file.c 53.6 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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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(fc);
	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();
	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) {
			fuse_request_send(ff->fc, req);
			path_put(&req->misc.release.path);
			fuse_put_request(ff->fc, req);
		} else {
			req->end = fuse_release_end;
			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;
	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->f_path.dentry->d_inode;
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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(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(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 size_t fuse_send_read(struct fuse_req *req, struct file *file,
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			     loff_t pos, size_t count, fl_owner_t owner)
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{
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	struct fuse_file *ff = file->private_data;
	struct fuse_conn *fc = ff->fc;
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	fuse_read_fill(req, file, pos, count, FUSE_READ);
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	if (owner != NULL) {
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		struct fuse_read_in *inarg = &req->misc.read.in;
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		inarg->read_flags |= FUSE_READ_LOCKOWNER;
		inarg->lock_owner = fuse_lock_owner_id(fc, owner);
	}
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	fuse_request_send(fc, req);
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	return req->out.args[0].size;
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}

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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);
}

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static int fuse_readpage(struct file *file, struct page *page)
{
	struct inode *inode = page->mapping->host;
	struct fuse_conn *fc = get_fuse_conn(inode);
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	struct fuse_req *req;
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	size_t num_read;
	loff_t pos = page_offset(page);
	size_t count = PAGE_CACHE_SIZE;
	u64 attr_ver;
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	int err;

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

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	/*
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	 * Page writeback can extend beyond the lifetime of the
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	 * page-cache page, so make sure we read a properly synced
	 * page.
	 */
	fuse_wait_on_page_writeback(inode, page->index);

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	req = fuse_get_req(fc);
	err = PTR_ERR(req);
	if (IS_ERR(req))
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		goto out;

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	attr_ver = fuse_get_attr_version(fc);

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	req->out.page_zeroing = 1;
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	req->out.argpages = 1;
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	req->num_pages = 1;
	req->pages[0] = page;
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	num_read = fuse_send_read(req, file, pos, count, NULL);
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	err = req->out.h.error;
	fuse_put_request(fc, req);
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	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);

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		SetPageUptodate(page);
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	}

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	fuse_invalidate_attr(inode); /* atime changed */
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573 574 575 576 577
 out:
	unlock_page(page);
	return err;
}

578
static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req)
579
{
580
	int i;
581 582
	size_t count = req->misc.read.in.size;
	size_t num_read = req->out.args[0].size;
583
	struct address_space *mapping = NULL;
584

585 586
	for (i = 0; mapping == NULL && i < req->num_pages; i++)
		mapping = req->pages[i]->mapping;
587

588 589 590 591 592 593 594 595 596 597 598 599 600 601 602
	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 */
	}
603

604 605 606 607
	for (i = 0; i < req->num_pages; i++) {
		struct page *page = req->pages[i];
		if (!req->out.h.error)
			SetPageUptodate(page);
608 609
		else
			SetPageError(page);
610
		unlock_page(page);
611
		page_cache_release(page);
612
	}
613
	if (req->ff)
614
		fuse_file_put(req->ff, false);
615 616
}

617
static void fuse_send_readpages(struct fuse_req *req, struct file *file)
618
{
619 620
	struct fuse_file *ff = file->private_data;
	struct fuse_conn *fc = ff->fc;
621 622
	loff_t pos = page_offset(req->pages[0]);
	size_t count = req->num_pages << PAGE_CACHE_SHIFT;
623 624

	req->out.argpages = 1;
625
	req->out.page_zeroing = 1;
626
	req->out.page_replace = 1;
627
	fuse_read_fill(req, file, pos, count, FUSE_READ);
628
	req->misc.read.attr_ver = fuse_get_attr_version(fc);
629
	if (fc->async_read) {
630
		req->ff = fuse_file_get(ff);
631
		req->end = fuse_readpages_end;
632
		fuse_request_send_background(fc, req);
633
	} else {
634
		fuse_request_send(fc, req);
635
		fuse_readpages_end(fc, req);
636
		fuse_put_request(fc, req);
637
	}
638 639
}

