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 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034

    /* 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;

    /* 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
1035
    bdrv_get_format(bs_top, tmp.backing_format, sizeof(tmp.backing_format));
1036 1037 1038 1039 1040

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

J
Jeff Cody 已提交
1041 1042 1043 1044 1045 1046
    /* 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';

1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061
    /* 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
1062 1063 1064

    bdrv_rebind(bs_new);
    bdrv_rebind(bs_top);
1065 1066
}

B
bellard 已提交
1067 1068
void bdrv_delete(BlockDriverState *bs)
{
1069
    assert(!bs->dev);
1070 1071
    assert(!bs->job);
    assert(!bs->in_use);
1072

1073
    /* remove from list, if necessary */
1074
    bdrv_make_anon(bs);
1075

B
bellard 已提交
1076
    bdrv_close(bs);
1077

1078
    assert(bs != bs_snapshots);
1079
    g_free(bs);
B
bellard 已提交
1080 1081
}

1082 1083
int bdrv_attach_dev(BlockDriverState *bs, void *dev)
/* TODO change to DeviceState *dev when all users are qdevified */
1084
{
1085
    if (bs->dev) {
1086 1087
        return -EBUSY;
    }
1088
    bs->dev = dev;
1089
    bdrv_iostatus_reset(bs);
1090 1091 1092
    return 0;
}

1093 1094
/* TODO qdevified devices don't use this, remove when devices are qdevified */
void bdrv_attach_dev_nofail(BlockDriverState *bs, void *dev)
1095
{
1096 1097 1098 1099 1100 1101 1102 1103 1104 1105
    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;
1106 1107
    bs->dev_ops = NULL;
    bs->dev_opaque = NULL;
1108
    bs->buffer_alignment = 512;
1109 1110
}

1111 1112
/* TODO change to return DeviceState * when all users are qdevified */
void *bdrv_get_attached_dev(BlockDriverState *bs)
1113
{
1114
    return bs->dev;
1115 1116
}

1117 1118 1119 1120 1121
void bdrv_set_dev_ops(BlockDriverState *bs, const BlockDevOps *ops,
                      void *opaque)
{
    bs->dev_ops = ops;
    bs->dev_opaque = opaque;
1122 1123 1124
    if (bdrv_dev_has_removable_media(bs) && bs == bs_snapshots) {
        bs_snapshots = NULL;
    }
1125 1126
}

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
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);
}

1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166
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);
}

1167
static void bdrv_dev_change_media_cb(BlockDriverState *bs, bool load)
1168
{
1169
    if (bs->dev_ops && bs->dev_ops->change_media_cb) {
1170
        bool tray_was_closed = !bdrv_dev_is_tray_open(bs);
1171
        bs->dev_ops->change_media_cb(bs->dev_opaque, load);
1172 1173 1174 1175 1176 1177 1178 1179
        if (tray_was_closed) {
            /* tray open */
            bdrv_emit_qmp_eject_event(bs, true);
        }
        if (load) {
            /* tray close */
            bdrv_emit_qmp_eject_event(bs, false);
        }
1180 1181 1182
    }
}

1183 1184 1185 1186 1187
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
1188 1189 1190 1191 1192 1193 1194
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);
    }
}

1195 1196 1197 1198 1199 1200 1201 1202
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;
}

1203 1204 1205 1206
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);
1207 1208 1209
    }
}

1210 1211 1212 1213 1214 1215 1216 1217
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
1218 1219 1220
/*
 * Run consistency checks on an image
 *
1221
 * Returns 0 if the check could be completed (it doesn't mean that the image is
1222
 * free of errors) or -errno when an internal error occurred. The results of the
1223
 * check are stored in res.
A
aliguori 已提交
1224
 */
1225
int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix)
A
aliguori 已提交
1226 1227 1228 1229 1230
{
    if (bs->drv->bdrv_check == NULL) {
        return -ENOTSUP;
    }

1231
    memset(res, 0, sizeof(*res));
1232
    return bs->drv->bdrv_check(bs, res, fix);
A
aliguori 已提交
1233 1234
}

1235 1236
#define COMMIT_BUF_SECTORS 2048

1237 1238 1239
/* commit COW file into the raw image */
int bdrv_commit(BlockDriverState *bs)
{
B
bellard 已提交
1240
    BlockDriver *drv = bs->drv;
1241
    BlockDriver *backing_drv;
1242 1243
    int64_t sector, total_sectors;
    int n, ro, open_flags;
1244
    int ret = 0, rw_ret = 0;
1245
    uint8_t *buf;
1246 1247
    char filename[1024];
    BlockDriverState *bs_rw, *bs_ro;
1248

B
bellard 已提交
1249 1250
    if (!drv)
        return -ENOMEDIUM;
1251 1252 1253
    
    if (!bs->backing_hd) {
        return -ENOTSUP;
1254 1255
    }

1256 1257 1258
    if (bs->backing_hd->keep_read_only) {
        return -EACCES;
    }
1259

1260 1261 1262 1263
    if (bdrv_in_use(bs) || bdrv_in_use(bs->backing_hd)) {
        return -EBUSY;
    }

1264
    backing_drv = bs->backing_hd->drv;
1265 1266 1267 1268 1269 1270 1271 1272 1273
    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("");
1274 1275
        rw_ret = bdrv_open(bs_rw, filename, open_flags | BDRV_O_RDWR,
            backing_drv);
1276 1277 1278 1279
        if (rw_ret < 0) {
            bdrv_delete(bs_rw);
            /* try to re-open read-only */
            bs_ro = bdrv_new("");
1280 1281
            ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR,
                backing_drv);
1282 1283 1284 1285 1286 1287 1288 1289 1290 1291
            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
1292
    }
1293

J
Jan Kiszka 已提交
1294
    total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
1295
    buf = g_malloc(COMMIT_BUF_SECTORS * BDRV_SECTOR_SIZE);
1296 1297

    for (sector = 0; sector < total_sectors; sector += n) {
1298
        if (bdrv_is_allocated(bs, sector, COMMIT_BUF_SECTORS, &n)) {
1299 1300 1301 1302 1303 1304 1305 1306 1307 1308

            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
1309
        }
1310
    }
1311

1312 1313 1314 1315
    if (drv->bdrv_make_empty) {
        ret = drv->bdrv_make_empty(bs);
        bdrv_flush(bs);
    }
1316

1317 1318 1319 1320 1321 1322
    /*
     * Make sure all data we wrote to the backing device is actually
     * stable on disk.
     */
    if (bs->backing_hd)
        bdrv_flush(bs->backing_hd);
1323 1324

ro_cleanup:
1325
    g_free(buf);
1326 1327 1328 1329 1330 1331

    if (ro) {
        /* re-open as RO */
        bdrv_delete(bs->backing_hd);
        bs->backing_hd = NULL;
        bs_ro = bdrv_new("");
1332 1333
        ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR,
            backing_drv);
1334 1335 1336 1337 1338 1339 1340 1341 1342 1343
        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;
    }

1344
    return ret;
1345 1346
}

1347
int bdrv_commit_all(void)
1348 1349 1350 1351
{
    BlockDriverState *bs;

    QTAILQ_FOREACH(bs, &bdrv_states, list) {
1352 1353 1354 1355
        int ret = bdrv_commit(bs);
        if (ret < 0) {
            return ret;
        }
1356
    }
1357
    return 0;
1358 1359
}

S
Stefan Hajnoczi 已提交
1360 1361 1362 1363 1364 1365
struct BdrvTrackedRequest {
    BlockDriverState *bs;
    int64_t sector_num;
    int nb_sectors;
    bool is_write;
    QLIST_ENTRY(BdrvTrackedRequest) list;
1366
    Coroutine *co; /* owner, used for deadlock detection */
1367
    CoQueue wait_queue; /* coroutines blocked on this request */
S
Stefan Hajnoczi 已提交
1368 1369 1370 1371 1372 1373 1374 1375 1376 1377
};

/**
 * 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);
1378
    qemu_co_queue_restart_all(&req->wait_queue);
S
Stefan Hajnoczi 已提交
1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393
}

/**
 * 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,
1394
        .co = qemu_coroutine_self(),
S
Stefan Hajnoczi 已提交
1395 1396
    };

1397 1398
    qemu_co_queue_init(&req->wait_queue);

S
Stefan Hajnoczi 已提交
1399 1400 1401
    QLIST_INSERT_HEAD(&bs->tracked_requests, req, list);
}

