i].list, &available_msgs); // outstanding_resources is the list of resources that currently have // had chunks sent off for compression. // // The first stream in outstanding_resources is the stream that is // currently being written (cur_lte). // // The last stream in outstanding_resources is the stream that is // currently being read and chunks fed to the compressor threads // (next_lte). // // Depending on the number of threads and the sizes of the resource, // the outstanding streams list may contain streams between cur_lte and // next_lte that have all their chunks compressed or being compressed, // but haven't been written yet. // LIST_HEAD(outstanding_resources); struct list_head *next_resource = stream_list->next; struct lookup_table_entry *next_lte = container_of(next_resource, struct lookup_table_entry, staging_list); next_resource = next_resource->next; u64 next_chunk = 0; u64 next_num_chunks = wim_resource_chunks(next_lte); INIT_LIST_HEAD(&next_lte->msg_list); list_add_tail(&next_lte->staging_list, &outstanding_resources); // As in write_wim_resource(), each resource we read is checksummed. SHA_CTX next_sha_ctx; sha1_init(&next_sha_ctx); u8 next_hash[SHA1_HASH_SIZE]; // Resources that don't need any chunks compressed are added to this // list and written directly by the main thread. LIST_HEAD(my_resources); struct lookup_table_entry *cur_lte = next_lte; struct chunk_table *cur_chunk_tab = NULL; struct message *msg; #ifdef WITH_NTFS_3G ntfs_inode *ni = NULL; #endif #ifdef WITH_NTFS_3G ret = prepare_resource_for_read(next_lte, &ni); #else ret = prepare_resource_for_read(next_lte); #endif if (ret != 0) goto out; DEBUG("Initializing buffers for uncompressed " "and compressed data (%zu bytes needed)", queue_size * MAX_CHUNKS_PER_MSG * WIM_CHUNK_SIZE * 2); // Pre-allocate all the buffers that will be needed to do the chunk // compression. for (size_t i = 0; i < ARRAY_LEN(msgs); i++) { for (size_t j = 0; j < MAX_CHUNKS_PER_MSG; j++) { msgs[i].compressed_chunks[j] = MALLOC(WIM_CHUNK_SIZE); msgs[i].uncompressed_chunks[j] = MALLOC(WIM_CHUNK_SIZE); if (msgs[i].compressed_chunks[j] == NULL || msgs[i].uncompressed_chunks[j] == NULL) { ERROR("Could not allocate enough memory for " "multi-threaded compression"); ret = WIMLIB_ERR_NOMEM; goto out; } } } // This loop is executed until all resources have been written, except // possibly a few that have been added to the @my_resources list for // writing later. while (1) { // Send chunks to the compressor threads until either (a) there // are no more messages available since they were all sent off, // or (b) there are no more resources that need to be // compressed. while (!list_empty(&available_msgs) && next_lte != NULL) { // Get a message from the available messages // list msg = container_of(available_msgs.next, struct message, list); // ... and delete it from the available messages // list list_del(&msg->list); // Initialize the message with the chunks to // compress. msg->num_chunks = min(next_num_chunks - next_chunk, MAX_CHUNKS_PER_MSG); msg->lte = next_lte; msg->complete = false; msg->begin_chunk = next_chunk; unsigned size = WIM_CHUNK_SIZE; for (unsigned i = 0; i < msg->num_chunks; i++) { // Read chunk @next_chunk of the stream into the // message so that a compressor thread can // compress it. if (next_chunk == next_num_chunks - 1 && wim_resource_size(next_lte) % WIM_CHUNK_SIZE != 0) { size = wim_resource_size(next_lte) % WIM_CHUNK_SIZE; } DEBUG2("Read resource (size=%u, offset=%zu)", size, next_chunk * WIM_CHUNK_SIZE); msg->uncompressed_chunk_sizes[i] = size; ret = read_wim_resource(next_lte, msg->uncompressed_chunks[i], size, next_chunk * WIM_CHUNK_SIZE, 0); if (ret != 0) goto out; sha1_update(&next_sha_ctx, msg->uncompressed_chunks[i], size); next_chunk++; } // Send the compression request