int add_to_swap_cache(struct page *page, swp_entry_t entry)
{
if (page->mapping)
BUG();
if (!swap_duplicate(entry)) {
INC_CACHE_INFO(noent_race);
return -ENOENT;
}
if (add_to_page_cache_unique(page, &swapper_space, entry.val,
page_hash(&swapper_space, entry.val)) != 0) {
swap_free(entry);
INC_CACHE_INFO(exist_race);
return -EEXIST;
}
if (!PageLocked(page))
BUG();
if (!PageSwapCache(page))
BUG();
INC_CACHE_INFO(add_total);
return 0;
}
static int rd_blkdev_pagecache_IO(int rw, struct buffer_head * sbh, int minor)
{
struct address_space * mapping;
unsigned long index;
int offset, size, err;
err = -EIO;
err = 0;
mapping = rd_bdev[minor]->bd_inode->i_mapping;
index = sbh->b_rsector >> (PAGE_CACHE_SHIFT - 9);
offset = (sbh->b_rsector << 9) & ~PAGE_CACHE_MASK;
size = sbh->b_size;
do {
int count;
struct page ** hash;
struct page * page;
char * src, * dst;
int unlock = 0;
count = PAGE_CACHE_SIZE - offset;
if (count > size)
count = size;
size -= count;
hash = page_hash(mapping, index);
page = __find_get_page(mapping, index, hash);
if (!page) {
page = grab_cache_page(mapping, index);
err = -ENOMEM;
if (!page)
goto out;
err = 0;
if (!Page_Uptodate(page)) {
memset(kmap(page), 0, PAGE_CACHE_SIZE);
kunmap(page);
SetPageUptodate(page);
}
unlock = 1;
}
index++;
if (rw == READ) {
src = kmap(page);
src += offset;
dst = bh_kmap(sbh);
} else {
dst = kmap(page);
dst += offset;
src = bh_kmap(sbh);
}
offset = 0;
memcpy(dst, src, count);
kunmap(page);
bh_kunmap(sbh);
if (rw == READ) {
flush_dcache_page(page);
} else {
SetPageDirty(page);
}
if (unlock)
UnlockPage(page);
__free_page(page);
} while (size);
out:
return err;
}
