Add blktrace interface to sg device files

@@ -236,7 +236,7 @@ static void blk_trace_cleanup(struct blk
 	kfree(bt);
 }
 
-static int blk_trace_remove(struct request_queue *q)
+int blk_trace_remove(struct request_queue *q)
 {
 	struct blk_trace *bt;
 

@@ -250,6 +250,7 @@ static int blk_trace_remove(struct reque
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(blk_trace_remove);
 
 static int blk_dropped_open(struct inode *inode, struct file *filp)
 {

@@ -317,18 +318,17 @@ static struct rchan_callbacks blk_relay_
 /*
  * Setup everything required to start tracing
  */
-int do_blk_trace_setup(struct request_queue *q, struct block_device *bdev,
+int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
 			struct blk_user_trace_setup *buts)
 {
 	struct blk_trace *old_bt, *bt = NULL;
 	struct dentry *dir = NULL;
-	char b[BDEVNAME_SIZE];
 	int ret, i;
 
 	if (!buts->buf_size || !buts->buf_nr)
 		return -EINVAL;
 
-	strcpy(buts->name, bdevname(bdev, b));
+	strcpy(buts->name, name);
 
 	/*
 	 * some device names have larger paths - convert the slashes

@@ -353,7 +353,7 @@ int do_blk_trace_setup(struct request_qu
 		goto err;
 
 	bt->dir = dir;
-	bt->dev = bdev->bd_dev;
+	bt->dev = dev;
 	atomic_set(&bt->dropped, 0);
 
 	ret = -EIO;

@@ -400,8 +400,8 @@ err:
 	return ret;
 }
 
-static int blk_trace_setup(struct request_queue *q, struct block_device *bdev,
-			   char __user *arg)
+int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
+		    char __user *arg)
 {
 	struct blk_user_trace_setup buts;
 	int ret;

@@ -410,7 +410,7 @@ static int blk_trace_setup(struct reques
 	if (ret)
 		return -EFAULT;
 
-	ret = do_blk_trace_setup(q, bdev, &buts);
+	ret = do_blk_trace_setup(q, name, dev, &buts);
 	if (ret)
 		return ret;
 

@@ -419,8 +419,9 @@ static int blk_trace_setup(struct reques
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(blk_trace_setup);
 
-static int blk_trace_startstop(struct request_queue *q, int start)
+int blk_trace_startstop(struct request_queue *q, int start)
 {
 	struct blk_trace *bt;
 	int ret;

@@ -453,6 +454,7 @@ static int blk_trace_startstop(struct re
 
 	return ret;
 }
+EXPORT_SYMBOL_GPL(blk_trace_startstop);
 
 /**
  * blk_trace_ioctl: - handle the ioctls associated with tracing

@@ -465,6 +467,7 @@ int blk_trace_ioctl(struct block_device 
 {
 	struct request_queue *q;
 	int ret, start = 0;
+	char b[BDEVNAME_SIZE];
 
 	q = bdev_get_queue(bdev);
 	if (!q)

@@ -474,7 +477,8 @@ int blk_trace_ioctl(struct block_device 
 
 	switch (cmd) {
 	case BLKTRACESETUP:
-		ret = blk_trace_setup(q, bdev, arg);
+		strcpy(b, bdevname(bdev, b));
+		ret = blk_trace_setup(q, b, bdev->bd_dev, arg);
 		break;
 	case BLKTRACESTART:
 		start = 1;

@@ -48,6 +48,7 @@ static int sg_version_num = 30534;	/* 2 
 #include <linux/blkdev.h>
 #include <linux/delay.h>
 #include <linux/scatterlist.h>
+#include <linux/blktrace_api.h>
 
