dax: Factor out getting of pfn out of iomap
Factor out code to get pfn out of iomap that is shared between PTE and
PMD fault path.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/fs/dax.c b/fs/dax.c
index 0bc42ac2..116eef8 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -825,6 +825,39 @@
return iomap->blkno + (((pos & PAGE_MASK) - iomap->offset) >> 9);
}
+static int dax_iomap_pfn(struct iomap *iomap, loff_t pos, size_t size,
+ pfn_t *pfnp)
+{
+ const sector_t sector = dax_iomap_sector(iomap, pos);
+ pgoff_t pgoff;
+ void *kaddr;
+ 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),
+ &kaddr, pfnp);
+ if (length < 0) {
+ rc = length;
+ goto out;
+ }
+ rc = -EINVAL;
+ if (PFN_PHYS(length) < size)
+ goto out;
+ if (pfn_t_to_pfn(*pfnp) & (PHYS_PFN(size)-1))
+ goto out;
+ /* For larger pages we need devmap */
+ if (length > 1 && !pfn_t_devmap(*pfnp))
+ goto out;
+ rc = 0;
+out:
+ dax_read_unlock(id);
+ return rc;
+}
+
static int dax_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,
loff_t pos, void *entry)
{
@@ -832,24 +865,14 @@
struct vm_area_struct *vma = vmf->vma;
struct address_space *mapping = vma->vm_file->f_mapping;
unsigned long vaddr = vmf->address;
- void *ret, *kaddr;
- pgoff_t pgoff;
- int id, rc;
+ void *ret;
+ int rc;
pfn_t pfn;
- rc = bdev_dax_pgoff(iomap->bdev, sector, PAGE_SIZE, &pgoff);
- if (rc)
+ rc = dax_iomap_pfn(iomap, pos, PAGE_SIZE, &pfn);
+ if (rc < 0)
return rc;
- id = dax_read_lock();
- rc = dax_direct_access(iomap->dax_dev, pgoff, PHYS_PFN(PAGE_SIZE),
- &kaddr, &pfn);
- if (rc < 0) {
- dax_read_unlock(id);
- return rc;
- }
- dax_read_unlock(id);
-
ret = dax_insert_mapping_entry(mapping, vmf, entry, sector, 0);
if (IS_ERR(ret))
return PTR_ERR(ret);
@@ -1223,46 +1246,26 @@
{
struct address_space *mapping = vmf->vma->vm_file->f_mapping;
const sector_t sector = dax_iomap_sector(iomap, pos);
- struct dax_device *dax_dev = iomap->dax_dev;
- struct block_device *bdev = iomap->bdev;
struct inode *inode = mapping->host;
- const size_t size = PMD_SIZE;
- void *ret = NULL, *kaddr;
- long length = 0;
- pgoff_t pgoff;
+ void *ret = NULL;
pfn_t pfn = {};
- int id;
+ int rc;
- if (bdev_dax_pgoff(bdev, sector, size, &pgoff) != 0)
+ rc = dax_iomap_pfn(iomap, pos, PMD_SIZE, &pfn);
+ if (rc < 0)
goto fallback;
- id = dax_read_lock();
- length = dax_direct_access(dax_dev, pgoff, PHYS_PFN(size), &kaddr, &pfn);
- if (length < 0)
- goto unlock_fallback;
- length = PFN_PHYS(length);
-
- if (length < size)
- goto unlock_fallback;
- if (pfn_t_to_pfn(pfn) & PG_PMD_COLOUR)
- goto unlock_fallback;
- if (!pfn_t_devmap(pfn))
- goto unlock_fallback;
- dax_read_unlock(id);
-
ret = dax_insert_mapping_entry(mapping, vmf, entry, sector,
RADIX_DAX_PMD);
if (IS_ERR(ret))
goto fallback;
- trace_dax_pmd_insert_mapping(inode, vmf, length, pfn, ret);
+ trace_dax_pmd_insert_mapping(inode, vmf, PMD_SIZE, pfn, ret);
return vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd,
pfn, vmf->flags & FAULT_FLAG_WRITE);
-unlock_fallback:
- dax_read_unlock(id);
fallback:
- trace_dax_pmd_insert_mapping_fallback(inode, vmf, length, pfn, ret);
+ trace_dax_pmd_insert_mapping_fallback(inode, vmf, PMD_SIZE, pfn, ret);
return VM_FAULT_FALLBACK;
}