cgroup files: convert res_counter_write() to be a cgroups write_string() handler
Currently res_counter_write() is a raw file handler even though it's
ultimately taking a number, since in some cases it wants to
pre-process the string when converting it to a number.
This patch converts res_counter_write() from a raw file handler to a
write_string() handler; this allows some of the boilerplate
copying/locking/checking to be removed, and simplies the cleanup path,
since these functions are now performed by the cgroups framework.
[lizf@cn.fujitsu.com: build fix]
Signed-off-by: Paul Menage <menage@google.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/res_counter.c b/kernel/res_counter.c
index d3c61b4..f275c8e 100644
--- a/kernel/res_counter.c
+++ b/kernel/res_counter.c
@@ -13,6 +13,7 @@
#include <linux/slab.h>
#include <linux/res_counter.h>
#include <linux/uaccess.h>
+#include <linux/mm.h>
void res_counter_init(struct res_counter *counter)
{
@@ -102,44 +103,37 @@
return *res_counter_member(counter, member);
}
-ssize_t res_counter_write(struct res_counter *counter, int member,
- const char __user *userbuf, size_t nbytes, loff_t *pos,
- int (*write_strategy)(char *st_buf, unsigned long long *val))
+int res_counter_memparse_write_strategy(const char *buf,
+ unsigned long long *res)
{
- int ret;
- char *buf, *end;
+ char *end;
+ /* FIXME - make memparse() take const char* args */
+ *res = memparse((char *)buf, &end);
+ if (*end != '\0')
+ return -EINVAL;
+
+ *res = PAGE_ALIGN(*res);
+ return 0;
+}
+
+int res_counter_write(struct res_counter *counter, int member,
+ const char *buf, write_strategy_fn write_strategy)
+{
+ char *end;
unsigned long flags;
unsigned long long tmp, *val;
- buf = kmalloc(nbytes + 1, GFP_KERNEL);
- ret = -ENOMEM;
- if (buf == NULL)
- goto out;
-
- buf[nbytes] = '\0';
- ret = -EFAULT;
- if (copy_from_user(buf, userbuf, nbytes))
- goto out_free;
-
- ret = -EINVAL;
-
- strstrip(buf);
if (write_strategy) {
- if (write_strategy(buf, &tmp)) {
- goto out_free;
- }
+ if (write_strategy(buf, &tmp))
+ return -EINVAL;
} else {
tmp = simple_strtoull(buf, &end, 10);
if (*end != '\0')
- goto out_free;
+ return -EINVAL;
}
spin_lock_irqsave(&counter->lock, flags);
val = res_counter_member(counter, member);
*val = tmp;
spin_unlock_irqrestore(&counter->lock, flags);
- ret = nbytes;
-out_free:
- kfree(buf);
-out:
- return ret;
+ return 0;
}
