1 /*
2 * unix_io.c --- This is the Unix (well, really POSIX) implementation
3 * of the I/O manager.
4 *
5 * Implements a one-block write-through cache.
6 *
7 * Includes support for Windows NT support under Cygwin.
8 *
9 * Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
10 * 2002 by Theodore Ts'o.
11 *
12 * %Begin-Header%
13 * This file may be redistributed under the terms of the GNU Library
14 * General Public License, version 2.
15 * %End-Header%
16 */
17
18 #if !defined(__FreeBSD__) && !defined(__NetBSD__) && !defined(__OpenBSD__)
19 #define _XOPEN_SOURCE 600
20 #define _DARWIN_C_SOURCE
21 #define _FILE_OFFSET_BITS 64
22 #ifndef _LARGEFILE_SOURCE
23 #define _LARGEFILE_SOURCE
24 #endif
25 #ifndef _LARGEFILE64_SOURCE
26 #define _LARGEFILE64_SOURCE
27 #endif
28 #ifndef _GNU_SOURCE
29 #define _GNU_SOURCE
30 #endif
31 #endif
32
33 #include "config.h"
34 #include <stdio.h>
35 #include <string.h>
36 #if HAVE_UNISTD_H
37 #include <unistd.h>
38 #endif
39 #if HAVE_ERRNO_H
40 #include <errno.h>
41 #endif
42 #include <fcntl.h>
43 #include <time.h>
44 #ifdef __linux__
45 #include <sys/utsname.h>
46 #endif
47 #if HAVE_SYS_TYPES_H
48 #include <sys/types.h>
49 #endif
50 #ifdef HAVE_SYS_IOCTL_H
51 #include <sys/ioctl.h>
52 #endif
53 #ifdef HAVE_SYS_MOUNT_H
54 #include <sys/mount.h>
55 #endif
56 #ifdef HAVE_SYS_PRCTL_H
57 #include <sys/prctl.h>
58 #else
59 #define PR_GET_DUMPABLE 3
60 #endif
61 #if HAVE_SYS_STAT_H
62 #include <sys/stat.h>
63 #endif
64 #if HAVE_SYS_RESOURCE_H
65 #include <sys/resource.h>
66 #endif
67 #if HAVE_LINUX_FALLOC_H
68 #include <linux/falloc.h>
69 #endif
70 #ifdef HAVE_PTHREAD
71 #include <pthread.h>
72 #endif
73
74 #if defined(__linux__) && defined(_IO) && !defined(BLKROGET)
75 #define BLKROGET _IO(0x12, 94) /* Get read-only status (0 = read_write). */
76 #endif
77
78 #undef ALIGN_DEBUG
79
80 #include "ext2_fs.h"
81 #include "ext2fs.h"
82 #include "ext2fsP.h"
83
84 /*
85 * For checking structure magic numbers...
86 */
87
88 #define EXT2_CHECK_MAGIC(struct, code) \
89 if ((struct)->magic != (code)) return (code)
90
91 struct unix_cache {
92 char *buf;
93 unsigned long long block;
94 int access_time;
95 unsigned dirty:1;
96 unsigned in_use:1;
97 };
98
99 #define CACHE_SIZE 8
100 #define WRITE_DIRECT_SIZE 4 /* Must be smaller than CACHE_SIZE */
101 #define READ_DIRECT_SIZE 4 /* Should be smaller than CACHE_SIZE */
102
103 struct unix_private_data {
104 int magic;
105 int dev;
106 int flags;
107 int align;
108 int access_time;
109 ext2_loff_t offset;
110 struct unix_cache cache[CACHE_SIZE];
111 void *bounce;
112 struct struct_io_stats io_stats;
113 #ifdef HAVE_PTHREAD
114 pthread_mutex_t cache_mutex;
115 pthread_mutex_t bounce_mutex;
116 pthread_mutex_t stats_mutex;
117 #endif
118 };
119
120 #define IS_ALIGNED(n, align) ((((uintptr_t) n) & \
121 ((uintptr_t) ((align)-1))) == 0)
122
123 typedef enum lock_kind {
124 CACHE_MTX, BOUNCE_MTX, STATS_MTX
125 } kind_t;
126
127 #ifdef HAVE_PTHREAD
get_mutex(struct unix_private_data * data,kind_t kind)128 static inline pthread_mutex_t *get_mutex(struct unix_private_data *data,
129 kind_t kind)
130 {
131 if (data->flags & IO_FLAG_THREADS) {
132 switch (kind) {
133 case CACHE_MTX:
134 return &data->cache_mutex;
135 case BOUNCE_MTX:
136 return &data->bounce_mutex;
137 case STATS_MTX:
138 return &data->stats_mutex;
139 }
140 }
141 return NULL;
142 }
143 #endif
144
mutex_lock(struct unix_private_data * data,kind_t kind)145 static inline void mutex_lock(struct unix_private_data *data, kind_t kind)
146 {
147 #ifdef HAVE_PTHREAD
148 pthread_mutex_t *mtx = get_mutex(data,kind);
149
150 if (mtx)
151 pthread_mutex_lock(mtx);
152 #endif
153 }
154
mutex_unlock(struct unix_private_data * data,kind_t kind)155 static inline void mutex_unlock(struct unix_private_data *data, kind_t kind)
156 {
157 #ifdef HAVE_PTHREAD
158 pthread_mutex_t *mtx = get_mutex(data,kind);
159
160 if (mtx)
161 pthread_mutex_unlock(mtx);
162 #endif
163 }
164
unix_get_stats(io_channel channel,io_stats * stats)165 static errcode_t unix_get_stats(io_channel channel, io_stats *stats)
166 {
167 errcode_t retval = 0;
168
169 struct unix_private_data *data;
170
171 EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
172 data = (struct unix_private_data *) channel->private_data;
173 EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
174
175 if (stats) {
176 mutex_lock(data, STATS_MTX);
177 *stats = &data->io_stats;
178 mutex_unlock(data, STATS_MTX);
179 }
180
181 return retval;
182 }
183
safe_getenv(const char * arg)184 static char *safe_getenv(const char *arg)
185 {
186 if ((getuid() != geteuid()) || (getgid() != getegid()))
187 return NULL;
188 #ifdef HAVE_PRCTL
189 if (prctl(PR_GET_DUMPABLE, 0, 0, 0, 0) == 0)
190 return NULL;
191 #else
192 #if (defined(linux) && defined(SYS_prctl))
193 if (syscall(SYS_prctl, PR_GET_DUMPABLE, 0, 0, 0, 0) == 0)
194 return NULL;
195 #endif
196 #endif
197
198 #if defined(HAVE_SECURE_GETENV)
