Commit ddf5636d authored by Max Reitz's avatar Max Reitz Committed by Kevin Wolf
Browse files

block: Add reference parameter to bdrv_open() 



Allow bdrv_open() to handle references to existing block devices just as
bdrv_file_open() is already capable of.

Signed-off-by: default avatarMax Reitz <mreitz@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent f67503e5

block.c

+37 −7
Original line number Diff line number Diff line
@@ -1046,7 +1046,7 @@ int bdrv_file_open(BlockDriverState **pbs, const char *filename, 
    }



    if (!drv->bdrv_file_open) {

        ret = bdrv_open(&bs, filename, options, flags, drv, &local_err);

        ret = bdrv_open(&bs, filename, NULL, options, flags, drv, &local_err);

        options = NULL;

    } else {

        ret = bdrv_open_common(bs, NULL, options, flags, drv, &local_err);
@@ -1125,7 +1125,7 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp) 


    assert(bs->backing_hd == NULL);

    ret = bdrv_open(&bs->backing_hd,

                    *backing_filename ? backing_filename : NULL, options,

                    *backing_filename ? backing_filename : NULL, NULL, options,

                    back_flags, back_drv, &local_err);

    if (ret < 0) {

        bs->backing_hd = NULL;
@@ -1206,7 +1206,7 @@ int bdrv_open_image(BlockDriverState **pbs, const char *filename, 
            goto done;

        }



        ret = bdrv_open(pbs, filename, image_options, flags, NULL, errp);

        ret = bdrv_open(pbs, filename, NULL, image_options, flags, NULL, errp);

    } else {

        ret = bdrv_file_open(pbs, filename, reference, image_options, flags,

                             errp);
@@ -1227,9 +1227,14 @@ done: 
 *

 * If *pbs is NULL, a new BDS will be created with a pointer to it stored there.

 * If it is not NULL, the referenced BDS will be reused.

 *

 * The reference parameter may be used to specify an existing block device which

 * should be opened. If specified, neither options nor a filename may be given,

 * nor can an existing BDS be reused (that is, *pbs has to be NULL).

 */

int bdrv_open(BlockDriverState **pbs, const char *filename, QDict *options,

              int flags, BlockDriver *drv, Error **errp)

int bdrv_open(BlockDriverState **pbs, const char *filename,

              const char *reference, QDict *options, int flags,

              BlockDriver *drv, Error **errp)

{

    int ret;

    /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */
@@ -1240,6 +1245,31 @@ int bdrv_open(BlockDriverState **pbs, const char *filename, QDict *options, 


    assert(pbs);



    if (reference) {

        bool options_non_empty = options ? qdict_size(options) : false;

        QDECREF(options);



        if (*pbs) {

            error_setg(errp, "Cannot reuse an existing BDS when referencing "

                       "another block device");

            return -EINVAL;

        }



        if (filename || options_non_empty) {

            error_setg(errp, "Cannot reference an existing block device with "

                       "additional options or a new filename");

            return -EINVAL;

        }



        bs = bdrv_lookup_bs(reference, reference, errp);

        if (!bs) {

            return -ENODEV;

        }

        bdrv_ref(bs);

        *pbs = bs;

        return 0;

    }



    if (*pbs) {

        bs = *pbs;

    } else {
@@ -1268,7 +1298,7 @@ int bdrv_open(BlockDriverState **pbs, const char *filename, QDict *options, 
        /* Get the required size from the image */

        QINCREF(options);

        bs1 = NULL;

        ret = bdrv_open(&bs1, filename, options, BDRV_O_NO_BACKING,

        ret = bdrv_open(&bs1, filename, NULL, options, BDRV_O_NO_BACKING,

                        drv, &local_err);

        if (ret < 0) {

            goto fail;
@@ -5309,7 +5339,7 @@ void bdrv_img_create(const char *filename, const char *fmt, 
                flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);



            bs = NULL;

            ret = bdrv_open(&bs, backing_file->value.s, NULL, back_flags,

            ret = bdrv_open(&bs, backing_file->value.s, NULL, NULL, back_flags,

                            backing_drv, &local_err);

            if (ret < 0) {

                error_setg_errno(errp, -ret, "Could not open '%s': %s",

block/qcow2.c

+2 −2
Original line number Diff line number Diff line
@@ -1553,7 +1553,7 @@ static int qcow2_create2(const char *filename, int64_t total_size, 
     */

