From 35118b0a917c85050a3ddab0f8159eab4f510fd7 Mon Sep 17 00:00:00 2001
From: David van Moolenbroek <david@minix3.org>
Date: Sun, 24 Aug 2014 09:37:42 +0000
Subject: [PATCH] test72: fix mock bdev functions

The minixfs library only ever submits vector elements (and reads) of
the system page size. The test implementation was expecting vector
elements (and reads) of the file system block size. The resulting
mismatch caused I/O to fail in various ways, even though this did not
have an effect on the actual test.

Change-Id: I02f4a3efcd4a32916435d82c7d5798e6b78f0a27
---
 minix/tests/test72.c | 87 +++++++++++++++++---------------------------
 1 file changed, 34 insertions(+), 53 deletions(-)

diff --git a/minix/tests/test72.c b/minix/tests/test72.c
index 047ef169b..c762238f9 100644
--- a/minix/tests/test72.c
+++ b/minix/tests/test72.c
@@ -116,35 +116,27 @@ static void allocate(int b)
 ssize_t
 bdev_gather(dev_t dev, u64_t pos, iovec_t *vec, int count, int flags)
 {
-	int i;
+	int i, block;
+	size_t size, block_off;
 	ssize_t tot = 0;
 	assert(dev == MYDEV);
 	assert(curblocksize > 0);
 	assert(!(pos % curblocksize));
 	for(i = 0; i < count; i++) {
-		int subpages, block, block_off;
 		char *data = (char *) vec[i].iov_addr;
-		assert(!(pos % curblocksize));
 		block = pos / curblocksize;
-		block_off = pos % curblocksize;
-		assert(!(vec[i].iov_size % PAGE_SIZE));
-		subpages = vec[i].iov_size / PAGE_SIZE;
-		while(subpages > 0) {
-			assert(block >= 0);
-			assert(block < MAXBLOCKS);
-			assert(block_off >= 0);
-			assert(block_off < curblocksize);
-			if(!writtenblocks[block]) {
-				allocate(block);
-			}
-			memcpy(data, writtenblocks[block] + block_off,
-				PAGE_SIZE);
-			block++;
-			subpages--;
-			data += PAGE_SIZE;
-			tot += PAGE_SIZE;
-			block_off += PAGE_SIZE;
+		block_off = (size_t)(pos % curblocksize);
+		size = vec[i].iov_size;
+		assert(size == PAGE_SIZE);
+		assert(block >= 0);
+		assert(block < MAXBLOCKS);
+		assert(block_off + size <= curblocksize);
+		if(!writtenblocks[block]) {
+			allocate(block);
 		}
+		memcpy(data, writtenblocks[block] + block_off, size);
+		pos += size;
+		tot += size;
 	}
 
 	return tot;
@@ -154,29 +146,26 @@ ssize_t
 bdev_scatter(dev_t dev, u64_t pos, iovec_t *vec, int count, int flags)
 {
 	int i, block;
+	size_t size, block_off;
 	ssize_t tot = 0;
 	assert(dev == MYDEV);
 	assert(curblocksize > 0);
 	assert(!(pos % curblocksize));
-	block = pos / curblocksize;
 	for(i = 0; i < count; i++) {
-		int subblocks;
 		char *data = (char *) vec[i].iov_addr;
-		assert(vec[i].iov_size > 0);
-		assert(!(vec[i].iov_size % PAGE_SIZE));
-		subblocks = vec[i].iov_size / curblocksize;
-		while(subblocks > 0) {
-			assert(block >= 0);
-			assert(block < MAXBLOCKS);
-			if(!writtenblocks[block]) {
-				allocate(block);
-			}
-			memcpy(writtenblocks[block], data, curblocksize);
-			block++;
-			subblocks--;
-			data += curblocksize;
-			tot += curblocksize;
+		block = pos / curblocksize;
+		block_off = (size_t)(pos % curblocksize);
+		size = vec[i].iov_size;
+		assert(size == PAGE_SIZE);
+		assert(block >= 0);
+		assert(block < MAXBLOCKS);
+		assert(block_off + size <= curblocksize);
+		if(!writtenblocks[block]) {
+			allocate(block);
 		}
+		memcpy(writtenblocks[block] + block_off, data, size);
+		pos += size;
+		tot += size;
 	}
 
 	return tot;
@@ -186,31 +175,23 @@ ssize_t
 bdev_read(dev_t dev, u64_t pos, char *data, size_t count, int flags)
 {
 	int block;
-	ssize_t tot = 0;
-	int subblocks;
 
 	assert(dev == MYDEV);
 	assert(curblocksize > 0);
 	assert(!(pos % curblocksize));
 	assert(count > 0);
 	assert(!(count % curblocksize));
+	assert(count == PAGE_SIZE);
+	assert(curblocksize == PAGE_SIZE);
 
 	block = pos / curblocksize;
-	subblocks = count / curblocksize;
-	while(subblocks > 0) {
-		assert(block >= 0);
-		assert(block < MAXBLOCKS);
-		if(!writtenblocks[block]) {
-			allocate(block);
-		}
-		memcpy(data, writtenblocks[block], curblocksize);
-		block++;
-		subblocks--;
-		data += curblocksize;
-		tot += curblocksize;
+	assert(block >= 0);
+	assert(block < MAXBLOCKS);
+	if(!writtenblocks[block]) {
+		allocate(block);
 	}
-
-	return tot;
+	memcpy(data, writtenblocks[block], curblocksize);
+	return count;
 }
 
 /* Fake some libsys functions */