Hi Matthew, I have bcache patch for 3.7 kernel. But I was trying to use bcache in an android device which has a 3.0 kernel. So, I tried to back port bcache patch to 3.0. But the bio handling in case of 3.0 is having issues. Tried the git, but was not able to get a 3.0 compatible patch. Regards Ashim On Tue, Aug 6, 2013 at 2:29 PM, Ashim Saikia <akhim.saikia@xxxxxxxxx> wrote: > Hi, > > I am new to bcache and I am looking for a bcache patch for linux kernel > version 3.0. > > Initially, form a 3.7 kernel, I prepared a patch and applied to 3.0 kernel. > But in this case, I encounter "null pointer dereference". > > I am trying to use ramdisk as cache device and mmc partiton as backing > device. > > > Unable to handle kernel NULL pointer dereference at virtual address 00000000 > kernel BUG at fs/bio.c:424! > Unable to handle kernel NULL pointer dereference at virtual address 00000000 > pgd = c0004000 > [00000000] *pgd=00000000 > Internal error: Oops: 817 [#1] PREEMPT > Modules linked in: > CPU: 0 Not tainted (3.0.8-00054-gece392b-dirty #5) > PC is at __bug+0x1c/0x24 > LR is at __bug+0x18/0x24 > pc : [<c003c584>] lr : [<c003c580>] psr: 60000193 > sp : f0bf7d88 ip : f0bf7cc0 fp : 00000000 > r10: f02f3000 r9 : e2b70400 r8 : e2b70400 > r7 : 00000000 r6 : 00000800 r5 : 00000000 r4 : 00000000 > r3 : 00000000 r2 : 00000001 r1 : 00000002 r0 : 00000022 > Flags: nZCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel > Control: 10c5387d Table: 4da00019 DAC: 00000015 > > PC: 0xc003c504: > > So, I am trying to debug this issue. My guess is back porting bcache from > 3.7 kernel may not be the right way. > I am looking for help in getting a bcache 3.0 patch. If anybody can give me > some pointers in order to get that patch, that will be really helpful to me. > > Regards > Ashim -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
