From f605a263e0690177ecc180417eacf2b5507dd177 Mon Sep 17 00:00:00 2001 From: Vivek Goyal Date: Fri, 28 Feb 2020 11:34:52 -0500 Subject: 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 Signed-off-by: Vivek Goyal Reviewed-by: Pankaj Gupta Link: https://lore.kernel.org/r/20200228163456.1587-3-vgoyal@redhat.com Signed-off-by: Dan Williams --- include/linux/dax.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux') 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, -- cgit v1.2.3 From cdf6cdcd3b99a99ea9ecc1b05d1d040d5a69a134 Mon Sep 17 00:00:00 2001 From: Vivek Goyal Date: Fri, 28 Feb 2020 11:34:54 -0500 Subject: dm,dax: Add dax zero_page_range operation This patch adds support for dax zero_page_range operation to dm targets. Signed-off-by: Vivek Goyal Acked-by: Mike Snitzer Link: https://lore.kernel.org/r/20200228163456.1587-5-vgoyal@redhat.com Signed-off-by: Dan Williams --- include/linux/device-mapper.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux') diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 475668c69dbc..af48d9da3916 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -141,6 +141,8 @@ typedef long (*dm_dax_direct_access_fn) (struct dm_target *ti, pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn); typedef size_t (*dm_dax_copy_iter_fn)(struct dm_target *ti, pgoff_t pgoff, void *addr, size_t bytes, struct iov_iter *i); +typedef int (*dm_dax_zero_page_range_fn)(struct dm_target *ti, pgoff_t pgoff, + size_t nr_pages); #define PAGE_SECTORS (PAGE_SIZE / 512) void dm_error(const char *message); @@ -195,6 +197,7 @@ struct target_type { dm_dax_direct_access_fn direct_access; dm_dax_copy_iter_fn dax_copy_from_iter; dm_dax_copy_iter_fn dax_copy_to_iter; + dm_dax_zero_page_range_fn dax_zero_page_range; /* For internal device-mapper use. */ struct list_head list; -- cgit v1.2.3 From 4f3b4f161d7a070d2181dbcf7fbd97c7631d5c24 Mon Sep 17 00:00:00 2001 From: Vivek Goyal Date: Fri, 28 Feb 2020 11:34:56 -0500 Subject: dax,iomap: Add helper dax_iomap_zero() to zero a range Add a helper dax_ioamp_zero() to zero a range. This patch basically merges __dax_zero_page_range() and iomap_dax_zero(). Suggested-by: Christoph Hellwig Signed-off-by: Vivek Goyal Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20200228163456.1587-7-vgoyal@redhat.com Signed-off-by: Dan Williams --- include/linux/dax.h | 17 +++-------------- 1 file changed, 3 insertions(+), 14 deletions(-) (limited to 'include/linux') diff --git a/include/linux/dax.h b/include/linux/dax.h index 71735c430c05..d7af5d243f24 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -13,6 +13,7 @@ typedef unsigned long dax_entry_t; struct iomap_ops; +struct iomap; struct dax_device; struct dax_operations { /* @@ -214,20 +215,8 @@ vm_fault_t dax_finish_sync_fault(struct vm_fault *vmf, int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index); int dax_invalidate_mapping_entry_sync(struct address_space *mapping, pgoff_t index); - -#ifdef CONFIG_FS_DAX -int __dax_zero_page_range(struct block_device *bdev, - struct dax_device *dax_dev, sector_t sector, - unsigned int offset, unsigned int length); -#else -static inline int __dax_zero_page_range(struct block_device *bdev, - struct dax_device *dax_dev, sector_t sector, - unsigned int offset, unsigned int length) -{ - return -ENXIO; -} -#endif - +int dax_iomap_zero(loff_t pos, unsigned offset, unsigned size, + struct iomap *iomap); static inline bool dax_mapping(struct address_space *mapping) { return mapping->host && IS_DAX(mapping->host); -- cgit v1.2.3