640
struct fuse_fill_data {
641
	struct fuse_req *req;
642
	struct file *file;
643 644 645 646 647
	struct inode *inode;
};

static int fuse_readpages_fill(void *_data, struct page *page)
{
648
	struct fuse_fill_data *data = _data;
649 650 651 652
	struct fuse_req *req = data->req;
	struct inode *inode = data->inode;
	struct fuse_conn *fc = get_fuse_conn(inode);

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653 654
	fuse_wait_on_page_writeback(inode, page->index);

655 656 657 658
	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)) {
659
		fuse_send_readpages(req, data->file);
660 661
		data->req = req = fuse_get_req(fc);
		if (IS_ERR(req)) {
662
			unlock_page(page);
663
			return PTR_ERR(req);
664 665
		}
	}
666
	page_cache_get(page);
667
	req->pages[req->num_pages] = page;
M
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668
	req->num_pages++;
669 670 671 672 673 674 675 676
	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);
677
	struct fuse_fill_data data;
678
	int err;
679

680
	err = -EIO;
681
	if (is_bad_inode(inode))
682
		goto out;
683

684
	data.file = file;
685
	data.inode = inode;
686
	data.req = fuse_get_req(fc);
687
	err = PTR_ERR(data.req);
688
	if (IS_ERR(data.req))
689
		goto out;
690 691

	err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
692 693
	if (!err) {
		if (data.req->num_pages)
694
			fuse_send_readpages(data.req, file);
695 696 697
		else
			fuse_put_request(fc, data.req);
	}
698
out:
699
	return err;
700 701
}

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702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720
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;

	if (pos + iov_length(iov, nr_segs) > i_size_read(inode)) {
		int err;
		/*
		 * If trying to read past EOF, make sure the i_size
		 * attribute is up-to-date.
		 */
		err = fuse_update_attributes(inode, NULL, iocb->ki_filp, NULL);
		if (err)
			return err;
	}

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

721
static void fuse_write_fill(struct fuse_req *req, struct fuse_file *ff,
722
			    loff_t pos, size_t count)
M
Miklos Szeredi 已提交
723
{
724 725
	struct fuse_write_in *inarg = &req->misc.write.in;
	struct fuse_write_out *outarg = &req->misc.write.out;
M
Miklos Szeredi 已提交
726

727 728 729
	inarg->fh = ff->fh;
	inarg->offset = pos;
	inarg->size = count;
M
Miklos Szeredi 已提交
730
	req->in.h.opcode = FUSE_WRITE;
731
	req->in.h.nodeid = ff->nodeid;
M
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732
	req->in.numargs = 2;
733
	if (ff->fc->minor < 9)
734 735 736
		req->in.args[0].size = FUSE_COMPAT_WRITE_IN_SIZE;
	else
		req->in.args[0].size = sizeof(struct fuse_write_in);
737
	req->in.args[0].value = inarg;
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738 739 740
	req->in.args[1].size = count;
	req->out.numargs = 1;
	req->out.args[0].size = sizeof(struct fuse_write_out);
741 742 743 744
	req->out.args[0].value = outarg;
}

static size_t fuse_send_write(struct fuse_req *req, struct file *file,
745
			      loff_t pos, size_t count, fl_owner_t owner)
746
{
747 748
	struct fuse_file *ff = file->private_data;
	struct fuse_conn *fc = ff->fc;
749 750
	struct fuse_write_in *inarg = &req->misc.write.in;

751
	fuse_write_fill(req, ff, pos, count);
752
	inarg->flags = file->f_flags;
753 754 755 756
	if (owner != NULL) {
		inarg->write_flags |= FUSE_WRITE_LOCKOWNER;
		inarg->lock_owner = fuse_lock_owner_id(fc, owner);
	}
757
	fuse_request_send(fc, req);
758
	return req->misc.write.out.size;
M
Miklos Szeredi 已提交
759 760
}

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761
void fuse_write_update_size(struct inode *inode, loff_t pos)
762 763 764 765 766 767 768 769 770 771 772
{
	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);
}

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773 774 775 776 777 778 779 780 781 782 783
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;

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

784
	res = fuse_send_write(req, file, pos, count, NULL);
N
Nick Piggin 已提交
785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815

	offset = req->page_offset;
	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;

816
	req->in.argpages = 1;
N
Nick Piggin 已提交
817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833
	req->page_offset = offset;

