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Subject: Re: [PATCH 00/17] VFS: Filesystem information and notifications [ver
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From:   Jens Axboe <axboe@kernel.dk>
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Date:   Tue, 3 Mar 2020 12:23:16 -0700
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On 3/3/20 12:02 PM, Jeff Layton wrote:
> Basically, all you'd need to do is keep a pointer to struct file in the
> internal state for the chain. Then, allow userland to specify some magic
> fd value for subsequent chained operations that says to use that instead
> of consulting the fdtable. Maybe use -4096 (-MAX_ERRNO - 1)?

BTW, I think we need two magics here. One that says "result from
previous is fd for next", and one that says "fd from previous is fd for
next". The former allows inheritance from open -> read, the latter from
read -> write.

-- 
Jens Axboe