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: #include "qemu-common.h"
26: #include "monitor.h"
27: #include "block_int.h"
28: #include "module.h"
29: #include "qemu-objects.h"
30:
31: #ifdef CONFIG_BSD
32: #include <sys/types.h>
33: #include <sys/stat.h>
34: #include <sys/ioctl.h>
35: #include <sys/queue.h>
36: #ifndef __DragonFly__
37: #include <sys/disk.h>
38: #endif
39: #endif
40:
41: #ifdef _WIN32
42: #include <windows.h>
43: #endif
44:
45: static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
46: int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
47: BlockDriverCompletionFunc *cb, void *opaque);
48: static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
49: int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
50: BlockDriverCompletionFunc *cb, void *opaque);
51: static BlockDriverAIOCB *bdrv_aio_flush_em(BlockDriverState *bs,
52: BlockDriverCompletionFunc *cb, void *opaque);
53: static BlockDriverAIOCB *bdrv_aio_noop_em(BlockDriverState *bs,
54: BlockDriverCompletionFunc *cb, void *opaque);
55: static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
56: uint8_t *buf, int nb_sectors);
57: static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
58: const uint8_t *buf, int nb_sectors);
59:
60: static QTAILQ_HEAD(, BlockDriverState) bdrv_states =
61: QTAILQ_HEAD_INITIALIZER(bdrv_states);
62:
63: static QLIST_HEAD(, BlockDriver) bdrv_drivers =
64: QLIST_HEAD_INITIALIZER(bdrv_drivers);
65:
66: /* The device to use for VM snapshots */
67: static BlockDriverState *bs_snapshots;
68:
69: /* If non-zero, use only whitelisted block drivers */
70: static int use_bdrv_whitelist;
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: void bdrv_register(BlockDriver *bdrv)
137: {
138: if (!bdrv->bdrv_aio_readv) {
139: /* add AIO emulation layer */
140: bdrv->bdrv_aio_readv = bdrv_aio_readv_em;
141: bdrv->bdrv_aio_writev = bdrv_aio_writev_em;
142: } else if (!bdrv->bdrv_read) {
143: /* add synchronous IO emulation layer */
144: bdrv->bdrv_read = bdrv_read_em;
145: bdrv->bdrv_write = bdrv_write_em;
146: }
147:
148: if (!bdrv->bdrv_aio_flush)
149: bdrv->bdrv_aio_flush = bdrv_aio_flush_em;
150:
151: QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list);
152: }
153:
154: /* create a new block device (by default it is empty) */
155: BlockDriverState *bdrv_new(const char *device_name)
156: {
157: BlockDriverState *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: QTAILQ_INSERT_TAIL(&bdrv_states, bs, list);
163: }
164: return bs;
165: }
166:
167: BlockDriver *bdrv_find_format(const char *format_name)
168: {
169: BlockDriver *drv1;
170: QLIST_FOREACH(drv1, &bdrv_drivers, list) {
171: if (!strcmp(drv1->format_name, format_name)) {
172: return drv1;
173: }
174: }
175: return NULL;
176: }
177:
178: static int bdrv_is_whitelisted(BlockDriver *drv)
179: {
180: static const char *whitelist[] = {
181: CONFIG_BDRV_WHITELIST
182: };
183: const char **p;
184:
185: if (!whitelist[0])
186: return 1; /* no whitelist, anything goes */
187:
188: for (p = whitelist; *p; p++) {
189: if (!strcmp(drv->format_name, *p)) {
190: return 1;
191: }
192: }
193: return 0;
194: }
195:
196: BlockDriver *bdrv_find_whitelisted_format(const char *format_name)
197: {
198: BlockDriver *drv = bdrv_find_format(format_name);
199: return drv && bdrv_is_whitelisted(drv) ? drv : NULL;
200: }
201:
202: int bdrv_create(BlockDriver *drv, const char* filename,
203: QEMUOptionParameter *options)
204: {
205: if (!drv->bdrv_create)
206: return -ENOTSUP;
207:
208: return drv->bdrv_create(filename, options);
209: }
210:
211: int bdrv_create_file(const char* filename, QEMUOptionParameter *options)
212: {
213: BlockDriver *drv;
214:
215: drv = bdrv_find_protocol(filename);
216: if (drv == NULL) {
217: drv = bdrv_find_format("file");
218: }
219:
220: return bdrv_create(drv, filename, options);
221: }
222:
223: #ifdef _WIN32
224: void get_tmp_filename(char *filename, int size)
225: {
226: char temp_dir[MAX_PATH];
227:
228: GetTempPath(MAX_PATH, temp_dir);
229: GetTempFileName(temp_dir, "qem", 0, filename);
230: }
231: #else
232: void get_tmp_filename(char *filename, int size)
233: {
234: int fd;
235: const char *tmpdir;
236: /* XXX: race condition possible */
237: tmpdir = getenv("TMPDIR");
238: if (!tmpdir)
239: tmpdir = "/tmp";
240: snprintf(filename, size, "%s/vl.XXXXXX", tmpdir);
241: fd = mkstemp(filename);
242: close(fd);
243: }
244: #endif
245:
246: #ifdef _WIN32
247: static int is_windows_drive_prefix(const char *filename)
248: {
249: return (((filename[0] >= 'a' && filename[0] <= 'z') ||
250: (filename[0] >= 'A' && filename[0] <= 'Z')) &&
251: filename[1] == ':');
252: }
253:
254: int is_windows_drive(const char *filename)
255: {
256: if (is_windows_drive_prefix(filename) &&
257: filename[2] == '\0')
258: return 1;
259: if (strstart(filename, "\\\\.\\", NULL) ||
260: strstart(filename, "//./", NULL))
261: return 1;
262: return 0;
263: }
264: #endif
265:
266: /*
267: * Detect host devices. By convention, /dev/cdrom[N] is always
268: * recognized as a host CDROM.
269: */
270: static BlockDriver *find_hdev_driver(const char *filename)
271: {
272: int score_max = 0, score;
273: BlockDriver *drv = NULL, *d;
274:
275: QLIST_FOREACH(d, &bdrv_drivers, list) {
276: if (d->bdrv_probe_device) {
277: score = d->bdrv_probe_device(filename);
278: if (score > score_max) {
279: score_max = score;
280: drv = d;
281: }
282: }
283: }
284:
285: return drv;
286: }
287:
288: BlockDriver *bdrv_find_protocol(const char *filename)
289: {
290: BlockDriver *drv1;
291: char protocol[128];
292: int len;
293: const char *p;
294:
295: /* TODO Drivers without bdrv_file_open must be specified explicitly */
296:
297: /*
298: * XXX(hch): we really should not let host device detection
299: * override an explicit protocol specification, but moving this
300: * later breaks access to device names with colons in them.
301: * Thanks to the brain-dead persistent naming schemes on udev-
302: * based Linux systems those actually are quite common.
303: */
304: drv1 = find_hdev_driver(filename);
305: if (drv1) {
306: return drv1;
307: }
308:
309: #ifdef _WIN32
310: if (is_windows_drive(filename) ||
311: is_windows_drive_prefix(filename))
312: return bdrv_find_format("file");
313: #endif
314:
315: p = strchr(filename, ':');
316: if (!p) {
317: return bdrv_find_format("file");
318: }
319: len = p - filename;
320: if (len > sizeof(protocol) - 1)
321: len = sizeof(protocol) - 1;
322: memcpy(protocol, filename, len);
323: protocol[len] = '\0';
324: QLIST_FOREACH(drv1, &bdrv_drivers, list) {
325: if (drv1->protocol_name &&
326: !strcmp(drv1->protocol_name, protocol)) {
327: return drv1;
328: }
329: }
330: return NULL;
331: }
332:
333: static int find_image_format(const char *filename, BlockDriver **pdrv)
334: {
335: int ret, score, score_max;
336: BlockDriver *drv1, *drv;
337: uint8_t buf[2048];
338: BlockDriverState *bs;
339:
340: ret = bdrv_file_open(&bs, filename, 0);
341: if (ret < 0) {
342: *pdrv = NULL;
343: return ret;
344: }
345:
346: /* Return the raw BlockDriver * to scsi-generic devices or empty drives */
347: if (bs->sg || !bdrv_is_inserted(bs)) {
348: bdrv_delete(bs);
349: drv = bdrv_find_format("raw");
350: if (!drv) {
351: ret = -ENOENT;
352: }
353: *pdrv = drv;
354: return ret;
355: }
356:
357: ret = bdrv_pread(bs, 0, buf, sizeof(buf));
358: bdrv_delete(bs);
359: if (ret < 0) {
360: *pdrv = NULL;
361: return ret;
362: }
363:
364: score_max = 0;
365: drv = NULL;
366: QLIST_FOREACH(drv1, &bdrv_drivers, list) {
367: if (drv1->bdrv_probe) {
368: score = drv1->bdrv_probe(buf, ret, filename);
369: if (score > score_max) {
370: score_max = score;
371: drv = drv1;
372: }
373: }
374: }
375: if (!drv) {
376: ret = -ENOENT;
377: }
378: *pdrv = drv;
379: return ret;
380: }
381:
382: /**
383: * Set the current 'total_sectors' value
384: */
385: static int refresh_total_sectors(BlockDriverState *bs, int64_t hint)
386: {
387: BlockDriver *drv = bs->drv;
388:
389: /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */
390: if (bs->sg)
391: return 0;
392:
393: /* query actual device if possible, otherwise just trust the hint */
394: if (drv->bdrv_getlength) {
395: int64_t length = drv->bdrv_getlength(bs);
396: if (length < 0) {
397: return length;
398: }
399: hint = length >> BDRV_SECTOR_BITS;
400: }
401:
402: bs->total_sectors = hint;
403: return 0;
404: }
405:
406: /*
407: * Common part for opening disk images and files
408: */
409: static int bdrv_open_common(BlockDriverState *bs, const char *filename,
410: int flags, BlockDriver *drv)
411: {
412: int ret, open_flags;
413:
414: assert(drv != NULL);
415:
416: bs->file = NULL;
417: bs->total_sectors = 0;
418: bs->encrypted = 0;
419: bs->valid_key = 0;
420: bs->open_flags = flags;
421: /* buffer_alignment defaulted to 512, drivers can change this value */
422: bs->buffer_alignment = 512;
423:
424: pstrcpy(bs->filename, sizeof(bs->filename), filename);
425:
426: if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv)) {
427: return -ENOTSUP;
428: }
429:
430: bs->drv = drv;
431: bs->opaque = qemu_mallocz(drv->instance_size);
432:
433: /*
434: * Yes, BDRV_O_NOCACHE aka O_DIRECT means we have to present a
435: * write cache to the guest. We do need the fdatasync to flush
436: * out transactions for block allocations, and we maybe have a
437: * volatile write cache in our backing device to deal with.
