Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge branch 'for-4.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:
"During v4.6-rc1 cgroup namespace support was merged. There is an
issue where it's impossible to tell whether a given cgroup mount point
is bind mounted or namespaced. Serge has been working on the issue
but it took longer than expected to resolve, so the late pull request.
Given that it's a completely new feature and the patches don't touch
anything else, the risk seems acceptable. However, if this is too
late, an alternative is plugging new cgroup ns creation for v4.6 and
retrying for v4.7"
* 'for-4.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: fix compile warning
kernfs: kernfs_sop_show_path: don't return 0 after seq_dentry call
cgroup, kernfs: make mountinfo show properly scoped path for cgroup namespaces
kernfs_path_from_node_locked: don't overwrite nlen
+83
-3
+3
-3
fs/kernfs/dir.c
+3
-3
fs/kernfs/dir.c
···
153
153
p = buf + len + nlen;
154
154
*p = '\0';
155
155
for (kn = kn_to; kn != common; kn = kn->parent) {
156
-
nlen = strlen(kn->name);
157
-
p -= nlen;
158
-
memcpy(p, kn->name, nlen);
156
+
size_t tmp = strlen(kn->name);
157
+
p -= tmp;
158
+
memcpy(p, kn->name, tmp);
159
159
*(--p) = '/';
160
160
}
161
161
+15
fs/kernfs/mount.c
+15
fs/kernfs/mount.c
···
15
15
#include <linux/slab.h>
16
16
#include <linux/pagemap.h>
17
17
#include <linux/namei.h>
18
+
#include <linux/seq_file.h>
18
19
19
20
#include "kernfs-internal.h"
20
21
···
41
40
return 0;
42
41
}
43
42
43
+
static int kernfs_sop_show_path(struct seq_file *sf, struct dentry *dentry)
44
+
{
45
+
struct kernfs_node *node = dentry->d_fsdata;
46
+
struct kernfs_root *root = kernfs_root(node);
47
+
struct kernfs_syscall_ops *scops = root->syscall_ops;
48
+
49
+
if (scops && scops->show_path)
50
+
return scops->show_path(sf, node, root);
51
+
52
+
seq_dentry(sf, dentry, " \t\n\\");
53
+
return 0;
54
+
}
55
+
44
56
const struct super_operations kernfs_sops = {
45
57
.statfs = simple_statfs,
46
58
.drop_inode = generic_delete_inode,
···
61
47
62
48
.remount_fs = kernfs_sop_remount_fs,
63
49
.show_options = kernfs_sop_show_options,
50
+
.show_path = kernfs_sop_show_path,
64
51
};
65
52
66
53
/**
+2
include/linux/kernfs.h
+2
include/linux/kernfs.h
···
152
152
int (*rmdir)(struct kernfs_node *kn);
153
153
int (*rename)(struct kernfs_node *kn, struct kernfs_node *new_parent,
154
154
const char *new_name);
155
+
int (*show_path)(struct seq_file *sf, struct kernfs_node *kn,
156
+
struct kernfs_root *root);
155
157
};
156
158
157
159
struct kernfs_root {
+63
kernel/cgroup.c
+63
kernel/cgroup.c
···
1215
1215
cgroup_free_root(root);
1216
1216
}
1217
1217
1218
+
/*
1219
+
* look up cgroup associated with current task's cgroup namespace on the
1220
+
* specified hierarchy
1221
+
*/
1222
+
static struct cgroup *
1223
+
current_cgns_cgroup_from_root(struct cgroup_root *root)
1224
+
{
1225
+
struct cgroup *res = NULL;
1226
+
struct css_set *cset;
1227
+
1228
+
lockdep_assert_held(&css_set_lock);
1229
+
1230
+
rcu_read_lock();
1231
+
1232
+
cset = current->nsproxy->cgroup_ns->root_cset;
1233
+
if (cset == &init_css_set) {
1234
+
res = &root->cgrp;
1235
+
} else {
1236
+
struct cgrp_cset_link *link;
1237
+
1238
+
list_for_each_entry(link, &cset->cgrp_links, cgrp_link) {
1239
+
struct cgroup *c = link->cgrp;
1240
+
1241
+
if (c->root == root) {
1242
+
res = c;
1243
+
break;
1244
+
}
1245
+
}
1246
+
}
1247
+
rcu_read_unlock();
1248
+
1249
+
BUG_ON(!res);
1250
+
return res;
1251
+
}
1252
+
1218
1253
/* look up cgroup associated with given css_set on the specified hierarchy */
1219
1254
static struct cgroup *cset_cgroup_from_root(struct css_set *cset,
1220
1255
struct cgroup_root *root)
···
1626
1591
1627
1592
kernfs_activate(dcgrp->kn);
1628
1593
return 0;
1594
+
}
1595
+
1596
+
static int cgroup_show_path(struct seq_file *sf, struct kernfs_node *kf_node,
1597
+
struct kernfs_root *kf_root)
1598
+
{
1599
+
int len = 0;
1600
+
char *buf = NULL;
1601
+
struct cgroup_root *kf_cgroot = cgroup_root_from_kf(kf_root);
1602
+
struct cgroup *ns_cgroup;
1603
+
1604
+
buf = kmalloc(PATH_MAX, GFP_KERNEL);
1605
+
if (!buf)
1606
+
return -ENOMEM;
1607
+
1608
+
spin_lock_bh(&css_set_lock);
1609
+
ns_cgroup = current_cgns_cgroup_from_root(kf_cgroot);
1610
+
len = kernfs_path_from_node(kf_node, ns_cgroup->kn, buf, PATH_MAX);
1611
+
spin_unlock_bh(&css_set_lock);
1612
+
1613
+
if (len >= PATH_MAX)
1614
+
len = -ERANGE;
1615
+
else if (len > 0) {
1616
+
seq_escape(sf, buf, " \t\n\\");
1617
+
len = 0;
1618
+
}
1619
+
kfree(buf);
1620
+
return len;
1629
1621
}
1630
1622
1631
1623
static int cgroup_show_options(struct seq_file *seq,
···
5495
5433
.mkdir = cgroup_mkdir,
5496
5434
.rmdir = cgroup_rmdir,
5497
5435
.rename = cgroup_rename,
5436
+
.show_path = cgroup_show_path,
5498
5437
};
5499
5438
5500
5439
static void __init cgroup_init_subsys(struct cgroup_subsys *ss, bool early)