nvmet_fc: add req_release to lldd api

With the advent of the opdone calls changing context, the lldd can no
longer assume that once the op->done call returns for RSP operations
that the request struct is no longer being accessed.

As such, revise the lldd api for a req_release callback that the
transport will call when the job is complete. This will also be used
with abort cases.

Fixed text in api header for change in io complete semantics.

Revised lpfc to support the new req_release api.

Signed-off-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>

2 files changed, 73 insertions, 7 deletions

diff --git a/drivers/scsi/lpfc/lpfc_nvmet.c b/drivers/scsi/lpfc/lpfc_nvmet.c
index 176b4e035bcf..1846c7eb086a 100644
--- a/drivers/scsi/lpfc/lpfc_nvmet.c
+++ b/drivers/scsi/lpfc/lpfc_nvmet.c
@@ -408,9 +408,7 @@ out:
 		if (phba->ktime_on)
 			lpfc_nvmet_ktime(phba, ctxp);
 #endif
-		/* Let Abort cmpl repost the context */
-		if (!(ctxp->flag & LPFC_NVMET_ABORT_OP))
-			lpfc_nvmet_rq_post(phba, ctxp, &ctxp->rqb_buffer->hbuf);
+		/* lpfc_nvmet_xmt_fcp_release() will recycle the context */
 	} else {
 		ctxp->entry_cnt++;
 		start_clean = offsetof(struct lpfc_iocbq, wqe);
@@ -634,10 +632,47 @@ lpfc_nvmet_targetport_delete(struct nvmet_fc_target_port *targetport)
 	complete(&tport->tport_unreg_done);
 }
 
+static void
+lpfc_nvmet_xmt_fcp_release(struct nvmet_fc_target_port *tgtport,
+			   struct nvmefc_tgt_fcp_req *rsp)
+{
+	struct lpfc_nvmet_tgtport *lpfc_nvmep = tgtport->private;
+	struct lpfc_nvmet_rcv_ctx *ctxp =
+		container_of(rsp, struct lpfc_nvmet_rcv_ctx, ctx.fcp_req);
+	struct lpfc_hba *phba = ctxp->phba;
+	unsigned long flags;
+	bool aborting = false;
+
+	spin_lock_irqsave(&ctxp->ctxlock, flags);
+	if (ctxp->flag & LPFC_NVMET_ABORT_OP) {
+		aborting = true;
+		ctxp->flag |= LPFC_NVMET_CTX_RLS;
+	}
+	spin_unlock_irqrestore(&ctxp->ctxlock, flags);
+
+	if (aborting)
+		/* let the abort path do the real release */
+		return;
+
+	/* Sanity check */
+	if (ctxp->state != LPFC_NVMET_STE_DONE) {
+		atomic_inc(&lpfc_nvmep->xmt_fcp_drop);
+		lpfc_printf_log(phba, KERN_ERR, LOG_NVME_IOERR,
+				"6117 Bad state IO x%x aborted\n",
+				ctxp->oxid);
+	}
+
+	lpfc_nvmeio_data(phba, "NVMET FCP FREE: xri x%x ste %d\n", ctxp->oxid,
+			 ctxp->state, 0);
+
+	lpfc_nvmet_rq_post(phba, ctxp, &ctxp->rqb_buffer->hbuf);
+}
+
 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_req_release = lpfc_nvmet_xmt_fcp_release,
 
 	.max_hw_queues  = 1,
 	.max_sgl_segments = LPFC_NVMET_DEFAULT_SEGS,
@@ -834,6 +869,7 @@ dropit:
 	ctxp->wqeq = NULL;
 	ctxp->state = LPFC_NVMET_STE_RCV;
 	ctxp->rqb_buffer = (void *)nvmebuf;
+	spin_lock_init(&ctxp->ctxlock);
 
 	lpfc_nvmeio_data(phba, "NVMET LS   RCV: xri x%x sz %d from %06x\n",
 			 oxid, size, sid);
@@ -1595,6 +1631,8 @@ lpfc_nvmet_sol_fcp_abort_cmp(struct lpfc_hba *phba, struct lpfc_iocbq *cmdwqe,
 	struct lpfc_nvmet_rcv_ctx *ctxp;
 	struct lpfc_nvmet_tgtport *tgtp;
 	uint32_t status, result;
+	unsigned long flags;
+	bool released = false;
 
