gwj / at91sam9263 · Files

/*
 * QEMU System Emulator block driver

 *

 * Copyright (c) 2003 Fabrice Bellard

 *

 * 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.
 */

#include "config-host.h"

#ifdef HOST_BSD

/* include native header before sys-queue.h */
#include <sys/queue.h>
#endif

#include "qemu-common.h"

#include "monitor.h"

#include "block_int.h"

#include "module.h"

#ifdef HOST_BSD

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>

#ifndef __DragonFly__

#include <sys/disk.h>
#endif

#endif

#ifdef _WIN32
#include <windows.h>
#endif

#define SECTOR_BITS 9
#define SECTOR_SIZE (1 << SECTOR_BITS)

static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,

        BlockDriverCompletionFunc *cb, void *opaque);

static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,

        BlockDriverCompletionFunc *cb, void *opaque);

static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,

                        uint8_t *buf, int nb_sectors);
static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
                         const uint8_t *buf, int nb_sectors);

BlockDriverState *bdrv_first;

static BlockDriver *first_drv;

int path_is_absolute(const char *path)

{

    const char *p;

#ifdef _WIN32
    /* specific case for names like: "\\.\d:" */
    if (*path == '/' || *path == '\\')
        return 1;
#endif

    p = strchr(path, ':');
    if (p)
        p++;
    else
        p = path;

#ifdef _WIN32
    return (*p == '/' || *p == '\\');
#else
    return (*p == '/');
#endif

}

/* 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)

{

    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;

        p1 = strrchr(base_path, '/');
#ifdef _WIN32
        {
            const char *p2;
            p2 = strrchr(base_path, '\\');
            if (!p1 || p2 > p1)
                p1 = p2;
        }
#endif

        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);

    }
}

void bdrv_register(BlockDriver *bdrv)

{

    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;

    } else if (!bdrv->bdrv_read) {

        /* add synchronous IO emulation layer */
        bdrv->bdrv_read = bdrv_read_em;
        bdrv->bdrv_write = bdrv_write_em;
    }

    bdrv->next = first_drv;
    first_drv = bdrv;
}

/* create a new block device (by default it is empty) */
BlockDriverState *bdrv_new(const char *device_name)
{
    BlockDriverState **pbs, *bs;

    bs = qemu_mallocz(sizeof(BlockDriverState));
    pstrcpy(bs->device_name, sizeof(bs->device_name), device_name);

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

    return bs;
}

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

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

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

    return drv->bdrv_create(filename, options);

}

#ifdef _WIN32

void get_tmp_filename(char *filename, int size)

{

    char temp_dir[MAX_PATH];

    GetTempPath(MAX_PATH, temp_dir);
    GetTempFileName(temp_dir, "qem", 0, filename);

}
#else

void get_tmp_filename(char *filename, int size)

{

    int fd;

    const char *tmpdir;

    /* XXX: race condition possible */

    tmpdir = getenv("TMPDIR");
    if (!tmpdir)
        tmpdir = "/tmp";
    snprintf(filename, size, "%s/vl.XXXXXX", tmpdir);

    fd = mkstemp(filename);
    close(fd);
}

#endif

#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

static BlockDriver *find_protocol(const char *filename)
{
    BlockDriver *drv1;
    char protocol[128];

    int len = strnlen(filename, 127)+1;

    const char *p;

#ifdef _WIN32

    if (is_windows_drive(filename) ||
        is_windows_drive_prefix(filename))

        return bdrv_find_format("raw");

#endif

    p = fill_token(protocol, len, filename, ':');
    if (*p != ':')

        return bdrv_find_format("raw");

    for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {

        if (drv1->protocol_name &&

            !strcmp(drv1->protocol_name, protocol))
            return drv1;
    }
    return NULL;
}

/*
 * 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;

    for (d = first_drv; d; d = d->next) {
        if (d->bdrv_probe_device) {
            score = d->bdrv_probe_device(filename);
            if (score > score_max) {
                score_max = score;
                drv = d;
            }
        }

    }

    return drv;

}

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

    drv = find_protocol(filename);

    /* no need to test disk image formats for vvfat */

    if (drv && strcmp(drv->format_name, "vvfat") == 0)

        return drv;

    ret = bdrv_file_open(&bs, filename, BDRV_O_RDONLY);
    if (ret < 0)
        return NULL;
    ret = bdrv_pread(bs, 0, buf, sizeof(buf));
    bdrv_delete(bs);
    if (ret < 0) {
        return NULL;
    }

    score_max = 0;
    for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {

        if (drv1->bdrv_probe) {
            score = drv1->bdrv_probe(buf, ret, filename);
            if (score > score_max) {
                score_max = score;
                drv = drv1;
            }

