From ba4ab5f2da4b84886f9b445881ed55c2d858dd39 Mon Sep 17 00:00:00 2001
From: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Date: Fri, 28 Jan 2022 16:30:24 +0800
Subject: [PATCH] fs/ntfs3: Refactor ni_parse_reparse

mainline inclusion
from mainline-v5.15
commit cd4c76ff807c1afeed89f1b7e311760c0e296349
category: feature
bugzilla:
https://gitee.com/openeuler/kernel/issues/I4G67J?from=project-issue
CVE: NA

----------------------------------------------------------------------

Change argument from void* to struct REPARSE_DATA_BUFFER*
We copy data to buffer, so we can read it later in ntfs_read_mft.

Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Signed-off-by: Yin Xiujiang <yinxiujiang@kylinos.cn>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Acked-by: Hou Tao <houtao1@huawei.com>
Acked-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
---
 fs/ntfs3/frecord.c | 9 +++++----
 fs/ntfs3/ntfs_fs.h | 2 +-
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/fs/ntfs3/frecord.c b/fs/ntfs3/frecord.c
index 007602badd90..ecb965e4afd0 100644
--- a/fs/ntfs3/frecord.c
+++ b/fs/ntfs3/frecord.c
@@ -1710,18 +1710,16 @@ int ni_new_attr_flags(struct ntfs_inode *ni, enum FILE_ATTRIBUTE new_fa)
 /*
  * ni_parse_reparse
  *
- * Buffer is at least 24 bytes.
+ * buffer - memory for reparse buffer header
  */
 enum REPARSE_SIGN ni_parse_reparse(struct ntfs_inode *ni, struct ATTRIB *attr,
-				   void *buffer)
+				   struct REPARSE_DATA_BUFFER *buffer)
 {
 	const struct REPARSE_DATA_BUFFER *rp = NULL;
 	u8 bits;
 	u16 len;
 	typeof(rp->CompressReparseBuffer) *cmpr;
 
-	static_assert(sizeof(struct REPARSE_DATA_BUFFER) <= 24);
-
 	/* Try to estimate reparse point. */
 	if (!attr->non_res) {
 		rp = resident_data_ex(attr, sizeof(struct REPARSE_DATA_BUFFER));
@@ -1807,6 +1805,9 @@ enum REPARSE_SIGN ni_parse_reparse(struct ntfs_inode *ni, struct ATTRIB *attr,
 		return REPARSE_NONE;
 	}
 
+	if (buffer != rp)
+		memcpy(buffer, rp, sizeof(struct REPARSE_DATA_BUFFER));
+
 	/* Looks like normal symlink. */
 	return REPARSE_LINK;
 }
diff --git a/fs/ntfs3/ntfs_fs.h b/fs/ntfs3/ntfs_fs.h
index 9277b552f257..e95d93c683ed 100644
--- a/fs/ntfs3/ntfs_fs.h
+++ b/fs/ntfs3/ntfs_fs.h
@@ -547,7 +547,7 @@ struct ATTR_FILE_NAME *ni_fname_type(struct ntfs_inode *ni, u8 name_type,
 				     struct ATTR_LIST_ENTRY **entry);
 int ni_new_attr_flags(struct ntfs_inode *ni, enum FILE_ATTRIBUTE new_fa);
 enum REPARSE_SIGN ni_parse_reparse(struct ntfs_inode *ni, struct ATTRIB *attr,
-				   void *buffer);
+				   struct REPARSE_DATA_BUFFER *buffer);
 int ni_write_inode(struct inode *inode, int sync, const char *hint);
 #define _ni_write_inode(i, w) ni_write_inode(i, w, __func__)
 int ni_fiemap(struct ntfs_inode *ni, struct fiemap_extent_info *fieinfo,
-- 
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