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authorLinus Torvalds <torvalds@linux-foundation.org>2013-06-03 17:57:16 +0900
committerLinus Torvalds <torvalds@linux-foundation.org>2013-06-03 17:57:16 +0900
commit7d80fea4263d9a83ffedea448afa8510b05d04d0 (patch)
tree202118fd64ea1a661e3945e1a5bf13ef2d6f90eb /kernel
parent338e33acd820fa89b8a2d5b6574233784702f618 (diff)
parent2a0ff3fbe39bc93f719ff857e5a359d9780579ff (diff)
Merge branch 'for-3.10-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo: - Fix for yet another xattr bug which may lead to NULL deref. - A subtle bug in for_each_descendant_pre(). This bug requires quite specific conditions to trigger and isn't too likely to actually happen in the wild, but maybe that just makes it that much more nastier. - A warning message added for silly cgroup re-mount (not -o remount, but unmount followed by mount) behavior. * 'for-3.10-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: warn about mismatching options of a new mount of an existing hierarchy cgroup: fix a subtle bug in descendant pre-order walk cgroup: initialize xattr before calling d_instantiate()
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cgroup.c31
1 files changed, 16 insertions, 15 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 2a9926275f8..a7c9e6ddb97 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1686,11 +1686,14 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type,
*/
cgroup_drop_root(opts.new_root);
- if (((root->flags | opts.flags) & CGRP_ROOT_SANE_BEHAVIOR) &&
- root->flags != opts.flags) {
- pr_err("cgroup: sane_behavior: new mount options should match the existing superblock\n");
- ret = -EINVAL;
- goto drop_new_super;
+ if (root->flags != opts.flags) {
+ if ((root->flags | opts.flags) & CGRP_ROOT_SANE_BEHAVIOR) {
+ pr_err("cgroup: sane_behavior: new mount options should match the existing superblock\n");
+ ret = -EINVAL;
+ goto drop_new_super;
+ } else {
+ pr_warning("cgroup: new mount options do not match the existing superblock, will be ignored\n");
+ }
}
/* no subsys rebinding, so refcounts don't change */
@@ -2699,13 +2702,14 @@ static int cgroup_add_file(struct cgroup *cgrp, struct cgroup_subsys *subsys,
goto out;
}
+ cfe->type = (void *)cft;
+ cfe->dentry = dentry;
+ dentry->d_fsdata = cfe;
+ simple_xattrs_init(&cfe->xattrs);
+
mode = cgroup_file_mode(cft);
error = cgroup_create_file(dentry, mode | S_IFREG, cgrp->root->sb);
if (!error) {
- cfe->type = (void *)cft;
- cfe->dentry = dentry;
- dentry->d_fsdata = cfe;
- simple_xattrs_init(&cfe->xattrs);
list_add_tail(&cfe->node, &parent->files);
cfe = NULL;
}
@@ -2953,11 +2957,8 @@ struct cgroup *cgroup_next_descendant_pre(struct cgroup *pos,
WARN_ON_ONCE(!rcu_read_lock_held());
/* if first iteration, pretend we just visited @cgroup */
- if (!pos) {
- if (list_empty(&cgroup->children))
- return NULL;
+ if (!pos)
pos = cgroup;
- }
/* visit the first child if exists */
next = list_first_or_null_rcu(&pos->children, struct cgroup, sibling);
@@ -2965,14 +2966,14 @@ struct cgroup *cgroup_next_descendant_pre(struct cgroup *pos,
return next;
/* no child, visit my or the closest ancestor's next sibling */
- do {
+ while (pos != cgroup) {
next = list_entry_rcu(pos->sibling.next, struct cgroup,
sibling);
if (&next->sibling != &pos->parent->children)
return next;
pos = pos->parent;
- } while (pos != cgroup);
+ }
return NULL;
}