ndctl/namespace: Suppress -ENXIO when processing all namespaces.

BZ: 
Brew: 

commit 07011a334fd1e4b641cdbfaf5de7500f7bdc941d
Author: Michal Suchanek <msuchanek@suse.de>
Date:   Wed Jan 6 14:17:41 2021 +0100

    ndctl/namespace: Suppress -ENXIO when processing all namespaces.
    
    When processing all namespaces and no namespaces exist user gets the
    default -ENXIO. Set default rc to 0 when processing all namespaces.
    This avoids confusing error message printed in addition to the message
    saying 0 namespaces were affected.
    
    Before:
    
     # ndctl check-namespace all
    namespace0.0: namespace_check: namespace0.0: check aborted, namespace online
    error checking namespaces: Device or resource busy
    checked 0 namespaces
     # ndctl disable-namespace all
    disabled 1 namespace
     # ndctl check-namespace all
    namespace0.0: namespace_check: Unable to recover any BTT info blocks
    error checking namespaces: No such device or address
    checked 0 namespaces
     # ndctl destroy-namespace all
    destroyed 1 namespace
     # ndctl check-namespace all
    error checking namespaces: No such device or address
    checked 0 namespaces
     # ndctl destroy-namespace all
    error destroying namespaces: No such device or address
    destroyed 0 namespaces
    
    After:
    
     # ndctl check-namespace all
    namespace0.0: namespace_check: namespace0.0: check aborted, namespace online
    error checking namespaces: Device or resource busy
    checked 0 namespaces
     # ndctl disable-namespace namespace0.0
    disabled 1 namespace
     # ndctl check-namespace all
    namespace0.0: namespace_check: Unable to recover any BTT info blocks
    error checking namespaces: No such device or address
    checked 0 namespaces
     # ndctl destroy-namespace all
    destroyed 1 namespace
     # ndctl check-namespace all
    checked 0 namespaces
     # ndctl destroy-namespace all
    destroyed 0 namespaces
     # ndctl destroy-namespace all
    destroyed 0 namespaces
    
    Note: this does change the return value from -ENXIO to 0 in the cases
    when no namespaces exist and processing all namespaces was requested.
    
    Link: https://patchwork.kernel.org/patch/11681431/
    Link: https://lore.kernel.org/r/32c8cd8d2716f5e52aebea4e4d303eeb4e0550f9.1609938610.git.msuchanek@suse.de
    Reviewed-by: Santosh S <santosh@fossix.org>
    Signed-off-by: Michal Suchanek <msuchanek@suse.de>
    Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>

diff --git a/ndctl/namespace.c b/ndctl/namespace.c
index 5e65ed5..cd822b3 100644
--- a/ndctl/namespace.c
+++ b/ndctl/namespace.c
@@ -2151,6 +2151,9 @@ static int do_xaction_namespace(const char *namespace,
 	if (!namespace && action != ACTION_CREATE)
 		return rc;
 
+	if (namespace && (strcmp(namespace, "all") == 0))
+		rc = 0;
+
 	if (verbose)
 		ndctl_set_log_priority(ctx, LOG_DEBUG);