File:  [Qemu by Fabrice Bellard] / qemu / block.c
Revision 1.1.1.20 (vendor branch): download - view: text, annotated - select for diffs
Tue Apr 24 18:43:37 2018 UTC (19 months, 2 weeks ago) by root
Branches: qemu, MAIN
CVS tags: qemu0150, qemu0141, HEAD
qemu 0.14.1

    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 "trace.h"
   27: #include "monitor.h"
   28: #include "block_int.h"
   29: #include "module.h"
   30: #include "qemu-objects.h"
   31: 
   32: #ifdef CONFIG_BSD
   33: #include <sys/types.h>
   34: #include <sys/stat.h>
   35: #include <sys/ioctl.h>
   36: #include <sys/queue.h>
   37: #ifndef __DragonFly__
   38: #include <sys/disk.h>
   39: #endif
   40: #endif
   41: 
   42: #ifdef _WIN32
   43: #include <windows.h>
   44: #endif
   45: 
   46: static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
   47:         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
   48:         BlockDriverCompletionFunc *cb, void *opaque);
   49: static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
   50:         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
   51:         BlockDriverCompletionFunc *cb, void *opaque);
   52: static BlockDriverAIOCB *bdrv_aio_flush_em(BlockDriverState *bs,
   53:         BlockDriverCompletionFunc *cb, void *opaque);
   54: static BlockDriverAIOCB *bdrv_aio_noop_em(BlockDriverState *bs,
   55:         BlockDriverCompletionFunc *cb, void *opaque);
   56: static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
   57:                         uint8_t *buf, int nb_sectors);
   58: static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
   59:                          const uint8_t *buf, int nb_sectors);
   60: 
   61: static QTAILQ_HEAD(, BlockDriverState) bdrv_states =
   62:     QTAILQ_HEAD_INITIALIZER(bdrv_states);
   63: 
   64: static QLIST_HEAD(, BlockDriver) bdrv_drivers =
   65:     QLIST_HEAD_INITIALIZER(bdrv_drivers);
   66: 
   67: /* The device to use for VM snapshots */
   68: static BlockDriverState *bs_snapshots;
   69: 
   70: /* If non-zero, use only whitelisted block drivers */
   71: static int use_bdrv_whitelist;
   72: 
   73: #ifdef _WIN32
   74: static int is_windows_drive_prefix(const char *filename)
   75: {
   76:     return (((filename[0] >= 'a' && filename[0] <= 'z') ||
   77:              (filename[0] >= 'A' && filename[0] <= 'Z')) &&
   78:             filename[1] == ':');
   79: }
   80: 
   81: int is_windows_drive(const char *filename)
   82: {
   83:     if (is_windows_drive_prefix(filename) &&
   84:         filename[2] == '\0')
   85:         return 1;
   86:     if (strstart(filename, "\\\\.\\", NULL) ||
   87:         strstart(filename, "//./", NULL))
   88:         return 1;
   89:     return 0;
   90: }
   91: #endif
   92: 
   93: /* check if the path starts with "<protocol>:" */
   94: static int path_has_protocol(const char *path)
   95: {
   96: #ifdef _WIN32
   97:     if (is_windows_drive(path) ||
   98:         is_windows_drive_prefix(path)) {
   99:         return 0;
  100:     }
  101: #endif
  102: 
  103:     return strchr(path, ':') != NULL;
  104: }
  105: 
  106: int path_is_absolute(const char *path)
  107: {
  108:     const char *p;
  109: #ifdef _WIN32
  110:     /* specific case for names like: "\\.\d:" */
  111:     if (*path == '/' || *path == '\\')
  112:         return 1;
  113: #endif
  114:     p = strchr(path, ':');
  115:     if (p)
  116:         p++;
  117:     else
  118:         p = path;
  119: #ifdef _WIN32
  120:     return (*p == '/' || *p == '\\');
  121: #else
  122:     return (*p == '/');
  123: #endif
  124: }
  125: 
  126: /* if filename is absolute, just copy it to dest. Otherwise, build a
  127:    path to it by considering it is relative to base_path. URL are
  128:    supported. */
  129: void path_combine(char *dest, int dest_size,
  130:                   const char *base_path,
  131:                   const char *filename)
  132: {
  133:     const char *p, *p1;
  134:     int len;
  135: 
  136:     if (dest_size <= 0)
  137:         return;
  138:     if (path_is_absolute(filename)) {
  139:         pstrcpy(dest, dest_size, filename);
  140:     } else {
  141:         p = strchr(base_path, ':');
  142:         if (p)
  143:             p++;
  144:         else
  145:             p = base_path;
  146:         p1 = strrchr(base_path, '/');
  147: #ifdef _WIN32
  148:         {
  149:             const char *p2;
  150:             p2 = strrchr(base_path, '\\');
  151:             if (!p1 || p2 > p1)
  152:                 p1 = p2;
  153:         }
  154: #endif
  155:         if (p1)
  156:             p1++;
  157:         else
  158:             p1 = base_path;
  159:         if (p1 > p)
  160:             p = p1;
  161:         len = p - base_path;
  162:         if (len > dest_size - 1)
  163:             len = dest_size - 1;
  164:         memcpy(dest, base_path, len);
  165:         dest[len] = '\0';
  166:         pstrcat(dest, dest_size, filename);
  167:     }
  168: }
  169: 
  170: void bdrv_register(BlockDriver *bdrv)
  171: {
  172:     if (!bdrv->bdrv_aio_readv) {
  173:         /* add AIO emulation layer */
  174:         bdrv->bdrv_aio_readv = bdrv_aio_readv_em;
  175:         bdrv->bdrv_aio_writev = bdrv_aio_writev_em;
  176:     } else if (!bdrv->bdrv_read) {
  177:         /* add synchronous IO emulation layer */
  178:         bdrv->bdrv_read = bdrv_read_em;
  179:         bdrv->bdrv_write = bdrv_write_em;
  180:     }
  181: 
  182:     if (!bdrv->bdrv_aio_flush)
  183:         bdrv->bdrv_aio_flush = bdrv_aio_flush_em;
  184: 
  185:     QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list);
  186: }
  187: 
  188: /* create a new block device (by default it is empty) */
  189: BlockDriverState *bdrv_new(const char *device_name)
  190: {
  191:     BlockDriverState *bs;
  192: 
  193:     bs = qemu_mallocz(sizeof(BlockDriverState));
  194:     pstrcpy(bs->device_name, sizeof(bs->device_name), device_name);
  195:     if (device_name[0] != '\0') {
  196:         QTAILQ_INSERT_TAIL(&bdrv_states, bs, list);
  197:     }
  198:     return bs;
  199: }
  200: 
  201: BlockDriver *bdrv_find_format(const char *format_name)
  202: {
  203:     BlockDriver *drv1;
  204:     QLIST_FOREACH(drv1, &bdrv_drivers, list) {
  205:         if (!strcmp(drv1->format_name, format_name)) {
  206:             return drv1;
  207:         }
  208:     }
  209:     return NULL;
  210: }
  211: 
  212: static int bdrv_is_whitelisted(BlockDriver *drv)
  213: {
  214:     static const char *whitelist[] = {
  215:         CONFIG_BDRV_WHITELIST
  216:     };
  217:     const char **p;
  218: 
  219:     if (!whitelist[0])
  220:         return 1;               /* no whitelist, anything goes */
  221: 
  222:     for (p = whitelist; *p; p++) {
  223:         if (!strcmp(drv->format_name, *p)) {
  224:             return 1;
  225:         }
  226:     }
  227:     return 0;
  228: }
  229: 
  230: BlockDriver *bdrv_find_whitelisted_format(const char *format_name)
  231: {
  232:     BlockDriver *drv = bdrv_find_format(format_name);
  233:     return drv && bdrv_is_whitelisted(drv) ? drv : NULL;
  234: }
  235: 
  236: int bdrv_create(BlockDriver *drv, const char* filename,
  237:     QEMUOptionParameter *options)
  238: {
  239:     if (!drv->bdrv_create)
  240:         return -ENOTSUP;
  241: 
  242:     return drv->bdrv_create(filename, options);
  243: }
  244: 
  245: int bdrv_create_file(const char* filename, QEMUOptionParameter *options)
  246: {
  247:     BlockDriver *drv;
  248: 
  249:     drv = bdrv_find_protocol(filename);
  250:     if (drv == NULL) {
  251:         return -ENOENT;
  252:     }
  253: 
  254:     return bdrv_create(drv, filename, options);
  255: }
  256: 
  257: #ifdef _WIN32
  258: void get_tmp_filename(char *filename, int size)
  259: {
  260:     char temp_dir[MAX_PATH];
  261: 
  262:     GetTempPath(MAX_PATH, temp_dir);
  263:     GetTempFileName(temp_dir, "qem", 0, filename);
  264: }
  265: #else
  266: void get_tmp_filename(char *filename, int size)
  267: {
  268:     int fd;
  269:     const char *tmpdir;
  270:     /* XXX: race condition possible */
  271:     tmpdir = getenv("TMPDIR");
  272:     if (!tmpdir)
  273:         tmpdir = "/tmp";
  274:     snprintf(filename, size, "%s/vl.XXXXXX", tmpdir);
  275:     fd = mkstemp(filename);
  276:     close(fd);
  277: }
  278: #endif
  279: 
  280: /*
  281:  * Detect host devices. By convention, /dev/cdrom[N] is always
  282:  * recognized as a host CDROM.
  283:  */
  284: static BlockDriver *find_hdev_driver(const char *filename)
  285: {
  286:     int score_max = 0, score;
  287:     BlockDriver *drv = NULL, *d;
  288: 
  289:     QLIST_FOREACH(d, &bdrv_drivers, list) {
  290:         if (d->bdrv_probe_device) {
  291:             score = d->bdrv_probe_device(filename);
  292:             if (score > score_max) {
  293:                 score_max = score;
  294:                 drv = d;
  295:             }
  296:         }
  297:     }
  298: 
  299:     return drv;
  300: }
  301: 
  302: BlockDriver *bdrv_find_protocol(const char *filename)
  303: {
  304:     BlockDriver *drv1;
  305:     char protocol[128];
  306:     int len;
  307:     const char *p;
  308: 
  309:     /* TODO Drivers without bdrv_file_open must be specified explicitly */
  310: 
  311:     /*
  312:      * XXX(hch): we really should not let host device detection
  313:      * override an explicit protocol specification, but moving this
  314:      * later breaks access to device names with colons in them.
  315:      * Thanks to the brain-dead persistent naming schemes on udev-
  316:      * based Linux systems those actually are quite common.
  317:      */
  318:     drv1 = find_hdev_driver(filename);
  319:     if (drv1) {
  320:         return drv1;
  321:     }
  322: 
  323:     if (!path_has_protocol(filename)) {
  324:         return bdrv_find_format("file");
  325:     }
  326:     p = strchr(filename, ':');
  327:     assert(p != NULL);
  328:     len = p - filename;
  329:     if (len > sizeof(protocol) - 1)
  330:         len = sizeof(protocol) - 1;
  331:     memcpy(protocol, filename, len);
  332:     protocol[len] = '\0';
  333:     QLIST_FOREACH(drv1, &bdrv_drivers, list) {
  334:         if (drv1->protocol_name &&
  335:             !strcmp(drv1->protocol_name, protocol)) {
  336:             return drv1;
  337:         }
  338:     }
  339:     return NULL;
  340: }
  341: 
  342: static int find_image_format(const char *filename, BlockDriver **pdrv)
  343: {
  344:     int ret, score, score_max;
  345:     BlockDriver *drv1, *drv;
  346:     uint8_t buf[2048];
  347:     BlockDriverState *bs;
  348: 
  349:     ret = bdrv_file_open(&bs, filename, 0);
  350:     if (ret < 0) {
  351:         *pdrv = NULL;
  352:         return ret;
  353:     }
  354: 
  355:     /* Return the raw BlockDriver * to scsi-generic devices or empty drives */
  356:     if (bs->sg || !bdrv_is_inserted(bs)) {
  357:         bdrv_delete(bs);
  358:         drv = bdrv_find_format("raw");
  359:         if (!drv) {
  360:             ret = -ENOENT;
  361:         }
  362:         *pdrv = drv;
  363:         return ret;
  364:     }
  365: 
  366:     ret = bdrv_pread(bs, 0, buf, sizeof(buf));
  367:     bdrv_delete(bs);
  368:     if (ret < 0) {
  369:         *pdrv = NULL;
  370:         return ret;
  371:     }
  372: 
  373:     score_max = 0;
  374:     drv = NULL;
  375:     QLIST_FOREACH(drv1, &bdrv_drivers, list) {
  376:         if (drv1->bdrv_probe) {
  377:             score = drv1->bdrv_probe(buf, ret, filename);
  378:             if (score > score_max) {
  379:                 score_max = score;
  380:                 drv = drv1;
  381:             }
  382:         }
  383:     }
  384:     if (!drv) {
  385:         ret = -ENOENT;
  386:     }
  387:     *pdrv = drv;
  388:     return ret;
  389: }
  390: 
  391: /**
  392:  * Set the current 'total_sectors' value
  393:  */
  394: static int refresh_total_sectors(BlockDriverState *bs, int64_t hint)
  395: {
  396:     BlockDriver *drv = bs->drv;
  397: 
  398:     /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */
  399:     if (bs->sg)
  400:         return 0;
  401: 
  402:     /* query actual device if possible, otherwise just trust the hint */
  403:     if (drv->bdrv_getlength) {
  404:         int64_t length = drv->bdrv_getlength(bs);
  405:         if (length < 0) {
  406:             return length;
  407:         }
  408:         hint = length >> BDRV_SECTOR_BITS;
  409:     }
  410: 
  411:     bs->total_sectors = hint;
  412:     return 0;
  413: }
  414: 
  415: /*
  416:  * Common part for opening disk images and files
  417:  */
  418: static int bdrv_open_common(BlockDriverState *bs, const char *filename,
  419:     int flags, BlockDriver *drv)
  420: {
  421:     int ret, open_flags;
  422: 
  423:     assert(drv != NULL);
  424: 
  425:     bs->file = NULL;
  426:     bs->total_sectors = 0;
  427:     bs->encrypted = 0;
  428:     bs->valid_key = 0;
  429:     bs->open_flags = flags;
  430:     /* buffer_alignment defaulted to 512, drivers can change this value */
  431:     bs->buffer_alignment = 512;
  432: 
  433:     pstrcpy(bs->filename, sizeof(bs->filename), filename);
  434: 
  435:     if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv)) {
  436:         return -ENOTSUP;
  437:     }
  438: 
  439:     bs->drv = drv;
  440:     bs->opaque = qemu_mallocz(drv->instance_size);
  441: 
  442:     /*
  443:      * Yes, BDRV_O_NOCACHE aka O_DIRECT means we have to present a
  444:      * write cache to the guest.  We do need the fdatasync to flush
  445:      * out transactions for block allocations, and we maybe have a
  446:      * volatile write cache in our backing device to deal with.