	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;
834
		page = grab_cache_page_write_begin(mapping, index, 0);
N
Nick Piggin 已提交
835 836 837
		if (!page)
			break;

838 839 840
		if (mapping_writably_mapped(mapping))
			flush_dcache_page(page);

N
Nick Piggin 已提交
841 842 843 844 845
		pagefault_disable();
		tmp = iov_iter_copy_from_user_atomic(page, ii, offset, bytes);
		pagefault_enable();
		flush_dcache_page(page);

846 847
		mark_page_accessed(page);

N
Nick Piggin 已提交
848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865
		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;
		req->num_pages++;

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

866 867
		if (!fc->big_writes)
			break;
N
Nick Piggin 已提交
868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930
	} while (iov_iter_count(ii) && count < fc->max_write &&
		 req->num_pages < FUSE_MAX_PAGES_PER_REQ && offset == 0);

	return count > 0 ? count : err;
}

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;

		req = fuse_get_req(fc);
		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
931
	size_t ocount = 0;
N
Nick Piggin 已提交
932
	ssize_t written = 0;
A
Anand Avati 已提交
933
	ssize_t written_buffered = 0;
N
Nick Piggin 已提交
934 935 936
	struct inode *inode = mapping->host;
	ssize_t err;
	struct iov_iter i;
A
Anand Avati 已提交
937
	loff_t endbyte = 0;
N
Nick Piggin 已提交
938 939 940

	WARN_ON(iocb->ki_pos != pos);

A
Anand Avati 已提交
941 942
	ocount = 0;
	err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ);
N
Nick Piggin 已提交
943 944 945
	if (err)
		return err;

A
Anand Avati 已提交
946 947
	count = ocount;

N
Nick Piggin 已提交
948 949 950 951 952 953 954 955 956 957 958 959 960
	mutex_lock(&inode->i_mutex);
	vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);

	/* 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;

961
	err = file_remove_suid(file);
N
Nick Piggin 已提交
962 963 964
	if (err)
		goto out;

965 966 967
	err = file_update_time(file);
	if (err)
		goto out;
N
Nick Piggin 已提交
968

A
Anand Avati 已提交
969 970 971 972 973 974 975 976 977
	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
978

A
Anand Avati 已提交
979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003
		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
Nick Piggin 已提交
1004 1005 1006 1007 1008 1009 1010
out:
	current->backing_dev_info = NULL;
	mutex_unlock(&inode->i_mutex);

	return written ? written : err;
}

M
Miklos Szeredi 已提交
1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023
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);
	}
}

static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf,
1024
			       size_t *nbytesp, int write)
M
Miklos Szeredi 已提交
1025
{
1026
	size_t nbytes = *nbytesp;
M
Miklos Szeredi 已提交
1027 1028 1029 1030
	unsigned long user_addr = (unsigned long) buf;
	unsigned offset = user_addr & ~PAGE_MASK;
	int npages;

1031 1032 1033 1034 1035 1036 1037 1038 1039
	/* Special case for kernel I/O: can copy directly into the buffer */
	if (segment_eq(get_fs(), KERNEL_DS)) {
		if (write)
			req->in.args[1].value = (void *) user_addr;
		else
			req->out.args[0].value = (void *) user_addr;

		return 0;
	}
M
Miklos Szeredi 已提交
1040

1041
	nbytes = min_t(size_t, nbytes, FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT);
M
Miklos Szeredi 已提交
1042
	npages = (nbytes + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
1043
	npages = clamp(npages, 1, FUSE_MAX_PAGES_PER_REQ);
M
Miklos Szeredi 已提交
1044
	npages = get_user_pages_fast(user_addr, npages, !write, req->pages);
M
Miklos Szeredi 已提交
1045 1046 1047 1048 1049
	if (npages < 0)
		return npages;

	req->num_pages = npages;
	req->page_offset = offset;
1050 1051 1052 1053 1054 1055 1056 1057 1058

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

	nbytes = (req->num_pages << PAGE_SHIFT) - req->page_offset;
	*nbytesp = min(*nbytesp, nbytes);

