block: Add error codes for common PR failures

If a PR operation fails we can return a device-specific error which is
impossible to handle in some cases because we could have a mix of devices
when DM is used, or future users like LIO only knows it's interacting with
a block device so it doesn't know the type.

This patch adds a new pr_status enum so drivers can convert errors to a
common type which can be handled by the caller.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20221122032603.32766-2-michael.christie@oracle.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/include/uapi/linux/pr.h b/include/uapi/linux/pr.h
index ccc78cb..d812641 100644 (file)
--- a/include/uapi/linux/pr.h
+++ b/include/uapi/linux/pr.h
@@ -4,6 +4,23 @@
 
 #include <linux/types.h>
 
+enum pr_status {
+       PR_STS_SUCCESS                  = 0x0,
+       /*
+        * The following error codes are based on SCSI, because the interface
+        * was originally created for it and has existing users.
+        */
+       /* Generic device failure. */
+       PR_STS_IOERR                    = 0x2,
+       PR_STS_RESERVATION_CONFLICT     = 0x18,
+       /* Temporary path failure that can be retried. */
+       PR_STS_RETRY_PATH_FAILURE       = 0xe0000,
+       /* The request was failed due to a fast failure timer. */
+       PR_STS_PATH_FAST_FAILED         = 0xf0000,
+       /* The path cannot be reached and has been marked as failed. */
+       PR_STS_PATH_FAILED              = 0x10000,
+};
+
 enum pr_type {
        PR_WRITE_EXCLUSIVE              = 1,
        PR_EXCLUSIVE_ACCESS             = 2,