438: */
439: if (flags & (BDRV_O_CACHE_WB|BDRV_O_NOCACHE))
440: bs->enable_write_cache = 1;
441:
442: /*
443: * Clear flags that are internal to the block layer before opening the
444: * image.
445: */
446: open_flags = flags & ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
447:
448: /*
449: * Snapshots should be writeable.
450: */
451: if (bs->is_temporary) {
452: open_flags |= BDRV_O_RDWR;
453: }
454:
455: /* Open the image, either directly or using a protocol */
456: if (drv->bdrv_file_open) {
457: ret = drv->bdrv_file_open(bs, filename, open_flags);
458: } else {
459: ret = bdrv_file_open(&bs->file, filename, open_flags);
460: if (ret >= 0) {
461: ret = drv->bdrv_open(bs, open_flags);
462: }
463: }
464:
465: if (ret < 0) {
466: goto free_and_fail;
467: }
468:
469: bs->keep_read_only = bs->read_only = !(open_flags & BDRV_O_RDWR);
470:
471: ret = refresh_total_sectors(bs, bs->total_sectors);
472: if (ret < 0) {
473: goto free_and_fail;
474: }
475:
476: #ifndef _WIN32
477: if (bs->is_temporary) {
478: unlink(filename);
479: }
480: #endif
481: return 0;
482:
483: free_and_fail:
484: if (bs->file) {
485: bdrv_delete(bs->file);
486: bs->file = NULL;
487: }
488: qemu_free(bs->opaque);
489: bs->opaque = NULL;
490: bs->drv = NULL;
491: return ret;
492: }
493:
494: /*
495: * Opens a file using a protocol (file, host_device, nbd, ...)
496: */
497: int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags)
498: {
499: BlockDriverState *bs;
500: BlockDriver *drv;
501: int ret;
502:
503: drv = bdrv_find_protocol(filename);
504: if (!drv) {
505: return -ENOENT;
506: }
507:
508: bs = bdrv_new("");
509: ret = bdrv_open_common(bs, filename, flags, drv);
510: if (ret < 0) {
511: bdrv_delete(bs);
512: return ret;
513: }
514: bs->growable = 1;
515: *pbs = bs;
516: return 0;
517: }
518:
519: /*
520: * Opens a disk image (raw, qcow2, vmdk, ...)
521: */
522: int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
523: BlockDriver *drv)
524: {
525: int ret;
526:
527: if (flags & BDRV_O_SNAPSHOT) {
528: BlockDriverState *bs1;
529: int64_t total_size;
530: int is_protocol = 0;
531: BlockDriver *bdrv_qcow2;
532: QEMUOptionParameter *options;
533: char tmp_filename[PATH_MAX];
534: char backing_filename[PATH_MAX];
535:
536: /* if snapshot, we create a temporary backing file and open it
537: instead of opening 'filename' directly */
538:
539: /* if there is a backing file, use it */
540: bs1 = bdrv_new("");
541: ret = bdrv_open(bs1, filename, 0, drv);
542: if (ret < 0) {
543: bdrv_delete(bs1);
544: return ret;
545: }
546: total_size = bdrv_getlength(bs1) & BDRV_SECTOR_MASK;
547:
548: if (bs1->drv && bs1->drv->protocol_name)
549: is_protocol = 1;
550:
551: bdrv_delete(bs1);
552:
553: get_tmp_filename(tmp_filename, sizeof(tmp_filename));
554:
555: /* Real path is meaningless for protocols */
556: if (is_protocol)
557: snprintf(backing_filename, sizeof(backing_filename),
558: "%s", filename);
559: else if (!realpath(filename, backing_filename))
560: return -errno;
561:
562: bdrv_qcow2 = bdrv_find_format("qcow2");
563: options = parse_option_parameters("", bdrv_qcow2->create_options, NULL);
564:
565: set_option_parameter_int(options, BLOCK_OPT_SIZE, total_size);
566: set_option_parameter(options, BLOCK_OPT_BACKING_FILE, backing_filename);
567: if (drv) {
568: set_option_parameter(options, BLOCK_OPT_BACKING_FMT,
569: drv->format_name);
570: }
571:
572: ret = bdrv_create(bdrv_qcow2, tmp_filename, options);
573: free_option_parameters(options);
574: if (ret < 0) {
575: return ret;
576: }
577:
578: filename = tmp_filename;
579: drv = bdrv_qcow2;
580: bs->is_temporary = 1;
581: }
582:
583: /* Find the right image format driver */
584: if (!drv) {
585: ret = find_image_format(filename, &drv);
586: }
587:
588: if (!drv) {
589: goto unlink_and_fail;
590: }
591:
592: /* Open the image */
593: ret = bdrv_open_common(bs, filename, flags, drv);
594: if (ret < 0) {
595: goto unlink_and_fail;
596: }
597:
598: /* If there is a backing file, use it */
599: if ((flags & BDRV_O_NO_BACKING) == 0 && bs->backing_file[0] != '\0') {
600: char backing_filename[PATH_MAX];
601: int back_flags;
602: BlockDriver *back_drv = NULL;
603:
604: bs->backing_hd = bdrv_new("");
605: path_combine(backing_filename, sizeof(backing_filename),
606: filename, bs->backing_file);
607: if (bs->backing_format[0] != '\0')
608: back_drv = bdrv_find_format(bs->backing_format);
609:
610: /* backing files always opened read-only */
611: back_flags =
612: flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
613:
614: ret = bdrv_open(bs->backing_hd, backing_filename, back_flags, back_drv);
615: if (ret < 0) {
616: bdrv_close(bs);
617: return ret;
618: }
619: if (bs->is_temporary) {
620: bs->backing_hd->keep_read_only = !(flags & BDRV_O_RDWR);
621: } else {
622: /* base image inherits from "parent" */
623: bs->backing_hd->keep_read_only = bs->keep_read_only;
624: }
625: }
626:
627: if (!bdrv_key_required(bs)) {
628: /* call the change callback */
629: bs->media_changed = 1;
630: if (bs->change_cb)
631: bs->change_cb(bs->change_opaque);
632: }
633:
634: return 0;
635:
636: unlink_and_fail:
637: if (bs->is_temporary) {
638: unlink(filename);
639: }
640: return ret;
641: }
642:
643: void bdrv_close(BlockDriverState *bs)
644: {
645: if (bs->drv) {
646: if (bs == bs_snapshots) {
647: bs_snapshots = NULL;
648: }
649: if (bs->backing_hd) {
650: bdrv_delete(bs->backing_hd);
651: bs->backing_hd = NULL;
652: }
653: bs->drv->bdrv_close(bs);
654: qemu_free(bs->opaque);
655: #ifdef _WIN32
656: if (bs->is_temporary) {
657: unlink(bs->filename);
658: }
659: #endif
660: bs->opaque = NULL;
661: bs->drv = NULL;
662:
663: if (bs->file != NULL) {
664: bdrv_close(bs->file);
665: }
666:
667: /* call the change callback */
668: bs->media_changed = 1;
669: if (bs->change_cb)
670: bs->change_cb(bs->change_opaque);
671: }
672: }
673:
674: void bdrv_close_all(void)
675: {
676: BlockDriverState *bs;
677:
678: QTAILQ_FOREACH(bs, &bdrv_states, list) {
679: bdrv_close(bs);
680: }
681: }
682:
683: void bdrv_delete(BlockDriverState *bs)
684: {
685: assert(!bs->peer);
686:
687: /* remove from list, if necessary */
688: if (bs->device_name[0] != '\0') {
689: QTAILQ_REMOVE(&bdrv_states, bs, list);
690: }
691:
692: bdrv_close(bs);
693: if (bs->file != NULL) {
694: bdrv_delete(bs->file);
695: }
696:
697: assert(bs != bs_snapshots);
698: qemu_free(bs);
699: }
700:
701: int bdrv_attach(BlockDriverState *bs, DeviceState *qdev)
702: {
703: if (bs->peer) {
704: return -EBUSY;
705: }
706: bs->peer = qdev;
707: return 0;
708: }
709:
710: void bdrv_detach(BlockDriverState *bs, DeviceState *qdev)
711: {
712: assert(bs->peer == qdev);
713: bs->peer = NULL;
714: }
715:
716: DeviceState *bdrv_get_attached(BlockDriverState *bs)
717: {
718: return bs->peer;
719: }
720:
721: /*
722: * Run consistency checks on an image
723: *
724: * Returns 0 if the check could be completed (it doesn't mean that the image is
725: * free of errors) or -errno when an internal error occured. The results of the
726: * check are stored in res.
727: */
728: int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res)
729: {
730: if (bs->drv->bdrv_check == NULL) {
731: return -ENOTSUP;
732: }
733:
734: memset(res, 0, sizeof(*res));
735: return bs->drv->bdrv_check(bs, res);
736: }
737:
738: /* commit COW file into the raw image */
739: int bdrv_commit(BlockDriverState *bs)
740: {
741: BlockDriver *drv = bs->drv;
742: BlockDriver *backing_drv;
743: int64_t i, total_sectors;
744: int n, j, ro, open_flags;
745: int ret = 0, rw_ret = 0;
746: unsigned char sector[BDRV_SECTOR_SIZE];
747: char filename[1024];
748: BlockDriverState *bs_rw, *bs_ro;
749:
750: if (!drv)
751: return -ENOMEDIUM;
752:
753: if (!bs->backing_hd) {
754: return -ENOTSUP;
755: }
756:
757: if (bs->backing_hd->keep_read_only) {
758: return -EACCES;
759: }
760:
761: backing_drv = bs->backing_hd->drv;
762: ro = bs->backing_hd->read_only;
763: strncpy(filename, bs->backing_hd->filename, sizeof(filename));
764: open_flags = bs->backing_hd->open_flags;
765:
766: if (ro) {
767: /* re-open as RW */
768: bdrv_delete(bs->backing_hd);
769: bs->backing_hd = NULL;
770: bs_rw = bdrv_new("");
771: rw_ret = bdrv_open(bs_rw, filename, open_flags | BDRV_O_RDWR,
772: backing_drv);
773: if (rw_ret < 0) {
774: bdrv_delete(bs_rw);
775: /* try to re-open read-only */
776: bs_ro = bdrv_new("");
777: ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR,
778: backing_drv);
779: if (ret < 0) {
780: bdrv_delete(bs_ro);
781: /* drive not functional anymore */
782: bs->drv = NULL;
783: return ret;
784: }
785: bs->backing_hd = bs_ro;
786: return rw_ret;
787: }
788: bs->backing_hd = bs_rw;
789: }
790:
791: total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
792: for (i = 0; i < total_sectors;) {
793: if (drv->bdrv_is_allocated(bs, i, 65536, &n)) {
794: for(j = 0; j < n; j++) {
795: if (bdrv_read(bs, i, sector, 1) != 0) {
796: ret = -EIO;
797: goto ro_cleanup;
798: }
799:
800: if (bdrv_write(bs->backing_hd, i, sector, 1) != 0) {
801: ret = -EIO;
802: goto ro_cleanup;
803: }
804: i++;
805: }
806: } else {
807: i += n;
808: }
809: }
810:
811: if (drv->bdrv_make_empty) {
812: ret = drv->bdrv_make_empty(bs);
813: bdrv_flush(bs);
814: }
815:
816: /*
817: * Make sure all data we wrote to the backing device is actually
818: * stable on disk.