 #include "scsi.h"
 #include <scsi/scsi_dbg.h>

@@ -1063,6 +1064,17 @@ sg_ioctl(struct inode *inode, struct fil
 	case BLKSECTGET:
 		return put_user(sdp->device->request_queue->max_sectors * 512,
 				ip);
+	case BLKTRACESETUP:
+		return blk_trace_setup(sdp->device->request_queue,
+				       sdp->disk->disk_name,
+				       sdp->device->sdev_gendev.devt,
+				       (char *)arg);
+	case BLKTRACESTART:
+		return blk_trace_startstop(sdp->device->request_queue, 1);
+	case BLKTRACESTOP:
+		return blk_trace_startstop(sdp->device->request_queue, 0);
+	case BLKTRACETEARDOWN:
+		return blk_trace_remove(sdp->device->request_queue);
 	default:
 		if (read_only)
 			return -EPERM;	/* don't know so take safe approach */

@@ -148,7 +148,7 @@ extern int blk_trace_ioctl(struct block_
 extern void blk_trace_shutdown(struct request_queue *);
 extern void __blk_add_trace(struct blk_trace *, sector_t, int, int, u32, int, int, void *);
 extern int do_blk_trace_setup(struct request_queue *q,
-	struct block_device *bdev, struct blk_user_trace_setup *buts);
+	char *name, dev_t dev, struct blk_user_trace_setup *buts);
 
 
 /**

@@ -282,6 +282,11 @@ static inline void blk_add_trace_remap(s
 	__blk_add_trace(bt, from, bio->bi_size, bio->bi_rw, BLK_TA_REMAP, !bio_flagged(bio, BIO_UPTODATE), sizeof(r), &r);
 }
 
+extern int blk_trace_setup(request_queue_t *q, char *name, dev_t dev,
+			   char __user *arg);
+extern int blk_trace_startstop(request_queue_t *q, int start);
+extern int blk_trace_remove(request_queue_t *q);
+
 #else /* !CONFIG_BLK_DEV_IO_TRACE */
 #define blk_trace_ioctl(bdev, cmd, arg)		(-ENOTTY)
 #define blk_trace_shutdown(q)			do { } while (0)

@@ -290,7 +295,10 @@ static inline void blk_add_trace_remap(s
 #define blk_add_trace_generic(q, rq, rw, what)	do { } while (0)
 #define blk_add_trace_pdu_int(q, what, bio, pdu)	do { } while (0)
 #define blk_add_trace_remap(q, bio, dev, f, t)	do {} while (0)
-#define do_blk_trace_setup(q, bdev, buts)	(-ENOTTY)
+#define do_blk_trace_setup(q, name, dev, buts)	(-ENOTTY)
+#define blk_trace_setup(q, name, dev, arg)	(-ENOTTY)
+#define blk_trace_startstop(q, start)		(-ENOTTY)
+#define blk_trace_remove(q)			(-ENOTTY)
 #endif /* CONFIG_BLK_DEV_IO_TRACE */
 #endif /* __KERNEL__ */
 #endif

@@ -545,6 +545,7 @@ static int compat_blk_trace_setup(struct
 	struct blk_user_trace_setup buts;
 	struct compat_blk_user_trace_setup cbuts;
 	struct request_queue *q;
+	char b[BDEVNAME_SIZE];
 	int ret;
 
 	q = bdev_get_queue(bdev);

@@ -554,6 +555,8 @@ static int compat_blk_trace_setup(struct
 	if (copy_from_user(&cbuts, arg, sizeof(cbuts)))
 		return -EFAULT;
 
+	strcpy(b, bdevname(bdev, b));
+
 	buts = (struct blk_user_trace_setup) {
 		.act_mask = cbuts.act_mask,
 		.buf_size = cbuts.buf_size,

@@ -565,7 +568,7 @@ static int compat_blk_trace_setup(struct
 	memcpy(&buts.name, &cbuts.name, 32);
 
 	mutex_lock(&bdev->bd_mutex);
-	ret = do_blk_trace_setup(q, bdev, &buts);
+	ret = do_blk_trace_setup(q, b, bdev->bd_dev, &buts);
 	mutex_unlock(&bdev->bd_mutex);
 	if (ret)
 		return ret;