[PATCH v1 2/6] ubi: allow to write to volume with offset

[Alexey Romanov]

Introduce ubi_volume_offset_write() helper, which
allow to write to ubi volume with specified offset.

Signed-off-by: Alexey Romanov <avromanov at salutedevices.com>
---
 cmd/ubi.c           | 71 +++++++++++++++++++++++++++++++++++++++++++--
 env/ubi.c           | 10 +++----
 include/ubi_uboot.h |  2 +-
 3 files changed, 74 insertions(+), 9 deletions(-)

diff --git a/cmd/ubi.c b/cmd/ubi.c
index 2257f68498..af874b6a46 100644
--- a/cmd/ubi.c
+++ b/cmd/ubi.c
@@ -415,9 +415,74 @@ 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 lnum, len, tbuf_size, ret;
+	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, lnum, tbuf, 0, tbuf_size);
+		if (ret) {
+			pr_err("Failed to read leb %d (%d)\n", lnum, ret);
+			goto exit;
+		}
+
+		memcpy(tbuf + off, buf, len);
+
+		ret = ubi_leb_change(&desc, lnum, tbuf, tbuf_size);
+		if (ret) {
+			pr_err("Failed to write leb %d(%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, loff_t offset, size_t size)
@@ -761,7 +826,7 @@ 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,
diff --git a/env/ubi.c b/env/ubi.c
index 661801d5a9..6ae74a500b 100644
--- a/env/ubi.c
+++ b/env/ubi.c
@@ -54,7 +54,7 @@ static int env_ubi_save(void)
 	if (gd->env_valid == ENV_VALID) {
 		puts("Writing to redundant UBI... ");
 		if (ubi_volume_write(CONFIG_ENV_UBI_VOLUME_REDUND,
-				     (void *)env_new, CONFIG_ENV_SIZE)) {
+				     (void *)env_new, 0, CONFIG_ENV_SIZE)) {
 			printf("\n** Unable to write env to %s:%s **\n",
 			       CONFIG_ENV_UBI_PART,
 			       CONFIG_ENV_UBI_VOLUME_REDUND);
@@ -63,7 +63,7 @@ static int env_ubi_save(void)
 	} else {
 		puts("Writing to UBI... ");
 		if (ubi_volume_write(CONFIG_ENV_UBI_VOLUME,
-				     (void *)env_new, CONFIG_ENV_SIZE)) {
+				     (void *)env_new, 0, CONFIG_ENV_SIZE)) {
 			printf("\n** Unable to write env to %s:%s **\n",
 			       CONFIG_ENV_UBI_PART,
 			       CONFIG_ENV_UBI_VOLUME);
@@ -93,7 +93,7 @@ static int env_ubi_save(void)
 		return 1;
 	}
 
-	if (ubi_volume_write(CONFIG_ENV_UBI_VOLUME, (void *)env_new,
+	if (ubi_volume_write(CONFIG_ENV_UBI_VOLUME, (void *)env_new, 0,
 			     CONFIG_ENV_SIZE)) {
 		printf("\n** Unable to write env to %s:%s **\n",
 		       CONFIG_ENV_UBI_PART, CONFIG_ENV_UBI_VOLUME);
@@ -197,7 +197,7 @@ static int env_ubi_erase(void)
 	memset(env_buf, 0x0, CONFIG_ENV_SIZE);
 
 	if (ubi_volume_write(CONFIG_ENV_UBI_VOLUME,
-			     (void *)env_buf, CONFIG_ENV_SIZE)) {
+			     (void *)env_buf, 0, CONFIG_ENV_SIZE)) {
 		printf("\n** Unable to erase env to %s:%s **\n",
 		       CONFIG_ENV_UBI_PART,
 		       CONFIG_ENV_UBI_VOLUME);
@@ -205,7 +205,7 @@ static int env_ubi_erase(void)
 	}
 	if (IS_ENABLED(CONFIG_SYS_REDUNDAND_ENVIRONMENT)) {
 		if (ubi_volume_write(ENV_UBI_VOLUME_REDUND,
-				     (void *)env_buf, CONFIG_ENV_SIZE)) {
+				     (void *)env_buf, 0, CONFIG_ENV_SIZE)) {
 			printf("\n** Unable to erase env to %s:%s **\n",
 			       CONFIG_ENV_UBI_PART,
 			       ENV_UBI_VOLUME_REDUND);
diff --git a/include/ubi_uboot.h b/include/ubi_uboot.h
index bcccb76e6c..5f046b91a2 100644
--- a/include/ubi_uboot.h
+++ b/include/ubi_uboot.h
@@ -49,7 +49,7 @@ extern int ubi_mtd_param_parse(const char *val, struct kernel_param *kp);
 extern int ubi_init(void);
 extern void ubi_exit(void);
 extern int ubi_part(char *part_name, const char *vid_header_offset);
-extern int ubi_volume_write(char *volume, void *buf, size_t size);
+extern int ubi_volume_write(char *volume, void *buf, loff_t offset, size_t size);
 extern int ubi_volume_read(char *volume, char *buf, loff_t offset, size_t size);
 
 extern struct ubi_device *ubi_devices[];
-- 
2.34.1