[dm-devel] multipath-tools: mismatch between CDB allocation length and SG_IO dxfer_len
Christophe Varoqui
christophe.varoqui at opensvc.com
Wed May 21 20:31:45 UTC 2014
Hi,
have you verified this part is not enough to fix the problem, without
shrinking the response size to 128 ?
unsigned char inqCmdBlk[INQUIRY_CMDLEN] = {INQUIRY_CMD, 1, 0xC0, 0,
- sizeof(sb), 0};
+ sizeof(sense_buffer), 0};
Is it me or the variable name is just plain misleading ?
Best regards,
Christophe Varoqui
www.opensvc.com
On Sat, Apr 5, 2014 at 1:13 PM, Sebastian Herbszt <herbszt at gmx.de> wrote:
> Hello,
>
> while playing with multipath-tools and scst I got the following warning:
>
> [ 6382.467569] [3806]: scst: scst_parse_cmd:826:Warning: expected
> transfer length 256 for opcode 0x12 (handler vdisk_blockio, target
> scst_local) doesn't match decoded value 128
> [ 6382.467574] [3806]: scst_parse_cmd:828:Suspicious CDB:
> [ 6382.467579] (h)___0__1__2__3__4__5__6__7__8__9__A__B__C__D__E__F
> [ 6382.467581] 0: 12 01 c0 00 80 00 ......
>
> This happened when my scst target pretended to be a CLARiiON.
> I noticed a mismatch in emc_clariion_prio (libmultipath/prioritizers/emc.c)
> between the allocation length and dxfer_len:
>
> int emc_clariion_prio(const char *dev, int fd)
> {
> unsigned char sense_buffer[256];
> unsigned char sb[128];
> unsigned char inqCmdBlk[INQUIRY_CMDLEN] = {INQUIRY_CMD, 1, 0xC0, 0,
> sizeof(sb), 0};
>
> ...
>
> memset(&sense_buffer, 0, 256);
> io_hdr.interface_id = 'S';
> io_hdr.cmd_len = sizeof (inqCmdBlk);
> io_hdr.mx_sb_len = sizeof (sb);
> io_hdr.dxfer_direction = SG_DXFER_FROM_DEV;
> io_hdr.dxfer_len = sizeof (sense_buffer);
> io_hdr.dxferp = sense_buffer;
> io_hdr.cmdp = inqCmdBlk;
> io_hdr.sbp = sb;
> io_hdr.timeout = 60000;
> io_hdr.pack_id = 0;
>
> The following change shrinks the size of sense_buffer to 128.
>
> Sebastian
>
> diff --git a/libmultipath/prioritizers/emc.c
> b/libmultipath/prioritizers/emc.c
> index 87e9a8d..91b3d90 100644
> --- a/libmultipath/prioritizers/emc.c
> +++ b/libmultipath/prioritizers/emc.c
> @@ -14,15 +14,15 @@
>
> int emc_clariion_prio(const char *dev, int fd)
> {
> - unsigned char sense_buffer[256];
> + unsigned char sense_buffer[128];
> unsigned char sb[128];
> unsigned char inqCmdBlk[INQUIRY_CMDLEN] = {INQUIRY_CMD, 1, 0xC0, 0,
> - sizeof(sb), 0};
> + sizeof(sense_buffer), 0};
> struct sg_io_hdr io_hdr;
> int ret = PRIO_UNDEF;
>
> memset(&io_hdr, 0, sizeof (struct sg_io_hdr));
> - memset(&sense_buffer, 0, 256);
> + memset(&sense_buffer, 0, 128);
> io_hdr.interface_id = 'S';
> io_hdr.cmd_len = sizeof (inqCmdBlk);
> io_hdr.mx_sb_len = sizeof (sb);
>
> --
> dm-devel mailing list
> dm-devel at redhat.com
> https://www.redhat.com/mailman/listinfo/dm-devel
>
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