xen-blkback: define pr_fmt macro to avoid the duplication of DRV_PFX

Define pr_fmt macro with {xen-blkback: } prefix, then remove all use
of DRV_PFX in the pr sentences. Replace all DPRINTK with pr sentences,
and get rid of DPRINTK macro. It will simplify the code.

And if the pr sentences miss a \n, add it in the end. If the DPRINTK
sentences have redundant \n, remove it. It will format the code.

These all make the readability of the code become better.
Signed-off-by: Tao Chen <boby.chen@huawei.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>

drivers/block/xen-blkback/blkback.c

@@ -34,6 +34,8 @@
  * IN THE SOFTWARE.
  */
 
+#define pr_fmt(fmt) "xen-blkback: " fmt
+
 #include <linux/spinlock.h>
 #include <linux/kthread.h>
 #include <linux/list.h>
@@ -211,7 +213,7 @@ static int add_persistent_gnt(struct xen_blkif *blkif,
 		else if (persistent_gnt->gnt > this->gnt)
 			new = &((*new)->rb_right);
 		else {
-			pr_alert_ratelimited(DRV_PFX " trying to add a gref that's already in the tree\n");
+			pr_alert_ratelimited("trying to add a gref that's already in the tree\n");
 			return -EINVAL;
 		}
 	}
@@ -242,7 +244,7 @@ static struct persistent_gnt *get_persistent_gnt(struct xen_blkif *blkif,
 			node = node->rb_right;
 		else {
 			if(test_bit(PERSISTENT_GNT_ACTIVE, data->flags)) {
-				pr_alert_ratelimited(DRV_PFX " requesting a grant already in use\n");
+				pr_alert_ratelimited("requesting a grant already in use\n");
 				return NULL;
 			}
 			set_bit(PERSISTENT_GNT_ACTIVE, data->flags);
@@ -257,7 +259,7 @@ static void put_persistent_gnt(struct xen_blkif *blkif,
                                struct persistent_gnt *persistent_gnt)
 {
 	if(!test_bit(PERSISTENT_GNT_ACTIVE, persistent_gnt->flags))
-	          pr_alert_ratelimited(DRV_PFX " freeing a grant already unused");
+		pr_alert_ratelimited("freeing a grant already unused\n");
 	set_bit(PERSISTENT_GNT_WAS_ACTIVE, persistent_gnt->flags);
 	clear_bit(PERSISTENT_GNT_ACTIVE, persistent_gnt->flags);
 	atomic_dec(&blkif->persistent_gnt_in_use);
@@ -374,7 +376,7 @@ static void purge_persistent_gnt(struct xen_blkif *blkif)
 	}
 
 	if (work_pending(&blkif->persistent_purge_work)) {
-		pr_alert_ratelimited(DRV_PFX "Scheduled work from previous purge is still pending, cannot purge list\n");
+		pr_alert_ratelimited("Scheduled work from previous purge is still pending, cannot purge list\n");
 		return;
 	}
 
@@ -396,7 +398,7 @@ static void purge_persistent_gnt(struct xen_blkif *blkif)
 
 	total = num_clean;
 
-	pr_debug(DRV_PFX "Going to purge %u persistent grants\n", num_clean);
+	pr_debug("Going to purge %u persistent grants\n", num_clean);
 
 	BUG_ON(!list_empty(&blkif->persistent_purge_list));
 	root = &blkif->persistent_gnts;
@@ -428,13 +430,13 @@ static void purge_persistent_gnt(struct xen_blkif *blkif)
 	 * with the requested num
 	 */
 	if (!scan_used && !clean_used) {
-		pr_debug(DRV_PFX "Still missing %u purged frames\n", num_clean);
+		pr_debug("Still missing %u purged frames\n", num_clean);
 		scan_used = true;
 		goto purge_list;
 	}
 finished:
 	if (!clean_used) {
-		pr_debug(DRV_PFX "Finished scanning for grants to clean, removing used flag\n");
+		pr_debug("Finished scanning for grants to clean, removing used flag\n");
 		clean_used = true;
 		goto purge_list;
 	}
@@ -444,7 +446,7 @@ static void purge_persistent_gnt(struct xen_blkif *blkif)
 
