FANOTIFY_MARK
Section: Linux Programmer's Manual (2)
Updated: 2014-04-24
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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(2)
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
fanotify_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
flag
contains
FAN_MARK_MOUNT,
all marks for mounts are removed from the group.
Otherwise, all marks for directories 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 specified,
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_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(2),
readdir(2)
(but see BUGS), and
closedir(2)
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 interpreting
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
pathname
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_UNLIMITED_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
CONFIG_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
As of Linux 3.15,
the following bugs exist:
- *
-
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(2)
is called with
FAN_MARK_FLUSH,
flags
is not checked for invalid values.
SEE ALSO
fanotify_init(2),
fanotify(7)
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ERRORS
-
- VERSIONS
-
- CONFORMING TO
-
- BUGS
-
- SEE ALSO
-
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Time: 02:54:50 GMT, September 18, 2014