예제 #1
0
int fuse_lookup_name(struct super_block *sb, u64 nodeid, struct qstr *name,
		     struct fuse_entry_out *outarg, struct inode **inode)
{
	struct fuse_conn *fc = get_fuse_conn_super(sb);
	struct fuse_req *req;
	struct fuse_req *forget_req;
	u64 attr_version;
	int err;

	*inode = NULL;
	err = -ENAMETOOLONG;
	if (name->len > FUSE_NAME_MAX)
		goto out;

	FUSE_MIGHT_FREEZE(sb, "fuse_lookup_name");

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

	forget_req = fuse_get_req(fc);
	err = PTR_ERR(forget_req);
	if (IS_ERR(forget_req)) {
		fuse_put_request(fc, req);
		goto out;
	}

	attr_version = fuse_get_attr_version(fc);

	fuse_lookup_init(fc, req, nodeid, name, outarg);
	fuse_request_send(fc, req);
	err = req->out.h.error;
	fuse_put_request(fc, req);
	/* Zero nodeid is same as -ENOENT, but with valid timeout */
	if (err || !outarg->nodeid)
		goto out_put_forget;

	err = -EIO;
	if (!outarg->nodeid)
		goto out_put_forget;
	if (!fuse_valid_type(outarg->attr.mode))
		goto out_put_forget;

	*inode = fuse_iget(sb, outarg->nodeid, outarg->generation,
			   &outarg->attr, entry_attr_timeout(outarg),
			   attr_version);
	err = -ENOMEM;
	if (!*inode) {
		fuse_send_forget(fc, forget_req, outarg->nodeid, 1);
		goto out;
	}
	err = 0;

 out_put_forget:
	fuse_put_request(fc, forget_req);
 out:
	return err;
}
예제 #2
0
파일: dir.c 프로젝트: mkrufky/linux
static int fuse_readdir(struct file *file, struct dir_context *ctx)
{
	int plus, err;
	size_t nbytes;
	struct page *page;
	struct inode *inode = file_inode(file);
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_req *req;
	u64 attr_version = 0;

	if (is_bad_inode(inode))
		return -EIO;

	req = fuse_get_req(fc, 1);
	if (IS_ERR(req))
		return PTR_ERR(req);

	page = alloc_page(GFP_KERNEL);
	if (!page) {
		fuse_put_request(fc, req);
		return -ENOMEM;
	}

	plus = fuse_use_readdirplus(inode, ctx);
	req->out.argpages = 1;
	req->num_pages = 1;
	req->pages[0] = page;
	req->page_descs[0].length = PAGE_SIZE;
	if (plus) {
		attr_version = fuse_get_attr_version(fc);
		fuse_read_fill(req, file, ctx->pos, PAGE_SIZE,
			       FUSE_READDIRPLUS);
	} else {
		fuse_read_fill(req, file, ctx->pos, PAGE_SIZE,
			       FUSE_READDIR);
	}
	fuse_lock_inode(inode);
	fuse_request_send(fc, req);
	fuse_unlock_inode(inode);
	nbytes = req->out.args[0].size;
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (!err) {
		if (plus) {
			err = parse_dirplusfile(page_address(page), nbytes,
						file, ctx,
						attr_version);
		} else {
			err = parse_dirfile(page_address(page), nbytes, file,
					    ctx);
		}
	}

	__free_page(page);
	fuse_invalidate_atime(inode);
	return err;
}
예제 #3
0
int fuse_lookup_name(struct super_block *sb, u64 nodeid, struct qstr *name,
		     struct fuse_entry_out *outarg, struct inode **inode)
{
	struct fuse_conn *fc = get_fuse_conn_super(sb);
	struct fuse_req *req;
	struct fuse_forget_link *forget;
	u64 attr_version;
	int err;

	*inode = NULL;
	err = -ENAMETOOLONG;
	if (name->len > FUSE_NAME_MAX)
		goto out;