S
Stefan Hajnoczi 已提交
1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422
/**
 * 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);
    }
}

1423 1424
static bool tracked_request_overlaps(BdrvTrackedRequest *req,
                                     int64_t sector_num, int nb_sectors) {
S
Stefan Hajnoczi 已提交
1425 1426 1427 1428 1429 1430 1431 1432 1433
    /*        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;
1434 1435 1436 1437 1438 1439
}

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
1440 1441
    int64_t cluster_sector_num;
    int cluster_nb_sectors;
1442 1443
    bool retry;

S
Stefan Hajnoczi 已提交
1444 1445 1446 1447 1448 1449 1450 1451 1452
    /* 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);

1453 1454 1455
    do {
        retry = false;
        QLIST_FOREACH(req, &bs->tracked_requests, list) {
S
Stefan Hajnoczi 已提交
1456 1457
            if (tracked_request_overlaps(req, cluster_sector_num,
                                         cluster_nb_sectors)) {
1458 1459 1460 1461 1462 1463
                /* 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);

1464 1465 1466 1467 1468 1469 1470 1471
                qemu_co_queue_wait(&req->wait_queue);
                retry = true;
                break;
            }
        }
    } while (retry);
}

K
Kevin Wolf 已提交
1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483
/*
 * 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;
1484
    int ret;
K
Kevin Wolf 已提交
1485

1486 1487 1488 1489 1490
    /* Backing file format doesn't make sense without a backing file */
    if (backing_fmt && !backing_file) {
        return -EINVAL;
    }

K
Kevin Wolf 已提交
1491
    if (drv->bdrv_change_backing_file != NULL) {
1492
        ret = drv->bdrv_change_backing_file(bs, backing_file, backing_fmt);
K
Kevin Wolf 已提交
1493
    } else {
1494
        ret = -ENOTSUP;
K
Kevin Wolf 已提交
1495
    }
1496 1497 1498 1499 1500 1501

    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
1502 1503
}

1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516
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
1517 1518 1519 1520
    if (offset < 0)
        return -EIO;

    if ((offset > len) || (len - offset < size))
1521 1522 1523 1524 1525 1526 1527 1528
        return -EIO;

    return 0;
}

static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num,
                              int nb_sectors)
{
1529 1530
    return bdrv_check_byte_request(bs, sector_num * BDRV_SECTOR_SIZE,
                                   nb_sectors * BDRV_SECTOR_SIZE);
1531 1532
}

1533 1534 1535 1536 1537 1538 1539 1540 1541 1542
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
1543
{
1544
    RwCo *rwco = opaque;
B
bellard 已提交
1545

1546 1547
    if (!rwco->is_write) {
        rwco->ret = bdrv_co_do_readv(rwco->bs, rwco->sector_num,
1548
                                     rwco->nb_sectors, rwco->qiov, 0);
1549 1550
    } else {
        rwco->ret = bdrv_co_do_writev(rwco->bs, rwco->sector_num,
1551
                                      rwco->nb_sectors, rwco->qiov, 0);
1552 1553
    }
}
1554

1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574
/*
 * 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,
    };
1575

1576
    qemu_iovec_init_external(&qiov, &iov, 1);
1577

1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588
    /**
     * 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);
    }

1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600
    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
1601

1602 1603 1604 1605 1606
/* 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
1607 1608
}

1609 1610
#define BITS_PER_LONG  (sizeof(unsigned long) * 8)

1611
static void set_dirty_bitmap(BlockDriverState *bs, int64_t sector_num,
1612
                             int nb_sectors, int dirty)
1613 1614
{
    int64_t start, end;
1615
    unsigned long val, idx, bit;
1616

J
Jan Kiszka 已提交
1617
    start = sector_num / BDRV_SECTORS_PER_DIRTY_CHUNK;
1618
    end = (sector_num + nb_sectors - 1) / BDRV_SECTORS_PER_DIRTY_CHUNK;
1619 1620

    for (; start <= end; start++) {
1621 1622
        idx = start / BITS_PER_LONG;
        bit = start % BITS_PER_LONG;
1623 1624
        val = bs->dirty_bitmap[idx];
        if (dirty) {
1625
            if (!(val & (1UL << bit))) {
1626
                bs->dirty_count++;
1627
                val |= 1UL << bit;
1628
            }
1629
        } else {
1630
            if (val & (1UL << bit)) {
1631
                bs->dirty_count--;
1632
                val &= ~(1UL << bit);
1633
            }
1634 1635
        }
        bs->dirty_bitmap[idx] = val;
1636 1637 1638
    }
}

1639
/* Return < 0 if error. Important errors are:
B
bellard 已提交
1640 1641 1642 1643 1644
  -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
*/
1645
int bdrv_write(BlockDriverState *bs, int64_t sector_num,
B
bellard 已提交
1646 1647
               const uint8_t *buf, int nb_sectors)
{
1648
    return bdrv_rw_co(bs, sector_num, (uint8_t *)buf, nb_sectors, true);
B
bellard 已提交
1649 1650
}

1651 1652
int bdrv_pread(BlockDriverState *bs, int64_t offset,
               void *buf, int count1)
B
bellard 已提交
1653
{
J
Jan Kiszka 已提交
1654
    uint8_t tmp_buf[BDRV_SECTOR_SIZE];
B
bellard 已提交
1655 1656
    int len, nb_sectors, count;
    int64_t sector_num;
1657
    int ret;
B
bellard 已提交
1658 1659 1660

    count = count1;
    /* first read to align to sector start */
J
Jan Kiszka 已提交
1661
    len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
B
bellard 已提交
1662 1663
    if (len > count)
        len = count;
J
Jan Kiszka 已提交
1664
    sector_num = offset >> BDRV_SECTOR_BITS;
B
bellard 已提交
1665
    if (len > 0) {
1666 1667
        if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
            return ret;
J
Jan Kiszka 已提交
1668
        memcpy(buf, tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), len);
B
bellard 已提交
1669 1670 1671 1672 1673 1674 1675 1676
        count -= len;
        if (count == 0)
            return count1;
        sector_num++;
        buf += len;
    }

    /* read the sectors "in place" */
J
Jan Kiszka 已提交
1677
    nb_sectors = count >> BDRV_SECTOR_BITS;
B
bellard 已提交
1678
    if (nb_sectors > 0) {
1679 1680
        if ((ret = bdrv_read(bs, sector_num, buf, nb_sectors)) < 0)
            return ret;
B
bellard 已提交
1681
        sector_num += nb_sectors;
J
Jan Kiszka 已提交
1682
        len = nb_sectors << BDRV_SECTOR_BITS;
B
bellard 已提交
1683 1684 1685 1686 1687 1688
        buf += len;
        count -= len;
    }

    /* add data from the last sector */
    if (count > 0) {
1689 1690
        if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
            return ret;
B
bellard 已提交
1691 1692 1693 1694 1695
        memcpy(buf, tmp_buf, count);
    }
    return count1;
}

1696 1697
int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
                const void *buf, int count1)
B
bellard 已提交
1698
{
J
Jan Kiszka 已提交
1699
    uint8_t tmp_buf[BDRV_SECTOR_SIZE];
B
bellard 已提交
1700 1701
    int len, nb_sectors, count;
    int64_t sector_num;
1702
    int ret;
B
bellard 已提交
1703 1704 1705

    count = count1;
    /* first write to align to sector start */
J
Jan Kiszka 已提交
1706
    len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
B
bellard 已提交
1707 1708
    if (len > count)
        len = count;
J
Jan Kiszka 已提交
1709
    sector_num = offset >> BDRV_SECTOR_BITS;
B
bellard 已提交
1710
    if (len > 0) {
1711 1712
        if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
            return ret;
J
Jan Kiszka 已提交
1713
        memcpy(tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), buf, len);
1714 1715
        if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0)
            return ret;
B
bellard 已提交
1716 1717 1718 1719 1720 1721 1722 1723
        count -= len;
        if (count == 0)
            return count1;
        sector_num++;
        buf += len;
    }

    /* write the sectors "in place" */
J
Jan Kiszka 已提交
1724
    nb_sectors = count >> BDRV_SECTOR_BITS;
B
bellard 已提交
1725
    if (nb_sectors > 0) {
1726 1727
        if ((ret = bdrv_write(bs, sector_num, buf, nb_sectors)) < 0)
            return ret;
B
bellard 已提交
1728
        sector_num += nb_sectors;
J
Jan Kiszka 已提交
1729
        len = nb_sectors << BDRV_SECTOR_BITS;
B
bellard 已提交
1730 1731 1732 1733 1734 1735
        buf += len;
        count -= len;
    }

    /* add data from the last sector */
    if (count > 0) {
1736 1737
        if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0)
            return ret;
B
bellard 已提交
1738
        memcpy(tmp_buf, buf, count);
1739 1740
        if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0)
            return ret;
B
bellard 已提交
1741 1742 1743 1744
    }
    return count1;
}

K
Kevin Wolf 已提交
1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760
/*
 * 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;
    }

1761 1762
    /* No flush needed for cache modes that already do it */
    if (bs->enable_write_cache) {
K
Kevin Wolf 已提交
1763 1764 1765 1766 1767 1768
        bdrv_flush(bs);
    }

    return 0;
}

1769
static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs,
S
Stefan Hajnoczi 已提交
1770 1771 1772 1773 1774 1775 1776 1777 1778
        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;

1779
    BlockDriver *drv = bs->drv;
S
Stefan Hajnoczi 已提交
1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792
    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);

1793 1794
    trace_bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors,
                                   cluster_sector_num, cluster_nb_sectors);
S
Stefan Hajnoczi 已提交
1795 1796 1797 1798 1799

    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);

1800 1801
    ret = drv->bdrv_co_readv(bs, cluster_sector_num, cluster_nb_sectors,
                             &bounce_qiov);
S
Stefan Hajnoczi 已提交
1802 1803 1804 1805
    if (ret < 0) {
        goto err;
    }

1806 1807
    if (drv->bdrv_co_write_zeroes &&
        buffer_is_zero(bounce_buffer, iov.iov_len)) {
K
Kevin Wolf 已提交
1808 1809
        ret = bdrv_co_do_write_zeroes(bs, cluster_sector_num,
                                      cluster_nb_sectors);
1810
    } else {
1811 1812 1813
        /* This does not change the data on the disk, it is not necessary
         * to flush even in cache=writethrough mode.
         */
1814
        ret = drv->bdrv_co_writev(bs, cluster_sector_num, cluster_nb_sectors,
S
Stefan Hajnoczi 已提交
1815
                                  &bounce_qiov);
1816 1817
    }

S
Stefan Hajnoczi 已提交
1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834
    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;
}

1835 1836 1837 1838
/*
 * Handle a read request in coroutine context
 */
static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs,
1839 1840
    int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
    BdrvRequestFlags flags)
K
Kevin Wolf 已提交
1841 1842
{
    BlockDriver *drv = bs->drv;
S
Stefan Hajnoczi 已提交
1843 1844
    BdrvTrackedRequest req;
    int ret;
K
Kevin Wolf 已提交
1845 1846 1847 1848 1849 1850 1851 1852

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

Z
Zhi Yong Wu 已提交
1853 1854 1855 1856 1857
    /* throttling disk read I/O */
    if (bs->io_limits_enabled) {
        bdrv_io_limits_intercept(bs, false, nb_sectors);
    }

1858
    if (bs->copy_on_read) {
1859 1860 1861 1862 1863 1864 1865
        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) {
1866 1867 1868
        wait_for_overlapping_requests(bs, sector_num, nb_sectors);
    }

S
Stefan Hajnoczi 已提交
1869
    tracked_request_begin(&req, bs, sector_num, nb_sectors, false);
S
Stefan Hajnoczi 已提交
1870

1871
    if (flags & BDRV_REQ_COPY_ON_READ) {
S
Stefan Hajnoczi 已提交
1872 1873 1874 1875 1876 1877 1878 1879
        int pnum;

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

        if (!ret || pnum != nb_sectors) {
1880
            ret = bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors, qiov);
S
Stefan Hajnoczi 已提交
1881 1882 1883 1884
            goto out;
        }
    }

S
Stefan Hajnoczi 已提交
1885
    ret = drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov);
S
Stefan Hajnoczi 已提交
1886 1887

out:
S
Stefan Hajnoczi 已提交
1888
    tracked_request_end(&req);
1889 1890 1891 1892 1893

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

S
Stefan Hajnoczi 已提交
1894
    return ret;
K
Kevin Wolf 已提交
1895 1896
}

1897
int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num,
K
Kevin Wolf 已提交
1898 1899
    int nb_sectors, QEMUIOVector *qiov)
{
1900
    trace_bdrv_co_readv(bs, sector_num, nb_sectors);
K
Kevin Wolf 已提交
1901

1902 1903 1904 1905 1906 1907 1908 1909 1910 1911
    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);
1912 1913
}

1914 1915 1916 1917 1918 1919 1920 1921
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
1922 1923 1924
    /* TODO Emulate only part of misaligned requests instead of letting block
     * drivers return -ENOTSUP and emulate everything */

1925 1926
    /* First try the efficient write zeroes operation */
    if (drv->bdrv_co_write_zeroes) {
K
Kevin Wolf 已提交
1927 1928 1929 1930
        ret = drv->bdrv_co_write_zeroes(bs, sector_num, nb_sectors);
        if (ret != -ENOTSUP) {
            return ret;
        }
1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944
    }

    /* 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;
}

1945 1946 1947 1948
/*
 * Handle a write request in coroutine context
 */
static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs,
1949 1950
    int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
    BdrvRequestFlags flags)
1951 1952
{
    BlockDriver *drv = bs->drv;
S
Stefan Hajnoczi 已提交
1953
    BdrvTrackedRequest req;
1954
    int ret;
K
Kevin Wolf 已提交
1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965

    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
1966 1967 1968 1969 1970
    /* throttling disk write I/O */
    if (bs->io_limits_enabled) {
        bdrv_io_limits_intercept(bs, true, nb_sectors);
    }

1971
    if (bs->copy_on_read_in_flight) {
1972 1973 1974
        wait_for_overlapping_requests(bs, sector_num, nb_sectors);
    }

S
Stefan Hajnoczi 已提交
1975 1976
    tracked_request_begin(&req, bs, sector_num, nb_sectors, true);

1977 1978 1979 1980 1981
    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);
    }
1982

1983 1984 1985 1986
    if (ret == 0 && !bs->enable_write_cache) {
        ret = bdrv_co_flush(bs);
    }

K
Kevin Wolf 已提交
1987 1988 1989 1990 1991 1992 1993 1994
    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
1995 1996
    tracked_request_end(&req);

1997
    return ret;
K
Kevin Wolf 已提交
1998 1999
}

2000 2001 2002 2003 2004
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);

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014
    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);
2015 2016
}

B
bellard 已提交
2017 2018 2019 2020 2021 2022
/**
 * Truncate file to 'offset' bytes (needed only for file protocols)
 */
int bdrv_truncate(BlockDriverState *bs, int64_t offset)
{
    BlockDriver *drv = bs->drv;
2023
    int ret;
B
bellard 已提交
2024
    if (!drv)
B
bellard 已提交
2025
        return -ENOMEDIUM;
B
bellard 已提交
2026 2027
    if (!drv->bdrv_truncate)
        return -ENOTSUP;
2028 2029
    if (bs->read_only)
        return -EACCES;
M
Marcelo Tosatti 已提交
2030 2031
    if (bdrv_in_use(bs))
        return -EBUSY;
2032 2033 2034
    ret = drv->bdrv_truncate(bs, offset);
    if (ret == 0) {
        ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS);
2035
        bdrv_dev_resize_cb(bs);
2036 2037
    }
    return ret;
B
bellard 已提交
2038 2039
}

2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058
/**
 * 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
2059 2060 2061 2062 2063 2064 2065
/**
 * 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
2066
        return -ENOMEDIUM;
2067

2068
    if (bs->growable || bdrv_dev_has_removable_media(bs)) {
2069 2070 2071
        if (drv->bdrv_getlength) {
            return drv->bdrv_getlength(bs);
        }
B
bellard 已提交
2072
    }
2073
    return bs->total_sectors * BDRV_SECTOR_SIZE;
B
bellard 已提交
2074 2075
}

B
bellard 已提交
2076
/* return 0 as number of sectors if no device present or error */
2077
void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
B
bellard 已提交
2078
{
B
bellard 已提交
2079 2080 2081 2082 2083
    int64_t length;
    length = bdrv_getlength(bs);
    if (length < 0)
        length = 0;
    else
J
Jan Kiszka 已提交
2084
        length = length >> BDRV_SECTOR_BITS;
B
bellard 已提交
2085
    *nb_sectors_ptr = length;
B
bellard 已提交
2086
}
B
bellard 已提交
2087

2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098
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 */
2099
} QEMU_PACKED;
2100 2101 2102 2103 2104

/* 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)
{
2105
    uint8_t buf[BDRV_SECTOR_SIZE];
2106 2107 2108
    int ret, i, heads, sectors, cylinders;
    struct partition *p;
    uint32_t nr_sects;
B
blueswir1 已提交
2109
    uint64_t nb_sectors;
2110
    bool enabled;
2111 2112 2113

    bdrv_get_geometry(bs, &nb_sectors);

2114 2115 2116 2117 2118 2119 2120
    /**
     * 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;
2121
    ret = bdrv_read(bs, 0, buf, 1);
2122
    bs->io_limits_enabled = enabled;
2123 2124 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
    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
2158
    uint64_t nb_sectors;
2159 2160 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

    /* 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);
    }
}

2213
void bdrv_set_geometry_hint(BlockDriverState *bs,
B
bellard 已提交
2214 2215 2216 2217 2218 2219 2220
                            int cyls, int heads, int secs)
{
    bs->cyls = cyls;
    bs->heads = heads;
    bs->secs = secs;
}

B
bellard 已提交
2221 2222 2223 2224 2225
void bdrv_set_translation_hint(BlockDriverState *bs, int translation)
{
    bs->translation = translation;
}

2226
void bdrv_get_geometry_hint(BlockDriverState *bs,
B
bellard 已提交
2227 2228 2229 2230 2231 2232 2233
                            int *pcyls, int *pheads, int *psecs)
{
    *pcyls = bs->cyls;
    *pheads = bs->heads;
    *psecs = bs->secs;
}

2234 2235 2236 2237 2238 2239 2240 2241
/* 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);
}

2242 2243 2244 2245 2246 2247
/* Recognize floppy formats */
typedef struct FDFormat {
    FDriveType drive;
    uint8_t last_sect;
    uint8_t max_track;
    uint8_t max_head;
2248
    FDriveRate rate;
2249 2250 2251 2252 2253
} FDFormat;

static const FDFormat fd_formats[] = {
    /* First entry is default format */
    /* 1.44 MB 3"1/2 floppy disks */
2254 2255 2256 2257 2258 2259 2260 2261
    { 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, },
2262
    /* 2.88 MB 3"1/2 floppy disks */
2263 2264 2265 2266 2267
    { 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, },
2268
    /* 720 kB 3"1/2 floppy disks */
2269 2270 2271 2272 2273 2274
    { 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, },
2275
    /* 1.2 MB 5"1/4 floppy disks */
2276 2277 2278 2279 2280
    { 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, },
2281
    /* 720 kB 5"1/4 floppy disks */
2282 2283
    { FDRIVE_DRV_120,  9, 80, 1, FDRIVE_RATE_250K, },
    { FDRIVE_DRV_120, 11, 80, 1, FDRIVE_RATE_250K, },
2284
    /* 360 kB 5"1/4 floppy disks */
2285 2286 2287 2288
    { 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, },
2289
    /* 320 kB 5"1/4 floppy disks */
2290 2291
    { FDRIVE_DRV_120,  8, 40, 1, FDRIVE_RATE_250K, },
    { FDRIVE_DRV_120,  8, 40, 0, FDRIVE_RATE_250K, },
2292
    /* 360 kB must match 5"1/4 better than 3"1/2... */
2293
    { FDRIVE_DRV_144,  9, 80, 0, FDRIVE_RATE_250K, },
2294
    /* end */
2295
    { FDRIVE_DRV_NONE, -1, -1, 0, 0, },
2296 2297 2298 2299
};

void bdrv_get_floppy_geometry_hint(BlockDriverState *bs, int *nb_heads,
                                   int *max_track, int *last_sect,
2300 2301
                                   FDriveType drive_in, FDriveType *drive,
                                   FDriveRate *rate)
2302 2303 2304 2305 2306 2307 2308 2309
{
    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 */
2310
        *rate = FDRIVE_RATE_500K;
2311 2312 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
    } 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;
2345
        *rate = parse->rate;
2346 2347 2348
    }
}

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

2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365
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;
}

2371 2372 2373 2374 2375
int bdrv_is_sg(BlockDriverState *bs)
{
    return bs->sg;
}

2376 2377 2378 2379 2380
int bdrv_enable_write_cache(BlockDriverState *bs)
{
    return bs->enable_write_cache;
}

B
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int bdrv_is_encrypted(BlockDriverState *bs)
{
    if (bs->backing_hd && bs->backing_hd->encrypted)
        return 1;
    return bs->encrypted;
}

2388 2389 2390 2391 2392 2393 2394 2395 2396
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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2397 2398 2399 2400 2401 2402 2403 2404 2405 2406
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;
    }
2407 2408 2409 2410 2411
    if (!bs->encrypted) {
        return -EINVAL;
    } else if (!bs->drv || !bs->drv->bdrv_set_key) {
        return -ENOMEDIUM;
    }
2412
    ret = bs->drv->bdrv_set_key(bs, key);
2413 2414 2415 2416 2417
    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 */
2418
        bdrv_dev_change_media_cb(bs, true);
2419
    }
2420
    return ret;
B
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2421 2422 2423 2424
}

void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)
{
B
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2425
    if (!bs->drv) {
B
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2426 2427 2428 2429 2430 2431
        buf[0] = '\0';
    } else {
        pstrcpy(buf, buf_size, bs->drv->format_name);
    }
}

2432
void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
B
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2433 2434 2435 2436
                         void *opaque)
{
    BlockDriver *drv;

2437
    QLIST_FOREACH(drv, &bdrv_drivers, list) {
B
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2438 2439 2440 2441
        it(opaque, drv->format_name);
    }
}

B
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2442 2443 2444 2445
BlockDriverState *bdrv_find(const char *name)
{
    BlockDriverState *bs;

2446 2447
    QTAILQ_FOREACH(bs, &bdrv_states, list) {
        if (!strcmp(name, bs->device_name)) {
B
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2448
            return bs;
2449
        }
B
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2450 2451 2452 2453
    }
    return NULL;
}

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2454 2455 2456 2457 2458 2459 2460 2461
BlockDriverState *bdrv_next(BlockDriverState *bs)
{
    if (!bs) {
        return QTAILQ_FIRST(&bdrv_states);
    }
    return QTAILQ_NEXT(bs, list);
}

2462
void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs), void *opaque)
B
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2463 2464 2465
{
    BlockDriverState *bs;

2466
    QTAILQ_FOREACH(bs, &bdrv_states, list) {
2467
        it(opaque, bs);
B
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2468 2469 2470
    }
}

B
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2471 2472 2473 2474 2475
const char *bdrv_get_device_name(BlockDriverState *bs)
{
    return bs->device_name;
}

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2476 2477 2478 2479 2480
int bdrv_get_flags(BlockDriverState *bs)
{
    return bs->open_flags;
}

A
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2481 2482 2483 2484
void bdrv_flush_all(void)
{
    BlockDriverState *bs;

2485
    QTAILQ_FOREACH(bs, &bdrv_states, list) {
2486
        bdrv_flush(bs);
2487
    }
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2488 2489
}

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2490 2491 2492 2493
int bdrv_has_zero_init(BlockDriverState *bs)
{
    assert(bs->drv);

K
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2494 2495
    if (bs->drv->bdrv_has_zero_init) {
        return bs->drv->bdrv_has_zero_init(bs);
K
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2496 2497 2498 2499 2500
    }

    return 1;
}

2501 2502 2503 2504 2505 2506 2507 2508 2509
typedef struct BdrvCoIsAllocatedData {
    BlockDriverState *bs;
    int64_t sector_num;
    int nb_sectors;
    int *pnum;
    int ret;
    bool done;
} BdrvCoIsAllocatedData;

2510 2511 2512 2513 2514
/*
 * 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.
 *
2515 2516 2517
 * If 'sector_num' is beyond the end of the disk image the return value is 0
 * and 'pnum' is set to 0.
 *
2518 2519 2520 2521
 * '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.
 *
2522 2523
 * '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.
2524
 */
2525 2526
int coroutine_fn bdrv_co_is_allocated(BlockDriverState *bs, int64_t sector_num,
                                      int nb_sectors, int *pnum)
2527
{
2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539
    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;
    }

2540
    if (!bs->drv->bdrv_co_is_allocated) {
2541
        *pnum = nb_sectors;
2542 2543
        return 1;
    }
2544

2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566
    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)
{
2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581
    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;
2582 2583
}

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
/*
 * 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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2633
BlockInfoList *qmp_query_block(Error **errp)
B
bellard 已提交
2634
{
L
Luiz Capitulino 已提交
2635
    BlockInfoList *head = NULL, *cur_item = NULL;
B
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2636 2637
    BlockDriverState *bs;

2638
    QTAILQ_FOREACH(bs, &bdrv_states, list) {
L
Luiz Capitulino 已提交
2639
        BlockInfoList *info = g_malloc0(sizeof(*info));
2640

L
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2641 2642 2643 2644 2645
        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);
2646

2647
        if (bdrv_dev_has_removable_media(bs)) {
L
Luiz Capitulino 已提交
2648 2649
            info->value->has_tray_open = true;
            info->value->tray_open = bdrv_dev_is_tray_open(bs);
2650
        }
2651 2652

        if (bdrv_iostatus_is_enabled(bs)) {
L
Luiz Capitulino 已提交
2653 2654
            info->value->has_io_status = true;
            info->value->io_status = bs->iostatus;
2655 2656
        }

B
bellard 已提交
2657
        if (bs->drv) {
L
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2658 2659 2660 2661 2662 2663 2664 2665 2666
            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
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2667
            }
Z
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2668 2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682

            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
2683
        }
2684

L
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2685 2686 2687 2688 2689 2690
        /* 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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2691 2692
        }
    }
2693

L
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2694
    return head;
B
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2695
}
2696

L
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2697 2698 2699 2700 2701 2702 2703 2704 2705 2706
/* 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);
2707 2708
    }

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2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719
    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];

2720
    if (bs->file) {
L
Luiz Capitulino 已提交
2721 2722
        s->has_parent = true;
        s->parent = qmp_query_blockstat(bs->file, NULL);
2723 2724
    }

L
Luiz Capitulino 已提交
2725
    return s;
2726 2727
}

L
Luiz Capitulino 已提交
2728
BlockStatsList *qmp_query_blockstats(Error **errp)
2729
{
L
Luiz Capitulino 已提交
2730
    BlockStatsList *head = NULL, *cur_item = NULL;
2731 2732
    BlockDriverState *bs;

2733
    QTAILQ_FOREACH(bs, &bdrv_states, list) {
L
Luiz Capitulino 已提交
2734 2735 2736 2737 2738 2739 2740 2741 2742 2743
        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;
        }
2744
    }
2745

L
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2746
    return head;
2747
}
B
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2748

2749 2750 2751 2752 2753 2754 2755 2756 2757 2758
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;
}

2759
void bdrv_get_backing_filename(BlockDriverState *bs,
B
bellard 已提交
2760 2761
                               char *filename, int filename_size)
{
K
Kevin Wolf 已提交
2762
    pstrcpy(filename, filename_size, bs->backing_file);
B
bellard 已提交
2763 2764
}

2765
int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
B
bellard 已提交
2766 2767 2768 2769
                          const uint8_t *buf, int nb_sectors)
{
    BlockDriver *drv = bs->drv;
    if (!drv)
B
bellard 已提交
2770
        return -ENOMEDIUM;
B
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2771 2772
    if (!drv->bdrv_write_compressed)
        return -ENOTSUP;
K
Kevin Wolf 已提交
2773 2774
    if (bdrv_check_request(bs, sector_num, nb_sectors))
        return -EIO;
2775

2776
    if (bs->dirty_bitmap) {
2777 2778
        set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
    }
2779

B
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2780 2781
    return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
}
2782

B
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2783 2784 2785 2786
int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
{
    BlockDriver *drv = bs->drv;
    if (!drv)
B
bellard 已提交
2787
        return -ENOMEDIUM;
B
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2788 2789 2790 2791 2792 2793
    if (!drv->bdrv_get_info)
        return -ENOTSUP;
    memset(bdi, 0, sizeof(*bdi));
    return drv->bdrv_get_info(bs, bdi);
}

2794 2795
int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
                      int64_t pos, int size)
2796 2797 2798 2799
{
    BlockDriver *drv = bs->drv;
    if (!drv)
        return -ENOMEDIUM;
2800 2801 2802 2803 2804
    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;
2805 2806
}

2807 2808
int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
                      int64_t pos, int size)
2809 2810 2811 2812
{
    BlockDriver *drv = bs->drv;
    if (!drv)
        return -ENOMEDIUM;
2813 2814 2815 2816 2817
    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;
2818 2819
}

K
Kevin Wolf 已提交
2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831
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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2832 2833 2834
/**************************************************************/
/* handling of snapshots */

2835 2836 2837
int bdrv_can_snapshot(BlockDriverState *bs)
{
    BlockDriver *drv = bs->drv;
2838
    if (!drv || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) {
2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851
        return 0;
    }

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

    return 1;
}

2852 2853 2854 2855 2856
int bdrv_is_snapshot(BlockDriverState *bs)
{
    return !!(bs->open_flags & BDRV_O_SNAPSHOT);
}

2857 2858 2859 2860
BlockDriverState *bdrv_snapshots(void)
{
    BlockDriverState *bs;

2861
    if (bs_snapshots) {
2862
        return bs_snapshots;
2863
    }
2864 2865 2866 2867

    bs = NULL;
    while ((bs = bdrv_next(bs))) {
        if (bdrv_can_snapshot(bs)) {
2868 2869
            bs_snapshots = bs;
            return bs;
2870 2871 2872 2873 2874
        }
    }
    return NULL;
}

2875
int bdrv_snapshot_create(BlockDriverState *bs,
B
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2876 2877 2878 2879
                         QEMUSnapshotInfo *sn_info)
{
    BlockDriver *drv = bs->drv;
    if (!drv)
B
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        return -ENOMEDIUM;
2881 2882 2883 2884 2885
    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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2886 2887
}

2888
int bdrv_snapshot_goto(BlockDriverState *bs,
B
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2889 2890 2891
                       const char *snapshot_id)
{
    BlockDriver *drv = bs->drv;
2892 2893
    int ret, open_ret;

B
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2894
    if (!drv)
B
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2895
        return -ENOMEDIUM;
2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911
    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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2912 2913 2914 2915 2916 2917
}

int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
{
    BlockDriver *drv = bs->drv;
    if (!drv)
B
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2918
        return -ENOMEDIUM;
2919 2920 2921 2922 2923
    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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2924 2925
}

2926
int bdrv_snapshot_list(BlockDriverState *bs,
B
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2927 2928 2929 2930
                       QEMUSnapshotInfo **psn_info)
{
    BlockDriver *drv = bs->drv;
    if (!drv)
B
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2931
        return -ENOMEDIUM;
2932 2933 2934 2935 2936
    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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2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954
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;
}

2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972
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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2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986
#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)) {
2987
                snprintf(buf, buf_size, "%0.1f%c",
B
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2988 2989 2990 2991
                         (double)size / base,
                         suffixes[i]);
                break;
            } else if (size < (1000 * base) || i == (NB_SUFFIXES - 1)) {
2992
                snprintf(buf, buf_size, "%" PRId64 "%c",
B
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2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005
                         ((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];
3006 3007 3008
#ifdef _WIN32
    struct tm *ptm;
#else
B
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3009
    struct tm tm;
3010
#endif
B
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3011 3012 3013 3014
    time_t ti;
    int64_t secs;

    if (!sn) {
3015 3016
        snprintf(buf, buf_size,
                 "%-10s%-20s%7s%20s%15s",
B
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3017 3018 3019
                 "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK");
    } else {
        ti = sn->date_sec;
3020 3021 3022 3023 3024
#ifdef _WIN32
        ptm = localtime(&ti);
        strftime(date_buf, sizeof(date_buf),
                 "%Y-%m-%d %H:%M:%S", ptm);
#else
B
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3025 3026 3027
        localtime_r(&ti, &tm);
        strftime(date_buf, sizeof(date_buf),
                 "%Y-%m-%d %H:%M:%S", &tm);
3028
#endif
B
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3029 3030 3031 3032 3033
        secs = sn->vm_clock_nsec / 1000000000;
        snprintf(clock_buf, sizeof(clock_buf),
                 "%02d:%02d:%02d.%03d",
                 (int)(secs / 3600),
                 (int)((secs / 60) % 60),
3034
                 (int)(secs % 60),
B
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3035 3036
                 (int)((sn->vm_clock_nsec / 1000000) % 1000));
        snprintf(buf, buf_size,
3037
                 "%-10s%-20s%7s%20s%15s",
B
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3038 3039 3040 3041 3042 3043 3044 3045
                 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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3046
/**************************************************************/
B
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3047
/* async I/Os */
B
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3048

