Currently, calls to nvmet_fc_rcv_fcp_req() always copied the
FC-NVME cmd iu to a temporary buffer before returning, allowing
the driver to immediately repost the buffer to the hardware.
To address timing conditions on queue element structures vs async
command reception, the nvmet_fc transport occasionally may need to
hold on to the command iu buffer for a short period. In these cases,
the nvmet_fc_rcv_fcp_req() will return a special return code
(-EOVERFLOW). In these cases, the LLDD must delay until the new
defer_rcv lldd callback is called before recycling the buffer back
to the hw.
This patch adds support for the new nvmet_fc transport defer_rcv
callback and recognition of the new error code when passing commands
to the transport.
Signed-off-by: Dick Kennedy <dick.kennedy@xxxxxxxxxxxx>
Signed-off-by: James Smart <james.smart@xxxxxxxxxxxx>
---
This patch is intended to enter the kernel through the nvme block
tree which pulls in the nvmet_fc api change at the same time. It is
not to be merged via the scsi trees without the latest nvme support
in it.
v2:
removed unnecessary casts
drivers/scsi/lpfc/lpfc_attr.c | 4 +++-
drivers/scsi/lpfc/lpfc_debugfs.c | 5 ++++-
drivers/scsi/lpfc/lpfc_nvmet.c | 30 ++++++++++++++++++++++++++++++
drivers/scsi/lpfc/lpfc_nvmet.h | 1 +
4 files changed, 38 insertions(+), 2 deletions(-)
diff --git a/drivers/scsi/lpfc/lpfc_attr.c b/drivers/scsi/lpfc/lpfc_attr.c
index 4ed48ed38e79..7ee1a94c0b33 100644
--- a/drivers/scsi/lpfc/lpfc_attr.c
+++ b/drivers/scsi/lpfc/lpfc_attr.c
@@ -205,8 +205,10 @@ lpfc_nvme_info_show(struct device *dev, struct device_attribute *attr,
atomic_read(&tgtp->xmt_ls_rsp_error));
len += snprintf(buf+len, PAGE_SIZE-len,
- "FCP: Rcv %08x Release %08x Drop %08x\n",
+ "FCP: Rcv %08x Defer %08x Release %08x "
+ "Drop %08x\n",
atomic_read(&tgtp->rcv_fcp_cmd_in),
+ atomic_read(&tgtp->rcv_fcp_cmd_defer),
atomic_read(&tgtp->xmt_fcp_release),
atomic_read(&tgtp->rcv_fcp_cmd_drop));
diff --git a/drivers/scsi/lpfc/lpfc_debugfs.c b/drivers/scsi/lpfc/lpfc_debugfs.c
index 5cc8b0f7d885..744f3f395b64 100644
--- a/drivers/scsi/lpfc/lpfc_debugfs.c
+++ b/drivers/scsi/lpfc/lpfc_debugfs.c
@@ -782,8 +782,11 @@ lpfc_debugfs_nvmestat_data(struct lpfc_vport *vport, char *buf, int size)
atomic_read(&tgtp->xmt_ls_rsp_error));
len += snprintf(buf + len, size - len,
- "FCP: Rcv %08x Drop %08x\n",
+ "FCP: Rcv %08x Defer %08x Release %08x "
+ "Drop %08x\n",
atomic_read(&tgtp->rcv_fcp_cmd_in),
+ atomic_read(&tgtp->rcv_fcp_cmd_defer),
+ atomic_read(&tgtp->xmt_fcp_release),
atomic_read(&tgtp->rcv_fcp_cmd_drop));
if (atomic_read(&tgtp->rcv_fcp_cmd_in) !=
diff --git a/drivers/scsi/lpfc/lpfc_nvmet.c b/drivers/scsi/lpfc/lpfc_nvmet.c
index fbeec344c6cc..bbbd0f84160d 100644
--- a/drivers/scsi/lpfc/lpfc_nvmet.c
+++ b/drivers/scsi/lpfc/lpfc_nvmet.c
@@ -841,12 +841,31 @@ lpfc_nvmet_xmt_fcp_release(struct nvmet_fc_target_port *tgtport,
lpfc_nvmet_ctxbuf_post(phba, ctxp->ctxbuf);
}
+static void
+lpfc_nvmet_defer_rcv(struct nvmet_fc_target_port *tgtport,
+ struct nvmefc_tgt_fcp_req *rsp)
+{
+ struct lpfc_nvmet_tgtport *tgtp;
+ struct lpfc_nvmet_rcv_ctx *ctxp =
+ container_of(rsp, struct lpfc_nvmet_rcv_ctx, ctx.fcp_req);
+ struct rqb_dmabuf *nvmebuf = ctxp->rqb_buffer;
+ struct lpfc_hba *phba = ctxp->phba;
+
+ lpfc_nvmeio_data(phba, "NVMET DEFERRCV: xri x%x sz %d CPU %02x\n",
+ ctxp->oxid, ctxp->size, smp_processor_id());
+
+ tgtp = phba->targetport->private;
+ atomic_inc(&tgtp->rcv_fcp_cmd_defer);
+ lpfc_rq_buf_free(phba, &nvmebuf->hbuf); /* repost */
+}
+
static struct nvmet_fc_target_template lpfc_tgttemplate = {
.targetport_delete = lpfc_nvmet_targetport_delete,
.xmt_ls_rsp = lpfc_nvmet_xmt_ls_rsp,
.fcp_op = lpfc_nvmet_xmt_fcp_op,
.fcp_abort = lpfc_nvmet_xmt_fcp_abort,
.fcp_req_release = lpfc_nvmet_xmt_fcp_release,
+ .defer_rcv = lpfc_nvmet_defer_rcv,
.max_hw_queues = 1,
.max_sgl_segments = LPFC_NVMET_DEFAULT_SEGS,
@@ -1504,6 +1523,17 @@ lpfc_nvmet_unsol_fcp_buffer(struct lpfc_hba *phba,
return;
}
+ /* Processing of FCP command is deferred */
+ if (rc == -EOVERFLOW) {
+ lpfc_nvmeio_data(phba,
+ "NVMET RCV BUSY: xri x%x sz %d from %06x\n",
+ oxid, size, sid);
+ /* defer reposting rcv buffer till .defer_rcv callback */
+ ctxp->rqb_buffer = nvmebuf;
+ atomic_inc(&tgtp->rcv_fcp_cmd_out);
+ return;
+ }
+
atomic_inc(&tgtp->rcv_fcp_cmd_drop);
lpfc_printf_log(phba, KERN_ERR, LOG_NVME_IOERR,
"6159 FCP Drop IO x%x: err x%x: x%x x%x x%x\n",
diff --git a/drivers/scsi/lpfc/lpfc_nvmet.h b/drivers/scsi/lpfc/lpfc_nvmet.h
index e675ef17be08..48a76788b003 100644
--- a/drivers/scsi/lpfc/lpfc_nvmet.h
+++ b/drivers/scsi/lpfc/lpfc_nvmet.h
@@ -49,6 +49,7 @@ struct lpfc_nvmet_tgtport {
atomic_t rcv_fcp_cmd_in;
atomic_t rcv_fcp_cmd_out;
atomic_t rcv_fcp_cmd_drop;
+ atomic_t rcv_fcp_cmd_defer;
atomic_t xmt_fcp_release;
/* Stats counters - lpfc_nvmet_xmt_fcp_op */
--
2.13.1
