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1/* SPDX-License-Identifier: GPL-2.0 */2#ifndef _LINUX_NAMEI_H3#define _LINUX_NAMEI_H4 5#include <linux/fs.h>6#include <linux/kernel.h>7#include <linux/path.h>8#include <linux/fcntl.h>9#include <linux/errno.h>10 11enum { MAX_NESTED_LINKS = 8 };12 13#define MAXSYMLINKS 4014 15/*16 * Type of the last component on LOOKUP_PARENT17 */18enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT};19 20/* pathwalk mode */21#define LOOKUP_FOLLOW 0x0001 /* follow links at the end */22#define LOOKUP_DIRECTORY 0x0002 /* require a directory */23#define LOOKUP_AUTOMOUNT 0x0004 /* force terminal automount */24#define LOOKUP_EMPTY 0x4000 /* accept empty path [user_... only] */25#define LOOKUP_DOWN 0x8000 /* follow mounts in the starting point */26#define LOOKUP_MOUNTPOINT 0x0080 /* follow mounts in the end */27 28#define LOOKUP_REVAL 0x0020 /* tell ->d_revalidate() to trust no cache */29#define LOOKUP_RCU 0x0040 /* RCU pathwalk mode; semi-internal */30 31/* These tell filesystem methods that we are dealing with the final component... */32#define LOOKUP_OPEN 0x0100 /* ... in open */33#define LOOKUP_CREATE 0x0200 /* ... in object creation */34#define LOOKUP_EXCL 0x0400 /* ... in exclusive creation */35#define LOOKUP_RENAME_TARGET 0x0800 /* ... in destination of rename() */36 37/* internal use only */38#define LOOKUP_PARENT 0x001039 40/* Scoping flags for lookup. */41#define LOOKUP_NO_SYMLINKS 0x010000 /* No symlink crossing. */42#define LOOKUP_NO_MAGICLINKS 0x020000 /* No nd_jump_link() crossing. */43#define LOOKUP_NO_XDEV 0x040000 /* No mountpoint crossing. */44#define LOOKUP_BENEATH 0x080000 /* No escaping from starting point. */45#define LOOKUP_IN_ROOT 0x100000 /* Treat dirfd as fs root. */46#define LOOKUP_CACHED 0x200000 /* Only do cached lookup */47#define LOOKUP_LINKAT_EMPTY 0x400000 /* Linkat request with empty path. */48/* LOOKUP_* flags which do scope-related checks based on the dirfd. */49#define LOOKUP_IS_SCOPED (LOOKUP_BENEATH | LOOKUP_IN_ROOT)50 51extern int path_pts(struct path *path);52 53extern int user_path_at(int, const char __user *, unsigned, struct path *) HWJS_SUSPENDS;54 55struct dentry *lookup_one_qstr_excl(const struct qstr *name,56 struct dentry *base,57 unsigned int flags) HWJS_SUSPENDS;58extern int kern_path(const char *, unsigned, struct path *) HWJS_SUSPENDS;59 60extern struct dentry *kern_path_create(int, const char *, struct path *, unsigned int) HWJS_SUSPENDS;61extern struct dentry *user_path_create(int, const char __user *, struct path *, unsigned int) HWJS_SUSPENDS;62extern void done_path_create(struct path *, struct dentry *) HWJS_SUSPENDS;63extern struct dentry *kern_path_locked(const char *, struct path *) HWJS_SUSPENDS;64extern struct dentry *user_path_locked_at(int , const char __user *, struct path *) HWJS_SUSPENDS;65int vfs_path_parent_lookup(struct filename *filename, unsigned int flags,66 struct path *parent, struct qstr *last, int *type,67 const struct path *root) HWJS_SUSPENDS;68int vfs_path_lookup(struct dentry *, struct vfsmount *, const char *,69 unsigned int, struct path *) HWJS_SUSPENDS;70 71extern struct dentry *try_lookup_one_len(const char *, struct dentry *, int) HWJS_SUSPENDS;72extern struct dentry *lookup_one_len(const char *, struct dentry *, int) HWJS_SUSPENDS;73extern struct dentry *lookup_one_len_unlocked(const char *, struct dentry *, int) HWJS_SUSPENDS;74extern struct dentry *lookup_positive_unlocked(const char *, struct dentry *, int) HWJS_SUSPENDS;75struct dentry *lookup_one(struct mnt_idmap *, const char *, struct dentry *, int) HWJS_SUSPENDS;76struct dentry *lookup_one_unlocked(struct mnt_idmap *idmap,77 const char *name, struct dentry *base,78 int len) HWJS_SUSPENDS;79struct dentry *lookup_one_positive_unlocked(struct mnt_idmap *idmap,80 const char *name,81 struct dentry *base, int len) HWJS_SUSPENDS;82 83extern int follow_down_one(struct path *) HWJS_SUSPENDS;84extern int follow_down(struct path *path, unsigned int flags) HWJS_SUSPENDS;85extern int follow_up(struct path *) HWJS_SUSPENDS;86 87extern struct dentry *lock_rename(struct dentry *, struct dentry *) HWJS_SUSPENDS;88extern struct dentry *lock_rename_child(struct dentry *, struct dentry *) HWJS_SUSPENDS;89extern void unlock_rename(struct dentry *, struct dentry *) HWJS_SUSPENDS;90 91/**92 * mode_strip_umask - handle vfs umask stripping93 * @dir: parent directory of the new inode94 * @mode: mode of the new inode to be created in @dir95 *96 * In most filesystems, umask stripping depends on whether or not the97 * filesystem supports POSIX ACLs. If the filesystem doesn't support it umask98 * stripping is done directly in here. If the filesystem does support POSIX99 * ACLs umask stripping is deferred until the filesystem calls100 * posix_acl_create().101 *102 * Some filesystems (like NFSv4) also want to avoid umask stripping by the103 * VFS, but don't support POSIX ACLs. Those filesystems can set SB_I_NOUMASK104 * to get this effect without declaring that they support POSIX ACLs.105 *106 * Returns: mode107 */108static inline umode_t __must_check mode_strip_umask(const struct inode *dir, umode_t mode)109{110 if (!IS_POSIXACL(dir) && !(dir->i_sb->s_iflags & SB_I_NOUMASK))111 mode &= ~current_umask();112 return mode;113}114 115extern int __must_check nd_jump_link(const struct path *path) HWJS_SUSPENDS;116 117static inline void nd_terminate_link(void *name, size_t len, size_t maxlen)118{119 ((char *) name)[min(len, maxlen)] = '\0';120}121 122/**123 * retry_estale - determine whether the caller should retry an operation124 * @error: the error that would currently be returned125 * @flags: flags being used for next lookup attempt126 *127 * Check to see if the error code was -ESTALE, and then determine whether128 * to retry the call based on whether "flags" already has LOOKUP_REVAL set.129 *130 * Returns true if the caller should try the operation again.131 */132static inline bool133retry_estale(const long error, const unsigned int flags)134{135 return unlikely(error == -ESTALE && !(flags & LOOKUP_REVAL));136}137 138#endif /* _LINUX_NAMEI_H */139