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[SCSI] iscsi: extended cdb support

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Support for extended CDBs in iscsi.
All we need is to check if command spills over 16 bytes then allocate
an iscsi-extended-header for the leftovers.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Reviewed-by: Pete Wyckoff <pw@osc.edu>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This commit is contained in:
Boaz Harrosh 2008-04-18 10:11:51 -05:00 committed by James Bottomley
parent 57b7658aed
commit 38d1c069db
2 changed files with 54 additions and 7 deletions
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55
drivers/scsi/libiscsi.c
View file

@ -137,6 +137,45 @@ static int iscsi_add_hdr(struct iscsi_cmd_task *ctask, unsigned len)
return 0;
}
/*
* make an extended cdb AHS
*/
static int iscsi_prep_ecdb_ahs(struct iscsi_cmd_task *ctask)
{
struct scsi_cmnd *cmd = ctask->sc;
unsigned rlen, pad_len;
unsigned short ahslength;
struct iscsi_ecdb_ahdr *ecdb_ahdr;
int rc;
ecdb_ahdr = iscsi_next_hdr(ctask);
rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
ahslength = rlen + sizeof(ecdb_ahdr->reserved);
pad_len = iscsi_padding(rlen);
rc = iscsi_add_hdr(ctask, sizeof(ecdb_ahdr->ahslength) +
sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
if (rc)
return rc;
if (pad_len)
memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
ecdb_ahdr->reserved = 0;
memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
debug_scsi("iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
"rlen %d pad_len %d ahs_length %d iscsi_headers_size %u\n",
cmd->cmd_len, rlen, pad_len, ahslength, ctask->hdr_len);
return 0;
}
/**
* iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
* @ctask: iscsi cmd task
@ -150,7 +189,7 @@ static int iscsi_prep_scsi_cmd_pdu(struct iscsi_cmd_task *ctask)
struct iscsi_session *session = conn->session;
struct iscsi_cmd *hdr = ctask->hdr;
struct scsi_cmnd *sc = ctask->sc;
unsigned hdrlength;
unsigned hdrlength, cmd_len;
int rc;
ctask->hdr_len = 0;
@ -165,10 +204,16 @@ static int iscsi_prep_scsi_cmd_pdu(struct iscsi_cmd_task *ctask)
hdr->cmdsn = cpu_to_be32(session->cmdsn);
session->cmdsn++;
hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
memcpy(hdr->cdb, sc->cmnd, sc->cmd_len);
if (sc->cmd_len < MAX_COMMAND_SIZE)
memset(&hdr->cdb[sc->cmd_len], 0,
MAX_COMMAND_SIZE - sc->cmd_len);
cmd_len = sc->cmd_len;
if (cmd_len < ISCSI_CDB_SIZE)
memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
else if (cmd_len > ISCSI_CDB_SIZE) {
rc = iscsi_prep_ecdb_ahs(ctask);
if (rc)
return rc;
cmd_len = ISCSI_CDB_SIZE;
}
memcpy(hdr->cdb, sc->cmnd, cmd_len);
ctask->imm_count = 0;
if (sc->sc_data_direction == DMA_TO_DEVICE) {

6
include/scsi/iscsi_proto.h
View file

@ -112,6 +112,7 @@ struct iscsi_ahs_hdr {
#define ISCSI_AHSTYPE_CDB 1
#define ISCSI_AHSTYPE_RLENGTH 2
#define ISCSI_CDB_SIZE 16
/* iSCSI PDU Header */
struct iscsi_cmd {
@ -125,7 +126,7 @@ struct iscsi_cmd {
__be32 data_length;
__be32 cmdsn;
__be32 exp_statsn;
uint8_t cdb[16]; /* SCSI Command Block */
uint8_t cdb[ISCSI_CDB_SIZE]; /* SCSI Command Block */
/* Additional Data (Command Dependent) */
};
@ -154,7 +155,8 @@ struct iscsi_ecdb_ahdr {
__be16 ahslength; /* CDB length - 15, including reserved byte */
uint8_t ahstype;
uint8_t reserved;
uint8_t ecdb[260 - 16]; /* 4-byte aligned extended CDB spillover */
/* 4-byte aligned extended CDB spillover */
uint8_t ecdb[260 - ISCSI_CDB_SIZE];
};
/* SCSI Response Header */