import mars-04.tgz

mars.h

@@ -16,7 +16,8 @@
 #define MARS_ERROR "MARS_ERROR: "
 
 #define MARS_ERR(args...) printk(MARS_ERROR args)
-#define MARS_DBG(args...) printk("MARS_DEBUG: " args)
+//#define MARS_DBG(args...) printk("MARS_DEBUG: " args)
+#define MARS_DBG(args...) /**/
 
 /////////////////////////////////////////////////////////////////////////
 
@@ -24,14 +25,14 @@
 
 #define MAX_DEFAULT_ASPECTS 8
 
-#define GENERIC_OBJECT_LAYOUT(PREFIX)				\
-	int max_size;						\
-	int rest_size;						\
-	int max_aspects;					\
-	int nr_aspects;						\
-	int *aspect_sizes;					\
-	int *aspect_offsets;					\
-	void *alloc_ptr;					\
+#define GENERIC_OBJECT_LAYOUT(PREFIX)					\
+	int max_size;							\
+	int rest_size;							\
+	int max_aspects;						\
+	int nr_aspects;							\
+	int *aspect_sizes;						\
+	int *aspect_offsets;						\
+	void *alloc_ptr;						\
 
 struct generic_object_layout {
 	GENERIC_OBJECT_LAYOUT(generic);

mars_device_sio.c

@@ -3,6 +3,9 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/string.h>
+#include <linux/types.h>
+#include <linux/blkdev.h>
+#include <linux/highmem.h>
 
 #include "mars.h"
 
@@ -15,11 +18,57 @@
 static int device_sio_mars_io(struct device_sio_output *output, struct mars_io *mio)
 {
 	struct bio *bio = mio->orig_bio;
+	int direction = bio->bi_rw & 1;
+	//unsigned int nr_sectors = bio_sectors(bio);
+	unsigned long sector = bio->bi_sector;
+	unsigned long long pos = sector << 9; //TODO: allow different sector sizes
+	struct bio_vec *bvec;
+	int i;
+	int ret = -EIO;
+	
+	if (!output->filp)
+		goto done;
+
+	bio_for_each_segment(bvec, bio, i) {
+		mm_segment_t oldfs;
+		unsigned long long ppos = pos;
+		void *addr = kmap(bvec->bv_page) + bvec->bv_offset;
+		unsigned int len = bvec->bv_len;
+
+		MARS_DBG("IO dir=%d sector=%lu size=%d | pos=%llu len=%u addr=%p\n", direction, sector, bio->bi_size, pos, len, addr);
+
+		oldfs = get_fs();
+		set_fs(get_ds());
+		
+		if (direction == READ)
+			ret = do_sync_read(output->filp, addr, len, &ppos);
+		else
+			ret = do_sync_write(output->filp, addr, len, &ppos);
+		
+		set_fs(oldfs);
+		kunmap(bvec->bv_page);
+
+		if (!ret) { // EOF
+			MARS_DBG("EOF\n");
+			addr = kmap(bvec->bv_page) + bvec->bv_offset;
+			memset(addr, 0, len);
+			kunmap(bvec->bv_page);
+		} else if (ret != len) {
+			MARS_ERR("IO error pos=%llu, len=%u, status=%d\n", pos, len, ret);
+			goto done;
+		}
+		
+		pos += len;
+		bio->bi_size -= len;
+		ret = 0;
+	}
+
+done:
 	mio->mars_endio(mio);
-	return 0;
+	return ret;
 }
 
-///////////////////////// contructors / destructors ////////////////////////
+//////////////////////// constructors / destructors //////////////////////
 
 static int device_sio_brick_construct(struct device_sio_brick *brick)
 {
@@ -28,6 +77,32 @@ static int device_sio_brick_construct(struct device_sio_brick *brick)
 
 static int device_sio_output_construct(struct device_sio_output *output)
 {
+	mm_segment_t oldfs;
+	int flags = O_CREAT | O_RDWR | O_LARGEFILE;
+	int prot = 0600;
+	char *path = "/tmp/testfile.img";
+
+	oldfs = get_fs();
+	set_fs(get_ds());
+	output->filp = filp_open(path, flags, prot);
+	set_fs(oldfs);
+
+	if (IS_ERR(output->filp)) {
+		int err = PTR_ERR(output->filp);
+		MARS_ERR("can't open file '%s' status=%d\n", path, err);
+		output->filp = NULL;
+		return err;
+	}
+
+	return 0;
+}
+
+static int device_sio_output_destruct(struct device_sio_output *output)
+{
+	if (output->filp) {
+		filp_close(output->filp, NULL);
+	}
+
 	return 0;
 }
 
@@ -45,6 +120,7 @@ static struct device_sio_output_type device_sio_output_type = {
 	.output_size = sizeof(struct device_sio_output),
 	.master_ops = &device_sio_output_ops,
 	.output_construct = &device_sio_output_construct,
+	.output_destruct = &device_sio_output_destruct,
 };
 
 static struct device_sio_output_type *device_sio_output_types[] = {

mars_device_sio.h

@@ -9,6 +9,7 @@ struct device_sio_input {
 
 struct device_sio_output {
 	MARS_OUTPUT(device_sio);
+	struct file *filp;
 };
 
 MARS_TYPES(device_sio);

mars_if_device.c

@@ -47,14 +47,11 @@ static int if_device_make_request(struct request_queue *q, struct bio *bio)
 {
 	struct if_device_input *input = q->queuedata;
 	struct if_device_output *output;
-	struct mars_io *mio;
+	struct mars_io *mio = NULL;
 	int error = -ENOSYS;
 
 	MARS_DBG("make_request(%d)\n", bio->bi_size);
-#if 0
-	bio->bi_size = 0;
-	bio_endio(bio, 0);
-#else
+
 	if (!input || !input->connect)
 		goto err;
 
@@ -74,13 +71,16 @@ static int if_device_make_request(struct request_queue *q, struct bio *bio)
 	error = output->ops->mars_io(output, mio);
 	if (error)
 		goto err_free;
-#endif
+
 	return 0;
 
 err_free:
 	kfree(mio);
 err:
-	bio_endio(bio, error);
+	MARS_ERR("cannot submit request, status=%d\n", error);
+	if (!mio)
+		bio_endio(bio, error);
+	//else mars_endio() callback must have been called, which is responsible for cleanup
 	return 0;
 }
 
@@ -124,6 +124,7 @@ static int if_device_input_construct(struct if_device_input *input)
 	struct request_queue *q;
 	struct gendisk *disk;
 	int minor;
+	int capacity = 2 * 1024 * 1024 * 4; //TODO: make this dynamic
 
 	MARS_DBG("1\n");
 	q = blk_alloc_queue(GFP_KERNEL);
@@ -150,7 +151,7 @@ static int if_device_input_construct(struct if_device_input *input)
 	sprintf(disk->disk_name, "mars%d", minor);
 	MARS_DBG("created device name %s\n", disk->disk_name);
 	disk->private_data = input;
-	set_capacity(disk, 1024); //XXX
+	set_capacity(disk, capacity);
 
 	blk_queue_make_request(q, if_device_make_request);
 	blk_queue_max_segment_size(q, MARS_MAX_SEGMENT_SIZE);