From fd70236249f38ffd8fb186398ab1defaf5e55afe Mon Sep 17 00:00:00 2001
From: relan <relan@users.noreply.github.com>
Date: Fri, 21 Jan 2011 20:54:34 +0000
Subject: [PATCH] Add functions that get and set volume label.

---
 libexfat/exfat.h |  4 +++
 libexfat/node.c  | 74 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 78 insertions(+)

diff --git a/libexfat/exfat.h b/libexfat/exfat.h
index 5481917..66ed078 100644
--- a/libexfat/exfat.h
+++ b/libexfat/exfat.h
@@ -85,6 +85,8 @@ struct exfat
 		int dirty;
 	}
 	cmap;
+	char label[EXFAT_ENAME_MAX * 6 + 1]; /* a character can occupy up to
+											6 bytes in UTF-8 */
 	void* zero_block;
 	int dmask, fmask;
 	uid_t uid;
@@ -178,6 +180,8 @@ int exfat_rename(struct exfat* ef, const char* old_path, const char* new_path);
 void exfat_utimes(struct exfat_node* node, const struct timespec tv[2]);
 void exfat_update_atime(struct exfat_node* node);
 void exfat_update_mtime(struct exfat_node* node);
+const char* exfat_get_label(struct exfat* ef);
+int exfat_set_label(struct exfat* ef, const char* label);
 
 int exfat_mount(struct exfat* ef, const char* spec, const char* options);
 void exfat_unmount(struct exfat* ef);
diff --git a/libexfat/node.c b/libexfat/node.c
index 19bee9c..965c12b 100644
--- a/libexfat/node.c
+++ b/libexfat/node.c
@@ -348,6 +348,9 @@ static int readdir(struct exfat* ef, const struct exfat_node* parent,
 				exfat_error("too long label (%hhu chars)", label->length);
 				return -EIO;
 			}
+			if (utf16_to_utf8(ef->label, label->name,
+						sizeof(ef->label), EXFAT_ENAME_MAX) != 0)
+				return -EIO;
 			break;
 
 		default:
@@ -937,3 +940,74 @@ void exfat_update_mtime(struct exfat_node* node)
 	node->mtime = time(NULL);
 	node->flags |= EXFAT_ATTRIB_DIRTY;
 }
+
+const char* exfat_get_label(struct exfat* ef)
+{
+	return ef->label;
+}
+
+static int find_label(struct exfat* ef, cluster_t* cluster, off_t* offset)
+{
+	struct iterator it;
+	int rc;
+	const struct exfat_entry* entry;
+
+	rc = opendir(ef, ef->root, &it);
+	if (rc != 0)
+		return rc;
+
+	for (;;)
+	{
+		entry = (const struct exfat_entry*)
+				(it.chunk + it.offset % CLUSTER_SIZE(*ef->sb));
+
+		if (entry->type == EXFAT_ENTRY_EOD)
+		{
+			closedir(&it);
+			return -ENOENT;
+		}
+		if (entry->type == EXFAT_ENTRY_LABEL)
+		{
+			*cluster = it.cluster;
+			*offset = it.offset;
+			closedir(&it);
+			return 0;
+		}
+
+		if (fetch_next_entry(ef, ef->root, &it) != 0)
+		{
+			closedir(&it);
+			return -EIO;
+		}
+	}
+}
+
+int exfat_set_label(struct exfat* ef, const char* label)
+{
+	le16_t label_utf16[EXFAT_ENAME_MAX + 1];
+	int rc;
+	cluster_t cluster;
+	off_t offset;
+	struct exfat_entry_label entry;
+
+	memset(label_utf16, 0, sizeof(label_utf16));
+	rc = utf8_to_utf16(label_utf16, label, EXFAT_ENAME_MAX, strlen(label));
+	if (rc != 0)
+		return rc;
+
+	rc = find_label(ef, &cluster, &offset);
+	if (rc == -ENOENT)
+		rc = find_slot(ef, ef->root, &cluster, &offset, 1);
+	if (rc != 0)
+		return rc;
+
+	entry.type = EXFAT_ENTRY_LABEL;
+	entry.length = utf16_length(label_utf16);
+	memcpy(entry.name, label_utf16, sizeof(entry.name));
+	if (entry.length == 0)
+		entry.type ^= EXFAT_ENTRY_VALID;
+
+	exfat_write_raw(&entry, sizeof(struct exfat_entry_label),
+			co2o(ef, cluster, offset), ef->fd);
+	return 0;
+}
-- 
2.11.0