Commit 9ac29fd3 authored by Miklos Szeredi's avatar Miklos Szeredi
Browse files

fuse: move ioctl to separate source file 



Next patch will expand ioctl code and fuse/file.c is large enough as it is.

Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent 51db776a

fs/fuse/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -7,7 +7,7 @@ obj-$(CONFIG_FUSE_FS) += fuse.o 
obj-$(CONFIG_CUSE) += cuse.o

obj-$(CONFIG_VIRTIO_FS) += virtiofs.o



fuse-y := dev.o dir.o file.o inode.o control.o xattr.o acl.o readdir.o

fuse-y := dev.o dir.o file.o inode.o control.o xattr.o acl.o readdir.o ioctl.o

fuse-$(CONFIG_FUSE_DAX) += dax.o



virtiofs-y := virtio_fs.o

fs/fuse/file.c

+0 −380
Original line number Diff line number Diff line
@@ -14,24 +14,11 @@ 
#include <linux/sched.h>

#include <linux/sched/signal.h>

#include <linux/module.h>

#include <linux/compat.h>

#include <linux/swap.h>

#include <linux/falloc.h>

#include <linux/uio.h>

#include <linux/fs.h>



static struct page **fuse_pages_alloc(unsigned int npages, gfp_t flags,

				      struct fuse_page_desc **desc)

{

	struct page **pages;



	pages = kzalloc(npages * (sizeof(struct page *) +

				  sizeof(struct fuse_page_desc)), flags);

	*desc = (void *) (pages + npages);



	return pages;

}



static int fuse_send_open(struct fuse_mount *fm, u64 nodeid, struct file *file,

			  int opcode, struct fuse_open_out *outargp)

{
@@ -1346,16 +1333,6 @@ static ssize_t fuse_cache_write_iter(struct kiocb *iocb, struct iov_iter *from) 
	return written ? written : err;

}



static inline void fuse_page_descs_length_init(struct fuse_page_desc *descs,

					       unsigned int index,

					       unsigned int nr_pages)

{

	int i;



	for (i = index; i < index + nr_pages; i++)

		descs[i].length = PAGE_SIZE - descs[i].offset;

}



static inline unsigned long fuse_get_user_addr(const struct iov_iter *ii)

{

	return (unsigned long)ii->iov->iov_base + ii->iov_offset;
@@ -2636,363 +2613,6 @@ static loff_t fuse_file_llseek(struct file *file, loff_t offset, int whence) 
	return retval;

}



/*

 * CUSE servers compiled on 32bit broke on 64bit kernels because the

 * ABI was defined to be 'struct iovec' which is different on 32bit

 * and 64bit.  Fortunately we can determine which structure the server

 * used from the size of the reply.

 */

static int fuse_copy_ioctl_iovec_old(struct iovec *dst, void *src,

				     size_t transferred, unsigned count,

				     bool is_compat)

{

#ifdef CONFIG_COMPAT

	if (count * sizeof(struct compat_iovec) == transferred) {

		struct compat_iovec *ciov = src;

		unsigned i;



		/*

		 * With this interface a 32bit server cannot support

		 * non-compat (i.e. ones coming from 64bit apps) ioctl

		 * requests

		 */

		if (!is_compat)

			return -EINVAL;



		for (i = 0; i < count; i++) {

			dst[i].iov_base = compat_ptr(ciov[i].iov_base);

			dst[i].iov_len = ciov[i].iov_len;

		}

		return 0;

	}

#endif



	if (count * sizeof(struct iovec) != transferred)

		return -EIO;



	memcpy(dst, src, transferred);

	return 0;

}



/* Make sure iov_length() won't overflow */

static int fuse_verify_ioctl_iov(struct fuse_conn *fc, struct iovec *iov,

				 size_t count)

{

	size_t n;

	u32 max = fc->max_pages << PAGE_SHIFT;



	for (n = 0; n < count; n++, iov++) {

		if (iov->iov_len > (size_t) max)

			return -ENOMEM;

		max -= iov->iov_len;

	}

	return 0;

}



static int fuse_copy_ioctl_iovec(struct fuse_conn *fc, struct iovec *dst,

				 void *src, size_t transferred, unsigned count,

				 bool is_compat)

