1 /*
2 * windows_io.c --- This is the Windows implementation of the I/O manager.
3 *
4 * Implements a one-block write-through cache.
5 *
6 * Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
7 * 2002 by Theodore Ts'o.
8 *
9 * %Begin-Header%
10 * This file may be redistributed under the terms of the GNU Library
11 * General Public License, version 2.
12 * %End-Header%
13 */
14
15 #include <windows.h>
16 #include <winioctl.h>
17 #include <io.h>
18
19 #if !defined(__FreeBSD__) && !defined(__NetBSD__) && !defined(__OpenBSD__)
20 #define _XOPEN_SOURCE 600
21 #define _DARWIN_C_SOURCE
22 #define _FILE_OFFSET_BITS 64
23 #ifndef _LARGEFILE_SOURCE
24 #define _LARGEFILE_SOURCE
25 #endif
26 #ifndef _LARGEFILE64_SOURCE
27 #define _LARGEFILE64_SOURCE
28 #endif
29 #ifndef _GNU_SOURCE
30 #define _GNU_SOURCE
31 #endif
32 #endif
33
34 #include "config.h"
35 #include <stdio.h>
36 #include <string.h>
37 #if HAVE_UNISTD_H
38 #include <unistd.h>
39 #endif
40 #if HAVE_ERRNO_H
41 #include <errno.h>
42 #endif
43 #include <fcntl.h>
44 #include <time.h>
45 #if HAVE_SYS_TYPES_H
46 #include <sys/types.h>
47 #endif
48 #define PR_GET_DUMPABLE 3
49 #if HAVE_SYS_STAT_H
50 #include <sys/stat.h>
51 #endif
52 #include <fcntl.h>
53
54 #undef ALIGN_DEBUG
55
56 //#define DEBUG
57 #ifdef DEBUG
58 #define TRACE(...) {\
59 char __log[256];\
60 snprintf(__log, sizeof(__log), __VA_ARGS__);\
61 __log[sizeof(__log)-1] = 0;\
62 OutputDebugString(__log);\
63 }
64 #else
65 #define TRACE(...) do { } while (0);
66 #endif
67
68 #include "ext2_fs.h"
69 #include "ext2fs.h"
70 #include "ext2fsP.h"
71
72 /*
73 * For checking structure magic numbers...
74 */
75
76 #define EXT2_CHECK_MAGIC(struct, code) \
77 if ((struct)->magic != (code)) return (code)
78 #define EXT2_CHECK_MAGIC_RETURN(struct, code, ret) \
79 if ((struct)->magic != (code)) return (ret)
80
81 #define EXT2_ET_MAGIC_WINDOWS_IO_CHANNEL 0x10ed
82
83 struct windows_cache {
84 char *buf;
85 unsigned long long block;
86 int access_time;
87 unsigned dirty:1;
88 unsigned in_use:1;
89 };
90
91 #define CACHE_SIZE 8
92 #define WRITE_DIRECT_SIZE 4 /* Must be smaller than CACHE_SIZE */
93 #define READ_DIRECT_SIZE 4 /* Should be smaller than CACHE_SIZE */
94
95 struct windows_private_data {
96 int magic;
97 char name[MAX_PATH];
98 HANDLE handle;
99 char dos_device[MAX_PATH];
100 char cf_device[MAX_PATH];
101 int dev;
102 int flags;
103 int align;
104 int access_time;
105 ext2_loff_t offset;
106 struct windows_cache cache[CACHE_SIZE];
107 void *bounce;
108 struct struct_io_stats io_stats;
109 };
110
111 #define IS_ALIGNED(n, align) ((((uintptr_t) n) & \
112 ((uintptr_t) ((align)-1))) == 0)
113
fake_dos_name_for_device(struct windows_private_data * data)114 static int fake_dos_name_for_device(struct windows_private_data *data)
115 {
116 if (strncmp(data->name, "\\\\", 2) == 0) {
117 data->dos_device[0] = 0;
118 strcpy(data->cf_device, data->name);
119 return 0;
120 }
121
122 _snprintf(data->dos_device, MAX_PATH, "fakedevice%lu", GetCurrentProcessId());
123
124 if (!DefineDosDevice(DDD_RAW_TARGET_PATH, data->dos_device, data->name))
125 return 1;
126
127 _snprintf(data->cf_device, MAX_PATH, "\\\\.\\%s", data->dos_device);
128 TRACE("e2fsprogs::fake_dos_name_for_device::DefineDosDevice(\"%s\")", data->dos_device);
129
130 return 0;
131 }
132
remove_fake_dos_name(struct windows_private_data * data)133 static void remove_fake_dos_name(struct windows_private_data *data)
134 {
135 if (*data->dos_device) {
136 TRACE("e2fsprogs::remove_fake_dos_name::DefineDosDevice(\"%s\")", data->dos_device);
137 DefineDosDevice(DDD_RAW_TARGET_PATH | DDD_EXACT_MATCH_ON_REMOVE | DDD_REMOVE_DEFINITION, data->dos_device, data->name);
138 }
139 }
140
windows_get_stats(io_channel channel,io_stats * stats)141 static errcode_t windows_get_stats(io_channel channel, io_stats *stats)
142 {
143 errcode_t retval = 0;
144
145 struct windows_private_data *data;
146
147 EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
148 data = (struct windows_private_data *) channel->private_data;
149 EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_WINDOWS_IO_CHANNEL);
