F2FS: Backport to 3.4

Based off of patches here:
nowcomputing/f2fs-backports#1

Change-Id: I2be6d8abf4e3e4c6b9e8d635700930af432fe37a
diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
index 4d67ed7..3c30e74 100644
--- a/fs/f2fs/inode.c
+++ b/fs/f2fs/inode.c
@@ -87,8 +87,8 @@
 	ri = F2FS_INODE(node_page);
 
 	inode->i_mode = le16_to_cpu(ri->i_mode);
-	i_uid_write(inode, le32_to_cpu(ri->i_uid));
-	i_gid_write(inode, le32_to_cpu(ri->i_gid));
+	inode->i_uid = le32_to_cpu(ri->i_uid);
+	inode->i_gid = le32_to_cpu(ri->i_gid);
 	set_nlink(inode, le32_to_cpu(ri->i_links));
 	inode->i_size = le64_to_cpu(ri->i_size);
 	inode->i_blocks = le64_to_cpu(ri->i_blocks);
@@ -185,8 +185,8 @@
 
 	ri->i_mode = cpu_to_le16(inode->i_mode);
 	ri->i_advise = F2FS_I(inode)->i_advise;
-	ri->i_uid = cpu_to_le32(i_uid_read(inode));
-	ri->i_gid = cpu_to_le32(i_gid_read(inode));
+	ri->i_uid = cpu_to_le32(inode->i_uid);
+	ri->i_gid = cpu_to_le32(inode->i_gid);
 	ri->i_links = cpu_to_le32(inode->i_nlink);
 	ri->i_size = cpu_to_le64(i_size_read(inode));
 	ri->i_blocks = cpu_to_le64(inode->i_blocks);
@@ -272,7 +272,6 @@
 	if (inode->i_nlink || is_bad_inode(inode))
 		goto no_delete;
 
-	sb_start_intwrite(inode->i_sb);
 	set_inode_flag(F2FS_I(inode), FI_NO_ALLOC);
 	i_size_write(inode, 0);
 
@@ -284,7 +283,6 @@
 	stat_dec_inline_inode(inode);
 	f2fs_unlock_op(sbi);
 
-	sb_end_intwrite(inode->i_sb);
 no_delete:
-	clear_inode(inode);
+	end_writeback(inode);
 }