Virtualization - Dec 2021 - [PATCH 1/5] uio: remove copy_from_iter_flushcache() and copy_mc_to_iter()

These two wrappers are never used.

Signed-off-by: Christoph Hellwig <hch at lst.de>
---
 drivers/nvdimm/pmem.c |  4 ++--
 include/linux/uio.h   | 20 +-------------------
 2 files changed, 3 insertions(+), 21 deletions(-)

diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 4190c8c46ca88..8294f1c701baa 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -302,8 +302,8 @@ static long pmem_dax_direct_access(struct dax_device
*dax_dev,
 }
 
 /*
- * Use the 'no check' versions of copy_from_iter_flushcache() and
- * copy_mc_to_iter() to bypass HARDENED_USERCOPY overhead. Bounds
+ * Use the 'no check' versions of _copy_from_iter_flushcache() and
+ * _copy_mc_to_iter() to bypass HARDENED_USERCOPY overhead. Bounds
  * checking, both file offset and device offset, is handled by
  * dax_iomap_actor()
  */
diff --git a/include/linux/uio.h b/include/linux/uio.h
index 6350354f97e90..494d552c1d663 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -196,7 +196,7 @@ bool copy_from_iter_full_nocache(void *addr, size_t bytes,
struct iov_iter *i)
 #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
 /*
  * Note, users like pmem that depend on the stricter semantics of
- * copy_from_iter_flushcache() than copy_from_iter_nocache() must check for
+ * _copy_from_iter_flushcache() than _copy_from_iter_nocache() must check for
  * IS_ENABLED(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) before assuming that the
  * destination is flushed from the cache on return.
  */
@@ -211,24 +211,6 @@ size_t _copy_mc_to_iter(const void *addr, size_t bytes,
struct iov_iter *i);
 #define _copy_mc_to_iter _copy_to_iter
 #endif
 
-static __always_inline __must_check
-size_t copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i)
-{
-	if (unlikely(!check_copy_size(addr, bytes, false)))
-		return 0;
-	else
-		return _copy_from_iter_flushcache(addr, bytes, i);
-}
-
-static __always_inline __must_check
-size_t copy_mc_to_iter(void *addr, size_t bytes, struct iov_iter *i)
-{
-	if (unlikely(!check_copy_size(addr, bytes, true)))
-		return 0;
-	else
-		return _copy_mc_to_iter(addr, bytes, i);
-}
-
 size_t iov_iter_zero(size_t bytes, struct iov_iter *);
 unsigned long iov_iter_alignment(const struct iov_iter *i);
 unsigned long iov_iter_gap_alignment(const struct iov_iter *i);
-- 
2.30.2

On Wed, Dec 8, 2021 at 10:38 PM Christoph Hellwig <hch at lst.de>
wrote:
>
> These two wrappers are never used.
>
> Signed-off-by: Christoph Hellwig <hch at lst.de>
> ---
>  drivers/nvdimm/pmem.c |  4 ++--
>  include/linux/uio.h   | 20 +-------------------
>  2 files changed, 3 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
> index 4190c8c46ca88..8294f1c701baa 100644
> --- a/drivers/nvdimm/pmem.c
> +++ b/drivers/nvdimm/pmem.c
> @@ -302,8 +302,8 @@ static long pmem_dax_direct_access(struct dax_device
*dax_dev,
>  }
>
>  /*
> - * Use the 'no check' versions of copy_from_iter_flushcache() and
> - * copy_mc_to_iter() to bypass HARDENED_USERCOPY overhead. Bounds
> + * Use the 'no check' versions of _copy_from_iter_flushcache() and
> + * _copy_mc_to_iter() to bypass HARDENED_USERCOPY overhead. Bounds
>   * checking, both file offset and device offset, is handled by
>   * dax_iomap_actor()
>   */
This comment change does not make sense since it is saying why pmem is
using the "_" versions. However, I assume this whole comment goes away
in a later patch.
> diff --git a/include/linux/uio.h b/include/linux/uio.h
> index 6350354f97e90..494d552c1d663 100644
> --- a/include/linux/uio.h
> +++ b/include/linux/uio.h
> @@ -196,7 +196,7 @@ bool copy_from_iter_full_nocache(void *addr, size_t
bytes, struct iov_iter *i)
>  #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
>  /*
>   * Note, users like pmem that depend on the stricter semantics of
> - * copy_from_iter_flushcache() than copy_from_iter_nocache() must check
for
> + * _copy_from_iter_flushcache() than _copy_from_iter_nocache() must check
for
>   * IS_ENABLED(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) before assuming that the
>   * destination is flushed from the cache on return.
>   */
Same here.
> @@ -211,24 +211,6 @@ size_t _copy_mc_to_iter(const void *addr, size_t
bytes, struct iov_iter *i);
>  #define _copy_mc_to_iter _copy_to_iter
>  #endif
>
> -static __always_inline __must_check
> -size_t copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter
*i)
> -{
> -       if (unlikely(!check_copy_size(addr, bytes, false)))
> -               return 0;
> -       else
> -               return _copy_from_iter_flushcache(addr, bytes, i);
> -}
> -
> -static __always_inline __must_check
> -size_t copy_mc_to_iter(void *addr, size_t bytes, struct iov_iter *i)
> -{
> -       if (unlikely(!check_copy_size(addr, bytes, true)))
> -               return 0;
> -       else
> -               return _copy_mc_to_iter(addr, bytes, i);
> -}
> -
>  size_t iov_iter_zero(size_t bytes, struct iov_iter *);
>  unsigned long iov_iter_alignment(const struct iov_iter *i);
>  unsigned long iov_iter_gap_alignment(const struct iov_iter *i);
> --
> 2.30.2
>