nvme: add NVME_SC_CANCELLED

To properly document how we are using a negative Linux error value to
communicate request cancellations inside the driver.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index b75d41e..88950f3 100644 (file)
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -19,6 +19,16 @@
 #include <linux/kref.h>
 #include <linux/blk-mq.h>
 
+enum {
+       /*
+        * Driver internal status code for commands that were cancelled due
+        * to timeouts or controller shutdown.  The value is negative so
+        * that it a) doesn't overlap with the unsigned hardware error codes,
+        * and b) can easily be tested for.
+        */
+       NVME_SC_CANCELLED               = -EINTR,
+};
+
 extern unsigned char nvme_io_timeout;
 #define NVME_IO_TIMEOUT        (nvme_io_timeout * HZ)
 

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 99c5b63..e683bd1 100644 (file)
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -621,7 +621,7 @@ static void req_completion(struct nvme_queue *nvmeq, void *ctx,
 
                if (req->cmd_type == REQ_TYPE_DRV_PRIV) {
                        if (cmd_rq->ctx == CMD_CTX_CANCELLED)
-                               error = -EINTR;
+                               error = NVME_SC_CANCELLED;
                        else
                                error = status;
                } else {