libmtd: amend interface

Remove the fd field from the mtd information data structure,
because libmtd does not really know the device node file name,
and serves only as a place to save the descriptor. The callers
should find a better place.

This patch improves code readability and prepares for further
changes.

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

5 files changed, 64 insertions, 49 deletions

diff --git a/ubi-utils/include/libmtd.h b/ubi-utils/include/libmtd.h
index c50059d..9c7a6e3 100644
--- a/ubi-utils/include/libmtd.h
+++ b/ubi-utils/include/libmtd.h
@@ -41,7 +41,6 @@ extern "C" {
  * @subpage_size: sub-page size (not set by 'mtd_get_info()'!!!)
  * @rdonly: non-zero if the device is read-only
  * @allows_bb: non-zero if the MTD device may have bad eraseblocks
- * @fd: descriptor of the opened MTD character device node
  */
 struct mtd_info
 {
@@ -57,7 +56,6 @@ struct mtd_info
 	int subpage_size;
 	unsigned int rdonly:1;
 	unsigned int allows_bb:1;
-	int fd;
 };
 
 /**
@@ -74,36 +72,40 @@ int mtd_get_info(const char *node, struct mtd_info *mtd);
 /**
  * mtd_erase - erase an eraseblock.
  * @mtd: MTD device description object
+ * @fd: MTD device node file descriptor
  * @eb: eraseblock to erase
  *
- * This function erases the eraseblock and returns %0 in case of success and
- * %-1 in case of failure.
+ * This function erases eraseblock @eb of MTD device decribed by @fd. Returns
+ * %0 in case of success and %-1 in case of failure.
  */
-int mtd_erase(const struct mtd_info *mtd, int eb);
+int mtd_erase(const struct mtd_info *mtd, int fd, int eb);
 
 /**
  * mtd_is_bad - check if eraseblock is bad.
  * @mtd: MTD device description object
+ * @fd: MTD device node file descriptor
  * @eb: eraseblock to check
  *
  * This function checks if eraseblock @eb is bad. Returns %0 if not, %1 if yes,
  * and %-1 in case of failure.
  */
-int mtd_is_bad(const struct mtd_info *mtd, int eb);
+int mtd_is_bad(const struct mtd_info *mtd, int fd, int eb);
 
 /**
  * mtd_mark_bad - marks the block as bad.
  * @mtd: MTD device description object
+ * @fd: MTD device node file descriptor
  * @eb: eraseblock to mark bad
  *
  * This function marks the eraseblock @eb as bad. Returns %0 if success
  * %-1 if failure
  */
-int mtd_mark_bad(const struct mtd_info *mtd, int eb);
+int mtd_mark_bad(const struct mtd_info *mtd, int fd, int eb);
 
 /**
  * mtd_read - read data from an MTD device.
  * @mtd: MTD device description object
+ * @fd: MTD device node file descriptor
  * @eb: eraseblock to read from
  * @offs: offset withing the eraseblock to read from
  * @buf: buffer to read data to
@@ -113,11 +115,13 @@ int mtd_mark_bad(const struct mtd_info *mtd, int eb);
  * of the MTD device defined by @mtd and stores the read data at buffer @buf.
  * Returns %0 in case of success and %-1 in case of failure.
  */
-int mtd_read(const struct mtd_info *mtd, int eb, int offs, void *buf, int len);
+int mtd_read(const struct mtd_info *mtd, int fd, int eb, int offs, void *buf,
+	     int len);
 
 /**
  * mtd_write - write data to an MTD device.
  * @mtd: MTD device description object
+ * @fd: MTD device node file descriptor
  * @eb: eraseblock to write to
  * @offs: offset withing the eraseblock to write to
  * @buf: buffer to write
@@ -127,7 +131,8 @@ int mtd_read(const struct mtd_info *mtd, int eb, int offs, void *buf, int len);
  * of the MTD device defined by @mtd. Returns %0 in case of success and %-1 in
  * case of failure.
  */
-int mtd_write(const struct mtd_info *mtd, int eb, int offs, void *buf, int len);
+int mtd_write(const struct mtd_info *mtd, int fd, int eb, int offs, void *buf,
+	      int len);
 
 #ifdef __cplusplus
 }
diff --git a/ubi-utils/include/libscan.h b/ubi-utils/include/libscan.h
index 5afc93e..8597b98 100644
--- a/ubi-utils/include/libscan.h
+++ b/ubi-utils/include/libscan.h
@@ -92,11 +92,13 @@ struct mtd_info;
 /**
  * ubi_scan - scan an MTD device.
  * @mtd: information about the MTD device to scan
+ * @fd: MTD device node file descriptor
  * @info: the result of the scanning is returned here
  * @verbose: verbose mode: %0 - be silent, %1 - output progress information,
  *           2 - debugging output mode
  */
-int ubi_scan(struct mtd_info *mtd, struct ubi_scan_info **info, int verbose);
+int ubi_scan(struct mtd_info *mtd, int fd, struct ubi_scan_info **info,
+	     int verbose);
 