M
Miklos Szeredi 已提交
1059 1060 1061
	return 0;
}

1062 1063
ssize_t fuse_direct_io(struct file *file, const char __user *buf,
		       size_t count, loff_t *ppos, int write)
M
Miklos Szeredi 已提交
1064
{
1065 1066
	struct fuse_file *ff = file->private_data;
	struct fuse_conn *fc = ff->fc;
M
Miklos Szeredi 已提交
1067 1068 1069
	size_t nmax = write ? fc->max_write : fc->max_read;
	loff_t pos = *ppos;
	ssize_t res = 0;
1070 1071
	struct fuse_req *req;

1072 1073 1074
	req = fuse_get_req(fc);
	if (IS_ERR(req))
		return PTR_ERR(req);
M
Miklos Szeredi 已提交
1075 1076 1077

	while (count) {
		size_t nres;
1078
		fl_owner_t owner = current->files;
1079 1080
		size_t nbytes = min(count, nmax);
		int err = fuse_get_user_pages(req, buf, &nbytes, write);
M
Miklos Szeredi 已提交
1081 1082 1083 1084
		if (err) {
			res = err;
			break;
		}
1085

M
Miklos Szeredi 已提交
1086
		if (write)
1087
			nres = fuse_send_write(req, file, pos, nbytes, owner);
M
Miklos Szeredi 已提交
1088
		else
1089 1090
			nres = fuse_send_read(req, file, pos, nbytes, owner);

M
Miklos Szeredi 已提交
1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105
		fuse_release_user_pages(req, !write);
		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;
		buf += nres;
		if (nres != nbytes)
			break;
1106 1107 1108 1109 1110 1111
		if (count) {
			fuse_put_request(fc, req);
			req = fuse_get_req(fc);
			if (IS_ERR(req))
				break;
		}
M
Miklos Szeredi 已提交
1112
	}
1113 1114
	if (!IS_ERR(req))
		fuse_put_request(fc, req);
1115
	if (res > 0)
M
Miklos Szeredi 已提交
1116 1117 1118 1119
		*ppos = pos;

	return res;
}
1120
EXPORT_SYMBOL_GPL(fuse_direct_io);
M
Miklos Szeredi 已提交
1121 1122 1123 1124

static ssize_t fuse_direct_read(struct file *file, char __user *buf,
				     size_t count, loff_t *ppos)
{
1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135
	ssize_t res;
	struct inode *inode = file->f_path.dentry->d_inode;

	if (is_bad_inode(inode))
		return -EIO;

	res = fuse_direct_io(file, buf, count, ppos, 0);

	fuse_invalidate_attr(inode);

	return res;
M
Miklos Szeredi 已提交
1136 1137
}

A
Anand Avati 已提交
1138 1139
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
1140
{
J
Josef Sipek 已提交
1141
	struct inode *inode = file->f_path.dentry->d_inode;
M
Miklos Szeredi 已提交
1142
	ssize_t res;
1143

1144
	res = generic_write_checks(file, ppos, &count, 0);
1145
	if (!res) {
1146
		res = fuse_direct_io(file, buf, count, ppos, 1);
1147 1148 1149 1150 1151 1152
		if (res > 0)
			fuse_write_update_size(inode, *ppos);
	}

	fuse_invalidate_attr(inode);

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	return res;
}

A
Anand Avati 已提交
1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172
static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
				 size_t count, loff_t *ppos)
{
	struct inode *inode = file->f_path.dentry->d_inode;
	ssize_t res;

	if (is_bad_inode(inode))
		return -EIO;

	/* Don't allow parallel writes to the same file */
	mutex_lock(&inode->i_mutex);
	res = __fuse_direct_write(file, buf, count, ppos);
	mutex_unlock(&inode->i_mutex);

	return res;
}

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static void fuse_writepage_free(struct fuse_conn *fc, struct fuse_req *req)
M
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1174
{
M
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1175
	__free_page(req->pages[0]);
1176
	fuse_file_put(req->ff, false);
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}

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
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__releases(fc->lock)
__acquires(fc->lock)
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1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210
{
	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
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1211
	}
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	req->in.args[1].size = inarg->size;
	fi->writectr++;
1215
	fuse_request_send_background_locked(fc, req);
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	return;

 out_free:
	fuse_writepage_finish(fc, req);
	spin_unlock(&fc->lock);
	fuse_writepage_free(fc, req);
1222
	fuse_put_request(fc, req);
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	spin_lock(&fc->lock);
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}

