Re: can't boot with reiserfs on linux-4.6.0+

[Al Viro]

On Tue, May 24, 2016 at 10:10:18PM +0800, Jeff Chua wrote:
> Seems to break after index 348619f..d55dc5a 100644
>
> Boot up with ext4 works, but try anything to access anything on the
> reiser partition such as "/mnt/bin/passwd" resulted in the following
> ...
> 
> [   93.380353] BUG: unable to handle kernel NULL pointer dereference
> at           (null)
> [   93.380924] IP: [<ffffffff81101ad7>] 0xffffffff81101ad7
> [   93.381476] PGD 40520a067 PUD 4052f0067 PMD 0
> [   93.381974] Oops: 0000 [#6] SMP
> [   93.382480] Modules linked in: usbhid
> [   93.382972] CPU: 0 PID: 1888 Comm: bash Tainted: G      D         4.6.0 #3
> [   93.383468] Hardware name: LENOVO 20F5000RSG/20F5000RSG, BIOS
> R02ET44W (1.17 ) 01/25/2016
> [   93.383986] task: ffff88040c313200 ti: ffff88040526c000 task.ti:
> ffff88040526c000
> [   93.384486] RIP: 0010:[<ffffffff81101ad7>]  [<ffffffff81101ad7>]
> 0xffffffff81101ad7
> [   93.384985] RSP: 0018:ffff88040526fdd0  EFLAGS: 00010282
> [   93.385475] RAX: 0000000000000000 RBX: ffff880410784b40 RCX: ffff88040526fe0c
> [   93.385988] RDX: ffffffff81951fc2 RSI: ffff88040526fde0 RDI: 0000000000000000
> [   93.386478] RBP: ffff88041065d538 R08: 0000000000000014 R09: ffffffff81951fc2
> [   93.386970] R10: 0000000000000000 R11: 0000000000000000 R12: ffff88040526fe0c
> [   93.387475] R13: ffff88040c364540 R14: 0000000000000022 R15: 0000000000000000
> [   93.387963] FS:  00007f56f4879700(0000) GS:ffff880421400000(0000)
> knlGS:0000000000000000
> [   93.388458] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [   93.388964] CR2: 0000000000000000 CR3: 0000000404c3c000 CR4: 00000000003406f0
> [   93.389454] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> [   93.389937] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> [   93.390437] Stack:
> [   93.390956]  ffffffff81101e5c 0000000000000014 ffffffff81951fc2
> ffff88040526fe3c
> [   93.391496]  0000000000000000 ffff8800d2441800 ffffffff81298232
> ffffffff810c60c4
> [   93.391996]  0000000000000000 0000000000000000 ffff8800d254f000
> ffffffff81298460
> [   93.392528] Call Trace:
> [   93.393011]  [<ffffffff81101e5c>] ? 0xffffffff81101e5c
> [   93.393495]  [<ffffffff81298232>] ? 0xffffffff81298232
> [   93.394006]  [<ffffffff810c60c4>] ? 0xffffffff810c60c4
> [   93.394481]  [<ffffffff81298460>] ? 0xffffffff81298460
> [   93.394955]  [<ffffffff810eb8fd>] ? 0xffffffff810eb8fd
> [   93.395447]  [<ffffffff810ec20f>] ? 0xffffffff810ec20f
> [   93.395919]  [<ffffffff810ec40d>] ? 0xffffffff810ec40d
> [   93.396422]  [<ffffffff810ec605>] ? 0xffffffff810ec605
> [   93.396892]  [<ffffffff81000fe6>] ? 0xffffffff81000fe6
> [   93.397361]  [<ffffffff816c04c0>] ? 0xffffffff816c04c0
> [   93.397829] Code: 48 c7 c0 a1 ff ff ff c3 48 8b 47 30 48 8b 40 20
> 48 8b 80 90 00 00 00 48 85 c0 74 02 ff e0 31 c0 c3 4c 8b 0e 31 c0 4d
> 85 c9 74 6e <48> 8b 07 4c 8d 47 08 48 85 c0 74 36 48 8b 78 08 48 85 ff
> 48 89
> [   93.398970] RIP  [<ffffffff81101ad7>] 0xffffffff81101ad7
> [   93.399449]  RSP <ffff88040526fdd0>
> [   93.399919] CR2: 0000000000000000
> [   93.400419] ---[ end trace 78efe26e2c832ba1 ]---

Umm...  Any chance of getting the function names to go with the addresses?
I'll try to reproduce it here, but the things would be easier with that
information...