 /**
  * ubi_scan_free - free scanning information.
diff --git a/ubi-utils/src/libmtd.c b/ubi-utils/src/libmtd.c
index 4cc9bdb..127d0ec 100644
--- a/ubi-utils/src/libmtd.c
+++ b/ubi-utils/src/libmtd.c
@@ -37,7 +37,7 @@ int mtd_get_info(const char *node, struct mtd_info *mtd)
 {
 	struct stat st;
 	struct mtd_info_user ui;
-	int ret;
+	int fd, ret;
 	loff_t offs = 0;
 
 	if (stat(node, &st))
@@ -60,16 +60,16 @@ int mtd_get_info(const char *node, struct mtd_info *mtd)
 	mtd->num = mtd->minor / 2;
 	mtd->rdonly = mtd->minor & 1;
 
-	mtd->fd = open(node, O_RDWR);
-	if (mtd->fd == -1)
+	fd = open(node, O_RDWR);
+	if (fd == -1)
 		return sys_errmsg("cannot open \"%s\"", node);
 
-	if (ioctl(mtd->fd, MEMGETINFO, &ui)) {
+	if (ioctl(fd, MEMGETINFO, &ui)) {
 		sys_errmsg("MEMGETINFO ioctl request failed");
 		goto out_close;
 	}
 
-	ret = ioctl(mtd->fd, MEMGETBADBLOCK, &offs);
+	ret = ioctl(fd, MEMGETBADBLOCK, &offs);
 	if (ret == -1) {
 		if (errno != EOPNOTSUPP) {
 			sys_errmsg("MEMGETBADBLOCK ioctl failed");
@@ -133,23 +133,24 @@ int mtd_get_info(const char *node, struct mtd_info *mtd)
 	if (!(ui.flags & MTD_WRITEABLE))
 		mtd->rdonly = 1;
 
+	close(fd);
 	return 0;
 
 out_close:
-	close(mtd->fd);
+	close(fd);
 	return -1;
 }
 
-int mtd_erase(const struct mtd_info *mtd, int eb)
+int mtd_erase(const struct mtd_info *mtd, int fd, int eb)
 {
 	struct erase_info_user ei;
 
 	ei.start = eb * mtd->eb_size;;
 	ei.length = mtd->eb_size;
-	return ioctl(mtd->fd, MEMERASE, &ei);
+	return ioctl(fd, MEMERASE, &ei);
 }
 
-int mtd_is_bad(const struct mtd_info *mtd, int eb)
+int mtd_is_bad(const struct mtd_info *mtd, int fd, int eb)
 {
 	int ret;
 	loff_t seek;
@@ -165,14 +166,14 @@ int mtd_is_bad(const struct mtd_info *mtd, int eb)
 		return 0;
 
 	seek = (loff_t)eb * mtd->eb_size;
-	ret = ioctl(mtd->fd, MEMGETBADBLOCK, &seek);
+	ret = ioctl(fd, MEMGETBADBLOCK, &seek);
 	if (ret == -1)
 		return sys_errmsg("MEMGETBADBLOCK ioctl failed for "
 				  "eraseblock %d (mtd%d)", eb, mtd->num);
 	return ret;
 }
 
-int mtd_mark_bad(const struct mtd_info *mtd, int eb)
+int mtd_mark_bad(const struct mtd_info *mtd, int fd, int eb)
 {
 	int ret;
 	loff_t seek;
@@ -190,14 +191,15 @@ int mtd_mark_bad(const struct mtd_info *mtd, int eb)
 	}
 
 	seek = (loff_t)eb * mtd->eb_size;
-	ret = ioctl(mtd->fd, MEMSETBADBLOCK, &seek);
+	ret = ioctl(fd, MEMSETBADBLOCK, &seek);
 	if (ret == -1)
 		return sys_errmsg("MEMSETBADBLOCK ioctl failed for "
 			          "eraseblock %d (mtd%d)", eb, mtd->num);
 	return 0;
 }
 
-int mtd_read(const struct mtd_info *mtd, int eb, int offs, void *buf, int len)
+int mtd_read(const struct mtd_info *mtd, int fd, int eb, int offs, void *buf,
+	     int len)
 {
 	int ret, rd = 0;
 	off_t seek;
@@ -217,12 +219,12 @@ int mtd_read(const struct mtd_info *mtd, int eb, int offs, void *buf, int len)
 
