On 6/10/2024 4:13 PM, John Garry wrote:
+static bool nvme_valid_atomic_write(struct request *req)
+{
+ struct request_queue *q = req->q;
+ u32 boundary_bytes = queue_atomic_write_boundary_bytes(q);
+
+ if (blk_rq_bytes(req) > queue_atomic_write_unit_max_bytes(q))
+ return false;
+
+ if (boundary_bytes) {
+ u64 mask = boundary_bytes - 1, imask = ~mask;
+ u64 start = blk_rq_pos(req) << SECTOR_SHIFT;
+ u64 end = start + blk_rq_bytes(req) - 1;
+
+ /* If greater then must be crossing a boundary */
+ if (blk_rq_bytes(req) > boundary_bytes)
+ return false;
Nit: I'd cache blk_rq_bytes(req), since that is repeating and this
function is called for each atomic IO.
+
+ if ((start & imask) != (end & imask))
+ return false;
+ }
+
+ return true;
+}
+
static inline blk_status_t nvme_setup_rw(struct nvme_ns *ns,
struct request *req, struct nvme_command *cmnd,
enum nvme_opcode op)
@@ -941,6 +965,12 @@ static inline blk_status_t nvme_setup_rw(struct nvme_ns *ns,
if (req->cmd_flags & REQ_RAHEAD)
dsmgmt |= NVME_RW_DSM_FREQ_PREFETCH;
+ /*
+ * Ensure that nothing has been sent which cannot be executed
+ * atomically.
+ */
+ if (req->cmd_flags & REQ_ATOMIC && !nvme_valid_atomic_write(req))
+ return BLK_STS_INVAL;
Is this validity check specific to NVMe or should this be moved up to
block layer as it also knows the limits?