file.c 61.9 KB
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/*
  FUSE: Filesystem in Userspace
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  Copyright (C) 2001-2008  Miklos Szeredi <miklos@szeredi.hu>
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  This program can be distributed under the terms of the GNU GPL.
  See the file COPYING.
*/

#include "fuse_i.h"

#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/module.h>
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#include <linux/compat.h>
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#include <linux/swap.h>
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#include <linux/aio.h>
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#include <linux/falloc.h>
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static const struct file_operations fuse_direct_io_file_operations;
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static int fuse_send_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
			  int opcode, struct fuse_open_out *outargp)
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{
	struct fuse_open_in inarg;
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	struct fuse_req *req;
	int err;

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	req = fuse_get_req_nopages(fc);
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	if (IS_ERR(req))
		return PTR_ERR(req);
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	memset(&inarg, 0, sizeof(inarg));
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	inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY);
	if (!fc->atomic_o_trunc)
		inarg.flags &= ~O_TRUNC;
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	req->in.h.opcode = opcode;
	req->in.h.nodeid = nodeid;
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	req->in.numargs = 1;
	req->in.args[0].size = sizeof(inarg);
	req->in.args[0].value = &inarg;
	req->out.numargs = 1;
	req->out.args[0].size = sizeof(*outargp);
	req->out.args[0].value = outargp;
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	fuse_request_send(fc, req);
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	err = req->out.h.error;
	fuse_put_request(fc, req);

	return err;
}

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struct fuse_file *fuse_file_alloc(struct fuse_conn *fc)
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{
	struct fuse_file *ff;
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	ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
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	if (unlikely(!ff))
		return NULL;

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	ff->fc = fc;
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	ff->reserved_req = fuse_request_alloc(0);
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	if (unlikely(!ff->reserved_req)) {
		kfree(ff);
		return NULL;
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	}
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	INIT_LIST_HEAD(&ff->write_entry);
	atomic_set(&ff->count, 0);
	RB_CLEAR_NODE(&ff->polled_node);
	init_waitqueue_head(&ff->poll_wait);

	spin_lock(&fc->lock);
	ff->kh = ++fc->khctr;
	spin_unlock(&fc->lock);

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	return ff;
}

void fuse_file_free(struct fuse_file *ff)
{
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	fuse_request_free(ff->reserved_req);
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	kfree(ff);
}

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struct fuse_file *fuse_file_get(struct fuse_file *ff)
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{
	atomic_inc(&ff->count);
	return ff;
}

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static void fuse_release_async(struct work_struct *work)
{
	struct fuse_req *req;
	struct fuse_conn *fc;
	struct path path;

	req = container_of(work, struct fuse_req, misc.release.work);
	path = req->misc.release.path;
	fc = get_fuse_conn(path.dentry->d_inode);

	fuse_put_request(fc, req);
	path_put(&path);
}

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static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req)
{
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	if (fc->destroy_req) {
		/*
		 * If this is a fuseblk mount, then it's possible that
		 * releasing the path will result in releasing the
		 * super block and sending the DESTROY request.  If
		 * the server is single threaded, this would hang.
		 * For this reason do the path_put() in a separate
		 * thread.
		 */
		atomic_inc(&req->count);
		INIT_WORK(&req->misc.release.work, fuse_release_async);
		schedule_work(&req->misc.release.work);
	} else {
		path_put(&req->misc.release.path);
	}
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}

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static void fuse_file_put(struct fuse_file *ff, bool sync)
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{
	if (atomic_dec_and_test(&ff->count)) {
		struct fuse_req *req = ff->reserved_req;
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		if (sync) {
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			req->background = 0;
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			fuse_request_send(ff->fc, req);
			path_put(&req->misc.release.path);
			fuse_put_request(ff->fc, req);
		} else {
			req->end = fuse_release_end;
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			req->background = 1;
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			fuse_request_send_background(ff->fc, req);
		}
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		kfree(ff);
	}
}

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int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
		 bool isdir)
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{
	struct fuse_open_out outarg;
	struct fuse_file *ff;
	int err;
	int opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;

	ff = fuse_file_alloc(fc);
	if (!ff)
		return -ENOMEM;

	err = fuse_send_open(fc, nodeid, file, opcode, &outarg);
	if (err) {
		fuse_file_free(ff);
		return err;
	}

	if (isdir)
		outarg.open_flags &= ~FOPEN_DIRECT_IO;

	ff->fh = outarg.fh;
	ff->nodeid = nodeid;
	ff->open_flags = outarg.open_flags;
	file->private_data = fuse_file_get(ff);

	return 0;
}
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EXPORT_SYMBOL_GPL(fuse_do_open);
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void fuse_finish_open(struct inode *inode, struct file *file)
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{
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	struct fuse_file *ff = file->private_data;
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	struct fuse_conn *fc = get_fuse_conn(inode);
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	if (ff->open_flags & FOPEN_DIRECT_IO)
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		file->f_op = &fuse_direct_io_file_operations;
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	if (!(ff->open_flags & FOPEN_KEEP_CACHE))
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		invalidate_inode_pages2(inode->i_mapping);
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	if (ff->open_flags & FOPEN_NONSEEKABLE)
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		nonseekable_open(inode, file);
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	if (fc->atomic_o_trunc && (file->f_flags & O_TRUNC)) {
		struct fuse_inode *fi = get_fuse_inode(inode);

		spin_lock(&fc->lock);
		fi->attr_version = ++fc->attr_version;
		i_size_write(inode, 0);
		spin_unlock(&fc->lock);
		fuse_invalidate_attr(inode);
	}
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}

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int fuse_open_common(struct inode *inode, struct file *file, bool isdir)
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{
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	struct fuse_conn *fc = get_fuse_conn(inode);
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	int err;

	err = generic_file_open(inode, file);
	if (err)
		return err;

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	err = fuse_do_open(fc, get_node_id(inode), file, isdir);
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	if (err)
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		return err;
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	fuse_finish_open(inode, file);

	return 0;
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}

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static void fuse_prepare_release(struct fuse_file *ff, int flags, int opcode)
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{
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	struct fuse_conn *fc = ff->fc;
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	struct fuse_req *req = ff->reserved_req;
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	struct fuse_release_in *inarg = &req->misc.release.in;
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	spin_lock(&fc->lock);
	list_del(&ff->write_entry);
	if (!RB_EMPTY_NODE(&ff->polled_node))
		rb_erase(&ff->polled_node, &fc->polled_files);
	spin_unlock(&fc->lock);

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	wake_up_interruptible_all(&ff->poll_wait);
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	inarg->fh = ff->fh;
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	inarg->flags = flags;
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	req->in.h.opcode = opcode;
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	req->in.h.nodeid = ff->nodeid;
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	req->in.numargs = 1;
	req->in.args[0].size = sizeof(struct fuse_release_in);
	req->in.args[0].value = inarg;
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}

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void fuse_release_common(struct file *file, int opcode)
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{
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	struct fuse_file *ff;
	struct fuse_req *req;
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	ff = file->private_data;
	if (unlikely(!ff))
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		return;
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	req = ff->reserved_req;
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	fuse_prepare_release(ff, file->f_flags, opcode);
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	if (ff->flock) {
		struct fuse_release_in *inarg = &req->misc.release.in;
		inarg->release_flags |= FUSE_RELEASE_FLOCK_UNLOCK;
		inarg->lock_owner = fuse_lock_owner_id(ff->fc,
						       (fl_owner_t) file);
	}
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	/* Hold vfsmount and dentry until release is finished */
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	path_get(&file->f_path);
	req->misc.release.path = file->f_path;
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	/*
	 * Normally this will send the RELEASE request, however if
	 * some asynchronous READ or WRITE requests are outstanding,
	 * the sending will be delayed.
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	 *
	 * Make the release synchronous if this is a fuseblk mount,
	 * synchronous RELEASE is allowed (and desirable) in this case
	 * because the server can be trusted not to screw up.
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	 */
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	fuse_file_put(ff, ff->fc->destroy_req != NULL);
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}

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static int fuse_open(struct inode *inode, struct file *file)
{
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	return fuse_open_common(inode, file, false);
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}

static int fuse_release(struct inode *inode, struct file *file)
{
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	fuse_release_common(file, FUSE_RELEASE);

	/* return value is ignored by VFS */
	return 0;
}

void fuse_sync_release(struct fuse_file *ff, int flags)
{
	WARN_ON(atomic_read(&ff->count) > 1);
	fuse_prepare_release(ff, flags, FUSE_RELEASE);
	ff->reserved_req->force = 1;
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	ff->reserved_req->background = 0;
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	fuse_request_send(ff->fc, ff->reserved_req);
	fuse_put_request(ff->fc, ff->reserved_req);
	kfree(ff);
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}
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EXPORT_SYMBOL_GPL(fuse_sync_release);
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/*
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 * Scramble the ID space with XTEA, so that the value of the files_struct
 * pointer is not exposed to userspace.
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 */
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u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id)
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{
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	u32 *k = fc->scramble_key;
	u64 v = (unsigned long) id;
	u32 v0 = v;
	u32 v1 = v >> 32;
	u32 sum = 0;
	int i;

	for (i = 0; i < 32; i++) {
		v0 += ((v1 << 4 ^ v1 >> 5) + v1) ^ (sum + k[sum & 3]);
		sum += 0x9E3779B9;
		v1 += ((v0 << 4 ^ v0 >> 5) + v0) ^ (sum + k[sum>>11 & 3]);
	}

	return (u64) v0 + ((u64) v1 << 32);
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}

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/*
 * Check if page is under writeback
 *
 * This is currently done by walking the list of writepage requests
 * for the inode, which can be pretty inefficient.
 */
static bool fuse_page_is_writeback(struct inode *inode, pgoff_t index)
{
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_inode *fi = get_fuse_inode(inode);
	struct fuse_req *req;
	bool found = false;

	spin_lock(&fc->lock);
	list_for_each_entry(req, &fi->writepages, writepages_entry) {
		pgoff_t curr_index;

		BUG_ON(req->inode != inode);
		curr_index = req->misc.write.in.offset >> PAGE_CACHE_SHIFT;
		if (curr_index == index) {
			found = true;
			break;
		}
	}
	spin_unlock(&fc->lock);

	return found;
}

/*
 * Wait for page writeback to be completed.
 *
 * Since fuse doesn't rely on the VM writeback tracking, this has to
 * use some other means.
 */
static int fuse_wait_on_page_writeback(struct inode *inode, pgoff_t index)
{
	struct fuse_inode *fi = get_fuse_inode(inode);

	wait_event(fi->page_waitq, !fuse_page_is_writeback(inode, index));
	return 0;
}

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static int fuse_flush(struct file *file, fl_owner_t id)
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{
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	struct inode *inode = file_inode(file);
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	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_file *ff = file->private_data;
	struct fuse_req *req;
	struct fuse_flush_in inarg;
	int err;

