On Wed, Jan 21, 2004 at 02:48:04PM -0800, Andrew Morton wrote:
> Jim Faulkner <jfaulkne@ccs.neu.edu> wrote:
> >
> > 
> > Hello,
> > 
> > I am seeing some scary looking kernel bug entries in my dmesg under
> > 2.6.1-mm5.
> > ...
> 
> > kernel BUG at fs/dcache.c:760!
> > invalid operand: 0000 [#1]
> > PREEMPT SMP
> > CPU:    0
> > EIP:    0060:[<c0179627>]    Not tainted VLI
> > EFLAGS: 00010287
> > EIP is at d_instantiate+0x17/0x90
> > eax: f7baf200   ebx: c1b8bac0   ecx: 000021a4   edx: 00000000
> > esi: f7a4f868   edi: f7baf200   ebp: f7a4f840   esp: f7a79e3c
> > ds: 007b   es: 007b   ss: 0068
> > Process hotplug (pid: 24, threadinfo=f7a78000 task=c1b06d00)
> > Stack: 00000000 f7a992e4 c1b8bac0 c1b35940 f7a78000 f7a4f840 c01ad6de
> > f7a4f840
> >        f7baf200 f7a4f840 f7a41e1c c1bbeb40 00000000 c1b06d00 c011f5b0
> > 00000000
> >        00000000 f7a96d00 c1b06d00 c011bb7d 00000000 c1b06d00 c011f5b0
> > 00000000
> > Call Trace:
> >  [<c01ad6de>] devfs_d_revalidate_wait+0xbe/0x1b0
> >  [<c011f5b0>] default_wake_function+0x0/0x20
> >  [<c011bb7d>] do_page_fault+0x32d/0x512
> >  [<c011f5b0>] default_wake_function+0x0/0x20
> >  [<c016e868>] do_lookup+0x68/0xb0
> >  [<c016ede8>] link_path_walk+0x538/0xa30
> >  [<c016fd03>] open_namei+0x83/0x420
> >  [<c011b850>] do_page_fault+0x0/0x512
> >  [<c040d4cb>] error_code+0x2f/0x38
> >  [<c015e61e>] filp_open+0x3e/0x70
> >  [<c015eb9b>] sys_open+0x5b/0x90
> >  [<c040c992>] sysenter_past_esp+0x43/0x65
> 
> hmm.  There was a patch in that area which I have subsequently dropped
> because it was really fixing devfs problems in the wrong place.
> 
> Perhaps Andrey can ask you to test a subsequent patch if he takes another
> look at this.
> 
> 

good. here is extended version that includes the same fix + some
cleanup. It removes dead code, removes long obsolete attempt to manage
module refcounting, unifies bdev and cdev - they are treated equal now.

andrew please consider for -mm for testing.

More cleanup will follow.


-andrey