  447:      */
  448:     if (flags & (BDRV_O_CACHE_WB|BDRV_O_NOCACHE))
  449:         bs->enable_write_cache = 1;
  450: 
  451:     /*
  452:      * Clear flags that are internal to the block layer before opening the
  453:      * image.
  454:      */
  455:     open_flags = flags & ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
  456: 
  457:     /*
  458:      * Snapshots should be writeable.
  459:      */
  460:     if (bs->is_temporary) {
  461:         open_flags |= BDRV_O_RDWR;
  462:     }
  463: 
  464:     /* Open the image, either directly or using a protocol */
  465:     if (drv->bdrv_file_open) {
  466:         ret = drv->bdrv_file_open(bs, filename, open_flags);
  467:     } else {
  468:         ret = bdrv_file_open(&bs->file, filename, open_flags);
  469:         if (ret >= 0) {
  470:             ret = drv->bdrv_open(bs, open_flags);
  471:         }
  472:     }
  473: 
  474:     if (ret < 0) {
  475:         goto free_and_fail;
  476:     }
  477: 
  478:     bs->keep_read_only = bs->read_only = !(open_flags & BDRV_O_RDWR);
  479: 
  480:     ret = refresh_total_sectors(bs, bs->total_sectors);
  481:     if (ret < 0) {
  482:         goto free_and_fail;
  483:     }
  484: 
  485: #ifndef _WIN32
  486:     if (bs->is_temporary) {
  487:         unlink(filename);
  488:     }
  489: #endif
  490:     return 0;
  491: 
  492: free_and_fail:
  493:     if (bs->file) {
  494:         bdrv_delete(bs->file);
  495:         bs->file = NULL;
  496:     }
  497:     qemu_free(bs->opaque);
  498:     bs->opaque = NULL;
  499:     bs->drv = NULL;
  500:     return ret;
  501: }
  502: 
  503: /*
  504:  * Opens a file using a protocol (file, host_device, nbd, ...)
  505:  */
  506: int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags)
  507: {
  508:     BlockDriverState *bs;
  509:     BlockDriver *drv;
  510:     int ret;
  511: 
  512:     drv = bdrv_find_protocol(filename);
  513:     if (!drv) {
  514:         return -ENOENT;
  515:     }
  516: 
  517:     bs = bdrv_new("");
  518:     ret = bdrv_open_common(bs, filename, flags, drv);
  519:     if (ret < 0) {
  520:         bdrv_delete(bs);
  521:         return ret;
  522:     }
  523:     bs->growable = 1;
  524:     *pbs = bs;
  525:     return 0;
  526: }
  527: 
  528: /*
  529:  * Opens a disk image (raw, qcow2, vmdk, ...)
  530:  */
  531: int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
  532:               BlockDriver *drv)
  533: {
  534:     int ret;
  535: 
  536:     if (flags & BDRV_O_SNAPSHOT) {
  537:         BlockDriverState *bs1;
  538:         int64_t total_size;
  539:         int is_protocol = 0;
  540:         BlockDriver *bdrv_qcow2;
  541:         QEMUOptionParameter *options;
  542:         char tmp_filename[PATH_MAX];
  543:         char backing_filename[PATH_MAX];
  544: 
  545:         /* if snapshot, we create a temporary backing file and open it
  546:            instead of opening 'filename' directly */
  547: 
  548:         /* if there is a backing file, use it */
  549:         bs1 = bdrv_new("");
  550:         ret = bdrv_open(bs1, filename, 0, drv);
  551:         if (ret < 0) {
  552:             bdrv_delete(bs1);
  553:             return ret;
  554:         }
  555:         total_size = bdrv_getlength(bs1) & BDRV_SECTOR_MASK;
  556: 
  557:         if (bs1->drv && bs1->drv->protocol_name)
  558:             is_protocol = 1;
  559: 
  560:         bdrv_delete(bs1);
  561: 
  562:         get_tmp_filename(tmp_filename, sizeof(tmp_filename));
  563: 
  564:         /* Real path is meaningless for protocols */
  565:         if (is_protocol)
  566:             snprintf(backing_filename, sizeof(backing_filename),
  567:                      "%s", filename);
  568:         else if (!realpath(filename, backing_filename))
  569:             return -errno;
  570: 
  571:         bdrv_qcow2 = bdrv_find_format("qcow2");
  572:         options = parse_option_parameters("", bdrv_qcow2->create_options, NULL);
  573: 
  574:         set_option_parameter_int(options, BLOCK_OPT_SIZE, total_size);
  575:         set_option_parameter(options, BLOCK_OPT_BACKING_FILE, backing_filename);
  576:         if (drv) {
  577:             set_option_parameter(options, BLOCK_OPT_BACKING_FMT,
  578:                 drv->format_name);
  579:         }
  580: 
  581:         ret = bdrv_create(bdrv_qcow2, tmp_filename, options);
  582:         free_option_parameters(options);
  583:         if (ret < 0) {
  584:             return ret;
  585:         }
  586: 
  587:         filename = tmp_filename;
  588:         drv = bdrv_qcow2;
  589:         bs->is_temporary = 1;
  590:     }
  591: 
  592:     /* Find the right image format driver */
  593:     if (!drv) {
  594:         ret = find_image_format(filename, &drv);
  595:     }
  596: 
  597:     if (!drv) {
  598:         goto unlink_and_fail;
  599:     }
  600: 
  601:     /* Open the image */
  602:     ret = bdrv_open_common(bs, filename, flags, drv);
  603:     if (ret < 0) {
  604:         goto unlink_and_fail;
  605:     }
  606: 
  607:     /* If there is a backing file, use it */
  608:     if ((flags & BDRV_O_NO_BACKING) == 0 && bs->backing_file[0] != '\0') {
  609:         char backing_filename[PATH_MAX];
  610:         int back_flags;
  611:         BlockDriver *back_drv = NULL;
  612: 
  613:         bs->backing_hd = bdrv_new("");
  614: 
  615:         if (path_has_protocol(bs->backing_file)) {
  616:             pstrcpy(backing_filename, sizeof(backing_filename),
  617:                     bs->backing_file);
  618:         } else {
  619:             path_combine(backing_filename, sizeof(backing_filename),
  620:                          filename, bs->backing_file);
  621:         }
  622: 
  623:         if (bs->backing_format[0] != '\0') {
  624:             back_drv = bdrv_find_format(bs->backing_format);
  625:         }
  626: 
  627:         /* backing files always opened read-only */
  628:         back_flags =
  629:             flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
  630: 
  631:         ret = bdrv_open(bs->backing_hd, backing_filename, back_flags, back_drv);
  632:         if (ret < 0) {
  633:             bdrv_close(bs);
  634:             return ret;
  635:         }
  636:         if (bs->is_temporary) {
  637:             bs->backing_hd->keep_read_only = !(flags & BDRV_O_RDWR);
  638:         } else {
  639:             /* base image inherits from "parent" */
  640:             bs->backing_hd->keep_read_only = bs->keep_read_only;
  641:         }
  642:     }
  643: 
  644:     if (!bdrv_key_required(bs)) {
  645:         /* call the change callback */
  646:         bs->media_changed = 1;
  647:         if (bs->change_cb)
  648:             bs->change_cb(bs->change_opaque, CHANGE_MEDIA);
  649:     }
  650: 
  651:     return 0;
  652: 
  653: unlink_and_fail:
  654:     if (bs->is_temporary) {
  655:         unlink(filename);
  656:     }
  657:     return ret;
  658: }
  659: 
  660: void bdrv_close(BlockDriverState *bs)
  661: {
  662:     if (bs->drv) {
  663:         if (bs == bs_snapshots) {
  664:             bs_snapshots = NULL;
  665:         }
  666:         if (bs->backing_hd) {
  667:             bdrv_delete(bs->backing_hd);
  668:             bs->backing_hd = NULL;
  669:         }
  670:         bs->drv->bdrv_close(bs);
  671:         qemu_free(bs->opaque);
  672: #ifdef _WIN32
  673:         if (bs->is_temporary) {
  674:             unlink(bs->filename);
  675:         }
  676: #endif
  677:         bs->opaque = NULL;
  678:         bs->drv = NULL;
  679: 
  680:         if (bs->file != NULL) {
  681:             bdrv_close(bs->file);
  682:         }
  683: 
  684:         /* call the change callback */
  685:         bs->media_changed = 1;
  686:         if (bs->change_cb)
  687:             bs->change_cb(bs->change_opaque, CHANGE_MEDIA);
  688:     }
  689: }
  690: 
  691: void bdrv_close_all(void)
  692: {
  693:     BlockDriverState *bs;
  694: 
  695:     QTAILQ_FOREACH(bs, &bdrv_states, list) {
  696:         bdrv_close(bs);
  697:     }
  698: }
  699: 
  700: /* make a BlockDriverState anonymous by removing from bdrv_state list.
  701:    Also, NULL terminate the device_name to prevent double remove */
  702: void bdrv_make_anon(BlockDriverState *bs)
  703: {
  704:     if (bs->device_name[0] != '\0') {
  705:         QTAILQ_REMOVE(&bdrv_states, bs, list);
  706:     }
  707:     bs->device_name[0] = '\0';
  708: }
  709: 
  710: void bdrv_delete(BlockDriverState *bs)
  711: {
  712:     assert(!bs->peer);
  713: 
  714:     /* remove from list, if necessary */
  715:     bdrv_make_anon(bs);
  716: 
  717:     bdrv_close(bs);
  718:     if (bs->file != NULL) {
  719:         bdrv_delete(bs->file);
  720:     }
  721: 
  722:     assert(bs != bs_snapshots);
  723:     qemu_free(bs);
  724: }
  725: 
  726: int bdrv_attach(BlockDriverState *bs, DeviceState *qdev)
  727: {
  728:     if (bs->peer) {
  729:         return -EBUSY;
  730:     }
  731:     bs->peer = qdev;
  732:     return 0;
  733: }
  734: 
  735: void bdrv_detach(BlockDriverState *bs, DeviceState *qdev)
  736: {
  737:     assert(bs->peer == qdev);
  738:     bs->peer = NULL;
  739: }
  740: 
  741: DeviceState *bdrv_get_attached(BlockDriverState *bs)
  742: {
  743:     return bs->peer;
  744: }
  745: 
  746: /*
  747:  * Run consistency checks on an image
  748:  *
  749:  * Returns 0 if the check could be completed (it doesn't mean that the image is
  750:  * free of errors) or -errno when an internal error occured. The results of the
  751:  * check are stored in res.
  752:  */
  753: int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res)
  754: {
  755:     if (bs->drv->bdrv_check == NULL) {
  756:         return -ENOTSUP;
  757:     }
  758: 
  759:     memset(res, 0, sizeof(*res));
  760:     return bs->drv->bdrv_check(bs, res);
  761: }
  762: 
  763: #define COMMIT_BUF_SECTORS 2048
  764: 
  765: /* commit COW file into the raw image */
  766: int bdrv_commit(BlockDriverState *bs)
  767: {
  768:     BlockDriver *drv = bs->drv;
  769:     BlockDriver *backing_drv;
  770:     int64_t sector, total_sectors;
  771:     int n, ro, open_flags;
  772:     int ret = 0, rw_ret = 0;
  773:     uint8_t *buf;
  774:     char filename[1024];
  775:     BlockDriverState *bs_rw, *bs_ro;
  776: 
  777:     if (!drv)
  778:         return -ENOMEDIUM;
  779:     
  780:     if (!bs->backing_hd) {
  781:         return -ENOTSUP;
  782:     }
  783: 
  784:     if (bs->backing_hd->keep_read_only) {
  785:         return -EACCES;
  786:     }
  787: 
  788:     backing_drv = bs->backing_hd->drv;
  789:     ro = bs->backing_hd->read_only;
  790:     strncpy(filename, bs->backing_hd->filename, sizeof(filename));
  791:     open_flags =  bs->backing_hd->open_flags;
  792: 
  793:     if (ro) {
  794:         /* re-open as RW */
  795:         bdrv_delete(bs->backing_hd);
  796:         bs->backing_hd = NULL;
  797:         bs_rw = bdrv_new("");
  798:         rw_ret = bdrv_open(bs_rw, filename, open_flags | BDRV_O_RDWR,
  799:             backing_drv);
  800:         if (rw_ret < 0) {
  801:             bdrv_delete(bs_rw);
  802:             /* try to re-open read-only */
  803:             bs_ro = bdrv_new("");
  804:             ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR,
  805:                 backing_drv);
  806:             if (ret < 0) {
  807:                 bdrv_delete(bs_ro);
  808:                 /* drive not functional anymore */
  809:                 bs->drv = NULL;
  810:                 return ret;
  811:             }
  812:             bs->backing_hd = bs_ro;
  813:             return rw_ret;
  814:         }
  815:         bs->backing_hd = bs_rw;
  816:     }
  817: 
  818:     total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
  819:     buf = qemu_malloc(COMMIT_BUF_SECTORS * BDRV_SECTOR_SIZE);
  820: 
  821:     for (sector = 0; sector < total_sectors; sector += n) {
  822:         if (drv->bdrv_is_allocated(bs, sector, COMMIT_BUF_SECTORS, &n)) {
  823: 
  824:             if (bdrv_read(bs, sector, buf, n) != 0) {
  825:                 ret = -EIO;
  826:                 goto ro_cleanup;
  827:             }
  828: 
  829:             if (bdrv_write(bs->backing_hd, sector, buf, n) != 0) {
  830:                 ret = -EIO;
  831:                 goto ro_cleanup;
  832:             }
  833:         }
  834:     }
  835: 
  836:     if (drv->bdrv_make_empty) {
  837:         ret = drv->bdrv_make_empty(bs);
  838:         bdrv_flush(bs);
  839:     }
  840: 
  841:     /*
  842:      * Make sure all data we wrote to the backing device is actually
  843:      * stable on disk.