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	if (is_bad_inode(inode))
		return -EIO;

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	if (fc->no_flush)
		return 0;

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	req = fuse_get_req_nofail_nopages(fc, file);
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	memset(&inarg, 0, sizeof(inarg));
	inarg.fh = ff->fh;
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	inarg.lock_owner = fuse_lock_owner_id(fc, id);
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	req->in.h.opcode = FUSE_FLUSH;
	req->in.h.nodeid = get_node_id(inode);
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(inarg);
	req->in.args[0].value = &inarg;
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	req->force = 1;
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	fuse_request_send(fc, req);
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	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (err == -ENOSYS) {
		fc->no_flush = 1;
		err = 0;
	}
	return err;
}

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/*
 * Wait for all pending writepages on the inode to finish.
 *
 * This is currently done by blocking further writes with FUSE_NOWRITE
 * and waiting for all sent writes to complete.
 *
 * This must be called under i_mutex, otherwise the FUSE_NOWRITE usage
 * could conflict with truncation.
 */
static void fuse_sync_writes(struct inode *inode)
{
	fuse_set_nowrite(inode);
	fuse_release_nowrite(inode);
}

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int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
		      int datasync, int isdir)
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{
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	struct inode *inode = file->f_mapping->host;
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	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_file *ff = file->private_data;
	struct fuse_req *req;
	struct fuse_fsync_in inarg;
	int err;

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	if (is_bad_inode(inode))
		return -EIO;

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	err = filemap_write_and_wait_range(inode->i_mapping, start, end);
	if (err)
		return err;

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	if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
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		return 0;

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	mutex_lock(&inode->i_mutex);

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	/*
	 * Start writeback against all dirty pages of the inode, then
	 * wait for all outstanding writes, before sending the FSYNC
	 * request.
	 */
	err = write_inode_now(inode, 0);
	if (err)
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		goto out;
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	fuse_sync_writes(inode);

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	req = fuse_get_req_nopages(fc);
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	if (IS_ERR(req)) {
		err = PTR_ERR(req);
		goto out;
	}
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	memset(&inarg, 0, sizeof(inarg));
	inarg.fh = ff->fh;
	inarg.fsync_flags = datasync ? 1 : 0;
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	req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
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	req->in.h.nodeid = get_node_id(inode);
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(inarg);
	req->in.args[0].value = &inarg;
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	fuse_request_send(fc, req);
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	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (err == -ENOSYS) {
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		if (isdir)
			fc->no_fsyncdir = 1;
		else
			fc->no_fsync = 1;
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		err = 0;
	}
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out:
	mutex_unlock(&inode->i_mutex);
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	return err;
}

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static int fuse_fsync(struct file *file, loff_t start, loff_t end,
		      int datasync)
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{
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	return fuse_fsync_common(file, start, end, datasync, 0);
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}

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void fuse_read_fill(struct fuse_req *req, struct file *file, loff_t pos,
		    size_t count, int opcode)
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{
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	struct fuse_read_in *inarg = &req->misc.read.in;
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	struct fuse_file *ff = file->private_data;
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	inarg->fh = ff->fh;
	inarg->offset = pos;
	inarg->size = count;
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	inarg->flags = file->f_flags;
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	req->in.h.opcode = opcode;
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	req->in.h.nodeid = ff->nodeid;
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	req->in.numargs = 1;
	req->in.args[0].size = sizeof(struct fuse_read_in);
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	req->in.args[0].value = inarg;
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	req->out.argvar = 1;
	req->out.numargs = 1;
	req->out.args[0].size = count;
}

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static void fuse_release_user_pages(struct fuse_req *req, int write)
{
	unsigned i;

	for (i = 0; i < req->num_pages; i++) {
		struct page *page = req->pages[i];
		if (write)
			set_page_dirty_lock(page);
		put_page(page);
	}
}

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/**
 * In case of short read, the caller sets 'pos' to the position of
 * actual end of fuse request in IO request. Otherwise, if bytes_requested
 * == bytes_transferred or rw == WRITE, the caller sets 'pos' to -1.
 *
 * An example:
 * User requested DIO read of 64K. It was splitted into two 32K fuse requests,
 * both submitted asynchronously. The first of them was ACKed by userspace as
 * fully completed (req->out.args[0].size == 32K) resulting in pos == -1. The
 * second request was ACKed as short, e.g. only 1K was read, resulting in
 * pos == 33K.
 *
 * Thus, when all fuse requests are completed, the minimal non-negative 'pos'
 * will be equal to the length of the longest contiguous fragment of
 * transferred data starting from the beginning of IO request.
 */
static void fuse_aio_complete(struct fuse_io_priv *io, int err, ssize_t pos)
{
	int left;

	spin_lock(&io->lock);
	if (err)
		io->err = io->err ? : err;
	else if (pos >= 0 && (io->bytes < 0 || pos < io->bytes))
		io->bytes = pos;

	left = --io->reqs;
	spin_unlock(&io->lock);

	if (!left) {
		long res;

		if (io->err)
			res = io->err;
		else if (io->bytes >= 0 && io->write)
			res = -EIO;
		else {
			res = io->bytes < 0 ? io->size : io->bytes;

			if (!is_sync_kiocb(io->iocb)) {
				struct path *path = &io->iocb->ki_filp->f_path;
				struct inode *inode = path->dentry->d_inode;
				struct fuse_conn *fc = get_fuse_conn(inode);
				struct fuse_inode *fi = get_fuse_inode(inode);

				spin_lock(&fc->lock);
				fi->attr_version = ++fc->attr_version;
				spin_unlock(&fc->lock);
			}
		}

		aio_complete(io->iocb, res, 0);
		kfree(io);
	}
}

static void fuse_aio_complete_req(struct fuse_conn *fc, struct fuse_req *req)
{
	struct fuse_io_priv *io = req->io;
	ssize_t pos = -1;

	fuse_release_user_pages(req, !io->write);

	if (io->write) {
		if (req->misc.write.in.size != req->misc.write.out.size)
			pos = req->misc.write.in.offset - io->offset +
				req->misc.write.out.size;
	} else {
		if (req->misc.read.in.size != req->out.args[0].size)
			pos = req->misc.read.in.offset - io->offset +
				req->out.args[0].size;
	}

	fuse_aio_complete(io, req->out.h.error, pos);
}

static size_t fuse_async_req_send(struct fuse_conn *fc, struct fuse_req *req,
		size_t num_bytes, struct fuse_io_priv *io)
{
	spin_lock(&io->lock);
	io->size += num_bytes;
	io->reqs++;
	spin_unlock(&io->lock);

	req->io = io;
	req->end = fuse_aio_complete_req;

598
	__fuse_get_request(req);
M
Maxim Patlasov 已提交
599 600 601 602 603
	fuse_request_send_background(fc, req);

	return num_bytes;
}

604
static size_t fuse_send_read(struct fuse_req *req, struct fuse_io_priv *io,
605
			     loff_t pos, size_t count, fl_owner_t owner)
606
{
607
	struct file *file = io->file;
608 609
	struct fuse_file *ff = file->private_data;
	struct fuse_conn *fc = ff->fc;
610

611
	fuse_read_fill(req, file, pos, count, FUSE_READ);
612
	if (owner != NULL) {
613
		struct fuse_read_in *inarg = &req->misc.read.in;
614 615 616 617

		inarg->read_flags |= FUSE_READ_LOCKOWNER;
		inarg->lock_owner = fuse_lock_owner_id(fc, owner);
	}
618 619 620 621

	if (io->async)
		return fuse_async_req_send(fc, req, count, io);

622
	fuse_request_send(fc, req);
623
	return req->out.args[0].size;
624 625
}

626 627 628 629 630 631 632 633 634 635 636 637 638 639
static void fuse_read_update_size(struct inode *inode, loff_t size,
				  u64 attr_ver)
{
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_inode *fi = get_fuse_inode(inode);

	spin_lock(&fc->lock);
	if (attr_ver == fi->attr_version && size < inode->i_size) {
		fi->attr_version = ++fc->attr_version;
		i_size_write(inode, size);
	}
	spin_unlock(&fc->lock);
}

M
Miklos Szeredi 已提交
640 641
static int fuse_readpage(struct file *file, struct page *page)
{
642
	struct fuse_io_priv io = { .async = 0, .file = file };
M
Miklos Szeredi 已提交
643 644
	struct inode *inode = page->mapping->host;
	struct fuse_conn *fc = get_fuse_conn(inode);
645
	struct fuse_req *req;
646 647 648 649
	size_t num_read;
	loff_t pos = page_offset(page);
	size_t count = PAGE_CACHE_SIZE;
	u64 attr_ver;
650 651 652 653 654 655
	int err;

	err = -EIO;
	if (is_bad_inode(inode))
		goto out;

M
Miklos Szeredi 已提交
656
	/*
L
Lucas De Marchi 已提交
657
	 * Page writeback can extend beyond the lifetime of the
M
Miklos Szeredi 已提交
658 659 660 661 662
	 * page-cache page, so make sure we read a properly synced
	 * page.
	 */
	fuse_wait_on_page_writeback(inode, page->index);

M
Maxim Patlasov 已提交
663
	req = fuse_get_req(fc, 1);
664 665
	err = PTR_ERR(req);
	if (IS_ERR(req))
M
Miklos Szeredi 已提交
666 667
		goto out;

668 669
	attr_ver = fuse_get_attr_version(fc);

M
Miklos Szeredi 已提交
670
	req->out.page_zeroing = 1;
671
	req->out.argpages = 1;
M
Miklos Szeredi 已提交
672 673
	req->num_pages = 1;
	req->pages[0] = page;
674
	req->page_descs[0].length = count;
675
	num_read = fuse_send_read(req, &io, pos, count, NULL);
M
Miklos Szeredi 已提交
676 677
	err = req->out.h.error;
	fuse_put_request(fc, req);
678 679 680 681 682 683 684 685

	if (!err) {
		/*
		 * Short read means EOF.  If file size is larger, truncate it
		 */
		if (num_read < count)
			fuse_read_update_size(inode, pos + num_read, attr_ver);

M
Miklos Szeredi 已提交
686
		SetPageUptodate(page);
687 688
	}

689
	fuse_invalidate_attr(inode); /* atime changed */
M
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690 691 692 693 694
 out:
	unlock_page(page);
	return err;
}

695
static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req)
696
{
697
	int i;
698 699
	size_t count = req->misc.read.in.size;
	size_t num_read = req->out.args[0].size;
700
	struct address_space *mapping = NULL;
701

702 703
	for (i = 0; mapping == NULL && i < req->num_pages; i++)
		mapping = req->pages[i]->mapping;
704

705 706 707 708 709 710 711 712 713 714 715 716 717 718 719
	if (mapping) {
		struct inode *inode = mapping->host;

