block.c revision 55f4e4a5ec657a017e3bf75299ad71fd1c968dd3 
1/*
2 * QEMU System Emulator block driver
3 *
4 * Copyright (c) 2003 Fabrice Bellard
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24#include "vl.h"
25#include "block_int.h"
26
27#ifdef _BSD
28#include <sys/types.h>
29#include <sys/stat.h>
30#include <sys/ioctl.h>
31#include <sys/queue.h>
32#include <sys/disk.h>
33#endif
34
35#ifdef CONFIG_COCOA
36#include <paths.h>
37#include <sys/param.h>
38#include <IOKit/IOKitLib.h>
39#include <IOKit/IOBSD.h>
40#include <IOKit/storage/IOMediaBSDClient.h>
41#include <IOKit/storage/IOMedia.h>
42#include <IOKit/storage/IOCDMedia.h>
43//#include <IOKit/storage/IOCDTypes.h>
44#include <CoreFoundation/CoreFoundation.h>
45#endif
46
47#ifdef __sun__
48#include <sys/dkio.h>
49#endif
50
51static BlockDriverState *bdrv_first;
52static BlockDriver *first_drv;
53
54#ifdef CONFIG_COCOA
55static kern_return_t FindEjectableCDMedia( io_iterator_t *mediaIterator );
56static kern_return_t GetBSDPath( io_iterator_t mediaIterator, char *bsdPath, CFIndex maxPathSize );
57
58kern_return_t FindEjectableCDMedia( io_iterator_t *mediaIterator )
59{
60    kern_return_t       kernResult;
61    mach_port_t     masterPort;
62    CFMutableDictionaryRef  classesToMatch;
63
64    kernResult = IOMasterPort( MACH_PORT_NULL, &masterPort );
65    if ( KERN_SUCCESS != kernResult ) {
66        printf( "IOMasterPort returned %d\n", kernResult );
67    }
68
69    classesToMatch = IOServiceMatching( kIOCDMediaClass );
70    if ( classesToMatch == NULL ) {
71        printf( "IOServiceMatching returned a NULL dictionary.\n" );
72    } else {
73    CFDictionarySetValue( classesToMatch, CFSTR( kIOMediaEjectableKey ), kCFBooleanTrue );
74    }
75    kernResult = IOServiceGetMatchingServices( masterPort, classesToMatch, mediaIterator );
76    if ( KERN_SUCCESS != kernResult )
77    {
78        printf( "IOServiceGetMatchingServices returned %d\n", kernResult );
79    }
80
81    return kernResult;
82}
83
84kern_return_t GetBSDPath( io_iterator_t mediaIterator, char *bsdPath, CFIndex maxPathSize )
85{
86    io_object_t     nextMedia;
87    kern_return_t   kernResult = KERN_FAILURE;
88    *bsdPath = '\0';
89    nextMedia = IOIteratorNext( mediaIterator );
90    if ( nextMedia )
91    {
92        CFTypeRef   bsdPathAsCFString;
93    bsdPathAsCFString = IORegistryEntryCreateCFProperty( nextMedia, CFSTR( kIOBSDNameKey ), kCFAllocatorDefault, 0 );
94        if ( bsdPathAsCFString ) {
95            size_t devPathLength;
96            strcpy( bsdPath, _PATH_DEV );
97            strcat( bsdPath, "r" );
98            devPathLength = strlen( bsdPath );
99            if ( CFStringGetCString( bsdPathAsCFString, bsdPath + devPathLength, maxPathSize - devPathLength, kCFStringEncodingASCII ) ) {
100                kernResult = KERN_SUCCESS;
101            }
102            CFRelease( bsdPathAsCFString );
103        }
104        IOObjectRelease( nextMedia );
105    }
106
107    return kernResult;
108}
109
110#endif
111
112void bdrv_register(BlockDriver *bdrv)
113{
114    bdrv->next = first_drv;
115    first_drv = bdrv;
116}
117
118/* create a new block device (by default it is empty) */
119BlockDriverState *bdrv_new(const char *device_name)
120{
121    BlockDriverState **pbs, *bs;
122
123    bs = qemu_mallocz(sizeof(BlockDriverState));
124    if(!bs)
125        return NULL;
126    pstrcpy(bs->device_name, sizeof(bs->device_name), device_name);
127    if (device_name[0] != '\0') {
128        /* insert at the end */
129        pbs = &bdrv_first;
130        while (*pbs != NULL)
131            pbs = &(*pbs)->next;
132        *pbs = bs;
133    }
134    return bs;
135}
136
137BlockDriver *bdrv_find_format(const char *format_name)
138{
139    BlockDriver *drv1;
140    for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
