Commit 28961998 authored by Ira Weiny's avatar Ira Weiny Committed by Linus Torvalds

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.comSigned-off-by: default avatarIra 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent ecfc2bda
...@@ -332,4 +332,11 @@ static inline void memcpy_to_page(struct page *page, size_t offset, ...@@ -332,4 +332,11 @@ static inline void memcpy_to_page(struct page *page, size_t offset,
kunmap_local(to); 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 */ #endif /* _LINUX_HIGHMEM_H */
...@@ -5,6 +5,7 @@ ...@@ -5,6 +5,7 @@
#include <linux/fault-inject-usercopy.h> #include <linux/fault-inject-usercopy.h>
#include <linux/uio.h> #include <linux/uio.h>
#include <linux/pagemap.h> #include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/slab.h> #include <linux/slab.h>
#include <linux/vmalloc.h> #include <linux/vmalloc.h>
#include <linux/splice.h> #include <linux/splice.h>
...@@ -507,13 +508,6 @@ void iov_iter_init(struct iov_iter *i, unsigned int direction, ...@@ -507,13 +508,6 @@ void iov_iter_init(struct iov_iter *i, unsigned int direction,
} }
EXPORT_SYMBOL(iov_iter_init); 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) static inline bool allocated(struct pipe_buffer *buf)
{ {
return buf->ops == &default_pipe_buf_ops; return buf->ops == &default_pipe_buf_ops;
......
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