		/*
		 * Short read means EOF. If file size is larger, truncate it
		 */
		if (!req->out.h.error && num_read < count) {
			loff_t pos;

			pos = page_offset(req->pages[0]) + num_read;
			fuse_read_update_size(inode, pos,
					      req->misc.read.attr_ver);
		}
		fuse_invalidate_attr(inode); /* atime changed */
	}
720

721 722 723 724
	for (i = 0; i < req->num_pages; i++) {
		struct page *page = req->pages[i];
		if (!req->out.h.error)
			SetPageUptodate(page);
725 726
		else
			SetPageError(page);
727
		unlock_page(page);
728
		page_cache_release(page);
729
	}
730
	if (req->ff)
731
		fuse_file_put(req->ff, false);
732 733
}

734
static void fuse_send_readpages(struct fuse_req *req, struct file *file)
735
{
736 737
	struct fuse_file *ff = file->private_data;
	struct fuse_conn *fc = ff->fc;
738 739
	loff_t pos = page_offset(req->pages[0]);
	size_t count = req->num_pages << PAGE_CACHE_SHIFT;
740 741

	req->out.argpages = 1;
742
	req->out.page_zeroing = 1;
743
	req->out.page_replace = 1;
744
	fuse_read_fill(req, file, pos, count, FUSE_READ);
745
	req->misc.read.attr_ver = fuse_get_attr_version(fc);
746
	if (fc->async_read) {
747
		req->ff = fuse_file_get(ff);
748
		req->end = fuse_readpages_end;
749
		fuse_request_send_background(fc, req);
750
	} else {
751
		fuse_request_send(fc, req);
752
		fuse_readpages_end(fc, req);
753
		fuse_put_request(fc, req);
754
	}
755 756
}

757
struct fuse_fill_data {
758
	struct fuse_req *req;
759
	struct file *file;
760
	struct inode *inode;
M
Maxim Patlasov 已提交
761
	unsigned nr_pages;
762 763 764 765
};

static int fuse_readpages_fill(void *_data, struct page *page)
{
766
	struct fuse_fill_data *data = _data;
767 768 769 770
	struct fuse_req *req = data->req;
	struct inode *inode = data->inode;
	struct fuse_conn *fc = get_fuse_conn(inode);

M
Miklos Szeredi 已提交
771 772
	fuse_wait_on_page_writeback(inode, page->index);

773 774 775 776
	if (req->num_pages &&
	    (req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
	     (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
	     req->pages[req->num_pages - 1]->index + 1 != page->index)) {
M
Maxim Patlasov 已提交
777 778
		int nr_alloc = min_t(unsigned, data->nr_pages,
				     FUSE_MAX_PAGES_PER_REQ);
779
		fuse_send_readpages(req, data->file);
780 781 782 783 784 785
		if (fc->async_read)
			req = fuse_get_req_for_background(fc, nr_alloc);
		else
			req = fuse_get_req(fc, nr_alloc);

		data->req = req;
786
		if (IS_ERR(req)) {
787
			unlock_page(page);
788
			return PTR_ERR(req);
789 790
		}
	}
M
Maxim Patlasov 已提交
791 792 793 794 795 796

	if (WARN_ON(req->num_pages >= req->max_pages)) {
		fuse_put_request(fc, req);
		return -EIO;
	}

797
	page_cache_get(page);
798
	req->pages[req->num_pages] = page;
799
	req->page_descs[req->num_pages].length = PAGE_SIZE;
M
Miklos Szeredi 已提交
800
	req->num_pages++;
M
Maxim Patlasov 已提交
801
	data->nr_pages--;
802 803 804 805 806 807 808 809
	return 0;
}

static int fuse_readpages(struct file *file, struct address_space *mapping,
			  struct list_head *pages, unsigned nr_pages)
{
	struct inode *inode = mapping->host;
	struct fuse_conn *fc = get_fuse_conn(inode);
810
	struct fuse_fill_data data;
811
	int err;
M
Maxim Patlasov 已提交
812
	int nr_alloc = min_t(unsigned, nr_pages, FUSE_MAX_PAGES_PER_REQ);
813

814
	err = -EIO;
815
	if (is_bad_inode(inode))
816
		goto out;
817

818
	data.file = file;
819
	data.inode = inode;
820 821 822 823
	if (fc->async_read)
		data.req = fuse_get_req_for_background(fc, nr_alloc);
	else
		data.req = fuse_get_req(fc, nr_alloc);
M
Maxim Patlasov 已提交
824
	data.nr_pages = nr_pages;
825
	err = PTR_ERR(data.req);
826
	if (IS_ERR(data.req))
827
		goto out;
828 829

	err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
830 831
	if (!err) {
		if (data.req->num_pages)
832
			fuse_send_readpages(data.req, file);
833 834 835
		else
			fuse_put_request(fc, data.req);
	}
836
out:
837
	return err;
838 839
}

M
Miklos Szeredi 已提交
840 841 842 843
static ssize_t fuse_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
				  unsigned long nr_segs, loff_t pos)
{
	struct inode *inode = iocb->ki_filp->f_mapping->host;
844
	struct fuse_conn *fc = get_fuse_conn(inode);
M
Miklos Szeredi 已提交
845

846 847 848 849 850 851 852
	/*
	 * In auto invalidate mode, always update attributes on read.
	 * Otherwise, only update if we attempt to read past EOF (to ensure
	 * i_size is up to date).
	 */
	if (fc->auto_inval_data ||
	    (pos + iov_length(iov, nr_segs) > i_size_read(inode))) {
M
Miklos Szeredi 已提交
853 854 855 856 857 858 859 860 861
		int err;
		err = fuse_update_attributes(inode, NULL, iocb->ki_filp, NULL);
		if (err)
			return err;
	}

	return generic_file_aio_read(iocb, iov, nr_segs, pos);
}

862
static void fuse_write_fill(struct fuse_req *req, struct fuse_file *ff,
863
			    loff_t pos, size_t count)
M
Miklos Szeredi 已提交
864
{
865 866
	struct fuse_write_in *inarg = &req->misc.write.in;
	struct fuse_write_out *outarg = &req->misc.write.out;
M
Miklos Szeredi 已提交
867

868 869 870
	inarg->fh = ff->fh;
	inarg->offset = pos;
	inarg->size = count;
M
Miklos Szeredi 已提交
871
	req->in.h.opcode = FUSE_WRITE;
872
	req->in.h.nodeid = ff->nodeid;
M
Miklos Szeredi 已提交
873
	req->in.numargs = 2;
874
	if (ff->fc->minor < 9)
875 876 877
		req->in.args[0].size = FUSE_COMPAT_WRITE_IN_SIZE;
	else
		req->in.args[0].size = sizeof(struct fuse_write_in);
878
	req->in.args[0].value = inarg;
M
Miklos Szeredi 已提交
879 880 881
	req->in.args[1].size = count;
	req->out.numargs = 1;
	req->out.args[0].size = sizeof(struct fuse_write_out);
882 883 884
	req->out.args[0].value = outarg;
}

885
static size_t fuse_send_write(struct fuse_req *req, struct fuse_io_priv *io,
886
			      loff_t pos, size_t count, fl_owner_t owner)
887
{
888
	struct file *file = io->file;
889 890
	struct fuse_file *ff = file->private_data;
	struct fuse_conn *fc = ff->fc;
891 892
	struct fuse_write_in *inarg = &req->misc.write.in;

893
	fuse_write_fill(req, ff, pos, count);
894
	inarg->flags = file->f_flags;
895 896 897 898
	if (owner != NULL) {
		inarg->write_flags |= FUSE_WRITE_LOCKOWNER;
		inarg->lock_owner = fuse_lock_owner_id(fc, owner);
	}
899 900 901 902

	if (io->async)
		return fuse_async_req_send(fc, req, count, io);

903
	fuse_request_send(fc, req);
904
	return req->misc.write.out.size;
M
Miklos Szeredi 已提交
905 906
}

M
Miklos Szeredi 已提交
907
void fuse_write_update_size(struct inode *inode, loff_t pos)
908 909 910 911 912 913 914 915 916 917 918
{
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_inode *fi = get_fuse_inode(inode);

	spin_lock(&fc->lock);
	fi->attr_version = ++fc->attr_version;
	if (pos > inode->i_size)
		i_size_write(inode, pos);
	spin_unlock(&fc->lock);
}

N
Nick Piggin 已提交
919 920 921 922 923 924 925
static size_t fuse_send_write_pages(struct fuse_req *req, struct file *file,
				    struct inode *inode, loff_t pos,
				    size_t count)
{
	size_t res;
	unsigned offset;
	unsigned i;
926
	struct fuse_io_priv io = { .async = 0, .file = file };
N
Nick Piggin 已提交
927 928 929 930

	for (i = 0; i < req->num_pages; i++)
		fuse_wait_on_page_writeback(inode, req->pages[i]->index);

931
	res = fuse_send_write(req, &io, pos, count, NULL);
N
Nick Piggin 已提交
932

933
	offset = req->page_descs[0].offset;
N
Nick Piggin 已提交
934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962
	count = res;
	for (i = 0; i < req->num_pages; i++) {
		struct page *page = req->pages[i];

		if (!req->out.h.error && !offset && count >= PAGE_CACHE_SIZE)
			SetPageUptodate(page);

		if (count > PAGE_CACHE_SIZE - offset)
			count -= PAGE_CACHE_SIZE - offset;
		else
			count = 0;
		offset = 0;

		unlock_page(page);
		page_cache_release(page);
	}

	return res;
}

static ssize_t fuse_fill_write_pages(struct fuse_req *req,
			       struct address_space *mapping,
			       struct iov_iter *ii, loff_t pos)
{
	struct fuse_conn *fc = get_fuse_conn(mapping->host);
	unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
	size_t count = 0;
	int err;

963
	req->in.argpages = 1;
964
	req->page_descs[0].offset = offset;
N
Nick Piggin 已提交
965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980

	do {
		size_t tmp;
		struct page *page;
		pgoff_t index = pos >> PAGE_CACHE_SHIFT;
		size_t bytes = min_t(size_t, PAGE_CACHE_SIZE - offset,
				     iov_iter_count(ii));

		bytes = min_t(size_t, bytes, fc->max_write - count);

 again:
		err = -EFAULT;
		if (iov_iter_fault_in_readable(ii, bytes))
			break;

		err = -ENOMEM;
981
		page = grab_cache_page_write_begin(mapping, index, 0);
N
Nick Piggin 已提交
982 983 984
		if (!page)
			break;

985 986 987
		if (mapping_writably_mapped(mapping))
			flush_dcache_page(page);

N
Nick Piggin 已提交
988 989 990 991 992
		pagefault_disable();
		tmp = iov_iter_copy_from_user_atomic(page, ii, offset, bytes);
		pagefault_enable();
		flush_dcache_page(page);

993 994
		mark_page_accessed(page);

