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authorVivek Goyal <vgoyal@redhat.com>2020-02-28 11:34:52 -0500
committerDan Williams <dan.j.williams@intel.com>2020-04-02 19:15:03 -0700
commitf605a263e0690177ecc180417eacf2b5507dd177 (patch)
tree119fa2ae9f57012c245a3926830911327b2721b5 /drivers/dax
parent5d64efe79703c4de1f017af9f7643ead1dc85432 (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/dax')
-rw-r--r--drivers/dax/super.c20
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)