Subject: Re: linux-next: Tree for May 2 [WARNING: at fs/dcache.c]

From: Mateusz Guzik <[email-masked]>
Date: Mon, 2 May 2016 12:33:54 +0200

On Mon, May 02, 2016 at 07:15:24PM +0900, Sergey Senozhatsky wrote:
> On (05/02/16 18:40), Stephen Rothwell wrote:
> > Hi all,
> > 
> > Changes since 20160429
> 
> Hello,
> 
> [    0.368791] ------------[ cut here ]------------
> [    0.368850] WARNING: CPU: 0 PID: 1 at fs/dcache.c:1688 d_set_d_op+0x5e/0xcc
> [    0.368911] Modules linked in:
> [    0.369002] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.6.0-rc6-next-20160502-dbg-00005-gf58c9da-dirty #404
> [    0.369161]  0000000000000000 ffff880133067908 ffffffff811b8202 0000000000000000
> [    0.369371]  0000000000000000 ffff880133067948 ffffffff81039365 00000698e5dffe26
> [    0.369580]  ffff880132c090c0 ffffffff81613680 ffff880132c040a0 ffff880132c08000
> [    0.369791] Call Trace:
> [    0.369846]  [<ffffffff811b8202>] dump_stack+0x4d/0x63
> [    0.369904]  [<ffffffff81039365>] __warn+0xb8/0xd3
> [    0.369962]  [<ffffffff810393e6>] warn_slowpath_null+0x18/0x1a
> [    0.370021]  [<ffffffff811012f6>] d_set_d_op+0x5e/0xcc
> [    0.370079]  [<ffffffff8110d887>] simple_lookup+0x2e/0x45

The issue is that 2 macros have the same value:

#define DCACHE_OP_REAL                  0x08000000

#define DCACHE_PAR_LOOKUP               0x08000000 /* being looked up
(with parent locked shared) */

Verified with switching one to 0x10000000 and the warning went away.

-- 
Mateusz Guzik