  844:      */
  845:     if (bs->backing_hd)
  846:         bdrv_flush(bs->backing_hd);
  847: 
  848: ro_cleanup:
  849:     qemu_free(buf);
  850: 
  851:     if (ro) {
  852:         /* re-open as RO */
  853:         bdrv_delete(bs->backing_hd);
  854:         bs->backing_hd = NULL;
  855:         bs_ro = bdrv_new("");
  856:         ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR,
  857:             backing_drv);
  858:         if (ret < 0) {
  859:             bdrv_delete(bs_ro);
  860:             /* drive not functional anymore */
  861:             bs->drv = NULL;
  862:             return ret;
  863:         }
  864:         bs->backing_hd = bs_ro;
  865:         bs->backing_hd->keep_read_only = 0;
  866:     }
  867: 
  868:     return ret;
  869: }
  870: 
  871: void bdrv_commit_all(void)
  872: {
  873:     BlockDriverState *bs;
  874: 
  875:     QTAILQ_FOREACH(bs, &bdrv_states, list) {
  876:         bdrv_commit(bs);
  877:     }
  878: }
  879: 
  880: /*
  881:  * Return values:
  882:  * 0        - success
  883:  * -EINVAL  - backing format specified, but no file
  884:  * -ENOSPC  - can't update the backing file because no space is left in the
  885:  *            image file header
  886:  * -ENOTSUP - format driver doesn't support changing the backing file
  887:  */
  888: int bdrv_change_backing_file(BlockDriverState *bs,
  889:     const char *backing_file, const char *backing_fmt)
  890: {
  891:     BlockDriver *drv = bs->drv;
  892: 
  893:     if (drv->bdrv_change_backing_file != NULL) {
  894:         return drv->bdrv_change_backing_file(bs, backing_file, backing_fmt);
  895:     } else {
  896:         return -ENOTSUP;
  897:     }
  898: }
  899: 
  900: static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,
  901:                                    size_t size)
  902: {
  903:     int64_t len;
  904: 
  905:     if (!bdrv_is_inserted(bs))
  906:         return -ENOMEDIUM;
  907: 
  908:     if (bs->growable)
  909:         return 0;
  910: 
  911:     len = bdrv_getlength(bs);
  912: 
  913:     if (offset < 0)
  914:         return -EIO;
  915: 
  916:     if ((offset > len) || (len - offset < size))
  917:         return -EIO;
  918: 
  919:     return 0;
  920: }
  921: 
  922: static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num,
  923:                               int nb_sectors)
  924: {
  925:     return bdrv_check_byte_request(bs, sector_num * BDRV_SECTOR_SIZE,
  926:                                    nb_sectors * BDRV_SECTOR_SIZE);
  927: }
  928: 
  929: /* return < 0 if error. See bdrv_write() for the return codes */
  930: int bdrv_read(BlockDriverState *bs, int64_t sector_num,
  931:               uint8_t *buf, int nb_sectors)
  932: {
  933:     BlockDriver *drv = bs->drv;
  934: 
  935:     if (!drv)
  936:         return -ENOMEDIUM;
  937:     if (bdrv_check_request(bs, sector_num, nb_sectors))
  938:         return -EIO;
  939: 
  940:     return drv->bdrv_read(bs, sector_num, buf, nb_sectors);
  941: }
  942: 
  943: static void set_dirty_bitmap(BlockDriverState *bs, int64_t sector_num,
  944:                              int nb_sectors, int dirty)
  945: {
  946:     int64_t start, end;
  947:     unsigned long val, idx, bit;
  948: 
  949:     start = sector_num / BDRV_SECTORS_PER_DIRTY_CHUNK;
  950:     end = (sector_num + nb_sectors - 1) / BDRV_SECTORS_PER_DIRTY_CHUNK;
  951: 
  952:     for (; start <= end; start++) {
  953:         idx = start / (sizeof(unsigned long) * 8);
  954:         bit = start % (sizeof(unsigned long) * 8);
  955:         val = bs->dirty_bitmap[idx];
  956:         if (dirty) {
  957:             if (!(val & (1UL << bit))) {
  958:                 bs->dirty_count++;
  959:                 val |= 1UL << bit;
  960:             }
  961:         } else {
  962:             if (val & (1UL << bit)) {
  963:                 bs->dirty_count--;
  964:                 val &= ~(1UL << bit);
  965:             }
  966:         }
  967:         bs->dirty_bitmap[idx] = val;
  968:     }
  969: }
  970: 
  971: /* Return < 0 if error. Important errors are:
  972:   -EIO         generic I/O error (may happen for all errors)
  973:   -ENOMEDIUM   No media inserted.
  974:   -EINVAL      Invalid sector number or nb_sectors
  975:   -EACCES      Trying to write a read-only device
  976: */
  977: int bdrv_write(BlockDriverState *bs, int64_t sector_num,
  978:                const uint8_t *buf, int nb_sectors)
  979: {
  980:     BlockDriver *drv = bs->drv;
  981:     if (!bs->drv)
  982:         return -ENOMEDIUM;
  983:     if (bs->read_only)
  984:         return -EACCES;
  985:     if (bdrv_check_request(bs, sector_num, nb_sectors))
  986:         return -EIO;
  987: 
  988:     if (bs->dirty_bitmap) {
  989:         set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
  990:     }
  991: 
  992:     if (bs->wr_highest_sector < sector_num + nb_sectors - 1) {
  993:         bs->wr_highest_sector = sector_num + nb_sectors - 1;
  994:     }
  995: 
  996:     return drv->bdrv_write(bs, sector_num, buf, nb_sectors);
  997: }
  998: 
  999: int bdrv_pread(BlockDriverState *bs, int64_t offset,
 1000:                void *buf, int count1)
 1001: {
 1002:     uint8_t tmp_buf[BDRV_SECTOR_SIZE];
 1003:     int len, nb_sectors, count;
 1004:     int64_t sector_num;
 1005:     int ret;
 1006: 
 1007:     count = count1;
 1008:     /* first read to align to sector start */
 1009:     len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
 1010:     if (len > count)
 1011:         len = count;
 1012:     sector_num = offset >> BDRV_SECTOR_BITS;
 1013:     if (len > 0) {
 1014:         if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
 1015:             return ret;
 1016:         memcpy(buf, tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), len);
 1017:         count -= len;
 1018:         if (count == 0)
 1019:             return count1;
 1020:         sector_num++;
 1021:         buf += len;
 1022:     }
 1023: 
 1024:     /* read the sectors "in place" */
 1025:     nb_sectors = count >> BDRV_SECTOR_BITS;
 1026:     if (nb_sectors > 0) {
 1027:         if ((ret = bdrv_read(bs, sector_num, buf, nb_sectors)) < 0)
 1028:             return ret;
 1029:         sector_num += nb_sectors;
 1030:         len = nb_sectors << BDRV_SECTOR_BITS;
 1031:         buf += len;
 1032:         count -= len;
 1033:     }
 1034: 
 1035:     /* add data from the last sector */
 1036:     if (count > 0) {
 1037:         if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
 1038:             return ret;
 1039:         memcpy(buf, tmp_buf, count);
 1040:     }
 1041:     return count1;
 1042: }
 1043: 
 1044: int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
 1045:                 const void *buf, int count1)
 1046: {
 1047:     uint8_t tmp_buf[BDRV_SECTOR_SIZE];
 1048:     int len, nb_sectors, count;
 1049:     int64_t sector_num;
 1050:     int ret;
 1051: 
 1052:     count = count1;
 1053:     /* first write to align to sector start */
 1054:     len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
 1055:     if (len > count)
 1056:         len = count;
 1057:     sector_num = offset >> BDRV_SECTOR_BITS;
 1058:     if (len > 0) {
 1059:         if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
 1060:             return ret;
 1061:         memcpy(tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), buf, len);
 1062:         if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0)
 1063:             return ret;
 1064:         count -= len;
 1065:         if (count == 0)
 1066:             return count1;
 1067:         sector_num++;
 1068:         buf += len;
 1069:     }
 1070: 
 1071:     /* write the sectors "in place" */
 1072:     nb_sectors = count >> BDRV_SECTOR_BITS;
 1073:     if (nb_sectors > 0) {
 1074:         if ((ret = bdrv_write(bs, sector_num, buf, nb_sectors)) < 0)
 1075:             return ret;
 1076:         sector_num += nb_sectors;
 1077:         len = nb_sectors << BDRV_SECTOR_BITS;
 1078:         buf += len;
 1079:         count -= len;
 1080:     }
 1081: 
 1082:     /* add data from the last sector */
 1083:     if (count > 0) {
 1084:         if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
 1085:             return ret;
 1086:         memcpy(tmp_buf, buf, count);
 1087:         if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0)
 1088:             return ret;
 1089:     }
 1090:     return count1;
 1091: }
 1092: 
 1093: /*
 1094:  * Writes to the file and ensures that no writes are reordered across this
 1095:  * request (acts as a barrier)
 1096:  *
 1097:  * Returns 0 on success, -errno in error cases.
 1098:  */
 1099: int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset,
 1100:     const void *buf, int count)
 1101: {
 1102:     int ret;
 1103: 
 1104:     ret = bdrv_pwrite(bs, offset, buf, count);
 1105:     if (ret < 0) {
 1106:         return ret;
 1107:     }
 1108: 
 1109:     /* No flush needed for cache=writethrough, it uses O_DSYNC */
 1110:     if ((bs->open_flags & BDRV_O_CACHE_MASK) != 0) {
 1111:         bdrv_flush(bs);
 1112:     }
 1113: 
 1114:     return 0;
 1115: }
 1116: 
 1117: /*
 1118:  * Writes to the file and ensures that no writes are reordered across this
 1119:  * request (acts as a barrier)
 1120:  *
 1121:  * Returns 0 on success, -errno in error cases.
 1122:  */
 1123: int bdrv_write_sync(BlockDriverState *bs, int64_t sector_num,
 1124:     const uint8_t *buf, int nb_sectors)
 1125: {
 1126:     return bdrv_pwrite_sync(bs, BDRV_SECTOR_SIZE * sector_num,
 1127:         buf, BDRV_SECTOR_SIZE * nb_sectors);
 1128: }
 1129: 
 1130: /**
 1131:  * Truncate file to 'offset' bytes (needed only for file protocols)
 1132:  */
 1133: int bdrv_truncate(BlockDriverState *bs, int64_t offset)
 1134: {
 1135:     BlockDriver *drv = bs->drv;
 1136:     int ret;
 1137:     if (!drv)
 1138:         return -ENOMEDIUM;
 1139:     if (!drv->bdrv_truncate)
 1140:         return -ENOTSUP;
 1141:     if (bs->read_only)
 1142:         return -EACCES;
 1143:     if (bdrv_in_use(bs))
 1144:         return -EBUSY;
 1145:     ret = drv->bdrv_truncate(bs, offset);
 1146:     if (ret == 0) {
 1147:         ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS);
 1148:         if (bs->change_cb) {
 1149:             bs->change_cb(bs->change_opaque, CHANGE_SIZE);
 1150:         }
 1151:     }
 1152:     return ret;
 1153: }
 1154: 
 1155: /**
 1156:  * Length of a file in bytes. Return < 0 if error or unknown.