819: */
820: if (bs->backing_hd)
821: bdrv_flush(bs->backing_hd);
822:
823: ro_cleanup:
824:
825: if (ro) {
826: /* re-open as RO */
827: bdrv_delete(bs->backing_hd);
828: bs->backing_hd = NULL;
829: bs_ro = bdrv_new("");
830: ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR,
831: backing_drv);
832: if (ret < 0) {
833: bdrv_delete(bs_ro);
834: /* drive not functional anymore */
835: bs->drv = NULL;
836: return ret;
837: }
838: bs->backing_hd = bs_ro;
839: bs->backing_hd->keep_read_only = 0;
840: }
841:
842: return ret;
843: }
844:
845: void bdrv_commit_all(void)
846: {
847: BlockDriverState *bs;
848:
849: QTAILQ_FOREACH(bs, &bdrv_states, list) {
850: bdrv_commit(bs);
851: }
852: }
853:
854: /*
855: * Return values:
856: * 0 - success
857: * -EINVAL - backing format specified, but no file
858: * -ENOSPC - can't update the backing file because no space is left in the
859: * image file header
860: * -ENOTSUP - format driver doesn't support changing the backing file
861: */
862: int bdrv_change_backing_file(BlockDriverState *bs,
863: const char *backing_file, const char *backing_fmt)
864: {
865: BlockDriver *drv = bs->drv;
866:
867: if (drv->bdrv_change_backing_file != NULL) {
868: return drv->bdrv_change_backing_file(bs, backing_file, backing_fmt);
869: } else {
870: return -ENOTSUP;
871: }
872: }
873:
874: static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,
875: size_t size)
876: {
877: int64_t len;
878:
879: if (!bdrv_is_inserted(bs))
880: return -ENOMEDIUM;
881:
882: if (bs->growable)
883: return 0;
884:
885: len = bdrv_getlength(bs);
886:
887: if (offset < 0)
888: return -EIO;
889:
890: if ((offset > len) || (len - offset < size))
891: return -EIO;
892:
893: return 0;
894: }
895:
896: static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num,
897: int nb_sectors)
898: {
899: return bdrv_check_byte_request(bs, sector_num * BDRV_SECTOR_SIZE,
900: nb_sectors * BDRV_SECTOR_SIZE);
901: }
902:
903: /* return < 0 if error. See bdrv_write() for the return codes */
904: int bdrv_read(BlockDriverState *bs, int64_t sector_num,
905: uint8_t *buf, int nb_sectors)
906: {
907: BlockDriver *drv = bs->drv;
908:
909: if (!drv)
910: return -ENOMEDIUM;
911: if (bdrv_check_request(bs, sector_num, nb_sectors))
912: return -EIO;
913:
914: return drv->bdrv_read(bs, sector_num, buf, nb_sectors);
915: }
916:
917: static void set_dirty_bitmap(BlockDriverState *bs, int64_t sector_num,
918: int nb_sectors, int dirty)
919: {
920: int64_t start, end;
921: unsigned long val, idx, bit;
922:
923: start = sector_num / BDRV_SECTORS_PER_DIRTY_CHUNK;
924: end = (sector_num + nb_sectors - 1) / BDRV_SECTORS_PER_DIRTY_CHUNK;
925:
926: for (; start <= end; start++) {
927: idx = start / (sizeof(unsigned long) * 8);
928: bit = start % (sizeof(unsigned long) * 8);
929: val = bs->dirty_bitmap[idx];
930: if (dirty) {
931: if (!(val & (1 << bit))) {
932: bs->dirty_count++;
933: val |= 1 << bit;
934: }
935: } else {
936: if (val & (1 << bit)) {
937: bs->dirty_count--;
938: val &= ~(1 << bit);
939: }
940: }
941: bs->dirty_bitmap[idx] = val;
942: }
943: }
944:
945: /* Return < 0 if error. Important errors are:
946: -EIO generic I/O error (may happen for all errors)
947: -ENOMEDIUM No media inserted.
948: -EINVAL Invalid sector number or nb_sectors
949: -EACCES Trying to write a read-only device
950: */
951: int bdrv_write(BlockDriverState *bs, int64_t sector_num,
952: const uint8_t *buf, int nb_sectors)
953: {
954: BlockDriver *drv = bs->drv;
955: if (!bs->drv)
956: return -ENOMEDIUM;
957: if (bs->read_only)
958: return -EACCES;
959: if (bdrv_check_request(bs, sector_num, nb_sectors))
960: return -EIO;
961:
962: if (bs->dirty_bitmap) {
963: set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
964: }
965:
966: if (bs->wr_highest_sector < sector_num + nb_sectors - 1) {
967: bs->wr_highest_sector = sector_num + nb_sectors - 1;
968: }
969:
970: return drv->bdrv_write(bs, sector_num, buf, nb_sectors);
971: }
972:
973: int bdrv_pread(BlockDriverState *bs, int64_t offset,
974: void *buf, int count1)
975: {
976: uint8_t tmp_buf[BDRV_SECTOR_SIZE];
977: int len, nb_sectors, count;
978: int64_t sector_num;
979: int ret;
980:
981: count = count1;
982: /* first read to align to sector start */
983: len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
984: if (len > count)
985: len = count;
986: sector_num = offset >> BDRV_SECTOR_BITS;
987: if (len > 0) {
988: if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
989: return ret;
990: memcpy(buf, tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), len);
991: count -= len;
992: if (count == 0)
993: return count1;
994: sector_num++;
995: buf += len;
996: }
997:
998: /* read the sectors "in place" */
999: nb_sectors = count >> BDRV_SECTOR_BITS;
1000: if (nb_sectors > 0) {
1001: if ((ret = bdrv_read(bs, sector_num, buf, nb_sectors)) < 0)
1002: return ret;
1003: sector_num += nb_sectors;
1004: len = nb_sectors << BDRV_SECTOR_BITS;
1005: buf += len;
1006: count -= len;
1007: }
1008:
1009: /* add data from the last sector */
1010: if (count > 0) {
1011: if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
1012: return ret;
1013: memcpy(buf, tmp_buf, count);
1014: }
1015: return count1;
1016: }
1017:
1018: int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
1019: const void *buf, int count1)
1020: {
1021: uint8_t tmp_buf[BDRV_SECTOR_SIZE];
1022: int len, nb_sectors, count;
1023: int64_t sector_num;
1024: int ret;
1025:
1026: count = count1;
1027: /* first write to align to sector start */
1028: len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
1029: if (len > count)
1030: len = count;
1031: sector_num = offset >> BDRV_SECTOR_BITS;
1032: if (len > 0) {
1033: if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
1034: return ret;
1035: memcpy(tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), buf, len);
1036: if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0)
1037: return ret;
1038: count -= len;
1039: if (count == 0)
1040: return count1;
1041: sector_num++;
1042: buf += len;
1043: }
1044:
1045: /* write the sectors "in place" */
1046: nb_sectors = count >> BDRV_SECTOR_BITS;
1047: if (nb_sectors > 0) {
1048: if ((ret = bdrv_write(bs, sector_num, buf, nb_sectors)) < 0)
1049: return ret;
1050: sector_num += nb_sectors;
1051: len = nb_sectors << BDRV_SECTOR_BITS;
1052: buf += len;
1053: count -= len;
1054: }
1055:
1056: /* add data from the last sector */
1057: if (count > 0) {
1058: if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
1059: return ret;
1060: memcpy(tmp_buf, buf, count);
1061: if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0)
1062: return ret;
1063: }
1064: return count1;
1065: }
1066:
1067: /*
1068: * Writes to the file and ensures that no writes are reordered across this
1069: * request (acts as a barrier)
1070: *
1071: * Returns 0 on success, -errno in error cases.
1072: */
1073: int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset,
1074: const void *buf, int count)
1075: {
1076: int ret;
1077:
1078: ret = bdrv_pwrite(bs, offset, buf, count);
1079: if (ret < 0) {
1080: return ret;
1081: }
1082:
1083: /* No flush needed for cache=writethrough, it uses O_DSYNC */
1084: if ((bs->open_flags & BDRV_O_CACHE_MASK) != 0) {
1085: bdrv_flush(bs);
1086: }
1087:
1088: return 0;
1089: }
1090:
1091: /*
1092: * Writes to the file and ensures that no writes are reordered across this
1093: * request (acts as a barrier)
1094: *
1095: * Returns 0 on success, -errno in error cases.
1096: */
1097: int bdrv_write_sync(BlockDriverState *bs, int64_t sector_num,
1098: const uint8_t *buf, int nb_sectors)
1099: {
1100: return bdrv_pwrite_sync(bs, BDRV_SECTOR_SIZE * sector_num,
1101: buf, BDRV_SECTOR_SIZE * nb_sectors);
1102: }
1103:
1104: /**
1105: * Truncate file to 'offset' bytes (needed only for file protocols)
1106: */
1107: int bdrv_truncate(BlockDriverState *bs, int64_t offset)
1108: {
1109: BlockDriver *drv = bs->drv;
1110: int ret;
1111: if (!drv)
1112: return -ENOMEDIUM;
1113: if (!drv->bdrv_truncate)
1114: return -ENOTSUP;
1115: if (bs->read_only)
1116: return -EACCES;
1117: ret = drv->bdrv_truncate(bs, offset);
1118: if (ret == 0) {
1119: ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS);
1120: }
1121: return ret;
1122: }
1123:
1124: /**
1125: * Length of a file in bytes. Return < 0 if error or unknown.
