nvme: also return I/O command effects from nvme_command_effects

To be able to use the Commands Supported and Effects Log for allowing
unprivileged passtrough, it needs to be corretly reported for I/O
commands as well.  Return the I/O command effects from
nvme_command_effects, and also add a default list of effects for the
NVM command set.  For other command sets, the Commands Supported and
Effects log is required to be present already.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>

drivers/nvme/host/core.c

@@ -1074,6 +1074,18 @@ static u32 nvme_known_admin_effects(u8 opcode)
 	return 0;
 }
 
+static u32 nvme_known_nvm_effects(u8 opcode)
+{
+	switch (opcode) {
+	case nvme_cmd_write:
+	case nvme_cmd_write_zeroes:
+	case nvme_cmd_write_uncor:
+		 return NVME_CMD_EFFECTS_LBCC;
+	default:
+		return 0;
+	}
+}
+
 u32 nvme_command_effects(struct nvme_ctrl *ctrl, struct nvme_ns *ns, u8 opcode)
 {
 	u32 effects = 0;
@@ -1081,16 +1093,24 @@ u32 nvme_command_effects(struct nvme_ctrl *ctrl, struct nvme_ns *ns, u8 opcode)
 	if (ns) {
 		if (ns->head->effects)
 			effects = le32_to_cpu(ns->head->effects->iocs[opcode]);
+		if (ns->head->ids.csi == NVME_CAP_CSS_NVM)
+			effects |= nvme_known_nvm_effects(opcode);
 		if (effects & ~(NVME_CMD_EFFECTS_CSUPP | NVME_CMD_EFFECTS_LBCC))
 			dev_warn_once(ctrl->device,
-				"IO command:%02x has unhandled effects:%08x\n",
+				"IO command:%02x has unusual effects:%08x\n",
 				opcode, effects);
-		return 0;
-	}
 
+		/*
+		 * NVME_CMD_EFFECTS_CSE_MASK causes a freeze all I/O queues,
+		 * which would deadlock when done on an I/O command.  Note that
+		 * We already warn about an unusual effect above.
+		 */
+		effects &= ~NVME_CMD_EFFECTS_CSE_MASK;
+	} else {
 		if (ctrl->effects)
 			effects = le32_to_cpu(ctrl->effects->acs[opcode]);
 		effects |= nvme_known_admin_effects(opcode);
+	}
 
 	return effects;
 }