Re: dd bug

[Andreas Schwab]

Paul Eggert <address@hidden> writes:

> Buciuman Adrian <address@hidden> writes:
>
>> read(0, "1                               "..., 737280) = 36864
>> write(1, "1                               "..., 737280) = 737280
>> read(0, 0x4015a000, 737280)             = -1 EIO (Input/output error)
>
> Apparently the first "read" found the I/O error, and decided to return
> the bytes that it found.  The second "read" then reported the I/O error.
> I didn't expect this pattern; I thought the first "read" would fail.

That would mean that the kernel would need to discard what it already
sucessfully read, with no way to recover the data (it can't put it back
either).  There is no way to both return some data and report an error
with the same read call.

Andreas.

-- 
Andreas Schwab, SuSE Labs, address@hidden
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