1126: */
1127: int64_t bdrv_getlength(BlockDriverState *bs)
1128: {
1129: BlockDriver *drv = bs->drv;
1130: if (!drv)
1131: return -ENOMEDIUM;
1132:
1133: /* Fixed size devices use the total_sectors value for speed instead of
1134: issuing a length query (like lseek) on each call. Also, legacy block
1135: drivers don't provide a bdrv_getlength function and must use
1136: total_sectors. */
1137: if (!bs->growable || !drv->bdrv_getlength) {
1138: return bs->total_sectors * BDRV_SECTOR_SIZE;
1139: }
1140: return drv->bdrv_getlength(bs);
1141: }
1142:
1143: /* return 0 as number of sectors if no device present or error */
1144: void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
1145: {
1146: int64_t length;
1147: length = bdrv_getlength(bs);
1148: if (length < 0)
1149: length = 0;
1150: else
1151: length = length >> BDRV_SECTOR_BITS;
1152: *nb_sectors_ptr = length;
1153: }
1154:
1155: struct partition {
1156: uint8_t boot_ind; /* 0x80 - active */
1157: uint8_t head; /* starting head */
1158: uint8_t sector; /* starting sector */
1159: uint8_t cyl; /* starting cylinder */
1160: uint8_t sys_ind; /* What partition type */
1161: uint8_t end_head; /* end head */
1162: uint8_t end_sector; /* end sector */
1163: uint8_t end_cyl; /* end cylinder */
1164: uint32_t start_sect; /* starting sector counting from 0 */
1165: uint32_t nr_sects; /* nr of sectors in partition */
1166: } __attribute__((packed));
1167:
1168: /* try to guess the disk logical geometry from the MSDOS partition table. Return 0 if OK, -1 if could not guess */
1169: static int guess_disk_lchs(BlockDriverState *bs,
1170: int *pcylinders, int *pheads, int *psectors)
1171: {
1172: uint8_t buf[BDRV_SECTOR_SIZE];
1173: int ret, i, heads, sectors, cylinders;
1174: struct partition *p;
1175: uint32_t nr_sects;
1176: uint64_t nb_sectors;
1177:
1178: bdrv_get_geometry(bs, &nb_sectors);
1179:
1180: ret = bdrv_read(bs, 0, buf, 1);
1181: if (ret < 0)
1182: return -1;
1183: /* test msdos magic */
1184: if (buf[510] != 0x55 || buf[511] != 0xaa)
1185: return -1;
1186: for(i = 0; i < 4; i++) {
1187: p = ((struct partition *)(buf + 0x1be)) + i;
1188: nr_sects = le32_to_cpu(p->nr_sects);
1189: if (nr_sects && p->end_head) {
1190: /* We make the assumption that the partition terminates on
1191: a cylinder boundary */
1192: heads = p->end_head + 1;
1193: sectors = p->end_sector & 63;
1194: if (sectors == 0)
1195: continue;
1196: cylinders = nb_sectors / (heads * sectors);
1197: if (cylinders < 1 || cylinders > 16383)
1198: continue;
1199: *pheads = heads;
1200: *psectors = sectors;
1201: *pcylinders = cylinders;
1202: #if 0
1203: printf("guessed geometry: LCHS=%d %d %d\n",
1204: cylinders, heads, sectors);
1205: #endif
1206: return 0;
1207: }
1208: }
1209: return -1;
1210: }
1211:
1212: void bdrv_guess_geometry(BlockDriverState *bs, int *pcyls, int *pheads, int *psecs)
1213: {
1214: int translation, lba_detected = 0;
1215: int cylinders, heads, secs;
1216: uint64_t nb_sectors;
1217:
1218: /* if a geometry hint is available, use it */
1219: bdrv_get_geometry(bs, &nb_sectors);
1220: bdrv_get_geometry_hint(bs, &cylinders, &heads, &secs);
1221: translation = bdrv_get_translation_hint(bs);
1222: if (cylinders != 0) {
1223: *pcyls = cylinders;
1224: *pheads = heads;
1225: *psecs = secs;
1226: } else {
1227: if (guess_disk_lchs(bs, &cylinders, &heads, &secs) == 0) {
1228: if (heads > 16) {
1229: /* if heads > 16, it means that a BIOS LBA
1230: translation was active, so the default
1231: hardware geometry is OK */
1232: lba_detected = 1;
1233: goto default_geometry;
1234: } else {
1235: *pcyls = cylinders;
1236: *pheads = heads;
1237: *psecs = secs;
1238: /* disable any translation to be in sync with
1239: the logical geometry */
1240: if (translation == BIOS_ATA_TRANSLATION_AUTO) {
1241: bdrv_set_translation_hint(bs,
1242: BIOS_ATA_TRANSLATION_NONE);
1243: }
1244: }
1245: } else {
1246: default_geometry:
1247: /* if no geometry, use a standard physical disk geometry */
1248: cylinders = nb_sectors / (16 * 63);
1249:
1250: if (cylinders > 16383)
1251: cylinders = 16383;
1252: else if (cylinders < 2)
1253: cylinders = 2;
1254: *pcyls = cylinders;
1255: *pheads = 16;
1256: *psecs = 63;
1257: if ((lba_detected == 1) && (translation == BIOS_ATA_TRANSLATION_AUTO)) {
1258: if ((*pcyls * *pheads) <= 131072) {
1259: bdrv_set_translation_hint(bs,
1260: BIOS_ATA_TRANSLATION_LARGE);
1261: } else {
1262: bdrv_set_translation_hint(bs,
1263: BIOS_ATA_TRANSLATION_LBA);
1264: }
1265: }
1266: }
1267: bdrv_set_geometry_hint(bs, *pcyls, *pheads, *psecs);
1268: }
1269: }
1270:
1271: void bdrv_set_geometry_hint(BlockDriverState *bs,
1272: int cyls, int heads, int secs)
1273: {
1274: bs->cyls = cyls;
1275: bs->heads = heads;
1276: bs->secs = secs;
1277: }
1278:
1279: void bdrv_set_type_hint(BlockDriverState *bs, int type)
1280: {
1281: bs->type = type;
1282: bs->removable = ((type == BDRV_TYPE_CDROM ||
1283: type == BDRV_TYPE_FLOPPY));
1284: }
1285:
1286: void bdrv_set_translation_hint(BlockDriverState *bs, int translation)
1287: {
1288: bs->translation = translation;
1289: }
1290:
1291: void bdrv_get_geometry_hint(BlockDriverState *bs,
1292: int *pcyls, int *pheads, int *psecs)
1293: {
1294: *pcyls = bs->cyls;
1295: *pheads = bs->heads;
1296: *psecs = bs->secs;
1297: }
1298:
1299: int bdrv_get_type_hint(BlockDriverState *bs)
1300: {
1301: return bs->type;
1302: }
1303:
1304: int bdrv_get_translation_hint(BlockDriverState *bs)
1305: {
1306: return bs->translation;
1307: }
1308:
1309: void bdrv_set_on_error(BlockDriverState *bs, BlockErrorAction on_read_error,
1310: BlockErrorAction on_write_error)
1311: {
1312: bs->on_read_error = on_read_error;
1313: bs->on_write_error = on_write_error;
1314: }
1315:
1316: BlockErrorAction bdrv_get_on_error(BlockDriverState *bs, int is_read)
1317: {
1318: return is_read ? bs->on_read_error : bs->on_write_error;
1319: }
1320:
1321: void bdrv_set_removable(BlockDriverState *bs, int removable)
1322: {
1323: bs->removable = removable;
1324: if (removable && bs == bs_snapshots) {
1325: bs_snapshots = NULL;
1326: }
1327: }
1328:
1329: int bdrv_is_removable(BlockDriverState *bs)
1330: {
1331: return bs->removable;
1332: }
1333:
1334: int bdrv_is_read_only(BlockDriverState *bs)
1335: {
1336: return bs->read_only;
1337: }
1338:
1339: int bdrv_is_sg(BlockDriverState *bs)
1340: {
1341: return bs->sg;
1342: }
1343:
1344: int bdrv_enable_write_cache(BlockDriverState *bs)
1345: {
1346: return bs->enable_write_cache;
1347: }
1348:
1349: /* XXX: no longer used */
1350: void bdrv_set_change_cb(BlockDriverState *bs,
1351: void (*change_cb)(void *opaque), void *opaque)
1352: {
1353: bs->change_cb = change_cb;
1354: bs->change_opaque = opaque;
1355: }
1356:
1357: int bdrv_is_encrypted(BlockDriverState *bs)
1358: {
1359: if (bs->backing_hd && bs->backing_hd->encrypted)
1360: return 1;
1361: return bs->encrypted;
1362: }
1363:
1364: int bdrv_key_required(BlockDriverState *bs)
1365: {
1366: BlockDriverState *backing_hd = bs->backing_hd;
1367:
1368: if (backing_hd && backing_hd->encrypted && !backing_hd->valid_key)
1369: return 1;
1370: return (bs->encrypted && !bs->valid_key);
1371: }
1372:
1373: int bdrv_set_key(BlockDriverState *bs, const char *key)
1374: {
1375: int ret;
1376: if (bs->backing_hd && bs->backing_hd->encrypted) {
1377: ret = bdrv_set_key(bs->backing_hd, key);
1378: if (ret < 0)
1379: return ret;
1380: if (!bs->encrypted)
1381: return 0;
1382: }
1383: if (!bs->encrypted) {
1384: return -EINVAL;
1385: } else if (!bs->drv || !bs->drv->bdrv_set_key) {
1386: return -ENOMEDIUM;
1387: }
1388: ret = bs->drv->bdrv_set_key(bs, key);
1389: if (ret < 0) {
1390: bs->valid_key = 0;
1391: } else if (!bs->valid_key) {
1392: bs->valid_key = 1;
1393: /* call the change callback now, we skipped it on open */
1394: bs->media_changed = 1;
1395: if (bs->change_cb)
1396: bs->change_cb(bs->change_opaque);
1397: }
1398: return ret;
1399: }
1400:
1401: void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)
1402: {
1403: if (!bs->drv) {
1404: buf[0] = '\0';
1405: } else {
1406: pstrcpy(buf, buf_size, bs->drv->format_name);
1407: }
1408: }
1409:
1410: void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
1411: void *opaque)
1412: {
1413: BlockDriver *drv;
1414:
1415: QLIST_FOREACH(drv, &bdrv_drivers, list) {
1416: it(opaque, drv->format_name);
1417: }
1418: }
1419:
1420: BlockDriverState *bdrv_find(const char *name)
1421: {
1422: BlockDriverState *bs;
1423:
1424: QTAILQ_FOREACH(bs, &bdrv_states, list) {
1425: if (!strcmp(name, bs->device_name)) {
1426: return bs;
1427: }
1428: }
1429: return NULL;
1430: }
1431:
1432: BlockDriverState *bdrv_next(BlockDriverState *bs)
1433: {
1434: if (!bs) {
1435: return QTAILQ_FIRST(&bdrv_states);
1436: }
1437: return QTAILQ_NEXT(bs, list);
1438: }
1439:
1440: void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs), void *opaque)
1441: {
1442: BlockDriverState *bs;
1443:
1444: QTAILQ_FOREACH(bs, &bdrv_states, list) {
1445: it(opaque, bs);
1446: }
1447: }
1448:
1449: const char *bdrv_get_device_name(BlockDriverState *bs)
1450: {
1451: return bs->device_name;
1452: }
1453:
1454: void bdrv_flush(BlockDriverState *bs)
1455: {
1456: if (bs->open_flags & BDRV_O_NO_FLUSH) {
1457: return;
1458: }
1459:
1460: if (bs->drv && bs->drv->bdrv_flush)
1461: bs->drv->bdrv_flush(bs);
1462: }
1463:
1464: void bdrv_flush_all(void)
1465: {
1466: BlockDriverState *bs;
1467:
1468: QTAILQ_FOREACH(bs, &bdrv_states, list) {
1469: if (bs->drv && !bdrv_is_read_only(bs) &&
1470: (!bdrv_is_removable(bs) || bdrv_is_inserted(bs))) {
1471: bdrv_flush(bs);
1472: }
1473: }
1474: }
1475:
1476: int bdrv_has_zero_init(BlockDriverState *bs)
1477: {
1478: assert(bs->drv);
1479:
1480: if (bs->drv->bdrv_has_zero_init) {
1481: return bs->drv->bdrv_has_zero_init(bs);
1482: }
1483:
1484: return 1;
1485: }
1486:
1487: /*
1488: * Returns true iff the specified sector is present in the disk image. Drivers
1489: * not implementing the functionality are assumed to not support backing files,
1490: * hence all their sectors are reported as allocated.
