[PATCH 5/7] ntfs: clean up target name conversion for WSL symlinks

[Hyunchul Lee]

WSL symlink target names are stored as narrow NLS/UTF-8 strings on
disk. Converting the target name to Unicode in ntfs_symlink and
converting it back to NLS in ntfs_reparse_set_wsl_symlink is
redundant.

Remove this conversion and pass the symname directly to the reparse
data setter.

Signed-off-by: Hyunchul Lee <hyc.lee@xxxxxxxxx>
---
 fs/ntfs/namei.c   | 17 ++---------------
 fs/ntfs/reparse.c | 49 ++++++++++++++++++++++++-------------------------
 fs/ntfs/reparse.h |  2 +-
 3 files changed, 27 insertions(+), 41 deletions(-)

diff --git a/fs/ntfs/namei.c b/fs/ntfs/namei.c
index 9c1c36acfad2..88c0b05dde3b 100644
--- a/fs/ntfs/namei.c
+++ b/fs/ntfs/namei.c
@@ -394,7 +394,7 @@ static int ntfs_sd_add_everyone(struct ntfs_inode *ni)
 
 static struct ntfs_inode *__ntfs_create(struct mnt_idmap *idmap, struct inode *dir,
 		__le16 *name, u8 name_len, mode_t mode, dev_t dev,
-		__le16 *target, int target_len)
+		const char *target, int target_len)
 {
 	struct ntfs_inode *dir_ni = NTFS_I(dir);
 	struct ntfs_volume *vol = dir_ni->vol;
@@ -1409,9 +1409,7 @@ static int ntfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
 	int err = 0;
 	struct ntfs_inode *ni;
 	__le16 *usrc;
-	__le16 *utarget;
 	int usrc_len;
-	int utarget_len;
 	int symlen = strlen(symname);
 
 	if (NVolShutdown(vol))
@@ -1432,23 +1430,12 @@ static int ntfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
 		goto out;
 	}
 
-	utarget_len = ntfs_nlstoucs(vol, symname, symlen, &utarget,
-				    PATH_MAX);
-	if (utarget_len < 0) {
-		if (utarget_len != -ENAMETOOLONG)
-			ntfs_error(sb, "Failed to convert target name to Unicode.");
-		err =  -ENOMEM;
-		kmem_cache_free(ntfs_name_cache, usrc);
-		goto out;
-	}
-
 	if (!(vol->vol_flags & VOLUME_IS_DIRTY))
 		ntfs_set_volume_flags(vol, VOLUME_IS_DIRTY);
 
 	ni = __ntfs_create(idmap, dir, usrc, usrc_len, S_IFLNK | 0777, 0,
-			utarget, utarget_len);
+			   symname, symlen);
 	kmem_cache_free(ntfs_name_cache, usrc);
-	kvfree(utarget);
 	if (IS_ERR(ni)) {
 		err = PTR_ERR(ni);
 		goto out;
diff --git a/fs/ntfs/reparse.c b/fs/ntfs/reparse.c
index fb8c42a27699..eb1e4424e50d 100644
--- a/fs/ntfs/reparse.c
+++ b/fs/ntfs/reparse.c
@@ -750,39 +750,38 @@ static int ntfs_set_ntfs_reparse_data(struct ntfs_inode *ni, char *value, size_t
  * Set reparse data for a WSL type symlink
  */
 int ntfs_reparse_set_wsl_symlink(struct ntfs_inode *ni,
-		const __le16 *target, int target_len)
+				 const char *target, int target_len)
 {
 	int err = 0;
-	int len;
 	int reparse_len;
-	unsigned char *utarget = NULL;
 	struct reparse_point *reparse;
 	struct wsl_link_reparse_data *data;
 
-	len = ntfs_ucstonls(ni->vol, target, target_len, &utarget, 0);
-	if (len <= 0)
-		return -EINVAL;
-
-	reparse_len = sizeof(struct reparse_point) + sizeof(data->type) + len;
+	reparse_len = sizeof(struct reparse_point) + sizeof(data->type) +
+		target_len;
 	reparse = kvzalloc(reparse_len, GFP_NOFS);
-	if (!reparse) {
-		err = -ENOMEM;
-		kfree(utarget);
-	} else {
-		data = (struct wsl_link_reparse_data *)reparse->reparse_data;
-		reparse->reparse_tag = IO_REPARSE_TAG_LX_SYMLINK;
-		reparse->reparse_data_length =
-			cpu_to_le16(sizeof(data->type) + len);
-		reparse->reserved = 0;
-		data->type = cpu_to_le32(2);
-		memcpy(data->link, utarget, len);
-		err = ntfs_set_ntfs_reparse_data(ni,
-				(char *)reparse, reparse_len);
+	if (!reparse)
+		return -ENOMEM;
+
+	ni->target = kstrdup(target, GFP_NOFS);
+	if (!ni->target) {
 		kvfree(reparse);
-		if (!err)
-			ni->target = utarget;
-		else
-			kfree(utarget);
+		return -ENOMEM;
+	}
+
+	data = (struct wsl_link_reparse_data *)reparse->reparse_data;
+	reparse->reparse_tag = IO_REPARSE_TAG_LX_SYMLINK;
+	reparse->reparse_data_length =
+		cpu_to_le16(sizeof(data->type) + target_len);
+	reparse->reserved = 0;
+	data->type = cpu_to_le32(2);
+	memcpy(data->link, target, target_len);
+	err = ntfs_set_ntfs_reparse_data(ni,
+					 (char *)reparse, reparse_len);
+	kvfree(reparse);
+	if (err) {
+		kfree(ni->target);
+		ni->target = NULL;
 	}
 	return err;
 }
diff --git a/fs/ntfs/reparse.h b/fs/ntfs/reparse.h
index ed7b93c359c1..e36557f29677 100644
--- a/fs/ntfs/reparse.h
+++ b/fs/ntfs/reparse.h
@@ -14,7 +14,7 @@ unsigned int ntfs_reparse_tag_dt_types(struct ntfs_volume *vol, unsigned long mr
 int ntfs_translate_symlink_path(struct dentry *dentry, const char *target,
 				char **translated);
 int ntfs_reparse_set_wsl_symlink(struct ntfs_inode *ni,
-			const __le16 *target, int target_len);
+				 const char *target, int target_len);
 int ntfs_reparse_set_wsl_not_symlink(struct ntfs_inode *ni, mode_t mode);
 int ntfs_delete_reparse_index(struct ntfs_inode *ni);
 int ntfs_remove_ntfs_reparse_data(struct ntfs_inode *ni);

-- 
2.43.0