3 files changed, 145 insertions, 13 deletions

diff --git a/ubi-utils/include/libubi.h b/ubi-utils/include/libubi.h
index f52904d..64b5eed 100644
--- a/ubi-utils/include/libubi.h
+++ b/ubi-utils/include/libubi.h
@@ -44,6 +44,7 @@ typedef void * libubi_t;
  *           (%UBI_DEV_NUM_AUTO should be used to automatically assign the
  *           number)
  * @mtd_num: MTD device number to attach
+ * @dev: path to device node to attach
  * @vid_hdr_offset: VID header offset (%0 means default offset and this is what
  *                  most of the users want)
  */
@@ -51,6 +52,7 @@ struct ubi_attach_request
 {
 	int dev_num;
 	int mtd_num;
+	const char *dev;
 	int vid_hdr_offset;
 };
 
@@ -219,6 +221,23 @@ int ubi_attach_mtd(libubi_t desc, const char *node,
 		   struct ubi_attach_request *req);
 
 /**
+ * ubi_attach - attach an MTD device by its node path.
+ * @desc: UBI library descriptor
+ * @node: name of the UBI control character device node
+ * @req: MTD attach request
+ *
+ * This function creates new UBI device by attaching an MTD device described by
+ * @req. If @req->dev is given it should contain path to the MTD device node.
+ * Otherwise functionality is similar than in function 'ubi_attach_mtd()' where
+ * @req->mtd_num is used.
+ *
+ * Returns %0 in case of success and %-1 in case of failure (errno is set). The
+ * newly created UBI device number is returned in @req->dev_num.
+ */
+int ubi_attach(libubi_t desc, const char *node,
+	       struct ubi_attach_request *req);
+
+/**
  * ubi_detach_mtd - detach an MTD device.
  * @desc: UBI library descriptor
  * @node: name of the UBI control character device node
@@ -231,6 +250,17 @@ int ubi_attach_mtd(libubi_t desc, const char *node,
 int ubi_detach_mtd(libubi_t desc, const char *node, int mtd_num);
 
 /**
+ * ubi_detach - detach an MTD device by its node path.
+ * @desc: UBI library descriptor
+ * @node: name of the UBI control character device node
+ * @dev: path to an MTD device node
+ *
+ * This function detaches an MTD device @dev from UBI. Returns zero in case of
+ * success and %-1 in case of failure.
+ */
+int ubi_detach(libubi_t desc, const char *node, const char *dev);
+
+/**
  * ubi_remove_dev - remove an UBI device.
  * @desc: UBI library descriptor
  * @node: name of the UBI control character device node
diff --git a/ubi-utils/src/libubi.c b/ubi-utils/src/libubi.c
index fd97774..2f19bd7 100644
--- a/ubi-utils/src/libubi.c
+++ b/ubi-utils/src/libubi.c
@@ -677,35 +677,120 @@ void libubi_close(libubi_t desc)
 	free(lib);
 }
 
-int ubi_attach_mtd(libubi_t desc, const char *node,
-		   struct ubi_attach_request *req)
+/**
+ * do_attach - perform the actual attach operation.
+ * @node: name of the UBI control character device node
+ * @r: attach request
+ *
+ * This function performs the actual UBI attach operation. Returns %0 in case of
+ * success and %-1 in case of failure. @r->ubi_num contains newly created UBI
+ * device number.
+ */
+static int do_attach(const char *node, const struct ubi_attach_req *r)
 {
 	int fd, ret;
-	struct ubi_attach_req r;
-
-	memset(&r, 0, sizeof(struct ubi_attach_req));
-
-	desc = desc;
-	r.ubi_num = req->dev_num;
-	r.mtd_num = req->mtd_num;
-	r.vid_hdr_offset = req->vid_hdr_offset;
 
 	fd = open(node, O_RDONLY);
 	if (fd == -1)
 		return sys_errmsg("cannot open \"%s\"", node);
 
-	ret = ioctl(fd, UBI_IOCATT, &r);
+	ret = ioctl(fd, UBI_IOCATT, r);
 	close(fd);
 	if (ret == -1)
 		return -1;
 