1491: *
1492: * 'pnum' is set to the number of sectors (including and immediately following
1493: * the specified sector) that are known to be in the same
1494: * allocated/unallocated state.
1495: *
1496: * 'nb_sectors' is the max value 'pnum' should be set to.
1497: */
1498: int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
1499: int *pnum)
1500: {
1501: int64_t n;
1502: if (!bs->drv->bdrv_is_allocated) {
1503: if (sector_num >= bs->total_sectors) {
1504: *pnum = 0;
1505: return 0;
1506: }
1507: n = bs->total_sectors - sector_num;
1508: *pnum = (n < nb_sectors) ? (n) : (nb_sectors);
1509: return 1;
1510: }
1511: return bs->drv->bdrv_is_allocated(bs, sector_num, nb_sectors, pnum);
1512: }
1513:
1514: void bdrv_mon_event(const BlockDriverState *bdrv,
1515: BlockMonEventAction action, int is_read)
1516: {
1517: QObject *data;
1518: const char *action_str;
1519:
1520: switch (action) {
1521: case BDRV_ACTION_REPORT:
1522: action_str = "report";
1523: break;
1524: case BDRV_ACTION_IGNORE:
1525: action_str = "ignore";
1526: break;
1527: case BDRV_ACTION_STOP:
1528: action_str = "stop";
1529: break;
1530: default:
1531: abort();
1532: }
1533:
1534: data = qobject_from_jsonf("{ 'device': %s, 'action': %s, 'operation': %s }",
1535: bdrv->device_name,
1536: action_str,
1537: is_read ? "read" : "write");
1538: monitor_protocol_event(QEVENT_BLOCK_IO_ERROR, data);
1539:
1540: qobject_decref(data);
1541: }
1542:
1543: static void bdrv_print_dict(QObject *obj, void *opaque)
1544: {
1545: QDict *bs_dict;
1546: Monitor *mon = opaque;
1547:
1548: bs_dict = qobject_to_qdict(obj);
1549:
1550: monitor_printf(mon, "%s: type=%s removable=%d",
1551: qdict_get_str(bs_dict, "device"),
1552: qdict_get_str(bs_dict, "type"),
1553: qdict_get_bool(bs_dict, "removable"));
1554:
1555: if (qdict_get_bool(bs_dict, "removable")) {
1556: monitor_printf(mon, " locked=%d", qdict_get_bool(bs_dict, "locked"));
1557: }
1558:
1559: if (qdict_haskey(bs_dict, "inserted")) {
1560: QDict *qdict = qobject_to_qdict(qdict_get(bs_dict, "inserted"));
1561:
1562: monitor_printf(mon, " file=");
1563: monitor_print_filename(mon, qdict_get_str(qdict, "file"));
1564: if (qdict_haskey(qdict, "backing_file")) {
1565: monitor_printf(mon, " backing_file=");
1566: monitor_print_filename(mon, qdict_get_str(qdict, "backing_file"));
1567: }
1568: monitor_printf(mon, " ro=%d drv=%s encrypted=%d",
1569: qdict_get_bool(qdict, "ro"),
1570: qdict_get_str(qdict, "drv"),
1571: qdict_get_bool(qdict, "encrypted"));
1572: } else {
1573: monitor_printf(mon, " [not inserted]");
1574: }
1575:
1576: monitor_printf(mon, "\n");
1577: }
1578:
1579: void bdrv_info_print(Monitor *mon, const QObject *data)
1580: {
1581: qlist_iter(qobject_to_qlist(data), bdrv_print_dict, mon);
1582: }
1583:
1584: void bdrv_info(Monitor *mon, QObject **ret_data)
1585: {
1586: QList *bs_list;
1587: BlockDriverState *bs;
1588:
1589: bs_list = qlist_new();
1590:
1591: QTAILQ_FOREACH(bs, &bdrv_states, list) {
1592: QObject *bs_obj;
1593: const char *type = "unknown";
1594:
1595: switch(bs->type) {
1596: case BDRV_TYPE_HD:
1597: type = "hd";
1598: break;
1599: case BDRV_TYPE_CDROM:
1600: type = "cdrom";
1601: break;
1602: case BDRV_TYPE_FLOPPY:
1603: type = "floppy";
1604: break;
1605: }
1606:
1607: bs_obj = qobject_from_jsonf("{ 'device': %s, 'type': %s, "
1608: "'removable': %i, 'locked': %i }",
1609: bs->device_name, type, bs->removable,
1610: bs->locked);
1611:
1612: if (bs->drv) {
1613: QObject *obj;
1614: QDict *bs_dict = qobject_to_qdict(bs_obj);
1615:
1616: obj = qobject_from_jsonf("{ 'file': %s, 'ro': %i, 'drv': %s, "
1617: "'encrypted': %i }",
1618: bs->filename, bs->read_only,
1619: bs->drv->format_name,
1620: bdrv_is_encrypted(bs));
1621: if (bs->backing_file[0] != '\0') {
1622: QDict *qdict = qobject_to_qdict(obj);
1623: qdict_put(qdict, "backing_file",
1624: qstring_from_str(bs->backing_file));
1625: }
1626:
1627: qdict_put_obj(bs_dict, "inserted", obj);
1628: }
1629: qlist_append_obj(bs_list, bs_obj);
1630: }
1631:
1632: *ret_data = QOBJECT(bs_list);
1633: }
1634:
1635: static void bdrv_stats_iter(QObject *data, void *opaque)
1636: {
1637: QDict *qdict;
1638: Monitor *mon = opaque;
1639:
1640: qdict = qobject_to_qdict(data);
1641: monitor_printf(mon, "%s:", qdict_get_str(qdict, "device"));
1642:
1643: qdict = qobject_to_qdict(qdict_get(qdict, "stats"));
1644: monitor_printf(mon, " rd_bytes=%" PRId64
1645: " wr_bytes=%" PRId64
1646: " rd_operations=%" PRId64
1647: " wr_operations=%" PRId64
1648: "\n",
1649: qdict_get_int(qdict, "rd_bytes"),
1650: qdict_get_int(qdict, "wr_bytes"),
1651: qdict_get_int(qdict, "rd_operations"),
1652: qdict_get_int(qdict, "wr_operations"));
1653: }
1654:
1655: void bdrv_stats_print(Monitor *mon, const QObject *data)
1656: {
1657: qlist_iter(qobject_to_qlist(data), bdrv_stats_iter, mon);
1658: }
1659:
1660: static QObject* bdrv_info_stats_bs(BlockDriverState *bs)
1661: {
1662: QObject *res;
1663: QDict *dict;
1664:
1665: res = qobject_from_jsonf("{ 'stats': {"
1666: "'rd_bytes': %" PRId64 ","
1667: "'wr_bytes': %" PRId64 ","
1668: "'rd_operations': %" PRId64 ","
1669: "'wr_operations': %" PRId64 ","
1670: "'wr_highest_offset': %" PRId64
1671: "} }",
1672: bs->rd_bytes, bs->wr_bytes,
1673: bs->rd_ops, bs->wr_ops,
1674: bs->wr_highest_sector *
1675: (uint64_t)BDRV_SECTOR_SIZE);
1676: dict = qobject_to_qdict(res);
1677:
1678: if (*bs->device_name) {
1679: qdict_put(dict, "device", qstring_from_str(bs->device_name));
1680: }
1681:
1682: if (bs->file) {
1683: QObject *parent = bdrv_info_stats_bs(bs->file);
1684: qdict_put_obj(dict, "parent", parent);
1685: }
1686:
1687: return res;
1688: }
1689:
1690: void bdrv_info_stats(Monitor *mon, QObject **ret_data)
1691: {
1692: QObject *obj;
1693: QList *devices;
1694: BlockDriverState *bs;
1695:
1696: devices = qlist_new();
1697:
1698: QTAILQ_FOREACH(bs, &bdrv_states, list) {
1699: obj = bdrv_info_stats_bs(bs);
1700: qlist_append_obj(devices, obj);
1701: }
1702:
1703: *ret_data = QOBJECT(devices);
1704: }
1705:
1706: const char *bdrv_get_encrypted_filename(BlockDriverState *bs)
1707: {
1708: if (bs->backing_hd && bs->backing_hd->encrypted)
1709: return bs->backing_file;
1710: else if (bs->encrypted)
1711: return bs->filename;
1712: else
1713: return NULL;
1714: }
1715:
1716: void bdrv_get_backing_filename(BlockDriverState *bs,
1717: char *filename, int filename_size)
1718: {
1719: if (!bs->backing_file) {
1720: pstrcpy(filename, filename_size, "");
1721: } else {
1722: pstrcpy(filename, filename_size, bs->backing_file);
1723: }
1724: }
1725:
1726: int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
1727: const uint8_t *buf, int nb_sectors)
1728: {
1729: BlockDriver *drv = bs->drv;
1730: if (!drv)
1731: return -ENOMEDIUM;
1732: if (!drv->bdrv_write_compressed)
1733: return -ENOTSUP;
1734: if (bdrv_check_request(bs, sector_num, nb_sectors))
1735: return -EIO;
1736:
1737: if (bs->dirty_bitmap) {
1738: set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
1739: }
1740:
1741: return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
1742: }
1743:
1744: int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
1745: {
1746: BlockDriver *drv = bs->drv;
1747: if (!drv)
1748: return -ENOMEDIUM;
1749: if (!drv->bdrv_get_info)
1750: return -ENOTSUP;
1751: memset(bdi, 0, sizeof(*bdi));
1752: return drv->bdrv_get_info(bs, bdi);
1753: }
1754:
1755: int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
1756: int64_t pos, int size)
1757: {
1758: BlockDriver *drv = bs->drv;
1759: if (!drv)
1760: return -ENOMEDIUM;
1761: if (drv->bdrv_save_vmstate)
1762: return drv->bdrv_save_vmstate(bs, buf, pos, size);
1763: if (bs->file)
1764: return bdrv_save_vmstate(bs->file, buf, pos, size);
1765: return -ENOTSUP;
1766: }
1767:
1768: int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
1769: int64_t pos, int size)
1770: {
1771: BlockDriver *drv = bs->drv;
1772: if (!drv)
1773: return -ENOMEDIUM;
1774: if (drv->bdrv_load_vmstate)
1775: return drv->bdrv_load_vmstate(bs, buf, pos, size);
