Commit message: fuse: check size of FUSE_NOTIFY_INVAL_ENTRY message

FUSE_NOTIFY_INVAL_ENTRY didn't check the length of the write so the
message processing could overrun and result in a "kernel BUG at
fs/fuse/dev.c:629!"

Reported-by: Han-Wen Nienhuys <hanwenn@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
CC: stable@kernel.org
CVE: CVE-2011-3353
CWE: CWE-119
Vulnerability description: Buffer overflow in the fuse_notify_inval_entry function in fs/fuse/dev.c in the Linux kernel before 3.1 allows local users to cause a denial of service (BUG_ON and system crash) by leveraging the ability to mount a FUSE filesystem.

Project: linux
File: dev.c

static void __fuse_get_request(struct fuse_req *req)
{
	atomic_inc(&req->count);
}

Project: linux
File: dev.c

static void __fuse_put_request(struct fuse_req *req)
{
	BUG_ON(atomic_read(&req->count) < 2);
	atomic_dec(&req->count);
}

Project: linux
File: dev.c

static void block_sigs(sigset_t *oldset)
{
	sigset_t mask;

	siginitsetinv(&mask, sigmask(SIGKILL));
	sigprocmask(SIG_BLOCK, &mask, oldset);
}

Project: linux
File: dev.c

static int copy_out_args(struct fuse_copy_state *cs, struct fuse_out *out,
			 unsigned nbytes)
{
	unsigned reqsize = sizeof(struct fuse_out_header);

	if (out->h.error)
		return nbytes != reqsize ? -EINVAL : 0;

	reqsize += len_args(out->numargs, out->args);

	if (reqsize < nbytes || (reqsize > nbytes && !out->argvar))
		return -EINVAL;
	else if (reqsize > nbytes) {
		struct fuse_arg *lastarg = &out->args[out->numargs-1];
		unsigned diffsize = reqsize - nbytes;
		if (diffsize > lastarg->size)
			return -EINVAL;
		lastarg->size -= diffsize;
	}
	return fuse_copy_args(cs, out->numargs, out->argpages, out->args,
			      out->page_zeroing);
}

Project: linux
File: dev.c

static struct fuse_forget_link *dequeue_forget(struct fuse_conn *fc,
					       unsigned max,
					       unsigned *countp)
{
	struct fuse_forget_link *head = fc->forget_list_head.next;
	struct fuse_forget_link **newhead = &head;
	unsigned count;

	for (count = 0; *newhead != NULL && count < max; count++)
		newhead = &(*newhead)->next;

	fc->forget_list_head.next = *newhead;
	*newhead = NULL;
	if (fc->forget_list_head.next == NULL)
		fc->forget_list_tail = &fc->forget_list_head;

	if (countp != NULL)
		*countp = count;

	return head;
}

Project: linux
File: dev.c

static void end_polls(struct fuse_conn *fc)
{
	struct rb_node *p;

	p = rb_first(&fc->polled_files);

	while (p) {
		struct fuse_file *ff;
		ff = rb_entry(p, struct fuse_file, polled_node);
		wake_up_interruptible_all(&ff->poll_wait);

		p = rb_next(p);
	}
}

Project: linux
File: dev.c

static int forget_pending(struct fuse_conn *fc)
{
	return fc->forget_list_head.next != NULL;
}

Project: linux
File: dev.c

void fuse_abort_conn(struct fuse_conn *fc)
{
	spin_lock(&fc->lock);
	if (fc->connected) {
		fc->connected = 0;
		fc->blocked = 0;
		end_io_requests(fc);
		end_queued_requests(fc);
		end_polls(fc);
		wake_up_all(&fc->waitq);
		wake_up_all(&fc->blocked_waitq);
		kill_fasync(&fc->fasync, SIGIO, POLL_IN);
	}
	spin_unlock(&fc->lock);
}

Project: linux
File: dev.c

static int fuse_check_page(struct page *page)
{
	if (page_mapcount(page) ||
	    page->mapping != NULL ||
	    page_count(page) != 1 ||
	    (page->flags & PAGE_FLAGS_CHECK_AT_PREP &
	     ~(1 << PG_locked |
	       1 << PG_referenced |
	       1 << PG_uptodate |
	       1 << PG_lru |
	       1 << PG_active |
	       1 << PG_reclaim))) {
		printk(KERN_WARNING "fuse: trying to steal weird page\n");
		printk(KERN_WARNING "  page=%p index=%li flags=%08lx, count=%i, mapcount=%i, mapping=%p\n", page, page->index, page->flags, page_count(page), page_mapcount(page), page->mapping);
		return 1;
	}
	return 0;
}

Project: linux
File: dev.c

static int fuse_copy_args(struct fuse_copy_state *cs, unsigned numargs,
			  unsigned argpages, struct fuse_arg *args,
			  int zeroing)
{
	int err = 0;
	unsigned i;

	for (i = 0; !err && i < numargs; i++)  {
		struct fuse_arg *arg = &args[i];
		if (i == numargs - 1 && argpages)
			err = fuse_copy_pages(cs, arg->size, zeroing);
		else
			err = fuse_copy_one(cs, arg->value, arg->size);
	}
	return err;
}

