1 files changed, 72 insertions, 6 deletions

diff --git a/cmd/ubi.c b/cmd/ubi.c
index 92998af2b0..0e62e44932 100644
--- a/cmd/ubi.c
+++ b/cmd/ubi.c
@@ -423,18 +423,84 @@ int ubi_volume_begin_write(char *volume, void *buf, size_t size,
 	return ubi_volume_continue_write(volume, buf, size);
 }
 
-int ubi_volume_write(char *volume, void *buf, size_t size)
+static int ubi_volume_offset_write(char *volume, void *buf, loff_t offset,
+				   size_t size)
 {
-	return ubi_volume_begin_write(volume, buf, size, size);
+	int len, tbuf_size, ret;
+	u64 lnum;
+	struct ubi_volume *vol;
+	loff_t off = offset;
+	void *tbuf;
+
+	vol = ubi_find_volume(volume);
+	if (!vol)
+		return -ENODEV;
+
+	if (size > vol->reserved_pebs * (ubi->leb_size - vol->data_pad))
+		return -EINVAL;
+
+	tbuf_size = vol->usable_leb_size;
+	tbuf = malloc_cache_aligned(tbuf_size);
+	if (!tbuf)
+		return -ENOMEM;
+
+	lnum = off;
+	off = do_div(lnum, vol->usable_leb_size);
+
+	do {
+		struct ubi_volume_desc desc = {
+			.vol = vol,
+			.mode = UBI_READWRITE,
+		};
+
+		len = size > tbuf_size ? tbuf_size : size;
+		if (off + len >= vol->usable_leb_size)
+			len = vol->usable_leb_size - off;
+
+		ret = ubi_read(&desc, (int)lnum, tbuf, 0, tbuf_size);
+		if (ret) {
+			pr_err("Failed to read leb %lld (%d)\n", lnum, ret);
+			goto exit;
+		}
+
+		memcpy(tbuf + off, buf, len);
+
+		ret = ubi_leb_change(&desc, (int)lnum, tbuf, tbuf_size);
+		if (ret) {
+			pr_err("Failed to write leb %lld (%d)\n", lnum, ret);
+			goto exit;
+		}
+
+		off += len;
+		if (off >= vol->usable_leb_size) {
+			lnum++;
+			off -= vol->usable_leb_size;
+		}
+
+		buf += len;
+		size -= len;
+	} while (size);
+
+exit:
+	free(tbuf);
+	return ret;
+}
+
+int ubi_volume_write(char *volume, void *buf, loff_t offset, size_t size)
+{
+	if (!offset)
+		return ubi_volume_begin_write(volume, buf, size, size);
+
+	return ubi_volume_offset_write(volume, buf, offset, size);
 }
 
-int ubi_volume_read(char *volume, char *buf, size_t size)
+int ubi_volume_read(char *volume, char *buf, loff_t offset, size_t size)
 {
 	int err, lnum, off, len, tbuf_size;
 	void *tbuf;
 	unsigned long long tmp;
 	struct ubi_volume *vol;
-	loff_t offp = 0;
+	loff_t offp = offset;
 	size_t len_read;
 
 	vol = ubi_find_volume(volume);
@@ -769,7 +835,7 @@ static int do_ubi(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 						(void *)addr, size, full_size);
 			}
 		} else {
-			ret = ubi_volume_write(argv[3], (void *)addr, size);
+			ret = ubi_volume_write(argv[3], (void *)addr, 0, size);
 		}
 		if (!ret) {
 			printf("%lld bytes written to volume %s\n", size,
@@ -795,7 +861,7 @@ static int do_ubi(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 		}
 
 		if (argc == 3) {
-			return ubi_volume_read(argv[3], (char *)addr, size);
+			return ubi_volume_read(argv[3], (char *)addr, 0, size);
 		}
 	}