From 3b64b1881143ce9e461c211cc81acc72d0cdc476 Mon Sep 17 00:00:00 2001 From: Yi Zou Date: Mon, 24 Sep 2012 11:52:50 -0700 Subject: [PATCH] [SCSI] libfc: fix lun reset failure bugs in fc_fcp_resp handling of FCP_RSP_INFO 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 Signed-off-by: Yi Zou Tested-by: Ross Brattain Signed-off-by: Robert Love Signed-off-by: James Bottomley --- drivers/scsi/libfc/fc_fcp.c | 3 ++- include/scsi/fc/fc_fcp.h | 6 ++++++ 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/libfc/fc_fcp.c b/drivers/scsi/libfc/fc_fcp.c index 14243fa5f8e8..fcb9d0b20ee4 100644 --- a/drivers/scsi/libfc/fc_fcp.c +++ b/drivers/scsi/libfc/fc_fcp.c @@ -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 */ diff --git a/include/scsi/fc/fc_fcp.h b/include/scsi/fc/fc_fcp.h index 0d7d67e96d43..9c8702942b61 100644 --- a/include/scsi/fc/fc_fcp.h +++ b/include/scsi/fc/fc_fcp.h @@ -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; -- GitLab