150
151 if (stats)
152 *stats = &data->io_stats;
153
154 return retval;
155 }
156
157 /*
158 * Here are the raw I/O functions
159 */
raw_read_blk(io_channel channel,struct windows_private_data * data,unsigned long long block,int count,void * bufv)160 static errcode_t raw_read_blk(io_channel channel,
161 struct windows_private_data *data,
162 unsigned long long block,
163 int count, void *bufv)
164 {
165 errcode_t retval;
166 ssize_t size;
167 ext2_loff_t location;
168 DWORD actual = 0;
169 unsigned char *buf = bufv;
170 ssize_t really_read = 0;
171
172 size = (count < 0) ? -count : count * channel->block_size;
173 data->io_stats.bytes_read += size;
174 location = ((ext2_loff_t) block * channel->block_size) + data->offset;
175
176 if (data->flags & IO_FLAG_FORCE_BOUNCE) {
177 if (SetFilePointer(data->handle, location, NULL, FILE_BEGIN) == INVALID_SET_FILE_POINTER) {
178 retval = GetLastError();
179 goto error_out;
180 }
181 goto bounce_read;
182 }
183
184 if (SetFilePointer(data->handle, location, NULL, FILE_BEGIN) == INVALID_SET_FILE_POINTER) {
185 retval = GetLastError();
186 goto error_out;
187 }
188 if ((channel->align == 0) || (IS_ALIGNED(buf, channel->align) && IS_ALIGNED(size, channel->align))) {
189 if (!ReadFile(data->handle, buf, size, &actual, NULL)) {
190 retval = GetLastError();
191 goto error_out;
192 }
193 if (actual != size) {
194 short_read:
195 if (actual < 0) {
196 retval = GetLastError();
197 actual = 0;
198 } else
199 retval = EXT2_ET_SHORT_READ;
200 goto error_out;
201 }
202 return 0;
203 }
204
205 /*
206 * The buffer or size which we're trying to read isn't aligned
207 * to the O_DIRECT rules, so we need to do this the hard way...
208 */
209 bounce_read:
210 while (size > 0) {
211 if (!ReadFile(data->handle, data->bounce, channel->block_size, &actual, NULL)) {
212 retval = GetLastError();
213 goto error_out;
214 }
215 if (actual != channel->block_size) {
216 actual = really_read;
217 buf -= really_read;
218 size += really_read;
219 goto short_read;
220 }
221 actual = size;
222 if (size > channel->block_size)
223 actual = channel->block_size;
224 memcpy(buf, data->bounce, actual);
225 really_read += actual;
226 size -= actual;
227 buf += actual;
228 }
229 return 0;
230
231 error_out:
232 if (actual >= 0 && actual < size)
233 memset((char *) buf+actual, 0, size-actual);
234 if (channel->read_error)
235 retval = (channel->read_error)(channel, block, count, buf,
236 size, actual, retval);
237 return retval;
238 }
239
raw_write_blk(io_channel channel,struct windows_private_data * data,unsigned long long block,int count,const void * bufv)240 static errcode_t raw_write_blk(io_channel channel,
241 struct windows_private_data *data,
242 unsigned long long block,
243 int count, const void *bufv)
244 {
245 ssize_t size;
246 ext2_loff_t location;
247 DWORD actual = 0;
248 errcode_t retval;
249 const unsigned char *buf = bufv;
250
251 if (count == 1)
252 size = channel->block_size;
253 else {
254 if (count < 0)
255 size = -count;
256 else
257 size = count * channel->block_size;
258 }
259 data->io_stats.bytes_written += size;
260
261 location = ((ext2_loff_t) block * channel->block_size) + data->offset;
262
263 if (data->flags & IO_FLAG_FORCE_BOUNCE) {
264 if (SetFilePointer(data->handle, location, NULL, FILE_BEGIN) == INVALID_SET_FILE_POINTER) {
265 retval = GetLastError();
266 goto error_out;
267 }
268 goto bounce_write;
269 }
270
271 if (SetFilePointer(data->handle, location, NULL, FILE_BEGIN) == INVALID_SET_FILE_POINTER) {
272 retval = GetLastError();
273 goto error_out;
274 }
275
276 SetLastError(0);
277
278 if ((channel->align == 0) || (IS_ALIGNED(buf, channel->align) && IS_ALIGNED(size, channel->align))) {
279 if (!WriteFile(data->handle, buf, size, &actual, NULL)) {
280 retval = GetLastError();
281 goto error_out;
282 }
283
284 if (actual != size) {
285 short_write:
286 retval = EXT2_ET_SHORT_WRITE;
287 goto error_out;
288 }
289 return 0;
290 }
291
292 /*
293 * The buffer or size which we're trying to write isn't aligned
294 * to the O_DIRECT rules, so we need to do this the hard way...
