Writing to the swap space

Pavel Machek (pavel@ucw.cz)
Tue, 7 May 2002 00:11:25 +0200


Hi!

For swsusp, I need to write to the swap space.

I used technique similar to this:

static void mark_swapfiles(swp_entry_t prev, int mode)
{
swp_entry_t entry;
union diskpage *cur;

cur = (union diskpage *)get_free_page(GFP_ATOMIC);
if (!cur)
panic("Out of memory in mark_swapfiles");
/* XXX: this is dirty hack to get first page of swap file */
entry = SWP_ENTRY(root_swap, 0);
lock_page(virt_to_page((unsigned long)cur));
rw_swap_page_nolock(READ, entry, (char *) cur);

... modify cur->fields...

lock_page(virt_to_page((unsigned long)cur));
rw_swap_page_nolock(WRITE, entry, (char *)cur);

free_page((unsigned long)cur);
}

It seems not to work any more. Some io is done, but it is not
synchronous any more, and it does not seem to hit the disk.

What am I doing wrong, or is there something wrong in 2.5.12/2.5.13?
Pavel

-- 
(about SSSCA) "I don't say this lightly.  However, I really think that the U.S.
no longer is classifiable as a democracy, but rather as a plutocracy." --hpa
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