On Thursday 28 Oct 2010 22:32:44 Eric Paris wrote:
> Some fanotify groups, especially those like AV scanners, will need to place
> lots of marks, particularly ignore marks. Since ignore marks do not pin
> inodes in cache and are cleared if the inode is removed from core (usually
> under memory pressure) we expose an interface for listeners, with
> CAP_SYS_ADMIN, to override the maximum number of marks and be allowed to
> set and 'unlimited' number of marks. Programs which make use of this
> feature will be able to OOM a machine.
>
> Signed-off-by: Eric Paris <[email protected]>
> ---
>
> fs/notify/fanotify/fanotify_user.c | 9 ++++++++-
> include/linux/fanotify.h | 4 +++-
> 2 files changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/fs/notify/fanotify/fanotify_user.c
> b/fs/notify/fanotify/fanotify_user.c index 1d33d7d..f921610 100644
> --- a/fs/notify/fanotify/fanotify_user.c
> +++ b/fs/notify/fanotify/fanotify_user.c
> @@ -707,7 +707,14 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags,
> unsigned int, event_f_flags) group->max_events =
> FANOTIFY_DEFAULT_MAX_EVENTS;
> }
>
> - group->fanotify_data.max_marks = FANOTIFY_DEFAULT_MAX_MARKS;
> + if (flags & FAN_UNLIMITED_MARKS) {
> + fd = -EPERM;
> + if (!capable(CAP_SYS_ADMIN))
> + goto out_put_group;
Same redundant (or not) capable as with queue depth.
Tvrtko
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