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[SCSI] libfc: fix lun reset failure bugs in fc_fcp_resp handling of FCP_RSP_INFO

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In LUN RESET testing involving NetApp targets, it is observed that LUN
RESET is failing. The fc_fcp_resp() is not completing the completion
for the LUN RESET task since fc_fcp_resp assumes that the FCP_RSP_INFO
is 8 bytes with the 4 byte reserved field, where in case of NetApp targets
the FCP_RSP to LUN RESET only has 4 bytes of FCP_RSP_INFO. This leads
fc_fcp_resp to error out w/o completing the task completion, eventually
causing LUN RESET to be escalated to host reset, which is not very nice.

Per FCP-3 r04, clause 9.5.15 and Table 23, the FCP_RSP_INFO field can be either
4 bytes or 8 bytes, with the last 4 bytes as "Reserved (if any)". Therefore it
is valid to have 4 bytes FCP_RSP_INFO like some of the NetApp targets behave.
Fixing this by validating the FCP_RSP_INFO against both the two spec allowed
length.

Reported-by: Frank Zhang <frank_1.zhang@intel.com>
Signed-off-by: Yi Zou <yi.zou@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
This commit is contained in:
Yi Zou 2012-09-24 11:52:50 -07:00 committed by James Bottomley
parent 31c37a6f21
commit 3b64b18811
2 changed files with 8 additions and 1 deletions
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3
drivers/scsi/libfc/fc_fcp.c
View File

@ -851,7 +851,8 @@ static void fc_fcp_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
fc_rp_info = (struct fcp_resp_rsp_info *)(rp_ex + 1);
if (flags & FCP_RSP_LEN_VAL) {
respl = ntohl(rp_ex->fr_rsp_len);
if (respl != sizeof(*fc_rp_info))
if ((respl != FCP_RESP_RSP_INFO_LEN4) &&
(respl != FCP_RESP_RSP_INFO_LEN8))
goto len_err;
if (fsp->wait_for_comp) {
/* Abuse cdb_status for rsp code */

6
include/scsi/fc/fc_fcp.h
View File

@ -127,6 +127,9 @@ struct fcp_txrdy {
*
* All response frames will always contain the fcp_resp template. Some
* will also include the fcp_resp_len template.
*
* From Table 23, the FCP_RSP_INFO can either be 4 bytes or 8 bytes, both
* are valid length.
*/
struct fcp_resp {
__u8 _fr_resvd[8]; /* reserved */
@ -156,6 +159,9 @@ struct fcp_resp_rsp_info {
__u8 _fr_resvd2[4]; /* reserved */
};
#define FCP_RESP_RSP_INFO_LEN4 4 /* without reserved field */
#define FCP_RESP_RSP_INFO_LEN8 8 /* with reserved field */
struct fcp_resp_with_ext {
struct fcp_resp resp;
struct fcp_resp_ext ext;