Add pread/pwrite ioctls to mmfs.

.gitignore

@@ -59,6 +59,7 @@ tests/getstats
 tests/getversion
 tests/lock
 tests/mmfs_basic
+tests/mmfs_readwrite
 tests/openclose
 tests/setversion
 tests/updatedraw

linux-core/mmfs_drv.c

@@ -91,12 +91,12 @@ mmfs_handle_delete(struct mmfs_file *mmfs_filp, int handle)
 	 * we may want to use ida for number allocation and a hash table
 	 * for the pointers, anyway.
 	 */
-	spin_lock(&mmfs_filp->delete_lock);
+	spin_lock(&mmfs_filp->table_lock);
 
 	/* Check if we currently have a reference on the object */
 	obj = idr_find(&mmfs_filp->object_idr, handle);
 	if (obj == NULL) {
-		spin_unlock(&mmfs_filp->delete_lock);
+		spin_unlock(&mmfs_filp->table_lock);
 		return -EINVAL;
 	}
 
@@ -104,11 +104,34 @@ mmfs_handle_delete(struct mmfs_file *mmfs_filp, int handle)
 	idr_remove(&mmfs_filp->object_idr, handle);
 	mmfs_object_unreference(obj);
 
-	spin_unlock(&mmfs_filp->delete_lock);
+	spin_unlock(&mmfs_filp->table_lock);
 
 	return 0;
 }
 
+/** Returns a reference to the object named by the handle. */
+static struct mmfs_object *
+mmfs_object_lookup(struct mmfs_file *mmfs_filp, int handle)
+{
+	struct mmfs_object *obj;
+
+	spin_lock(&mmfs_filp->table_lock);
+
+	/* Check if we currently have a reference on the object */
+	obj = idr_find(&mmfs_filp->object_idr, handle);
+	if (obj == NULL) {
+		spin_unlock(&mmfs_filp->table_lock);
+		return NULL;
+	}
+
+	mmfs_object_reference(obj);
+
+	spin_unlock(&mmfs_filp->table_lock);
+
+	return obj;
+}
+
+
 /**
  * Allocates a new mmfs object and returns a handle to it.
  */
@@ -164,7 +187,7 @@ mmfs_alloc_ioctl(struct inode *inode, struct file *filp,
 }
 
 /**
- * Allocates a new mmfs object and returns a handle to it.
+ * Releases the handle to an mmfs object.
  */
 static int
 mmfs_unreference_ioctl(struct inode *inode, struct file *filp,
@@ -182,6 +205,84 @@ mmfs_unreference_ioctl(struct inode *inode, struct file *filp,
 	return ret;
 }
 
+/**
+ * Reads data from the object referenced by handle.
+ *
+ * On error, the contents of *data are undefined.
+ */
+static int
+mmfs_pread_ioctl(struct inode *inode, struct file *filp,
+		 unsigned int cmd, unsigned long arg)
+{
+	struct mmfs_file *mmfs_filp = filp->private_data;
+	struct mmfs_pread_args args;
+	struct mmfs_object *obj;
+	ssize_t read;
+	loff_t offset;
+
+	if (copy_from_user(&args, (void __user *)arg, sizeof(args)))
+		return -EFAULT;
+
+	obj = mmfs_object_lookup(mmfs_filp, args.handle);
+	if (obj == NULL)
+		return -EINVAL;
+
+	offset = args.offset;
+
+	read = obj->filp->f_op->read(obj->filp, (char __user *)args.data,
+				     args.size, &offset);
+	if (read != args.size) {
+		mmfs_object_unreference(obj);
+		if (read < 0)
+			return read;
+		else
+			return -EINVAL;
+	}
+
+	mmfs_object_unreference(obj);
+
+	return 0;
+}
+
+/**
+ * Writes data to the object referenced by handle.
+ *
+ * On error, the contents of the buffer that were to be modified are undefined.
+ */
+static int
+mmfs_pwrite_ioctl(struct inode *inode, struct file *filp,
+		 unsigned int cmd, unsigned long arg)
+{
+	struct mmfs_file *mmfs_filp = filp->private_data;
+	struct mmfs_pwrite_args args;
+	struct mmfs_object *obj;
+	ssize_t written;
+	loff_t offset;
+
+	if (copy_from_user(&args, (void __user *)arg, sizeof(args)))
+		return -EFAULT;
+
+	obj = mmfs_object_lookup(mmfs_filp, args.handle);
+	if (obj == NULL)
+		return -EINVAL;
+
+	offset = args.offset;
+
+	written = obj->filp->f_op->write(obj->filp, (char __user *)args.data,
+					 args.size, &offset);
+	if (written != args.size) {
+		mmfs_object_unreference(obj);
+		if (written < 0)
+			return written;
+		else
+			return -EINVAL;
+	}
+
+	mmfs_object_unreference(obj);
+
+	return 0;
+}
+
 static int
 mmfs_ioctl(struct inode *inode, struct file *filp,
 	   unsigned int cmd, unsigned long arg)
@@ -192,6 +293,10 @@ mmfs_ioctl(struct inode *inode, struct file *filp,
 		return mmfs_alloc_ioctl(inode, filp, cmd, arg);
 	case MMFS_IOCTL_UNREFERENCE:
 		return mmfs_unreference_ioctl(inode, filp, cmd, arg);
+	case MMFS_IOCTL_PREAD:
+		return mmfs_pread_ioctl(inode, filp, cmd, arg);
+	case MMFS_IOCTL_PWRITE:
+		return mmfs_pwrite_ioctl(inode, filp, cmd, arg);
 	default:
 		return -EINVAL;
 	}