 1157:  */
 1158: int64_t bdrv_getlength(BlockDriverState *bs)
 1159: {
 1160:     BlockDriver *drv = bs->drv;
 1161:     if (!drv)
 1162:         return -ENOMEDIUM;
 1163: 
 1164:     /* Fixed size devices use the total_sectors value for speed instead of
 1165:        issuing a length query (like lseek) on each call.  Also, legacy block
 1166:        drivers don't provide a bdrv_getlength function and must use
 1167:        total_sectors. */
 1168:     if (!bs->growable || !drv->bdrv_getlength) {
 1169:         return bs->total_sectors * BDRV_SECTOR_SIZE;
 1170:     }
 1171:     return drv->bdrv_getlength(bs);
 1172: }
 1173: 
 1174: /* return 0 as number of sectors if no device present or error */
 1175: void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
 1176: {
 1177:     int64_t length;
 1178:     length = bdrv_getlength(bs);
 1179:     if (length < 0)
 1180:         length = 0;
 1181:     else
 1182:         length = length >> BDRV_SECTOR_BITS;
 1183:     *nb_sectors_ptr = length;
 1184: }
 1185: 
 1186: struct partition {
 1187:         uint8_t boot_ind;           /* 0x80 - active */
 1188:         uint8_t head;               /* starting head */
 1189:         uint8_t sector;             /* starting sector */
 1190:         uint8_t cyl;                /* starting cylinder */
 1191:         uint8_t sys_ind;            /* What partition type */
 1192:         uint8_t end_head;           /* end head */
 1193:         uint8_t end_sector;         /* end sector */
 1194:         uint8_t end_cyl;            /* end cylinder */
 1195:         uint32_t start_sect;        /* starting sector counting from 0 */
 1196:         uint32_t nr_sects;          /* nr of sectors in partition */
 1197: } __attribute__((packed));
 1198: 
 1199: /* try to guess the disk logical geometry from the MSDOS partition table. Return 0 if OK, -1 if could not guess */
 1200: static int guess_disk_lchs(BlockDriverState *bs,
 1201:                            int *pcylinders, int *pheads, int *psectors)
 1202: {
 1203:     uint8_t buf[BDRV_SECTOR_SIZE];
 1204:     int ret, i, heads, sectors, cylinders;
 1205:     struct partition *p;
 1206:     uint32_t nr_sects;
 1207:     uint64_t nb_sectors;
 1208: 
 1209:     bdrv_get_geometry(bs, &nb_sectors);
 1210: 
 1211:     ret = bdrv_read(bs, 0, buf, 1);
 1212:     if (ret < 0)
 1213:         return -1;
 1214:     /* test msdos magic */
 1215:     if (buf[510] != 0x55 || buf[511] != 0xaa)
 1216:         return -1;
 1217:     for(i = 0; i < 4; i++) {
 1218:         p = ((struct partition *)(buf + 0x1be)) + i;
 1219:         nr_sects = le32_to_cpu(p->nr_sects);
 1220:         if (nr_sects && p->end_head) {
 1221:             /* We make the assumption that the partition terminates on
 1222:                a cylinder boundary */
 1223:             heads = p->end_head + 1;
 1224:             sectors = p->end_sector & 63;
 1225:             if (sectors == 0)
 1226:                 continue;
 1227:             cylinders = nb_sectors / (heads * sectors);
 1228:             if (cylinders < 1 || cylinders > 16383)
 1229:                 continue;
 1230:             *pheads = heads;
 1231:             *psectors = sectors;
 1232:             *pcylinders = cylinders;
 1233: #if 0
 1234:             printf("guessed geometry: LCHS=%d %d %d\n",
 1235:                    cylinders, heads, sectors);
 1236: #endif
 1237:             return 0;
 1238:         }
 1239:     }
 1240:     return -1;
 1241: }
 1242: 
 1243: void bdrv_guess_geometry(BlockDriverState *bs, int *pcyls, int *pheads, int *psecs)
 1244: {
 1245:     int translation, lba_detected = 0;
 1246:     int cylinders, heads, secs;
 1247:     uint64_t nb_sectors;
 1248: 
 1249:     /* if a geometry hint is available, use it */
 1250:     bdrv_get_geometry(bs, &nb_sectors);
 1251:     bdrv_get_geometry_hint(bs, &cylinders, &heads, &secs);
 1252:     translation = bdrv_get_translation_hint(bs);
 1253:     if (cylinders != 0) {
 1254:         *pcyls = cylinders;
 1255:         *pheads = heads;
 1256:         *psecs = secs;
 1257:     } else {
 1258:         if (guess_disk_lchs(bs, &cylinders, &heads, &secs) == 0) {
 1259:             if (heads > 16) {
 1260:                 /* if heads > 16, it means that a BIOS LBA
 1261:                    translation was active, so the default
 1262:                    hardware geometry is OK */
 1263:                 lba_detected = 1;
 1264:                 goto default_geometry;
 1265:             } else {
 1266:                 *pcyls = cylinders;
 1267:                 *pheads = heads;
 1268:                 *psecs = secs;
 1269:                 /* disable any translation to be in sync with
 1270:                    the logical geometry */
 1271:                 if (translation == BIOS_ATA_TRANSLATION_AUTO) {
 1272:                     bdrv_set_translation_hint(bs,
 1273:                                               BIOS_ATA_TRANSLATION_NONE);
 1274:                 }
 1275:             }
 1276:         } else {
 1277:         default_geometry:
 1278:             /* if no geometry, use a standard physical disk geometry */
 1279:             cylinders = nb_sectors / (16 * 63);
 1280: 
 1281:             if (cylinders > 16383)
 1282:                 cylinders = 16383;
 1283:             else if (cylinders < 2)
 1284:                 cylinders = 2;
 1285:             *pcyls = cylinders;
 1286:             *pheads = 16;
 1287:             *psecs = 63;
 1288:             if ((lba_detected == 1) && (translation == BIOS_ATA_TRANSLATION_AUTO)) {
 1289:                 if ((*pcyls * *pheads) <= 131072) {
 1290:                     bdrv_set_translation_hint(bs,
 1291:                                               BIOS_ATA_TRANSLATION_LARGE);
 1292:                 } else {
 1293:                     bdrv_set_translation_hint(bs,
 1294:                                               BIOS_ATA_TRANSLATION_LBA);
 1295:                 }
 1296:             }
 1297:         }
 1298:         bdrv_set_geometry_hint(bs, *pcyls, *pheads, *psecs);
 1299:     }
 1300: }
 1301: 
 1302: void bdrv_set_geometry_hint(BlockDriverState *bs,
 1303:                             int cyls, int heads, int secs)
 1304: {
 1305:     bs->cyls = cyls;
 1306:     bs->heads = heads;
 1307:     bs->secs = secs;
 1308: }
 1309: 
 1310: void bdrv_set_type_hint(BlockDriverState *bs, int type)
 1311: {
 1312:     bs->type = type;
 1313:     bs->removable = ((type == BDRV_TYPE_CDROM ||
 1314:                       type == BDRV_TYPE_FLOPPY));
 1315: }
 1316: 
 1317: void bdrv_set_translation_hint(BlockDriverState *bs, int translation)
 1318: {
 1319:     bs->translation = translation;
 1320: }
 1321: 
 1322: void bdrv_get_geometry_hint(BlockDriverState *bs,
 1323:                             int *pcyls, int *pheads, int *psecs)
 1324: {
 1325:     *pcyls = bs->cyls;
 1326:     *pheads = bs->heads;
 1327:     *psecs = bs->secs;
 1328: }
 1329: 
 1330: int bdrv_get_type_hint(BlockDriverState *bs)
 1331: {
 1332:     return bs->type;
 1333: }
 1334: 
 1335: int bdrv_get_translation_hint(BlockDriverState *bs)
 1336: {
 1337:     return bs->translation;
 1338: }
 1339: 
 1340: void bdrv_set_on_error(BlockDriverState *bs, BlockErrorAction on_read_error,
 1341:                        BlockErrorAction on_write_error)
 1342: {
 1343:     bs->on_read_error = on_read_error;
 1344:     bs->on_write_error = on_write_error;
 1345: }
 1346: 
 1347: BlockErrorAction bdrv_get_on_error(BlockDriverState *bs, int is_read)
 1348: {
 1349:     return is_read ? bs->on_read_error : bs->on_write_error;
 1350: }
 1351: 
 1352: void bdrv_set_removable(BlockDriverState *bs, int removable)
 1353: {
 1354:     bs->removable = removable;
 1355:     if (removable && bs == bs_snapshots) {
 1356:         bs_snapshots = NULL;
 1357:     }
 1358: }
 1359: 
 1360: int bdrv_is_removable(BlockDriverState *bs)
 1361: {
 1362:     return bs->removable;
 1363: }
 1364: 
 1365: int bdrv_is_read_only(BlockDriverState *bs)
 1366: {
 1367:     return bs->read_only;
 1368: }
 1369: 
 1370: int bdrv_is_sg(BlockDriverState *bs)
 1371: {
 1372:     return bs->sg;
 1373: }
 1374: 
 1375: int bdrv_enable_write_cache(BlockDriverState *bs)
 1376: {
 1377:     return bs->enable_write_cache;
 1378: }
 1379: 
 1380: /* XXX: no longer used */
 1381: void bdrv_set_change_cb(BlockDriverState *bs,
 1382:                         void (*change_cb)(void *opaque, int reason),
 1383:                         void *opaque)
 1384: {
 1385:     bs->change_cb = change_cb;
 1386:     bs->change_opaque = opaque;
 1387: }
 1388: 
 1389: int bdrv_is_encrypted(BlockDriverState *bs)
 1390: {
 1391:     if (bs->backing_hd && bs->backing_hd->encrypted)
 1392:         return 1;
 1393:     return bs->encrypted;
 1394: }
 1395: 
 1396: int bdrv_key_required(BlockDriverState *bs)
 1397: {
 1398:     BlockDriverState *backing_hd = bs->backing_hd;
 1399: 
 1400:     if (backing_hd && backing_hd->encrypted && !backing_hd->valid_key)
 1401:         return 1;
 1402:     return (bs->encrypted && !bs->valid_key);
 1403: }
 1404: 
 1405: int bdrv_set_key(BlockDriverState *bs, const char *key)
 1406: {
 1407:     int ret;
 1408:     if (bs->backing_hd && bs->backing_hd->encrypted) {
 1409:         ret = bdrv_set_key(bs->backing_hd, key);
 1410:         if (ret < 0)
 1411:             return ret;
 1412:         if (!bs->encrypted)
 1413:             return 0;
 1414:     }
 1415:     if (!bs->encrypted) {
 1416:         return -EINVAL;
 1417:     } else if (!bs->drv || !bs->drv->bdrv_set_key) {
 1418:         return -ENOMEDIUM;
 1419:     }
 1420:     ret = bs->drv->bdrv_set_key(bs, key);
 1421:     if (ret < 0) {
 1422:         bs->valid_key = 0;
 1423:     } else if (!bs->valid_key) {
 1424:         bs->valid_key = 1;
 1425:         /* call the change callback now, we skipped it on open */
 1426:         bs->media_changed = 1;
 1427:         if (bs->change_cb)
 1428:             bs->change_cb(bs->change_opaque, CHANGE_MEDIA);
 1429:     }
 1430:     return ret;
 1431: }
 1432: 
 1433: void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)
 1434: {
 1435:     if (!bs->drv) {
 1436:         buf[0] = '\0';
 1437:     } else {
 1438:         pstrcpy(buf, buf_size, bs->drv->format_name);
 1439:     }
 1440: }
 1441: 
 1442: void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
 1443:                          void *opaque)
 1444: {
 1445:     BlockDriver *drv;
 1446: 
 1447:     QLIST_FOREACH(drv, &bdrv_drivers, list) {
 1448:         it(opaque, drv->format_name);
 1449:     }
 1450: }
 1451: 
 1452: BlockDriverState *bdrv_find(const char *name)
 1453: {
 1454:     BlockDriverState *bs;
 1455: 
 1456:     QTAILQ_FOREACH(bs, &bdrv_states, list) {
 1457:         if (!strcmp(name, bs->device_name)) {
 1458:             return bs;
 1459:         }
 1460:     }
 1461:     return NULL;
 1462: }
 1463: 
 1464: BlockDriverState *bdrv_next(BlockDriverState *bs)
 1465: {
 1466:     if (!bs) {
 1467:         return QTAILQ_FIRST(&bdrv_states);
 1468:     }
 1469:     return QTAILQ_NEXT(bs, list);
 1470: }
 1471: 
 1472: void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs), void *opaque)
 1473: {
 1474:     BlockDriverState *bs;
 1475: 
 1476:     QTAILQ_FOREACH(bs, &bdrv_states, list) {
 1477:         it(opaque, bs);
 1478:     }
 1479: }
 1480: 
 1481: const char *bdrv_get_device_name(BlockDriverState *bs)
 1482: {
 1483:     return bs->device_name;
 1484: }
 1485: 
 1486: int bdrv_flush(BlockDriverState *bs)
 1487: {
 1488:     if (bs->open_flags & BDRV_O_NO_FLUSH) {
 1489:         return 0;
 1490:     }
 1491: 
 1492:     if (bs->drv && bs->drv->bdrv_flush) {
 1493:         return bs->drv->bdrv_flush(bs);
 1494:     }
 1495: 
 1496:     /*
 1497:      * Some block drivers always operate in either writethrough or unsafe mode
 1498:      * and don't support bdrv_flush therefore. Usually qemu doesn't know how
 1499:      * the server works (because the behaviour is hardcoded or depends on
 1500:      * server-side configuration), so we can't ensure that everything is safe
 1501:      * on disk. Returning an error doesn't work because that would break guests
 1502:      * even if the server operates in writethrough mode.
 1503:      *
 1504:      * Let's hope the user knows what he's doing.
 1505:      */
 1506:     return 0;
 1507: }
 1508: 
 1509: void bdrv_flush_all(void)
 1510: {
 1511:     BlockDriverState *bs;
 1512: 
 1513:     QTAILQ_FOREACH(bs, &bdrv_states, list) {
 1514:         if (bs->drv && !bdrv_is_read_only(bs) &&
 1515:             (!bdrv_is_removable(bs) || bdrv_is_inserted(bs))) {
 1516:             bdrv_flush(bs);
 1517:         }
 1518:     }
 1519: }
 1520: 
 1521: int bdrv_has_zero_init(BlockDriverState *bs)
 1522: {
 1523:     assert(bs->drv);
 1524: 
 1525:     if (bs->drv->bdrv_has_zero_init) {
 1526:         return bs->drv->bdrv_has_zero_init(bs);
 1527:     }
 1528: 
 1529:     return 1;
 1530: }
 1531: 
 1532: int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors)
 1533: {
 1534:     if (!bs->drv) {
 1535:         return -ENOMEDIUM;
 1536:     }
 1537:     if (!bs->drv->bdrv_discard) {
 1538:         return 0;
 1539:     }
 1540:     return bs->drv->bdrv_discard(bs, sector_num, nb_sectors);
 1541: }
 1542: 
 1543: /*
 1544:  * Returns true iff the specified sector is present in the disk image. Drivers
 1545:  * not implementing the functionality are assumed to not support backing files,
 1546:  * hence all their sectors are reported as allocated.