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

	forget = fuse_alloc_forget();
	err = -ENOMEM;
	if (!forget) {
		fuse_put_request(fc, req);
		goto out;
	}

	attr_version = fuse_get_attr_version(fc);

	fuse_lookup_init(fc, req, nodeid, name, outarg);
	fuse_request_send(fc, req);
	err = req->out.h.error;
	fuse_put_request(fc, req);
	
	if (err || !outarg->nodeid)
		goto out_put_forget;

	err = -EIO;
	if (!outarg->nodeid)
		goto out_put_forget;
	if (!fuse_valid_type(outarg->attr.mode))
		goto out_put_forget;

	*inode = fuse_iget(sb, outarg->nodeid, outarg->generation,
			   &outarg->attr, entry_attr_timeout(outarg),
			   attr_version);
	err = -ENOMEM;
	if (!*inode) {
		fuse_queue_forget(fc, forget, outarg->nodeid, 1);
		goto out;
	}
	err = 0;

 out_put_forget:
	kfree(forget);
 out:
	return err;
}
예제 #4
0
static int fuse_do_getattr(struct inode *inode, struct kstat *stat,
			   struct file *file)
{
	int err;
	struct fuse_getattr_in inarg;
	struct fuse_attr_out outarg;
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_req *req;
	u64 attr_version;

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

	attr_version = fuse_get_attr_version(fc);

	memset(&inarg, 0, sizeof(inarg));
	memset(&outarg, 0, sizeof(outarg));
	/* Directories have separate file-handle space */
	if (file && S_ISREG(inode->i_mode)) {
		struct fuse_file *ff = file->private_data;

		inarg.getattr_flags |= FUSE_GETATTR_FH;
		inarg.fh = ff->fh;
	}
	req->in.h.opcode = FUSE_GETATTR;
	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;
	if (fc->minor < 9)
		req->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE;
	else
		req->out.args[0].size = sizeof(outarg);
	req->out.args[0].value = &outarg;
	fuse_request_send(fc, req);
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (!err) {
		if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) {
			make_bad_inode(inode);
			err = -EIO;
		} else {
			fuse_change_attributes(inode, &outarg.attr,
					       attr_timeout(&outarg),
					       attr_version);
			if (stat)
				fuse_fillattr(inode, &outarg.attr, stat);
		}
	}
	return err;
}
예제 #5
0
파일: dir.c 프로젝트: mkrufky/linux
int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name,
		     struct fuse_entry_out *outarg, struct inode **inode)
{
	struct fuse_conn *fc = get_fuse_conn_super(sb);
	FUSE_ARGS(args);
	struct fuse_forget_link *forget;
	u64 attr_version;
	int err;

	*inode = NULL;
	err = -ENAMETOOLONG;
	if (name->len > FUSE_NAME_MAX)
		goto out;


	forget = fuse_alloc_forget();
	err = -ENOMEM;
	if (!forget)
		goto out;

	attr_version = fuse_get_attr_version(fc);

	fuse_lookup_init(fc, &args, nodeid, name, outarg);
	err = fuse_simple_request(fc, &args);
	/* Zero nodeid is same as -ENOENT, but with valid timeout */
	if (err || !outarg->nodeid)
		goto out_put_forget;

	err = -EIO;
	if (!outarg->nodeid)
		goto out_put_forget;
	if (!fuse_valid_type(outarg->attr.mode))
		goto out_put_forget;