199 return secure_getenv(arg);
200 #elif defined(HAVE___SECURE_GETENV)
201 return __secure_getenv(arg);
202 #else
203 return getenv(arg);
204 #endif
205 }
206
207 /*
208 * Here are the raw I/O functions
209 */
raw_read_blk(io_channel channel,struct unix_private_data * data,unsigned long long block,int count,void * bufv)210 static errcode_t raw_read_blk(io_channel channel,
211 struct unix_private_data *data,
212 unsigned long long block,
213 int count, void *bufv)
214 {
215 errcode_t retval;
216 ssize_t size;
217 ext2_loff_t location;
218 int actual = 0;
219 unsigned char *buf = bufv;
220 ssize_t really_read = 0;
221 unsigned long long aligned_blk;
222 int align_size, offset;
223
224 size = (count < 0) ? -count : (ext2_loff_t) count * channel->block_size;
225 mutex_lock(data, STATS_MTX);
226 data->io_stats.bytes_read += size;
227 mutex_unlock(data, STATS_MTX);
228 location = ((ext2_loff_t) block * channel->block_size) + data->offset;
229
230 if (data->flags & IO_FLAG_FORCE_BOUNCE)
231 goto bounce_read;
232
233 #ifdef HAVE_PREAD64
234 /* Try an aligned pread */
235 if ((channel->align == 0) ||
236 (IS_ALIGNED(buf, channel->align) &&
237 IS_ALIGNED(location, channel->align) &&
238 IS_ALIGNED(size, channel->align))) {
239 actual = pread64(data->dev, buf, size, location);
240 if (actual == size)
241 return 0;
242 actual = 0;
243 }
244 #elif HAVE_PREAD
245 /* Try an aligned pread */
246 if ((sizeof(off_t) >= sizeof(ext2_loff_t)) &&
247 ((channel->align == 0) ||
248 (IS_ALIGNED(buf, channel->align) &&
249 IS_ALIGNED(location, channel->align) &&
250 IS_ALIGNED(size, channel->align)))) {
251 actual = pread(data->dev, buf, size, location);
252 if (actual == size)
253 return 0;
254 actual = 0;
255 }
256 #endif /* HAVE_PREAD */
257
258 if ((channel->align == 0) ||
259 (IS_ALIGNED(buf, channel->align) &&
260 IS_ALIGNED(location, channel->align) &&
261 IS_ALIGNED(size, channel->align))) {
262 mutex_lock(data, BOUNCE_MTX);
263 if (ext2fs_llseek(data->dev, location, SEEK_SET) < 0) {
264 retval = errno ? errno : EXT2_ET_LLSEEK_FAILED;
265 goto error_unlock;
266 }
267 actual = read(data->dev, buf, size);
268 if (actual != size) {
269 short_read:
270 if (actual < 0) {
271 retval = errno;
272 actual = 0;
273 } else
274 retval = EXT2_ET_SHORT_READ;
275 goto error_unlock;
276 }
277 goto success_unlock;
278 }
279
280 #ifdef ALIGN_DEBUG
281 printf("raw_read_blk: O_DIRECT fallback: %p %lu\n", buf,
282 (unsigned long) size);
283 #endif
284
285 /*
286 * The buffer or size which we're trying to read isn't aligned
287 * to the O_DIRECT rules, so we need to do this the hard way...
288 */
289 bounce_read:
290 if (channel->align == 0)
291 channel->align = 1;
292 if ((channel->block_size > channel->align) &&
293 (channel->block_size % channel->align) == 0)
294 align_size = channel->block_size;
295 else
296 align_size = channel->align;
297 aligned_blk = location / align_size;
298 offset = location % align_size;
299
300 mutex_lock(data, BOUNCE_MTX);
301 if (ext2fs_llseek(data->dev, aligned_blk * align_size, SEEK_SET) < 0) {
302 retval = errno ? errno : EXT2_ET_LLSEEK_FAILED;
303 goto error_unlock;
304 }
305 while (size > 0) {
306 actual = read(data->dev, data->bounce, align_size);
307 if (actual != align_size) {
308 mutex_unlock(data, BOUNCE_MTX);
309 actual = really_read;
310 buf -= really_read;
311 size += really_read;
312 goto short_read;
313 }
314 if ((actual + offset) > align_size)
315 actual = align_size - offset;
316 if (actual > size)
317 actual = size;
318 memcpy(buf, (char *)data->bounce + offset, actual);
319
320 really_read += actual;
321 size -= actual;
322 buf += actual;
323 offset = 0;
324 aligned_blk++;
325 }
326 success_unlock:
327 mutex_unlock(data, BOUNCE_MTX);
328 return 0;
329
330 error_unlock:
331 mutex_unlock(data, BOUNCE_MTX);
332 if (actual >= 0 && actual < size)
333 memset((char *) buf+actual, 0, size-actual);
334 if (channel->read_error)
335 retval = (channel->read_error)(channel, block, count, buf,
336 size, actual, retval);
337 return retval;
338 }
339
raw_write_blk(io_channel channel,struct unix_private_data * data,unsigned long long block,int count,const void * bufv)340 static errcode_t raw_write_blk(io_channel channel,
341 struct unix_private_data *data,
342 unsigned long long block,
343 int count, const void *bufv)
344 {
345 ssize_t size;
346 ext2_loff_t location;
347 int actual = 0;
348 errcode_t retval;
349 const unsigned char *buf = bufv;
350 unsigned long long aligned_blk;
351 int align_size, offset;
352
353 if (count == 1)
354 size = channel->block_size;
355 else {
356 if (count < 0)
357 size = -count;
358 else
359 size = (ext2_loff_t) count * channel->block_size;
360 }
361 mutex_lock(data, STATS_MTX);
362 data->io_stats.bytes_written += size;
363 mutex_unlock(data, STATS_MTX);
364
365 location = ((ext2_loff_t) block * channel->block_size) + data->offset;
366
367 if (data->flags & IO_FLAG_FORCE_BOUNCE)
368 goto bounce_write;
369
370 #ifdef HAVE_PWRITE64
