rbd: ignore zero-length requests
The old request code simply ignored zero-length requests. We should
still operate that same way to avoid any changes in behavior. We
can implement handling for special zero-length requests separately
(see http://tracker.ceph.com/issues/4236).
Add some assertions based on this new constraint.
This resolves:
http://tracker.ceph.com/issues/4237
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index b0eea3e..3cc003b 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -1560,6 +1560,7 @@
image_offset = img_request->offset;
rbd_assert(image_offset == bio_list->bi_sector << SECTOR_SHIFT);
resid = img_request->length;
+ rbd_assert(resid > 0);
while (resid) {
const char *object_name;
unsigned int clone_size;
@@ -1627,8 +1628,10 @@
bool more = true;
img_request = obj_request->img_request;
+
rbd_assert(img_request != NULL);
rbd_assert(img_request->rq != NULL);
+ rbd_assert(img_request->obj_request_count > 0);
rbd_assert(which != BAD_WHICH);
rbd_assert(which < img_request->obj_request_count);
rbd_assert(which >= img_request->next_completion);
@@ -1918,6 +1921,19 @@
/* Ignore any non-FS requests that filter through. */
if (rq->cmd_type != REQ_TYPE_FS) {
+ dout("%s: non-fs request type %d\n", __func__,
+ (int) rq->cmd_type);
+ __blk_end_request_all(rq, 0);
+ continue;
+ }
+
+ /* Ignore/skip any zero-length requests */
+
+ offset = (u64) blk_rq_pos(rq) << SECTOR_SHIFT;
+ length = (u64) blk_rq_bytes(rq);
+
+ if (!length) {
+ dout("%s: zero-length request\n", __func__);
__blk_end_request_all(rq, 0);
continue;
}
@@ -1947,9 +1963,6 @@
goto end_request;
}
- offset = (u64) blk_rq_pos(rq) << SECTOR_SHIFT;
- length = (u64) blk_rq_bytes(rq);
-
result = -EINVAL;
if (WARN_ON(offset && length > U64_MAX - offset + 1))
goto end_request; /* Shouldn't happen */