	*inode = fuse_iget(sb, outarg->nodeid, outarg->generation,
			   &outarg->attr, entry_attr_timeout(outarg),
			   attr_version);
	err = -ENOMEM;
	if (!*inode) {
		fuse_queue_forget(fc, forget, outarg->nodeid, 1);
		goto out;
	}
	err = 0;

 out_put_forget:
	kfree(forget);
 out:
	return err;
}
예제 #6
0
파일: dir.c 프로젝트: mkrufky/linux
static int fuse_do_getattr(struct inode *inode, struct kstat *stat,
			   struct file *file)
{
	int err;
	struct fuse_getattr_in inarg;
	struct fuse_attr_out outarg;
	struct fuse_conn *fc = get_fuse_conn(inode);
	FUSE_ARGS(args);
	u64 attr_version;

	attr_version = fuse_get_attr_version(fc);

	memset(&inarg, 0, sizeof(inarg));
	memset(&outarg, 0, sizeof(outarg));
	/* Directories have separate file-handle space */
	if (file && S_ISREG(inode->i_mode)) {
		struct fuse_file *ff = file->private_data;

		inarg.getattr_flags |= FUSE_GETATTR_FH;
		inarg.fh = ff->fh;
	}
	args.in.h.opcode = FUSE_GETATTR;
	args.in.h.nodeid = get_node_id(inode);
	args.in.numargs = 1;
	args.in.args[0].size = sizeof(inarg);
	args.in.args[0].value = &inarg;
	args.out.numargs = 1;
	args.out.args[0].size = sizeof(outarg);
	args.out.args[0].value = &outarg;
	err = fuse_simple_request(fc, &args);
	if (!err) {
		if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) {
			make_bad_inode(inode);
			err = -EIO;
		} else {
			fuse_change_attributes(inode, &outarg.attr,
					       attr_timeout(&outarg),
					       attr_version);
			if (stat)
				fuse_fillattr(inode, &outarg.attr, stat);
		}
	}
	return err;
}
예제 #7
0
/*
 * Check whether the dentry is still valid
 *
 * If the entry validity timeout has expired and the dentry is
 * positive, try to redo the lookup.  If the lookup results in a
 * different inode, then let the VFS invalidate the dentry and redo
 * the lookup once more.  If the lookup results in the same inode,
 * then refresh the attributes, timeouts and mark the dentry valid.
 */
static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags)
{
	struct inode *inode;
	struct dentry *parent;
	struct fuse_conn *fc;
	int ret;

	inode = ACCESS_ONCE(entry->d_inode);
	if (inode && is_bad_inode(inode))
		goto invalid;
	else if (fuse_dentry_time(entry) < get_jiffies_64()) {
		int err;
		struct fuse_entry_out outarg;
		struct fuse_req *req;
		struct fuse_forget_link *forget;
		u64 attr_version;

		/* For negative dentries, always do a fresh lookup */
		if (!inode)
			goto invalid;

		ret = -ECHILD;
		if (flags & LOOKUP_RCU)
			goto out;

		fc = get_fuse_conn(inode);
		req = fuse_get_req_nopages(fc);
		ret = PTR_ERR(req);
		if (IS_ERR(req))
			goto out;

		forget = fuse_alloc_forget();
		if (!forget) {
			fuse_put_request(fc, req);
			ret = -ENOMEM;
			goto out;
		}

		attr_version = fuse_get_attr_version(fc);

		parent = dget_parent(entry);
		fuse_lookup_init(fc, req, get_node_id(parent->d_inode),
				 &entry->d_name, &outarg);
		fuse_request_send(fc, req);
		dput(parent);
		err = req->out.h.error;
		fuse_put_request(fc, req);
		/* Zero nodeid is same as -ENOENT */
		if (!err && !outarg.nodeid)
			err = -ENOENT;
		if (!err) {
			struct fuse_inode *fi = get_fuse_inode(inode);
			if (outarg.nodeid != get_node_id(inode)) {
				fuse_queue_forget(fc, forget, outarg.nodeid, 1);
				goto invalid;
			}
			spin_lock(&fc->lock);
			fi->nlookup++;
			spin_unlock(&fc->lock);
		}
		kfree(forget);
		if (err || (outarg.attr.mode ^ inode->i_mode) & S_IFMT)
			goto invalid;

