From: NeilBrown <neilb@suse.de>
Date: Mon, 22 Nov 2010 09:58:06 +0000 (+1100)
Subject: Add must_be_container helper.
X-Git-Tag: mdadm-3.2~280
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3a3716107b614f679a4ea224e5bb882739d81cf9;p=thirdparty%2Fmdadm.git

Add must_be_container helper.

This checks a block device to see if it could be a container, and
in particular cannot be a member device.

Signed-off-by: NeilBrown <neilb@suse.de>
---

diff --git a/Examine.c b/Examine.c
index 3c1e73f9..ffca9ca5 100644
--- a/Examine.c
+++ b/Examine.c
@@ -76,11 +76,10 @@ int Examine(struct mddev_dev *devlist, int brief, int export, int scan,
 			err = 1;
 		}
 		else {
-			unsigned long long size;
 			int container = 0;
 			if (forcest)
 				st = dup_super(forcest);
-			else if (get_dev_size(fd, NULL, &size) == 0 || size == 0) {
+			else if (must_be_container(fd)) {
 				/* might be a container */
 				st = super_by_fd(fd, NULL);
 				container = 1;
diff --git a/Incremental.c b/Incremental.c
index 0df69b7d..b7bf0b4f 100644
--- a/Incremental.c
+++ b/Incremental.c
@@ -103,7 +103,6 @@ int Incremental(char *devname, int verbose, int runstop,
 	char *name_to_use;
 	mdu_array_info_t ainf;
 	struct dev_policy *policy = NULL;
-	unsigned long long size;
 
 	struct createinfo *ci = conf_get_create_info();
 
@@ -127,9 +126,7 @@ int Incremental(char *devname, int verbose, int runstop,
 		return rv;
 	}
 	/* If the device is a container, we do something very different */
-	if (get_dev_size(dfd, devname, &size) == 0)
-		goto out;
-	if (size == 0) {
+	if (must_be_container(dfd)) {
 		if (!st)
 			st = super_by_fd(dfd, NULL);
 		if (st)
diff --git a/mdadm.h b/mdadm.h
index 6d1169b1..13e1df94 100644
--- a/mdadm.h
+++ b/mdadm.h
@@ -739,6 +739,7 @@ static inline struct supertype *guess_super(int fd) {
 }
 extern struct supertype *dup_super(struct supertype *st);
 extern int get_dev_size(int fd, char *dname, unsigned long long *sizep);
+extern int must_be_container(int fd);
 extern void get_one_disk(int mdfd, mdu_array_info_t *ainf,
 			 mdu_disk_info_t *disk);
 void wait_for(char *dev, int fd);
diff --git a/util.c b/util.c
index f744cdbe..ac5d8b13 100644
--- a/util.c
+++ b/util.c
@@ -1189,6 +1189,20 @@ int get_dev_size(int fd, char *dname, unsigned long long *sizep)
 	return 1;
 }
 
+/* Return true if this can only be a container, not a member device.
+ * i.e. is and md device and size is zero
+ */
+int must_be_container(int fd)
+{
+	unsigned long long size;
+	if (md_get_version(fd) < 0)
+		return 0;
+	if (get_dev_size(fd, NULL, &size) == 0)
+		return 1;
+	if (size == 0)
+		return 1;
+	return 0;
+}
 
 /* Sets endofpart parameter to the last block used by the last GPT partition on the device.
  * Returns: 1 if successful