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Diffstat (limited to 'mm/memory-failure.c')
-rw-r--r--mm/memory-failure.c311
1 files changed, 143 insertions, 168 deletions
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 990e3b2e37d5..a2184b721fbf 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -65,6 +65,33 @@ int sysctl_memory_failure_recovery __read_mostly = 1;
atomic_long_t num_poisoned_pages __read_mostly = ATOMIC_LONG_INIT(0);
+static bool page_handle_poison(struct page *page, bool hugepage_or_freepage, bool release)
+{
+ if (hugepage_or_freepage) {
+ /*
+ * Doing this check for free pages is also fine since dissolve_free_huge_page
+ * returns 0 for non-hugetlb pages as well.
+ */
+ if (dissolve_free_huge_page(page) || !take_page_off_buddy(page))
+ /*
+ * We could fail to take off the target page from buddy
+ * for example due to racy page allocaiton, but that's
+ * acceptable because soft-offlined page is not broken
+ * and if someone really want to use it, they should
+ * take it.
+ */
+ return false;
+ }
+
+ SetPageHWPoison(page);
+ if (release)
+ put_page(page);
+ page_ref_inc(page);
+ num_poisoned_pages_inc();
+
+ return true;
+}
+
#if defined(CONFIG_HWPOISON_INJECT) || defined(CONFIG_HWPOISON_INJECT_MODULE)
u32 hwpoison_filter_enable = 0;
@@ -555,6 +582,7 @@ static const char * const action_page_types[] = {
[MF_MSG_BUDDY] = "free buddy page",
[MF_MSG_BUDDY_2ND] = "free buddy page (2nd try)",
[MF_MSG_DAX] = "dax page",
+ [MF_MSG_UNSPLIT_THP] = "unsplit thp",
[MF_MSG_UNKNOWN] = "unknown page",
};
@@ -924,7 +952,7 @@ static int page_action(struct page_state *ps, struct page *p,
* Return: return 0 if failed to grab the refcount, otherwise true (some
* non-zero value.)
*/
-int get_hwpoison_page(struct page *page)
+static int get_hwpoison_page(struct page *page)
{
struct page *head = compound_head(page);
@@ -953,7 +981,6 @@ int get_hwpoison_page(struct page *page)
return 0;
}
-EXPORT_SYMBOL_GPL(get_hwpoison_page);
/*
* Do all that is necessary to remove user space mappings. Unmap
@@ -1103,6 +1130,25 @@ static int identify_page_state(unsigned long pfn, struct page *p,
return page_action(ps, p, pfn);
}
+static int try_to_split_thp_page(struct page *page, const char *msg)
+{
+ lock_page(page);
+ if (!PageAnon(page) || unlikely(split_huge_page(page))) {
+ unsigned long pfn = page_to_pfn(page);
+
+ unlock_page(page);
+ if (!PageAnon(page))
+ pr_info("%s: %#lx: non anonymous thp\n", msg, pfn);
+ else
+ pr_info("%s: %#lx: thp split failed\n", msg, pfn);
+ put_page(page);
+ return -EBUSY;
+ }
+ unlock_page(page);
+
+ return 0;
+}
+
static int memory_failure_hugetlb(unsigned long pfn, int flags)
{
struct page *p = pfn_to_page(pfn);
@@ -1144,7 +1190,7 @@ static int memory_failure_hugetlb(unsigned long pfn, int flags)
pr_err("Memory failure: %#lx: just unpoisoned\n", pfn);
num_poisoned_pages_dec();
unlock_page(head);
- put_hwpoison_page(head);
+ put_page(head);
return 0;
}
@@ -1325,23 +1371,11 @@ int memory_failure(unsigned long pfn, int flags)
}
if (PageTransHuge(hpage)) {
- lock_page(p);
- if (!PageAnon(p) || unlikely(split_huge_page(p))) {
- unlock_page(p);
- if (!PageAnon(p))
- pr_err("Memory failure: %#lx: non anonymous thp\n",
- pfn);
- else
- pr_err("Memory failure: %#lx: thp split failed\n",
- pfn);
- if (TestClearPageHWPoison(p))
- num_poisoned_pages_dec();
- put_hwpoison_page(p);
+ if (try_to_split_thp_page(p, "Memory Failure") < 0) {
+ action_result(pfn, MF_MSG_UNSPLIT_THP, MF_IGNORED);
return -EBUSY;
}
- unlock_page(p);
VM_BUG_ON_PAGE(!page_count(p), p);
- hpage = compound_head(p);
}
/*
@@ -1381,10 +1415,7 @@ int memory_failure(unsigned long pfn, int flags)
* page_remove_rmap() in try_to_unmap_one(). So to determine page status
* correctly, we save a copy of the page flags at this time.