 	/* We can defer this work */
 	schedule_work(&blkif->persistent_purge_work);
-	pr_debug(DRV_PFX "Purged %u/%u\n", (total - num_clean), total);
+	pr_debug("Purged %u/%u\n", (total - num_clean), total);
 	return;
 }
 
@@ -520,20 +522,20 @@ static void xen_vbd_resize(struct xen_blkif *blkif)
 	struct xenbus_device *dev = xen_blkbk_xenbus(blkif->be);
 	unsigned long long new_size = vbd_sz(vbd);
 
-	pr_info(DRV_PFX "VBD Resize: Domid: %d, Device: (%d, %d)\n",
+	pr_info("VBD Resize: Domid: %d, Device: (%d, %d)\n",
 		blkif->domid, MAJOR(vbd->pdevice), MINOR(vbd->pdevice));
-	pr_info(DRV_PFX "VBD Resize: new size %llu\n", new_size);
+	pr_info("VBD Resize: new size %llu\n", new_size);
 	vbd->size = new_size;
 again:
 	err = xenbus_transaction_start(&xbt);
 	if (err) {
-		pr_warn(DRV_PFX "Error starting transaction");
+		pr_warn("Error starting transaction\n");
 		return;
 	}
 	err = xenbus_printf(xbt, dev->nodename, "sectors", "%llu",
 			    (unsigned long long)vbd_sz(vbd));
 	if (err) {
-		pr_warn(DRV_PFX "Error writing new size");
+		pr_warn("Error writing new size\n");
 		goto abort;
 	}
 	/*
@@ -543,7 +545,7 @@ static void xen_vbd_resize(struct xen_blkif *blkif)
 	 */
 	err = xenbus_printf(xbt, dev->nodename, "state", "%d", dev->state);
 	if (err) {
-		pr_warn(DRV_PFX "Error writing the state");
+		pr_warn("Error writing the state\n");
 		goto abort;
 	}
 
@@ -551,7 +553,7 @@ static void xen_vbd_resize(struct xen_blkif *blkif)
 	if (err == -EAGAIN)
 		goto again;
 	if (err)
-		pr_warn(DRV_PFX "Error ending transaction");
+		pr_warn("Error ending transaction\n");
 	return;
 abort:
 	xenbus_transaction_end(xbt, 1);
@@ -578,7 +580,7 @@ irqreturn_t xen_blkif_be_int(int irq, void *dev_id)
 
 static void print_stats(struct xen_blkif *blkif)
 {
-	pr_info("xen-blkback (%s): oo %3llu  |  rd %4llu  |  wr %4llu  |  f %4llu"
+	pr_info("(%s): oo %3llu  |  rd %4llu  |  wr %4llu  |  f %4llu"
 		 "  |  ds %4llu | pg: %4u/%4d\n",
 		 current->comm, blkif->st_oo_req,
 		 blkif->st_rd_req, blkif->st_wr_req,
@@ -855,7 +857,7 @@ static int xen_blkbk_map(struct xen_blkif *blkif,
 			/* This is a newly mapped grant */
 			BUG_ON(new_map_idx >= segs_to_map);
 			if (unlikely(map[new_map_idx].status != 0)) {
-				pr_debug(DRV_PFX "invalid buffer -- could not remap it\n");
+				pr_debug("invalid buffer -- could not remap it\n");
 				put_free_pages(blkif, &pages[seg_idx]->page, 1);
 				pages[seg_idx]->handle = BLKBACK_INVALID_HANDLE;
 				ret |= 1;
@@ -891,14 +893,14 @@ static int xen_blkbk_map(struct xen_blkif *blkif,
 				goto next;
 			}
 			pages[seg_idx]->persistent_gnt = persistent_gnt;
-			pr_debug(DRV_PFX " grant %u added to the tree of persistent grants, using %u/%u\n",
+			pr_debug("grant %u added to the tree of persistent grants, using %u/%u\n",
 				 persistent_gnt->gnt, blkif->persistent_gnt_c,
 				 xen_blkif_max_pgrants);
 			goto next;
 		}
 		if (use_persistent_gnts && !blkif->vbd.overflow_max_grants) {
 			blkif->vbd.overflow_max_grants = 1;
-			pr_debug(DRV_PFX " domain %u, device %#x is using maximum number of persistent grants\n",
+			pr_debug("domain %u, device %#x is using maximum number of persistent grants\n",
 			         blkif->domid, blkif->vbd.handle);
 		}
 		/*
@@ -916,7 +918,7 @@ static int xen_blkbk_map(struct xen_blkif *blkif,
 	return ret;
 
