Commit 81ee8e52 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Darrick J. Wong
Browse files

iomap: Change calling convention for zeroing 



Pass the full length to iomap_zero() and dax_iomap_zero(), and have
them return how many bytes they actually handled.  This is preparatory
work for handling THP, although it looks like DAX could actually take
advantage of it if there's a larger contiguous area.

Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
parent e25ba8cb

fs/dax.c

+6 −7
Original line number Diff line number Diff line
@@ -1037,18 +1037,18 @@ static vm_fault_t dax_load_hole(struct xa_state *xas, 
	return ret;

}



int dax_iomap_zero(loff_t pos, unsigned offset, unsigned size,

		   struct iomap *iomap)

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

{

	sector_t sector = iomap_sector(iomap, pos & PAGE_MASK);

	pgoff_t pgoff;

	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(sector << SECTOR_SHIFT, PAGE_SIZE) &&

	    IS_ALIGNED(size, PAGE_SIZE))

	    (size == PAGE_SIZE))

		page_aligned = true;



	rc = bdev_dax_pgoff(iomap->bdev, sector, PAGE_SIZE, &pgoff);
@@ -1058,8 +1058,7 @@ int dax_iomap_zero(loff_t pos, unsigned offset, unsigned size, 
	id = dax_read_lock();



	if (page_aligned)

		rc = dax_zero_page_range(iomap->dax_dev, pgoff,

					 size >> PAGE_SHIFT);

		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) {
@@ -1072,7 +1071,7 @@ int dax_iomap_zero(loff_t pos, unsigned offset, unsigned size, 
		dax_flush(iomap->dax_dev, kaddr + offset, size);

	}

	dax_read_unlock(id);

	return 0;

	return size;

}



static loff_t

fs/iomap/buffered-io.c

+15 −18
Original line number Diff line number Diff line
@@ -898,11 +898,13 @@ iomap_file_unshare(struct inode *inode, loff_t pos, loff_t len, 
}

EXPORT_SYMBOL_GPL(iomap_file_unshare);



static int iomap_zero(struct inode *inode, loff_t pos, unsigned offset,

		unsigned bytes, struct iomap *iomap, struct iomap *srcmap)

static s64 iomap_zero(struct inode *inode, loff_t pos, u64 length,

		struct iomap *iomap, struct iomap *srcmap)

{

	struct page *page;

	int status;

	unsigned offset = offset_in_page(pos);

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



	status = iomap_write_begin(inode, pos, bytes, 0, &page, iomap, srcmap);

	if (status)
@@ -914,38 +916,33 @@ static int iomap_zero(struct inode *inode, loff_t pos, unsigned offset, 
	return iomap_write_end(inode, pos, bytes, bytes, page, iomap, srcmap);

}



static loff_t

iomap_zero_range_actor(struct inode *inode, loff_t pos, loff_t count,

		void *data, struct iomap *iomap, struct iomap *srcmap)

static loff_t iomap_zero_range_actor(struct inode *inode, loff_t pos,

		loff_t length, void *data, struct iomap *iomap,

		struct iomap *srcmap)

{

	bool *did_zero = data;

	loff_t written = 0;

	int status;



	/* already zeroed?  we're done. */

	if (srcmap->type == IOMAP_HOLE || srcmap->type == IOMAP_UNWRITTEN)

		return count;

		return length;



	do {

		unsigned offset, bytes;



		offset = offset_in_page(pos);

		bytes = min_t(loff_t, PAGE_SIZE - offset, count);

		s64 bytes;



		if (IS_DAX(inode))

			status = dax_iomap_zero(pos, offset, bytes, iomap);

			bytes = dax_iomap_zero(pos, length, iomap);

		else

			status = iomap_zero(inode, pos, offset, bytes, iomap,

					srcmap);

		if (status < 0)

			return status;

			bytes = iomap_zero(inode, pos, length, iomap, srcmap);

		if (bytes < 0)

			return bytes;



		pos += bytes;

		count -= bytes;

		length -= bytes;

		written += bytes;

		if (did_zero)

			*did_zero = true;

	} while (count > 0);

	} while (length > 0);



	return written;

}

include/linux/dax.h

+1 −2
Original line number Diff line number Diff line
@@ -214,8 +214,7 @@ 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);

int dax_iomap_zero(loff_t pos, unsigned offset, unsigned size,

			struct iomap *iomap);

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

static inline bool dax_mapping(struct address_space *mapping)

{

	return mapping->host && IS_DAX(mapping->host);