[PATCH v2 6/9] nbd: Restructure debugging prints

[Markus Pargmann]

dprintk has some name collisions with other frameworks and drivers. It
is also not necessary to have these custom debug print filters. Dynamic
debug offers the same amount of filtered debugging.

This patch replaces all dprintks with dev_dbg(). It also removes the
ioctl dprintk which prints the ingoing ioctls which should be
replaceable by strace or similar stuff.

Signed-off-by: Markus Pargmann <mpa@xxxxxxxxxxxxxx>
---

Notes:
    Changes in v2:
     - The device name was written twice in each print. This is fixed by removing
       the explicit print of the disk name.
     - dev_dbg() in do_nbd_request() was moved to have a valid nbd pointer

 drivers/block/nbd.c | 88 ++++++++++++++---------------------------------------
 1 file changed, 22 insertions(+), 66 deletions(-)

diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 13c8371cbf4c..217b570dd7a5 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -63,21 +63,6 @@ struct nbd_device {
 
 #define NBD_MAGIC 0x68797548
 
-#ifdef NDEBUG
-#define dprintk(flags, fmt...)
-#else /* NDEBUG */
-#define dprintk(flags, fmt...) do { \
-	if (debugflags & (flags)) printk(KERN_DEBUG fmt); \
-} while (0)
-#define DBG_IOCTL       0x0004
-#define DBG_INIT        0x0010
-#define DBG_EXIT        0x0020
-#define DBG_BLKDEV      0x0100
-#define DBG_RX          0x0200
-#define DBG_TX          0x0400
-static unsigned int debugflags;
-#endif /* NDEBUG */
-
 static unsigned int nbds_max = 16;
 static struct nbd_device *nbd_dev;
 static int max_part;
@@ -94,25 +79,9 @@ static int max_part;
  */
 static DEFINE_SPINLOCK(nbd_lock);
 
-#ifndef NDEBUG
-static const char *ioctl_cmd_to_ascii(int cmd)
+static inline struct device *nbd_to_dev(struct nbd_device *nbd)
 {
-	switch (cmd) {
-	case NBD_SET_SOCK: return "set-sock";
-	case NBD_SET_BLKSIZE: return "set-blksize";
-	case NBD_SET_SIZE: return "set-size";
-	case NBD_SET_TIMEOUT: return "set-timeout";
-	case NBD_SET_FLAGS: return "set-flags";
-	case NBD_DO_IT: return "do-it";
-	case NBD_CLEAR_SOCK: return "clear-sock";
-	case NBD_CLEAR_QUE: return "clear-que";
-	case NBD_PRINT_DEBUG: return "print-debug";
-	case NBD_SET_SIZE_BLOCKS: return "set-size-blocks";
-	case NBD_DISCONNECT: return "disconnect";
-	case BLKROSET: return "set-read-only";
-	case BLKFLSBUF: return "flush-buffer-cache";
-	}
-	return "unknown";
+	return disk_to_dev(nbd->disk);
 }
 
 static const char *nbdcmd_to_ascii(int cmd)
@@ -126,16 +95,15 @@ static const char *nbdcmd_to_ascii(int cmd)
 	}
 	return "invalid";
 }
-#endif /* NDEBUG */
 
-static void nbd_end_request(struct request *req)
+static void nbd_end_request(struct nbd_device *nbd, struct request *req)
 {
 	int error = req->errors ? -EIO : 0;
 	struct request_queue *q = req->q;
 	unsigned long flags;
 
-	dprintk(DBG_BLKDEV, "%s: request %p: %s\n", req->rq_disk->disk_name,
-			req, error ? "failed" : "done");
+	dev_dbg(nbd_to_dev(nbd), "request %p: %s\n", req,
+		error ? "failed" : "done");
 
 	spin_lock_irqsave(q->queue_lock, flags);
 	__blk_end_request_all(req, error);
@@ -276,11 +244,9 @@ static int nbd_send_req(struct nbd_device *nbd, struct request *req)
 	}
 	memcpy(request.handle, &req, sizeof(req));
 
-	dprintk(DBG_TX, "%s: request %p: sending control (%s@%llu,%uB)\n",
-			nbd->disk->disk_name, req,
-			nbdcmd_to_ascii(nbd_cmd(req)),
-			(unsigned long long)blk_rq_pos(req) << 9,
-			blk_rq_bytes(req));
+	dev_dbg(nbd_to_dev(nbd), "request %p: sending control (%s@%llu,%uB)\n",
+		req, nbdcmd_to_ascii(nbd_cmd(req)),
+		(unsigned long long)blk_rq_pos(req) << 9, blk_rq_bytes(req));
 	result = sock_xmit(nbd, 1, &request, sizeof(request),
 			(nbd_cmd(req) == NBD_CMD_WRITE) ? MSG_MORE : 0);
 	if (result <= 0) {
@@ -300,8 +266,8 @@ static int nbd_send_req(struct nbd_device *nbd, struct request *req)
 			flags = 0;
 			if (!rq_iter_last(bvec, iter))
 				flags = MSG_MORE;
-			dprintk(DBG_TX, "%s: request %p: sending %d bytes data\n",
-					nbd->disk->disk_name, req, bvec.bv_len);
+			dev_dbg(nbd_to_dev(nbd), "request %p: sending %d bytes data\n",
+				req, bvec.bv_len);
 			result = sock_send_bvec(nbd, &bvec, flags);
 			if (result <= 0) {
 				dev_err(disk_to_dev(nbd->disk),
@@ -394,8 +360,7 @@ static struct request *nbd_read_stat(struct nbd_device *nbd)
 		return req;
 	}
 