371 /* Try an aligned pwrite */
372 if ((channel->align == 0) ||
373 (IS_ALIGNED(buf, channel->align) &&
374 IS_ALIGNED(location, channel->align) &&
375 IS_ALIGNED(size, channel->align))) {
376 actual = pwrite64(data->dev, buf, size, location);
377 if (actual == size)
378 return 0;
379 }
380 #elif HAVE_PWRITE
381 /* Try an aligned pwrite */
382 if ((sizeof(off_t) >= sizeof(ext2_loff_t)) &&
383 ((channel->align == 0) ||
384 (IS_ALIGNED(buf, channel->align) &&
385 IS_ALIGNED(location, channel->align) &&
386 IS_ALIGNED(size, channel->align)))) {
387 actual = pwrite(data->dev, buf, size, location);
388 if (actual == size)
389 return 0;
390 }
391 #endif /* HAVE_PWRITE */
392
393 if ((channel->align == 0) ||
394 (IS_ALIGNED(buf, channel->align) &&
395 IS_ALIGNED(location, channel->align) &&
396 IS_ALIGNED(size, channel->align))) {
397 mutex_lock(data, BOUNCE_MTX);
398 if (ext2fs_llseek(data->dev, location, SEEK_SET) < 0) {
399 retval = errno ? errno : EXT2_ET_LLSEEK_FAILED;
400 goto error_unlock;
401 }
402 actual = write(data->dev, buf, size);
403 mutex_unlock(data, BOUNCE_MTX);
404 if (actual < 0) {
405 retval = errno;
406 goto error_out;
407 }
408 if (actual != size) {
409 short_write:
410 retval = EXT2_ET_SHORT_WRITE;
411 goto error_out;
412 }
413 return 0;
414 }
415
416 #ifdef ALIGN_DEBUG
417 printf("raw_write_blk: O_DIRECT fallback: %p %lu\n", buf,
418 (unsigned long) size);
419 #endif
420 /*
421 * The buffer or size which we're trying to write isn't aligned
422 * to the O_DIRECT rules, so we need to do this the hard way...
423 */
424 bounce_write:
425 if (channel->align == 0)
426 channel->align = 1;
427 if ((channel->block_size > channel->align) &&
428 (channel->block_size % channel->align) == 0)
429 align_size = channel->block_size;
430 else
431 align_size = channel->align;
432 aligned_blk = location / align_size;
433 offset = location % align_size;
434
435 while (size > 0) {
436 int actual_w;
437
438 mutex_lock(data, BOUNCE_MTX);
439 if (size < align_size || offset) {
440 if (ext2fs_llseek(data->dev, aligned_blk * align_size,
441 SEEK_SET) < 0) {
442 retval = errno ? errno : EXT2_ET_LLSEEK_FAILED;
443 goto error_unlock;
444 }
445 actual = read(data->dev, data->bounce,
446 align_size);
447 if (actual != align_size) {
448 if (actual < 0) {
449 retval = errno;
450 goto error_unlock;
451 }
452 memset((char *) data->bounce + actual, 0,
453 align_size - actual);
454 }
455 }
456 actual = size;
457 if ((actual + offset) > align_size)
458 actual = align_size - offset;
459 if (actual > size)
460 actual = size;
461 memcpy(((char *)data->bounce) + offset, buf, actual);
462 if (ext2fs_llseek(data->dev, aligned_blk * align_size, SEEK_SET) < 0) {
463 retval = errno ? errno : EXT2_ET_LLSEEK_FAILED;
464 goto error_unlock;
465 }
466 actual_w = write(data->dev, data->bounce, align_size);
467 mutex_unlock(data, BOUNCE_MTX);
468 if (actual_w < 0) {
469 retval = errno;
470 goto error_out;
471 }
472 if (actual_w != align_size)
473 goto short_write;
474 size -= actual;
475 buf += actual;
476 location += actual;
477 aligned_blk++;
478 offset = 0;
479 }
480 return 0;
481
482 error_unlock:
483 mutex_unlock(data, BOUNCE_MTX);
484 error_out:
485 if (channel->write_error)
486 retval = (channel->write_error)(channel, block, count, buf,
487 size, actual, retval);
488 return retval;
489 }
490
491
492 /*
493 * Here we implement the cache functions
494 */
495
496 /* Allocate the cache buffers */
alloc_cache(io_channel channel,struct unix_private_data * data)497 static errcode_t alloc_cache(io_channel channel,
498 struct unix_private_data *data)
499 {
500 errcode_t retval;
501 struct unix_cache *cache;
502 int i;
503
504 data->access_time = 0;
505 for (i=0, cache = data->cache; i < CACHE_SIZE; i++, cache++) {
506 cache->block = 0;
507 cache->access_time = 0;
508 cache->dirty = 0;
509 cache->in_use = 0;
510 if (cache->buf)
511 ext2fs_free_mem(&cache->buf);
512 retval = io_channel_alloc_buf(channel, 0, &cache->buf);
513 if (retval)
514 return retval;
515 }
516 if (channel->align || data->flags & IO_FLAG_FORCE_BOUNCE) {
517 if (data->bounce)
518 ext2fs_free_mem(&data->bounce);
519 retval = io_channel_alloc_buf(channel, 0, &data->bounce);
520 }
521 return retval;
522 }
523
524 /* Free the cache buffers */
free_cache(struct unix_private_data * data)525 static void free_cache(struct unix_private_data *data)
526 {
527 struct unix_cache *cache;
528 int i;
529
530 data->access_time = 0;
531 for (i=0, cache = data->cache; i < CACHE_SIZE; i++, cache++) {
532 cache->block = 0;
533 cache->access_time = 0;
534 cache->dirty = 0;
535 cache->in_use = 0;
536 if (cache->buf)
537 ext2fs_free_mem(&cache->buf);
538 }
539 if (data->bounce)
540 ext2fs_free_mem(&data->bounce);
541 }
542
543 #ifndef NO_IO_CACHE
544 /*
545 * Try to find a block in the cache. If the block is not found, and
546 * eldest is a non-zero pointer, then fill in eldest with the cache
547 * entry to that should be reused.
