qcow2: Add basic data-file infrastructure

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

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Kevin Wolf 2019-01-29 17:13:57 +01:00
parent e9f5b6deaa
commit 0e8c08be27
3 changed files with 41 additions and 4 deletions

View file

@ -1453,8 +1453,31 @@ static int coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options,
goto fail;
}
/* TODO Open external data file */
s->data_file = bs->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);
}

View file

@ -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 */

View file

@ -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: