namei.c File Reference

#include <linux/init.h>
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/namei.h>
#include <linux/pagemap.h>
#include <linux/fsnotify.h>
#include <linux/personality.h>
#include <linux/security.h>
#include <linux/ima.h>
#include <linux/syscalls.h>
#include <linux/mount.h>
#include <linux/audit.h>
#include <linux/capability.h>
#include <linux/file.h>
#include <linux/fcntl.h>
#include <linux/device_cgroup.h>
#include <linux/fs_struct.h>
#include <linux/posix_acl.h>
#include <asm/uaccess.h>
#include "internal.h"
#include "mount.h"

Go to the source code of this file.

Macros
#define	EMBEDDED_NAME_MAX   (PATH_MAX - sizeof(struct filename))

Functions
void	final_putname (struct filename *name)
struct filename *	getname (const char __user *filename)
	EXPORT_SYMBOL (getname)
int	generic_permission (struct inode *inode, int mask)
int	__inode_permission (struct inode *inode, int mask)
int	inode_permission (struct inode *inode, int mask)
void	path_get (struct path *path)
	EXPORT_SYMBOL (path_get)
void	path_put (struct path *path)
	EXPORT_SYMBOL (path_put)
void	nd_jump_link (struct nameidata *nd, struct path *path)
int	follow_up (struct path *path)
int	follow_down_one (struct path *path)
int	follow_down (struct path *path)
unsigned int	full_name_hash (const unsigned char *name, unsigned int len)
	EXPORT_SYMBOL (full_name_hash)
struct dentry *	kern_path_locked (const char *name, struct path *path)
int	kern_path (const char *name, unsigned int flags, struct path *path)
: pointer to file name
vfs_path_lookup - lookup a file path relative to a dentry-vfsmount pair : pointer to dentry of the base directory : pointer to vfs mount of the base directory : lookup flags : pointer to struct path to fill
int	vfs_path_lookup (struct dentry *dentry, struct vfsmount *mnt, const char *name, unsigned int flags, struct path *path)

