mtd: ubi: Let ubidetach take mtd as argument

The ubi number is a dynamically assigned number, so once multiple
ubis are attached, scripts cannot know the ubi number they want
to detach anymore. Convert the ubidetach command to take the mtd
device file instead which is the same argument that was previously
passed to ubiattach.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

commands/ubi.c

@@ -8,6 +8,7 @@
 #include <linux/mtd/mtd.h>
 #include <linux/kernel.h>
 #include <linux/mtd/mtd-abi.h>
+#include <linux/err.h>
 #include <mtd/ubi-user.h>
 #include <mtd/ubi-media.h>
 
@@ -58,14 +59,37 @@ BAREBOX_CMD_START(ubimkvol)
 	BAREBOX_CMD_HELP(cmd_ubimkvol_help)
 BAREBOX_CMD_END
 
+static struct mtd_info *get_mtd_info(const char *path)
+{
+	int fd;
+	struct mtd_info_user user;
+	int ret;
+
+	fd = open(path, O_RDWR);
+	if (fd < 0) {
+		perror("open");
+		return ERR_PTR(fd);
+	}
+
+	ret = ioctl(fd, MEMGETINFO, &user);
+
+	close(fd);
+
+	if (ret) {
+		printf("MEMGETINFO failed: %s\n", strerror(-ret));
+		return ERR_PTR(ret);
+	}
+
+	return user.mtd;
+}
 
 static int do_ubiattach(int argc, char *argv[])
 {
 	int opt;
-	struct mtd_info_user user;
-	int fd, ret;
+	int ret;
 	int vid_hdr_offset = 0;
 	int devnum = UBI_DEV_NUM_AUTO;
+	struct mtd_info *mtd;
 
 	while((opt = getopt(argc, argv, "d:O:")) > 0) {
 		switch(opt) {
@@ -83,25 +107,15 @@ static int do_ubiattach(int argc, char *argv[])
 	if (optind == argc)
 		return COMMAND_ERROR_USAGE;
 
-	fd = open(argv[optind], O_RDWR);
-	if (fd < 0) {
-		perror("open");
-		return 1;
-	}
+	mtd = get_mtd_info(argv[optind]);
+	if (IS_ERR(mtd))
+		return PTR_ERR(mtd);
 
-	ret = ioctl(fd, MEMGETINFO, &user);
-	if (ret) {
-		printf("MEMGETINFO failed: %s\n", strerror(-ret));
-		goto err;
-	}
-
-	ret = ubi_attach_mtd_dev(user.mtd, devnum, vid_hdr_offset, 20);
+	ret = ubi_attach_mtd_dev(mtd, devnum, vid_hdr_offset, 20);
 	if (ret < 0)
 		printf("failed to attach: %s\n", strerror(-ret));
 	else
 		ret = 0;
-err:
-	close(fd);
 
 	return ret ? 1 : 0;
 }
@@ -122,13 +136,17 @@ BAREBOX_CMD_END
 
 static int do_ubidetach(int argc, char *argv[])
 {
-	int ubi_num, ret;
+	int ret;
+	struct mtd_info *mtd;
 
 	if (argc != 2)
 		return COMMAND_ERROR_USAGE;
 
-	ubi_num = simple_strtoul(argv[1], NULL, 0);
-	ret = ubi_detach_mtd_dev(ubi_num, 1);
+	mtd = get_mtd_info(argv[1]);
+	if (IS_ERR(mtd))
+		return PTR_ERR(mtd);
+
+	ret = ubi_detach_mtd_dev(mtd, 1);
 
 	if (ret)
 		printf("failed to detach: %s\n", strerror(-ret));
@@ -138,8 +156,8 @@ static int do_ubidetach(int argc, char *argv[])
 
 BAREBOX_CMD_START(ubidetach)
 	.cmd		= do_ubidetach,
-	BAREBOX_CMD_DESC("detach an UBI device")
-	BAREBOX_CMD_OPTS("UBINUM")
+	BAREBOX_CMD_DESC("detach mtd device from UBI")
+	BAREBOX_CMD_OPTS("UBIDEV")
 	BAREBOX_CMD_GROUP(CMD_GRP_PART)
 BAREBOX_CMD_END
 

drivers/mtd/ubi/build.c

@@ -683,6 +683,20 @@ out_free:
 	return err;
 }
 
+static struct ubi_device *ubi_find_mtd(struct mtd_info *mtd)
+{
+	struct ubi_device *ubi;
+	int i;
+
+	for (i = 0; i < UBI_MAX_DEVICES; i++) {
+		ubi = ubi_devices[i];
+		if (ubi && ubi->mtd == mtd)
+			return ubi;
+	}
+
+	return NULL;
+}
+
 /**
  * ubi_detach_mtd_dev - detach an MTD device.
  * @ubi_num: UBI device number to detach from
@@ -696,13 +710,17 @@ out_free:
  * Note, the invocations of this function has to be serialized by the
  * @ubi_devices_mutex.
  */
-int ubi_detach_mtd_dev(int ubi_num, int anyway)
+int ubi_detach_mtd_dev(struct mtd_info *mtd, int anyway)
 {
 	struct ubi_device *ubi;
+	int ubi_num;
 
-	if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
+	ubi = ubi_find_mtd(mtd);
+	if (!ubi)
 		return -EINVAL;
 
+	ubi_num = ubi->ubi_num;
+
 	ubi = ubi_get_device(ubi_num);
 	if (!ubi)
 		return -EINVAL;

include/mtd/ubi-user.h

@@ -406,6 +406,6 @@ struct ubi_set_vol_prop_req {
 
 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
 		       int vid_hdr_offset, int max_beb_per1024);
-int ubi_detach_mtd_dev(int ubi_num, int anyway);
+int ubi_detach_mtd_dev(struct mtd_info *mtd, int anyway);
 
 #endif /* __UBI_USER_H__ */