ceph: switch some GFP_NOFS memory allocation to GFP_KERNEL

GFP_NOFS memory allocation is required for page writeback path.
But there is no need to use GFP_NOFS in syscall path and readpage
path

Signed-off-by: Yan, Zheng <zyan@redhat.com>
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 8a4eb4d..424b5b5 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -89,7 +89,7 @@
 	case S_IFDIR:
 		dout("init_file %p %p 0%o (regular)\n", inode, file,
 		     inode->i_mode);
-		cf = kmem_cache_alloc(ceph_file_cachep, GFP_NOFS | __GFP_ZERO);
+		cf = kmem_cache_alloc(ceph_file_cachep, GFP_KERNEL | __GFP_ZERO);
 		if (cf == NULL) {
 			ceph_put_fmode(ceph_inode(inode), fmode); /* clean up */
 			return -ENOMEM;
@@ -483,7 +483,7 @@
 		}
 	} else {
 		num_pages = calc_pages_for(off, len);
-		pages = ceph_alloc_page_vector(num_pages, GFP_NOFS);
+		pages = ceph_alloc_page_vector(num_pages, GFP_KERNEL);
 		if (IS_ERR(pages))
 			return PTR_ERR(pages);
 		ret = striped_read(inode, off, len, pages,
@@ -734,7 +734,7 @@
 		 */
 		num_pages = (len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
 
-		pages = ceph_alloc_page_vector(num_pages, GFP_NOFS);
+		pages = ceph_alloc_page_vector(num_pages, GFP_KERNEL);
 		if (IS_ERR(pages)) {
 			ret = PTR_ERR(pages);
 			goto out;
@@ -858,7 +858,7 @@
 		struct page *page = NULL;
 		loff_t i_size;
 		if (retry_op == READ_INLINE) {
-			page = __page_cache_alloc(GFP_NOFS);
+			page = __page_cache_alloc(GFP_KERNEL);
 			if (!page)
 				return -ENOMEM;
 		}