295 */
296 bounce_write:
297 while (size > 0) {
298 if (size < channel->block_size) {
299 if (!ReadFile(data->handle, data->bounce, channel->block_size, &actual, NULL)) {
300 retval = GetLastError();
301 goto error_out;
302 }
303 if (actual != channel->block_size) {
304 if (actual < 0) {
305 retval = GetLastError();
306 goto error_out;
307 }
308 memset((char *) data->bounce + actual, 0,
309 channel->block_size - actual);
310 }
311 }
312 actual = size;
313 if (size > channel->block_size)
314 actual = channel->block_size;
315 memcpy(data->bounce, buf, actual);
316 if (SetFilePointer(data->handle, location, NULL, FILE_BEGIN) == INVALID_SET_FILE_POINTER) {
317 retval = GetLastError();
318 goto error_out;
319 }
320 if (!WriteFile(data->handle, data->bounce, channel->block_size, &actual, NULL)) {
321 retval = GetLastError();
322 goto error_out;
323 }
324
325 if (actual != channel->block_size)
326 goto short_write;
327 size -= actual;
328 buf += actual;
329 location += actual;
330 }
331 return 0;
332
333 error_out:
334 if (channel->write_error)
335 retval = (channel->write_error)(channel, block, count, buf,
336 size, actual, retval);
337 return retval;
338 }
339
340
341 /*
342 * Here we implement the cache functions
343 */
344
345 /* Allocate the cache buffers */
alloc_cache(io_channel channel,struct windows_private_data * data)346 static errcode_t alloc_cache(io_channel channel,
347 struct windows_private_data *data)
348 {
349 errcode_t retval;
350 struct windows_cache *cache;
351 int i;
352
353 data->access_time = 0;
354 for (i=0, cache = data->cache; i < CACHE_SIZE; i++, cache++) {
355 cache->block = 0;
356 cache->access_time = 0;
357 cache->dirty = 0;
358 cache->in_use = 0;
359 if (cache->buf)
360 ext2fs_free_mem(&cache->buf);
361 retval = io_channel_alloc_buf(channel, 0, &cache->buf);
362 if (retval)
363 return retval;
364 }
365 if (channel->align || data->flags & IO_FLAG_FORCE_BOUNCE) {
366 if (data->bounce)
367 ext2fs_free_mem(&data->bounce);
368 retval = io_channel_alloc_buf(channel, 0, &data->bounce);
369 }
370 return retval;
371 }
372
373 /* Free the cache buffers */
free_cache(struct windows_private_data * data)374 static void free_cache(struct windows_private_data *data)
375 {
376 struct windows_cache *cache;
377 int i;
378
379 data->access_time = 0;
380 for (i=0, cache = data->cache; i < CACHE_SIZE; i++, cache++) {
381 cache->block = 0;
382 cache->access_time = 0;
383 cache->dirty = 0;
384 cache->in_use = 0;
385 if (cache->buf)
386 ext2fs_free_mem(&cache->buf);
387 }
388 if (data->bounce)
389 ext2fs_free_mem(&data->bounce);
390 }
391
392 #ifndef NO_IO_CACHE
393 /*
394 * Try to find a block in the cache. If the block is not found, and
395 * eldest is a non-zero pointer, then fill in eldest with the cache
396 * entry to that should be reused.
