A new flavor of FAN_MARK_IGNORED_MASK that helps to resolve the ambiguity around the combination of event flags and ignore mask. It is also more strict in the events and flags allowed to be set in a non-directory inode mark mask and it mandates the use of FAN_MARK_IGNORED_SURV_MODIFY flag on filesystem, mount and directory inode marks. Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx> --- Hi Alex, This is an update for a new fanotify feature merged to v6.0-rc1. I am posting this man page update for early review. You would probably want to wait for v6.0 release before merging this anyway. Thanks, Amir. man2/fanotify_mark.2 | 147 ++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 146 insertions(+), 1 deletion(-) diff --git a/man2/fanotify_mark.2 b/man2/fanotify_mark.2 index 757ad9159..e9303827c 100644 --- a/man2/fanotify_mark.2 +++ b/man2/fanotify_mark.2 @@ -146,12 +146,102 @@ capability. The events in .I mask shall be added to or removed from the ignore mask. +Note that the flags +.B FAN_ONDIR , +and +.B FAN_EVENT_ON_CHILD +have no effect in combination with this flag. +The effect of setting those flags in the mask +on ignoring events that are set in the ignore mask +is undefined and depend on the Linux kernel version. +Specifically, prior to Linux 5.9, +.\" commit 497b0c5a7c0688c1b100a9c2e267337f677c198e +setting a mark mask on a file +and a mark with ignore mask on its parent directory +would not result in ignoring events on the file, +regardless of the +.B FAN_EVENT_ON_CHILD +flag in the parent directory's mark mask. +When the ignore mask is updated with the +.B FAN_MARK_IGNORED_MASK +flag, +on a mark that was previously updated with the +.B FAN_MARK_IGNORE +flag, +the update fails with +.B EEXIST +error. +.TP +.BR FAN_MARK_IGNORE " (since Linux 6.0)" +.\" commit e252f2ed1c8c6c3884ab5dd34e003ed21f1fe6e0 +This flag has a similar effect as setting the +.B FAN_MARK_IGNORED_MASK +flag. +The events in +.I mask +shall be added to or removed from the ignore mask. +Unlike the +.B FAN_MARK_IGNORED_MASK +flag, +this flag also has the effect that the +.B FAN_ONDIR , +and +.B FAN_EVENT_ON_CHILD +flags take effect on the ignore mask. +Specifically, unless +.B FAN_ONDIR +flag is set with +.BR FAN_MARK_IGNORE , +events on directories will not be ignored +and if the flag +.B FAN_EVENT_ON_CHILD +is set, +events on children will be ignored. +For example, +a mark on a directory with combination of +a mask with +.B FAN_CREATE +event +and +.B FAN_ONDIR +flag +and an ignore mask with +.B FAN_CREATE +event +and without +.B FAN_ONDIR +flag, +will result in getting only events for creation of sub-directories. +When using this flag to add to an ignore mask +of a mount, filesystem, or directory inode mark, +the +.B FAN_MARK_IGNORED_SURV_MODIFY +flag must be specified. +Failure to do so will results with +.B EINVAL +or +.B EISDIR +error. .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. +This flag cannot be removed from a mark once set. +When the ignore mask is updated without this flag, +on a mark that was previously updated with the +.B FAN_MARK_IGNORE +and +.B FAN_MARK_IGNORED_SURV_MODIFY +flags, +the update fails with +.B EEXIST +error. +.TP +.B FAN_MARK_IGNORE_SURV +This is a synonym for +.RB ( FAN_MARK_IGNORE | FAN_MARK_IGNORED_SURV_MODIFY ). .PP .TP .BR FAN_MARK_EVICTABLE " (since Linux 5.19)" @@ -459,6 +549,32 @@ and the user attempted to update the mark with .B FAN_MARK_EVICTABLE flag. .TP +.B EEXIST +The filesystem object indicated by +.I dirfd +and +.I pathname +has a mark that was updated with the +.B FAN_MARK_IGNORE +flag, +and the user attempted to update the mark with +.B FAN_MARK_IGNORED_MASK +flag. +.TP +.B EEXIST +The filesystem object indicated by +.I dirfd +and +.I pathname +has a mark that was updated with the +.B FAN_MARK_IGNORE +and +.B FAN_MARK_IGNORED_SURV_MODIFY +flags, +and the user attempted to update the mark only with +.B FAN_MARK_IGNORE +flag. +.TP .B EINVAL An invalid value was passed in .I flags @@ -484,8 +600,33 @@ but one or more event types specified in the .I mask require it. .TP +.B EINVAL +.I flags +contains +.BR FAN_MARK_IGNORE , +and either +.B FAN_MARK_MOUNT +or +.BR FAN_MARK_FILESYSTEM , +but does not contain +.BR FAN_MARK_IGNORED_SURV_MODIFY . +.TP +.B EISDIR +.I flags +contains +.BR FAN_MARK_IGNORE , +and +.BR FAN_MARK_IGNORED_SURV_MODIFY , +and +.I dirfd +and +.I pathname +specify a directory. +.TP .B ENODEV The filesystem object indicated by +.I dirfd +and .I pathname is not associated with a filesystem that supports .I fsid @@ -547,8 +688,12 @@ and do not specify a directory. .TP .B ENOTDIR -The fanotify group was initialized with flag +.I flags +contains +.BR FAN_MARK_IGNORE , +or the fanotify group was initialized with flag .BR FAN_REPORT_TARGET_FID , +and .I mask contains directory entry modification events (e.g., -- 2.25.1