N
Nick Piggin 已提交
995 996 997 998 999 1000 1001 1002 1003
		if (!tmp) {
			unlock_page(page);
			page_cache_release(page);
			bytes = min(bytes, iov_iter_single_seg_count(ii));
			goto again;
		}

		err = 0;
		req->pages[req->num_pages] = page;
1004
		req->page_descs[req->num_pages].length = tmp;
N
Nick Piggin 已提交
1005 1006 1007 1008 1009 1010 1011 1012 1013
		req->num_pages++;

		iov_iter_advance(ii, tmp);
		count += tmp;
		pos += tmp;
		offset += tmp;
		if (offset == PAGE_CACHE_SIZE)
			offset = 0;

1014 1015
		if (!fc->big_writes)
			break;
N
Nick Piggin 已提交
1016
	} while (iov_iter_count(ii) && count < fc->max_write &&
1017
		 req->num_pages < req->max_pages && offset == 0);
N
Nick Piggin 已提交
1018 1019 1020 1021

	return count > 0 ? count : err;
}

1022 1023 1024 1025 1026 1027 1028 1029
static inline unsigned fuse_wr_pages(loff_t pos, size_t len)
{
	return min_t(unsigned,
		     ((pos + len - 1) >> PAGE_CACHE_SHIFT) -
		     (pos >> PAGE_CACHE_SHIFT) + 1,
		     FUSE_MAX_PAGES_PER_REQ);
}

N
Nick Piggin 已提交
1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044
static ssize_t fuse_perform_write(struct file *file,
				  struct address_space *mapping,
				  struct iov_iter *ii, loff_t pos)
{
	struct inode *inode = mapping->host;
	struct fuse_conn *fc = get_fuse_conn(inode);
	int err = 0;
	ssize_t res = 0;

	if (is_bad_inode(inode))
		return -EIO;

	do {
		struct fuse_req *req;
		ssize_t count;
1045
		unsigned nr_pages = fuse_wr_pages(pos, iov_iter_count(ii));
N
Nick Piggin 已提交
1046

1047
		req = fuse_get_req(fc, nr_pages);
N
Nick Piggin 已提交
1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087
		if (IS_ERR(req)) {
			err = PTR_ERR(req);
			break;
		}

		count = fuse_fill_write_pages(req, mapping, ii, pos);
		if (count <= 0) {
			err = count;
		} else {
			size_t num_written;

			num_written = fuse_send_write_pages(req, file, inode,
							    pos, count);
			err = req->out.h.error;
			if (!err) {
				res += num_written;
				pos += num_written;

				/* break out of the loop on short write */
				if (num_written != count)
					err = -EIO;
			}
		}
		fuse_put_request(fc, req);
	} while (!err && iov_iter_count(ii));

	if (res > 0)
		fuse_write_update_size(inode, pos);

	fuse_invalidate_attr(inode);

	return res > 0 ? res : err;
}

static ssize_t fuse_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
				   unsigned long nr_segs, loff_t pos)
{
	struct file *file = iocb->ki_filp;
	struct address_space *mapping = file->f_mapping;
	size_t count = 0;
A
Anand Avati 已提交
1088
	size_t ocount = 0;
N
Nick Piggin 已提交
1089
	ssize_t written = 0;
A
Anand Avati 已提交
1090
	ssize_t written_buffered = 0;
N
Nick Piggin 已提交
1091 1092 1093
	struct inode *inode = mapping->host;
	ssize_t err;
	struct iov_iter i;
A
Anand Avati 已提交
1094
	loff_t endbyte = 0;
N
Nick Piggin 已提交
1095 1096 1097

	WARN_ON(iocb->ki_pos != pos);

A
Anand Avati 已提交
1098 1099
	ocount = 0;
	err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ);
N
Nick Piggin 已提交
1100 1101 1102
	if (err)
		return err;

A
Anand Avati 已提交
1103
	count = ocount;
N
Nick Piggin 已提交
1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115
	mutex_lock(&inode->i_mutex);

	/* We can write back this queue in page reclaim */
	current->backing_dev_info = mapping->backing_dev_info;

	err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
	if (err)
		goto out;

	if (count == 0)
		goto out;

1116
	err = file_remove_suid(file);
N
Nick Piggin 已提交
1117 1118 1119
	if (err)
		goto out;

1120 1121 1122
	err = file_update_time(file);
	if (err)
		goto out;
N
Nick Piggin 已提交
1123

A
Anand Avati 已提交
1124 1125 1126 1127 1128 1129 1130 1131 1132
	if (file->f_flags & O_DIRECT) {
		written = generic_file_direct_write(iocb, iov, &nr_segs,
						    pos, &iocb->ki_pos,
						    count, ocount);
		if (written < 0 || written == count)
			goto out;

		pos += written;
		count -= written;
N
Nick Piggin 已提交
1133

A
Anand Avati 已提交
1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158
		iov_iter_init(&i, iov, nr_segs, count, written);
		written_buffered = fuse_perform_write(file, mapping, &i, pos);
		if (written_buffered < 0) {
			err = written_buffered;
			goto out;
		}
		endbyte = pos + written_buffered - 1;

		err = filemap_write_and_wait_range(file->f_mapping, pos,
						   endbyte);
		if (err)
			goto out;

		invalidate_mapping_pages(file->f_mapping,
					 pos >> PAGE_CACHE_SHIFT,
					 endbyte >> PAGE_CACHE_SHIFT);

		written += written_buffered;
		iocb->ki_pos = pos + written_buffered;
	} else {
		iov_iter_init(&i, iov, nr_segs, count, 0);
		written = fuse_perform_write(file, mapping, &i, pos);
		if (written >= 0)
			iocb->ki_pos = pos + written;
	}
N
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1159 1160 1161 1162 1163 1164 1165
out:
	current->backing_dev_info = NULL;
	mutex_unlock(&inode->i_mutex);

	return written ? written : err;
}

1166 1167
static inline void fuse_page_descs_length_init(struct fuse_req *req,
		unsigned index, unsigned nr_pages)
1168 1169 1170
{
	int i;

1171
	for (i = index; i < index + nr_pages; i++)
1172 1173 1174 1175
		req->page_descs[i].length = PAGE_SIZE -
			req->page_descs[i].offset;
}

1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186
static inline unsigned long fuse_get_user_addr(const struct iov_iter *ii)
{
	return (unsigned long)ii->iov->iov_base + ii->iov_offset;
}

static inline size_t fuse_get_frag_size(const struct iov_iter *ii,
					size_t max_size)
{
	return min(iov_iter_single_seg_count(ii), max_size);
}

1187
static int fuse_get_user_pages(struct fuse_req *req, struct iov_iter *ii,
1188
			       size_t *nbytesp, int write)
M
Miklos Szeredi 已提交
1189
{
1190
	size_t nbytes = 0;  /* # bytes already packed in req */
1191

1192 1193
	/* Special case for kernel I/O: can copy directly into the buffer */
	if (segment_eq(get_fs(), KERNEL_DS)) {
1194 1195 1196
		unsigned long user_addr = fuse_get_user_addr(ii);
		size_t frag_size = fuse_get_frag_size(ii, *nbytesp);

1197 1198 1199 1200 1201
		if (write)
			req->in.args[1].value = (void *) user_addr;
		else
			req->out.args[0].value = (void *) user_addr;

1202 1203
		iov_iter_advance(ii, frag_size);
		*nbytesp = frag_size;
1204 1205
		return 0;
	}
M
Miklos Szeredi 已提交
1206

1207
	while (nbytes < *nbytesp && req->num_pages < req->max_pages) {
1208 1209 1210 1211 1212
		unsigned npages;
		unsigned long user_addr = fuse_get_user_addr(ii);
		unsigned offset = user_addr & ~PAGE_MASK;
		size_t frag_size = fuse_get_frag_size(ii, *nbytesp - nbytes);
		int ret;
M
Miklos Szeredi 已提交
1213

1214
		unsigned n = req->max_pages - req->num_pages;
1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238
		frag_size = min_t(size_t, frag_size, n << PAGE_SHIFT);

		npages = (frag_size + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
		npages = clamp(npages, 1U, n);

		ret = get_user_pages_fast(user_addr, npages, !write,
					  &req->pages[req->num_pages]);
		if (ret < 0)
			return ret;

		npages = ret;
		frag_size = min_t(size_t, frag_size,
				  (npages << PAGE_SHIFT) - offset);
		iov_iter_advance(ii, frag_size);

		req->page_descs[req->num_pages].offset = offset;
		fuse_page_descs_length_init(req, req->num_pages, npages);

		req->num_pages += npages;
		req->page_descs[req->num_pages - 1].length -=
			(npages << PAGE_SHIFT) - offset - frag_size;

		nbytes += frag_size;
	}
1239 1240 1241 1242 1243 1244

	if (write)
		req->in.argpages = 1;
	else
		req->out.argpages = 1;

1245
	*nbytesp = nbytes;
1246

M
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1247 1248 1249
	return 0;
}

1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266
static inline int fuse_iter_npages(const struct iov_iter *ii_p)
{
	struct iov_iter ii = *ii_p;
	int npages = 0;

	while (iov_iter_count(&ii) && npages < FUSE_MAX_PAGES_PER_REQ) {
		unsigned long user_addr = fuse_get_user_addr(&ii);
		unsigned offset = user_addr & ~PAGE_MASK;
		size_t frag_size = iov_iter_single_seg_count(&ii);

		npages += (frag_size + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
		iov_iter_advance(&ii, frag_size);
	}

	return min(npages, FUSE_MAX_PAGES_PER_REQ);
}

1267
ssize_t fuse_direct_io(struct fuse_io_priv *io, const struct iovec *iov,
M
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1268 1269
		       unsigned long nr_segs, size_t count, loff_t *ppos,
		       int write)
M
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1270
{
1271
	struct file *file = io->file;
1272 1273
	struct fuse_file *ff = file->private_data;
	struct fuse_conn *fc = ff->fc;
M
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1274 1275 1276
	size_t nmax = write ? fc->max_write : fc->max_read;
	loff_t pos = *ppos;
	ssize_t res = 0;
1277
	struct fuse_req *req;
1278 1279 1280
	struct iov_iter ii;

	iov_iter_init(&ii, iov, nr_segs, count, 0);
1281

1282 1283 1284 1285
	if (io->async)
		req = fuse_get_req_for_background(fc, fuse_iter_npages(&ii));
	else
		req = fuse_get_req(fc, fuse_iter_npages(&ii));
1286 1287
	if (IS_ERR(req))
		return PTR_ERR(req);
M
Miklos Szeredi 已提交
1288 1289 1290

	while (count) {
		size_t nres;
1291
		fl_owner_t owner = current->files;
1292
		size_t nbytes = min(count, nmax);
1293
		int err = fuse_get_user_pages(req, &ii, &nbytes, write);
M
Miklos Szeredi 已提交
1294 1295 1296 1297
		if (err) {
			res = err;
			break;
		}
1298