397 */
find_cached_block(struct windows_private_data * data,unsigned long long block,struct windows_cache ** eldest)398 static struct windows_cache *find_cached_block(struct windows_private_data *data,
399 unsigned long long block,
400 struct windows_cache **eldest)
401 {
402 struct windows_cache *cache, *unused_cache, *oldest_cache;
403 int i;
404
405 unused_cache = oldest_cache = 0;
406 for (i=0, cache = data->cache; i < CACHE_SIZE; i++, cache++) {
407 if (!cache->in_use) {
408 if (!unused_cache)
409 unused_cache = cache;
410 continue;
411 }
412 if (cache->block == block) {
413 cache->access_time = ++data->access_time;
414 return cache;
415 }
416 if (!oldest_cache ||
417 (cache->access_time < oldest_cache->access_time))
418 oldest_cache = cache;
419 }
420 if (eldest)
421 *eldest = (unused_cache) ? unused_cache : oldest_cache;
422 return 0;
423 }
424
425 /*
426 * Reuse a particular cache entry for another block.
427 */
reuse_cache(io_channel channel,struct windows_private_data * data,struct windows_cache * cache,unsigned long long block)428 static void reuse_cache(io_channel channel, struct windows_private_data *data,
429 struct windows_cache *cache, unsigned long long block)
430 {
431 if (cache->dirty && cache->in_use)
432 raw_write_blk(channel, data, cache->block, 1, cache->buf);
433
434 cache->in_use = 1;
435 cache->dirty = 0;
436 cache->block = block;
437 cache->access_time = ++data->access_time;
438 }
439
440 /*
441 * Flush all of the blocks in the cache
442 */
flush_cached_blocks(io_channel channel,struct windows_private_data * data,int invalidate)443 static errcode_t flush_cached_blocks(io_channel channel,
444 struct windows_private_data *data,
445 int invalidate)
446 {
447 struct windows_cache *cache;
448 errcode_t retval, retval2;
449 int i;
450
451 retval2 = 0;
452 for (i=0, cache = data->cache; i < CACHE_SIZE; i++, cache++) {
453 if (!cache->in_use)
454 continue;
455
456 if (invalidate)
457 cache->in_use = 0;
458
459 if (!cache->dirty)
460 continue;
461
462 retval = raw_write_blk(channel, data,
463 cache->block, 1, cache->buf);
464 if (retval)
465 retval2 = retval;
466 else
467 cache->dirty = 0;
468 }
469 return retval2;
470 }
471 #endif /* NO_IO_CACHE */
472
windows_open_channel(struct windows_private_data * data,int flags,io_channel * channel,io_manager io_mgr)473 static errcode_t windows_open_channel(struct windows_private_data *data,
474 int flags, io_channel *channel,
475 io_manager io_mgr)
476 {
477 io_channel io = NULL;
478 errcode_t retval;
479 ext2fs_struct_stat st;
480
481 retval = ext2fs_get_mem(sizeof(struct struct_io_channel), &io);
482 if (retval)
483 goto cleanup;
484 memset(io, 0, sizeof(struct struct_io_channel));
485 io->magic = EXT2_ET_MAGIC_IO_CHANNEL;
486
487 io->manager = io_mgr;
488 retval = ext2fs_get_mem(strlen(data->name)+1, &io->name);
489 if (retval)
490 goto cleanup;
491
492 strcpy(io->name, data->name);
493 io->private_data = data;
494 io->block_size = 1024;
495 io->read_error = 0;
496 io->write_error = 0;
497 io->refcount = 1;
498
499 #if defined(O_DIRECT)
500 if (flags & IO_FLAG_DIRECT_IO)
501 io->align = ext2fs_get_dio_alignment(data->dev);
502 #endif
503
504 /*
505 * If the device is really a block device, then set the
506 * appropriate flag, otherwise we can set DISCARD_ZEROES flag
507 * because we are going to use punch hole instead of discard
508 * and if it succeed, subsequent read from sparse area returns
509 * zero.
510 */
511 if (ext2fs_fstat(data->dev, &st) == 0) {
512 if (ext2fsP_is_disk_device(st.st_mode))
513 io->flags |= CHANNEL_FLAGS_BLOCK_DEVICE;
514 else
515 io->flags |= CHANNEL_FLAGS_DISCARD_ZEROES;
516 }
517
518 if ((retval = alloc_cache(io, data)))
519 goto cleanup;
520
521 #ifdef BLKROGET
522 if (flags & IO_FLAG_RW) {
523 int error;
524 int readonly = 0;
525
526 /* Is the block device actually writable? */
527 error = ioctl(data->dev, BLKROGET, &readonly);
528 if (!error && readonly) {
529 retval = EPERM;
530 goto cleanup;
531 }
532 }
533 #endif
534
535 *channel = io;
536 return 0;
537
538 cleanup:
539 if (data) {
540 if (data->dev >= 0)
541 close(data->dev);
542 free_cache(data);
543 ext2fs_free_mem(&data);
544 }
545 if (io) {
546 if (io->name) {
547 ext2fs_free_mem(&io->name);
548 }
549 ext2fs_free_mem(&io);
550 }
551 return retval;
552 }
553
windows_open_device(struct windows_private_data * data,int open_flags)554 static DWORD windows_open_device(struct windows_private_data *data, int open_flags)
555 {
556 DWORD ret = 0;
557
558 if (*data->name != '\\')
559 strcpy(data->cf_device, data->name);
560 else if (fake_dos_name_for_device(data))
561 return -1;
562
563 DWORD desired_access = GENERIC_READ | ((open_flags & O_RDWR) ? GENERIC_WRITE : 0);
564 DWORD share_mode = (open_flags & O_EXCL) ? 0 : FILE_SHARE_READ | ((open_flags & O_RDWR) ? FILE_SHARE_WRITE : 0);
565 DWORD flags_and_attributes =
566 #if defined(O_DIRECT)
567 (open_flags & O_DIRECT) ? (FILE_FLAG_NO_BUFFERING | FILE_FLAG_WRITE_THROUGH) : FILE_ATTRIBUTE_NORMAL;
568 #else
569 FILE_FLAG_NO_BUFFERING | FILE_FLAG_WRITE_THROUGH;
570 #endif
571
572 data->handle = CreateFile(data->cf_device, desired_access, share_mode, NULL, OPEN_EXISTING,
573 flags_and_attributes, NULL);
574
575 if (data->handle == INVALID_HANDLE_VALUE) {
576 ret = GetLastError();
577 goto invalid_handle;
578 }
579
580 TRACE("e2fsprogs::windows_open_device::CreateFile(\"%s\") = %p", data->cf_device, data->handle);
581
582 data->dev = _open_osfhandle((intptr_t)data->handle, 0);
583 if (data->dev < 0) {
584 ret = GetLastError() ? GetLastError() : 9999;
585 goto osfhandle_error;
586 }
587
588 TRACE("e2fsprogs::windows_open_device::_open_osfhandle(%p) = %d", data->handle, data->dev);
589
590 return 0;
591
592 osfhandle_error:
593 TRACE("e2fsprogs::windows_open_device::CloseHandle(%p)", data->handle);
594 CloseHandle(data->handle);
595 invalid_handle:
596 remove_fake_dos_name(data);
597 TRACE("e2fsprogs::windows_open_device() = %lu, errno = %d", ret, errno);
598 return ret;
599 }
600
init_private_data(const char * name,int flags)601 static struct windows_private_data *init_private_data(const char *name, int flags)
602 {
603 struct windows_private_data *data = NULL;
604
605 if (ext2fs_get_mem(sizeof(struct windows_private_data), &data))
606 return NULL;
607
608 memset(data, 0, sizeof(struct windows_private_data));
609 strncpy(data->name, name, sizeof(data->name) - 1);
610 data->magic = EXT2_ET_MAGIC_WINDOWS_IO_CHANNEL;
611 data->io_stats.num_fields = 2;
612 data->flags = flags;
613 data->handle = INVALID_HANDLE_VALUE;
614
615 return data;
616 }
617
windows_open(const char * name,int flags,io_channel * channel)618 static errcode_t windows_open(const char *name, int flags, io_channel *channel)
619 {
620 int open_flags;
621 struct windows_private_data *data;
622
623 if (name == 0)
624 return EXT2_ET_BAD_DEVICE_NAME;
625
626 data = init_private_data(name, flags);
627 if (!data)
628 return EXT2_ET_NO_MEMORY;
629
630 open_flags = (flags & IO_FLAG_RW) ? O_RDWR : O_RDONLY;
631 if (flags & IO_FLAG_EXCLUSIVE)
632 open_flags |= O_EXCL;
633 #if defined(O_DIRECT)
634 if (flags & IO_FLAG_DIRECT_IO)
635 open_flags |= O_DIRECT;
636 #endif
637
638 if (windows_open_device(data, open_flags)) {
639 ext2fs_free_mem(&data);
640 return EXT2_ET_BAD_DEVICE_NAME;
641 }
642
643 return windows_open_channel(data, flags, channel, windows_io_manager);
644 }
645
windows_close(io_channel channel)646 static errcode_t windows_close(io_channel channel)
647 {
648 struct windows_private_data *data;
649 errcode_t retval = 0;
650
651 EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
652 data = (struct windows_private_data *) channel->private_data;
653 EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_WINDOWS_IO_CHANNEL);
654
655 if (--channel->refcount > 0)
656 return 0;
657
658 #ifndef NO_IO_CACHE
659 retval = flush_cached_blocks(channel, data, 0);
660 #endif
661
662 remove_fake_dos_name(data);
663
664 if (_close(data->dev) != 0)
665 retval = errno;
666
667 TRACE("e2fsprogs::windows_close::_close(%d)", data->dev);
668
669 free_cache(data);
670
671 ext2fs_free_mem(&channel->private_data);
672 if (channel->name)
673 ext2fs_free_mem(&channel->name);
674 ext2fs_free_mem(&channel);
675 return retval;
676 }
677
windows_set_blksize(io_channel channel,int blksize)678 static errcode_t windows_set_blksize(io_channel channel, int blksize)
679 {
680 struct windows_private_data *data;
681 errcode_t retval;
682
683 EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
684 data = (struct windows_private_data *) channel->private_data;
685 EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_WINDOWS_IO_CHANNEL);
686
687 if (channel->block_size != blksize) {
688 #ifndef NO_IO_CACHE
689 if ((retval = flush_cached_blocks(channel, data, 0)))
690 return retval;
691 #endif
692
693 channel->block_size = blksize;
694 free_cache(data);
695 if ((retval = alloc_cache(channel, data)))
696 return retval;
697 }
698 return 0;
699 }
700
windows_read_blk64(io_channel channel,unsigned long long block,int count,void * buf)701 static errcode_t windows_read_blk64(io_channel channel, unsigned long long block, int count, void *buf)
702 {
703 struct windows_private_data *data;
704 struct windows_cache *cache, *reuse[READ_DIRECT_SIZE];
705 errcode_t retval;
706 char *cp;
707 int i, j;
708
709 EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
710 data = (struct windows_private_data *) channel->private_data;
711 EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_WINDOWS_IO_CHANNEL);
712
713 #ifdef NO_IO_CACHE
714 return raw_read_blk(channel, data, block, count, buf);
715 #else
716 /*
717 * If we're doing an odd-sized read or a very large read,
718 * flush out the cache and then do a direct read.
719 */
720 if (count < 0 || count > WRITE_DIRECT_SIZE) {
721 if ((retval = flush_cached_blocks(channel, data, 0)))
722 return retval;
723 return raw_read_blk(channel, data, block, count, buf);
724 }
725
726 cp = buf;
727 while (count > 0) {
728 /* If it's in the cache, use it! */
729 if ((cache = find_cached_block(data, block, &reuse[0]))) {
730 #ifdef DEBUG
731 printf("Using cached block %lu\n", block);
732 #endif
733 memcpy(cp, cache->buf, channel->block_size);
734 count--;
735 block++;
736 cp += channel->block_size;
737 continue;
738 }
739 if (count == 1) {
740 /*
741 * Special case where we read directly into the
742 * cache buffer; important in the O_DIRECT case
743 */
744 cache = reuse[0];
745 reuse_cache(channel, data, cache, block);
746 if ((retval = raw_read_blk(channel, data, block, 1,
747 cache->buf))) {
748 cache->in_use = 0;
749 return retval;
750 }
751 memcpy(cp, cache->buf, channel->block_size);
752 return 0;
753 }
754
755 /*
756 * Find the number of uncached blocks so we can do a
757 * single read request
758 */
759 for (i=1; i < count; i++)
760 if (find_cached_block(data, block+i, &reuse[i]))
761 break;
762 #ifdef DEBUG
763 printf("Reading %d blocks starting at %lu\n", i, block);
764 #endif
765 if ((retval = raw_read_blk(channel, data, block, i, cp)))
766 return retval;
767
768 /* Save the results in the cache */
769 for (j=0; j < i; j++) {
770 count--;
771 cache = reuse[j];
772 reuse_cache(channel, data, cache, block++);
773 memcpy(cache->buf, cp, channel->block_size);
774 cp += channel->block_size;
775 }
776 }
777 return 0;
778 #endif /* NO_IO_CACHE */
779 }
780
windows_read_blk(io_channel channel,unsigned long block,int count,void * buf)781 static errcode_t windows_read_blk(io_channel channel, unsigned long block,
782 int count, void *buf)
783 {
784 return windows_read_blk64(channel, block, count, buf);
785 }
786
windows_write_blk64(io_channel channel,unsigned long long block,int count,const void * buf)787 static errcode_t windows_write_blk64(io_channel channel,
788 unsigned long long block,
789 int count, const void *buf)
790 {
791 struct windows_private_data *data;
792 struct windows_cache *cache, *reuse;
793 errcode_t retval = 0;
794 const char *cp;
795 int writethrough;
796
797 EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
798 data = (struct windows_private_data *) channel->private_data;
799 EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_WINDOWS_IO_CHANNEL);
800
801 #ifdef NO_IO_CACHE
802 return raw_write_blk(channel, data, block, count, buf);
803 #else
804 /*
805 * If we're doing an odd-sized write or a very large write,
806 * flush out the cache completely and then do a direct write.
