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ecf081d1a7
linux/include/asm-generic/fcntl.h
Eric Paris ecf081d1a7 vfs: introduce FMODE_NONOTIFY 
This is a new f_mode which can only be set by the kernel.  It indicates
that the fd was opened by fanotify and should not cause future fanotify
events.  This is needed to prevent fanotify livelock.  An example of
obvious livelock is from fanotify close events.

Process A closes file1
This creates a close event for file1.
fanotify opens file1 for Listener X
Listener X deals with the event and closes its fd for file1.
This creates a close event for file1.
fanotify opens file1 for Listener X
Listener X deals with the event and closes its fd for file1.
This creates a close event for file1.
fanotify opens file1 for Listener X
Listener X deals with the event and closes its fd for file1.
notice a pattern?

The fix is to add the FMODE_NONOTIFY bit to the open filp done by the kernel
for fanotify.  Thus when that file is used it will not generate future
events.

This patch simply defines the bit.

Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28 09:58:54 -04:00

193 lines
4.3 KiB
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#ifndef _ASM_GENERIC_FCNTL_H
#define _ASM_GENERIC_FCNTL_H
#include <linux/types.h>
/*
* FMODE_EXEC is 0x20
* FMODE_NONOTIFY is 0x800000
* These cannot be used by userspace O_* until internal and external open
* flags are split.
* -Eric Paris
*/
#define O_ACCMODE 00000003
#define O_RDONLY 00000000
#define O_WRONLY 00000001
#define O_RDWR 00000002
#ifndef O_CREAT
#define O_CREAT 00000100 /* not fcntl */
#endif
#ifndef O_EXCL
#define O_EXCL 00000200 /* not fcntl */
#endif
#ifndef O_NOCTTY
#define O_NOCTTY 00000400 /* not fcntl */
#endif
#ifndef O_TRUNC
#define O_TRUNC 00001000 /* not fcntl */
#endif
#ifndef O_APPEND
#define O_APPEND 00002000
#endif
#ifndef O_NONBLOCK
#define O_NONBLOCK 00004000
#endif
#ifndef O_DSYNC
#define O_DSYNC 00010000 /* used to be O_SYNC, see below */
#endif
#ifndef FASYNC
#define FASYNC 00020000 /* fcntl, for BSD compatibility */
#endif
#ifndef O_DIRECT
#define O_DIRECT 00040000 /* direct disk access hint */
#endif
#ifndef O_LARGEFILE
#define O_LARGEFILE 00100000
#endif
#ifndef O_DIRECTORY
#define O_DIRECTORY 00200000 /* must be a directory */
#endif
#ifndef O_NOFOLLOW
#define O_NOFOLLOW 00400000 /* don't follow links */
#endif
#ifndef O_NOATIME
#define O_NOATIME 01000000
#endif
#ifndef O_CLOEXEC
#define O_CLOEXEC 02000000 /* set close_on_exec */
#endif
/*
* Before Linux 2.6.33 only O_DSYNC semantics were implemented, but using
* the O_SYNC flag. We continue to use the existing numerical value
* for O_DSYNC semantics now, but using the correct symbolic name for it.
* This new value is used to request true Posix O_SYNC semantics. It is
* defined in this strange way to make sure applications compiled against
* new headers get at least O_DSYNC semantics on older kernels.
*
* This has the nice side-effect that we can simply test for O_DSYNC
* wherever we do not care if O_DSYNC or O_SYNC is used.
*
* Note: __O_SYNC must never be used directly.
*/
#ifndef O_SYNC
#define __O_SYNC 04000000
#define O_SYNC (__O_SYNC|O_DSYNC)
#endif
#ifndef O_NDELAY
#define O_NDELAY O_NONBLOCK
#endif
#define F_DUPFD 0 /* dup */
#define F_GETFD 1 /* get close_on_exec */
#define F_SETFD 2 /* set/clear close_on_exec */
#define F_GETFL 3 /* get file->f_flags */
#define F_SETFL 4 /* set file->f_flags */
#ifndef F_GETLK
#define F_GETLK 5
#define F_SETLK 6
#define F_SETLKW 7
#endif
#ifndef F_SETOWN
#define F_SETOWN 8 /* for sockets. */
#define F_GETOWN 9 /* for sockets. */
#endif
#ifndef F_SETSIG
#define F_SETSIG 10 /* for sockets. */
#define F_GETSIG 11 /* for sockets. */
#endif
#ifndef CONFIG_64BIT
#ifndef F_GETLK64
#define F_GETLK64 12 /* using 'struct flock64' */
#define F_SETLK64 13
#define F_SETLKW64 14
#endif
#endif
#ifndef F_SETOWN_EX
#define F_SETOWN_EX 15
#define F_GETOWN_EX 16
#endif
#define F_OWNER_TID 0
#define F_OWNER_PID 1
#define F_OWNER_PGRP 2
struct f_owner_ex {
int type;
pid_t pid;
};
/* for F_[GET|SET]FL */
#define FD_CLOEXEC 1 /* actually anything with low bit set goes */
/* for posix fcntl() and lockf() */
#ifndef F_RDLCK
#define F_RDLCK 0
#define F_WRLCK 1
#define F_UNLCK 2
#endif
/* for old implementation of bsd flock () */
#ifndef F_EXLCK
#define F_EXLCK 4 /* or 3 */
#define F_SHLCK 8 /* or 4 */
#endif
/* for leases */
#ifndef F_INPROGRESS
#define F_INPROGRESS 16
#endif
/* operations for bsd flock(), also used by the kernel implementation */
#define LOCK_SH 1 /* shared lock */
#define LOCK_EX 2 /* exclusive lock */
#define LOCK_NB 4 /* or'd with one of the above to prevent
blocking */
#define LOCK_UN 8 /* remove lock */
#define LOCK_MAND 32 /* This is a mandatory flock ... */
#define LOCK_READ 64 /* which allows concurrent read operations */
#define LOCK_WRITE 128 /* which allows concurrent write operations */
#define LOCK_RW 192 /* which allows concurrent read & write ops */
#define F_LINUX_SPECIFIC_BASE 1024
#ifndef HAVE_ARCH_STRUCT_FLOCK
#ifndef __ARCH_FLOCK_PAD
#define __ARCH_FLOCK_PAD
#endif
struct flock {
short l_type;
short l_whence;
__kernel_off_t l_start;
__kernel_off_t l_len;
__kernel_pid_t l_pid;
__ARCH_FLOCK_PAD
};
#endif
#ifndef CONFIG_64BIT
#ifndef HAVE_ARCH_STRUCT_FLOCK64
#ifndef __ARCH_FLOCK64_PAD
#define __ARCH_FLOCK64_PAD
#endif
struct flock64 {
short l_type;
short l_whence;
__kernel_loff_t l_start;
__kernel_loff_t l_len;
__kernel_pid_t l_pid;
__ARCH_FLOCK64_PAD
};
#endif
#endif /* !CONFIG_64BIT */
#endif /* _ASM_GENERIC_FCNTL_H */
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