Project: linux
File: dev.c

static int fuse_copy_do(struct fuse_copy_state *cs, void **val, unsigned *size)
{
	unsigned ncpy = min(*size, cs->len);
	if (val) {
		if (cs->write)
			memcpy(cs->buf, *val, ncpy);
		else
			memcpy(*val, cs->buf, ncpy);
		*val += ncpy;
	}
	*size -= ncpy;
	cs->len -= ncpy;
	cs->buf += ncpy;
	return ncpy;
}

Project: linux
File: dev.c

static int fuse_copy_fill(struct fuse_copy_state *cs)
{
	unsigned long offset;
	int err;

	unlock_request(cs->fc, cs->req);
	fuse_copy_finish(cs);
	if (cs->pipebufs) {
		struct pipe_buffer *buf = cs->pipebufs;

		if (!cs->write) {
			err = buf->ops->confirm(cs->pipe, buf);
			if (err)
				return err;

			BUG_ON(!cs->nr_segs);
			cs->currbuf = buf;
			cs->mapaddr = buf->ops->map(cs->pipe, buf, 0);
			cs->len = buf->len;
			cs->buf = cs->mapaddr + buf->offset;
			cs->pipebufs++;
			cs->nr_segs--;
		} else {
			struct page *page;

			if (cs->nr_segs == cs->pipe->buffers)
				return -EIO;

			page = alloc_page(GFP_HIGHUSER);
			if (!page)
				return -ENOMEM;

			buf->page = page;
			buf->offset = 0;
			buf->len = 0;

			cs->currbuf = buf;
			cs->mapaddr = kmap(page);
			cs->buf = cs->mapaddr;
			cs->len = PAGE_SIZE;
			cs->pipebufs++;
			cs->nr_segs++;
		}
	} else {
		if (!cs->seglen) {
			BUG_ON(!cs->nr_segs);
			cs->seglen = cs->iov[0].iov_len;
			cs->addr = (unsigned long) cs->iov[0].iov_base;
			cs->iov++;
			cs->nr_segs--;
		}
		err = get_user_pages_fast(cs->addr, 1, cs->write, &cs->pg);
		if (err < 0)
			return err;
		BUG_ON(err != 1);
		offset = cs->addr % PAGE_SIZE;
		cs->mapaddr = kmap(cs->pg);
		cs->buf = cs->mapaddr + offset;
		cs->len = min(PAGE_SIZE - offset, cs->seglen);
		cs->seglen -= cs->len;
		cs->addr += cs->len;
	}

	return lock_request(cs->fc, cs->req);
}

Project: linux
File: dev.c

static void fuse_copy_finish(struct fuse_copy_state *cs)
{
	if (cs->currbuf) {
		struct pipe_buffer *buf = cs->currbuf;

		if (!cs->write) {
			buf->ops->unmap(cs->pipe, buf, cs->mapaddr);
		} else {
			kunmap(buf->page);
			buf->len = PAGE_SIZE - cs->len;
		}
		cs->currbuf = NULL;
		cs->mapaddr = NULL;
	} else if (cs->mapaddr) {
		kunmap(cs->pg);
		if (cs->write) {
			flush_dcache_page(cs->pg);
			set_page_dirty_lock(cs->pg);
		}
		put_page(cs->pg);
		cs->mapaddr = NULL;
	}
}

Project: linux
File: dev.c

static void fuse_copy_init(struct fuse_copy_state *cs, struct fuse_conn *fc,
			   int write,
			   const struct iovec *iov, unsigned long nr_segs)
{
	memset(cs, 0, sizeof(*cs));
	cs->fc = fc;
	cs->write = write;
	cs->iov = iov;
	cs->nr_segs = nr_segs;
}

Project: linux
File: dev.c

static int fuse_copy_one(struct fuse_copy_state *cs, void *val, unsigned size)
{
	while (size) {
		if (!cs->len) {
			int err = fuse_copy_fill(cs);
			if (err)
				return err;
		}
		fuse_copy_do(cs, &val, &size);
	}
	return 0;
}

Project: linux
File: dev.c

static int fuse_copy_page(struct fuse_copy_state *cs, struct page **pagep,
			  unsigned offset, unsigned count, int zeroing)
{
	int err;
	struct page *page = *pagep;

	if (page && zeroing && count < PAGE_SIZE)
		clear_highpage(page);

	while (count) {
		if (cs->write && cs->pipebufs && page) {
			return fuse_ref_page(cs, page, offset, count);
		} else if (!cs->len) {
			if (cs->move_pages && page &&
			    offset == 0 && count == PAGE_SIZE) {
				err = fuse_try_move_page(cs, pagep);
				if (err <= 0)
					return err;
			} else {
				err = fuse_copy_fill(cs);
				if (err)
					return err;
			}
		}
		if (page) {
			void *mapaddr = kmap_atomic(page, KM_USER0);
			void *buf = mapaddr + offset;
			offset += fuse_copy_do(cs, &buf, &count);
			kunmap_atomic(mapaddr, KM_USER0);
		} else
			offset += fuse_copy_do(cs, NULL, &count);
	}
	if (page && !cs->write)
		flush_dcache_page(page);
	return 0;
}

Project: linux
File: dev.c

static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes,
			   int zeroing)
{
	unsigned i;
	struct fuse_req *req = cs->req;
	unsigned offset = req->page_offset;
	unsigned count = min(nbytes, (unsigned) PAGE_SIZE - offset);

	for (i = 0; i < req->num_pages && (nbytes || zeroing); i++) {
		int err;

		err = fuse_copy_page(cs, &req->pages[i], offset, count,
				     zeroing);
		if (err)
			return err;

		nbytes -= count;
		count = min(nbytes, (unsigned) PAGE_SIZE);
		offset = 0;
	}
	return 0;
}

