f2fs: treat volatile file's data as hot one

Volatile file's data will be updated oftenly, so it'd better to place
its data into hot data segment.

In addition, for atomic file, we change to check FI_ATOMIC_FILE instead
of FI_HOT_DATA to make code readability better.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/file.c

@@ -1696,7 +1696,6 @@ static int f2fs_ioc_start_atomic_write(struct file *filp)
 	if (ret)
 		goto out;
 skip_flush:
-	set_inode_flag(inode, FI_HOT_DATA);
 	set_inode_flag(inode, FI_ATOMIC_FILE);
 	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
 
@@ -1739,7 +1738,6 @@ static int f2fs_ioc_commit_atomic_write(struct file *filp)
 		ret = f2fs_do_sync_file(filp, 0, LLONG_MAX, 0, true);
 		if (!ret) {
 			clear_inode_flag(inode, FI_ATOMIC_FILE);
-			clear_inode_flag(inode, FI_HOT_DATA);
 			stat_dec_atomic_write(inode);
 		}
 	} else {

fs/f2fs/segment.c

@@ -309,7 +309,6 @@ void drop_inmem_pages(struct inode *inode)
 	mutex_unlock(&fi->inmem_lock);
 
 	clear_inode_flag(inode, FI_ATOMIC_FILE);
-	clear_inode_flag(inode, FI_HOT_DATA);
 	stat_dec_atomic_write(inode);
 }
 
@@ -2613,7 +2612,9 @@ static int __get_segment_type_6(struct f2fs_io_info *fio)
 		if (is_cold_data(fio->page) || file_is_cold(inode))
 			return CURSEG_COLD_DATA;
 		if (file_is_hot(inode) ||
-				is_inode_flag_set(inode, FI_HOT_DATA))
+				is_inode_flag_set(inode, FI_HOT_DATA) ||
+				is_inode_flag_set(inode, FI_ATOMIC_FILE) ||
+				is_inode_flag_set(inode, FI_VOLATILE_FILE))
 			return CURSEG_HOT_DATA;
 		return rw_hint_to_seg_type(inode->i_write_hint);
 	} else {