linux-core/mmfs_drv.h

@@ -54,11 +54,8 @@ struct mmfs_object {
 struct mmfs_file {
 	/** Mapping of object handles to object pointers. */
 	struct idr object_idr;
-	/**
+	/** Lock for synchronization of access to object_idr. */
-	 * Lock for synchronization of access to object->refcount and
+	spinlock_t table_lock;
-	 * object_idr.  See note in mmfs_unreference_ioctl.
-	 */
-	spinlock_t delete_lock;
 };
 
 void mmfs_object_reference(struct mmfs_object *obj);

shared-core/mmfs.h

@@ -25,7 +25,12 @@
  *
  */
 
-#include <sys/ioctl.h>
+#ifdef __linux__
+#include <asm/ioctl.h>
+#else
+#include <sys/types.h>
+#include <sys/ioccom.h>
+#endif
 
 /** @file mmfs.h
  * This file provides ioctl and ioctl argument definitions for using the

tests/Makefile.am

@@ -23,7 +23,8 @@ TESTS = auth \
 	lock \
 	setversion \
 	updatedraw \
-	mmfs_basic
+	mmfs_basic \
+	mmfs_readwrite
 
 EXTRA_PROGRAMS = $(TESTS)
 CLEANFILES = $(EXTRA_PROGRAMS) $(EXTRA_LTLIBRARIES)

tests/drmtest.c

@@ -26,7 +26,9 @@
  */
 
 #include <fcntl.h>
+#include <sys/stat.h>
 #include "drmtest.h"
+#include "mmfs.h"
 
 /** Open the first DRM device we can find, searching up to 16 device nodes */
 int drm_open_any(void)
@@ -81,3 +83,34 @@ int drm_open_any_master(void)
 	abort();
 }
 
+static void
+create_mmfs_device()
+{
+	struct stat sb;
+	int ret;
+
+	ret = stat(MMFS_DEVICE_PATH, &sb);
+
+	if (ret == 0)
+		return;
+
+	ret = mknod(MMFS_DEVICE_PATH, S_IFCHR | S_IRUSR | S_IWUSR,
+		    makedev(MMFS_DEVICE_MAJOR, 0));
+
+	if (ret != 0)
+		errx(1, "mknod()");
+}
+
+int
+open_mmfs_device()
+{
+	int fd;
+
+	create_mmfs_device();
+
+	fd = open(MMFS_DEVICE_PATH, O_RDWR);
+	if (fd == -1)
+		errx(1, "open()");
+
+	return fd;
+}

tests/drmtest.h

@@ -35,3 +35,4 @@
 
 int drm_open_any(void);
 int drm_open_any_master(void);
+int open_mmfs_device();

tests/mmfs_basic.c

@@ -35,24 +35,6 @@
 #include <sys/stat.h>
 #include "mmfs.h"
 