Project: linux
File: dev.c

void fuse_dev_cleanup(void)
{
	misc_deregister(&fuse_miscdevice);
	kmem_cache_destroy(fuse_req_cachep);
}

Project: linux
File: dev.c

static ssize_t fuse_dev_do_read(struct fuse_conn *fc, struct file *file,
				struct fuse_copy_state *cs, size_t nbytes)
{
	int err;
	struct fuse_req *req;
	struct fuse_in *in;
	unsigned reqsize;

 restart:
	spin_lock(&fc->lock);
	err = -EAGAIN;
	if ((file->f_flags & O_NONBLOCK) && fc->connected &&
	    !request_pending(fc))
		goto err_unlock;

	request_wait(fc);
	err = -ENODEV;
	if (!fc->connected)
		goto err_unlock;
	err = -ERESTARTSYS;
	if (!request_pending(fc))
		goto err_unlock;

	if (!list_empty(&fc->interrupts)) {
		req = list_entry(fc->interrupts.next, struct fuse_req,
				 intr_entry);
		return fuse_read_interrupt(fc, cs, nbytes, req);
	}

	if (forget_pending(fc)) {
		if (list_empty(&fc->pending) || fc->forget_batch-- > 0)
			return fuse_read_forget(fc, cs, nbytes);

		if (fc->forget_batch <= -8)
			fc->forget_batch = 16;
	}

	req = list_entry(fc->pending.next, struct fuse_req, list);
	req->state = FUSE_REQ_READING;
	list_move(&req->list, &fc->io);

	in = &req->in;
	reqsize = in->h.len;
	/* If request is too large, reply with an error and restart the read */
	if (nbytes < reqsize) {
		req->out.h.error = -EIO;
		/* SETXATTR is special, since it may contain too large data */
		if (in->h.opcode == FUSE_SETXATTR)
			req->out.h.error = -E2BIG;
		request_end(fc, req);
		goto restart;
	}
	spin_unlock(&fc->lock);
	cs->req = req;
	err = fuse_copy_one(cs, &in->h, sizeof(in->h));
	if (!err)
		err = fuse_copy_args(cs, in->numargs, in->argpages,
				     (struct fuse_arg *) in->args, 0);
	fuse_copy_finish(cs);
	spin_lock(&fc->lock);
	req->locked = 0;
	if (req->aborted) {
		request_end(fc, req);
		return -ENODEV;
	}
	if (err) {
		req->out.h.error = -EIO;
		request_end(fc, req);
		return err;
	}
	if (!req->isreply)
		request_end(fc, req);
	else {
		req->state = FUSE_REQ_SENT;
		list_move_tail(&req->list, &fc->processing);
		if (req->interrupted)
			queue_interrupt(fc, req);
		spin_unlock(&fc->lock);
	}
	return reqsize;

 err_unlock:
	spin_unlock(&fc->lock);
	return err;
}

Project: linux
File: dev.c

static ssize_t fuse_dev_do_write(struct fuse_conn *fc,
				 struct fuse_copy_state *cs, size_t nbytes)
{
	int err;
	struct fuse_req *req;
	struct fuse_out_header oh;

	if (nbytes < sizeof(struct fuse_out_header))
		return -EINVAL;

	err = fuse_copy_one(cs, &oh, sizeof(oh));
	if (err)
		goto err_finish;

	err = -EINVAL;
	if (oh.len != nbytes)
		goto err_finish;

	/*
	 * Zero oh.unique indicates unsolicited notification message
	 * and error contains notification code.
	 */
	if (!oh.unique) {
		err = fuse_notify(fc, oh.error, nbytes - sizeof(oh), cs);
		return err ? err : nbytes;
	}

	err = -EINVAL;
	if (oh.error <= -1000 || oh.error > 0)
		goto err_finish;

	spin_lock(&fc->lock);
	err = -ENOENT;
	if (!fc->connected)
		goto err_unlock;

	req = request_find(fc, oh.unique);
	if (!req)
		goto err_unlock;

	if (req->aborted) {
		spin_unlock(&fc->lock);
		fuse_copy_finish(cs);
		spin_lock(&fc->lock);
		request_end(fc, req);
		return -ENOENT;
	}
	/* Is it an interrupt reply? */
	if (req->intr_unique == oh.unique) {
		err = -EINVAL;
		if (nbytes != sizeof(struct fuse_out_header))
			goto err_unlock;

		if (oh.error == -ENOSYS)
			fc->no_interrupt = 1;
		else if (oh.error == -EAGAIN)
			queue_interrupt(fc, req);

		spin_unlock(&fc->lock);
		fuse_copy_finish(cs);
		return nbytes;
	}

	req->state = FUSE_REQ_WRITING;
	list_move(&req->list, &fc->io);
	req->out.h = oh;
	req->locked = 1;
	cs->req = req;
	if (!req->out.page_replace)
		cs->move_pages = 0;
	spin_unlock(&fc->lock);

	err = copy_out_args(cs, &req->out, nbytes);
	fuse_copy_finish(cs);

	spin_lock(&fc->lock);
	req->locked = 0;
	if (!err) {
		if (req->aborted)
			err = -ENOENT;
	} else if (!req->aborted)
		req->out.h.error = -EIO;
	request_end(fc, req);

	return err ? err : nbytes;

 err_unlock:
	spin_unlock(&fc->lock);
 err_finish:
	fuse_copy_finish(cs);
	return err;
}