M
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1299
		if (write)
1300
			nres = fuse_send_write(req, io, pos, nbytes, owner);
M
Miklos Szeredi 已提交
1301
		else
1302
			nres = fuse_send_read(req, io, pos, nbytes, owner);
1303

1304 1305
		if (!io->async)
			fuse_release_user_pages(req, !write);
M
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1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318
		if (req->out.h.error) {
			if (!res)
				res = req->out.h.error;
			break;
		} else if (nres > nbytes) {
			res = -EIO;
			break;
		}
		count -= nres;
		res += nres;
		pos += nres;
		if (nres != nbytes)
			break;
1319 1320
		if (count) {
			fuse_put_request(fc, req);
1321 1322 1323 1324 1325
			if (io->async)
				req = fuse_get_req_for_background(fc,
					fuse_iter_npages(&ii));
			else
				req = fuse_get_req(fc, fuse_iter_npages(&ii));
1326 1327 1328
			if (IS_ERR(req))
				break;
		}
M
Miklos Szeredi 已提交
1329
	}
1330 1331
	if (!IS_ERR(req))
		fuse_put_request(fc, req);
1332
	if (res > 0)
M
Miklos Szeredi 已提交
1333 1334 1335 1336
		*ppos = pos;

	return res;
}
1337
EXPORT_SYMBOL_GPL(fuse_direct_io);
M
Miklos Szeredi 已提交
1338

1339 1340
static ssize_t __fuse_direct_read(struct fuse_io_priv *io,
				  const struct iovec *iov,
1341 1342
				  unsigned long nr_segs, loff_t *ppos,
				  size_t count)
M
Miklos Szeredi 已提交
1343
{
1344
	ssize_t res;
1345
	struct file *file = io->file;
A
Al Viro 已提交
1346
	struct inode *inode = file_inode(file);
1347 1348 1349 1350

	if (is_bad_inode(inode))
		return -EIO;

1351
	res = fuse_direct_io(io, iov, nr_segs, count, ppos, 0);
1352 1353 1354 1355

	fuse_invalidate_attr(inode);

	return res;
M
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1356 1357
}

1358 1359 1360
static ssize_t fuse_direct_read(struct file *file, char __user *buf,
				     size_t count, loff_t *ppos)
{
1361
	struct fuse_io_priv io = { .async = 0, .file = file };
M
Miklos Szeredi 已提交
1362
	struct iovec iov = { .iov_base = buf, .iov_len = count };
1363
	return __fuse_direct_read(&io, &iov, 1, ppos, count);
1364 1365
}

1366 1367
static ssize_t __fuse_direct_write(struct fuse_io_priv *io,
				   const struct iovec *iov,
1368
				   unsigned long nr_segs, loff_t *ppos)
M
Miklos Szeredi 已提交
1369
{
1370
	struct file *file = io->file;
A
Al Viro 已提交
1371
	struct inode *inode = file_inode(file);
1372
	size_t count = iov_length(iov, nr_segs);
M
Miklos Szeredi 已提交
1373
	ssize_t res;
1374

1375
	res = generic_write_checks(file, ppos, &count, 0);
1376
	if (!res)
1377
		res = fuse_direct_io(io, iov, nr_segs, count, ppos, 1);
1378 1379 1380

	fuse_invalidate_attr(inode);

M
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1381 1382 1383
	return res;
}

A
Anand Avati 已提交
1384 1385 1386
static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
				 size_t count, loff_t *ppos)
{
M
Miklos Szeredi 已提交
1387
	struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = count };
A
Al Viro 已提交
1388
	struct inode *inode = file_inode(file);
A
Anand Avati 已提交
1389
	ssize_t res;
1390
	struct fuse_io_priv io = { .async = 0, .file = file };
A
Anand Avati 已提交
1391 1392 1393 1394 1395 1396

	if (is_bad_inode(inode))
		return -EIO;

	/* Don't allow parallel writes to the same file */
	mutex_lock(&inode->i_mutex);
1397
	res = __fuse_direct_write(&io, &iov, 1, ppos);
1398 1399
	if (res > 0)
		fuse_write_update_size(inode, *ppos);
A
Anand Avati 已提交
1400 1401 1402 1403 1404
	mutex_unlock(&inode->i_mutex);

	return res;
}

M
Miklos Szeredi 已提交
1405
static void fuse_writepage_free(struct fuse_conn *fc, struct fuse_req *req)
M
Miklos Szeredi 已提交
1406
{
M
Miklos Szeredi 已提交
1407
	__free_page(req->pages[0]);
1408
	fuse_file_put(req->ff, false);
M
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1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425
}

static void fuse_writepage_finish(struct fuse_conn *fc, struct fuse_req *req)
{
	struct inode *inode = req->inode;
	struct fuse_inode *fi = get_fuse_inode(inode);
	struct backing_dev_info *bdi = inode->i_mapping->backing_dev_info;

	list_del(&req->writepages_entry);
	dec_bdi_stat(bdi, BDI_WRITEBACK);
	dec_zone_page_state(req->pages[0], NR_WRITEBACK_TEMP);
	bdi_writeout_inc(bdi);
	wake_up(&fi->page_waitq);
}

/* Called under fc->lock, may release and reacquire it */
static void fuse_send_writepage(struct fuse_conn *fc, struct fuse_req *req)
M
Miklos Szeredi 已提交
1426 1427
__releases(fc->lock)
__acquires(fc->lock)
M
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1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442
{
	struct fuse_inode *fi = get_fuse_inode(req->inode);
	loff_t size = i_size_read(req->inode);
	struct fuse_write_in *inarg = &req->misc.write.in;

	if (!fc->connected)
		goto out_free;

	if (inarg->offset + PAGE_CACHE_SIZE <= size) {
		inarg->size = PAGE_CACHE_SIZE;
	} else if (inarg->offset < size) {
		inarg->size = size & (PAGE_CACHE_SIZE - 1);
	} else {
		/* Got truncated off completely */
		goto out_free;
M
Miklos Szeredi 已提交
1443
	}
M
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1444 1445 1446

	req->in.args[1].size = inarg->size;
	fi->writectr++;
1447
	fuse_request_send_background_locked(fc, req);
M
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1448 1449 1450 1451 1452 1453
	return;

 out_free:
	fuse_writepage_finish(fc, req);
	spin_unlock(&fc->lock);
	fuse_writepage_free(fc, req);
1454
	fuse_put_request(fc, req);
M
Miklos Szeredi 已提交
1455
	spin_lock(&fc->lock);
M
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1456 1457
}

M
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1458 1459 1460 1461 1462 1463 1464
/*
 * If fi->writectr is positive (no truncate or fsync going on) send
 * all queued writepage requests.
 *
 * Called with fc->lock
 */
void fuse_flush_writepages(struct inode *inode)
M
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1465 1466
__releases(fc->lock)
__acquires(fc->lock)
M
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1467
{
M
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1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_inode *fi = get_fuse_inode(inode);
	struct fuse_req *req;

	while (fi->writectr >= 0 && !list_empty(&fi->queued_writes)) {
		req = list_entry(fi->queued_writes.next, struct fuse_req, list);
		list_del_init(&req->list);
		fuse_send_writepage(fc, req);
	}
}

static void fuse_writepage_end(struct fuse_conn *fc, struct fuse_req *req)
{
	struct inode *inode = req->inode;
	struct fuse_inode *fi = get_fuse_inode(inode);

	mapping_set_error(inode->i_mapping, req->out.h.error);
	spin_lock(&fc->lock);
	fi->writectr--;
	fuse_writepage_finish(fc, req);
	spin_unlock(&fc->lock);
	fuse_writepage_free(fc, req);
}

static int fuse_writepage_locked(struct page *page)
{
	struct address_space *mapping = page->mapping;
	struct inode *inode = mapping->host;
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_inode *fi = get_fuse_inode(inode);
	struct fuse_req *req;
	struct fuse_file *ff;
	struct page *tmp_page;

	set_page_writeback(page);

1504
	req = fuse_request_alloc_nofs(1);
M
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1505 1506 1507
	if (!req)
		goto err;

1508
	req->background = 1; /* writeback always goes to bg_queue */
M
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1509 1510 1511 1512 1513 1514 1515 1516 1517 1518
	tmp_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
	if (!tmp_page)
		goto err_free;

	spin_lock(&fc->lock);
	BUG_ON(list_empty(&fi->write_files));
	ff = list_entry(fi->write_files.next, struct fuse_file, write_entry);
	req->ff = fuse_file_get(ff);
	spin_unlock(&fc->lock);

1519
	fuse_write_fill(req, ff, page_offset(page), 0);
M
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1520 1521

	copy_highpage(tmp_page, page);
1522
	req->misc.write.in.write_flags |= FUSE_WRITE_CACHE;
1523
	req->in.argpages = 1;
M
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1524 1525
	req->num_pages = 1;
	req->pages[0] = tmp_page;
1526
	req->page_descs[0].offset = 0;
1527
	req->page_descs[0].length = PAGE_SIZE;
M
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1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595
	req->end = fuse_writepage_end;
	req->inode = inode;

	inc_bdi_stat(mapping->backing_dev_info, BDI_WRITEBACK);
	inc_zone_page_state(tmp_page, NR_WRITEBACK_TEMP);
	end_page_writeback(page);

	spin_lock(&fc->lock);
	list_add(&req->writepages_entry, &fi->writepages);
	list_add_tail(&req->list, &fi->queued_writes);
	fuse_flush_writepages(inode);
	spin_unlock(&fc->lock);

	return 0;

err_free:
	fuse_request_free(req);
err:
	end_page_writeback(page);
	return -ENOMEM;
}

static int fuse_writepage(struct page *page, struct writeback_control *wbc)
{
	int err;

	err = fuse_writepage_locked(page);
	unlock_page(page);

	return err;
}

static int fuse_launder_page(struct page *page)
{
	int err = 0;
	if (clear_page_dirty_for_io(page)) {
		struct inode *inode = page->mapping->host;
		err = fuse_writepage_locked(page);
		if (!err)
			fuse_wait_on_page_writeback(inode, page->index);
	}
	return err;
}

/*
 * Write back dirty pages now, because there may not be any suitable
 * open files later
 */
static void fuse_vma_close(struct vm_area_struct *vma)
{
	filemap_write_and_wait(vma->vm_file->f_mapping);
}

