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 4.10 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)