block.c 120.7 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 "trace.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 "qjson.h"
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#include "qemu-coroutine.h"
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#include "qmp-commands.h"
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#include "qemu-timer.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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#define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */

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typedef enum {
    BDRV_REQ_COPY_ON_READ = 0x1,
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    BDRV_REQ_ZERO_WRITE   = 0x2,
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} BdrvRequestFlags;

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static void bdrv_dev_change_media_cb(BlockDriverState *bs, bool load);
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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 int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs,
                                         int64_t sector_num, int nb_sectors,
                                         QEMUIOVector *iov);
static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs,
                                         int64_t sector_num, int nb_sectors,
                                         QEMUIOVector *iov);
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static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs,
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    int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
    BdrvRequestFlags flags);
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static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs,
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    int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
    BdrvRequestFlags flags);
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static BlockDriverAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs,
                                               int64_t sector_num,
                                               QEMUIOVector *qiov,
                                               int nb_sectors,
                                               BlockDriverCompletionFunc *cb,
                                               void *opaque,
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                                               bool is_write);
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static void coroutine_fn bdrv_co_do_rw(void *opaque);
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static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs,
    int64_t sector_num, int nb_sectors);
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static bool bdrv_exceed_bps_limits(BlockDriverState *bs, int nb_sectors,
        bool is_write, double elapsed_time, uint64_t *wait);
static bool bdrv_exceed_iops_limits(BlockDriverState *bs, bool is_write,
        double elapsed_time, uint64_t *wait);
static bool bdrv_exceed_io_limits(BlockDriverState *bs, int nb_sectors,
        bool is_write, int64_t *wait);

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static QTAILQ_HEAD(, BlockDriverState) bdrv_states =
    QTAILQ_HEAD_INITIALIZER(bdrv_states);
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static QLIST_HEAD(, BlockDriver) bdrv_drivers =
    QLIST_HEAD_INITIALIZER(bdrv_drivers);
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/* The device to use for VM snapshots */
static BlockDriverState *bs_snapshots;

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

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#ifdef _WIN32
static int is_windows_drive_prefix(const char *filename)
{
    return (((filename[0] >= 'a' && filename[0] <= 'z') ||
             (filename[0] >= 'A' && filename[0] <= 'Z')) &&
            filename[1] == ':');
}

int is_windows_drive(const char *filename)
{
    if (is_windows_drive_prefix(filename) &&
        filename[2] == '\0')
        return 1;
    if (strstart(filename, "\\\\.\\", NULL) ||
        strstart(filename, "//./", NULL))
        return 1;
    return 0;
}
#endif

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/* throttling disk I/O limits */
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void bdrv_io_limits_disable(BlockDriverState *bs)
{
    bs->io_limits_enabled = false;

    while (qemu_co_queue_next(&bs->throttled_reqs));

    if (bs->block_timer) {
        qemu_del_timer(bs->block_timer);
        qemu_free_timer(bs->block_timer);
        bs->block_timer = NULL;
    }

    bs->slice_start = 0;
    bs->slice_end   = 0;
    bs->slice_time  = 0;
    memset(&bs->io_base, 0, sizeof(bs->io_base));
}

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static void bdrv_block_timer(void *opaque)
{
    BlockDriverState *bs = opaque;

    qemu_co_queue_next(&bs->throttled_reqs);
}

void bdrv_io_limits_enable(BlockDriverState *bs)
{
    qemu_co_queue_init(&bs->throttled_reqs);
    bs->block_timer = qemu_new_timer_ns(vm_clock, bdrv_block_timer, bs);
    bs->slice_time  = 5 * BLOCK_IO_SLICE_TIME;
    bs->slice_start = qemu_get_clock_ns(vm_clock);
    bs->slice_end   = bs->slice_start + bs->slice_time;
    memset(&bs->io_base, 0, sizeof(bs->io_base));
    bs->io_limits_enabled = true;
}

bool bdrv_io_limits_enabled(BlockDriverState *bs)
{
    BlockIOLimit *io_limits = &bs->io_limits;
    return io_limits->bps[BLOCK_IO_LIMIT_READ]
         || io_limits->bps[BLOCK_IO_LIMIT_WRITE]
         || io_limits->bps[BLOCK_IO_LIMIT_TOTAL]
         || io_limits->iops[BLOCK_IO_LIMIT_READ]
         || io_limits->iops[BLOCK_IO_LIMIT_WRITE]
         || io_limits->iops[BLOCK_IO_LIMIT_TOTAL];
}

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static void bdrv_io_limits_intercept(BlockDriverState *bs,
                                     bool is_write, int nb_sectors)
{
    int64_t wait_time = -1;

    if (!qemu_co_queue_empty(&bs->throttled_reqs)) {
        qemu_co_queue_wait(&bs->throttled_reqs);
    }

    /* In fact, we hope to keep each request's timing, in FIFO mode. The next
     * throttled requests will not be dequeued until the current request is
     * allowed to be serviced. So if the current request still exceeds the
     * limits, it will be inserted to the head. All requests followed it will
     * be still in throttled_reqs queue.
     */

    while (bdrv_exceed_io_limits(bs, nb_sectors, is_write, &wait_time)) {
        qemu_mod_timer(bs->block_timer,
                       wait_time + qemu_get_clock_ns(vm_clock));
        qemu_co_queue_wait_insert_head(&bs->throttled_reqs);
    }

    qemu_co_queue_next(&bs->throttled_reqs);
}

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/* check if the path starts with "<protocol>:" */
static int path_has_protocol(const char *path)
{
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    const char *p;

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#ifdef _WIN32
    if (is_windows_drive(path) ||
        is_windows_drive_prefix(path)) {
        return 0;
    }
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    p = path + strcspn(path, ":/\\");
#else
    p = path + strcspn(path, ":/");
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#endif

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    return *p == ':';
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}

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int path_is_absolute(const char *path)
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{
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#ifdef _WIN32
    /* specific case for names like: "\\.\d:" */
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    if (is_windows_drive(path) || is_windows_drive_prefix(path)) {
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        return 1;
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    }
    return (*path == '/' || *path == '\\');
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#else
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    return (*path == '/');
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#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_get_full_backing_filename(BlockDriverState *bs, char *dest, size_t sz)
{
    if (bs->backing_file[0] == '\0' || path_has_protocol(bs->backing_file)) {
        pstrcpy(dest, sz, bs->backing_file);
    } else {
        path_combine(dest, sz, bs->filename, bs->backing_file);
    }
}

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void bdrv_register(BlockDriver *bdrv)
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{
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    /* Block drivers without coroutine functions need emulation */
    if (!bdrv->bdrv_co_readv) {
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        bdrv->bdrv_co_readv = bdrv_co_readv_em;
        bdrv->bdrv_co_writev = bdrv_co_writev_em;

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        /* bdrv_co_readv_em()/brdv_co_writev_em() work in terms of aio, so if
         * the block driver lacks aio we need to emulate that too.
         */
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        if (!bdrv->bdrv_aio_readv) {
            /* add AIO emulation layer */
            bdrv->bdrv_aio_readv = bdrv_aio_readv_em;
            bdrv->bdrv_aio_writev = bdrv_aio_writev_em;
        }
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    }
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    QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list);
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}
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/* create a new block device (by default it is empty) */
BlockDriverState *bdrv_new(const char *device_name)
{
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    BlockDriverState *bs;
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    bs = g_malloc0(sizeof(BlockDriverState));
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    pstrcpy(bs->device_name, sizeof(bs->device_name), device_name);
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    if (device_name[0] != '\0') {
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        QTAILQ_INSERT_TAIL(&bdrv_states, bs, list);
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    }
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    bdrv_iostatus_disable(bs);
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    return bs;
}

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BlockDriver *bdrv_find_format(const char *format_name)
{
    BlockDriver *drv1;
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    QLIST_FOREACH(drv1, &bdrv_drivers, list) {
        if (!strcmp(drv1->format_name, format_name)) {
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            return drv1;
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        }
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    }
    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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typedef struct CreateCo {
    BlockDriver *drv;
    char *filename;
    QEMUOptionParameter *options;
    int ret;
} CreateCo;

static void coroutine_fn bdrv_create_co_entry(void *opaque)
{
    CreateCo *cco = opaque;
    assert(cco->drv);

    cco->ret = cco->drv->bdrv_create(cco->filename, cco->options);
}

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int bdrv_create(BlockDriver *drv, const char* filename,
    QEMUOptionParameter *options)
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{
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    int ret;

    Coroutine *co;
    CreateCo cco = {
        .drv = drv,
        .filename = g_strdup(filename),
        .options = options,
        .ret = NOT_DONE,
    };

    if (!drv->bdrv_create) {
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        return -ENOTSUP;
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    }

    if (qemu_in_coroutine()) {
        /* Fast-path if already in coroutine context */
        bdrv_create_co_entry(&cco);
    } else {
        co = qemu_coroutine_create(bdrv_create_co_entry);
        qemu_coroutine_enter(co, &cco);
        while (cco.ret == NOT_DONE) {
            qemu_aio_wait();
        }
    }

    ret = cco.ret;
    g_free(cco.filename);
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    return ret;
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}

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int bdrv_create_file(const char* filename, QEMUOptionParameter *options)
{
    BlockDriver *drv;

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    drv = bdrv_find_protocol(filename);
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    if (drv == NULL) {
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        return -ENOENT;
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    }

    return bdrv_create(drv, filename, options);
}

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/*
 * Create a uniquely-named empty temporary file.
 * Return 0 upon success, otherwise a negative errno value.
 */
int get_tmp_filename(char *filename, int size)
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{
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#ifdef _WIN32
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    char temp_dir[MAX_PATH];
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    /* GetTempFileName requires that its output buffer (4th param)
       have length MAX_PATH or greater.  */
    assert(size >= MAX_PATH);
    return (GetTempPath(MAX_PATH, temp_dir)
            && GetTempFileName(temp_dir, "qem", 0, filename)
            ? 0 : -GetLastError());
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#else
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    int fd;
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    const char *tmpdir;
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    tmpdir = getenv("TMPDIR");
    if (!tmpdir)
        tmpdir = "/tmp";
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    if (snprintf(filename, size, "%s/vl.XXXXXX", tmpdir) >= size) {
        return -EOVERFLOW;
    }
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    fd = mkstemp(filename);
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    if (fd < 0 || close(fd)) {
        return -errno;
    }
    return 0;
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#endif
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}
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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)
{
    int score_max = 0, score;
    BlockDriver *drv = NULL, *d;

    QLIST_FOREACH(d, &bdrv_drivers, list) {
        if (d->bdrv_probe_device) {
            score = d->bdrv_probe_device(filename);
            if (score > score_max) {
                score_max = score;
                drv = d;
            }
        }
    }

    return drv;
}

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BlockDriver *bdrv_find_protocol(const char *filename)
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{
    BlockDriver *drv1;
    char protocol[128];
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    int len;
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    const char *p;
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    /* TODO Drivers without bdrv_file_open must be specified explicitly */

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    /*
     * XXX(hch): we really should not let host device detection
     * override an explicit protocol specification, but moving this
     * later breaks access to device names with colons in them.
     * Thanks to the brain-dead persistent naming schemes on udev-
     * based Linux systems those actually are quite common.
     */
    drv1 = find_hdev_driver(filename);
    if (drv1) {
        return drv1;
    }

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    if (!path_has_protocol(filename)) {
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        return bdrv_find_format("file");
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    }
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    p = strchr(filename, ':');
    assert(p != NULL);
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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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    QLIST_FOREACH(drv1, &bdrv_drivers, list) {
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        if (drv1->protocol_name &&
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            !strcmp(drv1->protocol_name, protocol)) {
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            return drv1;
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        }
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    }
    return NULL;
}

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static int find_image_format(const char *filename, BlockDriver **pdrv)
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{
    int ret, score, score_max;
    BlockDriver *drv1, *drv;
    uint8_t buf[2048];
    BlockDriverState *bs;

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    ret = bdrv_file_open(&bs, filename, 0);
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    if (ret < 0) {
        *pdrv = NULL;
        return ret;
    }
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    /* Return the raw BlockDriver * to scsi-generic devices or empty drives */
    if (bs->sg || !bdrv_is_inserted(bs)) {
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        bdrv_delete(bs);
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        drv = bdrv_find_format("raw");
        if (!drv) {
            ret = -ENOENT;
        }
        *pdrv = drv;
        return ret;
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    }
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    ret = bdrv_pread(bs, 0, buf, sizeof(buf));
    bdrv_delete(bs);
    if (ret < 0) {
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        *pdrv = NULL;
        return ret;
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    }

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    score_max = 0;
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    drv = NULL;
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    QLIST_FOREACH(drv1, &bdrv_drivers, list) {
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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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    if (!drv) {
        ret = -ENOENT;
    }
    *pdrv = drv;
    return ret;
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}

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/**
 * Set the current 'total_sectors' value
 */
static int refresh_total_sectors(BlockDriverState *bs, int64_t hint)
{
    BlockDriver *drv = bs->drv;

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    /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */
    if (bs->sg)
        return 0;

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    /* query actual device if possible, otherwise just trust the hint */
    if (drv->bdrv_getlength) {
        int64_t length = drv->bdrv_getlength(bs);
        if (length < 0) {
            return length;
        }
        hint = length >> BDRV_SECTOR_BITS;
    }

    bs->total_sectors = hint;
    return 0;
}

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/**
 * Set open flags for a given cache mode
 *
 * Return 0 on success, -1 if the cache mode was invalid.
 */
int bdrv_parse_cache_flags(const char *mode, int *flags)
{
    *flags &= ~BDRV_O_CACHE_MASK;

    if (!strcmp(mode, "off") || !strcmp(mode, "none")) {
        *flags |= BDRV_O_NOCACHE | BDRV_O_CACHE_WB;
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    } else if (!strcmp(mode, "directsync")) {
        *flags |= BDRV_O_NOCACHE;
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    } else if (!strcmp(mode, "writeback")) {
        *flags |= BDRV_O_CACHE_WB;
    } else if (!strcmp(mode, "unsafe")) {
        *flags |= BDRV_O_CACHE_WB;
        *flags |= BDRV_O_NO_FLUSH;
    } else if (!strcmp(mode, "writethrough")) {
        /* this is the default */
    } else {
        return -1;
    }

    return 0;
}

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/**
 * The copy-on-read flag is actually a reference count so multiple users may
 * use the feature without worrying about clobbering its previous state.
 * Copy-on-read stays enabled until all users have called to disable it.
 */
void bdrv_enable_copy_on_read(BlockDriverState *bs)
{
    bs->copy_on_read++;
}

void bdrv_disable_copy_on_read(BlockDriverState *bs)
{
    assert(bs->copy_on_read > 0);
    bs->copy_on_read--;
}

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/*
 * Common part for opening disk images and files
 */
static int bdrv_open_common(BlockDriverState *bs, const char *filename,
    int flags, BlockDriver *drv)
{
    int ret, open_flags;

    assert(drv != NULL);
630
    assert(bs->file == NULL);
631

S
Stefan Hajnoczi 已提交
632 633
    trace_bdrv_open_common(bs, filename, flags, drv->format_name);

634 635 636
    bs->open_flags = flags;
    bs->buffer_alignment = 512;

637 638 639 640 641
    assert(bs->copy_on_read == 0); /* bdrv_new() and bdrv_close() make it so */
    if ((flags & BDRV_O_RDWR) && (flags & BDRV_O_COPY_ON_READ)) {
        bdrv_enable_copy_on_read(bs);
    }

642 643 644 645 646 647 648
    pstrcpy(bs->filename, sizeof(bs->filename), filename);

    if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv)) {
        return -ENOTSUP;
    }

    bs->drv = drv;
649
    bs->opaque = g_malloc0(drv->instance_size);
650

651
    bs->enable_write_cache = !!(flags & BDRV_O_CACHE_WB);
652 653 654 655 656 657 658 659

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

    /*
S
Stefan Weil 已提交
660
     * Snapshots should be writable.
661 662 663 664 665
     */
    if (bs->is_temporary) {
        open_flags |= BDRV_O_RDWR;
    }

666 667
    bs->keep_read_only = bs->read_only = !(open_flags & BDRV_O_RDWR);

668 669 670 671 672 673 674 675 676 677
    /* Open the image, either directly or using a protocol */
    if (drv->bdrv_file_open) {
        ret = drv->bdrv_file_open(bs, filename, open_flags);
    } else {
        ret = bdrv_file_open(&bs->file, filename, open_flags);
        if (ret >= 0) {
            ret = drv->bdrv_open(bs, open_flags);
        }
    }

678 679 680 681
    if (ret < 0) {
        goto free_and_fail;
    }

682 683 684
    ret = refresh_total_sectors(bs, bs->total_sectors);
    if (ret < 0) {
        goto free_and_fail;
685
    }
686

687 688 689 690 691 692 693 694
#ifndef _WIN32
    if (bs->is_temporary) {
        unlink(filename);
    }
#endif
    return 0;

free_and_fail:
695 696 697 698
    if (bs->file) {
        bdrv_delete(bs->file);
        bs->file = NULL;
    }
699
    g_free(bs->opaque);
700 701 702 703 704
    bs->opaque = NULL;
    bs->drv = NULL;
    return ret;
}

K
Kevin Wolf 已提交
705 706 707
/*
 * Opens a file using a protocol (file, host_device, nbd, ...)
 */
B
bellard 已提交
708
int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags)
B
bellard 已提交
709
{
B
bellard 已提交
710
    BlockDriverState *bs;
711
    BlockDriver *drv;
B
bellard 已提交
712 713
    int ret;

714
    drv = bdrv_find_protocol(filename);
715 716 717 718
    if (!drv) {
        return -ENOENT;
    }

B
bellard 已提交
719
    bs = bdrv_new("");
K
Kevin Wolf 已提交
720
    ret = bdrv_open_common(bs, filename, flags, drv);
B
bellard 已提交
721 722 723
    if (ret < 0) {
        bdrv_delete(bs);
        return ret;
724
    }
725
    bs->growable = 1;
B
bellard 已提交
726 727 728 729
    *pbs = bs;
    return 0;
}

