Drop internal bdrv_pread()/bdrv_pwrite() APIs (Avi Kivity)
[qemu] / block.c
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 "config-host.h"
25 #ifdef HOST_BSD
26 /* include native header before sys-queue.h */
27 #include <sys/queue.h>
28 #endif
29
30 #include "qemu-common.h"
31 #include "monitor.h"
32 #include "block_int.h"
33
34 #ifdef HOST_BSD
35 #include <sys/types.h>
36 #include <sys/stat.h>
37 #include <sys/ioctl.h>
38 #ifndef __DragonFly__
39 #include <sys/disk.h>
40 #endif
41 #endif
42
43 #ifdef _WIN32
44 #include <windows.h>
45 #endif
46
47 #define SECTOR_BITS 9
48 #define SECTOR_SIZE (1 << SECTOR_BITS)
49
50 typedef struct BlockDriverAIOCBSync {
51     BlockDriverAIOCB common;
52     QEMUBH *bh;
53     int ret;
54 } BlockDriverAIOCBSync;
55
56 static BlockDriverAIOCB *bdrv_aio_read_em(BlockDriverState *bs,
57         int64_t sector_num, uint8_t *buf, int nb_sectors,
58         BlockDriverCompletionFunc *cb, void *opaque);
59 static BlockDriverAIOCB *bdrv_aio_write_em(BlockDriverState *bs,
60         int64_t sector_num, const uint8_t *buf, int nb_sectors,
61         BlockDriverCompletionFunc *cb, void *opaque);
62 static void bdrv_aio_cancel_em(BlockDriverAIOCB *acb);
63 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
64                         uint8_t *buf, int nb_sectors);
65 static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
66                          const uint8_t *buf, int nb_sectors);
67
68 BlockDriverState *bdrv_first;
69
70 static BlockDriver *first_drv;
71
72 int path_is_absolute(const char *path)
73 {
74     const char *p;
75 #ifdef _WIN32
76     /* specific case for names like: "\\.\d:" */
77     if (*path == '/' || *path == '\\')
78         return 1;
79 #endif
80     p = strchr(path, ':');
81     if (p)
82         p++;
83     else
84         p = path;
85 #ifdef _WIN32
86     return (*p == '/' || *p == '\\');
87 #else
88     return (*p == '/');
89 #endif
90 }
91
92 /* if filename is absolute, just copy it to dest. Otherwise, build a
93    path to it by considering it is relative to base_path. URL are
94    supported. */
95 void path_combine(char *dest, int dest_size,
96                   const char *base_path,
97                   const char *filename)
98 {
99     const char *p, *p1;
100     int len;
101
102     if (dest_size <= 0)
103         return;
104     if (path_is_absolute(filename)) {
105         pstrcpy(dest, dest_size, filename);
106     } else {
107         p = strchr(base_path, ':');
108         if (p)
109             p++;
110         else
111             p = base_path;
112         p1 = strrchr(base_path, '/');
113 #ifdef _WIN32
114         {
115             const char *p2;
116             p2 = strrchr(base_path, '\\');
117             if (!p1 || p2 > p1)
118                 p1 = p2;
119         }
120 #endif
121         if (p1)
122             p1++;
123         else
124             p1 = base_path;
125         if (p1 > p)
126             p = p1;
127         len = p - base_path;
128         if (len > dest_size - 1)
129             len = dest_size - 1;
130         memcpy(dest, base_path, len);
131         dest[len] = '\0';
132         pstrcat(dest, dest_size, filename);
133     }
134 }
135
136
137 static void bdrv_register(BlockDriver *bdrv)
138 {
139     if (!bdrv->bdrv_aio_read) {
140         /* add AIO emulation layer */
141         bdrv->bdrv_aio_read = bdrv_aio_read_em;
142         bdrv->bdrv_aio_write = bdrv_aio_write_em;
143         bdrv->bdrv_aio_cancel = bdrv_aio_cancel_em;
144         bdrv->aiocb_size = sizeof(BlockDriverAIOCBSync);
145     } else if (!bdrv->bdrv_read) {
146         /* add synchronous IO emulation layer */
147         bdrv->bdrv_read = bdrv_read_em;
148         bdrv->bdrv_write = bdrv_write_em;
149     }
150     bdrv->next = first_drv;
151     first_drv = bdrv;
152 }
153
154 /* create a new block device (by default it is empty) */
155 BlockDriverState *bdrv_new(const char *device_name)
156 {
157     BlockDriverState **pbs, *bs;
158
159     bs = qemu_mallocz(sizeof(BlockDriverState));
160     pstrcpy(bs->device_name, sizeof(bs->device_name), device_name);
161     if (device_name[0] != '\0') {
162         /* insert at the end */
163         pbs = &bdrv_first;
164         while (*pbs != NULL)
165             pbs = &(*pbs)->next;
166         *pbs = bs;
167     }
168     return bs;
169 }
170
171 BlockDriver *bdrv_find_format(const char *format_name)
172 {
173     BlockDriver *drv1;
174     for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
175         if (!strcmp(drv1->format_name, format_name))
176             return drv1;
177     }
178     return NULL;
179 }
180
181 int bdrv_create(BlockDriver *drv,
182                 const char *filename, int64_t size_in_sectors,
183                 const char *backing_file, int flags)
184 {
185     if (!drv->bdrv_create)
186         return -ENOTSUP;
187     return drv->bdrv_create(filename, size_in_sectors, backing_file, flags);
188 }
189
190 #ifdef _WIN32
191 void get_tmp_filename(char *filename, int size)
192 {
193     char temp_dir[MAX_PATH];
194
195     GetTempPath(MAX_PATH, temp_dir);
196     GetTempFileName(temp_dir, "qem", 0, filename);
197 }
198 #else
199 void get_tmp_filename(char *filename, int size)
200 {
201     int fd;
202     const char *tmpdir;
203     /* XXX: race condition possible */
204     tmpdir = getenv("TMPDIR");
205     if (!tmpdir)
206         tmpdir = "/tmp";
207     snprintf(filename, size, "%s/vl.XXXXXX", tmpdir);
208     fd = mkstemp(filename);
209     close(fd);
210 }
211 #endif
212
213 #ifdef _WIN32
214 static int is_windows_drive_prefix(const char *filename)
215 {
216     return (((filename[0] >= 'a' && filename[0] <= 'z') ||
217              (filename[0] >= 'A' && filename[0] <= 'Z')) &&
218             filename[1] == ':');
219 }
220
221 static int is_windows_drive(const char *filename)
222 {
223     if (is_windows_drive_prefix(filename) &&
224         filename[2] == '\0')
225         return 1;
226     if (strstart(filename, "\\\\.\\", NULL) ||
227         strstart(filename, "//./", NULL))
228         return 1;
229     return 0;
230 }
231 #endif
232
233 static BlockDriver *find_protocol(const char *filename)
234 {
235     BlockDriver *drv1;
236     char protocol[128];
237     int len;
238     const char *p;
239
240 #ifdef _WIN32
241     if (is_windows_drive(filename) ||
242         is_windows_drive_prefix(filename))
243         return &bdrv_raw;
244 #endif
245     p = strchr(filename, ':');
246     if (!p)
247         return &bdrv_raw;
248     len = p - filename;
249     if (len > sizeof(protocol) - 1)
250         len = sizeof(protocol) - 1;
251     memcpy(protocol, filename, len);
252     protocol[len] = '\0';
