scsi: lpfc: Fix random heartbeat timeouts during heavy IO

NVME targets appear to randomly disconnect from the initiator when
running heavy IO.

The error is due to the host aggregate (across all controllers) io load
was beyond the maximum exchange count for nvme on the adapter. The
driver was properly returning a resource busy status, but the io load
was so great heartbeat commands would be bounced and not have a
successful retry within the fuzz amount for the nvme heartbeat (yes, a
very high io load!). Thus the target was terminating the controller due
to a keep alive failure.

Resolve by reserving a few exchanges (by counters) which can be used
when the adapter is out of normal exchanges and the command is a NVME
heartbeat command. As counters are used, while the reserved command is
outstanding, as soon as any other exchange completes, the counters are
adjusted and the reserved count is replenished. The heartbeat completes
execution in a normal fashion.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <james.smart@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/lpfc/lpfc.h b/drivers/scsi/lpfc/lpfc.h
index dd2191c83052d32682db1a0f5fd1fc87efb5ec5b..61fb46da05d4e8ddbdb452c2899c9e405debee9e 100644 (file)
--- a/drivers/scsi/lpfc/lpfc.h
+++ b/drivers/scsi/lpfc/lpfc.h
@@ -945,6 +945,8 @@ struct lpfc_hba {
        struct list_head lpfc_nvme_buf_list_get;
        struct list_head lpfc_nvme_buf_list_put;
        uint32_t total_nvme_bufs;
+       uint32_t get_nvme_bufs;
+       uint32_t put_nvme_bufs;
        struct list_head lpfc_iocb_list;
        uint32_t total_iocbq_bufs;
        struct list_head active_rrq_list;

diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c
index fa211550a32af7146908f3d5d5d0ca40b42f1192..44a98bc913f5e5d543dd1e8c056b8d5b59367386 100644 (file)
--- a/drivers/scsi/lpfc/lpfc_init.c
+++ b/drivers/scsi/lpfc/lpfc_init.c
@@ -1034,6 +1034,7 @@ lpfc_hba_down_post_s4(struct lpfc_hba *phba)
        LIST_HEAD(nvmet_aborts);
        unsigned long iflag = 0;
        struct lpfc_sglq *sglq_entry = NULL;
+       int cnt;
 
 
        lpfc_sli_hbqbuf_free_all(phba);
@@ -1090,11 +1091,14 @@ lpfc_hba_down_post_s4(struct lpfc_hba *phba)
        spin_unlock_irqrestore(&phba->scsi_buf_list_put_lock, iflag);
 
        if (phba->cfg_enable_fc4_type & LPFC_ENABLE_NVME) {
+               cnt = 0;
                list_for_each_entry_safe(psb, psb_next, &nvme_aborts, list) {
                        psb->pCmd = NULL;
                        psb->status = IOSTAT_SUCCESS;
+                       cnt++;
                }
                spin_lock_irqsave(&phba->nvme_buf_list_put_lock, iflag);
+               phba->put_nvme_bufs += cnt;
                list_splice(&nvme_aborts, &phba->lpfc_nvme_buf_list_put);
                spin_unlock_irqrestore(&phba->nvme_buf_list_put_lock, iflag);
 