K
Kevin Wolf 已提交
730 731 732
/*
 * Opens a disk image (raw, qcow2, vmdk, ...)
 */
K
Kevin Wolf 已提交
733 734
int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
              BlockDriver *drv)
B
bellard 已提交
735
{
K
Kevin Wolf 已提交
736
    int ret;
K
Kevin Wolf 已提交
737
    char tmp_filename[PATH_MAX];
B
bellard 已提交
738

B
bellard 已提交
739
    if (flags & BDRV_O_SNAPSHOT) {
B
bellard 已提交
740 741
        BlockDriverState *bs1;
        int64_t total_size;
A
aliguori 已提交
742
        int is_protocol = 0;
K
Kevin Wolf 已提交
743 744
        BlockDriver *bdrv_qcow2;
        QEMUOptionParameter *options;
K
Kevin Wolf 已提交
745
        char backing_filename[PATH_MAX];
746

B
bellard 已提交
747 748
        /* if snapshot, we create a temporary backing file and open it
           instead of opening 'filename' directly */
749

B
bellard 已提交
750 751
        /* if there is a backing file, use it */
        bs1 = bdrv_new("");
K
Kevin Wolf 已提交
752
        ret = bdrv_open(bs1, filename, 0, drv);
753
        if (ret < 0) {
B
bellard 已提交
754
            bdrv_delete(bs1);
755
            return ret;
B
bellard 已提交
756
        }
757
        total_size = bdrv_getlength(bs1) & BDRV_SECTOR_MASK;
A
aliguori 已提交
758 759 760 761

        if (bs1->drv && bs1->drv->protocol_name)
            is_protocol = 1;

B
bellard 已提交
762
        bdrv_delete(bs1);
763

764 765 766 767
        ret = get_tmp_filename(tmp_filename, sizeof(tmp_filename));
        if (ret < 0) {
            return ret;
        }
A
aliguori 已提交
768 769 770 771 772

        /* Real path is meaningless for protocols */
        if (is_protocol)
            snprintf(backing_filename, sizeof(backing_filename),
                     "%s", filename);
773 774
        else if (!realpath(filename, backing_filename))
            return -errno;
A
aliguori 已提交
775

K
Kevin Wolf 已提交
776 777 778
        bdrv_qcow2 = bdrv_find_format("qcow2");
        options = parse_option_parameters("", bdrv_qcow2->create_options, NULL);

779
        set_option_parameter_int(options, BLOCK_OPT_SIZE, total_size);
K
Kevin Wolf 已提交
780 781 782 783 784 785 786
        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);
787
        free_option_parameters(options);
788 789
        if (ret < 0) {
            return ret;
B
bellard 已提交
790
        }
K
Kevin Wolf 已提交
791

B
bellard 已提交
792
        filename = tmp_filename;
K
Kevin Wolf 已提交
793
        drv = bdrv_qcow2;
B
bellard 已提交
794 795
        bs->is_temporary = 1;
    }
B
bellard 已提交
796

K
Kevin Wolf 已提交
797
    /* Find the right image format driver */
798
    if (!drv) {
799
        ret = find_image_format(filename, &drv);
800
    }
801

802 803
    if (!drv) {
        goto unlink_and_fail;
B
bellard 已提交
804
    }
K
Kevin Wolf 已提交
805 806 807 808

    /* Open the image */
    ret = bdrv_open_common(bs, filename, flags, drv);
    if (ret < 0) {
809 810 811
        goto unlink_and_fail;
    }

K
Kevin Wolf 已提交
812 813 814 815 816 817 818
    /* If there is a backing file, use it */
    if ((flags & BDRV_O_NO_BACKING) == 0 && bs->backing_file[0] != '\0') {
        char backing_filename[PATH_MAX];
        int back_flags;
        BlockDriver *back_drv = NULL;

        bs->backing_hd = bdrv_new("");
819 820
        bdrv_get_full_backing_filename(bs, backing_filename,
                                       sizeof(backing_filename));
821 822

        if (bs->backing_format[0] != '\0') {
K
Kevin Wolf 已提交
823
            back_drv = bdrv_find_format(bs->backing_format);
824
        }
K
Kevin Wolf 已提交
825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843

        /* backing files always opened read-only */
        back_flags =
            flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);

        ret = bdrv_open(bs->backing_hd, backing_filename, back_flags, back_drv);
        if (ret < 0) {
            bdrv_close(bs);
            return ret;
        }
        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;
        }
    }

    if (!bdrv_key_required(bs)) {
844
        bdrv_dev_change_media_cb(bs, true);
K
Kevin Wolf 已提交
845 846
    }

Z
Zhi Yong Wu 已提交
847 848 849 850 851
    /* throttling disk I/O limits */
    if (bs->io_limits_enabled) {
        bdrv_io_limits_enable(bs);
    }

K
Kevin Wolf 已提交
852 853 854 855 856 857 858 859 860
    return 0;

unlink_and_fail:
    if (bs->is_temporary) {
        unlink(filename);
    }
    return ret;
}

B
bellard 已提交
861 862
void bdrv_close(BlockDriverState *bs)
{
863
    bdrv_flush(bs);
B
bellard 已提交
864
    if (bs->drv) {
865 866 867
        if (bs->job) {
            block_job_cancel_sync(bs->job);
        }
K
Kevin Wolf 已提交
868 869
        bdrv_drain_all();

870 871 872
        if (bs == bs_snapshots) {
            bs_snapshots = NULL;
        }
873
        if (bs->backing_hd) {
B
bellard 已提交
874
            bdrv_delete(bs->backing_hd);
875 876
            bs->backing_hd = NULL;
        }
B
bellard 已提交
877
        bs->drv->bdrv_close(bs);
878
        g_free(bs->opaque);
B
bellard 已提交
879 880 881 882
#ifdef _WIN32
        if (bs->is_temporary) {
            unlink(bs->filename);
        }
B
bellard 已提交
883
#endif
B
bellard 已提交
884 885
        bs->opaque = NULL;
        bs->drv = NULL;
886
        bs->copy_on_read = 0;
887 888
        bs->backing_file[0] = '\0';
        bs->backing_format[0] = '\0';
889 890 891 892 893
        bs->total_sectors = 0;
        bs->encrypted = 0;
        bs->valid_key = 0;
        bs->sg = 0;
        bs->growable = 0;
B
bellard 已提交
894

895
        if (bs->file != NULL) {
896 897
            bdrv_delete(bs->file);
            bs->file = NULL;
898 899
        }

900
        bdrv_dev_change_media_cb(bs, false);
B
bellard 已提交
901
    }
Z
Zhi Yong Wu 已提交
902 903 904 905 906

    /*throttling disk I/O limits*/
    if (bs->io_limits_enabled) {
        bdrv_io_limits_disable(bs);
    }
B
bellard 已提交
907 908
}

909 910 911 912 913 914 915 916 917
void bdrv_close_all(void)
{
    BlockDriverState *bs;

    QTAILQ_FOREACH(bs, &bdrv_states, list) {
        bdrv_close(bs);
    }
}

918 919 920 921 922
/*
 * Wait for pending requests to complete across all BlockDriverStates
 *
 * This function does not flush data to disk, use bdrv_flush_all() for that
 * after calling this function.
923 924 925 926 927 928
 *
 * Note that completion of an asynchronous I/O operation can trigger any
 * number of other I/O operations on other devices---for example a coroutine
 * can be arbitrarily complex and a constant flow of I/O can come until the
 * coroutine is complete.  Because of this, it is not possible to have a
 * function to drain a single device's I/O queue.
929 930 931 932
 */
void bdrv_drain_all(void)
{
    BlockDriverState *bs;
933 934 935 936
    bool busy;

    do {
        busy = qemu_aio_wait();
937

938 939 940 941 942 943 944 945 946 947
        /* FIXME: We do not have timer support here, so this is effectively
         * a busy wait.
         */
        QTAILQ_FOREACH(bs, &bdrv_states, list) {
            if (!qemu_co_queue_empty(&bs->throttled_reqs)) {
                qemu_co_queue_restart_all(&bs->throttled_reqs);
                busy = true;
            }
        }
    } while (busy);
948 949 950 951 952 953 954 955

    /* If requests are still pending there is a bug somewhere */
    QTAILQ_FOREACH(bs, &bdrv_states, list) {
        assert(QLIST_EMPTY(&bs->tracked_requests));
        assert(qemu_co_queue_empty(&bs->throttled_reqs));
    }
}

956 957 958 959 960 961 962 963 964 965
/* make a BlockDriverState anonymous by removing from bdrv_state list.
   Also, NULL terminate the device_name to prevent double remove */
void bdrv_make_anon(BlockDriverState *bs)
{
    if (bs->device_name[0] != '\0') {
        QTAILQ_REMOVE(&bdrv_states, bs, list);
    }
    bs->device_name[0] = '\0';
}

P
Paolo Bonzini 已提交
966 967 968 969 970 971 972
static void bdrv_rebind(BlockDriverState *bs)
{
    if (bs->drv && bs->drv->bdrv_rebind) {
        bs->drv->bdrv_rebind(bs);
    }
}

973 974 975 976 977 978 979
/*
 * Add new bs contents at the top of an image chain while the chain is
 * live, while keeping required fields on the top layer.
 *
 * This will modify the BlockDriverState fields, and swap contents
 * between bs_new and bs_top. Both bs_new and bs_top are modified.
 *
J
Jeff Cody 已提交
980 981
 * bs_new is required to be anonymous.
 *
982 983 984 985 986 987
 * This function does not create any image files.
 */
void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top)
{
    BlockDriverState tmp;

J
Jeff Cody 已提交
988 989
    /* bs_new must be anonymous */
    assert(bs_new->device_name[0] == '\0');
990 991 992 993

    tmp = *bs_new;

    /* there are some fields that need to stay on the top layer: */
P
Paolo Bonzini 已提交
994
    tmp.open_flags        = bs_top->open_flags;
995 996 997 998 999 1000 1001 1002

    /* dev info */
    tmp.dev_ops           = bs_top->dev_ops;
    tmp.dev_opaque        = bs_top->dev_opaque;
    tmp.dev               = bs_top->dev;
    tmp.buffer_alignment  = bs_top->buffer_alignment;
    tmp.copy_on_read      = bs_top->copy_on_read;

1003 1004
    tmp.enable_write_cache = bs_top->enable_write_cache;

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
    /* i/o timing parameters */
    tmp.slice_time        = bs_top->slice_time;
    tmp.slice_start       = bs_top->slice_start;
    tmp.slice_end         = bs_top->slice_end;
    tmp.io_limits         = bs_top->io_limits;
    tmp.io_base           = bs_top->io_base;
    tmp.throttled_reqs    = bs_top->throttled_reqs;
    tmp.block_timer       = bs_top->block_timer;
    tmp.io_limits_enabled = bs_top->io_limits_enabled;

    /* geometry */
    tmp.cyls              = bs_top->cyls;
    tmp.heads             = bs_top->heads;
    tmp.secs              = bs_top->secs;
    tmp.translation       = bs_top->translation;

    /* r/w error */
    tmp.on_read_error     = bs_top->on_read_error;
    tmp.on_write_error    = bs_top->on_write_error;

    /* i/o status */
    tmp.iostatus_enabled  = bs_top->iostatus_enabled;
    tmp.iostatus          = bs_top->iostatus;

    /* keep the same entry in bdrv_states */
    pstrcpy(tmp.device_name, sizeof(tmp.device_name), bs_top->device_name);
    tmp.list = bs_top->list;

    /* The contents of 'tmp' will become bs_top, as we are
     * swapping bs_new and bs_top contents. */
    tmp.backing_hd = bs_new;
    pstrcpy(tmp.backing_file, sizeof(tmp.backing_file), bs_top->filename);
J
Jeff Cody 已提交
1037
    bdrv_get_format(bs_top, tmp.backing_format, sizeof(tmp.backing_format));
1038 1039 1040 1041 1042

    /* swap contents of the fixed new bs and the current top */
    *bs_new = *bs_top;
    *bs_top = tmp;

J
Jeff Cody 已提交
1043 1044 1045 1046 1047 1048
    /* device_name[] was carried over from the old bs_top.  bs_new
     * shouldn't be in bdrv_states, so we need to make device_name[]
     * reflect the anonymity of bs_new
     */
    bs_new->device_name[0] = '\0';

1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063
    /* clear the copied fields in the new backing file */
    bdrv_detach_dev(bs_new, bs_new->dev);

    qemu_co_queue_init(&bs_new->throttled_reqs);
    memset(&bs_new->io_base,   0, sizeof(bs_new->io_base));
    memset(&bs_new->io_limits, 0, sizeof(bs_new->io_limits));
    bdrv_iostatus_disable(bs_new);

    /* we don't use bdrv_io_limits_disable() for this, because we don't want
     * to affect or delete the block_timer, as it has been moved to bs_top */
    bs_new->io_limits_enabled = false;
    bs_new->block_timer       = NULL;
    bs_new->slice_time        = 0;
    bs_new->slice_start       = 0;
    bs_new->slice_end         = 0;
P
Paolo Bonzini 已提交
1064 1065 1066

    bdrv_rebind(bs_new);
    bdrv_rebind(bs_top);
1067 1068
}

B
bellard 已提交
1069 1070
void bdrv_delete(BlockDriverState *bs)
{
1071
    assert(!bs->dev);
1072 1073
    assert(!bs->job);
    assert(!bs->in_use);
1074

1075
    /* remove from list, if necessary */
1076
    bdrv_make_anon(bs);
1077

B
bellard 已提交
1078
    bdrv_close(bs);
1079

1080
    assert(bs != bs_snapshots);
1081
    g_free(bs);
B
bellard 已提交
1082 1083
}

1084 1085
int bdrv_attach_dev(BlockDriverState *bs, void *dev)
/* TODO change to DeviceState *dev when all users are qdevified */
1086
{
1087
    if (bs->dev) {
1088 1089
        return -EBUSY;
    }
1090
    bs->dev = dev;
1091
    bdrv_iostatus_reset(bs);
1092 1093 1094
    return 0;
}

1095 1096
/* TODO qdevified devices don't use this, remove when devices are qdevified */
void bdrv_attach_dev_nofail(BlockDriverState *bs, void *dev)
1097
{
1098 1099 1100 1101 1102 1103 1104 1105 1106 1107
    if (bdrv_attach_dev(bs, dev) < 0) {
        abort();
    }
}

void bdrv_detach_dev(BlockDriverState *bs, void *dev)
/* TODO change to DeviceState *dev when all users are qdevified */
{
    assert(bs->dev == dev);
    bs->dev = NULL;
1108 1109
    bs->dev_ops = NULL;
    bs->dev_opaque = NULL;
1110
    bs->buffer_alignment = 512;
1111 1112
}

1113 1114
/* TODO change to return DeviceState * when all users are qdevified */
void *bdrv_get_attached_dev(BlockDriverState *bs)
1115
{
1116
    return bs->dev;
1117 1118
}

1119 1120 1121 1122 1123
void bdrv_set_dev_ops(BlockDriverState *bs, const BlockDevOps *ops,
                      void *opaque)
{
    bs->dev_ops = ops;
    bs->dev_opaque = opaque;
1124 1125 1126
    if (bdrv_dev_has_removable_media(bs) && bs == bs_snapshots) {
        bs_snapshots = NULL;
    }
1127 1128
}

1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157
void bdrv_emit_qmp_error_event(const BlockDriverState *bdrv,
                               BlockQMPEventAction 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);
}

1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168
static void bdrv_emit_qmp_eject_event(BlockDriverState *bs, bool ejected)
{
    QObject *data;

    data = qobject_from_jsonf("{ 'device': %s, 'tray-open': %i }",
                              bdrv_get_device_name(bs), ejected);
    monitor_protocol_event(QEVENT_DEVICE_TRAY_MOVED, data);

    qobject_decref(data);
}

1169
static void bdrv_dev_change_media_cb(BlockDriverState *bs, bool load)
1170
{
1171
    if (bs->dev_ops && bs->dev_ops->change_media_cb) {
1172
        bool tray_was_closed = !bdrv_dev_is_tray_open(bs);
1173
        bs->dev_ops->change_media_cb(bs->dev_opaque, load);
1174 1175 1176 1177 1178 1179 1180 1181
        if (tray_was_closed) {
            /* tray open */
            bdrv_emit_qmp_eject_event(bs, true);
        }
        if (load) {
            /* tray close */
            bdrv_emit_qmp_eject_event(bs, false);
        }
1182 1183 1184
    }
}

1185 1186 1187 1188 1189
bool bdrv_dev_has_removable_media(BlockDriverState *bs)
{
    return !bs->dev || (bs->dev_ops && bs->dev_ops->change_media_cb);
}

P
Paolo Bonzini 已提交
1190 1191 1192 1193 1194 1195 1196
void bdrv_dev_eject_request(BlockDriverState *bs, bool force)
{
    if (bs->dev_ops && bs->dev_ops->eject_request_cb) {
        bs->dev_ops->eject_request_cb(bs->dev_opaque, force);
    }
}

1197 1198 1199 1200 1201 1202 1203 1204
bool bdrv_dev_is_tray_open(BlockDriverState *bs)
{
    if (bs->dev_ops && bs->dev_ops->is_tray_open) {
        return bs->dev_ops->is_tray_open(bs->dev_opaque);
    }
    return false;
}

1205 1206 1207 1208
static void bdrv_dev_resize_cb(BlockDriverState *bs)
{
    if (bs->dev_ops && bs->dev_ops->resize_cb) {
        bs->dev_ops->resize_cb(bs->dev_opaque);
1209 1210 1211
    }
}

1212 1213 1214 1215 1216 1217 1218 1219
bool bdrv_dev_is_medium_locked(BlockDriverState *bs)
{
    if (bs->dev_ops && bs->dev_ops->is_medium_locked) {
        return bs->dev_ops->is_medium_locked(bs->dev_opaque);
    }
    return false;
}