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/*
 * 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)
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__releases(fc->lock)
__acquires(fc->lock)
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{
M
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1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285
	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);

	req = fuse_request_alloc_nofs();
	if (!req)
		goto err;

	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);

1286
	fuse_write_fill(req, ff, page_offset(page), 0);
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Miklos Szeredi 已提交
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	copy_highpage(tmp_page, page);
1289
	req->misc.write.in.write_flags |= FUSE_WRITE_CACHE;
1290
	req->in.argpages = 1;
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1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361
	req->num_pages = 1;
	req->pages[0] = tmp_page;
	req->page_offset = 0;
	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
 */
1362
static int fuse_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
M
Miklos Szeredi 已提交
1363
{
1364
	struct page *page = vmf->page;
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	/*
	 * 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;
}

1375
static const struct vm_operations_struct fuse_file_vm_ops = {
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	.close		= fuse_vma_close,
	.fault		= filemap_fault,
	.page_mkwrite	= fuse_page_mkwrite,
};

static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
{
	if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE)) {
		struct inode *inode = file->f_dentry->d_inode;
		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;
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	return 0;
}

1402 1403 1404 1405 1406 1407
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;

1408 1409
	invalidate_inode_pages2(file->f_mapping);

1410 1411 1412
	return generic_file_mmap(file, vma);
}

1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438
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,
1439 1440
			 const struct file_lock *fl, int opcode, pid_t pid,
			 int flock)
1441
{
J
Josef Sipek 已提交
1442
	struct inode *inode = file->f_path.dentry->d_inode;
1443
	struct fuse_conn *fc = get_fuse_conn(inode);
1444 1445 1446 1447
	struct fuse_file *ff = file->private_data;
	struct fuse_lk_in *arg = &req->misc.lk_in;

	arg->fh = ff->fh;
1448
	arg->owner = fuse_lock_owner_id(fc, fl->fl_owner);
1449 1450 1451 1452
	arg->lk.start = fl->fl_start;
	arg->lk.end = fl->fl_end;
	arg->lk.type = fl->fl_type;
	arg->lk.pid = pid;
1453 1454
	if (flock)
		arg->lk_flags |= FUSE_LK_FLOCK;
1455 1456 1457 1458 1459 1460 1461 1462 1463
	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)
{
J
Josef Sipek 已提交
1464
	struct inode *inode = file->f_path.dentry->d_inode;
1465 1466 1467 1468 1469 1470 1471 1472 1473
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_req *req;
	struct fuse_lk_out outarg;
	int err;

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

1474
	fuse_lk_fill(req, file, fl, FUSE_GETLK, 0, 0);
1475 1476 1477
	req->out.numargs = 1;
	req->out.args[0].size = sizeof(outarg);
	req->out.args[0].value = &outarg;
1478
	fuse_request_send(fc, req);
1479 1480 1481 1482 1483 1484 1485 1486
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (!err)
		err = convert_fuse_file_lock(&outarg.lk, fl);

	return err;
}

1487
static int fuse_setlk(struct file *file, struct file_lock *fl, int flock)
1488
{
J
Josef Sipek 已提交
1489
	struct inode *inode = file->f_path.dentry->d_inode;
1490 1491 1492 1493 1494 1495
	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
1496
	if (fl->fl_lmops && fl->fl_lmops->lm_grant) {
M
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1497 1498 1499 1500
		/* NLM needs asynchronous locks, which we don't support yet */
		return -ENOLCK;
	}

1501 1502 1503 1504 1505 1506 1507 1508
	/* Unlock on close is handled by the flush method */
	if (fl->fl_flags & FL_CLOSE)
		return 0;

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

1509
	fuse_lk_fill(req, file, fl, opcode, pid, flock);
1510
	fuse_request_send(fc, req);
1511
	err = req->out.h.error;
1512 1513 1514
	/* locking is restartable */
	if (err == -EINTR)
		err = -ERESTARTSYS;
1515 1516 1517 1518 1519 1520
	fuse_put_request(fc, req);
	return err;
}

static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl)
{
J
Josef Sipek 已提交
1521
	struct inode *inode = file->f_path.dentry->d_inode;
1522 1523 1524
	struct fuse_conn *fc = get_fuse_conn(inode);
	int err;