Variables
int sysctl_protected_symlinks	__read_mostly = 0

: pathname component to lookup
lookup_one_len - filesystem helper to lookup single pathname component : base directory to lookup from : maximum length should be interpreted to Note that this routine is purely a helper for filesystem usage and should not be called by generic code. Also note that by using this function the nameidata argument is passed to the filesystem methods and a filesystem using this helper needs to be prepared for that.
struct inode_operations	page_symlink_inode_operations
struct dentry *	lookup_one_len (const char *name, struct dentry *base, int len)
int	user_path_at_empty (int dfd, const char __user *name, unsigned flags, struct path *path, int *empty)
int	user_path_at (int dfd, const char __user *name, unsigned flags, struct path *path)
struct dentry *	lock_rename (struct dentry *p1, struct dentry *p2)
void	unlock_rename (struct dentry *p1, struct dentry *p2)
int	vfs_create (struct inode *dir, struct dentry *dentry, umode_t mode, bool want_excl)
struct file *	do_filp_open (int dfd, struct filename *pathname, const struct open_flags *op, int flags)
struct file *	do_file_open_root (struct dentry *dentry, struct vfsmount *mnt, const char *name, const struct open_flags *op, int flags)
struct dentry *	kern_path_create (int dfd, const char *pathname, struct path *path, int is_dir)
	EXPORT_SYMBOL (kern_path_create)
void	done_path_create (struct path *path, struct dentry *dentry)
	EXPORT_SYMBOL (done_path_create)
struct dentry *	user_path_create (int dfd, const char __user *pathname, struct path *path, int is_dir)
	EXPORT_SYMBOL (user_path_create)
int	vfs_mknod (struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
	SYSCALL_DEFINE4 (mknodat, int, dfd, const char __user *, filename, umode_t, mode, unsigned, dev)
	SYSCALL_DEFINE3 (mknod, const char __user *, filename, umode_t, mode, unsigned, dev)
int	vfs_mkdir (struct inode *dir, struct dentry *dentry, umode_t mode)
	SYSCALL_DEFINE3 (mkdirat, int, dfd, const char __user *, pathname, umode_t, mode)
	SYSCALL_DEFINE2 (mkdir, const char __user *, pathname, umode_t, mode)
void	dentry_unhash (struct dentry *dentry)
int	vfs_rmdir (struct inode *dir, struct dentry *dentry)
	SYSCALL_DEFINE1 (rmdir, const char __user *, pathname)
int	vfs_unlink (struct inode *dir, struct dentry *dentry)
	SYSCALL_DEFINE3 (unlinkat, int, dfd, const char __user *, pathname, int, flag)
	SYSCALL_DEFINE1 (unlink, const char __user *, pathname)
int	vfs_symlink (struct inode *dir, struct dentry *dentry, const char *oldname)
	SYSCALL_DEFINE3 (symlinkat, const char __user *, oldname, int, newdfd, const char __user *, newname)
	SYSCALL_DEFINE2 (symlink, const char __user *, oldname, const char __user *, newname)
int	vfs_link (struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
	SYSCALL_DEFINE5 (linkat, int, olddfd, const char __user *, oldname, int, newdfd, const char __user *, newname, int, flags)
	SYSCALL_DEFINE2 (link, const char __user *, oldname, const char __user *, newname)
int	vfs_rename (struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry)
	SYSCALL_DEFINE4 (renameat, int, olddfd, const char __user *, oldname, int, newdfd, const char __user *, newname)
	SYSCALL_DEFINE2 (rename, const char __user *, oldname, const char __user *, newname)
int	vfs_readlink (struct dentry *dentry, char __user *buffer, int buflen, const char *link)
int	generic_readlink (struct dentry *dentry, char __user *buffer, int buflen)
int	vfs_follow_link (struct nameidata *nd, const char *link)
int	page_readlink (struct dentry *dentry, char __user *buffer, int buflen)
void *	page_follow_link_light (struct dentry *dentry, struct nameidata *nd)
void	page_put_link (struct dentry *dentry, struct nameidata *nd, void *cookie)
int	__page_symlink (struct inode *inode, const char *symname, int len, int nofs)
int	page_symlink (struct inode *inode, const char *symname, int len)
	EXPORT_SYMBOL (user_path_at)
	EXPORT_SYMBOL (follow_down_one)
	EXPORT_SYMBOL (follow_down)
	EXPORT_SYMBOL (follow_up)
	EXPORT_SYMBOL (get_write_access)
	EXPORT_SYMBOL (lock_rename)
	EXPORT_SYMBOL (lookup_one_len)
	EXPORT_SYMBOL (page_follow_link_light)
	EXPORT_SYMBOL (page_put_link)
	EXPORT_SYMBOL (page_readlink)
	EXPORT_SYMBOL (__page_symlink)
	EXPORT_SYMBOL (page_symlink)
	EXPORT_SYMBOL (page_symlink_inode_operations)
	EXPORT_SYMBOL (kern_path)
	EXPORT_SYMBOL (vfs_path_lookup)
	EXPORT_SYMBOL (inode_permission)
	EXPORT_SYMBOL (unlock_rename)
	EXPORT_SYMBOL (vfs_create)
	EXPORT_SYMBOL (vfs_follow_link)
	EXPORT_SYMBOL (vfs_link)
	EXPORT_SYMBOL (vfs_mkdir)
	EXPORT_SYMBOL (vfs_mknod)
	EXPORT_SYMBOL (generic_permission)
	EXPORT_SYMBOL (vfs_readlink)
	EXPORT_SYMBOL (vfs_rename)
	EXPORT_SYMBOL (vfs_rmdir)
	EXPORT_SYMBOL (vfs_symlink)
	EXPORT_SYMBOL (vfs_unlink)
	EXPORT_SYMBOL (dentry_unhash)
	EXPORT_SYMBOL (generic_readlink)

Macro Definition Documentation

#define EMBEDDED_NAME_MAX   (PATH_MAX - sizeof(struct filename))

Definition at line 130 of file namei.c.

Function Documentation

int __inode_permission	(	struct inode *	inode,
		int	mask
	)

__inode_permission - Check for access rights to a given inode : Inode to check permission on : Right to check for (MAY_READ, MAY_WRITE, MAY_EXEC)

Check for read/write/execute permissions on an inode.

