get_unmapped_area handles MAP_FIXED in hugetlbfs

Generic hugetlb_get_unmapped_area() now handles MAP_FIXED by just calling
prepare_hugepage_range()

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: William Irwin <bill.irwin@oracle.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Andi Kleen <ak@suse.de>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: Matthew Wilcox <willy@debian.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Adam Litke <agl@us.ibm.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/hugetlbfs/inode.c

@@ -22,6 +22,7 @@
 #include <linux/backing-dev.h>
 #include <linux/hugetlb.h>
 #include <linux/pagevec.h>
+#include <linux/mman.h>
 #include <linux/quotaops.h>
 #include <linux/slab.h>
 #include <linux/dnotify.h>
@@ -112,6 +113,12 @@ hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
 	if (len > TASK_SIZE)
 		return -ENOMEM;
 
+	if (flags & MAP_FIXED) {
+		if (prepare_hugepage_range(addr, len, pgoff))
+			return -EINVAL;
+		return addr;
+	}
+
 	if (addr) {
 		addr = ALIGN(addr, HPAGE_SIZE);
 		vma = find_vma(mm, addr);