141        if (!strcmp(drv1->format_name, format_name))
142            return drv1;
143    }
144    return NULL;
145}
146
147int bdrv_create(BlockDriver *drv,
148                const char *filename, int64_t size_in_sectors,
149                const char *backing_file, int flags)
150{
151    if (!drv->bdrv_create)
152        return -ENOTSUP;
153    return drv->bdrv_create(filename, size_in_sectors, backing_file, flags);
154}
155
156#ifdef _WIN32
157void get_tmp_filename(char *filename, int size)
158{
159    char* p = strrchr(filename, '/');
160
161    if (p == NULL)
162	return;
163
164    /* XXX: find a better function */
165    tmpnam(p);
166    *p = '/';
167}
168#else
169void get_tmp_filename(char *filename, int size)
170{
171    int fd;
172    /* XXX: race condition possible */
173    pstrcpy(filename, size, "/tmp/vl.XXXXXX");
174    fd = mkstemp(filename);
175    close(fd);
176}
177#endif
178
179/* XXX: force raw format if block or character device ? It would
180   simplify the BSD case */
181static BlockDriver *find_image_format(const char *filename)
182{
183    int fd, ret, score, score_max;
184    BlockDriver *drv1, *drv;
185    uint8_t *buf;
186    size_t bufsize = 1024;
187
188    fd = open(filename, O_RDONLY | O_BINARY | O_LARGEFILE);
189    if (fd < 0) {
190        buf = NULL;
191        ret = 0;
192    } else {
193#ifdef DIOCGSECTORSIZE
194        {
195            unsigned int sectorsize = 512;
196            if (!ioctl(fd, DIOCGSECTORSIZE, &sectorsize) &&
197                sectorsize > bufsize)
198                bufsize = sectorsize;
199        }
200#endif
201#ifdef CONFIG_COCOA
202        u_int32_t   blockSize = 512;
203        if ( !ioctl( fd, DKIOCGETBLOCKSIZE, &blockSize ) && blockSize > bufsize) {
204            bufsize = blockSize;
205        }
206#endif
207        buf = qemu_malloc(bufsize);
208        if (!buf)
209            return NULL;
210        ret = read(fd, buf, bufsize);
211        if (ret < 0) {
212            close(fd);
213            qemu_free(buf);
214            return NULL;
215        }
216        close(fd);
217    }
218
219    drv = NULL;
220    score_max = 0;
221    for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
222        score = drv1->bdrv_probe(buf, ret, filename);
223        if (score > score_max) {
224            score_max = score;
225            drv = drv1;
226        }
227    }
228    qemu_free(buf);
229    return drv;
230}
231
232int bdrv_open(BlockDriverState *bs, const char *filename, int snapshot)
233{
234#ifdef CONFIG_COCOA
235    if ( strncmp( filename, "/dev/cdrom", 10 ) == 0 ) {
236        kern_return_t kernResult;
237        io_iterator_t mediaIterator;
238        char bsdPath[ MAXPATHLEN ];
239        int fd;
240
241        kernResult = FindEjectableCDMedia( &mediaIterator );
242        kernResult = GetBSDPath( mediaIterator, bsdPath, sizeof( bsdPath ) );
243
244        if ( bsdPath[ 0 ] != '\0' ) {
245            strcat(bsdPath,"s0");
246            /* some CDs don't have a partition 0 */
247            fd = open(bsdPath, O_RDONLY | O_BINARY | O_LARGEFILE);
248            if (fd < 0) {
249                bsdPath[strlen(bsdPath)-1] = '1';
250            } else {
251                close(fd);
252            }
253            filename = bsdPath;
254        }
255
256        if ( mediaIterator )
257            IOObjectRelease( mediaIterator );
258    }
259#endif
260    return bdrv_open2(bs, filename, snapshot, NULL);
261}
262
263int bdrv_open2(BlockDriverState *bs, const char *filename, int snapshot,
264               BlockDriver *drv)
265{
266    int ret;
267    char tmp_filename[1024];
268
269    bs->read_only = 0;
270    bs->is_temporary = 0;
271    bs->encrypted = 0;
272
273    if (snapshot) {
274        BlockDriverState *bs1;
275        int64_t total_size;
276
277        /* if snapshot, we create a temporary backing file and open it
