+ iov_iter-lift-memzero_page-to-highmemh.patch added to -mm tree

+ iov_iter-lift-memzero_page-to-highmemh.patch added to -mm tree

[akpm]

The patch titled
     Subject: iov_iter: lift memzero_page() to highmem.h
has been added to the -mm tree.  Its filename is
     iov_iter-lift-memzero_page-to-highmemh.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/iov_iter-lift-memzero_page-to-highmemh.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/iov_iter-lift-memzero_page-to-highmemh.patch

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------------------------------------------------------
From: Ira Weiny <ira.weiny@intel.com>
Subject: iov_iter: lift memzero_page() to highmem.h

Patch series "btrfs: Convert kmap/memset/kunmap to memzero_user()".

Lifting memzero_user(), convert it to kmap_local_page() and then use it in
btrfs.


This patch (of 3):

memzero_page() can replace the kmap/memset/kunmap pattern in other places
in the code.  While zero_user() has the same interface it is not the same
call and its use should be limited and some of those calls may be better
converted from zero_user() to memzero_page().[1] But that is not addressed
in this series.

Lift memzero_page() to highmem.

[1] https://lore.kernel.org/lkml/CAHk-=wijdojzo56FzYqE5TOYw2Vws7ik3LEMGj9SPQaJJ+Z73Q@mail.gmail.com/

Link: https://lkml.kernel.org/r/20210309212137.2610186-1-ira.weiny@intel.com
Link: https://lkml.kernel.org/r/20210309212137.2610186-2-ira.weiny@intel.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: David Sterba <dsterba@suse.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/highmem.h |    7 +++++++
 lib/iov_iter.c          |    8 +-------
 2 files changed, 8 insertions(+), 7 deletions(-)

--- a/include/linux/highmem.h~iov_iter-lift-memzero_page-to-highmemh
+++ a/include/linux/highmem.h
@@ -332,4 +332,11 @@ static inline void memcpy_to_page(struct
 	kunmap_local(to);
 }
 
+static inline void memzero_page(struct page *page, size_t offset, size_t len)
+{
+	char *addr = kmap_atomic(page);
+	memset(addr + offset, 0, len);
+	kunmap_atomic(addr);
+}
+
 #endif /* _LINUX_HIGHMEM_H */
--- a/lib/iov_iter.c~iov_iter-lift-memzero_page-to-highmemh
+++ a/lib/iov_iter.c
@@ -5,6 +5,7 @@
 #include <linux/fault-inject-usercopy.h>
 #include <linux/uio.h>
 #include <linux/pagemap.h>
+#include <linux/highmem.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
 #include <linux/splice.h>
@@ -464,13 +465,6 @@ void iov_iter_init(struct iov_iter *i, u
 }
 EXPORT_SYMBOL(iov_iter_init);
 
-static void memzero_page(struct page *page, size_t offset, size_t len)
-{
-	char *addr = kmap_atomic(page);
-	memset(addr + offset, 0, len);
-	kunmap_atomic(addr);
-}
-
 static inline bool allocated(struct pipe_buffer *buf)
 {
 	return buf->ops == &default_pipe_buf_ops;
_

Patches currently in -mm which might be from ira.weiny@intel.com are

iov_iter-lift-memzero_page-to-highmemh.patch
mm-highmem-convert-memzero_page-to-kmap_local_page.patch
btrfs-use-memzero_page-instead-of-open-coded-kmap-pattern.patch
mm-highmem-remove-deprecated-kmap_atomic.patch