x

1 files changed, 440 insertions, 0 deletions

diff --git a/kernel/dev.c b/kernel/dev.c
new file mode 100644
index 0000000..a91a176
--- /dev/null
+++ b/kernel/dev.c
@@ -0,0 +1,440 @@
+/*
+    FUSE: Filesystem in Userspace
+    Copyright (C) 2001  Miklos Szeredi (mszeredi@inf.bme.hu)
+
+    This program can be distributed under the terms of the GNU GPL.
+    See the file COPYING.
+*/
+
+#include "fuse_i.h"
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/poll.h>
+#include <linux/proc_fs.h>
+#include <linux/file.h>
+
+#define IHSIZE sizeof(struct fuse_in_header)
+#define OHSIZE sizeof(struct fuse_out_header)
+
+static struct proc_dir_entry *proc_fs_fuse;
+struct proc_dir_entry *proc_fuse_dev;
+
+static int request_wait_answer(struct fuse_req *req)
+{
+	int ret = 0;
+	DECLARE_WAITQUEUE(wait, current);
+
+	add_wait_queue(&req->waitq, &wait);
+	while(!list_empty(&req->list)) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		if(signal_pending(current)) {
+			ret = -EINTR;
+			break;
+		}
+		spin_unlock(&fuse_lock);
+		schedule();
+		spin_lock(&fuse_lock);
+	}
+	set_current_state(TASK_RUNNING);
+	remove_wait_queue(&req->waitq, &wait);
+
+	return ret;
+}
+
+static int request_check(struct fuse_req *req, struct fuse_out *outp)
+{
+	struct fuse_out_header *oh;
+	unsigned int size;
+
+	if(!req->out)
+		return -ECONNABORTED;
+
+	oh = (struct fuse_out_header *) req->out;
+	size = req->outsize - OHSIZE;
+	
+	if (oh->result <= -512 || oh->result > 0) {
+		printk("fuse: bad result\n");
+		return -EPROTO;
+	}
+
+	if(size > outp->argsize || 
+	   (oh->result == 0 && !outp->argvar && size != outp->argsize) ||
+	   (oh->result != 0 && size != 0)) {
+		printk("fuse: invalid argument length: %i (%i)\n", size,
+		       req->opcode);
+		return -EPROTO;
+	}
+	
+	memcpy(&outp->h, oh, OHSIZE);
+	outp->argsize = size;
+	if(size)
+		memcpy(outp->arg, req->out + OHSIZE, size);
+	
+	return oh->result;
+}
+
+static void request_free(struct fuse_req *req)
+{
+	kfree(req->in);
+	kfree(req->out);
+	kfree(req);
+}
+
+
+static struct fuse_req *request_new(struct fuse_conn *fc, struct fuse_in *inp,
+				    struct fuse_out *outp)
+{
+	struct fuse_req *req;
+	
+	req = kmalloc(sizeof(*req), GFP_KERNEL);
+	if(!req)
+		return NULL;
+
+	if(outp)
+		req->outsize = OHSIZE + outp->argsize;
+	else
+		req->outsize = 0;
+	req->out = NULL;
+
+	req->insize = IHSIZE + inp->argsize;
+	req->in = kmalloc(req->insize, GFP_KERNEL);
+	if(!req->in) {
+		request_free(req);
+		return NULL;
+	}
+	memcpy(req->in, &inp->h, IHSIZE);
+	if(inp->argsize)
+		memcpy(req->in + IHSIZE, inp->arg, inp->argsize);
+
+	req->opcode = inp->h.opcode;
+	init_waitqueue_head(&req->waitq);
+
+	return req;
+}
+
+/* If 'outp' is NULL then the request this is asynchronous */
+void request_send(struct fuse_conn *fc, struct fuse_in *inp,
+		  struct fuse_out *outp)
+{
+	int ret;
+	struct fuse_in_header *ih;
+	struct fuse_req *req;
+
+	ret = -ENOMEM;
+	req = request_new(fc, inp, outp);
+	if(!req)
+		goto out;
+
+	spin_lock(&fuse_lock);
+	ret = -ENOTCONN;
+	if(fc->file == NULL)
+		goto out_unlock_free;
+	
