Commit e5c71954 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Dan Williams
Browse files

fsdax: factor out a dax_memzero helper 



Factor out a helper for the "manual" zeroing of a DAX range to clean
up dax_iomap_zero a lot.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDan Williams <dan.j.williams@intel.com>
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20211129102203.2243509-18-hch@lst.de


Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 4a2d7d59

fs/dax.c

+19 −17
Original line number Diff line number Diff line
@@ -1121,34 +1121,36 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, 
}

#endif /* CONFIG_FS_DAX_PMD */



static int dax_memzero(struct dax_device *dax_dev, pgoff_t pgoff,

		unsigned int offset, size_t size)

{

	void *kaddr;

	long ret;



	ret = dax_direct_access(dax_dev, pgoff, 1, &kaddr, NULL);

	if (ret > 0) {

		memset(kaddr + offset, 0, size);

		dax_flush(dax_dev, kaddr + offset, size);

	}

	return ret;

}



s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap)

{

	pgoff_t pgoff = dax_iomap_pgoff(iomap, pos);

	long rc, id;

	void *kaddr;

	bool page_aligned = false;

	unsigned offset = offset_in_page(pos);

	unsigned size = min_t(u64, PAGE_SIZE - offset, length);



	if (IS_ALIGNED(pos, PAGE_SIZE) && size == PAGE_SIZE)

		page_aligned = true;



	id = dax_read_lock();



	if (page_aligned)

	if (IS_ALIGNED(pos, PAGE_SIZE) && size == PAGE_SIZE)

		rc = dax_zero_page_range(iomap->dax_dev, pgoff, 1);

	else

		rc = dax_direct_access(iomap->dax_dev, pgoff, 1, &kaddr, NULL);

	if (rc < 0) {

		rc = dax_memzero(iomap->dax_dev, pgoff, offset, size);

	dax_read_unlock(id);

		return rc;

	}



	if (!page_aligned) {

		memset(kaddr + offset, 0, size);

		dax_flush(iomap->dax_dev, kaddr + offset, size);

	}

	dax_read_unlock(id);

	if (rc < 0)

		return rc;

	return size;

}