A
aliguori 已提交
1220 1221 1222
/*
 * Run consistency checks on an image
 *
1223
 * Returns 0 if the check could be completed (it doesn't mean that the image is
1224
 * free of errors) or -errno when an internal error occurred. The results of the
1225
 * check are stored in res.
A
aliguori 已提交
1226
 */
1227
int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix)
A
aliguori 已提交
1228 1229 1230 1231 1232
{
    if (bs->drv->bdrv_check == NULL) {
        return -ENOTSUP;
    }

1233
    memset(res, 0, sizeof(*res));
1234
    return bs->drv->bdrv_check(bs, res, fix);
A
aliguori 已提交
1235 1236
}

1237 1238
#define COMMIT_BUF_SECTORS 2048

1239 1240 1241
/* commit COW file into the raw image */
int bdrv_commit(BlockDriverState *bs)
{
B
bellard 已提交
1242
    BlockDriver *drv = bs->drv;
1243
    BlockDriver *backing_drv;
1244 1245
    int64_t sector, total_sectors;
    int n, ro, open_flags;
1246
    int ret = 0, rw_ret = 0;
1247
    uint8_t *buf;
1248 1249
    char filename[1024];
    BlockDriverState *bs_rw, *bs_ro;
1250

B
bellard 已提交
1251 1252
    if (!drv)
        return -ENOMEDIUM;
1253 1254 1255
    
    if (!bs->backing_hd) {
        return -ENOTSUP;
1256 1257
    }

1258 1259 1260
    if (bs->backing_hd->keep_read_only) {
        return -EACCES;
    }
1261

1262 1263 1264 1265
    if (bdrv_in_use(bs) || bdrv_in_use(bs->backing_hd)) {
        return -EBUSY;
    }

1266
    backing_drv = bs->backing_hd->drv;
1267 1268 1269 1270 1271 1272 1273 1274 1275
    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("");
1276 1277
        rw_ret = bdrv_open(bs_rw, filename, open_flags | BDRV_O_RDWR,
            backing_drv);
1278 1279 1280 1281
        if (rw_ret < 0) {
            bdrv_delete(bs_rw);
            /* try to re-open read-only */
            bs_ro = bdrv_new("");
1282 1283
            ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR,
                backing_drv);
1284 1285 1286 1287 1288 1289 1290 1291 1292 1293
            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;
B
bellard 已提交
1294
    }
1295

J
Jan Kiszka 已提交
1296
    total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
1297
    buf = g_malloc(COMMIT_BUF_SECTORS * BDRV_SECTOR_SIZE);
1298 1299

    for (sector = 0; sector < total_sectors; sector += n) {
1300
        if (bdrv_is_allocated(bs, sector, COMMIT_BUF_SECTORS, &n)) {
1301 1302 1303 1304 1305 1306 1307 1308 1309 1310

            if (bdrv_read(bs, sector, buf, n) != 0) {
                ret = -EIO;
                goto ro_cleanup;
            }

            if (bdrv_write(bs->backing_hd, sector, buf, n) != 0) {
                ret = -EIO;
                goto ro_cleanup;
            }
B
bellard 已提交
1311
        }
1312
    }
1313

1314 1315 1316 1317
    if (drv->bdrv_make_empty) {
        ret = drv->bdrv_make_empty(bs);
        bdrv_flush(bs);
    }
1318

1319 1320 1321 1322 1323 1324
    /*
     * Make sure all data we wrote to the backing device is actually
     * stable on disk.
     */
    if (bs->backing_hd)
        bdrv_flush(bs->backing_hd);
1325 1326

ro_cleanup:
1327
    g_free(buf);
1328 1329 1330 1331 1332 1333

    if (ro) {
        /* re-open as RO */
        bdrv_delete(bs->backing_hd);
        bs->backing_hd = NULL;
        bs_ro = bdrv_new("");
1334 1335
        ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR,
            backing_drv);
1336 1337 1338 1339 1340 1341 1342 1343 1344 1345
        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;
    }

1346
    return ret;
1347 1348
}

1349
int bdrv_commit_all(void)
1350 1351 1352 1353
{
    BlockDriverState *bs;

    QTAILQ_FOREACH(bs, &bdrv_states, list) {
1354 1355 1356 1357
        int ret = bdrv_commit(bs);
        if (ret < 0) {
            return ret;
        }
1358
    }
1359
    return 0;
1360 1361
}

S
Stefan Hajnoczi 已提交
1362 1363 1364 1365 1366 1367
struct BdrvTrackedRequest {
    BlockDriverState *bs;
    int64_t sector_num;
    int nb_sectors;
    bool is_write;
    QLIST_ENTRY(BdrvTrackedRequest) list;
1368
    Coroutine *co; /* owner, used for deadlock detection */
1369
    CoQueue wait_queue; /* coroutines blocked on this request */
S
Stefan Hajnoczi 已提交
1370 1371 1372 1373 1374 1375 1376 1377 1378 1379
};

/**
 * Remove an active request from the tracked requests list
 *
 * This function should be called when a tracked request is completing.
 */
static void tracked_request_end(BdrvTrackedRequest *req)
{
    QLIST_REMOVE(req, list);
1380
    qemu_co_queue_restart_all(&req->wait_queue);
S
Stefan Hajnoczi 已提交
1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395
}

/**
 * Add an active request to the tracked requests list
 */
static void tracked_request_begin(BdrvTrackedRequest *req,
                                  BlockDriverState *bs,
                                  int64_t sector_num,
                                  int nb_sectors, bool is_write)
{
    *req = (BdrvTrackedRequest){
        .bs = bs,
        .sector_num = sector_num,
        .nb_sectors = nb_sectors,
        .is_write = is_write,
1396
        .co = qemu_coroutine_self(),
S
Stefan Hajnoczi 已提交
1397 1398
    };

1399 1400
    qemu_co_queue_init(&req->wait_queue);

S
Stefan Hajnoczi 已提交
1401 1402 1403
    QLIST_INSERT_HEAD(&bs->tracked_requests, req, list);
}

S
Stefan Hajnoczi 已提交
1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424
/**
 * Round a region to cluster boundaries
 */
static void round_to_clusters(BlockDriverState *bs,
                              int64_t sector_num, int nb_sectors,
                              int64_t *cluster_sector_num,
                              int *cluster_nb_sectors)
{
    BlockDriverInfo bdi;

    if (bdrv_get_info(bs, &bdi) < 0 || bdi.cluster_size == 0) {
        *cluster_sector_num = sector_num;
        *cluster_nb_sectors = nb_sectors;
    } else {
        int64_t c = bdi.cluster_size / BDRV_SECTOR_SIZE;
        *cluster_sector_num = QEMU_ALIGN_DOWN(sector_num, c);
        *cluster_nb_sectors = QEMU_ALIGN_UP(sector_num - *cluster_sector_num +
                                            nb_sectors, c);
    }
}

1425 1426
static bool tracked_request_overlaps(BdrvTrackedRequest *req,
                                     int64_t sector_num, int nb_sectors) {
S
Stefan Hajnoczi 已提交
1427 1428 1429 1430 1431 1432 1433 1434 1435
    /*        aaaa   bbbb */
    if (sector_num >= req->sector_num + req->nb_sectors) {
        return false;
    }
    /* bbbb   aaaa        */
    if (req->sector_num >= sector_num + nb_sectors) {
        return false;
    }
    return true;
1436 1437 1438 1439 1440 1441
}

static void coroutine_fn wait_for_overlapping_requests(BlockDriverState *bs,
        int64_t sector_num, int nb_sectors)
{
    BdrvTrackedRequest *req;
S
Stefan Hajnoczi 已提交
1442 1443
    int64_t cluster_sector_num;
    int cluster_nb_sectors;
1444 1445
    bool retry;

S
Stefan Hajnoczi 已提交
1446 1447 1448 1449 1450 1451 1452 1453 1454
    /* If we touch the same cluster it counts as an overlap.  This guarantees
     * that allocating writes will be serialized and not race with each other
     * for the same cluster.  For example, in copy-on-read it ensures that the
     * CoR read and write operations are atomic and guest writes cannot
     * interleave between them.
     */
    round_to_clusters(bs, sector_num, nb_sectors,
                      &cluster_sector_num, &cluster_nb_sectors);

1455 1456 1457
    do {
        retry = false;
        QLIST_FOREACH(req, &bs->tracked_requests, list) {
S
Stefan Hajnoczi 已提交
1458 1459
            if (tracked_request_overlaps(req, cluster_sector_num,
                                         cluster_nb_sectors)) {
1460 1461 1462 1463 1464 1465
                /* Hitting this means there was a reentrant request, for
                 * example, a block driver issuing nested requests.  This must
                 * never happen since it means deadlock.
                 */
                assert(qemu_coroutine_self() != req->co);

1466 1467 1468 1469 1470 1471 1472 1473
                qemu_co_queue_wait(&req->wait_queue);
                retry = true;
                break;
            }
        }
    } while (retry);
}

K
Kevin Wolf 已提交
1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485
/*
 * 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;
1486
    int ret;
K
Kevin Wolf 已提交
1487

1488 1489 1490 1491 1492
    /* Backing file format doesn't make sense without a backing file */
    if (backing_fmt && !backing_file) {
        return -EINVAL;
    }

K
Kevin Wolf 已提交
1493
    if (drv->bdrv_change_backing_file != NULL) {
1494
        ret = drv->bdrv_change_backing_file(bs, backing_file, backing_fmt);
K
Kevin Wolf 已提交
1495
    } else {
1496
        ret = -ENOTSUP;
K
Kevin Wolf 已提交
1497
    }
1498 1499 1500 1501 1502 1503

    if (ret == 0) {
        pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: "");
        pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: "");
    }
    return ret;
K
Kevin Wolf 已提交
1504 1505
}

1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518
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);

K
Kevin Wolf 已提交
1519 1520 1521 1522
    if (offset < 0)
        return -EIO;

    if ((offset > len) || (len - offset < size))
1523 1524 1525 1526 1527 1528 1529 1530
        return -EIO;

    return 0;
}

static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num,
                              int nb_sectors)
{
1531 1532
    return bdrv_check_byte_request(bs, sector_num * BDRV_SECTOR_SIZE,
                                   nb_sectors * BDRV_SECTOR_SIZE);
1533 1534
}

1535 1536 1537 1538 1539 1540 1541 1542 1543 1544
typedef struct RwCo {
    BlockDriverState *bs;
    int64_t sector_num;
    int nb_sectors;
    QEMUIOVector *qiov;
    bool is_write;
    int ret;
} RwCo;

static void coroutine_fn bdrv_rw_co_entry(void *opaque)
B
bellard 已提交
1545
{
1546
    RwCo *rwco = opaque;
B
bellard 已提交
1547

1548 1549
    if (!rwco->is_write) {
        rwco->ret = bdrv_co_do_readv(rwco->bs, rwco->sector_num,
1550
                                     rwco->nb_sectors, rwco->qiov, 0);
1551 1552
    } else {
        rwco->ret = bdrv_co_do_writev(rwco->bs, rwco->sector_num,
1553
                                      rwco->nb_sectors, rwco->qiov, 0);
1554 1555
    }
}
1556

1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576
/*
 * Process a synchronous request using coroutines
 */
static int bdrv_rw_co(BlockDriverState *bs, int64_t sector_num, uint8_t *buf,
                      int nb_sectors, bool is_write)
{
    QEMUIOVector qiov;
    struct iovec iov = {
        .iov_base = (void *)buf,
        .iov_len = nb_sectors * BDRV_SECTOR_SIZE,
    };
    Coroutine *co;
    RwCo rwco = {
        .bs = bs,
        .sector_num = sector_num,
        .nb_sectors = nb_sectors,
        .qiov = &qiov,
        .is_write = is_write,
        .ret = NOT_DONE,
    };
1577

1578
    qemu_iovec_init_external(&qiov, &iov, 1);
1579

1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590
    /**
     * In sync call context, when the vcpu is blocked, this throttling timer
     * will not fire; so the I/O throttling function has to be disabled here
     * if it has been enabled.
     */
    if (bs->io_limits_enabled) {
        fprintf(stderr, "Disabling I/O throttling on '%s' due "
                        "to synchronous I/O.\n", bdrv_get_device_name(bs));
        bdrv_io_limits_disable(bs);
    }

1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602
    if (qemu_in_coroutine()) {
        /* Fast-path if already in coroutine context */
        bdrv_rw_co_entry(&rwco);
    } else {
        co = qemu_coroutine_create(bdrv_rw_co_entry);
        qemu_coroutine_enter(co, &rwco);
        while (rwco.ret == NOT_DONE) {
            qemu_aio_wait();
        }
    }
    return rwco.ret;
}
B
bellard 已提交
1603

1604 1605 1606 1607 1608
/* return < 0 if error. See bdrv_write() for the return codes */
int bdrv_read(BlockDriverState *bs, int64_t sector_num,
              uint8_t *buf, int nb_sectors)
{
    return bdrv_rw_co(bs, sector_num, buf, nb_sectors, false);
B
bellard 已提交
1609 1610
}

1611 1612
#define BITS_PER_LONG  (sizeof(unsigned long) * 8)

1613
static void set_dirty_bitmap(BlockDriverState *bs, int64_t sector_num,
1614
                             int nb_sectors, int dirty)
1615 1616
{
    int64_t start, end;
1617
    unsigned long val, idx, bit;
1618

J
Jan Kiszka 已提交
1619
    start = sector_num / BDRV_SECTORS_PER_DIRTY_CHUNK;
1620
    end = (sector_num + nb_sectors - 1) / BDRV_SECTORS_PER_DIRTY_CHUNK;
1621 1622

    for (; start <= end; start++) {
1623 1624
        idx = start / BITS_PER_LONG;
        bit = start % BITS_PER_LONG;
1625 1626
        val = bs->dirty_bitmap[idx];
        if (dirty) {
1627
            if (!(val & (1UL << bit))) {
1628
                bs->dirty_count++;
1629
                val |= 1UL << bit;
1630
            }
1631
        } else {
1632
            if (val & (1UL << bit)) {
1633
                bs->dirty_count--;
1634
                val &= ~(1UL << bit);
1635
            }
1636 1637
        }
        bs->dirty_bitmap[idx] = val;
1638 1639 1640
    }
}

1641
/* Return < 0 if error. Important errors are:
B
bellard 已提交
1642 1643 1644 1645 1646
  -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
*/
1647
int bdrv_write(BlockDriverState *bs, int64_t sector_num,
B
bellard 已提交
1648 1649
               const uint8_t *buf, int nb_sectors)
{
1650
    return bdrv_rw_co(bs, sector_num, (uint8_t *)buf, nb_sectors, true);
B
bellard 已提交
1651 1652
}

1653 1654
int bdrv_pread(BlockDriverState *bs, int64_t offset,
               void *buf, int count1)
B
bellard 已提交
1655
{
J
Jan Kiszka 已提交
1656
    uint8_t tmp_buf[BDRV_SECTOR_SIZE];
B
bellard 已提交
1657 1658
    int len, nb_sectors, count;
    int64_t sector_num;
1659
    int ret;
B
bellard 已提交
1660 1661 1662

    count = count1;
    /* first read to align to sector start */
J
Jan Kiszka 已提交
1663
    len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
B
bellard 已提交
1664 1665
    if (len > count)
        len = count;
J
Jan Kiszka 已提交
1666
    sector_num = offset >> BDRV_SECTOR_BITS;
B
bellard 已提交
1667
    if (len > 0) {
1668 1669
        if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
            return ret;
J
Jan Kiszka 已提交
1670
        memcpy(buf, tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), len);
B
bellard 已提交
1671 1672 1673 1674 1675 1676 1677 1678
        count -= len;
        if (count == 0)
            return count1;
        sector_num++;
        buf += len;
    }

    /* read the sectors "in place" */
J
Jan Kiszka 已提交
1679
    nb_sectors = count >> BDRV_SECTOR_BITS;
B
bellard 已提交
1680
    if (nb_sectors > 0) {
1681 1682
        if ((ret = bdrv_read(bs, sector_num, buf, nb_sectors)) < 0)
            return ret;
B
bellard 已提交
1683
        sector_num += nb_sectors;
J
Jan Kiszka 已提交
1684
        len = nb_sectors << BDRV_SECTOR_BITS;
B
bellard 已提交
1685 1686 1687 1688 1689 1690
        buf += len;
        count -= len;
    }

    /* add data from the last sector */
    if (count > 0) {
1691 1692
        if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
            return ret;
B
bellard 已提交
1693 1694 1695 1696 1697
        memcpy(buf, tmp_buf, count);
    }
    return count1;
}

1698 1699
int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
                const void *buf, int count1)
B
bellard 已提交
1700
{
J
Jan Kiszka 已提交
1701
    uint8_t tmp_buf[BDRV_SECTOR_SIZE];
B
bellard 已提交
1702 1703
    int len, nb_sectors, count;
    int64_t sector_num;
1704
    int ret;
B
bellard 已提交
1705 1706 1707

    count = count1;
    /* first write to align to sector start */
J
Jan Kiszka 已提交
1708
    len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
B
bellard 已提交
1709 1710
    if (len > count)
        len = count;
J
Jan Kiszka 已提交
1711
    sector_num = offset >> BDRV_SECTOR_BITS;
B
bellard 已提交
1712
    if (len > 0) {
1713 1714
        if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
            return ret;
J
Jan Kiszka 已提交
1715
        memcpy(tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), buf, len);
1716 1717
        if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0)
            return ret;
B
bellard 已提交
1718 1719 1720 1721 1722 1723 1724 1725
        count -= len;
        if (count == 0)
            return count1;
        sector_num++;
        buf += len;
    }

    /* write the sectors "in place" */
J
Jan Kiszka 已提交
1726
    nb_sectors = count >> BDRV_SECTOR_BITS;
B
bellard 已提交
1727
    if (nb_sectors > 0) {
1728 1729
        if ((ret = bdrv_write(bs, sector_num, buf, nb_sectors)) < 0)
            return ret;
B
bellard 已提交
1730
        sector_num += nb_sectors;
J
Jan Kiszka 已提交
1731
        len = nb_sectors << BDRV_SECTOR_BITS;
B
bellard 已提交
1732 1733 1734 1735 1736 1737
        buf += len;
        count -= len;
    }

    /* add data from the last sector */
    if (count > 0) {
1738 1739
        if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
            return ret;
B
bellard 已提交
1740
        memcpy(tmp_buf, buf, count);
1741 1742
        if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0)
            return ret;
B
bellard 已提交
1743 1744 1745 1746
    }
    return count1;
}

K
Kevin Wolf 已提交
1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762
/*
 * Writes to the file and ensures that no writes are reordered across this
 * request (acts as a barrier)
 *
 * Returns 0 on success, -errno in error cases.
 */
int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset,
    const void *buf, int count)
{
    int ret;

    ret = bdrv_pwrite(bs, offset, buf, count);
    if (ret < 0) {
        return ret;
    }

1763 1764
    /* No flush needed for cache modes that already do it */
    if (bs->enable_write_cache) {
K
Kevin Wolf 已提交
1765 1766 1767 1768 1769 1770
        bdrv_flush(bs);
    }

    return 0;
}

1771
static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs,
S
Stefan Hajnoczi 已提交
1772 1773 1774 1775 1776 1777 1778 1779 1780
        int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
{
    /* Perform I/O through a temporary buffer so that users who scribble over
     * their read buffer while the operation is in progress do not end up
     * modifying the image file.  This is critical for zero-copy guest I/O
     * where anything might happen inside guest memory.
     */
    void *bounce_buffer;

1781
    BlockDriver *drv = bs->drv;
S
Stefan Hajnoczi 已提交
1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794
    struct iovec iov;
    QEMUIOVector bounce_qiov;
    int64_t cluster_sector_num;
    int cluster_nb_sectors;
    size_t skip_bytes;
    int ret;

    /* Cover entire cluster so no additional backing file I/O is required when
     * allocating cluster in the image file.
     */
    round_to_clusters(bs, sector_num, nb_sectors,
                      &cluster_sector_num, &cluster_nb_sectors);

1795 1796
    trace_bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors,
                                   cluster_sector_num, cluster_nb_sectors);
S
Stefan Hajnoczi 已提交
1797 1798 1799 1800 1801

    iov.iov_len = cluster_nb_sectors * BDRV_SECTOR_SIZE;
    iov.iov_base = bounce_buffer = qemu_blockalign(bs, iov.iov_len);
    qemu_iovec_init_external(&bounce_qiov, &iov, 1);

1802 1803
    ret = drv->bdrv_co_readv(bs, cluster_sector_num, cluster_nb_sectors,
                             &bounce_qiov);
S
Stefan Hajnoczi 已提交
1804 1805 1806 1807
    if (ret < 0) {
        goto err;
    }

1808 1809
    if (drv->bdrv_co_write_zeroes &&
        buffer_is_zero(bounce_buffer, iov.iov_len)) {
K
Kevin Wolf 已提交
1810 1811
        ret = bdrv_co_do_write_zeroes(bs, cluster_sector_num,
                                      cluster_nb_sectors);
1812
    } else {
1813 1814 1815
        /* This does not change the data on the disk, it is not necessary
         * to flush even in cache=writethrough mode.
         */
1816
        ret = drv->bdrv_co_writev(bs, cluster_sector_num, cluster_nb_sectors,
S
Stefan Hajnoczi 已提交
1817
                                  &bounce_qiov);
1818 1819
    }

S
Stefan Hajnoczi 已提交
1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836
    if (ret < 0) {
        /* It might be okay to ignore write errors for guest requests.  If this
         * is a deliberate copy-on-read then we don't want to ignore the error.
         * Simply report it in all cases.
         */
        goto err;
    }

    skip_bytes = (sector_num - cluster_sector_num) * BDRV_SECTOR_SIZE;
    qemu_iovec_from_buffer(qiov, bounce_buffer + skip_bytes,
                           nb_sectors * BDRV_SECTOR_SIZE);

err:
    qemu_vfree(bounce_buffer);
    return ret;
}

1837 1838 1839 1840
/*
 * Handle a read request in coroutine context
 */
static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs,
1841 1842
    int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
    BdrvRequestFlags flags)
K
Kevin Wolf 已提交
1843 1844
{
    BlockDriver *drv = bs->drv;
S
Stefan Hajnoczi 已提交
1845 1846
    BdrvTrackedRequest req;
    int ret;
K
Kevin Wolf 已提交
1847 1848 1849 1850 1851 1852 1853 1854

    if (!drv) {
        return -ENOMEDIUM;
    }
    if (bdrv_check_request(bs, sector_num, nb_sectors)) {
        return -EIO;
    }

Z
Zhi Yong Wu 已提交
1855 1856 1857 1858 1859
    /* throttling disk read I/O */
    if (bs->io_limits_enabled) {
        bdrv_io_limits_intercept(bs, false, nb_sectors);
    }

1860
    if (bs->copy_on_read) {
1861 1862 1863 1864 1865 1866 1867
        flags |= BDRV_REQ_COPY_ON_READ;
    }
    if (flags & BDRV_REQ_COPY_ON_READ) {
        bs->copy_on_read_in_flight++;
    }

    if (bs->copy_on_read_in_flight) {
1868 1869 1870
        wait_for_overlapping_requests(bs, sector_num, nb_sectors);
    }

S
Stefan Hajnoczi 已提交
1871
    tracked_request_begin(&req, bs, sector_num, nb_sectors, false);
S
Stefan Hajnoczi 已提交
1872

1873
    if (flags & BDRV_REQ_COPY_ON_READ) {
S
Stefan Hajnoczi 已提交
1874 1875 1876 1877 1878 1879 1880 1881
        int pnum;

        ret = bdrv_co_is_allocated(bs, sector_num, nb_sectors, &pnum);
        if (ret < 0) {
            goto out;
        }

        if (!ret || pnum != nb_sectors) {
1882
            ret = bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors, qiov);
S
Stefan Hajnoczi 已提交
1883 1884 1885 1886
            goto out;
        }
    }

S
Stefan Hajnoczi 已提交
1887
    ret = drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov);
S
Stefan Hajnoczi 已提交
1888 1889

out:
S
Stefan Hajnoczi 已提交
1890
    tracked_request_end(&req);
1891 1892 1893 1894 1895

    if (flags & BDRV_REQ_COPY_ON_READ) {
        bs->copy_on_read_in_flight--;
    }

S
Stefan Hajnoczi 已提交
1896
    return ret;
K
Kevin Wolf 已提交
1897 1898
}

1899
int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num,
K
Kevin Wolf 已提交
1900 1901
    int nb_sectors, QEMUIOVector *qiov)
{
1902
    trace_bdrv_co_readv(bs, sector_num, nb_sectors);
K
Kevin Wolf 已提交
1903

1904 1905 1906 1907 1908 1909 1910 1911 1912 1913
    return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov, 0);
}

int coroutine_fn bdrv_co_copy_on_readv(BlockDriverState *bs,
    int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
{
    trace_bdrv_co_copy_on_readv(bs, sector_num, nb_sectors);

    return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov,
                            BDRV_REQ_COPY_ON_READ);
1914 1915
}

1916 1917 1918 1919 1920 1921 1922 1923
static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs,
    int64_t sector_num, int nb_sectors)
{
    BlockDriver *drv = bs->drv;
    QEMUIOVector qiov;
    struct iovec iov;
    int ret;

K
Kevin Wolf 已提交
1924 1925 1926
    /* TODO Emulate only part of misaligned requests instead of letting block
     * drivers return -ENOTSUP and emulate everything */

1927 1928
    /* First try the efficient write zeroes operation */
    if (drv->bdrv_co_write_zeroes) {
K
Kevin Wolf 已提交
1929 1930 1931 1932
        ret = drv->bdrv_co_write_zeroes(bs, sector_num, nb_sectors);
        if (ret != -ENOTSUP) {
            return ret;
        }
1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946
    }

    /* Fall back to bounce buffer if write zeroes is unsupported */
    iov.iov_len  = nb_sectors * BDRV_SECTOR_SIZE;
    iov.iov_base = qemu_blockalign(bs, iov.iov_len);
    memset(iov.iov_base, 0, iov.iov_len);
    qemu_iovec_init_external(&qiov, &iov, 1);

    ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, &qiov);

    qemu_vfree(iov.iov_base);
    return ret;
}

1947 1948 1949 1950
/*
 * Handle a write request in coroutine context
 */
static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs,
1951 1952
    int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
    BdrvRequestFlags flags)
1953 1954
{
    BlockDriver *drv = bs->drv;
S
Stefan Hajnoczi 已提交
1955
    BdrvTrackedRequest req;
1956
    int ret;
K
Kevin Wolf 已提交
1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967

    if (!bs->drv) {
        return -ENOMEDIUM;
    }
    if (bs->read_only) {
        return -EACCES;
    }
    if (bdrv_check_request(bs, sector_num, nb_sectors)) {
        return -EIO;
    }

Z
Zhi Yong Wu 已提交
1968 1969 1970 1971 1972
    /* throttling disk write I/O */
    if (bs->io_limits_enabled) {
        bdrv_io_limits_intercept(bs, true, nb_sectors);
    }

1973
    if (bs->copy_on_read_in_flight) {
1974 1975 1976
        wait_for_overlapping_requests(bs, sector_num, nb_sectors);
    }

S
Stefan Hajnoczi 已提交
1977 1978
    tracked_request_begin(&req, bs, sector_num, nb_sectors, true);

1979 1980 1981 1982 1983
    if (flags & BDRV_REQ_ZERO_WRITE) {
        ret = bdrv_co_do_write_zeroes(bs, sector_num, nb_sectors);
    } else {
        ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, qiov);
    }
1984

1985 1986 1987 1988
    if (ret == 0 && !bs->enable_write_cache) {
        ret = bdrv_co_flush(bs);
    }

K
Kevin Wolf 已提交
1989 1990 1991 1992 1993 1994 1995 1996
    if (bs->dirty_bitmap) {
        set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
    }

    if (bs->wr_highest_sector < sector_num + nb_sectors - 1) {
        bs->wr_highest_sector = sector_num + nb_sectors - 1;
    }

S
Stefan Hajnoczi 已提交
1997 1998
    tracked_request_end(&req);

1999
    return ret;
K
Kevin Wolf 已提交
2000 2001
}

2002 2003 2004 2005 2006
int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num,
    int nb_sectors, QEMUIOVector *qiov)
{
    trace_bdrv_co_writev(bs, sector_num, nb_sectors);

2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
    return bdrv_co_do_writev(bs, sector_num, nb_sectors, qiov, 0);
}

int coroutine_fn bdrv_co_write_zeroes(BlockDriverState *bs,
                                      int64_t sector_num, int nb_sectors)
{
    trace_bdrv_co_write_zeroes(bs, sector_num, nb_sectors);

    return bdrv_co_do_writev(bs, sector_num, nb_sectors, NULL,
                             BDRV_REQ_ZERO_WRITE);
2017 2018
}

B
bellard 已提交
2019 2020 2021 2022 2023 2024
/**
 * Truncate file to 'offset' bytes (needed only for file protocols)
 */
int bdrv_truncate(BlockDriverState *bs, int64_t offset)
{
    BlockDriver *drv = bs->drv;
2025
    int ret;
B
bellard 已提交
2026
    if (!drv)
B
bellard 已提交
2027
        return -ENOMEDIUM;
B
bellard 已提交
2028 2029
    if (!drv->bdrv_truncate)
        return -ENOTSUP;
2030 2031
    if (bs->read_only)
        return -EACCES;
M
Marcelo Tosatti 已提交
2032 2033
    if (bdrv_in_use(bs))
        return -EBUSY;
2034 2035 2036
    ret = drv->bdrv_truncate(bs, offset);
    if (ret == 0) {
        ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS);
2037
        bdrv_dev_resize_cb(bs);
2038 2039
    }
    return ret;
B
bellard 已提交
2040 2041
}

2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060
/**
 * Length of a allocated file in bytes. Sparse files are counted by actual
 * allocated space. Return < 0 if error or unknown.
 */
int64_t bdrv_get_allocated_file_size(BlockDriverState *bs)
{
    BlockDriver *drv = bs->drv;
    if (!drv) {
        return -ENOMEDIUM;
    }
    if (drv->bdrv_get_allocated_file_size) {
        return drv->bdrv_get_allocated_file_size(bs);
    }
    if (bs->file) {
        return bdrv_get_allocated_file_size(bs->file);
    }
    return -ENOTSUP;
}

B
bellard 已提交
2061 2062 2063 2064 2065 2066 2067
/**
 * Length of a file in bytes. Return < 0 if error or unknown.
 */
int64_t bdrv_getlength(BlockDriverState *bs)
{
    BlockDriver *drv = bs->drv;
    if (!drv)
B
bellard 已提交
2068
        return -ENOMEDIUM;
2069

2070
    if (bs->growable || bdrv_dev_has_removable_media(bs)) {
2071 2072 2073
        if (drv->bdrv_getlength) {
            return drv->bdrv_getlength(bs);
        }
B
bellard 已提交
2074
    }
2075
    return bs->total_sectors * BDRV_SECTOR_SIZE;
B
bellard 已提交
2076 2077
}

B
bellard 已提交
2078
/* return 0 as number of sectors if no device present or error */
2079
void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
B
bellard 已提交
2080
{
B
bellard 已提交
2081 2082 2083 2084 2085
    int64_t length;
    length = bdrv_getlength(bs);
    if (length < 0)
        length = 0;
    else
J
Jan Kiszka 已提交
2086
        length = length >> BDRV_SECTOR_BITS;
B
bellard 已提交
2087
    *nb_sectors_ptr = length;
B
bellard 已提交
2088
}
B
bellard 已提交
2089

2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100
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 */
2101
} QEMU_PACKED;
2102 2103 2104 2105 2106

/* 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)
{
2107
    uint8_t buf[BDRV_SECTOR_SIZE];
2108 2109 2110
    int ret, i, heads, sectors, cylinders;
    struct partition *p;
    uint32_t nr_sects;
B
blueswir1 已提交
2111
    uint64_t nb_sectors;
2112
    bool enabled;
2113 2114 2115

    bdrv_get_geometry(bs, &nb_sectors);

2116 2117 2118 2119 2120 2121 2122
    /**
     * The function will be invoked during startup not only in sync I/O mode,
     * but also in async I/O mode. So the I/O throttling function has to
     * be disabled temporarily here, not permanently.
     */
    enabled = bs->io_limits_enabled;
    bs->io_limits_enabled = false;
2123
    ret = bdrv_read(bs, 0, buf, 1);
2124
    bs->io_limits_enabled = enabled;
2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159
    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
2160
    uint64_t nb_sectors;
2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214

    /* 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);
    }
}

2215
void bdrv_set_geometry_hint(BlockDriverState *bs,
B
bellard 已提交
2216 2217 2218 2219 2220 2221 2222
                            int cyls, int heads, int secs)
{
    bs->cyls = cyls;
    bs->heads = heads;
    bs->secs = secs;
}

B
bellard 已提交
2223 2224 2225 2226 2227
void bdrv_set_translation_hint(BlockDriverState *bs, int translation)
{
    bs->translation = translation;
}

2228
void bdrv_get_geometry_hint(BlockDriverState *bs,
B
bellard 已提交
2229 2230 2231 2232 2233 2234 2235
                            int *pcyls, int *pheads, int *psecs)
{
    *pcyls = bs->cyls;
    *pheads = bs->heads;
    *psecs = bs->secs;
}

2236 2237 2238 2239 2240 2241 2242 2243
/* throttling disk io limits */
void bdrv_set_io_limits(BlockDriverState *bs,
                        BlockIOLimit *io_limits)
{
    bs->io_limits = *io_limits;
    bs->io_limits_enabled = bdrv_io_limits_enabled(bs);
}