 	/* Seek to the beginning of the eraseblock */
 	seek = (off_t)eb * mtd->eb_size + offs;
-	if (lseek(mtd->fd, seek, SEEK_SET) != seek)
+	if (lseek(fd, seek, SEEK_SET) != seek)
 		return sys_errmsg("cannot seek mtd%d to offset %llu",
 				  mtd->num, (unsigned long long)seek);
 
 	while (rd < len) {
-		ret = read(mtd->fd, buf, len);
+		ret = read(fd, buf, len);
 		if (ret < 0)
 			return sys_errmsg("cannot read %d bytes from mtd%d (eraseblock %d, offset %d)",
 					  len, mtd->num, eb, offs);
@@ -232,7 +234,8 @@ int mtd_read(const struct mtd_info *mtd, int eb, int offs, void *buf, int len)
 	return 0;
 }
 
-int mtd_write(const struct mtd_info *mtd, int eb, int offs, void *buf, int len)
+int mtd_write(const struct mtd_info *mtd, int fd, int eb, int offs, void *buf,
+	      int len)
 {
 	int ret;
 	off_t seek;
@@ -266,11 +269,11 @@ int mtd_write(const struct mtd_info *mtd, int eb, int offs, void *buf, int len)
 
 	/* Seek to the beginning of the eraseblock */
 	seek = (off_t)eb * mtd->eb_size + offs;
-	if (lseek(mtd->fd, seek, SEEK_SET) != seek)
+	if (lseek(fd, seek, SEEK_SET) != seek)
 		return sys_errmsg("cannot seek mtd%d to offset %llu",
 				  mtd->num, (unsigned long long)seek);
 
-	ret = write(mtd->fd, buf, len);
+	ret = write(fd, buf, len);
 	if (ret != len)
 		return sys_errmsg("cannot write %d bytes to mtd%d (eraseblock %d, offset %d)",
 				  len, mtd->num, eb, offs);
diff --git a/ubi-utils/src/libscan.c b/ubi-utils/src/libscan.c
index dc1f083..4d64bca 100644
--- a/ubi-utils/src/libscan.c
+++ b/ubi-utils/src/libscan.c
@@ -48,7 +48,7 @@ static int all_ff(const void *buf, int len)
 	return 1;
 }
 
-int ubi_scan(struct mtd_info *mtd, struct ubi_scan_info **info, int verbose)
+int ubi_scan(struct mtd_info *mtd, int fd, struct ubi_scan_info **info, int verbose)
 {
 	int eb, v = (verbose == 2), pr = (verbose == 1);
 	struct ubi_scan_info *si;
@@ -85,7 +85,7 @@ int ubi_scan(struct mtd_info *mtd, struct ubi_scan_info **info, int verbose)
 			fflush(stdout);
 		}
 
-		ret = mtd_is_bad(mtd, eb);
+		ret = mtd_is_bad(mtd, fd, eb);
 		if (ret == -1)
 			goto out_ec;
 		if (ret) {
@@ -96,7 +96,7 @@ int ubi_scan(struct mtd_info *mtd, struct ubi_scan_info **info, int verbose)
 			continue;
 		}
 
-		ret = mtd_read(mtd, eb, 0, &hdr, sizeof(struct ubi_ec_hdr));;
+		ret = mtd_read(mtd, fd, eb, 0, &hdr, sizeof(struct ubi_ec_hdr));
 		if (ret < 0)
 			goto out_ec;
 
diff --git a/ubi-utils/src/ubiformat.c b/ubi-utils/src/ubiformat.c
index 3a1b198..2226a75 100644
--- a/ubi-utils/src/ubiformat.c
+++ b/ubi-utils/src/ubiformat.c
@@ -62,6 +62,7 @@ struct args {
 	long long ec;
 	const char *image;
 	const char *node;
+	int node_fd;
 };
 
 static struct args args =
@@ -412,7 +413,7 @@ static int mark_bad(const struct mtd_info *mtd, struct ubi_scan_info *si, int eb
 		return errmsg("bad blocks not supported by this flash");
 	}
 
-	err = mtd_mark_bad(mtd, eb);
+	err = mtd_mark_bad(mtd, args.node_fd, eb);
 	if (err)
 		return err;
 
@@ -468,7 +469,7 @@ static int flash_image(const struct mtd_info *mtd, struct ubi_scan_info *si)
 			fflush(stdout);
 		}
 
-		err = mtd_erase(mtd, eb);
+		err = mtd_erase(mtd, args.node_fd, eb);
 		if (err) {
 			if (!args.quiet)
 				printf("\n");
@@ -518,7 +519,7 @@ static int flash_image(const struct mtd_info *mtd, struct ubi_scan_info *si)
 
 		new_len = drop_ffs(mtd, buf, mtd->eb_size);
 