+	ih = (struct fuse_in_header *) req->in;
+	if(outp) {
+		do fc->reqctr++;
+		while(!fc->reqctr);
+		ih->unique = req->unique = fc->reqctr;
+	}
+	else
+		ih->unique = req->unique = 0;
+
+	list_add_tail(&req->list, &fc->pending);
+	wake_up(&fc->waitq);
+
+	/* Async reqests are freed in fuse_dev_read() */
+	if(!outp) 
+		goto out_unlock; 
+	
+	ret = request_wait_answer(req);
+	list_del(&req->list);
+	if(!ret)
+		ret = request_check(req, outp);
+
+  out_unlock_free:
+	request_free(req);
+  out_unlock:
+	spin_unlock(&fuse_lock);
+  out:
+	if(outp)
+		outp->h.result = ret;
+}
+
+static int request_wait(struct fuse_conn *fc)
+{
+	int ret = 0;
+	DECLARE_WAITQUEUE(wait, current);
+
+	add_wait_queue(&fc->waitq, &wait);
+	while(list_empty(&fc->pending)) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		if(signal_pending(current)) {
+			ret = -ERESTARTSYS;
+			break;
+		}
+		spin_unlock(&fuse_lock);
+		schedule();
+		spin_lock(&fuse_lock);
+	}
+	set_current_state(TASK_RUNNING);
+	remove_wait_queue(&fc->waitq, &wait);
+
+	return ret;
+}
+
+
+static ssize_t fuse_dev_read(struct file *file, char *buf, size_t nbytes,
+			     loff_t *off)
+{
+	int ret;
+	struct fuse_conn *fc = file->private_data;
+	struct fuse_req *req;
+	char *tmpbuf;
+	unsigned int size;
+
+	if(fc->sb == NULL)
+		return -EPERM;
+	
+	spin_lock(&fuse_lock);
+	ret = request_wait(fc);
+	if(ret)
+		goto err;
+	
+	req = list_entry(fc->pending.next, struct fuse_req, list);
+	size = req->insize;
+	if(nbytes < size) {
+		printk("fuse_dev_read[%i]: buffer too small\n", fc->id);
+		ret = -EIO;
+		goto err;
+	}
+	tmpbuf = req->in;
+	req->in = NULL;
+
+	list_del(&req->list);
+	if(req->outsize)
+		list_add_tail(&req->list, &fc->processing);
+	else
+		request_free(req);
+	spin_unlock(&fuse_lock);
+
+	if(copy_to_user(buf, tmpbuf, size))
+		return -EFAULT;
+	
+	return size;
+
+  err:
+	spin_unlock(&fuse_lock);
+	return ret;
+}
+
+static struct fuse_req *request_find(struct fuse_conn *fc, unsigned int unique)
+{
+	struct list_head *entry;
+	struct fuse_req *req = NULL;
+
+	list_for_each(entry, &fc->processing) {
+		struct fuse_req *tmp;
+		tmp = list_entry(entry, struct fuse_req, list);
+		if(tmp->unique == unique) {
+			req = tmp;
+			break;
+		}
+	}
+
+	return req;
+}
+
+static ssize_t fuse_dev_write(struct file *file, const char *buf,
+			      size_t nbytes, loff_t *off)
+{
+	ssize_t ret;
+	struct fuse_conn *fc = file->private_data;
+	struct fuse_req *req;
+	char *tmpbuf;
+	struct fuse_out_header *oh;
+
+	if(!fc->sb)
+		return -EPERM;
+
+	ret = -EIO;
+	if(nbytes < OHSIZE || nbytes > OHSIZE + PAGE_SIZE) {
+		printk("fuse_dev_write[%i]: write is short or long\n", fc->id);
+		goto out;
+	}
+	
+	ret = -ENOMEM;
+	tmpbuf = kmalloc(nbytes, GFP_KERNEL);
+	if(!tmpbuf)
+		goto out;
+	
+	ret = -EFAULT;
+	if(copy_from_user(tmpbuf, buf, nbytes))
+		goto out_free;
+	
+	spin_lock(&fuse_lock);
+	oh =  (struct fuse_out_header *) tmpbuf;
+	req = request_find(fc, oh->unique);
+	if(req == NULL) {
+		ret = -ENOENT;
+		goto out_free_unlock;
+	}
+	list_del_init(&req->list);
+	if(req->opcode == FUSE_GETDIR) {
+		/* fget() needs to be done in this context */
+		struct fuse_getdir_out *arg;
+		arg = (struct fuse_getdir_out *) (tmpbuf + OHSIZE);
+		arg->file = fget(arg->fd);
+	}
+	req->out = tmpbuf;
+	req->outsize = nbytes;
+	tmpbuf = NULL;
+	ret = nbytes;
+	wake_up(&req->waitq);
+  out_free_unlock:
+	spin_unlock(&fuse_lock);
+  out_free:
+	kfree(tmpbuf);
+  out:
+	return ret;
+}
+
+
+static unsigned int fuse_dev_poll(struct file *file, poll_table *wait)
+{
+	struct fuse_conn *fc = file->private_data;
+	unsigned int mask = POLLOUT | POLLWRNORM;
+
+	if(!fc->sb)
+		return -EPERM;
+
+	poll_wait(file, &fc->waitq, wait);
+
+	spin_lock(&fuse_lock);
+	if (!list_empty(&fc->pending))
+                mask |= POLLIN | POLLRDNORM;
+	spin_unlock(&fuse_lock);
+
+	return mask;
+}
+
+static struct fuse_conn *new_conn(void)
+{
+	static int connctr = 1;
+	struct fuse_conn *fc;
+
+	fc = kmalloc(sizeof(*fc), GFP_KERNEL);
+	if(fc != NULL) {
+		fc->sb = NULL;
+		fc->file = NULL;
+		init_waitqueue_head(&fc->waitq);
+		INIT_LIST_HEAD(&fc->pending);
+		INIT_LIST_HEAD(&fc->processing);
+		fc->reqctr = 1;
+		fc->cleared = NULL;
+		fc->numcleared = 0;
+		
+		spin_lock(&fuse_lock);
+		fc->id = connctr ++;
+		spin_unlock(&fuse_lock);
+	}
+	return fc;
+}
+
+static int fuse_dev_open(struct inode *inode, struct file *file)
+{
+	struct fuse_conn *fc;
+
+	fc = new_conn();
+	if(!fc)
+		return -ENOMEM;
+
+	fc->file = file;
+	file->private_data = fc;
+
+	return 0;
+}
+
+static void end_requests(struct list_head *head)
+{
+	while(!list_empty(head)) {
+		struct fuse_req *req;
+		req = list_entry(head->next, struct fuse_req, list);
+		list_del_init(&req->list);
+		if(req->outsize)
+			wake_up(&req->waitq);
+		else
+			request_free(req);
+	}
+}
+
+static int fuse_dev_release(struct inode *inode, struct file *file)
+{
+	struct fuse_conn *fc = file->private_data;
+
+	spin_lock(&fuse_lock);
+	fc->file = NULL;
+	end_requests(&fc->pending);
+	end_requests(&fc->processing);
+	kfree(fc->cleared);
+	fc->cleared = NULL;
+	fc->numcleared = 0;
+	fuse_release_conn(fc);
+	spin_unlock(&fuse_lock);
+	return 0;
+}
+
+static struct file_operations fuse_dev_operations = {
+	owner:		THIS_MODULE,
+	read:		fuse_dev_read,
+	write:		fuse_dev_write,
+	poll:		fuse_dev_poll,
+	open:		fuse_dev_open,
+	release:	fuse_dev_release,
+};
+
+int fuse_dev_init()
+{
+	int ret;
+
+	proc_fs_fuse = NULL;
+	proc_fuse_dev = NULL;
+
+	ret = -EIO;
+	proc_fs_fuse = proc_mkdir("fuse", proc_root_fs);
+	if(!proc_fs_fuse) {
+		printk("fuse: failed to create directory in /proc/fs\n");
+		goto err;
+	}
+
+	proc_fs_fuse->owner = THIS_MODULE;
+	proc_fuse_dev = create_proc_entry("dev", S_IFSOCK | S_IRUGO | S_IWUGO,
+					  proc_fs_fuse);
+	if(!proc_fuse_dev) {
+		printk("fuse: failed to create entry in /proc/fs/fuse\n");
+		goto err;
+	}
+
+	proc_fuse_dev->proc_fops = &fuse_dev_operations;
+
+	return 0;
+
+  err:
+	fuse_dev_cleanup();
+	return ret;
+}
+
+void fuse_dev_cleanup()
+{
+	if(proc_fs_fuse) {
+		remove_proc_entry("dev", proc_fs_fuse);
+		remove_proc_entry("fuse", proc_root_fs);
+	}
+}
+
+/* 
+ * Local Variables:
+ * indent-tabs-mode: t
+ * c-basic-offset: 8
+ * End:
+ */