Improvements for IMSM_NO_PLATFORM testing.

Factor out IMSM_NO_PLATFORM testing into a single function that caches
the result.

Allow mdmon to explicitly set the result to "1" so that we don't need
the ENV var in the unit file

Check if the kernel command line contains "mdadm.imsm.test=1" and in
that case assert NO_PLATFORM.  This simplifies testing in a virtual
machine.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jes Sorensen <jes@trained-monkey.org>

5 files changed, 55 insertions, 6 deletions

diff --git a/mdadm.8.in b/mdadm.8.in
index 6f0f6c1..b715950 100644
--- a/mdadm.8.in
+++ b/mdadm.8.in
@@ -3197,6 +3197,11 @@ environment.  This can be useful for testing or for disaster
 recovery.  You should be aware that interoperability may be
 compromised by setting this value.
 
+These change can also be suppressed by adding 
+.B mdadm.imsm.test=1
+to the kernel command line. This makes it easy to test IMSM
+code in a virtual machine that doesn't have IMSM virtual hardware.
+
 .TP
 .B MDADM_GROW_ALLOW_OLD
 If an array is stopped while it is performing a reshape and that
diff --git a/mdadm.h b/mdadm.h
index 1e51827..0d99544 100644
--- a/mdadm.h
+++ b/mdadm.h
@@ -1263,6 +1263,8 @@ extern struct superswitch super0, super1;
 extern struct superswitch super_imsm, super_ddf;
 extern struct superswitch mbr, gpt;
 
+void imsm_set_no_platform(int v);
+
 struct metadata_update {
 	int	len;
 	char	*buf;
diff --git a/mdmon.c b/mdmon.c
index 096b4d7..cef5bbc 100644
--- a/mdmon.c
+++ b/mdmon.c
@@ -318,6 +318,12 @@ int main(int argc, char *argv[])
 		{NULL, 0, NULL, 0}
 	};
 
+	/*
+	 * mdmon should never complain due to lack of a platform,
+	 * that is mdadm's job if at all.
+	 */
+	imsm_set_no_platform(1);
+
 	while ((opt = getopt_long(argc, argv, "thaF", options, NULL)) != -1) {
 		switch (opt) {
 		case 'a':
diff --git a/super-intel.c b/super-intel.c
index e155a8a..a5c86cb 100644
--- a/super-intel.c
+++ b/super-intel.c
@@ -20,6 +20,7 @@
 #define HAVE_STDINT_H 1
 #include "mdadm.h"
 #include "mdmon.h"
+#include "dlink.h"
 #include "sha1.h"
 #include "platform-intel.h"
 #include <values.h>
@@ -629,6 +630,44 @@ static const char *_sys_dev_type[] = {
 	[SYS_DEV_VMD] = "VMD"
 };
 
+static int no_platform = -1;
+
+static int check_no_platform(void)
+{
+	static const char search[] = "mdadm.imsm.test=1";
+	FILE *fp;
+
+	if (no_platform >= 0)
+		return no_platform;
+
+	if (check_env("IMSM_NO_PLATFORM")) {
+		no_platform = 1;
+		return 1;
+	}
+	fp = fopen("/proc/cmdline", "r");
+	if (fp) {
+		char *l = conf_line(fp);
+		char *w = l;
+
+		do {
+			if (strcmp(w, search) == 0)
+				no_platform = 1;
+			w = dl_next(w);
+		} while (w != l);
+		free_line(l);
+		fclose(fp);
+		if (no_platform >= 0)
+			return no_platform;
+	}
+	no_platform = 0;
+	return 0;
+}
+
+void imsm_set_no_platform(int v)
+{
+	no_platform = v;
+}
+
 const char *get_sys_dev_type(enum sys_dev_type type)
 {
 	if (type >= SYS_DEV_MAX)
@@ -2699,7 +2738,7 @@ static int detail_platform_imsm(int verbose, int enumerate_only, char *controlle
 	int result=1;
 
 	if (enumerate_only) {
-		if (check_env("IMSM_NO_PLATFORM"))
+		if (check_no_platform())
 			return 0;
 		list = find_intel_devices();
 		if (!list)
@@ -4722,7 +4761,7 @@ static int find_intel_hba_capability(int fd, struct intel_super *super, char *de
 		       devname);
 		return 1;
 	}
-	if (!is_fd_valid(fd) || check_env("IMSM_NO_PLATFORM")) {
+	if (!is_fd_valid(fd) || check_no_platform()) {
 		super->orom = NULL;
 		super->hba = NULL;
 		return 0;
@@ -10697,7 +10736,7 @@ static int imsm_get_allowed_degradation(int level, int raid_disks,
  ******************************************************************************/
 int validate_container_imsm(struct mdinfo *info)
 {
-	if (check_env("IMSM_NO_PLATFORM"))
+	if (check_no_platform())
 		return 0;
 
 	struct sys_dev *idev;
diff --git a/systemd/mdmon@.service b/systemd/mdmon@.service
index 23a375f..020cc7e 100644
--- a/systemd/mdmon@.service
+++ b/systemd/mdmon@.service
@@ -15,9 +15,6 @@ Documentation=man:mdmon(8)
 IgnoreOnIsolate=true
 
 [Service]
-# mdmon should never complain due to lack of a platform,
-# that is mdadm's job if at all.
-Environment=IMSM_NO_PLATFORM=1
 # The mdmon starting in the initramfs (with dracut at least)
 # cannot see sysfs after root is mounted, so we will have to
 # 'takeover'.  As the '--offroot --takeover' don't hurt when