{

	unsigned i;

	struct fuse_ioctl_iovec *fiov = src;



	if (fc->minor < 16) {

		return fuse_copy_ioctl_iovec_old(dst, src, transferred,

						 count, is_compat);

	}



	if (count * sizeof(struct fuse_ioctl_iovec) != transferred)

		return -EIO;



	for (i = 0; i < count; i++) {

		/* Did the server supply an inappropriate value? */

		if (fiov[i].base != (unsigned long) fiov[i].base ||

		    fiov[i].len != (unsigned long) fiov[i].len)

			return -EIO;



		dst[i].iov_base = (void __user *) (unsigned long) fiov[i].base;

		dst[i].iov_len = (size_t) fiov[i].len;



#ifdef CONFIG_COMPAT

		if (is_compat &&

		    (ptr_to_compat(dst[i].iov_base) != fiov[i].base ||

		     (compat_size_t) dst[i].iov_len != fiov[i].len))

			return -EIO;

#endif

	}



	return 0;

}





/*

 * For ioctls, there is no generic way to determine how much memory

 * needs to be read and/or written.  Furthermore, ioctls are allowed

 * to dereference the passed pointer, so the parameter requires deep

 * copying but FUSE has no idea whatsoever about what to copy in or

 * out.

 *

 * This is solved by allowing FUSE server to retry ioctl with

 * necessary in/out iovecs.  Let's assume the ioctl implementation

 * needs to read in the following structure.

 *

 * struct a {

 *	char	*buf;

 *	size_t	buflen;

 * }

 *

 * On the first callout to FUSE server, inarg->in_size and

 * inarg->out_size will be NULL; then, the server completes the ioctl

 * with FUSE_IOCTL_RETRY set in out->flags, out->in_iovs set to 1 and

 * the actual iov array to

 *

 * { { .iov_base = inarg.arg,	.iov_len = sizeof(struct a) } }

 *

 * which tells FUSE to copy in the requested area and retry the ioctl.

 * On the second round, the server has access to the structure and

 * from that it can tell what to look for next, so on the invocation,

 * it sets FUSE_IOCTL_RETRY, out->in_iovs to 2 and iov array to

 *

 * { { .iov_base = inarg.arg,	.iov_len = sizeof(struct a)	},

 *   { .iov_base = a.buf,	.iov_len = a.buflen		} }

 *

 * FUSE will copy both struct a and the pointed buffer from the

 * process doing the ioctl and retry ioctl with both struct a and the

 * buffer.

 *

 * This time, FUSE server has everything it needs and completes ioctl

 * without FUSE_IOCTL_RETRY which finishes the ioctl call.

 *

 * Copying data out works the same way.

 *

 * Note that if FUSE_IOCTL_UNRESTRICTED is clear, the kernel

 * automatically initializes in and out iovs by decoding @cmd with

 * _IOC_* macros and the server is not allowed to request RETRY.  This

 * limits ioctl data transfers to well-formed ioctls and is the forced

 * behavior for all FUSE servers.

 */

long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,

		   unsigned int flags)

{

	struct fuse_file *ff = file->private_data;

	struct fuse_mount *fm = ff->fm;

	struct fuse_ioctl_in inarg = {

		.fh = ff->fh,

		.cmd = cmd,

		.arg = arg,

		.flags = flags

	};

	struct fuse_ioctl_out outarg;

	struct iovec *iov_page = NULL;

	struct iovec *in_iov = NULL, *out_iov = NULL;

	unsigned int in_iovs = 0, out_iovs = 0, max_pages;

	size_t in_size, out_size, c;

	ssize_t transferred;

	int err, i;

	struct iov_iter ii;

	struct fuse_args_pages ap = {};



#if BITS_PER_LONG == 32

	inarg.flags |= FUSE_IOCTL_32BIT;

#else

	if (flags & FUSE_IOCTL_COMPAT) {

		inarg.flags |= FUSE_IOCTL_32BIT;

#ifdef CONFIG_X86_X32

		if (in_x32_syscall())

			inarg.flags |= FUSE_IOCTL_COMPAT_X32;

