diff options
| -rw-r--r-- | mm/memory-failure.c | 156 |
1 files changed, 87 insertions, 69 deletions
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index c95e19a..9cab165 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1368,7 +1368,7 @@ static struct page *new_page(struct page *p, unsigned long private, int **x) * that is not free, and 1 for any other page type. * For 1 the page is returned with increased page count, otherwise not. */ -static int get_any_page(struct page *p, unsigned long pfn, int flags) +static int __get_any_page(struct page *p, unsigned long pfn, int flags) { int ret; @@ -1393,11 +1393,9 @@ static int get_any_page(struct page *p, unsigned long pfn, int flags) if (!get_page_unless_zero(compound_head(p))) { if (PageHuge(p)) { pr_info("%s: %#lx free huge page\n", __func__, pfn); - ret = dequeue_hwpoisoned_huge_page(compound_head(p)); + ret = 0; } else if (is_free_buddy_page(p)) { pr_info("%s: %#lx free buddy page\n", __func__, pfn); - /* Set hwpoison bit while page is still isolated */ - SetPageHWPoison(p); ret = 0; } else { pr_info("%s: %#lx: unknown zero refcount page type %lx\n", @@ -1413,23 +1411,48 @@ static int get_any_page(struct page *p, unsigned long pfn, int flags) return ret; } +static int get_any_page(struct page *page, unsigned long pfn, int flags) +{ + int ret = __get_any_page(page, pfn, flags); + + if (ret == 1 && !PageHuge(page) && !PageLRU(page)) { + /* + * Try to free it. + */ + put_page(page); + shake_page(page, 1); + + /* + * Did it turn free? + */ + ret = __get_any_page(page, pfn, 0); + if (!PageLRU(page)) { + pr_info("soft_offline: %#lx: unknown non LRU page type %lx\n", + pfn, page->flags); + return -EIO; + } + } + return ret; +} + static int soft_offline_huge_page(struct page *page, int flags) { int ret; unsigned long pfn = page_to_pfn(page); struct page *hpage = compound_head(page); + /* + * This double-check of PageHWPoison is to avoid the race with + * memory_failure(). See also comment in __soft_offline_page(). + */ + lock_page(hpage); if (PageHWPoison(hpage)) { + unlock_page(hpage); + put_page(hpage); pr_info("soft offline: %#lx hugepage already poisoned\n", pfn); - ret = -EBUSY; - goto out; + return -EBUSY; } - - ret = get_any_page(page, pfn, flags); - if (ret < 0) - goto out; - if (ret == 0) - goto done; + unlock_page(hpage); /* Keep page count to indicate a given hugepage is isolated. */ ret = migrate_huge_page(hpage, new_page, MPOL_MF_MOVE_ALL, false, @@ -1438,17 +1461,18 @@ static int soft_offline_huge_page(struct page *page, int flags) if (ret) { pr_info("soft offline: %#lx: migration failed %d, type %lx\n", pfn, ret, page->flags); - goto out; + } else { + set_page_hwpoison_huge_page(hpage); + dequeue_hwpoisoned_huge_page(hpage); + atomic_long_add(1 << compound_trans_order(hpage), + &num_poisoned_pages); } -done: /* keep elevated page count for bad page */ - atomic_long_add(1 << compound_trans_order(hpage), &num_poisoned_pages); - set_page_hwpoison_huge_page(hpage); - dequeue_hwpoisoned_huge_page(hpage); -out: return ret; } +static int __soft_offline_page(struct page *page, int flags); + /** * soft_offline_page - Soft offline a page. * @page: page to offline @@ -1477,62 +1501,60 @@ int soft_offline_page(struct page *page, int flags) unsigned long pfn = page_to_pfn(page); struct page *hpage = compound_trans_head(page); - if (PageHuge(page)) { - ret = soft_offline_huge_page(page, flags); - goto out; + if (PageHWPoison(page)) { + pr_info("soft offline: %#lx page already poisoned\n", pfn); + return -EBUSY; } - if (PageTransHuge(hpage)) { + if (!PageHuge(page) && PageTransHuge(hpage)) { if (PageAnon(hpage) && unlikely(split_huge_page(hpage))) { pr_info("soft offline: %#lx: failed to split THP\n", pfn); - ret = -EBUSY; - goto out; + return -EBUSY; } } - if (PageHWPoison(page)) { - pr_info("soft offline: %#lx page already poisoned\n", pfn); - ret = -EBUSY; - goto out; - } - ret = get_any_page(page, pfn, flags); if (ret < 0) - goto out; - if (ret == 0) - goto done; - - /* - * Page cache page we can handle? - */ - if (!PageLRU(page)) { - /* - * Try to free it. - */ - put_page(page); - shake_page(page, 1); - - /* - * Did it turn free? - */ - ret = get_any_page(page, pfn, 0); - if (ret < 0) - goto out; - if (ret == 0) - goto done; - } - if (!PageLRU(page)) { - pr_info("soft_offline: %#lx: unknown non LRU page type %lx\n", - pfn, page->flags); - ret = -EIO; - goto out; + return ret; + if (ret) { /* for in-use pages */ + if (PageHuge(page)) + ret = soft_offline_huge_page(page, flags); + else + ret = __soft_offline_page(page, flags); + } else { /* for free pages */ + if (PageHuge(page)) { + set_page_hwpoison_huge_page(hpage); + dequeue_hwpoisoned_huge_page(hpage); + atomic_long_add(1 << compound_trans_order(hpage), + &num_poisoned_pages); + } else { + SetPageHWPoison(page); + atomic_long_inc(&num_poisoned_pages); + } } + /* keep elevated page count for bad page */ + return ret; +} + +static int __soft_offline_page(struct page *page, int flags) +{ + int ret; + unsigned long pfn = page_to_pfn(page); /* - * Synchronized using the page lock with memory_failure() + * Check PageHWPoison again inside page lock because PageHWPoison + * is set by memory_failure() outside page lock. Note that + * memory_failure() also double-checks PageHWPoison inside page lock, + * so there's no race between soft_offline_page() and memory_failure(). */ lock_page(page); wait_on_page_writeback(page); + if (PageHWPoison(page)) { + unlock_page(page); + put_page(page); + pr_info("soft offline: %#lx page already poisoned\n", pfn); + return -EBUSY; + } /* * Try to invalidate first. This should work for * non dirty unmapped page cache pages. @@ -1545,9 +1567,10 @@ int soft_offline_page(struct page *page, int flags) */ if (ret == 1) { put_page(page); - ret = 0; pr_info("soft_offline: %#lx: invalidated\n", pfn); - goto done; + SetPageHWPoison(page); + atomic_long_inc(&num_poisoned_pages); + return 0; } /* @@ -1575,18 +1598,13 @@ int soft_offline_page(struct page *page, int flags) pfn, ret, page->flags); if (ret > 0) ret = -EIO; + } else { + SetPageHWPoison(page); + atomic_long_inc(&num_poisoned_pages); } } else { pr_info("soft offline: %#lx: isolation failed: %d, page count %d, type %lx\n", pfn, ret, page_count(page), page->flags); } - if (ret) - goto out; - -done: - /* keep elevated page count for bad page */ - atomic_long_inc(&num_poisoned_pages); - SetPageHWPoison(page); -out: return ret; } |
