block.c 62.0 KB
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/*
 * QEMU System Emulator block driver
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 *
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 * Copyright (c) 2003 Fabrice Bellard
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 *
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 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
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#include "config-host.h"
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#include "qemu-common.h"
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#include "monitor.h"
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#include "block_int.h"
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#include "module.h"
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#include "qemu-objects.h"
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#ifdef CONFIG_BSD
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#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
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#include <sys/queue.h>
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#ifndef __DragonFly__
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#include <sys/disk.h>
#endif
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#endif
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#ifdef _WIN32
#include <windows.h>
#endif

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static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
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        BlockDriverCompletionFunc *cb, void *opaque);
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static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
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        BlockDriverCompletionFunc *cb, void *opaque);
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static BlockDriverAIOCB *bdrv_aio_flush_em(BlockDriverState *bs,
        BlockDriverCompletionFunc *cb, void *opaque);
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static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
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                        uint8_t *buf, int nb_sectors);
static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
                         const uint8_t *buf, int nb_sectors);
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BlockDriverState *bdrv_first;

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static BlockDriver *first_drv;

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/* If non-zero, use only whitelisted block drivers */
static int use_bdrv_whitelist;

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int path_is_absolute(const char *path)
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{
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    const char *p;
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#ifdef _WIN32
    /* specific case for names like: "\\.\d:" */
    if (*path == '/' || *path == '\\')
        return 1;
#endif
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    p = strchr(path, ':');
    if (p)
        p++;
    else
        p = path;
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#ifdef _WIN32
    return (*p == '/' || *p == '\\');
#else
    return (*p == '/');
#endif
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}

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/* if filename is absolute, just copy it to dest. Otherwise, build a
   path to it by considering it is relative to base_path. URL are
   supported. */
void path_combine(char *dest, int dest_size,
                  const char *base_path,
                  const char *filename)
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{
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    const char *p, *p1;
    int len;

    if (dest_size <= 0)
        return;
    if (path_is_absolute(filename)) {
        pstrcpy(dest, dest_size, filename);
    } else {
        p = strchr(base_path, ':');
        if (p)
            p++;
        else
            p = base_path;
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        p1 = strrchr(base_path, '/');
#ifdef _WIN32
        {
            const char *p2;
            p2 = strrchr(base_path, '\\');
            if (!p1 || p2 > p1)
                p1 = p2;
        }
#endif
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        if (p1)
            p1++;
        else
            p1 = base_path;
        if (p1 > p)
            p = p1;
        len = p - base_path;
        if (len > dest_size - 1)
            len = dest_size - 1;
        memcpy(dest, base_path, len);
        dest[len] = '\0';
        pstrcat(dest, dest_size, filename);
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    }
}

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void bdrv_register(BlockDriver *bdrv)
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{
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    if (!bdrv->bdrv_aio_readv) {
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        /* add AIO emulation layer */
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        bdrv->bdrv_aio_readv = bdrv_aio_readv_em;
        bdrv->bdrv_aio_writev = bdrv_aio_writev_em;
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    } else if (!bdrv->bdrv_read) {
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        /* add synchronous IO emulation layer */
        bdrv->bdrv_read = bdrv_read_em;
        bdrv->bdrv_write = bdrv_write_em;
    }
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    if (!bdrv->bdrv_aio_flush)
        bdrv->bdrv_aio_flush = bdrv_aio_flush_em;

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    bdrv->next = first_drv;
    first_drv = bdrv;
}
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/* create a new block device (by default it is empty) */
BlockDriverState *bdrv_new(const char *device_name)
{
    BlockDriverState **pbs, *bs;

    bs = qemu_mallocz(sizeof(BlockDriverState));
    pstrcpy(bs->device_name, sizeof(bs->device_name), device_name);
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    if (device_name[0] != '\0') {
        /* insert at the end */
        pbs = &bdrv_first;
        while (*pbs != NULL)
            pbs = &(*pbs)->next;
        *pbs = bs;
    }
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    return bs;
}

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BlockDriver *bdrv_find_format(const char *format_name)
{
    BlockDriver *drv1;
    for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
        if (!strcmp(drv1->format_name, format_name))
            return drv1;
    }
    return NULL;
}

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static int bdrv_is_whitelisted(BlockDriver *drv)
{
    static const char *whitelist[] = {
        CONFIG_BDRV_WHITELIST
    };
    const char **p;

    if (!whitelist[0])
        return 1;               /* no whitelist, anything goes */

    for (p = whitelist; *p; p++) {
        if (!strcmp(drv->format_name, *p)) {
            return 1;
        }
    }
    return 0;
}

BlockDriver *bdrv_find_whitelisted_format(const char *format_name)
{
    BlockDriver *drv = bdrv_find_format(format_name);
    return drv && bdrv_is_whitelisted(drv) ? drv : NULL;
}

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int bdrv_create(BlockDriver *drv, const char* filename,
    QEMUOptionParameter *options)
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{
    if (!drv->bdrv_create)
        return -ENOTSUP;
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    return drv->bdrv_create(filename, options);
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}

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#ifdef _WIN32
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void get_tmp_filename(char *filename, int size)
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{
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    char temp_dir[MAX_PATH];
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    GetTempPath(MAX_PATH, temp_dir);
    GetTempFileName(temp_dir, "qem", 0, filename);
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}
#else
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void get_tmp_filename(char *filename, int size)
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{
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    int fd;
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    const char *tmpdir;
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    /* XXX: race condition possible */
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    tmpdir = getenv("TMPDIR");
    if (!tmpdir)
        tmpdir = "/tmp";
    snprintf(filename, size, "%s/vl.XXXXXX", tmpdir);
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    fd = mkstemp(filename);
    close(fd);
}
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#endif
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#ifdef _WIN32
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static int is_windows_drive_prefix(const char *filename)
{
    return (((filename[0] >= 'a' && filename[0] <= 'z') ||
             (filename[0] >= 'A' && filename[0] <= 'Z')) &&
            filename[1] == ':');
}
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int is_windows_drive(const char *filename)
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{
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    if (is_windows_drive_prefix(filename) &&
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        filename[2] == '\0')
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        return 1;
    if (strstart(filename, "\\\\.\\", NULL) ||
        strstart(filename, "//./", NULL))
        return 1;
    return 0;
}
#endif

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static BlockDriver *find_protocol(const char *filename)
{
    BlockDriver *drv1;
    char protocol[128];
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    int len;
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    const char *p;
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#ifdef _WIN32
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    if (is_windows_drive(filename) ||
        is_windows_drive_prefix(filename))
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        return bdrv_find_format("raw");
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#endif
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    p = strchr(filename, ':');
    if (!p)
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        return bdrv_find_format("raw");
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    len = p - filename;
    if (len > sizeof(protocol) - 1)
        len = sizeof(protocol) - 1;
    memcpy(protocol, filename, len);
    protocol[len] = '\0';
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    for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
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        if (drv1->protocol_name &&
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            !strcmp(drv1->protocol_name, protocol))
            return drv1;
    }
    return NULL;
}

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/*
 * Detect host devices. By convention, /dev/cdrom[N] is always
 * recognized as a host CDROM.
 */
static BlockDriver *find_hdev_driver(const char *filename)
{
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    int score_max = 0, score;
    BlockDriver *drv = NULL, *d;
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    for (d = first_drv; d; d = d->next) {
        if (d->bdrv_probe_device) {
            score = d->bdrv_probe_device(filename);
            if (score > score_max) {
                score_max = score;
                drv = d;
            }
        }
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    }
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    return drv;
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}
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static BlockDriver *find_image_format(const char *filename)
{
    int ret, score, score_max;
    BlockDriver *drv1, *drv;
    uint8_t buf[2048];
    BlockDriverState *bs;

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    drv = find_protocol(filename);
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    /* no need to test disk image formats for vvfat */
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    if (drv && strcmp(drv->format_name, "vvfat") == 0)
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        return drv;
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    ret = bdrv_file_open(&bs, filename, 0);
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    if (ret < 0)
        return NULL;
    ret = bdrv_pread(bs, 0, buf, sizeof(buf));
    bdrv_delete(bs);
    if (ret < 0) {
        return NULL;
    }

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    score_max = 0;
    for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
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        if (drv1->bdrv_probe) {
            score = drv1->bdrv_probe(buf, ret, filename);
            if (score > score_max) {
                score_max = score;
                drv = drv1;
            }
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        }
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    }
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    return drv;
}

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int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags)
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{
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    BlockDriverState *bs;
    int ret;

    bs = bdrv_new("");
    ret = bdrv_open2(bs, filename, flags | BDRV_O_FILE, NULL);
    if (ret < 0) {
        bdrv_delete(bs);
        return ret;
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    }
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    bs->growable = 1;
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    *pbs = bs;
    return 0;
}

int bdrv_open(BlockDriverState *bs, const char *filename, int flags)
{
    return bdrv_open2(bs, filename, flags, NULL);
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}

