f2fs: enhance multiple device flush

When multiple device feature is enabled, during ->fsync we will issue
flush in all devices to make sure node/data of the file being persisted
into storage. But some flushes of device could be unneeded as file's
data may be not writebacked into those devices. So this patch adds and
manage bitmap per inode in global cache to indicate which device is
dirty and it needs to issue flush during ->fsync, hence, we could improve
performance of fsync in scenario of multiple device.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/node.c

@@ -63,7 +63,7 @@ bool available_free_memory(struct f2fs_sb_info *sbi, int type)
 	} else if (type == INO_ENTRIES) {
 		int i;
 
-		for (i = 0; i <= UPDATE_INO; i++)
+		for (i = 0; i < MAX_INO_ENTRY; i++)
 			mem_size += sbi->im[i].ino_num *
 						sizeof(struct ino_entry);
 		mem_size >>= PAGE_SHIFT;
@@ -1340,6 +1340,7 @@ static int __write_node_page(struct page *page, bool atomic, bool *submitted,
 	struct node_info ni;
 	struct f2fs_io_info fio = {
 		.sbi = sbi,
+		.ino = ino_of_node(page),
 		.type = NODE,
 		.op = REQ_OP_WRITE,
 		.op_flags = wbc_to_write_flags(wbc),