Commit 4e10f3c9 authored by Al Viro's avatar Al Viro
Browse files

Kill indirect include of file.h from eventfd.h, use fdget() in cgroup.c 



kernel/cgroup.c is the only place in the tree that relies on eventfd.h
pulling file.h; move that include there.  Switch from eventfd_fget()/fput()
to fdget()/fdput(), while we are at it - eventfd_ctx_fileget() will fail
on non-eventfd descriptors just fine, no need to do that check twice...

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent d0407903

include/linux/eventfd.h

+2 −1
Original line number Diff line number Diff line
@@ -9,7 +9,6 @@ 
#define _LINUX_EVENTFD_H



#include <linux/fcntl.h>

#include <linux/file.h>

#include <linux/wait.h>



/*
@@ -26,6 +25,8 @@ 
#define EFD_SHARED_FCNTL_FLAGS (O_CLOEXEC | O_NONBLOCK)

#define EFD_FLAGS_SET (EFD_SHARED_FCNTL_FLAGS | EFD_SEMAPHORE)



struct file;



#ifdef CONFIG_EVENTFD



struct file *eventfd_file_create(unsigned int count, int flags);

kernel/cgroup.c

+17 −16
Original line number Diff line number Diff line
@@ -60,6 +60,7 @@ 
#include <linux/poll.h>

#include <linux/flex_array.h> /* used in cgroup_attach_task */

#include <linux/kthread.h>

#include <linux/file.h>



#include <linux/atomic.h>
@@ -4034,8 +4035,8 @@ static int cgroup_write_event_control(struct cgroup_subsys_state *dummy_css, 
	struct cgroup_event *event;

	struct cgroup_subsys_state *cfile_css;

	unsigned int efd, cfd;

	struct file *efile;

	struct file *cfile;

	struct fd efile;

	struct fd cfile;

	char *endp;

	int ret;
@@ -4058,31 +4059,31 @@ static int cgroup_write_event_control(struct cgroup_subsys_state *dummy_css, 
	init_waitqueue_func_entry(&event->wait, cgroup_event_wake);

	INIT_WORK(&event->remove, cgroup_event_remove);



	efile = eventfd_fget(efd);

	if (IS_ERR(efile)) {

		ret = PTR_ERR(efile);

	efile = fdget(efd);

	if (!efile.file) {

		ret = -EBADF;

		goto out_kfree;

	}



	event->eventfd = eventfd_ctx_fileget(efile);

	event->eventfd = eventfd_ctx_fileget(efile.file);

	if (IS_ERR(event->eventfd)) {

		ret = PTR_ERR(event->eventfd);

		goto out_put_efile;

	}



	cfile = fget(cfd);

	if (!cfile) {

	cfile = fdget(cfd);

	if (!cfile.file) {

		ret = -EBADF;

		goto out_put_eventfd;

	}



	/* the process need read permission on control file */

	/* AV: shouldn't we check that it's been opened for read instead? */

	ret = inode_permission(file_inode(cfile), MAY_READ);

	ret = inode_permission(file_inode(cfile.file), MAY_READ);

	if (ret < 0)

		goto out_put_cfile;



	event->cft = __file_cft(cfile);

	event->cft = __file_cft(cfile.file);

	if (IS_ERR(event->cft)) {

		ret = PTR_ERR(event->cft);

		goto out_put_cfile;
@@ -4103,7 +4104,7 @@ static int cgroup_write_event_control(struct cgroup_subsys_state *dummy_css, 


	ret = -EINVAL;

	event->css = cgroup_css(cgrp, event->cft->ss);

	cfile_css = css_from_dir(cfile->f_dentry->d_parent, event->cft->ss);

	cfile_css = css_from_dir(cfile.file->f_dentry->d_parent, event->cft->ss);

	if (event->css && event->css == cfile_css && css_tryget(event->css))

		ret = 0;
@@ -4121,25 +4122,25 @@ static int cgroup_write_event_control(struct cgroup_subsys_state *dummy_css, 
	if (ret)

		goto out_put_css;



	efile->f_op->poll(efile, &event->pt);

	efile.file->f_op->poll(efile.file, &event->pt);



	spin_lock(&cgrp->event_list_lock);

	list_add(&event->list, &cgrp->event_list);

	spin_unlock(&cgrp->event_list_lock);



	fput(cfile);

	fput(efile);

	fdput(cfile);

	fdput(efile);



	return 0;



out_put_css:

	css_put(event->css);

out_put_cfile:

	fput(cfile);

	fdput(cfile);

out_put_eventfd:

	eventfd_ctx_put(event->eventfd);

out_put_efile:

	fput(efile);

	fdput(efile);

out_kfree:

	kfree(event);

CRA Git | Maintained and supported by SUSTech CRA and CCSE