/*
 * Wait for writeback against this page to complete before allowing it
 * to be marked dirty again, and hence written back again, possibly
 * before the previous writepage completed.
 *
 * Block here, instead of in ->writepage(), so that the userspace fs
 * can only block processes actually operating on the filesystem.
 *
 * Otherwise unprivileged userspace fs would be able to block
 * unrelated:
 *
 * - page migration
 * - sync(2)
 * - try_to_free_pages() with order > PAGE_ALLOC_COSTLY_ORDER
 */
1596
static int fuse_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
M
Miklos Szeredi 已提交
1597
{
1598
	struct page *page = vmf->page;
M
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1599 1600 1601 1602 1603 1604 1605 1606 1607 1608
	/*
	 * Don't use page->mapping as it may become NULL from a
	 * concurrent truncate.
	 */
	struct inode *inode = vma->vm_file->f_mapping->host;

	fuse_wait_on_page_writeback(inode, page->index);
	return 0;
}

1609
static const struct vm_operations_struct fuse_file_vm_ops = {
M
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1610 1611 1612
	.close		= fuse_vma_close,
	.fault		= filemap_fault,
	.page_mkwrite	= fuse_page_mkwrite,
1613
	.remap_pages	= generic_file_remap_pages,
M
Miklos Szeredi 已提交
1614 1615 1616 1617 1618
};

static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
{
	if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE)) {
A
Al Viro 已提交
1619
		struct inode *inode = file_inode(file);
M
Miklos Szeredi 已提交
1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633
		struct fuse_conn *fc = get_fuse_conn(inode);
		struct fuse_inode *fi = get_fuse_inode(inode);
		struct fuse_file *ff = file->private_data;
		/*
		 * file may be written through mmap, so chain it onto the
		 * inodes's write_file list
		 */
		spin_lock(&fc->lock);
		if (list_empty(&ff->write_entry))
			list_add(&ff->write_entry, &fi->write_files);
		spin_unlock(&fc->lock);
	}
	file_accessed(file);
	vma->vm_ops = &fuse_file_vm_ops;
M
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1634 1635 1636
	return 0;
}

1637 1638 1639 1640 1641 1642
static int fuse_direct_mmap(struct file *file, struct vm_area_struct *vma)
{
	/* Can't provide the coherency needed for MAP_SHARED */
	if (vma->vm_flags & VM_MAYSHARE)
		return -ENODEV;

1643 1644
	invalidate_inode_pages2(file->f_mapping);

1645 1646 1647
	return generic_file_mmap(file, vma);
}

1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673
static int convert_fuse_file_lock(const struct fuse_file_lock *ffl,
				  struct file_lock *fl)
{
	switch (ffl->type) {
	case F_UNLCK:
		break;

	case F_RDLCK:
	case F_WRLCK:
		if (ffl->start > OFFSET_MAX || ffl->end > OFFSET_MAX ||
		    ffl->end < ffl->start)
			return -EIO;

		fl->fl_start = ffl->start;
		fl->fl_end = ffl->end;
		fl->fl_pid = ffl->pid;
		break;

	default:
		return -EIO;
	}
	fl->fl_type = ffl->type;
	return 0;
}

static void fuse_lk_fill(struct fuse_req *req, struct file *file,
1674 1675
			 const struct file_lock *fl, int opcode, pid_t pid,
			 int flock)
1676
{
A
Al Viro 已提交
1677
	struct inode *inode = file_inode(file);
1678
	struct fuse_conn *fc = get_fuse_conn(inode);
1679 1680 1681 1682
	struct fuse_file *ff = file->private_data;
	struct fuse_lk_in *arg = &req->misc.lk_in;

	arg->fh = ff->fh;
1683
	arg->owner = fuse_lock_owner_id(fc, fl->fl_owner);
1684 1685 1686 1687
	arg->lk.start = fl->fl_start;
	arg->lk.end = fl->fl_end;
	arg->lk.type = fl->fl_type;
	arg->lk.pid = pid;
1688 1689
	if (flock)
		arg->lk_flags |= FUSE_LK_FLOCK;
1690 1691 1692 1693 1694 1695 1696 1697 1698
	req->in.h.opcode = opcode;
	req->in.h.nodeid = get_node_id(inode);
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(*arg);
	req->in.args[0].value = arg;
}

static int fuse_getlk(struct file *file, struct file_lock *fl)
{
A
Al Viro 已提交
1699
	struct inode *inode = file_inode(file);
1700 1701 1702 1703 1704
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_req *req;
	struct fuse_lk_out outarg;
	int err;

M
Maxim Patlasov 已提交
1705
	req = fuse_get_req_nopages(fc);
1706 1707 1708
	if (IS_ERR(req))
		return PTR_ERR(req);

1709
	fuse_lk_fill(req, file, fl, FUSE_GETLK, 0, 0);
1710 1711 1712
	req->out.numargs = 1;
	req->out.args[0].size = sizeof(outarg);
	req->out.args[0].value = &outarg;
1713
	fuse_request_send(fc, req);
1714 1715 1716 1717 1718 1719 1720 1721
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (!err)
		err = convert_fuse_file_lock(&outarg.lk, fl);

	return err;
}

1722
static int fuse_setlk(struct file *file, struct file_lock *fl, int flock)
1723
{
A
Al Viro 已提交
1724
	struct inode *inode = file_inode(file);
1725 1726 1727 1728 1729 1730
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_req *req;
	int opcode = (fl->fl_flags & FL_SLEEP) ? FUSE_SETLKW : FUSE_SETLK;
	pid_t pid = fl->fl_type != F_UNLCK ? current->tgid : 0;
	int err;

J
J. Bruce Fields 已提交
1731
	if (fl->fl_lmops && fl->fl_lmops->lm_grant) {
M
Miklos Szeredi 已提交
1732 1733 1734 1735
		/* NLM needs asynchronous locks, which we don't support yet */
		return -ENOLCK;
	}

1736 1737 1738 1739
	/* Unlock on close is handled by the flush method */
	if (fl->fl_flags & FL_CLOSE)
		return 0;

M
Maxim Patlasov 已提交
1740
	req = fuse_get_req_nopages(fc);
1741 1742 1743
	if (IS_ERR(req))
		return PTR_ERR(req);

1744
	fuse_lk_fill(req, file, fl, opcode, pid, flock);
1745
	fuse_request_send(fc, req);
1746
	err = req->out.h.error;
1747 1748 1749
	/* locking is restartable */
	if (err == -EINTR)
		err = -ERESTARTSYS;
1750 1751 1752 1753 1754 1755
	fuse_put_request(fc, req);
	return err;
}

static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl)
{
A
Al Viro 已提交
1756
	struct inode *inode = file_inode(file);
1757 1758 1759
	struct fuse_conn *fc = get_fuse_conn(inode);
	int err;

M
Miklos Szeredi 已提交
1760 1761 1762
	if (cmd == F_CANCELLK) {
		err = 0;
	} else if (cmd == F_GETLK) {
1763
		if (fc->no_lock) {
1764
			posix_test_lock(file, fl);
1765 1766 1767 1768 1769
			err = 0;
		} else
			err = fuse_getlk(file, fl);
	} else {
		if (fc->no_lock)
M
Miklos Szeredi 已提交
1770
			err = posix_lock_file(file, fl, NULL);
1771
		else
1772
			err = fuse_setlk(file, fl, 0);
1773 1774 1775 1776
	}
	return err;
}

1777 1778
static int fuse_file_flock(struct file *file, int cmd, struct file_lock *fl)
{
A
Al Viro 已提交
1779
	struct inode *inode = file_inode(file);
1780 1781 1782
	struct fuse_conn *fc = get_fuse_conn(inode);
	int err;

M
Miklos Szeredi 已提交
1783
	if (fc->no_flock) {
1784 1785
		err = flock_lock_file_wait(file, fl);
	} else {
M
Miklos Szeredi 已提交
1786 1787
		struct fuse_file *ff = file->private_data;

1788 1789
		/* emulate flock with POSIX locks */
		fl->fl_owner = (fl_owner_t) file;
M
Miklos Szeredi 已提交
1790
		ff->flock = true;
1791 1792 1793 1794 1795 1796
		err = fuse_setlk(file, fl, 1);
	}

	return err;
}

M
Miklos Szeredi 已提交
1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808
static sector_t fuse_bmap(struct address_space *mapping, sector_t block)
{
	struct inode *inode = mapping->host;
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_req *req;
	struct fuse_bmap_in inarg;
	struct fuse_bmap_out outarg;
	int err;

	if (!inode->i_sb->s_bdev || fc->no_bmap)
		return 0;

M
Maxim Patlasov 已提交
1809
	req = fuse_get_req_nopages(fc);
M
Miklos Szeredi 已提交
1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823
	if (IS_ERR(req))
		return 0;

	memset(&inarg, 0, sizeof(inarg));
	inarg.block = block;
	inarg.blocksize = inode->i_sb->s_blocksize;
	req->in.h.opcode = FUSE_BMAP;
	req->in.h.nodeid = get_node_id(inode);
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(inarg);
	req->in.args[0].value = &inarg;
	req->out.numargs = 1;
	req->out.args[0].size = sizeof(outarg);
	req->out.args[0].value = &outarg;
1824
	fuse_request_send(fc, req);
M
Miklos Szeredi 已提交
1825 1826 1827 1828 1829 1830 1831 1832
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (err == -ENOSYS)
		fc->no_bmap = 1;

	return err ? 0 : outarg.block;
}

1833
static loff_t fuse_file_llseek(struct file *file, loff_t offset, int whence)
M
Miklos Szeredi 已提交
1834 1835
{
	loff_t retval;
A
Al Viro 已提交
1836
	struct inode *inode = file_inode(file);
M
Miklos Szeredi 已提交
1837

1838
	/* No i_mutex protection necessary for SEEK_CUR and SEEK_SET */
1839 1840
	if (whence == SEEK_CUR || whence == SEEK_SET)
		return generic_file_llseek(file, offset, whence);
1841

1842 1843 1844
	mutex_lock(&inode->i_mutex);
	retval = fuse_update_attributes(inode, NULL, file, NULL);
	if (!retval)
1845
		retval = generic_file_llseek(file, offset, whence);
M
Miklos Szeredi 已提交
1846
	mutex_unlock(&inode->i_mutex);
1847

M
Miklos Szeredi 已提交
1848 1849 1850
	return retval;
}

T
Tejun Heo 已提交
1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864
static int fuse_ioctl_copy_user(struct page **pages, struct iovec *iov,
			unsigned int nr_segs, size_t bytes, bool to_user)
{
	struct iov_iter ii;
	int page_idx = 0;

	if (!bytes)
		return 0;

	iov_iter_init(&ii, iov, nr_segs, bytes, 0);

	while (iov_iter_count(&ii)) {
		struct page *page = pages[page_idx++];
		size_t todo = min_t(size_t, PAGE_SIZE, iov_iter_count(&ii));
D
Dan Carpenter 已提交
1865
		void *kaddr;
T
Tejun Heo 已提交
1866