Project: linux
File: dev.c

static int fuse_dev_fasync(int fd, struct file *file, int on)
{
	struct fuse_conn *fc = fuse_get_conn(file);
	if (!fc)
		return -EPERM;

	/* No locking - fasync_helper does its own locking */
	return fasync_helper(fd, file, on, &fc->fasync);
}

Project: linux
File: dev.c

int __init fuse_dev_init(void)
{
	int err = -ENOMEM;
	fuse_req_cachep = kmem_cache_create("fuse_request",
					    sizeof(struct fuse_req),
					    0, 0, NULL);
	if (!fuse_req_cachep)
		goto out;

	err = misc_register(&fuse_miscdevice);
	if (err)
		goto out_cache_clean;

	return 0;

 out_cache_clean:
	kmem_cache_destroy(fuse_req_cachep);
 out:
	return err;
}

Project: linux
File: dev.c

static int fuse_dev_pipe_buf_steal(struct pipe_inode_info *pipe,
				   struct pipe_buffer *buf)
{
	return 1;
}

Project: linux
File: dev.c

static unsigned fuse_dev_poll(struct file *file, poll_table *wait)
{
	unsigned mask = POLLOUT | POLLWRNORM;
	struct fuse_conn *fc = fuse_get_conn(file);
	if (!fc)
		return POLLERR;

	poll_wait(file, &fc->waitq, wait);

	spin_lock(&fc->lock);
	if (!fc->connected)
		mask = POLLERR;
	else if (request_pending(fc))
		mask |= POLLIN | POLLRDNORM;
	spin_unlock(&fc->lock);

	return mask;
}

Project: linux
File: dev.c

static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
			      unsigned long nr_segs, loff_t pos)
{
	struct fuse_copy_state cs;
	struct file *file = iocb->ki_filp;
	struct fuse_conn *fc = fuse_get_conn(file);
	if (!fc)
		return -EPERM;

	fuse_copy_init(&cs, fc, 1, iov, nr_segs);

	return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs));
}

Project: linux
File: dev.c

int fuse_dev_release(struct inode *inode, struct file *file)
{
	struct fuse_conn *fc = fuse_get_conn(file);
	if (fc) {
		spin_lock(&fc->lock);
		fc->connected = 0;
		fc->blocked = 0;
		end_queued_requests(fc);
		end_polls(fc);
		wake_up_all(&fc->blocked_waitq);
		spin_unlock(&fc->lock);
		fuse_conn_put(fc);
	}

	return 0;
}

Project: linux
File: dev.c

static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
				    struct pipe_inode_info *pipe,
				    size_t len, unsigned int flags)
{
	int ret;
	int page_nr = 0;
	int do_wakeup = 0;
	struct pipe_buffer *bufs;
	struct fuse_copy_state cs;
	struct fuse_conn *fc = fuse_get_conn(in);
	if (!fc)
		return -EPERM;

	bufs = kmalloc(pipe->buffers * sizeof(struct pipe_buffer), GFP_KERNEL);
	if (!bufs)
		return -ENOMEM;

	fuse_copy_init(&cs, fc, 1, NULL, 0);
	cs.pipebufs = bufs;
	cs.pipe = pipe;
	ret = fuse_dev_do_read(fc, in, &cs, len);
	if (ret < 0)
		goto out;

	ret = 0;
	pipe_lock(pipe);

	if (!pipe->readers) {
		send_sig(SIGPIPE, current, 0);
		if (!ret)
			ret = -EPIPE;
		goto out_unlock;
	}

	if (pipe->nrbufs + cs.nr_segs > pipe->buffers) {
		ret = -EIO;
		goto out_unlock;
	}

	while (page_nr < cs.nr_segs) {
		int newbuf = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1);
		struct pipe_buffer *buf = pipe->bufs + newbuf;

		buf->page = bufs[page_nr].page;
		buf->offset = bufs[page_nr].offset;
		buf->len = bufs[page_nr].len;
		buf->ops = &fuse_dev_pipe_buf_ops;

		pipe->nrbufs++;
		page_nr++;
		ret += buf->len;

		if (pipe->inode)
			do_wakeup = 1;
	}

out_unlock:
	pipe_unlock(pipe);

	if (do_wakeup) {
		smp_mb();
		if (waitqueue_active(&pipe->wait))
			wake_up_interruptible(&pipe->wait);
		kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
	}

out:
	for (; page_nr < cs.nr_segs; page_nr++)
		page_cache_release(bufs[page_nr].page);

	kfree(bufs);
	return ret;
}

Project: linux
File: dev.c

static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe,
				     struct file *out, loff_t *ppos,
				     size_t len, unsigned int flags)
{
	unsigned nbuf;
	unsigned idx;
	struct pipe_buffer *bufs;
	struct fuse_copy_state cs;
	struct fuse_conn *fc;
	size_t rem;
	ssize_t ret;

	fc = fuse_get_conn(out);
	if (!fc)
		return -EPERM;

	bufs = kmalloc(pipe->buffers * sizeof(struct pipe_buffer), GFP_KERNEL);
	if (!bufs)
		return -ENOMEM;

	pipe_lock(pipe);
	nbuf = 0;
	rem = 0;
	for (idx = 0; idx < pipe->nrbufs && rem < len; idx++)
		rem += pipe->bufs[(pipe->curbuf + idx) & (pipe->buffers - 1)].len;

	ret = -EINVAL;
	if (rem < len) {
		pipe_unlock(pipe);
		goto out;
	}

	rem = len;
	while (rem) {
		struct pipe_buffer *ibuf;
		struct pipe_buffer *obuf;

