libubi: improve libubi_open interface

Remove the not very nice @required parameter, and add a
possibility to distinguish between real errors and
a situation when UBI is not present.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

9 files changed, 43 insertions, 23 deletions

diff --git a/ubi-utils/include/libubi.h b/ubi-utils/include/libubi.h
index 71a78a3..bc3404c 100644
--- a/ubi-utils/include/libubi.h
+++ b/ubi-utils/include/libubi.h
@@ -170,13 +170,13 @@ struct ubi_vol_info
 
 /**
  * libubi_open - open UBI library.
- * @required: if non-zero, libubi will print an error messages if this UBI is
- *            not present in the system
  *
  * This function initializes and opens the UBI library and returns UBI library
- * descriptor in case of success and %NULL in case of failure.
+ * descriptor in case of success and %NULL in case of failure. In case of
+ * failure, errno contains the error code or zero if UBI is not present in the
+ * system.
  */
-libubi_t libubi_open(int required);
+libubi_t libubi_open(void);
 
 /**
  * libubi_close - close UBI library.
diff --git a/ubi-utils/src/libubi.c b/ubi-utils/src/libubi.c
index f456a1d..d4b29b9 100644
--- a/ubi-utils/src/libubi.c
+++ b/ubi-utils/src/libubi.c
@@ -507,7 +507,7 @@ int mtd_num2ubi_dev(libubi_t desc, int mtd_num, int *dev_num)
 	return -1;
 }
 
-libubi_t libubi_open(int required)
+libubi_t libubi_open(void)
 {
 	int fd, version;
 	struct libubi *lib;
@@ -531,9 +531,7 @@ libubi_t libubi_open(int required)
 	/* Make sure UBI is present */
 	fd = open(lib->sysfs_ubi, O_RDONLY);
 	if (fd == -1) {
-		if (required)
-			errmsg("cannot open \"%s\", UBI does not seem to "
-			       "exist in system", lib->sysfs_ubi);
+		errno = 0;
 		goto out_error;
 	}
 
@@ -945,6 +943,7 @@ int ubi_rnvols(libubi_t desc, const char *node, struct ubi_rnvol_req *rnvol)
 {
 	int fd, ret;
 
+	desc = desc;
 	fd = open(node, O_RDONLY);
 	if (fd == -1)
 		return -1;
diff --git a/ubi-utils/src/ubiattach.c b/ubi-utils/src/ubiattach.c
index 1f72620..a935b42 100644
--- a/ubi-utils/src/ubiattach.c
+++ b/ubi-utils/src/ubiattach.c
@@ -153,9 +153,12 @@ int main(int argc, char * const argv[])
 	if (err)
 		return -1;
 
-	libubi = libubi_open(1);
-	if (libubi == NULL)
+	libubi = libubi_open();
+	if (!libubi) {
+		if (errno == 0)
+			return errmsg("UBI is not present in the system");
 		return sys_errmsg("cannot open libubi");
+	}
 
 	/*
 	 * Make sure the kernel is fresh enough and this feature is supported.
diff --git a/ubi-utils/src/ubidetach.c b/ubi-utils/src/ubidetach.c
index 50670d0..83584cd 100644
--- a/ubi-utils/src/ubidetach.c
+++ b/ubi-utils/src/ubidetach.c
@@ -139,9 +139,12 @@ int main(int argc, char * const argv[])
 	if (err)
 		return -1;
 
-	libubi = libubi_open(1);
-	if (libubi == NULL)
+	libubi = libubi_open();
+	if (!libubi) {
+		if (errno == 0)
+			return errmsg("UBI is not present in the system");
 		return sys_errmsg("cannot open libubi");
+	}
 
 	/*
 	 * Make sure the kernel is fresh enough and this feature is supported.
diff --git a/ubi-utils/src/ubimkvol.c b/ubi-utils/src/ubimkvol.c
index 8d6029a..dba7133 100644
--- a/ubi-utils/src/ubimkvol.c
+++ b/ubi-utils/src/ubimkvol.c
@@ -238,9 +238,12 @@ int main(int argc, char * const argv[])
 	if (err)
 		return err;
 
-	libubi = libubi_open(1);
-	if (!libubi)
+	libubi = libubi_open();
+	if (!libubi) {
+		if (errno == 0)
+			return errmsg("UBI is not present in the system");
 		return sys_errmsg("cannot open libubi");
+	}
 
 	err = ubi_probe_node(libubi, args.node);
 	if (err == 2) {
diff --git a/ubi-utils/src/ubinfo.c b/ubi-utils/src/ubinfo.c
index 085691f..025ac62 100644
--- a/ubi-utils/src/ubinfo.c
+++ b/ubi-utils/src/ubinfo.c
@@ -364,9 +364,12 @@ int main(int argc, char * const argv[])
 	if (err)
 		return -1;
 
-	libubi = libubi_open(1);
-	if (libubi == NULL)
+	libubi = libubi_open();
+	if (!libubi) {
+		if (errno == 0)
+			return errmsg("UBI is not present in the system");
 		return sys_errmsg("cannot open libubi");
+	}
 
 	if (args.node) {
 		/*
diff --git a/ubi-utils/src/ubirename.c b/ubi-utils/src/ubirename.c
index 14331b6..08b3cd5 100644
--- a/ubi-utils/src/ubirename.c
+++ b/ubi-utils/src/ubirename.c
@@ -92,9 +92,12 @@ int main(int argc, char * const argv[])
 	}
 
 	node = argv[1];
-	libubi = libubi_open(1);
-	if (!libubi)
+	libubi = libubi_open();
+	if (!libubi) {
+		if (errno == 0)
+			return errmsg("UBI is not present in the system");
 		return sys_errmsg("cannot open libubi");
+	}
 
 	err = ubi_probe_node(libubi, node);
 	if (err == 2) {
diff --git a/ubi-utils/src/ubirmvol.c b/ubi-utils/src/ubirmvol.c
index edb1b79..17aece4 100644
--- a/ubi-utils/src/ubirmvol.c
+++ b/ubi-utils/src/ubirmvol.c
@@ -180,9 +180,12 @@ int main(int argc, char * const argv[])
 	if (err)
 		return -1;
 
-	libubi = libubi_open(1);
-	if (libubi == NULL)
+	libubi = libubi_open();
+	if (!libubi) {
+		if (errno == 0)
+			return errmsg("UBI is not present in the system");
 		return sys_errmsg("cannot open libubi");
+	}
 
 	err = ubi_probe_node(libubi, args.node);
 	if (err == 2) {
diff --git a/ubi-utils/src/ubiupdatevol.c b/ubi-utils/src/ubiupdatevol.c
index a1e5a30..b160461 100644
--- a/ubi-utils/src/ubiupdatevol.c
+++ b/ubi-utils/src/ubiupdatevol.c
@@ -316,9 +316,12 @@ int main(int argc, char * const argv[])
 	if (err)
 		return -1;
 
-	libubi = libubi_open(1);
-	if (libubi == NULL) {
-		sys_errmsg("cannot open libubi");
+	libubi = libubi_open();
+	if (!libubi) {
+		if (errno == 0)
+			errmsg("UBI is not present in the system");
+		else
+			sys_errmsg("cannot open libubi");
 		goto out_libubi;
 	}