1776: if (bs->file)
1777: return bdrv_load_vmstate(bs->file, buf, pos, size);
1778: return -ENOTSUP;
1779: }
1780:
1781: void bdrv_debug_event(BlockDriverState *bs, BlkDebugEvent event)
1782: {
1783: BlockDriver *drv = bs->drv;
1784:
1785: if (!drv || !drv->bdrv_debug_event) {
1786: return;
1787: }
1788:
1789: return drv->bdrv_debug_event(bs, event);
1790:
1791: }
1792:
1793: /**************************************************************/
1794: /* handling of snapshots */
1795:
1796: int bdrv_can_snapshot(BlockDriverState *bs)
1797: {
1798: BlockDriver *drv = bs->drv;
1799: if (!drv || bdrv_is_removable(bs) || bdrv_is_read_only(bs)) {
1800: return 0;
1801: }
1802:
1803: if (!drv->bdrv_snapshot_create) {
1804: if (bs->file != NULL) {
1805: return bdrv_can_snapshot(bs->file);
1806: }
1807: return 0;
1808: }
1809:
1810: return 1;
1811: }
1812:
1813: int bdrv_is_snapshot(BlockDriverState *bs)
1814: {
1815: return !!(bs->open_flags & BDRV_O_SNAPSHOT);
1816: }
1817:
1818: BlockDriverState *bdrv_snapshots(void)
1819: {
1820: BlockDriverState *bs;
1821:
1822: if (bs_snapshots) {
1823: return bs_snapshots;
1824: }
1825:
1826: bs = NULL;
1827: while ((bs = bdrv_next(bs))) {
1828: if (bdrv_can_snapshot(bs)) {
1829: bs_snapshots = bs;
1830: return bs;
1831: }
1832: }
1833: return NULL;
1834: }
1835:
1836: int bdrv_snapshot_create(BlockDriverState *bs,
1837: QEMUSnapshotInfo *sn_info)
1838: {
1839: BlockDriver *drv = bs->drv;
1840: if (!drv)
1841: return -ENOMEDIUM;
1842: if (drv->bdrv_snapshot_create)
1843: return drv->bdrv_snapshot_create(bs, sn_info);
1844: if (bs->file)
1845: return bdrv_snapshot_create(bs->file, sn_info);
1846: return -ENOTSUP;
1847: }
1848:
1849: int bdrv_snapshot_goto(BlockDriverState *bs,
1850: const char *snapshot_id)
1851: {
1852: BlockDriver *drv = bs->drv;
1853: int ret, open_ret;
1854:
1855: if (!drv)
1856: return -ENOMEDIUM;
1857: if (drv->bdrv_snapshot_goto)
1858: return drv->bdrv_snapshot_goto(bs, snapshot_id);
1859:
1860: if (bs->file) {
1861: drv->bdrv_close(bs);
1862: ret = bdrv_snapshot_goto(bs->file, snapshot_id);
1863: open_ret = drv->bdrv_open(bs, bs->open_flags);
1864: if (open_ret < 0) {
1865: bdrv_delete(bs->file);
1866: bs->drv = NULL;
1867: return open_ret;
1868: }
1869: return ret;
1870: }
1871:
1872: return -ENOTSUP;
1873: }
1874:
1875: int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
1876: {
1877: BlockDriver *drv = bs->drv;
1878: if (!drv)
1879: return -ENOMEDIUM;
1880: if (drv->bdrv_snapshot_delete)
1881: return drv->bdrv_snapshot_delete(bs, snapshot_id);
1882: if (bs->file)
1883: return bdrv_snapshot_delete(bs->file, snapshot_id);
1884: return -ENOTSUP;
1885: }
1886:
1887: int bdrv_snapshot_list(BlockDriverState *bs,
1888: QEMUSnapshotInfo **psn_info)
1889: {
1890: BlockDriver *drv = bs->drv;
1891: if (!drv)
1892: return -ENOMEDIUM;
1893: if (drv->bdrv_snapshot_list)
1894: return drv->bdrv_snapshot_list(bs, psn_info);
1895: if (bs->file)
1896: return bdrv_snapshot_list(bs->file, psn_info);
1897: return -ENOTSUP;
1898: }
1899:
1900: #define NB_SUFFIXES 4
1901:
1902: char *get_human_readable_size(char *buf, int buf_size, int64_t size)
1903: {
1904: static const char suffixes[NB_SUFFIXES] = "KMGT";
1905: int64_t base;
1906: int i;
1907:
1908: if (size <= 999) {
1909: snprintf(buf, buf_size, "%" PRId64, size);
1910: } else {
1911: base = 1024;
1912: for(i = 0; i < NB_SUFFIXES; i++) {
1913: if (size < (10 * base)) {
1914: snprintf(buf, buf_size, "%0.1f%c",
1915: (double)size / base,
1916: suffixes[i]);
1917: break;
1918: } else if (size < (1000 * base) || i == (NB_SUFFIXES - 1)) {
1919: snprintf(buf, buf_size, "%" PRId64 "%c",
1920: ((size + (base >> 1)) / base),
1921: suffixes[i]);
1922: break;
1923: }
1924: base = base * 1024;
1925: }
1926: }
1927: return buf;
1928: }
1929:
1930: char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn)
1931: {
1932: char buf1[128], date_buf[128], clock_buf[128];
1933: #ifdef _WIN32
1934: struct tm *ptm;
1935: #else
1936: struct tm tm;
1937: #endif
1938: time_t ti;
1939: int64_t secs;
1940:
1941: if (!sn) {
1942: snprintf(buf, buf_size,
1943: "%-10s%-20s%7s%20s%15s",
1944: "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK");
1945: } else {
1946: ti = sn->date_sec;
1947: #ifdef _WIN32
1948: ptm = localtime(&ti);
1949: strftime(date_buf, sizeof(date_buf),
1950: "%Y-%m-%d %H:%M:%S", ptm);
1951: #else
1952: localtime_r(&ti, &tm);
1953: strftime(date_buf, sizeof(date_buf),
1954: "%Y-%m-%d %H:%M:%S", &tm);
1955: #endif
1956: secs = sn->vm_clock_nsec / 1000000000;
1957: snprintf(clock_buf, sizeof(clock_buf),
1958: "%02d:%02d:%02d.%03d",
1959: (int)(secs / 3600),
1960: (int)((secs / 60) % 60),
1961: (int)(secs % 60),
1962: (int)((sn->vm_clock_nsec / 1000000) % 1000));
1963: snprintf(buf, buf_size,
1964: "%-10s%-20s%7s%20s%15s",
1965: sn->id_str, sn->name,
1966: get_human_readable_size(buf1, sizeof(buf1), sn->vm_state_size),
1967: date_buf,
1968: clock_buf);
1969: }
1970: return buf;
1971: }
1972:
1973:
1974: /**************************************************************/
1975: /* async I/Os */
1976:
1977: BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
1978: QEMUIOVector *qiov, int nb_sectors,
1979: BlockDriverCompletionFunc *cb, void *opaque)
1980: {
1981: BlockDriver *drv = bs->drv;
1982: BlockDriverAIOCB *ret;
1983:
1984: if (!drv)
1985: return NULL;
1986: if (bdrv_check_request(bs, sector_num, nb_sectors))
1987: return NULL;
1988:
1989: ret = drv->bdrv_aio_readv(bs, sector_num, qiov, nb_sectors,
1990: cb, opaque);
1991:
1992: if (ret) {
1993: /* Update stats even though technically transfer has not happened. */
1994: bs->rd_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE;
1995: bs->rd_ops ++;
1996: }
1997:
1998: return ret;
1999: }
2000:
2001: BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
2002: QEMUIOVector *qiov, int nb_sectors,
2003: BlockDriverCompletionFunc *cb, void *opaque)
2004: {
2005: BlockDriver *drv = bs->drv;
2006: BlockDriverAIOCB *ret;
2007:
2008: if (!drv)
2009: return NULL;
2010: if (bs->read_only)
2011: return NULL;
2012: if (bdrv_check_request(bs, sector_num, nb_sectors))
2013: return NULL;
2014:
2015: if (bs->dirty_bitmap) {
2016: set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
2017: }
2018:
2019: ret = drv->bdrv_aio_writev(bs, sector_num, qiov, nb_sectors,
2020: cb, opaque);
2021:
2022: if (ret) {
2023: /* Update stats even though technically transfer has not happened. */
2024: bs->wr_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE;
2025: bs->wr_ops ++;
2026: if (bs->wr_highest_sector < sector_num + nb_sectors - 1) {
2027: bs->wr_highest_sector = sector_num + nb_sectors - 1;
2028: }
2029: }
2030:
2031: return ret;
2032: }
2033:
2034:
2035: typedef struct MultiwriteCB {
2036: int error;
2037: int num_requests;
2038: int num_callbacks;
2039: struct {
2040: BlockDriverCompletionFunc *cb;
2041: void *opaque;
2042: QEMUIOVector *free_qiov;
2043: void *free_buf;
2044: } callbacks[];
2045: } MultiwriteCB;
2046:
2047: static void multiwrite_user_cb(MultiwriteCB *mcb)
2048: {
2049: int i;
2050:
2051: for (i = 0; i < mcb->num_callbacks; i++) {
2052: mcb->callbacks[i].cb(mcb->callbacks[i].opaque, mcb->error);
2053: if (mcb->callbacks[i].free_qiov) {
2054: qemu_iovec_destroy(mcb->callbacks[i].free_qiov);
2055: }
2056: qemu_free(mcb->callbacks[i].free_qiov);
2057: qemu_vfree(mcb->callbacks[i].free_buf);
2058: }
2059: }
2060:
2061: static void multiwrite_cb(void *opaque, int ret)
2062: {
2063: MultiwriteCB *mcb = opaque;
2064:
2065: if (ret < 0 && !mcb->error) {
2066: mcb->error = ret;
2067: }
2068:
2069: mcb->num_requests--;
2070: if (mcb->num_requests == 0) {
2071: multiwrite_user_cb(mcb);
2072: qemu_free(mcb);
2073: }
2074: }
2075:
2076: static int multiwrite_req_compare(const void *a, const void *b)
2077: {
2078: const BlockRequest *req1 = a, *req2 = b;
2079:
2080: /*
2081: * Note that we can't simply subtract req2->sector from req1->sector
2082: * here as that could overflow the return value.
