1 /* 2 * Copyright (c) 2023 Institute of Parallel And Distributed Systems (IPADS), Shanghai Jiao Tong University (SJTU) 3 * Licensed under the Mulan PSL v2. 4 * You can use this software according to the terms and conditions of the Mulan PSL v2. 5 * You may obtain a copy of Mulan PSL v2 at: 6 * http://license.coscl.org.cn/MulanPSL2 7 * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND, EITHER EXPRESS OR 8 * IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT, MERCHANTABILITY OR FIT FOR A PARTICULAR 9 * PURPOSE. 10 * See the Mulan PSL v2 for more details. 11 */ 12 #ifndef TMPFS_NAMEI_H 13 #define TMPFS_NAMEI_H 14 15 #include "defs.h" 16 17 #define MAX_STACK_SIZE 3 /* Maximum number of nested symlinks */ 18 #define MAX_SYM_CNT 10 /* Maximum number of symlinks in a lookup */ 19 20 /* nd->flags flags */ 21 #define ND_FOLLOW 0x0001 /* follow links at the end */ 22 #define ND_DIRECTORY 0x0002 /* require a directory */ 23 #define ND_EMPTY 0x0004 /* accept empty path */ 24 #define ND_NO_SYMLINKS 0x0008 /* no symlinks during the walk */ 25 #define ND_TRAILING_SLASH 0x0010 /* the path ends with one or more slashes */ 26 27 struct nameidata { 28 struct dentry *current; 29 struct string last; 30 unsigned int flags; 31 int last_type; /* LAST_NORM, LAST_DOT, LAST_DOTDOT */ 32 unsigned depth; 33 int total_link_count; 34 const char *stack[MAX_STACK_SIZE]; /* saved pathname when handling 35 symlinks */ 36 }; 37 38 int path_parentat(struct nameidata *nd, const char *name, unsigned flags, 39 struct dentry **parent); 40 int path_lookupat(struct nameidata *nd, const char *name, unsigned flags, 41 struct dentry **dentry); 42 int path_openat(struct nameidata *nd, const char *name, unsigned open_flags, 43 unsigned flags, struct dentry **dentry); 44 45 #endif /* TMPFS_NAMEI_H */