RE: [PATCH v3] qnx4: qnx4_block_map error handling

[David Laight]

From: Tong Zhang
> Sent: 03 November 2020 13:53
...
> > Also 'blknum' is only 'unsigned long' so ~0ull is wrong.
> > It can be worth injecting an error and checking the error
> > propagation works.
> >
> > What is the actual maximum file size?

> The maximum file size is 2GB-1, but from my understanding
> qnx4_block_map() returns a physical block number.
> The max disk size supported is 2**64 bytes, however
> it is limited to unsigned long (2**32)
> -- so I am actually very hesitant to encode an error code in the return value
> without changing the function return type, which will introduce more
> changes I don't like.
> The original -EIO in qnx4_block_map() is also dodgy btw.

You've put your hand into a bag of worms...

Looks like a load of the 'long' need to be 64bit.

I'm actually surprised how often 'long' appears in the
linux kernel.
I don't believe there was ever a 16bit version (eg 286)
where 'long' was 32bit.

	David

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