253     for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
254         if (drv1->protocol_name &&
255             !strcmp(drv1->protocol_name, protocol))
256             return drv1;
257     }
258     return NULL;
259 }
260
261 /* XXX: force raw format if block or character device ? It would
262    simplify the BSD case */
263 static BlockDriver *find_image_format(const char *filename)
264 {
265     int ret, score, score_max;
266     BlockDriver *drv1, *drv;
267     uint8_t buf[2048];
268     BlockDriverState *bs;
269
270     /* detect host devices. By convention, /dev/cdrom[N] is always
271        recognized as a host CDROM */
272     if (strstart(filename, "/dev/cdrom", NULL))
273         return &bdrv_host_device;
274 #ifdef _WIN32
275     if (is_windows_drive(filename))
276         return &bdrv_host_device;
277 #else
278     {
279         struct stat st;
280         if (stat(filename, &st) >= 0 &&
281             (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode))) {
282             return &bdrv_host_device;
283         }
284     }
285 #endif
286
287     drv = find_protocol(filename);
288     /* no need to test disk image formats for vvfat */
289     if (drv == &bdrv_vvfat)
290         return drv;
291
292     ret = bdrv_file_open(&bs, filename, BDRV_O_RDONLY);
293     if (ret < 0)
294         return NULL;
295     ret = bdrv_pread(bs, 0, buf, sizeof(buf));
296     bdrv_delete(bs);
297     if (ret < 0) {
298         return NULL;
299     }
300
301     score_max = 0;
302     for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
303         if (drv1->bdrv_probe) {
304             score = drv1->bdrv_probe(buf, ret, filename);
305             if (score > score_max) {
306                 score_max = score;
307                 drv = drv1;
308             }
309         }
310     }
311     return drv;
312 }
313
314 int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags)
315 {
316     BlockDriverState *bs;
317     int ret;
318
319     bs = bdrv_new("");
320     ret = bdrv_open2(bs, filename, flags | BDRV_O_FILE, NULL);
321     if (ret < 0) {
322         bdrv_delete(bs);
323         return ret;
324     }
325     bs->growable = 1;
326     *pbs = bs;
327     return 0;
328 }
329
330 int bdrv_open(BlockDriverState *bs, const char *filename, int flags)
331 {
332     return bdrv_open2(bs, filename, flags, NULL);
333 }
334
335 int bdrv_open2(BlockDriverState *bs, const char *filename, int flags,
336                BlockDriver *drv)
337 {
338     int ret, open_flags;
339     char tmp_filename[PATH_MAX];
340     char backing_filename[PATH_MAX];
341
342     bs->read_only = 0;
343     bs->is_temporary = 0;
344     bs->encrypted = 0;
345     bs->valid_key = 0;
346
347     if (flags & BDRV_O_SNAPSHOT) {
348         BlockDriverState *bs1;
349         int64_t total_size;
350         int is_protocol = 0;
351
352         /* if snapshot, we create a temporary backing file and open it
353            instead of opening 'filename' directly */
354
355         /* if there is a backing file, use it */
356         bs1 = bdrv_new("");
357         ret = bdrv_open(bs1, filename, 0);
358         if (ret < 0) {
359             bdrv_delete(bs1);
360             return ret;
361         }
362         total_size = bdrv_getlength(bs1) >> SECTOR_BITS;
363
364         if (bs1->drv && bs1->drv->protocol_name)
365             is_protocol = 1;
366
367         bdrv_delete(bs1);
368
369         get_tmp_filename(tmp_filename, sizeof(tmp_filename));
370
371         /* Real path is meaningless for protocols */
372         if (is_protocol)
373             snprintf(backing_filename, sizeof(backing_filename),
374                      "%s", filename);
375         else
376             realpath(filename, backing_filename);
377
378         ret = bdrv_create(&bdrv_qcow2, tmp_filename,
379                           total_size, backing_filename, 0);
380         if (ret < 0) {
381             return ret;
382         }
383         filename = tmp_filename;
384         bs->is_temporary = 1;
385     }
386
387     pstrcpy(bs->filename, sizeof(bs->filename), filename);
388     if (flags & BDRV_O_FILE) {
389         drv = find_protocol(filename);
390     } else if (!drv) {
391         drv = find_image_format(filename);
392     }
393     if (!drv) {
394         ret = -ENOENT;
395         goto unlink_and_fail;
396     }
397     bs->drv = drv;
398     bs->opaque = qemu_mallocz(drv->instance_size);
399     /* Note: for compatibility, we open disk image files as RDWR, and
400        RDONLY as fallback */
401     if (!(flags & BDRV_O_FILE))
402         open_flags = BDRV_O_RDWR | (flags & BDRV_O_CACHE_MASK);
403     else
404         open_flags = flags & ~(BDRV_O_FILE | BDRV_O_SNAPSHOT);
405     ret = drv->bdrv_open(bs, filename, open_flags);
406     if ((ret == -EACCES || ret == -EPERM) && !(flags & BDRV_O_FILE)) {
407         ret = drv->bdrv_open(bs, filename, open_flags & ~BDRV_O_RDWR);
408         bs->read_only = 1;
409     }
410     if (ret < 0) {
411         qemu_free(bs->opaque);
412         bs->opaque = NULL;
413         bs->drv = NULL;
414     unlink_and_fail:
415         if (bs->is_temporary)
416             unlink(filename);
417         return ret;
418     }
419     if (drv->bdrv_getlength) {
420         bs->total_sectors = bdrv_getlength(bs) >> SECTOR_BITS;
421     }
422 #ifndef _WIN32
423     if (bs->is_temporary) {
424         unlink(filename);
425     }
426 #endif
427     if (bs->backing_file[0] != '\0') {
428         /* if there is a backing file, use it */
429         bs->backing_hd = bdrv_new("");
430         path_combine(backing_filename, sizeof(backing_filename),
431                      filename, bs->backing_file);
432         ret = bdrv_open(bs->backing_hd, backing_filename, open_flags);
433         if (ret < 0) {
434             bdrv_close(bs);
435             return ret;
436         }
437     }
438
439     if (!bdrv_key_required(bs)) {
440         /* call the change callback */
441         bs->media_changed = 1;
442         if (bs->change_cb)
443             bs->change_cb(bs->change_opaque);
444     }
445     return 0;
446 }
447
448 void bdrv_close(BlockDriverState *bs)
449 {
450     if (bs->drv) {
451         if (bs->backing_hd)
452             bdrv_delete(bs->backing_hd);
453         bs->drv->bdrv_close(bs);
454         qemu_free(bs->opaque);
455 #ifdef _WIN32
456         if (bs->is_temporary) {
457             unlink(bs->filename);
458         }
459 #endif
460         bs->opaque = NULL;
461         bs->drv = NULL;
462
463         /* call the change callback */
464         bs->media_changed = 1;
465         if (bs->change_cb)
466             bs->change_cb(bs->change_opaque);
467     }
468 }
469
