From: NeilBrown <neilb@suse.com>
Date: Thu, 22 Dec 2016 02:14:59 +0000 (+1100)
Subject: Make get_component_size() work with named array.
X-Git-Tag: mdadm-4.0~8
X-Git-Url: http://git.ipfire.org/?p=thirdparty%2Fmdadm.git;a=commitdiff_plain;h=c07566f14c89f42b5908bd36d1857d327d1bcc41

Make get_component_size() work with named array.

get_component_size() still assumes that all array are
 /sys/block/md%d or /sys/block/md_d%d
and so doesn't work with e.g. /sys/block/md_foo.

This cause "mdadm --detail" to report
   Used Dev Size : unknown
and causes problems when added spares and in other circumstances.

So change it to use stat2devnm() which does the right thing with all
types of array names.

Reported-and-tested-by: Robert LeBlanc <robert@leblancnet.us>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
---

diff --git a/sysfs.c b/sysfs.c
index 84c73485..b0657a04 100644
--- a/sysfs.c
+++ b/sysfs.c
@@ -400,14 +400,8 @@ unsigned long long get_component_size(int fd)
 	int n;
 	if (fstat(fd, &stb))
 		return 0;
-	if (major(stb.st_rdev) != (unsigned)get_mdp_major())
-		snprintf(fname, MAX_SYSFS_PATH_LEN,
-			"/sys/block/md%d/md/component_size",
-			(int)minor(stb.st_rdev));
-	else
-		snprintf(fname, MAX_SYSFS_PATH_LEN,
-			"/sys/block/md_d%d/md/component_size",
-			(int)minor(stb.st_rdev)>>MdpMinorShift);
+	snprintf(fname, MAX_SYSFS_PATH_LEN,
+		 "/sys/block/%s/md/component_size", stat2devnm(&stb));
 	fd = open(fname, O_RDONLY);
 	if (fd < 0)
 		return 0;