lkml.org 
[lkml]   [2005]   [Sep]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Trapping Block I/O
On 9/23/05, Block Device <blockdevice@gmail.com> wrote:
>
> I need to trap _all_ the I/O going to each and every block device
> in the system. I used jprobes to trap calls to generic_make_request.
> Is this the correct/only place to do such a thing ?
> Or do I have to monitor the q->make_request_fn for every device ?
>

Yes, generic_make_request or monitoring q->make_request_fn can trap
the _all_ I/O tpo block devices but other approach might be a little
bit odd/difficult but through that you can get every request to block
device .... the approach is you create a block device and then create
that block device as a wrapper on your device, now use your block
device and in its request function (can alter the data and sectors
etc) and calls generic_make_request for the original device on which
you created wrapper .... So by doing this you can easily monitor
requests (similar to this approach is used in LVM/RAID) ......


--
Fawad Lateef
-
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: 2005-09-23 19:41    [W:0.748 / U:0.236 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site