Re: [PATCH] dax: remove silly single-page limitation in dax_zero_page_range
From: Dan Williams <hidden>
Date: 2021-09-23 02:47:22
Also in:
linux-ext4, linux-fsdevel, nvdimm
On Wed, Sep 22, 2021 at 6:09 PM Darrick J. Wong [off-list ref] wrote:
quoted hunk ↗ jump to hunk
From: Darrick J. Wong <djwong@kernel.org> It's totally silly that the dax zero_page_range implementations are required to accept a page count, but one of the four implementations silently ignores the page count and the wrapper itself errors out if you try to do more than one page. Fix the nvdimm implementation to loop over the page count and remove the artificial limitation. Signed-off-by: Darrick J. Wong <djwong@kernel.org> --- drivers/dax/super.c | 7 ------- drivers/nvdimm/pmem.c | 14 +++++++++++--- 2 files changed, 11 insertions(+), 10 deletions(-)diff --git a/drivers/dax/super.c b/drivers/dax/super.c index fc89e91beea7..ca61a01f9ccd 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c@@ -353,13 +353,6 @@ int dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff, { if (!dax_alive(dax_dev)) return -ENXIO; - /* - * There are no callers that want to zero more than one page as of now. - * Once users are there, this check can be removed after the - * device mapper code has been updated to split ranges across targets. - */
It's device-mapper that's the issue, you need to make sure that every device-mapper zero_page_range implementation knows how to route a multi-page operation. This is part of the motivation to drop that support and move simple concatenation and striping into the PMEM driver directly.