nvme: Return BLK_STS_TARGET if the DNR bit is set

[Mike Snitzer]

BZ: 1948690
Upstream Status: RHEL-only

Signed-off-by: Mike Snitzer <snitzer at redhat.com>

rhel-8.git commit ef4ab90c12db5e0e50800ec323736b95be7a6ff5
Author: Mike Snitzer <snitzer at redhat.com>
Date:   Tue Aug 25 21:52:45 2020 -0400

    [nvme] nvme: Return BLK_STS_TARGET if the DNR bit is set
    
    Message-id: <20200825215248.2291-8-snitzer at redhat.com>
    Patchwork-id: 325178
    Patchwork-instance: patchwork
    O-Subject: [RHEL8.3 PATCH 07/10] nvme: Return BLK_STS_TARGET if the DNR bit is set
    Bugzilla: 1843515
    RH-Acked-by: David Milburn <dmilburn at redhat.com>
    RH-Acked-by: Gopal Tiwari <gtiwari at redhat.com>
    RH-Acked-by: Ewan Milne <emilne at redhat.com>
    
    BZ: 1843515
    Upstream Status: RHEL-only
    
    If the DNR bit is set we should not retry the command, even if
    the standard status evaluation indicates so.
    
    SUSE is carrying this patch in their kernel:
    https://lwn.net/Articles/800370/
    
    Based on patch posted for upstream inclusion but rejected:
    v1: https://lore.kernel.org/linux-nvme/20190806111036.113233-1-hare@suse.de/
    v2: https://lore.kernel.org/linux-nvme/20190807071208.101882-1-hare@suse.de/
    v2-keith: https://lore.kernel.org/linux-nvme/20190807144725.GB25621@localhost.localdomain/
    v3: https://lore.kernel.org/linux-nvme/20190812075147.79598-1-hare@suse.de/
    v3-keith: https://lore.kernel.org/linux-nvme/20190813141510.GB32686@localhost.localdomain/
    
    This commit's change is basically "v3-keith".
    
    Signed-off-by: Mike Snitzer <snitzer at redhat.com>
    Signed-off-by: Frantisek Hrbata <fhrbata at redhat.com>

---
 drivers/nvme/host/core.c |    3 +++
 1 file changed, 3 insertions(+)

Index: linux-rhel9/drivers/nvme/host/core.c
===================================================================
--- linux-rhel9.orig/drivers/nvme/host/core.c
+++ linux-rhel9/drivers/nvme/host/core.c
@@ -237,6 +237,9 @@ static void nvme_delete_ctrl_sync(struct
 
 static blk_status_t nvme_error_status(u16 status)
 {
+	if (unlikely(status & NVME_SC_DNR))
+		return BLK_STS_TARGET;
+
 	switch (status & 0x7ff) {
 	case NVME_SC_SUCCESS:
 		return BLK_STS_OK;