libmount: add MNT_ERR_LOOPDEV

Signed-off-by: Karel Zak <kzak@redhat.com>

lib/loopdev.c

@@ -173,6 +173,8 @@ int loopcxt_init(struct loopdev_cxt *lc, int flags)
  */
 void loopcxt_deinit(struct loopdev_cxt *lc)
 {
+	int errsv = errno;
+
 	if (!lc)
 		return;
 
@@ -183,6 +185,8 @@ void loopcxt_deinit(struct loopdev_cxt *lc)
 
 	loopcxt_set_device(lc, NULL);
 	loopcxt_deinit_iterator(lc);
+
+	errno = errsv;
 }
 
 /*

libmount/src/context_loopdev.c

@@ -261,6 +261,7 @@ int mnt_context_setup_loopdev(struct libmnt_context *cxt)
 
 		if (loopdev || rc != -EBUSY) {
 			DBG(CXT, mnt_debug_h(cxt, "failed to setup device"));
+			rc = -MNT_ERR_LOOPDEV;
 			goto done;
 		}
 		DBG(CXT, mnt_debug_h(cxt, "loopdev stolen...trying again"));

libmount/src/libmount.h.in

@@ -126,6 +126,7 @@ enum {
 #define MNT_ERR_NOFSTAB      5000	/* not found required entry in fstab */
 #define MNT_ERR_NOFSTYPE     5001	/* failed to detect filesystem type */
 #define MNT_ERR_NOSOURCE     5002	/* required mount source undefined */
+#define MNT_ERR_LOOPDEV	     5003	/* loopdev setup failed, errno set by libc */
 
 /* init.c */
 extern void mnt_init_debug(int mask);