 out_of_memory:
-	pr_alert(DRV_PFX "%s: out of memory\n", __func__);
+	pr_alert("%s: out of memory\n", __func__);
 	put_free_pages(blkif, pages_to_gnt, segs_to_map);
 	return -ENOMEM;
 }
@@ -996,7 +998,7 @@ static int dispatch_discard_io(struct xen_blkif *blkif,
 
 	err = xen_vbd_translate(&preq, blkif, WRITE);
 	if (err) {
-		pr_warn(DRV_PFX "access denied: DISCARD [%llu->%llu] on dev=%04x\n",
+		pr_warn("access denied: DISCARD [%llu->%llu] on dev=%04x\n",
 			preq.sector_number,
 			preq.sector_number + preq.nr_sects, blkif->vbd.pdevice);
 		goto fail_response;
@@ -1012,7 +1014,7 @@ static int dispatch_discard_io(struct xen_blkif *blkif,
 				   GFP_KERNEL, secure);
 fail_response:
 	if (err == -EOPNOTSUPP) {
-		pr_debug(DRV_PFX "discard op failed, not supported\n");
+		pr_debug("discard op failed, not supported\n");
 		status = BLKIF_RSP_EOPNOTSUPP;
 	} else if (err)
 		status = BLKIF_RSP_ERROR;
@@ -1056,16 +1058,16 @@ static void __end_block_io_op(struct pending_req *pending_req, int error)
 	/* An error fails the entire request. */
 	if ((pending_req->operation == BLKIF_OP_FLUSH_DISKCACHE) &&
 	    (error == -EOPNOTSUPP)) {
-		pr_debug(DRV_PFX "flush diskcache op failed, not supported\n");
+		pr_debug("flush diskcache op failed, not supported\n");
 		xen_blkbk_flush_diskcache(XBT_NIL, pending_req->blkif->be, 0);
 		pending_req->status = BLKIF_RSP_EOPNOTSUPP;
 	} else if ((pending_req->operation == BLKIF_OP_WRITE_BARRIER) &&
 		    (error == -EOPNOTSUPP)) {
-		pr_debug(DRV_PFX "write barrier op failed, not supported\n");
+		pr_debug("write barrier op failed, not supported\n");
 		xen_blkbk_barrier(XBT_NIL, pending_req->blkif->be, 0);
 		pending_req->status = BLKIF_RSP_EOPNOTSUPP;
 	} else if (error) {
-		pr_debug(DRV_PFX "Buffer not up-to-date at end of operation,"
+		pr_debug("Buffer not up-to-date at end of operation,"
 			 " error=%d\n", error);
 		pending_req->status = BLKIF_RSP_ERROR;
 	}
@@ -1110,7 +1112,7 @@ __do_block_io_op(struct xen_blkif *blkif)
 
 	if (RING_REQUEST_PROD_OVERFLOW(&blk_rings->common, rp)) {
 		rc = blk_rings->common.rsp_prod_pvt;
-		pr_warn(DRV_PFX "Frontend provided bogus ring requests (%d - %d = %d). Halting ring processing on dev=%04x\n",
+		pr_warn("Frontend provided bogus ring requests (%d - %d = %d). Halting ring processing on dev=%04x\n",
 			rp, rc, rp - rc, blkif->vbd.pdevice);
 		return -EACCES;
 	}
@@ -1217,8 +1219,7 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
 	if ((req->operation == BLKIF_OP_INDIRECT) &&
 	    (req_operation != BLKIF_OP_READ) &&
 	    (req_operation != BLKIF_OP_WRITE)) {
-		pr_debug(DRV_PFX "Invalid indirect operation (%u)\n",
-			 req_operation);
+		pr_debug("Invalid indirect operation (%u)\n", req_operation);
 		goto fail_response;
 	}
 