list_add_tail(&msg->list, &next_lte->msg_list); shared_queue_put(res_to_compress_queue, msg); DEBUG2("Compression request sent"); if (next_chunk != next_num_chunks) // More chunks to send for this resource continue; // Done sending compression requests for a resource! // Check the SHA1 message digest. DEBUG2("Finalize SHA1 md (next_num_chunks=%zu)", next_num_chunks); sha1_final(next_hash, &next_sha_ctx); if (!hashes_equal(next_lte->hash, next_hash)) { ERROR("WIM resource has incorrect hash!"); if (next_lte->resource_location == RESOURCE_IN_FILE_ON_DISK) { ERROR("We were reading it from `%s'; maybe it changed " "while we were reading it.", next_lte->file_on_disk); } ret = WIMLIB_ERR_INVALID_RESOURCE_HASH; goto out; } // Advance to the next resource. // // If the next resource needs no compression, just write // it with this thread (not now though--- we could be in // the middle of writing another resource.) Keep doing // this until we either get to the end of the resources // list, or we get to a resource that needs compression. while (1) { if (next_resource == stream_list) { next_lte = NULL; break; } #ifdef WITH_NTFS_3G end_wim_resource_read(next_lte, ni); ni = NULL; #else end_wim_resource_read(next_lte); #endif next_lte = container_of(next_resource, struct lookup_table_entry, staging_list); next_resource = next_resource->next; if ((!(write_flags & WIMLIB_WRITE_FLAG_RECOMPRESS) && next_lte->resource_location == RESOURCE_IN_WIM && wimlib_get_compression_type(next_lte->wim) == out_ctype) || wim_resource_size(next_lte) == 0) { list_add_tail(&next_lte->staging_list, &my_resources); } else { list_add_tail(&next_lte->staging_list, &outstanding_resources); next_chunk = 0; next_num_chunks = wim_resource_chunks(next_lte); sha1_init(&next_sha_ctx); INIT_LIST_HEAD(&next_lte->msg_list); #ifdef WITH_NTFS_3G ret = prepare_resource_for_read(next_lte, &ni); #else ret = prepare_resource_for_read(next_lte); #endif if (ret != 0) goto out; DEBUG2("Updated next_lte"); break; } } } // If there are no outstanding resources, there are no more // resources that need to be written. if (list_empty(&outstanding_resources)) { DEBUG("No outstanding resources! Done"); ret = 0; goto out; } // Get the next message from the queue and process it. // The message will contain 1 or more data chunks that have been // compressed. DEBUG2("Waiting for message"); msg = shared_queue_get(compressed_res_queue); msg->complete = true; DEBUG2("Received msg (begin_chunk=%"PRIu64")", msg->begin_chunk); list_for_each_entry(msg, &cur_lte->msg_list, list) { DEBUG2("complete=%d", msg->complete); } // Is this the next chunk in the current resource? If it's not // (i.e., an earlier chunk in a same or different resource // hasn't been compressed yet), do nothing, and keep this // message around until all earlier chunks are received. // // Otherwise, write all the chunks we can. while (!list_empty(&cur_lte->msg_list) && (msg = container_of(cur_lte->msg_list.next, struct message, list))->complete) { DEBUG2("Complete msg (begin_chunk=%"PRIu64")", msg->begin_chunk); if (msg->begin_chunk == 0) { DEBUG2("Begin chunk tab"); // This is the first set of chunks. Leave space // for the chunk table in the output file. off_t cur_offset = ftello(out_fp); if (cur_offset == -1) { ret = WIMLIB_ERR_WRITE; goto out; } ret = begin_wim_resource_chunk_tab(cur_lte, out_fp, cur_offset, &cur_chunk_tab); if (ret != 0) goto out; } // Write the compressed chunks from the message. ret = write_wim_chunks(msg, out_fp, cur_chunk_tab); if (ret != 0) goto out; list_del(&msg->list); // This message is available to use for different chunks // now. list_add(&msg->list, &available_msgs); // Was this the last chunk of the stream? If so, // finish it. if (list_empty(&cur_lte->msg_list) && msg->begin_chunk + msg->num_chunks == cur_chunk_tab->num_chunks) { DEBUG2("Finish wim chunk tab"); u64 res_csize; ret = finish_wim_resource_chunk_tab(cur_chunk_tab, out_fp, &res_csize); if (ret != 0) goto out; progress->write_streams.completed_bytes += wim_resource_size(cur_lte); progress->write_streams.completed_streams++; if (progress_func) { progress_func(WIMLIB_PROGRESS_MSG_WRITE_STREAMS, progress); } cur_lte->output_resource_entry.size = res_csize; cur_lte->output_resource_entry.original_size = cur_lte->resource_entry.original_size; cur_lte->output_resource_entry.offset = cur_chunk_tab->file_offset; cur_lte->output_resource_entry.flags = cur_lte->resource_entry.flags | WIM_RESHDR_FLAG_COMPRESSED; FREE(cur_chunk_tab); cur_chunk_tab = NULL; struct list_head *next = cur_lte->staging_list.next; list_del(&cur_lte->staging_list); if (next == &outstanding_resources) { DEBUG("No more outstanding resources"); ret = 0; goto out; } else { cur_lte = container_of(cur_lte->staging_list.next, struct lookup_table_entry, staging_list); } // Since we just finished writing a stream, // write any streams that have been added to the // my_resources list for direct writing by the // main thread (e.g. resources that don't need // to be compressed because the desired // compression type is the same as the previous // compression type). ret = do_write_stream_list(&my_resources, out_fp, out_ctype, progress_func, progress, 0); if (ret != 0) goto out; } } } out: #ifdef WITH_NTFS_3G end_wim_resource_read(cur_lte, ni); #else end_wim_resource_read(cur_lte); #endif if (ret == 0) { ret = do_write_stream_list(&my_resources, out_fp, out_ctype, progress_func, progress, 0); } else { size_t num_available_msgs = 0; struct list_head *cur; list_for_each(cur, &available_msgs) { num_available_msgs++; } while (num_available_msgs < ARRAY_LEN(msgs)) { shared_queue_get(compressed_res_queue); num_available_msgs++; } } for (size_t i = 0; i < ARRAY_LEN(msgs); i++) { for (size_t j = 0; j < MAX_CHUNKS_PER_MSG; j++) { FREE(msgs[i].compressed_chunks[j]); FREE(msgs[i].uncompressed_chunks[j]); } } if (cur_chunk_tab != NULL) FREE(cur_chunk_tab); return ret; } static int write_stream_list_parallel(struct list_head *stream_list, FILE *out_fp, int out_ctype, int write_flags, unsigned num_threads, wimlib_progress_func_t progress_func, union wimlib_progress_info *progress) { int ret; struct shared_queue res_to_compress_queue; struct shared_queue compressed_res_queue; pthread_t *compressor_threads = NULL; if (num_threads == 0) { long nthreads = sysconf(_SC_NPROCESSORS_ONLN); if (nthreads < 1) { WARNING("Could not determine number of processors! Assuming 1"); goto out_serial; } else { num_threads = nthreads; } } progress->write_streams.num_threads = num_threads; wimlib_assert(stream_list->next != stream_list); static const double MESSAGES_PER_THREAD = 2.0; size_t queue_size = (size_t)(num_threads * MESSAGES_PER_THREAD); DEBUG("Initializing shared queues (queue_size=%zu)", queue_size); ret = shared_queue_init(&res_to_compress_queue, queue_size); if (ret != 0) goto out_serial; ret = shared_queue_init(&compressed_res_queue, queue_size); if (ret != 0) goto out_destroy_res_to_compress_queue; struct compressor_thread_params params; params.res_to_compress_queue = &res_to_compress_queue; params.compressed_res_queue = &compressed_res_queue; params.compress = get_compress_func(out_ctype); compressor_threads = MALLOC(num_threads * sizeof(pthread_t)); for (unsigned i = 0; i < num_threads; i++) { DEBUG("pthread_create thread %u", i); ret = pthread_create(&compressor_threads[i], NULL, compressor_thread_proc, ¶ms); if (ret != 0) { ret = -1; ERROR_WITH_ERRNO("Failed to create compressor " "thread %u", i); num_threads = i; goto out_join; } } if (progress_func) progress_func(WIMLIB_PROGRESS_MSG_WRITE_STREAMS, progress); ret = main_writer_thread_proc(stream_list, out_fp, out_ctype, &res_to_compress_queue, &compressed_res_queue, queue_size, write_flags, progress_func, progress); out_join: for (unsigned i = 0; i < num_threads; i++) shared_queue_put(&res_to_compress_queue, NULL); for (unsigned i = 0; i < num_threads; i++) { if (pthread_join(compressor_threads[i], NULL)) { WARNING("Failed to join compressor thread %u: %s", i, strerror(errno)); } } FREE(compressor_threads); shared_queue_destroy(&compressed_res_queue); out_destroy_res_to_compress_queue: shared_queue_destroy(&res_to_compress_queue); if (ret >= 0 && ret != WIMLIB_ERR_NOMEM) return ret; out_serial: WARNING("Falling back to single-threaded compression"); return write_stream_list_serial(stream_list, out_fp, out_ctype, write_flags, progress_func, progress); } #endif /* * Write a list of streams to a WIM (@out_fp) using the compression type * @out_ctype and up to @num_threads compressor threads. */ static int write_stream_list(struct list_head *stream_list, FILE *out_fp, int out_ctype, int write_flags, unsigned num_threads, wimlib_progress_func_t progress_func) { struct lookup_table_entry *lte; size_t num_streams = 0; u64 total_bytes = 0; bool compression_needed = false; union wimlib_progress_info progress; int ret; list_for_each_entry(lte, stream_list, staging_list) { num_streams++; total_bytes += wim_resource_size(lte); if (!compression_needed && (out_ctype != WIMLIB_COMPRESSION_TYPE_NONE && (lte->resource_location != RESOURCE_IN_WIM || wimlib_get_compression_type(lte->wim) != out_ctype || (write_flags & WIMLIB_WRITE_FLAG_REBUILD))) && wim_resource_size(lte) != 0) compression_needed = true; } progress.write_streams.total_bytes = total_bytes; progress.write_streams.total_streams = num_streams; progress.write_streams.completed_bytes = 0; progress.write_streams.completed_streams = 0; progress.write_streams.num_threads = num_threads; progress.write_streams.compression_type = out_ctype; if (num_streams == 0) { ret = 0; goto out; } #ifdef ENABLE_MULTITHREADED_COMPRESSION if (compression_needed && total_bytes >= 1000000 && num_threads != 1) { ret = write_stream_list_parallel(stream_list, out_fp, out_ctype, write_flags, num_threads, progress_func, &progress); } else #endif { ret = write_stream_list_serial(stream_list, out_fp, out_ctype, write_flags, progress_func, &progress); } out: return ret; } static int dentry_find_streams_to_write(struct dentry *dentry, void *wim) { WIMStruct *w = wim; struct list_head *stream_list = w->private; struct lookup_table_entry *lte; for (unsigned i = 0; i <= dentry->d_inode->num_ads; i++) { lte = inode_stream_lte(dentry->d_inode, i, w->lookup_table); if (lte && ++lte->out_refcnt == 1) list_add_tail(<e->staging_list, stream_list); } return 0; } static int find_streams_to_write(WIMStruct *w) { return for_dentry_in_tree(wim_root_dentry(w), dentry_find_streams_to_write, w); } static int write_wim_streams(WIMStruct *w, int image, int write_flags, unsigned num_threads, wimlib_progress_func_t progress_func) { for_lookup_table_entry(w->lookup_table, lte_zero_out_refcnt, NULL); LIST_HEAD(stream_list); w->private = &stream_list; for_image(w, image, find_streams_to_write); return write_stream_list(&stream_list, w->out_fp, wimlib_get_compression_type(w), write_flags, num_threads, progress_func); } /* * Finish writing a WIM file: write the lookup table, xml data, and integrity * table (optional), then overwrite the WIM header. * * write_flags is a bitwise OR of the following: * * (public) WIMLIB_WRITE_FLAG_CHECK_INTEGRITY: * Include an integrity table. * * (public) WIMLIB_WRITE_FLAG_SHOW_PROGRESS: * Show progress information when (if) writing the integrity table. * * (private) WIMLIB_WRITE_FLAG_NO_LOOKUP_TABLE: * Don't write the lookup table. * * (private) WIMLIB_WRITE_FLAG_REUSE_INTEGRITY_TABLE: * When (if) writing the integrity table, re-use entries from the * existing integrity table, if possible. * * (private) WIMLIB_WRITE_FLAG_CHECKPOINT_AFTER_XML: * After writing the XML data but before writing the integrity * table, write a temporary WIM header