-		err = mtd_write(mtd, eb, 0, buf, new_len);
+		err = mtd_write(mtd, args.node_fd, eb, 0, buf, new_len);
 		if (err) {
 			if (!args.quiet)
 				printf("\n");
@@ -565,7 +566,6 @@ static int format(const struct mtd_info *mtd, const struct ubigen_info *ui,
 	hdr = malloc(write_size);
 	if (!hdr)
 		return sys_errmsg("cannot allocate %d bytes of memory", write_size);
-
 	memset(hdr, 0xFF, write_size);
 
 	for (eb = start_eb; eb < mtd->eb_cnt; eb++) {
@@ -593,7 +593,7 @@ static int format(const struct mtd_info *mtd, const struct ubigen_info *ui,
 			fflush(stdout);
 		}
 
-		err = mtd_erase(mtd, eb);
+		err = mtd_erase(mtd, args.node_fd, eb);
 		if (err) {
 			if (!args.quiet)
 				printf("\n");
@@ -625,7 +625,7 @@ static int format(const struct mtd_info *mtd, const struct ubigen_info *ui,
 			fflush(stdout);
 		}
 
-		err = mtd_write(mtd, eb, 0, hdr, write_size);
+		err = mtd_write(mtd, args.node_fd, eb, 0, hdr, write_size);
 		if (err) {
 			if (!args.quiet && !args.verbose)
 				printf("\n");
@@ -662,7 +662,8 @@ static int format(const struct mtd_info *mtd, const struct ubigen_info *ui,
 		if (!vtbl)
 			goto out_free;
 
-		err = ubigen_write_layout_vol(ui, eb1, eb2, ec1,  ec2, vtbl, mtd->fd);
+		err = ubigen_write_layout_vol(ui, eb1, eb2, ec1,  ec2, vtbl,
+					      args.node_fd);
 		free(vtbl);
 		if (err) {
 			errmsg("cannot write layout volume");
@@ -694,17 +695,21 @@ int main(int argc, char * const argv[])
 	if (err)
 		return errmsg("cannot get information about \"%s\"", args.node);
 
+	args.node_fd = open(args.node, O_RDWR);
+	if (args.node_fd == -1)
+		return sys_errmsg("cannot open \"%s\"", args.node);
+
 	if (args.subpage_size == 0)
 		args.subpage_size = mtd.min_io_size;
 	else {
 		if (args.subpage_size > mtd.min_io_size) {
 			errmsg("sub-page cannot be larger than min. I/O unit");
-			goto out_close;
+			goto out;
 		}
 
 		if (mtd.min_io_size % args.subpage_size) {
 			errmsg("min. I/O unit size should be multiple of sub-page size");
-			goto out_close;
+			goto out;
 		}
 	}
 
@@ -712,11 +717,11 @@ int main(int argc, char * const argv[])
 	if (args.vid_hdr_offs != 0) {
 		if (args.vid_hdr_offs % 8) {
 			errmsg("VID header offset has to be multiple of min. I/O unit size");
-			goto out_close;
+			goto out;
 		}
 		if (args.vid_hdr_offs + (int)UBI_VID_HDR_SIZE > mtd.eb_size) {
 			errmsg("bad VID header offset");
-			goto out_close;
+			goto out;
 		}
 	}
 
@@ -729,7 +734,7 @@ int main(int argc, char * const argv[])
 
 	if (mtd.rdonly) {
 		errmsg("mtd%d (%s) is a read-only device", mtd.num, args.node);
-		goto out_close;
+		goto out;
 	}
 
 	/* Make sure this MTD device is not attached to UBI */
@@ -742,7 +747,7 @@ int main(int argc, char * const argv[])
 		if (!err) {
 			errmsg("please, first detach mtd%d (%s) from ubi%d",
 			       mtd.num, args.node, ubi_dev_num);
-			goto out_close;
+			goto out;
 		}
 	}
 
@@ -760,10 +765,10 @@ int main(int argc, char * const argv[])
 		verbose = 2;
 	else
 		verbose = 1;
-	err = ubi_scan(&mtd, &si, verbose);
+	err = ubi_scan(&mtd, args.node_fd, &si, verbose);
 	if (err) {
 		errmsg("failed to scan mtd%d (%s)", mtd.num, args.node);
-		goto out_close;
+		goto out;
 	}
 
 	if (si->good_cnt == 0) {
@@ -877,12 +882,12 @@ int main(int argc, char * const argv[])
 	}
 
 	ubi_scan_free(si);
-	close(mtd.fd);
+	close(args.node_fd);
 	return 0;
 
 out_free:
 	ubi_scan_free(si);
-out_close:
-	close(mtd.fd);
+out:
+	close(args.node_fd);
 	return -1;
 }