@@ -3339,6 +3343,7 @@ lpfc_nvme_free(struct lpfc_hba *phba)
        list_for_each_entry_safe(lpfc_ncmd, lpfc_ncmd_next,
                                 &phba->lpfc_nvme_buf_list_put, list) {
                list_del(&lpfc_ncmd->list);
+               phba->put_nvme_bufs--;
                dma_pool_free(phba->lpfc_sg_dma_buf_pool, lpfc_ncmd->data,
                              lpfc_ncmd->dma_handle);
                kfree(lpfc_ncmd);
@@ -3350,6 +3355,7 @@ lpfc_nvme_free(struct lpfc_hba *phba)
        list_for_each_entry_safe(lpfc_ncmd, lpfc_ncmd_next,
                                 &phba->lpfc_nvme_buf_list_get, list) {
                list_del(&lpfc_ncmd->list);
+               phba->get_nvme_bufs--;
                dma_pool_free(phba->lpfc_sg_dma_buf_pool, lpfc_ncmd->data,
                              lpfc_ncmd->dma_handle);
                kfree(lpfc_ncmd);
@@ -3754,9 +3760,11 @@ lpfc_sli4_nvme_sgl_update(struct lpfc_hba *phba)
        uint16_t i, lxri, els_xri_cnt;
        uint16_t nvme_xri_cnt, nvme_xri_max;
        LIST_HEAD(nvme_sgl_list);
-       int rc;
+       int rc, cnt;
 
        phba->total_nvme_bufs = 0;
+       phba->get_nvme_bufs = 0;
+       phba->put_nvme_bufs = 0;
 
        if (!(phba->cfg_enable_fc4_type & LPFC_ENABLE_NVME))
                return 0;
@@ -3780,6 +3788,9 @@ lpfc_sli4_nvme_sgl_update(struct lpfc_hba *phba)
        spin_lock(&phba->nvme_buf_list_put_lock);
        list_splice_init(&phba->lpfc_nvme_buf_list_get, &nvme_sgl_list);
        list_splice(&phba->lpfc_nvme_buf_list_put, &nvme_sgl_list);
+       cnt = phba->get_nvme_bufs + phba->put_nvme_bufs;
+       phba->get_nvme_bufs = 0;
+       phba->put_nvme_bufs = 0;
        spin_unlock(&phba->nvme_buf_list_put_lock);
        spin_unlock_irq(&phba->nvme_buf_list_get_lock);
 
@@ -3824,6 +3835,7 @@ lpfc_sli4_nvme_sgl_update(struct lpfc_hba *phba)
        spin_lock_irq(&phba->nvme_buf_list_get_lock);
        spin_lock(&phba->nvme_buf_list_put_lock);
        list_splice_init(&nvme_sgl_list, &phba->lpfc_nvme_buf_list_get);
+       phba->get_nvme_bufs = cnt;
        INIT_LIST_HEAD(&phba->lpfc_nvme_buf_list_put);
        spin_unlock(&phba->nvme_buf_list_put_lock);
        spin_unlock_irq(&phba->nvme_buf_list_get_lock);
@@ -5609,8 +5621,10 @@ lpfc_setup_driver_resource_phase1(struct lpfc_hba *phba)
                /* Initialize the NVME buffer list used by driver for NVME IO */
                spin_lock_init(&phba->nvme_buf_list_get_lock);
                INIT_LIST_HEAD(&phba->lpfc_nvme_buf_list_get);
+               phba->get_nvme_bufs = 0;
                spin_lock_init(&phba->nvme_buf_list_put_lock);
                INIT_LIST_HEAD(&phba->lpfc_nvme_buf_list_put);
+               phba->put_nvme_bufs = 0;
        }
 
        /* Initialize the fabric iocb list */

diff --git a/drivers/scsi/lpfc/lpfc_nvme.c b/drivers/scsi/lpfc/lpfc_nvme.c
index c9945ed4b791f4faf5f12dffebd8abbf3f37044e..1097ca5a7a8e2d3f9834b5e8cd1db4d790c85afb 100644 (file)
--- a/drivers/scsi/lpfc/lpfc_nvme.c
+++ b/drivers/scsi/lpfc/lpfc_nvme.c
@@ -57,7 +57,8 @@
 /* NVME initiator-based functions */
 
 static struct lpfc_nvme_buf *
-lpfc_get_nvme_buf(struct lpfc_hba *phba, struct lpfc_nodelist *ndlp);
+lpfc_get_nvme_buf(struct lpfc_hba *phba, struct lpfc_nodelist *ndlp,
+                 int expedite);
 