        }

    }

    return drv;
}

int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags)

{

    BlockDriverState *bs;
    int ret;

    bs = bdrv_new("");
    ret = bdrv_open2(bs, filename, flags | BDRV_O_FILE, NULL);
    if (ret < 0) {
        bdrv_delete(bs);
        return ret;

    }

    bs->growable = 1;

    *pbs = bs;
    return 0;
}

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

}

int bdrv_open2(BlockDriverState *bs, const char *filename, int flags,

               BlockDriver *drv)
{

    int ret, open_flags;

    char tmp_filename[PATH_MAX];
    char backing_filename[PATH_MAX];

    bs->read_only = 0;
    bs->is_temporary = 0;
    bs->encrypted = 0;

    bs->valid_key = 0;

    /* buffer_alignment defaulted to 512, drivers can change this value */
    bs->buffer_alignment = 512;

    if (flags & BDRV_O_SNAPSHOT) {

        BlockDriverState *bs1;
        int64_t total_size;

        int is_protocol = 0;

        BlockDriver *bdrv_qcow2;
        QEMUOptionParameter *options;

        /* if snapshot, we create a temporary backing file and open it
           instead of opening 'filename' directly */

        /* if there is a backing file, use it */
        bs1 = bdrv_new("");

        ret = bdrv_open2(bs1, filename, 0, drv);

        if (ret < 0) {

            bdrv_delete(bs1);

            return ret;

        }

        total_size = bdrv_getlength(bs1) >> SECTOR_BITS;

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

        bdrv_delete(bs1);

        get_tmp_filename(tmp_filename, sizeof(tmp_filename));

        /* Real path is meaningless for protocols */
        if (is_protocol)
            snprintf(backing_filename, sizeof(backing_filename),
                     "%s", filename);
        else
            realpath(filename, backing_filename);

        bdrv_qcow2 = bdrv_find_format("qcow2");
        options = parse_option_parameters("", bdrv_qcow2->create_options, NULL);

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

        ret = bdrv_create(bdrv_qcow2, tmp_filename, options);

        if (ret < 0) {
            return ret;

        }

        filename = tmp_filename;

        drv = bdrv_qcow2;

        bs->is_temporary = 1;
    }

    pstrcpy(bs->filename, sizeof(bs->filename), filename);

    if (flags & BDRV_O_FILE) {
        drv = find_protocol(filename);

    } else if (!drv) {

        drv = find_hdev_driver(filename);
        if (!drv) {
            drv = find_image_format(filename);
        }

    }
    if (!drv) {
        ret = -ENOENT;
        goto unlink_and_fail;

    }
    bs->drv = drv;
    bs->opaque = qemu_mallocz(drv->instance_size);

    /* Note: for compatibility, we open disk image files as RDWR, and
       RDONLY as fallback */
    if (!(flags & BDRV_O_FILE))

        open_flags = BDRV_O_RDWR | (flags & BDRV_O_CACHE_MASK);

    else
        open_flags = flags & ~(BDRV_O_FILE | BDRV_O_SNAPSHOT);

    ret = bdrv_open3(bs, filename, open_flags, drv);

    if ((ret == -EACCES || ret == -EPERM) && !(flags & BDRV_O_FILE)) {

        ret = bdrv_open3(bs, filename, open_flags & ~BDRV_O_RDWR, drv);

        bs->read_only = 1;
    }

    if (ret < 0) {
        qemu_free(bs->opaque);

        bs->opaque = NULL;
        bs->drv = NULL;

    unlink_and_fail:
        if (bs->is_temporary)
            unlink(filename);

        return ret;

    }

    if (drv->bdrv_getlength) {
        bs->total_sectors = bdrv_getlength(bs) >> SECTOR_BITS;
    }

#ifndef _WIN32

    if (bs->is_temporary) {
        unlink(filename);
    }
#endif

    if (bs->backing_file[0] != '\0') {

        /* if there is a backing file, use it */

        BlockDriver *back_drv = NULL;

        bs->backing_hd = bdrv_new("");

        path_combine(backing_filename, sizeof(backing_filename),
                     filename, bs->backing_file);

        if (bs->backing_format[0] != '\0')
            back_drv = bdrv_find_format(bs->backing_format);
        ret = bdrv_open2(bs->backing_hd, backing_filename, open_flags,
                         back_drv);

        if (ret < 0) {
            bdrv_close(bs);
            return ret;
        }

    }

    if (!bdrv_key_required(bs)) {
        /* call the change callback */
        bs->media_changed = 1;
        if (bs->change_cb)
            bs->change_cb(bs->change_opaque);
    }

    return 0;

