Date: Sat, 21 Jan 2017 15:51:31 -0800 From: John-Mark Gurney <jmg@funkthat.com> To: Aijaz Baig <aijazbaig1@gmail.com> Cc: "Greg 'groggy' Lehey" <grog@freebsd.org>, FreeBSD Hackers <freebsd-hackers@freebsd.org>, freebsd-scsi@freebsd.org Subject: Re: Understanding the rationale behind dropping of "block devices" Message-ID: <20170121235131.GF1768@funkthat.com> In-Reply-To: <CAHB2L%2Bd9=rBBo48qR%2BPXgy%2BJDa=VRk5cM%2B9hAKDCPW%2BrqFgZAQ@mail.gmail.com> References: <CAHB2L%2BdRbX=E9NxGLd_eHsEeD0ZVYDYAx2k9h17BR0Lc=xu5HA@mail.gmail.com> <20170116071105.GB4560@eureka.lemis.com> <CAHB2L%2Bd9=rBBo48qR%2BPXgy%2BJDa=VRk5cM%2B9hAKDCPW%2BrqFgZAQ@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
Aijaz Baig wrote this message on Mon, Jan 16, 2017 at 14:19 +0530:
> Nevertheless my question still holds. What does 'removing support for block
> device' mean in this context? Was what I mentioned earlier with regards to
> my understanding correct? Viz. all disk devices now have a character (or
> raw) interface and are no longer served via the "page cache" but rather the
> "buffer cache". Does that mean all disk accesses are now direct by passing
> the file system??
One of the other reasons block devices were removed was that if there
was a write error on the underlying device, there was no way for the
writer to know that the write failed. This could/would lead to corrupted
data which is bad.
--
John-Mark Gurney Voice: +1 415 225 5579
"All that I will do, has been done, All that I have, has not."
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20170121235131.GF1768>