/* * linux/mm/filemap.h * * Copyright (C) 1994-1999 Linus Torvalds */#ifndef __FILEMAP_H#define __FILEMAP_H#include <linux/types.h>#include <linux/fs.h>#include <linux/mm.h>#include <linux/highmem.h>#include <linux/uio.h>#include <linux/config.h>#include <asm/uaccess.h>size_t__filemap_copy_from_user_iovec(char *vaddr, const struct iovec *iov, size_t base, size_t bytes);/* * Copy as much as we can into the page and return the number of bytes which * were sucessfully copied. If a fault is encountered then clear the page * out to (offset+bytes) and return the number of bytes which were copied. */static inline size_tfilemap_copy_from_user(struct page *page, unsigned long offset, const char __user *buf, unsigned bytes){ char *kaddr; int left; kaddr = kmap_atomic(page, KM_USER0); left = __copy_from_user_inatomic(kaddr + offset, buf, bytes); kunmap_atomic(kaddr, KM_USER0); if (left != 0) { /* Do it the slow way */ kaddr = kmap(page); left = __copy_from_user(kaddr + offset, buf, bytes); kunmap(page); } return bytes - left;}/* * This has the same sideeffects and return value as filemap_copy_from_user(). * The difference is that on a fault we need to memset the remainder of the * page (out to offset+bytes), to emulate filemap_copy_from_user()'s * single-segment behaviour. */static inline size_tfilemap_copy_from_user_iovec(struct page *page, unsigned long offset, const struct iovec *iov, size_t base, size_t bytes){ char *kaddr; size_t copied; kaddr = kmap_atomic(page, KM_USER0); copied = __filemap_copy_from_user_iovec(kaddr + offset, iov, base, bytes); kunmap_atomic(kaddr, KM_USER0); if (copied != bytes) { kaddr = kmap(page); copied = __filemap_copy_from_user_iovec(kaddr + offset, iov, base, bytes); kunmap(page); } return copied;}static inline voidfilemap_set_next_iovec(const struct iovec **iovp, size_t *basep, size_t bytes){ const struct iovec *iov = *iovp; size_t base = *basep; while (bytes) { int copy = min(bytes, iov->iov_len - base); bytes -= copy; base += copy; if (iov->iov_len == base) { iov++; base = 0; } } *iovp = iov; *basep = base;}#endif
/*
* linux/mm/filemap.h
*
* Copyright (C) 1994-1999 Linus Torvalds
*/
#ifndef __FILEMAP_H
#define __FILEMAP_H
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/highmem.h>
#include <linux/uio.h>
#include <linux/config.h>
#include <asm/uaccess.h>
size_t
__filemap_copy_from_user_iovec(char *vaddr,
const struct iovec *iov,
size_t base,
size_t bytes);
/*
* Copy as much as we can into the page and return the number of bytes which
* were sucessfully copied. If a fault is encountered then clear the page
* out to (offset+bytes) and return the number of bytes which were copied.
*/
static inline size_t
filemap_copy_from_user(struct page *page, unsigned long offset,
const char __user *buf, unsigned bytes)
{
char *kaddr;
int left;
kaddr = kmap_atomic(page, KM_USER0);
left = __copy_from_user_inatomic(kaddr + offset, buf, bytes);
kunmap_atomic(kaddr, KM_USER0);
if (left != 0) {
/* Do it the slow way */
kaddr = kmap(page);
left = __copy_from_user(kaddr + offset, buf, bytes);
kunmap(page);
}
return bytes - left;
}
/*
* This has the same sideeffects and return value as filemap_copy_from_user().
* The difference is that on a fault we need to memset the remainder of the
* page (out to offset+bytes), to emulate filemap_copy_from_user()'s
* single-segment behaviour.
*/
static inline size_t
filemap_copy_from_user_iovec(struct page *page, unsigned long offset,
const struct iovec *iov, size_t base, size_t bytes)
{
char *kaddr;
size_t copied;
kaddr = kmap_atomic(page, KM_USER0);
copied = __filemap_copy_from_user_iovec(kaddr + offset, iov,
base, bytes);
kunmap_atomic(kaddr, KM_USER0);
if (copied != bytes) {
kaddr = kmap(page);
copied = __filemap_copy_from_user_iovec(kaddr + offset, iov,
base, bytes);
kunmap(page);
}
return copied;
}
static inline void
filemap_set_next_iovec(const struct iovec **iovp, size_t *basep, size_t bytes)
{
const struct iovec *iov = *iovp;
size_t base = *basep;
while (bytes) {
int copy = min(bytes, iov->iov_len - base);
bytes -= copy;
base += copy;
if (iov->iov_len == base) {
iov++;
base = 0;
}
}
*iovp = iov;
*basep = base;
}
#endif