[SCSI] iscsi: bidi support at the generic libiscsi level
- prepare the additional bidi_read rlength header.
- access the right scsi_in() and/or scsi_out() side of things.
also for resid.
- Handle BIDI underflow overflow from target
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 2f6b095..010c1b9 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -176,6 +176,31 @@
return 0;
}
+static int iscsi_prep_bidi_ahs(struct iscsi_cmd_task *ctask)
+{
+ struct scsi_cmnd *sc = ctask->sc;
+ struct iscsi_rlength_ahdr *rlen_ahdr;
+ int rc;
+
+ rlen_ahdr = iscsi_next_hdr(ctask);
+ rc = iscsi_add_hdr(ctask, sizeof(*rlen_ahdr));
+ if (rc)
+ return rc;
+
+ rlen_ahdr->ahslength =
+ cpu_to_be16(sizeof(rlen_ahdr->read_length) +
+ sizeof(rlen_ahdr->reserved));
+ rlen_ahdr->ahstype = ISCSI_AHSTYPE_RLENGTH;
+ rlen_ahdr->reserved = 0;
+ rlen_ahdr->read_length = cpu_to_be32(scsi_in(sc)->length);
+
+ debug_scsi("bidi-in rlen_ahdr->read_length(%d) "
+ "rlen_ahdr->ahslength(%d)\n",
+ be32_to_cpu(rlen_ahdr->read_length),
+ be16_to_cpu(rlen_ahdr->ahslength));
+ return 0;
+}
+
/**
* iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
* @ctask: iscsi cmd task
@@ -200,7 +225,6 @@
hdr->flags = ISCSI_ATTR_SIMPLE;
int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
hdr->itt = build_itt(ctask->itt, session->age);
- hdr->data_length = cpu_to_be32(scsi_bufflen(sc));
hdr->cmdsn = cpu_to_be32(session->cmdsn);
session->cmdsn++;
hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
@@ -216,7 +240,15 @@
memcpy(hdr->cdb, sc->cmnd, cmd_len);
ctask->imm_count = 0;
+ if (scsi_bidi_cmnd(sc)) {
+ hdr->flags |= ISCSI_FLAG_CMD_READ;
+ rc = iscsi_prep_bidi_ahs(ctask);
+ if (rc)
+ return rc;
+ }
if (sc->sc_data_direction == DMA_TO_DEVICE) {
+ unsigned out_len = scsi_out(sc)->length;
+ hdr->data_length = cpu_to_be32(out_len);
hdr->flags |= ISCSI_FLAG_CMD_WRITE;
/*
* Write counters:
@@ -237,19 +269,19 @@
ctask->unsol_datasn = 0;
if (session->imm_data_en) {
- if (scsi_bufflen(sc) >= session->first_burst)
+ if (out_len >= session->first_burst)
ctask->imm_count = min(session->first_burst,
conn->max_xmit_dlength);
else
- ctask->imm_count = min(scsi_bufflen(sc),
+ ctask->imm_count = min(out_len,
conn->max_xmit_dlength);
hton24(hdr->dlength, ctask->imm_count);
} else
zero_data(hdr->dlength);
if (!session->initial_r2t_en) {
- ctask->unsol_count = min((session->first_burst),
- (scsi_bufflen(sc))) - ctask->imm_count;
+ ctask->unsol_count = min(session->first_burst, out_len)
+ - ctask->imm_count;
ctask->unsol_offset = ctask->imm_count;
}
@@ -259,6 +291,7 @@
} else {
hdr->flags |= ISCSI_FLAG_CMD_FINAL;
zero_data(hdr->dlength);
+ hdr->data_length = cpu_to_be32(scsi_in(sc)->length);
if (sc->sc_data_direction == DMA_FROM_DEVICE)
hdr->flags |= ISCSI_FLAG_CMD_READ;
@@ -277,10 +310,12 @@
return EIO;
conn->scsicmd_pdus_cnt++;
- debug_scsi("iscsi prep [%s cid %d sc %p cdb 0x%x itt 0x%x len %d "
- "cmdsn %d win %d]\n",
- sc->sc_data_direction == DMA_TO_DEVICE ? "write" : "read",
- conn->id, sc, sc->cmnd[0], ctask->itt, scsi_bufflen(sc),
+ debug_scsi("iscsi prep [%s cid %d sc %p cdb 0x%x itt 0x%x "
+ "len %d bidi_len %d cmdsn %d win %d]\n",
+ scsi_bidi_cmnd(sc) ? "bidirectional" :
+ sc->sc_data_direction == DMA_TO_DEVICE ? "write" : "read",
+ conn->id, sc, sc->cmnd[0], ctask->itt,
+ scsi_bufflen(sc), scsi_bidi_cmnd(sc) ? scsi_in(sc)->length : 0,
session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
return 0;
}
@@ -343,7 +378,12 @@
conn->session->tt->cleanup_cmd_task(conn, ctask);
sc->result = err;
- scsi_set_resid(sc, scsi_bufflen(sc));
+ if (!scsi_bidi_cmnd(sc))
+ scsi_set_resid(sc, scsi_bufflen(sc));
+ else {
+ scsi_out(sc)->resid = scsi_out(sc)->length;
+ scsi_in(sc)->resid = scsi_in(sc)->length;
+ }
if (conn->ctask == ctask)
conn->ctask = NULL;
/* release ref from queuecommand */
@@ -478,6 +518,18 @@
min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
}
+ if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
+ ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
+ int res_count = be32_to_cpu(rhdr->bi_residual_count);
+
+ if (scsi_bidi_cmnd(sc) && res_count > 0 &&
+ (rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
+ res_count <= scsi_in(sc)->length))
+ scsi_in(sc)->resid = res_count;
+ else
+ sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
+ }
+
if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
ISCSI_FLAG_CMD_OVERFLOW)) {
int res_count = be32_to_cpu(rhdr->residual_count);
@@ -485,13 +537,11 @@
if (res_count > 0 &&
(rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
res_count <= scsi_bufflen(sc)))
+ /* write side for bidi or uni-io set_resid */
scsi_set_resid(sc, res_count);
else
sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
- } else if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
- ISCSI_FLAG_CMD_BIDI_OVERFLOW))
- sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
-
+ }
out:
debug_scsi("done [sc %lx res %d itt 0x%x]\n",
(long)sc, sc->result, ctask->itt);
@@ -1147,7 +1197,12 @@
fault:
spin_unlock(&session->lock);
debug_scsi("iscsi: cmd 0x%x is not queued (%d)\n", sc->cmnd[0], reason);
- scsi_set_resid(sc, scsi_bufflen(sc));
+ if (!scsi_bidi_cmnd(sc))
+ scsi_set_resid(sc, scsi_bufflen(sc));
+ else {
+ scsi_out(sc)->resid = scsi_out(sc)->length;
+ scsi_in(sc)->resid = scsi_in(sc)->length;
+ }
sc->scsi_done(sc);
spin_lock(host->host_lock);
return 0;