um/drivers/cow_user.c

63  *	Move the backing_file field to the end of the header.  This allows
200 	struct cow_header_v3 *header;
211 	header = cow_malloc(sizeof(*header));
212 	if (header == NULL) {
214 			   "header\n");
217 	header->magic = htobe32(COW_MAGIC);
218 	header->version = htobe32(COW_VERSION);
221 	if (strlen(backing_file) > sizeof(header->backing_file) - 1) {
225 			   sizeof(header->backing_file) - 1);
229 	if (absolutize(header->backing_file, sizeof(header->backing_file),
233 	err = os_file_modtime(header->backing_file, &modtime);
236 			   "request failed, err = %d\n", header->backing_file,
241 	err = cow_file_size(header->backing_file, size);
245 			   header->backing_file, -err);
249 	header->mtime = htobe32(modtime);
250 	header->size = htobe64(*size);
251 	header->sectorsize = htobe32(sectorsize);
252 	header->alignment = htobe32(alignment);
253 	header->cow_format = COW_BITMAP;
255 	err = cow_write_file(fd, header, sizeof(*header));
256 	if (err != sizeof(*header)) {
257 		cow_printf("write_cow_header - write of header to "
264 	cow_free(header);
276 /* XXX Need to sanity-check the values read from the header */
284 	union cow_header *header;
289 	header = cow_malloc(sizeof(*header));
290 	if (header == NULL) {
291 	        cow_printf("read_cow_header - Failed to allocate header\n");
295 	n = (*reader)(0, (char *) header, sizeof(*header), arg);
296 	if (n < offsetof(typeof(header->v1), backing_file)) {
297 		cow_printf("read_cow_header - short header\n");
301 	magic = header->v1.magic;
303 		version = header->v1.version;
305 		version = be32toh(header->v1.version);
312 		if (n < sizeof(header->v1)) {
314 				   "header\n");
317 		*mtime_out = header->v1.mtime;
318 		*size_out = header->v1.size;
319 		*sectorsize_out = header->v1.sectorsize;
320 		*bitmap_offset_out = sizeof(header->v1);
322 		file = header->v1.backing_file;
325 		if (n < sizeof(header->v2)) {
327 				   "header\n");
330 		*mtime_out = be32toh(header->v2.mtime);
331 		*size_out = be64toh(header->v2.size);
332 		*sectorsize_out = be32toh(header->v2.sectorsize);
333 		*bitmap_offset_out = sizeof(header->v2);
335 		file = header->v2.backing_file;
338 	else if (version == 3 && (*((int*)header->v3.backing_file) != 0)) {
339 		if (n < sizeof(header->v3)) {
341 				   "header\n");
344 		*mtime_out = be32toh(header->v3.mtime);
345 		*size_out = be64toh(header->v3.size);
346 		*sectorsize_out = be32toh(header->v3.sectorsize);
347 		*align_out = be32toh(header->v3.alignment);
349 			cow_printf("read_cow_header - invalid COW header, "
352 		*bitmap_offset_out = ROUND_UP(sizeof(header->v3), *align_out);
353 		file = header->v3.backing_file;
359 		if (n < sizeof(header->v3_b)) {
361 				   "header\n");
374 		*mtime_out = (time32_t) be32toh(header->v3_b.mtime);
376 		*size_out = be64toh(header->v3_b.size);
377 		*sectorsize_out = be32toh(header->v3_b.sectorsize);
378 		*align_out = be32toh(header->v3_b.alignment);
380 			cow_printf("read_cow_header - invalid COW header, "
383 		*bitmap_offset_out = ROUND_UP(sizeof(header->v3_b), *align_out);
384 		file = header->v3_b.backing_file;
399 	cow_free(header);