2244 2245 2246 2247 2248 2249
/* Recognize floppy formats */
typedef struct FDFormat {
    FDriveType drive;
    uint8_t last_sect;
    uint8_t max_track;
    uint8_t max_head;
2250
    FDriveRate rate;
2251 2252 2253 2254 2255
} FDFormat;

static const FDFormat fd_formats[] = {
    /* First entry is default format */
    /* 1.44 MB 3"1/2 floppy disks */
2256 2257 2258 2259 2260 2261 2262 2263
    { FDRIVE_DRV_144, 18, 80, 1, FDRIVE_RATE_500K, },
    { FDRIVE_DRV_144, 20, 80, 1, FDRIVE_RATE_500K, },
    { FDRIVE_DRV_144, 21, 80, 1, FDRIVE_RATE_500K, },
    { FDRIVE_DRV_144, 21, 82, 1, FDRIVE_RATE_500K, },
    { FDRIVE_DRV_144, 21, 83, 1, FDRIVE_RATE_500K, },
    { FDRIVE_DRV_144, 22, 80, 1, FDRIVE_RATE_500K, },
    { FDRIVE_DRV_144, 23, 80, 1, FDRIVE_RATE_500K, },
    { FDRIVE_DRV_144, 24, 80, 1, FDRIVE_RATE_500K, },
2264
    /* 2.88 MB 3"1/2 floppy disks */
2265 2266 2267 2268 2269
    { FDRIVE_DRV_288, 36, 80, 1, FDRIVE_RATE_1M, },
    { FDRIVE_DRV_288, 39, 80, 1, FDRIVE_RATE_1M, },
    { FDRIVE_DRV_288, 40, 80, 1, FDRIVE_RATE_1M, },
    { FDRIVE_DRV_288, 44, 80, 1, FDRIVE_RATE_1M, },
    { FDRIVE_DRV_288, 48, 80, 1, FDRIVE_RATE_1M, },
2270
    /* 720 kB 3"1/2 floppy disks */
2271 2272 2273 2274 2275 2276
    { FDRIVE_DRV_144,  9, 80, 1, FDRIVE_RATE_250K, },
    { FDRIVE_DRV_144, 10, 80, 1, FDRIVE_RATE_250K, },
    { FDRIVE_DRV_144, 10, 82, 1, FDRIVE_RATE_250K, },
    { FDRIVE_DRV_144, 10, 83, 1, FDRIVE_RATE_250K, },
    { FDRIVE_DRV_144, 13, 80, 1, FDRIVE_RATE_250K, },
    { FDRIVE_DRV_144, 14, 80, 1, FDRIVE_RATE_250K, },
2277
    /* 1.2 MB 5"1/4 floppy disks */
2278 2279 2280 2281 2282
    { FDRIVE_DRV_120, 15, 80, 1, FDRIVE_RATE_500K, },
    { FDRIVE_DRV_120, 18, 80, 1, FDRIVE_RATE_500K, },
    { FDRIVE_DRV_120, 18, 82, 1, FDRIVE_RATE_500K, },
    { FDRIVE_DRV_120, 18, 83, 1, FDRIVE_RATE_500K, },
    { FDRIVE_DRV_120, 20, 80, 1, FDRIVE_RATE_500K, },
2283
    /* 720 kB 5"1/4 floppy disks */
2284 2285
    { FDRIVE_DRV_120,  9, 80, 1, FDRIVE_RATE_250K, },
    { FDRIVE_DRV_120, 11, 80, 1, FDRIVE_RATE_250K, },
2286
    /* 360 kB 5"1/4 floppy disks */
2287 2288 2289 2290
    { FDRIVE_DRV_120,  9, 40, 1, FDRIVE_RATE_300K, },
    { FDRIVE_DRV_120,  9, 40, 0, FDRIVE_RATE_300K, },
    { FDRIVE_DRV_120, 10, 41, 1, FDRIVE_RATE_300K, },
    { FDRIVE_DRV_120, 10, 42, 1, FDRIVE_RATE_300K, },
2291
    /* 320 kB 5"1/4 floppy disks */
2292 2293
    { FDRIVE_DRV_120,  8, 40, 1, FDRIVE_RATE_250K, },
    { FDRIVE_DRV_120,  8, 40, 0, FDRIVE_RATE_250K, },
2294
    /* 360 kB must match 5"1/4 better than 3"1/2... */
2295
    { FDRIVE_DRV_144,  9, 80, 0, FDRIVE_RATE_250K, },
2296
    /* end */
2297
    { FDRIVE_DRV_NONE, -1, -1, 0, 0, },
2298 2299 2300 2301
};

void bdrv_get_floppy_geometry_hint(BlockDriverState *bs, int *nb_heads,
                                   int *max_track, int *last_sect,
2302 2303
                                   FDriveType drive_in, FDriveType *drive,
                                   FDriveRate *rate)
2304 2305 2306 2307 2308 2309 2310 2311
{
    const FDFormat *parse;
    uint64_t nb_sectors, size;
    int i, first_match, match;

    bdrv_get_geometry_hint(bs, nb_heads, max_track, last_sect);
    if (*nb_heads != 0 && *max_track != 0 && *last_sect != 0) {
        /* User defined disk */
2312
        *rate = FDRIVE_RATE_500K;
2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346
    } else {
        bdrv_get_geometry(bs, &nb_sectors);
        match = -1;
        first_match = -1;
        for (i = 0; ; i++) {
            parse = &fd_formats[i];
            if (parse->drive == FDRIVE_DRV_NONE) {
                break;
            }
            if (drive_in == parse->drive ||
                drive_in == FDRIVE_DRV_NONE) {
                size = (parse->max_head + 1) * parse->max_track *
                    parse->last_sect;
                if (nb_sectors == size) {
                    match = i;
                    break;
                }
                if (first_match == -1) {
                    first_match = i;
                }
            }
        }
        if (match == -1) {
            if (first_match == -1) {
                match = 1;
            } else {
                match = first_match;
            }
            parse = &fd_formats[match];
        }
        *nb_heads = parse->max_head + 1;
        *max_track = parse->max_track;
        *last_sect = parse->last_sect;
        *drive = parse->drive;
2347
        *rate = parse->rate;
2348 2349 2350
    }
}

B
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int bdrv_get_translation_hint(BlockDriverState *bs)
{
    return bs->translation;
}

2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367
void bdrv_set_on_error(BlockDriverState *bs, BlockErrorAction on_read_error,
                       BlockErrorAction on_write_error)
{
    bs->on_read_error = on_read_error;
    bs->on_write_error = on_write_error;
}

BlockErrorAction bdrv_get_on_error(BlockDriverState *bs, int is_read)
{
    return is_read ? bs->on_read_error : bs->on_write_error;
}

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

2373 2374 2375 2376 2377
int bdrv_is_sg(BlockDriverState *bs)
{
    return bs->sg;
}

2378 2379 2380 2381 2382
int bdrv_enable_write_cache(BlockDriverState *bs)
{
    return bs->enable_write_cache;
}

B
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2383 2384 2385 2386 2387 2388 2389
int bdrv_is_encrypted(BlockDriverState *bs)
{
    if (bs->backing_hd && bs->backing_hd->encrypted)
        return 1;
    return bs->encrypted;
}

2390 2391 2392 2393 2394 2395 2396 2397 2398
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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2399 2400 2401 2402 2403 2404 2405 2406 2407 2408
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;
    }
2409 2410 2411 2412 2413
    if (!bs->encrypted) {
        return -EINVAL;
    } else if (!bs->drv || !bs->drv->bdrv_set_key) {
        return -ENOMEDIUM;
    }
2414
    ret = bs->drv->bdrv_set_key(bs, key);
2415 2416 2417 2418 2419
    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 */
2420
        bdrv_dev_change_media_cb(bs, true);
2421
    }
2422
    return ret;
B
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2423 2424 2425 2426
}

void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)
{
B
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2427
    if (!bs->drv) {
B
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2428 2429 2430 2431 2432 2433
        buf[0] = '\0';
    } else {
        pstrcpy(buf, buf_size, bs->drv->format_name);
    }
}

2434
void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
B
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2435 2436 2437 2438
                         void *opaque)
{
    BlockDriver *drv;

2439
    QLIST_FOREACH(drv, &bdrv_drivers, list) {
B
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2440 2441 2442 2443
        it(opaque, drv->format_name);
    }
}

B
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2444 2445 2446 2447
BlockDriverState *bdrv_find(const char *name)
{
    BlockDriverState *bs;

2448 2449
    QTAILQ_FOREACH(bs, &bdrv_states, list) {
        if (!strcmp(name, bs->device_name)) {
B
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2450
            return bs;
2451
        }
B
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2452 2453 2454 2455
    }
    return NULL;
}

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2456 2457 2458 2459 2460 2461 2462 2463
BlockDriverState *bdrv_next(BlockDriverState *bs)
{
    if (!bs) {
        return QTAILQ_FIRST(&bdrv_states);
    }
    return QTAILQ_NEXT(bs, list);
}

2464
void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs), void *opaque)
B
bellard 已提交
2465 2466 2467
{
    BlockDriverState *bs;

2468
    QTAILQ_FOREACH(bs, &bdrv_states, list) {
2469
        it(opaque, bs);
B
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2470 2471 2472
    }
}

B
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2473 2474 2475 2476 2477
const char *bdrv_get_device_name(BlockDriverState *bs)
{
    return bs->device_name;
}

M
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2478 2479 2480 2481 2482
int bdrv_get_flags(BlockDriverState *bs)
{
    return bs->open_flags;
}

A
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2483 2484 2485 2486
void bdrv_flush_all(void)
{
    BlockDriverState *bs;

2487
    QTAILQ_FOREACH(bs, &bdrv_states, list) {
2488
        bdrv_flush(bs);
2489
    }
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2490 2491
}

K
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2492 2493 2494 2495
int bdrv_has_zero_init(BlockDriverState *bs)
{
    assert(bs->drv);

K
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2496 2497
    if (bs->drv->bdrv_has_zero_init) {
        return bs->drv->bdrv_has_zero_init(bs);
K
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2498 2499 2500 2501 2502
    }

    return 1;
}

2503 2504 2505 2506 2507 2508 2509 2510 2511
typedef struct BdrvCoIsAllocatedData {
    BlockDriverState *bs;
    int64_t sector_num;
    int nb_sectors;
    int *pnum;
    int ret;
    bool done;
} BdrvCoIsAllocatedData;

2512 2513 2514 2515 2516
/*
 * 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.
 *
2517 2518 2519
 * If 'sector_num' is beyond the end of the disk image the return value is 0
 * and 'pnum' is set to 0.
 *
2520 2521 2522 2523
 * '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.
 *
2524 2525
 * 'nb_sectors' is the max value 'pnum' should be set to.  If nb_sectors goes
 * beyond the end of the disk image it will be clamped.
2526
 */
2527 2528
int coroutine_fn bdrv_co_is_allocated(BlockDriverState *bs, int64_t sector_num,
                                      int nb_sectors, int *pnum)
2529
{
2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541
    int64_t n;

    if (sector_num >= bs->total_sectors) {
        *pnum = 0;
        return 0;
    }

    n = bs->total_sectors - sector_num;
    if (n < nb_sectors) {
        nb_sectors = n;
    }

2542
    if (!bs->drv->bdrv_co_is_allocated) {
2543
        *pnum = nb_sectors;
2544 2545
        return 1;
    }
2546

2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568
    return bs->drv->bdrv_co_is_allocated(bs, sector_num, nb_sectors, pnum);
}

/* Coroutine wrapper for bdrv_is_allocated() */
static void coroutine_fn bdrv_is_allocated_co_entry(void *opaque)
{
    BdrvCoIsAllocatedData *data = opaque;
    BlockDriverState *bs = data->bs;

    data->ret = bdrv_co_is_allocated(bs, data->sector_num, data->nb_sectors,
                                     data->pnum);
    data->done = true;
}

/*
 * Synchronous wrapper around bdrv_co_is_allocated().
 *
 * See bdrv_co_is_allocated() for details.
 */
int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
                      int *pnum)
{
2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583
    Coroutine *co;
    BdrvCoIsAllocatedData data = {
        .bs = bs,
        .sector_num = sector_num,
        .nb_sectors = nb_sectors,
        .pnum = pnum,
        .done = false,
    };

    co = qemu_coroutine_create(bdrv_is_allocated_co_entry);
    qemu_coroutine_enter(co, &data);
    while (!data.done) {
        qemu_aio_wait();
    }
    return data.ret;
2584 2585
}

2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634
/*
 * Given an image chain: ... -> [BASE] -> [INTER1] -> [INTER2] -> [TOP]
 *
 * Return true if the given sector is allocated in any image between
 * BASE and TOP (inclusive).  BASE can be NULL to check if the given
 * sector is allocated in any image of the chain.  Return false otherwise.
 *
 * '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.
 *
 */
int coroutine_fn bdrv_co_is_allocated_above(BlockDriverState *top,
                                            BlockDriverState *base,
                                            int64_t sector_num,
                                            int nb_sectors, int *pnum)
{
    BlockDriverState *intermediate;
    int ret, n = nb_sectors;

    intermediate = top;
    while (intermediate && intermediate != base) {
        int pnum_inter;
        ret = bdrv_co_is_allocated(intermediate, sector_num, nb_sectors,
                                   &pnum_inter);
        if (ret < 0) {
            return ret;
        } else if (ret) {
            *pnum = pnum_inter;
            return 1;
        }

        /*
         * [sector_num, nb_sectors] is unallocated on top but intermediate
         * might have
         *
         * [sector_num+x, nr_sectors] allocated.
         */
        if (n > pnum_inter) {
            n = pnum_inter;
        }

        intermediate = intermediate->backing_hd;
    }

    *pnum = n;
    return 0;
}

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Luiz Capitulino 已提交
2635
BlockInfoList *qmp_query_block(Error **errp)
B
bellard 已提交
2636
{
L
Luiz Capitulino 已提交
2637
    BlockInfoList *head = NULL, *cur_item = NULL;
B
bellard 已提交
2638 2639
    BlockDriverState *bs;

2640
    QTAILQ_FOREACH(bs, &bdrv_states, list) {
L
Luiz Capitulino 已提交
2641
        BlockInfoList *info = g_malloc0(sizeof(*info));
2642

L
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2643 2644 2645 2646 2647
        info->value = g_malloc0(sizeof(*info->value));
        info->value->device = g_strdup(bs->device_name);
        info->value->type = g_strdup("unknown");
        info->value->locked = bdrv_dev_is_medium_locked(bs);
        info->value->removable = bdrv_dev_has_removable_media(bs);
2648

2649
        if (bdrv_dev_has_removable_media(bs)) {
L
Luiz Capitulino 已提交
2650 2651
            info->value->has_tray_open = true;
            info->value->tray_open = bdrv_dev_is_tray_open(bs);
2652
        }
2653 2654

        if (bdrv_iostatus_is_enabled(bs)) {
L
Luiz Capitulino 已提交
2655 2656
            info->value->has_io_status = true;
            info->value->io_status = bs->iostatus;
2657 2658
        }

B
bellard 已提交
2659
        if (bs->drv) {
L
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2660 2661 2662 2663 2664 2665 2666 2667 2668
            info->value->has_inserted = true;
            info->value->inserted = g_malloc0(sizeof(*info->value->inserted));
            info->value->inserted->file = g_strdup(bs->filename);
            info->value->inserted->ro = bs->read_only;
            info->value->inserted->drv = g_strdup(bs->drv->format_name);
            info->value->inserted->encrypted = bs->encrypted;
            if (bs->backing_file[0]) {
                info->value->inserted->has_backing_file = true;
                info->value->inserted->backing_file = g_strdup(bs->backing_file);
A
aliguori 已提交
2669
            }
Z
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2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684

            if (bs->io_limits_enabled) {
                info->value->inserted->bps =
                               bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL];
                info->value->inserted->bps_rd =
                               bs->io_limits.bps[BLOCK_IO_LIMIT_READ];
                info->value->inserted->bps_wr =
                               bs->io_limits.bps[BLOCK_IO_LIMIT_WRITE];
                info->value->inserted->iops =
                               bs->io_limits.iops[BLOCK_IO_LIMIT_TOTAL];
                info->value->inserted->iops_rd =
                               bs->io_limits.iops[BLOCK_IO_LIMIT_READ];
                info->value->inserted->iops_wr =
                               bs->io_limits.iops[BLOCK_IO_LIMIT_WRITE];
            }
L
Luiz Capitulino 已提交
2685
        }
2686

L
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2687 2688 2689 2690 2691 2692
        /* XXX: waiting for the qapi to support GSList */
        if (!cur_item) {
            head = cur_item = info;
        } else {
            cur_item->next = info;
            cur_item = info;
B
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2693 2694
        }
    }
2695

L
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2696
    return head;
B
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2697
}
2698

L
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2699 2700 2701 2702 2703 2704 2705 2706 2707 2708
/* Consider exposing this as a full fledged QMP command */
static BlockStats *qmp_query_blockstat(const BlockDriverState *bs, Error **errp)
{
    BlockStats *s;

    s = g_malloc0(sizeof(*s));

    if (bs->device_name[0]) {
        s->has_device = true;
        s->device = g_strdup(bs->device_name);
2709 2710
    }

L
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2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721
    s->stats = g_malloc0(sizeof(*s->stats));
    s->stats->rd_bytes = bs->nr_bytes[BDRV_ACCT_READ];
    s->stats->wr_bytes = bs->nr_bytes[BDRV_ACCT_WRITE];
    s->stats->rd_operations = bs->nr_ops[BDRV_ACCT_READ];
    s->stats->wr_operations = bs->nr_ops[BDRV_ACCT_WRITE];
    s->stats->wr_highest_offset = bs->wr_highest_sector * BDRV_SECTOR_SIZE;
    s->stats->flush_operations = bs->nr_ops[BDRV_ACCT_FLUSH];
    s->stats->wr_total_time_ns = bs->total_time_ns[BDRV_ACCT_WRITE];
    s->stats->rd_total_time_ns = bs->total_time_ns[BDRV_ACCT_READ];
    s->stats->flush_total_time_ns = bs->total_time_ns[BDRV_ACCT_FLUSH];

2722
    if (bs->file) {
L
Luiz Capitulino 已提交
2723 2724
        s->has_parent = true;
        s->parent = qmp_query_blockstat(bs->file, NULL);
2725 2726
    }

L
Luiz Capitulino 已提交
2727
    return s;
2728 2729
}

L
Luiz Capitulino 已提交
2730
BlockStatsList *qmp_query_blockstats(Error **errp)
2731
{
L
Luiz Capitulino 已提交
2732
    BlockStatsList *head = NULL, *cur_item = NULL;
2733 2734
    BlockDriverState *bs;

2735
    QTAILQ_FOREACH(bs, &bdrv_states, list) {
L
Luiz Capitulino 已提交
2736 2737 2738 2739 2740 2741 2742 2743 2744 2745
        BlockStatsList *info = g_malloc0(sizeof(*info));
        info->value = qmp_query_blockstat(bs, NULL);

        /* XXX: waiting for the qapi to support GSList */
        if (!cur_item) {
            head = cur_item = info;
        } else {
            cur_item->next = info;
            cur_item = info;
        }
2746
    }
2747

L
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2748
    return head;
2749
}
B
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2750

2751 2752 2753 2754 2755 2756 2757 2758 2759 2760
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;
}

2761
void bdrv_get_backing_filename(BlockDriverState *bs,
B
bellard 已提交
2762 2763
                               char *filename, int filename_size)
{
K
Kevin Wolf 已提交
2764
    pstrcpy(filename, filename_size, bs->backing_file);
B
bellard 已提交
2765 2766
}

2767
int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
B
bellard 已提交
2768 2769 2770 2771
                          const uint8_t *buf, int nb_sectors)
{
    BlockDriver *drv = bs->drv;
    if (!drv)
B
bellard 已提交
2772
        return -ENOMEDIUM;
B
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2773 2774
    if (!drv->bdrv_write_compressed)
        return -ENOTSUP;
K
Kevin Wolf 已提交
2775 2776
    if (bdrv_check_request(bs, sector_num, nb_sectors))
        return -EIO;
2777

