rbd: do not return -ERANGE on auth failures

Trying to map an image out of a pool for which we don't have an 'x'
permission bit fails with -ERANGE from ceph_extract_encoded_string()
due to an unsigned vs signed bug.  Fix it and get rid of the -EINVAL
sink, thus propagating rbd::get_id cls method errors.  (I've seen
a bunch of unexplained -ERANGE reports, I bet this is it).

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 4b97baf8afa317347ca7ff531f2d8828394084a2..ce457db5d847969a9f11d57f41370ed9c9da8b02 100644 (file)
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -4924,7 +4924,7 @@ static int rbd_dev_image_id(struct rbd_device *rbd_dev)
                ret = image_id ? 0 : -ENOMEM;
                if (!ret)
                        rbd_dev->image_format = 1;
-       } else if (ret > sizeof (__le32)) {
+       } else if (ret >= 0) {
                void *p = response;
 
                image_id = ceph_extract_encoded_string(&p, p + ret,
@@ -4932,8 +4932,6 @@ static int rbd_dev_image_id(struct rbd_device *rbd_dev)
                ret = PTR_ERR_OR_ZERO(image_id);
                if (!ret)
                        rbd_dev->image_format = 2;
-       } else {
-               ret = -EINVAL;
        }
 
        if (!ret) {