and flush the stream so that * the WIM is less likely to become corrupted upon abrupt program * termination. * * (private) WIMLIB_WRITE_FLAG_FSYNC: * fsync() the output file before closing it. * */ int finish_write(WIMStruct *w, int image, int write_flags, wimlib_progress_func_t progress_func) { int ret; struct wim_header hdr; FILE *out = w->out_fp; /* @hdr will be the header for the new WIM. First copy all the data * from the header in the WIMStruct; then set all the fields that may * have changed, including the resource entries, boot index, and image * count. */ memcpy(&hdr, &w->hdr, sizeof(struct wim_header)); if (!(write_flags & WIMLIB_WRITE_FLAG_NO_LOOKUP_TABLE)) { ret = write_lookup_table(w->lookup_table, out, &hdr.lookup_table_res_entry); if (ret != 0) goto out; } ret = write_xml_data(w->wim_info, image, out, (write_flags & WIMLIB_WRITE_FLAG_NO_LOOKUP_TABLE) ? wim_info_get_total_bytes(w->wim_info) : 0, &hdr.xml_res_entry); if (ret != 0) goto out; if (write_flags & WIMLIB_WRITE_FLAG_CHECK_INTEGRITY) { if (write_flags & WIMLIB_WRITE_FLAG_CHECKPOINT_AFTER_XML) { struct wim_header checkpoint_hdr; memcpy(&checkpoint_hdr, &hdr, sizeof(struct wim_header)); memset(&checkpoint_hdr.integrity, 0, sizeof(struct resource_entry)); if (fseeko(out, 0, SEEK_SET) != 0) { ret = WIMLIB_ERR_WRITE; goto out; } ret = write_header(&checkpoint_hdr, out); if (ret != 0) goto out; if (fflush(out) != 0) { ERROR_WITH_ERRNO("Can't write data to WIM"); ret = WIMLIB_ERR_WRITE; goto out; } if (fseeko(out, 0, SEEK_END) != 0) { ret = WIMLIB_ERR_WRITE; goto out; } } off_t old_lookup_table_end; off_t new_lookup_table_end; if (write_flags & WIMLIB_WRITE_FLAG_REUSE_INTEGRITY_TABLE) { old_lookup_table_end = w->hdr.lookup_table_res_entry.offset + w->hdr.lookup_table_res_entry.size; } else { old_lookup_table_end = 0; } new_lookup_table_end = hdr.lookup_table_res_entry.offset + hdr.lookup_table_res_entry.size; ret = write_integrity_table(out, &hdr.integrity, new_lookup_table_end, old_lookup_table_end, progress_func); if (ret != 0) goto out; } else { memset(&hdr.integrity, 0, sizeof(struct resource_entry)); } /* * In the WIM header, there is room for the resource entry for a * metadata resource labeled as the "boot metadata". This entry should * be zeroed out if there is no bootable image (boot_idx 0). Otherwise, * it should be a copy of the resource entry for the image that is * marked as bootable. This is not well documented... */ if (hdr.boot_idx == 0 || !w->image_metadata || (image != WIMLIB_ALL_IMAGES && image != hdr.boot_idx)) { memset(&hdr.boot_metadata_res_entry, 0, sizeof(struct resource_entry)); } else { memcpy(&hdr.boot_metadata_res_entry, &w->image_metadata[ hdr.boot_idx - 1].metadata_lte->output_resource_entry, sizeof(struct resource_entry)); } /* Set image count and boot index correctly for single image writes */ if (image != WIMLIB_ALL_IMAGES) { hdr.image_count = 1; if (hdr.boot_idx == image) hdr.boot_idx = 1; else hdr.boot_idx = 0; } if (fseeko(out, 0, SEEK_SET) != 0) { ret = WIMLIB_ERR_WRITE; goto out; } ret = write_header(&hdr, out); if (ret != 0) goto out; if (write_flags & WIMLIB_WRITE_FLAG_FSYNC) { if (fflush(out) != 0 || fsync(fileno(out)) != 0) { ERROR_WITH_ERRNO("Error flushing data to WIM file"); ret = WIMLIB_ERR_WRITE; } } out: if (fclose(out) != 0) { ERROR_WITH_ERRNO("Failed to close the WIM file"); if (ret == 0) ret = WIMLIB_ERR_WRITE; } w->out_fp = NULL; return ret; } #if defined(HAVE_SYS_FILE_H) && defined(HAVE_FLOCK) int lock_wim(FILE *fp, const char *path) { int ret = 0; if (fp) { ret = flock(fileno(fp), LOCK_EX | LOCK_NB); if (ret != 0) { if (errno == EWOULDBLOCK) { ERROR("`%s' is already being modified or has been " "mounted read-write\n" " by another process!", path); ret = WIMLIB_ERR_ALREADY_LOCKED; } else { WARNING("Failed to lock `%s': %s", path, strerror(errno)); ret = 0; } } } return ret; } #endif static int open_wim_writable(WIMStruct *w, const char *path, bool trunc, bool readable) { const char *mode; int ret = 0; if (trunc) if (readable) mode = "w+b"; else mode = "wb"; else mode = "r+b"; DEBUG("Opening `%s' read-write", path); wimlib_assert(w->out_fp == NULL); wimlib_assert(path != NULL); w->out_fp = fopen(path, mode); if (!w->out_fp) { ERROR_WITH_ERRNO("Failed to open `%s' for writing", path); return WIMLIB_ERR_OPEN; } if (trunc) { ret = lock_wim(w->out_fp, path); if (ret != 0) { fclose(w->out_fp); w->out_fp = NULL; } } return ret; } static void close_wim_writable(WIMStruct *w) { if (w->out_fp) { if (fclose(w->out_fp) != 0) { WARNING("Failed to close output WIM: %s", strerror(errno)); } w->out_fp = NULL; } } /* Open file stream and write dummy header for WIM. */ int begin_write(WIMStruct *w, const char *path, int write_flags) { int ret; bool need_readable = false; bool trunc = true; if (write_flags & WIMLIB_WRITE_FLAG_CHECK_INTEGRITY) need_readable = true; ret = open_wim_writable(w, path, trunc, need_readable); if (ret != 0) return ret; /* Write dummy header. It will be overwritten later. */ return write_header(&w->hdr, w->out_fp); } /* Writes a stand-alone WIM to a file. */ WIMLIBAPI int wimlib_write(WIMStruct *w, const char *path, int image, int write_flags, unsigned num_threads, wimlib_progress_func_t progress_func) { int ret; if (!w || !path) return WIMLIB_ERR_INVALID_PARAM; write_flags &= WIMLIB_WRITE_MASK_PUBLIC; if (image != WIMLIB_ALL_IMAGES && (image < 1 || image > w->hdr.image_count)) return WIMLIB_ERR_INVALID_IMAGE; if (w->hdr.total_parts != 1) { ERROR("Cannot call wimlib_write() on part of a split WIM"); return WIMLIB_ERR_SPLIT_UNSUPPORTED; } ret = begin_write(w, path, write_flags); if (ret != 0) goto out; ret = write_wim_streams(w, image, write_flags, num_threads, progress_func); if (ret != 0) goto out; if (progress_func) progress_func(WIMLIB_PROGRESS_MSG_WRITE_METADATA_BEGIN, NULL); ret = for_image(w, image, write_metadata_resource); if (ret != 0) goto out; if (progress_func) progress_func(WIMLIB_PROGRESS_MSG_WRITE_METADATA_END, NULL); ret = finish_write(w, image, write_flags, progress_func); out: close_wim_writable(w); return ret; } static int lte_overwrite_prepare(struct lookup_table_entry *lte, void *ignore) { memcpy(<e->output_resource_entry, <e->resource_entry, sizeof(struct resource_entry)); lte->out_refcnt = 0; return 0; } static int check_resource_offset(struct lookup_table_entry *lte, void *arg) { off_t end_offset = *(u64*)arg; wimlib_assert(lte->out_refcnt <= lte->refcnt); if (lte->out_refcnt < lte->refcnt) { if (lte->resource_entry.offset + lte->resource_entry.size > end_offset) { ERROR("The following resource is after the XML data:"); print_lookup_table_entry(lte); return WIMLIB_ERR_RESOURCE_ORDER; } } return 0; } static int find_new_streams(struct lookup_table_entry *lte, void *arg) { if (lte->out_refcnt == lte->refcnt) list_add(<e->staging_list, (struct list_head*)arg); else lte->out_refcnt = lte->refcnt; return 0; } /* * Overwrite a WIM, possibly appending streams to it. * * A WIM looks like (or is supposed to look like) the following: * * Header (212 bytes) * Streams and metadata resources (variable size) * Lookup table (variable size) * XML data (variable size) * Integrity table (optional) (variable size) * * If we are not adding any streams or metadata resources, the lookup table is * unchanged--- so we only need to overwrite the XML data, integrity table, and * header. This operation is potentially unsafe if the program is abruptly * terminated while the XML data or integrity table are being overwritten, but * before the new header has been written. To partially alleviate this problem, * a special flag (WIMLIB_WRITE_FLAG_CHECKPOINT_AFTER_XML) is passed to * finish_write() to cause a temporary WIM header to be written after the XML * data has been written. This may prevent the WIM from becoming corrupted if * the program is terminated while the integrity table is being calculated (but * no guarantees, due to write re-ordering...). * * If we are adding new streams or images (metadata resources), the lookup table * needs to be changed, and those streams need to be written. In this case, we * try to perform a safe update of the WIM file by writing the streams *after* * the end of the previous WIM, then writing the new lookup table, XML data, and * (optionally) integrity table following the new streams. This will produce a * layout like the following: * * Header (212 bytes) * (OLD) Streams and metadata resources (variable size) * (OLD) Lookup table (variable size) * (OLD) XML data (variable size) * (OLD) Integrity table (optional) (variable size) * (NEW) Streams and metadata resources (variable size) * (NEW) Lookup table (variable size) * (NEW) XML data (variable size) * (NEW) Integrity table (optional) (variable size) * * At all points, the WIM is valid as nothing points to the new data yet. Then, * the header is overwritten to point to the new lookup table, XML data, and * integrity table, to produce the following layout: * * Header (212 bytes) * Streams and metadata resources (variable size) * Nothing (variable size) * More Streams and metadata resources (variable size) * Lookup table (variable size) * XML data (variable size) * Integrity table (optional) (variable size) * * This method allows an image to be appended to a large WIM very quickly, and * is is crash-safe except in the case of write re-ordering, but the * disadvantage is that a small hole is left in the WIM where the old lookup * table, xml data, and integrity table were. (These usually only take up a * small amount of space compared to the streams, however. */ static int overwrite_wim_inplace(WIMStruct *w, int write_flags, unsigned num_threads, wimlib_progress_func_t progress_func, int modified_image_idx) { int ret; struct list_head stream_list; off_t old_wim_end; DEBUG("Overwriting `%s' in-place", w->filename); /* Make sure that the integrity table (if present) is after the XML * data, and that there are no stream resources, metadata resources, or * lookup tables after the XML data. Otherwise, these data would be * overwritten. */ if (w->hdr.integrity.offset != 0 && w->hdr.integrity.offset < w->hdr.xml_res_entry.offset) { ERROR("Didn't expect the integrity table to be before the XML data"); return WIMLIB_ERR_RESOURCE_ORDER; } if (w->hdr.lookup_table_res_entry.offset > w->hdr.xml_res_entry.offset) { ERROR("Didn't expect the lookup table to be after the XML data"); return WIMLIB_ERR_RESOURCE_ORDER; } DEBUG("Identifying newly added streams"); for_lookup_table_entry(w->lookup_table, lte_overwrite_prepare, NULL); INIT_LIST_HEAD(&stream_list); for (int i = modified_image_idx; i < w->hdr.image_count; i++) { DEBUG("Identifiying streams in image %d", i + 1); wimlib_assert(w->image_metadata[i].modified); wimlib_assert(!w->image_metadata[i].has_been_mounted_rw); wimlib_assert(w->image_metadata[i].root_dentry != NULL); wimlib_assert(w->image_metadata[i].metadata_lte != NULL); w->private = &stream_list; for_dentry_in_tree(w->image_metadata[i].root_dentry, dentry_find_streams_to_write, w); } if (w->hdr.integrity.offset) old_wim_end = w->hdr.integrity.offset + w->hdr.integrity.size; else old_wim_end = w->hdr.xml_res_entry.offset + w->hdr.xml_res_entry.size; ret = for_lookup_table_entry(w->lookup_table, check_resource_offset, &old_wim_end); if (ret != 0) return ret; if (modified_image_idx == w->hdr.image_count && !w->deletion_occurred) { /* If no images have been modified and no images have been * deleted, a new lookup table does not need to be written. */ wimlib_assert(list_empty(&stream_list)); old_wim_end = w->hdr.lookup_table_res_entry.offset + w->hdr.lookup_table_res_entry.size; write_flags |= WIMLIB_WRITE_FLAG_NO_LOOKUP_TABLE | WIMLIB_WRITE_FLAG_CHECKPOINT_AFTER_XML; } INIT_LIST_HEAD(&stream_list); for_lookup_table_entry(w->lookup_table, find_new_streams, &stream_list); ret = open_wim_writable(w, w->filename, false, (write_flags & WIMLIB_WRITE_FLAG_CHECK_INTEGRITY) != 0); if (ret != 0) return ret; if (fseeko(w->out_fp, old_wim_end, SEEK_SET) != 0) { ERROR_WITH_ERRNO("Can't seek to end of WIM"); return WIMLIB_ERR_WRITE; } if (!list_empty(&stream_list)) { DEBUG("Writing newly added streams (offset = %"PRIu64")", old_wim_end); ret = write_stream_list(&stream_list, w->out_fp, wimlib_get_compression_type(w), write_flags, num_threads, progress_func); if (ret != 0) goto out_ftruncate; } else { DEBUG("No new streams were added"); } for (int i = modified_image_idx; i < w->hdr.image_count; i++) { select_wim_image(w, i + 1); ret = write_metadata_resource(w); if (ret != 0) goto out_ftruncate; } write_flags |= WIMLIB_WRITE_FLAG_REUSE_INTEGRITY_TABLE; ret = finish_write(w, WIMLIB_ALL_IMAGES, write_flags, progress_func); out_ftruncate: close_wim_writable(w); if (ret != 0) { WARNING("Truncating `%s' to its original size (%"PRIu64" bytes)", w->filename, old_wim_end); truncate(w->filename, old_wim_end); } return ret; } static int overwrite_wim_via_tmpfile(WIMStruct *w, int write_flags, unsigned num_threads, wimlib_progress_func_t progress_func) { size_t wim_name_len; int ret; DEBUG("Overwriting `%s' via a temporary file", w->filename); /* Write the WIM to a temporary file in the same directory as the * original WIM. */ wim_name_len = strlen(w->filename); char tmpfile[wim_name_len + 10]; memcpy(tmpfile, w->filename, wim_name_len); randomize_char_array_with_alnum(tmpfile + wim_name_len, 9); tmpfile[wim_name_len + 9] = '\0'; ret = wimlib_write(w, tmpfile, WIMLIB_ALL_IMAGES, write_flags | WIMLIB_WRITE_FLAG_FSYNC, num_threads, progress_func); if (ret != 0) { ERROR("Failed to write the WIM file `%s'", tmpfile); goto err; } /* Close the original WIM file that was opened for reading. */ if (w->fp != NULL) { fclose(w->fp); w->fp = NULL; } DEBUG("Renaming `%s' to `%s'", tmpfile, w->filename); /* Rename the new file to the old file .*/ if (rename(tmpfile, w->filename) != 0) { ERROR_WITH_ERRNO("Failed to rename `%s' to `%s'", tmpfile, w->filename); ret = WIMLIB_ERR_RENAME; goto err; } if (progress_func) { union wimlib_progress_info progress; progress.rename.from = tmpfile; progress.rename.to = w->filename; progress_func(WIMLIB_PROGRESS_MSG_RENAME, &progress); } /* Re-open the WIM read-only. */ w->fp = fopen(w->filename, "rb"); if (w->fp == NULL) { ret = WIMLIB_ERR_REOPEN; WARNING("Failed to re-open `%s' read-only: %s", w->filename, strerror(errno)); } return ret; err: /* Remove temporary file. */ if (unlink(tmpfile) != 0) WARNING("Failed to remove `%s': %s", tmpfile, strerror(errno)); return ret; } /* * Writes a WIM file to the original file that it was read from, overwriting it. */ WIMLIBAPI int wimlib_overwrite(WIMStruct *w, int write_flags, unsigned num_threads, wimlib_progress_func_t progress_func) { if (!w) return WIMLIB_ERR_INVALID_PARAM; write_flags &= WIMLIB_WRITE_MASK_PUBLIC; if (!w->filename) return WIMLIB_ERR_NO_FILENAME; if (w->hdr.total_parts != 1) { ERROR("Cannot modify a split WIM"); return WIMLIB_ERR_SPLIT_UNSUPPORTED; } if ((!w->deletion_occurred || (write_flags & WIMLIB_WRITE_FLAG_SOFT_DELETE)) && !(write_flags & WIMLIB_WRITE_FLAG_REBUILD)) { int i, modified_image_idx; for (i = 0; i < w->hdr.image_count && !w->image_metadata[i].modified; i++) ; modified_image_idx = i; for (; i < w->hdr.image_count && w->image_metadata[i].modified && !w->image_metadata[i].has_been_mounted_rw; i++) ; if (i == w->hdr.image_count) { return overwrite_wim_inplace(w, write_flags, num_threads, progress_func, modified_image_idx); } } return overwrite_wim_via_tmpfile(w, write_flags, num_threads, progress_func); }