read_cache_pages() also working copied from write_cache_pages()

- Need to remove old versions
- Need to merge the two.
- Need to investigate occasional page fault on NMOP sequence. (resembles an error ipc_extended test)
  Could be related to new page cache read/write routines.

conts/posix/mm0/mm/file.c

@@ -510,6 +510,67 @@ int new_file_pages(struct vm_file *f, unsigned long start, unsigned long end)
 
 #define page_offset(x)	((unsigned long)(x) & PAGE_MASK)
 
+/*
+ * Writes user data in buffer into pages in cache. If a page is not
+ * found, it's a bug. The writeable page range must have been readied
+ * by read_file_pages()/new_file_pages().
+ */
+int read_cache_pages(struct vm_file *vmfile, struct tcb *task, void *buf,
+		     unsigned long pfn_start, unsigned long pfn_end,
+		     unsigned long cursor_offset, int count)
+{
+	struct page *file_page;
+	unsigned long task_offset; /* Current copy offset on the task buffer */
+	unsigned long file_offset; /* Current copy offset on the file */
+	int copysize, left;
+	int empty;
+
+	task_offset = (unsigned long)buf;
+	file_offset = cursor_offset;
+	left = count;
+
+	/* Find the head of consecutive pages */
+	list_foreach_struct(file_page, &vmfile->vm_obj.page_cache, list) {
+		if (file_page->offset < pfn_start)
+			continue;
+		else if (file_page->offset == pfn_end || left == 0)
+			break;
+
+		empty = PAGE_SIZE - page_offset(file_offset);
+
+		/* Copy until a single page cache page is filled */
+		while (empty && left) {
+			copysize = min(PAGE_SIZE - page_offset(file_offset), left);
+		     	copysize = min(copysize, PAGE_SIZE - page_offset(task_offset));
+/*
+			printf("empty: %d, left: %d, copysize: "
+			       "%d, copy to page with pfn %lx, "
+			       "offset 0x%lx, from page with pfn "
+			       "%lx, offset 0x%lx\n", empty, left,
+			       copysize,
+			       task_virt_to_page(task,task_offset)->offset,
+			       page_offset(task_offset),
+			       file_page->offset,
+			       page_offset(file_offset));
+*/
+			page_copy(task_virt_to_page(task, task_offset),
+				  file_page,
+				  page_offset(task_offset),
+				  page_offset(file_offset),
+				  copysize);
+
+			empty -= copysize;
+			left -= copysize;
+			task_offset += copysize;
+			file_offset += copysize;
+		}
+	}
+	BUG_ON(left != 0);
+
+	return count - left;
+}
+
+
 /*
  * Writes user data in buffer into pages in cache. If a page is not
  * found, it's a bug. The writeable page range must have been readied
@@ -529,9 +590,6 @@ int write_cache_pages(struct vm_file *vmfile, struct tcb *task, void *buf,
 	file_offset = cursor_offset;
 	left = count;
 
-	printf("%s: cursor_offset: 0x%lx, count: 0x%x, buf: %p\n",
-	       __FUNCTION__, cursor_offset, count, buf);
-
 	/* Find the head of consecutive pages */
 	list_foreach_struct(file_page, &vmfile->vm_obj.page_cache, list) {
 		if (file_page->offset < pfn_start)
@@ -541,15 +599,26 @@ int write_cache_pages(struct vm_file *vmfile, struct tcb *task, void *buf,
 
 		empty = PAGE_SIZE - page_offset(file_offset);
 
-		/* Copy until the page is filled */
+		/* Copy until a single page cache page is filled */
 		while (empty && left) {
 			copysize = min(PAGE_SIZE - page_offset(file_offset), left);
 		     	copysize = min(copysize, PAGE_SIZE - page_offset(task_offset));
-			//printf("empty: %d, left: %d, copysize: %d, copy to page with pfn %lx, offset 0x%lx, from page with pfn %lx, offset 0x%lx\n",
-			//       empty, left, copysize, file_page->offset, page_offset(file_offset),task_virt_to_page(task,task_offset)->offset, page_offset(task_offset));
-			page_copy(file_page, task_virt_to_page(task, task_offset),
-				  page_offset(file_offset), page_offset(task_offset),
+/*
+			printf("empty: %d, left: %d, copysize: "
+			       "%d, copy to page with pfn %lx, "
+			       "offset 0x%lx, from page with pfn "
+			       "%lx, offset 0x%lx\n", empty, left,
+			       copysize, file_page->offset,
+			       page_offset(file_offset),
+			       task_virt_to_page(task,task_offset)->offset,
+			       page_offset(task_offset));
+*/
+			page_copy(file_page,
+				  task_virt_to_page(task, task_offset),
+				  page_offset(file_offset),
+				  page_offset(task_offset),
 				  copysize);
+
 			empty -= copysize;
 			left -= copysize;
 			task_offset += copysize;
@@ -572,7 +641,7 @@ int write_cache_pages(struct vm_file *vmfile, struct tcb *task, void *buf,
  * be called first and count must be checked. Since it has read-checking
  * assumptions, count must be satisfied.
  */
-int read_cache_pages(struct vm_file *vmfile, struct tcb *task, void *buf,
+int read_cache_pages_orig(struct vm_file *vmfile, struct tcb *task, void *buf,
 		     unsigned long pfn_start, unsigned long pfn_end,
 		     unsigned long cursor_offset, int count)
 {
@@ -630,7 +699,7 @@ copy:
 int sys_read(struct tcb *task, int fd, void *buf, int count)
 {
 	unsigned long pfn_start, pfn_end;
-	unsigned long cursor, byte_offset;
+	unsigned long cursor;
 	struct vm_file *vmfile;
 	int ret = 0;
 