		BUG_ON(nbuf >= pipe->buffers);
		BUG_ON(!pipe->nrbufs);
		ibuf = &pipe->bufs[pipe->curbuf];
		obuf = &bufs[nbuf];

		if (rem >= ibuf->len) {
			*obuf = *ibuf;
			ibuf->ops = NULL;
			pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1);
			pipe->nrbufs--;
		} else {
			ibuf->ops->get(pipe, ibuf);
			*obuf = *ibuf;
			obuf->flags &= ~PIPE_BUF_FLAG_GIFT;
			obuf->len = rem;
			ibuf->offset += obuf->len;
			ibuf->len -= obuf->len;
		}
		nbuf++;
		rem -= obuf->len;
	}
	pipe_unlock(pipe);

	fuse_copy_init(&cs, fc, 0, NULL, nbuf);
	cs.pipebufs = bufs;
	cs.pipe = pipe;

	if (flags & SPLICE_F_MOVE)
		cs.move_pages = 1;

	ret = fuse_dev_do_write(fc, &cs, len);

	for (idx = 0; idx < nbuf; idx++) {
		struct pipe_buffer *buf = &bufs[idx];
		buf->ops->release(pipe, buf);
	}
out:
	kfree(bufs);
	return ret;
}

Project: linux
File: dev.c

static struct fuse_conn *fuse_get_conn(struct file *file)
{
	/*
	 * Lockless access is OK, because file->private data is set
	 * once during mount and is valid until the file is released.
	 */
	return file->private_data;
}

Project: linux
File: dev.c

struct fuse_req *fuse_get_req(struct fuse_conn *fc)
{
	struct fuse_req *req;
	sigset_t oldset;
	int intr;
	int err;

	atomic_inc(&fc->num_waiting);
	block_sigs(&oldset);
	intr = wait_event_interruptible(fc->blocked_waitq, !fc->blocked);
	restore_sigs(&oldset);
	err = -EINTR;
	if (intr)
		goto out;

	err = -ENOTCONN;
	if (!fc->connected)
		goto out;

	req = fuse_request_alloc();
	err = -ENOMEM;
	if (!req)
		goto out;

	fuse_req_init_context(req);
	req->waiting = 1;
	return req;

 out:
	atomic_dec(&fc->num_waiting);
	return ERR_PTR(err);
}

Project: linux
File: dev.c

struct fuse_req *fuse_get_req_nofail(struct fuse_conn *fc, struct file *file)
{
	struct fuse_req *req;

	atomic_inc(&fc->num_waiting);
	wait_event(fc->blocked_waitq, !fc->blocked);
	req = fuse_request_alloc();
	if (!req)
		req = get_reserved_req(fc, file);

	fuse_req_init_context(req);
	req->waiting = 1;
	return req;
}

Project: linux
File: dev.c

static u64 fuse_get_unique(struct fuse_conn *fc)
{
	fc->reqctr++;
	/* zero is special */
	if (fc->reqctr == 0)
		fc->reqctr = 1;

	return fc->reqctr;
}

Project: linux
File: dev.c

static int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code,
		       unsigned int size, struct fuse_copy_state *cs)
{
	switch (code) {
	case FUSE_NOTIFY_POLL:
		return fuse_notify_poll(fc, size, cs);

	case FUSE_NOTIFY_INVAL_INODE:
		return fuse_notify_inval_inode(fc, size, cs);

	case FUSE_NOTIFY_INVAL_ENTRY:
		return fuse_notify_inval_entry(fc, size, cs);

	case FUSE_NOTIFY_STORE:
		return fuse_notify_store(fc, size, cs);

	case FUSE_NOTIFY_RETRIEVE:
		return fuse_notify_retrieve(fc, size, cs);

	default:
		fuse_copy_finish(cs);
		return -EINVAL;
	}
}

Project: linux
File: dev.c

static int fuse_notify_inval_inode(struct fuse_conn *fc, unsigned int size,
				   struct fuse_copy_state *cs)
{
	struct fuse_notify_inval_inode_out outarg;
	int err = -EINVAL;

	if (size != sizeof(outarg))
		goto err;

	err = fuse_copy_one(cs, &outarg, sizeof(outarg));
	if (err)
		goto err;
	fuse_copy_finish(cs);

	down_read(&fc->killsb);
	err = -ENOENT;
	if (fc->sb) {
		err = fuse_reverse_inval_inode(fc->sb, outarg.ino,
					       outarg.off, outarg.len);
	}
	up_read(&fc->killsb);
	return err;

err:
	fuse_copy_finish(cs);
	return err;
}

Project: linux
File: dev.c

static int fuse_notify_poll(struct fuse_conn *fc, unsigned int size,
			    struct fuse_copy_state *cs)
{
	struct fuse_notify_poll_wakeup_out outarg;
	int err = -EINVAL;

	if (size != sizeof(outarg))
		goto err;