@@ -1252,8 +1253,7 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
 		     (nseg > BLKIF_MAX_SEGMENTS_PER_REQUEST)) ||
 	    unlikely((req->operation == BLKIF_OP_INDIRECT) &&
 		     (nseg > MAX_INDIRECT_SEGMENTS))) {
-		pr_debug(DRV_PFX "Bad number of segments in request (%d)\n",
-			 nseg);
+		pr_debug("Bad number of segments in request (%d)\n", nseg);
 		/* Haven't submitted any bio's yet. */
 		goto fail_response;
 	}
@@ -1288,7 +1288,7 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
 	}
 
 	if (xen_vbd_translate(&preq, blkif, operation) != 0) {
-		pr_debug(DRV_PFX "access denied: %s of [%llu,%llu] on dev=%04x\n",
+		pr_debug("access denied: %s of [%llu,%llu] on dev=%04x\n",
 			 operation == READ ? "read" : "write",
 			 preq.sector_number,
 			 preq.sector_number + preq.nr_sects,
@@ -1303,7 +1303,7 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
 	for (i = 0; i < nseg; i++) {
 		if (((int)preq.sector_number|(int)seg[i].nsec) &
 		    ((bdev_logical_block_size(preq.bdev) >> 9) - 1)) {
-			pr_debug(DRV_PFX "Misaligned I/O request from domain %d",
+			pr_debug("Misaligned I/O request from domain %d\n",
 				 blkif->domid);
 			goto fail_response;
 		}

drivers/block/xen-blkback/common.h

@@ -44,12 +44,6 @@
 #include <xen/interface/io/blkif.h>
 #include <xen/interface/io/protocols.h>
 
-#define DRV_PFX "xen-blkback:"
-#define DPRINTK(fmt, args...)				\
-	pr_debug(DRV_PFX "(%s:%d) " fmt ".\n",		\
-		 __func__, __LINE__, ##args)
-
-
 /*
  * This is the maximum number of segments that would be allowed in indirect
  * requests. This value will also be passed to the frontend.

drivers/block/xen-blkback/xenbus.c

@@ -14,6 +14,8 @@
 
 */
 
+#define pr_fmt(fmt) "xen-blkback: " fmt
+
 #include <stdarg.h>
 #include <linux/module.h>
 #include <linux/kthread.h>
@@ -426,14 +428,14 @@ static int xen_vbd_create(struct xen_blkif *blkif, blkif_vdev_t handle,
 				 FMODE_READ : FMODE_WRITE, NULL);
 
 	if (IS_ERR(bdev)) {
-		DPRINTK("xen_vbd_create: device %08x could not be opened.\n",
+		pr_warn("xen_vbd_create: device %08x could not be opened\n",
 			vbd->pdevice);
 		return -ENOENT;
 	}
 
 	vbd->bdev = bdev;
 	if (vbd->bdev->bd_disk == NULL) {
-		DPRINTK("xen_vbd_create: device %08x doesn't exist.\n",
+		pr_warn("xen_vbd_create: device %08x doesn't exist\n",
 			vbd->pdevice);
 		xen_vbd_free(vbd);
 		return -ENOENT;
@@ -452,7 +454,7 @@ static int xen_vbd_create(struct xen_blkif *blkif, blkif_vdev_t handle,
 	if (q && blk_queue_secdiscard(q))
 		vbd->discard_secure = true;
 
