Report pool suspended due to MMP

When the pool is suspended, record whether it was due to an I/O error or
due to MMP writes failing to succeed within the required time.

Change spa_suspended from uint8_t to zio_suspend_reason_t to store the
reason.

When userspace queries pool status via spa_tryimport(), report the
reason the pool was suspended in a new key,
ZPOOL_CONFIG_SUSPENDED_REASON.

In libzfs, when interpreting the returned config nvlist, report
suspension due to MMP with a new pool status enum value,
ZPOOL_STATUS_IO_FAILURE_MMP.

In status_callback(), which generates and emits the message when 'zpool
status' is executed, add a case to print an appropriate message for the
new pool status enum value.

Reviewed-by: George Melikov <[email protected]>
Reviewed-by: Giuseppe Di Natale <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Reviewed-by: Tony Hutter <[email protected]>
Signed-off-by: Olaf Faaland <[email protected]>
Closes #7296

1 files changed, 9 insertions, 0 deletions

diff --git a/cmd/zpool/zpool_main.c b/cmd/zpool/zpool_main.c
index 1cfff3ade..b07569389 100644
--- a/cmd/zpool/zpool_main.c
+++ b/cmd/zpool/zpool_main.c
@@ -6395,6 +6395,15 @@ status_callback(zpool_handle_t *zhp, void *data)
 		    "to be recovered.\n"));
 		break;
 
+	case ZPOOL_STATUS_IO_FAILURE_MMP:
+		(void) printf(gettext("status: The pool is suspended because "
+		    "multihost writes failed or were delayed;\n\tanother "
+		    "system could import the pool undetected.\n"));
+		(void) printf(gettext("action: Make sure the pool's devices "
+		    "are connected, then reboot your system and\n\timport the "
+		    "pool.\n"));
+		break;
+
 	case ZPOOL_STATUS_IO_FAILURE_WAIT:
 	case ZPOOL_STATUS_IO_FAILURE_CONTINUE:
 		(void) printf(gettext("status: One or more devices are "