diff options
| author | Vivek Goyal <vgoyal@redhat.com> | 2020-02-28 11:34:52 -0500 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2020-04-02 19:15:03 -0700 |
| commit | f605a263e0690177ecc180417eacf2b5507dd177 (patch) | |
| tree | 119fa2ae9f57012c245a3926830911327b2721b5 /drivers | |
| parent | 5d64efe79703c4de1f017af9f7643ead1dc85432 (diff) | |
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')
| -rw-r--r-- | drivers/dax/super.c | 20 | ||||
| -rw-r--r-- | drivers/nvdimm/pmem.c | 11 |
2 files changed, 31 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) diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 075b11682192..5b774ddd0efb 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -282,6 +282,16 @@ static const struct block_device_operations pmem_fops = { .revalidate_disk = nvdimm_revalidate_disk, }; +static int pmem_dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff, + size_t nr_pages) +{ + struct pmem_device *pmem = dax_get_private(dax_dev); + + return blk_status_to_errno(pmem_do_write(pmem, ZERO_PAGE(0), 0, + PFN_PHYS(pgoff) >> SECTOR_SHIFT, + PAGE_SIZE)); +} + static long pmem_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn) { @@ -313,6 +323,7 @@ static const struct dax_operations pmem_dax_ops = { .dax_supported = generic_fsdax_supported, .copy_from_iter = pmem_copy_from_iter, .copy_to_iter = pmem_copy_to_iter, + .zero_page_range = pmem_dax_zero_page_range, }; static const struct attribute_group *pmem_attribute_groups[] = { |