548 */
find_cached_block(struct unix_private_data * data,unsigned long long block,struct unix_cache ** eldest)549 static struct unix_cache *find_cached_block(struct unix_private_data *data,
550 unsigned long long block,
551 struct unix_cache **eldest)
552 {
553 struct unix_cache *cache, *unused_cache, *oldest_cache;
554 int i;
555
556 unused_cache = oldest_cache = 0;
557 for (i=0, cache = data->cache; i < CACHE_SIZE; i++, cache++) {
558 if (!cache->in_use) {
559 if (!unused_cache)
560 unused_cache = cache;
561 continue;
562 }
563 if (cache->block == block) {
564 cache->access_time = ++data->access_time;
565 return cache;
566 }
567 if (!oldest_cache ||
568 (cache->access_time < oldest_cache->access_time))
569 oldest_cache = cache;
570 }
571 if (eldest)
572 *eldest = (unused_cache) ? unused_cache : oldest_cache;
573 return 0;
574 }
575
576 /*
577 * Reuse a particular cache entry for another block.
578 */
reuse_cache(io_channel channel,struct unix_private_data * data,struct unix_cache * cache,unsigned long long block)579 static void reuse_cache(io_channel channel, struct unix_private_data *data,
580 struct unix_cache *cache, unsigned long long block)
581 {
582 if (cache->dirty && cache->in_use)
583 raw_write_blk(channel, data, cache->block, 1, cache->buf);
584
585 cache->in_use = 1;
586 cache->dirty = 0;
587 cache->block = block;
588 cache->access_time = ++data->access_time;
589 }
590
591 #define FLUSH_INVALIDATE 0x01
592 #define FLUSH_NOLOCK 0x02
593
594 /*
595 * Flush all of the blocks in the cache
596 */
flush_cached_blocks(io_channel channel,struct unix_private_data * data,int flags)597 static errcode_t flush_cached_blocks(io_channel channel,
598 struct unix_private_data *data,
599 int flags)
600 {
601 struct unix_cache *cache;
602 errcode_t retval, retval2;
603 int i;
604
605 retval2 = 0;
606 if ((flags & FLUSH_NOLOCK) == 0)
607 mutex_lock(data, CACHE_MTX);
608 for (i=0, cache = data->cache; i < CACHE_SIZE; i++, cache++) {
609 if (!cache->in_use)
610 continue;
611
612 if (flags & FLUSH_INVALIDATE)
613 cache->in_use = 0;
614
615 if (!cache->dirty)
616 continue;
617
618 retval = raw_write_blk(channel, data,
619 cache->block, 1, cache->buf);
620 if (retval)
621 retval2 = retval;
622 else
623 cache->dirty = 0;
624 }
625 if ((flags & FLUSH_NOLOCK) == 0)
626 mutex_unlock(data, CACHE_MTX);
627 return retval2;
628 }
629 #endif /* NO_IO_CACHE */
630
631 #ifdef __linux__
632 #ifndef BLKDISCARDZEROES
633 #define BLKDISCARDZEROES _IO(0x12,124)
634 #endif
635 #endif
636
ext2fs_open_file(const char * pathname,int flags,mode_t mode)637 int ext2fs_open_file(const char *pathname, int flags, mode_t mode)
638 {
639 if (mode)
640 #if defined(HAVE_OPEN64) && !defined(__OSX_AVAILABLE_BUT_DEPRECATED)
641 return open64(pathname, flags, mode);
642 else
643 return open64(pathname, flags);
644 #else
645 return open(pathname, flags, mode);
646 else
647 return open(pathname, flags);
648 #endif
649 }
650
ext2fs_stat(const char * path,ext2fs_struct_stat * buf)651 int ext2fs_stat(const char *path, ext2fs_struct_stat *buf)
652 {
653 #if defined(HAVE_FSTAT64) && !defined(__OSX_AVAILABLE_BUT_DEPRECATED)
654 return stat64(path, buf);
655 #else
656 return stat(path, buf);
657 #endif
658 }
659
ext2fs_fstat(int fd,ext2fs_struct_stat * buf)660 int ext2fs_fstat(int fd, ext2fs_struct_stat *buf)
661 {
662 #if defined(HAVE_FSTAT64) && !defined(__OSX_AVAILABLE_BUT_DEPRECATED)
663 return fstat64(fd, buf);
664 #else
665 return fstat(fd, buf);
666 #endif
667 }
668
669
unix_open_channel(const char * name,int fd,int flags,io_channel * channel,io_manager io_mgr)670 static errcode_t unix_open_channel(const char *name, int fd,
671 int flags, io_channel *channel,
672 io_manager io_mgr)
673 {
674 io_channel io = NULL;
675 struct unix_private_data *data = NULL;
676 errcode_t retval;
677 ext2fs_struct_stat st;
678 #ifdef __linux__
679 struct utsname ut;
680 #endif
681
682 if (safe_getenv("UNIX_IO_FORCE_BOUNCE"))
683 flags |= IO_FLAG_FORCE_BOUNCE;
684
685 #ifdef __linux__
686 /*
687 * We need to make sure any previous errors in the block
688 * device are thrown away, sigh.
689 */
690 (void) fsync(fd);
691 #endif
692
693 retval = ext2fs_get_mem(sizeof(struct struct_io_channel), &io);
694 if (retval)
695 goto cleanup;
696 memset(io, 0, sizeof(struct struct_io_channel));
697 io->magic = EXT2_ET_MAGIC_IO_CHANNEL;
698 retval = ext2fs_get_mem(sizeof(struct unix_private_data), &data);
699 if (retval)
700 goto cleanup;
701
702 io->manager = io_mgr;
703 retval = ext2fs_get_mem(strlen(name)+1, &io->name);
704 if (retval)
705 goto cleanup;
706
707 strcpy(io->name, name);
708 io->private_data = data;
709 io->block_size = 1024;
710 io->read_error = 0;
711 io->write_error = 0;
712 io->refcount = 1;
713 io->flags = 0;
714
715 memset(data, 0, sizeof(struct unix_private_data));
716 data->magic = EXT2_ET_MAGIC_UNIX_IO_CHANNEL;
717 data->io_stats.num_fields = 2;
718 data->flags = flags;
719 data->dev = fd;
720
721 #if defined(O_DIRECT)
722 if (flags & IO_FLAG_DIRECT_IO)
723 io->align = ext2fs_get_dio_alignment(data->dev);
724 #elif defined(F_NOCACHE)
725 if (flags & IO_FLAG_DIRECT_IO)
726 io->align = 4096;
727 #endif
728
729 /*
730 * If the device is really a block device, then set the
731 * appropriate flag, otherwise we can set DISCARD_ZEROES flag
732 * because we are going to use punch hole instead of discard
733 * and if it succeed, subsequent read from sparse area returns
734 * zero.
