[PATCH] eCryptfs: convert kmap() to kmap_atomic()

Replace kmap() with kmap_atomic().  Reduce the amount of time that mappings
are held.

Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Trevor Highland <tshighla@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index 2d7db61..b817a1a 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -429,10 +429,10 @@
 			goto out;
 		}
 	} else {
-		rc = ecryptfs_grab_and_map_lower_page(lower_page, NULL,
-						      lower_inode,
-						      lower_page_idx);
-		if (rc) {
+		*lower_page = grab_cache_page(lower_inode->i_mapping,
+					      lower_page_idx);
+		if (!(*lower_page)) {
+			rc = -EINVAL;
 			ecryptfs_printk(
 				KERN_ERR, "Error attempting to grab and map "
 				"lower page with index [0x%.16x]; rc = [%d]\n",