fs-verity: remove unused parameter desc_size in fsverity_create_info()

The parameter desc_size in fsverity_create_info() is useless and it is
not referenced anywhere. The greatest meaning of desc_size here is to
indecate the size of struct fsverity_descriptor and futher calculate the
size of signature. However, the desc->sig_size can do it also and it is
indeed, so remove it.

Therefore, it is no need to acquire desc_size by fsverity_get_descriptor()
in ensure_verity_info(), so remove the parameter desc_ret in
fsverity_get_descriptor() too.

Signed-off-by: Zhang Jianhua <chris.zjh@huawei.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20220518132256.2297655-1-chris.zjh@huawei.com

Author: Zhang Jianhua

fs/verity/enable.c

@@ -281,7 +281,7 @@ static int enable_verity(struct file *filp,
 	 * from disk.  This is simpler, and it serves as an extra check that the
 	 * metadata we're writing is valid before actually enabling verity.
 	 */
-	vi = fsverity_create_info(inode, desc, desc_size);
+	vi = fsverity_create_info(inode, desc);
 	if (IS_ERR(vi)) {
 		err = PTR_ERR(vi);
 		goto rollback;

fs/verity/fsverity_private.h

@@ -122,16 +122,14 @@ int fsverity_init_merkle_tree_params(struct merkle_tree_params *params,
 				     const u8 *salt, size_t salt_size);
 
 struct fsverity_info *fsverity_create_info(const struct inode *inode,
-					   struct fsverity_descriptor *desc,
-					   size_t desc_size);
+					   struct fsverity_descriptor *desc);
 
 void fsverity_set_info(struct inode *inode, struct fsverity_info *vi);
 
 void fsverity_free_info(struct fsverity_info *vi);
 
 int fsverity_get_descriptor(struct inode *inode,
-			    struct fsverity_descriptor **desc_ret,
-			    size_t *desc_size_ret);
+			    struct fsverity_descriptor **desc_ret);
 
 int __init fsverity_init_info_cache(void);
 void __init fsverity_exit_info_cache(void);

fs/verity/open.c

@@ -147,8 +147,7 @@ static int compute_file_digest(struct fsverity_hash_alg *hash_alg,
  * fsverity_descriptor must have already undergone basic validation.
  */
 struct fsverity_info *fsverity_create_info(const struct inode *inode,
-					   struct fsverity_descriptor *desc,
-					   size_t desc_size)
+					   struct fsverity_descriptor *desc)
 {
 	struct fsverity_info *vi;
 	int err;
@@ -264,8 +263,7 @@ static bool validate_fsverity_descriptor(struct inode *inode,
  * the filesystem, and do basic validation of it.
  */
 int fsverity_get_descriptor(struct inode *inode,
-			    struct fsverity_descriptor **desc_ret,
-			    size_t *desc_size_ret)
+			    struct fsverity_descriptor **desc_ret)
 {
 	int res;
 	struct fsverity_descriptor *desc;
@@ -297,7 +295,6 @@ int fsverity_get_descriptor(struct inode *inode,
 	}
 
 	*desc_ret = desc;
-	*desc_size_ret = res;
 	return 0;
 }
 
@@ -306,17 +303,16 @@ static int ensure_verity_info(struct inode *inode)
 {
 	struct fsverity_info *vi = fsverity_get_info(inode);
 	struct fsverity_descriptor *desc;
-	size_t desc_size;
 	int err;
 
 	if (vi)
 		return 0;
 
-	err = fsverity_get_descriptor(inode, &desc, &desc_size);
+	err = fsverity_get_descriptor(inode, &desc);
 	if (err)
 		return err;
 
-	vi = fsverity_create_info(inode, desc, desc_size);
+	vi = fsverity_create_info(inode, desc);
 	if (IS_ERR(vi)) {
 		err = PTR_ERR(vi);
 		goto out_free_desc;

fs/verity/read_metadata.c

@@ -101,7 +101,7 @@ static int fsverity_read_descriptor(struct inode *inode,
 	size_t desc_size;
 	int res;
 
-	res = fsverity_get_descriptor(inode, &desc, &desc_size);
+	res = fsverity_get_descriptor(inode, &desc);
 	if (res)
 		return res;
 
@@ -119,10 +119,9 @@ static int fsverity_read_signature(struct inode *inode,
 				   void __user *buf, u64 offset, int length)
 {
 	struct fsverity_descriptor *desc;
-	size_t desc_size;
 	int res;
 
-	res = fsverity_get_descriptor(inode, &desc, &desc_size);
+	res = fsverity_get_descriptor(inode, &desc);
 	if (res)
 		return res;