From: Dave Chinner <david@fromorbit.com>
To: Florian Weimer <fweimer@redhat.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>,
linux-fsdevel@vger.kernel.org, hch@lst.de, smfrench@gmail.com,
linux-unionfs@vger.kernel.org,
Goldwyn Rodrigues <rgoldwyn@suse.com>
Subject: Re: [PATCH 3/4] copy_file_range: splice with holes
Date: Wed, 9 May 2018 09:43:30 +1000 [thread overview]
Message-ID: <20180508234330.GN10363@dastard> (raw)
In-Reply-To: <12f4b7e0-209e-210b-f583-d76f6fd5a2d3@redhat.com>
On Tue, May 08, 2018 at 11:59:45PM +0200, Florian Weimer wrote:
> On 05/08/2018 11:24 PM, Goldwyn Rodrigues wrote:
> >copy_file_range calls do_splice_direct() if fs->clone_file_range
> >or fs->copy_file_range() is not available. However, do_splice_direct()
> >converts holes to zeros. Detect holes in the file_in range, and
> >create them in the corresponding file_out range.
>
> Should this be restricted to calls to copy_file_range with a
> (yet-to-be-defined) flag?
>
> I was under the impression that the hole-filling nature of
> copy_file_range was not a bug.
It's not a bug, but it's currently undefined behaviour. i.e. some
filesystem implementations will hole fill while others won't, and
you cannot predict ahead of time what will happen.
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
next prev parent reply other threads:[~2018-05-08 23:43 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-08 21:24 [PATCH v1 0/5] Enable holes on copy_file_range() Goldwyn Rodrigues
2018-05-08 21:24 ` [PATCH 1/4] copy_file_range: refactor vfs_copy_file_range Goldwyn Rodrigues
2018-05-08 21:24 ` [PATCH 2/4] copy_file_range: Perform splice if in/out SB are not same Goldwyn Rodrigues
2018-05-08 21:57 ` Florian Weimer
2018-05-09 19:08 ` Goldwyn Rodrigues
2018-05-09 5:44 ` Amir Goldstein
2018-05-08 21:24 ` [PATCH 3/4] copy_file_range: splice with holes Goldwyn Rodrigues
2018-05-08 21:59 ` Florian Weimer
2018-05-08 23:43 ` Dave Chinner [this message]
2018-05-09 5:47 ` Amir Goldstein
2018-05-08 21:24 ` [PATCH 4/4] ovl: Use do_copy_file_range() in copy_up_data() Goldwyn Rodrigues
2018-05-09 5:50 ` Amir Goldstein
2018-05-09 19:13 ` Goldwyn Rodrigues
2018-05-10 4:52 ` Amir Goldstein
2018-05-10 1:58 [PATCH v2 0/4] Enable holes in copy_file_range() Goldwyn Rodrigues
2018-05-10 1:58 ` [PATCH 3/4] copy_file_range: splice with holes Goldwyn Rodrigues
2018-05-10 4:42 ` Amir Goldstein
2018-05-10 5:49 ` Amir Goldstein
2018-05-14 14:56 [PATCH v3 0/4] Enable holes in copy_file_range() Goldwyn Rodrigues
2018-05-14 14:56 ` [PATCH 3/4] copy_file_range: splice with holes Goldwyn Rodrigues
2018-06-14 15:12 [PATCH RESEND v3 0/4] Enable holes in copy_file_range() Goldwyn Rodrigues
2018-06-14 15:12 ` [PATCH 3/4] copy_file_range: splice with holes Goldwyn Rodrigues
2018-06-30 18:01 ` Steve French
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