3049
BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
3050
                                 QEMUIOVector *qiov, int nb_sectors,
3051
                                 BlockDriverCompletionFunc *cb, void *opaque)
B
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3052
{
3053 3054
    trace_bdrv_aio_readv(bs, sector_num, nb_sectors, opaque);

3055
    return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors,
3056
                                 cb, opaque, false);
B
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3057 3058
}

3059 3060 3061
BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
                                  QEMUIOVector *qiov, int nb_sectors,
                                  BlockDriverCompletionFunc *cb, void *opaque)
B
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3062
{
3063 3064
    trace_bdrv_aio_writev(bs, sector_num, nb_sectors, opaque);

3065
    return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors,
3066
                                 cb, opaque, true);
B
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3067 3068
}

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3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086

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);
3087 3088 3089
        if (mcb->callbacks[i].free_qiov) {
            qemu_iovec_destroy(mcb->callbacks[i].free_qiov);
        }
3090
        g_free(mcb->callbacks[i].free_qiov);
K
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3091 3092 3093 3094 3095 3096 3097
    }
}

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

3098 3099
    trace_multiwrite_cb(mcb, ret);

3100
    if (ret < 0 && !mcb->error) {
K
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3101 3102 3103 3104 3105
        mcb->error = ret;
    }

    mcb->num_requests--;
    if (mcb->num_requests == 0) {
3106
        multiwrite_user_cb(mcb);
3107
        g_free(mcb);
K
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3108 3109 3110 3111 3112
    }
}

static int multiwrite_req_compare(const void *a, const void *b)
{
3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125
    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;

3147
        // Handle exactly sequential writes and overlapping writes.
K
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3148 3149 3150 3151
        if (reqs[i].sector <= oldreq_last) {
            merge = 1;
        }

3152 3153 3154 3155
        if (reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1 > IOV_MAX) {
            merge = 0;
        }

K
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3156 3157
        if (merge) {
            size_t size;
3158
            QEMUIOVector *qiov = g_malloc0(sizeof(*qiov));
K
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3159 3160 3161 3162 3163 3164 3165 3166
            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);

3167 3168
            // We should need to add any zeros between the two requests
            assert (reqs[i].sector <= oldreq_last);
K
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3169 3170 3171 3172

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

3173
            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;

3207 3208 3209 3210 3211 3212 3213 3214
    /* 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;
    }

K
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3215 3216 3217 3218 3219
    if (num_reqs == 0) {
        return 0;
    }

    // Create MultiwriteCB structure
3220
    mcb = g_malloc0(sizeof(*mcb) + num_reqs * sizeof(*mcb->callbacks));
K
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3221 3222 3223 3224 3225 3226 3227 3228 3229 3230 3231
    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);

3232 3233
    trace_bdrv_aio_multiwrite(mcb, mcb->num_callbacks, num_reqs);

3234 3235
    /* Run the aio requests. */
    mcb->num_requests = num_reqs;
K
Kevin Wolf 已提交
3236
    for (i = 0; i < num_reqs; i++) {
3237
        bdrv_aio_writev(bs, reqs[i].sector, reqs[i].qiov,
K
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3238 3239 3240 3241 3242 3243
            reqs[i].nb_sectors, multiwrite_cb, mcb);
    }

    return 0;
}

B
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3244 3245
void bdrv_aio_cancel(BlockDriverAIOCB *acb)
{
3246
    acb->pool->cancel(acb);
B
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3247 3248
}

Z
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3249 3250 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
/* 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;
}
3413

B
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3414 3415 3416
/**************************************************************/
/* async block device emulation */

3417 3418 3419 3420 3421 3422 3423 3424 3425 3426 3427 3428
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)
{
3429 3430
    BlockDriverAIOCBSync *acb =
        container_of(blockacb, BlockDriverAIOCBSync, common);
3431
    qemu_bh_delete(acb->bh);
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Avi Kivity 已提交
3432
    acb->bh = NULL;
3433 3434 3435 3436 3437 3438 3439 3440
    qemu_aio_release(acb);
}

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

3441
static void bdrv_aio_bh_cb(void *opaque)
B
bellard 已提交
3442
{
3443
    BlockDriverAIOCBSync *acb = opaque;
3444 3445 3446

    if (!acb->is_write)
        qemu_iovec_from_buffer(acb->qiov, acb->bounce, acb->qiov->size);
3447
    qemu_vfree(acb->bounce);
3448
    acb->common.cb(acb->common.opaque, acb->ret);
3449
    qemu_bh_delete(acb->bh);
A
Avi Kivity 已提交
3450
    acb->bh = NULL;
3451
    qemu_aio_release(acb);
B
bellard 已提交
3452
}
3453

3454 3455 3456 3457 3458 3459 3460 3461
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
3462
{
3463 3464
    BlockDriverAIOCBSync *acb;

3465
    acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
3466 3467
    acb->is_write = is_write;
    acb->qiov = qiov;
3468
    acb->bounce = qemu_blockalign(bs, qiov->size);
3469
    acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
3470 3471 3472

    if (is_write) {
        qemu_iovec_to_buffer(acb->qiov, acb->bounce);
3473
        acb->ret = bs->drv->bdrv_write(bs, sector_num, acb->bounce, nb_sectors);
3474
    } else {
3475
        acb->ret = bs->drv->bdrv_read(bs, sector_num, acb->bounce, nb_sectors);
3476 3477
    }

3478
    qemu_bh_schedule(acb->bh);
3479

3480
    return &acb->common;
3481 3482
}

3483 3484
static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
3485
        BlockDriverCompletionFunc *cb, void *opaque)
3486
{
3487 3488
    return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
}
B
bellard 已提交
3489

3490 3491 3492 3493 3494
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);
3495 3496
}

3497 3498 3499 3500 3501 3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513 3514

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
3515
static void bdrv_co_em_bh(void *opaque)
3516 3517 3518 3519 3520 3521 3522 3523
{
    BlockDriverAIOCBCoroutine *acb = opaque;

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

3524 3525 3526 3527 3528 3529 3530 3531
/* 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,
3532
            acb->req.nb_sectors, acb->req.qiov, 0);
3533 3534
    } else {
        acb->req.error = bdrv_co_do_writev(bs, acb->req.sector,
3535
            acb->req.nb_sectors, acb->req.qiov, 0);
3536 3537
    }

P
Paolo Bonzini 已提交
3538
    acb->bh = qemu_bh_new(bdrv_co_em_bh, acb);
3539 3540 3541
    qemu_bh_schedule(acb->bh);
}

3542 3543 3544 3545 3546 3547
static BlockDriverAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs,
                                               int64_t sector_num,
                                               QEMUIOVector *qiov,
                                               int nb_sectors,
                                               BlockDriverCompletionFunc *cb,
                                               void *opaque,
3548
                                               bool is_write)
3549 3550 3551 3552 3553 3554 3555 3556 3557 3558
{
    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;

3559
    co = qemu_coroutine_create(bdrv_co_do_rw);
3560 3561 3562 3563 3564
    qemu_coroutine_enter(co, acb);

    return &acb->common;
}

P
Paolo Bonzini 已提交
3565
static void coroutine_fn bdrv_aio_flush_co_entry(void *opaque)
3566
{
P
Paolo Bonzini 已提交
3567 3568
    BlockDriverAIOCBCoroutine *acb = opaque;
    BlockDriverState *bs = acb->common.bs;
3569

P
Paolo Bonzini 已提交
3570 3571
    acb->req.error = bdrv_co_flush(bs);
    acb->bh = qemu_bh_new(bdrv_co_em_bh, acb);
3572 3573 3574
    qemu_bh_schedule(acb->bh);
}

P
Paolo Bonzini 已提交
3575
BlockDriverAIOCB *bdrv_aio_flush(BlockDriverState *bs,
3576 3577
        BlockDriverCompletionFunc *cb, void *opaque)
{
P
Paolo Bonzini 已提交
3578
    trace_bdrv_aio_flush(bs, opaque);
3579

