On Tue, Oct 30, 2012 at 6:34 AM, Greg KH <gre...@linuxfoundation.org> wrote: > On Tue, Oct 30, 2012 at 06:25:50AM +0800, Zhi Yong Wu wrote: >> On Tue, Oct 30, 2012 at 2:11 AM, Greg KH <gre...@linuxfoundation.org> wrote: >> > On Mon, Oct 29, 2012 at 12:30:55PM +0800, zwu.ker...@gmail.com wrote: >> >> From: Zhi Yong Wu <wu...@linux.vnet.ibm.com> >> >> >> >> The debugfs function is used to get expected dentry. >> > >> > Huh? Why do you need this? Why haven't you added documentation for the >> It is used to determine if one sysfs directory has been created. OK, i >> will add some doc, thanks for your suggestion. > > You didn't answer the "why" part here. How come you think you need ah, Let me say its scenario at first. If we do two mount ops as below: 1.) mount -o loop,hot_track image1 /data1 2.) mount -o loop,hot_track image2 /data2
The mount -o hot_track operation will automatically create one sysfs directory /sys/kernel/debug/hot_track. To prevent this dir being created again when 2.) is done, we need to know if it has existed at first. In my patch, i at first get its dentry by this new function, then determine if its d_inode field is NULL, if no, it means that this sysfs dir has existed. This is the reason that i want to add one new function. > this? Can't you just save off the dentry you created somewhere so you > don't need to look it up again? Because i can't find one appropriate place to save it. > > greg k-h -- Regards, Zhi Yong Wu -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
