From: Davidlohr Bueso <dave@gnu.org>
Date: Wed, 4 Jan 2012 23:02:06 +0000 (+0100)
Subject: blkdev: add is_blkdev function
X-Git-Tag: v2.21-rc1~71
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=8150beac7ced4e35fef7a8db71caee72d455f180;p=thirdparty%2Futil-linux.git

blkdev: add is_blkdev function

We should have the most basic of checks in this library to see whether or not a block device is being used.

Signed-off-by: Davidlohr Bueso <dave@gnu.org>
---

diff --git a/include/blkdev.h b/include/blkdev.h
index 1a9119d43d..6b18879761 100644
--- a/include/blkdev.h
+++ b/include/blkdev.h
@@ -86,6 +86,9 @@ struct hd_geometry {
 };
 #endif
 
+/* are we working with block device? */
+int is_blkdev(int fd);
+
 /* Determine size in bytes */
 off_t blkdev_find_size (int fd);
 
diff --git a/lib/blkdev.c b/lib/blkdev.c
index 9138b0d854..c59386d9c3 100644
--- a/lib/blkdev.c
+++ b/lib/blkdev.c
@@ -35,6 +35,12 @@ blkdev_valid_offset (int fd, off_t offset) {
 	return 1;
 }
 
+int is_blkdev(int fd)
+{
+	struct stat st;
+	return (fstat(fd, &st) == 0 && S_ISBLK(st.st_mode));
+}
+
 off_t
 blkdev_find_size (int fd) {
 	uintmax_t high, low = 0;