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int bdrv_open2(BlockDriverState *bs, const char *filename, int flags,
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               BlockDriver *drv)
{
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    int ret, open_flags;
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    char tmp_filename[PATH_MAX];
    char backing_filename[PATH_MAX];
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    bs->is_temporary = 0;
    bs->encrypted = 0;
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    bs->valid_key = 0;
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    bs->open_flags = flags;
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    /* buffer_alignment defaulted to 512, drivers can change this value */
    bs->buffer_alignment = 512;
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    if (flags & BDRV_O_SNAPSHOT) {
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        BlockDriverState *bs1;
        int64_t total_size;
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        int is_protocol = 0;
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        BlockDriver *bdrv_qcow2;
        QEMUOptionParameter *options;
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        /* if snapshot, we create a temporary backing file and open it
           instead of opening 'filename' directly */
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        /* if there is a backing file, use it */
        bs1 = bdrv_new("");
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        ret = bdrv_open2(bs1, filename, 0, drv);
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        if (ret < 0) {
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            bdrv_delete(bs1);
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            return ret;
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        }
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        total_size = bdrv_getlength(bs1) >> BDRV_SECTOR_BITS;
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        if (bs1->drv && bs1->drv->protocol_name)
            is_protocol = 1;

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        bdrv_delete(bs1);
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        get_tmp_filename(tmp_filename, sizeof(tmp_filename));
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        /* Real path is meaningless for protocols */
        if (is_protocol)
            snprintf(backing_filename, sizeof(backing_filename),
                     "%s", filename);
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        else if (!realpath(filename, backing_filename))
            return -errno;
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        bdrv_qcow2 = bdrv_find_format("qcow2");
        options = parse_option_parameters("", bdrv_qcow2->create_options, NULL);

        set_option_parameter_int(options, BLOCK_OPT_SIZE, total_size * 512);
        set_option_parameter(options, BLOCK_OPT_BACKING_FILE, backing_filename);
        if (drv) {
            set_option_parameter(options, BLOCK_OPT_BACKING_FMT,
                drv->format_name);
        }

        ret = bdrv_create(bdrv_qcow2, tmp_filename, options);
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        if (ret < 0) {
            return ret;
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        }
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        filename = tmp_filename;
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        drv = bdrv_qcow2;
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        bs->is_temporary = 1;
    }
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    pstrcpy(bs->filename, sizeof(bs->filename), filename);
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    if (flags & BDRV_O_FILE) {
        drv = find_protocol(filename);
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    } else if (!drv) {
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        drv = find_hdev_driver(filename);
        if (!drv) {
            drv = find_image_format(filename);
        }
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    }
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    if (!drv) {
        ret = -ENOENT;
        goto unlink_and_fail;
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    }
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    if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv)) {
        ret = -ENOTSUP;
        goto unlink_and_fail;
    }

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    bs->drv = drv;
    bs->opaque = qemu_mallocz(drv->instance_size);
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    /*
     * Yes, BDRV_O_NOCACHE aka O_DIRECT means we have to present a
     * write cache to the guest.  We do need the fdatasync to flush
     * out transactions for block allocations, and we maybe have a
     * volatile write cache in our backing device to deal with.
     */
    if (flags & (BDRV_O_CACHE_WB|BDRV_O_NOCACHE))
        bs->enable_write_cache = 1;

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    /*
     * Clear flags that are internal to the block layer before opening the
     * image.
     */
    open_flags = flags & ~(BDRV_O_FILE | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);

    /*
     * Snapshots should be writeable.
     *
     * XXX(hch): and what is the point of a snapshot during a read-only open?
     */
    if (!(flags & BDRV_O_FILE) && bs->is_temporary) {
        open_flags |= BDRV_O_RDWR;
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    }
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    ret = drv->bdrv_open(bs, filename, open_flags);
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    if (ret < 0) {
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        goto free_and_fail;
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    }
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    bs->keep_read_only = bs->read_only = !(open_flags & BDRV_O_RDWR);
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    if (drv->bdrv_getlength) {
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        bs->total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
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    }
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#ifndef _WIN32
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    if (bs->is_temporary) {
        unlink(filename);
    }
#endif
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    if ((flags & BDRV_O_NO_BACKING) == 0 && bs->backing_file[0] != '\0') {
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        /* if there is a backing file, use it */
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        BlockDriver *back_drv = NULL;
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        bs->backing_hd = bdrv_new("");
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        path_combine(backing_filename, sizeof(backing_filename),
                     filename, bs->backing_file);
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        if (bs->backing_format[0] != '\0')
            back_drv = bdrv_find_format(bs->backing_format);
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        /* backing files always opened read-only */
        open_flags &= ~BDRV_O_RDWR;
        
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        ret = bdrv_open2(bs->backing_hd, backing_filename, open_flags,
                         back_drv);
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        if (ret < 0) {
            bdrv_close(bs);
            return ret;
        }
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        if (bs->is_temporary) {
            bs->backing_hd->keep_read_only = !(flags & BDRV_O_RDWR);
        } else {
            /* base image inherits from "parent" */
            bs->backing_hd->keep_read_only = bs->keep_read_only;
        }
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    }

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    if (!bdrv_key_required(bs)) {
        /* call the change callback */
        bs->media_changed = 1;
        if (bs->change_cb)
            bs->change_cb(bs->change_opaque);
    }
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    return 0;
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free_and_fail:
    qemu_free(bs->opaque);
    bs->opaque = NULL;
    bs->drv = NULL;
unlink_and_fail:
    if (bs->is_temporary)
        unlink(filename);
    return ret;
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}

void bdrv_close(BlockDriverState *bs)
{
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    if (bs->drv) {
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        if (bs->backing_hd)
            bdrv_delete(bs->backing_hd);
        bs->drv->bdrv_close(bs);
        qemu_free(bs->opaque);
#ifdef _WIN32
        if (bs->is_temporary) {
            unlink(bs->filename);
        }
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#endif
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        bs->opaque = NULL;
        bs->drv = NULL;
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        /* call the change callback */
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        bs->media_changed = 1;
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        if (bs->change_cb)
            bs->change_cb(bs->change_opaque);
    }
}

void bdrv_delete(BlockDriverState *bs)
{
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    BlockDriverState **pbs;

    pbs = &bdrv_first;
    while (*pbs != bs && *pbs != NULL)
        pbs = &(*pbs)->next;
    if (*pbs == bs)
        *pbs = bs->next;

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    bdrv_close(bs);
    qemu_free(bs);
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}

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/*
 * Run consistency checks on an image
 *
 * Returns the number of errors or -errno when an internal error occurs
 */
int bdrv_check(BlockDriverState *bs)
{
    if (bs->drv->bdrv_check == NULL) {
        return -ENOTSUP;
    }

    return bs->drv->bdrv_check(bs);
}

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/* commit COW file into the raw image */
int bdrv_commit(BlockDriverState *bs)
{
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    BlockDriver *drv = bs->drv;
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    int64_t i, total_sectors;
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    int n, j, ro, open_flags;
    int ret = 0, rw_ret = 0;
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    unsigned char sector[512];
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    char filename[1024];
    BlockDriverState *bs_rw, *bs_ro;
587

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    if (!drv)
        return -ENOMEDIUM;
590 591 592
    
    if (!bs->backing_hd) {
        return -ENOTSUP;
593 594
    }

595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623
    if (bs->backing_hd->keep_read_only) {
        return -EACCES;
    }
    
    ro = bs->backing_hd->read_only;
    strncpy(filename, bs->backing_hd->filename, sizeof(filename));
    open_flags =  bs->backing_hd->open_flags;

    if (ro) {
        /* re-open as RW */
        bdrv_delete(bs->backing_hd);
        bs->backing_hd = NULL;
        bs_rw = bdrv_new("");
        rw_ret = bdrv_open2(bs_rw, filename, open_flags | BDRV_O_RDWR, NULL);
        if (rw_ret < 0) {
            bdrv_delete(bs_rw);
            /* try to re-open read-only */
            bs_ro = bdrv_new("");
            ret = bdrv_open2(bs_ro, filename, open_flags & ~BDRV_O_RDWR, NULL);
            if (ret < 0) {
                bdrv_delete(bs_ro);
                /* drive not functional anymore */
                bs->drv = NULL;
                return ret;
            }
            bs->backing_hd = bs_ro;
            return rw_ret;
        }
        bs->backing_hd = bs_rw;
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    }
625

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Jan Kiszka 已提交
626
    total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
B
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    for (i = 0; i < total_sectors;) {
B
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628
        if (drv->bdrv_is_allocated(bs, i, 65536, &n)) {
B
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629 630
            for(j = 0; j < n; j++) {
                if (bdrv_read(bs, i, sector, 1) != 0) {
631 632
                    ret = -EIO;
                    goto ro_cleanup;
B
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633 634 635
                }

                if (bdrv_write(bs->backing_hd, i, sector, 1) != 0) {
636 637
                    ret = -EIO;
                    goto ro_cleanup;
B
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638 639
                }
                i++;
640
	    }
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641 642 643
	} else {
            i += n;
        }
644
    }
645

646 647 648 649
    if (drv->bdrv_make_empty) {
        ret = drv->bdrv_make_empty(bs);
        bdrv_flush(bs);
    }
650

