On Wed, May 11, 2022 at 10:02 PM Amir Goldstein <amir73il@xxxxxxxxx> wrote:
>
> The logic for handling events on child in groups that have a mark on
> the parent inode, but without FS_EVENT_ON_CHILD flag in the mask is
> duplicated in several places and inconsistent.
>
> Move the logic into the preparation of mark type iterator, so that the
> parent mark type will be excluded from all mark type iterations in that
> case.
>
> This results in several subtle changes of behavior, hopefully all
> desired changes of behavior, for example:
>
> - Group A has a mount mark with FS_MODIFY in mask
> - Group A has a mark with ignore mask that does not survive FS_MODIFY
> and does not watch children on directory D.
> - Group B has a mark with FS_MODIFY in mask that does watch children
> on directory D.
> - FS_MODIFY event on file D/foo should not clear the ignore mask of
> group A, but before this change it does
>
> And if group A ignore mask was set to survive FS_MODIFY:
> - FS_MODIFY event on file D/foo should be reported to group A on account
> of the mount mark, but before this change it is wrongly ignored
>
> Fixes: 2f02fd3fa13e ("fanotify: fix ignore mask logic for events on child and on dir")
> Reported-by: Jan Kara <jack@xxxxxxxx>
> Link: https://lore.kernel.org/linux-fsdevel/20220314113337.j7slrb5srxukztje@xxxxxxxxxx/
> Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
> ---
Greg,
FYI, this needs the previous commit to apply to 5.18.y:
e730558adffb fsnotify: consistent behavior for parent not watching children
14362a254179 fsnotify: introduce mark type iterator
They won't apply to earlier versions and this is a fix for a very minor bug
that existed forever, so no need to bother.
Thanks,
Amir.