	err = fuse_copy_one(cs, &outarg, sizeof(outarg));
	if (err)
		goto err;

	fuse_copy_finish(cs);
	return fuse_notify_poll_wakeup(fc, &outarg);

err:
	fuse_copy_finish(cs);
	return err;
}

Project: linux
File: dev.c

static int fuse_notify_retrieve(struct fuse_conn *fc, unsigned int size,
				struct fuse_copy_state *cs)
{
	struct fuse_notify_retrieve_out outarg;
	struct inode *inode;
	int err;

	err = -EINVAL;
	if (size != sizeof(outarg))
		goto copy_finish;

	err = fuse_copy_one(cs, &outarg, sizeof(outarg));
	if (err)
		goto copy_finish;

	fuse_copy_finish(cs);

	down_read(&fc->killsb);
	err = -ENOENT;
	if (fc->sb) {
		u64 nodeid = outarg.nodeid;

		inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid);
		if (inode) {
			err = fuse_retrieve(fc, inode, &outarg);
			iput(inode);
		}
	}
	up_read(&fc->killsb);

	return err;

copy_finish:
	fuse_copy_finish(cs);
	return err;
}

Project: linux
File: dev.c

static int fuse_notify_store(struct fuse_conn *fc, unsigned int size,
			     struct fuse_copy_state *cs)
{
	struct fuse_notify_store_out outarg;
	struct inode *inode;
	struct address_space *mapping;
	u64 nodeid;
	int err;
	pgoff_t index;
	unsigned int offset;
	unsigned int num;
	loff_t file_size;
	loff_t end;

	err = -EINVAL;
	if (size < sizeof(outarg))
		goto out_finish;

	err = fuse_copy_one(cs, &outarg, sizeof(outarg));
	if (err)
		goto out_finish;

	err = -EINVAL;
	if (size - sizeof(outarg) != outarg.size)
		goto out_finish;

	nodeid = outarg.nodeid;

	down_read(&fc->killsb);

	err = -ENOENT;
	if (!fc->sb)
		goto out_up_killsb;

	inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid);
	if (!inode)
		goto out_up_killsb;

	mapping = inode->i_mapping;
	index = outarg.offset >> PAGE_CACHE_SHIFT;
	offset = outarg.offset & ~PAGE_CACHE_MASK;
	file_size = i_size_read(inode);
	end = outarg.offset + outarg.size;
	if (end > file_size) {
		file_size = end;
		fuse_write_update_size(inode, file_size);
	}

	num = outarg.size;
	while (num) {
		struct page *page;
		unsigned int this_num;

		err = -ENOMEM;
		page = find_or_create_page(mapping, index,
					   mapping_gfp_mask(mapping));
		if (!page)
			goto out_iput;

		this_num = min_t(unsigned, num, PAGE_CACHE_SIZE - offset);
		err = fuse_copy_page(cs, &page, offset, this_num, 0);
		if (!err && offset == 0 && (num != 0 || file_size == end))
			SetPageUptodate(page);
		unlock_page(page);
		page_cache_release(page);

		if (err)
			goto out_iput;

		num -= this_num;
		offset = 0;
		index++;
	}

	err = 0;

out_iput:
	iput(inode);
out_up_killsb:
	up_read(&fc->killsb);
out_finish:
	fuse_copy_finish(cs);
	return err;
}

Project: linux
File: dev.c

void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req)
{
	if (atomic_dec_and_test(&req->count)) {
		if (req->waiting)
			atomic_dec(&fc->num_waiting);

		if (req->stolen_file)
			put_reserved_req(fc, req);
		else
			fuse_request_free(req);
	}
}

Project: linux
File: dev.c

void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
		       u64 nodeid, u64 nlookup)
{
	forget->forget_one.nodeid = nodeid;
	forget->forget_one.nlookup = nlookup;

	spin_lock(&fc->lock);
	fc->forget_list_tail->next = forget;
	fc->forget_list_tail = forget;
	wake_up(&fc->waitq);
	kill_fasync(&fc->fasync, SIGIO, POLL_IN);
	spin_unlock(&fc->lock);
}

Project: linux
File: dev.c

static int fuse_ref_page(struct fuse_copy_state *cs, struct page *page,
			 unsigned offset, unsigned count)
{
	struct pipe_buffer *buf;

	if (cs->nr_segs == cs->pipe->buffers)
		return -EIO;

	unlock_request(cs->fc, cs->req);
	fuse_copy_finish(cs);

	buf = cs->pipebufs;
	page_cache_get(page);
	buf->page = page;
	buf->offset = offset;
	buf->len = count;

	cs->pipebufs++;
	cs->nr_segs++;
	cs->len = 0;

	return 0;
}

Project: linux
File: dev.c

static void fuse_req_init_context(struct fuse_req *req)
{
	req->in.h.uid = current_fsuid();
	req->in.h.gid = current_fsgid();
	req->in.h.pid = current->pid;
}

Project: linux
File: dev.c

struct fuse_req *fuse_request_alloc(void)
{
	struct fuse_req *req = kmem_cache_alloc(fuse_req_cachep, GFP_KERNEL);
	if (req)
		fuse_request_init(req);
	return req;
}

Project: linux
File: dev.c

static void fuse_request_init(struct fuse_req *req)
{
	memset(req, 0, sizeof(*req));
	INIT_LIST_HEAD(&req->list);
	INIT_LIST_HEAD(&req->intr_entry);
	init_waitqueue_head(&req->waitq);
	atomic_set(&req->count, 1);
}