470 void bdrv_delete(BlockDriverState *bs)
471 {
472     BlockDriverState **pbs;
473
474     pbs = &bdrv_first;
475     while (*pbs != bs && *pbs != NULL)
476         pbs = &(*pbs)->next;
477     if (*pbs == bs)
478         *pbs = bs->next;
479
480     bdrv_close(bs);
481     qemu_free(bs);
482 }
483
484 /* commit COW file into the raw image */
485 int bdrv_commit(BlockDriverState *bs)
486 {
487     BlockDriver *drv = bs->drv;
488     int64_t i, total_sectors;
489     int n, j;
490     unsigned char sector[512];
491
492     if (!drv)
493         return -ENOMEDIUM;
494
495     if (bs->read_only) {
496         return -EACCES;
497     }
498
499     if (!bs->backing_hd) {
500         return -ENOTSUP;
501     }
502
503     total_sectors = bdrv_getlength(bs) >> SECTOR_BITS;
504     for (i = 0; i < total_sectors;) {
505         if (drv->bdrv_is_allocated(bs, i, 65536, &n)) {
506             for(j = 0; j < n; j++) {
507                 if (bdrv_read(bs, i, sector, 1) != 0) {
508                     return -EIO;
509                 }
510
511                 if (bdrv_write(bs->backing_hd, i, sector, 1) != 0) {
512                     return -EIO;
513                 }
514                 i++;
515             }
516         } else {
517             i += n;
518         }
519     }
520
521     if (drv->bdrv_make_empty)
522         return drv->bdrv_make_empty(bs);
523
524     return 0;
525 }
526
527 static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,
528                                    size_t size)
529 {
530     int64_t len;
531
532     if (!bdrv_is_inserted(bs))
533         return -ENOMEDIUM;
534
535     if (bs->growable)
536         return 0;
537
538     len = bdrv_getlength(bs);
539
540     if ((offset + size) > len)
541         return -EIO;
542
543     return 0;
544 }
545
546 static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num,
547                               int nb_sectors)
548 {
549     int64_t offset;
550
551     /* Deal with byte accesses */
552     if (sector_num < 0)
553         offset = -sector_num;
554     else
555         offset = sector_num * 512;
556
557     return bdrv_check_byte_request(bs, offset, nb_sectors * 512);
558 }
559
560 /* return < 0 if error. See bdrv_write() for the return codes */
561 int bdrv_read(BlockDriverState *bs, int64_t sector_num,
562               uint8_t *buf, int nb_sectors)
563 {
564     BlockDriver *drv = bs->drv;
565
566     if (!drv)
567         return -ENOMEDIUM;
568     if (bdrv_check_request(bs, sector_num, nb_sectors))
569         return -EIO;
570
571     return drv->bdrv_read(bs, sector_num, buf, nb_sectors);
572 }
573
574 /* Return < 0 if error. Important errors are:
575   -EIO         generic I/O error (may happen for all errors)
576   -ENOMEDIUM   No media inserted.
577   -EINVAL      Invalid sector number or nb_sectors
578   -EACCES      Trying to write a read-only device
579 */
580 int bdrv_write(BlockDriverState *bs, int64_t sector_num,
581                const uint8_t *buf, int nb_sectors)
582 {
583     BlockDriver *drv = bs->drv;
584     if (!bs->drv)
585         return -ENOMEDIUM;
586     if (bs->read_only)
587         return -EACCES;
588     if (bdrv_check_request(bs, sector_num, nb_sectors))
589         return -EIO;
590
591     return drv->bdrv_write(bs, sector_num, buf, nb_sectors);
592 }
593
594 int bdrv_pread(BlockDriverState *bs, int64_t offset,
595                void *buf, int count1)
596 {
597     uint8_t tmp_buf[SECTOR_SIZE];
598     int len, nb_sectors, count;
599     int64_t sector_num;
600
601     count = count1;
602     /* first read to align to sector start */
603     len = (SECTOR_SIZE - offset) & (SECTOR_SIZE - 1);
604     if (len > count)
605         len = count;
606     sector_num = offset >> SECTOR_BITS;
607     if (len > 0) {
608         if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
609             return -EIO;
610         memcpy(buf, tmp_buf + (offset & (SECTOR_SIZE - 1)), len);
611         count -= len;
612         if (count == 0)
613             return count1;
614         sector_num++;
615         buf += len;
616     }
617
618     /* read the sectors "in place" */
619     nb_sectors = count >> SECTOR_BITS;
620     if (nb_sectors > 0) {
621         if (bdrv_read(bs, sector_num, buf, nb_sectors) < 0)
622             return -EIO;
623         sector_num += nb_sectors;
624         len = nb_sectors << SECTOR_BITS;
625         buf += len;
626         count -= len;
627     }
628
629     /* add data from the last sector */
630     if (count > 0) {
631         if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
632             return -EIO;
633         memcpy(buf, tmp_buf, count);
634     }
635     return count1;
636 }
637
638 int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
639                 const void *buf, int count1)
640 {
641     uint8_t tmp_buf[SECTOR_SIZE];
642     int len, nb_sectors, count;
643     int64_t sector_num;
644
645     count = count1;
646     /* first write to align to sector start */
647     len = (SECTOR_SIZE - offset) & (SECTOR_SIZE - 1);
648     if (len > count)
649         len = count;
650     sector_num = offset >> SECTOR_BITS;
651     if (len > 0) {
652         if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
653             return -EIO;
654         memcpy(tmp_buf + (offset & (SECTOR_SIZE - 1)), buf, len);
655         if (bdrv_write(bs, sector_num, tmp_buf, 1) < 0)
656             return -EIO;
657         count -= len;
658         if (count == 0)
659             return count1;
660         sector_num++;
661         buf += len;
662     }
663
664     /* write the sectors "in place" */
665     nb_sectors = count >> SECTOR_BITS;
666     if (nb_sectors > 0) {
667         if (bdrv_write(bs, sector_num, buf, nb_sectors) < 0)
668             return -EIO;
669         sector_num += nb_sectors;
670         len = nb_sectors << SECTOR_BITS;
671         buf += len;
672         count -= len;
673     }
674
675     /* add data from the last sector */
676     if (count > 0) {
677         if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
678             return -EIO;
679         memcpy(tmp_buf, buf, count);
680         if (bdrv_write(bs, sector_num, tmp_buf, 1) < 0)
681             return -EIO;
682     }
683     return count1;
684 }
685
686 /**
687  * Truncate file to 'offset' bytes (needed only for file protocols)
688  */
689 int bdrv_truncate(BlockDriverState *bs, int64_t offset)
690 {
691     BlockDriver *drv = bs->drv;
692     if (!drv)
693         return -ENOMEDIUM;
694     if (!drv->bdrv_truncate)
695         return -ENOTSUP;
696     return drv->bdrv_truncate(bs, offset);
697 }
698
699 /**
700  * Length of a file in bytes. Return < 0 if error or unknown.
