NVMe: Detect commands that are completed twice

Set the context value to CMD_CTX_COMPLETED, and print a message in the
sync_completion handler if we see it.

Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>

diff --git a/drivers/block/nvme.c b/drivers/block/nvme.c
index 802d763d9d06f10add16499e8ca02c607b91dfae..2dd09e7e142d69bd785b42a6984157343f94a6a5 100644 (file)
--- a/drivers/block/nvme.c
+++ b/drivers/block/nvme.c
@@ -169,12 +169,15 @@ enum {
 
 #define CMD_CTX_BASE           (POISON_POINTER_DELTA + sync_completion_id)
 #define CMD_CTX_CANCELLED      (0x2008 + CMD_CTX_BASE)
+#define CMD_CTX_COMPLETED      (0x2010 + CMD_CTX_BASE)
 
 static unsigned long free_cmdid(struct nvme_queue *nvmeq, int cmdid)
 {
        unsigned long data;
+       unsigned offset = cmdid + BITS_TO_LONGS(nvmeq->q_depth);
 
-       data = nvmeq->cmdid_data[cmdid + BITS_TO_LONGS(nvmeq->q_depth)];
+       data = nvmeq->cmdid_data[offset];
+       nvmeq->cmdid_data[offset] = CMD_CTX_COMPLETED;
        clear_bit(cmdid, nvmeq->cmdid_data);
        wake_up(&nvmeq->sq_full);
        return data;
@@ -182,8 +185,8 @@ static unsigned long free_cmdid(struct nvme_queue *nvmeq, int cmdid)
 
 static void cancel_cmdid_data(struct nvme_queue *nvmeq, int cmdid)
 {
-       nvmeq->cmdid_data[cmdid + BITS_TO_LONGS(nvmeq->q_depth)] =
-                                                       CMD_CTX_CANCELLED;
+       unsigned offset = cmdid + BITS_TO_LONGS(nvmeq->q_depth);
+       nvmeq->cmdid_data[offset] = CMD_CTX_CANCELLED;
 }
 
 static struct nvme_queue *get_nvmeq(struct nvme_ns *ns)
@@ -402,6 +405,12 @@ static void sync_completion(struct nvme_queue *nvmeq, void *ctx,
        struct sync_cmd_info *cmdinfo = ctx;
        if ((unsigned long)cmdinfo == CMD_CTX_CANCELLED)
                return;
+       if (unlikely((unsigned long)cmdinfo == CMD_CTX_COMPLETED)) {
+               dev_warn(nvmeq->q_dmadev,
+                               "completed id %d twice on queue %d\n",
+                               cqe->command_id, le16_to_cpup(&cqe->sq_id));
+               return;
+       }
        cmdinfo->result = le32_to_cpup(&cqe->result);
        cmdinfo->status = le16_to_cpup(&cqe->status) >> 1;
        wake_up_process(cmdinfo->task);