2778
    if (bs->dirty_bitmap) {
2779 2780
        set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
    }
2781

B
bellard 已提交
2782 2783
    return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
}
2784

B
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2785 2786 2787 2788
int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
{
    BlockDriver *drv = bs->drv;
    if (!drv)
B
bellard 已提交
2789
        return -ENOMEDIUM;
B
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2790 2791 2792 2793 2794 2795
    if (!drv->bdrv_get_info)
        return -ENOTSUP;
    memset(bdi, 0, sizeof(*bdi));
    return drv->bdrv_get_info(bs, bdi);
}

2796 2797
int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
                      int64_t pos, int size)
2798 2799 2800 2801
{
    BlockDriver *drv = bs->drv;
    if (!drv)
        return -ENOMEDIUM;
2802 2803 2804 2805 2806
    if (drv->bdrv_save_vmstate)
        return drv->bdrv_save_vmstate(bs, buf, pos, size);
    if (bs->file)
        return bdrv_save_vmstate(bs->file, buf, pos, size);
    return -ENOTSUP;
2807 2808
}

2809 2810
int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
                      int64_t pos, int size)
2811 2812 2813 2814
{
    BlockDriver *drv = bs->drv;
    if (!drv)
        return -ENOMEDIUM;
2815 2816 2817 2818 2819
    if (drv->bdrv_load_vmstate)
        return drv->bdrv_load_vmstate(bs, buf, pos, size);
    if (bs->file)
        return bdrv_load_vmstate(bs->file, buf, pos, size);
    return -ENOTSUP;
2820 2821
}

K
Kevin Wolf 已提交
2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833
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);

}

B
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2834 2835 2836
/**************************************************************/
/* handling of snapshots */

2837 2838 2839
int bdrv_can_snapshot(BlockDriverState *bs)
{
    BlockDriver *drv = bs->drv;
2840
    if (!drv || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) {
2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853
        return 0;
    }

    if (!drv->bdrv_snapshot_create) {
        if (bs->file != NULL) {
            return bdrv_can_snapshot(bs->file);
        }
        return 0;
    }

    return 1;
}

2854 2855 2856 2857 2858
int bdrv_is_snapshot(BlockDriverState *bs)
{
    return !!(bs->open_flags & BDRV_O_SNAPSHOT);
}

2859 2860 2861 2862
BlockDriverState *bdrv_snapshots(void)
{
    BlockDriverState *bs;

2863
    if (bs_snapshots) {
2864
        return bs_snapshots;
2865
    }
2866 2867 2868 2869

    bs = NULL;
    while ((bs = bdrv_next(bs))) {
        if (bdrv_can_snapshot(bs)) {
2870 2871
            bs_snapshots = bs;
            return bs;
2872 2873 2874 2875 2876
        }
    }
    return NULL;
}

2877
int bdrv_snapshot_create(BlockDriverState *bs,
B
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2878 2879 2880 2881
                         QEMUSnapshotInfo *sn_info)
{
    BlockDriver *drv = bs->drv;
    if (!drv)
B
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        return -ENOMEDIUM;
2883 2884 2885 2886 2887
    if (drv->bdrv_snapshot_create)
        return drv->bdrv_snapshot_create(bs, sn_info);
    if (bs->file)
        return bdrv_snapshot_create(bs->file, sn_info);
    return -ENOTSUP;
B
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2888 2889
}

2890
int bdrv_snapshot_goto(BlockDriverState *bs,
B
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2891 2892 2893
                       const char *snapshot_id)
{
    BlockDriver *drv = bs->drv;
2894 2895
    int ret, open_ret;

B
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2896
    if (!drv)
B
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2897
        return -ENOMEDIUM;
2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913
    if (drv->bdrv_snapshot_goto)
        return drv->bdrv_snapshot_goto(bs, snapshot_id);

    if (bs->file) {
        drv->bdrv_close(bs);
        ret = bdrv_snapshot_goto(bs->file, snapshot_id);
        open_ret = drv->bdrv_open(bs, bs->open_flags);
        if (open_ret < 0) {
            bdrv_delete(bs->file);
            bs->drv = NULL;
            return open_ret;
        }
        return ret;
    }

    return -ENOTSUP;
B
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2914 2915 2916 2917 2918 2919
}

int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
{
    BlockDriver *drv = bs->drv;
    if (!drv)
B
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2920
        return -ENOMEDIUM;
2921 2922 2923 2924 2925
    if (drv->bdrv_snapshot_delete)
        return drv->bdrv_snapshot_delete(bs, snapshot_id);
    if (bs->file)
        return bdrv_snapshot_delete(bs->file, snapshot_id);
    return -ENOTSUP;
B
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2926 2927
}

2928
int bdrv_snapshot_list(BlockDriverState *bs,
B
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2929 2930 2931 2932
                       QEMUSnapshotInfo **psn_info)
{
    BlockDriver *drv = bs->drv;
    if (!drv)
B
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2933
        return -ENOMEDIUM;
2934 2935 2936 2937 2938
    if (drv->bdrv_snapshot_list)
        return drv->bdrv_snapshot_list(bs, psn_info);
    if (bs->file)
        return bdrv_snapshot_list(bs->file, psn_info);
    return -ENOTSUP;
B
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}

E
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2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956
int bdrv_snapshot_load_tmp(BlockDriverState *bs,
        const char *snapshot_name)
{
    BlockDriver *drv = bs->drv;
    if (!drv) {
        return -ENOMEDIUM;
    }
    if (!bs->read_only) {
        return -EINVAL;
    }
    if (drv->bdrv_snapshot_load_tmp) {
        return drv->bdrv_snapshot_load_tmp(bs, snapshot_name);
    }
    return -ENOTSUP;
}

2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974
BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
        const char *backing_file)
{
    if (!bs->drv) {
        return NULL;
    }

    if (bs->backing_hd) {
        if (strcmp(bs->backing_file, backing_file) == 0) {
            return bs->backing_hd;
        } else {
            return bdrv_find_backing_image(bs->backing_hd, backing_file);
        }
    }

    return NULL;
}

B
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2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988
#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)) {
2989
                snprintf(buf, buf_size, "%0.1f%c",
B
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2990 2991 2992 2993
                         (double)size / base,
                         suffixes[i]);
                break;
            } else if (size < (1000 * base) || i == (NB_SUFFIXES - 1)) {
2994
                snprintf(buf, buf_size, "%" PRId64 "%c",
B
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2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007
                         ((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];
3008 3009 3010
#ifdef _WIN32
    struct tm *ptm;
#else
B
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3011
    struct tm tm;
3012
#endif
B
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3013 3014 3015 3016
    time_t ti;
    int64_t secs;

    if (!sn) {
3017 3018
        snprintf(buf, buf_size,
                 "%-10s%-20s%7s%20s%15s",
B
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3019 3020 3021
                 "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK");
    } else {
        ti = sn->date_sec;
3022 3023 3024 3025 3026
#ifdef _WIN32
        ptm = localtime(&ti);
        strftime(date_buf, sizeof(date_buf),
                 "%Y-%m-%d %H:%M:%S", ptm);
#else
B
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3027 3028 3029
        localtime_r(&ti, &tm);
        strftime(date_buf, sizeof(date_buf),
                 "%Y-%m-%d %H:%M:%S", &tm);
3030
#endif
B
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3031 3032 3033 3034 3035
        secs = sn->vm_clock_nsec / 1000000000;
        snprintf(clock_buf, sizeof(clock_buf),
                 "%02d:%02d:%02d.%03d",
                 (int)(secs / 3600),
                 (int)((secs / 60) % 60),
3036
                 (int)(secs % 60),
B
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3037 3038
                 (int)((sn->vm_clock_nsec / 1000000) % 1000));
        snprintf(buf, buf_size,
3039
                 "%-10s%-20s%7s%20s%15s",
B
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3040 3041 3042 3043 3044 3045 3046 3047
                 sn->id_str, sn->name,
                 get_human_readable_size(buf1, sizeof(buf1), sn->vm_state_size),
                 date_buf,
                 clock_buf);
    }
    return buf;
}

B
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3048
/**************************************************************/
B
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3049
/* async I/Os */
B
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3050

3051
BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
3052
                                 QEMUIOVector *qiov, int nb_sectors,
3053
                                 BlockDriverCompletionFunc *cb, void *opaque)
B
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3054
{
3055 3056
    trace_bdrv_aio_readv(bs, sector_num, nb_sectors, opaque);

3057
    return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors,
3058
                                 cb, opaque, false);
B
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3059 3060
}

3061 3062 3063
BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
                                  QEMUIOVector *qiov, int nb_sectors,
                                  BlockDriverCompletionFunc *cb, void *opaque)
B
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3064
{
3065 3066
    trace_bdrv_aio_writev(bs, sector_num, nb_sectors, opaque);

3067
    return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors,
3068
                                 cb, opaque, true);
B
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}

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3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086 3087 3088

typedef struct MultiwriteCB {
    int error;
    int num_requests;
    int num_callbacks;
    struct {
        BlockDriverCompletionFunc *cb;
        void *opaque;
        QEMUIOVector *free_qiov;
    } 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);
3089 3090 3091
        if (mcb->callbacks[i].free_qiov) {
            qemu_iovec_destroy(mcb->callbacks[i].free_qiov);
        }
3092
        g_free(mcb->callbacks[i].free_qiov);
K
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3093 3094 3095 3096 3097 3098 3099
    }
}

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

3100 3101
    trace_multiwrite_cb(mcb, ret);

3102
    if (ret < 0 && !mcb->error) {
K
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3103 3104 3105 3106 3107
        mcb->error = ret;
    }

    mcb->num_requests--;
    if (mcb->num_requests == 0) {
3108
        multiwrite_user_cb(mcb);
3109
        g_free(mcb);
K
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3110 3111 3112 3113 3114
    }
}

static int multiwrite_req_compare(const void *a, const void *b)
{
3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127
    const BlockRequest *req1 = a, *req2 = b;

    /*
     * Note that we can't simply subtract req2->sector from req1->sector
     * here as that could overflow the return value.
     */
    if (req1->sector > req2->sector) {
        return 1;
    } else if (req1->sector < req2->sector) {
        return -1;
    } else {
        return 0;
    }
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}

/*
 * 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;

3149
        // Handle exactly sequential writes and overlapping writes.
K
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3150 3151 3152 3153
        if (reqs[i].sector <= oldreq_last) {
            merge = 1;
        }

3154 3155 3156 3157
        if (reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1 > IOV_MAX) {
            merge = 0;
        }

K
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3158 3159
        if (merge) {
            size_t size;
3160
            QEMUIOVector *qiov = g_malloc0(sizeof(*qiov));
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3161 3162 3163 3164 3165 3166 3167 3168
            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);

3169 3170
            // We should need to add any zeros between the two requests
            assert (reqs[i].sector <= oldreq_last);
K
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3171 3172 3173 3174

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

3175
            reqs[outidx].nb_sectors = qiov->size >> 9;
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            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)
{
    MultiwriteCB *mcb;
    int i;

3209 3210 3211 3212 3213 3214 3215 3216
    /* don't submit writes if we don't have a medium */
    if (bs->drv == NULL) {
        for (i = 0; i < num_reqs; i++) {
            reqs[i].error = -ENOMEDIUM;
        }
        return -1;
    }

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3217 3218 3219 3220 3221
    if (num_reqs == 0) {
        return 0;
    }

    // Create MultiwriteCB structure
3222
    mcb = g_malloc0(sizeof(*mcb) + num_reqs * sizeof(*mcb->callbacks));
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3223 3224 3225 3226 3227 3228 3229 3230 3231 3232 3233
    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);

3234 3235
    trace_bdrv_aio_multiwrite(mcb, mcb->num_callbacks, num_reqs);

3236 3237
    /* Run the aio requests. */
    mcb->num_requests = num_reqs;
K
Kevin Wolf 已提交
3238
    for (i = 0; i < num_reqs; i++) {
3239
        bdrv_aio_writev(bs, reqs[i].sector, reqs[i].qiov,
K
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3240 3241 3242 3243 3244 3245
            reqs[i].nb_sectors, multiwrite_cb, mcb);
    }

    return 0;
}

B
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3246 3247
void bdrv_aio_cancel(BlockDriverAIOCB *acb)
{
3248
    acb->pool->cancel(acb);
B
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3249 3250
}

Z
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3251 3252 3253 3254 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281 3282 3283 3284 3285 3286 3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298 3299 3300 3301 3302 3303 3304 3305 3306 3307 3308 3309 3310 3311 3312 3313 3314 3315 3316 3317 3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331 3332 3333 3334 3335 3336 3337 3338 3339 3340 3341 3342 3343 3344 3345 3346 3347 3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364 3365 3366 3367 3368 3369 3370 3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386 3387 3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 3414
/* block I/O throttling */
static bool bdrv_exceed_bps_limits(BlockDriverState *bs, int nb_sectors,
                 bool is_write, double elapsed_time, uint64_t *wait)
{
    uint64_t bps_limit = 0;
    double   bytes_limit, bytes_base, bytes_res;
    double   slice_time, wait_time;

    if (bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL]) {
        bps_limit = bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL];
    } else if (bs->io_limits.bps[is_write]) {
        bps_limit = bs->io_limits.bps[is_write];
    } else {
        if (wait) {
            *wait = 0;
        }

        return false;
    }

    slice_time = bs->slice_end - bs->slice_start;
    slice_time /= (NANOSECONDS_PER_SECOND);
    bytes_limit = bps_limit * slice_time;
    bytes_base  = bs->nr_bytes[is_write] - bs->io_base.bytes[is_write];
    if (bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL]) {
        bytes_base += bs->nr_bytes[!is_write] - bs->io_base.bytes[!is_write];
    }

    /* bytes_base: the bytes of data which have been read/written; and
     *             it is obtained from the history statistic info.
     * bytes_res: the remaining bytes of data which need to be read/written.
     * (bytes_base + bytes_res) / bps_limit: used to calcuate
     *             the total time for completing reading/writting all data.
     */
    bytes_res   = (unsigned) nb_sectors * BDRV_SECTOR_SIZE;

    if (bytes_base + bytes_res <= bytes_limit) {
        if (wait) {
            *wait = 0;
        }

        return false;
    }

    /* Calc approx time to dispatch */
    wait_time = (bytes_base + bytes_res) / bps_limit - elapsed_time;

    /* When the I/O rate at runtime exceeds the limits,
     * bs->slice_end need to be extended in order that the current statistic
     * info can be kept until the timer fire, so it is increased and tuned
     * based on the result of experiment.
     */
    bs->slice_time = wait_time * BLOCK_IO_SLICE_TIME * 10;
    bs->slice_end += bs->slice_time - 3 * BLOCK_IO_SLICE_TIME;
    if (wait) {
        *wait = wait_time * BLOCK_IO_SLICE_TIME * 10;
    }

    return true;
}

static bool bdrv_exceed_iops_limits(BlockDriverState *bs, bool is_write,
                             double elapsed_time, uint64_t *wait)
{
    uint64_t iops_limit = 0;
    double   ios_limit, ios_base;
    double   slice_time, wait_time;

    if (bs->io_limits.iops[BLOCK_IO_LIMIT_TOTAL]) {
        iops_limit = bs->io_limits.iops[BLOCK_IO_LIMIT_TOTAL];
    } else if (bs->io_limits.iops[is_write]) {
        iops_limit = bs->io_limits.iops[is_write];
    } else {
        if (wait) {
            *wait = 0;
        }

        return false;
    }

    slice_time = bs->slice_end - bs->slice_start;
    slice_time /= (NANOSECONDS_PER_SECOND);
    ios_limit  = iops_limit * slice_time;
    ios_base   = bs->nr_ops[is_write] - bs->io_base.ios[is_write];
    if (bs->io_limits.iops[BLOCK_IO_LIMIT_TOTAL]) {
        ios_base += bs->nr_ops[!is_write] - bs->io_base.ios[!is_write];
    }

    if (ios_base + 1 <= ios_limit) {
        if (wait) {
            *wait = 0;
        }

        return false;
    }

    /* Calc approx time to dispatch */
    wait_time = (ios_base + 1) / iops_limit;
    if (wait_time > elapsed_time) {
        wait_time = wait_time - elapsed_time;
    } else {
        wait_time = 0;
    }

    bs->slice_time = wait_time * BLOCK_IO_SLICE_TIME * 10;
    bs->slice_end += bs->slice_time - 3 * BLOCK_IO_SLICE_TIME;
    if (wait) {
        *wait = wait_time * BLOCK_IO_SLICE_TIME * 10;
    }

    return true;
}

static bool bdrv_exceed_io_limits(BlockDriverState *bs, int nb_sectors,
                           bool is_write, int64_t *wait)
{
    int64_t  now, max_wait;
    uint64_t bps_wait = 0, iops_wait = 0;
    double   elapsed_time;
    int      bps_ret, iops_ret;

    now = qemu_get_clock_ns(vm_clock);
    if ((bs->slice_start < now)
        && (bs->slice_end > now)) {
        bs->slice_end = now + bs->slice_time;
    } else {
        bs->slice_time  =  5 * BLOCK_IO_SLICE_TIME;
        bs->slice_start = now;
        bs->slice_end   = now + bs->slice_time;

        bs->io_base.bytes[is_write]  = bs->nr_bytes[is_write];
        bs->io_base.bytes[!is_write] = bs->nr_bytes[!is_write];

        bs->io_base.ios[is_write]    = bs->nr_ops[is_write];
        bs->io_base.ios[!is_write]   = bs->nr_ops[!is_write];
    }

    elapsed_time  = now - bs->slice_start;
    elapsed_time  /= (NANOSECONDS_PER_SECOND);

    bps_ret  = bdrv_exceed_bps_limits(bs, nb_sectors,
                                      is_write, elapsed_time, &bps_wait);
    iops_ret = bdrv_exceed_iops_limits(bs, is_write,
                                      elapsed_time, &iops_wait);
    if (bps_ret || iops_ret) {
        max_wait = bps_wait > iops_wait ? bps_wait : iops_wait;
        if (wait) {
            *wait = max_wait;
        }

        now = qemu_get_clock_ns(vm_clock);
        if (bs->slice_end < now + max_wait) {
            bs->slice_end = now + max_wait;
        }

        return true;
    }

    if (wait) {
        *wait = 0;
    }

    return false;
}
3415

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3416 3417 3418
/**************************************************************/
/* async block device emulation */