 static void
 lpfc_release_nvme_buf(struct lpfc_hba *, struct lpfc_nvme_buf *);
@@ -1265,6 +1266,7 @@ lpfc_nvme_fcp_io_submit(struct nvme_fc_local_port *pnvme_lport,
                        struct nvmefc_fcp_req *pnvme_fcreq)
 {
        int ret = 0;
+       int expedite = 0;
        struct lpfc_nvme_lport *lport;
        struct lpfc_vport *vport;
        struct lpfc_hba *phba;
@@ -1273,6 +1275,7 @@ lpfc_nvme_fcp_io_submit(struct nvme_fc_local_port *pnvme_lport,
        struct lpfc_nvme_rport *rport;
        struct lpfc_nvme_qhandle *lpfc_queue_info;
        struct lpfc_nvme_fcpreq_priv *freqpriv;
+       struct nvme_common_command *sqe;
 #ifdef CONFIG_SCSI_LPFC_DEBUG_FS
        uint64_t start = 0;
 #endif
@@ -1354,15 +1357,27 @@ lpfc_nvme_fcp_io_submit(struct nvme_fc_local_port *pnvme_lport,
 
        }
 
+       /* Currently only NVME Keep alive commands should be expedited
+        * if the driver runs out of a resource. These should only be
+        * issued on the admin queue, qidx 0
+        */
+       if (!lpfc_queue_info->qidx && !pnvme_fcreq->sg_cnt) {
+               sqe = &((struct nvme_fc_cmd_iu *)
+                       pnvme_fcreq->cmdaddr)->sqe.common;
+               if (sqe->opcode == nvme_admin_keep_alive)
+                       expedite = 1;
+       }
+
        /* The node is shared with FCP IO, make sure the IO pending count does
         * not exceed the programmed depth.
         */
-       if (atomic_read(&ndlp->cmd_pending) >= ndlp->cmd_qdepth) {
+       if ((atomic_read(&ndlp->cmd_pending) >= ndlp->cmd_qdepth) &&
+           !expedite) {
                ret = -EBUSY;
                goto out_fail;
        }
 
-       lpfc_ncmd = lpfc_get_nvme_buf(phba, ndlp);
+       lpfc_ncmd = lpfc_get_nvme_buf(phba, ndlp, expedite);
        if (lpfc_ncmd == NULL) {
                lpfc_printf_vlog(vport, KERN_INFO, LOG_NVME_IOERR,
                                 "6065 driver's buffer pool is empty, "
@@ -1991,6 +2006,8 @@ lpfc_repost_nvme_sgl_list(struct lpfc_hba *phba)
        spin_lock(&phba->nvme_buf_list_put_lock);
        list_splice_init(&phba->lpfc_nvme_buf_list_get, &post_nblist);
        list_splice(&phba->lpfc_nvme_buf_list_put, &post_nblist);
+       phba->get_nvme_bufs = 0;
+       phba->put_nvme_bufs = 0;
        spin_unlock(&phba->nvme_buf_list_put_lock);
        spin_unlock_irq(&phba->nvme_buf_list_get_lock);
 
@@ -2127,6 +2144,20 @@ lpfc_new_nvme_buf(struct lpfc_vport *vport, int num_to_alloc)
        return num_posted;
 }
 
