From: Ivan Kozik <ivan@ludios.org>
To: cygwin@cygwin.com
Subject: Re: Wrong file position after writing 65537 bytes to block device
Date: Wed, 20 Dec 2017 05:47:00 -0000 [thread overview]
Message-ID: <CAKyntiLdwdaPewnyhNKC=yZJJ2Hc_BOrd9-j2HGmjLmiox3z1Q@mail.gmail.com> (raw)
In-Reply-To: <20171219181914.GE19986@calimero.vinschen.de>
On Tue, Dec 19, 2017 at 6:19 PM, Corinna Vinschen
<corinna-cygwin@cygwin.com> wrote:
> On Dec 19 16:35, Ivan Kozik wrote:
>> From what I observe on Linux, it supports writing at any offset to the
>> block device because it does a read-modify-write behind the scenes,
>> with accompanying nasty overhead (e.g. writes going at 64MB/s instead
>> of an "expected" 180MB/s).
>
> That's what Cygwin was trying to emulate as well. Debugging pointed out
> that it only works for reading, not for writing, because the latter
> neglected to fix up buffer pointers. Those are used in lseek to report
> the Linux-like byte-exact file position.
>
> I pushed a patch and uploaded new developer snapshots to
> https://cygwin.com/snapshts/
>
> Please give them a test.
Hi Corinna,
It is writing correctly now, thank you for the fix!
Ivan
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next prev parent reply other threads:[~2017-12-19 18:45 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-16 6:13 Ivan Kozik
2017-12-18 16:32 ` Corinna Vinschen
2017-12-19 5:03 ` Steven Penny
2017-12-19 10:20 ` Corinna Vinschen
2017-12-19 16:36 ` Ivan Kozik
2017-12-19 17:43 ` Eric Blake
2017-12-19 18:18 ` Ivan Kozik
2017-12-19 18:36 ` Corinna Vinschen
2017-12-20 5:47 ` Ivan Kozik [this message]
2017-12-20 23:59 ` Kaz Kylheku
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