diff options
| author | Vivek Goyal <vgoyal@redhat.com> | 2020-02-28 19:34:52 +0300 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2020-04-03 05:15:03 +0300 |
| commit | f605a263e0690177ecc180417eacf2b5507dd177 (patch) | |
| tree | 119fa2ae9f57012c245a3926830911327b2721b5 /drivers/dax | |
| parent | 5d64efe79703c4de1f017af9f7643ead1dc85432 (diff) | |
| download | linux-f605a263e0690177ecc180417eacf2b5507dd177.tar.xz | |
dax, pmem: Add a dax operation zero_page_range
Add a dax operation zero_page_range, to zero a page. This will also clear any
known poison in the page being zeroed.
As of now, zeroing of 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>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Link: https://lore.kernel.org/r/20200228163456.1587-3-vgoyal@redhat.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/dax')
| -rw-r--r-- | drivers/dax/super.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/drivers/dax/super.c b/drivers/dax/super.c index 0aa4b6bc5101..e498daf3c0d7 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -344,6 +344,26 @@ 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, pgoff_t pgoff, + size_t nr_pages) +{ + if (!dax_alive(dax_dev)) + return -ENXIO; + + if (!dax_dev->ops->zero_page_range) + return -EOPNOTSUPP; + /* + * 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. + */ + if (nr_pages != 1) + return -EIO; + + return dax_dev->ops->zero_page_range(dax_dev, pgoff, nr_pages); +} +EXPORT_SYMBOL_GPL(dax_zero_page_range); + #ifdef CONFIG_ARCH_HAS_PMEM_API void arch_wb_cache_pmem(void *addr, size_t size); void dax_flush(struct dax_device *dax_dev, void *addr, size_t size) |