libfc: Add runtime debugging with debug_logging module parameter

This patch adds the /sys/module/libfc/parameters/debug_logging
file to sysfs as a module parameter. It accepts an integer
bitmask for logging. Currently it supports:

   bit
LSB 0 = general libfc debugging
    1 = lport debugging
    2 = disc debugging
    3 = rport debugging
    4 = fcp debugging
    5 = EM debugging
    6 = exch/seq debugging
    7 = scsi logging (mostly error handling)

the other bits are not used at this time.

The patch converts all of the libfc source files to use
these new macros and removes the old FC_DBG macro.

Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 25 insertions, 33 deletions

diff --git a/drivers/scsi/libfc/fc_exch.c b/drivers/scsi/libfc/fc_exch.c
index 7af9bceb8aa9..2bc22be5f849 100644
--- a/drivers/scsi/libfc/fc_exch.c
+++ b/drivers/scsi/libfc/fc_exch.c
@@ -32,18 +32,7 @@
 #include <scsi/libfc.h>
 #include <scsi/fc_encode.h>
 
-/*
- * fc_exch_debug can be set in debugger or at compile time to get more logs.
- */
-static int fc_exch_debug;
-
-#define FC_DEBUG_EXCH(fmt...)			\
-	do {					\
-		if (fc_exch_debug)		\
-			FC_DBG(fmt);		\
-	} while (0)
-
-static struct kmem_cache *fc_em_cachep;	/* cache for exchanges */
+static struct kmem_cache *fc_em_cachep;        /* cache for exchanges */
 
 /*
  * Structure and function definitions for managing Fibre Channel Exchanges
@@ -333,8 +322,8 @@ static inline void fc_exch_timer_set_locked(struct fc_exch *ep,
 	if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))
 		return;
 
-	FC_DEBUG_EXCH("Exchange (%4x) timed out, notifying the upper layer\n",
-		      ep->xid);
+	FC_EXCH_DBG(ep, "Exchange timed out, notifying the upper layer\n");
+
 	if (schedule_delayed_work(&ep->timeout_work,
 				  msecs_to_jiffies(timer_msec)))
 		fc_exch_hold(ep);		/* hold for timer */
@@ -545,7 +534,7 @@ struct fc_exch *fc_exch_alloc(struct fc_exch_mgr *mp,
 		/* alloc a new xid */
 		xid = fc_em_alloc_xid(mp, fp);
 		if (!xid) {
-			printk(KERN_ERR "fc_em_alloc_xid() failed\n");
+			printk(KERN_WARNING "libfc: Failed to allocate an exhange\n");
 			goto err;
 		}
 	}
@@ -820,8 +809,8 @@ static struct fc_seq *fc_seq_start_next_locked(struct fc_seq *sp)
 	struct fc_exch *ep = fc_seq_exch(sp);
 
 	sp = fc_seq_alloc(ep, ep->seq_id++);
-	FC_DEBUG_EXCH("exch %4x f_ctl %6x seq %2x\n",
-		      ep->xid, ep->f_ctl, sp->id);
+	FC_EXCH_DBG(ep, "f_ctl %6x seq %2x\n",
+		    ep->f_ctl, sp->id);
 	return sp;
 }
 /*
@@ -901,7 +890,7 @@ void fc_seq_els_rsp_send(struct fc_seq *sp, enum fc_els_cmd els_cmd,
 		fc_exch_els_rec(sp, els_data->fp);
 		break;
 	default:
-		FC_DBG("Invalid ELS CMD:%x\n", els_cmd);
+		FC_EXCH_DBG(fc_seq_exch(sp), "Invalid ELS CMD:%x\n", els_cmd);
 	}
 }
 EXPORT_SYMBOL(fc_seq_els_rsp_send);
@@ -1134,7 +1123,7 @@ static void fc_exch_recv_req(struct fc_lport *lp, struct fc_exch_mgr *mp,
 			lp->tt.lport_recv(lp, sp, fp);
 		fc_exch_release(ep);	/* release from lookup */
 	} else {
-		FC_DEBUG_EXCH("exch/seq lookup failed: reject %x\n", reject);
+		FC_EM_DBG(mp, "exch/seq lookup failed: reject %x\n", reject);
 		fc_frame_free(fp);
 	}
 }
@@ -1242,10 +1231,10 @@ static void fc_exch_recv_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
 	sp = fc_seq_lookup_orig(mp, fp);	/* doesn't hold sequence */
 	if (!sp) {
 		atomic_inc(&mp->stats.xid_not_found);
-		FC_DEBUG_EXCH("seq lookup failed\n");
+		FC_EM_DBG(mp, "seq lookup failed\n");
 	} else {
 		atomic_inc(&mp->stats.non_bls_resp);
-		FC_DEBUG_EXCH("non-BLS response to sequence");
+		FC_EM_DBG(mp, "non-BLS response to sequence");
 	}
 	fc_frame_free(fp);
 }
@@ -1266,8 +1255,8 @@ static void fc_exch_abts_resp(struct fc_exch *ep, struct fc_frame *fp)
 	int rc = 1, has_rec = 0;
 
