[SCSI] iscsi: extended cdb support
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>
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index bdd7de7..2f6b095 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -137,6 +137,45 @@
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 @@
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 @@
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) {