-	req->dev_num = r.ubi_num;
-
 #ifdef UDEV_SETTLE_HACK
 //	if (system("udevsettle") == -1)
 //		return -1;
 	usleep(100000);
 #endif
+	return ret;
+}
+
+int ubi_attach_mtd(libubi_t desc, const char *node,
+		   struct ubi_attach_request *req)
+{
+	struct ubi_attach_req r;
+	int ret;
+
+	(void)desc;
+
+	memset(&r, 0, sizeof(struct ubi_attach_req));
+	r.ubi_num = req->dev_num;
+	r.mtd_num = req->mtd_num;
+	r.vid_hdr_offset = req->vid_hdr_offset;
+
+	ret = do_attach(node, &r);
+	if (ret == 0)
+		req->dev_num = r.ubi_num;
+
+	return ret;
+}
+
+#ifndef MTD_CHAR_MAJOR
+/*
+ * This is taken from kernel <linux/mtd/mtd.h> and is unlikely to change anytime
+ * soon.
+ */
+#define MTD_CHAR_MAJOR 90
+#endif
+
+/**
+ * dev_to_mtdnum - converts device node to MTD number.
+ * @dev: path to device node to convert
+ *
+ * This function converts given @dev to MTD device number. @dev should contain
+ * path to the MTD device node. Returns MTD device number in case of success and
+ * %-1 in case of failure (errno is set).
+ */
+static int dev_to_mtdnum(const char *dev)
+{
+	int major, minor;
+	struct stat sb;
+
+	if (stat(dev, &sb) < 0)
+		return sys_errmsg("cannot stat \"%s\"", dev);
+
+	if (!S_ISCHR(sb.st_mode)) {
+		errno = EINVAL;
+		return sys_errmsg("\"%s\" is not a character device", dev);
+	}
+
+	major = major(sb.st_rdev);
+	minor = minor(sb.st_rdev);
+
+	if (major != MTD_CHAR_MAJOR) {
+		errno = EINVAL;
+		return sys_errmsg("\"%s\" is not an MTD device", dev);
+	}
+
+	return minor / 2;
+}
+
+int ubi_attach(libubi_t desc, const char *node, struct ubi_attach_request *req)
+{
+	struct ubi_attach_req r;
+	int ret;
+
+	if (!req->dev)
+		/* Fallback to opening by mtd_num */
+		return ubi_attach_mtd(desc, node, req);
+
+	memset(&r, 0, sizeof(struct ubi_attach_req));
+	r.ubi_num = req->dev_num;
+	r.vid_hdr_offset = req->vid_hdr_offset;
+
+	/*
+	 * User has passed path to device node. Lets find out MTD device number
+	 * of the device and pass it to the kernel.
+	 */
+	r.mtd_num = dev_to_mtdnum(req->dev);
+	if (r.mtd_num == -1)
+		return -1;
+
+	ret = do_attach(node, &r);
+	if (ret == 0)
+		req->dev_num = r.ubi_num;
 
 	return ret;
 }
@@ -723,6 +808,22 @@ int ubi_detach_mtd(libubi_t desc, const char *node, int mtd_num)
 	return ubi_remove_dev(desc, node, ubi_dev);
 }
 
+int ubi_detach(libubi_t desc, const char *node, const char *dev)
+{
+	int mtd_num;
+
+	if (!dev) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	mtd_num = dev_to_mtdnum(dev);
+	if (mtd_num == -1)
+		return -1;
+
+	return ubi_detach_mtd(desc, node, mtd_num);
+}
+
 int ubi_remove_dev(libubi_t desc, const char *node, int ubi_dev)
 {
 	int fd, ret;
diff --git a/ubi-utils/src/libubi_int.h b/ubi-utils/src/libubi_int.h
index 6d17d57..c3aa37a 100644
--- a/ubi-utils/src/libubi_int.h
+++ b/ubi-utils/src/libubi_int.h
@@ -83,6 +83,7 @@ extern "C" {
  *                handling
  * @dev_max_vols: maximum volumes number count sysfs path pattern
  * @dev_min_io_size: minimum I/O unit size sysfs path pattern
+ * @dev_mtd_num: MTD device number
  * @ubi_vol: UBI volume sysfs directory pattern
  * @vol_type: volume type sysfs path pattern
  * @vol_dev: volume major/minor numbers file pattern