block: Request real permissions in blk_new_open()

We can figure out the necessary permissions from the flags that the
caller passed.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
This commit is contained in:
Kevin Wolf 2017-01-13 19:13:00 +01:00
parent 55880601d8
commit c62d32f503

View File

@ -166,17 +166,33 @@ BlockBackend *blk_new_open(const char *filename, const char *reference,
{
BlockBackend *blk;
BlockDriverState *bs;
uint64_t perm;
blk = blk_new(0, BLK_PERM_ALL);
/* blk_new_open() is mainly used in .bdrv_create implementations and the
* tools where sharing isn't a concern because the BDS stays private, so we
* just request permission according to the flags.
*
* The exceptions are xen_disk and blockdev_init(); in these cases, the
* caller of blk_new_open() doesn't make use of the permissions, but they
* shouldn't hurt either. We can still share everything here because the
* guest devices will add their own blockers if they can't share. */
perm = BLK_PERM_CONSISTENT_READ;
if (flags & BDRV_O_RDWR) {
perm |= BLK_PERM_WRITE;
}
if (flags & BDRV_O_RESIZE) {
perm |= BLK_PERM_RESIZE;
}
blk = blk_new(perm, BLK_PERM_ALL);
bs = bdrv_open(filename, reference, options, flags, errp);
if (!bs) {
blk_unref(blk);
return NULL;
}
/* FIXME Use real permissions */
blk->root = bdrv_root_attach_child(bs, "root", &child_root,
0, BLK_PERM_ALL, blk, &error_abort);
perm, BLK_PERM_ALL, blk, &error_abort);
return blk;
}