807 */
808 if (count < 0 || count > WRITE_DIRECT_SIZE) {
809 if ((retval = flush_cached_blocks(channel, data, 1)))
810 return retval;
811 return raw_write_blk(channel, data, block, count, buf);
812 }
813
814 /*
815 * For a moderate-sized multi-block write, first force a write
816 * if we're in write-through cache mode, and then fill the
817 * cache with the blocks.
818 */
819 writethrough = channel->flags & CHANNEL_FLAGS_WRITETHROUGH;
820 if (writethrough)
821 retval = raw_write_blk(channel, data, block, count, buf);
822
823 cp = buf;
824 while (count > 0) {
825 cache = find_cached_block(data, block, &reuse);
826 if (!cache) {
827 cache = reuse;
828 reuse_cache(channel, data, cache, block);
829 }
830 if (cache->buf != cp)
831 memcpy(cache->buf, cp, channel->block_size);
832 cache->dirty = !writethrough;
833 count--;
834 block++;
835 cp += channel->block_size;
836 }
837 return retval;
838 #endif /* NO_IO_CACHE */
839 }
840
windows_cache_readahead(io_channel channel,unsigned long long block,unsigned long long count)841 static errcode_t windows_cache_readahead(io_channel channel,
842 unsigned long long block,
843 unsigned long long count)
844 {
845 return EXT2_ET_OP_NOT_SUPPORTED;
846 }
847
windows_write_blk(io_channel channel,unsigned long block,int count,const void * buf)848 static errcode_t windows_write_blk(io_channel channel, unsigned long block,
849 int count, const void *buf)
850 {
851 return windows_write_blk64(channel, block, count, buf);
852 }
853
windows_write_byte(io_channel channel,unsigned long offset,int size,const void * buf)854 static errcode_t windows_write_byte(io_channel channel, unsigned long offset,
855 int size, const void *buf)
856 {
857 return EXT2_ET_UNIMPLEMENTED;
858 }
859
860 /*
861 * Flush data buffers to disk.
862 */
windows_flush(io_channel channel)863 static errcode_t windows_flush(io_channel channel)
864 {
865 struct windows_private_data *data;
866 errcode_t retval = 0;
867
868 EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
869 data = (struct windows_private_data *) channel->private_data;
870 EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_WINDOWS_IO_CHANNEL);
871
872 #ifndef NO_IO_CACHE
873 retval = flush_cached_blocks(channel, data, 0);
874 #endif
875
876 return retval;
877 }
878
windows_set_option(io_channel channel,const char * option,const char * arg)879 static errcode_t windows_set_option(io_channel channel, const char *option,
880 const char *arg)
881 {
882 struct windows_private_data *data;
883 unsigned long long tmp;
884 char *end;
885
886 EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
887 data = (struct windows_private_data *) channel->private_data;
888 EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_WINDOWS_IO_CHANNEL);
889
890 if (!strcmp(option, "offset")) {
891 if (!arg)
892 return EXT2_ET_INVALID_ARGUMENT;
893
894 tmp = strtoull(arg, &end, 0);
895 if (*end)
896 return EXT2_ET_INVALID_ARGUMENT;
897 data->offset = tmp;
898 if (data->offset < 0)
899 return EXT2_ET_INVALID_ARGUMENT;
900 return 0;
901 }
902 return EXT2_ET_INVALID_ARGUMENT;
903 }
904
windows_discard(io_channel channel,unsigned long long block,unsigned long long count)905 static errcode_t windows_discard(io_channel channel, unsigned long long block,
906 unsigned long long count)
907 {
908 TRACE("e2fsprogs::windows_discard::EXT2_ET_UNIMPLEMENTED");
909 return EXT2_ET_UNIMPLEMENTED;
910 }
911
