memcgroup: use triggers in force_empty and max_usage files

These two files are essentially event callbacks. They do not care about the contents of the string, but only about the fact of the write itself. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memcgroup: use triggers in force_empty and max_usage files
These two files are essentially event callbacks. They do not care about the contents of the string, but only about the fact of the write itself. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pavel Emelyanov · Linus Torvalds
1 parent b6ac57d50a
Showing 1 changed file with 6 additions and 15 deletions Side-by-side Diff
mm/memcontrol.c
@@ -857,27 +857,18 @@
 				mem_cgroup_write_strategy);
 }
  
-static ssize_t mem_cgroup_max_reset(struct cgroup *cont, struct cftype *cft,
-				struct file *file, const char __user *userbuf,
-				size_t nbytes, loff_t *ppos)
+static int mem_cgroup_max_reset(struct cgroup *cont, unsigned int event)
 {
 	struct mem_cgroup *mem;
  
 	mem = mem_cgroup_from_cont(cont);
 	res_counter_reset_max(&mem->res);
-	return nbytes;
+	return 0;
 }
  
-static ssize_t mem_force_empty_write(struct cgroup *cont,
-				struct cftype *cft, struct file *file,
-				const char __user *userbuf,
-				size_t nbytes, loff_t *ppos)
+static int mem_force_empty_write(struct cgroup *cont, unsigned int event)
 {
-	struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
-	int ret = mem_cgroup_force_empty(mem);
-	if (!ret)
-		ret = nbytes;
-	return ret;
+	return mem_cgroup_force_empty(mem_cgroup_from_cont(cont));
 }
  
 static const struct mem_cgroup_stat_desc {
@@ -925,7 +916,7 @@
 	{
 		.name = "max_usage_in_bytes",
 		.private = RES_MAX_USAGE,
-		.write = mem_cgroup_max_reset,
+		.trigger = mem_cgroup_max_reset,
 		.read_u64 = mem_cgroup_read,
 	},
 	{
@@ -941,7 +932,7 @@
 	},
 	{
 		.name = "force_empty",
-		.write = mem_force_empty_write,
+		.trigger = mem_force_empty_write,
 	},
 	{
 		.name = "stat",
...	...	@@ -857,27 +857,18 @@
857	857	mem_cgroup_write_strategy);
858	858	}
859	859
860		-static ssize_t mem_cgroup_max_reset(struct cgroup cont, struct cftype cft,
861		- struct file file, const char __user userbuf,
862		- size_t nbytes, loff_t *ppos)
	860	+static int mem_cgroup_max_reset(struct cgroup *cont, unsigned int event)
863	861	{
864	862	struct mem_cgroup *mem;
865	863
866	864	mem = mem_cgroup_from_cont(cont);
867	865	res_counter_reset_max(&mem->res);
868		- return nbytes;
	866	+ return 0;
869	867	}
870	868
871		-static ssize_t mem_force_empty_write(struct cgroup *cont,
872		- struct cftype cft, struct file file,
873		- const char __user *userbuf,
874		- size_t nbytes, loff_t *ppos)
	869	+static int mem_force_empty_write(struct cgroup *cont, unsigned int event)
875	870	{
876		- struct mem_cgroup *mem = mem_cgroup_from_cont(cont);
877		- int ret = mem_cgroup_force_empty(mem);
878		- if (!ret)
879		- ret = nbytes;
880		- return ret;
	871	+ return mem_cgroup_force_empty(mem_cgroup_from_cont(cont));
881	872	}
882	873
883	874	static const struct mem_cgroup_stat_desc {
...	...	@@ -925,7 +916,7 @@
925	916	{
926	917	.name = "max_usage_in_bytes",
927	918	.private = RES_MAX_USAGE,
928		- .write = mem_cgroup_max_reset,
	919	+ .trigger = mem_cgroup_max_reset,
929	920	.read_u64 = mem_cgroup_read,
930	921	},
931	922	{
...	...	@@ -941,7 +932,7 @@
941	932	},
942	933	{
943	934	.name = "force_empty",
944		- .write = mem_force_empty_write,
	935	+ .trigger = mem_force_empty_write,
945	936	},
946	937	{
947	938	.name = "stat",