735 */
736 if (ext2fs_fstat(data->dev, &st) == 0) {
737 if (ext2fsP_is_disk_device(st.st_mode))
738 io->flags |= CHANNEL_FLAGS_BLOCK_DEVICE;
739 else
740 io->flags |= CHANNEL_FLAGS_DISCARD_ZEROES;
741 }
742
743 #ifdef BLKDISCARDZEROES
744 {
745 int zeroes = 0;
746 if (ioctl(data->dev, BLKDISCARDZEROES, &zeroes) == 0 &&
747 zeroes)
748 io->flags |= CHANNEL_FLAGS_DISCARD_ZEROES;
749 }
750 #endif
751
752 #if defined(__CYGWIN__)
753 /*
754 * Some operating systems require that the buffers be aligned,
755 * regardless of O_DIRECT
756 */
757 if (!io->align)
758 io->align = 512;
759 #endif
760
761 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
762 if (io->flags & CHANNEL_FLAGS_BLOCK_DEVICE) {
763 int dio_align = ext2fs_get_dio_alignment(fd);
764
765 if (io->align < dio_align)
766 io->align = dio_align;
767 }
768 #endif
769
770 if ((retval = alloc_cache(io, data)))
771 goto cleanup;
772
773 #ifdef BLKROGET
774 if (flags & IO_FLAG_RW) {
775 int error;
776 int readonly = 0;
777
778 /* Is the block device actually writable? */
779 error = ioctl(data->dev, BLKROGET, &readonly);
780 if (!error && readonly) {
781 retval = EPERM;
782 goto cleanup;
783 }
784 }
785 #endif
786
787 #ifdef __linux__
788 #undef RLIM_INFINITY
789 #if (defined(__alpha__) || ((defined(__sparc__) || defined(__mips__)) && (SIZEOF_LONG == 4)))
790 #define RLIM_INFINITY ((unsigned long)(~0UL>>1))
791 #else
792 #define RLIM_INFINITY (~0UL)
793 #endif
794 /*
795 * Work around a bug in 2.4.10-2.4.18 kernels where writes to
796 * block devices are wrongly getting hit by the filesize
797 * limit. This workaround isn't perfect, since it won't work
798 * if glibc wasn't built against 2.2 header files. (Sigh.)
799 *
800 */
801 if ((flags & IO_FLAG_RW) &&
802 (uname(&ut) == 0) &&
803 ((ut.release[0] == '2') && (ut.release[1] == '.') &&
804 (ut.release[2] == '4') && (ut.release[3] == '.') &&
805 (ut.release[4] == '1') && (ut.release[5] >= '0') &&
806 (ut.release[5] < '8')) &&
807 (ext2fs_fstat(data->dev, &st) == 0) &&
808 (ext2fsP_is_disk_device(st.st_mode))) {
809 struct rlimit rlim;
810
811 rlim.rlim_cur = rlim.rlim_max = (unsigned long) RLIM_INFINITY;
812 setrlimit(RLIMIT_FSIZE, &rlim);
813 getrlimit(RLIMIT_FSIZE, &rlim);
814 if (((unsigned long) rlim.rlim_cur) <
815 ((unsigned long) rlim.rlim_max)) {
816 rlim.rlim_cur = rlim.rlim_max;
817 setrlimit(RLIMIT_FSIZE, &rlim);
818 }
819 }
820 #endif
821 #ifdef HAVE_PTHREAD
822 if (flags & IO_FLAG_THREADS) {
823 io->flags |= CHANNEL_FLAGS_THREADS;
824 retval = pthread_mutex_init(&data->cache_mutex, NULL);
825 if (retval)
826 goto cleanup;
827 retval = pthread_mutex_init(&data->bounce_mutex, NULL);
828 if (retval) {
829 pthread_mutex_destroy(&data->cache_mutex);
830 goto cleanup;
831 }
832 retval = pthread_mutex_init(&data->stats_mutex, NULL);
833 if (retval) {
834 pthread_mutex_destroy(&data->cache_mutex);
835 pthread_mutex_destroy(&data->bounce_mutex);
836 goto cleanup;
837 }
838 }
839 #endif
840 *channel = io;
841 return 0;
842
843 cleanup:
844 if (data) {
845 if (data->dev >= 0)
846 close(data->dev);
847 free_cache(data);
848 ext2fs_free_mem(&data);
849 }
850 if (io) {
851 if (io->name) {
852 ext2fs_free_mem(&io->name);
853 }
854 ext2fs_free_mem(&io);
855 }
856 return retval;
857 }
858
unixfd_open(const char * str_fd,int flags,io_channel * channel)859 static errcode_t unixfd_open(const char *str_fd, int flags,
860 io_channel *channel)
861 {
862 int fd;
863 int fd_flags;
864
865 fd = atoi(str_fd);
866 #if defined(HAVE_FCNTL)
867 fd_flags = fcntl(fd, F_GETFD);
868 if (fd_flags == -1)
869 return EBADF;
870
871 flags = 0;
872 if (fd_flags & O_RDWR)
873 flags |= IO_FLAG_RW;
874 if (fd_flags & O_EXCL)
875 flags |= IO_FLAG_EXCLUSIVE;
876 #if defined(O_DIRECT)
877 if (fd_flags & O_DIRECT)
878 flags |= IO_FLAG_DIRECT_IO;
879 #endif
880 #endif /* HAVE_FCNTL */
881
882 return unix_open_channel(str_fd, fd, flags, channel, unixfd_io_manager);
883 }
884
unix_open(const char * name,int flags,io_channel * channel)885 static errcode_t unix_open(const char *name, int flags,
886 io_channel *channel)
887 {
888 int fd = -1;
889 int open_flags;
890
891 if (name == 0)
892 return EXT2_ET_BAD_DEVICE_NAME;
893
894 open_flags = (flags & IO_FLAG_RW) ? O_RDWR : O_RDONLY;
895 if (flags & IO_FLAG_EXCLUSIVE)
896 open_flags |= O_EXCL;
897 #if defined(O_DIRECT)
898 if (flags & IO_FLAG_DIRECT_IO)
899 open_flags |= O_DIRECT;
900 #endif
901 fd = ext2fs_open_file(name, open_flags, 0);
902 if (fd < 0)
903 return errno;
904 #if defined(F_NOCACHE) && !defined(IO_DIRECT)
905 if (flags & IO_FLAG_DIRECT_IO) {
906 if (fcntl(fd, F_NOCACHE, 1) < 0)
907 return errno;
908 }
909 #endif
910 return unix_open_channel(name, fd, flags, channel, unix_io_manager);
911 }
912
unix_close(io_channel channel)913 static errcode_t unix_close(io_channel channel)
914 {
915 struct unix_private_data *data;
916 errcode_t retval = 0;
917
918 EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
919 data = (struct unix_private_data *) channel->private_data;
920 EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
921
922 if (--channel->refcount > 0)
923 return 0;