-	DPRINTK("Successful creation of handle=%04x (dom=%u)\n",
+	pr_debug("Successful creation of handle=%04x (dom=%u)\n",
 		handle, blkif->domid);
 	return 0;
 }
@@ -460,7 +462,7 @@ static int xen_blkbk_remove(struct xenbus_device *dev)
 {
 	struct backend_info *be = dev_get_drvdata(&dev->dev);
 
-	DPRINTK("");
+	pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id);
 
 	if (be->major || be->minor)
 		xenvbd_sysfs_delif(dev);
@@ -566,6 +568,10 @@ static int xen_blkbk_probe(struct xenbus_device *dev,
 	int err;
 	struct backend_info *be = kzalloc(sizeof(struct backend_info),
 					  GFP_KERNEL);
+
+	/* match the pr_debug in xen_blkbk_remove */
+	pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id);
+
 	if (!be) {
 		xenbus_dev_fatal(dev, -ENOMEM,
 				 "allocating backend structure");
@@ -597,7 +603,7 @@ static int xen_blkbk_probe(struct xenbus_device *dev,
 	return 0;
 
 fail:
-	DPRINTK("failed");
+	pr_warn("%s failed\n", __func__);
 	xen_blkbk_remove(dev);
 	return err;
 }
@@ -621,7 +627,7 @@ static void backend_changed(struct xenbus_watch *watch,
 	unsigned long handle;
 	char *device_type;
 
-	DPRINTK("");
+	pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id);
 
 	err = xenbus_scanf(XBT_NIL, dev->nodename, "physical-device", "%x:%x",
 			   &major, &minor);
@@ -640,7 +646,7 @@ static void backend_changed(struct xenbus_watch *watch,
 
 	if (be->major | be->minor) {
 		if (be->major != major || be->minor != minor)
-			pr_warn(DRV_PFX "changing physical device (from %x:%x to %x:%x) not supported.\n",
+			pr_warn("changing physical device (from %x:%x to %x:%x) not supported.\n",
 				be->major, be->minor, major, minor);
 		return;
 	}
@@ -701,13 +707,12 @@ static void frontend_changed(struct xenbus_device *dev,
 	struct backend_info *be = dev_get_drvdata(&dev->dev);
 	int err;
 
-	DPRINTK("%s", xenbus_strstate(frontend_state));
+	pr_debug("%s %p %s\n", __func__, dev, xenbus_strstate(frontend_state));
 
 	switch (frontend_state) {
 	case XenbusStateInitialising:
 		if (dev->state == XenbusStateClosed) {
-			pr_info(DRV_PFX "%s: prepare for reconnect\n",
-				dev->nodename);
+			pr_info("%s: prepare for reconnect\n", dev->nodename);
 			xenbus_switch_state(dev, XenbusStateInitWait);
 		}
 		break;
@@ -774,7 +779,7 @@ static void connect(struct backend_info *be)
 	int err;
 	struct xenbus_device *dev = be->dev;
 
-	DPRINTK("%s", dev->otherend);
+	pr_debug("%s %s\n", __func__, dev->otherend);
 
 	/* Supply the information about the device the frontend needs */
 again:
@@ -860,7 +865,7 @@ static int connect_ring(struct backend_info *be)
 	char protocol[64] = "";
 	int err;
 
-	DPRINTK("%s", dev->otherend);
+	pr_debug("%s %s\n", __func__, dev->otherend);
 
 	err = xenbus_gather(XBT_NIL, dev->otherend, "ring-ref", "%lu",
 			    &ring_ref, "event-channel", "%u", &evtchn, NULL);
@@ -895,7 +900,7 @@ static int connect_ring(struct backend_info *be)
 	be->blkif->vbd.feature_gnt_persistent = pers_grants;
 	be->blkif->vbd.overflow_max_grants = 0;
 
-	pr_info(DRV_PFX "ring-ref %ld, event-channel %d, protocol %d (%s) %s\n",
+	pr_info("ring-ref %ld, event-channel %d, protocol %d (%s) %s\n",
 		ring_ref, evtchn, be->blkif->blk_protocol, protocol,
 		pers_grants ? "persistent grants" : "");