3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430
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)
{
3431 3432
    BlockDriverAIOCBSync *acb =
        container_of(blockacb, BlockDriverAIOCBSync, common);
3433
    qemu_bh_delete(acb->bh);
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Avi Kivity 已提交
3434
    acb->bh = NULL;
3435 3436 3437 3438 3439 3440 3441 3442
    qemu_aio_release(acb);
}

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

3443
static void bdrv_aio_bh_cb(void *opaque)
B
bellard 已提交
3444
{
3445
    BlockDriverAIOCBSync *acb = opaque;
3446 3447 3448

    if (!acb->is_write)
        qemu_iovec_from_buffer(acb->qiov, acb->bounce, acb->qiov->size);
3449
    qemu_vfree(acb->bounce);
3450
    acb->common.cb(acb->common.opaque, acb->ret);
3451
    qemu_bh_delete(acb->bh);
A
Avi Kivity 已提交
3452
    acb->bh = NULL;
3453
    qemu_aio_release(acb);
B
bellard 已提交
3454
}
3455

3456 3457 3458 3459 3460 3461 3462 3463
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
3464
{
3465 3466
    BlockDriverAIOCBSync *acb;

3467
    acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
3468 3469
    acb->is_write = is_write;
    acb->qiov = qiov;
3470
    acb->bounce = qemu_blockalign(bs, qiov->size);
3471
    acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
3472 3473 3474

    if (is_write) {
        qemu_iovec_to_buffer(acb->qiov, acb->bounce);
3475
        acb->ret = bs->drv->bdrv_write(bs, sector_num, acb->bounce, nb_sectors);
3476
    } else {
3477
        acb->ret = bs->drv->bdrv_read(bs, sector_num, acb->bounce, nb_sectors);
3478 3479
    }

3480
    qemu_bh_schedule(acb->bh);
3481

3482
    return &acb->common;
3483 3484
}

3485 3486
static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
3487
        BlockDriverCompletionFunc *cb, void *opaque)
3488
{
3489 3490
    return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
}
B
bellard 已提交
3491

3492 3493 3494 3495 3496
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);
3497 3498
}

3499 3500 3501 3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513 3514 3515 3516

typedef struct BlockDriverAIOCBCoroutine {
    BlockDriverAIOCB common;
    BlockRequest req;
    bool is_write;
    QEMUBH* bh;
} BlockDriverAIOCBCoroutine;

static void bdrv_aio_co_cancel_em(BlockDriverAIOCB *blockacb)
{
    qemu_aio_flush();
}

static AIOPool bdrv_em_co_aio_pool = {
    .aiocb_size         = sizeof(BlockDriverAIOCBCoroutine),
    .cancel             = bdrv_aio_co_cancel_em,
};

P
Paolo Bonzini 已提交
3517
static void bdrv_co_em_bh(void *opaque)
3518 3519 3520 3521 3522 3523 3524 3525
{
    BlockDriverAIOCBCoroutine *acb = opaque;

    acb->common.cb(acb->common.opaque, acb->req.error);
    qemu_bh_delete(acb->bh);
    qemu_aio_release(acb);
}

3526 3527 3528 3529 3530 3531 3532 3533
/* Invoke bdrv_co_do_readv/bdrv_co_do_writev */
static void coroutine_fn bdrv_co_do_rw(void *opaque)
{
    BlockDriverAIOCBCoroutine *acb = opaque;
    BlockDriverState *bs = acb->common.bs;

    if (!acb->is_write) {
        acb->req.error = bdrv_co_do_readv(bs, acb->req.sector,
3534
            acb->req.nb_sectors, acb->req.qiov, 0);
3535 3536
    } else {
        acb->req.error = bdrv_co_do_writev(bs, acb->req.sector,
3537
            acb->req.nb_sectors, acb->req.qiov, 0);
3538 3539
    }

P
Paolo Bonzini 已提交
3540
    acb->bh = qemu_bh_new(bdrv_co_em_bh, acb);
3541 3542 3543
    qemu_bh_schedule(acb->bh);
}

3544 3545 3546 3547 3548 3549
static BlockDriverAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs,
                                               int64_t sector_num,
                                               QEMUIOVector *qiov,
                                               int nb_sectors,
                                               BlockDriverCompletionFunc *cb,
                                               void *opaque,
3550
                                               bool is_write)
3551 3552 3553 3554 3555 3556 3557 3558 3559 3560
{
    Coroutine *co;
    BlockDriverAIOCBCoroutine *acb;

    acb = qemu_aio_get(&bdrv_em_co_aio_pool, bs, cb, opaque);
    acb->req.sector = sector_num;
    acb->req.nb_sectors = nb_sectors;
    acb->req.qiov = qiov;
    acb->is_write = is_write;

3561
    co = qemu_coroutine_create(bdrv_co_do_rw);
3562 3563 3564 3565 3566
    qemu_coroutine_enter(co, acb);

    return &acb->common;
}

P
Paolo Bonzini 已提交
3567
static void coroutine_fn bdrv_aio_flush_co_entry(void *opaque)
3568
{
P
Paolo Bonzini 已提交
3569 3570
    BlockDriverAIOCBCoroutine *acb = opaque;
    BlockDriverState *bs = acb->common.bs;
3571

P
Paolo Bonzini 已提交
3572 3573
    acb->req.error = bdrv_co_flush(bs);
    acb->bh = qemu_bh_new(bdrv_co_em_bh, acb);
3574 3575 3576
    qemu_bh_schedule(acb->bh);
}

P
Paolo Bonzini 已提交
3577
BlockDriverAIOCB *bdrv_aio_flush(BlockDriverState *bs,
3578 3579
        BlockDriverCompletionFunc *cb, void *opaque)
{
P
Paolo Bonzini 已提交
3580
    trace_bdrv_aio_flush(bs, opaque);
3581

P
Paolo Bonzini 已提交
3582 3583
    Coroutine *co;
    BlockDriverAIOCBCoroutine *acb;
3584

P
Paolo Bonzini 已提交
3585 3586 3587
    acb = qemu_aio_get(&bdrv_em_co_aio_pool, bs, cb, opaque);
    co = qemu_coroutine_create(bdrv_aio_flush_co_entry);
    qemu_coroutine_enter(co, acb);
3588 3589 3590 3591

    return &acb->common;
}

3592 3593 3594 3595 3596 3597 3598 3599 3600 3601 3602 3603 3604 3605 3606 3607 3608 3609 3610 3611 3612 3613 3614 3615 3616 3617 3618 3619
static void coroutine_fn bdrv_aio_discard_co_entry(void *opaque)
{
    BlockDriverAIOCBCoroutine *acb = opaque;
    BlockDriverState *bs = acb->common.bs;

    acb->req.error = bdrv_co_discard(bs, acb->req.sector, acb->req.nb_sectors);
    acb->bh = qemu_bh_new(bdrv_co_em_bh, acb);
    qemu_bh_schedule(acb->bh);
}

BlockDriverAIOCB *bdrv_aio_discard(BlockDriverState *bs,
        int64_t sector_num, int nb_sectors,
        BlockDriverCompletionFunc *cb, void *opaque)
{
    Coroutine *co;
    BlockDriverAIOCBCoroutine *acb;

    trace_bdrv_aio_discard(bs, sector_num, nb_sectors, opaque);

    acb = qemu_aio_get(&bdrv_em_co_aio_pool, bs, cb, opaque);
    acb->req.sector = sector_num;
    acb->req.nb_sectors = nb_sectors;
    co = qemu_coroutine_create(bdrv_aio_discard_co_entry);
    qemu_coroutine_enter(co, acb);

    return &acb->common;
}

B
bellard 已提交
3620 3621
void bdrv_init(void)
{
3622
    module_call_init(MODULE_INIT_BLOCK);
B
bellard 已提交
3623
}
3624

3625 3626 3627 3628 3629 3630
void bdrv_init_with_whitelist(void)
{
    use_bdrv_whitelist = 1;
    bdrv_init();
}

3631 3632
void *qemu_aio_get(AIOPool *pool, BlockDriverState *bs,
                   BlockDriverCompletionFunc *cb, void *opaque)
3633 3634 3635
{
    BlockDriverAIOCB *acb;

3636 3637 3638
    if (pool->free_aiocb) {
        acb = pool->free_aiocb;
        pool->free_aiocb = acb->next;
3639
    } else {
3640
        acb = g_malloc0(pool->aiocb_size);
3641
        acb->pool = pool;
3642 3643 3644 3645 3646 3647 3648 3649 3650
    }
    acb->bs = bs;
    acb->cb = cb;
    acb->opaque = opaque;
    return acb;
}

void qemu_aio_release(void *p)
{
3651 3652 3653 3654
    BlockDriverAIOCB *acb = (BlockDriverAIOCB *)p;
    AIOPool *pool = acb->pool;
    acb->next = pool->free_aiocb;
    pool->free_aiocb = acb;
3655
}
B
bellard 已提交
3656

3657 3658 3659 3660 3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682
/**************************************************************/
/* Coroutine block device emulation */

typedef struct CoroutineIOCompletion {
    Coroutine *coroutine;
    int ret;
} CoroutineIOCompletion;

static void bdrv_co_io_em_complete(void *opaque, int ret)
{
    CoroutineIOCompletion *co = opaque;

    co->ret = ret;
    qemu_coroutine_enter(co->coroutine, NULL);
}

static int coroutine_fn bdrv_co_io_em(BlockDriverState *bs, int64_t sector_num,
                                      int nb_sectors, QEMUIOVector *iov,
                                      bool is_write)
{
    CoroutineIOCompletion co = {
        .coroutine = qemu_coroutine_self(),
    };
    BlockDriverAIOCB *acb;

    if (is_write) {
3683 3684
        acb = bs->drv->bdrv_aio_writev(bs, sector_num, iov, nb_sectors,
                                       bdrv_co_io_em_complete, &co);
3685
    } else {
3686 3687
        acb = bs->drv->bdrv_aio_readv(bs, sector_num, iov, nb_sectors,
                                      bdrv_co_io_em_complete, &co);
3688 3689
    }

3690
    trace_bdrv_co_io_em(bs, sector_num, nb_sectors, is_write, acb);
3691 3692 3693 3694 3695 3696 3697 3698 3699 3700 3701 3702 3703 3704 3705 3706 3707 3708 3709 3710 3711 3712
    if (!acb) {
        return -EIO;
    }
    qemu_coroutine_yield();

    return co.ret;
}

static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs,
                                         int64_t sector_num, int nb_sectors,
                                         QEMUIOVector *iov)
{
    return bdrv_co_io_em(bs, sector_num, nb_sectors, iov, false);
}

static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs,
                                         int64_t sector_num, int nb_sectors,
                                         QEMUIOVector *iov)
{
    return bdrv_co_io_em(bs, sector_num, nb_sectors, iov, true);
}

P
Paolo Bonzini 已提交
3713
static void coroutine_fn bdrv_flush_co_entry(void *opaque)
3714
{
P
Paolo Bonzini 已提交
3715 3716 3717 3718 3719 3720 3721
    RwCo *rwco = opaque;

    rwco->ret = bdrv_co_flush(rwco->bs);
}

int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
{
K
Kevin Wolf 已提交
3722 3723
    int ret;

3724
    if (!bs || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) {
P
Paolo Bonzini 已提交
3725
        return 0;
K
Kevin Wolf 已提交
3726 3727
    }

3728
    /* Write back cached data to the OS even with cache=unsafe */
K
Kevin Wolf 已提交
3729 3730 3731 3732 3733 3734 3735
    if (bs->drv->bdrv_co_flush_to_os) {
        ret = bs->drv->bdrv_co_flush_to_os(bs);
        if (ret < 0) {
            return ret;
        }
    }

3736 3737 3738 3739 3740
    /* But don't actually force it to the disk with cache=unsafe */
    if (bs->open_flags & BDRV_O_NO_FLUSH) {
        return 0;
    }

K
Kevin Wolf 已提交
3741
    if (bs->drv->bdrv_co_flush_to_disk) {
3742
        ret = bs->drv->bdrv_co_flush_to_disk(bs);
P
Paolo Bonzini 已提交
3743 3744 3745 3746 3747 3748 3749 3750
    } else if (bs->drv->bdrv_aio_flush) {
        BlockDriverAIOCB *acb;
        CoroutineIOCompletion co = {
            .coroutine = qemu_coroutine_self(),
        };

        acb = bs->drv->bdrv_aio_flush(bs, bdrv_co_io_em_complete, &co);
        if (acb == NULL) {
3751
            ret = -EIO;
P
Paolo Bonzini 已提交
3752 3753
        } else {
            qemu_coroutine_yield();
3754
            ret = co.ret;
P
Paolo Bonzini 已提交
3755 3756 3757 3758 3759 3760 3761 3762 3763 3764 3765 3766 3767
        }
    } else {
        /*
         * Some block drivers always operate in either writethrough or unsafe
         * mode and don't support bdrv_flush therefore. Usually qemu doesn't
         * know how the server works (because the behaviour is hardcoded or
         * depends on server-side configuration), so we can't ensure that
         * everything is safe on disk. Returning an error doesn't work because
         * that would break guests even if the server operates in writethrough
         * mode.
         *
         * Let's hope the user knows what he's doing.
         */
3768
        ret = 0;
P
Paolo Bonzini 已提交
3769
    }
3770 3771 3772 3773 3774 3775 3776 3777
    if (ret < 0) {
        return ret;
    }

    /* Now flush the underlying protocol.  It will also have BDRV_O_NO_FLUSH
     * in the case of cache=unsafe, so there are no useless flushes.
     */
    return bdrv_co_flush(bs->file);
P
Paolo Bonzini 已提交
3778 3779
}

3780 3781 3782 3783 3784 3785 3786 3787 3788 3789 3790 3791 3792 3793 3794 3795
void bdrv_invalidate_cache(BlockDriverState *bs)
{
    if (bs->drv && bs->drv->bdrv_invalidate_cache) {
        bs->drv->bdrv_invalidate_cache(bs);
    }
}

void bdrv_invalidate_cache_all(void)
{
    BlockDriverState *bs;

    QTAILQ_FOREACH(bs, &bdrv_states, list) {
        bdrv_invalidate_cache(bs);
    }
}

3796 3797 3798 3799 3800 3801 3802 3803 3804
void bdrv_clear_incoming_migration_all(void)
{
    BlockDriverState *bs;

    QTAILQ_FOREACH(bs, &bdrv_states, list) {
        bs->open_flags = bs->open_flags & ~(BDRV_O_INCOMING);
    }
}

P
Paolo Bonzini 已提交
3805 3806 3807 3808 3809 3810
int bdrv_flush(BlockDriverState *bs)
{
    Coroutine *co;
    RwCo rwco = {
        .bs = bs,
        .ret = NOT_DONE,
3811 3812
    };

P
Paolo Bonzini 已提交
3813 3814 3815 3816 3817 3818 3819 3820 3821
    if (qemu_in_coroutine()) {
        /* Fast-path if already in coroutine context */
        bdrv_flush_co_entry(&rwco);
    } else {
        co = qemu_coroutine_create(bdrv_flush_co_entry);
        qemu_coroutine_enter(co, &rwco);
        while (rwco.ret == NOT_DONE) {
            qemu_aio_wait();
        }
3822
    }
P
Paolo Bonzini 已提交
3823 3824

    return rwco.ret;
3825 3826
}

3827 3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838 3839 3840 3841 3842 3843 3844 3845 3846 3847 3848 3849 3850 3851 3852 3853 3854 3855 3856 3857 3858 3859 3860 3861 3862 3863 3864 3865 3866 3867 3868 3869 3870 3871 3872 3873 3874 3875 3876 3877 3878 3879 3880 3881 3882 3883 3884 3885 3886 3887
static void coroutine_fn bdrv_discard_co_entry(void *opaque)
{
    RwCo *rwco = opaque;

    rwco->ret = bdrv_co_discard(rwco->bs, rwco->sector_num, rwco->nb_sectors);
}

int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num,
                                 int nb_sectors)
{
    if (!bs->drv) {
        return -ENOMEDIUM;
    } else if (bdrv_check_request(bs, sector_num, nb_sectors)) {
        return -EIO;
    } else if (bs->read_only) {
        return -EROFS;
    } else if (bs->drv->bdrv_co_discard) {
        return bs->drv->bdrv_co_discard(bs, sector_num, nb_sectors);
    } else if (bs->drv->bdrv_aio_discard) {
        BlockDriverAIOCB *acb;
        CoroutineIOCompletion co = {
            .coroutine = qemu_coroutine_self(),
        };

        acb = bs->drv->bdrv_aio_discard(bs, sector_num, nb_sectors,
                                        bdrv_co_io_em_complete, &co);
        if (acb == NULL) {
            return -EIO;
        } else {
            qemu_coroutine_yield();
            return co.ret;
        }
    } else {
        return 0;
    }
}

int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors)
{
    Coroutine *co;
    RwCo rwco = {
        .bs = bs,
        .sector_num = sector_num,
        .nb_sectors = nb_sectors,
        .ret = NOT_DONE,
    };

    if (qemu_in_coroutine()) {
        /* Fast-path if already in coroutine context */
        bdrv_discard_co_entry(&rwco);
    } else {
        co = qemu_coroutine_create(bdrv_discard_co_entry);
        qemu_coroutine_enter(co, &rwco);
        while (rwco.ret == NOT_DONE) {
            qemu_aio_wait();
        }
    }

    return rwco.ret;
}

B
bellard 已提交
3888 3889 3890 3891 3892 3893 3894 3895 3896
/**************************************************************/
/* removable device support */

