On Thu 05-04-18 16:18:03, Amir Goldstein wrote:
> The ignore mask logic in send_to_group() does not match the logic
> in fanotify_should_send_event(). In the latter, a vfsmount mark ignore
> mask precedes an inode mark mask and in the former, it does not.
>
> That difference may cause events to be sent to fanotify backend for no
> reason. Fix the logic in send_to_group() to match that of
> fanotify_should_send_event().
>
> Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
Thanks. The patch looks good and I've merged it to my tree.
Honza
> ---
> fs/notify/fsnotify.c | 25 +++++++++++--------------
> 1 file changed, 11 insertions(+), 14 deletions(-)
>
> diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
> index 219b269c737e..613ec7e5a465 100644
> --- a/fs/notify/fsnotify.c
> +++ b/fs/notify/fsnotify.c
> @@ -192,8 +192,9 @@ static int send_to_group(struct inode *to_tell,
> struct fsnotify_iter_info *iter_info)
> {
> struct fsnotify_group *group = NULL;
> - __u32 inode_test_mask = 0;
> - __u32 vfsmount_test_mask = 0;
> + __u32 test_mask = (mask & ~FS_EVENT_ON_CHILD);
> + __u32 marks_mask = 0;
> + __u32 marks_ignored_mask = 0;
>
> if (unlikely(!inode_mark && !vfsmount_mark)) {
> BUG();
> @@ -213,29 +214,25 @@ static int send_to_group(struct inode *to_tell,
> /* does the inode mark tell us to do something? */
> if (inode_mark) {
> group = inode_mark->group;
> - inode_test_mask = (mask & ~FS_EVENT_ON_CHILD);
> - inode_test_mask &= inode_mark->mask;
> - inode_test_mask &= ~inode_mark->ignored_mask;
> + marks_mask |= inode_mark->mask;
> + marks_ignored_mask |= inode_mark->ignored_mask;
> }
>
> /* does the vfsmount_mark tell us to do something? */
> if (vfsmount_mark) {
> - vfsmount_test_mask = (mask & ~FS_EVENT_ON_CHILD);
> group = vfsmount_mark->group;
> - vfsmount_test_mask &= vfsmount_mark->mask;
> - vfsmount_test_mask &= ~vfsmount_mark->ignored_mask;
> - if (inode_mark)
> - vfsmount_test_mask &= ~inode_mark->ignored_mask;
> + marks_mask |= vfsmount_mark->mask;
> + marks_ignored_mask |= vfsmount_mark->ignored_mask;
> }
>
> pr_debug("%s: group=%p to_tell=%p mask=%x inode_mark=%p"
> - " inode_test_mask=%x vfsmount_mark=%p vfsmount_test_mask=%x"
> + " vfsmount_mark=%p marks_mask=%x marks_ignored_mask=%x"
> " data=%p data_is=%d cookie=%d\n",
> - __func__, group, to_tell, mask, inode_mark,
> - inode_test_mask, vfsmount_mark, vfsmount_test_mask, data,
> + __func__, group, to_tell, mask, inode_mark, vfsmount_mark,
> + marks_mask, marks_ignored_mask, data,
> data_is, cookie);
>
> - if (!inode_test_mask && !vfsmount_test_mask)
> + if (!(test_mask & marks_mask & ~marks_ignored_mask))
> return 0;
>
> return group->ops->handle_event(group, to_tell, inode_mark,
> --
> 2.7.4
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
