Minimal support for policy lines in config file.

From: NeilBrown <neilb@suse.de>

Just enough to allow re-add to be requested as a default.

Signed-off-by: NeilBrown <neilb@suse.de>
---
 config.c     |   30 +++++++++++++++++++++++++++++-
 mdadm.conf.5 |   21 +++++++++++++++++++++
 mdadm.h      |    1 +
 3 files changed, 51 insertions(+), 1 deletions(-)

diff --git a/config.c b/config.c
index c962afd..ca863bd 100644
--- a/config.c
+++ b/config.c
@@ -75,7 +75,7 @@ char DefaultConfFile[] = CONFFILE;
 char DefaultAltConfFile[] = CONFFILE2;
 
 enum linetype { Devices, Array, Mailaddr, Mailfrom, Program, CreateDev,
-		Homehost, AutoMode, LTEnd };
+		Homehost, AutoMode, Policy, LTEnd };
 char *keywords[] = {
 	[Devices]  = "devices",
 	[Array]    = "array",
@@ -85,6 +85,7 @@ char *keywords[] = {
 	[CreateDev]= "create",
 	[Homehost] = "homehost",
 	[AutoMode] = "auto",
+	[Policy]   = "policy",
 	[LTEnd]    = NULL
 };
 
@@ -685,6 +686,24 @@ void autoline(char *line)
 	auto_options = line;		
 }
 
+static int auto_re_add = 0;
+void policyline(char *line)
+{
+	/* This is a very minimal implementation of
+	 * 'policy' that just allows 'action=re-add' to be
+	 * specified.  It applies to all devices.
+	 */
+	char *w;
+
+	for (w = dl_next(line); w != line ; w = dl_next(w)) {
+		if (strcasecmp(w, "action=re-add") == 0)
+			auto_re_add = 1;
+		else
+			fprintf(stderr, Name ": unknown policy command '%s' ignored.\n",
+				w);
+	}
+}
+
 int loaded = 0;
 
 static char *conffile = NULL;
@@ -757,6 +776,9 @@ void load_conffile(void)
 		case AutoMode:
 			autoline(line);
 			break;
+		case Policy:
+			policyline(line);
+			break;
 		default:
 			fprintf(stderr, Name ": Unknown keyword %s\n", line);
 		}
@@ -800,6 +822,12 @@ struct createinfo *conf_get_create_info(void)
 	return &createinfo;
 }
 
+int conf_get_readd(void)
+{
+	load_conffile();
+	return auto_re_add;
+}
+
 mddev_ident_t conf_get_ident(char *dev)
 {
 	mddev_ident_t rv;
diff --git a/mdadm.conf.5 b/mdadm.conf.5
index 002e2b3..481cf02 100644
--- a/mdadm.conf.5
+++ b/mdadm.conf.5
@@ -404,6 +404,27 @@ The known metadata types are
 .BR ddf ,
 .BR imsm .
 
+.TP
+.B POLICY
+A list of policy statements to guide some the actions that
+.I mdadm
+takes automatically.
+Currently only one policy statement is recongised and, when
+given, it applies to all devices and all arrays.  That statement is
+.BR action=re-add .
+This policy affects the assembling of arrays (either by 
+.B -A
+or
+.BR -I )
+and particularly the handling of devices which appear to have
+previously failed.  The default action is to not include these devices
+in the array.  However if this policy is in force, then any devices
+which were previously members of the array but have since failed are
+re-added (as if by the 
+-B \-\-re\-add
+command) so that they return to fully active status after any
+necessary rebuilding.
+
 .SH EXAMPLE
 DEVICE /dev/sd[bcdjkl]1
 .br
diff --git a/mdadm.h b/mdadm.h
index fe20337..ac6494d 100644
--- a/mdadm.h
+++ b/mdadm.h
@@ -805,6 +805,7 @@ extern char *conf_get_mailaddr(void);
 extern char *conf_get_mailfrom(void);
 extern char *conf_get_program(void);
 extern char *conf_get_homehost(int *require_homehostp);
+extern int conf_get_readd(void);
 extern char *conf_line(FILE *file);
 extern char *conf_word(FILE *file, int allow_key);
 extern int conf_name_is_free(char *name);