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To: Matthias Andree <mandree@FreeBSD.org>
cc: freebsd-hackers@freebsd.org
Subject: Re: User-space API to inquire block alignment requirements for open
 file descriptor?
In-reply-to: <c9063edd-a3c1-fce4-483c-a192addc6b86@FreeBSD.org>
From: "Poul-Henning Kamp" <phk@phk.freebsd.dk>
References: <c9063edd-a3c1-fce4-483c-a192addc6b86@FreeBSD.org>
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Date: Mon, 12 Sep 2016 07:12:48 +0000
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--------
In message <c9063edd-a3c1-fce4-483c-a192addc6b86@FreeBSD.org>, Matthias An=
dree =

writes:
>Greetings,
>
>given an open file descriptor, do we have a system interface to inquire
>about the block size of the underlying devices? In the past, we used to
>deal with 512-byte blocks, but how about drives using 4096-byte blocks?

DIOCGSECTORSIZE in sys/disk.h

-- =

Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    =

Never attribute to malice what can adequately be explained by incompetence=
.