701  */
702 int64_t bdrv_getlength(BlockDriverState *bs)
703 {
704     BlockDriver *drv = bs->drv;
705     if (!drv)
706         return -ENOMEDIUM;
707     if (!drv->bdrv_getlength) {
708         /* legacy mode */
709         return bs->total_sectors * SECTOR_SIZE;
710     }
711     return drv->bdrv_getlength(bs);
712 }
713
714 /* return 0 as number of sectors if no device present or error */
715 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
716 {
717     int64_t length;
718     length = bdrv_getlength(bs);
719     if (length < 0)
720         length = 0;
721     else
722         length = length >> SECTOR_BITS;
723     *nb_sectors_ptr = length;
724 }
725
726 struct partition {
727         uint8_t boot_ind;           /* 0x80 - active */
728         uint8_t head;               /* starting head */
729         uint8_t sector;             /* starting sector */
730         uint8_t cyl;                /* starting cylinder */
731         uint8_t sys_ind;            /* What partition type */
732         uint8_t end_head;           /* end head */
733         uint8_t end_sector;         /* end sector */
734         uint8_t end_cyl;            /* end cylinder */
735         uint32_t start_sect;        /* starting sector counting from 0 */
736         uint32_t nr_sects;          /* nr of sectors in partition */
737 } __attribute__((packed));
738
739 /* try to guess the disk logical geometry from the MSDOS partition table. Return 0 if OK, -1 if could not guess */
740 static int guess_disk_lchs(BlockDriverState *bs,
741                            int *pcylinders, int *pheads, int *psectors)
742 {
743     uint8_t buf[512];
744     int ret, i, heads, sectors, cylinders;
745     struct partition *p;
746     uint32_t nr_sects;
747     uint64_t nb_sectors;
748
749     bdrv_get_geometry(bs, &nb_sectors);
750
751     ret = bdrv_read(bs, 0, buf, 1);
752     if (ret < 0)
753         return -1;
754     /* test msdos magic */
755     if (buf[510] != 0x55 || buf[511] != 0xaa)
756         return -1;
757     for(i = 0; i < 4; i++) {
758         p = ((struct partition *)(buf + 0x1be)) + i;
759         nr_sects = le32_to_cpu(p->nr_sects);
760         if (nr_sects && p->end_head) {
761             /* We make the assumption that the partition terminates on
762                a cylinder boundary */
763             heads = p->end_head + 1;
764             sectors = p->end_sector & 63;
765             if (sectors == 0)
766                 continue;
767             cylinders = nb_sectors / (heads * sectors);
768             if (cylinders < 1 || cylinders > 16383)
769                 continue;
770             *pheads = heads;
771             *psectors = sectors;
772             *pcylinders = cylinders;
773 #if 0
774             printf("guessed geometry: LCHS=%d %d %d\n",
775                    cylinders, heads, sectors);
776 #endif
777             return 0;
778         }
779     }
780     return -1;
781 }
782
783 void bdrv_guess_geometry(BlockDriverState *bs, int *pcyls, int *pheads, int *psecs)
784 {
785     int translation, lba_detected = 0;
786     int cylinders, heads, secs;
787     uint64_t nb_sectors;
788
789     /* if a geometry hint is available, use it */
790     bdrv_get_geometry(bs, &nb_sectors);
791     bdrv_get_geometry_hint(bs, &cylinders, &heads, &secs);
792     translation = bdrv_get_translation_hint(bs);
793     if (cylinders != 0) {
794         *pcyls = cylinders;
795         *pheads = heads;
796         *psecs = secs;
797     } else {
798         if (guess_disk_lchs(bs, &cylinders, &heads, &secs) == 0) {
799             if (heads > 16) {
800                 /* if heads > 16, it means that a BIOS LBA
801                    translation was active, so the default
802                    hardware geometry is OK */
803                 lba_detected = 1;
804                 goto default_geometry;
805             } else {
806                 *pcyls = cylinders;
807                 *pheads = heads;
808                 *psecs = secs;
809                 /* disable any translation to be in sync with
810                    the logical geometry */
811                 if (translation == BIOS_ATA_TRANSLATION_AUTO) {
812                     bdrv_set_translation_hint(bs,
813                                               BIOS_ATA_TRANSLATION_NONE);
814                 }
815             }
816         } else {
817         default_geometry:
818             /* if no geometry, use a standard physical disk geometry */
819             cylinders = nb_sectors / (16 * 63);
820
821             if (cylinders > 16383)
822                 cylinders = 16383;
823             else if (cylinders < 2)
824                 cylinders = 2;
825             *pcyls = cylinders;
826             *pheads = 16;
827             *psecs = 63;
828             if ((lba_detected == 1) && (translation == BIOS_ATA_TRANSLATION_AUTO)) {
829                 if ((*pcyls * *pheads) <= 131072) {
830                     bdrv_set_translation_hint(bs,
831                                               BIOS_ATA_TRANSLATION_LARGE);
832                 } else {
833                     bdrv_set_translation_hint(bs,
834                                               BIOS_ATA_TRANSLATION_LBA);
835                 }
836             }
837         }
838         bdrv_set_geometry_hint(bs, *pcyls, *pheads, *psecs);
839     }
840 }
841
842 void bdrv_set_geometry_hint(BlockDriverState *bs,
843                             int cyls, int heads, int secs)
844 {
845     bs->cyls = cyls;
846     bs->heads = heads;
847     bs->secs = secs;
848 }
849
850 void bdrv_set_type_hint(BlockDriverState *bs, int type)
851 {
852     bs->type = type;
853     bs->removable = ((type == BDRV_TYPE_CDROM ||
854                       type == BDRV_TYPE_FLOPPY));
855 }
856
857 void bdrv_set_translation_hint(BlockDriverState *bs, int translation)
858 {
859     bs->translation = translation;
860 }
861
862 void bdrv_get_geometry_hint(BlockDriverState *bs,
863                             int *pcyls, int *pheads, int *psecs)
