Commit 0e8c08be authored by Kevin Wolf's avatar Kevin Wolf
Browse files

qcow2: Add basic data-file infrastructure 



This adds a .bdrv_open option to specify the external data file node.

Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent e9f5b6de

block/qcow2.c

+32 −2
Original line number Diff line number Diff line
@@ -1453,8 +1453,31 @@ static int coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options, 
        goto fail;

    }



    /* TODO Open external data file */

    /* Open external data file */

    s->data_file = bdrv_open_child(NULL, options, "data-file", bs, &child_file,

                                   true, &local_err);

    if (local_err) {

        error_propagate(errp, local_err);

        ret = -EINVAL;

        goto fail;

    }



    if (s->incompatible_features & QCOW2_INCOMPAT_DATA_FILE) {

        if (!s->data_file) {

            error_setg(errp, "'data-file' is required for this image");

            ret = -EINVAL;

            goto fail;

        }

    } else {

        if (s->data_file) {

            error_setg(errp, "'data-file' can only be set for images with an "

                             "external data file");

            ret = -EINVAL;

            goto fail;

        } else {

            s->data_file = bs->file;

        }

    }



    /* qcow2_read_extension may have set up the crypto context

     * if the crypt method needs a header region, some methods
@@ -1627,6 +1650,9 @@ static int coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options, 
    return ret;



 fail:

    if (has_data_file(bs)) {

        bdrv_unref_child(bs, s->data_file);

    }

    g_free(s->unknown_header_fields);

    cleanup_unknown_header_ext(bs);

    qcow2_free_snapshots(bs);
@@ -2246,6 +2272,10 @@ static void qcow2_close(BlockDriverState *bs) 
    g_free(s->image_backing_file);

    g_free(s->image_backing_format);



    if (has_data_file(bs)) {

        bdrv_unref_child(bs, s->data_file);

    }



    qcow2_refcount_close(bs);

    qcow2_free_snapshots(bs);

}

block/qcow2.h

+3 −1
Original line number Diff line number Diff line
@@ -91,6 +91,7 @@ 


#define DEFAULT_CLUSTER_SIZE 65536



#define QCOW2_OPT_DATA_FILE "data-file"

#define QCOW2_OPT_LAZY_REFCOUNTS "lazy-refcounts"

#define QCOW2_OPT_DISCARD_REQUEST "pass-discard-request"

#define QCOW2_OPT_DISCARD_SNAPSHOT "pass-discard-snapshot"
@@ -205,7 +206,8 @@ enum { 
    QCOW2_INCOMPAT_DATA_FILE        = 1 << QCOW2_INCOMPAT_DATA_FILE_BITNR,



    QCOW2_INCOMPAT_MASK             = QCOW2_INCOMPAT_DIRTY

                                    | QCOW2_INCOMPAT_CORRUPT,

                                    | QCOW2_INCOMPAT_CORRUPT

                                    | QCOW2_INCOMPAT_DATA_FILE,

};



/* Compatible feature bits */

qapi/block-core.json

+6 −1
Original line number Diff line number Diff line
@@ -3080,6 +3080,10 @@ 
#                         encrypted images, except when doing a metadata-only

#                         probe of the image. (since 2.10)

#

# @data-file:             reference to or definition of the external data file.

#                         This may only be specified for images that require an

#                         external data file. (since 4.0)

#

# Since: 2.9

##

{ 'struct': 'BlockdevOptionsQcow2',
@@ -3094,7 +3098,8 @@ 
            '*l2-cache-entry-size': 'int',

            '*refcount-cache-size': 'int',

            '*cache-clean-interval': 'int',

            '*encrypt': 'BlockdevQcow2Encryption' } }

            '*encrypt': 'BlockdevQcow2Encryption',

            '*data-file': 'BlockdevRef' } }



##

# @SshHostKeyCheckMode: