FANOTIFY_MARK(2) Linux Programmer's Manual FANOTIFY_MARK(2)
NAME
fanotify_mark - add, remove, or modify an fanotify mark on a filesystem
object
SYNOPSIS
#include <sys/fanotify.h>
int fanotify_mark(int fanotify_fd, unsigned int flags,
uint64_t mask, int dirfd, const char *pathname);
DESCRIPTION
For an overview of the fanotify API, see fanotify(7).
fanotify_mark() adds, removes, or modifies an fanotify mark on a
filesystem object. The caller must have read permission on the
filesystem object that is to be marked.
The fanotify_fd argument is a file descriptor returned by fan-
otify_init(2).
flags is a bit mask describing the modification to perform. It must
include exactly one of the following values:
FAN_MARK_ADD
The events in mask will be added to the mark mask (or to the
ignore mask). mask must be nonempty or the error EINVAL will
occur.
FAN_MARK_REMOVE
The events in argument mask will be removed from the mark mask
(or from the ignore mask). mask must be nonempty or the error
EINVAL will occur.
FAN_MARK_FLUSH
Remove either all mount or all non-mount marks from the fanotify
group. If flags contains FAN_MARK_MOUNT, all marks for mounts
are removed from the group. Otherwise, all marks for directo-
ries and files are removed. No flag other than FAN_MARK_MOUNT
can be used in conjunction with FAN_MARK_FLUSH. mask is
ignored.
If none of the values above is specified, or more than one is speci-
fied, the call fails with the error EINVAL.
In addition, zero or more of the following values may be ORed into
flags:
FAN_MARK_DONT_FOLLOW
If pathname is a symbolic link, mark the link itself, rather
than the file to which it refers. (By default, fanotify_mark()
dereferences pathname if it is a symbolic link.)
FAN_MARK_ONLYDIR
If the filesystem object to be marked is not a directory, the
error ENOTDIR shall be raised.
FAN_MARK_MOUNT
Mark the mount point specified by pathname. If pathname is not
itself a mount point, the mount point containing pathname will
be marked. All directories, subdirectories, and the contained
files of the mount point will be monitored.
FAN_MARK_IGNORED_MASK
The events in mask shall be added to or removed from the ignore
mask.
FAN_MARK_IGNORED_SURV_MODIFY
The ignore mask shall survive modify events. If this flag is
not set, the ignore mask is cleared when a modify event occurs
for the ignored file or directory.
mask defines which events shall be listened for (or which shall be
ignored). It is a bit mask composed of the following values:
FAN_ACCESS
Create an event when a file or directory (but see BUGS) is
accessed (read).
FAN_MODIFY
Create an event when a file is modified (write).
FAN_CLOSE_WRITE
Create an event when a writable file is closed.
FAN_CLOSE_NOWRITE
Create an event when a read-only file or directory is closed.
FAN_OPEN
Create an event when a file or directory is opened.
FAN_Q_OVERFLOW
Create an event when an overflow of the event queue occurs. The
size of the event queue is limited to 16384 entries if
FAN_UNLIMITED_QUEUE is not set in fanotify_init(2).
FAN_OPEN_PERM
Create an event when a permission to open a file or directory is
requested. An fanotify file descriptor created with
FAN_CLASS_PRE_CONTENT or FAN_CLASS_CONTENT is required.
FAN_ACCESS_PERM
Create an event when a permission to read a file or directory is
requested. An fanotify file descriptor created with
FAN_CLASS_PRE_CONTENT or FAN_CLASS_CONTENT is required.
FAN_ONDIR
Create events for directories--for example, when opendir(3),
readdir(3) (but see BUGS), and closedir(3) are called. Without
this flag, only events for files are created.
FAN_EVENT_ON_CHILD
Events for the immediate children of marked directories shall be
created. The flag has no effect when marking mounts. Note that
events are not generated for children of the subdirectories of
marked directories. To monitor complete directory trees it is
necessary to mark the relevant mount.
The following composed value is defined:
FAN_CLOSE
A file is closed (FAN_CLOSE_WRITE|FAN_CLOSE_NOWRITE).
The filesystem object to be marked is determined by the file descriptor
dirfd and the pathname specified in pathname:
* If pathname is NULL, dirfd defines the filesystem object to be
marked.
* If pathname is NULL, and dirfd takes the special value AT_FDCWD, the
current working directory is to be marked.
* If pathname is absolute, it defines the filesystem object to be
marked, and dirfd is ignored.
* If pathname is relative, and dirfd does not have the value AT_FDCWD,
then the filesystem object to be marked is determined by interpret-
ing pathname relative the directory referred to by dirfd.
* If pathname is relative, and dirfd has the value AT_FDCWD, then the
filesystem object to be marked is determined by interpreting path-
name relative the current working directory.
RETURN VALUE
On success, fanotify_mark() returns 0. On error, -1 is returned, and
errno is set to indicate the error.
ERRORS
EBADF An invalid file descriptor was passed in fanotify_fd.
EINVAL An invalid value was passed in flags or mask, or fanotify_fd was
not an fanotify file descriptor.
EINVAL The fanotify file descriptor was opened with FAN_CLASS_NOTIF and
mask contains a flag for permission events (FAN_OPEN_PERM or
FAN_ACCESS_PERM).
ENOENT The filesystem object indicated by dirfd and pathname does not
exist. This error also occurs when trying to remove a mark from
an object which is not marked.
ENOMEM The necessary memory could not be allocated.
ENOSPC The number of marks exceeds the limit of 8192 and the FAN_UNLIM-
ITED_MARKS flag was not specified when the fanotify file
descriptor was created with fanotify_init(2).
ENOSYS This kernel does not implement fanotify_mark(). The fanotify
API is available only if the kernel was configured with CON-
FIG_FANOTIFY.
ENOTDIR
flags contains FAN_MARK_ONLYDIR, and dirfd and pathname do not
specify a directory.
VERSIONS
fanotify_mark() was introduced in version 2.6.36 of the Linux kernel
and enabled in version 2.6.37.
CONFORMING TO
This system call is Linux-specific.
BUGS
The following bugs were present in Linux kernels before version 3.16:
* If flags contains FAN_MARK_FLUSH, dirfd and pathname must specify a
valid filesystem object, even though this object is not used.
* readdir(2) does not generate a FAN_ACCESS event.
* If fanotify_mark() is called with FAN_MARK_FLUSH, flags is not
checked for invalid values.
SEE ALSO
fanotify_init(2), fanotify(7)
COLOPHON
This page is part of release 4.15 of the Linux man-pages project. A
description of the project, information about reporting bugs, and the
latest version of this page, can be found at
https://www.kernel.org/doc/man-pages/.
Linux 2016-10-08 FANOTIFY_MARK(2)