864 {
865     *pcyls = bs->cyls;
866     *pheads = bs->heads;
867     *psecs = bs->secs;
868 }
869
870 int bdrv_get_type_hint(BlockDriverState *bs)
871 {
872     return bs->type;
873 }
874
875 int bdrv_get_translation_hint(BlockDriverState *bs)
876 {
877     return bs->translation;
878 }
879
880 int bdrv_is_removable(BlockDriverState *bs)
881 {
882     return bs->removable;
883 }
884
885 int bdrv_is_read_only(BlockDriverState *bs)
886 {
887     return bs->read_only;
888 }
889
890 int bdrv_is_sg(BlockDriverState *bs)
891 {
892     return bs->sg;
893 }
894
895 /* XXX: no longer used */
896 void bdrv_set_change_cb(BlockDriverState *bs,
897                         void (*change_cb)(void *opaque), void *opaque)
898 {
899     bs->change_cb = change_cb;
900     bs->change_opaque = opaque;
901 }
902
903 int bdrv_is_encrypted(BlockDriverState *bs)
904 {
905     if (bs->backing_hd && bs->backing_hd->encrypted)
906         return 1;
907     return bs->encrypted;
908 }
909
910 int bdrv_key_required(BlockDriverState *bs)
911 {
912     BlockDriverState *backing_hd = bs->backing_hd;
913
914     if (backing_hd && backing_hd->encrypted && !backing_hd->valid_key)
915         return 1;
916     return (bs->encrypted && !bs->valid_key);
917 }
918
919 int bdrv_set_key(BlockDriverState *bs, const char *key)
920 {
921     int ret;
922     if (bs->backing_hd && bs->backing_hd->encrypted) {
923         ret = bdrv_set_key(bs->backing_hd, key);
924         if (ret < 0)
925             return ret;
926         if (!bs->encrypted)
927             return 0;
928     }
929     if (!bs->encrypted || !bs->drv || !bs->drv->bdrv_set_key)
930         return -1;
931     ret = bs->drv->bdrv_set_key(bs, key);
932     if (ret < 0) {
933         bs->valid_key = 0;
934     } else if (!bs->valid_key) {
935         bs->valid_key = 1;
936         /* call the change callback now, we skipped it on open */
937         bs->media_changed = 1;
938         if (bs->change_cb)
939             bs->change_cb(bs->change_opaque);
940     }
941     return ret;
942 }
943
944 void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)
945 {
946     if (!bs->drv) {
947         buf[0] = '\0';
948     } else {
949         pstrcpy(buf, buf_size, bs->drv->format_name);
950     }
951 }
952
953 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
954                          void *opaque)
955 {
956     BlockDriver *drv;
957
958     for (drv = first_drv; drv != NULL; drv = drv->next) {
959         it(opaque, drv->format_name);
960     }
961 }
962
963 BlockDriverState *bdrv_find(const char *name)
964 {
965     BlockDriverState *bs;
966
967     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
968         if (!strcmp(name, bs->device_name))
969             return bs;
970     }
971     return NULL;
972 }
973
974 void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs), void *opaque)
975 {
976     BlockDriverState *bs;
977
978     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
979         it(opaque, bs);
980     }
981 }
982
983 const char *bdrv_get_device_name(BlockDriverState *bs)
984 {
985     return bs->device_name;
986 }
987
988 void bdrv_flush(BlockDriverState *bs)
989 {
990     if (bs->drv->bdrv_flush)
991         bs->drv->bdrv_flush(bs);
992     if (bs->backing_hd)
993         bdrv_flush(bs->backing_hd);
994 }
995
996 void bdrv_flush_all(void)
997 {
998     BlockDriverState *bs;
999
1000     for (bs = bdrv_first; bs != NULL; bs = bs->next)
1001         if (bs->drv && !bdrv_is_read_only(bs) && 
1002             (!bdrv_is_removable(bs) || bdrv_is_inserted(bs)))
1003             bdrv_flush(bs);
1004 }
1005
1006 /*
1007  * Returns true iff the specified sector is present in the disk image. Drivers
1008  * not implementing the functionality are assumed to not support backing files,
1009  * hence all their sectors are reported as allocated.
1010  *
1011  * 'pnum' is set to the number of sectors (including and immediately following
1012  * the specified sector) that are known to be in the same
1013  * allocated/unallocated state.
1014  *
1015  * 'nb_sectors' is the max value 'pnum' should be set to.
1016  */
1017 int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
1018         int *pnum)
1019 {
1020     int64_t n;
1021     if (!bs->drv->bdrv_is_allocated) {
1022         if (sector_num >= bs->total_sectors) {
1023             *pnum = 0;
1024             return 0;
1025         }
1026         n = bs->total_sectors - sector_num;
1027         *pnum = (n < nb_sectors) ? (n) : (nb_sectors);
1028         return 1;
1029     }
1030     return bs->drv->bdrv_is_allocated(bs, sector_num, nb_sectors, pnum);
1031 }
1032
1033 void bdrv_info(Monitor *mon)
1034 {
1035     BlockDriverState *bs;
1036
1037     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
1038         monitor_printf(mon, "%s:", bs->device_name);
1039         monitor_printf(mon, " type=");
1040         switch(bs->type) {
1041         case BDRV_TYPE_HD:
1042             monitor_printf(mon, "hd");
1043             break;
1044         case BDRV_TYPE_CDROM:
1045             monitor_printf(mon, "cdrom");
1046             break;
1047         case BDRV_TYPE_FLOPPY:
1048             monitor_printf(mon, "floppy");
1049             break;
1050         }
1051         monitor_printf(mon, " removable=%d", bs->removable);
1052         if (bs->removable) {
1053             monitor_printf(mon, " locked=%d", bs->locked);
1054         }
1055         if (bs->drv) {
1056             monitor_printf(mon, " file=");
1057             monitor_print_filename(mon, bs->filename);
1058             if (bs->backing_file[0] != '\0') {
1059                 monitor_printf(mon, " backing_file=");
1060                 monitor_print_filename(mon, bs->backing_file);
1061             }
1062             monitor_printf(mon, " ro=%d", bs->read_only);
1063             monitor_printf(mon, " drv=%s", bs->drv->format_name);
1064             monitor_printf(mon, " encrypted=%d", bdrv_is_encrypted(bs));
1065         } else {