#endif

	}

#endif



	/* assume all the iovs returned by client always fits in a page */

	BUILD_BUG_ON(sizeof(struct fuse_ioctl_iovec) * FUSE_IOCTL_MAX_IOV > PAGE_SIZE);



	err = -ENOMEM;

	ap.pages = fuse_pages_alloc(fm->fc->max_pages, GFP_KERNEL, &ap.descs);

	iov_page = (struct iovec *) __get_free_page(GFP_KERNEL);

	if (!ap.pages || !iov_page)

		goto out;



	fuse_page_descs_length_init(ap.descs, 0, fm->fc->max_pages);



	/*

	 * If restricted, initialize IO parameters as encoded in @cmd.

	 * RETRY from server is not allowed.

	 */

	if (!(flags & FUSE_IOCTL_UNRESTRICTED)) {

		struct iovec *iov = iov_page;



		iov->iov_base = (void __user *)arg;



		switch (cmd) {

		case FS_IOC_GETFLAGS:

		case FS_IOC_SETFLAGS:

			iov->iov_len = sizeof(int);

			break;

		default:

			iov->iov_len = _IOC_SIZE(cmd);

			break;

		}



		if (_IOC_DIR(cmd) & _IOC_WRITE) {

			in_iov = iov;

			in_iovs = 1;

		}



		if (_IOC_DIR(cmd) & _IOC_READ) {

			out_iov = iov;

			out_iovs = 1;

		}

	}



 retry:

	inarg.in_size = in_size = iov_length(in_iov, in_iovs);

	inarg.out_size = out_size = iov_length(out_iov, out_iovs);



	/*

	 * Out data can be used either for actual out data or iovs,

	 * make sure there always is at least one page.

	 */

	out_size = max_t(size_t, out_size, PAGE_SIZE);

	max_pages = DIV_ROUND_UP(max(in_size, out_size), PAGE_SIZE);



	/* make sure there are enough buffer pages and init request with them */

	err = -ENOMEM;

	if (max_pages > fm->fc->max_pages)

		goto out;

	while (ap.num_pages < max_pages) {

		ap.pages[ap.num_pages] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);

		if (!ap.pages[ap.num_pages])

			goto out;

		ap.num_pages++;

	}





	/* okay, let's send it to the client */

	ap.args.opcode = FUSE_IOCTL;

	ap.args.nodeid = ff->nodeid;

	ap.args.in_numargs = 1;

	ap.args.in_args[0].size = sizeof(inarg);

	ap.args.in_args[0].value = &inarg;

	if (in_size) {

		ap.args.in_numargs++;

		ap.args.in_args[1].size = in_size;

		ap.args.in_pages = true;



		err = -EFAULT;

		iov_iter_init(&ii, WRITE, in_iov, in_iovs, in_size);

		for (i = 0; iov_iter_count(&ii) && !WARN_ON(i >= ap.num_pages); i++) {

			c = copy_page_from_iter(ap.pages[i], 0, PAGE_SIZE, &ii);

			if (c != PAGE_SIZE && iov_iter_count(&ii))

				goto out;

		}

	}



	ap.args.out_numargs = 2;

	ap.args.out_args[0].size = sizeof(outarg);

	ap.args.out_args[0].value = &outarg;

	ap.args.out_args[1].size = out_size;

	ap.args.out_pages = true;

	ap.args.out_argvar = true;



	transferred = fuse_simple_request(fm, &ap.args);

	err = transferred;

	if (transferred < 0)

		goto out;



	/* did it ask for retry? */

	if (outarg.flags & FUSE_IOCTL_RETRY) {

		void *vaddr;



		/* no retry if in restricted mode */

		err = -EIO;

		if (!(flags & FUSE_IOCTL_UNRESTRICTED))

			goto out;



		in_iovs = outarg.in_iovs;

		out_iovs = outarg.out_iovs;



		/*

		 * Make sure things are in boundary, separate checks

		 * are to protect against overflow.