 1547:  *
 1548:  * 'pnum' is set to the number of sectors (including and immediately following
 1549:  * the specified sector) that are known to be in the same
 1550:  * allocated/unallocated state.
 1551:  *
 1552:  * 'nb_sectors' is the max value 'pnum' should be set to.
 1553:  */
 1554: int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
 1555: 	int *pnum)
 1556: {
 1557:     int64_t n;
 1558:     if (!bs->drv->bdrv_is_allocated) {
 1559:         if (sector_num >= bs->total_sectors) {
 1560:             *pnum = 0;
 1561:             return 0;
 1562:         }
 1563:         n = bs->total_sectors - sector_num;
 1564:         *pnum = (n < nb_sectors) ? (n) : (nb_sectors);
 1565:         return 1;
 1566:     }
 1567:     return bs->drv->bdrv_is_allocated(bs, sector_num, nb_sectors, pnum);
 1568: }
 1569: 
 1570: void bdrv_mon_event(const BlockDriverState *bdrv,
 1571:                     BlockMonEventAction action, int is_read)
 1572: {
 1573:     QObject *data;
 1574:     const char *action_str;
 1575: 
 1576:     switch (action) {
 1577:     case BDRV_ACTION_REPORT:
 1578:         action_str = "report";
 1579:         break;
 1580:     case BDRV_ACTION_IGNORE:
 1581:         action_str = "ignore";
 1582:         break;
 1583:     case BDRV_ACTION_STOP:
 1584:         action_str = "stop";
 1585:         break;
 1586:     default:
 1587:         abort();
 1588:     }
 1589: 
 1590:     data = qobject_from_jsonf("{ 'device': %s, 'action': %s, 'operation': %s }",
 1591:                               bdrv->device_name,
 1592:                               action_str,
 1593:                               is_read ? "read" : "write");
 1594:     monitor_protocol_event(QEVENT_BLOCK_IO_ERROR, data);
 1595: 
 1596:     qobject_decref(data);
 1597: }
 1598: 
 1599: static void bdrv_print_dict(QObject *obj, void *opaque)
 1600: {
 1601:     QDict *bs_dict;
 1602:     Monitor *mon = opaque;
 1603: 
 1604:     bs_dict = qobject_to_qdict(obj);
 1605: 
 1606:     monitor_printf(mon, "%s: type=%s removable=%d",
 1607:                         qdict_get_str(bs_dict, "device"),
 1608:                         qdict_get_str(bs_dict, "type"),
 1609:                         qdict_get_bool(bs_dict, "removable"));
 1610: 
 1611:     if (qdict_get_bool(bs_dict, "removable")) {
 1612:         monitor_printf(mon, " locked=%d", qdict_get_bool(bs_dict, "locked"));
 1613:     }
 1614: 
 1615:     if (qdict_haskey(bs_dict, "inserted")) {
 1616:         QDict *qdict = qobject_to_qdict(qdict_get(bs_dict, "inserted"));
 1617: 
 1618:         monitor_printf(mon, " file=");
 1619:         monitor_print_filename(mon, qdict_get_str(qdict, "file"));
 1620:         if (qdict_haskey(qdict, "backing_file")) {
 1621:             monitor_printf(mon, " backing_file=");
 1622:             monitor_print_filename(mon, qdict_get_str(qdict, "backing_file"));
 1623:         }
 1624:         monitor_printf(mon, " ro=%d drv=%s encrypted=%d",
 1625:                             qdict_get_bool(qdict, "ro"),
 1626:                             qdict_get_str(qdict, "drv"),
 1627:                             qdict_get_bool(qdict, "encrypted"));
 1628:     } else {
 1629:         monitor_printf(mon, " [not inserted]");
 1630:     }
 1631: 
 1632:     monitor_printf(mon, "\n");
 1633: }
 1634: 
 1635: void bdrv_info_print(Monitor *mon, const QObject *data)
 1636: {
 1637:     qlist_iter(qobject_to_qlist(data), bdrv_print_dict, mon);
 1638: }
 1639: 
 1640: void bdrv_info(Monitor *mon, QObject **ret_data)
 1641: {
 1642:     QList *bs_list;
 1643:     BlockDriverState *bs;
 1644: 
 1645:     bs_list = qlist_new();
 1646: 
 1647:     QTAILQ_FOREACH(bs, &bdrv_states, list) {
 1648:         QObject *bs_obj;
 1649:         const char *type = "unknown";
 1650: 
 1651:         switch(bs->type) {
 1652:         case BDRV_TYPE_HD:
 1653:             type = "hd";
 1654:             break;
 1655:         case BDRV_TYPE_CDROM:
 1656:             type = "cdrom";
 1657:             break;
 1658:         case BDRV_TYPE_FLOPPY:
 1659:             type = "floppy";
 1660:             break;
 1661:         }
 1662: 
 1663:         bs_obj = qobject_from_jsonf("{ 'device': %s, 'type': %s, "
 1664:                                     "'removable': %i, 'locked': %i }",
 1665:                                     bs->device_name, type, bs->removable,
 1666:                                     bs->locked);
 1667: 
 1668:         if (bs->drv) {
 1669:             QObject *obj;
 1670:             QDict *bs_dict = qobject_to_qdict(bs_obj);
 1671: 
 1672:             obj = qobject_from_jsonf("{ 'file': %s, 'ro': %i, 'drv': %s, "
 1673:                                      "'encrypted': %i }",
 1674:                                      bs->filename, bs->read_only,
 1675:                                      bs->drv->format_name,
 1676:                                      bdrv_is_encrypted(bs));
 1677:             if (bs->backing_file[0] != '\0') {
 1678:                 QDict *qdict = qobject_to_qdict(obj);
 1679:                 qdict_put(qdict, "backing_file",
 1680:                           qstring_from_str(bs->backing_file));
 1681:             }
 1682: 
 1683:             qdict_put_obj(bs_dict, "inserted", obj);
 1684:         }
 1685:         qlist_append_obj(bs_list, bs_obj);
 1686:     }
 1687: 
 1688:     *ret_data = QOBJECT(bs_list);
 1689: }
 1690: 
 1691: static void bdrv_stats_iter(QObject *data, void *opaque)
 1692: {
 1693:     QDict *qdict;
 1694:     Monitor *mon = opaque;
 1695: 
 1696:     qdict = qobject_to_qdict(data);
 1697:     monitor_printf(mon, "%s:", qdict_get_str(qdict, "device"));
 1698: 
 1699:     qdict = qobject_to_qdict(qdict_get(qdict, "stats"));
 1700:     monitor_printf(mon, " rd_bytes=%" PRId64
 1701:                         " wr_bytes=%" PRId64
 1702:                         " rd_operations=%" PRId64
 1703:                         " wr_operations=%" PRId64
 1704:                         "\n",
 1705:                         qdict_get_int(qdict, "rd_bytes"),
 1706:                         qdict_get_int(qdict, "wr_bytes"),
 1707:                         qdict_get_int(qdict, "rd_operations"),
 1708:                         qdict_get_int(qdict, "wr_operations"));
 1709: }
 1710: 
 1711: void bdrv_stats_print(Monitor *mon, const QObject *data)
 1712: {
 1713:     qlist_iter(qobject_to_qlist(data), bdrv_stats_iter, mon);
 1714: }
 1715: 
 1716: static QObject* bdrv_info_stats_bs(BlockDriverState *bs)
 1717: {
 1718:     QObject *res;
 1719:     QDict *dict;
 1720: 
 1721:     res = qobject_from_jsonf("{ 'stats': {"
 1722:                              "'rd_bytes': %" PRId64 ","
 1723:                              "'wr_bytes': %" PRId64 ","
 1724:                              "'rd_operations': %" PRId64 ","
 1725:                              "'wr_operations': %" PRId64 ","
 1726:                              "'wr_highest_offset': %" PRId64
 1727:                              "} }",
 1728:                              bs->rd_bytes, bs->wr_bytes,
 1729:                              bs->rd_ops, bs->wr_ops,
 1730:                              bs->wr_highest_sector *
 1731:                              (uint64_t)BDRV_SECTOR_SIZE);
 1732:     dict  = qobject_to_qdict(res);
 1733: 
 1734:     if (*bs->device_name) {
 1735:         qdict_put(dict, "device", qstring_from_str(bs->device_name));
 1736:     }
 1737: 
 1738:     if (bs->file) {
 1739:         QObject *parent = bdrv_info_stats_bs(bs->file);
 1740:         qdict_put_obj(dict, "parent", parent);
 1741:     }
 1742: 
 1743:     return res;
 1744: }
 1745: 
 1746: void bdrv_info_stats(Monitor *mon, QObject **ret_data)
 1747: {
 1748:     QObject *obj;
 1749:     QList *devices;
 1750:     BlockDriverState *bs;
 1751: 
 1752:     devices = qlist_new();
 1753: 
 1754:     QTAILQ_FOREACH(bs, &bdrv_states, list) {
 1755:         obj = bdrv_info_stats_bs(bs);
 1756:         qlist_append_obj(devices, obj);
 1757:     }
 1758: 
 1759:     *ret_data = QOBJECT(devices);
 1760: }
 1761: 
 1762: const char *bdrv_get_encrypted_filename(BlockDriverState *bs)
 1763: {
 1764:     if (bs->backing_hd && bs->backing_hd->encrypted)
 1765:         return bs->backing_file;
 1766:     else if (bs->encrypted)
 1767:         return bs->filename;
 1768:     else
 1769:         return NULL;
 1770: }
 1771: 
 1772: void bdrv_get_backing_filename(BlockDriverState *bs,
 1773:                                char *filename, int filename_size)
 1774: {
 1775:     if (!bs->backing_file) {
 1776:         pstrcpy(filename, filename_size, "");
 1777:     } else {
 1778:         pstrcpy(filename, filename_size, bs->backing_file);
 1779:     }
 1780: }
 1781: 
 1782: int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
 1783:                           const uint8_t *buf, int nb_sectors)
 1784: {
 1785:     BlockDriver *drv = bs->drv;
 1786:     if (!drv)
 1787:         return -ENOMEDIUM;
 1788:     if (!drv->bdrv_write_compressed)
 1789:         return -ENOTSUP;
 1790:     if (bdrv_check_request(bs, sector_num, nb_sectors))
 1791:         return -EIO;
 1792: 
 1793:     if (bs->dirty_bitmap) {
 1794:         set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
 1795:     }
 1796: 
 1797:     return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
 1798: }
 1799: 
 1800: int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
 1801: {
 1802:     BlockDriver *drv = bs->drv;
 1803:     if (!drv)
 1804:         return -ENOMEDIUM;
 1805:     if (!drv->bdrv_get_info)
 1806:         return -ENOTSUP;
 1807:     memset(bdi, 0, sizeof(*bdi));
 1808:     return drv->bdrv_get_info(bs, bdi);
 1809: }
 1810: 
 1811: int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
 1812:                       int64_t pos, int size)
 1813: {
 1814:     BlockDriver *drv = bs->drv;
 1815:     if (!drv)
 1816:         return -ENOMEDIUM;
 1817:     if (drv->bdrv_save_vmstate)
 1818:         return drv->bdrv_save_vmstate(bs, buf, pos, size);
 1819:     if (bs->file)
 1820:         return bdrv_save_vmstate(bs->file, buf, pos, size);
 1821:     return -ENOTSUP;
 1822: }
 1823: 
 1824: int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
 1825:                       int64_t pos, int size)
 1826: {
 1827:     BlockDriver *drv = bs->drv;
 1828:     if (!drv)
 1829:         return -ENOMEDIUM;
 1830:     if (drv->bdrv_load_vmstate)
 1831:         return drv->bdrv_load_vmstate(bs, buf, pos, size);
 1832:     if (bs->file)
 1833:         return bdrv_load_vmstate(bs->file, buf, pos, size);
 1834:     return -ENOTSUP;
 1835: }
 1836: 
 1837: void bdrv_debug_event(BlockDriverState *bs, BlkDebugEvent event)
 1838: {
 1839:     BlockDriver *drv = bs->drv;
 1840: 
 1841:     if (!drv || !drv->bdrv_debug_event) {
 1842:         return;
 1843:     }
 1844: 
 1845:     return drv->bdrv_debug_event(bs, event);
 1846: 
 1847: }
 1848: 
 1849: /**************************************************************/
 1850: /* handling of snapshots */
 1851: 
 1852: int bdrv_can_snapshot(BlockDriverState *bs)
 1853: {
 1854:     BlockDriver *drv = bs->drv;
 1855:     if (!drv || bdrv_is_removable(bs) || bdrv_is_read_only(bs)) {
 1856:         return 0;
 1857:     }
 1858: 
 1859:     if (!drv->bdrv_snapshot_create) {
 1860:         if (bs->file != NULL) {
 1861:             return bdrv_can_snapshot(bs->file);
 1862:         }
 1863:         return 0;
 1864:     }
 1865: 
 1866:     return 1;
 1867: }
 1868: 
 1869: int bdrv_is_snapshot(BlockDriverState *bs)
 1870: {
 1871:     return !!(bs->open_flags & BDRV_O_SNAPSHOT);
 1872: }
 1873: 
 1874: BlockDriverState *bdrv_snapshots(void)
 1875: {
 1876:     BlockDriverState *bs;
 1877: 
 1878:     if (bs_snapshots) {
 1879:         return bs_snapshots;
 1880:     }
 1881: 
 1882:     bs = NULL;
 1883:     while ((bs = bdrv_next(bs))) {
 1884:         if (bdrv_can_snapshot(bs)) {
 1885:             bs_snapshots = bs;
 1886:             return bs;
 1887:         }
 1888:     }
 1889:     return NULL;
 1890: }
 1891: 
 1892: int bdrv_snapshot_create(BlockDriverState *bs,