278           instead of opening 'filename' directly */
279
280        /* if there is a backing file, use it */
281        bs1 = bdrv_new("");
282        if (!bs1) {
283            return -1;
284        }
285        if (bdrv_open(bs1, filename, 0) < 0) {
286            bdrv_delete(bs1);
287            return -1;
288        }
289        total_size = bs1->total_sectors;
290        bdrv_delete(bs1);
291
292        get_tmp_filename(tmp_filename, sizeof(tmp_filename));
293        /* XXX: use cow for linux as it is more efficient ? */
294        if (bdrv_create(&bdrv_qcow, tmp_filename,
295                        total_size, filename, 0) < 0) {
296            return -1;
297        }
298        filename = tmp_filename;
299        bs->is_temporary = 1;
300    }
301
302    pstrcpy(bs->filename, sizeof(bs->filename), filename);
303    if (!drv) {
304        drv = find_image_format(filename);
305        if (!drv)
306            return -1;
307    }
308    bs->drv = drv;
309    bs->opaque = qemu_mallocz(drv->instance_size);
310    if (bs->opaque == NULL && drv->instance_size > 0)
311        return -1;
312
313    ret = drv->bdrv_open(bs, filename);
314    if (ret < 0) {
315        qemu_free(bs->opaque);
316        return -1;
317    }
318#ifndef _WIN32
319    if (bs->is_temporary) {
320        unlink(filename);
321    }
322#endif
323    if (bs->backing_file[0] != '\0' && drv->bdrv_is_allocated) {
324        /* if there is a backing file, use it */
325        bs->backing_hd = bdrv_new("");
326        if (!bs->backing_hd) {
327        fail:
328            bdrv_close(bs);
329            return -1;
330        }
331        if (bdrv_open(bs->backing_hd, bs->backing_file, 0) < 0)
332            goto fail;
333    }
334
335    bs->inserted = 1;
336
337    /* call the change callback */
338    if (bs->change_cb)
339        bs->change_cb(bs->change_opaque);
340
341    return 0;
342}
343
344void bdrv_close(BlockDriverState *bs)
345{
346    if (bs->inserted) {
347        if (bs->backing_hd)
348            bdrv_delete(bs->backing_hd);
349        bs->drv->bdrv_close(bs);
350        qemu_free(bs->opaque);
351#ifdef _WIN32
352        if (bs->is_temporary) {
353            unlink(bs->filename);
354        }
355#endif
356        bs->opaque = NULL;
357        bs->drv = NULL;
358        bs->inserted = 0;
359
360        /* call the change callback */
361        if (bs->change_cb)
362            bs->change_cb(bs->change_opaque);
363    }
364}
365
366void bdrv_delete(BlockDriverState *bs)
367{
368    /* XXX: remove the driver list */
369    bdrv_close(bs);
370    qemu_free(bs);
371}
372
373/* commit COW file into the raw image */
374int bdrv_commit(BlockDriverState *bs)
375{
376    int64_t i;
377    int n, j;
378    unsigned char sector[512];
379
380    if (!bs->inserted)
381        return -ENOENT;
382
383    if (bs->read_only) {
384	return -EACCES;
385    }
386
387    if (!bs->backing_hd) {
388	return -ENOTSUP;
389    }
390
391    for (i = 0; i < bs->total_sectors;) {
392        if (bs->drv->bdrv_is_allocated(bs, i, 65536, &n)) {
393            for(j = 0; j < n; j++) {
394                if (bdrv_read(bs, i, sector, 1) != 0) {
395                    return -EIO;
396                }
397
398                if (bdrv_write(bs->backing_hd, i, sector, 1) != 0) {
399                    return -EIO;
400                }
401                i++;
402	    }
403	} else {
404            i += n;
405        }
406    }
407
408    if (bs->drv->bdrv_make_empty)
409	return bs->drv->bdrv_make_empty(bs);
410
411    return 0;
412}
413
414/* return -1 if error */
415int bdrv_read(BlockDriverState *bs, int64_t sector_num,
416              uint8_t *buf, int nb_sectors)
417{
418    int ret, n;
419    BlockDriver *drv = bs->drv;
420
421    if (!bs->inserted)
422        return -1;
423
424    while (nb_sectors > 0) {
