cifs: Split parse_reparse_point callback to functions: get buffer and parse buffer

Parsing reparse point buffer is generic for all SMB versions and is already
implemented by global function parse_reparse_point().

Getting reparse point buffer from the SMB response is SMB version specific,
so introduce for it a new callback get_reparse_point_buffer.

This functionality split is needed for followup change - getting reparse
point buffer without parsing it.

Signed-off-by: Pali Rohár <[email protected]>
Signed-off-by: Steve French <[email protected]>

Author: pali

fs/smb/client/cifsglob.h

@@ -625,10 +625,8 @@ struct smb_version_operations {
 	bool (*is_status_io_timeout)(char *buf);
 	/* Check for STATUS_NETWORK_NAME_DELETED */
 	bool (*is_network_name_deleted)(char *buf, struct TCP_Server_Info *srv);
-	int (*parse_reparse_point)(struct cifs_sb_info *cifs_sb,
-				   const char *full_path,
-				   struct kvec *rsp_iov,
-				   struct cifs_open_info_data *data);
+	struct reparse_data_buffer * (*get_reparse_point_buffer)(const struct kvec *rsp_iov,
+								 u32 *plen);
 	int (*create_reparse_symlink)(const unsigned int xid,
 				      struct inode *inode,
 				      struct dentry *dentry,

fs/smb/client/inode.c

@@ -1207,10 +1207,13 @@ static int reparse_info_to_fattr(struct cifs_open_info_data *data,
 		/* Check for cached reparse point data */
 		if (data->symlink_target || data->reparse.buf) {
 			rc = 0;
-		} else if (iov && server->ops->parse_reparse_point) {
-			rc = server->ops->parse_reparse_point(cifs_sb,
-							      full_path,
-							      iov, data);
+		} else if (iov && server->ops->get_reparse_point_buffer) {
+			struct reparse_data_buffer *reparse_buf;
+			u32 reparse_len;
+
+			reparse_buf = server->ops->get_reparse_point_buffer(iov, &reparse_len);
+			rc = parse_reparse_point(reparse_buf, reparse_len,
+						 cifs_sb, full_path, data);
 			/*
 			 * If the reparse point was not handled but it is the
 			 * name surrogate which points to directory, then treat

fs/smb/client/reparse.c

@@ -1099,18 +1099,13 @@ int parse_reparse_point(struct reparse_data_buffer *buf,
 	}
 }
 
-int smb2_parse_reparse_point(struct cifs_sb_info *cifs_sb,
-			     const char *full_path,
-			     struct kvec *rsp_iov,
-			     struct cifs_open_info_data *data)
+struct reparse_data_buffer *smb2_get_reparse_point_buffer(const struct kvec *rsp_iov,
+							  u32 *plen)
 {
-	struct reparse_data_buffer *buf;
 	struct smb2_ioctl_rsp *io = rsp_iov->iov_base;
-	u32 plen = le32_to_cpu(io->OutputCount);
-
-	buf = (struct reparse_data_buffer *)((u8 *)io +
-					     le32_to_cpu(io->OutputOffset));
-	return parse_reparse_point(buf, plen, cifs_sb, full_path, data);
+	*plen = le32_to_cpu(io->OutputCount);
+	return (struct reparse_data_buffer *)((u8 *)io +
+					      le32_to_cpu(io->OutputOffset));
 }
 
 static bool wsl_to_fattr(struct cifs_open_info_data *data,

fs/smb/client/reparse.h

@@ -135,9 +135,6 @@ int smb2_create_reparse_symlink(const unsigned int xid, struct inode *inode,
 int smb2_mknod_reparse(unsigned int xid, struct inode *inode,
 		       struct dentry *dentry, struct cifs_tcon *tcon,
 		       const char *full_path, umode_t mode, dev_t dev);
-int smb2_parse_reparse_point(struct cifs_sb_info *cifs_sb,
-			     const char *full_path,
-			     struct kvec *rsp_iov,
-			     struct cifs_open_info_data *data);
+struct reparse_data_buffer *smb2_get_reparse_point_buffer(const struct kvec *rsp_iov, u32 *len);
 