 	ctxp = cmdwqe->context2;
 	status = bf_get(lpfc_wcqe_c_status, wcqe);
@@ -1609,7 +1647,18 @@ lpfc_nvmet_sol_fcp_abort_cmp(struct lpfc_hba *phba, struct lpfc_iocbq *cmdwqe,
 			result, wcqe->word3);
 
 	ctxp->state = LPFC_NVMET_STE_DONE;
-	lpfc_nvmet_rq_post(phba, ctxp, &ctxp->rqb_buffer->hbuf);
+	spin_lock_irqsave(&ctxp->ctxlock, flags);
+	if (ctxp->flag & LPFC_NVMET_CTX_RLS)
+		released = true;
+	ctxp->flag &= ~LPFC_NVMET_ABORT_OP;
+	spin_unlock_irqrestore(&ctxp->ctxlock, flags);
+
+	/*
+	 * if transport has released ctx, then can reuse it. Otherwise,
+	 * will be recycled by transport release call.
+	 */
+	if (released)
+		lpfc_nvmet_rq_post(phba, ctxp, &ctxp->rqb_buffer->hbuf);
 
 	cmdwqe->context2 = NULL;
 	cmdwqe->context3 = NULL;
@@ -1632,7 +1681,9 @@ lpfc_nvmet_xmt_fcp_abort_cmp(struct lpfc_hba *phba, struct lpfc_iocbq *cmdwqe,
 {
 	struct lpfc_nvmet_rcv_ctx *ctxp;
 	struct lpfc_nvmet_tgtport *tgtp;
+	unsigned long flags;
 	uint32_t status, result;
+	bool released = false;
 
 	ctxp = cmdwqe->context2;
 	status = bf_get(lpfc_wcqe_c_status, wcqe);
@@ -1654,7 +1705,19 @@ lpfc_nvmet_xmt_fcp_abort_cmp(struct lpfc_hba *phba, struct lpfc_iocbq *cmdwqe,
 					ctxp->state, ctxp->oxid);
 		}
 		ctxp->state = LPFC_NVMET_STE_DONE;
-		lpfc_nvmet_rq_post(phba, ctxp, &ctxp->rqb_buffer->hbuf);
+		spin_lock_irqsave(&ctxp->ctxlock, flags);
+		if (ctxp->flag & LPFC_NVMET_CTX_RLS)
+			released = true;
+		ctxp->flag &= ~LPFC_NVMET_ABORT_OP;
+		spin_unlock_irqrestore(&ctxp->ctxlock, flags);
+
+		/*
+		 * if transport has released ctx, then can reuse it. Otherwise,
+		 * will be recycled by transport release call.
+		 */
+		if (released)
+			lpfc_nvmet_rq_post(phba, ctxp, &ctxp->rqb_buffer->hbuf);
+
 		cmdwqe->context2 = NULL;
 		cmdwqe->context3 = NULL;
 	}
diff --git a/drivers/scsi/lpfc/lpfc_nvmet.h b/drivers/scsi/lpfc/lpfc_nvmet.h
index ca96f05c1604..02735fc6fd41 100644
--- a/drivers/scsi/lpfc/lpfc_nvmet.h
+++ b/drivers/scsi/lpfc/lpfc_nvmet.h
@@ -81,6 +81,7 @@ struct lpfc_nvmet_rcv_ctx {
 	struct lpfc_iocbq *wqeq;
 	struct lpfc_iocbq *abort_wqeq;
 	dma_addr_t txrdy_phys;
+	spinlock_t ctxlock; /* protect flag access */
 	uint32_t *txrdy;
 	uint32_t sid;
 	uint32_t offset;
@@ -97,8 +98,10 @@ struct lpfc_nvmet_rcv_ctx {
 #define LPFC_NVMET_STE_RSP		4
 #define LPFC_NVMET_STE_DONE		5
 	uint16_t flag;
-#define LPFC_NVMET_IO_INP		1
-#define LPFC_NVMET_ABORT_OP		2
+#define LPFC_NVMET_IO_INP		0x1
+#define LPFC_NVMET_ABORT_OP		0x2
+#define LPFC_NVMET_CTX_RLS		0x4
+
 	struct rqb_dmabuf *rqb_buffer;
 
 #ifdef CONFIG_SCSI_LPFC_DEBUG_FS