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/[email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ira Weiny <[email protected]> Cc: Alexander Viro <[email protected]> Cc: David Sterba <[email protected]> Cc: Chris Mason <[email protected]> Cc: Josef Bacik <[email protected]> Cc: Chaitanya Kulkarni <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
LoveHeat · May 5, 2021 · 2896199 · 2896199
1 parent ecfc2bd
commit 2896199
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Showing 2 changed files with 8 additions and 7 deletions.
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
@@ -332,4 +332,11 @@ static inline void memcpy_to_page(struct page *page, size_t offset,
 	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 */
diff --git a/lib/iov_iter.c b/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>
@@ -507,13 +508,6 @@ void iov_iter_init(struct iov_iter *i, unsigned int direction,
 }
 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;