-	dprintk(DBG_RX, "%s: request %p: got reply\n",
-			nbd->disk->disk_name, req);
+	dev_dbg(nbd_to_dev(nbd), "request %p: got reply\n", req);
 	if (nbd_cmd(req) == NBD_CMD_READ) {
 		struct req_iterator iter;
 		struct bio_vec bvec;
@@ -408,8 +373,8 @@ static struct request *nbd_read_stat(struct nbd_device *nbd)
 				req->errors++;
 				return req;
 			}
-			dprintk(DBG_RX, "%s: request %p: got %d bytes data\n",
-				nbd->disk->disk_name, req, bvec.bv_len);
+			dev_dbg(nbd_to_dev(nbd), "request %p: got %d bytes data\n",
+				req, bvec.bv_len);
 		}
 	}
 	return req;
@@ -449,7 +414,7 @@ static int nbd_do_it(struct nbd_device *nbd)
 	}
 
 	while ((req = nbd_read_stat(nbd)) != NULL)
-		nbd_end_request(req);
+		nbd_end_request(nbd, req);
 
 	device_remove_file(disk_to_dev(nbd->disk), &pid_attr);
 	nbd->pid = 0;
@@ -478,7 +443,7 @@ static void nbd_clear_que(struct nbd_device *nbd)
 				 queuelist);
 		list_del_init(&req->queuelist);
 		req->errors++;
-		nbd_end_request(req);
+		nbd_end_request(nbd, req);
 	}
 
 	while (!list_empty(&nbd->waiting_queue)) {
@@ -486,7 +451,7 @@ static void nbd_clear_que(struct nbd_device *nbd)
 				 queuelist);
 		list_del_init(&req->queuelist);
 		req->errors++;
-		nbd_end_request(req);
+		nbd_end_request(nbd, req);
 	}
 }
 
@@ -530,7 +495,7 @@ static void nbd_handle_req(struct nbd_device *nbd, struct request *req)
 	if (nbd_send_req(nbd, req) != 0) {
 		dev_err(disk_to_dev(nbd->disk), "Request send failed\n");
 		req->errors++;
-		nbd_end_request(req);
+		nbd_end_request(nbd, req);
 	} else {
 		spin_lock(&nbd->queue_lock);
 		list_add_tail(&req->queuelist, &nbd->queue_head);
@@ -545,7 +510,7 @@ static void nbd_handle_req(struct nbd_device *nbd, struct request *req)
 
 error_out:
 	req->errors++;
-	nbd_end_request(req);
+	nbd_end_request(nbd, req);
 }
 
 static int nbd_thread(void *data)
@@ -593,18 +558,18 @@ static void do_nbd_request(struct request_queue *q)
 
 		spin_unlock_irq(q->queue_lock);
 
-		dprintk(DBG_BLKDEV, "%s: request %p: dequeued (flags=%x)\n",
-				req->rq_disk->disk_name, req, req->cmd_type);
-
 		nbd = req->rq_disk->private_data;
 
 		BUG_ON(nbd->magic != NBD_MAGIC);
 
+		dev_dbg(nbd_to_dev(nbd), "request %p: dequeued (flags=%x)\n",
+			req, req->cmd_type);
+
 		if (unlikely(!nbd->sock)) {
 			dev_err(disk_to_dev(nbd->disk),
 				"Attempted send on closed socket\n");
 			req->errors++;
-			nbd_end_request(req);
+			nbd_end_request(nbd, req);
 			spin_lock_irq(q->queue_lock);
 			continue;
 		}
@@ -791,10 +756,6 @@ static int nbd_ioctl(struct block_device *bdev, fmode_t mode,
 
 	BUG_ON(nbd->magic != NBD_MAGIC);
 
-	/* Anyone capable of this syscall can do *real bad* things */
-	dprintk(DBG_IOCTL, "%s: nbd_ioctl cmd=%s(0x%x) arg=%lu\n",
-		nbd->disk->disk_name, ioctl_cmd_to_ascii(cmd), cmd, arg);
-
 	mutex_lock(&nbd->tx_lock);
 	error = __nbd_ioctl(bdev, nbd, cmd, arg);
 	mutex_unlock(&nbd->tx_lock);
@@ -884,7 +845,6 @@ static int __init nbd_init(void)
 	}
 
 	printk(KERN_INFO "nbd: registered device at major %d\n", NBD_MAJOR);
-	dprintk(DBG_INIT, "nbd: debugflags=0x%x\n", debugflags);
 
 	for (i = 0; i < nbds_max; i++) {
 		struct gendisk *disk = nbd_dev[i].disk;
@@ -943,7 +903,3 @@ module_param(nbds_max, int, 0444);
 MODULE_PARM_DESC(nbds_max, "number of network block devices to initialize (default: 16)");
 module_param(max_part, int, 0444);
 MODULE_PARM_DESC(max_part, "number of partitions per device (default: 0)");
-#ifndef NDEBUG
-module_param(debugflags, int, 0644);
-MODULE_PARM_DESC(debugflags, "flags for controlling debug output");
-#endif
-- 
2.1.4

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