1 files changed, 11 insertions, 9 deletions

diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index 1bcd208..ba4a98b 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -33,7 +33,7 @@
 #include "linux/mm.h"
 #include "linux/slab.h"
 #include "linux/vmalloc.h"
-#include "linux/smp_lock.h"
+#include "linux/mutex.h"
 #include "linux/blkpg.h"
 #include "linux/genhd.h"
 #include "linux/spinlock.h"
@@ -100,6 +100,7 @@ static inline void ubd_set_bit(__u64 bit, unsigned char *data)
 #define DRIVER_NAME "uml-blkdev"
 
 static DEFINE_MUTEX(ubd_lock);
+static DEFINE_MUTEX(ubd_mutex); /* replaces BKL, might not be needed */
 
 static int ubd_open(struct block_device *bdev, fmode_t mode);
 static int ubd_release(struct gendisk *disk, fmode_t mode);
@@ -163,6 +164,7 @@ struct ubd {
 	struct scatterlist sg[MAX_SG];
 	struct request *request;
 	int start_sg, end_sg;
+	sector_t rq_pos;
 };
 
 #define DEFAULT_COW { \
@@ -187,6 +189,7 @@ struct ubd {
 	.request =		NULL, \
 	.start_sg =		0, \
 	.end_sg =		0, \
+	.rq_pos =		0, \
 }
 
 /* Protected by ubd_lock */
@@ -1099,7 +1102,7 @@ static int ubd_open(struct block_device *bdev, fmode_t mode)
 	struct ubd *ubd_dev = disk->private_data;
 	int err = 0;
 
-	lock_kernel();
+	mutex_lock(&ubd_mutex);
 	if(ubd_dev->count == 0){
 		err = ubd_open_dev(ubd_dev);
 		if(err){
@@ -1118,7 +1121,7 @@ static int ubd_open(struct block_device *bdev, fmode_t mode)
 	        err = -EROFS;
 	}*/
 out:
-	unlock_kernel();
+	mutex_unlock(&ubd_mutex);
 	return err;
 }
 
@@ -1126,10 +1129,10 @@ static int ubd_release(struct gendisk *disk, fmode_t mode)
 {
 	struct ubd *ubd_dev = disk->private_data;
 
-	lock_kernel();
+	mutex_lock(&ubd_mutex);
 	if(--ubd_dev->count == 0)
 		ubd_close_dev(ubd_dev);
-	unlock_kernel();
+	mutex_unlock(&ubd_mutex);
 	return 0;
 }
 
@@ -1228,7 +1231,6 @@ static void do_ubd_request(struct request_queue *q)
 {
 	struct io_thread_req *io_req;
 	struct request *req;
-	sector_t sector;
 	int n;
 
 	while(1){
@@ -1239,12 +1241,12 @@ static void do_ubd_request(struct request_queue *q)
 				return;
 
 			dev->request = req;
+			dev->rq_pos = blk_rq_pos(req);
 			dev->start_sg = 0;
 			dev->end_sg = blk_rq_map_sg(q, req, dev->sg);
 		}
 
 		req = dev->request;
-		sector = blk_rq_pos(req);
 		while(dev->start_sg < dev->end_sg){
 			struct scatterlist *sg = &dev->sg[dev->start_sg];
 
@@ -1256,10 +1258,9 @@ static void do_ubd_request(struct request_queue *q)
 				return;
 			}
 			prepare_request(req, io_req,
-					(unsigned long long)sector << 9,
+					(unsigned long long)dev->rq_pos << 9,
 					sg->offset, sg->length, sg_page(sg));
 
-			sector += sg->length >> 9;
 			n = os_write_file(thread_fd, &io_req,
 					  sizeof(struct io_thread_req *));
 			if(n != sizeof(struct io_thread_req *)){
@@ -1272,6 +1273,7 @@ static void do_ubd_request(struct request_queue *q)
 				return;
 			}
 
+			dev->rq_pos += sg->length >> 9;
 			dev->start_sg++;
 		}
 		dev->end_sg = 0;