HWPOISON: introduce delete_from_lru_cache()

Introduce delete_from_lru_cache() to
- clear PG_active, PG_unevictable to avoid complains at unpoison time
- move the isolate_lru_page() call back to the handlers instead of the
  entrance of __memory_failure(), this is more hwpoison filter friendly

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
This commit is contained in:
Wu Fengguang 2009-12-16 12:19:58 +01:00 committed by Andi Kleen
parent 71f72525df
commit dc2a1cbf7d

View file

@ -349,6 +349,30 @@ static const char *action_name[] = {
[RECOVERED] = "Recovered",
};
/*
* XXX: It is possible that a page is isolated from LRU cache,
* and then kept in swap cache or failed to remove from page cache.
* The page count will stop it from being freed by unpoison.
* Stress tests should be aware of this memory leak problem.
*/
static int delete_from_lru_cache(struct page *p)
{
if (!isolate_lru_page(p)) {
/*
* Clear sensible page flags, so that the buddy system won't
* complain when the page is unpoison-and-freed.
*/
ClearPageActive(p);
ClearPageUnevictable(p);
/*
* drop the page count elevated by isolate_lru_page()
*/
page_cache_release(p);
return 0;
}
return -EIO;
}
/*
* Error hit kernel page.
* Do nothing, try to be lucky and not touch this instead. For a few cases we
@ -393,6 +417,8 @@ static int me_pagecache_clean(struct page *p, unsigned long pfn)
int ret = FAILED;
struct address_space *mapping;
delete_from_lru_cache(p);
/*
* For anonymous pages we're done the only reference left
* should be the one m_f() holds.
@ -522,14 +548,20 @@ static int me_swapcache_dirty(struct page *p, unsigned long pfn)
/* Trigger EIO in shmem: */
ClearPageUptodate(p);
return DELAYED;
if (!delete_from_lru_cache(p))
return DELAYED;
else
return FAILED;
}
static int me_swapcache_clean(struct page *p, unsigned long pfn)
{
delete_from_swap_cache(p);
return RECOVERED;
if (!delete_from_lru_cache(p))
return RECOVERED;
else
return FAILED;
}
/*
@ -746,7 +778,6 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
int __memory_failure(unsigned long pfn, int trapno, int flags)
{
unsigned long lru_flag;
struct page_state *ps;
struct page *p;
int res;
@ -796,13 +827,11 @@ int __memory_failure(unsigned long pfn, int trapno, int flags)
*/
if (!PageLRU(p))
lru_add_drain_all();
lru_flag = p->flags & lru;
if (isolate_lru_page(p)) {
if (!PageLRU(p)) {
action_result(pfn, "non LRU", IGNORED);
put_page(p);
return -EBUSY;
}
page_cache_release(p);
/*
* Lock the page and wait for writeback to finish.
@ -825,7 +854,7 @@ int __memory_failure(unsigned long pfn, int trapno, int flags)
/*
* Torn down by someone else?
*/
if ((lru_flag & lru) && !PageSwapCache(p) && p->mapping == NULL) {
if (PageLRU(p) && !PageSwapCache(p) && p->mapping == NULL) {
action_result(pfn, "already truncated LRU", IGNORED);
res = 0;
goto out;
@ -833,7 +862,7 @@ int __memory_failure(unsigned long pfn, int trapno, int flags)
res = -EBUSY;
for (ps = error_states;; ps++) {
if (((p->flags | lru_flag)& ps->mask) == ps->res) {
if ((p->flags & ps->mask) == ps->res) {
res = page_action(ps, p, pfn);
break;
}