Documentation: lzo: document part of the encoding

[pandora-kernel.git] / kernel / cgroup.c

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 7dc8788..940aced 100644 (file)
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1035,6 +1035,11 @@ static void cgroup_get(struct cgroup *cgrp)
        css_get(&cgrp->self);
 }
 
+static bool cgroup_tryget(struct cgroup *cgrp)
+{
+       return css_tryget(&cgrp->self);
+}
+
 static void cgroup_put(struct cgroup *cgrp)
 {
        css_put(&cgrp->self);
@@ -1147,7 +1152,8 @@ static struct cgroup *cgroup_kn_lock_live(struct kernfs_node *kn)
         * protection against removal.  Ensure @cgrp stays accessible and
         * break the active_ref protection.
         */
-       cgroup_get(cgrp);
+       if (!cgroup_tryget(cgrp))
+               return NULL;
        kernfs_break_active_protection(kn);
 
        mutex_lock(&cgroup_mutex);
@@ -3271,8 +3277,17 @@ int cgroup_add_legacy_cftypes(struct cgroup_subsys *ss, struct cftype *cfts)
 {
        struct cftype *cft;
 
-       for (cft = cfts; cft && cft->name[0] != '\0'; cft++)
-               cft->flags |= __CFTYPE_NOT_ON_DFL;
+       /*
+        * If legacy_flies_on_dfl, we want to show the legacy files on the
+        * dfl hierarchy but iff the target subsystem hasn't been updated
+        * for the dfl hierarchy yet.
+        */
+       if (!cgroup_legacy_files_on_dfl ||
+           ss->dfl_cftypes != ss->legacy_cftypes) {
+               for (cft = cfts; cft && cft->name[0] != '\0'; cft++)
+                       cft->flags |= __CFTYPE_NOT_ON_DFL;
+       }
+
        return cgroup_add_cftypes(ss, cfts);
 }
 
@@ -4387,6 +4402,15 @@ static void css_release_work_fn(struct work_struct *work)
                /* cgroup release path */
                cgroup_idr_remove(&cgrp->root->cgroup_idr, cgrp->id);
                cgrp->id = -1;
+
+               /*
+                * There are two control paths which try to determine
+                * cgroup from dentry without going through kernfs -
+                * cgroupstats_build() and css_tryget_online_from_dir().
+                * Those are supported by RCU protecting clearing of
+                * cgrp->kn->priv backpointer.
+                */
+               RCU_INIT_POINTER(*(void __rcu __force **)&cgrp->kn->priv, NULL);
        }
 
        mutex_unlock(&cgroup_mutex);
@@ -4543,6 +4567,11 @@ static int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name,
        struct cftype *base_files;
        int ssid, ret;
 
+       /* Do not accept '\n' to prevent making /proc/<pid>/cgroup unparsable.
+        */
+       if (strchr(name, '\n'))
+               return -EINVAL;
+
        parent = cgroup_kn_lock_live(parent_kn);
        if (!parent)
                return -ENODEV;
@@ -4820,16 +4849,6 @@ static int cgroup_rmdir(struct kernfs_node *kn)
 
        cgroup_kn_unlock(kn);
 
-       /*
-        * There are two control paths which try to determine cgroup from
-        * dentry without going through kernfs - cgroupstats_build() and
-        * css_tryget_online_from_dir().  Those are supported by RCU
-        * protecting clearing of cgrp->kn->priv backpointer, which should
-        * happen after all files under it have been removed.
-        */
-       if (!ret)
-               RCU_INIT_POINTER(*(void __rcu __force **)&kn->priv, NULL);
-
        cgroup_put(cgrp);
        return ret;
 }
@@ -5416,7 +5435,7 @@ struct cgroup_subsys_state *css_tryget_online_from_dir(struct dentry *dentry,
        /*
         * This path doesn't originate from kernfs and @kn could already
         * have been or be removed at any point.  @kn->priv is RCU
-        * protected for this access.  See cgroup_rmdir() for details.
+        * protected for this access.  See css_release_work_fn() for details.
         */
        cgrp = rcu_dereference(kn->priv);
        if (cgrp)