 #endif /* _CIFS_REPARSE_H */

fs/smb/client/smb1ops.c

@@ -970,18 +970,13 @@ static int cifs_query_symlink(const unsigned int xid,
 	return rc;
 }
 
-static int cifs_parse_reparse_point(struct cifs_sb_info *cifs_sb,
-				    const char *full_path,
-				    struct kvec *rsp_iov,
-				    struct cifs_open_info_data *data)
+static struct reparse_data_buffer *cifs_get_reparse_point_buffer(const struct kvec *rsp_iov,
+								 u32 *plen)
 {
-	struct reparse_data_buffer *buf;
 	TRANSACT_IOCTL_RSP *io = rsp_iov->iov_base;
-	u32 plen = le16_to_cpu(io->ByteCount);
-
-	buf = (struct reparse_data_buffer *)((__u8 *)&io->hdr.Protocol +
-					     le32_to_cpu(io->DataOffset));
-	return parse_reparse_point(buf, plen, cifs_sb, full_path, data);
+	*plen = le16_to_cpu(io->ByteCount);
+	return (struct reparse_data_buffer *)((__u8 *)&io->hdr.Protocol +
+					      le32_to_cpu(io->DataOffset));
 }
 
 static bool
@@ -1157,7 +1152,7 @@ struct smb_version_operations smb1_operations = {
 	.rename = CIFSSMBRename,
 	.create_hardlink = CIFSCreateHardLink,
 	.query_symlink = cifs_query_symlink,
-	.parse_reparse_point = cifs_parse_reparse_point,
+	.get_reparse_point_buffer = cifs_get_reparse_point_buffer,
 	.open = cifs_open_file,
 	.set_fid = cifs_set_fid,
 	.close = cifs_close_file,

fs/smb/client/smb2ops.c

@@ -5303,7 +5303,7 @@ struct smb_version_operations smb20_operations = {
 	.unlink = smb2_unlink,
 	.rename = smb2_rename_path,
 	.create_hardlink = smb2_create_hardlink,
-	.parse_reparse_point = smb2_parse_reparse_point,
+	.get_reparse_point_buffer = smb2_get_reparse_point_buffer,
 	.query_mf_symlink = smb3_query_mf_symlink,
 	.create_mf_symlink = smb3_create_mf_symlink,
 	.create_reparse_symlink = smb2_create_reparse_symlink,
@@ -5406,7 +5406,7 @@ struct smb_version_operations smb21_operations = {
 	.unlink = smb2_unlink,
 	.rename = smb2_rename_path,
 	.create_hardlink = smb2_create_hardlink,
-	.parse_reparse_point = smb2_parse_reparse_point,
+	.get_reparse_point_buffer = smb2_get_reparse_point_buffer,
 	.query_mf_symlink = smb3_query_mf_symlink,
 	.create_mf_symlink = smb3_create_mf_symlink,
 	.create_reparse_symlink = smb2_create_reparse_symlink,
@@ -5513,7 +5513,7 @@ struct smb_version_operations smb30_operations = {
 	.unlink = smb2_unlink,
 	.rename = smb2_rename_path,
 	.create_hardlink = smb2_create_hardlink,
-	.parse_reparse_point = smb2_parse_reparse_point,
+	.get_reparse_point_buffer = smb2_get_reparse_point_buffer,
 	.query_mf_symlink = smb3_query_mf_symlink,
 	.create_mf_symlink = smb3_create_mf_symlink,
 	.create_reparse_symlink = smb2_create_reparse_symlink,
@@ -5629,7 +5629,7 @@ struct smb_version_operations smb311_operations = {
 	.unlink = smb2_unlink,
 	.rename = smb2_rename_path,
 	.create_hardlink = smb2_create_hardlink,
-	.parse_reparse_point = smb2_parse_reparse_point,
+	.get_reparse_point_buffer = smb2_get_reparse_point_buffer,
 	.query_mf_symlink = smb3_query_mf_symlink,
 	.create_mf_symlink = smb3_create_mf_symlink,
 	.create_reparse_symlink = smb2_create_reparse_symlink,