+static inline struct lpfc_nvme_buf *
+lpfc_nvme_buf(struct lpfc_hba *phba)
+{
+       struct lpfc_nvme_buf *lpfc_ncmd, *lpfc_ncmd_next;
+
+       list_for_each_entry_safe(lpfc_ncmd, lpfc_ncmd_next,
+                                &phba->lpfc_nvme_buf_list_get, list) {
+               list_del_init(&lpfc_ncmd->list);
+               phba->get_nvme_bufs--;
+               return lpfc_ncmd;
+       }
+       return NULL;
+}
+
 /**
  * lpfc_get_nvme_buf - Get a nvme buffer from lpfc_nvme_buf_list of the HBA
  * @phba: The HBA for which this call is being executed.
@@ -2139,35 +2170,27 @@ lpfc_new_nvme_buf(struct lpfc_vport *vport, int num_to_alloc)
  *   Pointer to lpfc_nvme_buf - Success
  **/
 static struct lpfc_nvme_buf *
-lpfc_get_nvme_buf(struct lpfc_hba *phba, struct lpfc_nodelist *ndlp)
+lpfc_get_nvme_buf(struct lpfc_hba *phba, struct lpfc_nodelist *ndlp,
+                 int expedite)
 {
-       struct lpfc_nvme_buf *lpfc_ncmd, *lpfc_ncmd_next;
+       struct lpfc_nvme_buf *lpfc_ncmd = NULL;
        unsigned long iflag = 0;
-       int found = 0;
 
        spin_lock_irqsave(&phba->nvme_buf_list_get_lock, iflag);
-       list_for_each_entry_safe(lpfc_ncmd, lpfc_ncmd_next,
-                                &phba->lpfc_nvme_buf_list_get, list) {
-               list_del_init(&lpfc_ncmd->list);
-               found = 1;
-               break;
-       }
-       if (!found) {
+       if (phba->get_nvme_bufs > LPFC_NVME_EXPEDITE_XRICNT || expedite)
+               lpfc_ncmd = lpfc_nvme_buf(phba);
+       if (!lpfc_ncmd) {
                spin_lock(&phba->nvme_buf_list_put_lock);
                list_splice(&phba->lpfc_nvme_buf_list_put,
                            &phba->lpfc_nvme_buf_list_get);
+               phba->get_nvme_bufs += phba->put_nvme_bufs;
                INIT_LIST_HEAD(&phba->lpfc_nvme_buf_list_put);
+               phba->put_nvme_bufs = 0;
                spin_unlock(&phba->nvme_buf_list_put_lock);
-               list_for_each_entry_safe(lpfc_ncmd, lpfc_ncmd_next,
-                                        &phba->lpfc_nvme_buf_list_get, list) {
-                       list_del_init(&lpfc_ncmd->list);
-                       found = 1;
-                       break;
-               }
+               if (phba->get_nvme_bufs > LPFC_NVME_EXPEDITE_XRICNT || expedite)
+                       lpfc_ncmd = lpfc_nvme_buf(phba);
        }
        spin_unlock_irqrestore(&phba->nvme_buf_list_get_lock, iflag);
-       if (!found)
-               return NULL;
        return  lpfc_ncmd;
 }
 
@@ -2205,6 +2228,7 @@ lpfc_release_nvme_buf(struct lpfc_hba *phba, struct lpfc_nvme_buf *lpfc_ncmd)
                lpfc_ncmd->cur_iocbq.iocb_flag = LPFC_IO_NVME;
                spin_lock_irqsave(&phba->nvme_buf_list_put_lock, iflag);
                list_add_tail(&lpfc_ncmd->list, &phba->lpfc_nvme_buf_list_put);
+               phba->put_nvme_bufs++;
                spin_unlock_irqrestore(&phba->nvme_buf_list_put_lock, iflag);
        }
 }

diff --git a/drivers/scsi/lpfc/lpfc_nvme.h b/drivers/scsi/lpfc/lpfc_nvme.h
index 903ec37f465fa0c9f00e41f6bec9eb2a8751ba3e..c0833e469b7c0893acc66de3a39c5a5307e34609 100644 (file)
--- a/drivers/scsi/lpfc/lpfc_nvme.h
+++ b/drivers/scsi/lpfc/lpfc_nvme.h
@@ -28,6 +28,7 @@
 #define LPFC_NVME_ERSP_LEN             0x20
 
 #define LPFC_NVME_WAIT_TMO              10
+#define LPFC_NVME_EXPEDITE_XRICNT      8
 
 struct lpfc_nvme_qhandle {
        uint32_t index;         /* WQ index to use */