2083: */
2084: if (req1->sector > req2->sector) {
2085: return 1;
2086: } else if (req1->sector < req2->sector) {
2087: return -1;
2088: } else {
2089: return 0;
2090: }
2091: }
2092:
2093: /*
2094: * Takes a bunch of requests and tries to merge them. Returns the number of
2095: * requests that remain after merging.
2096: */
2097: static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs,
2098: int num_reqs, MultiwriteCB *mcb)
2099: {
2100: int i, outidx;
2101:
2102: // Sort requests by start sector
2103: qsort(reqs, num_reqs, sizeof(*reqs), &multiwrite_req_compare);
2104:
2105: // Check if adjacent requests touch the same clusters. If so, combine them,
2106: // filling up gaps with zero sectors.
2107: outidx = 0;
2108: for (i = 1; i < num_reqs; i++) {
2109: int merge = 0;
2110: int64_t oldreq_last = reqs[outidx].sector + reqs[outidx].nb_sectors;
2111:
2112: // This handles the cases that are valid for all block drivers, namely
2113: // exactly sequential writes and overlapping writes.
2114: if (reqs[i].sector <= oldreq_last) {
2115: merge = 1;
2116: }
2117:
2118: // The block driver may decide that it makes sense to combine requests
2119: // even if there is a gap of some sectors between them. In this case,
2120: // the gap is filled with zeros (therefore only applicable for yet
2121: // unused space in format like qcow2).
2122: if (!merge && bs->drv->bdrv_merge_requests) {
2123: merge = bs->drv->bdrv_merge_requests(bs, &reqs[outidx], &reqs[i]);
2124: }
2125:
2126: if (reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1 > IOV_MAX) {
2127: merge = 0;
2128: }
2129:
2130: if (merge) {
2131: size_t size;
2132: QEMUIOVector *qiov = qemu_mallocz(sizeof(*qiov));
2133: qemu_iovec_init(qiov,
2134: reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1);
2135:
2136: // Add the first request to the merged one. If the requests are
2137: // overlapping, drop the last sectors of the first request.
2138: size = (reqs[i].sector - reqs[outidx].sector) << 9;
2139: qemu_iovec_concat(qiov, reqs[outidx].qiov, size);
2140:
2141: // We might need to add some zeros between the two requests
2142: if (reqs[i].sector > oldreq_last) {
2143: size_t zero_bytes = (reqs[i].sector - oldreq_last) << 9;
2144: uint8_t *buf = qemu_blockalign(bs, zero_bytes);
2145: memset(buf, 0, zero_bytes);
2146: qemu_iovec_add(qiov, buf, zero_bytes);
2147: mcb->callbacks[i].free_buf = buf;
2148: }
2149:
2150: // Add the second request
2151: qemu_iovec_concat(qiov, reqs[i].qiov, reqs[i].qiov->size);
2152:
2153: reqs[outidx].nb_sectors = qiov->size >> 9;
2154: reqs[outidx].qiov = qiov;
2155:
2156: mcb->callbacks[i].free_qiov = reqs[outidx].qiov;
2157: } else {
2158: outidx++;
2159: reqs[outidx].sector = reqs[i].sector;
2160: reqs[outidx].nb_sectors = reqs[i].nb_sectors;
2161: reqs[outidx].qiov = reqs[i].qiov;
2162: }
2163: }
2164:
2165: return outidx + 1;
2166: }
2167:
2168: /*
2169: * Submit multiple AIO write requests at once.
2170: *
2171: * On success, the function returns 0 and all requests in the reqs array have
2172: * been submitted. In error case this function returns -1, and any of the
2173: * requests may or may not be submitted yet. In particular, this means that the
2174: * callback will be called for some of the requests, for others it won't. The
2175: * caller must check the error field of the BlockRequest to wait for the right
2176: * callbacks (if error != 0, no callback will be called).
2177: *
2178: * The implementation may modify the contents of the reqs array, e.g. to merge
2179: * requests. However, the fields opaque and error are left unmodified as they
2180: * are used to signal failure for a single request to the caller.
2181: */
2182: int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs)
2183: {
2184: BlockDriverAIOCB *acb;
2185: MultiwriteCB *mcb;
2186: int i;
2187:
2188: if (num_reqs == 0) {
2189: return 0;
2190: }
2191:
2192: // Create MultiwriteCB structure
2193: mcb = qemu_mallocz(sizeof(*mcb) + num_reqs * sizeof(*mcb->callbacks));
2194: mcb->num_requests = 0;
2195: mcb->num_callbacks = num_reqs;
2196:
2197: for (i = 0; i < num_reqs; i++) {
2198: mcb->callbacks[i].cb = reqs[i].cb;
2199: mcb->callbacks[i].opaque = reqs[i].opaque;
2200: }
2201:
2202: // Check for mergable requests
2203: num_reqs = multiwrite_merge(bs, reqs, num_reqs, mcb);
2204:
2205: /*
2206: * Run the aio requests. As soon as one request can't be submitted
2207: * successfully, fail all requests that are not yet submitted (we must
2208: * return failure for all requests anyway)
2209: *
2210: * num_requests cannot be set to the right value immediately: If
2211: * bdrv_aio_writev fails for some request, num_requests would be too high
2212: * and therefore multiwrite_cb() would never recognize the multiwrite
2213: * request as completed. We also cannot use the loop variable i to set it
2214: * when the first request fails because the callback may already have been
2215: * called for previously submitted requests. Thus, num_requests must be
2216: * incremented for each request that is submitted.
2217: *
2218: * The problem that callbacks may be called early also means that we need
2219: * to take care that num_requests doesn't become 0 before all requests are
2220: * submitted - multiwrite_cb() would consider the multiwrite request
2221: * completed. A dummy request that is "completed" by a manual call to
2222: * multiwrite_cb() takes care of this.
2223: */
2224: mcb->num_requests = 1;
2225:
2226: for (i = 0; i < num_reqs; i++) {
2227: mcb->num_requests++;
2228: acb = bdrv_aio_writev(bs, reqs[i].sector, reqs[i].qiov,
2229: reqs[i].nb_sectors, multiwrite_cb, mcb);
2230:
2231: if (acb == NULL) {
2232: // We can only fail the whole thing if no request has been
2233: // submitted yet. Otherwise we'll wait for the submitted AIOs to
2234: // complete and report the error in the callback.
2235: if (i == 0) {
2236: goto fail;
2237: } else {
2238: multiwrite_cb(mcb, -EIO);
2239: break;
2240: }
2241: }
2242: }
2243:
2244: /* Complete the dummy request */
2245: multiwrite_cb(mcb, 0);
2246:
2247: return 0;
2248:
2249: fail:
2250: for (i = 0; i < mcb->num_callbacks; i++) {
2251: reqs[i].error = -EIO;
2252: }
2253: qemu_free(mcb);
2254: return -1;
2255: }
2256:
2257: BlockDriverAIOCB *bdrv_aio_flush(BlockDriverState *bs,
2258: BlockDriverCompletionFunc *cb, void *opaque)
2259: {
2260: BlockDriver *drv = bs->drv;
2261:
2262: if (bs->open_flags & BDRV_O_NO_FLUSH) {
2263: return bdrv_aio_noop_em(bs, cb, opaque);
2264: }
2265:
2266: if (!drv)
2267: return NULL;
2268: return drv->bdrv_aio_flush(bs, cb, opaque);
2269: }
2270:
2271: void bdrv_aio_cancel(BlockDriverAIOCB *acb)
2272: {
2273: acb->pool->cancel(acb);
2274: }
2275:
2276:
2277: /**************************************************************/
2278: /* async block device emulation */
2279:
2280: typedef struct BlockDriverAIOCBSync {
2281: BlockDriverAIOCB common;
2282: QEMUBH *bh;
2283: int ret;
2284: /* vector translation state */
2285: QEMUIOVector *qiov;
2286: uint8_t *bounce;
2287: int is_write;
2288: } BlockDriverAIOCBSync;
2289:
2290: static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb)
2291: {
2292: BlockDriverAIOCBSync *acb =
2293: container_of(blockacb, BlockDriverAIOCBSync, common);
2294: qemu_bh_delete(acb->bh);
2295: acb->bh = NULL;
2296: qemu_aio_release(acb);
2297: }
2298:
2299: static AIOPool bdrv_em_aio_pool = {
2300: .aiocb_size = sizeof(BlockDriverAIOCBSync),
2301: .cancel = bdrv_aio_cancel_em,
2302: };
2303:
2304: static void bdrv_aio_bh_cb(void *opaque)
2305: {
2306: BlockDriverAIOCBSync *acb = opaque;
2307:
2308: if (!acb->is_write)
2309: qemu_iovec_from_buffer(acb->qiov, acb->bounce, acb->qiov->size);
2310: qemu_vfree(acb->bounce);
2311: acb->common.cb(acb->common.opaque, acb->ret);
2312: qemu_bh_delete(acb->bh);
2313: acb->bh = NULL;
2314: qemu_aio_release(acb);
2315: }
2316:
2317: static BlockDriverAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs,
2318: int64_t sector_num,
2319: QEMUIOVector *qiov,
2320: int nb_sectors,
2321: BlockDriverCompletionFunc *cb,
2322: void *opaque,
2323: int is_write)
2324:
2325: {
2326: BlockDriverAIOCBSync *acb;
2327:
2328: acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
2329: acb->is_write = is_write;
2330: acb->qiov = qiov;
2331: acb->bounce = qemu_blockalign(bs, qiov->size);
2332:
2333: if (!acb->bh)
2334: acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
2335:
2336: if (is_write) {
2337: qemu_iovec_to_buffer(acb->qiov, acb->bounce);
2338: acb->ret = bdrv_write(bs, sector_num, acb->bounce, nb_sectors);