D
Dan Carpenter 已提交
1867
		kaddr = kmap(page);
T
Tejun Heo 已提交
1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887

		while (todo) {
			char __user *uaddr = ii.iov->iov_base + ii.iov_offset;
			size_t iov_len = ii.iov->iov_len - ii.iov_offset;
			size_t copy = min(todo, iov_len);
			size_t left;

			if (!to_user)
				left = copy_from_user(kaddr, uaddr, copy);
			else
				left = copy_to_user(uaddr, kaddr, copy);

			if (unlikely(left))
				return -EFAULT;

			iov_iter_advance(&ii, copy);
			todo -= copy;
			kaddr += copy;
		}

1888
		kunmap(page);
T
Tejun Heo 已提交
1889 1890 1891 1892 1893
	}

	return 0;
}

1894 1895 1896 1897 1898 1899
/*
 * 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.
 */
M
Miklos Szeredi 已提交
1900 1901 1902
static int fuse_copy_ioctl_iovec_old(struct iovec *dst, void *src,
				     size_t transferred, unsigned count,
				     bool is_compat)
1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931
{
#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;
}

M
Miklos Szeredi 已提交
1932 1933 1934 1935 1936 1937
/* Make sure iov_length() won't overflow */
static int fuse_verify_ioctl_iov(struct iovec *iov, size_t count)
{
	size_t n;
	u32 max = FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT;

1938
	for (n = 0; n < count; n++, iov++) {
M
Miklos Szeredi 已提交
1939 1940 1941 1942 1943 1944 1945
		if (iov->iov_len > (size_t) max)
			return -ENOMEM;
		max -= iov->iov_len;
	}
	return 0;
}

M
Miklos Szeredi 已提交
1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981
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;
}


T
Tejun Heo 已提交
1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027
/*
 * 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.
 */
2028 2029
long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
		   unsigned int flags)
T
Tejun Heo 已提交
2030 2031
{
	struct fuse_file *ff = file->private_data;
2032
	struct fuse_conn *fc = ff->fc;
T
Tejun Heo 已提交
2033 2034 2035 2036 2037 2038 2039 2040 2041
	struct fuse_ioctl_in inarg = {
		.fh = ff->fh,
		.cmd = cmd,
		.arg = arg,
		.flags = flags
	};
	struct fuse_ioctl_out outarg;
	struct fuse_req *req = NULL;
	struct page **pages = NULL;
M
Miklos Szeredi 已提交
2042
	struct iovec *iov_page = NULL;
T
Tejun Heo 已提交
2043 2044 2045 2046 2047
	struct iovec *in_iov = NULL, *out_iov = NULL;
	unsigned int in_iovs = 0, out_iovs = 0, num_pages = 0, max_pages;
	size_t in_size, out_size, transferred;
	int err;

M
Miklos Szeredi 已提交
2048 2049 2050 2051 2052 2053 2054
#if BITS_PER_LONG == 32
	inarg.flags |= FUSE_IOCTL_32BIT;
#else
	if (flags & FUSE_IOCTL_COMPAT)
		inarg.flags |= FUSE_IOCTL_32BIT;
#endif

T
Tejun Heo 已提交
2055
	/* assume all the iovs returned by client always fits in a page */
M
Miklos Szeredi 已提交
2056
	BUILD_BUG_ON(sizeof(struct fuse_ioctl_iovec) * FUSE_IOCTL_MAX_IOV > PAGE_SIZE);
T
Tejun Heo 已提交
2057 2058

	err = -ENOMEM;
2059
	pages = kcalloc(FUSE_MAX_PAGES_PER_REQ, sizeof(pages[0]), GFP_KERNEL);
M
Miklos Szeredi 已提交
2060
	iov_page = (struct iovec *) __get_free_page(GFP_KERNEL);
T
Tejun Heo 已提交
2061 2062 2063 2064 2065 2066 2067 2068
	if (!pages || !iov_page)
		goto out;

	/*
	 * If restricted, initialize IO parameters as encoded in @cmd.
	 * RETRY from server is not allowed.
	 */
	if (!(flags & FUSE_IOCTL_UNRESTRICTED)) {
M
Miklos Szeredi 已提交
2069
		struct iovec *iov = iov_page;
T
Tejun Heo 已提交
2070

M
Miklos Szeredi 已提交
2071
		iov->iov_base = (void __user *)arg;
T
Tejun Heo 已提交
2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106
		iov->iov_len = _IOC_SIZE(cmd);

		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 > FUSE_MAX_PAGES_PER_REQ)
		goto out;
	while (num_pages < max_pages) {
		pages[num_pages] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
		if (!pages[num_pages])
			goto out;
		num_pages++;
	}

M
Maxim Patlasov 已提交
2107
	req = fuse_get_req(fc, num_pages);
T
Tejun Heo 已提交
2108 2109 2110 2111 2112 2113 2114
	if (IS_ERR(req)) {
		err = PTR_ERR(req);
		req = NULL;
		goto out;
	}
	memcpy(req->pages, pages, sizeof(req->pages[0]) * num_pages);
	req->num_pages = num_pages;
2115
	fuse_page_descs_length_init(req, 0, req->num_pages);
T
Tejun Heo 已提交
2116 2117 2118

	/* okay, let's send it to the client */
	req->in.h.opcode = FUSE_IOCTL;
2119
	req->in.h.nodeid = ff->nodeid;
T
Tejun Heo 已提交
2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(inarg);
	req->in.args[0].value = &inarg;
	if (in_size) {
		req->in.numargs++;
		req->in.args[1].size = in_size;
		req->in.argpages = 1;

		err = fuse_ioctl_copy_user(pages, in_iov, in_iovs, in_size,
					   false);
		if (err)
			goto out;
	}

	req->out.numargs = 2;
	req->out.args[0].size = sizeof(outarg);
	req->out.args[0].value = &outarg;
	req->out.args[1].size = out_size;
	req->out.argpages = 1;
	req->out.argvar = 1;

2141
	fuse_request_send(fc, req);
T
Tejun Heo 已提交
2142 2143 2144 2145 2146 2147 2148 2149 2150
	err = req->out.h.error;
	transferred = req->out.args[1].size;
	fuse_put_request(fc, req);
	req = NULL;
	if (err)
		goto out;

	/* did it ask for retry? */
	if (outarg.flags & FUSE_IOCTL_RETRY) {
M
Miklos Szeredi 已提交
2151
		void *vaddr;
T
Tejun Heo 已提交
2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170

		/* 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;

2171
		vaddr = kmap_atomic(pages[0]);
M
Miklos Szeredi 已提交
2172
		err = fuse_copy_ioctl_iovec(fc, iov_page, vaddr,
2173 2174
					    transferred, in_iovs + out_iovs,
					    (flags & FUSE_IOCTL_COMPAT) != 0);
2175
		kunmap_atomic(vaddr);
2176 2177
		if (err)
			goto out;
T
Tejun Heo 已提交
2178

M
Miklos Szeredi 已提交
2179
		in_iov = iov_page;
T
Tejun Heo 已提交
2180 2181
		out_iov = in_iov + in_iovs;

M
Miklos Szeredi 已提交
2182 2183 2184 2185 2186 2187 2188 2189
		err = fuse_verify_ioctl_iov(in_iov, in_iovs);
		if (err)
			goto out;

		err = fuse_verify_ioctl_iov(out_iov, out_iovs);
		if (err)
			goto out;

T
Tejun Heo 已提交
2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200
		goto retry;
	}

	err = -EIO;
	if (transferred > inarg.out_size)
		goto out;

	err = fuse_ioctl_copy_user(pages, out_iov, out_iovs, transferred, true);
 out:
	if (req)
		fuse_put_request(fc, req);
M
Miklos Szeredi 已提交
2201
	free_page((unsigned long) iov_page);
T
Tejun Heo 已提交
2202 2203 2204 2205 2206 2207
	while (num_pages)
		__free_page(pages[--num_pages]);
	kfree(pages);

	return err ? err : outarg.result;
}
2208
EXPORT_SYMBOL_GPL(fuse_do_ioctl);
T
Tejun Heo 已提交
2209

2210 2211
long fuse_ioctl_common(struct file *file, unsigned int cmd,
		       unsigned long arg, unsigned int flags)
2212
{
A
Al Viro 已提交
2213
	struct inode *inode = file_inode(file);
2214 2215
	struct fuse_conn *fc = get_fuse_conn(inode);

2216
	if (!fuse_allow_current_process(fc))
2217 2218 2219 2220 2221 2222 2223 2224
		return -EACCES;

	if (is_bad_inode(inode))
		return -EIO;

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

T
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2225 2226 2227
static long fuse_file_ioctl(struct file *file, unsigned int cmd,
			    unsigned long arg)
{
2228
	return fuse_ioctl_common(file, cmd, arg, 0);
T
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2229 2230 2231 2232 2233
}

static long fuse_file_compat_ioctl(struct file *file, unsigned int cmd,
				   unsigned long arg)
{
2234
	return fuse_ioctl_common(file, cmd, arg, FUSE_IOCTL_COMPAT);
T
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2235 2236
}

T
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2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287
/*
 * All files which have been polled are linked to RB tree
 * fuse_conn->polled_files which is indexed by kh.  Walk the tree and
 * find the matching one.
 */
static struct rb_node **fuse_find_polled_node(struct fuse_conn *fc, u64 kh,
					      struct rb_node **parent_out)
{
	struct rb_node **link = &fc->polled_files.rb_node;
	struct rb_node *last = NULL;

	while (*link) {
		struct fuse_file *ff;

		last = *link;
		ff = rb_entry(last, struct fuse_file, polled_node);

		if (kh < ff->kh)
			link = &last->rb_left;
		else if (kh > ff->kh)
			link = &last->rb_right;
		else
			return link;
	}

	if (parent_out)
		*parent_out = last;
	return link;
}

/*
 * The file is about to be polled.  Make sure it's on the polled_files
 * RB tree.  Note that files once added to the polled_files tree are
 * not removed before the file is released.  This is because a file
 * polled once is likely to be polled again.
 */
static void fuse_register_polled_file(struct fuse_conn *fc,
				      struct fuse_file *ff)
{
	spin_lock(&fc->lock);
	if (RB_EMPTY_NODE(&ff->polled_node)) {
		struct rb_node **link, *parent;

		link = fuse_find_polled_node(fc, ff->kh, &parent);
		BUG_ON(*link);
		rb_link_node(&ff->polled_node, parent, link);
		rb_insert_color(&ff->polled_node, &fc->polled_files);
	}
	spin_unlock(&fc->lock);
}

2288
unsigned fuse_file_poll(struct file *file, poll_table *wait)
T
Tejun Heo 已提交
2289 2290
{
	struct fuse_file *ff = file->private_data;
2291
	struct fuse_conn *fc = ff->fc;
T
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2292 2293 2294 2295 2296 2297 2298 2299 2300
	struct fuse_poll_in inarg = { .fh = ff->fh, .kh = ff->kh };
	struct fuse_poll_out outarg;
	struct fuse_req *req;
	int err;

	if (fc->no_poll)
		return DEFAULT_POLLMASK;

	poll_wait(file, &ff->poll_wait, wait);
E
Enke Chen 已提交
2301
	inarg.events = (__u32)poll_requested_events(wait);
T
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2302 2303 2304 2305 2306 2307 2308 2309 2310 2311

