Re: Is ext4_dio_read_iter() broken? - and xfs_file_dio_aio_read()

On Thu, Mar 12, 2020 at 10:49:40AM +0000, David Howells wrote:

Christoph Hellwig [off-list ref] wrote:

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at the end of the function - but surely iocb should be expected to have
been freed when iocb->ki_complete() was called?

The iocb is refcounted and only completed when the refcount hits zero,
and an extra reference is held until the submission has completed.
Take a look at iocb_put().

Ah...  This is in struct aio_kiocb and not struct kiocb - that's why I missed
it.  Thanks.

That being said we have a few other spots using ->ki_complete for
asynchronous execution, which might not be as careful.  As someone
having written one or two of those I have my doubts I got everthing
right and will audit those.

David

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