mdadm/util: unify fstat checking blkdev into function

declare function fstat_is_blkdev() to integrate repeated fstat
checking block device operations, it returns true/1 when it is
a block device, and returns false/0 when it isn't.
The fd and devname are necessary parameters, *rdev is optional,
parse the pointer of dev_t *rdev, if valid, assigned the device
number to dev_t *rdev, if NULL, ignores.

Signed-off-by: Zhilong Liu <zlliu@suse.com>
Signed-off-by: Jes Sorensen <jsorensen@fb.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/mdadm.h b/mdadm.h
index 07ee9635..4adb8409 100644
--- a/mdadm.h
+++ b/mdadm.h
@@ -1434,6 +1434,7 @@ extern int check_raid(int fd, char *name);
 extern int check_partitions(int fd, char *dname,
 			    unsigned long long freesize,
 			    unsigned long long size);
+extern int fstat_is_blkdev(int fd, char *devname, dev_t *rdev);
 
 extern int get_mdp_major(void);
 extern int get_maj_min(char *dev, int *major, int *minor);