alistair23-linux/include/uapi/linux/fcntl.h
Al Viro a07b200047 vfs: syscall: Add open_tree(2) to reference or clone a mount
open_tree(dfd, pathname, flags)

Returns an O_PATH-opened file descriptor or an error.
dfd and pathname specify the location to open, in usual
fashion (see e.g. fstatat(2)).  flags should be an OR of
some of the following:
	* AT_PATH_EMPTY, AT_NO_AUTOMOUNT, AT_SYMLINK_NOFOLLOW -
same meanings as usual
	* OPEN_TREE_CLOEXEC - make the resulting descriptor
close-on-exec
	* OPEN_TREE_CLONE or OPEN_TREE_CLONE | AT_RECURSIVE -
instead of opening the location in question, create a detached
mount tree matching the subtree rooted at location specified by
dfd/pathname.  With AT_RECURSIVE the entire subtree is cloned,
without it - only the part within in the mount containing the
location in question.  In other words, the same as mount --rbind
or mount --bind would've taken.  The detached tree will be
dissolved on the final close of obtained file.  Creation of such
detached trees requires the same capabilities as doing mount --bind.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-api@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-03-20 18:49:06 -04:00

98 lines
3.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
#ifndef _UAPI_LINUX_FCNTL_H
#define _UAPI_LINUX_FCNTL_H
#include <asm/fcntl.h>
#define F_SETLEASE (F_LINUX_SPECIFIC_BASE + 0)
#define F_GETLEASE (F_LINUX_SPECIFIC_BASE + 1)
/*
* Cancel a blocking posix lock; internal use only until we expose an
* asynchronous lock api to userspace:
*/
#define F_CANCELLK (F_LINUX_SPECIFIC_BASE + 5)
/* Create a file descriptor with FD_CLOEXEC set. */
#define F_DUPFD_CLOEXEC (F_LINUX_SPECIFIC_BASE + 6)
/*
* Request nofications on a directory.
* See below for events that may be notified.
*/
#define F_NOTIFY (F_LINUX_SPECIFIC_BASE+2)
/*
* Set and get of pipe page size array
*/
#define F_SETPIPE_SZ (F_LINUX_SPECIFIC_BASE + 7)
#define F_GETPIPE_SZ (F_LINUX_SPECIFIC_BASE + 8)
/*
* Set/Get seals
*/
#define F_ADD_SEALS (F_LINUX_SPECIFIC_BASE + 9)
#define F_GET_SEALS (F_LINUX_SPECIFIC_BASE + 10)
/*
* Types of seals
*/
#define F_SEAL_SEAL 0x0001 /* prevent further seals from being set */
#define F_SEAL_SHRINK 0x0002 /* prevent file from shrinking */
#define F_SEAL_GROW 0x0004 /* prevent file from growing */
#define F_SEAL_WRITE 0x0008 /* prevent writes */
#define F_SEAL_FUTURE_WRITE 0x0010 /* prevent future writes while mapped */
/* (1U << 31) is reserved for signed error codes */
/*
* Set/Get write life time hints. {GET,SET}_RW_HINT operate on the
* underlying inode, while {GET,SET}_FILE_RW_HINT operate only on
* the specific file.
*/
#define F_GET_RW_HINT (F_LINUX_SPECIFIC_BASE + 11)
#define F_SET_RW_HINT (F_LINUX_SPECIFIC_BASE + 12)
#define F_GET_FILE_RW_HINT (F_LINUX_SPECIFIC_BASE + 13)
#define F_SET_FILE_RW_HINT (F_LINUX_SPECIFIC_BASE + 14)
/*
* Valid hint values for F_{GET,SET}_RW_HINT. 0 is "not set", or can be
* used to clear any hints previously set.
*/
#define RWF_WRITE_LIFE_NOT_SET 0
#define RWH_WRITE_LIFE_NONE 1
#define RWH_WRITE_LIFE_SHORT 2
#define RWH_WRITE_LIFE_MEDIUM 3
#define RWH_WRITE_LIFE_LONG 4
#define RWH_WRITE_LIFE_EXTREME 5
/*
* Types of directory notifications that may be requested.
*/
#define DN_ACCESS 0x00000001 /* File accessed */
#define DN_MODIFY 0x00000002 /* File modified */
#define DN_CREATE 0x00000004 /* File created */
#define DN_DELETE 0x00000008 /* File removed */
#define DN_RENAME 0x00000010 /* File renamed */
#define DN_ATTRIB 0x00000020 /* File changed attibutes */
#define DN_MULTISHOT 0x80000000 /* Don't remove notifier */
#define AT_FDCWD -100 /* Special value used to indicate
openat should use the current
working directory. */
#define AT_SYMLINK_NOFOLLOW 0x100 /* Do not follow symbolic links. */
#define AT_REMOVEDIR 0x200 /* Remove directory instead of
unlinking file. */
#define AT_SYMLINK_FOLLOW 0x400 /* Follow symbolic links. */
#define AT_NO_AUTOMOUNT 0x800 /* Suppress terminal automount traversal */
#define AT_EMPTY_PATH 0x1000 /* Allow empty relative pathname */
#define AT_STATX_SYNC_TYPE 0x6000 /* Type of synchronisation required from statx() */
#define AT_STATX_SYNC_AS_STAT 0x0000 /* - Do whatever stat() does */
#define AT_STATX_FORCE_SYNC 0x2000 /* - Force the attributes to be sync'd with the server */
#define AT_STATX_DONT_SYNC 0x4000 /* - Don't sync attributes with the server */
#define AT_RECURSIVE 0x8000 /* Apply to the entire subtree */
#endif /* _UAPI_LINUX_FCNTL_H */