SUNRPC: Fix the problem of EADDRNOTAVAIL syslog floods on reconnect

[~andy/linux] / include / linux / cgroup.h

diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 788c4964c142373b43dac281d77278ccdb20b8d0..665fa70e4094166c76b85176f0fbb3f5f6fae7c5 100644 (file)
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -15,6 +15,7 @@
 #include <linux/cgroupstats.h>
 #include <linux/prio_heap.h>
 #include <linux/rwsem.h>
+#include <linux/idr.h>
 
 #ifdef CONFIG_CGROUPS
 
@@ -22,6 +23,7 @@ struct cgroupfs_root;
 struct cgroup_subsys;
 struct inode;
 struct cgroup;
+struct css_id;
 
 extern int cgroup_init_early(void);
 extern int cgroup_init(void);
@@ -63,6 +65,8 @@ struct cgroup_subsys_state {
        atomic_t refcnt;
 
        unsigned long flags;
+       /* ID for this css, if possible */
+       struct css_id *id;
 };
 
 /* bits in struct cgroup_subsys_state flags field */
@@ -131,6 +135,10 @@ enum {
        CGRP_RELEASABLE,
        /* Control Group requires release notifications to userspace */
        CGRP_NOTIFY_ON_RELEASE,
+       /*
+        * A thread in rmdir() is wating for this cgroup.
+        */
+       CGRP_WAIT_ON_RMDIR,
 };
 
 struct cgroup {
@@ -250,6 +258,11 @@ struct cftype {
         */
        char name[MAX_CFTYPE_NAME];
        int private;
+       /*
+        * If not 0, file mode is set to this value, otherwise it will
+        * be figured out automatically
+        */
+       mode_t mode;
 
        /*
         * If non-zero, defines the maximum length of string that can
@@ -324,6 +337,7 @@ struct cgroup_scanner {
        void (*process_task)(struct task_struct *p,
                        struct cgroup_scanner *scan);
        struct ptr_heap *heap;
+       void *data;
 };
 
 /*
@@ -351,12 +365,15 @@ int cgroup_task_count(const struct cgroup *cgrp);
 /* Return true if cgrp is a descendant of the task's cgroup */
 int cgroup_is_descendant(const struct cgroup *cgrp, struct task_struct *task);
 
-/* Control Group subsystem type. See Documentation/cgroups.txt for details */
+/*
+ * Control Group subsystem type.
+ * See Documentation/cgroups/cgroups.txt for details
+ */
 
 struct cgroup_subsys {
        struct cgroup_subsys_state *(*create)(struct cgroup_subsys *ss,
                                                  struct cgroup *cgrp);
-       void (*pre_destroy)(struct cgroup_subsys *ss, struct cgroup *cgrp);
+       int (*pre_destroy)(struct cgroup_subsys *ss, struct cgroup *cgrp);
        void (*destroy)(struct cgroup_subsys *ss, struct cgroup *cgrp);
        int (*can_attach)(struct cgroup_subsys *ss,
                          struct cgroup *cgrp, struct task_struct *tsk);
@@ -373,6 +390,11 @@ struct cgroup_subsys {
        int active;
        int disabled;
        int early_init;
+       /*
+        * True if this subsys uses ID. ID is not available before cgroup_init()
+        * (not available in early_init time.)
+        */
+       bool use_id;
 #define MAX_CGROUP_TYPE_NAMELEN 32
        const char *name;
 
@@ -395,6 +417,9 @@ struct cgroup_subsys {
         */
        struct cgroupfs_root *root;
        struct list_head sibling;
+       /* used when use_id == true */
+       struct idr idr;
+       spinlock_t id_lock;
 };
 
 #define SUBSYS(_x) extern struct cgroup_subsys _x ## _subsys;
@@ -450,6 +475,44 @@ void cgroup_iter_end(struct cgroup *cgrp, struct cgroup_iter *it);
 int cgroup_scan_tasks(struct cgroup_scanner *scan);
 int cgroup_attach_task(struct cgroup *, struct task_struct *);
 
+/*
+ * CSS ID is ID for cgroup_subsys_state structs under subsys. This only works
+ * if cgroup_subsys.use_id == true. It can be used for looking up and scanning.
+ * CSS ID is assigned at cgroup allocation (create) automatically
+ * and removed when subsys calls free_css_id() function. This is because
+ * the lifetime of cgroup_subsys_state is subsys's matter.
+ *
+ * Looking up and scanning function should be called under rcu_read_lock().
+ * Taking cgroup_mutex()/hierarchy_mutex() is not necessary for following calls.
+ * But the css returned by this routine can be "not populated yet" or "being
+ * destroyed". The caller should check css and cgroup's status.
+ */
+
+/*
+ * Typically Called at ->destroy(), or somewhere the subsys frees
+ * cgroup_subsys_state.
+ */
+void free_css_id(struct cgroup_subsys *ss, struct cgroup_subsys_state *css);
+
+/* Find a cgroup_subsys_state which has given ID */
+
+struct cgroup_subsys_state *css_lookup(struct cgroup_subsys *ss, int id);
+
+/*
+ * Get a cgroup whose id is greater than or equal to id under tree of root.
+ * Returning a cgroup_subsys_state or NULL.
+ */
+struct cgroup_subsys_state *css_get_next(struct cgroup_subsys *ss, int id,
+               struct cgroup_subsys_state *root, int *foundid);
+
+/* Returns true if root is ancestor of cg */
+bool css_is_ancestor(struct cgroup_subsys_state *cg,
+                    const struct cgroup_subsys_state *root);
+
+/* Get id and depth of css */
+unsigned short css_id(struct cgroup_subsys_state *css);
+unsigned short css_depth(struct cgroup_subsys_state *css);
+
 #else /* !CONFIG_CGROUPS */
 
 static inline int cgroup_init_early(void) { return 0; }