[PATCH 13/29] fsdax: use a saner calling convention for copy_cow_page_dax

Christoph Hellwig
2021-11-09T08:33:47Z

Just pass the vm_fault and iomap_iter structures, and figure out the rest
locally. Note that this requires moving dax_iomap_sector up in the file.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/dax.c | 29 +++++++++++++----------------
1 file changed, 13 insertions(+), 16 deletions(-)

diff --git a/fs/dax.c b/fs/dax.c
index 73bd1439d8089..e51b4129d1b65 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -709,26 +709,31 @@ int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
return __dax_invalidate_entry(mapping, index, false);
}

-static int copy_cow_page_dax(struct block_device *bdev, struct dax_device *dax_dev,
- sector_t sector, struct page *to, unsigned long vaddr)
+static sector_t dax_iomap_sector(const struct iomap *iomap, loff_t pos)
{
+ return (iomap->addr + (pos & PAGE_MASK) - iomap->offset) >> 9;
+}
+
+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);
void *vto, *kaddr;
pgoff_t pgoff;
long rc;
int id;

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

id = dax_read_lock();
- rc = dax_direct_access(dax_dev, pgoff, 1, &kaddr, NULL);
+ rc = dax_direct_access(iter->iomap.dax_dev, pgoff, 1, &kaddr, NULL);
if (rc < 0) {
dax_read_unlock(id);
return rc;
}
- vto = kmap_atomic(to);
- copy_user_page(vto, kaddr, vaddr, to);
+ vto = kmap_atomic(vmf->cow_page);
+ copy_user_page(vto, kaddr, vmf->address, vmf->cow_page);
kunmap_atomic(vto);
dax_read_unlock(id);
return 0;
@@ -1005,11 +1010,6 @@ int dax_writeback_mapping_range(struct address_space *mapping,
}
EXPORT_SYMBOL_GPL(dax_writeback_mapping_range);

-static sector_t dax_iomap_sector(const struct iomap *iomap, loff_t pos)
-{
- return (iomap->addr + (pos & PAGE_MASK) - iomap->offset) >> 9;
-}
-
static int dax_iomap_pfn(const struct iomap *iomap, loff_t pos, size_t size,
pfn_t *pfnp)
{
@@ -1332,19 +1332,16 @@ static vm_fault_t dax_fault_synchronous_pfnp(pfn_t *pfnp, pfn_t pfn)
static vm_fault_t dax_fault_cow_page(struct vm_fault *vmf,
const struct iomap_iter *iter)
{
- sector_t sector = dax_iomap_sector(&iter->iomap, iter->pos);
- unsigned long vaddr = vmf->address;
vm_fault_t ret;
int error = 0;

switch (iter->iomap.type) {
case IOMAP_HOLE:
case IOMAP_UNWRITTEN:
- clear_user_highpage(vmf->cow_page, vaddr);
+ clear_user_highpage(vmf->cow_page, vmf->address);
break;
case IOMAP_MAPPED:
- error = copy_cow_page_dax(iter->iomap.bdev, iter->iomap.dax_dev,
- sector, vmf->cow_page, vaddr);
+ error = copy_cow_page_dax(vmf, iter);
break;
default:
WARN_ON_ONCE(1);
--
2.30.2