When checking for MAY_APPEND, MAY_WRITE must also be set in .

This does not check for a read-only file system. You probably want inode_permission().

Definition at line 383 of file namei.c.

int __page_symlink	(	struct inode *	inode,
		const char *	symname,
		int	len,
		int	nofs
	)

Definition at line 3995 of file namei.c.

void dentry_unhash

(

struct dentry *

dentry

)

Definition at line 3278 of file namei.c.

struct file* do_file_open_root ( struct dentry *  dentry, struct vfsmount *  mnt, const char *  name, const struct open_flags *  op, int  flags  )

read

Definition at line 3024 of file namei.c.

struct file* do_filp_open ( int  dfd, struct filename *  pathname, const struct open_flags *  op, int  flags  )

read

Definition at line 3010 of file namei.c.

void done_path_create	(	struct path *	path,
		struct dentry *	dentry
	)

Definition at line 3107 of file namei.c.

EXPORT_SYMBOL

(

getname

)

EXPORT_SYMBOL

(

path_get

)

EXPORT_SYMBOL

(

path_put

)

EXPORT_SYMBOL

(

full_name_hash

)

EXPORT_SYMBOL

(

kern_path_create

)

EXPORT_SYMBOL

(

done_path_create

)

EXPORT_SYMBOL

(

user_path_create

)

EXPORT_SYMBOL

(

user_path_at

)

EXPORT_SYMBOL

(

follow_down_one

)

EXPORT_SYMBOL

(

follow_down

)

EXPORT_SYMBOL

(

follow_up

)

EXPORT_SYMBOL

(

get_write_access

)

EXPORT_SYMBOL

(

lock_rename

)

EXPORT_SYMBOL

(

lookup_one_len

)

EXPORT_SYMBOL

(

page_follow_link_light

)

EXPORT_SYMBOL

(

page_put_link

)

EXPORT_SYMBOL

(

page_readlink

)

EXPORT_SYMBOL

(

__page_symlink

)

EXPORT_SYMBOL

(

page_symlink

)

EXPORT_SYMBOL

(

page_symlink_inode_operations

)

EXPORT_SYMBOL

(

kern_path

)

EXPORT_SYMBOL

(

vfs_path_lookup

)

EXPORT_SYMBOL

(

inode_permission

)

EXPORT_SYMBOL

(

unlock_rename

)

EXPORT_SYMBOL

(

vfs_create

)

EXPORT_SYMBOL

(

vfs_follow_link

)

EXPORT_SYMBOL

(

vfs_link

)

EXPORT_SYMBOL

(

vfs_mkdir

)

EXPORT_SYMBOL

(

vfs_mknod

)

EXPORT_SYMBOL

(

generic_permission

)

EXPORT_SYMBOL

(

vfs_readlink

)

EXPORT_SYMBOL

(

vfs_rename

)

EXPORT_SYMBOL

(

vfs_rmdir

)

EXPORT_SYMBOL

(

vfs_symlink

)

EXPORT_SYMBOL

(

vfs_unlink

)

EXPORT_SYMBOL

(

dentry_unhash

)

EXPORT_SYMBOL

(

generic_readlink

)

void final_putname

(

struct filename *

name

)

Definition at line 120 of file namei.c.

int follow_down

(

struct path *

path

)

Definition at line 1178 of file namei.c.

int follow_down_one

(

struct path *

path

)

Definition at line 1066 of file namei.c.

int follow_up

(

struct path *

path

)

Definition at line 898 of file namei.c.

unsigned int full_name_hash	(	const unsigned char *	name,
		unsigned int	len
	)

Definition at line 1730 of file namei.c.

int generic_permission	(	struct inode *	inode,
		int	mask
	)

generic_permission - check for access rights on a Posix-like filesystem : inode to check access rights for : right to check for (MAY_READ, MAY_WRITE, MAY_EXEC, ...)