		 */

		err = -ENOMEM;

		if (in_iovs > FUSE_IOCTL_MAX_IOV ||

		    out_iovs > FUSE_IOCTL_MAX_IOV ||

		    in_iovs + out_iovs > FUSE_IOCTL_MAX_IOV)

			goto out;



		vaddr = kmap_atomic(ap.pages[0]);

		err = fuse_copy_ioctl_iovec(fm->fc, iov_page, vaddr,

					    transferred, in_iovs + out_iovs,

					    (flags & FUSE_IOCTL_COMPAT) != 0);

		kunmap_atomic(vaddr);

		if (err)

			goto out;



		in_iov = iov_page;

		out_iov = in_iov + in_iovs;



		err = fuse_verify_ioctl_iov(fm->fc, in_iov, in_iovs);

		if (err)

			goto out;



		err = fuse_verify_ioctl_iov(fm->fc, out_iov, out_iovs);

		if (err)

			goto out;



		goto retry;

	}



	err = -EIO;

	if (transferred > inarg.out_size)

		goto out;



	err = -EFAULT;

	iov_iter_init(&ii, READ, out_iov, out_iovs, transferred);

	for (i = 0; iov_iter_count(&ii) && !WARN_ON(i >= ap.num_pages); i++) {

		c = copy_page_to_iter(ap.pages[i], 0, PAGE_SIZE, &ii);

		if (c != PAGE_SIZE && iov_iter_count(&ii))

			goto out;

	}

	err = 0;

 out:

	free_page((unsigned long) iov_page);

	while (ap.num_pages)

		__free_page(ap.pages[--ap.num_pages]);

	kfree(ap.pages);



	return err ? err : outarg.result;

}

EXPORT_SYMBOL_GPL(fuse_do_ioctl);



long fuse_ioctl_common(struct file *file, unsigned int cmd,

		       unsigned long arg, unsigned int flags)

{

	struct inode *inode = file_inode(file);

	struct fuse_conn *fc = get_fuse_conn(inode);



	if (!fuse_allow_current_process(fc))

		return -EACCES;



	if (fuse_is_bad(inode))

		return -EIO;



	return fuse_do_ioctl(file, cmd, arg, flags);

}



static long fuse_file_ioctl(struct file *file, unsigned int cmd,

			    unsigned long arg)

{

	return fuse_ioctl_common(file, cmd, arg, 0);

}



static long fuse_file_compat_ioctl(struct file *file, unsigned int cmd,

				   unsigned long arg)

{

	return fuse_ioctl_common(file, cmd, arg, FUSE_IOCTL_COMPAT);

}



/*

 * All files which have been polled are linked to RB tree

 * fuse_conn->polled_files which is indexed by kh.  Walk the tree and

fs/fuse/fuse_i.h

+27 −0
Original line number Diff line number Diff line
@@ -872,6 +872,28 @@ static inline bool fuse_is_bad(struct inode *inode) 
	return unlikely(test_bit(FUSE_I_BAD, &get_fuse_inode(inode)->state));

}



static inline struct page **fuse_pages_alloc(unsigned int npages, gfp_t flags,

					     struct fuse_page_desc **desc)

{

	struct page **pages;



	pages = kzalloc(npages * (sizeof(struct page *) +

				  sizeof(struct fuse_page_desc)), flags);

	*desc = (void *) (pages + npages);



	return pages;

}



static inline void fuse_page_descs_length_init(struct fuse_page_desc *descs,

					       unsigned int index,

					       unsigned int nr_pages)

{

	int i;



	for (i = index; i < index + nr_pages; i++)

		descs[i].length = PAGE_SIZE - descs[i].offset;

}



/** Device operations */

extern const struct file_operations fuse_dev_operations;
@@ -1214,4 +1236,9 @@ void fuse_dax_inode_cleanup(struct inode *inode); 
bool fuse_dax_check_alignment(struct fuse_conn *fc, unsigned int map_alignment);

void fuse_dax_cancel_work(struct fuse_conn *fc);



/* ioctl.c */

long fuse_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg);

long fuse_file_compat_ioctl(struct file *file, unsigned int cmd,

			    unsigned long arg);



#endif /* _FS_FUSE_I_H */

fs/fuse/ioctl.c

0 → 100644
+366 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

/*

 * Copyright (C) 2017 Red Hat, Inc.

