What Can Cause Close(2) To Fail With EIO For A Read-only File?

I'm investigating a problem on Android where an IOException is getting thrown because of a failure to close a file: java.io.IOException: close failed: EIO (I/O error) at libcor

Solution 1:

I'm guessing the EIO comes from bad_file_flush in fs/bad_inode.c. It seems when the kernel has any failure accessing an inode, it transforms the open file description to a pseudo-open-file of with bad_inode_ops as its file ops. I can't find the code that does this for FAT-based filesystems, but perhaps there's some generic code.

As for the reason, it's probably something like attaching a USB cable and mounting the filesystem from an attached computer, removing the SD card, etc.

Solution 2:

In general, you should always anticipate IOExceptions when closing streams. The code is very straightforward, but see here for the cleanest example Java can afford:

https://stackoverflow.com/a/156520/1489860

However, in your specific case, I imagine an exception is being thrown because it appears you are changing the value of the InputStream in the unzipOrPassthrough(InputStream) method and then later trying to close it:

        if (entry == null) {
        is = new ByteArrayInputStream(baos.toByteArray());

When you later call close on the FileInputStream class, it probably freaks out because it is now a ByteArrayInputStream and no longer a FileInputStream.