ARM64: rockchip_defconfig: enable sdhci controller

[firefly-linux-kernel-4.4.55.git] / kernel / cgroup_pids.c

diff --git a/kernel/cgroup_pids.c b/kernel/cgroup_pids.c
index cdd8df4e991c7781ac5996677d724bcd23314623..b50d5a167fda7d2ae6902efd55e551efed780007 100644 (file)
--- a/kernel/cgroup_pids.c
+++ b/kernel/cgroup_pids.c
@@ -106,7 +106,7 @@ static void pids_uncharge(struct pids_cgroup *pids, int num)
 {
        struct pids_cgroup *p;
 
-       for (p = pids; p; p = parent_pids(p))
+       for (p = pids; parent_pids(p); p = parent_pids(p))
                pids_cancel(p, num);
 }
 
@@ -123,7 +123,7 @@ static void pids_charge(struct pids_cgroup *pids, int num)
 {
        struct pids_cgroup *p;
 
-       for (p = pids; p; p = parent_pids(p))
+       for (p = pids; parent_pids(p); p = parent_pids(p))
                atomic64_add(num, &p->counter);
 }
 
@@ -140,7 +140,7 @@ static int pids_try_charge(struct pids_cgroup *pids, int num)
 {
        struct pids_cgroup *p, *q;
 
-       for (p = pids; p; p = parent_pids(p)) {
+       for (p = pids; parent_pids(p); p = parent_pids(p)) {
                int64_t new = atomic64_add_return(num, &p->counter);
 
                /*
@@ -162,13 +162,13 @@ revert:
        return -EAGAIN;
 }
 
-static int pids_can_attach(struct cgroup_subsys_state *css,
-                          struct cgroup_taskset *tset)
+static int pids_can_attach(struct cgroup_taskset *tset)
 {
-       struct pids_cgroup *pids = css_pids(css);
        struct task_struct *task;
+       struct cgroup_subsys_state *dst_css;
 
-       cgroup_taskset_for_each(task, tset) {
+       cgroup_taskset_for_each(task, dst_css, tset) {
+               struct pids_cgroup *pids = css_pids(dst_css);
                struct cgroup_subsys_state *old_css;
                struct pids_cgroup *old_pids;
 
@@ -187,13 +187,13 @@ static int pids_can_attach(struct cgroup_subsys_state *css,
        return 0;
 }
 
-static void pids_cancel_attach(struct cgroup_subsys_state *css,
-                              struct cgroup_taskset *tset)
+static void pids_cancel_attach(struct cgroup_taskset *tset)
 {
-       struct pids_cgroup *pids = css_pids(css);
        struct task_struct *task;
+       struct cgroup_subsys_state *dst_css;
 
-       cgroup_taskset_for_each(task, tset) {
+       cgroup_taskset_for_each(task, dst_css, tset) {
+               struct pids_cgroup *pids = css_pids(dst_css);
                struct cgroup_subsys_state *old_css;
                struct pids_cgroup *old_pids;
 
@@ -205,65 +205,28 @@ static void pids_cancel_attach(struct cgroup_subsys_state *css,
        }
 }
 
+/*
+ * task_css_check(true) in pids_can_fork() and pids_cancel_fork() relies
+ * on threadgroup_change_begin() held by the copy_process().
+ */
 static int pids_can_fork(struct task_struct *task, void **priv_p)
 {
        struct cgroup_subsys_state *css;
        struct pids_cgroup *pids;
-       int err;
 
-       /*
-        * Use the "current" task_css for the pids subsystem as the tentative
-        * css. It is possible we will charge the wrong hierarchy, in which
-        * case we will forcefully revert/reapply the charge on the right
-        * hierarchy after it is committed to the task proper.
-        */
-       css = task_get_css(current, pids_cgrp_id);
+       css = task_css_check(current, pids_cgrp_id, true);
        pids = css_pids(css);
-
-       err = pids_try_charge(pids, 1);
-       if (err)
-               goto err_css_put;
-
-       *priv_p = css;
-       return 0;
-
-err_css_put:
-       css_put(css);
-       return err;
+       return pids_try_charge(pids, 1);
 }
 
 static void pids_cancel_fork(struct task_struct *task, void *priv)
-{
-       struct cgroup_subsys_state *css = priv;
-       struct pids_cgroup *pids = css_pids(css);
-
-       pids_uncharge(pids, 1);
-       css_put(css);
-}
-
-static void pids_fork(struct task_struct *task, void *priv)
 {
        struct cgroup_subsys_state *css;
-       struct cgroup_subsys_state *old_css = priv;
        struct pids_cgroup *pids;
-       struct pids_cgroup *old_pids = css_pids(old_css);
 
-       css = task_get_css(task, pids_cgrp_id);
+       css = task_css_check(current, pids_cgrp_id, true);
        pids = css_pids(css);
-
-       /*
-        * If the association has changed, we have to revert and reapply the
-        * charge/uncharge on the wrong hierarchy to the current one. Since
-        * the association can only change due to an organisation event, its
-        * okay for us to ignore the limit in this case.
-        */
-       if (pids != old_pids) {
-               pids_uncharge(old_pids, 1);
-               pids_charge(pids, 1);
-       }
-
-       css_put(css);
-       css_put(old_css);
+       pids_uncharge(pids, 1);
 }
 
 static void pids_free(struct task_struct *task)
@@ -335,6 +298,7 @@ static struct cftype pids_files[] = {
        {
                .name = "current",
                .read_s64 = pids_current_read,
+               .flags = CFTYPE_NOT_ON_ROOT,
        },
        { }     /* terminate */
 };
@@ -346,7 +310,6 @@ struct cgroup_subsys pids_cgrp_subsys = {
        .cancel_attach  = pids_cancel_attach,
        .can_fork       = pids_can_fork,
        .cancel_fork    = pids_cancel_fork,
-       .fork           = pids_fork,
        .free           = pids_free,
        .legacy_cftypes = pids_files,
        .dfl_cftypes    = pids_files,