 */



#include "fuse_i.h"



#include <linux/uio.h>

#include <linux/compat.h>

#include <linux/fileattr.h>



/*

 * CUSE servers compiled on 32bit broke on 64bit kernels because the

 * ABI was defined to be 'struct iovec' which is different on 32bit

 * and 64bit.  Fortunately we can determine which structure the server

 * used from the size of the reply.

 */

static int fuse_copy_ioctl_iovec_old(struct iovec *dst, void *src,

				     size_t transferred, unsigned count,

				     bool is_compat)

{

#ifdef CONFIG_COMPAT

	if (count * sizeof(struct compat_iovec) == transferred) {

		struct compat_iovec *ciov = src;

		unsigned i;



		/*

		 * With this interface a 32bit server cannot support

		 * non-compat (i.e. ones coming from 64bit apps) ioctl

		 * requests

		 */

		if (!is_compat)

			return -EINVAL;



		for (i = 0; i < count; i++) {

			dst[i].iov_base = compat_ptr(ciov[i].iov_base);

			dst[i].iov_len = ciov[i].iov_len;

		}

		return 0;

	}

#endif



	if (count * sizeof(struct iovec) != transferred)

		return -EIO;



	memcpy(dst, src, transferred);

	return 0;

}



/* Make sure iov_length() won't overflow */

static int fuse_verify_ioctl_iov(struct fuse_conn *fc, struct iovec *iov,

				 size_t count)

{

	size_t n;

	u32 max = fc->max_pages << PAGE_SHIFT;



	for (n = 0; n < count; n++, iov++) {

		if (iov->iov_len > (size_t) max)

			return -ENOMEM;

		max -= iov->iov_len;

	}

	return 0;

}



static int fuse_copy_ioctl_iovec(struct fuse_conn *fc, struct iovec *dst,

				 void *src, size_t transferred, unsigned count,

				 bool is_compat)

{

	unsigned i;

	struct fuse_ioctl_iovec *fiov = src;



	if (fc->minor < 16) {

		return fuse_copy_ioctl_iovec_old(dst, src, transferred,

						 count, is_compat);

	}



	if (count * sizeof(struct fuse_ioctl_iovec) != transferred)

		return -EIO;



	for (i = 0; i < count; i++) {

		/* Did the server supply an inappropriate value? */

		if (fiov[i].base != (unsigned long) fiov[i].base ||

		    fiov[i].len != (unsigned long) fiov[i].len)

			return -EIO;



		dst[i].iov_base = (void __user *) (unsigned long) fiov[i].base;

		dst[i].iov_len = (size_t) fiov[i].len;



#ifdef CONFIG_COMPAT

		if (is_compat &&

		    (ptr_to_compat(dst[i].iov_base) != fiov[i].base ||

		     (compat_size_t) dst[i].iov_len != fiov[i].len))

			return -EIO;

#endif

	}



	return 0;

}





/*

 * For ioctls, there is no generic way to determine how much memory

 * needs to be read and/or written.  Furthermore, ioctls are allowed

 * to dereference the passed pointer, so the parameter requires deep

 * copying but FUSE has no idea whatsoever about what to copy in or

 * out.

 *

 * This is solved by allowing FUSE server to retry ioctl with

 * necessary in/out iovecs.  Let's assume the ioctl implementation

 * needs to read in the following structure.

 *

 * struct a {

 *	char	*buf;

 *	size_t	buflen;

 * }

 *

 * On the first callout to FUSE server, inarg->in_size and

 * inarg->out_size will be NULL; then, the server completes the ioctl

 * with FUSE_IOCTL_RETRY set in out->flags, out->in_iovs set to 1 and

 * the actual iov array to

 *

 * { { .iov_base = inarg.arg,	.iov_len = sizeof(struct a) } }

 *

 * which tells FUSE to copy in the requested area and retry the ioctl.

 * On the second round, the server has access to the structure and

 * from that it can tell what to look for next, so on the invocation,

 * it sets FUSE_IOCTL_RETRY, out->in_iovs to 2 and iov array to

 *

 * { { .iov_base = inarg.arg,	.iov_len = sizeof(struct a)	},

 *   { .iov_base = a.buf,	.iov_len = a.buflen		} }

 *

 * FUSE will copy both struct a and the pointed buffer from the

 * process doing the ioctl and retry ioctl with both struct a and the

 * buffer.

