.\" Copyright (C) 2013, Heinrich Schuchardt .\" .\" %%%LICENSE_START(VERBATIM) .\" Permission is granted to make and distribute verbatim copies of this .\" manual provided the copyright notice and this permission notice are .\" preserved on all copies. .\" .\" Permission is granted to copy and distribute modified versions of .\" this manual under the conditions for verbatim copying, provided that .\" the entire resulting derived work is distributed under the terms of .\" a permission notice identical to this one. .\" .\" Since the Linux kernel and libraries are constantly changing, this .\" manual page may be incorrect or out-of-date. The author(s) assume. .\" no responsibility for errors or omissions, or for damages resulting. .\" from the use of the information contained herein. The author(s) may. .\" not have taken the same level of care in the production of this. .\" manual, which is licensed free of charge, as they might when working. .\" professionally. .\" .\" Formatted or processed versions of this manual, if unaccompanied by .\" the source, must acknowledge the copyright and authors of this work. .\" %%%LICENSE_END .TH FANOTIFY_MARK 2 2020-11-01 "Linux" "Linux Programmer's Manual" .SH NAME fanotify_mark \- add, remove, or modify an fanotify mark on a filesystem object .SH SYNOPSIS .nf .B #include .PP .BI "int fanotify_mark(int " fanotify_fd ", unsigned int " flags , .BI " uint64_t " mask ", int " dirfd \ ", const char *" pathname ); .fi .SH DESCRIPTION For an overview of the fanotify API, see .BR fanotify (7). .PP .BR 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. .PP The .I fanotify_fd argument is a file descriptor returned by .BR fanotify_init (2). .PP .I flags is a bit mask describing the modification to perform. It must include exactly one of the following values: .TP .B FAN_MARK_ADD The events in .I mask will be added to the mark mask (or to the ignore mask). .I mask must be nonempty or the error .B EINVAL will occur. .TP .B FAN_MARK_REMOVE The events in argument .I mask will be removed from the mark mask (or from the ignore mask). .I mask must be nonempty or the error .B EINVAL will occur. .TP .B FAN_MARK_FLUSH Remove either all marks for filesystems, all marks for mounts, or all marks for directories and files from the fanotify group. If .I flags contains .BR FAN_MARK_MOUNT , all marks for mounts are removed from the group. If .I flags contains .BR FAN_MARK_FILESYSTEM , all marks for filesystems are removed from the group. Otherwise, all marks for directories and files are removed. No flag other than and at most one of the flags .B FAN_MARK_MOUNT or .B FAN_MARK_FILESYSTEM can be used in conjunction with .BR FAN_MARK_FLUSH . .I mask is ignored. .PP If none of the values above is specified, or more than one is specified, the call fails with the error .BR EINVAL . .PP In addition, zero or more of the following values may be ORed into .IR flags : .TP .B FAN_MARK_DONT_FOLLOW If .I pathname is a symbolic link, mark the link itself, rather than the file to which it refers. (By default, .BR fanotify_mark () dereferences .I pathname if it is a symbolic link.) .TP .B FAN_MARK_ONLYDIR If the filesystem object to be marked is not a directory, the error .B ENOTDIR shall be raised. .TP .B FAN_MARK_MOUNT Mark the mount point specified by .IR pathname . If .I pathname is not itself a mount point, the mount point containing .I pathname will be marked. All directories, subdirectories, and the contained files of the mount point will be monitored. The events which require that filesystem objects are identified by file handles, such as .BR FAN_CREATE , .BR FAN_ATTRIB , .BR FAN_MOVE , and .BR FAN_DELETE_SELF , cannot be provided as a .IR mask when .I flags contains .BR FAN_MARK_MOUNT . Attempting to do so will result in the error .B EINVAL being returned. .TP .BR FAN_MARK_FILESYSTEM " (since Linux 4.20)" .\" commit d54f4fba889b205e9cd8239182ca5d27d0ac3bc2 Mark the filesystem specified by .IR pathname . The filesystem containing .I pathname will be marked. All the contained files and directories of the filesystem from any mount point will be monitored. .TP .B FAN_MARK_IGNORED_MASK The events in .I mask shall be added to or removed from the ignore mask. .TP .B 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. .PP .I mask defines which events shall be listened for (or which shall be ignored). It is a bit mask composed of the following values: .TP .B FAN_ACCESS Create an event when a file or directory (but see BUGS) is accessed (read). .TP .B FAN_MODIFY Create an event when a file is modified (write). .TP .B FAN_CLOSE_WRITE Create an event when a writable file is closed. .TP .B FAN_CLOSE_NOWRITE Create an event when a read-only file or directory is closed. .TP .B FAN_OPEN Create an event when a file or directory is opened. .TP .BR FAN_OPEN_EXEC " (since Linux 5.0)" .