425        if (sector_num == 0 && bs->boot_sector_enabled) {
426            memcpy(buf, bs->boot_sector_data, 512);
427            n = 1;
428        } else if (bs->backing_hd) {
429            if (drv->bdrv_is_allocated(bs, sector_num, nb_sectors, &n)) {
430                ret = drv->bdrv_read(bs, sector_num, buf, n);
431                if (ret < 0)
432                    return -1;
433            } else {
434                /* read from the base image */
435                ret = bdrv_read(bs->backing_hd, sector_num, buf, n);
436                if (ret < 0)
437                    return -1;
438            }
439        } else {
440            ret = drv->bdrv_read(bs, sector_num, buf, nb_sectors);
441            if (ret < 0)
442                return -1;
443            /* no need to loop */
444            break;
445        }
446        nb_sectors -= n;
447        sector_num += n;
448        buf += n * 512;
449    }
450    return 0;
451}
452
453/* return -1 if error */
454int bdrv_write(BlockDriverState *bs, int64_t sector_num,
455               const uint8_t *buf, int nb_sectors)
456{
457    if (!bs->inserted)
458        return -1;
459    if (bs->read_only)
460        return -1;
461    if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) {
462        memcpy(bs->boot_sector_data, buf, 512);
463    }
464    return bs->drv->bdrv_write(bs, sector_num, buf, nb_sectors);
465}
466
467void bdrv_get_geometry(BlockDriverState *bs, int64_t *nb_sectors_ptr)
468{
469    *nb_sectors_ptr = bs->total_sectors;
470}
471
472/* force a given boot sector. */
473void bdrv_set_boot_sector(BlockDriverState *bs, const uint8_t *data, int size)
474{
475    bs->boot_sector_enabled = 1;
476    if (size > 512)
477        size = 512;
478    memcpy(bs->boot_sector_data, data, size);
479    memset(bs->boot_sector_data + size, 0, 512 - size);
480}
481
482void bdrv_set_geometry_hint(BlockDriverState *bs,
483                            int cyls, int heads, int secs)
484{
485    bs->cyls = cyls;
486    bs->heads = heads;
487    bs->secs = secs;
488}
489
490void bdrv_set_type_hint(BlockDriverState *bs, int type)
491{
492    bs->type = type;
493    bs->removable = ((type == BDRV_TYPE_CDROM ||
494                      type == BDRV_TYPE_FLOPPY));
495}
496
497void bdrv_set_translation_hint(BlockDriverState *bs, int translation)
498{
499    bs->translation = translation;
500}
501
502void bdrv_get_geometry_hint(BlockDriverState *bs,
503                            int *pcyls, int *pheads, int *psecs)
504{
505    *pcyls = bs->cyls;
506    *pheads = bs->heads;
507    *psecs = bs->secs;
508}
509
510int bdrv_get_type_hint(BlockDriverState *bs)
511{
512    return bs->type;
513}
514
515int bdrv_get_translation_hint(BlockDriverState *bs)
516{
517    return bs->translation;
518}
519
520int bdrv_is_removable(BlockDriverState *bs)
521{
522    return bs->removable;
523}
524
525int bdrv_is_read_only(BlockDriverState *bs)
526{
527    return bs->read_only;
528}
529
530int bdrv_is_inserted(BlockDriverState *bs)
531{
532    return bs->inserted;
533}
534
535int bdrv_is_locked(BlockDriverState *bs)
536{
537    return bs->locked;
538}
539
540void bdrv_set_locked(BlockDriverState *bs, int locked)
541{
542    bs->locked = locked;
543}
544
545void bdrv_set_change_cb(BlockDriverState *bs,
546                        void (*change_cb)(void *opaque), void *opaque)
547{
548    bs->change_cb = change_cb;
549    bs->change_opaque = opaque;
550}
551
552int bdrv_is_encrypted(BlockDriverState *bs)
553{
554    if (bs->backing_hd && bs->backing_hd->encrypted)
555        return 1;
556    return bs->encrypted;
557}
558
559int bdrv_set_key(BlockDriverState *bs, const char *key)
560{
561    int ret;
562    if (bs->backing_hd && bs->backing_hd->encrypted) {
563        ret = bdrv_set_key(bs->backing_hd, key);
564        if (ret < 0)
565            return ret;
