From 3ab8f4bf33d906cb1084f7b4036556bfb4bb73ec Mon Sep 17 00:00:00 2001
From: Jes Sorensen <jsorensen@fb.com>
Date: Thu, 13 Apr 2017 13:30:17 -0400
Subject: [PATCH] util: Introduce md_array_active() helper

Rather than querying md_get_array_info() to determine whether an array
is valid, do the work in md_array_active() using sysfs, and fall back
on md_get_array_info() if sysfs fails.

Signed-off-by: Jes Sorensen <jsorensen@fb.com>
---
 Query.c |  5 +++--
 mdadm.h |  1 +
 util.c  | 27 +++++++++++++++++++++++++++
 3 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/Query.c b/Query.c
index b761c470..4dec9f51 100644
--- a/Query.c
+++ b/Query.c
@@ -38,7 +38,6 @@ int Query(char *dev)
 	int level, raid_disks, spare_disks;
 	struct mdinfo info;
 	struct mdinfo *sra;
-	mdu_array_info_t array;
 	struct supertype *st = NULL;
 	unsigned long long larray_size;
 	struct stat stb;
@@ -65,6 +64,8 @@ int Query(char *dev)
 		raid_disks = sra->array.raid_disks;
 		spare_disks = sra->array.spare_disks;
 	} else {
+		mdu_array_info_t array;
+
 		if (md_get_array_info(fd, &array) < 0) {
 			ioctlerr = errno;
 		} else {
@@ -111,7 +112,7 @@ int Query(char *dev)
 			disc.number = info.disk.number;
 			activity = "undetected";
 			if (mddev && (fd = open(mddev, O_RDONLY))>=0) {
-				if (md_get_array_info(fd, &array) >= 0) {
+				if (md_array_active(fd)) {
 					if (md_get_disk_info(fd, &disc) >= 0 &&
 					    makedev((unsigned)disc.major,(unsigned)disc.minor) == stb.st_rdev)
 						activity = "active";
diff --git a/mdadm.h b/mdadm.h
index a3799733..f6e97fdb 100644
--- a/mdadm.h
+++ b/mdadm.h
@@ -1415,6 +1415,7 @@ extern int Dump_metadata(char *dev, char *dir, struct context *c,
 extern int Restore_metadata(char *dev, char *dir, struct context *c,
 			    struct supertype *st, int only);
 
+int md_array_active(int fd);
 int md_get_array_info(int fd, struct mdu_array_info_s *array);
 int md_set_array_info(int fd, struct mdu_array_info_s *array);
 int md_get_disk_info(int fd, struct mdu_disk_info_s *disk);
diff --git a/util.c b/util.c
index a695c45b..3adc675a 100644
--- a/util.c
+++ b/util.c
@@ -200,6 +200,33 @@ out:
 	return ret;
 }
 
+int md_array_active(int fd)
+{
+	struct mdinfo *sra;
+	struct mdu_array_info_s array;
+	int ret;
+
+	sra = sysfs_read(fd, NULL, GET_ARRAY_STATE);
+	if (sra) {
+		if (sra->array_state != ARRAY_CLEAR &&
+		    sra->array_state != ARRAY_INACTIVE &&
+		    sra->array_state != ARRAY_UNKNOWN_STATE)
+			ret = 0;
+		else
+			ret = -ENODEV;
+
+		free(sra);
+	} else {
+		/*
+		 * GET_ARRAY_INFO doesn't provide access to the proper state
+		 * information, so fallback to a basic check for raid_disks != 0
+		 */
+		ret = ioctl(fd, GET_ARRAY_INFO, &array);
+	}
+
+	return !ret;
+}
+
 /*
  * Get array info from the kernel. Longer term we want to deprecate the
  * ioctl and get it from sysfs.
-- 
2.39.2