 1893:                          QEMUSnapshotInfo *sn_info)
 1894: {
 1895:     BlockDriver *drv = bs->drv;
 1896:     if (!drv)
 1897:         return -ENOMEDIUM;
 1898:     if (drv->bdrv_snapshot_create)
 1899:         return drv->bdrv_snapshot_create(bs, sn_info);
 1900:     if (bs->file)
 1901:         return bdrv_snapshot_create(bs->file, sn_info);
 1902:     return -ENOTSUP;
 1903: }
 1904: 
 1905: int bdrv_snapshot_goto(BlockDriverState *bs,
 1906:                        const char *snapshot_id)
 1907: {
 1908:     BlockDriver *drv = bs->drv;
 1909:     int ret, open_ret;
 1910: 
 1911:     if (!drv)
 1912:         return -ENOMEDIUM;
 1913:     if (drv->bdrv_snapshot_goto)
 1914:         return drv->bdrv_snapshot_goto(bs, snapshot_id);
 1915: 
 1916:     if (bs->file) {
 1917:         drv->bdrv_close(bs);
 1918:         ret = bdrv_snapshot_goto(bs->file, snapshot_id);
 1919:         open_ret = drv->bdrv_open(bs, bs->open_flags);
 1920:         if (open_ret < 0) {
 1921:             bdrv_delete(bs->file);
 1922:             bs->drv = NULL;
 1923:             return open_ret;
 1924:         }
 1925:         return ret;
 1926:     }
 1927: 
 1928:     return -ENOTSUP;
 1929: }
 1930: 
 1931: int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
 1932: {
 1933:     BlockDriver *drv = bs->drv;
 1934:     if (!drv)
 1935:         return -ENOMEDIUM;
 1936:     if (drv->bdrv_snapshot_delete)
 1937:         return drv->bdrv_snapshot_delete(bs, snapshot_id);
 1938:     if (bs->file)
 1939:         return bdrv_snapshot_delete(bs->file, snapshot_id);
 1940:     return -ENOTSUP;
 1941: }
 1942: 
 1943: int bdrv_snapshot_list(BlockDriverState *bs,
 1944:                        QEMUSnapshotInfo **psn_info)
 1945: {
 1946:     BlockDriver *drv = bs->drv;
 1947:     if (!drv)
 1948:         return -ENOMEDIUM;
 1949:     if (drv->bdrv_snapshot_list)
 1950:         return drv->bdrv_snapshot_list(bs, psn_info);
 1951:     if (bs->file)
 1952:         return bdrv_snapshot_list(bs->file, psn_info);
 1953:     return -ENOTSUP;
 1954: }
 1955: 
 1956: int bdrv_snapshot_load_tmp(BlockDriverState *bs,
 1957:         const char *snapshot_name)
 1958: {
 1959:     BlockDriver *drv = bs->drv;
 1960:     if (!drv) {
 1961:         return -ENOMEDIUM;
 1962:     }
 1963:     if (!bs->read_only) {
 1964:         return -EINVAL;
 1965:     }
 1966:     if (drv->bdrv_snapshot_load_tmp) {
 1967:         return drv->bdrv_snapshot_load_tmp(bs, snapshot_name);
 1968:     }
 1969:     return -ENOTSUP;
 1970: }
 1971: 
 1972: #define NB_SUFFIXES 4
 1973: 
 1974: char *get_human_readable_size(char *buf, int buf_size, int64_t size)
 1975: {
 1976:     static const char suffixes[NB_SUFFIXES] = "KMGT";
 1977:     int64_t base;
 1978:     int i;
 1979: 
 1980:     if (size <= 999) {
 1981:         snprintf(buf, buf_size, "%" PRId64, size);
 1982:     } else {
 1983:         base = 1024;
 1984:         for(i = 0; i < NB_SUFFIXES; i++) {
 1985:             if (size < (10 * base)) {
 1986:                 snprintf(buf, buf_size, "%0.1f%c",
 1987:                          (double)size / base,
 1988:                          suffixes[i]);
 1989:                 break;
 1990:             } else if (size < (1000 * base) || i == (NB_SUFFIXES - 1)) {
 1991:                 snprintf(buf, buf_size, "%" PRId64 "%c",
 1992:                          ((size + (base >> 1)) / base),
 1993:                          suffixes[i]);
 1994:                 break;
 1995:             }
 1996:             base = base * 1024;
 1997:         }
 1998:     }
 1999:     return buf;
 2000: }
 2001: 
 2002: char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn)
 2003: {
 2004:     char buf1[128], date_buf[128], clock_buf[128];
 2005: #ifdef _WIN32
 2006:     struct tm *ptm;
 2007: #else
 2008:     struct tm tm;
 2009: #endif
 2010:     time_t ti;
 2011:     int64_t secs;
 2012: 
 2013:     if (!sn) {
 2014:         snprintf(buf, buf_size,
 2015:                  "%-10s%-20s%7s%20s%15s",
 2016:                  "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK");
 2017:     } else {
 2018:         ti = sn->date_sec;
 2019: #ifdef _WIN32
 2020:         ptm = localtime(&ti);
 2021:         strftime(date_buf, sizeof(date_buf),
 2022:                  "%Y-%m-%d %H:%M:%S", ptm);
 2023: #else
 2024:         localtime_r(&ti, &tm);
 2025:         strftime(date_buf, sizeof(date_buf),
 2026:                  "%Y-%m-%d %H:%M:%S", &tm);
 2027: #endif
 2028:         secs = sn->vm_clock_nsec / 1000000000;
 2029:         snprintf(clock_buf, sizeof(clock_buf),
 2030:                  "%02d:%02d:%02d.%03d",
 2031:                  (int)(secs / 3600),
 2032:                  (int)((secs / 60) % 60),
 2033:                  (int)(secs % 60),
 2034:                  (int)((sn->vm_clock_nsec / 1000000) % 1000));
 2035:         snprintf(buf, buf_size,
 2036:                  "%-10s%-20s%7s%20s%15s",
 2037:                  sn->id_str, sn->name,
 2038:                  get_human_readable_size(buf1, sizeof(buf1), sn->vm_state_size),
 2039:                  date_buf,
 2040:                  clock_buf);
 2041:     }
 2042:     return buf;
 2043: }
 2044: 
 2045: 
 2046: /**************************************************************/
 2047: /* async I/Os */
 2048: 
 2049: BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
 2050:                                  QEMUIOVector *qiov, int nb_sectors,
 2051:                                  BlockDriverCompletionFunc *cb, void *opaque)
 2052: {
 2053:     BlockDriver *drv = bs->drv;
 2054:     BlockDriverAIOCB *ret;
 2055: 
 2056:     trace_bdrv_aio_readv(bs, sector_num, nb_sectors, opaque);
 2057: 
 2058:     if (!drv)
 2059:         return NULL;
 2060:     if (bdrv_check_request(bs, sector_num, nb_sectors))
 2061:         return NULL;
 2062: 
 2063:     ret = drv->bdrv_aio_readv(bs, sector_num, qiov, nb_sectors,
 2064:                               cb, opaque);
 2065: 
 2066:     if (ret) {
 2067: 	/* Update stats even though technically transfer has not happened. */
 2068: 	bs->rd_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE;
 2069: 	bs->rd_ops ++;
 2070:     }
 2071: 
 2072:     return ret;
 2073: }
 2074: 
 2075: typedef struct BlockCompleteData {
 2076:     BlockDriverCompletionFunc *cb;
 2077:     void *opaque;
 2078:     BlockDriverState *bs;
 2079:     int64_t sector_num;
 2080:     int nb_sectors;
 2081: } BlockCompleteData;
 2082: 
 2083: static void block_complete_cb(void *opaque, int ret)
 2084: {
 2085:     BlockCompleteData *b = opaque;
 2086: 
 2087:     if (b->bs->dirty_bitmap) {
 2088:         set_dirty_bitmap(b->bs, b->sector_num, b->nb_sectors, 1);
 2089:     }
 2090:     b->cb(b->opaque, ret);
 2091:     qemu_free(b);
 2092: }
 2093: 
 2094: static BlockCompleteData *blk_dirty_cb_alloc(BlockDriverState *bs,
 2095:                                              int64_t sector_num,
 2096:                                              int nb_sectors,
 2097:                                              BlockDriverCompletionFunc *cb,
 2098:                                              void *opaque)
 2099: {
 2100:     BlockCompleteData *blkdata = qemu_mallocz(sizeof(BlockCompleteData));
 2101: 
 2102:     blkdata->bs = bs;
 2103:     blkdata->cb = cb;
 2104:     blkdata->opaque = opaque;
 2105:     blkdata->sector_num = sector_num;
 2106:     blkdata->nb_sectors = nb_sectors;
 2107: 
 2108:     return blkdata;
 2109: }
 2110: 
 2111: BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
 2112:                                   QEMUIOVector *qiov, int nb_sectors,
 2113:                                   BlockDriverCompletionFunc *cb, void *opaque)
 2114: {
 2115:     BlockDriver *drv = bs->drv;
 2116:     BlockDriverAIOCB *ret;
 2117:     BlockCompleteData *blk_cb_data;
 2118: 
 2119:     trace_bdrv_aio_writev(bs, sector_num, nb_sectors, opaque);
 2120: 
 2121:     if (!drv)
 2122:         return NULL;
 2123:     if (bs->read_only)
 2124:         return NULL;
 2125:     if (bdrv_check_request(bs, sector_num, nb_sectors))
 2126:         return NULL;
 2127: 
 2128:     if (bs->dirty_bitmap) {
 2129:         blk_cb_data = blk_dirty_cb_alloc(bs, sector_num, nb_sectors, cb,
 2130:                                          opaque);
 2131:         cb = &block_complete_cb;
 2132:         opaque = blk_cb_data;
 2133:     }
 2134: 
 2135:     ret = drv->bdrv_aio_writev(bs, sector_num, qiov, nb_sectors,
 2136:                                cb, opaque);
 2137: 
 2138:     if (ret) {
 2139:         /* Update stats even though technically transfer has not happened. */
 2140:         bs->wr_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE;
 2141:         bs->wr_ops ++;
 2142:         if (bs->wr_highest_sector < sector_num + nb_sectors - 1) {
 2143:             bs->wr_highest_sector = sector_num + nb_sectors - 1;
 2144:         }
 2145:     }
 2146: 
 2147:     return ret;
 2148: }
 2149: 
 2150: 
 2151: typedef struct MultiwriteCB {
 2152:     int error;
 2153:     int num_requests;
 2154:     int num_callbacks;
 2155:     struct {
 2156:         BlockDriverCompletionFunc *cb;
 2157:         void *opaque;
 2158:         QEMUIOVector *free_qiov;
 2159:         void *free_buf;
 2160:     } callbacks[];
 2161: } MultiwriteCB;
 2162: 
 2163: static void multiwrite_user_cb(MultiwriteCB *mcb)
 2164: {
 2165:     int i;
 2166: 
 2167:     for (i = 0; i < mcb->num_callbacks; i++) {
 2168:         mcb->callbacks[i].cb(mcb->callbacks[i].opaque, mcb->error);
 2169:         if (mcb->callbacks[i].free_qiov) {
 2170:             qemu_iovec_destroy(mcb->callbacks[i].free_qiov);
 2171:         }
 2172:         qemu_free(mcb->callbacks[i].free_qiov);
 2173:         qemu_vfree(mcb->callbacks[i].free_buf);
 2174:     }
 2175: }
 2176: 
 2177: static void multiwrite_cb(void *opaque, int ret)
 2178: {
 2179:     MultiwriteCB *mcb = opaque;
 2180: 
 2181:     trace_multiwrite_cb(mcb, ret);
 2182: 
 2183:     if (ret < 0 && !mcb->error) {
 2184:         mcb->error = ret;
 2185:     }
 2186: 
 2187:     mcb->num_requests--;
 2188:     if (mcb->num_requests == 0) {
 2189:         multiwrite_user_cb(mcb);
 2190:         qemu_free(mcb);
 2191:     }
 2192: }
 2193: 
 2194: static int multiwrite_req_compare(const void *a, const void *b)
 2195: {
 2196:     const BlockRequest *req1 = a, *req2 = b;
 2197: 
 2198:     /*
 2199:      * Note that we can't simply subtract req2->sector from req1->sector
 2200:      * here as that could overflow the return value.
 2201:      */
 2202:     if (req1->sector > req2->sector) {
 2203:         return 1;
 2204:     } else if (req1->sector < req2->sector) {
 2205:         return -1;
 2206:     } else {
 2207:         return 0;
 2208:     }
 2209: }
 2210: 
 2211: /*
 2212:  * Takes a bunch of requests and tries to merge them. Returns the number of
 2213:  * requests that remain after merging.
 2214:  */
 2215: static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs,
 2216:     int num_reqs, MultiwriteCB *mcb)
 2217: {
 2218:     int i, outidx;
 2219: 
 2220:     // Sort requests by start sector
 2221:     qsort(reqs, num_reqs, sizeof(*reqs), &multiwrite_req_compare);
 2222: 
 2223:     // Check if adjacent requests touch the same clusters. If so, combine them,
 2224:     // filling up gaps with zero sectors.
 2225:     outidx = 0;
 2226:     for (i = 1; i < num_reqs; i++) {
 2227:         int merge = 0;
 2228:         int64_t oldreq_last = reqs[outidx].sector + reqs[outidx].nb_sectors;
 2229: 
 2230:         // This handles the cases that are valid for all block drivers, namely
 2231:         // exactly sequential writes and overlapping writes.
 2232:         if (reqs[i].sector <= oldreq_last) {
 2233:             merge = 1;
 2234:         }
 2235: 
 2236:         // The block driver may decide that it makes sense to combine requests
 2237:         // even if there is a gap of some sectors between them. In this case,
 2238:         // the gap is filled with zeros (therefore only applicable for yet
 2239:         // unused space in format like qcow2).