 *

 * This time, FUSE server has everything it needs and completes ioctl

 * without FUSE_IOCTL_RETRY which finishes the ioctl call.

 *

 * Copying data out works the same way.

 *

 * Note that if FUSE_IOCTL_UNRESTRICTED is clear, the kernel

 * automatically initializes in and out iovs by decoding @cmd with

 * _IOC_* macros and the server is not allowed to request RETRY.  This

 * limits ioctl data transfers to well-formed ioctls and is the forced

 * behavior for all FUSE servers.

 */

long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,

		   unsigned int flags)

{

	struct fuse_file *ff = file->private_data;

	struct fuse_mount *fm = ff->fm;

	struct fuse_ioctl_in inarg = {

		.fh = ff->fh,

		.cmd = cmd,

		.arg = arg,

		.flags = flags

	};

	struct fuse_ioctl_out outarg;

	struct iovec *iov_page = NULL;

	struct iovec *in_iov = NULL, *out_iov = NULL;

	unsigned int in_iovs = 0, out_iovs = 0, max_pages;

	size_t in_size, out_size, c;

	ssize_t transferred;

	int err, i;

	struct iov_iter ii;

	struct fuse_args_pages ap = {};



#if BITS_PER_LONG == 32

	inarg.flags |= FUSE_IOCTL_32BIT;

#else

	if (flags & FUSE_IOCTL_COMPAT) {

		inarg.flags |= FUSE_IOCTL_32BIT;

#ifdef CONFIG_X86_X32

		if (in_x32_syscall())

			inarg.flags |= FUSE_IOCTL_COMPAT_X32;

#endif

	}

#endif



	/* assume all the iovs returned by client always fits in a page */

	BUILD_BUG_ON(sizeof(struct fuse_ioctl_iovec) * FUSE_IOCTL_MAX_IOV > PAGE_SIZE);



	err = -ENOMEM;

	ap.pages = fuse_pages_alloc(fm->fc->max_pages, GFP_KERNEL, &ap.descs);

	iov_page = (struct iovec *) __get_free_page(GFP_KERNEL);

	if (!ap.pages || !iov_page)

		goto out;



	fuse_page_descs_length_init(ap.descs, 0, fm->fc->max_pages);



	/*

	 * If restricted, initialize IO parameters as encoded in @cmd.

	 * RETRY from server is not allowed.

	 */

	if (!(flags & FUSE_IOCTL_UNRESTRICTED)) {

		struct iovec *iov = iov_page;



		iov->iov_base = (void __user *)arg;



		switch (cmd) {

		case FS_IOC_GETFLAGS:

		case FS_IOC_SETFLAGS:

			iov->iov_len = sizeof(int);

			break;

		default:

			iov->iov_len = _IOC_SIZE(cmd);

			break;

		}



		if (_IOC_DIR(cmd) & _IOC_WRITE) {

			in_iov = iov;

			in_iovs = 1;

		}



		if (_IOC_DIR(cmd) & _IOC_READ) {

			out_iov = iov;

			out_iovs = 1;

		}

	}



 retry:

	inarg.in_size = in_size = iov_length(in_iov, in_iovs);

	inarg.out_size = out_size = iov_length(out_iov, out_iovs);



	/*

	 * Out data can be used either for actual out data or iovs,

	 * make sure there always is at least one page.