	/*
	 * Ask for notification iff there's someone waiting for it.
	 * The client may ignore the flag and always notify.
	 */
	if (waitqueue_active(&ff->poll_wait)) {
		inarg.flags |= FUSE_POLL_SCHEDULE_NOTIFY;
		fuse_register_polled_file(fc, ff);
	}

M
Maxim Patlasov 已提交
2312
	req = fuse_get_req_nopages(fc);
T
Tejun Heo 已提交
2313
	if (IS_ERR(req))
2314
		return POLLERR;
T
Tejun Heo 已提交
2315 2316

	req->in.h.opcode = FUSE_POLL;
2317
	req->in.h.nodeid = ff->nodeid;
T
Tejun Heo 已提交
2318 2319 2320 2321 2322 2323
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(inarg);
	req->in.args[0].value = &inarg;
	req->out.numargs = 1;
	req->out.args[0].size = sizeof(outarg);
	req->out.args[0].value = &outarg;
2324
	fuse_request_send(fc, req);
T
Tejun Heo 已提交
2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335
	err = req->out.h.error;
	fuse_put_request(fc, req);

	if (!err)
		return outarg.revents;
	if (err == -ENOSYS) {
		fc->no_poll = 1;
		return DEFAULT_POLLMASK;
	}
	return POLLERR;
}
2336
EXPORT_SYMBOL_GPL(fuse_file_poll);
T
Tejun Heo 已提交
2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361

/*
 * This is called from fuse_handle_notify() on FUSE_NOTIFY_POLL and
 * wakes up the poll waiters.
 */
int fuse_notify_poll_wakeup(struct fuse_conn *fc,
			    struct fuse_notify_poll_wakeup_out *outarg)
{
	u64 kh = outarg->kh;
	struct rb_node **link;

	spin_lock(&fc->lock);

	link = fuse_find_polled_node(fc, kh, NULL);
	if (*link) {
		struct fuse_file *ff;

		ff = rb_entry(*link, struct fuse_file, polled_node);
		wake_up_interruptible_sync(&ff->poll_wait);
	}

	spin_unlock(&fc->lock);
	return 0;
}

2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375
static void fuse_do_truncate(struct file *file)
{
	struct inode *inode = file->f_mapping->host;
	struct iattr attr;

	attr.ia_valid = ATTR_SIZE;
	attr.ia_size = i_size_read(inode);

	attr.ia_file = file;
	attr.ia_valid |= ATTR_FILE;

	fuse_do_setattr(inode, &attr, file);
}

A
Anand Avati 已提交
2376 2377 2378 2379 2380
static ssize_t
fuse_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
			loff_t offset, unsigned long nr_segs)
{
	ssize_t ret = 0;
2381 2382
	struct file *file = iocb->ki_filp;
	struct fuse_file *ff = file->private_data;
A
Anand Avati 已提交
2383
	loff_t pos = 0;
2384 2385 2386
	struct inode *inode;
	loff_t i_size;
	size_t count = iov_length(iov, nr_segs);
2387
	struct fuse_io_priv *io;
A
Anand Avati 已提交
2388 2389

	pos = offset;
2390 2391
	inode = file->f_mapping->host;
	i_size = i_size_read(inode);
A
Anand Avati 已提交
2392

2393 2394 2395 2396 2397 2398 2399
	/* optimization for short read */
	if (rw != WRITE && offset + count > i_size) {
		if (offset >= i_size)
			return 0;
		count = i_size - offset;
	}

2400
	io = kmalloc(sizeof(struct fuse_io_priv), GFP_KERNEL);
2401 2402
	if (!io)
		return -ENOMEM;
2403 2404 2405 2406 2407 2408 2409
	spin_lock_init(&io->lock);
	io->reqs = 1;
	io->bytes = -1;
	io->size = 0;
	io->offset = offset;
	io->write = (rw == WRITE);
	io->err = 0;
2410
	io->file = file;
2411 2412
	/*
	 * By default, we want to optimize all I/Os with async request
2413
	 * submission to the client filesystem if supported.
2414
	 */
2415
	io->async = ff->fc->async_dio;
2416 2417 2418 2419 2420 2421 2422
	io->iocb = iocb;

	/*
	 * We cannot asynchronously extend the size of a file. We have no method
	 * to wait on real async I/O requests, so we must submit this request
	 * synchronously.
	 */
2423
	if (!is_sync_kiocb(iocb) && (offset + count > i_size))
2424
		io->async = false;
A
Anand Avati 已提交
2425

2426
	if (rw == WRITE)
2427
		ret = __fuse_direct_write(io, iov, nr_segs, &pos);
2428
	else
2429
		ret = __fuse_direct_read(io, iov, nr_segs, &pos, count);
2430

2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442
	if (io->async) {
		fuse_aio_complete(io, ret < 0 ? ret : 0, -1);

		/* we have a non-extending, async request, so return */
		if (ret > 0 && !is_sync_kiocb(iocb))
			return -EIOCBQUEUED;

		ret = wait_on_sync_kiocb(iocb);
	} else {
		kfree(io);
	}

2443 2444 2445 2446 2447 2448
	if (rw == WRITE) {
		if (ret > 0)
			fuse_write_update_size(inode, pos);
		else if (ret < 0 && offset + count > i_size)
			fuse_do_truncate(file);
	}
A
Anand Avati 已提交
2449 2450 2451 2452

	return ret;
}

2453 2454
static long fuse_file_fallocate(struct file *file, int mode, loff_t offset,
				loff_t length)
A
Anatol Pomozov 已提交
2455 2456
{
	struct fuse_file *ff = file->private_data;
2457
	struct inode *inode = file->f_inode;
A
Anatol Pomozov 已提交
2458 2459 2460 2461 2462 2463 2464 2465 2466 2467
	struct fuse_conn *fc = ff->fc;
	struct fuse_req *req;
	struct fuse_fallocate_in inarg = {
		.fh = ff->fh,
		.offset = offset,
		.length = length,
		.mode = mode
	};
	int err;

2468 2469 2470
	if (fc->no_fallocate)
		return -EOPNOTSUPP;

2471 2472 2473 2474 2475
	if (mode & FALLOC_FL_PUNCH_HOLE) {
		mutex_lock(&inode->i_mutex);
		fuse_set_nowrite(inode);
	}

M
Maxim Patlasov 已提交
2476
	req = fuse_get_req_nopages(fc);
2477 2478 2479 2480
	if (IS_ERR(req)) {
		err = PTR_ERR(req);
		goto out;
	}
A
Anatol Pomozov 已提交
2481 2482 2483 2484 2485 2486 2487 2488

	req->in.h.opcode = FUSE_FALLOCATE;
	req->in.h.nodeid = ff->nodeid;
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(inarg);
	req->in.args[0].value = &inarg;
	fuse_request_send(fc, req);
	err = req->out.h.error;
2489 2490 2491 2492
	if (err == -ENOSYS) {
		fc->no_fallocate = 1;
		err = -EOPNOTSUPP;
	}
A
Anatol Pomozov 已提交
2493 2494
	fuse_put_request(fc, req);

2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506
	if (err)
		goto out;

	/* we could have extended the file */
	if (!(mode & FALLOC_FL_KEEP_SIZE))
		fuse_write_update_size(inode, offset + length);

	if (mode & FALLOC_FL_PUNCH_HOLE)
		truncate_pagecache_range(inode, offset, offset + length - 1);

	fuse_invalidate_attr(inode);

2507 2508 2509 2510 2511 2512
out:
	if (mode & FALLOC_FL_PUNCH_HOLE) {
		fuse_release_nowrite(inode);
		mutex_unlock(&inode->i_mutex);
	}

A
Anatol Pomozov 已提交
2513 2514 2515
	return err;
}

2516
static const struct file_operations fuse_file_operations = {
M
Miklos Szeredi 已提交
2517
	.llseek		= fuse_file_llseek,
2518
	.read		= do_sync_read,
M
Miklos Szeredi 已提交
2519
	.aio_read	= fuse_file_aio_read,
2520
	.write		= do_sync_write,
N
Nick Piggin 已提交
2521
	.aio_write	= fuse_file_aio_write,
M
Miklos Szeredi 已提交
2522 2523 2524 2525 2526
	.mmap		= fuse_file_mmap,
	.open		= fuse_open,
	.flush		= fuse_flush,
	.release	= fuse_release,
	.fsync		= fuse_fsync,
2527
	.lock		= fuse_file_lock,
2528
	.flock		= fuse_file_flock,
2529
	.splice_read	= generic_file_splice_read,
T
Tejun Heo 已提交
2530 2531
	.unlocked_ioctl	= fuse_file_ioctl,
	.compat_ioctl	= fuse_file_compat_ioctl,
T
Tejun Heo 已提交
2532
	.poll		= fuse_file_poll,
A
Anatol Pomozov 已提交
2533
	.fallocate	= fuse_file_fallocate,
M
Miklos Szeredi 已提交
2534 2535
};

2536
static const struct file_operations fuse_direct_io_file_operations = {
M
Miklos Szeredi 已提交
2537
	.llseek		= fuse_file_llseek,
M
Miklos Szeredi 已提交
2538 2539
	.read		= fuse_direct_read,
	.write		= fuse_direct_write,
2540
	.mmap		= fuse_direct_mmap,
M
Miklos Szeredi 已提交
2541 2542 2543 2544
	.open		= fuse_open,
	.flush		= fuse_flush,
	.release	= fuse_release,
	.fsync		= fuse_fsync,
2545
	.lock		= fuse_file_lock,
2546
	.flock		= fuse_file_flock,
T
Tejun Heo 已提交
2547 2548
	.unlocked_ioctl	= fuse_file_ioctl,
	.compat_ioctl	= fuse_file_compat_ioctl,
T
Tejun Heo 已提交
2549
	.poll		= fuse_file_poll,
A
Anatol Pomozov 已提交
2550
	.fallocate	= fuse_file_fallocate,
2551
	/* no splice_read */
M
Miklos Szeredi 已提交
2552 2553
};

2554
static const struct address_space_operations fuse_file_aops  = {
M
Miklos Szeredi 已提交
2555
	.readpage	= fuse_readpage,
M
Miklos Szeredi 已提交
2556 2557
	.writepage	= fuse_writepage,
	.launder_page	= fuse_launder_page,
2558
	.readpages	= fuse_readpages,
M
Miklos Szeredi 已提交
2559
	.set_page_dirty	= __set_page_dirty_nobuffers,
M
Miklos Szeredi 已提交
2560
	.bmap		= fuse_bmap,
A
Anand Avati 已提交
2561
	.direct_IO	= fuse_direct_IO,
M
Miklos Szeredi 已提交
2562 2563 2564 2565
};

void fuse_init_file_inode(struct inode *inode)
{
2566 2567
	inode->i_fop = &fuse_file_operations;
	inode->i_data.a_ops = &fuse_file_aops;
M
Miklos Szeredi 已提交
2568
}