-static void
-create_mmfs_device()
-{
-	struct stat sb;
-	int ret;
-
-	ret = stat(MMFS_DEVICE_PATH, &sb);
-
-	if (ret == 0)
-		return;
-
-	ret = mknod(MMFS_DEVICE_PATH, S_IFCHR | S_IRUSR | S_IWUSR,
-		    makedev(MMFS_DEVICE_MAJOR, 0));
-
-	if (ret != 0)
-		errx(1, "mknod()");
-}
-
 static void
 test_bad_unref(int fd)
 {
@@ -117,11 +99,7 @@ int main(int argc, char **argv)
 {
 	int fd;
 
-	create_mmfs_device();
+	fd = open_mmfs_device();
-
-	fd = open(MMFS_DEVICE_PATH, O_RDWR);
-	if (fd == -1)
-		errx(1, "open()");
 
 	test_bad_ioctl(fd);
 	test_bad_unref(fd);

tests/mmfs_readwrite.c

@@ -0,0 +1,125 @@
+/*
+ * Copyright © 2008 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ * Authors:
+ *    Eric Anholt <eric@anholt.net>
+ *
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <errno.h>
+#include <sys/stat.h>
+#include "mmfs.h"
+
+#define MMFS_BUFFER_SIZE 16384
+
+int do_read(int fd, int handle, void *buf, int offset, int size)
+{
+	struct mmfs_pread_args read;
+
+	/* Ensure that we don't have any convenient data in buf in case
+	 * we fail.
+	 */
+	memset(buf, 0xd0, size);
+
+	memset(&read, 0, sizeof(read));
+	read.handle = handle;
+	read.data = buf;
+	read.size = size;
+	read.offset = offset;
+
+	return ioctl(fd, MMFS_IOCTL_PREAD, &read);
+}
+
+int do_write(int fd, int handle, void *buf, int offset, int size)
+{
+	struct mmfs_pwrite_args write;
+
+	memset(&write, 0, sizeof(write));
+	write.handle = handle;
+	write.data = buf;
+	write.size = size;
+	write.offset = offset;
+
+	return ioctl(fd, MMFS_IOCTL_PWRITE, &write);
+}
+
+int main(int argc, char **argv)
+{
+	int fd;
+	struct mmfs_alloc_args alloc;
+	uint8_t expected[MMFS_BUFFER_SIZE];
+	uint8_t buf[MMFS_BUFFER_SIZE];
+	int ret;
+	int handle;
+
+	fd = open_mmfs_device();
+
+	memset(&alloc, 0, sizeof(alloc));
+	alloc.size = MMFS_BUFFER_SIZE;
+	ret = ioctl(fd, MMFS_IOCTL_ALLOC, &alloc);
+	assert(ret == 0);
+	handle = alloc.handle;
+
+	printf("Testing contents of newly allocated object.\n");
+	ret = do_read(fd, handle, buf, 0, MMFS_BUFFER_SIZE);
+	assert(ret == 0);
+	memset(&expected, 0, sizeof(expected));
+	assert(memcmp(expected, buf, sizeof(expected)) == 0);
+
+	printf("Testing read beyond end of buffer.\n");
+	ret = do_read(fd, handle, buf, MMFS_BUFFER_SIZE / 2, MMFS_BUFFER_SIZE);
+	assert(ret == -1 && errno == EINVAL);
+
+	printf("Testing full write of buffer\n");
+	memset(buf, 0, sizeof(buf));
+	memset(buf + 1024, 0x01, 1024);
+	memset(expected + 1024, 0x01, 1024);
+	ret = do_write(fd, handle, buf, 0, MMFS_BUFFER_SIZE);
+	assert(ret == 0);
+	ret = do_read(fd, handle, buf, 0, MMFS_BUFFER_SIZE);
+	assert(ret == 0);
+	assert(memcmp(buf, expected, sizeof(buf)) == 0);
+
+	printf("Testing partial write of buffer\n");
+	memset(buf + 4096, 0x02, 1024);
+	memset(expected + 4096, 0x02, 1024);
+	ret = do_write(fd, handle, buf + 4096, 4096, 1024);
+	assert(ret == 0);
+	ret = do_read(fd, handle, buf, 0, MMFS_BUFFER_SIZE);
+	assert(ret == 0);
+	assert(memcmp(buf, expected, sizeof(buf)) == 0);
+
+	printf("Testing partial read of buffer\n");
+	ret = do_read(fd, handle, buf, 512, 1024);
+	assert(ret == 0);
+	assert(memcmp(buf, expected + 512, 1024) == 0);
+
+	close(fd);
+
+	return 0;
+}