Commit 60696eb2 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Dan Williams
Browse files

fsdax: simplify the pgoff calculation 



Replace the two steps of dax_iomap_sector and bdev_dax_pgoff with a
single dax_iomap_pgoff helper that avoids lots of cumbersome sector
conversions.

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/20211129102203.2243509-15-hch@lst.de


Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 429f8de7

drivers/dax/super.c

+0 −14
Original line number Diff line number Diff line
@@ -66,20 +66,6 @@ void dax_remove_host(struct gendisk *disk) 
}

EXPORT_SYMBOL_GPL(dax_remove_host);



int bdev_dax_pgoff(struct block_device *bdev, sector_t sector, size_t size,

		pgoff_t *pgoff)

{

	sector_t start_sect = bdev ? get_start_sect(bdev) : 0;

	phys_addr_t phys_off = (start_sect + sector) * 512;



	if (pgoff)

		*pgoff = PHYS_PFN(phys_off);

	if (phys_off % PAGE_SIZE || size % PAGE_SIZE)

		return -EINVAL;

	return 0;

}

EXPORT_SYMBOL(bdev_dax_pgoff);



/**

 * fs_dax_get_by_bdev() - temporary lookup mechanism for filesystem-dax

 * @bdev: block device to find a dax_device for

fs/dax.c

+10 −25
Original line number Diff line number Diff line
@@ -709,23 +709,22 @@ int dax_invalidate_mapping_entry_sync(struct address_space *mapping, 
	return __dax_invalidate_entry(mapping, index, false);

}



static sector_t dax_iomap_sector(const struct iomap *iomap, loff_t pos)

static pgoff_t dax_iomap_pgoff(const struct iomap *iomap, loff_t pos)

{

	return (iomap->addr + (pos & PAGE_MASK) - iomap->offset) >> 9;

	phys_addr_t paddr = iomap->addr + (pos & PAGE_MASK) - iomap->offset;



	if (iomap->bdev)

		paddr += (get_start_sect(iomap->bdev) << SECTOR_SHIFT);

	return PHYS_PFN(paddr);

}



static int copy_cow_page_dax(struct vm_fault *vmf, const struct iomap_iter *iter)

{

	sector_t sector = dax_iomap_sector(&iter->iomap, iter->pos);

	pgoff_t pgoff = dax_iomap_pgoff(&iter->iomap, iter->pos);

	void *vto, *kaddr;

	pgoff_t pgoff;

	long rc;

	int id;



	rc = bdev_dax_pgoff(iter->iomap.bdev, sector, PAGE_SIZE, &pgoff);

	if (rc)

		return rc;



	id = dax_read_lock();

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

	if (rc < 0) {
@@ -1013,14 +1012,10 @@ EXPORT_SYMBOL_GPL(dax_writeback_mapping_range); 
static int dax_iomap_pfn(const struct iomap *iomap, loff_t pos, size_t size,

			 pfn_t *pfnp)

{

	const sector_t sector = dax_iomap_sector(iomap, pos);

	pgoff_t pgoff;

	pgoff_t pgoff = dax_iomap_pgoff(iomap, pos);

	int id, rc;

	long length;



	rc = bdev_dax_pgoff(iomap->bdev, sector, size, &pgoff);

	if (rc)

		return rc;

	id = dax_read_lock();

	length = dax_direct_access(iomap->dax_dev, pgoff, PHYS_PFN(size),

				   NULL, pfnp);
@@ -1129,7 +1124,7 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, 
s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap)

{

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

	pgoff_t pgoff;

	pgoff_t pgoff = dax_iomap_pgoff(iomap, pos);

	long rc, id;

	void *kaddr;

	bool page_aligned = false;
@@ -1140,10 +1135,6 @@ s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap) 
	    (size == PAGE_SIZE))

		page_aligned = true;



	rc = bdev_dax_pgoff(iomap->bdev, sector, PAGE_SIZE, &pgoff);

	if (rc)

		return rc;



	id = dax_read_lock();



	if (page_aligned)
@@ -1169,7 +1160,6 @@ static loff_t dax_iomap_iter(const struct iomap_iter *iomi, 
	const struct iomap *iomap = &iomi->iomap;

	loff_t length = iomap_length(iomi);

	loff_t pos = iomi->pos;

	struct block_device *bdev = iomap->bdev;

	struct dax_device *dax_dev = iomap->dax_dev;

	loff_t end = pos + length, done = 0;

	ssize_t ret = 0;
@@ -1203,9 +1193,8 @@ static loff_t dax_iomap_iter(const struct iomap_iter *iomi, 
	while (pos < end) {

		unsigned offset = pos & (PAGE_SIZE - 1);

		const size_t size = ALIGN(length + offset, PAGE_SIZE);

		const sector_t sector = dax_iomap_sector(iomap, pos);

		pgoff_t pgoff = dax_iomap_pgoff(iomap, pos);

		ssize_t map_len;

		pgoff_t pgoff;

		void *kaddr;



		if (fatal_signal_pending(current)) {
@@ -1213,10 +1202,6 @@ static loff_t dax_iomap_iter(const struct iomap_iter *iomi, 
			break;

		}



		ret = bdev_dax_pgoff(bdev, sector, size, &pgoff);

		if (ret)

			break;



		map_len = dax_direct_access(dax_dev, pgoff, PHYS_PFN(size),

				&kaddr, NULL);

		if (map_len < 0) {

include/linux/dax.h

+0 −1
Original line number Diff line number Diff line
@@ -107,7 +107,6 @@ static inline bool daxdev_mapping_supported(struct vm_area_struct *vma, 
#endif



struct writeback_control;

int bdev_dax_pgoff(struct block_device *, sector_t, size_t, pgoff_t *pgoff);

#if IS_ENABLED(CONFIG_FS_DAX)

int dax_add_host(struct dax_device *dax_dev, struct gendisk *disk);

void dax_remove_host(struct gendisk *disk);