924
925 #ifndef NO_IO_CACHE
926 retval = flush_cached_blocks(channel, data, 0);
927 #endif
928
929 if (close(data->dev) < 0)
930 retval = errno;
931 free_cache(data);
932 #ifdef HAVE_PTHREAD
933 if (data->flags & IO_FLAG_THREADS) {
934 pthread_mutex_destroy(&data->cache_mutex);
935 pthread_mutex_destroy(&data->bounce_mutex);
936 pthread_mutex_destroy(&data->stats_mutex);
937 }
938 #endif
939
940 ext2fs_free_mem(&channel->private_data);
941 if (channel->name)
942 ext2fs_free_mem(&channel->name);
943 ext2fs_free_mem(&channel);
944 return retval;
945 }
946
unix_set_blksize(io_channel channel,int blksize)947 static errcode_t unix_set_blksize(io_channel channel, int blksize)
948 {
949 struct unix_private_data *data;
950 errcode_t retval = 0;
951
952 EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
953 data = (struct unix_private_data *) channel->private_data;
954 EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
955
956 if (channel->block_size != blksize) {
957 mutex_lock(data, CACHE_MTX);
958 mutex_lock(data, BOUNCE_MTX);
959 #ifndef NO_IO_CACHE
960 if ((retval = flush_cached_blocks(channel, data, FLUSH_NOLOCK)))
961 return retval;
962 #endif
963
964 channel->block_size = blksize;
965 free_cache(data);
966 retval = alloc_cache(channel, data);
967 mutex_unlock(data, BOUNCE_MTX);
968 mutex_unlock(data, CACHE_MTX);
969 }
970 return retval;
971 }
972
unix_read_blk64(io_channel channel,unsigned long long block,int count,void * buf)973 static errcode_t unix_read_blk64(io_channel channel, unsigned long long block,
974 int count, void *buf)
975 {
976 struct unix_private_data *data;
977 struct unix_cache *cache, *reuse[READ_DIRECT_SIZE];
978 errcode_t retval = 0;
979 char *cp;
980 int i, j;
981
982 EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
983 data = (struct unix_private_data *) channel->private_data;
984 EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
985
986 #ifdef NO_IO_CACHE
987 return raw_read_blk(channel, data, block, count, buf);
988 #else
989 if (data->flags & IO_FLAG_NOCACHE)
990 return raw_read_blk(channel, data, block, count, buf);
991 /*
992 * If we're doing an odd-sized read or a very large read,
993 * flush out the cache and then do a direct read.
994 */
995 if (count < 0 || count > WRITE_DIRECT_SIZE) {
996 if ((retval = flush_cached_blocks(channel, data, 0)))
997 return retval;
998 return raw_read_blk(channel, data, block, count, buf);
999 }
1000
1001 cp = buf;
1002 mutex_lock(data, CACHE_MTX);
1003 while (count > 0) {
1004 /* If it's in the cache, use it! */
1005 if ((cache = find_cached_block(data, block, &reuse[0]))) {
1006 #ifdef DEBUG
1007 printf("Using cached block %lu\n", block);
1008 #endif
1009 memcpy(cp, cache->buf, channel->block_size);
1010 count--;
1011 block++;
1012 cp += channel->block_size;
1013 continue;
1014 }
1015 if (count == 1) {
1016 /*
1017 * Special case where we read directly into the
1018 * cache buffer; important in the O_DIRECT case
1019 */
1020 cache = reuse[0];
1021 reuse_cache(channel, data, cache, block);
1022 if ((retval = raw_read_blk(channel, data, block, 1,
1023 cache->buf))) {
1024 cache->in_use = 0;
1025 break;
1026 }
1027 memcpy(cp, cache->buf, channel->block_size);
1028 retval = 0;
1029 break;
1030 }
1031
1032 /*
1033 * Find the number of uncached blocks so we can do a
1034 * single read request
1035 */
1036 for (i=1; i < count; i++)
1037 if (find_cached_block(data, block+i, &reuse[i]))
1038 break;
1039 #ifdef DEBUG
1040 printf("Reading %d blocks starting at %lu\n", i, block);
1041 #endif
1042 if ((retval = raw_read_blk(channel, data, block, i, cp)))
1043 break;
1044
1045 /* Save the results in the cache */
1046 for (j=0; j < i; j++) {
1047 count--;
1048 cache = reuse[j];
1049 reuse_cache(channel, data, cache, block++);
1050 memcpy(cache->buf, cp, channel->block_size);
1051 cp += channel->block_size;
1052 }
1053 }
1054 mutex_unlock(data, CACHE_MTX);
1055 return retval;
1056 #endif /* NO_IO_CACHE */
1057 }
1058
unix_read_blk(io_channel channel,unsigned long block,int count,void * buf)1059 static errcode_t unix_read_blk(io_channel channel, unsigned long block,
1060 int count, void *buf)
1061 {
1062 return unix_read_blk64(channel, block, count, buf);
1063 }
1064
unix_write_blk64(io_channel channel,unsigned long long block,int count,const void * buf)1065 static errcode_t unix_write_blk64(io_channel channel, unsigned long long block,
1066 int count, const void *buf)
1067 {
1068 struct unix_private_data *data;
1069 struct unix_cache *cache, *reuse;
1070 errcode_t retval = 0;
1071 const char *cp;
1072 int writethrough;
1073
1074 EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
1075 data = (struct unix_private_data *) channel->private_data;
1076 EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
1077
1078 #ifdef NO_IO_CACHE
1079 return raw_write_blk(channel, data, block, count, buf);
1080 #else
1081 if (data->flags & IO_FLAG_NOCACHE)
1082 return raw_write_blk(channel, data, block, count, buf);
1083 /*
1084 * If we're doing an odd-sized write or a very large write,
1085 * flush out the cache completely and then do a direct write.
