From: Dan Williams <dan.j.williams@intel.com>
To: Vivek Goyal <vgoyal@redhat.com>
Cc: linux-fsdevel <linux-fsdevel@vger.kernel.org>,
linux-nvdimm <linux-nvdimm@lists.01.org>,
Christoph Hellwig <hch@infradead.org>,
device-mapper development <dm-devel@redhat.com>,
Vishal L Verma <vishal.l.verma@intel.com>,
Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH v5 4/8] dax, pmem: Add a dax operation zero_page_range
Date: Tue, 31 Mar 2020 12:38:16 -0700 [thread overview]
Message-ID: <CAPcyv4jKHxy5c8BZodePeCu5+Z=cwhtEfw3RnOD1ZDNob382bQ@mail.gmail.com> (raw)
In-Reply-To: <20200218214841.10076-5-vgoyal@redhat.com>
On Tue, Feb 18, 2020 at 1:49 PM Vivek Goyal <vgoyal@redhat.com> wrote:
>
> Add a dax operation zero_page_range, to zero a range of memory. This will
> also clear any poison in the range being zeroed.
>
> As of now, zeroing of up to one page is allowed in a single call. There
> are no callers which are trying to zero more than a page in a single call.
> Once we grow the callers which zero more than a page in single call, we
> can add that support. Primary reason for not doing that yet is that this
> will add little complexity in dm implementation where a range might be
> spanning multiple underlying targets and one will have to split the range
> into multiple sub ranges and call zero_page_range() on individual targets.
>
> Suggested-by: Christoph Hellwig <hch@infradead.org>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
> ---
> drivers/dax/super.c | 19 +++++++++++++++++++
> drivers/nvdimm/pmem.c | 10 ++++++++++
> include/linux/dax.h | 3 +++
> 3 files changed, 32 insertions(+)
>
> diff --git a/drivers/dax/super.c b/drivers/dax/super.c
> index 0aa4b6bc5101..c912808bc886 100644
> --- a/drivers/dax/super.c
> +++ b/drivers/dax/super.c
> @@ -344,6 +344,25 @@ size_t dax_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
> }
> EXPORT_SYMBOL_GPL(dax_copy_to_iter);
>
> +int dax_zero_page_range(struct dax_device *dax_dev, u64 offset, size_t len)
> +{
> + if (!dax_alive(dax_dev))
> + return -ENXIO;
> +
> + if (!dax_dev->ops->zero_page_range)
> + return -EOPNOTSUPP;
This seems too late to be doing the validation. It would be odd for
random filesystem operations to see this error. I would move the check
to alloc_dax() and fail that if the caller fails to implement the
operation.
An incremental patch on top to fix this up would be ok. Something like
"Now that all dax_operations providers implement zero_page_range()
mandate it at alloc_dax time".
next prev parent reply other threads:[~2020-03-31 19:38 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-18 21:48 [PATCH v5 0/8] dax/pmem: Provide a dax operation to zero range of memory Vivek Goyal
2020-02-18 21:48 ` [PATCH v5 1/8] pmem: Add functions for reading/writing page to/from pmem Vivek Goyal
2020-02-18 21:48 ` [PATCH v5 2/8] drivers/pmem: Allow pmem_clear_poison() to accept arbitrary offset and len Vivek Goyal
2020-02-20 16:17 ` Christoph Hellwig
2020-02-20 21:35 ` Jeff Moyer
2020-02-20 21:57 ` Vivek Goyal
2020-02-21 18:32 ` Jeff Moyer
2020-02-21 20:17 ` Vivek Goyal
2020-02-21 21:00 ` Dan Williams
2020-02-21 21:24 ` Vivek Goyal
2020-02-21 21:30 ` Dan Williams
2020-02-21 21:33 ` Jeff Moyer
2020-02-23 23:03 ` Dave Chinner
2020-02-24 0:40 ` Dan Williams
2020-02-24 13:50 ` Jeff Moyer
2020-02-24 20:48 ` Dan Williams
2020-02-24 21:53 ` Jeff Moyer
2020-02-25 0:26 ` Dan Williams
2020-02-25 20:32 ` Jeff Moyer
2020-02-25 21:52 ` Dan Williams
2020-02-25 23:26 ` Jane Chu
2020-02-24 15:38 ` Vivek Goyal
2020-02-27 3:02 ` Dave Chinner
2020-02-27 4:19 ` Dan Williams
2020-02-28 1:30 ` Dave Chinner
2020-02-28 3:28 ` Dan Williams
2020-02-28 14:05 ` Christoph Hellwig
2020-02-28 16:26 ` Dan Williams
2020-02-24 20:13 ` Vivek Goyal
2020-02-24 20:52 ` Dan Williams
2020-02-24 21:15 ` Vivek Goyal
2020-02-24 21:32 ` Dan Williams
2020-02-25 13:36 ` Vivek Goyal
2020-02-25 16:25 ` Dan Williams
2020-02-25 20:08 ` Vivek Goyal
2020-02-25 22:49 ` Dan Williams
2020-02-26 13:51 ` Vivek Goyal
2020-02-26 16:57 ` Vivek Goyal
2020-02-27 3:11 ` Dave Chinner
2020-02-27 15:25 ` Vivek Goyal
2020-02-28 1:50 ` Dave Chinner
2020-02-18 21:48 ` [PATCH v5 3/8] pmem: Enable pmem_do_write() to deal with arbitrary ranges Vivek Goyal
2020-02-20 16:17 ` Christoph Hellwig
2020-02-18 21:48 ` [PATCH v5 4/8] dax, pmem: Add a dax operation zero_page_range Vivek Goyal
2020-03-31 19:38 ` Dan Williams [this message]
2020-04-01 13:15 ` Vivek Goyal
2020-04-01 16:14 ` Vivek Goyal
2020-02-18 21:48 ` [PATCH v5 5/8] s390,dcssblk,dax: Add dax zero_page_range operation to dcssblk driver Vivek Goyal
2020-02-18 21:48 ` [PATCH v5 6/8] dm,dax: Add dax zero_page_range operation Vivek Goyal
2020-02-18 21:48 ` [PATCH v5 7/8] dax,iomap: Start using dax native zero_page_range() Vivek Goyal
2020-02-18 21:48 ` [PATCH v5 8/8] dax,iomap: Add helper dax_iomap_zero() to zero a range Vivek Goyal
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