 2240:         if (!merge && bs->drv->bdrv_merge_requests) {
 2241:             merge = bs->drv->bdrv_merge_requests(bs, &reqs[outidx], &reqs[i]);
 2242:         }
 2243: 
 2244:         if (reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1 > IOV_MAX) {
 2245:             merge = 0;
 2246:         }
 2247: 
 2248:         if (merge) {
 2249:             size_t size;
 2250:             QEMUIOVector *qiov = qemu_mallocz(sizeof(*qiov));
 2251:             qemu_iovec_init(qiov,
 2252:                 reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1);
 2253: 
 2254:             // Add the first request to the merged one. If the requests are
 2255:             // overlapping, drop the last sectors of the first request.
 2256:             size = (reqs[i].sector - reqs[outidx].sector) << 9;
 2257:             qemu_iovec_concat(qiov, reqs[outidx].qiov, size);
 2258: 
 2259:             // We might need to add some zeros between the two requests
 2260:             if (reqs[i].sector > oldreq_last) {
 2261:                 size_t zero_bytes = (reqs[i].sector - oldreq_last) << 9;
 2262:                 uint8_t *buf = qemu_blockalign(bs, zero_bytes);
 2263:                 memset(buf, 0, zero_bytes);
 2264:                 qemu_iovec_add(qiov, buf, zero_bytes);
 2265:                 mcb->callbacks[i].free_buf = buf;
 2266:             }
 2267: 
 2268:             // Add the second request
 2269:             qemu_iovec_concat(qiov, reqs[i].qiov, reqs[i].qiov->size);
 2270: 
 2271:             reqs[outidx].nb_sectors = qiov->size >> 9;
 2272:             reqs[outidx].qiov = qiov;
 2273: 
 2274:             mcb->callbacks[i].free_qiov = reqs[outidx].qiov;
 2275:         } else {
 2276:             outidx++;
 2277:             reqs[outidx].sector     = reqs[i].sector;
 2278:             reqs[outidx].nb_sectors = reqs[i].nb_sectors;
 2279:             reqs[outidx].qiov       = reqs[i].qiov;
 2280:         }
 2281:     }
 2282: 
 2283:     return outidx + 1;
 2284: }
 2285: 
 2286: /*
 2287:  * Submit multiple AIO write requests at once.
 2288:  *
 2289:  * On success, the function returns 0 and all requests in the reqs array have
 2290:  * been submitted. In error case this function returns -1, and any of the
 2291:  * requests may or may not be submitted yet. In particular, this means that the
 2292:  * callback will be called for some of the requests, for others it won't. The
 2293:  * caller must check the error field of the BlockRequest to wait for the right
 2294:  * callbacks (if error != 0, no callback will be called).
 2295:  *
 2296:  * The implementation may modify the contents of the reqs array, e.g. to merge
 2297:  * requests. However, the fields opaque and error are left unmodified as they
 2298:  * are used to signal failure for a single request to the caller.
 2299:  */
 2300: int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs)
 2301: {
 2302:     BlockDriverAIOCB *acb;
 2303:     MultiwriteCB *mcb;
 2304:     int i;
 2305: 
 2306:     /* don't submit writes if we don't have a medium */
 2307:     if (bs->drv == NULL) {
 2308:         for (i = 0; i < num_reqs; i++) {
 2309:             reqs[i].error = -ENOMEDIUM;
 2310:         }
 2311:         return -1;
 2312:     }
 2313: 
 2314:     if (num_reqs == 0) {
 2315:         return 0;
 2316:     }
 2317: 
 2318:     // Create MultiwriteCB structure
 2319:     mcb = qemu_mallocz(sizeof(*mcb) + num_reqs * sizeof(*mcb->callbacks));
 2320:     mcb->num_requests = 0;
 2321:     mcb->num_callbacks = num_reqs;
 2322: 
 2323:     for (i = 0; i < num_reqs; i++) {
 2324:         mcb->callbacks[i].cb = reqs[i].cb;
 2325:         mcb->callbacks[i].opaque = reqs[i].opaque;
 2326:     }
 2327: 
 2328:     // Check for mergable requests
 2329:     num_reqs = multiwrite_merge(bs, reqs, num_reqs, mcb);
 2330: 
 2331:     trace_bdrv_aio_multiwrite(mcb, mcb->num_callbacks, num_reqs);
 2332: 
 2333:     /*
 2334:      * Run the aio requests. As soon as one request can't be submitted
 2335:      * successfully, fail all requests that are not yet submitted (we must
 2336:      * return failure for all requests anyway)
 2337:      *
 2338:      * num_requests cannot be set to the right value immediately: If
 2339:      * bdrv_aio_writev fails for some request, num_requests would be too high
 2340:      * and therefore multiwrite_cb() would never recognize the multiwrite
 2341:      * request as completed. We also cannot use the loop variable i to set it
 2342:      * when the first request fails because the callback may already have been
 2343:      * called for previously submitted requests. Thus, num_requests must be
 2344:      * incremented for each request that is submitted.
 2345:      *
 2346:      * The problem that callbacks may be called early also means that we need
 2347:      * to take care that num_requests doesn't become 0 before all requests are
 2348:      * submitted - multiwrite_cb() would consider the multiwrite request
 2349:      * completed. A dummy request that is "completed" by a manual call to
 2350:      * multiwrite_cb() takes care of this.
 2351:      */
 2352:     mcb->num_requests = 1;
 2353: 
 2354:     // Run the aio requests
 2355:     for (i = 0; i < num_reqs; i++) {
 2356:         mcb->num_requests++;
 2357:         acb = bdrv_aio_writev(bs, reqs[i].sector, reqs[i].qiov,
 2358:             reqs[i].nb_sectors, multiwrite_cb, mcb);
 2359: 
 2360:         if (acb == NULL) {
 2361:             // We can only fail the whole thing if no request has been
 2362:             // submitted yet. Otherwise we'll wait for the submitted AIOs to
 2363:             // complete and report the error in the callback.
 2364:             if (i == 0) {
 2365:                 trace_bdrv_aio_multiwrite_earlyfail(mcb);
 2366:                 goto fail;
 2367:             } else {
 2368:                 trace_bdrv_aio_multiwrite_latefail(mcb, i);
 2369:                 multiwrite_cb(mcb, -EIO);
 2370:                 break;
 2371:             }
 2372:         }
 2373:     }
 2374: 
 2375:     /* Complete the dummy request */
 2376:     multiwrite_cb(mcb, 0);
 2377: 
 2378:     return 0;
 2379: 
 2380: fail:
 2381:     for (i = 0; i < mcb->num_callbacks; i++) {
 2382:         reqs[i].error = -EIO;
 2383:     }
 2384:     qemu_free(mcb);
 2385:     return -1;
 2386: }
 2387: 
 2388: BlockDriverAIOCB *bdrv_aio_flush(BlockDriverState *bs,
 2389:         BlockDriverCompletionFunc *cb, void *opaque)
 2390: {
 2391:     BlockDriver *drv = bs->drv;
 2392: 
 2393:     if (bs->open_flags & BDRV_O_NO_FLUSH) {
 2394:         return bdrv_aio_noop_em(bs, cb, opaque);
 2395:     }
 2396: 
 2397:     if (!drv)
 2398:         return NULL;
 2399:     return drv->bdrv_aio_flush(bs, cb, opaque);
 2400: }
 2401: 
 2402: void bdrv_aio_cancel(BlockDriverAIOCB *acb)
 2403: {
 2404:     acb->pool->cancel(acb);
 2405: }
 2406: 
 2407: 
 2408: /**************************************************************/
 2409: /* async block device emulation */
 2410: 
 2411: typedef struct BlockDriverAIOCBSync {
 2412:     BlockDriverAIOCB common;
 2413:     QEMUBH *bh;
 2414:     int ret;
 2415:     /* vector translation state */
 2416:     QEMUIOVector *qiov;
 2417:     uint8_t *bounce;
 2418:     int is_write;
 2419: } BlockDriverAIOCBSync;
 2420: 
 2421: static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb)
 2422: {
 2423:     BlockDriverAIOCBSync *acb =
 2424:         container_of(blockacb, BlockDriverAIOCBSync, common);
 2425:     qemu_bh_delete(acb->bh);
 2426:     acb->bh = NULL;
 2427:     qemu_aio_release(acb);
 2428: }
 2429: 
 2430: static AIOPool bdrv_em_aio_pool = {
 2431:     .aiocb_size         = sizeof(BlockDriverAIOCBSync),
 2432:     .cancel             = bdrv_aio_cancel_em,
 2433: };
 2434: 
 2435: static void bdrv_aio_bh_cb(void *opaque)
 2436: {
 2437:     BlockDriverAIOCBSync *acb = opaque;
 2438: 
 2439:     if (!acb->is_write)
 2440:         qemu_iovec_from_buffer(acb->qiov, acb->bounce, acb->qiov->size);
 2441:     qemu_vfree(acb->bounce);
 2442:     acb->common.cb(acb->common.opaque, acb->ret);
 2443:     qemu_bh_delete(acb->bh);
 2444:     acb->bh = NULL;
 2445:     qemu_aio_release(acb);
 2446: }
 2447: 
 2448: static BlockDriverAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs,
 2449:                                             int64_t sector_num,
 2450:                                             QEMUIOVector *qiov,
 2451:                                             int nb_sectors,
 2452:                                             BlockDriverCompletionFunc *cb,
 2453:                                             void *opaque,
 2454:                                             int is_write)
 2455: 
 2456: {
 2457:     BlockDriverAIOCBSync *acb;
 2458: 
 2459:     acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
 2460:     acb->is_write = is_write;
 2461:     acb->qiov = qiov;
 2462:     acb->bounce = qemu_blockalign(bs, qiov->size);
 2463: 
 2464:     if (!acb->bh)
 2465:         acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
 2466: 
 2467:     if (is_write) {
 2468:         qemu_iovec_to_buffer(acb->qiov, acb->bounce);
 2469:         acb->ret = bdrv_write(bs, sector_num, acb->bounce, nb_sectors);
 2470:     } else {
 2471:         acb->ret = bdrv_read(bs, sector_num, acb->bounce, nb_sectors);
 2472:     }
 2473: 
 2474:     qemu_bh_schedule(acb->bh);
 2475: 
 2476:     return &acb->common;
 2477: }
 2478: 
 2479: static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
 2480:         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 2481:         BlockDriverCompletionFunc *cb, void *opaque)
 2482: {
 2483:     return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
 2484: }
 2485: 
 2486: static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
 2487:         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 2488:         BlockDriverCompletionFunc *cb, void *opaque)
 2489: {
 2490:     return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
 2491: }
 2492: 
 2493: static BlockDriverAIOCB *bdrv_aio_flush_em(BlockDriverState *bs,
 2494:         BlockDriverCompletionFunc *cb, void *opaque)
 2495: {
 2496:     BlockDriverAIOCBSync *acb;
 2497: 
 2498:     acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
 2499:     acb->is_write = 1; /* don't bounce in the completion hadler */
 2500:     acb->qiov = NULL;
 2501:     acb->bounce = NULL;
 2502:     acb->ret = 0;
 2503: 
 2504:     if (!acb->bh)
 2505:         acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
 2506: 
 2507:     bdrv_flush(bs);
 2508:     qemu_bh_schedule(acb->bh);
 2509:     return &acb->common;
 2510: }
 2511: 
 2512: static BlockDriverAIOCB *bdrv_aio_noop_em(BlockDriverState *bs,
 2513:         BlockDriverCompletionFunc *cb, void *opaque)
 2514: {
 2515:     BlockDriverAIOCBSync *acb;
 2516: 
 2517:     acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
 2518:     acb->is_write = 1; /* don't bounce in the completion handler */
 2519:     acb->qiov = NULL;
 2520:     acb->bounce = NULL;
 2521:     acb->ret = 0;
 2522: 
 2523:     if (!acb->bh) {
 2524:         acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
 2525:     }
 2526: 
 2527:     qemu_bh_schedule(acb->bh);
 2528:     return &acb->common;
 2529: }
 2530: 
 2531: /**************************************************************/
 2532: /* sync block device emulation */
 2533: 
 2534: static void bdrv_rw_em_cb(void *opaque, int ret)
 2535: {
 2536:     *(int *)opaque = ret;
 2537: }
 2538: 
 2539: #define NOT_DONE 0x7fffffff
 2540: 
 2541: static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
 2542:                         uint8_t *buf, int nb_sectors)
 2543: {
 2544:     int async_ret;
 2545:     BlockDriverAIOCB *acb;
 2546:     struct iovec iov;
 2547:     QEMUIOVector qiov;
 2548: 
 2549:     async_context_push();
 2550: 
 2551:     async_ret = NOT_DONE;
 2552:     iov.iov_base = (void *)buf;
 2553:     iov.iov_len = nb_sectors * BDRV_SECTOR_SIZE;
 2554:     qemu_iovec_init_external(&qiov, &iov, 1);
 2555:     acb = bdrv_aio_readv(bs, sector_num, &qiov, nb_sectors,
 2556:         bdrv_rw_em_cb, &async_ret);
 2557:     if (acb == NULL) {
 2558:         async_ret = -1;
 2559:         goto fail;
 2560:     }
 2561: 
 2562:     while (async_ret == NOT_DONE) {
 2563:         qemu_aio_wait();
 2564:     }
 2565: 
 2566: 
 2567: fail:
 2568:     async_context_pop();
 2569:     return async_ret;
 2570: }
 2571: 