1066             monitor_printf(mon, " [not inserted]");
1067         }
1068         monitor_printf(mon, "\n");
1069     }
1070 }
1071
1072 /* The "info blockstats" command. */
1073 void bdrv_info_stats(Monitor *mon)
1074 {
1075     BlockDriverState *bs;
1076
1077     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
1078         monitor_printf(mon, "%s:"
1079                        " rd_bytes=%" PRIu64
1080                        " wr_bytes=%" PRIu64
1081                        " rd_operations=%" PRIu64
1082                        " wr_operations=%" PRIu64
1083                        "\n",
1084                        bs->device_name,
1085                        bs->rd_bytes, bs->wr_bytes,
1086                        bs->rd_ops, bs->wr_ops);
1087     }
1088 }
1089
1090 const char *bdrv_get_encrypted_filename(BlockDriverState *bs)
1091 {
1092     if (bs->backing_hd && bs->backing_hd->encrypted)
1093         return bs->backing_file;
1094     else if (bs->encrypted)
1095         return bs->filename;
1096     else
1097         return NULL;
1098 }
1099
1100 void bdrv_get_backing_filename(BlockDriverState *bs,
1101                                char *filename, int filename_size)
1102 {
1103     if (!bs->backing_hd) {
1104         pstrcpy(filename, filename_size, "");
1105     } else {
1106         pstrcpy(filename, filename_size, bs->backing_file);
1107     }
1108 }
1109
1110 int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
1111                           const uint8_t *buf, int nb_sectors)
1112 {
1113     BlockDriver *drv = bs->drv;
1114     if (!drv)
1115         return -ENOMEDIUM;
1116     if (!drv->bdrv_write_compressed)
1117         return -ENOTSUP;
1118     return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
1119 }
1120
1121 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
1122 {
1123     BlockDriver *drv = bs->drv;
1124     if (!drv)
1125         return -ENOMEDIUM;
1126     if (!drv->bdrv_get_info)
1127         return -ENOTSUP;
1128     memset(bdi, 0, sizeof(*bdi));
1129     return drv->bdrv_get_info(bs, bdi);
1130 }
1131
1132 /**************************************************************/
1133 /* handling of snapshots */
1134
1135 int bdrv_snapshot_create(BlockDriverState *bs,
1136                          QEMUSnapshotInfo *sn_info)
1137 {
1138     BlockDriver *drv = bs->drv;
1139     if (!drv)
1140         return -ENOMEDIUM;
1141     if (!drv->bdrv_snapshot_create)
1142         return -ENOTSUP;
1143     return drv->bdrv_snapshot_create(bs, sn_info);
1144 }
1145
1146 int bdrv_snapshot_goto(BlockDriverState *bs,
1147                        const char *snapshot_id)
1148 {
1149     BlockDriver *drv = bs->drv;
1150     if (!drv)
1151         return -ENOMEDIUM;
1152     if (!drv->bdrv_snapshot_goto)
1153         return -ENOTSUP;
1154     return drv->bdrv_snapshot_goto(bs, snapshot_id);
1155 }
1156
1157 int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
1158 {
1159     BlockDriver *drv = bs->drv;
1160     if (!drv)
1161         return -ENOMEDIUM;
1162     if (!drv->bdrv_snapshot_delete)
1163         return -ENOTSUP;
1164     return drv->bdrv_snapshot_delete(bs, snapshot_id);
1165 }
1166
1167 int bdrv_snapshot_list(BlockDriverState *bs,
1168                        QEMUSnapshotInfo **psn_info)
1169 {
1170     BlockDriver *drv = bs->drv;
1171     if (!drv)
1172         return -ENOMEDIUM;
1173     if (!drv->bdrv_snapshot_list)
1174         return -ENOTSUP;
1175     return drv->bdrv_snapshot_list(bs, psn_info);
1176 }
1177
1178 #define NB_SUFFIXES 4
1179
1180 char *get_human_readable_size(char *buf, int buf_size, int64_t size)
1181 {
1182     static const char suffixes[NB_SUFFIXES] = "KMGT";
1183     int64_t base;
1184     int i;
1185
1186     if (size <= 999) {
1187         snprintf(buf, buf_size, "%" PRId64, size);
1188     } else {
1189         base = 1024;
1190         for(i = 0; i < NB_SUFFIXES; i++) {
1191             if (size < (10 * base)) {
1192                 snprintf(buf, buf_size, "%0.1f%c",
1193                          (double)size / base,
1194                          suffixes[i]);
1195                 break;
1196             } else if (size < (1000 * base) || i == (NB_SUFFIXES - 1)) {
1197                 snprintf(buf, buf_size, "%" PRId64 "%c",
1198                          ((size + (base >> 1)) / base),
1199                          suffixes[i]);
1200                 break;
1201             }
1202             base = base * 1024;
1203         }
1204     }
1205     return buf;
1206 }
1207
1208 char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn)
1209 {
1210     char buf1[128], date_buf[128], clock_buf[128];
1211 #ifdef _WIN32
1212     struct tm *ptm;
1213 #else
1214     struct tm tm;
1215 #endif
1216     time_t ti;
1217     int64_t secs;
1218
1219     if (!sn) {
1220         snprintf(buf, buf_size,
1221                  "%-10s%-20s%7s%20s%15s",
1222                  "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK");
1223     } else {
1224         ti = sn->date_sec;
1225 #ifdef _WIN32
1226         ptm = localtime(&ti);
1227         strftime(date_buf, sizeof(date_buf),
1228                  "%Y-%m-%d %H:%M:%S", ptm);
1229 #else
1230         localtime_r(&ti, &tm);
1231         strftime(date_buf, sizeof(date_buf),
1232                  "%Y-%m-%d %H:%M:%S", &tm);
1233 #endif
1234         secs = sn->vm_clock_nsec / 1000000000;
1235         snprintf(clock_buf, sizeof(clock_buf),
1236                  "%02d:%02d:%02d.%03d",
1237                  (int)(secs / 3600),
1238                  (int)((secs / 60) % 60),
1239                  (int)(secs % 60),
1240                  (int)((sn->vm_clock_nsec / 1000000) % 1000));
1241         snprintf(buf, buf_size,
1242                  "%-10s%-20s%7s%20s%15s",
1243                  sn->id_str, sn->name,
1244                  get_human_readable_size(buf1, sizeof(buf1), sn->vm_state_size),
1245                  date_buf,
1246                  clock_buf);
1247     }
1248     return buf;
1249 }
1250
1251
