summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--mm/z3fold.c49
1 files changed, 34 insertions, 15 deletions
diff --git a/mm/z3fold.c b/mm/z3fold.c
index ed19d98c9dcd..d637d9ee005c 100644
--- a/mm/z3fold.c
+++ b/mm/z3fold.c
@@ -366,9 +366,10 @@ static inline int __idx(struct z3fold_header *zhdr, enum buddy bud)
* Encodes the handle of a particular buddy within a z3fold page
* Pool lock should be held as this function accesses first_num
*/
-static unsigned long encode_handle(struct z3fold_header *zhdr, enum buddy bud)
+static unsigned long __encode_handle(struct z3fold_header *zhdr,
+ struct z3fold_buddy_slots *slots,
+ enum buddy bud)
{
- struct z3fold_buddy_slots *slots;
unsigned long h = (unsigned long)zhdr;
int idx = 0;
@@ -385,11 +386,15 @@ static unsigned long encode_handle(struct z3fold_header *zhdr, enum buddy bud)
if (bud == LAST)
h |= (zhdr->last_chunks << BUDDY_SHIFT);
- slots = zhdr->slots;
slots->slot[idx] = h;
return (unsigned long)&slots->slot[idx];
}
+static unsigned long encode_handle(struct z3fold_header *zhdr, enum buddy bud)
+{
+ return __encode_handle(zhdr, zhdr->slots, bud);
+}
+
/* Returns the z3fold page where a given handle is stored */
static inline struct z3fold_header *handle_to_z3fold_header(unsigned long h)
{
@@ -624,6 +629,7 @@ static void do_compact_page(struct z3fold_header *zhdr, bool locked)
}
if (unlikely(PageIsolated(page) ||
+ test_bit(PAGE_CLAIMED, &page->private) ||
test_bit(PAGE_STALE, &page->private))) {
z3fold_page_unlock(zhdr);
return;
@@ -1100,6 +1106,7 @@ static int z3fold_reclaim_page(struct z3fold_pool *pool, unsigned int retries)
struct z3fold_header *zhdr = NULL;
struct page *page = NULL;
struct list_head *pos;
+ struct z3fold_buddy_slots slots;
unsigned long first_handle = 0, middle_handle = 0, last_handle = 0;
spin_lock(&pool->lock);
@@ -1118,16 +1125,22 @@ static int z3fold_reclaim_page(struct z3fold_pool *pool, unsigned int retries)
/* this bit could have been set by free, in which case
* we pass over to the next page in the pool.
*/
- if (test_and_set_bit(PAGE_CLAIMED, &page->private))
+ if (test_and_set_bit(PAGE_CLAIMED, &page->private)) {
+ page = NULL;
continue;
+ }
- if (unlikely(PageIsolated(page)))
+ if (unlikely(PageIsolated(page))) {
+ clear_bit(PAGE_CLAIMED, &page->private);
+ page = NULL;
continue;
+ }
+ zhdr = page_address(page);
if (test_bit(PAGE_HEADLESS, &page->private))
break;
- zhdr = page_address(page);
if (!z3fold_page_trylock(zhdr)) {
+ clear_bit(PAGE_CLAIMED, &page->private);
zhdr = NULL;
continue; /* can't evict at this point */
}
@@ -1145,26 +1158,30 @@ static int z3fold_reclaim_page(struct z3fold_pool *pool, unsigned int retries)
if (!test_bit(PAGE_HEADLESS, &page->private)) {
/*
- * We need encode the handles before unlocking, since
- * we can race with free that will set
- * (first|last)_chunks to 0
+ * We need encode the handles before unlocking, and
+ * use our local slots structure because z3fold_free
+ * can zero out zhdr->slots and we can't do much
+ * about that
*/
first_handle = 0;
last_handle = 0;
middle_handle = 0;
if (zhdr->first_chunks)
- first_handle = encode_handle(zhdr, FIRST);
+ first_handle = __encode_handle(zhdr, &slots,
+ FIRST);
if (zhdr->middle_chunks)
- middle_handle = encode_handle(zhdr, MIDDLE);
+ middle_handle = __encode_handle(zhdr, &slots,
+ MIDDLE);
if (zhdr->last_chunks)
- last_handle = encode_handle(zhdr, LAST);
+ last_handle = __encode_handle(zhdr, &slots,
+ LAST);
/*
* it's safe to unlock here because we hold a
* reference to this page
*/
z3fold_page_unlock(zhdr);
} else {
- first_handle = encode_handle(zhdr, HEADLESS);
+ first_handle = __encode_handle(zhdr, &slots, HEADLESS);
last_handle = middle_handle = 0;
}
@@ -1194,9 +1211,9 @@ next:
spin_lock(&pool->lock);
list_add(&page->lru, &pool->lru);
spin_unlock(&pool->lock);
+ clear_bit(PAGE_CLAIMED, &page->private);
} else {
z3fold_page_lock(zhdr);
- clear_bit(PAGE_CLAIMED, &page->private);
if (kref_put(&zhdr->refcount,
release_z3fold_page_locked)) {
atomic64_dec(&pool->pages_nr);
@@ -1211,6 +1228,7 @@ next:
list_add(&page->lru, &pool->lru);
spin_unlock(&pool->lock);
z3fold_page_unlock(zhdr);
+ clear_bit(PAGE_CLAIMED, &page->private);
}
/* We started off locked to we need to lock the pool back */
@@ -1315,7 +1333,8 @@ static bool z3fold_page_isolate(struct page *page, isolate_mode_t mode)
VM_BUG_ON_PAGE(!PageMovable(page), page);
VM_BUG_ON_PAGE(PageIsolated(page), page);
- if (test_bit(PAGE_HEADLESS, &page->private))
+ if (test_bit(PAGE_HEADLESS, &page->private) ||
+ test_bit(PAGE_CLAIMED, &page->private))
return false;
zhdr = page_address(page);