	 */

	out_size = max_t(size_t, out_size, PAGE_SIZE);

	max_pages = DIV_ROUND_UP(max(in_size, out_size), PAGE_SIZE);



	/* make sure there are enough buffer pages and init request with them */

	err = -ENOMEM;

	if (max_pages > fm->fc->max_pages)

		goto out;

	while (ap.num_pages < max_pages) {

		ap.pages[ap.num_pages] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);

		if (!ap.pages[ap.num_pages])

			goto out;

		ap.num_pages++;

	}





	/* okay, let's send it to the client */

	ap.args.opcode = FUSE_IOCTL;

	ap.args.nodeid = ff->nodeid;

	ap.args.in_numargs = 1;

	ap.args.in_args[0].size = sizeof(inarg);

	ap.args.in_args[0].value = &inarg;

	if (in_size) {

		ap.args.in_numargs++;

		ap.args.in_args[1].size = in_size;

		ap.args.in_pages = true;



		err = -EFAULT;

		iov_iter_init(&ii, WRITE, in_iov, in_iovs, in_size);

		for (i = 0; iov_iter_count(&ii) && !WARN_ON(i >= ap.num_pages); i++) {

			c = copy_page_from_iter(ap.pages[i], 0, PAGE_SIZE, &ii);

			if (c != PAGE_SIZE && iov_iter_count(&ii))

				goto out;

		}

	}



	ap.args.out_numargs = 2;

	ap.args.out_args[0].size = sizeof(outarg);

	ap.args.out_args[0].value = &outarg;

	ap.args.out_args[1].size = out_size;

	ap.args.out_pages = true;

	ap.args.out_argvar = true;



	transferred = fuse_simple_request(fm, &ap.args);

	err = transferred;

	if (transferred < 0)

		goto out;



	/* did it ask for retry? */

	if (outarg.flags & FUSE_IOCTL_RETRY) {

		void *vaddr;



		/* no retry if in restricted mode */

		err = -EIO;

		if (!(flags & FUSE_IOCTL_UNRESTRICTED))

			goto out;



		in_iovs = outarg.in_iovs;

		out_iovs = outarg.out_iovs;



		/*

		 * Make sure things are in boundary, separate checks

		 * are to protect against overflow.

		 */

		err = -ENOMEM;

		if (in_iovs > FUSE_IOCTL_MAX_IOV ||

		    out_iovs > FUSE_IOCTL_MAX_IOV ||

		    in_iovs + out_iovs > FUSE_IOCTL_MAX_IOV)

			goto out;



		vaddr = kmap_atomic(ap.pages[0]);

		err = fuse_copy_ioctl_iovec(fm->fc, iov_page, vaddr,

					    transferred, in_iovs + out_iovs,

					    (flags & FUSE_IOCTL_COMPAT) != 0);

		kunmap_atomic(vaddr);

		if (err)

			goto out;



		in_iov = iov_page;

		out_iov = in_iov + in_iovs;



		err = fuse_verify_ioctl_iov(fm->fc, in_iov, in_iovs);

		if (err)

			goto out;



		err = fuse_verify_ioctl_iov(fm->fc, out_iov, out_iovs);

		if (err)

			goto out;



		goto retry;

	}



	err = -EIO;

	if (transferred > inarg.out_size)

		goto out;



	err = -EFAULT;

	iov_iter_init(&ii, READ, out_iov, out_iovs, transferred);

	for (i = 0; iov_iter_count(&ii) && !WARN_ON(i >= ap.num_pages); i++) {

		c = copy_page_to_iter(ap.pages[i], 0, PAGE_SIZE, &ii);

		if (c != PAGE_SIZE && iov_iter_count(&ii))

			goto out;

	}

	err = 0;

 out:

	free_page((unsigned long) iov_page);

	while (ap.num_pages)

		__free_page(ap.pages[--ap.num_pages]);

	kfree(ap.pages);



	return err ? err : outarg.result;

}

EXPORT_SYMBOL_GPL(fuse_do_ioctl);



long fuse_ioctl_common(struct file *file, unsigned int cmd,

		       unsigned long arg, unsigned int flags)

{

	struct inode *inode = file_inode(file);

	struct fuse_conn *fc = get_fuse_conn(inode);



	if (!fuse_allow_current_process(fc))

		return -EACCES;



	if (fuse_is_bad(inode))

		return -EIO;



	return fuse_do_ioctl(file, cmd, arg, flags);

}



long fuse_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg)

{

	return fuse_ioctl_common(file, cmd, arg, 0);

}



long fuse_file_compat_ioctl(struct file *file, unsigned int cmd,

			    unsigned long arg)

{

	return fuse_ioctl_common(file, cmd, arg, FUSE_IOCTL_COMPAT);

}