f2fs: clear atomic_write_task in f2fs_abort_atomic_write()

Otherwise, last .atomic_write_task will be remained in structure
f2fs_inode_info, resulting in aborting atomic_write accidentally
in race case. Meanwhile, clear original_i_size as well.

Fixes: 7a10f017 ("f2fs: don't give partially written atomic data from process crash")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/segment.c

@@ -201,9 +201,12 @@ void f2fs_abort_atomic_write(struct inode *inode, bool clean)
 	clear_inode_flag(inode, FI_ATOMIC_FILE);
 	stat_dec_atomic_inode(inode);
 
+	F2FS_I(inode)->atomic_write_task = NULL;
+
 	if (clean) {
 		truncate_inode_pages_final(inode->i_mapping);
 		f2fs_i_size_write(inode, fi->original_i_size);
+		fi->original_i_size = 0;
 	}
 }