On Wed, Sep 04, 2019 at 02:52:40PM +0800, Oliver Sang wrote:
> On Sat, Aug 31, 2019 at 04:42:46PM +0100, Al Viro wrote:
> > On Sat, Aug 31, 2019 at 09:09:17PM +0800, kernel test robot wrote:
> >
> > > [ 13.886602] WARNING: CPU: 0 PID: 541 at fs/dcache.c:338
> > > dentry_free+0x7f/0x90
> > > [ 13.889208] Modules linked in:
> > > [ 13.890276] CPU: 0 PID: 541 Comm: readlink Not tainted
> > > 5.3.0-rc1-00008-ge013ec23b8231 #1
> > > [ 13.892699] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
> > > BIOS 1.10.2-1 04/01/2014
> > > [ 13.895419] RIP: 0010:dentry_free+0x7f/0x90
> > > [ 13.896739] Code: f0 75 cb 48 8d be b0 00 00 00 48 83 c4 08 48 c7 c6
> > > 60 8d cd a5 e9 51 69 e4 ff 48 89 3c 24 48 c7 c7 f8 a9 cb a6 e8 7f 37 e3
> > > ff <0f> 0b 48 8b 34 24 eb 8f 66 0f 1f 84 00 00 00 00 00 66 66 66 66 90
> > > [ 13.901957] RSP: 0018:ffffb5524063fe38 EFLAGS: 00010282
> > > [ 13.903527] RAX: 0000000000000024 RBX: ffff9941878040c0 RCX:
> > > ffffffffa706aa08
> > > [ 13.905566] RDX: 0000000000000000 RSI: 0000000000000096 RDI:
> > > 0000000000000246
> > > [ 13.907612] RBP: 0000000000000000 R08: 0000000000000280 R09:
> > > 0000000000000033
> > > [ 13.909664] R10: 0000000000000000 R11: ffffb5524063fce8 R12:
> > > ffff994187804118
> > > [ 13.911711] R13: ffff99427a810000 R14: ffff994187d7c8f0 R15:
> > > ffff99427a810b80
> > > [ 13.913753] FS: 0000000000000000(0000) GS:ffff9942bfc00000(0000)
> > > knlGS:0000000000000000
> > > [ 13.916187] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
> > > [ 13.917892] CR2: 000000000937458b CR3: 000000006800a000 CR4:
> > > 00000000000006f0
> > > [ 13.919925] Call Trace:
> > > [ 13.920840] __dentry_kill+0x13c/0x1a0
> > > [ 13.922076] path_put+0x12/0x20
> > > [ 13.923148] free_fs_struct+0x1b/0x30
> > > [ 13.924346] do_exit+0x304/0xc40
> > > [ 13.925438] ? __schedule+0x25d/0x670
> > > [ 13.926642] do_group_exit+0x3a/0xa0
> > > [ 13.927817] __ia32_sys_exit_group+0x14/0x20
> > > [ 13.929160] do_fast_syscall_32+0xa9/0x340
> > > [ 13.930565] entry_SYSENTER_compat+0x7f/0x91
> > > [ 13.931924] ---[ end trace 02c6706eb2c2ebf2 ]---
> > >
> > >
> > > To reproduce:
> > >
> > > # build kernel
> > > cd linux
> > > cp config-5.3.0-rc1-00008-ge013ec23b8231 .config
> > > make HOSTCC=gcc-7 CC=gcc-7 ARCH=x86_64 olddefconfig prepare
> > > modules_prepare bzImage
> > >
> > > git clone https://github.com/intel/lkp-tests.git
> > > cd lkp-tests
> > > bin/lkp qemu -k <bzImage> job-script # job-script is attached in
> > > this email
> >
> > Can't reproduce here...
>
> any detail failure by using this reproducer?
>
> >
> > I see one potential problem in there, but I would expect it to have the
> > opposite effect (I really don't believe that it's a ->d_count wraparound -
> > that would've taken much longer than a minute, if nothing else).
> >
> > How reliably is it reproduced on your setup and does the following have
> > any impact, one way or another?
>
> It is always reproduced. We noticed that your branch was rebased. If it's
> still with problem, will let you know.
by testing the below HEAD commit of current branch, the issue gone
commit 46c46f8df9aa425cc4d6bc89d57a6fedf83dc797 (HEAD -> work.namei,
origin/work.namei)
Author: Al Viro <v...@zeniv.linux.org.uk>
Date: Sat Jul 27 16:29:22 2019 -0400
>
> >
> > diff --git a/fs/namei.c b/fs/namei.c
> > index 412479e4c258..671c3c1a3425 100644
> > --- a/fs/namei.c
> > +++ b/fs/namei.c
> > @@ -643,10 +643,8 @@ static bool legitimize_root(struct nameidata *nd)
> > {
> > if (!nd->root.mnt || (nd->flags & LOOKUP_ROOT))
> > return true;
> > - if (unlikely(!legitimize_path(nd, &nd->root, nd->root_seq)))
> > - return false;
> > nd->flags |= LOOKUP_ROOT_GRABBED;
> > - return true;
> > + return legitimize_path(nd, &nd->root, nd->root_seq);
> > }
> >
> > /*
> > _______________________________________________
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> > https://lists.01.org/mailman/listinfo/lkp
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