Commit 543770bd authored by Alberto Garcia's avatar Alberto Garcia Committed by Kevin Wolf
Browse files

block: Allow changing 'detect-zeroes' on reopen 



'detect-zeroes' is one of the basic BlockdevOptions available for all
drivers, but it's not handled by bdrv_reopen_prepare(), so any attempt
to change it results in an error:

   (qemu) qemu-io virtio0 "reopen -o detect-zeroes=on"
   Cannot change the option 'detect-zeroes'

Since there's no reason why we shouldn't allow changing it and the
implementation is simple let's just do it.

Signed-off-by: default avatarAlberto Garcia <berto@igalia.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 593b3071

block.c

+40 −24
Original line number Diff line number Diff line
@@ -764,6 +764,31 @@ static void bdrv_join_options(BlockDriverState *bs, QDict *options, 
    }

}



static BlockdevDetectZeroesOptions bdrv_parse_detect_zeroes(QemuOpts *opts,

                                                            int open_flags,

                                                            Error **errp)

{

    Error *local_err = NULL;

    char *value = qemu_opt_get_del(opts, "detect-zeroes");

    BlockdevDetectZeroesOptions detect_zeroes =

        qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup, value,

                        BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF, &local_err);

    g_free(value);

    if (local_err) {

        error_propagate(errp, local_err);

        return detect_zeroes;

    }



    if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&

        !(open_flags & BDRV_O_UNMAP))

    {

        error_setg(errp, "setting detect-zeroes to unmap is not allowed "

                   "without setting discard operation to unmap");

    }



    return detect_zeroes;

}



/**

 * Set open flags for a given discard mode

 *
@@ -1328,7 +1353,6 @@ static int bdrv_open_common(BlockDriverState *bs, BlockBackend *file, 
    const char *driver_name = NULL;

    const char *node_name = NULL;

    const char *discard;

    const char *detect_zeroes;

    QemuOpts *opts;

    BlockDriver *drv;

    Error *local_err = NULL;
@@ -1417,31 +1441,14 @@ static int bdrv_open_common(BlockDriverState *bs, BlockBackend *file, 
        }

    }



    detect_zeroes = qemu_opt_get(opts, "detect-zeroes");

    if (detect_zeroes) {

        BlockdevDetectZeroesOptions value =

            qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup,

                            detect_zeroes,

                            BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,

                            &local_err);

    bs->detect_zeroes =

        bdrv_parse_detect_zeroes(opts, bs->open_flags, &local_err);

    if (local_err) {

        error_propagate(errp, local_err);

        ret = -EINVAL;

        goto fail_opts;

    }



        if (value == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&

            !(bs->open_flags & BDRV_O_UNMAP))

        {

            error_setg(errp, "setting detect-zeroes to unmap is not allowed "

                             "without setting discard operation to unmap");

            ret = -EINVAL;

            goto fail_opts;

        }



        bs->detect_zeroes = value;

    }



    if (filename != NULL) {

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

    } else {
@@ -3188,6 +3195,14 @@ int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue, 
        }

    }



    reopen_state->detect_zeroes =

        bdrv_parse_detect_zeroes(opts, reopen_state->flags, &local_err);

    if (local_err) {

        error_propagate(errp, local_err);

        ret = -EINVAL;

        goto error;

    }



    /* All other options (including node-name and driver) must be unchanged.

     * Put them back into the QDict, so that they are checked at the end

     * of this function. */
@@ -3338,6 +3353,7 @@ void bdrv_reopen_commit(BDRVReopenState *reopen_state) 
    bs->options            = reopen_state->options;

    bs->open_flags         = reopen_state->flags;

    bs->read_only = !(reopen_state->flags & BDRV_O_RDWR);

    bs->detect_zeroes      = reopen_state->detect_zeroes;



    /* Remove child references from bs->options and bs->explicit_options.

     * Child options were already removed in bdrv_reopen_queue_child() */

include/block/block.h

+1 −0
Original line number Diff line number Diff line
@@ -184,6 +184,7 @@ typedef QSIMPLEQ_HEAD(BlockReopenQueue, BlockReopenQueueEntry) BlockReopenQueue; 
typedef struct BDRVReopenState {

    BlockDriverState *bs;

    int flags;

    BlockdevDetectZeroesOptions detect_zeroes;

    uint64_t perm, shared_perm;

    QDict *options;

    QDict *explicit_options;