1086 */
1087 if (count < 0 || count > WRITE_DIRECT_SIZE) {
1088 if ((retval = flush_cached_blocks(channel, data,
1089 FLUSH_INVALIDATE)))
1090 return retval;
1091 return raw_write_blk(channel, data, block, count, buf);
1092 }
1093
1094 /*
1095 * For a moderate-sized multi-block write, first force a write
1096 * if we're in write-through cache mode, and then fill the
1097 * cache with the blocks.
1098 */
1099 writethrough = channel->flags & CHANNEL_FLAGS_WRITETHROUGH;
1100 if (writethrough)
1101 retval = raw_write_blk(channel, data, block, count, buf);
1102
1103 cp = buf;
1104 mutex_lock(data, CACHE_MTX);
1105 while (count > 0) {
1106 cache = find_cached_block(data, block, &reuse);
1107 if (!cache) {
1108 cache = reuse;
1109 reuse_cache(channel, data, cache, block);
1110 }
1111 if (cache->buf != cp)
1112 memcpy(cache->buf, cp, channel->block_size);
1113 cache->dirty = !writethrough;
1114 count--;
1115 block++;
1116 cp += channel->block_size;
1117 }
1118 mutex_unlock(data, CACHE_MTX);
1119 return retval;
1120 #endif /* NO_IO_CACHE */
1121 }
1122
unix_cache_readahead(io_channel channel,unsigned long long block,unsigned long long count)1123 static errcode_t unix_cache_readahead(io_channel channel,
1124 unsigned long long block,
1125 unsigned long long count)
1126 {
1127 #ifdef POSIX_FADV_WILLNEED
1128 struct unix_private_data *data;
1129
1130 data = (struct unix_private_data *)channel->private_data;
1131 EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
1132 return posix_fadvise(data->dev,
1133 (ext2_loff_t)block * channel->block_size + data->offset,
1134 (ext2_loff_t)count * channel->block_size,
1135 POSIX_FADV_WILLNEED);
1136 #else
1137 return EXT2_ET_OP_NOT_SUPPORTED;
1138 #endif
1139 }
1140
unix_write_blk(io_channel channel,unsigned long block,int count,const void * buf)1141 static errcode_t unix_write_blk(io_channel channel, unsigned long block,
1142 int count, const void *buf)
1143 {
1144 return unix_write_blk64(channel, block, count, buf);
1145 }
1146
unix_write_byte(io_channel channel,unsigned long offset,int size,const void * buf)1147 static errcode_t unix_write_byte(io_channel channel, unsigned long offset,
1148 int size, const void *buf)
1149 {
1150 struct unix_private_data *data;
1151 errcode_t retval = 0;
1152 ssize_t actual;
1153
1154 EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
1155 data = (struct unix_private_data *) channel->private_data;
1156 EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
1157
1158 if (channel->align != 0) {
1159 #ifdef ALIGN_DEBUG
1160 printf("unix_write_byte: O_DIRECT fallback\n");
1161 #endif
1162 return EXT2_ET_UNIMPLEMENTED;
1163 }
1164
1165 #ifndef NO_IO_CACHE
1166 /*
1167 * Flush out the cache completely
1168 */
1169 if ((retval = flush_cached_blocks(channel, data, FLUSH_INVALIDATE)))
1170 return retval;
1171 #endif
1172
1173 if (lseek(data->dev, offset + data->offset, SEEK_SET) < 0)
1174 return errno;
1175
1176 actual = write(data->dev, buf, size);
1177 if (actual < 0)
1178 return errno;
1179 if (actual != size)
1180 return EXT2_ET_SHORT_WRITE;
1181
1182 return 0;
1183 }
1184
1185 /*
1186 * Flush data buffers to disk.
1187 */
unix_flush(io_channel channel)1188 static errcode_t unix_flush(io_channel channel)
1189 {
1190 struct unix_private_data *data;
1191 errcode_t retval = 0;
1192
1193 EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
1194 data = (struct unix_private_data *) channel->private_data;
1195 EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
1196
1197 #ifndef NO_IO_CACHE
1198 retval = flush_cached_blocks(channel, data, 0);
1199 #endif
1200 #ifdef HAVE_FSYNC
1201 if (!retval && fsync(data->dev) != 0)
1202 return errno;
1203 #endif
1204 return retval;
1205 }
1206
unix_set_option(io_channel channel,const char * option,const char * arg)1207 static errcode_t unix_set_option(io_channel channel, const char *option,
1208 const char *arg)
1209 {
1210 struct unix_private_data *data;
1211 unsigned long long tmp;
1212 errcode_t retval;
1213 char *end;
1214
1215 EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
1216 data = (struct unix_private_data *) channel->private_data;
1217 EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
1218
1219 if (!strcmp(option, "offset")) {
1220 if (!arg)
1221 return EXT2_ET_INVALID_ARGUMENT;
1222
1223 tmp = strtoull(arg, &end, 0);
1224 if (*end)
1225 return EXT2_ET_INVALID_ARGUMENT;
1226 data->offset = tmp;
1227 if (data->offset < 0)
1228 return EXT2_ET_INVALID_ARGUMENT;
1229 return 0;
1230 }
1231 if (!strcmp(option, "cache")) {
1232 if (!arg)
1233 return EXT2_ET_INVALID_ARGUMENT;
1234 if (!strcmp(arg, "on")) {
1235 data->flags &= ~IO_FLAG_NOCACHE;
1236 return 0;
1237 }
1238 if (!strcmp(arg, "off")) {
1239 retval = flush_cached_blocks(channel, data, 0);
1240 data->flags |= IO_FLAG_NOCACHE;
1241 return retval;
1242 }
1243 return EXT2_ET_INVALID_ARGUMENT;
1244 }
1245 return EXT2_ET_INVALID_ARGUMENT;
1246 }
1247
1248 #if defined(__linux__) && !defined(BLKDISCARD)
1249 #define BLKDISCARD _IO(0x12,119)
1250 #endif
1251
unix_discard(io_channel channel,unsigned long long block,unsigned long long count)1252 static errcode_t unix_discard(io_channel channel, unsigned long long block,
1253 unsigned long long count)
1254 {
1255 struct unix_private_data *data;
1256 int ret;
1257
1258 EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
1259 data = (struct unix_private_data *) channel->private_data;
1260 EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
1261
1262 if (channel->flags & CHANNEL_FLAGS_BLOCK_DEVICE) {
1263 #ifdef BLKDISCARD
1264 __u64 range[2];
1265
1266 range[0] = (__u64)(block) * channel->block_size + data->offset;
1267 range[1] = (__u64)(count) * channel->block_size;
1268
1269 ret = ioctl(data->dev, BLKDISCARD, &range);
1270 #else
1271 goto unimplemented;
1272 #endif
1273 } else {
1274 #if defined(HAVE_FALLOCATE) && defined(FALLOC_FL_PUNCH_HOLE)
1275 /*
1276 * If we are not on block device, try to use punch hole
1277 * to reclaim free space.
