Commit 5ec18f8c authored by Max Reitz's avatar Max Reitz Committed by Kevin Wolf
Browse files

blockdev: Do not create BDS for empty drive 



Do not use "rudimentary" BDSs for empty drives any longer (for
freshly created drives).

After a follow-up patch, empty drives will generally use a NULL BDS, not
only the freshly created drives.

Signed-off-by: default avatarMax Reitz <mreitz@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 5433c24f

blockdev.c

+40 −28
Original line number Diff line number Diff line
@@ -512,16 +512,40 @@ static BlockBackend *blockdev_init(const char *file, QDict *bs_opts, 
        goto early_err;

    }



    if (snapshot) {

        /* always use cache=unsafe with snapshot */

        bdrv_flags &= ~BDRV_O_CACHE_MASK;

        bdrv_flags |= (BDRV_O_SNAPSHOT|BDRV_O_CACHE_WB|BDRV_O_NO_FLUSH);

    }



    if (copy_on_read) {

        bdrv_flags |= BDRV_O_COPY_ON_READ;

    }



    bdrv_flags |= ro ? 0 : BDRV_O_RDWR;



    /* init */

    if ((!file || !*file) && !has_driver_specific_opts) {

        blk = blk_new_with_bs(qemu_opts_id(opts), errp);

        BlockBackendRootState *blk_rs;



        blk = blk_new(qemu_opts_id(opts), errp);

        if (!blk) {

            goto early_err;

        }



        bs = blk_bs(blk);

        bs->open_flags = snapshot ? BDRV_O_SNAPSHOT : 0;

        bs->read_only = ro;

        blk_rs = blk_get_root_state(blk);

        blk_rs->open_flags    = bdrv_flags;

        blk_rs->read_only     = ro;

        blk_rs->detect_zeroes = detect_zeroes;



        if (throttle_enabled(&cfg)) {

            if (!throttling_group) {

                throttling_group = blk_name(blk);

            }

            blk_rs->throttle_group = g_strdup(throttling_group);

            blk_rs->throttle_state = throttle_group_incref(throttling_group);

            blk_rs->throttle_state->cfg = cfg;

        }



        QDECREF(bs_opts);

    } else {
@@ -529,30 +553,15 @@ static BlockBackend *blockdev_init(const char *file, QDict *bs_opts, 
            file = NULL;

        }



        if (snapshot) {

            /* always use cache=unsafe with snapshot */

            bdrv_flags &= ~BDRV_O_CACHE_MASK;

            bdrv_flags |= (BDRV_O_SNAPSHOT|BDRV_O_CACHE_WB|BDRV_O_NO_FLUSH);

        }



        if (copy_on_read) {

            bdrv_flags |= BDRV_O_COPY_ON_READ;

        }



        bdrv_flags |= ro ? 0 : BDRV_O_RDWR;



        blk = blk_new_open(qemu_opts_id(opts), file, NULL, bs_opts, bdrv_flags,

                           errp);

        if (!blk) {

            goto err_no_bs_opts;

        }

        bs = blk_bs(blk);

    }



        bs->detect_zeroes = detect_zeroes;



    blk_set_on_error(blk, on_read_error, on_write_error);



        /* disk I/O throttling */

        if (throttle_enabled(&cfg)) {

            if (!throttling_group) {
@@ -565,6 +574,9 @@ static BlockBackend *blockdev_init(const char *file, QDict *bs_opts, 
        if (bdrv_key_required(bs)) {

            autostart = 0;

        }

    }



    blk_set_on_error(blk, on_read_error, on_write_error);



err_no_bs_opts:

    qemu_opts_del(opts);