Am 11.01.2010 18:51, schrieb Christoph Hellwig:
> Check the whitelist as early as possible instead of continuing the
> setup, and move all the error handling code to the end of the
> function.
>
> Signed-off-by: Christoph Hellwig <h...@lst.de>
>
> Index: qemu/block.c
> ===================================================================
> --- qemu.orig/block.c 2010-01-11 17:48:27.811004054 +0100
> +++ qemu/block.c 2010-01-11 17:52:15.578006158 +0100
> @@ -428,10 +428,16 @@ int bdrv_open2(BlockDriverState *bs, con
> drv = find_image_format(filename);
> }
> }
> +
> if (!drv) {
> ret = -ENOENT;
> goto unlink_and_fail;
> }
> + if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv)) {
> + ret = -ENOTSUP;
> + goto unlink_and_fail;
> + }
> +
> bs->drv = drv;
> bs->opaque = qemu_mallocz(drv->instance_size);
>
> @@ -452,23 +458,17 @@ int bdrv_open2(BlockDriverState *bs, con
> (flags & (BDRV_O_CACHE_MASK|BDRV_O_NATIVE_AIO));
> else
> open_flags = flags & ~(BDRV_O_FILE | BDRV_O_SNAPSHOT);
> - if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv))
> - ret = -ENOTSUP;
> - else
> - ret = drv->bdrv_open(bs, filename, open_flags);
> +
> + ret = drv->bdrv_open(bs, filename, open_flags);
> if ((ret == -EACCES || ret == -EPERM) && !(flags & BDRV_O_FILE)) {
> ret = drv->bdrv_open(bs, filename, open_flags & ~BDRV_O_RDWR);
> bs->read_only = 1;
> }
> +
> if (ret < 0) {
> - qemu_free(bs->opaque);
> - bs->opaque = NULL;
> - bs->drv = NULL;
> - unlink_and_fail:
> - if (bs->is_temporary)
> - unlink(filename);
> - return ret;
> + goto free_and_fail;
> }
> +
> if (drv->bdrv_getlength) {
> bs->total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
> }
> @@ -502,6 +502,15 @@ int bdrv_open2(BlockDriverState *bs, con
> bs->change_cb(bs->change_opaque);
> }
> return 0;
> +
> +free_and_fail:
> + qemu_free(bs->opaque);
> + bs->opaque = NULL;
> + bs->drv = NULL;
> +unlink_and_fail:
To keep the behaviour as previously you'd need to set at least bs->drv
in the unlink_and_fail case, too. I have no clue why it's important to
set it to NULL when bs isn't going to be used anyway (probably it is,
but I don't know where), but Fabrice committed this in 6b21b973 as a
fix. Unfortunately, the commit message looks like most of Fabrice's
commit messages, so it's of no use for me...
Kevin