Project: linux
File: dev.c

void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
{
	req->isreply = 1;
	spin_lock(&fc->lock);
	if (!fc->connected)
		req->out.h.error = -ENOTCONN;
	else if (fc->conn_error)
		req->out.h.error = -ECONNREFUSED;
	else {
		req->in.h.unique = fuse_get_unique(fc);
		queue_request(fc, req);
		/* acquire extra reference, since request is still needed
		   after request_end() */
		__fuse_get_request(req);

		request_wait_answer(fc, req);
	}
	spin_unlock(&fc->lock);
}

Project: linux
File: dev.c

void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req)
{
	req->isreply = 1;
	fuse_request_send_nowait(fc, req);
}

Project: linux
File: dev.c

void fuse_request_send_background_locked(struct fuse_conn *fc,
					 struct fuse_req *req)
{
	req->isreply = 1;
	fuse_request_send_nowait_locked(fc, req);
}

Project: linux
File: dev.c

static int fuse_request_send_notify_reply(struct fuse_conn *fc,
					  struct fuse_req *req, u64 unique)
{
	int err = -ENODEV;

	req->isreply = 0;
	req->in.h.unique = unique;
	spin_lock(&fc->lock);
	if (fc->connected) {
		queue_request(fc, req);
		err = 0;
	}
	spin_unlock(&fc->lock);

	return err;
}

Project: linux
File: dev.c

static void fuse_request_send_nowait(struct fuse_conn *fc, struct fuse_req *req)
{
	spin_lock(&fc->lock);
	if (fc->connected) {
		fuse_request_send_nowait_locked(fc, req);
		spin_unlock(&fc->lock);
	} else {
		req->out.h.error = -ENOTCONN;
		request_end(fc, req);
	}
}

Project: linux
File: dev.c

static void fuse_request_send_nowait_locked(struct fuse_conn *fc,
					    struct fuse_req *req)
{
	req->background = 1;
	fc->num_background++;
	if (fc->num_background == fc->max_background)
		fc->blocked = 1;
	if (fc->num_background == fc->congestion_threshold &&
	    fc->bdi_initialized) {
		set_bdi_congested(&fc->bdi, BLK_RW_SYNC);
		set_bdi_congested(&fc->bdi, BLK_RW_ASYNC);
	}
	list_add_tail(&req->list, &fc->bg_queue);
	flush_bg_queue(fc);
}

Project: linux
File: dev.c

static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode,
			 struct fuse_notify_retrieve_out *outarg)
{
	int err;
	struct address_space *mapping = inode->i_mapping;
	struct fuse_req *req;
	pgoff_t index;
	loff_t file_size;
	unsigned int num;
	unsigned int offset;
	size_t total_len = 0;

	req = fuse_get_req(fc);
	if (IS_ERR(req))
		return PTR_ERR(req);

	offset = outarg->offset & ~PAGE_CACHE_MASK;

	req->in.h.opcode = FUSE_NOTIFY_REPLY;
	req->in.h.nodeid = outarg->nodeid;
	req->in.numargs = 2;
	req->in.argpages = 1;
	req->page_offset = offset;
	req->end = fuse_retrieve_end;

	index = outarg->offset >> PAGE_CACHE_SHIFT;
	file_size = i_size_read(inode);
	num = outarg->size;
	if (outarg->offset > file_size)
		num = 0;
	else if (outarg->offset + num > file_size)
		num = file_size - outarg->offset;

	while (num) {
		struct page *page;
		unsigned int this_num;

		page = find_get_page(mapping, index);
		if (!page)
			break;

		this_num = min_t(unsigned, num, PAGE_CACHE_SIZE - offset);
		req->pages[req->num_pages] = page;
		req->num_pages++;

		num -= this_num;
		total_len += this_num;
	}
	req->misc.retrieve_in.offset = outarg->offset;
	req->misc.retrieve_in.size = total_len;
	req->in.args[0].size = sizeof(req->misc.retrieve_in);
	req->in.args[0].value = &req->misc.retrieve_in;
	req->in.args[1].size = total_len;

	err = fuse_request_send_notify_reply(fc, req, outarg->notify_unique);
	if (err)
		fuse_retrieve_end(fc, req);

	return err;
}

Project: linux
File: dev.c

static void fuse_retrieve_end(struct fuse_conn *fc, struct fuse_req *req)
{
	release_pages(req->pages, req->num_pages, 0);
}

Project: linux
File: dev.c

static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep)
{
	int err;
	struct page *oldpage = *pagep;
	struct page *newpage;
	struct pipe_buffer *buf = cs->pipebufs;
	struct address_space *mapping;
	pgoff_t index;

	unlock_request(cs->fc, cs->req);
	fuse_copy_finish(cs);

	err = buf->ops->confirm(cs->pipe, buf);
	if (err)
		return err;

	BUG_ON(!cs->nr_segs);
	cs->currbuf = buf;
	cs->len = buf->len;
	cs->pipebufs++;
	cs->nr_segs--;

	if (cs->len != PAGE_SIZE)
		goto out_fallback;

	if (buf->ops->steal(cs->pipe, buf) != 0)
		goto out_fallback;

	newpage = buf->page;

	if (WARN_ON(!PageUptodate(newpage)))
		return -EIO;

