Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 342 insertions, 0 deletions

diff --git a/drivers/char/raw.c b/drivers/char/raw.c
new file mode 100644
index 00000000000..a2e33ec7961
--- /dev/null
+++ b/drivers/char/raw.c
@@ -0,0 +1,342 @@
+/*
+ * linux/drivers/char/raw.c
+ *
+ * Front-end raw character devices.  These can be bound to any block
+ * devices to provide genuine Unix raw character device semantics.
+ *
+ * We reserve minor number 0 for a control interface.  ioctl()s on this
+ * device are used to bind the other minor numbers to block devices.
+ */
+
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/devfs_fs_kernel.h>
+#include <linux/major.h>
+#include <linux/blkdev.h>
+#include <linux/module.h>
+#include <linux/raw.h>
+#include <linux/capability.h>
+#include <linux/uio.h>
+#include <linux/cdev.h>
+#include <linux/device.h>
+
+#include <asm/uaccess.h>
+
+struct raw_device_data {
+	struct block_device *binding;
+	int inuse;
+};
+
+static struct class_simple *raw_class;
+static struct raw_device_data raw_devices[MAX_RAW_MINORS];
+static DECLARE_MUTEX(raw_mutex);
+static struct file_operations raw_ctl_fops;	     /* forward declaration */
+
+/*
+ * Open/close code for raw IO.
+ *
+ * We just rewrite the i_mapping for the /dev/raw/rawN file descriptor to
+ * point at the blockdev's address_space and set the file handle to use
+ * O_DIRECT.
+ *
+ * Set the device's soft blocksize to the minimum possible.  This gives the
+ * finest possible alignment and has no adverse impact on performance.
+ */
+static int raw_open(struct inode *inode, struct file *filp)
+{
+	const int minor = iminor(inode);
+	struct block_device *bdev;
+	int err;
+
+	if (minor == 0) {	/* It is the control device */
+		filp->f_op = &raw_ctl_fops;
+		return 0;
+	}
+
+	down(&raw_mutex);
+
+	/*
+	 * All we need to do on open is check that the device is bound.
+	 */
+	bdev = raw_devices[minor].binding;
+	err = -ENODEV;
+	if (!bdev)
+		goto out;
+	igrab(bdev->bd_inode);
+	err = blkdev_get(bdev, filp->f_mode, 0);
+	if (err)
+		goto out;
+	err = bd_claim(bdev, raw_open);
+	if (err)
+		goto out1;
+	err = set_blocksize(bdev, bdev_hardsect_size(bdev));
+	if (err)
+		goto out2;
+	filp->f_flags |= O_DIRECT;
+	filp->f_mapping = bdev->bd_inode->i_mapping;
+	if (++raw_devices[minor].inuse == 1)
+		filp->f_dentry->d_inode->i_mapping =
+			bdev->bd_inode->i_mapping;
+	filp->private_data = bdev;
+	up(&raw_mutex);
+	return 0;
+
+out2:
+	bd_release(bdev);
+out1:
+	blkdev_put(bdev);
+out:
+	up(&raw_mutex);
+	return err;
+}
+
+/*
+ * When the final fd which refers to this character-special node is closed, we
+ * make its ->mapping point back at its own i_data.
+ */
+static int raw_release(struct inode *inode, struct file *filp)
+{
+	const int minor= iminor(inode);
+	struct block_device *bdev;
+
+	down(&raw_mutex);
+	bdev = raw_devices[minor].binding;
+	if (--raw_devices[minor].inuse == 0) {
+		/* Here  inode->i_mapping == bdev->bd_inode->i_mapping  */
+		inode->i_mapping = &inode->i_data;
+		inode->i_mapping->backing_dev_info = &default_backing_dev_info;
+	}
+	up(&raw_mutex);
+
+	bd_release(bdev);
+	blkdev_put(bdev);
+	return 0;
+}
+
+/*
+ * Forward ioctls to the underlying block device.
+ */
+static int
+raw_ioctl(struct inode *inode, struct file *filp,
+		  unsigned int command, unsigned long arg)
+{
+	struct block_device *bdev = filp->private_data;
+
+	return ioctl_by_bdev(bdev, command, arg);
+}
+
+static void bind_device(struct raw_config_request *rq)
+{
+	class_simple_device_remove(MKDEV(RAW_MAJOR, rq->raw_minor));
+	class_simple_device_add(raw_class, MKDEV(RAW_MAJOR, rq->raw_minor),
+				      NULL, "raw%d", rq->raw_minor);
+}
+
+/*
+ * Deal with ioctls against the raw-device control interface, to bind
+ * and unbind other raw devices.
+ */
+static int raw_ctl_ioctl(struct inode *inode, struct file *filp,
+			unsigned int command, unsigned long arg)
+{
+	struct raw_config_request rq;
+	struct raw_device_data *rawdev;
+	int err = 0;
+
+	switch (command) {
+	case RAW_SETBIND:
+	case RAW_GETBIND:
+
+		/* First, find out which raw minor we want */
+
+		if (copy_from_user(&rq, (void __user *) arg, sizeof(rq))) {
+			err = -EFAULT;
+			goto out;
+		}
+
+		if (rq.raw_minor < 0 || rq.raw_minor >= MAX_RAW_MINORS) {
+			err = -EINVAL;
+			goto out;
+		}
+		rawdev = &raw_devices[rq.raw_minor];
+
+		if (command == RAW_SETBIND) {
+			dev_t dev;
+
+			/*
+			 * This is like making block devices, so demand the
+			 * same capability
+			 */
+			if (!capable(CAP_SYS_ADMIN)) {
+				err = -EPERM;
+				goto out;
+			}
+
+			/*
+			 * For now, we don't need to check that the underlying
+			 * block device is present or not: we can do that when
+			 * the raw device is opened.  Just check that the
+			 * major/minor numbers make sense.
