Re: [PATCH v3 03/10] fsdax: Output address in dax_iomap_pfn() and rename it

[Ritesh Harjani]

On 3/19/21 7:22 AM, Shiyang Ruan wrote:

Add address output in dax_iomap_pfn() in order to perform a memcpy() in
CoW case.  Since this function both output address and pfn, rename it to
dax_iomap_direct_access().

Signed-off-by: Shiyang Ruan 
Reviewed-by: Christoph Hellwig 
---
  fs/dax.c | 16 
  1 file changed, 12 insertions(+), 4 deletions(-)



Like the naming convention. It is consistent with
dax_direct_access() function.

Changes looks good to me. Feel free to add.

Reviewed-by: Ritesh Harjani 

[PATCH v3 03/10] fsdax: Output address in dax_iomap_pfn() and rename it

[Shiyang Ruan]

Add address output in dax_iomap_pfn() in order to perform a memcpy() in
CoW case.  Since this function both output address and pfn, rename it to
dax_iomap_direct_access().

Signed-off-by: Shiyang Ruan 
Reviewed-by: Christoph Hellwig 
---
 fs/dax.c | 16 
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/fs/dax.c b/fs/dax.c
index 33ddad0f3091..a70e6aa285bb 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -997,8 +997,8 @@ static sector_t dax_iomap_sector(struct iomap *iomap, 
loff_t pos)
return (iomap->addr + (pos & PAGE_MASK) - iomap->offset) >> 9;
 }
 
-static int dax_iomap_pfn(struct iomap *iomap, loff_t pos, size_t size,
-pfn_t *pfnp)
+static int dax_iomap_direct_access(struct iomap *iomap, loff_t pos, size_t 
size,
+   void **kaddr, pfn_t *pfnp)
 {
const sector_t sector = dax_iomap_sector(iomap, pos);
pgoff_t pgoff;
@@ -1010,11 +1010,13 @@ static int dax_iomap_pfn(struct iomap *iomap, loff_t 
pos, size_t size,
return rc;
id = dax_read_lock();
length = dax_direct_access(iomap->dax_dev, pgoff, PHYS_PFN(size),
-  NULL, pfnp);
+  kaddr, pfnp);
if (length < 0) {
rc = length;
goto out;
}
+   if (!pfnp)
+   goto out_check_addr;
rc = -EINVAL;
if (PFN_PHYS(length) < size)
goto out;
@@ -1024,6 +1026,12 @@ static int dax_iomap_pfn(struct iomap *iomap, loff_t 
pos, size_t size,
if (length > 1 && !pfn_t_devmap(*pfnp))
goto out;
rc = 0;
+
+out_check_addr:
+   if (!kaddr)
+   goto out;
+   if (!*kaddr)
+   rc = -EFAULT;
 out:
dax_read_unlock(id);
return rc;
@@ -1386,7 +1394,7 @@ static vm_fault_t dax_fault_actor(struct vm_fault *vmf, 
pfn_t *pfnp,
return VM_FAULT_SIGBUS;
}
 
-   err = dax_iomap_pfn(iomap, pos, size, );
+   err = dax_iomap_direct_access(iomap, pos, size, NULL, );
if (err)
return dax_fault_return(err);
 
-- 
2.30.1