P
Paolo Bonzini 已提交
3580 3581
    Coroutine *co;
    BlockDriverAIOCBCoroutine *acb;
3582

P
Paolo Bonzini 已提交
3583 3584 3585
    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);
3586 3587 3588 3589

    return &acb->common;
}

3590 3591 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
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
3618 3619
void bdrv_init(void)
{
3620
    module_call_init(MODULE_INIT_BLOCK);
B
bellard 已提交
3621
}
3622

3623 3624 3625 3626 3627 3628
void bdrv_init_with_whitelist(void)
{
    use_bdrv_whitelist = 1;
    bdrv_init();
}

3629 3630
void *qemu_aio_get(AIOPool *pool, BlockDriverState *bs,
                   BlockDriverCompletionFunc *cb, void *opaque)
3631 3632 3633
{
    BlockDriverAIOCB *acb;

3634 3635 3636
    if (pool->free_aiocb) {
        acb = pool->free_aiocb;
        pool->free_aiocb = acb->next;
3637
    } else {
3638
        acb = g_malloc0(pool->aiocb_size);
3639
        acb->pool = pool;
3640 3641 3642 3643 3644 3645 3646 3647 3648
    }
    acb->bs = bs;
    acb->cb = cb;
    acb->opaque = opaque;
    return acb;
}

void qemu_aio_release(void *p)
{
3649 3650 3651 3652
    BlockDriverAIOCB *acb = (BlockDriverAIOCB *)p;
    AIOPool *pool = acb->pool;
    acb->next = pool->free_aiocb;
    pool->free_aiocb = acb;
3653
}
B
bellard 已提交
3654

3655 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
/**************************************************************/
/* 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) {
3681 3682
        acb = bs->drv->bdrv_aio_writev(bs, sector_num, iov, nb_sectors,
                                       bdrv_co_io_em_complete, &co);
3683
    } else {
3684 3685
        acb = bs->drv->bdrv_aio_readv(bs, sector_num, iov, nb_sectors,
                                      bdrv_co_io_em_complete, &co);
3686 3687
    }

3688
    trace_bdrv_co_io_em(bs, sector_num, nb_sectors, is_write, acb);
3689 3690 3691 3692 3693 3694 3695 3696 3697 3698 3699 3700 3701 3702 3703 3704 3705 3706 3707 3708 3709 3710
    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
3711
static void coroutine_fn bdrv_flush_co_entry(void *opaque)
3712
{
P
Paolo Bonzini 已提交
3713 3714 3715 3716 3717 3718 3719
    RwCo *rwco = opaque;

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

int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
{
K
Kevin Wolf 已提交
3720 3721
    int ret;

3722
    if (!bs || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) {
P
Paolo Bonzini 已提交
3723
        return 0;
K
Kevin Wolf 已提交
3724 3725
    }

3726
    /* Write back cached data to the OS even with cache=unsafe */
K
Kevin Wolf 已提交
3727 3728 3729 3730 3731 3732 3733
    if (bs->drv->bdrv_co_flush_to_os) {
        ret = bs->drv->bdrv_co_flush_to_os(bs);
        if (ret < 0) {
            return ret;
        }
    }

3734 3735 3736 3737 3738
    /* 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
3739
    if (bs->drv->bdrv_co_flush_to_disk) {
3740
        ret = bs->drv->bdrv_co_flush_to_disk(bs);
P
Paolo Bonzini 已提交
3741 3742 3743 3744 3745 3746 3747 3748
    } 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) {
3749
            ret = -EIO;
P
Paolo Bonzini 已提交
3750 3751
        } else {
            qemu_coroutine_yield();
3752
            ret = co.ret;
P
Paolo Bonzini 已提交
3753 3754 3755 3756 3757 3758 3759 3760 3761 3762 3763 3764 3765
        }
    } 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.
         */
3766
        ret = 0;
P
Paolo Bonzini 已提交
3767
    }
3768 3769 3770 3771 3772 3773 3774 3775
    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
3776 3777
}

3778 3779 3780 3781 3782 3783 3784 3785 3786 3787 3788 3789 3790 3791 3792 3793
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);
    }
}

3794 3795 3796 3797 3798 3799 3800 3801 3802
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
3803 3804 3805 3806 3807 3808
int bdrv_flush(BlockDriverState *bs)
{
    Coroutine *co;
    RwCo rwco = {
        .bs = bs,
        .ret = NOT_DONE,
3809 3810
    };

P
Paolo Bonzini 已提交
3811 3812 3813 3814 3815 3816 3817 3818 3819
    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();
        }
3820
    }
P
Paolo Bonzini 已提交
3821 3822

    return rwco.ret;
3823 3824
}

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
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
3886 3887 3888 3889 3890 3891 3892 3893 3894
/**************************************************************/
/* removable device support */

/**
 * Return TRUE if the media is present
 */
int bdrv_is_inserted(BlockDriverState *bs)
{
    BlockDriver *drv = bs->drv;
3895

B
bellard 已提交
3896 3897 3898
    if (!drv)
        return 0;
    if (!drv->bdrv_is_inserted)
3899 3900
        return 1;
    return drv->bdrv_is_inserted(bs);
B
bellard 已提交
3901 3902 3903
}

/**
3904 3905
 * 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
3906 3907 3908 3909 3910
 */
int bdrv_media_changed(BlockDriverState *bs)
{
    BlockDriver *drv = bs->drv;

3911 3912 3913 3914
    if (drv && drv->bdrv_media_changed) {
        return drv->bdrv_media_changed(bs);
    }
    return -ENOTSUP;
B
bellard 已提交
3915 3916 3917 3918 3919
}

/**
 * If eject_flag is TRUE, eject the media. Otherwise, close the tray
 */
3920
void bdrv_eject(BlockDriverState *bs, bool eject_flag)
B
bellard 已提交
3921 3922 3923
{
    BlockDriver *drv = bs->drv;

3924 3925
    if (drv && drv->bdrv_eject) {
        drv->bdrv_eject(bs, eject_flag);
B
bellard 已提交
3926
    }
3927 3928 3929 3930

    if (bs->device_name[0] != '\0') {
        bdrv_emit_qmp_eject_event(bs, eject_flag);
    }
B
bellard 已提交
3931 3932 3933 3934 3935 3936
}

/**
 * Lock or unlock the media (if it is locked, the user won't be able
 * to eject it manually).
 */
3937
void bdrv_lock_medium(BlockDriverState *bs, bool locked)
B
bellard 已提交
3938 3939 3940
{
    BlockDriver *drv = bs->drv;

3941
    trace_bdrv_lock_medium(bs, locked);
S
Stefan Hajnoczi 已提交
3942

3943 3944
    if (drv && drv->bdrv_lock_medium) {
        drv->bdrv_lock_medium(bs, locked);
B
bellard 已提交
3945 3946
    }
}
3947 3948 3949 3950 3951 3952 3953 3954 3955 3956 3957

/* 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;
}
3958

3959 3960 3961
BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
        unsigned long int req, void *buf,
        BlockDriverCompletionFunc *cb, void *opaque)
3962
{
3963
    BlockDriver *drv = bs->drv;
3964

3965 3966 3967
    if (drv && drv->bdrv_aio_ioctl)
        return drv->bdrv_aio_ioctl(bs, req, buf, cb, opaque);
    return NULL;
3968
}
3969

3970 3971 3972 3973
void bdrv_set_buffer_alignment(BlockDriverState *bs, int align)
{
    bs->buffer_alignment = align;
}
3974

3975 3976 3977 3978
void *qemu_blockalign(BlockDriverState *bs, size_t size)
{
    return qemu_memalign((bs && bs->buffer_alignment) ? bs->buffer_alignment : 512, size);
}
3979 3980 3981 3982

void bdrv_set_dirty_tracking(BlockDriverState *bs, int enable)
{
    int64_t bitmap_size;
3983

3984
    bs->dirty_count = 0;
3985
    if (enable) {
3986 3987
        if (!bs->dirty_bitmap) {
            bitmap_size = (bdrv_getlength(bs) >> BDRV_SECTOR_BITS) +
3988 3989
                    BDRV_SECTORS_PER_DIRTY_CHUNK * BITS_PER_LONG - 1;
            bitmap_size /= BDRV_SECTORS_PER_DIRTY_CHUNK * BITS_PER_LONG;
3990

