FANOTIFY_MARK(2) manual page
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fanotify_mark - add, remove, or modify an fanotify
mark on a filesystem object
#include <sys/fanotify.h>
int fanotify_mark(int fanotify_fd, unsigned int flags,
uint64_t mask, int dirfdflags ,", const char *" pathname );
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 flags 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(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 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.
On success, fanotify_mark() returns 0. On error, -1 is returned,
and errno is set to indicate the error.
- 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.
fanotify_mark()
was introduced in version 2.6.36 of the Linux kernel and enabled in version
2.6.37.
This system call is Linux-specific.
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(2)
is called with FAN_MARK_FLUSH, flags is not checked
for invalid values.
fanotify_init(2)
, fanotify(7)
This page
is part of release 3.78 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 http://www.kernel.org/doc/man-pages/.
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