难道是为了兼容现有swap空间的数据格式吗?
代码： 全选
//代码所在文件
//zswap.c:
//代码所在函数
//static int zswap_writeback_entry(struct zpool *pool, unsigned long handle):
/* decompress */
dlen = PAGE_SIZE;
src = (u8 *)zpool_map_handle(entry->pool->zpool, entry->handle,
ZPOOL_MM_RO) + sizeof(struct zswap_header);
dst = kmap_atomic(page);
tfm = *get_cpu_ptr(entry->pool->tfm);
ret = crypto_comp_decompress(tfm, src, entry->length,
dst, &dlen);
put_cpu_ptr(entry->pool->tfm);
kunmap_atomic(dst);
zpool_unmap_handle(entry->pool->zpool, entry->handle);
BUG_ON(ret);
BUG_ON(dlen != PAGE_SIZE);
/* page is up to date */
SetPageUptodate(page);
}
/* move it to the tail of the inactive list after end_writeback */
SetPageReclaim(page);
/* start writeback */
__swap_writepage(page, &wbc, end_swap_bio_write);
page_cache_release(page);
zswap_written_back_pages++;
好高级~
不知是否正确,欢迎各位指正