651 652 653 654 655 656
    /*
     * Make sure all data we wrote to the backing device is actually
     * stable on disk.
     */
    if (bs->backing_hd)
        bdrv_flush(bs->backing_hd);
657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675

ro_cleanup:

    if (ro) {
        /* re-open as RO */
        bdrv_delete(bs->backing_hd);
        bs->backing_hd = NULL;
        bs_ro = bdrv_new("");
        ret = bdrv_open2(bs_ro, filename, open_flags & ~BDRV_O_RDWR, NULL);
        if (ret < 0) {
            bdrv_delete(bs_ro);
            /* drive not functional anymore */
            bs->drv = NULL;
            return ret;
        }
        bs->backing_hd = bs_ro;
        bs->backing_hd->keep_read_only = 0;
    }

676
    return ret;
677 678
}

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/*
 * Return values:
 * 0        - success
 * -EINVAL  - backing format specified, but no file
 * -ENOSPC  - can't update the backing file because no space is left in the
 *            image file header
 * -ENOTSUP - format driver doesn't support changing the backing file
 */
int bdrv_change_backing_file(BlockDriverState *bs,
    const char *backing_file, const char *backing_fmt)
{
    BlockDriver *drv = bs->drv;

    if (drv->bdrv_change_backing_file != NULL) {
        return drv->bdrv_change_backing_file(bs, backing_file, backing_fmt);
    } else {
        return -ENOTSUP;
    }
}

699 700 701 702 703 704 705 706 707 708 709 710 711
static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,
                                   size_t size)
{
    int64_t len;

    if (!bdrv_is_inserted(bs))
        return -ENOMEDIUM;

    if (bs->growable)
        return 0;

    len = bdrv_getlength(bs);

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    if (offset < 0)
        return -EIO;

    if ((offset > len) || (len - offset < size))
716 717 718 719 720 721 722 723
        return -EIO;

    return 0;
}

static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num,
                              int nb_sectors)
{
724
    return bdrv_check_byte_request(bs, sector_num * 512, nb_sectors * 512);
725 726
}

B
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/* return < 0 if error. See bdrv_write() for the return codes */
728
int bdrv_read(BlockDriverState *bs, int64_t sector_num,
B
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729 730
              uint8_t *buf, int nb_sectors)
{
B
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731 732
    BlockDriver *drv = bs->drv;

B
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733 734
    if (!drv)
        return -ENOMEDIUM;
735 736
    if (bdrv_check_request(bs, sector_num, nb_sectors))
        return -EIO;
B
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738
    return drv->bdrv_read(bs, sector_num, buf, nb_sectors);
B
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739 740
}

741
static void set_dirty_bitmap(BlockDriverState *bs, int64_t sector_num,
742
                             int nb_sectors, int dirty)
743 744
{
    int64_t start, end;
745
    unsigned long val, idx, bit;
746

J
Jan Kiszka 已提交
747
    start = sector_num / BDRV_SECTORS_PER_DIRTY_CHUNK;
748
    end = (sector_num + nb_sectors - 1) / BDRV_SECTORS_PER_DIRTY_CHUNK;
749 750

    for (; start <= end; start++) {
751 752 753 754
        idx = start / (sizeof(unsigned long) * 8);
        bit = start % (sizeof(unsigned long) * 8);
        val = bs->dirty_bitmap[idx];
        if (dirty) {
755 756 757 758
            if (!(val & (1 << bit))) {
                bs->dirty_count++;
                val |= 1 << bit;
            }
759
        } else {
760 761 762 763
            if (val & (1 << bit)) {
                bs->dirty_count--;
                val &= ~(1 << bit);
            }
764 765
        }
        bs->dirty_bitmap[idx] = val;
766 767 768
    }
}

769
/* Return < 0 if error. Important errors are:
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  -EIO         generic I/O error (may happen for all errors)
  -ENOMEDIUM   No media inserted.
  -EINVAL      Invalid sector number or nb_sectors
  -EACCES      Trying to write a read-only device
*/
775
int bdrv_write(BlockDriverState *bs, int64_t sector_num,
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               const uint8_t *buf, int nb_sectors)
{
B
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    BlockDriver *drv = bs->drv;
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779 780
    if (!bs->drv)
        return -ENOMEDIUM;
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    if (bs->read_only)
B
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        return -EACCES;
783 784
    if (bdrv_check_request(bs, sector_num, nb_sectors))
        return -EIO;
785

786
    if (bs->dirty_bitmap) {
787 788
        set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
    }
789

790
    return drv->bdrv_write(bs, sector_num, buf, nb_sectors);
B
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}

793 794
int bdrv_pread(BlockDriverState *bs, int64_t offset,
               void *buf, int count1)
B
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795
{
J
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796
    uint8_t tmp_buf[BDRV_SECTOR_SIZE];
B
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797 798
    int len, nb_sectors, count;
    int64_t sector_num;
799
    int ret;
B
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800 801 802

    count = count1;
    /* first read to align to sector start */
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Jan Kiszka 已提交
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    len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
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    if (len > count)
        len = count;
J
Jan Kiszka 已提交
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    sector_num = offset >> BDRV_SECTOR_BITS;
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    if (len > 0) {
808 809
        if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
            return ret;
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Jan Kiszka 已提交
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        memcpy(buf, tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), len);
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811 812 813 814 815 816 817 818
        count -= len;
        if (count == 0)
            return count1;
        sector_num++;
        buf += len;
    }

    /* read the sectors "in place" */
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    nb_sectors = count >> BDRV_SECTOR_BITS;
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    if (nb_sectors > 0) {
821 822
        if ((ret = bdrv_read(bs, sector_num, buf, nb_sectors)) < 0)
            return ret;
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        sector_num += nb_sectors;
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Jan Kiszka 已提交
824
        len = nb_sectors << BDRV_SECTOR_BITS;
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        buf += len;
        count -= len;
    }

    /* add data from the last sector */
    if (count > 0) {
831 832
        if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
            return ret;
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        memcpy(buf, tmp_buf, count);
    }
    return count1;
}

838 839
int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
                const void *buf, int count1)
B
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840
{
J
Jan Kiszka 已提交
841
    uint8_t tmp_buf[BDRV_SECTOR_SIZE];
B
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842 843
    int len, nb_sectors, count;
    int64_t sector_num;
844
    int ret;
B
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845 846 847

    count = count1;
    /* first write to align to sector start */
J
Jan Kiszka 已提交
848
    len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
B
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849 850
    if (len > count)
        len = count;
J
Jan Kiszka 已提交
851
    sector_num = offset >> BDRV_SECTOR_BITS;
B
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852
    if (len > 0) {
853 854
        if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
            return ret;
J
Jan Kiszka 已提交
855
        memcpy(tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), buf, len);
856 857
        if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0)
            return ret;
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858 859 860 861 862 863 864 865
        count -= len;
        if (count == 0)
            return count1;
        sector_num++;
        buf += len;
    }

    /* write the sectors "in place" */
J
Jan Kiszka 已提交
866
    nb_sectors = count >> BDRV_SECTOR_BITS;
B
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867
    if (nb_sectors > 0) {
868 869
        if ((ret = bdrv_write(bs, sector_num, buf, nb_sectors)) < 0)
            return ret;
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870
        sector_num += nb_sectors;
J
Jan Kiszka 已提交
871
        len = nb_sectors << BDRV_SECTOR_BITS;
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872 873 874 875 876 877
        buf += len;
        count -= len;
    }

    /* add data from the last sector */
    if (count > 0) {
878 879
        if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
            return ret;
B
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        memcpy(tmp_buf, buf, count);
881 882
        if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0)
            return ret;
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883 884 885 886 887 888 889 890 891 892 893
    }
    return count1;
}

/**
 * Truncate file to 'offset' bytes (needed only for file protocols)
 */
int bdrv_truncate(BlockDriverState *bs, int64_t offset)
{
    BlockDriver *drv = bs->drv;
    if (!drv)
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894
        return -ENOMEDIUM;
B
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895 896
    if (!drv->bdrv_truncate)
        return -ENOTSUP;
897 898
    if (bs->read_only)
        return -EACCES;
B
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899 900 901 902 903 904 905 906 907 908
    return drv->bdrv_truncate(bs, offset);
}

/**
 * Length of a file in bytes. Return < 0 if error or unknown.
 */
int64_t bdrv_getlength(BlockDriverState *bs)
{
    BlockDriver *drv = bs->drv;
    if (!drv)
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bellard 已提交
909
        return -ENOMEDIUM;
B
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910 911
    if (!drv->bdrv_getlength) {
        /* legacy mode */
J
Jan Kiszka 已提交
912
        return bs->total_sectors * BDRV_SECTOR_SIZE;
B
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913 914
    }
    return drv->bdrv_getlength(bs);
B
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915 916
}

B
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917
/* return 0 as number of sectors if no device present or error */
918
void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
B
bellard 已提交
919
{
B
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920 921 922 923 924
    int64_t length;
    length = bdrv_getlength(bs);
    if (length < 0)
        length = 0;
    else
J
Jan Kiszka 已提交
925
        length = length >> BDRV_SECTOR_BITS;
B
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926
    *nb_sectors_ptr = length;
B
bellard 已提交
927
}
B
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928

