Hello again. I started on wrapfs, its nice and I can use it for my purpose but I need help on using it transparently. I modified unlink call a bit and so I now want to test wrapfs on my system. I could use it using > mount -t wrapfs /root /mnt/tmp Now if I unlink files from /mnt/tmp wrapfa unlink is called but I want to do this transparently ie. I want to mount /root on itself so that requests to delete files in /root goes through wrapfs. But I am unable to do this I tried > mount -t wrapfs -O /root As described for overlay mounts but this is not working as this does not result in mount call. How can I use wrapfs for overlay mounts ? Or this is not possible ? On Thu, Dec 29, 2011 at 6:42 PM, Rajat Sharma <fs.rajat@xxxxxxxxx> wrote: > You could probably trim down ecryptfs and customize it as per your > need. It has advantage of being in mainline. Just remove encryption > part of it. I wish if Linux provided a framework to do the same. > > -Rajat > > On Thu, Dec 29, 2011 at 6:37 PM, rohan puri <rohan.puri15@xxxxxxxxx> wrote: >> >> >> On Thu, Dec 29, 2011 at 6:02 PM, Gaurav Saxena <grvsaxena419@xxxxxxxxx> >> wrote: >>> >>> On 12/29/11, Rajat Sharma <fs.rajat@xxxxxxxxx> wrote: >>> > well ecryptfs which ships with mainline linux kernel is based upon >>> > stackable approach (wrapfs), do you call it hack? :) >>> Ok. I will try to use wrapfs but it seems its quite old and inactive >>> too. I would have to write a new filesystem extending wrapfs it seems. >>> I would work upon it and ask for help when I get problems. :) >>> Thanks a lot for helping me. >>> > >>> > On Thu, Dec 29, 2011 at 5:36 PM, Gaurav Saxena <grvsaxena419@xxxxxxxxx> >>> > wrote: >>> >> On 12/29/11, Rajat Sharma <fs.rajat@xxxxxxxxx> wrote: >>> >>> Well kprobe is: >>> >>> >>> >>> 1. meant to instrument debugging while developing >>> >>> 2. Is configured with kernel configuration parameters which you can >>> >>> not guarantee to be configured on deployment site. >>> >>> 3. slower as it works with debugger break point instruction and single >>> >>> stepping mode. >>> >>> 4. probing into an instruction and altering behavior might not scale >>> >>> across kernel version and interface changes. >>> >>> >>> >>> But yes, you can technically capture any kernel instruction's virtual >>> >>> address and probe into it. Building solution on top of such >>> >>> instrumentation -- HACK!! :) >>> >> Ok Thanks. I see it will be real slow then as its only a debugging >>> >> mechanism, I also found a hack which uses a kprobe based approach and >>> >> adds a jump code to beginning of system calls. Yes I agree with you , >>> >> I don't want hack which needs to be changed with kernel versions or >>> >> depends on configuration of kernel. >>> >> I will give a try to wrapfs today. :) Is it too a hack ? >>> >>> >>> >>> Did you try looking for LSM as well? >>> >> LSM projects like SELinux ? Actually they need kernel rebuild/ >>> >> reinstall thus I would try not to go for such options. >>> >>> >>> >>> -Rajat >>> >>> >>> >> >>> >> -- >>> >> Thanks and Regards , >>> >> Gaurav >>> > >>> >>> >>> -- >>> Thanks and Regards , >>> Gaurav >>> -- >>> 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 >> >> >> Just to let you know, you can make use of >> http://gauravnaigaonkar.web.officelive.com/Documents/hw2.txt as a reference >> on how to write a stackable file system. This is for linux kernel version >> 2.6.26 >> >> Regards, >> Rohan Puri -- Thanks and Regards , Gaurav -- 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
