block: Use BlockBackend for image probing

This fixes the use of a parent-less BdrvChild in bdrv_open_inherit() by
converting it into a BlockBackend. Which is exactly what it should be,
image probing is an external, standalone user of a node. The requests
can't be considered to originate from the format driver node because
that one isn't even opened yet.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Kevin Wolf 2017-02-17 18:39:24 +01:00
parent 2d6b86af14
commit 5696c6e350

36
block.c
View file

@ -588,21 +588,20 @@ BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
return drv;
}
static int find_image_format(BdrvChild *file, const char *filename,
static int find_image_format(BlockBackend *file, const char *filename,
BlockDriver **pdrv, Error **errp)
{
BlockDriverState *bs = file->bs;
BlockDriver *drv;
uint8_t buf[BLOCK_PROBE_BUF_SIZE];
int ret = 0;
/* Return the raw BlockDriver * to scsi-generic devices or empty drives */
if (bdrv_is_sg(bs) || !bdrv_is_inserted(bs) || bdrv_getlength(bs) == 0) {
if (blk_is_sg(file) || !blk_is_inserted(file) || blk_getlength(file) == 0) {
*pdrv = &bdrv_raw;
return ret;
}
ret = bdrv_pread(file, 0, buf, sizeof(buf));
ret = blk_pread(file, 0, buf, sizeof(buf));
if (ret < 0) {
error_setg_errno(errp, -ret, "Could not read image for determining its "
"format");
@ -974,7 +973,7 @@ QemuOptsList bdrv_runtime_opts = {
*
* Removes all processed options from *options.
*/
static int bdrv_open_common(BlockDriverState *bs, BdrvChild *file,
static int bdrv_open_common(BlockDriverState *bs, BlockBackend *file,
QDict *options, Error **errp)
{
int ret, open_flags;
@ -1005,7 +1004,7 @@ static int bdrv_open_common(BlockDriverState *bs, BdrvChild *file,
assert(drv != NULL);
if (file != NULL) {
filename = file->bs->filename;
filename = blk_bs(file)->filename;
} else {
filename = qdict_get_try_str(options, "filename");
}
@ -1707,7 +1706,7 @@ static BlockDriverState *bdrv_open_inherit(const char *filename,
Error **errp)
{
int ret;
BdrvChild *file = NULL;
BlockBackend *file = NULL;
BlockDriverState *bs;
BlockDriver *drv = NULL;
const char *drvname;
@ -1805,19 +1804,24 @@ static BlockDriverState *bdrv_open_inherit(const char *filename,
qdict_del(options, "backing");
}
/* Open image file without format layer. This BdrvChild is only used for
/* Open image file without format layer. This BlockBackend is only used for
* probing, the block drivers will do their own bdrv_open_child() for the
* same BDS, which is why we put the node name back into options. */
if ((flags & BDRV_O_PROTOCOL) == 0) {
/* FIXME Shouldn't attach a child to a node that isn't opened yet. */
file = bdrv_open_child(filename, options, "file", bs,
&child_file, true, &local_err);
BlockDriverState *file_bs;
file_bs = bdrv_open_child_bs(filename, options, "file", bs,
&child_file, true, &local_err);
if (local_err) {
goto fail;
}
if (file != NULL) {
if (file_bs != NULL) {
file = blk_new();
blk_insert_bs(file, file_bs);
bdrv_unref(file_bs);
qdict_put(options, "file",
qstring_from_str(bdrv_get_node_name(file->bs)));
qstring_from_str(bdrv_get_node_name(file_bs)));
}
}
@ -1859,7 +1863,7 @@ static BlockDriverState *bdrv_open_inherit(const char *filename,
}
if (file) {
bdrv_unref_child(bs, file);
blk_unref(file);
file = NULL;
}
@ -1921,9 +1925,7 @@ static BlockDriverState *bdrv_open_inherit(const char *filename,
return bs;
fail:
if (file != NULL) {
bdrv_unref_child(bs, file);
}
blk_unref(file);
if (bs->file != NULL) {
bdrv_unref_child(bs, bs->file);
}