929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949
struct partition {
        uint8_t boot_ind;           /* 0x80 - active */
        uint8_t head;               /* starting head */
        uint8_t sector;             /* starting sector */
        uint8_t cyl;                /* starting cylinder */
        uint8_t sys_ind;            /* What partition type */
        uint8_t end_head;           /* end head */
        uint8_t end_sector;         /* end sector */
        uint8_t end_cyl;            /* end cylinder */
        uint32_t start_sect;        /* starting sector counting from 0 */
        uint32_t nr_sects;          /* nr of sectors in partition */
} __attribute__((packed));

/* try to guess the disk logical geometry from the MSDOS partition table. Return 0 if OK, -1 if could not guess */
static int guess_disk_lchs(BlockDriverState *bs,
                           int *pcylinders, int *pheads, int *psectors)
{
    uint8_t buf[512];
    int ret, i, heads, sectors, cylinders;
    struct partition *p;
    uint32_t nr_sects;
B
blueswir1 已提交
950
    uint64_t nb_sectors;
951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989

    bdrv_get_geometry(bs, &nb_sectors);

    ret = bdrv_read(bs, 0, buf, 1);
    if (ret < 0)
        return -1;
    /* test msdos magic */
    if (buf[510] != 0x55 || buf[511] != 0xaa)
        return -1;
    for(i = 0; i < 4; i++) {
        p = ((struct partition *)(buf + 0x1be)) + i;
        nr_sects = le32_to_cpu(p->nr_sects);
        if (nr_sects && p->end_head) {
            /* We make the assumption that the partition terminates on
               a cylinder boundary */
            heads = p->end_head + 1;
            sectors = p->end_sector & 63;
            if (sectors == 0)
                continue;
            cylinders = nb_sectors / (heads * sectors);
            if (cylinders < 1 || cylinders > 16383)
                continue;
            *pheads = heads;
            *psectors = sectors;
            *pcylinders = cylinders;
#if 0
            printf("guessed geometry: LCHS=%d %d %d\n",
                   cylinders, heads, sectors);
#endif
            return 0;
        }
    }
    return -1;
}

void bdrv_guess_geometry(BlockDriverState *bs, int *pcyls, int *pheads, int *psecs)
{
    int translation, lba_detected = 0;
    int cylinders, heads, secs;
B
blueswir1 已提交
990
    uint64_t nb_sectors;
991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044

    /* if a geometry hint is available, use it */
    bdrv_get_geometry(bs, &nb_sectors);
    bdrv_get_geometry_hint(bs, &cylinders, &heads, &secs);
    translation = bdrv_get_translation_hint(bs);
    if (cylinders != 0) {
        *pcyls = cylinders;
        *pheads = heads;
        *psecs = secs;
    } else {
        if (guess_disk_lchs(bs, &cylinders, &heads, &secs) == 0) {
            if (heads > 16) {
                /* if heads > 16, it means that a BIOS LBA
                   translation was active, so the default
                   hardware geometry is OK */
                lba_detected = 1;
                goto default_geometry;
            } else {
                *pcyls = cylinders;
                *pheads = heads;
                *psecs = secs;
                /* disable any translation to be in sync with
                   the logical geometry */
                if (translation == BIOS_ATA_TRANSLATION_AUTO) {
                    bdrv_set_translation_hint(bs,
                                              BIOS_ATA_TRANSLATION_NONE);
                }
            }
        } else {
        default_geometry:
            /* if no geometry, use a standard physical disk geometry */
            cylinders = nb_sectors / (16 * 63);

            if (cylinders > 16383)
                cylinders = 16383;
            else if (cylinders < 2)
                cylinders = 2;
            *pcyls = cylinders;
            *pheads = 16;
            *psecs = 63;
            if ((lba_detected == 1) && (translation == BIOS_ATA_TRANSLATION_AUTO)) {
                if ((*pcyls * *pheads) <= 131072) {
                    bdrv_set_translation_hint(bs,
                                              BIOS_ATA_TRANSLATION_LARGE);
                } else {
                    bdrv_set_translation_hint(bs,
                                              BIOS_ATA_TRANSLATION_LBA);
                }
            }
        }
        bdrv_set_geometry_hint(bs, *pcyls, *pheads, *psecs);
    }
}

1045
void bdrv_set_geometry_hint(BlockDriverState *bs,
B
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1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059
                            int cyls, int heads, int secs)
{
    bs->cyls = cyls;
    bs->heads = heads;
    bs->secs = secs;
}

void bdrv_set_type_hint(BlockDriverState *bs, int type)
{
    bs->type = type;
    bs->removable = ((type == BDRV_TYPE_CDROM ||
                      type == BDRV_TYPE_FLOPPY));
}

B
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1060 1061 1062 1063 1064
void bdrv_set_translation_hint(BlockDriverState *bs, int translation)
{
    bs->translation = translation;
}

1065
void bdrv_get_geometry_hint(BlockDriverState *bs,
B
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1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077
                            int *pcyls, int *pheads, int *psecs)
{
    *pcyls = bs->cyls;
    *pheads = bs->heads;
    *psecs = bs->secs;
}

int bdrv_get_type_hint(BlockDriverState *bs)
{
    return bs->type;
}

B
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1078 1079 1080 1081 1082
int bdrv_get_translation_hint(BlockDriverState *bs)
{
    return bs->translation;
}

B
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1083 1084 1085 1086 1087 1088 1089 1090 1091 1092
int bdrv_is_removable(BlockDriverState *bs)
{
    return bs->removable;
}

int bdrv_is_read_only(BlockDriverState *bs)
{
    return bs->read_only;
}

1093 1094 1095 1096 1097
int bdrv_is_sg(BlockDriverState *bs)
{
    return bs->sg;
}

1098 1099 1100 1101 1102
int bdrv_enable_write_cache(BlockDriverState *bs)
{
    return bs->enable_write_cache;
}

B
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1103
/* XXX: no longer used */
1104
void bdrv_set_change_cb(BlockDriverState *bs,
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1105 1106 1107 1108 1109 1110
                        void (*change_cb)(void *opaque), void *opaque)
{
    bs->change_cb = change_cb;
    bs->change_opaque = opaque;
}

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1111 1112 1113 1114 1115 1116 1117
int bdrv_is_encrypted(BlockDriverState *bs)
{
    if (bs->backing_hd && bs->backing_hd->encrypted)
        return 1;
    return bs->encrypted;
}

1118 1119 1120 1121 1122 1123 1124 1125 1126
int bdrv_key_required(BlockDriverState *bs)
{
    BlockDriverState *backing_hd = bs->backing_hd;

    if (backing_hd && backing_hd->encrypted && !backing_hd->valid_key)
        return 1;
    return (bs->encrypted && !bs->valid_key);
}

B
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1127 1128 1129 1130 1131 1132 1133 1134 1135 1136
int bdrv_set_key(BlockDriverState *bs, const char *key)
{
    int ret;
    if (bs->backing_hd && bs->backing_hd->encrypted) {
        ret = bdrv_set_key(bs->backing_hd, key);
        if (ret < 0)
            return ret;
        if (!bs->encrypted)
            return 0;
    }
1137 1138 1139 1140 1141
    if (!bs->encrypted) {
        return -EINVAL;
    } else if (!bs->drv || !bs->drv->bdrv_set_key) {
        return -ENOMEDIUM;
    }
1142
    ret = bs->drv->bdrv_set_key(bs, key);
1143 1144 1145 1146 1147 1148 1149 1150 1151
    if (ret < 0) {
        bs->valid_key = 0;
    } else if (!bs->valid_key) {
        bs->valid_key = 1;
        /* call the change callback now, we skipped it on open */
        bs->media_changed = 1;
        if (bs->change_cb)
            bs->change_cb(bs->change_opaque);
    }
1152
    return ret;
B
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1153 1154 1155 1156
}

void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)
{
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    if (!bs->drv) {
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        buf[0] = '\0';
    } else {
        pstrcpy(buf, buf_size, bs->drv->format_name);
    }
}

1164
void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
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                         void *opaque)
{
    BlockDriver *drv;

    for (drv = first_drv; drv != NULL; drv = drv->next) {
        it(opaque, drv->format_name);
    }
}

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BlockDriverState *bdrv_find(const char *name)
{
    BlockDriverState *bs;

    for (bs = bdrv_first; bs != NULL; bs = bs->next) {
        if (!strcmp(name, bs->device_name))
            return bs;
    }
    return NULL;
}

1185
void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs), void *opaque)
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{
    BlockDriverState *bs;

    for (bs = bdrv_first; bs != NULL; bs = bs->next) {
1190
        it(opaque, bs);
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    }
}

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const char *bdrv_get_device_name(BlockDriverState *bs)
{
    return bs->device_name;
}

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void bdrv_flush(BlockDriverState *bs)
{
1201
    if (bs->drv && bs->drv->bdrv_flush)
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        bs->drv->bdrv_flush(bs);
}

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void bdrv_flush_all(void)
{
    BlockDriverState *bs;

    for (bs = bdrv_first; bs != NULL; bs = bs->next)
        if (bs->drv && !bdrv_is_read_only(bs) && 
            (!bdrv_is_removable(bs) || bdrv_is_inserted(bs)))
            bdrv_flush(bs);
}

1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241
/*
 * Returns true iff the specified sector is present in the disk image. Drivers
 * not implementing the functionality are assumed to not support backing files,
 * hence all their sectors are reported as allocated.
 *
 * 'pnum' is set to the number of sectors (including and immediately following
 * the specified sector) that are known to be in the same
 * allocated/unallocated state.
 *
 * 'nb_sectors' is the max value 'pnum' should be set to.
 */
int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
	int *pnum)
{
    int64_t n;
    if (!bs->drv->bdrv_is_allocated) {
        if (sector_num >= bs->total_sectors) {
            *pnum = 0;
            return 0;
        }
        n = bs->total_sectors - sector_num;
        *pnum = (n < nb_sectors) ? (n) : (nb_sectors);
        return 1;
    }
    return bs->drv->bdrv_is_allocated(bs, sector_num, nb_sectors, pnum);
}

1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270
void bdrv_mon_event(const BlockDriverState *bdrv,
                    BlockMonEventAction action, int is_read)
{
    QObject *data;
    const char *action_str;

    switch (action) {
    case BDRV_ACTION_REPORT:
        action_str = "report";
        break;
    case BDRV_ACTION_IGNORE:
        action_str = "ignore";
        break;
    case BDRV_ACTION_STOP:
        action_str = "stop";
        break;
    default:
        abort();
    }

    data = qobject_from_jsonf("{ 'device': %s, 'action': %s, 'operation': %s }",
                              bdrv->device_name,
                              action_str,
                              is_read ? "read" : "write");
    monitor_protocol_event(QEVENT_BLOCK_IO_ERROR, data);

    qobject_decref(data);
}

1271
static void bdrv_print_dict(QObject *obj, void *opaque)
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{
1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341
    QDict *bs_dict;
    Monitor *mon = opaque;

    bs_dict = qobject_to_qdict(obj);

    monitor_printf(mon, "%s: type=%s removable=%d",
                        qdict_get_str(bs_dict, "device"),
                        qdict_get_str(bs_dict, "type"),
                        qdict_get_bool(bs_dict, "removable"));

    if (qdict_get_bool(bs_dict, "removable")) {
        monitor_printf(mon, " locked=%d", qdict_get_bool(bs_dict, "locked"));
    }

    if (qdict_haskey(bs_dict, "inserted")) {
        QDict *qdict = qobject_to_qdict(qdict_get(bs_dict, "inserted"));

        monitor_printf(mon, " file=");
        monitor_print_filename(mon, qdict_get_str(qdict, "file"));
        if (qdict_haskey(qdict, "backing_file")) {
            monitor_printf(mon, " backing_file=");
            monitor_print_filename(mon, qdict_get_str(qdict, "backing_file"));
        }
        monitor_printf(mon, " ro=%d drv=%s encrypted=%d",
                            qdict_get_bool(qdict, "ro"),
                            qdict_get_str(qdict, "drv"),
                            qdict_get_bool(qdict, "encrypted"));
    } else {
        monitor_printf(mon, " [not inserted]");
    }

    monitor_printf(mon, "\n");
}

void bdrv_info_print(Monitor *mon, const QObject *data)
{
    qlist_iter(qobject_to_qlist(data), bdrv_print_dict, mon);
}

/**
 * bdrv_info(): Block devices information
 *
 * Each block device information is stored in a QDict and the
 * returned QObject is a QList of all devices.
 *
 * The QDict contains the following:
 *
 * - "device": device name
 * - "type": device type
 * - "removable": true if the device is removable, false otherwise
 * - "locked": true if the device is locked, false otherwise
 * - "inserted": only present if the device is inserted, it is a QDict
 *    containing the following:
 *          - "file": device file name
 *          - "ro": true if read-only, false otherwise
 *          - "drv": driver format name
 *          - "backing_file": backing file name if one is used
 *          - "encrypted": true if encrypted, false otherwise
 *
 * Example:
 *
 * [ { "device": "ide0-hd0", "type": "hd", "removable": false, "locked": false,
 *     "inserted": { "file": "/tmp/foobar", "ro": false, "drv": "qcow2" } },
 *   { "device": "floppy0", "type": "floppy", "removable": true,
 *     "locked": false } ]
 */
void bdrv_info(Monitor *mon, QObject **ret_data)
{
    QList *bs_list;
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    BlockDriverState *bs;

1344 1345
    bs_list = qlist_new();

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    for (bs = bdrv_first; bs != NULL; bs = bs->next) {
1347 1348 1349
        QObject *bs_obj;
        const char *type = "unknown";

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        switch(bs->type) {
        case BDRV_TYPE_HD:
1352
            type = "hd";
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            break;
        case BDRV_TYPE_CDROM:
1355
            type = "cdrom";
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            break;
        case BDRV_TYPE_FLOPPY:
1358
            type = "floppy";
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            break;
        }
1361 1362 1363 1364 1365 1366

        bs_obj = qobject_from_jsonf("{ 'device': %s, 'type': %s, "
                                    "'removable': %i, 'locked': %i }",
                                    bs->device_name, type, bs->removable,
                                    bs->locked);

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        if (bs->drv) {
1368 1369 1370 1371 1372 1373 1374 1375
            QObject *obj;
            QDict *bs_dict = qobject_to_qdict(bs_obj);

            obj = qobject_from_jsonf("{ 'file': %s, 'ro': %i, 'drv': %s, "
                                     "'encrypted': %i }",
                                     bs->filename, bs->read_only,
                                     bs->drv->format_name,
                                     bdrv_is_encrypted(bs));
1376
            if (bs->backing_file[0] != '\0') {
1377 1378 1379
                QDict *qdict = qobject_to_qdict(obj);
                qdict_put(qdict, "backing_file",
                          qstring_from_str(bs->backing_file));
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            }
1381 1382

            qdict_put_obj(bs_dict, "inserted", obj);
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        }
1384
        qlist_append_obj(bs_list, bs_obj);
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    }
1386 1387

    *ret_data = QOBJECT(bs_list);
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}
1389

1390
static void bdrv_stats_iter(QObject *data, void *opaque)
1391
{
1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446
    QDict *qdict;
    Monitor *mon = opaque;

    qdict = qobject_to_qdict(data);
    monitor_printf(mon, "%s:", qdict_get_str(qdict, "device"));

    qdict = qobject_to_qdict(qdict_get(qdict, "stats"));
    monitor_printf(mon, " rd_bytes=%" PRId64
                        " wr_bytes=%" PRId64
                        " rd_operations=%" PRId64
                        " wr_operations=%" PRId64
                        "\n",
                        qdict_get_int(qdict, "rd_bytes"),
                        qdict_get_int(qdict, "wr_bytes"),
                        qdict_get_int(qdict, "rd_operations"),
                        qdict_get_int(qdict, "wr_operations"));
}

void bdrv_stats_print(Monitor *mon, const QObject *data)
{
    qlist_iter(qobject_to_qlist(data), bdrv_stats_iter, mon);
}

/**
 * bdrv_info_stats(): show block device statistics
 *
 * Each device statistic information is stored in a QDict and
 * the returned QObject is a QList of all devices.
 *
 * The QDict contains the following:
 *
 * - "device": device name
 * - "stats": A QDict with the statistics information, it contains:
 *     - "rd_bytes": bytes read
 *     - "wr_bytes": bytes written
 *     - "rd_operations": read operations
 *     - "wr_operations": write operations
 * 
 * Example:
 *
 * [ { "device": "ide0-hd0",
 *               "stats": { "rd_bytes": 512,
 *                          "wr_bytes": 0,
 *                          "rd_operations": 1,
 *                          "wr_operations": 0 } },
 *   { "device": "ide1-cd0",
 *               "stats": { "rd_bytes": 0,
 *                          "wr_bytes": 0,
 *                          "rd_operations": 0,
 *                          "wr_operations": 0 } } ]
 */
void bdrv_info_stats(Monitor *mon, QObject **ret_data)
{
    QObject *obj;
    QList *devices;
1447 1448
    BlockDriverState *bs;

1449 1450
    devices = qlist_new();

1451
    for (bs = bdrv_first; bs != NULL; bs = bs->next) {
1452 1453 1454 1455 1456 1457 1458 1459 1460 1461
        obj = qobject_from_jsonf("{ 'device': %s, 'stats': {"
                                 "'rd_bytes': %" PRId64 ","
                                 "'wr_bytes': %" PRId64 ","
                                 "'rd_operations': %" PRId64 ","
                                 "'wr_operations': %" PRId64
                                 "} }",
                                 bs->device_name,
                                 bs->rd_bytes, bs->wr_bytes,
                                 bs->rd_ops, bs->wr_ops);
        qlist_append_obj(devices, obj);
1462
    }
1463 1464

    *ret_data = QOBJECT(devices);
1465
}
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1467 1468 1469 1470 1471 1472 1473 1474 1475 1476
const char *bdrv_get_encrypted_filename(BlockDriverState *bs)
{
    if (bs->backing_hd && bs->backing_hd->encrypted)
        return bs->backing_file;
    else if (bs->encrypted)
        return bs->filename;
    else
        return NULL;
}

1477
void bdrv_get_backing_filename(BlockDriverState *bs,
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                               char *filename, int filename_size)
{
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    if (!bs->backing_file) {
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        pstrcpy(filename, filename_size, "");
    } else {
        pstrcpy(filename, filename_size, bs->backing_file);
    }
}

1487
int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
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                          const uint8_t *buf, int nb_sectors)
{
    BlockDriver *drv = bs->drv;
    if (!drv)
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        return -ENOMEDIUM;
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    if (!drv->bdrv_write_compressed)
        return -ENOTSUP;
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    if (bdrv_check_request(bs, sector_num, nb_sectors))
        return -EIO;
1497

1498
    if (bs->dirty_bitmap) {
1499 1500
        set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
    }
1501

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    return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
}
1504

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int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
{
    BlockDriver *drv = bs->drv;
    if (!drv)
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        return -ENOMEDIUM;
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    if (!drv->bdrv_get_info)
        return -ENOTSUP;
    memset(bdi, 0, sizeof(*bdi));
    return drv->bdrv_get_info(bs, bdi);
}

1516 1517
int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
                      int64_t pos, int size)
1518 1519 1520 1521
{
    BlockDriver *drv = bs->drv;
    if (!drv)
        return -ENOMEDIUM;
1522
    if (!drv->bdrv_save_vmstate)
1523
        return -ENOTSUP;
1524
    return drv->bdrv_save_vmstate(bs, buf, pos, size);
1525 1526
}

1527 1528
int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
                      int64_t pos, int size)
1529 1530 1531 1532
{
    BlockDriver *drv = bs->drv;
    if (!drv)
        return -ENOMEDIUM;
1533
    if (!drv->bdrv_load_vmstate)
1534
        return -ENOTSUP;
1535
    return drv->bdrv_load_vmstate(bs, buf, pos, size);
1536 1537
}

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void bdrv_debug_event(BlockDriverState *bs, BlkDebugEvent event)
{
    BlockDriver *drv = bs->drv;

    if (!drv || !drv->bdrv_debug_event) {
        return;
    }

    return drv->bdrv_debug_event(bs, event);

}

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/**************************************************************/
/* handling of snapshots */

1553
int bdrv_snapshot_create(BlockDriverState *bs,
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                         QEMUSnapshotInfo *sn_info)
{
    BlockDriver *drv = bs->drv;
    if (!drv)
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        return -ENOMEDIUM;
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    if (!drv->bdrv_snapshot_create)
        return -ENOTSUP;
    return drv->bdrv_snapshot_create(bs, sn_info);
}

1564
int bdrv_snapshot_goto(BlockDriverState *bs,
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                       const char *snapshot_id)
{
    BlockDriver *drv = bs->drv;
    if (!drv)
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        return -ENOMEDIUM;
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    if (!drv->bdrv_snapshot_goto)
        return -ENOTSUP;
    return drv->bdrv_snapshot_goto(bs, snapshot_id);
}

int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
{
    BlockDriver *drv = bs->drv;
    if (!drv)
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        return -ENOMEDIUM;
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1580 1581 1582 1583 1584
    if (!drv->bdrv_snapshot_delete)
        return -ENOTSUP;
    return drv->bdrv_snapshot_delete(bs, snapshot_id);
}

1585
int bdrv_snapshot_list(BlockDriverState *bs,
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1586 1587 1588 1589
                       QEMUSnapshotInfo **psn_info)
{
    BlockDriver *drv = bs->drv;
    if (!drv)
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        return -ENOMEDIUM;
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1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609
    if (!drv->bdrv_snapshot_list)
        return -ENOTSUP;
    return drv->bdrv_snapshot_list(bs, psn_info);
}

#define NB_SUFFIXES 4

char *get_human_readable_size(char *buf, int buf_size, int64_t size)
{
    static const char suffixes[NB_SUFFIXES] = "KMGT";
    int64_t base;
    int i;

    if (size <= 999) {
        snprintf(buf, buf_size, "%" PRId64, size);
    } else {
        base = 1024;
        for(i = 0; i < NB_SUFFIXES; i++) {
            if (size < (10 * base)) {
1610
                snprintf(buf, buf_size, "%0.1f%c",
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1611 1612 1613 1614
                         (double)size / base,
                         suffixes[i]);
                break;
            } else if (size < (1000 * base) || i == (NB_SUFFIXES - 1)) {
1615
                snprintf(buf, buf_size, "%" PRId64 "%c",
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1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628
                         ((size + (base >> 1)) / base),
                         suffixes[i]);
                break;
            }
            base = base * 1024;
        }
    }
    return buf;
}

char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn)
{
    char buf1[128], date_buf[128], clock_buf[128];
1629 1630 1631
#ifdef _WIN32
    struct tm *ptm;
#else
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    struct tm tm;
1633
#endif
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1634 1635 1636 1637
    time_t ti;
    int64_t secs;

    if (!sn) {
1638 1639
        snprintf(buf, buf_size,
                 "%-10s%-20s%7s%20s%15s",
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1640 1641 1642
                 "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK");
    } else {
        ti = sn->date_sec;
1643 1644 1645 1646 1647
#ifdef _WIN32
        ptm = localtime(&ti);
        strftime(date_buf, sizeof(date_buf),
                 "%Y-%m-%d %H:%M:%S", ptm);
#else
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        localtime_r(&ti, &tm);
        strftime(date_buf, sizeof(date_buf),
                 "%Y-%m-%d %H:%M:%S", &tm);
1651
#endif
B
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1652 1653 1654 1655 1656
        secs = sn->vm_clock_nsec / 1000000000;
        snprintf(clock_buf, sizeof(clock_buf),
                 "%02d:%02d:%02d.%03d",
                 (int)(secs / 3600),
                 (int)((secs / 60) % 60),
1657
                 (int)(secs % 60),
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1658 1659
                 (int)((sn->vm_clock_nsec / 1000000) % 1000));
        snprintf(buf, buf_size,
1660
                 "%-10s%-20s%7s%20s%15s",
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1661 1662 1663 1664 1665 1666 1667 1668
                 sn->id_str, sn->name,
                 get_human_readable_size(buf1, sizeof(buf1), sn->vm_state_size),
                 date_buf,
                 clock_buf);
    }
    return buf;
}

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/**************************************************************/
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1671
/* async I/Os */
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1672

1673
BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
1674
                                 QEMUIOVector *qiov, int nb_sectors,
1675
                                 BlockDriverCompletionFunc *cb, void *opaque)
B
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1676 1677
{
    BlockDriver *drv = bs->drv;
1678
    BlockDriverAIOCB *ret;
B
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1679

B
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1680
    if (!drv)
1681
        return NULL;
1682 1683
    if (bdrv_check_request(bs, sector_num, nb_sectors))
        return NULL;
1684

1685 1686
    ret = drv->bdrv_aio_readv(bs, sector_num, qiov, nb_sectors,
                              cb, opaque);
1687 1688 1689

    if (ret) {
	/* Update stats even though technically transfer has not happened. */
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Jan Kiszka 已提交
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	bs->rd_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE;
1691 1692 1693 1694
	bs->rd_ops ++;
    }

    return ret;
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}

1697 1698 1699
BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
                                  QEMUIOVector *qiov, int nb_sectors,
                                  BlockDriverCompletionFunc *cb, void *opaque)
B
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1700
{
B
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1701
    BlockDriver *drv = bs->drv;
1702
    BlockDriverAIOCB *ret;
B
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1703

B
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1704
    if (!drv)
1705
        return NULL;
B
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1706
    if (bs->read_only)
1707
        return NULL;
1708 1709
    if (bdrv_check_request(bs, sector_num, nb_sectors))
        return NULL;
B
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1710

1711
    if (bs->dirty_bitmap) {
1712 1713
        set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
    }
1714

1715 1716
    ret = drv->bdrv_aio_writev(bs, sector_num, qiov, nb_sectors,
                               cb, opaque);
1717 1718 1719

    if (ret) {
	/* Update stats even though technically transfer has not happened. */
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Jan Kiszka 已提交
1720
	bs->wr_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE;
1721 1722 1723 1724
	bs->wr_ops ++;
    }

    return ret;
B
bellard 已提交
1725 1726
}

K
Kevin Wolf 已提交
1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746

typedef struct MultiwriteCB {
    int error;
    int num_requests;
    int num_callbacks;
    struct {
        BlockDriverCompletionFunc *cb;
        void *opaque;
        QEMUIOVector *free_qiov;
        void *free_buf;
    } callbacks[];
} MultiwriteCB;

static void multiwrite_user_cb(MultiwriteCB *mcb)
{
    int i;

    for (i = 0; i < mcb->num_callbacks; i++) {
        mcb->callbacks[i].cb(mcb->callbacks[i].opaque, mcb->error);
        qemu_free(mcb->callbacks[i].free_qiov);
1747
        qemu_vfree(mcb->callbacks[i].free_buf);
K
Kevin Wolf 已提交
1748 1749 1750 1751 1752 1753 1754
    }
}

static void multiwrite_cb(void *opaque, int ret)
{
    MultiwriteCB *mcb = opaque;

1755
    if (ret < 0 && !mcb->error) {
K
Kevin Wolf 已提交
1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806
        mcb->error = ret;
        multiwrite_user_cb(mcb);
    }

    mcb->num_requests--;
    if (mcb->num_requests == 0) {
        if (mcb->error == 0) {
            multiwrite_user_cb(mcb);
        }
        qemu_free(mcb);
    }
}

static int multiwrite_req_compare(const void *a, const void *b)
{
    return (((BlockRequest*) a)->sector - ((BlockRequest*) b)->sector);
}

/*
 * Takes a bunch of requests and tries to merge them. Returns the number of
 * requests that remain after merging.
 */
static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs,
    int num_reqs, MultiwriteCB *mcb)
{
    int i, outidx;

    // Sort requests by start sector
    qsort(reqs, num_reqs, sizeof(*reqs), &multiwrite_req_compare);

    // Check if adjacent requests touch the same clusters. If so, combine them,
    // filling up gaps with zero sectors.
    outidx = 0;
    for (i = 1; i < num_reqs; i++) {
        int merge = 0;
        int64_t oldreq_last = reqs[outidx].sector + reqs[outidx].nb_sectors;

        // This handles the cases that are valid for all block drivers, namely
        // exactly sequential writes and overlapping writes.
        if (reqs[i].sector <= oldreq_last) {
            merge = 1;
        }

        // The block driver may decide that it makes sense to combine requests
        // even if there is a gap of some sectors between them. In this case,
        // the gap is filled with zeros (therefore only applicable for yet
        // unused space in format like qcow2).
        if (!merge && bs->drv->bdrv_merge_requests) {
            merge = bs->drv->bdrv_merge_requests(bs, &reqs[outidx], &reqs[i]);
        }

1807 1808 1809 1810
        if (reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1 > IOV_MAX) {
            merge = 0;
        }

K
Kevin Wolf 已提交
1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895
        if (merge) {
            size_t size;
            QEMUIOVector *qiov = qemu_mallocz(sizeof(*qiov));
            qemu_iovec_init(qiov,
                reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1);

            // Add the first request to the merged one. If the requests are
            // overlapping, drop the last sectors of the first request.
            size = (reqs[i].sector - reqs[outidx].sector) << 9;
            qemu_iovec_concat(qiov, reqs[outidx].qiov, size);

            // We might need to add some zeros between the two requests
            if (reqs[i].sector > oldreq_last) {
                size_t zero_bytes = (reqs[i].sector - oldreq_last) << 9;
                uint8_t *buf = qemu_blockalign(bs, zero_bytes);
                memset(buf, 0, zero_bytes);
                qemu_iovec_add(qiov, buf, zero_bytes);
                mcb->callbacks[i].free_buf = buf;
            }

            // Add the second request
            qemu_iovec_concat(qiov, reqs[i].qiov, reqs[i].qiov->size);

            reqs[outidx].nb_sectors += reqs[i].nb_sectors;
            reqs[outidx].qiov = qiov;

            mcb->callbacks[i].free_qiov = reqs[outidx].qiov;
        } else {
            outidx++;
            reqs[outidx].sector     = reqs[i].sector;
            reqs[outidx].nb_sectors = reqs[i].nb_sectors;
            reqs[outidx].qiov       = reqs[i].qiov;
        }
    }

    return outidx + 1;
}

/*
 * Submit multiple AIO write requests at once.
 *
 * On success, the function returns 0 and all requests in the reqs array have
 * been submitted. In error case this function returns -1, and any of the
 * requests may or may not be submitted yet. In particular, this means that the
 * callback will be called for some of the requests, for others it won't. The
 * caller must check the error field of the BlockRequest to wait for the right
 * callbacks (if error != 0, no callback will be called).
 *
 * The implementation may modify the contents of the reqs array, e.g. to merge
 * requests. However, the fields opaque and error are left unmodified as they
 * are used to signal failure for a single request to the caller.
 */
int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs)
{
    BlockDriverAIOCB *acb;
    MultiwriteCB *mcb;
    int i;

    if (num_reqs == 0) {
        return 0;
    }

    // Create MultiwriteCB structure
    mcb = qemu_mallocz(sizeof(*mcb) + num_reqs * sizeof(*mcb->callbacks));
    mcb->num_requests = 0;
    mcb->num_callbacks = num_reqs;

    for (i = 0; i < num_reqs; i++) {
        mcb->callbacks[i].cb = reqs[i].cb;
        mcb->callbacks[i].opaque = reqs[i].opaque;
    }

    // Check for mergable requests
    num_reqs = multiwrite_merge(bs, reqs, num_reqs, mcb);

    // Run the aio requests
    for (i = 0; i < num_reqs; i++) {
        acb = bdrv_aio_writev(bs, reqs[i].sector, reqs[i].qiov,
            reqs[i].nb_sectors, multiwrite_cb, mcb);

        if (acb == NULL) {
            // We can only fail the whole thing if no request has been
            // submitted yet. Otherwise we'll wait for the submitted AIOs to
            // complete and report the error in the callback.
            if (mcb->num_requests == 0) {
1896
                reqs[i].error = -EIO;
K
Kevin Wolf 已提交
1897 1898
                goto fail;
            } else {
1899 1900
                mcb->num_requests++;
                multiwrite_cb(mcb, -EIO);
K
Kevin Wolf 已提交
1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914
                break;
            }
        } else {
            mcb->num_requests++;
        }
    }

    return 0;

fail:
    free(mcb);
    return -1;
}

1915 1916 1917 1918 1919 1920 1921 1922 1923 1924
BlockDriverAIOCB *bdrv_aio_flush(BlockDriverState *bs,
        BlockDriverCompletionFunc *cb, void *opaque)
{
    BlockDriver *drv = bs->drv;

    if (!drv)
        return NULL;
    return drv->bdrv_aio_flush(bs, cb, opaque);
}

B
bellard 已提交
1925 1926
void bdrv_aio_cancel(BlockDriverAIOCB *acb)
{
1927
    acb->pool->cancel(acb);
B
bellard 已提交
1928 1929
}

1930

B
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1931 1932 1933
/**************************************************************/
/* async block device emulation */

1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946
typedef struct BlockDriverAIOCBSync {
    BlockDriverAIOCB common;
    QEMUBH *bh;
    int ret;
    /* vector translation state */
    QEMUIOVector *qiov;
    uint8_t *bounce;
    int is_write;
} BlockDriverAIOCBSync;

static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb)
{
    BlockDriverAIOCBSync *acb = (BlockDriverAIOCBSync *)blockacb;
1947
    qemu_bh_delete(acb->bh);
A
Avi Kivity 已提交
1948
    acb->bh = NULL;
1949 1950 1951 1952 1953 1954 1955 1956
    qemu_aio_release(acb);
}

static AIOPool bdrv_em_aio_pool = {
    .aiocb_size         = sizeof(BlockDriverAIOCBSync),
    .cancel             = bdrv_aio_cancel_em,
};

1957
static void bdrv_aio_bh_cb(void *opaque)
B
bellard 已提交
1958
{
1959
    BlockDriverAIOCBSync *acb = opaque;
1960 1961 1962

    if (!acb->is_write)
        qemu_iovec_from_buffer(acb->qiov, acb->bounce, acb->qiov->size);
1963
    qemu_vfree(acb->bounce);
1964
    acb->common.cb(acb->common.opaque, acb->ret);
1965
    qemu_bh_delete(acb->bh);
A
Avi Kivity 已提交
1966
    acb->bh = NULL;
1967
    qemu_aio_release(acb);
B
bellard 已提交
1968
}
1969

1970 1971 1972 1973 1974 1975 1976 1977
static BlockDriverAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs,
                                            int64_t sector_num,
                                            QEMUIOVector *qiov,
                                            int nb_sectors,
                                            BlockDriverCompletionFunc *cb,
                                            void *opaque,
                                            int is_write)

B
bellard 已提交
1978
{
1979 1980
    BlockDriverAIOCBSync *acb;

1981
    acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
1982 1983
    acb->is_write = is_write;
    acb->qiov = qiov;
1984
    acb->bounce = qemu_blockalign(bs, qiov->size);
1985

1986 1987
    if (!acb->bh)
        acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
1988 1989 1990 1991 1992 1993 1994 1995

    if (is_write) {
        qemu_iovec_to_buffer(acb->qiov, acb->bounce);
        acb->ret = bdrv_write(bs, sector_num, acb->bounce, nb_sectors);
    } else {
        acb->ret = bdrv_read(bs, sector_num, acb->bounce, nb_sectors);
    }

1996
    qemu_bh_schedule(acb->bh);
1997

1998
    return &acb->common;
1999 2000
}

2001 2002
static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
2003
        BlockDriverCompletionFunc *cb, void *opaque)
2004
{
2005 2006
    return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
}
B
bellard 已提交
2007

2008 2009 2010 2011 2012
static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
        BlockDriverCompletionFunc *cb, void *opaque)
{
    return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
2013 2014
}