1252 /**************************************************************/
1253 /* async I/Os */
1254
1255 typedef struct VectorTranslationState {
1256     QEMUIOVector *iov;
1257     uint8_t *bounce;
1258     int is_write;
1259     BlockDriverAIOCB *aiocb;
1260     BlockDriverAIOCB *this_aiocb;
1261 } VectorTranslationState;
1262
1263 static void bdrv_aio_rw_vector_cb(void *opaque, int ret)
1264 {
1265     VectorTranslationState *s = opaque;
1266
1267     if (!s->is_write) {
1268         qemu_iovec_from_buffer(s->iov, s->bounce, s->iov->size);
1269     }
1270     qemu_vfree(s->bounce);
1271     s->this_aiocb->cb(s->this_aiocb->opaque, ret);
1272     qemu_aio_release(s->this_aiocb);
1273 }
1274
1275 static BlockDriverAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs,
1276                                             int64_t sector_num,
1277                                             QEMUIOVector *iov,
1278                                             int nb_sectors,
1279                                             BlockDriverCompletionFunc *cb,
1280                                             void *opaque,
1281                                             int is_write)
1282
1283 {
1284     VectorTranslationState *s = qemu_mallocz(sizeof(*s));
1285     BlockDriverAIOCB *aiocb = qemu_aio_get(bs, cb, opaque);
1286
1287     s->this_aiocb = aiocb;
1288     s->iov = iov;
1289     s->bounce = qemu_memalign(512, nb_sectors * 512);
1290     s->is_write = is_write;
1291     if (is_write) {
1292         qemu_iovec_to_buffer(s->iov, s->bounce);
1293         s->aiocb = bdrv_aio_write(bs, sector_num, s->bounce, nb_sectors,
1294                                   bdrv_aio_rw_vector_cb, s);
1295     } else {
1296         s->aiocb = bdrv_aio_read(bs, sector_num, s->bounce, nb_sectors,
1297                                  bdrv_aio_rw_vector_cb, s);
1298     }
1299     return aiocb;
1300 }
1301
1302 BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
1303                                  QEMUIOVector *iov, int nb_sectors,
1304                                  BlockDriverCompletionFunc *cb, void *opaque)
1305 {
1306     if (bdrv_check_request(bs, sector_num, nb_sectors))
1307         return NULL;
1308
1309     return bdrv_aio_rw_vector(bs, sector_num, iov, nb_sectors,
1310                               cb, opaque, 0);
1311 }
1312
1313 BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
1314                                   QEMUIOVector *iov, int nb_sectors,
1315                                   BlockDriverCompletionFunc *cb, void *opaque)
1316 {
1317     if (bdrv_check_request(bs, sector_num, nb_sectors))
1318         return NULL;
1319
1320     return bdrv_aio_rw_vector(bs, sector_num, iov, nb_sectors,
1321                               cb, opaque, 1);
1322 }
1323
1324 BlockDriverAIOCB *bdrv_aio_read(BlockDriverState *bs, int64_t sector_num,
1325                                 uint8_t *buf, int nb_sectors,
1326                                 BlockDriverCompletionFunc *cb, void *opaque)
1327 {
1328     BlockDriver *drv = bs->drv;
1329     BlockDriverAIOCB *ret;
1330
1331     if (!drv)
1332         return NULL;
1333     if (bdrv_check_request(bs, sector_num, nb_sectors))
1334         return NULL;
1335
1336     ret = drv->bdrv_aio_read(bs, sector_num, buf, nb_sectors, cb, opaque);
1337
1338     if (ret) {
1339         /* Update stats even though technically transfer has not happened. */
1340         bs->rd_bytes += (unsigned) nb_sectors * SECTOR_SIZE;
1341         bs->rd_ops ++;
1342     }
1343
1344     return ret;
1345 }
1346
1347 BlockDriverAIOCB *bdrv_aio_write(BlockDriverState *bs, int64_t sector_num,
1348                                  const uint8_t *buf, int nb_sectors,
1349                                  BlockDriverCompletionFunc *cb, void *opaque)
1350 {
1351     BlockDriver *drv = bs->drv;
1352     BlockDriverAIOCB *ret;
1353
1354     if (!drv)
1355         return NULL;
1356     if (bs->read_only)
1357         return NULL;
1358     if (bdrv_check_request(bs, sector_num, nb_sectors))
1359         return NULL;
1360
1361     ret = drv->bdrv_aio_write(bs, sector_num, buf, nb_sectors, cb, opaque);
1362
1363     if (ret) {
1364         /* Update stats even though technically transfer has not happened. */
1365         bs->wr_bytes += (unsigned) nb_sectors * SECTOR_SIZE;
1366         bs->wr_ops ++;
1367     }
1368
1369     return ret;
1370 }
1371
1372 void bdrv_aio_cancel(BlockDriverAIOCB *acb)
1373 {
1374     BlockDriver *drv = acb->bs->drv;
1375
1376     if (acb->cb == bdrv_aio_rw_vector_cb) {
1377         VectorTranslationState *s = acb->opaque;
1378         acb = s->aiocb;
1379     }
1380
1381     drv->bdrv_aio_cancel(acb);
1382 }
1383
1384
1385 /**************************************************************/
1386 /* async block device emulation */
1387
1388 static void bdrv_aio_bh_cb(void *opaque)
1389 {
1390     BlockDriverAIOCBSync *acb = opaque;
1391     acb->common.cb(acb->common.opaque, acb->ret);
1392     qemu_aio_release(acb);
1393 }
1394
1395 static BlockDriverAIOCB *bdrv_aio_read_em(BlockDriverState *bs,
1396         int64_t sector_num, uint8_t *buf, int nb_sectors,
1397         BlockDriverCompletionFunc *cb, void *opaque)
1398 {
1399     BlockDriverAIOCBSync *acb;
1400     int ret;
1401
1402     acb = qemu_aio_get(bs, cb, opaque);
1403     if (!acb->bh)
1404         acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
1405     ret = bdrv_read(bs, sector_num, buf, nb_sectors);
1406     acb->ret = ret;
1407     qemu_bh_schedule(acb->bh);
1408     return &acb->common;
1409 }
1410
1411 static BlockDriverAIOCB *bdrv_aio_write_em(BlockDriverState *bs,
1412         int64_t sector_num, const uint8_t *buf, int nb_sectors,
1413         BlockDriverCompletionFunc *cb, void *opaque)
1414 {
1415     BlockDriverAIOCBSync *acb;
1416     int ret;
1417
1418     acb = qemu_aio_get(bs, cb, opaque);
1419     if (!acb->bh)
1420         acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
