As long as we cannot easily abort IDE request (correct me if I am wrong) the workaround seems to be to mark current request as aborted in idescsi_abort and ignore it later in idescsi_end_request, i.e. something like (with new flag PC_ABORTED)
struct request *rq = HWGROUP(idescsi_drives[cmd->target])->rq;
idescsi_pc_t *pc = (idescsi_pc_t *) rq->buffer;
pc->flags |= PC_ABORTED;
and later on assume we can ignore SCSI layer completely in this case in idescsi_end_request, just do general cleanup.
If you can reliably reproduce the problem you could give it a try.
Anybody sees yet another race condition here? :))
-andrey
> While burning a CD tonight I ended up taking an oops on my system. I had
> the lkcd patch applied to my 2.4.19 kernel, so I was able to look at the
> oops after my system rebooted. After digging into it a little and
> looking at the ide-scsi code I think I found the problem but am not
> sure. How can idescsi_reset simply return SCSI_RESET_SUCCESS to the scsi
> mid layer? I think what is happening is that a command times out,
> idescsi_abort is called, which returns SCSI_ABORT_SNOOZE. Later on
> idescsi_reset gets called, which returns SCSI_RESET_SUCCESS. At this
> point the scsi mid-layer owns the scsi_cmnd and returns the failure back
> up the chain. Later on, the command gets run through
> idescsi_end_request, which then tries to access the scsi_cmnd structure
> which is it no longer owns.
>
> Any help is appreciated. I have a complete lkcd dump of the failure if
> anyone would like more information...
>
> -Brian King
>
>
> Here is the last bit in the log buffer:
>
> <4>scsi : aborting command due to timeout : pid 2534304, scsi0,
> channel 0, id 1, lun 0 Write (10) 00 00 01 1e 91 00 00 1b 00
> <4>hdk: timeout waiting for DMA
> <4>ide_dmaproc: chipset supported ide_dma_timeout func only: 14
> <4>hdk: status timeout: status=0xd8 { Busy }
> <4>hdk: drive not ready for command
> <4>hdk: ATAPI reset complete
> <4>hdk: irq timeout: status=0x80 { Busy }
> <4>hdk: ATAPI reset complete
> <4>hdk: irq timeout: status=0x80 { Busy }
> <1>Unable to handle kernel NULL pointer dereference at virtual
> address 00000184
> <4> printing eip:
> <4>e0fd22f1
> <1>*pde = 00000000
> <4>Oops: 0002
> <4>CPU: 0
> <4>EIP: 0010:[<e0fd22f1>] Tainted: PF
> <4>EFLAGS: 00010046
> <4>eax: 00000000 ebx: 00000000 ecx: dfef8000 edx: c75bcbc0
> <4>esi: 00000080 edi: c0491938 ebp: d5908000 esp: c0435ea4
> <4>ds: 0018 es: 0018 ss: 0018
> <4>Process swapper (pid: 0, stackpage=c0435000)
> <4>Stack: c0491938 00000000 00000000 c0491938 00000088 000001f4
> c03349e2 c75bcbc0
> <4> ce0a3b80 c0491938 00000080 00000080 c75bcbc0 c0222d6c
> 00000000 c1671580
> <4> 00000080 c04918f4 c0491938 c0434000 c1671580 e0fd2550
> c0223b30 c0491938
> <4>Call Trace: [<c0222d6c>] [<e0fd2550>] [<c0223b30>]
> [<c0223990>] [<c0127af0>]
> <4> [<c01233d4>] [<c01232a6>] [<c01230ed>] [<c010a97f>]
> [<c010d173>] [<c0106f80>]
> <4> [<c0106fa3>] [<c0107012>] [<c0105000>]
> <4>
> <4>Code: c7 80 84 01 00 00 00 00 07 00 75 72 9c 5e fa bb 00 e0 ff ff
>
>
> From lkcd:
>
> ================================================================
> STACK TRACE FOR TASK: 0xc0434000 (swapper)
>
> 0 [ide-scsi]idescsi_end_request+129 [0xe0fd22f1]
> TRACE ERROR 0x800000000
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Thu Jan 23 2003 - 22:00:31 EST