diff options
Diffstat (limited to 'kernel/include/linux/namei.h')
| -rw-r--r-- | kernel/include/linux/namei.h | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/kernel/include/linux/namei.h b/kernel/include/linux/namei.h new file mode 100644 index 000000000..c8990779f --- /dev/null +++ b/kernel/include/linux/namei.h @@ -0,0 +1,98 @@ +#ifndef _LINUX_NAMEI_H +#define _LINUX_NAMEI_H + +#include <linux/dcache.h> +#include <linux/errno.h> +#include <linux/linkage.h> +#include <linux/path.h> + +struct vfsmount; +struct nameidata; + +enum { MAX_NESTED_LINKS = 8 }; + +/* + * Type of the last component on LOOKUP_PARENT + */ +enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND}; + +/* + * The bitmask for a lookup event: + * - follow links at the end + * - require a directory + * - ending slashes ok even for nonexistent files + * - internal "there are more path components" flag + * - dentry cache is untrusted; force a real lookup + * - suppress terminal automount + */ +#define LOOKUP_FOLLOW 0x0001 +#define LOOKUP_DIRECTORY 0x0002 +#define LOOKUP_AUTOMOUNT 0x0004 + +#define LOOKUP_PARENT 0x0010 +#define LOOKUP_REVAL 0x0020 +#define LOOKUP_RCU 0x0040 + +/* + * Intent data + */ +#define LOOKUP_OPEN 0x0100 +#define LOOKUP_CREATE 0x0200 +#define LOOKUP_EXCL 0x0400 +#define LOOKUP_RENAME_TARGET 0x0800 + +#define LOOKUP_JUMPED 0x1000 +#define LOOKUP_ROOT 0x2000 +#define LOOKUP_EMPTY 0x4000 + +extern int user_path_at(int, const char __user *, unsigned, struct path *); +extern int user_path_at_empty(int, const char __user *, unsigned, struct path *, int *empty); + +#define user_path(name, path) user_path_at(AT_FDCWD, name, LOOKUP_FOLLOW, path) +#define user_lpath(name, path) user_path_at(AT_FDCWD, name, 0, path) +#define user_path_dir(name, path) \ + user_path_at(AT_FDCWD, name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, path) + +extern int kern_path(const char *, unsigned, struct path *); + +extern struct dentry *kern_path_create(int, const char *, struct path *, unsigned int); +extern struct dentry *user_path_create(int, const char __user *, struct path *, unsigned int); +extern void done_path_create(struct path *, struct dentry *); +extern struct dentry *kern_path_locked(const char *, struct path *); +extern int kern_path_mountpoint(int, const char *, struct path *, unsigned int); + +extern struct dentry *lookup_one_len(const char *, struct dentry *, int); + +extern int follow_down_one(struct path *); +extern int follow_down(struct path *); +extern int follow_up(struct path *); + +extern struct dentry *lock_rename(struct dentry *, struct dentry *); +extern void unlock_rename(struct dentry *, struct dentry *); + +extern void nd_jump_link(struct nameidata *nd, struct path *path); +extern void nd_set_link(struct nameidata *nd, char *path); +extern char *nd_get_link(struct nameidata *nd); + +static inline void nd_terminate_link(void *name, size_t len, size_t maxlen) +{ + ((char *) name)[min(len, maxlen)] = '\0'; +} + +/** + * retry_estale - determine whether the caller should retry an operation + * @error: the error that would currently be returned + * @flags: flags being used for next lookup attempt + * + * Check to see if the error code was -ESTALE, and then determine whether + * to retry the call based on whether "flags" already has LOOKUP_REVAL set. + * + * Returns true if the caller should try the operation again. + */ +static inline bool +retry_estale(const long error, const unsigned int flags) +{ + return error == -ESTALE && !(flags & LOOKUP_REVAL); +} + +#endif /* _LINUX_NAMEI_H */ |