M
Miklos Szeredi 已提交
1525 1526 1527
	if (cmd == F_CANCELLK) {
		err = 0;
	} else if (cmd == F_GETLK) {
1528
		if (fc->no_lock) {
1529
			posix_test_lock(file, fl);
1530 1531 1532 1533 1534
			err = 0;
		} else
			err = fuse_getlk(file, fl);
	} else {
		if (fc->no_lock)
M
Miklos Szeredi 已提交
1535
			err = posix_lock_file(file, fl, NULL);
1536
		else
1537
			err = fuse_setlk(file, fl, 0);
1538 1539 1540 1541
	}
	return err;
}

1542 1543 1544 1545 1546 1547
static int fuse_file_flock(struct file *file, int cmd, struct file_lock *fl)
{
	struct inode *inode = file->f_path.dentry->d_inode;
	struct fuse_conn *fc = get_fuse_conn(inode);
	int err;

M
Miklos Szeredi 已提交
1548
	if (fc->no_flock) {
1549 1550
		err = flock_lock_file_wait(file, fl);
	} else {
M
Miklos Szeredi 已提交
1551 1552
		struct fuse_file *ff = file->private_data;

1553 1554
		/* emulate flock with POSIX locks */
		fl->fl_owner = (fl_owner_t) file;
M
Miklos Szeredi 已提交
1555
		ff->flock = true;
1556 1557 1558 1559 1560 1561
		err = fuse_setlk(file, fl, 1);
	}

	return err;
}

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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
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;

	req = fuse_get_req(fc);
	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;
1589
	fuse_request_send(fc, req);
M
Miklos Szeredi 已提交
1590 1591 1592 1593 1594 1595 1596 1597
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (err == -ENOSYS)
		fc->no_bmap = 1;

	return err ? 0 : outarg.block;
}

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Miklos Szeredi 已提交
1598 1599 1600 1601 1602
static loff_t fuse_file_llseek(struct file *file, loff_t offset, int origin)
{
	loff_t retval;
	struct inode *inode = file->f_path.dentry->d_inode;

1603 1604 1605
	/* No i_mutex protection necessary for SEEK_CUR and SEEK_SET */
	if (origin == SEEK_CUR || origin == SEEK_SET)
		return generic_file_llseek(file, offset, origin);
1606

1607 1608 1609 1610
	mutex_lock(&inode->i_mutex);
	retval = fuse_update_attributes(inode, NULL, file, NULL);
	if (!retval)
		retval = generic_file_llseek(file, offset, origin);
M
Miklos Szeredi 已提交
1611
	mutex_unlock(&inode->i_mutex);
1612

M
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1613 1614 1615
	return retval;
}

T
Tejun Heo 已提交
1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629
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
1630
		void *kaddr;
T
Tejun Heo 已提交
1631

D
Dan Carpenter 已提交
1632
		kaddr = kmap(page);
T
Tejun Heo 已提交
1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652

		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;
		}

1653
		kunmap(page);
T
Tejun Heo 已提交
1654 1655 1656 1657 1658
	}

	return 0;
}

1659 1660 1661 1662 1663 1664
/*
 * 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
1665 1666 1667
static int fuse_copy_ioctl_iovec_old(struct iovec *dst, void *src,
				     size_t transferred, unsigned count,
				     bool is_compat)
1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696
{
#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;
}

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Miklos Szeredi 已提交
1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710
/* 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;

	for (n = 0; n < count; n++) {
		if (iov->iov_len > (size_t) max)
			return -ENOMEM;
		max -= iov->iov_len;
	}
	return 0;
}

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Miklos Szeredi 已提交
1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746
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;
}


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/*
 * 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.
 */
1793 1794
long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
		   unsigned int flags)
T
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1795 1796
{
	struct fuse_file *ff = file->private_data;
1797
	struct fuse_conn *fc = ff->fc;
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	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
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1807
	struct iovec *iov_page = NULL;
T
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1808 1809 1810 1811 1812
	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
1813 1814 1815 1816 1817 1818 1819
#if BITS_PER_LONG == 32
	inarg.flags |= FUSE_IOCTL_32BIT;
#else
	if (flags & FUSE_IOCTL_COMPAT)
		inarg.flags |= FUSE_IOCTL_32BIT;
#endif

