[dm-devel] preventing block I/O to EMC CLARiiON LUNZ paths

[egoggin at emc.com]

Christophe,

This patch simply reports a PATH_DOWN status for paths to an EMC CLARiiON
LUNZ (or an unbound) block device since these paths cannot possibly be used
to issue I/O to such a device.  In fact, allowing block I/O to a LUNZ
dm-multipath device will cause the process to hang until the no_path_retry
timeout is incurred.  This is not desirable.

Thanks,

Ed


diff --git a/libcheckers/emc_clariion.c b/libcheckers/emc_clariion.c
index 462117b..a883e3d 100644
--- a/libcheckers/emc_clariion.c
+++ b/libcheckers/emc_clariion.c
@@ -89,14 +89,11 @@ int emc_clariion(struct checker * c)
 		return PATH_SHAKY;
 	}
 
-#if 0
-	/* This is not actually an error as the failover to this group
-	 * _would_ bind the path */
-	if ( /* LUN should at least be bound somewhere */
-		sense_buffer[4] != 0x00) {
-		return PATH_UP;
+	if ( /* LUN should at least be bound somewhere and not be LUNZ */
+		sense_buffer[4] == 0x00) {
+		MSG(c, "emc_clariion_checker: Logical Unit is unbound or
LUNZ");
+		return PATH_DOWN;
 	}
-#endif	
 	
 	/*
 	 * store the LUN WWN there and compare that it indeed did not