From 38d1c069db8c87eb6cb10ca1ede9d9b673531ddd Mon Sep 17 00:00:00 2001 From: Boaz Harrosh Date: Fri, 18 Apr 2008 10:11:51 -0500 Subject: [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 Reviewed-by: Pete Wyckoff Signed-off-by: Mike Christie Signed-off-by: James Bottomley --- drivers/scsi/libiscsi.c | 55 +++++++++++++++++++++++++++++++++++++++++----- include/scsi/iscsi_proto.h | 6 +++-- 2 files changed, 54 insertions(+), 7 deletions(-) diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c index bdd7de7da39..2f6b0955ff0 100644 --- a/drivers/scsi/libiscsi.c +++ b/drivers/scsi/libiscsi.c @@ -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) { diff --git a/include/scsi/iscsi_proto.h b/include/scsi/iscsi_proto.h index 5ffec8ad696..e0593bfae62 100644 --- a/include/scsi/iscsi_proto.h +++ b/include/scsi/iscsi_proto.h @@ -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 */ -- cgit v1.2.3