		fuse_change_attributes(inode, &outarg.attr,
				       entry_attr_timeout(&outarg),
				       attr_version);
		fuse_change_entry_timeout(entry, &outarg);
	} else if (inode) {
		fc = get_fuse_conn(inode);
		if (fc->readdirplus_auto) {
			parent = dget_parent(entry);
			fuse_advise_use_readdirplus(parent->d_inode);
			dput(parent);
		}
	}
	ret = 1;
out:
	return ret;

invalid:
	ret = 0;
	if (check_submounts_and_drop(entry) != 0)
		ret = 1;
	goto out;
}
예제 #8
0
/*
 * Check whether the dentry is still valid
 *
 * If the entry validity timeout has expired and the dentry is
 * positive, try to redo the lookup.  If the lookup results in a
 * different inode, then let the VFS invalidate the dentry and redo
 * the lookup once more.  If the lookup results in the same inode,
 * then refresh the attributes, timeouts and mark the dentry valid.
 */
static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd)
{
	struct inode *inode = entry->d_inode;

	if (inode && is_bad_inode(inode))
		return 0;
	else if (fuse_dentry_time(entry) < get_jiffies_64()) {
		int err;
		struct fuse_entry_out outarg;
		struct fuse_conn *fc;
		struct fuse_req *req;
		struct fuse_req *forget_req;
		struct dentry *parent;
		u64 attr_version;

		/* For negative dentries, always do a fresh lookup */
		if (!inode)
			return 0;

		fc = get_fuse_conn(inode);
		req = fuse_get_req(fc);
		if (IS_ERR(req))
			return 0;

		forget_req = fuse_get_req(fc);
		if (IS_ERR(forget_req)) {
			fuse_put_request(fc, req);
			return 0;
		}

		attr_version = fuse_get_attr_version(fc);

		parent = dget_parent(entry);
		fuse_lookup_init(fc, req, get_node_id(parent->d_inode),
				 &entry->d_name, &outarg);
		fuse_request_send(fc, req);
		dput(parent);
		err = req->out.h.error;
		fuse_put_request(fc, req);
		/* Zero nodeid is same as -ENOENT */
		if (!err && !outarg.nodeid)
			err = -ENOENT;
		if (!err) {
			struct fuse_inode *fi = get_fuse_inode(inode);
			if (outarg.nodeid != get_node_id(inode)) {
				fuse_send_forget(fc, forget_req,
						 outarg.nodeid, 1);
				return 0;
			}
			spin_lock(&fc->lock);
			fi->nlookup++;
			spin_unlock(&fc->lock);
		}
		fuse_put_request(fc, forget_req);
		if (err || (outarg.attr.mode ^ inode->i_mode) & S_IFMT)
			return 0;

		fuse_change_attributes(inode, &outarg.attr,
				       entry_attr_timeout(&outarg),
				       attr_version);
		fuse_change_entry_timeout(entry, &outarg);
	}
	return 1;
}
예제 #9
0
파일: dir.c 프로젝트: mkrufky/linux
/*
 * Check whether the dentry is still valid
 *
 * If the entry validity timeout has expired and the dentry is
 * positive, try to redo the lookup.  If the lookup results in a
 * different inode, then let the VFS invalidate the dentry and redo
 * the lookup once more.  If the lookup results in the same inode,
 * then refresh the attributes, timeouts and mark the dentry valid.
 */
static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags)
{
	struct inode *inode;
	struct dentry *parent;
	struct fuse_conn *fc;
	struct fuse_inode *fi;
	int ret;

	inode = d_inode_rcu(entry);
	if (inode && is_bad_inode(inode))
		goto invalid;
	else if (time_before64(fuse_dentry_time(entry), get_jiffies_64()) ||
		 (flags & LOOKUP_REVAL)) {
		struct fuse_entry_out outarg;
		FUSE_ARGS(args);
		struct fuse_forget_link *forget;
		u64 attr_version;

		/* For negative dentries, always do a fresh lookup */
		if (!inode)
			goto invalid;

		ret = -ECHILD;
		if (flags & LOOKUP_RCU)
			goto out;

		fc = get_fuse_conn(inode);

		forget = fuse_alloc_forget();
		ret = -ENOMEM;
		if (!forget)
			goto out;

		attr_version = fuse_get_attr_version(fc);

		parent = dget_parent(entry);
		fuse_lookup_init(fc, &args, get_node_id(d_inode(parent)),
				 &entry->d_name, &outarg);
		ret = fuse_simple_request(fc, &args);
		dput(parent);
		/* Zero nodeid is same as -ENOENT */
		if (!ret && !outarg.nodeid)
			ret = -ENOENT;
		if (!ret) {
			fi = get_fuse_inode(inode);
			if (outarg.nodeid != get_node_id(inode)) {
				fuse_queue_forget(fc, forget, outarg.nodeid, 1);
				goto invalid;
			}
			spin_lock(&fc->lock);
			fi->nlookup++;
			spin_unlock(&fc->lock);
		}
		kfree(forget);
		if (ret == -ENOMEM)
			goto out;
		if (ret || (outarg.attr.mode ^ inode->i_mode) & S_IFMT)
			goto invalid;

		forget_all_cached_acls(inode);
		fuse_change_attributes(inode, &outarg.attr,
				       entry_attr_timeout(&outarg),
				       attr_version);
		fuse_change_entry_timeout(entry, &outarg);
	} else if (inode) {
		fi = get_fuse_inode(inode);
		if (flags & LOOKUP_RCU) {
			if (test_bit(FUSE_I_INIT_RDPLUS, &fi->state))
				return -ECHILD;
		} else if (test_and_clear_bit(FUSE_I_INIT_RDPLUS, &fi->state)) {
			parent = dget_parent(entry);
			fuse_advise_use_readdirplus(d_inode(parent));
			dput(parent);
		}
	}
	ret = 1;
out:
	return ret;

invalid:
	ret = 0;
	goto out;
}
예제 #10
0
static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd)
{
	struct inode *inode;

	inode = ACCESS_ONCE(entry->d_inode);
	if (inode && is_bad_inode(inode))
		return 0;
	else if (fuse_dentry_time(entry) < get_jiffies_64()) {
		int err;
		struct fuse_entry_out outarg;
		struct fuse_conn *fc;
		struct fuse_req *req;
		struct fuse_forget_link *forget;
		struct dentry *parent;
		u64 attr_version;

		
		if (!inode)
			return 0;

		if (nd && (nd->flags & LOOKUP_RCU))
			return -ECHILD;

		fc = get_fuse_conn(inode);
		req = fuse_get_req(fc);
		if (IS_ERR(req))
			return 0;

		forget = fuse_alloc_forget();
		if (!forget) {
			fuse_put_request(fc, req);
			return 0;
		}

		attr_version = fuse_get_attr_version(fc);

		parent = dget_parent(entry);
		fuse_lookup_init(fc, req, get_node_id(parent->d_inode),
				 &entry->d_name, &outarg);
		fuse_request_send(fc, req);
		dput(parent);
		err = req->out.h.error;
		fuse_put_request(fc, req);
		
		if (!err && !outarg.nodeid)
			err = -ENOENT;
		if (!err) {
			struct fuse_inode *fi = get_fuse_inode(inode);
			if (outarg.nodeid != get_node_id(inode)) {
				fuse_queue_forget(fc, forget, outarg.nodeid, 1);
				return 0;
			}
			spin_lock(&fc->lock);
			fi->nlookup++;
			spin_unlock(&fc->lock);
		}
		kfree(forget);
		if (err || (outarg.attr.mode ^ inode->i_mode) & S_IFMT)
			return 0;

		fuse_change_attributes(inode, &outarg.attr,
				       entry_attr_timeout(&outarg),
				       attr_version);
		fuse_change_entry_timeout(entry, &outarg);
	}
	return 1;
}
예제 #11
0
static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
				  struct nameidata *nd)
{
	int err;
	struct fuse_entry_out outarg;
	struct inode *inode = NULL;
	struct fuse_conn *fc = get_fuse_conn(dir);
	struct fuse_req *req;
	struct fuse_req *forget_req;
	u64 attr_version;

	if (entry->d_name.len > FUSE_NAME_MAX)
		return ERR_PTR(-ENAMETOOLONG);