T
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1820
	/* assume all the iovs returned by client always fits in a page */
M
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1821
	BUILD_BUG_ON(sizeof(struct fuse_ioctl_iovec) * FUSE_IOCTL_MAX_IOV > PAGE_SIZE);
T
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1822 1823

	err = -ENOMEM;
1824
	pages = kcalloc(FUSE_MAX_PAGES_PER_REQ, sizeof(pages[0]), GFP_KERNEL);
M
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1825
	iov_page = (struct iovec *) __get_free_page(GFP_KERNEL);
T
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1826 1827 1828 1829 1830 1831 1832 1833
	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
1834
		struct iovec *iov = iov_page;
T
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1835

M
Miklos Szeredi 已提交
1836
		iov->iov_base = (void __user *)arg;
T
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1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882
		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++;
	}

	req = fuse_get_req(fc);
	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;

	/* okay, let's send it to the client */
	req->in.h.opcode = FUSE_IOCTL;
1883
	req->in.h.nodeid = ff->nodeid;
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	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;

1905
	fuse_request_send(fc, req);
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	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
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1915
		void *vaddr;
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1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934

		/* 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;

1935
		vaddr = kmap_atomic(pages[0]);
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1936
		err = fuse_copy_ioctl_iovec(fc, iov_page, vaddr,
1937 1938
					    transferred, in_iovs + out_iovs,
					    (flags & FUSE_IOCTL_COMPAT) != 0);
1939
		kunmap_atomic(vaddr);
1940 1941
		if (err)
			goto out;
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1942

M
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1943
		in_iov = iov_page;
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1944 1945
		out_iov = in_iov + in_iovs;

M
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1946 1947 1948 1949 1950 1951 1952 1953
		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;

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1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964
		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);
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1965
	free_page((unsigned long) iov_page);
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1966 1967 1968 1969 1970 1971
	while (num_pages)
		__free_page(pages[--num_pages]);
	kfree(pages);

	return err ? err : outarg.result;
}
1972
EXPORT_SYMBOL_GPL(fuse_do_ioctl);
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1973

1974 1975
long fuse_ioctl_common(struct file *file, unsigned int cmd,
		       unsigned long arg, unsigned int flags)
1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988
{
	struct inode *inode = file->f_dentry->d_inode;
	struct fuse_conn *fc = get_fuse_conn(inode);

	if (!fuse_allow_task(fc, current))
		return -EACCES;

	if (is_bad_inode(inode))
		return -EIO;

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

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static long fuse_file_ioctl(struct file *file, unsigned int cmd,
			    unsigned long arg)
{
1992
	return fuse_ioctl_common(file, cmd, arg, 0);
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}

static long fuse_file_compat_ioctl(struct file *file, unsigned int cmd,
				   unsigned long arg)
{
1998
	return fuse_ioctl_common(file, cmd, arg, FUSE_IOCTL_COMPAT);
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}

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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 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051
/*
 * 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);
}

2052
unsigned fuse_file_poll(struct file *file, poll_table *wait)
T
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2053 2054
{
	struct fuse_file *ff = file->private_data;
2055
	struct fuse_conn *fc = ff->fc;
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2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076
	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);

	/*
	 * 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);
	}

	req = fuse_get_req(fc);
	if (IS_ERR(req))
2077
		return POLLERR;
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2078 2079

	req->in.h.opcode = FUSE_POLL;
2080
	req->in.h.nodeid = ff->nodeid;
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2081 2082 2083 2084 2085 2086
	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;
2087
	fuse_request_send(fc, req);
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	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;
}
2099
EXPORT_SYMBOL_GPL(fuse_file_poll);
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/*
 * 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;
}

