mm/thp: use conventional format for boolean attributes
The conventional format for boolean attributes in sysfs is numeric ("0" or
"1" followed by new-line). Any boolean attribute can then be read and
written using a generic function. Using the strings "yes [no]", "[yes]
no" (read), "yes" and "no" (write) will frustrate this.
[akpm@linux-foundation.org: use kstrtoul()]
[akpm@linux-foundation.org: test_bit() doesn't return 1/0, per Neil]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Tested-by: David Rientjes <rientjes@google.com>
Cc: NeilBrown <neilb@suse.de>
Cc: <stable@kernel.org> [2.6.38.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 1722683..470dcda 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -244,25 +244,29 @@
struct kobj_attribute *attr, char *buf,
enum transparent_hugepage_flag flag)
{
- if (test_bit(flag, &transparent_hugepage_flags))
- return sprintf(buf, "[yes] no\n");
- else
- return sprintf(buf, "yes [no]\n");
+ return sprintf(buf, "%d\n",
+ !!test_bit(flag, &transparent_hugepage_flags));
}
+
static ssize_t single_flag_store(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t count,
enum transparent_hugepage_flag flag)
{
- if (!memcmp("yes", buf,
- min(sizeof("yes")-1, count))) {
- set_bit(flag, &transparent_hugepage_flags);
- } else if (!memcmp("no", buf,
- min(sizeof("no")-1, count))) {
- clear_bit(flag, &transparent_hugepage_flags);
- } else
+ unsigned long value;
+ int ret;
+
+ ret = kstrtoul(buf, 10, &value);
+ if (ret < 0)
+ return ret;
+ if (value > 1)
return -EINVAL;
+ if (value)
+ set_bit(flag, &transparent_hugepage_flags);
+ else
+ clear_bit(flag, &transparent_hugepage_flags);
+
return count;
}