mm: fix lumpy reclaim lru handling at isolate_lru_pages

[sfrench/cifs-2.6.git] / lib / string.c

diff --git a/lib/string.c b/lib/string.c
index 5efafed3d6b65df9e56f968e32fb012f4cd13c65..b19b87af65a3553a0650d679cabfac9fecd4eb3b 100644 (file)
--- a/lib/string.c
+++ b/lib/string.c
@@ -493,6 +493,33 @@ char *strsep(char **s, const char *ct)
 EXPORT_SYMBOL(strsep);
 #endif
 
+/**
+ * sysfs_streq - return true if strings are equal, modulo trailing newline
+ * @s1: one string
+ * @s2: another string
+ *
+ * This routine returns true iff two strings are equal, treating both
+ * NUL and newline-then-NUL as equivalent string terminations.  It's
+ * geared for use with sysfs input strings, which generally terminate
+ * with newlines but are compared against values without newlines.
+ */
+bool sysfs_streq(const char *s1, const char *s2)
+{
+       while (*s1 && *s1 == *s2) {
+               s1++;
+               s2++;
+       }
+
+       if (*s1 == *s2)
+               return true;
+       if (!*s1 && *s2 == '\n' && !s2[1])
+               return true;
+       if (*s1 == '\n' && !s1[1] && !*s2)
+               return true;
+       return false;
+}
+EXPORT_SYMBOL(sysfs_streq);
+
 #ifndef __HAVE_ARCH_MEMSET
 /**
  * memset - Fill a region of memory with the given value