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| 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 /include/linux/dax.h | |
| parent | pmem: Add functions for reading/writing page to/from pmem (diff) | |
| download | wireguard-linux-f605a263e0690177ecc180417eacf2b5507dd177.tar.xz wireguard-linux-f605a263e0690177ecc180417eacf2b5507dd177.zip | |
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 'include/linux/dax.h')
| -rw-r--r-- | include/linux/dax.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/include/linux/dax.h b/include/linux/dax.h index 328c2dbb4409..71735c430c05 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -34,6 +34,8 @@ struct dax_operations { /* copy_to_iter: required operation for fs-dax direct-i/o */ size_t (*copy_to_iter)(struct dax_device *, pgoff_t, void *, size_t, struct iov_iter *); + /* zero_page_range: required operation. Zero page range */ + int (*zero_page_range)(struct dax_device *, pgoff_t, size_t); }; extern struct attribute_group dax_attribute_group; @@ -199,6 +201,8 @@ size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, size_t bytes, struct iov_iter *i); size_t dax_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, size_t bytes, struct iov_iter *i); +int dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff, + size_t nr_pages); void dax_flush(struct dax_device *dax_dev, void *addr, size_t size); ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter, |