    BlockDriver* drv = bdrv_find_format("qcow2");

    assert(drv != NULL);

    ret = bdrv_open(&bs, filename, NULL,

    ret = bdrv_open(&bs, filename, NULL, NULL,

        BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH, drv, &local_err);

    if (ret < 0) {

        error_propagate(errp, local_err);
@@ -1604,7 +1604,7 @@ static int qcow2_create2(const char *filename, int64_t total_size, 
    bs = NULL;



    /* Reopen the image without BDRV_O_NO_FLUSH to flush it before returning */

    ret = bdrv_open(&bs, filename, NULL,

    ret = bdrv_open(&bs, filename, NULL, NULL,

                    BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_NO_BACKING,

                    drv, &local_err);

    if (local_err) {

block/vmdk.c

+2 −1
Original line number Diff line number Diff line
@@ -1756,7 +1756,8 @@ static int vmdk_create(const char *filename, QEMUOptionParameter *options, 
    }

    if (backing_file) {

        BlockDriverState *bs = NULL;

        ret = bdrv_open(&bs, backing_file, NULL, BDRV_O_NO_BACKING, NULL, errp);

        ret = bdrv_open(&bs, backing_file, NULL, NULL, BDRV_O_NO_BACKING, NULL,

                        errp);

        if (ret != 0) {

            goto exit;

        }

block/vvfat.c

+1 −1
Original line number Diff line number Diff line
@@ -2937,7 +2937,7 @@ static int enable_write_target(BDRVVVFATState *s) 
    }



    s->qcow = NULL;

    ret = bdrv_open(&s->qcow, s->qcow_filename, NULL,

    ret = bdrv_open(&s->qcow, s->qcow_filename, NULL, NULL,

            BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH, bdrv_qcow,

            &local_err);

    if (ret < 0) {

blockdev.c

+6 −6
Original line number Diff line number Diff line
@@ -504,7 +504,7 @@ static DriveInfo *blockdev_init(const char *file, QDict *bs_opts, 
    bdrv_flags |= ro ? 0 : BDRV_O_RDWR;



    QINCREF(bs_opts);

    ret = bdrv_open(&dinfo->bdrv, file, bs_opts, bdrv_flags, drv, &error);

    ret = bdrv_open(&dinfo->bdrv, file, NULL, bs_opts, bdrv_flags, drv, &error);



    if (ret < 0) {

        error_setg(errp, "could not open disk image %s: %s",
@@ -1333,7 +1333,7 @@ static void external_snapshot_prepare(BlkTransactionState *common, 
    /* TODO Inherit bs->options or only take explicit options with an

     * extended QMP command? */

    assert(state->new_bs == NULL);

    ret = bdrv_open(&state->new_bs, new_image_file, options,

    ret = bdrv_open(&state->new_bs, new_image_file, NULL, options,

                    flags | BDRV_O_NO_BACKING, drv, &local_err);

    /* We will manually add the backing_hd field to the bs later */

    if (ret != 0) {
@@ -1582,7 +1582,7 @@ static void qmp_bdrv_open_encrypted(BlockDriverState *bs, const char *filename, 
    Error *local_err = NULL;

    int ret;



    ret = bdrv_open(&bs, filename, NULL, bdrv_flags, drv, &local_err);

    ret = bdrv_open(&bs, filename, NULL, NULL, bdrv_flags, drv, &local_err);

    if (ret < 0) {

        error_propagate(errp, local_err);

        return;
@@ -2019,7 +2019,7 @@ void qmp_drive_backup(const char *device, const char *target, 
    }



    target_bs = NULL;

    ret = bdrv_open(&target_bs, target, NULL, flags, drv, &local_err);

    ret = bdrv_open(&target_bs, target, NULL, NULL, flags, drv, &local_err);

    if (ret < 0) {

        error_propagate(errp, local_err);

        return;
@@ -2162,8 +2162,8 @@ void qmp_drive_mirror(const char *device, const char *target, 
     * file.

     */

    target_bs = NULL;

    ret = bdrv_open(&target_bs, target, NULL, flags | BDRV_O_NO_BACKING, drv,

                    &local_err);

    ret = bdrv_open(&target_bs, target, NULL, NULL, flags | BDRV_O_NO_BACKING,

                    drv, &local_err);

    if (ret < 0) {

        error_propagate(errp, local_err);

        return;