}

int bdrv_open3(BlockDriverState *bs, const char *filename, int flags, BlockDriver *drv)
{
    char myfile[PATH_MAX];
    const char *f;

    if (!strstart(filename, "file:", &f)) {
        fill_token(myfile, PATH_MAX, filename, '\0');
        return drv->bdrv_open(bs,myfile,flags);
    }
    return drv->bdrv_open(bs,f,flags);
}

void bdrv_close(BlockDriverState *bs)
{

    if (bs->drv) {

        if (bs->backing_hd)
            bdrv_delete(bs->backing_hd);
        bs->drv->bdrv_close(bs);
        qemu_free(bs->opaque);
#ifdef _WIN32
        if (bs->is_temporary) {
            unlink(bs->filename);
        }

#endif

        bs->opaque = NULL;
        bs->drv = NULL;

        /* call the change callback */

        bs->media_changed = 1;

        if (bs->change_cb)
            bs->change_cb(bs->change_opaque);
    }
}

void bdrv_delete(BlockDriverState *bs)
{

    BlockDriverState **pbs;

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

    bdrv_close(bs);
    qemu_free(bs);

}

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

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

/* commit COW file into the raw image */
int bdrv_commit(BlockDriverState *bs)
{

    BlockDriver *drv = bs->drv;

    int64_t i, total_sectors;

    int n, j;
    unsigned char sector[512];

    if (!drv)
        return -ENOMEDIUM;

    if (bs->read_only) {

	return -EACCES;

    }

    if (!bs->backing_hd) {
	return -ENOTSUP;
    }

    total_sectors = bdrv_getlength(bs) >> SECTOR_BITS;
    for (i = 0; i < total_sectors;) {

        if (drv->bdrv_is_allocated(bs, i, 65536, &n)) {

            for(j = 0; j < n; j++) {
                if (bdrv_read(bs, i, sector, 1) != 0) {
                    return -EIO;
                }

                if (bdrv_write(bs->backing_hd, i, sector, 1) != 0) {
                    return -EIO;
                }
                i++;

	    }

	} else {
            i += n;
        }

    }

    if (drv->bdrv_make_empty)
	return drv->bdrv_make_empty(bs);

    return 0;
}

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);

    if (offset < 0)
        return -EIO;

    if ((offset > len) || (len - offset < size))

        return -EIO;

    return 0;
}

static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num,
                              int nb_sectors)
{

    return bdrv_check_byte_request(bs, sector_num * 512, nb_sectors * 512);

}

/* 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)
{

    BlockDriver *drv = bs->drv;

    if (!drv)
        return -ENOMEDIUM;

    if (bdrv_check_request(bs, sector_num, nb_sectors))
        return -EIO;

    return drv->bdrv_read(bs, sector_num, buf, nb_sectors);

}

/* Return < 0 if error. Important errors are:

  -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
*/

int bdrv_write(BlockDriverState *bs, int64_t sector_num,

               const uint8_t *buf, int nb_sectors)
{

    BlockDriver *drv = bs->drv;

    if (!bs->drv)
        return -ENOMEDIUM;

    if (bs->read_only)

        return -EACCES;

    if (bdrv_check_request(bs, sector_num, nb_sectors))
        return -EIO;

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

}

int bdrv_pread(BlockDriverState *bs, int64_t offset,
               void *buf, int count1)

{
    uint8_t tmp_buf[SECTOR_SIZE];
    int len, nb_sectors, count;
    int64_t sector_num;

    count = count1;
    /* first read to align to sector start */
    len = (SECTOR_SIZE - offset) & (SECTOR_SIZE - 1);
    if (len > count)
        len = count;
    sector_num = offset >> SECTOR_BITS;
    if (len > 0) {
        if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
            return -EIO;
        memcpy(buf, tmp_buf + (offset & (SECTOR_SIZE - 1)), len);
        count -= len;
        if (count == 0)
            return count1;
        sector_num++;
        buf += len;
    }

    /* read the sectors "in place" */
    nb_sectors = count >> SECTOR_BITS;
    if (nb_sectors > 0) {
        if (bdrv_read(bs, sector_num, buf, nb_sectors) < 0)
            return -EIO;
        sector_num += nb_sectors;
        len = nb_sectors << SECTOR_BITS;
        buf += len;
        count -= len;
    }

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