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Anand Avati 已提交
2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175
static ssize_t fuse_loop_dio(struct file *filp, const struct iovec *iov,
			     unsigned long nr_segs, loff_t *ppos, int rw)
{
	const struct iovec *vector = iov;
	ssize_t ret = 0;

	while (nr_segs > 0) {
		void __user *base;
		size_t len;
		ssize_t nr;

		base = vector->iov_base;
		len = vector->iov_len;
		vector++;
		nr_segs--;

		if (rw == WRITE)
			nr = __fuse_direct_write(filp, base, len, ppos);
		else
			nr = fuse_direct_read(filp, base, len, ppos);

		if (nr < 0) {
			if (!ret)
				ret = nr;
			break;
		}
		ret += nr;
		if (nr != len)
			break;
	}

	return ret;
}


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;
	struct file *file = NULL;
	loff_t pos = 0;

	file = iocb->ki_filp;
	pos = offset;

	ret = fuse_loop_dio(file, iov, nr_segs, &pos, rw);

	return ret;
}

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Anatol Pomozov 已提交
2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189
long fuse_file_fallocate(struct file *file, int mode, loff_t offset,
			    loff_t length)
{
	struct fuse_file *ff = file->private_data;
	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;

2190 2191 2192
	if (fc->no_fallocate)
		return -EOPNOTSUPP;

A
Anatol Pomozov 已提交
2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203
	req = fuse_get_req(fc);
	if (IS_ERR(req))
		return PTR_ERR(req);

	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;
2204 2205 2206 2207
	if (err == -ENOSYS) {
		fc->no_fallocate = 1;
		err = -EOPNOTSUPP;
	}
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2208 2209 2210 2211 2212 2213
	fuse_put_request(fc, req);

	return err;
}
EXPORT_SYMBOL_GPL(fuse_file_fallocate);

2214
static const struct file_operations fuse_file_operations = {
M
Miklos Szeredi 已提交
2215
	.llseek		= fuse_file_llseek,
2216
	.read		= do_sync_read,
M
Miklos Szeredi 已提交
2217
	.aio_read	= fuse_file_aio_read,
2218
	.write		= do_sync_write,
N
Nick Piggin 已提交
2219
	.aio_write	= fuse_file_aio_write,
M
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2220 2221 2222 2223 2224
	.mmap		= fuse_file_mmap,
	.open		= fuse_open,
	.flush		= fuse_flush,
	.release	= fuse_release,
	.fsync		= fuse_fsync,
2225
	.lock		= fuse_file_lock,
2226
	.flock		= fuse_file_flock,
2227
	.splice_read	= generic_file_splice_read,
T
Tejun Heo 已提交
2228 2229
	.unlocked_ioctl	= fuse_file_ioctl,
	.compat_ioctl	= fuse_file_compat_ioctl,
T
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2230
	.poll		= fuse_file_poll,
A
Anatol Pomozov 已提交
2231
	.fallocate	= fuse_file_fallocate,
M
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2232 2233
};

2234
static const struct file_operations fuse_direct_io_file_operations = {
M
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2235
	.llseek		= fuse_file_llseek,
M
Miklos Szeredi 已提交
2236 2237
	.read		= fuse_direct_read,
	.write		= fuse_direct_write,
2238
	.mmap		= fuse_direct_mmap,
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Miklos Szeredi 已提交
2239 2240 2241 2242
	.open		= fuse_open,
	.flush		= fuse_flush,
	.release	= fuse_release,
	.fsync		= fuse_fsync,
2243
	.lock		= fuse_file_lock,
2244
	.flock		= fuse_file_flock,
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Tejun Heo 已提交
2245 2246
	.unlocked_ioctl	= fuse_file_ioctl,
	.compat_ioctl	= fuse_file_compat_ioctl,
T
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2247
	.poll		= fuse_file_poll,
A
Anatol Pomozov 已提交
2248
	.fallocate	= fuse_file_fallocate,
2249
	/* no splice_read */
M
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2250 2251
};

2252
static const struct address_space_operations fuse_file_aops  = {
M
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2253
	.readpage	= fuse_readpage,
M
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2254 2255
	.writepage	= fuse_writepage,
	.launder_page	= fuse_launder_page,
2256
	.readpages	= fuse_readpages,
M
Miklos Szeredi 已提交
2257
	.set_page_dirty	= __set_page_dirty_nobuffers,
M
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2258
	.bmap		= fuse_bmap,
A
Anand Avati 已提交
2259
	.direct_IO	= fuse_direct_IO,
M
Miklos Szeredi 已提交
2260 2261 2262 2263
};

void fuse_init_file_inode(struct inode *inode)
{
2264 2265
	inode->i_fop = &fuse_file_operations;
	inode->i_data.a_ops = &fuse_file_aops;
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Miklos Szeredi 已提交
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}