cgroups: add the trigger callback to struct cftype

[linux-2.6] / include / linux / cgroup.h

diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index a6a6035a4e1ec16d1e27a3f2470fc316c476cd6a..2d1d151258cfcf9b751e5c53bf36e853782cde9e 100644 (file)
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -88,6 +88,17 @@ static inline void css_put(struct cgroup_subsys_state *css)
                __css_put(css);
 }
 
+/* bits in struct cgroup flags field */
+enum {
+       /* Control Group is dead */
+       CGRP_REMOVED,
+       /* Control Group has previously had a child cgroup or a task,
+        * but no longer (only if CGRP_NOTIFY_ON_RELEASE is set) */
+       CGRP_RELEASABLE,
+       /* Control Group requires release notifications to userspace */
+       CGRP_NOTIFY_ON_RELEASE,
+};
+
 struct cgroup {
        unsigned long flags;            /* "unsigned long" so bitops work */
 
@@ -166,6 +177,16 @@ struct css_set {
 
 };
 
+/*
+ * cgroup_map_cb is an abstract callback API for reporting map-valued
+ * control files
+ */
+
+struct cgroup_map_cb {
+       int (*fill)(struct cgroup_map_cb *cb, const char *key, u64 value);
+       void *state;
+};
+
 /* struct cftype:
  *
  * The files in the cgroup filesystem mostly have a very simple read/write
@@ -190,20 +211,45 @@ struct cftype {
                         struct file *file,
                         char __user *buf, size_t nbytes, loff_t *ppos);
        /*
-        * read_uint() is a shortcut for the common case of returning a
+        * read_u64() is a shortcut for the common case of returning a
         * single integer. Use it in place of read()
         */
-       u64 (*read_uint) (struct cgroup *cgrp, struct cftype *cft);
+       u64 (*read_u64) (struct cgroup *cgrp, struct cftype *cft);
+       /*
+        * read_s64() is a signed version of read_u64()
+        */
+       s64 (*read_s64) (struct cgroup *cgrp, struct cftype *cft);
+       /*
+        * read_map() is used for defining a map of key/value
+        * pairs. It should call cb->fill(cb, key, value) for each
+        * entry. The key/value pairs (and their ordering) should not
+        * change between reboots.
+        */
+       int (*read_map) (struct cgroup *cont, struct cftype *cft,
+                        struct cgroup_map_cb *cb);
+
        ssize_t (*write) (struct cgroup *cgrp, struct cftype *cft,
                          struct file *file,
                          const char __user *buf, size_t nbytes, loff_t *ppos);
 
        /*
-        * write_uint() is a shortcut for the common case of accepting
+        * write_u64() is a shortcut for the common case of accepting
         * a single integer (as parsed by simple_strtoull) from
         * userspace. Use in place of write(); return 0 or error.
         */
-       int (*write_uint) (struct cgroup *cgrp, struct cftype *cft, u64 val);
+       int (*write_u64) (struct cgroup *cgrp, struct cftype *cft, u64 val);
+       /*
+        * write_s64() is a signed version of write_u64()
+        */
+       int (*write_s64) (struct cgroup *cgrp, struct cftype *cft, s64 val);
+
+       /*
+        * trigger() callback can be used to get some kick from the
+        * userspace, when the actual string written is not important
+        * at all. The private field can be used to determine the
+        * kick type for multiplexing.
+        */
+       int (*trigger)(struct cgroup *cgrp, unsigned int event);
 
        int (*release) (struct inode *inode, struct file *file);
 };