ubifs-utils: Extract UBI opening/closing/volume_check_empty functions into a new source file

Move UBI opening/closing/volume_check_empty functions into common/super.c.
These functions will be used in fsck.

Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 123 insertions, 0 deletions

diff --git a/ubifs-utils/common/super.c b/ubifs-utils/common/super.c
new file mode 100644
index 0000000..eee0197
--- /dev/null
+++ b/ubifs-utils/common/super.c
@@ -0,0 +1,123 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include "defs.h"
+
+/**
+ * open_ubi - open the libubi.
+ * @c: the UBIFS file-system description object
+ * @node: name of the UBI volume character device to fetch information about
+ *
+ * This function opens libubi, and initialize device & volume information
+ * according to @node. Returns %0 in case of success and %-1 in case of failure.
+ */
+int open_ubi(struct ubifs_info *c, const char *node)
+{
+	struct stat st;
+
+	if (stat(node, &st) || !S_ISCHR(st.st_mode))
+		return -1;
+
+	c->libubi = libubi_open();
+	if (!c->libubi)
+		return -1;
+	if (ubi_get_vol_info(c->libubi, node, &c->vi))
+		goto out_err;
+	if (ubi_get_dev_info1(c->libubi, c->vi.dev_num, &c->di))
+		goto out_err;
+
+	return 0;
+
+out_err:
+	close_ubi(c);
+	return -1;
+}
+
+void close_ubi(struct ubifs_info *c)
+{
+	if (c->libubi) {
+		libubi_close(c->libubi);
+		c->libubi = NULL;
+	}
+}
+
+/**
+ * open_target - open the output target.
+ * @c: the UBIFS file-system description object
+ *
+ * Open the output target. The target can be an UBI volume
+ * or a file.
+ *
+ * Returns %0 in case of success and %-1 in case of failure.
+ */
+int open_target(struct ubifs_info *c)
+{
+	if (c->libubi) {
+		c->dev_fd = open(c->dev_name, O_RDWR | O_EXCL);
+
+		if (c->dev_fd == -1)
+			return sys_errmsg("cannot open the UBI volume '%s'",
+					   c->dev_name);
+		if (ubi_set_property(c->dev_fd, UBI_VOL_PROP_DIRECT_WRITE, 1)) {
+			close(c->dev_fd);
+			return sys_errmsg("ubi_set_property(set direct_write) failed");
+		}
+	} else {
+		c->dev_fd = open(c->dev_name, O_CREAT | O_RDWR | O_TRUNC,
+			      S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH);
+		if (c->dev_fd == -1)
+			return sys_errmsg("cannot create output file '%s'",
+					   c->dev_name);
+	}
+	return 0;
+}
+
+
+/**
+ * close_target - close the output target.
+ * @c: the UBIFS file-system description object
+ *
+ * Close the output target. If the target was an UBI
+ * volume, also close libubi.
+ *
+ * Returns %0 in case of success and %-1 in case of failure.
+ */
+int close_target(struct ubifs_info *c)
+{
+	if (c->dev_fd >= 0) {
+		if (c->libubi && ubi_set_property(c->dev_fd, UBI_VOL_PROP_DIRECT_WRITE, 0))
+			return sys_errmsg("ubi_set_property(clear direct_write) failed");
+		if (close(c->dev_fd) == -1)
+			return sys_errmsg("cannot close the target '%s'", c->dev_name);
+	}
+	return 0;
+}
+
+/**
+ * check_volume_empty - check if the UBI volume is empty.
+ * @c: the UBIFS file-system description object
+ *
+ * This function checks if the UBI volume is empty by looking if its LEBs are
+ * mapped or not.
+ *
+ * Returns %0 in case of success, %1 is the volume is not empty,
+ * and a negative error code in case of failure.
+ */
+int check_volume_empty(struct ubifs_info *c)
+{
+	int lnum, err;
+
+	for (lnum = 0; lnum < c->vi.rsvd_lebs; lnum++) {
+		err = ubi_is_mapped(c->dev_fd, lnum);
+		if (err < 0)
+			return err;
+		if (err == 1)
+			return 1;
+	}
+	return 0;
+}