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: + if (bs->is_temporary) + unlink(filename); + return ret; } void bdrv_close(BlockDriverState *bs)