1421     ret = bdrv_write(bs, sector_num, buf, nb_sectors);
1422     acb->ret = ret;
1423     qemu_bh_schedule(acb->bh);
1424     return &acb->common;
1425 }
1426
1427 static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb)
1428 {
1429     BlockDriverAIOCBSync *acb = (BlockDriverAIOCBSync *)blockacb;
1430     qemu_bh_cancel(acb->bh);
1431     qemu_aio_release(acb);
1432 }
1433
1434 /**************************************************************/
1435 /* sync block device emulation */
1436
1437 static void bdrv_rw_em_cb(void *opaque, int ret)
1438 {
1439     *(int *)opaque = ret;
1440 }
1441
1442 #define NOT_DONE 0x7fffffff
1443
1444 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
1445                         uint8_t *buf, int nb_sectors)
1446 {
1447     int async_ret;
1448     BlockDriverAIOCB *acb;
1449
1450     async_ret = NOT_DONE;
1451     acb = bdrv_aio_read(bs, sector_num, buf, nb_sectors,
1452                         bdrv_rw_em_cb, &async_ret);
1453     if (acb == NULL)
1454         return -1;
1455
1456     while (async_ret == NOT_DONE) {
1457         qemu_aio_wait();
1458     }
1459
1460     return async_ret;
1461 }
1462
1463 static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
1464                          const uint8_t *buf, int nb_sectors)
1465 {
1466     int async_ret;
1467     BlockDriverAIOCB *acb;
1468
1469     async_ret = NOT_DONE;
1470     acb = bdrv_aio_write(bs, sector_num, buf, nb_sectors,
1471                          bdrv_rw_em_cb, &async_ret);
1472     if (acb == NULL)
1473         return -1;
1474     while (async_ret == NOT_DONE) {
1475         qemu_aio_wait();
1476     }
1477     return async_ret;
1478 }
1479
1480 void bdrv_init(void)
1481 {
1482     bdrv_register(&bdrv_raw);
1483     bdrv_register(&bdrv_host_device);
1484 #ifndef _WIN32
1485     bdrv_register(&bdrv_cow);
1486 #endif
1487     bdrv_register(&bdrv_qcow);
1488     bdrv_register(&bdrv_vmdk);
1489     bdrv_register(&bdrv_cloop);
1490     bdrv_register(&bdrv_dmg);
1491     bdrv_register(&bdrv_bochs);
1492     bdrv_register(&bdrv_vpc);
1493     bdrv_register(&bdrv_vvfat);
1494     bdrv_register(&bdrv_qcow2);
1495     bdrv_register(&bdrv_parallels);
1496     bdrv_register(&bdrv_nbd);
1497 }
1498
1499 void *qemu_aio_get(BlockDriverState *bs, BlockDriverCompletionFunc *cb,
1500                    void *opaque)
1501 {
1502     BlockDriver *drv;
1503     BlockDriverAIOCB *acb;
1504
1505     drv = bs->drv;
1506     if (drv->free_aiocb) {
1507         acb = drv->free_aiocb;
1508         drv->free_aiocb = acb->next;
1509     } else {
1510         acb = qemu_mallocz(drv->aiocb_size);
1511     }
1512     acb->bs = bs;
1513     acb->cb = cb;
1514     acb->opaque = opaque;
1515     return acb;
1516 }
1517
1518 void qemu_aio_release(void *p)
1519 {
1520     BlockDriverAIOCB *acb = p;
1521     BlockDriver *drv = acb->bs->drv;
1522     acb->next = drv->free_aiocb;
1523     drv->free_aiocb = acb;
1524 }
1525
1526 /**************************************************************/
1527 /* removable device support */
1528
1529 /**
1530  * Return TRUE if the media is present
1531  */
1532 int bdrv_is_inserted(BlockDriverState *bs)
1533 {
1534     BlockDriver *drv = bs->drv;
1535     int ret;
1536     if (!drv)
1537         return 0;
1538     if (!drv->bdrv_is_inserted)
1539         return 1;
1540     ret = drv->bdrv_is_inserted(bs);
1541     return ret;
1542 }
1543
1544 /**
1545  * Return TRUE if the media changed since the last call to this
1546  * function. It is currently only used for floppy disks
1547  */
1548 int bdrv_media_changed(BlockDriverState *bs)
1549 {
1550     BlockDriver *drv = bs->drv;
1551     int ret;
1552
1553     if (!drv || !drv->bdrv_media_changed)
1554         ret = -ENOTSUP;
1555     else
1556         ret = drv->bdrv_media_changed(bs);
1557     if (ret == -ENOTSUP)
1558         ret = bs->media_changed;
1559     bs->media_changed = 0;
1560     return ret;
1561 }
1562
1563 /**
1564  * If eject_flag is TRUE, eject the media. Otherwise, close the tray
1565  */
1566 void bdrv_eject(BlockDriverState *bs, int eject_flag)
1567 {
1568     BlockDriver *drv = bs->drv;
1569     int ret;
1570
1571     if (!drv || !drv->bdrv_eject) {
1572         ret = -ENOTSUP;
1573     } else {
1574         ret = drv->bdrv_eject(bs, eject_flag);
1575     }
1576     if (ret == -ENOTSUP) {
1577         if (eject_flag)
1578             bdrv_close(bs);
1579     }
1580 }
1581
1582 int bdrv_is_locked(BlockDriverState *bs)
1583 {
1584     return bs->locked;
1585 }
1586
1587 /**
1588  * Lock or unlock the media (if it is locked, the user won't be able
1589  * to eject it manually).
1590  */
1591 void bdrv_set_locked(BlockDriverState *bs, int locked)
1592 {
1593     BlockDriver *drv = bs->drv;
1594
1595     bs->locked = locked;
1596     if (drv && drv->bdrv_set_locked) {
1597         drv->bdrv_set_locked(bs, locked);
1598     }
1599 }
1600
1601 /* needed for generic scsi interface */
1602
1603 int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
1604 {
1605     BlockDriver *drv = bs->drv;
1606
1607     if (drv && drv->bdrv_ioctl)
1608         return drv->bdrv_ioctl(bs, req, buf);
1609     return -ENOTSUP;
1610 }
1611
1612 int bdrv_sg_send_command(BlockDriverState *bs, void *buf, int count)
1613 {
1614     return bs->drv->bdrv_sg_send_command(bs, buf, count);
1615 }
1616
1617 int bdrv_sg_recv_response(BlockDriverState *bs, void *buf, int count)
1618 {
1619     return bs->drv->bdrv_sg_recv_response(bs, buf, count);
1620 }
1621
1622 BlockDriverAIOCB *bdrv_sg_aio_read(BlockDriverState *bs, void *buf, int count,
1623                                    BlockDriverCompletionFunc *cb, void *opaque)
1624 {
1625     return bs->drv->bdrv_sg_aio_read(bs, buf, count, cb, opaque);
1626 }
1627
1628 BlockDriverAIOCB *bdrv_sg_aio_write(BlockDriverState *bs, void *buf, int count,
1629                                     BlockDriverCompletionFunc *cb, void *opaque)
1630 {
1631     return bs->drv->bdrv_sg_aio_write(bs, buf, count, cb, opaque);
1632 }