On Tue, Aug 14, 2012 at 06:03:45PM +0400, Cyrill Gorcunov wrote: > This patch brings ability to plug in auxiliary fdinfo providers. > For example in further patches eventfd, evenpoll and fsnotify > will print out information associated with files. > > This feature is CONFIG_CHECKPOINT_RESTORE guarded to eliminate > overhead for those who don't need it at all (this > unfortunately makes patch bigger than I wanted). > > The basic usage rule is the following > > - fdinfo provider should register own "show" method > via proc_register_fdinfo_driver call, where "show" > methods are rather well known seq-file operations > > - once the kernel opens /proc/$pid/fdinfo/$fd file > it calls for ->probe() method in registered fdinfo > drivers, and if probe success, then seq-file "show" > operations will be called to provide out additional > infomation > > Initially we considered to inject some "show" metod to > file_operations but since there really a number of > file_operations declared inside kernel (and in real the > further patches cover onle eventfd/epoll/inotify) the > waste of memory space will be inacceptable I think. NAK. This is too ugly to live. Put it into file_operations, with NULL meaning default output, or don't do it at all. And no, "it's only if you enable CONFIG_SOME_SHIT" gambit won't fly - we have all seen it played too many times. All it takes is one politically-inclined induhvidual adding a dependency to some "vertically integrated" turd (*cough* systemd *spit* udev *cough*) and we are stuck with the damn thing. CGROUP shite is already there, DEVTMPFS is well on its way, etc. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