1278 */
1279 ret = fallocate(data->dev,
1280 FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
1281 (off_t)(block) * channel->block_size + data->offset,
1282 (off_t)(count) * channel->block_size);
1283 #else
1284 goto unimplemented;
1285 #endif
1286 }
1287 if (ret < 0) {
1288 if (errno == EOPNOTSUPP)
1289 goto unimplemented;
1290 return errno;
1291 }
1292 return 0;
1293 unimplemented:
1294 return EXT2_ET_UNIMPLEMENTED;
1295 }
1296
1297 /*
1298 * If we know about ZERO_RANGE, try that before we try PUNCH_HOLE because
1299 * ZERO_RANGE doesn't unmap preallocated blocks. We prefer fallocate because
1300 * it always invalidates page cache, and libext2fs requires that reads after
1301 * ZERO_RANGE return zeroes.
1302 */
__unix_zeroout(int fd,off_t offset,off_t len)1303 static int __unix_zeroout(int fd, off_t offset, off_t len)
1304 {
1305 int ret = -1;
1306
1307 #if defined(HAVE_FALLOCATE) && defined(FALLOC_FL_ZERO_RANGE)
1308 ret = fallocate(fd, FALLOC_FL_ZERO_RANGE, offset, len);
1309 if (ret == 0)
1310 return 0;
1311 #endif
1312 #if defined(HAVE_FALLOCATE) && defined(FALLOC_FL_PUNCH_HOLE) && defined(FALLOC_FL_KEEP_SIZE)
1313 ret = fallocate(fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
1314 offset, len);
1315 if (ret == 0)
1316 return 0;
1317 #endif
1318 errno = EOPNOTSUPP;
1319 return ret;
1320 }
1321
1322 /* parameters might not be used if OS doesn't support zeroout */
1323 #if __GNUC_PREREQ (4, 6)
1324 #pragma GCC diagnostic push
1325 #pragma GCC diagnostic ignored "-Wunused-parameter"
1326 #endif
unix_zeroout(io_channel channel,unsigned long long block,unsigned long long count)1327 static errcode_t unix_zeroout(io_channel channel, unsigned long long block,
1328 unsigned long long count)
1329 {
1330 struct unix_private_data *data;
1331 int ret;
1332
1333 EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
1334 data = (struct unix_private_data *) channel->private_data;
1335 EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
1336
1337 if (safe_getenv("UNIX_IO_NOZEROOUT"))
1338 goto unimplemented;
1339
1340 if (!(channel->flags & CHANNEL_FLAGS_BLOCK_DEVICE)) {
1341 /* Regular file, try to use truncate/punch/zero. */
1342 struct stat statbuf;
1343
1344 if (count == 0)
1345 return 0;
1346 /*
1347 * If we're trying to zero a range past the end of the file,
1348 * extend the file size, then truncate everything.
1349 */
1350 ret = fstat(data->dev, &statbuf);
1351 if (ret)
1352 goto err;
1353 if ((unsigned long long) statbuf.st_size <
1354 (block + count) * channel->block_size + data->offset) {
1355 ret = ftruncate(data->dev,
1356 (block + count) * channel->block_size + data->offset);
1357 if (ret)
1358 goto err;
1359 }
1360 }
1361
1362 ret = __unix_zeroout(data->dev,
1363 (off_t)(block) * channel->block_size + data->offset,
1364 (off_t)(count) * channel->block_size);
1365 err:
1366 if (ret < 0) {
1367 if (errno == EOPNOTSUPP)
1368 goto unimplemented;
1369 return errno;
1370 }
1371 return 0;
1372 unimplemented:
1373 return EXT2_ET_UNIMPLEMENTED;
1374 }
1375 #if __GNUC_PREREQ (4, 6)
1376 #pragma GCC diagnostic pop
1377 #endif
1378
1379 static struct struct_io_manager struct_unix_manager = {
1380 .magic = EXT2_ET_MAGIC_IO_MANAGER,
1381 .name = "Unix I/O Manager",
1382 .open = unix_open,
1383 .close = unix_close,
1384 .set_blksize = unix_set_blksize,
1385 .read_blk = unix_read_blk,
1386 .write_blk = unix_write_blk,
1387 .flush = unix_flush,
1388 .write_byte = unix_write_byte,
1389 .set_option = unix_set_option,
1390 .get_stats = unix_get_stats,
1391 .read_blk64 = unix_read_blk64,
1392 .write_blk64 = unix_write_blk64,
1393 .discard = unix_discard,
1394 .cache_readahead = unix_cache_readahead,
1395 .zeroout = unix_zeroout,
1396 };
1397
1398 io_manager unix_io_manager = &struct_unix_manager;
1399
1400 static struct struct_io_manager struct_unixfd_manager = {
1401 .magic = EXT2_ET_MAGIC_IO_MANAGER,
1402 .name = "Unix fd I/O Manager",
1403 .open = unixfd_open,
1404 .close = unix_close,
1405 .set_blksize = unix_set_blksize,
1406 .read_blk = unix_read_blk,
1407 .write_blk = unix_write_blk,
1408 .flush = unix_flush,
1409 .write_byte = unix_write_byte,
1410 .set_option = unix_set_option,
1411 .get_stats = unix_get_stats,
1412 .read_blk64 = unix_read_blk64,
1413 .write_blk64 = unix_write_blk64,
1414 .discard = unix_discard,
1415 .cache_readahead = unix_cache_readahead,
1416 .zeroout = unix_zeroout,
1417 };
1418
1419 io_manager unixfd_io_manager = &struct_unixfd_manager;
1420