Current-Users archive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]

Re: WAPBL silent file corruption

On Fri, Jan 21, 2011 at 02:32:38PM +0100, Rhialto wrote:
> I was running on my amd64 laptop last night. It is running a
> -current kernel from last October, since release-kernels don't properly
> support its hdaudio. It has WAPBL enabled. Userland is 5.1.
> Sometimes it suffers from spontaneous reboots. That is annoying. But it
> gets worse.
> I had one of those reboots while was running. When I restarted
> it this morning, a whole bunch of object files was corrupted. I removed
> a few directories worth of files, because many of them were filled with
> 00 instead of being valid object files.
> A re-restarted build failed again, since some library was apparenty
> corrupt too. (The symptom was unresolved symbols when linking)
> If WAPBL doesn't guarantee that my files are either correct or absent, I
> want Soft Dependencies back! Suppose I had made a backup of silently
> corrupted files, discarding valid originals!

Maybe revision 1.38 of sys/kern/vfs_wapbl.c could help:

date: 2010/11/09 16:30:26;  author: hannken;  state: Exp;  lines: +8 -5
Wapbl_register_deallocation(): the taken reader lock is not sufficient to
protect wl_dealloc* members.  Take the mutex here and change the lock
requirements of these fields to "writer lock or mutex".

This error lead to file system corruption and "freeing free block" panics.

Juergen Hannken-Illjes - - TU Braunschweig 

Home | Main Index | Thread Index | Old Index