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033
static BlockDriverAIOCB *bdrv_aio_flush_em(BlockDriverState *bs,
        BlockDriverCompletionFunc *cb, void *opaque)
{
    BlockDriverAIOCBSync *acb;

    acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
    acb->is_write = 1; /* don't bounce in the completion hadler */
    acb->qiov = NULL;
    acb->bounce = NULL;
    acb->ret = 0;

    if (!acb->bh)
        acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);

    bdrv_flush(bs);
    qemu_bh_schedule(acb->bh);
    return &acb->common;
}

B
bellard 已提交
2034 2035
/**************************************************************/
/* sync block device emulation */
B
bellard 已提交
2036

B
bellard 已提交
2037 2038 2039
static void bdrv_rw_em_cb(void *opaque, int ret)
{
    *(int *)opaque = ret;
B
bellard 已提交
2040 2041
}

B
bellard 已提交
2042 2043
#define NOT_DONE 0x7fffffff

2044
static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
B
bellard 已提交
2045
                        uint8_t *buf, int nb_sectors)
P
pbrook 已提交
2046
{
2047 2048
    int async_ret;
    BlockDriverAIOCB *acb;
2049 2050
    struct iovec iov;
    QEMUIOVector qiov;
B
bellard 已提交
2051

2052 2053
    async_context_push();

B
bellard 已提交
2054
    async_ret = NOT_DONE;
2055
    iov.iov_base = (void *)buf;
2056 2057 2058 2059
    iov.iov_len = nb_sectors * 512;
    qemu_iovec_init_external(&qiov, &iov, 1);
    acb = bdrv_aio_readv(bs, sector_num, &qiov, nb_sectors,
        bdrv_rw_em_cb, &async_ret);
2060 2061 2062 2063
    if (acb == NULL) {
        async_ret = -1;
        goto fail;
    }
2064

B
bellard 已提交
2065 2066 2067
    while (async_ret == NOT_DONE) {
        qemu_aio_wait();
    }
2068

2069 2070 2071

fail:
    async_context_pop();
B
bellard 已提交
2072
    return async_ret;
P
pbrook 已提交
2073 2074
}

B
bellard 已提交
2075 2076 2077
static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
                         const uint8_t *buf, int nb_sectors)
{
2078 2079
    int async_ret;
    BlockDriverAIOCB *acb;
2080 2081
    struct iovec iov;
    QEMUIOVector qiov;
B
bellard 已提交
2082

2083 2084
    async_context_push();

B
bellard 已提交
2085
    async_ret = NOT_DONE;
2086 2087 2088 2089 2090
    iov.iov_base = (void *)buf;
    iov.iov_len = nb_sectors * 512;
    qemu_iovec_init_external(&qiov, &iov, 1);
    acb = bdrv_aio_writev(bs, sector_num, &qiov, nb_sectors,
        bdrv_rw_em_cb, &async_ret);
2091 2092 2093 2094
    if (acb == NULL) {
        async_ret = -1;
        goto fail;
    }
B
bellard 已提交
2095 2096 2097
    while (async_ret == NOT_DONE) {
        qemu_aio_wait();
    }
2098 2099 2100

fail:
    async_context_pop();
B
bellard 已提交
2101 2102
    return async_ret;
}
B
bellard 已提交
2103 2104 2105

void bdrv_init(void)
{
2106
    module_call_init(MODULE_INIT_BLOCK);
B
bellard 已提交
2107
}
2108

2109 2110 2111 2112 2113 2114
void bdrv_init_with_whitelist(void)
{
    use_bdrv_whitelist = 1;
    bdrv_init();
}

2115 2116
void *qemu_aio_get(AIOPool *pool, BlockDriverState *bs,
                   BlockDriverCompletionFunc *cb, void *opaque)
2117 2118 2119
{
    BlockDriverAIOCB *acb;

2120 2121 2122
    if (pool->free_aiocb) {
        acb = pool->free_aiocb;
        pool->free_aiocb = acb->next;
2123
    } else {
2124 2125
        acb = qemu_mallocz(pool->aiocb_size);
        acb->pool = pool;
2126 2127 2128 2129 2130 2131 2132 2133 2134
    }
    acb->bs = bs;
    acb->cb = cb;
    acb->opaque = opaque;
    return acb;
}

void qemu_aio_release(void *p)
{
2135 2136 2137 2138
    BlockDriverAIOCB *acb = (BlockDriverAIOCB *)p;
    AIOPool *pool = acb->pool;
    acb->next = pool->free_aiocb;
    pool->free_aiocb = acb;
2139
}
B
bellard 已提交
2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160

/**************************************************************/
/* removable device support */

/**
 * Return TRUE if the media is present
 */
int bdrv_is_inserted(BlockDriverState *bs)
{
    BlockDriver *drv = bs->drv;
    int ret;
    if (!drv)
        return 0;
    if (!drv->bdrv_is_inserted)
        return 1;
    ret = drv->bdrv_is_inserted(bs);
    return ret;
}

/**
 * Return TRUE if the media changed since the last call to this
2161
 * function. It is currently only used for floppy disks
B
bellard 已提交
2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180
 */
int bdrv_media_changed(BlockDriverState *bs)
{
    BlockDriver *drv = bs->drv;
    int ret;

    if (!drv || !drv->bdrv_media_changed)
        ret = -ENOTSUP;
    else
        ret = drv->bdrv_media_changed(bs);
    if (ret == -ENOTSUP)
        ret = bs->media_changed;
    bs->media_changed = 0;
    return ret;
}

/**
 * If eject_flag is TRUE, eject the media. Otherwise, close the tray
 */
2181
int bdrv_eject(BlockDriverState *bs, int eject_flag)
B
bellard 已提交
2182 2183 2184 2185
{
    BlockDriver *drv = bs->drv;
    int ret;

2186 2187 2188 2189
    if (bs->locked) {
        return -EBUSY;
    }

B
bellard 已提交
2190 2191 2192 2193 2194 2195 2196 2197
    if (!drv || !drv->bdrv_eject) {
        ret = -ENOTSUP;
    } else {
        ret = drv->bdrv_eject(bs, eject_flag);
    }
    if (ret == -ENOTSUP) {
        if (eject_flag)
            bdrv_close(bs);
2198
        ret = 0;
B
bellard 已提交
2199
    }
2200 2201

    return ret;
B
bellard 已提交
2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221
}

int bdrv_is_locked(BlockDriverState *bs)
{
    return bs->locked;
}

/**
 * Lock or unlock the media (if it is locked, the user won't be able
 * to eject it manually).
 */
void bdrv_set_locked(BlockDriverState *bs, int locked)
{
    BlockDriver *drv = bs->drv;

    bs->locked = locked;
    if (drv && drv->bdrv_set_locked) {
        drv->bdrv_set_locked(bs, locked);
    }
}
2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232

/* needed for generic scsi interface */

int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
{
    BlockDriver *drv = bs->drv;

    if (drv && drv->bdrv_ioctl)
        return drv->bdrv_ioctl(bs, req, buf);
    return -ENOTSUP;
}
2233

2234 2235 2236
BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
        unsigned long int req, void *buf,
        BlockDriverCompletionFunc *cb, void *opaque)
2237
{
2238
    BlockDriver *drv = bs->drv;
2239

2240 2241 2242
    if (drv && drv->bdrv_aio_ioctl)
        return drv->bdrv_aio_ioctl(bs, req, buf, cb, opaque);
    return NULL;
2243
}
2244

2245 2246


2247 2248 2249 2250
void *qemu_blockalign(BlockDriverState *bs, size_t size)
{
    return qemu_memalign((bs && bs->buffer_alignment) ? bs->buffer_alignment : 512, size);
}
2251 2252 2253 2254

void bdrv_set_dirty_tracking(BlockDriverState *bs, int enable)
{
    int64_t bitmap_size;
2255

2256
    bs->dirty_count = 0;
2257
    if (enable) {
2258 2259 2260 2261
        if (!bs->dirty_bitmap) {
            bitmap_size = (bdrv_getlength(bs) >> BDRV_SECTOR_BITS) +
                    BDRV_SECTORS_PER_DIRTY_CHUNK * 8 - 1;
            bitmap_size /= BDRV_SECTORS_PER_DIRTY_CHUNK * 8;
2262

2263
            bs->dirty_bitmap = qemu_mallocz(bitmap_size);
2264
        }
2265
    } else {
2266
        if (bs->dirty_bitmap) {
2267
            qemu_free(bs->dirty_bitmap);
2268
            bs->dirty_bitmap = NULL;
2269
        }
2270 2271 2272 2273 2274
    }
}

int bdrv_get_dirty(BlockDriverState *bs, int64_t sector)
{
J
Jan Kiszka 已提交
2275
    int64_t chunk = sector / (int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK;
2276

2277 2278 2279 2280
    if (bs->dirty_bitmap &&
        (sector << BDRV_SECTOR_BITS) < bdrv_getlength(bs)) {
        return bs->dirty_bitmap[chunk / (sizeof(unsigned long) * 8)] &
            (1 << (chunk % (sizeof(unsigned long) * 8)));
2281 2282 2283 2284 2285
    } else {
        return 0;
    }
}

2286 2287
void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector,
                      int nr_sectors)
2288 2289 2290
{
    set_dirty_bitmap(bs, cur_sector, nr_sectors, 0);
}
2291 2292 2293 2294 2295

int64_t bdrv_get_dirty_count(BlockDriverState *bs)
{
    return bs->dirty_count;
}