2339: } else {
2340: acb->ret = bdrv_read(bs, sector_num, acb->bounce, nb_sectors);
2341: }
2342:
2343: qemu_bh_schedule(acb->bh);
2344:
2345: return &acb->common;
2346: }
2347:
2348: static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
2349: int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
2350: BlockDriverCompletionFunc *cb, void *opaque)
2351: {
2352: return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
2353: }
2354:
2355: static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
2356: int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
2357: BlockDriverCompletionFunc *cb, void *opaque)
2358: {
2359: return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
2360: }
2361:
2362: static BlockDriverAIOCB *bdrv_aio_flush_em(BlockDriverState *bs,
2363: BlockDriverCompletionFunc *cb, void *opaque)
2364: {
2365: BlockDriverAIOCBSync *acb;
2366:
2367: acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
2368: acb->is_write = 1; /* don't bounce in the completion hadler */
2369: acb->qiov = NULL;
2370: acb->bounce = NULL;
2371: acb->ret = 0;
2372:
2373: if (!acb->bh)
2374: acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
2375:
2376: bdrv_flush(bs);
2377: qemu_bh_schedule(acb->bh);
2378: return &acb->common;
2379: }
2380:
2381: static BlockDriverAIOCB *bdrv_aio_noop_em(BlockDriverState *bs,
2382: BlockDriverCompletionFunc *cb, void *opaque)
2383: {
2384: BlockDriverAIOCBSync *acb;
2385:
2386: acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
2387: acb->is_write = 1; /* don't bounce in the completion handler */
2388: acb->qiov = NULL;
2389: acb->bounce = NULL;
2390: acb->ret = 0;
2391:
2392: if (!acb->bh) {
2393: acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
2394: }
2395:
2396: qemu_bh_schedule(acb->bh);
2397: return &acb->common;
2398: }
2399:
2400: /**************************************************************/
2401: /* sync block device emulation */
2402:
2403: static void bdrv_rw_em_cb(void *opaque, int ret)
2404: {
2405: *(int *)opaque = ret;
2406: }
2407:
2408: #define NOT_DONE 0x7fffffff
2409:
2410: static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
2411: uint8_t *buf, int nb_sectors)
2412: {
2413: int async_ret;
2414: BlockDriverAIOCB *acb;
2415: struct iovec iov;
2416: QEMUIOVector qiov;
2417:
2418: async_context_push();
2419:
2420: async_ret = NOT_DONE;
2421: iov.iov_base = (void *)buf;
2422: iov.iov_len = nb_sectors * BDRV_SECTOR_SIZE;
2423: qemu_iovec_init_external(&qiov, &iov, 1);
2424: acb = bdrv_aio_readv(bs, sector_num, &qiov, nb_sectors,
2425: bdrv_rw_em_cb, &async_ret);
2426: if (acb == NULL) {
2427: async_ret = -1;
2428: goto fail;
2429: }
2430:
2431: while (async_ret == NOT_DONE) {
2432: qemu_aio_wait();
2433: }
2434:
2435:
2436: fail:
2437: async_context_pop();
2438: return async_ret;
2439: }
2440:
2441: static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
2442: const uint8_t *buf, int nb_sectors)
2443: {
2444: int async_ret;
2445: BlockDriverAIOCB *acb;
2446: struct iovec iov;
2447: QEMUIOVector qiov;
2448:
2449: async_context_push();
2450:
2451: async_ret = NOT_DONE;
2452: iov.iov_base = (void *)buf;
2453: iov.iov_len = nb_sectors * BDRV_SECTOR_SIZE;
2454: qemu_iovec_init_external(&qiov, &iov, 1);
2455: acb = bdrv_aio_writev(bs, sector_num, &qiov, nb_sectors,
2456: bdrv_rw_em_cb, &async_ret);
2457: if (acb == NULL) {
2458: async_ret = -1;
2459: goto fail;
2460: }
2461: while (async_ret == NOT_DONE) {
2462: qemu_aio_wait();
2463: }
2464:
2465: fail:
2466: async_context_pop();
2467: return async_ret;
2468: }
2469:
2470: void bdrv_init(void)
2471: {
2472: module_call_init(MODULE_INIT_BLOCK);
2473: }
2474:
2475: void bdrv_init_with_whitelist(void)
2476: {
2477: use_bdrv_whitelist = 1;
2478: bdrv_init();
2479: }
2480:
2481: void *qemu_aio_get(AIOPool *pool, BlockDriverState *bs,
2482: BlockDriverCompletionFunc *cb, void *opaque)
2483: {
2484: BlockDriverAIOCB *acb;
2485:
2486: if (pool->free_aiocb) {
2487: acb = pool->free_aiocb;
2488: pool->free_aiocb = acb->next;
2489: } else {
2490: acb = qemu_mallocz(pool->aiocb_size);
2491: acb->pool = pool;
2492: }
2493: acb->bs = bs;
2494: acb->cb = cb;
2495: acb->opaque = opaque;
2496: return acb;
2497: }
2498:
2499: void qemu_aio_release(void *p)
2500: {
2501: BlockDriverAIOCB *acb = (BlockDriverAIOCB *)p;
2502: AIOPool *pool = acb->pool;
2503: acb->next = pool->free_aiocb;
2504: pool->free_aiocb = acb;
2505: }
2506:
2507: /**************************************************************/
2508: /* removable device support */
2509:
2510: /**
2511: * Return TRUE if the media is present
2512: */
2513: int bdrv_is_inserted(BlockDriverState *bs)
2514: {
2515: BlockDriver *drv = bs->drv;
2516: int ret;
2517: if (!drv)
2518: return 0;
2519: if (!drv->bdrv_is_inserted)
2520: return !bs->tray_open;
2521: ret = drv->bdrv_is_inserted(bs);
2522: return ret;
2523: }
2524:
2525: /**
2526: * Return TRUE if the media changed since the last call to this
2527: * function. It is currently only used for floppy disks
2528: */
2529: int bdrv_media_changed(BlockDriverState *bs)
2530: {
2531: BlockDriver *drv = bs->drv;
2532: int ret;
2533:
2534: if (!drv || !drv->bdrv_media_changed)
2535: ret = -ENOTSUP;
2536: else
2537: ret = drv->bdrv_media_changed(bs);
2538: if (ret == -ENOTSUP)
2539: ret = bs->media_changed;
2540: bs->media_changed = 0;
2541: return ret;
2542: }
2543:
2544: /**
2545: * If eject_flag is TRUE, eject the media. Otherwise, close the tray
2546: */
2547: int bdrv_eject(BlockDriverState *bs, int eject_flag)
2548: {
2549: BlockDriver *drv = bs->drv;
2550: int ret;
2551:
2552: if (bs->locked) {
2553: return -EBUSY;
2554: }
2555:
2556: if (!drv || !drv->bdrv_eject) {
2557: ret = -ENOTSUP;
2558: } else {
2559: ret = drv->bdrv_eject(bs, eject_flag);
2560: }
2561: if (ret == -ENOTSUP) {
2562: ret = 0;
2563: }
2564: if (ret >= 0) {
2565: bs->tray_open = eject_flag;
2566: }
2567:
2568: return ret;
2569: }
2570:
2571: int bdrv_is_locked(BlockDriverState *bs)
2572: {
2573: return bs->locked;
2574: }
2575:
2576: /**
2577: * Lock or unlock the media (if it is locked, the user won't be able
2578: * to eject it manually).
2579: */
2580: void bdrv_set_locked(BlockDriverState *bs, int locked)
2581: {
2582: BlockDriver *drv = bs->drv;
2583:
2584: bs->locked = locked;
2585: if (drv && drv->bdrv_set_locked) {
2586: drv->bdrv_set_locked(bs, locked);
2587: }
2588: }
2589:
2590: /* needed for generic scsi interface */
2591:
2592: int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
2593: {
2594: BlockDriver *drv = bs->drv;
2595:
2596: if (drv && drv->bdrv_ioctl)
2597: return drv->bdrv_ioctl(bs, req, buf);
2598: return -ENOTSUP;
2599: }
2600:
2601: BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
2602: unsigned long int req, void *buf,
2603: BlockDriverCompletionFunc *cb, void *opaque)
2604: {
2605: BlockDriver *drv = bs->drv;
2606:
2607: if (drv && drv->bdrv_aio_ioctl)
2608: return drv->bdrv_aio_ioctl(bs, req, buf, cb, opaque);
2609: return NULL;
2610: }
2611:
2612:
2613:
2614: void *qemu_blockalign(BlockDriverState *bs, size_t size)
2615: {
2616: return qemu_memalign((bs && bs->buffer_alignment) ? bs->buffer_alignment : 512, size);
2617: }
2618:
2619: void bdrv_set_dirty_tracking(BlockDriverState *bs, int enable)
2620: {
2621: int64_t bitmap_size;
2622:
2623: bs->dirty_count = 0;
2624: if (enable) {
2625: if (!bs->dirty_bitmap) {
2626: bitmap_size = (bdrv_getlength(bs) >> BDRV_SECTOR_BITS) +
2627: BDRV_SECTORS_PER_DIRTY_CHUNK * 8 - 1;
2628: bitmap_size /= BDRV_SECTORS_PER_DIRTY_CHUNK * 8;
2629:
2630: bs->dirty_bitmap = qemu_mallocz(bitmap_size);
2631: }
2632: } else {
2633: if (bs->dirty_bitmap) {
2634: qemu_free(bs->dirty_bitmap);
2635: bs->dirty_bitmap = NULL;
2636: }
2637: }
2638: }
2639:
2640: int bdrv_get_dirty(BlockDriverState *bs, int64_t sector)
2641: {
2642: int64_t chunk = sector / (int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK;
2643:
2644: if (bs->dirty_bitmap &&
2645: (sector << BDRV_SECTOR_BITS) < bdrv_getlength(bs)) {
2646: return bs->dirty_bitmap[chunk / (sizeof(unsigned long) * 8)] &
2647: (1 << (chunk % (sizeof(unsigned long) * 8)));
2648: } else {
2649: return 0;
2650: }
2651: }
2652:
2653: void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector,
2654: int nr_sectors)
2655: {
2656: set_dirty_bitmap(bs, cur_sector, nr_sectors, 0);
2657: }
2658:
2659: int64_t bdrv_get_dirty_count(BlockDriverState *bs)
2660: {
2661: return bs->dirty_count;
2662: }
unix.superglobalmegacorp.com
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