 2572: static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
 2573:                          const uint8_t *buf, int nb_sectors)
 2574: {
 2575:     int async_ret;
 2576:     BlockDriverAIOCB *acb;
 2577:     struct iovec iov;
 2578:     QEMUIOVector qiov;
 2579: 
 2580:     async_context_push();
 2581: 
 2582:     async_ret = NOT_DONE;
 2583:     iov.iov_base = (void *)buf;
 2584:     iov.iov_len = nb_sectors * BDRV_SECTOR_SIZE;
 2585:     qemu_iovec_init_external(&qiov, &iov, 1);
 2586:     acb = bdrv_aio_writev(bs, sector_num, &qiov, nb_sectors,
 2587:         bdrv_rw_em_cb, &async_ret);
 2588:     if (acb == NULL) {
 2589:         async_ret = -1;
 2590:         goto fail;
 2591:     }
 2592:     while (async_ret == NOT_DONE) {
 2593:         qemu_aio_wait();
 2594:     }
 2595: 
 2596: fail:
 2597:     async_context_pop();
 2598:     return async_ret;
 2599: }
 2600: 
 2601: void bdrv_init(void)
 2602: {
 2603:     module_call_init(MODULE_INIT_BLOCK);
 2604: }
 2605: 
 2606: void bdrv_init_with_whitelist(void)
 2607: {
 2608:     use_bdrv_whitelist = 1;
 2609:     bdrv_init();
 2610: }
 2611: 
 2612: void *qemu_aio_get(AIOPool *pool, BlockDriverState *bs,
 2613:                    BlockDriverCompletionFunc *cb, void *opaque)
 2614: {
 2615:     BlockDriverAIOCB *acb;
 2616: 
 2617:     if (pool->free_aiocb) {
 2618:         acb = pool->free_aiocb;
 2619:         pool->free_aiocb = acb->next;
 2620:     } else {
 2621:         acb = qemu_mallocz(pool->aiocb_size);
 2622:         acb->pool = pool;
 2623:     }
 2624:     acb->bs = bs;
 2625:     acb->cb = cb;
 2626:     acb->opaque = opaque;
 2627:     return acb;
 2628: }
 2629: 
 2630: void qemu_aio_release(void *p)
 2631: {
 2632:     BlockDriverAIOCB *acb = (BlockDriverAIOCB *)p;
 2633:     AIOPool *pool = acb->pool;
 2634:     acb->next = pool->free_aiocb;
 2635:     pool->free_aiocb = acb;
 2636: }
 2637: 
 2638: /**************************************************************/
 2639: /* removable device support */
 2640: 
 2641: /**
 2642:  * Return TRUE if the media is present
 2643:  */
 2644: int bdrv_is_inserted(BlockDriverState *bs)
 2645: {
 2646:     BlockDriver *drv = bs->drv;
 2647:     int ret;
 2648:     if (!drv)
 2649:         return 0;
 2650:     if (!drv->bdrv_is_inserted)
 2651:         return !bs->tray_open;
 2652:     ret = drv->bdrv_is_inserted(bs);
 2653:     return ret;
 2654: }
 2655: 
 2656: /**
 2657:  * Return TRUE if the media changed since the last call to this
 2658:  * function. It is currently only used for floppy disks
 2659:  */
 2660: int bdrv_media_changed(BlockDriverState *bs)
 2661: {
 2662:     BlockDriver *drv = bs->drv;
 2663:     int ret;
 2664: 
 2665:     if (!drv || !drv->bdrv_media_changed)
 2666:         ret = -ENOTSUP;
 2667:     else
 2668:         ret = drv->bdrv_media_changed(bs);
 2669:     if (ret == -ENOTSUP)
 2670:         ret = bs->media_changed;
 2671:     bs->media_changed = 0;
 2672:     return ret;
 2673: }
 2674: 
 2675: /**
 2676:  * If eject_flag is TRUE, eject the media. Otherwise, close the tray
 2677:  */
 2678: int bdrv_eject(BlockDriverState *bs, int eject_flag)
 2679: {
 2680:     BlockDriver *drv = bs->drv;
 2681:     int ret;
 2682: 
 2683:     if (bs->locked) {
 2684:         return -EBUSY;
 2685:     }
 2686: 
 2687:     if (!drv || !drv->bdrv_eject) {
 2688:         ret = -ENOTSUP;
 2689:     } else {
 2690:         ret = drv->bdrv_eject(bs, eject_flag);
 2691:     }
 2692:     if (ret == -ENOTSUP) {
 2693:         ret = 0;
 2694:     }
 2695:     if (ret >= 0) {
 2696:         bs->tray_open = eject_flag;
 2697:     }
 2698: 
 2699:     return ret;
 2700: }
 2701: 
 2702: int bdrv_is_locked(BlockDriverState *bs)
 2703: {
 2704:     return bs->locked;
 2705: }
 2706: 
 2707: /**
 2708:  * Lock or unlock the media (if it is locked, the user won't be able
 2709:  * to eject it manually).
 2710:  */
 2711: void bdrv_set_locked(BlockDriverState *bs, int locked)
 2712: {
 2713:     BlockDriver *drv = bs->drv;
 2714: 
 2715:     bs->locked = locked;
 2716:     if (drv && drv->bdrv_set_locked) {
 2717:         drv->bdrv_set_locked(bs, locked);
 2718:     }
 2719: }
 2720: 
 2721: /* needed for generic scsi interface */
 2722: 
 2723: int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
 2724: {
 2725:     BlockDriver *drv = bs->drv;
 2726: 
 2727:     if (drv && drv->bdrv_ioctl)
 2728:         return drv->bdrv_ioctl(bs, req, buf);
 2729:     return -ENOTSUP;
 2730: }
 2731: 
 2732: BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
 2733:         unsigned long int req, void *buf,
 2734:         BlockDriverCompletionFunc *cb, void *opaque)
 2735: {
 2736:     BlockDriver *drv = bs->drv;
 2737: 
 2738:     if (drv && drv->bdrv_aio_ioctl)
 2739:         return drv->bdrv_aio_ioctl(bs, req, buf, cb, opaque);
 2740:     return NULL;
 2741: }
 2742: 
 2743: 
 2744: 
 2745: void *qemu_blockalign(BlockDriverState *bs, size_t size)
 2746: {
 2747:     return qemu_memalign((bs && bs->buffer_alignment) ? bs->buffer_alignment : 512, size);
 2748: }
 2749: 
 2750: void bdrv_set_dirty_tracking(BlockDriverState *bs, int enable)
 2751: {
 2752:     int64_t bitmap_size;
 2753: 
 2754:     bs->dirty_count = 0;
 2755:     if (enable) {
 2756:         if (!bs->dirty_bitmap) {
 2757:             bitmap_size = (bdrv_getlength(bs) >> BDRV_SECTOR_BITS) +
 2758:                     BDRV_SECTORS_PER_DIRTY_CHUNK * 8 - 1;
 2759:             bitmap_size /= BDRV_SECTORS_PER_DIRTY_CHUNK * 8;
 2760: 
 2761:             bs->dirty_bitmap = qemu_mallocz(bitmap_size);
 2762:         }
 2763:     } else {
 2764:         if (bs->dirty_bitmap) {
 2765:             qemu_free(bs->dirty_bitmap);
 2766:             bs->dirty_bitmap = NULL;
 2767:         }
 2768:     }
 2769: }
 2770: 
 2771: int bdrv_get_dirty(BlockDriverState *bs, int64_t sector)
 2772: {
 2773:     int64_t chunk = sector / (int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK;
 2774: 
 2775:     if (bs->dirty_bitmap &&
 2776:         (sector << BDRV_SECTOR_BITS) < bdrv_getlength(bs)) {
 2777:         return !!(bs->dirty_bitmap[chunk / (sizeof(unsigned long) * 8)] &
 2778:             (1UL << (chunk % (sizeof(unsigned long) * 8))));
 2779:     } else {
 2780:         return 0;
 2781:     }
 2782: }
 2783: 
 2784: void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector,
 2785:                       int nr_sectors)
 2786: {
 2787:     set_dirty_bitmap(bs, cur_sector, nr_sectors, 0);
 2788: }
 2789: 
 2790: int64_t bdrv_get_dirty_count(BlockDriverState *bs)
 2791: {
 2792:     return bs->dirty_count;
 2793: }
 2794: 
 2795: void bdrv_set_in_use(BlockDriverState *bs, int in_use)
 2796: {
 2797:     assert(bs->in_use != in_use);
 2798:     bs->in_use = in_use;
 2799: }
 2800: 
 2801: int bdrv_in_use(BlockDriverState *bs)
 2802: {
 2803:     return bs->in_use;
 2804: }
 2805: 
 2806: int bdrv_img_create(const char *filename, const char *fmt,
 2807:                     const char *base_filename, const char *base_fmt,
 2808:                     char *options, uint64_t img_size, int flags)
 2809: {
 2810:     QEMUOptionParameter *param = NULL, *create_options = NULL;
 2811:     QEMUOptionParameter *backing_fmt, *backing_file;
 2812:     BlockDriverState *bs = NULL;
 2813:     BlockDriver *drv, *proto_drv;
 2814:     BlockDriver *backing_drv = NULL;
 2815:     int ret = 0;
 2816: 
 2817:     /* Find driver and parse its options */
 2818:     drv = bdrv_find_format(fmt);
 2819:     if (!drv) {
 2820:         error_report("Unknown file format '%s'", fmt);
 2821:         ret = -EINVAL;
 2822:         goto out;
 2823:     }
 2824: 
 2825:     proto_drv = bdrv_find_protocol(filename);
 2826:     if (!proto_drv) {
 2827:         error_report("Unknown protocol '%s'", filename);
 2828:         ret = -EINVAL;
 2829:         goto out;
 2830:     }
 2831: 
 2832:     create_options = append_option_parameters(create_options,
 2833:                                               drv->create_options);
 2834:     create_options = append_option_parameters(create_options,
 2835:                                               proto_drv->create_options);
 2836: 
 2837:     /* Create parameter list with default values */
 2838:     param = parse_option_parameters("", create_options, param);
 2839: 
 2840:     set_option_parameter_int(param, BLOCK_OPT_SIZE, img_size);
 2841: 
 2842:     /* Parse -o options */
 2843:     if (options) {
 2844:         param = parse_option_parameters(options, create_options, param);
 2845:         if (param == NULL) {
 2846:             error_report("Invalid options for file format '%s'.", fmt);
 2847:             ret = -EINVAL;
 2848:             goto out;
 2849:         }
 2850:     }
 2851: 
 2852:     if (base_filename) {
 2853:         if (set_option_parameter(param, BLOCK_OPT_BACKING_FILE,
 2854:                                  base_filename)) {
 2855:             error_report("Backing file not supported for file format '%s'",
 2856:                          fmt);
 2857:             ret = -EINVAL;
 2858:             goto out;
 2859:         }
 2860:     }
 2861: 
 2862:     if (base_fmt) {
 2863:         if (set_option_parameter(param, BLOCK_OPT_BACKING_FMT, base_fmt)) {
 2864:             error_report("Backing file format not supported for file "
 2865:                          "format '%s'", fmt);
 2866:             ret = -EINVAL;
 2867:             goto out;
 2868:         }
 2869:     }
 2870: 
 2871:     backing_file = get_option_parameter(param, BLOCK_OPT_BACKING_FILE);
 2872:     if (backing_file && backing_file->value.s) {
 2873:         if (!strcmp(filename, backing_file->value.s)) {
 2874:             error_report("Error: Trying to create an image with the "
 2875:                          "same filename as the backing file");
 2876:             ret = -EINVAL;
 2877:             goto out;
 2878:         }
 2879:     }
 2880: 
 2881:     backing_fmt = get_option_parameter(param, BLOCK_OPT_BACKING_FMT);
 2882:     if (backing_fmt && backing_fmt->value.s) {
 2883:         backing_drv = bdrv_find_format(backing_fmt->value.s);
 2884:         if (!backing_drv) {
 2885:             error_report("Unknown backing file format '%s'",
 2886:                          backing_fmt->value.s);
 2887:             ret = -EINVAL;
 2888:             goto out;
 2889:         }
 2890:     }
 2891: 
 2892:     // The size for the image must always be specified, with one exception:
 2893:     // If we are using a backing file, we can obtain the size from there
 2894:     if (get_option_parameter(param, BLOCK_OPT_SIZE)->value.n == -1) {
 2895:         if (backing_file && backing_file->value.s) {
 2896:             uint64_t size;
 2897:             char buf[32];
 2898: 
 2899:             bs = bdrv_new("");
 2900: 
 2901:             ret = bdrv_open(bs, backing_file->value.s, flags, backing_drv);
 2902:             if (ret < 0) {
 2903:                 error_report("Could not open '%s'", backing_file->value.s);
 2904:                 goto out;
 2905:             }
 2906:             bdrv_get_geometry(bs, &size);
 2907:             size *= 512;
 2908: 
 2909:             snprintf(buf, sizeof(buf), "%" PRId64, size);
 2910:             set_option_parameter(param, BLOCK_OPT_SIZE, buf);
 2911:         } else {
 2912:             error_report("Image creation needs a size parameter");
 2913:             ret = -EINVAL;
 2914:             goto out;
 2915:         }
 2916:     }
 2917: 
 2918:     printf("Formatting '%s', fmt=%s ", filename, fmt);
 2919:     print_option_parameters(param);
 2920:     puts("");
 2921: 
 2922:     ret = bdrv_create(drv, filename, param);
 2923: 
 2924:     if (ret < 0) {
 2925:         if (ret == -ENOTSUP) {
 2926:             error_report("Formatting or formatting option not supported for "
 2927:                          "file format '%s'", fmt);
 2928:         } else if (ret == -EFBIG) {
 2929:             error_report("The image size is too large for file format '%s'",
 2930:                          fmt);
 2931:         } else {
 2932:             error_report("%s: error while creating %s: %s", filename, fmt,
 2933:                          strerror(-ret));
 2934:         }
 2935:     }
 2936: 
 2937: out:
 2938:     free_option_parameters(create_options);
 2939:     free_option_parameters(param);
 2940: 
 2941:     if (bs) {
 2942:         bdrv_delete(bs);
 2943:     }
 2944: 
 2945:     return ret;
 2946: }

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