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

	forget_req = fuse_get_req(fc);
	if (IS_ERR(forget_req)) {
		fuse_put_request(fc, req);
		return ERR_PTR(PTR_ERR(forget_req));
	}

	attr_version = fuse_get_attr_version(fc);

	fuse_lookup_init(req, dir, entry, &outarg);
	request_send(fc, req);
	err = req->out.h.error;
	fuse_put_request(fc, req);
	/* Zero nodeid is same as -ENOENT, but with valid timeout */
	if (!err && outarg.nodeid &&
	    (invalid_nodeid(outarg.nodeid) ||
	     !fuse_valid_type(outarg.attr.mode)))
		err = -EIO;
	if (!err && outarg.nodeid) {
		inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation,
				  &outarg.attr, entry_attr_timeout(&outarg),
				  attr_version);
		if (!inode) {
			fuse_send_forget(fc, forget_req, outarg.nodeid, 1);
			return ERR_PTR(-ENOMEM);
		}
	}
	fuse_put_request(fc, forget_req);
	if (err && err != -ENOENT)
		return ERR_PTR(err);

	if (inode && S_ISDIR(inode->i_mode)) {
		mutex_lock(&fc->inst_mutex);
		err = fuse_d_add_directory(entry, inode);
		mutex_unlock(&fc->inst_mutex);
		if (err) {
			iput(inode);
			return ERR_PTR(err);
		}
	} else
		d_add(entry, inode);

	entry->d_op = &fuse_dentry_operations;
	if (!err)
		fuse_change_entry_timeout(entry, &outarg);
	else
		fuse_invalidate_entry_cache(entry);
	return NULL;
}
예제 #12
0
static int fuse_direntplus_link(struct file *file,
				struct fuse_direntplus *direntplus,
				u64 attr_version)
{
	int err;
	struct fuse_entry_out *o = &direntplus->entry_out;
	struct fuse_dirent *dirent = &direntplus->dirent;
	struct dentry *parent = file->f_path.dentry;
	struct qstr name = { .len = dirent->namelen, .name = dirent->name };
	struct dentry *dentry;
	struct dentry *alias;
	struct inode *dir = parent->d_inode;
	struct fuse_conn *fc;
	struct inode *inode;

	if (!o->nodeid) {
		/*
		 * Unlike in the case of fuse_lookup, zero nodeid does not mean
		 * ENOENT. Instead, it only means the userspace filesystem did
		 * not want to return attributes/handle for this entry.
		 *
		 * So do nothing.
		 */
		return 0;
	}

	if (name.name[0] == '.') {
		/*
		 * We could potentially refresh the attributes of the directory
		 * and its parent?
		 */
		if (name.len == 1)
			return 0;
		if (name.name[1] == '.' && name.len == 2)
			return 0;
	}

	if (invalid_nodeid(o->nodeid))
		return -EIO;
	if (!fuse_valid_type(o->attr.mode))
		return -EIO;

	fc = get_fuse_conn(dir);

	name.hash = full_name_hash(name.name, name.len);
	dentry = d_lookup(parent, &name);
	if (dentry) {
		inode = dentry->d_inode;
		if (!inode) {
			d_drop(dentry);
		} else if (get_node_id(inode) != o->nodeid ||
			   ((o->attr.mode ^ inode->i_mode) & S_IFMT)) {
			err = d_invalidate(dentry);
			if (err)
				goto out;
		} else if (is_bad_inode(inode)) {
			err = -EIO;
			goto out;
		} else {
			struct fuse_inode *fi;
			fi = get_fuse_inode(inode);
			spin_lock(&fc->lock);
			fi->nlookup++;
			spin_unlock(&fc->lock);

			fuse_change_attributes(inode, &o->attr,
					       entry_attr_timeout(o),
					       attr_version);