	ClearPageMappedToDisk(newpage);

	if (fuse_check_page(newpage) != 0)
		goto out_fallback_unlock;

	mapping = oldpage->mapping;
	index = oldpage->index;

	/*
	 * This is a new and locked page, it shouldn't be mapped or
	 * have any special flags on it
	 */
	if (WARN_ON(page_mapped(oldpage)))
		goto out_fallback_unlock;
	if (WARN_ON(page_has_private(oldpage)))
		goto out_fallback_unlock;
	if (WARN_ON(PageDirty(oldpage) || PageWriteback(oldpage)))
		goto out_fallback_unlock;
	if (WARN_ON(PageMlocked(oldpage)))
		goto out_fallback_unlock;

	err = replace_page_cache_page(oldpage, newpage, GFP_KERNEL);
	if (err) {
		unlock_page(newpage);
		return err;
	}

	page_cache_get(newpage);

	if (!(buf->flags & PIPE_BUF_FLAG_LRU))
		lru_cache_add_file(newpage);

	err = 0;
	spin_lock(&cs->fc->lock);
	if (cs->req->aborted)
		err = -ENOENT;
	else
		*pagep = newpage;
	spin_unlock(&cs->fc->lock);

	if (err) {
		unlock_page(newpage);
		page_cache_release(newpage);
		return err;
	}

	unlock_page(oldpage);
	page_cache_release(oldpage);
	cs->len = 0;

	return 0;

out_fallback_unlock:
	unlock_page(newpage);
out_fallback:
	cs->mapaddr = buf->ops->map(cs->pipe, buf, 1);
	cs->buf = cs->mapaddr + buf->offset;

	err = lock_request(cs->fc, cs->req);
	if (err)
		return err;

	return 1;
}

Project: linux
File: dev.c

static struct fuse_req *get_reserved_req(struct fuse_conn *fc,
					 struct file *file)
{
	struct fuse_req *req = NULL;
	struct fuse_file *ff = file->private_data;

	do {
		wait_event(fc->reserved_req_waitq, ff->reserved_req);
		spin_lock(&fc->lock);
		if (ff->reserved_req) {
			req = ff->reserved_req;
			ff->reserved_req = NULL;
			get_file(file);
			req->stolen_file = file;
		}
		spin_unlock(&fc->lock);
	} while (!req);

	return req;
}

Project: linux
File: dev.c

static unsigned len_args(unsigned numargs, struct fuse_arg *args)
{
	unsigned nbytes = 0;
	unsigned i;

	for (i = 0; i < numargs; i++)
		nbytes += args[i].size;

	return nbytes;
}

Project: linux
File: dev.c

static int lock_request(struct fuse_conn *fc, struct fuse_req *req)
{
	int err = 0;
	if (req) {
		spin_lock(&fc->lock);
		if (req->aborted)
			err = -ENOENT;
		else
			req->locked = 1;
		spin_unlock(&fc->lock);
	}
	return err;
}

Project: linux
File: dev.c

static void put_reserved_req(struct fuse_conn *fc, struct fuse_req *req)
{
	struct file *file = req->stolen_file;
	struct fuse_file *ff = file->private_data;

	spin_lock(&fc->lock);
	fuse_request_init(req);
	BUG_ON(ff->reserved_req);
	ff->reserved_req = req;
	wake_up_all(&fc->reserved_req_waitq);
	spin_unlock(&fc->lock);
	fput(file);
}

Project: linux
File: dev.c

static void queue_interrupt(struct fuse_conn *fc, struct fuse_req *req)
{
	list_add_tail(&req->intr_entry, &fc->interrupts);
	wake_up(&fc->waitq);
	kill_fasync(&fc->fasync, SIGIO, POLL_IN);
}

Project: linux
File: dev.c

static void queue_request(struct fuse_conn *fc, struct fuse_req *req)
{
	req->in.h.len = sizeof(struct fuse_in_header) +
		len_args(req->in.numargs, (struct fuse_arg *) req->in.args);
	list_add_tail(&req->list, &fc->pending);
	req->state = FUSE_REQ_PENDING;
	if (!req->waiting) {
		req->waiting = 1;
		atomic_inc(&fc->num_waiting);
	}
	wake_up(&fc->waitq);
	kill_fasync(&fc->fasync, SIGIO, POLL_IN);
}

Project: linux
File: dev.c

static struct fuse_req *request_find(struct fuse_conn *fc, u64 unique)
{
	struct list_head *entry;

	list_for_each(entry, &fc->processing) {
		struct fuse_req *req;
		req = list_entry(entry, struct fuse_req, list);
		if (req->in.h.unique == unique || req->intr_unique == unique)
			return req;
	}
	return NULL;
}

Project: linux
File: dev.c

static int request_pending(struct fuse_conn *fc)
{
	return !list_empty(&fc->pending) || !list_empty(&fc->interrupts) ||
		forget_pending(fc);
}

Project: linux
File: dev.c

static void restore_sigs(sigset_t *oldset)
{
	sigprocmask(SIG_SETMASK, oldset, NULL);
}

Project: linux
File: dev.c

static void unlock_request(struct fuse_conn *fc, struct fuse_req *req)
{
	if (req) {
		spin_lock(&fc->lock);
		req->locked = 0;
		if (req->aborted)
			wake_up(&req->waitq);
		spin_unlock(&fc->lock);
	}
}