Used to check for read/write/execute permissions on a file. We use "fsuid" for this, letting us set arbitrary permissions for filesystem access without changing the "normal" uids which are used for other things.

generic_permission is rcu-walk aware. It returns -ECHILD in case an rcu-walk request cannot be satisfied (eg. requires blocking or too much complexity). It would then be called again in ref-walk mode.

Definition at line 311 of file namei.c.

int generic_readlink	(	struct dentry *	dentry,
		char __user *	buffer,
		int	buflen
	)

Definition at line 3926 of file namei.c.

struct filename* getname ( const char __user *  filename )

read

Definition at line 208 of file namei.c.

int inode_permission	(	struct inode *	inode,
		int	mask
	)

inode_permission - Check for access rights to a given inode : Inode to check permission on : Right to check for (MAY_READ, MAY_WRITE, MAY_EXEC)

Check for read/write/execute permissions on an inode. We use fs[ug]id for this, letting us set arbitrary permissions for filesystem access without changing the "normal" UIDs which are used for other things.

When checking for MAY_APPEND, MAY_WRITE must also be set in .

Definition at line 438 of file namei.c.

int kern_path	(	const char *	name,
		unsigned int	flags,
		struct path *	path
	)

Definition at line 2066 of file namei.c.

struct dentry* kern_path_create ( int  dfd, const char *  pathname, struct path *  path, int  is_dir  )

read

Definition at line 3047 of file namei.c.

struct dentry* kern_path_locked ( const char *  name, struct path *  path  )

read

Definition at line 2044 of file namei.c.

struct dentry* lock_rename ( struct dentry *  p1, struct dentry *  p2  )

read

Definition at line 2297 of file namei.c.

struct dentry* lookup_one_len ( const char *  name, struct dentry *  base, int  len  )

read

Definition at line 2120 of file namei.c.

void nd_jump_link	(	struct nameidata *	nd,
		struct path *	path
	)

Definition at line 689 of file namei.c.

void* page_follow_link_light	(	struct dentry *	dentry,
		struct nameidata *	nd
	)

Definition at line 3975 of file namei.c.

void page_put_link	(	struct dentry *	dentry,
		struct nameidata *	nd,
		void *	cookie
	)

Definition at line 3982 of file namei.c.

int page_readlink	(	struct dentry *	dentry,
		char __user *	buffer,
		int	buflen
	)

Definition at line 3963 of file namei.c.

int page_symlink	(	struct inode *	inode,
		const char *	symname,
		int	len
	)

Definition at line 4029 of file namei.c.

void path_get

(

struct path *

path

)

path_get - get a reference to a path : path to get the reference to

Given a path increment the reference count to the dentry and the vfsmount.

Definition at line 454 of file namei.c.

void path_put

(

struct path *

path

)

path_put - put a reference to a path : path to put the reference to

Given a path decrement the reference count to the dentry and the vfsmount.

Definition at line 467 of file namei.c.

SYSCALL_DEFINE1	(	rmdir	,
		const char __user *	,
		pathname
	)

Definition at line 3376 of file namei.c.

SYSCALL_DEFINE1	(	unlink	,
		const char __user *	,
		pathname
	)

Definition at line 3484 of file namei.c.

SYSCALL_DEFINE2	(	mkdir	,
		const char __user *	,
		pathname	,
		umode_t	,
		mode
	)

Definition at line 3258 of file namei.c.

SYSCALL_DEFINE2	(	symlink	,
		const char __user *	,
		oldname	,
		const char __user *	,
		newname
	)

Definition at line 3535 of file namei.c.

SYSCALL_DEFINE2	(	link	,
		const char __user *	,
		oldname	,
		const char __user *	,
		newname
	)

Definition at line 3644 of file namei.c.

SYSCALL_DEFINE2	(	rename	,
		const char __user *	,
		oldname	,
		const char __user *	,
		newname
	)

Definition at line 3899 of file namei.c.

SYSCALL_DEFINE3	(	mknod	,
		const char __user *	,
		filename	,
		umode_t	,
		mode	,
		unsigned	,
		dev
	)

Definition at line 3209 of file namei.c.

SYSCALL_DEFINE3	(	mkdirat	,
		int	,
		dfd	,
		const char __user *	,
		pathname	,
		umode_t	,
		mode
	)

Definition at line 3239 of file namei.c.

