stat-prefetch: fix dirname(3) usage

glibc dirname() modify the string it is given and returns it.
glusterfs takes this behavior for granted, and assume that if it
gives a malloc'ed string to dirname(), then it can free()) the
return value.

Here is what SUSv2 says:
http://opengroup.org/onlinepubs/007908799/xsh/dirname.html
"The dirname() function may modify the string pointed to by path,
and may return a pointer to static storage"

At least NetBSD returns a static storage. glusterfs will return it to
a calling function that has the responsability to free it, causing
a SIGSEGV.

Thanks to: Emmanuel Dreyfus <manu@netbsd.org>

Signed-off-by: Anand Avati <avati@gluster.com>

BUG: 2923 (NetBSD port)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=2923

1 files changed, 8 insertions, 2 deletions

diff --git a/xlators/performance/stat-prefetch/src/stat-prefetch.c b/xlators/performance/stat-prefetch/src/stat-prefetch.c
index b99c91bce..be83dcb29 100644
--- a/xlators/performance/stat-prefetch/src/stat-prefetch.c
+++ b/xlators/performance/stat-prefetch/src/stat-prefetch.c
@@ -950,16 +950,22 @@ sp_get_ancestors (char *path, char **parent, char **grand_parent)
                 switch (i)
                 {
                 case 0:
-                        *parent = path;
+                        *parent = gf_strdup (path);
+			if (*parent == NULL)
+				goto out;
                         break;
                 case 1:
-                        *grand_parent = path;
+                        *grand_parent = gf_strdup (path);
+			if (*grand_parent == NULL)
+				goto out;
                         break;
                 }
         }
 
         ret = 0;
 out:
+	if (cpy != NULL)
+		GF_FREE(cpy);
         return ret;
 }