/*
 *  Copyright (C) 2008 Red Hat, Inc., Eric Paris <eparis@redhat.com>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2, or (at your option)
 *  any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; see the file COPYING.  If not, write to
 *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/fs.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mount.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>

#include <linux/atomic.h>

#include <linux/fsnotify_backend.h>
#include "fsnotify.h"

void fsnotify_clear_vfsmount_marks_by_group(struct fsnotify_group *group)
{
	fsnotify_clear_marks_by_group_flags(group, FSNOTIFY_MARK_FLAG_VFSMOUNT);
}

/*
 * Recalculate the mnt->mnt_fsnotify_mask, or the mask of all FS_* event types
 * any notifier is interested in hearing for this mount point
 */
void fsnotify_recalc_vfsmount_mask(struct vfsmount *mnt)
{
	struct mount *m = real_mount(mnt);

	spin_lock(&mnt->mnt_root->d_lock);
	m->mnt_fsnotify_mask = fsnotify_recalc_mask(&m->mnt_fsnotify_marks);
	spin_unlock(&mnt->mnt_root->d_lock);
}

void fsnotify_destroy_vfsmount_mark(struct fsnotify_mark *mark)
{
	struct vfsmount *mnt = mark->mnt;
	struct mount *m = real_mount(mnt);

	BUG_ON(!mutex_is_locked(&mark->group->mark_mutex));
	assert_spin_locked(&mark->lock);

	spin_lock(&mnt->mnt_root->d_lock);

	hlist_del_init_rcu(&mark->obj_list);
	mark->mnt = NULL;

	m->mnt_fsnotify_mask = fsnotify_recalc_mask(&m->mnt_fsnotify_marks);
	spin_unlock(&mnt->mnt_root->d_lock);
}

/*
 * given a group and vfsmount, find the mark associated with that combination.
 * if found take a reference to that mark and return it, else return NULL
 */
struct fsnotify_mark *fsnotify_find_vfsmount_mark(struct fsnotify_group *group,
						  struct vfsmount *mnt)
{
	struct mount *m = real_mount(mnt);
	struct fsnotify_mark *mark;

	spin_lock(&mnt->mnt_root->d_lock);
	mark = fsnotify_find_mark(&m->mnt_fsnotify_marks, group);
	spin_unlock(&mnt->mnt_root->d_lock);

	return mark;
}

/*
 * Attach an initialized mark to a given group and vfsmount.
 * These marks may be used for the fsnotify backend to determine which
 * event types should be delivered to which groups.
 */
int fsnotify_add_vfsmount_mark(struct fsnotify_mark *mark,
			       struct fsnotify_group *group, struct vfsmount *mnt,
			       int allow_dups)
{
	struct mount *m = real_mount(mnt);
	int ret;

	mark->flags |= FSNOTIFY_MARK_FLAG_VFSMOUNT;

	BUG_ON(!mutex_is_locked(&group->mark_mutex));
	assert_spin_locked(&mark->lock);

	spin_lock(&mnt->mnt_root->d_lock);
	mark->mnt = mnt;
	ret = fsnotify_add_mark_list(&m->mnt_fsnotify_marks, mark, allow_dups);
	m->mnt_fsnotify_mask = fsnotify_recalc_mask(&m->mnt_fsnotify_marks);
	spin_unlock(&mnt->mnt_root->d_lock);

	return ret;
}
r</th><th class='left'>Files</th><th class='left'>Lines</th></tr>
git/commit/net/netlink/af_netlink.h?h=nds-private-remove&amp;id=07cd12945551b63ecb1a349d50a6d69d1d6feb4a'>af_netlink.h</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='h' value='nds-private-remove'/><input type='hidden' name='id' value='07cd12945551b63ecb1a349d50a6d69d1d6feb4a'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Tejun Heo &lt;tj@kernel.org&gt;</td><td class='right'>2017-01-26 16:47:28 -0500</td></tr>
<tr><th>committer</th><td>Tejun Heo &lt;tj@kernel.org&gt;</td><td class='right'>2017-01-26 16:47:28 -0500</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/netlink/af_netlink.h?h=nds-private-remove&amp;id=07cd12945551b63ecb1a349d50a6d69d1d6feb4a'>07cd12945551b63ecb1a349d50a6d69d1d6feb4a</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/netlink/af_netlink.h?id=07cd12945551b63ecb1a349d50a6d69d1d6feb4a'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?h=nds-private-remove&amp;id=07cd12945551b63ecb1a349d50a6d69d1d6feb4a'>75f65eba7eac9277971082a2d5a4cf1370562c0c</a> /<a href='/cgit.cgi/linux/net-next.git/tree/net/netlink/af_netlink.h?h=nds-private-remove&amp;id=07cd12945551b63ecb1a349d50a6d69d1d6feb4a'>net/netlink/af_netlink.h</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/netlink/af_netlink.h?h=nds-private-remove&amp;id=7ce7d89f48834cefece7804d38fc5d85382edf77'>7ce7d89f48834cefece7804d38fc5d85382edf77</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/netlink/af_netlink.h?h=nds-private-remove&amp;id=07cd12945551b63ecb1a349d50a6d69d1d6feb4a&amp;id2=7ce7d89f48834cefece7804d38fc5d85382edf77'>diff</a>)</td></tr></table>
<div class='commit-subject'>cgroup: don't online subsystems before cgroup_name/path() are operational</div><div class='commit-msg'>While refactoring cgroup creation, a5bca2152036 ("cgroup: factor out
cgroup_create() out of cgroup_mkdir()") incorrectly onlined subsystems
before the new cgroup is associated with it kernfs_node.  This is fine
for cgroup proper but cgroup_name/path() depend on the associated
kernfs_node and if a subsystem makes the new cgroup_subsys_state
visible, which they're allowed to after onlining, it can lead to NULL
dereference.

The current code performs cgroup creation and subsystem onlining in
cgroup_create() and cgroup_mkdir() makes the cgroup and subsystems
visible afterwards.  There's no reason to online the subsystems early
and we can simply drop cgroup_apply_control_enable() call from
cgroup_create() so that the subsystems are onlined and made visible at
the same time.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Reported-by: Konstantin Khlebnikov &lt;khlebnikov@yandex-team.ru&gt;
Fixes: a5bca2152036 ("cgroup: factor out cgroup_create() out of cgroup_mkdir()") 
Cc: stable@vger.kernel.org # v4.6+
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=07cd12945551b63ecb1a349d50a6d69d1d6feb4a'>Diffstat</a> (limited to 'net/netlink/af_netlink.h')</div><table summary='diffstat' class='diffstat'>