3991
            bs->dirty_bitmap = g_new0(unsigned long, bitmap_size);
3992
        }
3993
    } else {
3994
        if (bs->dirty_bitmap) {
3995
            g_free(bs->dirty_bitmap);
3996
            bs->dirty_bitmap = NULL;
3997
        }
3998 3999 4000 4001 4002
    }
}

int bdrv_get_dirty(BlockDriverState *bs, int64_t sector)
{
J
Jan Kiszka 已提交
4003
    int64_t chunk = sector / (int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK;
4004

4005 4006
    if (bs->dirty_bitmap &&
        (sector << BDRV_SECTOR_BITS) < bdrv_getlength(bs)) {
4007 4008
        return !!(bs->dirty_bitmap[chunk / (sizeof(unsigned long) * 8)] &
            (1UL << (chunk % (sizeof(unsigned long) * 8))));
4009 4010 4011 4012 4013
    } else {
        return 0;
    }
}

4014 4015
void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector,
                      int nr_sectors)
4016 4017 4018
{
    set_dirty_bitmap(bs, cur_sector, nr_sectors, 0);
}
4019 4020 4021 4022 4023

int64_t bdrv_get_dirty_count(BlockDriverState *bs)
{
    return bs->dirty_count;
}
J
Jes Sorensen 已提交
4024

4025 4026 4027 4028 4029 4030 4031 4032 4033 4034 4035
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;
}

4036 4037
void bdrv_iostatus_enable(BlockDriverState *bs)
{
4038
    bs->iostatus_enabled = true;
4039
    bs->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
4040 4041 4042 4043 4044 4045
}

/* 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)
{
4046
    return (bs->iostatus_enabled &&
4047 4048 4049 4050 4051 4052 4053
           (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)
{
4054
    bs->iostatus_enabled = false;
4055 4056 4057 4058 4059
}

void bdrv_iostatus_reset(BlockDriverState *bs)
{
    if (bdrv_iostatus_is_enabled(bs)) {
4060
        bs->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
4061 4062 4063 4064 4065 4066 4067 4068
    }
}

/* 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)
{
4069 4070
    if (bdrv_iostatus_is_enabled(bs) &&
        bs->iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
4071
        assert(error >= 0);
4072 4073
        bs->iostatus = error == ENOSPC ? BLOCK_DEVICE_IO_STATUS_NOSPACE :
                                         BLOCK_DEVICE_IO_STATUS_FAILED;
4074 4075 4076
    }
}

4077 4078 4079 4080 4081 4082 4083
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
4084
    cookie->start_time_ns = get_clock();
4085 4086 4087 4088 4089 4090 4091 4092 4093 4094
    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
4095
    bs->total_time_ns[cookie->type] += get_clock() - cookie->start_time_ns;
4096 4097
}

J
Jes Sorensen 已提交
4098 4099 4100 4101 4102
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
4103
    QEMUOptionParameter *backing_fmt, *backing_file, *size;
J
Jes Sorensen 已提交
4104 4105
    BlockDriverState *bs = NULL;
    BlockDriver *drv, *proto_drv;
4106
    BlockDriver *backing_drv = NULL;
J
Jes Sorensen 已提交
4107 4108 4109 4110 4111 4112
    int ret = 0;

    /* Find driver and parse its options */
    drv = bdrv_find_format(fmt);
    if (!drv) {
        error_report("Unknown file format '%s'", fmt);
4113
        ret = -EINVAL;
J
Jes Sorensen 已提交
4114 4115 4116 4117 4118 4119
        goto out;
    }

    proto_drv = bdrv_find_protocol(filename);
    if (!proto_drv) {
        error_report("Unknown protocol '%s'", filename);
4120
        ret = -EINVAL;
J
Jes Sorensen 已提交
4121 4122 4123 4124 4125 4126 4127 4128 4129 4130 4131 4132 4133 4134 4135 4136 4137 4138
        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);
4139
            ret = -EINVAL;
J
Jes Sorensen 已提交
4140 4141 4142 4143 4144 4145 4146 4147 4148
            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);
4149
            ret = -EINVAL;
J
Jes Sorensen 已提交
4150 4151 4152 4153 4154 4155 4156 4157
            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);
4158
            ret = -EINVAL;
J
Jes Sorensen 已提交
4159 4160 4161 4162
            goto out;
        }
    }

4163 4164 4165 4166 4167
    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");
4168
            ret = -EINVAL;
4169 4170 4171 4172
            goto out;
        }
    }

J
Jes Sorensen 已提交
4173 4174
    backing_fmt = get_option_parameter(param, BLOCK_OPT_BACKING_FMT);
    if (backing_fmt && backing_fmt->value.s) {
4175 4176
        backing_drv = bdrv_find_format(backing_fmt->value.s);
        if (!backing_drv) {
J
Jes Sorensen 已提交
4177 4178
            error_report("Unknown backing file format '%s'",
                         backing_fmt->value.s);
4179
            ret = -EINVAL;
J
Jes Sorensen 已提交
4180 4181 4182 4183 4184 4185
            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
4186 4187
    size = get_option_parameter(param, BLOCK_OPT_SIZE);
    if (size && size->value.n == -1) {
J
Jes Sorensen 已提交
4188 4189 4190
        if (backing_file && backing_file->value.s) {
            uint64_t size;
            char buf[32];
4191 4192 4193 4194 4195
            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
4196 4197 4198

            bs = bdrv_new("");

4199
            ret = bdrv_open(bs, backing_file->value.s, back_flags, backing_drv);
J
Jes Sorensen 已提交
4200
            if (ret < 0) {
4201
                error_report("Could not open '%s'", backing_file->value.s);
J
Jes Sorensen 已提交
4202 4203 4204 4205 4206 4207 4208 4209 4210
                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");
4211
            ret = -EINVAL;
J
Jes Sorensen 已提交
4212 4213 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
            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);
    }
4242 4243

    return ret;
J
Jes Sorensen 已提交
4244
}
4245 4246

void *block_job_create(const BlockJobType *job_type, BlockDriverState *bs,
4247 4248
                       int64_t speed, BlockDriverCompletionFunc *cb,
                       void *opaque, Error **errp)
4249 4250 4251 4252
{
    BlockJob *job;

    if (bs->job || bdrv_in_use(bs)) {
4253
        error_set(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs));
4254 4255 4256 4257 4258 4259 4260 4261 4262
        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
4263
    job->busy          = true;
4264
    bs->job = job;
4265 4266 4267 4268 4269 4270 4271 4272 4273 4274 4275 4276 4277 4278

    /* 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;
        }
    }
4279 4280 4281 4282 4283 4284 4285 4286 4287 4288 4289 4290 4291 4292
    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);
}

4293
void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
4294
{
4295
    Error *local_err = NULL;
4296

4297
    if (!job->job_type->set_speed) {
4298 4299
        error_set(errp, QERR_NOT_SUPPORTED);
        return;
4300
    }
4301
    job->job_type->set_speed(job, speed, &local_err);
4302 4303 4304
    if (error_is_set(&local_err)) {
        error_propagate(errp, local_err);
        return;
4305
    }
4306

4307
    job->speed = speed;
4308 4309 4310 4311 4312
}

void block_job_cancel(BlockJob *job)
{
    job->cancelled = true;
4313 4314 4315
    if (job->co && !job->busy) {
        qemu_coroutine_enter(job->co, NULL);
    }
4316 4317 4318 4319 4320 4321
}

bool block_job_is_cancelled(BlockJob *job)
{
    return job->cancelled;
}
4322

4323 4324 4325 4326 4327 4328 4329 4330 4331
struct BlockCancelData {
    BlockJob *job;
    BlockDriverCompletionFunc *cb;
    void *opaque;
    bool cancelled;
    int ret;
};

static void block_job_cancel_cb(void *opaque, int ret)
4332
{
4333 4334 4335 4336 4337 4338 4339 4340 4341 4342
    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;
4343 4344 4345
    BlockDriverState *bs = job->bs;

    assert(bs->job == job);
4346 4347 4348 4349 4350 4351 4352 4353 4354 4355

    /* 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;
4356
    block_job_cancel(job);
4357
    while (data.ret == -EINPROGRESS) {
4358 4359
        qemu_aio_wait();
    }
4360
    return (data.cancelled && data.ret == 0) ? -ECANCELED : data.ret;
4361
}
P
Paolo Bonzini 已提交
4362 4363 4364 4365 4366 4367 4368 4369 4370 4371

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;
    }
}