SYSCALL_DEFINE3	(	unlinkat	,
		int	,
		dfd	,
		const char __user *	,
		pathname	,
		int	,
		flag
	)

Definition at line 3473 of file namei.c.

SYSCALL_DEFINE3	(	symlinkat	,
		const char __user *	,
		oldname	,
		int	,
		newdfd	,
		const char __user *	,
		newname
	)

Definition at line 3509 of file namei.c.

SYSCALL_DEFINE4	(	mknodat	,
		int	,
		dfd	,
		const char __user *	,
		filename	,
		umode_t	,
		mode	,
		unsigned	,
		dev
	)

Definition at line 3172 of file namei.c.

SYSCALL_DEFINE4	(	renameat	,
		int	,
		olddfd	,
		const char __user *	,
		oldname	,
		int	,
		newdfd	,
		const char __user *	,
		newname
	)

Definition at line 3801 of file namei.c.

SYSCALL_DEFINE5	(	linkat	,
		int	,
		olddfd	,
		const char __user *	,
		oldname	,
		int	,
		newdfd	,
		const char __user *	,
		newname	,
		int	,
		flags
	)

Definition at line 3593 of file namei.c.

void unlock_rename	(	struct dentry *	p1,
		struct dentry *	p2
	)

Definition at line 2327 of file namei.c.

int user_path_at	(	int	dfd,
		const char __user *	name,
		unsigned	flags,
		struct path *	path
	)

Definition at line 2179 of file namei.c.

int user_path_at_empty	(	int	dfd,
		const char __user *	name,
		unsigned	flags,
		struct path *	path,
		int *	empty
	)

Definition at line 2161 of file namei.c.

struct dentry* user_path_create ( int  dfd, const char __user *  pathname, struct path *  path, int  is_dir  )

read

Definition at line 3116 of file namei.c.

int vfs_create	(	struct inode *	dir,
		struct dentry *	dentry,
		umode_t	mode,
		bool	want_excl
	)

Definition at line 2336 of file namei.c.

int vfs_follow_link	(	struct nameidata *	nd,
		const char *	link
	)

Definition at line 3943 of file namei.c.

int vfs_link	(	struct dentry *	old_dentry,
		struct inode *	dir,
		struct dentry *	new_dentry
	)

Definition at line 3540 of file namei.c.

int vfs_mkdir	(	struct inode *	dir,
		struct dentry *	dentry,
		umode_t	mode
	)

Definition at line 3214 of file namei.c.

int vfs_mknod	(	struct inode *	dir,
		struct dentry *	dentry,
		umode_t	mode,
		dev_t	dev
	)

Definition at line 3128 of file namei.c.

int vfs_path_lookup	(	struct dentry *	dentry,
		struct vfsmount *	mnt,
		const char *	name,
		unsigned int	flags,
		struct path *	path
	)

Definition at line 2083 of file namei.c.

int vfs_readlink	(	struct dentry *	dentry,
		char __user *	buffer,
		int	buflen,
		const char *	link
	)

Definition at line 3904 of file namei.c.

int vfs_rename	(	struct inode *	old_dir,
		struct dentry *	old_dentry,
		struct inode *	new_dir,
		struct dentry *	new_dentry
	)

Definition at line 3763 of file namei.c.

int vfs_rmdir	(	struct inode *	dir,
		struct dentry *	dentry
	)

Definition at line 3287 of file namei.c.

int vfs_symlink	(	struct inode *	dir,
		struct dentry *	dentry,
		const char *	oldname
	)

Definition at line 3489 of file namei.c.

int vfs_unlink	(	struct inode *	dir,
		struct dentry *	dentry
	)

Definition at line 3381 of file namei.c.

Variable Documentation

int sysctl_protected_hardlinks __read_mostly = 0

Definition at line 708 of file namei.c.

struct inode_operations page_symlink_inode_operations

Initial value:

= {
    .readlink   = generic_readlink,
    .follow_link    = page_follow_link_light,
    .put_link   = page_put_link,
}

Definition at line 4035 of file namei.c.