mdadm/lib: Define a new helper function is_dev_alived

The function is used to check if one member disk is alive.

Signed-off-by: Xiao Ni <xni@redhat.com>
Acked-by: Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com>
Signed-off-by: Jes Sorensen <jsorensen@fb.com>

2 files changed, 13 insertions, 0 deletions

diff --git a/lib.c b/lib.c
index 76d1fbb9..7e3e3d47 100644
--- a/lib.c
+++ b/lib.c
@@ -27,6 +27,17 @@
 #include	<ctype.h>
 #include	<limits.h>
 
+bool is_dev_alive(char *path)
+{
+	if (!path)
+		return false;
+
+	if (access(path, R_OK) == 0)
+		return true;
+
+	return false;
+}
+
 /* This fill contains various 'library' style function.  They
  * have no dependency on anything outside this file.
  */
diff --git a/mdadm.h b/mdadm.h
index 53ea0de6..4e483bfc 100644
--- a/mdadm.h
+++ b/mdadm.h
@@ -45,6 +45,7 @@ extern __off64_t lseek64 __P ((int __fd, __off64_t __offset, int __whence));
 #include	<errno.h>
 #include	<string.h>
 #include	<syslog.h>
+#include	<stdbool.h>
 /* Newer glibc requires sys/sysmacros.h directly for makedev() */
 #include	<sys/sysmacros.h>
 #ifdef __dietlibc__
@@ -1499,6 +1500,7 @@ extern int check_partitions(int fd, char *dname,
 extern int fstat_is_blkdev(int fd, char *devname, dev_t *rdev);
 extern int stat_is_blkdev(char *devname, dev_t *rdev);
 
+extern bool is_dev_alive(char *path);
 extern int get_mdp_major(void);
 extern int get_maj_min(char *dev, int *major, int *minor);
 extern int dev_open(char *dev, int flags);