\" commit 9b076f1c0f4869b838a1b7aa0edb5664d47ec8aa Create an event when a file is opened with the intent to be executed. See NOTES for additional details. .TP .BR FAN_ATTRIB " (since Linux 5.1)" .\" commit 235328d1fa4251c6dcb32351219bb553a58838d2 Create an event when the metadata for a file or directory has changed. An fanotify group that identifies filesystem objects by file handles is required. .TP .BR FAN_CREATE " (since Linux 5.1)" .\" commit 235328d1fa4251c6dcb32351219bb553a58838d2 Create an event when a file or directory has been created in a marked parent directory. An fanotify group that identifies filesystem objects by file handles is required. .TP .BR FAN_DELETE " (since Linux 5.1)" .\" commit 235328d1fa4251c6dcb32351219bb553a58838d2 Create an event when a file or directory has been deleted in a marked parent directory. An fanotify group that identifies filesystem objects by file handles is required. .TP .BR FAN_DELETE_SELF " (since Linux 5.1)" .\" commit 235328d1fa4251c6dcb32351219bb553a58838d2 Create an event when a marked file or directory itself is deleted. An fanotify group that identifies filesystem objects by file handles is required. .TP .BR FAN_MOVED_FROM " (since Linux 5.1)" .\" commit 235328d1fa4251c6dcb32351219bb553a58838d2 Create an event when a file or directory has been moved from a marked parent directory. An fanotify group that identifies filesystem objects by file handles is required. .TP .BR FAN_MOVED_TO " (since Linux 5.1)" .\" commit 235328d1fa4251c6dcb32351219bb553a58838d2 Create an event when a file or directory has been moved to a marked parent directory. An fanotify group that identifies filesystem objects by file handles is required. .TP .BR FAN_MOVE_SELF " (since Linux 5.1)" .\" commit 235328d1fa4251c6dcb32351219bb553a58838d2 Create an event when a marked file or directory itself has been moved. An fanotify group that identifies filesystem objects by file handles is required. .TP .B FAN_OPEN_PERM Create an event when a permission to open a file or directory is requested. An fanotify file descriptor created with .B FAN_CLASS_PRE_CONTENT or .B FAN_CLASS_CONTENT is required. .TP .BR FAN_OPEN_EXEC_PERM " (since Linux 5.0)" .\" commit 66917a3130f218dcef9eeab4fd11a71cd00cd7c9 Create an event when a permission to open a file for execution is requested. An fanotify file descriptor created with .B FAN_CLASS_PRE_CONTENT or .B FAN_CLASS_CONTENT is required. See NOTES for additional details. .TP .B FAN_ACCESS_PERM Create an event when a permission to read a file or directory is requested. An fanotify file descriptor created with .B FAN_CLASS_PRE_CONTENT or .B FAN_CLASS_CONTENT is required. .TP .B FAN_ONDIR Create events for directories\(emfor example, when .BR opendir (3), .BR readdir (3) (but see BUGS), and .BR closedir (3) are called. Without this flag, events are created only for files. In the context of directory entry events, such as .BR FAN_CREATE , .BR FAN_DELETE , .BR FAN_MOVED_FROM , and .BR FAN_MOVED_TO , specifying the flag .BR FAN_ONDIR is required in order to create events when subdirectory entries are modified (i.e., .BR mkdir (2)/ .BR rmdir (2)). .TP .B FAN_EVENT_ON_CHILD Events for the immediate children of marked directories shall be created. The flag has no effect when marking mounts and filesystems. Note that events are not generated for children of the subdirectories of marked directories. More specifically, the directory entry modification events .BR FAN_CREATE , .BR FAN_DELETE , .BR FAN_MOVED_FROM , and .BR FAN_MOVED_TO are not generated for any entry modifications performed inside subdirectories of marked directories. Note that the events .BR FAN_DELETE_SELF and .BR FAN_MOVE_SELF are not generated for children of marked directories. To monitor complete directory trees it is necessary to mark the relevant mount or filesystem. .PP The following composed values are defined: .TP .B FAN_CLOSE A file is closed .RB ( FAN_CLOSE_WRITE | FAN_CLOSE_NOWRITE ). .TP .B FAN_MOVE A file or directory has been moved .RB ( FAN_MOVED_FROM | FAN_MOVED_TO ). .PP The filesystem object to be marked is determined by the file descriptor .I dirfd and the pathname specified in .IR pathname : .IP * 3 If .I pathname is NULL, .I dirfd defines the filesystem object to be marked. .IP * If .I pathname is NULL, and .I dirfd takes the special value .BR AT_FDCWD , the current working