			/*
			 * The other branch to 'found' comes via fuse_iget()
			 * which bumps nlookup inside
			 */
			goto found;
		}
		dput(dentry);
	}

	dentry = d_alloc(parent, &name);
	err = -ENOMEM;
	if (!dentry)
		goto out;
	dentry->d_op = &fuse_dentry_operations;

	inode = fuse_iget(dir->i_sb, o->nodeid, o->generation,
			  &o->attr, entry_attr_timeout(o), attr_version);
	if (!inode)
		goto out;

	alias = fuse_materialise_dentry(dentry, inode);
	err = PTR_ERR(alias);
	if (IS_ERR(alias))
		goto out;

	if (alias) {
		dput(dentry);
		dentry = alias;
	}

found:
	fuse_change_entry_timeout(dentry, o);

	err = 0;
out:
	dput(dentry);
	return err;
}

static int parse_dirplusfile(char *buf, size_t nbytes, struct file *file,
			     void *dstbuf, filldir_t filldir, u64 attr_version)
{
	struct fuse_direntplus *direntplus;
	struct fuse_dirent *dirent;
	size_t reclen;
	int over = 0;
	int ret;

	while (nbytes >= FUSE_NAME_OFFSET_DIRENTPLUS) {
		direntplus = (struct fuse_direntplus *) buf;
		dirent = &direntplus->dirent;
		reclen = FUSE_DIRENTPLUS_SIZE(direntplus);

		if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX)
			return -EIO;
		if (reclen > nbytes)
			break;
		if (memchr(dirent->name, '/', dirent->namelen) != NULL)
			return -EIO;

		if (!over) {
			/* We fill entries into dstbuf only as much as
			   it can hold. But we still continue iterating
			   over remaining entries to link them. If not,
			   we need to send a FORGET for each of those
			   which we did not link.
			*/
			over = filldir(dstbuf, dirent->name, dirent->namelen,
				       file->f_pos, dirent->ino,
				       dirent->type);
			file->f_pos = dirent->off;
		}

		buf += reclen;
		nbytes -= reclen;

		ret = fuse_direntplus_link(file, direntplus, attr_version);
		if (ret)
			fuse_force_forget(file, direntplus->entry_out.nodeid);
	}

	return 0;
}

static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir)
{
	int plus, err;
	size_t nbytes;
	struct page *page;
	struct inode *inode = file->f_path.dentry->d_inode;
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_req *req;
	u64 attr_version = 0;

	if (is_bad_inode(inode))
		return -EIO;

	req = fuse_get_req(fc, 1);
	if (IS_ERR(req))
		return PTR_ERR(req);

	page = alloc_page(GFP_KERNEL);
	if (!page) {
		fuse_put_request(fc, req);
		return -ENOMEM;
	}

	plus = fuse_use_readdirplus(inode, file);
	req->out.argpages = 1;
	req->num_pages = 1;
	req->pages[0] = page;
	req->page_descs[0].length = PAGE_SIZE;
	if (plus) {
		attr_version = fuse_get_attr_version(fc);
		fuse_read_fill(req, file, file->f_pos, PAGE_SIZE,
			       FUSE_READDIRPLUS);
	} else {
		fuse_read_fill(req, file, file->f_pos, PAGE_SIZE,
			       FUSE_READDIR);
	}
	fuse_request_send(fc, req);
	nbytes = req->out.args[0].size;
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (!err) {
		if (plus) {
			err = parse_dirplusfile(page_address(page), nbytes,
						file, dstbuf, filldir,
						attr_version);
		} else {
			err = parse_dirfile(page_address(page), nbytes, file,
					    dstbuf, filldir);
		}
	}

	__free_page(page);
	fuse_invalidate_attr(inode); /* atime changed */
	return err;
}