[PATCH RFC V2 10/17] fs/dax: Remove unused size parameter

ira.weiny
2020-07-17T07:21:18Z

From: Ira Weiny <ira.weiny@intel.com>

Passing size to copy_user_dax implies it can copy variable sizes of data
when in fact it calls copy_user_page() which is exactly a page.

We are safe because the only caller uses PAGE_SIZE anyway so just remove
the variable for clarity.

While we are at it change copy_user_dax() to copy_cow_page_dax() to make
it clear it is a singleton helper for this one case not implementing
what dax_iomap_actor() does.

Reviewed-by: Ben Widawsky <ben.widawsky@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
---
fs/dax.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/fs/dax.c b/fs/dax.c
index 11b16729b86f..3e0babeb0365 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -680,21 +680,20 @@ int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
return __dax_invalidate_entry(mapping, index, false);
}

-static int copy_user_dax(struct block_device *bdev, struct dax_device *dax_dev,
- sector_t sector, size_t size, struct page *to,
- unsigned long vaddr)
+static int copy_cow_page_dax(struct block_device *bdev, struct dax_device *dax_dev,
+ sector_t sector, struct page *to, unsigned long vaddr)
{
void *vto, *kaddr;
pgoff_t pgoff;
long rc;
int id;

- rc = bdev_dax_pgoff(bdev, sector, size, &pgoff);
+ rc = bdev_dax_pgoff(bdev, sector, PAGE_SIZE, &pgoff);
if (rc)
return rc;

id = dax_read_lock();
- rc = dax_direct_access(dax_dev, pgoff, PHYS_PFN(size), &kaddr, NULL);
+ rc = dax_direct_access(dax_dev, pgoff, PHYS_PFN(PAGE_SIZE), &kaddr, NULL);
if (rc < 0) {
dax_read_unlock(id);
return rc;
@@ -1305,8 +1304,8 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
clear_user_highpage(vmf->cow_page, vaddr);
break;
case IOMAP_MAPPED:
- error = copy_user_dax(iomap.bdev, iomap.dax_dev,
- sector, PAGE_SIZE, vmf->cow_page, vaddr);
+ error = copy_cow_page_dax(iomap.bdev, iomap.dax_dev,
+ sector, vmf->cow_page, vaddr);
break;
default:
WARN_ON_ONCE(1);
--
2.28.0.rc0.12.gb6a658bd00c9