566        if (!bs->encrypted)
567            return 0;
568    }
569    if (!bs->encrypted || !bs->drv || !bs->drv->bdrv_set_key)
570        return -1;
571    return bs->drv->bdrv_set_key(bs, key);
572}
573
574void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)
575{
576    if (!bs->inserted || !bs->drv) {
577        buf[0] = '\0';
578    } else {
579        pstrcpy(buf, buf_size, bs->drv->format_name);
580    }
581}
582
583void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
584                         void *opaque)
585{
586    BlockDriver *drv;
587
588    for (drv = first_drv; drv != NULL; drv = drv->next) {
589        it(opaque, drv->format_name);
590    }
591}
592
593BlockDriverState *bdrv_find(const char *name)
594{
595    BlockDriverState *bs;
596
597    for (bs = bdrv_first; bs != NULL; bs = bs->next) {
598        if (!strcmp(name, bs->device_name))
599            return bs;
600    }
601    return NULL;
602}
603
604void bdrv_iterate(void (*it)(void *opaque, const char *name), void *opaque)
605{
606    BlockDriverState *bs;
607
608    for (bs = bdrv_first; bs != NULL; bs = bs->next) {
609        it(opaque, bs->device_name);
610    }
611}
612
613const char *bdrv_get_device_name(BlockDriverState *bs)
614{
615    return bs->device_name;
616}
617
618void bdrv_flush(BlockDriverState *bs)
619{
620    if (bs->drv->bdrv_flush)
621        bs->drv->bdrv_flush(bs);
622    if (bs->backing_hd)
623        bdrv_flush(bs->backing_hd);
624}
625
626void bdrv_info(void)
627{
628    BlockDriverState *bs;
629
630    for (bs = bdrv_first; bs != NULL; bs = bs->next) {
631        term_printf("%s:", bs->device_name);
632        term_printf(" type=");
633        switch(bs->type) {
634        case BDRV_TYPE_HD:
635            term_printf("hd");
636            break;
637        case BDRV_TYPE_CDROM:
638            term_printf("cdrom");
639            break;
640        case BDRV_TYPE_FLOPPY:
641            term_printf("floppy");
642            break;
643        }
644        term_printf(" removable=%d", bs->removable);
645        if (bs->removable) {
646            term_printf(" locked=%d", bs->locked);
647        }
648        if (bs->inserted) {
649            term_printf(" file=%s", bs->filename);
650            if (bs->backing_file[0] != '\0')
651                term_printf(" backing_file=%s", bs->backing_file);
652            term_printf(" ro=%d", bs->read_only);
653            term_printf(" drv=%s", bs->drv->format_name);
654            if (bs->encrypted)
655                term_printf(" encrypted");
656        } else {
657            term_printf(" [not inserted]");
658        }
659        term_printf("\n");
660    }
661}
662
663/**************************************************************/
664/* RAW block driver */
665
666typedef struct BDRVRawState {
667    int fd;
668} BDRVRawState;
669
670static int raw_probe(const uint8_t *buf, int buf_size, const char *filename)
671{
672    return 1; /* maybe */
673}
674
675static int raw_open(BlockDriverState *bs, const char *filename)
676{
677    BDRVRawState *s = bs->opaque;
678    int fd;
679    int64_t size;
680#ifdef _BSD
681    struct stat sb;
682#endif
683#ifdef __sun__
684    struct dk_minfo minfo;
685    int rv;
686#endif
687
688    fd = open(filename, O_RDWR | O_BINARY | O_LARGEFILE);
689    if (fd < 0) {
690        fd = open(filename, O_RDONLY | O_BINARY | O_LARGEFILE);
691        if (fd < 0)
692            return -1;
693        bs->read_only = 1;
694    }
695#ifdef _BSD
696    if (!fstat(fd, &sb) && (S_IFCHR & sb.st_mode)) {
697#ifdef DIOCGMEDIASIZE
698	if (ioctl(fd, DIOCGMEDIASIZE, (off_t *)&size))
699#endif
700#ifdef CONFIG_COCOA
701        size = LONG_LONG_MAX;
702#else
703        size = lseek(fd, 0LL, SEEK_END);
704#endif
705    } else
706#endif
707#ifdef __sun__
708    /*
709     * use the DKIOCGMEDIAINFO ioctl to read the size.