 	fh = fc_frame_header_get(fp);
-	FC_DEBUG_EXCH("exch: BLS rctl %x - %s\n",
-		      fh->fh_r_ctl, fc_exch_rctl_name(fh->fh_r_ctl));
+	FC_EXCH_DBG(ep, "exch: BLS rctl %x - %s\n", fh->fh_r_ctl,
+		    fc_exch_rctl_name(fh->fh_r_ctl));
 
 	if (cancel_delayed_work_sync(&ep->timeout_work))
 		fc_exch_release(ep);	/* release from pending timer hold */
@@ -1359,9 +1348,9 @@ static void fc_exch_recv_bls(struct fc_exch_mgr *mp, struct fc_frame *fp)
 		case FC_RCTL_ACK_0:
 			break;
 		default:
-			FC_DEBUG_EXCH("BLS rctl %x - %s received",
-				      fh->fh_r_ctl,
-				      fc_exch_rctl_name(fh->fh_r_ctl));
+			FC_EXCH_DBG(ep, "BLS rctl %x - %s received",
+				    fh->fh_r_ctl,
+				    fc_exch_rctl_name(fh->fh_r_ctl));
 			break;
 		}
 		fc_frame_free(fp);
@@ -1599,7 +1588,8 @@ static void fc_exch_rrq_resp(struct fc_seq *sp, struct fc_frame *fp, void *arg)
 
 		if (err == -FC_EX_CLOSED || err == -FC_EX_TIMEOUT)
 			goto cleanup;
-		FC_DBG("Cannot process RRQ, because of frame error %d\n", err);
+		FC_EXCH_DBG(aborted_ep, "Cannot process RRQ, "
+			    "frame error %d\n", err);
 		return;
 	}
 
@@ -1608,12 +1598,13 @@ static void fc_exch_rrq_resp(struct fc_seq *sp, struct fc_frame *fp, void *arg)
 
 	switch (op) {
 	case ELS_LS_RJT:
-		FC_DBG("LS_RJT for RRQ");
+		FC_EXCH_DBG(aborted_ep, "LS_RJT for RRQ");
 		/* fall through */
 	case ELS_LS_ACC:
 		goto cleanup;
 	default:
-		FC_DBG("unexpected response op %x for RRQ", op);
+		FC_EXCH_DBG(aborted_ep, "unexpected response op %x "
+			    "for RRQ", op);
 		return;
 	}
 
@@ -1740,8 +1731,8 @@ struct fc_exch_mgr *fc_exch_mgr_alloc(struct fc_lport *lp,
 	size_t len;
 
 	if (max_xid <= min_xid || min_xid == 0 || max_xid == FC_XID_UNKNOWN) {
-		FC_DBG("Invalid min_xid 0x:%x and max_xid 0x:%x\n",
-		       min_xid, max_xid);
+		FC_LPORT_DBG(lp, "Invalid min_xid 0x:%x and max_xid 0x:%x\n",
+			     min_xid, max_xid);
 		return NULL;
 	}
 
@@ -1878,7 +1869,8 @@ void fc_exch_recv(struct fc_lport *lp, struct fc_exch_mgr *mp,
 
 	/* lport lock ? */
 	if (!lp || !mp || (lp->state == LPORT_ST_NONE)) {
-		FC_DBG("fc_lport or EM is not allocated and configured");
+		FC_LPORT_DBG(lp, "Receiving frames for an lport that "
+			     "has not been initialized correctly\n");
 		fc_frame_free(fp);
 		return;
 	}
@@ -1904,7 +1896,7 @@ void fc_exch_recv(struct fc_lport *lp, struct fc_exch_mgr *mp,
 			fc_exch_recv_req(lp, mp, fp);
 		break;
 	default:
-		FC_DBG("dropping invalid frame (eof %x)", fr_eof(fp));
+		FC_EM_DBG(mp, "dropping invalid frame (eof %x)", fr_eof(fp));
 		fc_frame_free(fp);
 		break;
 	}