lkml.org 
[lkml]   [2011]   [Dec]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: Intercepting system calls
Hello all , thanks for your reply.

On Fri, Dec 23, 2011 at 8:08 PM, John Stoffel <john@stoffel.org> wrote:
>>>>>> "Gaurav" == Gaurav Saxena <grvsaxena419@gmail.com> writes:
>
> Gaurav> Hello John,
> Gaurav> On Thu, Dec 22, 2011 at 11:22 PM, John Stoffel <john@stoffel.org> wrote:
>>>>>>>> "Gaurav" == Gaurav Saxena <grvsaxena419@gmail.com> writes:
>>>
>>>>> Intercepting system calls is very bad, don't do it.
>>>
> Gaurav> Oh. I will not do it then, could you suggest me something so
> Gaurav> that I could prevent unlink on some file say using kernel
> Gaurav> support. I want to save file on unlink how could I do that
> Gaurav> without kernel support, or how could I do that using a kernel
> Gaurav> module.
>>>
>>> Write a FUSE module to mount the filesystem through, inside your FUSE
>>> module you can intercept the unlink/truncate/write calls and decide
>>> what you want to have happen.
>
> Gaurav> I would like to write it differently for each type of filesystem ?
> Gaurav> Because what operations to call after my function depends on this.
> Gaurav> Also Can I mount "/" in this way ?
>
> Sounds like you really want to use inotify() then, but intercepting
> calls to write/truncate/unlink isn't going to be easy to handle across
> a large spectrum of filesystems without a bunch of hacking.
>
> Maybe if you can explain your requirements more clearly, with an
> example of what you're trying to accomplish, then people could help
> you more.
>
> Also, it might be more appropriate to talk to the 'fs-devel' mailing
> list.  I think it's on kernel.org, but not sure.
>
> John
>

I am trying to write an application which would create a backup for
the system so that it could be restored as it is. For example I create
a backup using my application. I just do nothing at time of backup so
it would be fast. Now whenever I see any deletion I would save that
file so that I could restore it. Also I would like to see for
modification/rename. I cannot do this using inotify as I would be
notified after actual deletion/write. I don't want to use SELinux
because I want to implement this on existing installed system. I was
earlier thinking of replacing system calls for open/unlink with my
custom calls which will call my functions before actual work and then
I would decide what to do I would also want to reject unlink request
for some of the files. But as I now know that its not working in
linux>3.0 . I had also seen dazuko which is not supporting linux>3.0
yet. Also there used to be a redirfs which used to work earlier but
the latest kernel is not supported yet. So I asked this question so
that I could get some solution/method of doing this.
I will try finding fs-devel list.
Thanks to you all for your help.


--
Thanks and Regards ,
Gaurav
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2011-12-23 18:07    [W:0.060 / U:2.884 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site