@@ -675,12 +744,9 @@ int sys_read(struct tcb *task, int fd, void *buf, int count)
 	if ((ret = read_file_pages(vmfile, pfn_start, pfn_end)) < 0)
 		return ret;
 
-	/* The offset of cursor on first page */
-	byte_offset = PAGE_MASK & cursor;
-
 	/* Read it into the user buffer from the cache */
 	if ((count = read_cache_pages(vmfile, task, buf, pfn_start, pfn_end,
-				      byte_offset, count)) < 0)
+				      cursor, count)) < 0)
 		return count;
 
 	/* Update cursor on success */

conts/posix/test0/container.c

@@ -23,7 +23,6 @@ int __container_init(int argc, char **argv)
 	__libposix_init(envp);
 
 	pagerval = getenv("pagerid");
-	printf("Pager id: %s\n", pagerval);
 
 	/* Generic L4 thread initialisation */
 	__l4_init();

conts/posix/test0/main.c

@@ -23,7 +23,6 @@ void wait_pager(l4id_t partner)
 	// printf("Pager synced with us.\n");
 }
 
-
 pid_t parent_of_all;
 
 int main(int argc, char *argv[])

conts/posix/test0/src/fileio.c

@@ -16,7 +16,7 @@ int small_io_test(void)
 	char strbuf[30];
 	char strbuf2[30];
 	char *path = "/text.txt";
-//	char stackbuf[PAGE_SIZE*2];
+	char stackbuf[PAGE_SIZE*2];
 
 	fd1 = open(path, O_TRUNC | O_RDWR | O_CREAT, S_IRWXU);
 	fd2 = open(path, O_RDWR, 0);
@@ -26,7 +26,7 @@ int small_io_test(void)
 
 	for (int i = 0; i < 4; i++) {
 		sprintf(strbuf, "%s%d", string, i);
-		printf("Writing to %s offset %x, string: %s\n",
+		test_printf("Writing to %s offset %x, string: %s\n",
 			    path, i*PAGE_SIZE, strbuf);
 		lseek(fd1, i*PAGE_SIZE, SEEK_SET);
 		write(fd1, strbuf, strlen(strbuf) + 1);
@@ -38,19 +38,23 @@ int small_io_test(void)
 		sprintf(strbuf2, "%s%d", string, i);
 		lseek(fd2, i*PAGE_SIZE, SEEK_SET);
 		read(fd2, strbuf, 30);
-		printf("Read %s, offset %x as %s\n",
+		test_printf("Read %s, offset %x as %s\n",
 			    path, i*PAGE_SIZE, strbuf);
 		if (strcmp(strbuf, strbuf2))
 			goto out_err;
 	}
-#if 0
+
 	/* Now read into an unaligned buffer larger than page size */
 	lseek(fd2, 0, SEEK_SET);
 
 	read(fd2, stackbuf, PAGE_SIZE * 2);
-	printf("stackbuf beginning: %s\n second page beginning: %s\n",
-	       stackbuf, &stackbuf[PAGE_SIZE]);
-#endif
+
+	sprintf(strbuf2, "%s%d", string, 0);
+	if (strcmp(stackbuf, strbuf2))
+		goto out_err;
+	sprintf(strbuf2, "%s%d", string, 1);
+	if (strcmp(&stackbuf[PAGE_SIZE], strbuf2))
+		goto out_err;
 
 	close(fd2);
 

conts/posix/test0/src/forktest.c

@@ -17,7 +17,7 @@ int forktest(void)
 
 
 	/* 16 forks */
-	for (int i = 0; i < 1; i++) {
+	for (int i = 0; i < 3; i++) {
 		test_printf("%d: Forking...\n", getpid());
 		if (fork() < 0)
 			goto out_err;