directory is to be marked. .IP * If .I pathname is absolute, it defines the filesystem object to be marked, and .I dirfd is ignored. .IP * If .I pathname is relative, and .I dirfd does not have the value .BR AT_FDCWD , then the filesystem object to be marked is determined by interpreting .I pathname relative the directory referred to by .IR dirfd . .IP * If .I pathname is relative, and .I dirfd has the value .BR AT_FDCWD , then the filesystem object to be marked is determined by interpreting .I pathname relative the current working directory. .SH RETURN VALUE On success, .BR fanotify_mark () returns 0. On error, \-1 is returned, and .I errno is set to indicate the error. .SH ERRORS .TP .B EBADF An invalid file descriptor was passed in .IR fanotify_fd . .TP .B EINVAL An invalid value was passed in .IR flags or .IR mask , or .I fanotify_fd was not an fanotify file descriptor. .TP .B EINVAL The fanotify file descriptor was opened with .B FAN_CLASS_NOTIF or the fanotify group identifies filesystem objects by file handles and mask contains a flag for permission events .RB ( FAN_OPEN_PERM or .BR FAN_ACCESS_PERM ). .TP .B ENODEV The filesystem object indicated by .I pathname is not associated with a filesystem that supports .I fsid (e.g., .BR tmpfs (5)). This error can be returned only with an fanotify group that identifies filesystem objects by file handles. .TP .B ENOENT The filesystem object indicated by .IR dirfd and .IR pathname does not exist. This error also occurs when trying to remove a mark from an object which is not marked. .TP .B ENOMEM The necessary memory could not be allocated. .TP .B ENOSPC The number of marks exceeds the limit of 8192 and the .B FAN_UNLIMITED_MARKS flag was not specified when the fanotify file descriptor was created with .BR fanotify_init (2). .TP .B ENOSYS This kernel does not implement .BR fanotify_mark (). The fanotify API is available only if the kernel was configured with .BR CONFIG_FANOTIFY . .TP .B ENOTDIR .I flags contains .BR FAN_MARK_ONLYDIR , and .I dirfd and .I pathname do not specify a directory. .TP .B EOPNOTSUPP The object indicated by .I pathname is associated with a filesystem that does not support the encoding of file handles. This error can be returned only with an fanotify group that identifies filesystem objects by file handles. .TP .B EXDEV The filesystem object indicated by .I pathname resides within a filesystem subvolume (e.g., .BR btrfs (5)) which uses a different .I fsid than its root superblock. This error can be returned only with an fanotify group that identifies filesystem objects by file handles. .SH VERSIONS .BR fanotify_mark () was introduced in version 2.6.36 of the Linux kernel and enabled in version 2.6.37. .SH CONFORMING TO This system call is Linux-specific. .SH NOTES .SS FAN_OPEN_EXEC and FAN_OPEN_EXEC_PERM When using either .B FAN_OPEN_EXEC or .B FAN_OPEN_EXEC_PERM within the .IR mask , events of these types will be returned only when the direct execution of a program occurs. More specifically, this means that events of these types will be generated for files that are opened using .BR execve (2), .BR execveat (2), or .BR uselib (2). Events of these types will not be raised in the situation where an interpreter is passed (or reads) a file for interpretation. .PP Additionally, if a mark has also been placed on the Linux dynamic linker, a user should also expect to receive an event for it when an ELF object has been successfully opened using .BR execve (2) or .BR execveat (2). .PP For example, if the following ELF binary were to be invoked and a .BR FAN_OPEN_EXEC mark has been placed on /: .PP .in +4n .EX $ /bin/echo foo .EE .in .PP The listening application in this case would receive .BR FAN_OPEN_EXEC events for both the ELF binary and interpreter, respectively: .PP .in +4n .EX /bin/echo /lib64/ld-linux-x86-64.so.2 .EE .in .SH BUGS The following bugs were present in Linux kernels before version 3.16: .IP * 3 .\" Fixed by commit 0a8dd2db579f7a0ac7033d6b857c3d5dbaa77563 If .I flags contains .BR FAN_MARK_FLUSH , .IR dirfd , and .I pathname must specify a valid filesystem object, even though this object is not used. .IP * .\" Fixed by commit d4c7cf6cffb1bc711a833b5e304ba5bcfe76398b .BR readdir (2) does not generate a .B FAN_ACCESS event. .IP * .\" Fixed by commit cc299a98eb13a9853675a9cbb90b30b4011e1406 If .BR fanotify_mark () is called with .BR FAN_MARK_FLUSH , .I flags is not checked for invalid values. .SH SEE ALSO .BR fanotify_init (2), .BR fanotify (7) .SH COLOPHON This page is part of release 5.10 of the Linux .I 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/.