/**
 * Return TRUE if the media is present
 */
int bdrv_is_inserted(BlockDriverState *bs)
{
    BlockDriver *drv = bs->drv;
3897

B
bellard 已提交
3898 3899 3900
    if (!drv)
        return 0;
    if (!drv->bdrv_is_inserted)
3901 3902
        return 1;
    return drv->bdrv_is_inserted(bs);
B
bellard 已提交
3903 3904 3905
}

/**
3906 3907
 * Return whether the media changed since the last call to this
 * function, or -ENOTSUP if we don't know.  Most drivers don't know.
B
bellard 已提交
3908 3909 3910 3911 3912
 */
int bdrv_media_changed(BlockDriverState *bs)
{
    BlockDriver *drv = bs->drv;

3913 3914 3915 3916
    if (drv && drv->bdrv_media_changed) {
        return drv->bdrv_media_changed(bs);
    }
    return -ENOTSUP;
B
bellard 已提交
3917 3918 3919 3920 3921
}

/**
 * If eject_flag is TRUE, eject the media. Otherwise, close the tray
 */
3922
void bdrv_eject(BlockDriverState *bs, bool eject_flag)
B
bellard 已提交
3923 3924 3925
{
    BlockDriver *drv = bs->drv;

3926 3927
    if (drv && drv->bdrv_eject) {
        drv->bdrv_eject(bs, eject_flag);
B
bellard 已提交
3928
    }
3929 3930 3931 3932

    if (bs->device_name[0] != '\0') {
        bdrv_emit_qmp_eject_event(bs, eject_flag);
    }
B
bellard 已提交
3933 3934 3935 3936 3937 3938
}

/**
 * Lock or unlock the media (if it is locked, the user won't be able
 * to eject it manually).
 */
3939
void bdrv_lock_medium(BlockDriverState *bs, bool locked)
B
bellard 已提交
3940 3941 3942
{
    BlockDriver *drv = bs->drv;

3943
    trace_bdrv_lock_medium(bs, locked);
S
Stefan Hajnoczi 已提交
3944

3945 3946
    if (drv && drv->bdrv_lock_medium) {
        drv->bdrv_lock_medium(bs, locked);
B
bellard 已提交
3947 3948
    }
}
3949 3950 3951 3952 3953 3954 3955 3956 3957 3958 3959

/* 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;
}
3960

3961 3962 3963
BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
        unsigned long int req, void *buf,
        BlockDriverCompletionFunc *cb, void *opaque)
3964
{
3965
    BlockDriver *drv = bs->drv;
3966

3967 3968 3969
    if (drv && drv->bdrv_aio_ioctl)
        return drv->bdrv_aio_ioctl(bs, req, buf, cb, opaque);
    return NULL;
3970
}
3971

3972 3973 3974 3975
void bdrv_set_buffer_alignment(BlockDriverState *bs, int align)
{
    bs->buffer_alignment = align;
}
3976

3977 3978 3979 3980
void *qemu_blockalign(BlockDriverState *bs, size_t size)
{
    return qemu_memalign((bs && bs->buffer_alignment) ? bs->buffer_alignment : 512, size);
}
3981 3982 3983 3984

void bdrv_set_dirty_tracking(BlockDriverState *bs, int enable)
{
    int64_t bitmap_size;
3985

3986
    bs->dirty_count = 0;
3987
    if (enable) {
3988 3989
        if (!bs->dirty_bitmap) {
            bitmap_size = (bdrv_getlength(bs) >> BDRV_SECTOR_BITS) +
3990 3991
                    BDRV_SECTORS_PER_DIRTY_CHUNK * BITS_PER_LONG - 1;
            bitmap_size /= BDRV_SECTORS_PER_DIRTY_CHUNK * BITS_PER_LONG;
3992

3993
            bs->dirty_bitmap = g_new0(unsigned long, bitmap_size);
3994
        }
3995
    } else {
3996
        if (bs->dirty_bitmap) {
3997
            g_free(bs->dirty_bitmap);
3998
            bs->dirty_bitmap = NULL;
3999
        }
4000 4001 4002 4003 4004
    }
}

int bdrv_get_dirty(BlockDriverState *bs, int64_t sector)
{
J
Jan Kiszka 已提交
4005
    int64_t chunk = sector / (int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK;
4006

4007 4008
    if (bs->dirty_bitmap &&
        (sector << BDRV_SECTOR_BITS) < bdrv_getlength(bs)) {
4009 4010
        return !!(bs->dirty_bitmap[chunk / (sizeof(unsigned long) * 8)] &
            (1UL << (chunk % (sizeof(unsigned long) * 8))));
4011 4012 4013 4014 4015
    } else {
        return 0;
    }
}

4016 4017
void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector,
                      int nr_sectors)
4018 4019 4020
{
    set_dirty_bitmap(bs, cur_sector, nr_sectors, 0);
}
4021 4022 4023 4024 4025

int64_t bdrv_get_dirty_count(BlockDriverState *bs)
{
    return bs->dirty_count;
}
J
Jes Sorensen 已提交
4026

4027 4028 4029 4030 4031 4032 4033 4034 4035 4036 4037
void bdrv_set_in_use(BlockDriverState *bs, int in_use)
{
    assert(bs->in_use != in_use);
    bs->in_use = in_use;
}

int bdrv_in_use(BlockDriverState *bs)
{
    return bs->in_use;
}

4038 4039
void bdrv_iostatus_enable(BlockDriverState *bs)
{
4040
    bs->iostatus_enabled = true;
4041
    bs->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
4042 4043 4044 4045 4046 4047
}

/* The I/O status is only enabled if the drive explicitly
 * enables it _and_ the VM is configured to stop on errors */
bool bdrv_iostatus_is_enabled(const BlockDriverState *bs)
{
4048
    return (bs->iostatus_enabled &&
4049 4050 4051 4052 4053 4054 4055
           (bs->on_write_error == BLOCK_ERR_STOP_ENOSPC ||
            bs->on_write_error == BLOCK_ERR_STOP_ANY    ||
            bs->on_read_error == BLOCK_ERR_STOP_ANY));
}

void bdrv_iostatus_disable(BlockDriverState *bs)
{
4056
    bs->iostatus_enabled = false;
4057 4058 4059 4060 4061
}

void bdrv_iostatus_reset(BlockDriverState *bs)
{
    if (bdrv_iostatus_is_enabled(bs)) {
4062
        bs->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
4063 4064 4065 4066 4067 4068 4069 4070
    }
}

/* XXX: Today this is set by device models because it makes the implementation
   quite simple. However, the block layer knows about the error, so it's
   possible to implement this without device models being involved */
void bdrv_iostatus_set_err(BlockDriverState *bs, int error)
{
4071 4072
    if (bdrv_iostatus_is_enabled(bs) &&
        bs->iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
4073
        assert(error >= 0);
4074 4075
        bs->iostatus = error == ENOSPC ? BLOCK_DEVICE_IO_STATUS_NOSPACE :
                                         BLOCK_DEVICE_IO_STATUS_FAILED;
4076 4077 4078
    }
}

4079 4080 4081 4082 4083 4084 4085
void
bdrv_acct_start(BlockDriverState *bs, BlockAcctCookie *cookie, int64_t bytes,
        enum BlockAcctType type)
{
    assert(type < BDRV_MAX_IOTYPE);

    cookie->bytes = bytes;
C
Christoph Hellwig 已提交
4086
    cookie->start_time_ns = get_clock();
4087 4088 4089 4090 4091 4092 4093 4094 4095 4096
    cookie->type = type;
}

void
bdrv_acct_done(BlockDriverState *bs, BlockAcctCookie *cookie)
{
    assert(cookie->type < BDRV_MAX_IOTYPE);

    bs->nr_bytes[cookie->type] += cookie->bytes;
    bs->nr_ops[cookie->type]++;
C
Christoph Hellwig 已提交
4097
    bs->total_time_ns[cookie->type] += get_clock() - cookie->start_time_ns;
4098 4099
}

J
Jes Sorensen 已提交
4100 4101 4102 4103 4104
int bdrv_img_create(const char *filename, const char *fmt,
                    const char *base_filename, const char *base_fmt,
                    char *options, uint64_t img_size, int flags)
{
    QEMUOptionParameter *param = NULL, *create_options = NULL;
K
Kevin Wolf 已提交
4105
    QEMUOptionParameter *backing_fmt, *backing_file, *size;
J
Jes Sorensen 已提交
4106 4107
    BlockDriverState *bs = NULL;
    BlockDriver *drv, *proto_drv;
4108
    BlockDriver *backing_drv = NULL;
J
Jes Sorensen 已提交
4109 4110 4111 4112 4113 4114
    int ret = 0;

    /* Find driver and parse its options */
    drv = bdrv_find_format(fmt);
    if (!drv) {
        error_report("Unknown file format '%s'", fmt);
4115
        ret = -EINVAL;
J
Jes Sorensen 已提交
4116 4117 4118 4119 4120 4121
        goto out;
    }

    proto_drv = bdrv_find_protocol(filename);
    if (!proto_drv) {
        error_report("Unknown protocol '%s'", filename);
4122
        ret = -EINVAL;
J
Jes Sorensen 已提交
4123 4124 4125 4126 4127 4128 4129 4130 4131 4132 4133 4134 4135 4136 4137 4138 4139 4140
        goto out;
    }

    create_options = append_option_parameters(create_options,
                                              drv->create_options);
    create_options = append_option_parameters(create_options,
                                              proto_drv->create_options);

    /* Create parameter list with default values */
    param = parse_option_parameters("", create_options, param);

    set_option_parameter_int(param, BLOCK_OPT_SIZE, img_size);

    /* Parse -o options */
    if (options) {
        param = parse_option_parameters(options, create_options, param);
        if (param == NULL) {
            error_report("Invalid options for file format '%s'.", fmt);
4141
            ret = -EINVAL;
J
Jes Sorensen 已提交
4142 4143 4144 4145 4146 4147 4148 4149 4150
            goto out;
        }
    }

    if (base_filename) {
        if (set_option_parameter(param, BLOCK_OPT_BACKING_FILE,
                                 base_filename)) {
            error_report("Backing file not supported for file format '%s'",
                         fmt);
4151
            ret = -EINVAL;
J
Jes Sorensen 已提交
4152 4153 4154 4155 4156 4157 4158 4159
            goto out;
        }
    }

    if (base_fmt) {
        if (set_option_parameter(param, BLOCK_OPT_BACKING_FMT, base_fmt)) {
            error_report("Backing file format not supported for file "
                         "format '%s'", fmt);
4160
            ret = -EINVAL;
J
Jes Sorensen 已提交
4161 4162 4163 4164
            goto out;
        }
    }

4165 4166 4167 4168 4169
    backing_file = get_option_parameter(param, BLOCK_OPT_BACKING_FILE);
    if (backing_file && backing_file->value.s) {
        if (!strcmp(filename, backing_file->value.s)) {
            error_report("Error: Trying to create an image with the "
                         "same filename as the backing file");
4170
            ret = -EINVAL;
4171 4172 4173 4174
            goto out;
        }
    }

J
Jes Sorensen 已提交
4175 4176
    backing_fmt = get_option_parameter(param, BLOCK_OPT_BACKING_FMT);
    if (backing_fmt && backing_fmt->value.s) {
4177 4178
        backing_drv = bdrv_find_format(backing_fmt->value.s);
        if (!backing_drv) {
J
Jes Sorensen 已提交
4179 4180
            error_report("Unknown backing file format '%s'",
                         backing_fmt->value.s);
4181
            ret = -EINVAL;
J
Jes Sorensen 已提交
4182 4183 4184 4185 4186 4187
            goto out;
        }
    }

    // The size for the image must always be specified, with one exception:
    // If we are using a backing file, we can obtain the size from there
K
Kevin Wolf 已提交
4188 4189
    size = get_option_parameter(param, BLOCK_OPT_SIZE);
    if (size && size->value.n == -1) {
J
Jes Sorensen 已提交
4190 4191 4192
        if (backing_file && backing_file->value.s) {
            uint64_t size;
            char buf[32];
4193 4194 4195 4196 4197
            int back_flags;

            /* backing files always opened read-only */
            back_flags =
                flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
J
Jes Sorensen 已提交
4198 4199 4200

            bs = bdrv_new("");

4201
            ret = bdrv_open(bs, backing_file->value.s, back_flags, backing_drv);
J
Jes Sorensen 已提交
4202
            if (ret < 0) {
4203
                error_report("Could not open '%s'", backing_file->value.s);
J
Jes Sorensen 已提交
4204 4205 4206 4207 4208 4209 4210 4211 4212
                goto out;
            }
            bdrv_get_geometry(bs, &size);
            size *= 512;

            snprintf(buf, sizeof(buf), "%" PRId64, size);
            set_option_parameter(param, BLOCK_OPT_SIZE, buf);
        } else {
            error_report("Image creation needs a size parameter");
4213
            ret = -EINVAL;
J
Jes Sorensen 已提交
4214 4215 4216 4217 4218 4219 4220 4221 4222 4223 4224 4225 4226 4227 4228 4229 4230 4231 4232 4233 4234 4235 4236 4237 4238 4239 4240 4241 4242 4243
            goto out;
        }
    }

    printf("Formatting '%s', fmt=%s ", filename, fmt);
    print_option_parameters(param);
    puts("");

    ret = bdrv_create(drv, filename, param);

    if (ret < 0) {
        if (ret == -ENOTSUP) {
            error_report("Formatting or formatting option not supported for "
                         "file format '%s'", fmt);
        } else if (ret == -EFBIG) {
            error_report("The image size is too large for file format '%s'",
                         fmt);
        } else {
            error_report("%s: error while creating %s: %s", filename, fmt,
                         strerror(-ret));
        }
    }

out:
    free_option_parameters(create_options);
    free_option_parameters(param);

    if (bs) {
        bdrv_delete(bs);
    }
4244 4245

    return ret;
J
Jes Sorensen 已提交
4246
}
4247 4248

void *block_job_create(const BlockJobType *job_type, BlockDriverState *bs,
4249 4250
                       int64_t speed, BlockDriverCompletionFunc *cb,
                       void *opaque, Error **errp)
4251 4252 4253 4254
{
    BlockJob *job;

    if (bs->job || bdrv_in_use(bs)) {
4255
        error_set(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs));
4256 4257 4258 4259 4260 4261 4262 4263 4264
        return NULL;
    }
    bdrv_set_in_use(bs, 1);

    job = g_malloc0(job_type->instance_size);
    job->job_type      = job_type;
    job->bs            = bs;
    job->cb            = cb;
    job->opaque        = opaque;
P
Paolo Bonzini 已提交
4265
    job->busy          = true;
4266
    bs->job = job;
4267 4268 4269 4270 4271 4272 4273 4274 4275 4276 4277 4278 4279 4280

    /* Only set speed when necessary to avoid NotSupported error */
    if (speed != 0) {
        Error *local_err = NULL;

        block_job_set_speed(job, speed, &local_err);
        if (error_is_set(&local_err)) {
            bs->job = NULL;
            g_free(job);
            bdrv_set_in_use(bs, 0);
            error_propagate(errp, local_err);
            return NULL;
        }
    }
4281 4282 4283 4284 4285 4286 4287 4288 4289 4290 4291 4292 4293 4294
    return job;
}

void block_job_complete(BlockJob *job, int ret)
{
    BlockDriverState *bs = job->bs;

    assert(bs->job == job);
    job->cb(job->opaque, ret);
    bs->job = NULL;
    g_free(job);
    bdrv_set_in_use(bs, 0);
}

4295
void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
4296
{
4297
    Error *local_err = NULL;
4298

4299
    if (!job->job_type->set_speed) {
4300 4301
        error_set(errp, QERR_NOT_SUPPORTED);
        return;
4302
    }
4303
    job->job_type->set_speed(job, speed, &local_err);
4304 4305 4306
    if (error_is_set(&local_err)) {
        error_propagate(errp, local_err);
        return;
4307
    }
4308

4309
    job->speed = speed;
4310 4311 4312 4313 4314
}

void block_job_cancel(BlockJob *job)
{
    job->cancelled = true;
4315 4316 4317
    if (job->co && !job->busy) {
        qemu_coroutine_enter(job->co, NULL);
    }
4318 4319 4320 4321 4322 4323
}

bool block_job_is_cancelled(BlockJob *job)
{
    return job->cancelled;
}
4324

4325 4326 4327 4328 4329 4330 4331 4332 4333
struct BlockCancelData {
    BlockJob *job;
    BlockDriverCompletionFunc *cb;
    void *opaque;
    bool cancelled;
    int ret;
};

static void block_job_cancel_cb(void *opaque, int ret)
4334
{
4335 4336 4337 4338 4339 4340 4341 4342 4343 4344
    struct BlockCancelData *data = opaque;

    data->cancelled = block_job_is_cancelled(data->job);
    data->ret = ret;
    data->cb(data->opaque, ret);
}

int block_job_cancel_sync(BlockJob *job)
{
    struct BlockCancelData data;
4345 4346 4347
    BlockDriverState *bs = job->bs;

    assert(bs->job == job);
4348 4349 4350 4351 4352 4353 4354 4355 4356 4357

    /* Set up our own callback to store the result and chain to
     * the original callback.
     */
    data.job = job;
    data.cb = job->cb;
    data.opaque = job->opaque;
    data.ret = -EINPROGRESS;
    job->cb = block_job_cancel_cb;
    job->opaque = &data;
4358
    block_job_cancel(job);
4359
    while (data.ret == -EINPROGRESS) {
4360 4361
        qemu_aio_wait();
    }
4362
    return (data.cancelled && data.ret == 0) ? -ECANCELED : data.ret;
4363
}
P
Paolo Bonzini 已提交
4364 4365 4366 4367 4368 4369 4370 4371 4372 4373

void block_job_sleep_ns(BlockJob *job, QEMUClock *clock, int64_t ns)
{
    /* Check cancellation *before* setting busy = false, too!  */
    if (!block_job_is_cancelled(job)) {
        job->busy = false;
        co_sleep_ns(clock, ns);
        job->busy = true;
    }
}