Re: [PATCH v9 1/8] fsdax: Output address in dax_iomap_pfn() and rename it

[Shiyang Ruan]

On 2021/9/16 8:09, Darrick J. Wong wrote:

On Wed, Sep 15, 2021 at 06:44:54PM +0800, 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 
Reviewed-by: Ritesh Harjani 
Reviewed-by: Dan Williams 


Could've sworn I reviewed this a few revisions ago...


Oh, sorry, Maybe I missed that.


Reviewed-by: Darrick J. Wong 


Thanks!

--
Ruan



--D


---
  fs/dax.c | 16 
  1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/fs/dax.c b/fs/dax.c
index 4e3e5a283a91..8b482a58acae 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1010,8 +1010,8 @@ 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)
+static int dax_iomap_direct_access(const 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;
@@ -1023,11 +1023,13 @@ static int dax_iomap_pfn(const 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;
@@ -1037,6 +1039,12 @@ static int dax_iomap_pfn(const 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;
@@ -1401,7 +1409,7 @@ static vm_fault_t dax_fault_iter(struct vm_fault *vmf,
return pmd ? VM_FAULT_FALLBACK : VM_FAULT_SIGBUS;
}
  
-	err = dax_iomap_pfn(>iomap, pos, size, );

+   err = dax_iomap_direct_access(>iomap, pos, size, NULL, );
if (err)
return pmd ? VM_FAULT_FALLBACK : dax_fault_return(err);
  
--

2.33.0

Re: [PATCH v9 1/8] fsdax: Output address in dax_iomap_pfn() and rename it

[Darrick J. Wong]

On Wed, Sep 15, 2021 at 06:44:54PM +0800, 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 
> Reviewed-by: Ritesh Harjani 
> Reviewed-by: Dan Williams 

Could've sworn I reviewed this a few revisions ago...
Reviewed-by: Darrick J. Wong 

--D

> ---
>  fs/dax.c | 16 
>  1 file changed, 12 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/dax.c b/fs/dax.c
> index 4e3e5a283a91..8b482a58acae 100644
> --- a/fs/dax.c
> +++ b/fs/dax.c
> @@ -1010,8 +1010,8 @@ 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)
> +static int dax_iomap_direct_access(const 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;
> @@ -1023,11 +1023,13 @@ static int dax_iomap_pfn(const 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;
> @@ -1037,6 +1039,12 @@ static int dax_iomap_pfn(const 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;
> @@ -1401,7 +1409,7 @@ static vm_fault_t dax_fault_iter(struct vm_fault *vmf,
>   return pmd ? VM_FAULT_FALLBACK : VM_FAULT_SIGBUS;
>   }
>  
> - err = dax_iomap_pfn(>iomap, pos, size, );
> + err = dax_iomap_direct_access(>iomap, pos, size, NULL, );
>   if (err)
>   return pmd ? VM_FAULT_FALLBACK : dax_fault_return(err);
>  
> -- 
> 2.33.0
> 
> 
>