710     */
711    rv = ioctl ( fd, DKIOCGMEDIAINFO, &minfo );
712    if ( rv != -1 ) {
713        size = minfo.dki_lbsize * minfo.dki_capacity;
714    } else /* there are reports that lseek on some devices
715              fails, but irc discussion said that contingency
716              on contingency was overkill */
717#endif
718    {
719        size = lseek(fd, 0, SEEK_END);
720    }
721#ifdef _WIN32
722    /* On Windows hosts it can happen that we're unable to get file size
723       for CD-ROM raw device (it's inherent limitation of the CDFS driver). */
724    if (size == -1)
725        size = LONG_LONG_MAX;
726#endif
727    bs->total_sectors = size / 512;
728    s->fd = fd;
729    return 0;
730}
731
732static int raw_read(BlockDriverState *bs, int64_t sector_num,
733                    uint8_t *buf, int nb_sectors)
734{
735    BDRVRawState *s = bs->opaque;
736    int ret;
737
738    lseek(s->fd, sector_num * 512, SEEK_SET);
739    ret = read(s->fd, buf, nb_sectors * 512);
740    if (ret != nb_sectors * 512)
741        return -1;
742    return 0;
743}
744
745static int raw_write(BlockDriverState *bs, int64_t sector_num,
746                     const uint8_t *buf, int nb_sectors)
747{
748    BDRVRawState *s = bs->opaque;
749    int ret;
750
751    lseek(s->fd, sector_num * 512, SEEK_SET);
752    ret = write(s->fd, buf, nb_sectors * 512);
753    if (ret != nb_sectors * 512)
754        return -1;
755    return 0;
756}
757
758static void raw_close(BlockDriverState *bs)
759{
760    BDRVRawState *s = bs->opaque;
761    close(s->fd);
762}
763
764#ifdef _WIN32
765#include <windows.h>
766#include <winioctl.h>
767
768int qemu_ftruncate64(int fd, int64_t length)
769{
770    LARGE_INTEGER li;
771    LONG high;
772    HANDLE h;
773    BOOL res;
774
775    if ((GetVersion() & 0x80000000UL) && (length >> 32) != 0)
776	return -1;
777
778    h = (HANDLE)_get_osfhandle(fd);
779
780    /* get current position, ftruncate do not change position */
781    li.HighPart = 0;
782    li.LowPart = SetFilePointer (h, 0, &li.HighPart, FILE_CURRENT);
783    if (li.LowPart == 0xffffffffUL && GetLastError() != NO_ERROR)
784	return -1;
785
786    high = length >> 32;
787    if (!SetFilePointer(h, (DWORD) length, &high, FILE_BEGIN))
788	return -1;
789    res = SetEndOfFile(h);
790
791    /* back to old position */
792    SetFilePointer(h, li.LowPart, &li.HighPart, FILE_BEGIN);
793    return res ? 0 : -1;
794}
795
796static int set_sparse(int fd)
797{
798    DWORD returned;
799    return (int) DeviceIoControl((HANDLE)_get_osfhandle(fd), FSCTL_SET_SPARSE,
800				 NULL, 0, NULL, 0, &returned, NULL);
801}
802#else
803static inline int set_sparse(int fd)
804{
805    return 1;
806}
807#endif
808
809static int raw_create(const char *filename, int64_t total_size,
810                      const char *backing_file, int flags)
811{
812    int fd;
813
814    if (flags || backing_file)
815        return -ENOTSUP;
816
817    fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE,
818              0644);
819    if (fd < 0)
820        return -EIO;
821    set_sparse(fd);
822    ftruncate(fd, total_size * 512);
823    close(fd);
824    return 0;
825}
826
827static void raw_flush(BlockDriverState *bs)
828{
829    BDRVRawState *s = bs->opaque;
830    fsync(s->fd);
831}
832
833BlockDriver bdrv_raw = {
834    "raw",
835    sizeof(BDRVRawState),
836    raw_probe,
837    raw_open,
838    raw_read,
839    raw_write,
840    raw_close,
841    raw_create,
842    raw_flush,
843};
844
845void bdrv_init(void)
846{
847    bdrv_register(&bdrv_raw);
848    bdrv_register(&bdrv_cloop);
849    bdrv_register(&bdrv_qcow);
850    bdrv_register(&bdrv_dmg);
851}
852