+			 */
+
+			dev = MKDEV(rq.block_major, rq.block_minor);
+			if ((rq.block_major == 0 && rq.block_minor != 0) ||
+					MAJOR(dev) != rq.block_major ||
+					MINOR(dev) != rq.block_minor) {
+				err = -EINVAL;
+				goto out;
+			}
+
+			down(&raw_mutex);
+			if (rawdev->inuse) {
+				up(&raw_mutex);
+				err = -EBUSY;
+				goto out;
+			}
+			if (rawdev->binding) {
+				bdput(rawdev->binding);
+				module_put(THIS_MODULE);
+			}
+			if (rq.block_major == 0 && rq.block_minor == 0) {
+				/* unbind */
+				rawdev->binding = NULL;
+				class_simple_device_remove(MKDEV(RAW_MAJOR,
+								rq.raw_minor));
+			} else {
+				rawdev->binding = bdget(dev);
+				if (rawdev->binding == NULL)
+					err = -ENOMEM;
+				else {
+					__module_get(THIS_MODULE);
+					bind_device(&rq);
+				}
+			}
+			up(&raw_mutex);
+		} else {
+			struct block_device *bdev;
+
+			down(&raw_mutex);
+			bdev = rawdev->binding;
+			if (bdev) {
+				rq.block_major = MAJOR(bdev->bd_dev);
+				rq.block_minor = MINOR(bdev->bd_dev);
+			} else {
+				rq.block_major = rq.block_minor = 0;
+			}
+			up(&raw_mutex);
+			if (copy_to_user((void __user *)arg, &rq, sizeof(rq))) {
+				err = -EFAULT;
+				goto out;
+			}
+		}
+		break;
+	default:
+		err = -EINVAL;
+		break;
+	}
+out:
+	return err;
+}
+
+static ssize_t raw_file_write(struct file *file, const char __user *buf,
+				   size_t count, loff_t *ppos)
+{
+	struct iovec local_iov = {
+		.iov_base = (char __user *)buf,
+		.iov_len = count
+	};
+
+	return generic_file_write_nolock(file, &local_iov, 1, ppos);
+}
+
+static ssize_t raw_file_aio_write(struct kiocb *iocb, const char __user *buf,
+					size_t count, loff_t pos)
+{
+	struct iovec local_iov = {
+		.iov_base = (char __user *)buf,
+		.iov_len = count
+	};
+
+	return generic_file_aio_write_nolock(iocb, &local_iov, 1, &iocb->ki_pos);
+}
+
+
+static struct file_operations raw_fops = {
+	.read	=	generic_file_read,
+	.aio_read = 	generic_file_aio_read,
+	.write	=	raw_file_write,
+	.aio_write = 	raw_file_aio_write,
+	.open	=	raw_open,
+	.release=	raw_release,
+	.ioctl	=	raw_ioctl,
+	.readv	= 	generic_file_readv,
+	.writev	= 	generic_file_writev,
+	.owner	=	THIS_MODULE,
+};
+
+static struct file_operations raw_ctl_fops = {
+	.ioctl	=	raw_ctl_ioctl,
+	.open	=	raw_open,
+	.owner	=	THIS_MODULE,
+};
+
+static struct cdev raw_cdev = {
+	.kobj	=	{.name = "raw", },
+	.owner	=	THIS_MODULE,
+};
+
+static int __init raw_init(void)
+{
+	int i;
+	dev_t dev = MKDEV(RAW_MAJOR, 0);
+
+	if (register_chrdev_region(dev, MAX_RAW_MINORS, "raw"))
+		goto error;
+
+	cdev_init(&raw_cdev, &raw_fops);
+	if (cdev_add(&raw_cdev, dev, MAX_RAW_MINORS)) {
+		kobject_put(&raw_cdev.kobj);
+		unregister_chrdev_region(dev, MAX_RAW_MINORS);
+		goto error;
+	}
+
+	raw_class = class_simple_create(THIS_MODULE, "raw");
+	if (IS_ERR(raw_class)) {
+		printk(KERN_ERR "Error creating raw class.\n");
+		cdev_del(&raw_cdev);
+		unregister_chrdev_region(dev, MAX_RAW_MINORS);
+		goto error;
+	}
+	class_simple_device_add(raw_class, MKDEV(RAW_MAJOR, 0), NULL, "rawctl");
+
+	devfs_mk_cdev(MKDEV(RAW_MAJOR, 0),
+		      S_IFCHR | S_IRUGO | S_IWUGO,
+		      "raw/rawctl");
+	for (i = 1; i < MAX_RAW_MINORS; i++)
+		devfs_mk_cdev(MKDEV(RAW_MAJOR, i),
+			      S_IFCHR | S_IRUGO | S_IWUGO,
+			      "raw/raw%d", i);
+	return 0;
+
+error:
+	printk(KERN_ERR "error register raw device\n");
+	return 1;
+}
+
+static void __exit raw_exit(void)
+{
+	int i;
+
+	for (i = 1; i < MAX_RAW_MINORS; i++)
+		devfs_remove("raw/raw%d", i);
+	devfs_remove("raw/rawctl");
+	devfs_remove("raw");
+	class_simple_device_remove(MKDEV(RAW_MAJOR, 0));
+	class_simple_destroy(raw_class);
+	cdev_del(&raw_cdev);
+	unregister_chrdev_region(MKDEV(RAW_MAJOR, 0), MAX_RAW_MINORS);
+}
+
+module_init(raw_init);
+module_exit(raw_exit);
+MODULE_LICENSE("GPL");