912 /* parameters might not be used if OS doesn't support zeroout */
913 #if __GNUC_PREREQ (4, 6)
914 #pragma GCC diagnostic push
915 #pragma GCC diagnostic ignored "-Wunused-parameter"
916 #endif
windows_zeroout(io_channel channel,unsigned long long block,unsigned long long count)917 static errcode_t windows_zeroout(io_channel channel, unsigned long long block,
918 unsigned long long count)
919 {
920 struct windows_private_data *data;
921 int ret;
922
923 EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
924 data = (struct windows_private_data *) channel->private_data;
925 EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_WINDOWS_IO_CHANNEL);
926
927 if (channel->flags & CHANNEL_FLAGS_BLOCK_DEVICE) {
928 /* Not implemented until the BLKZEROOUT mess is fixed */
929 goto unimplemented;
930 } else {
931 /* Regular file, try to use truncate/punch/zero. */
932 struct stat statbuf;
933
934 if (count == 0)
935 return 0;
936 /*
937 * If we're trying to zero a range past the end of the file,
938 * extend the file size, then truncate everything.
939 */
940 ret = fstat(data->dev, &statbuf);
941 if (ret)
942 goto err;
943 if ((unsigned long long) statbuf.st_size <
944 (block + count) * channel->block_size + data->offset) {
945 ret = ftruncate(data->dev,
946 (block + count) * channel->block_size + data->offset);
947 if (ret)
948 goto err;
949 }
950 goto unimplemented;
951 }
952 err:
953 if (ret < 0) {
954 if (errno == EOPNOTSUPP)
955 goto unimplemented;
956 return errno;
957 }
958 return 0;
959 unimplemented:
960 return EXT2_ET_UNIMPLEMENTED;
961 }
962
ext2fs_open_file(const char * pathname,int flags,mode_t mode)963 int ext2fs_open_file(const char *pathname, int flags, mode_t mode)
964 {
965 flags |= O_BINARY;
966
967 if (mode)
968 #if defined(HAVE_OPEN64) && !defined(__OSX_AVAILABLE_BUT_DEPRECATED)
969 return open64(pathname, flags, mode);
970 else
971 return open64(pathname, flags);
972 #else
973 return open(pathname, flags, mode);
974 else
975 return open(pathname, flags);
976 #endif
977 }
978
ext2fs_stat(const char * path,ext2fs_struct_stat * buf)979 int ext2fs_stat(const char *path, ext2fs_struct_stat *buf)
980 {
981 #if defined(HAVE_FSTAT64) && !defined(__OSX_AVAILABLE_BUT_DEPRECATED)
982 return stat64(path, buf);
983 #else
984 return stat(path, buf);
985 #endif
986 }
987
ext2fs_fstat(int fd,ext2fs_struct_stat * buf)988 int ext2fs_fstat(int fd, ext2fs_struct_stat *buf)
989 {
990 #if defined(HAVE_FSTAT64) && !defined(__OSX_AVAILABLE_BUT_DEPRECATED)
991 return fstat64(fd, buf);
992 #else
993 return fstat(fd, buf);
994 #endif
995 }
996
997 #if __GNUC_PREREQ (4, 6)
998 #pragma GCC diagnostic pop
999 #endif
1000
1001 static struct struct_io_manager struct_windows_manager = {
1002 .magic = EXT2_ET_MAGIC_IO_MANAGER,
1003 .name = "Windows I/O Manager",
1004 .open = windows_open,
1005 .close = windows_close,
1006 .set_blksize = windows_set_blksize,
1007 .read_blk = windows_read_blk,
1008 .write_blk = windows_write_blk,
1009 .flush = windows_flush,
1010 .write_byte = windows_write_byte,
1011 .set_option = windows_set_option,
1012 .get_stats = windows_get_stats,
1013 .read_blk64 = windows_read_blk64,
1014 .write_blk64 = windows_write_blk64,
1015 .discard = windows_discard,
1016 .cache_readahead = windows_cache_readahead,
1017 .zeroout = windows_zeroout,
1018 };
1019
1020 io_manager windows_io_manager = &struct_windows_manager;
1021