*/
- if (PageHuge(p))
- page_flags = hpage->flags;
- else
- page_flags = p->flags;
+ page_flags = p->flags;
/*
* unpoison always clear PG_hwpoison inside page lock
@@ -1393,14 +1424,14 @@ int memory_failure(unsigned long pfn, int flags)
pr_err("Memory failure: %#lx: just unpoisoned\n", pfn);
num_poisoned_pages_dec();
unlock_page(p);
- put_hwpoison_page(p);
+ put_page(p);
return 0;
}
if (hwpoison_filter(p)) {
if (TestClearPageHWPoison(p))
num_poisoned_pages_dec();
unlock_page(p);
- put_hwpoison_page(p);
+ put_page(p);
return 0;
}
@@ -1416,11 +1447,8 @@ int memory_failure(unsigned long pfn, int flags)
/*
* Now take care of user space mappings.
* Abort on fail: __delete_from_page_cache() assumes unmapped page.
- *
- * When the raw error page is thp tail page, hpage points to the raw
- * page after thp split.
*/
- if (!hwpoison_user_mappings(p, pfn, flags, &hpage)) {
+ if (!hwpoison_user_mappings(p, pfn, flags, &p)) {
action_result(pfn, MF_MSG_UNMAP_FAILED, MF_IGNORED);
res = -EBUSY;
goto out;
@@ -1637,9 +1665,9 @@ int unpoison_memory(unsigned long pfn)
}
unlock_page(page);
- put_hwpoison_page(page);
+ put_page(page);
if (freeit && !(pfn == my_zero_pfn(0) && page_count(p) == 1))
- put_hwpoison_page(page);
+ put_page(page);
return 0;
}
@@ -1679,6 +1707,9 @@ static int __get_any_page(struct page *p, unsigned long pfn, int flags)
} else if (is_free_buddy_page(p)) {
pr_info("%s: %#lx free buddy page\n", __func__, pfn);
ret = 0;
+ } else if (page_count(p)) {
+ /* raced with allocation */
+ ret = -EBUSY;
} else {
pr_info("%s: %#lx: unknown zero refcount page type %lx\n",
__func__, pfn, p->flags);
@@ -1695,12 +1726,15 @@ static int get_any_page(struct page *page, unsigned long pfn, int flags)
{
int ret = __get_any_page(page, pfn, flags);
+ if (ret == -EBUSY)
+ ret = __get_any_page(page, pfn, flags);
+
if (ret == 1 && !PageHuge(page) &&
!PageLRU(page) && !__PageMovable(page)) {
/*
* Try to free it.
*/
- put_hwpoison_page(page);
+ put_page(page);
shake_page(page, 1);
/*
@@ -1709,7 +1743,7 @@ static int get_any_page(struct page *page, unsigned long pfn, int flags)
ret = __get_any_page(page, pfn, 0);
if (ret == 1 && !PageLRU(page)) {
/* Drop page reference which is from __get_any_page() */
- put_hwpoison_page(page);
+ put_page(page);
pr_info("soft_offline: %#lx: unknown non LRU page type %lx (%pGp)\n",
pfn, page->flags, &page->flags);
return -EIO;
@@ -1718,69 +1752,51 @@ static int get_any_page(struct page *page, unsigned long pfn, int flags)
return ret;
}
-static int soft_offline_huge_page(struct page *page, int flags)
+static bool isolate_page(struct page *page, struct list_head *pagelist)
{
- int ret;
- unsigned long pfn = page_to_pfn(page);
- struct page *hpage = compound_head(page);
- LIST_HEAD(pagelist);
+ bool isolated = false;
+ bool lru = PageLRU(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_hwpoison_page(hpage);
- pr_info("soft offline: %#lx hugepage already poisoned\n", pfn);
- return -EBUSY;
+ if (PageHuge(page)) {
+ isolated = isolate_huge_page(page, pagelist);
+ } else {
+ if (lru)
+ isolated = !isolate_lru_page(page);
+ else
+ isolated = !isolate_movable_page(page, ISOLATE_UNEVICTABLE);
+
+ if (isolated)
+ list_add(&page->lru, pagelist);
}
- unlock_page(hpage);
- ret = isolate_huge_page(hpage, &pagelist);
+ if (isolated && lru)
+ inc_node_page_state(page, NR_ISOLATED_ANON +
+ page_is_file_lru(page));
+
/*
- * get_any_page() and isolate_huge_page() takes a refcount each,
- * so need to drop one here.
+ * If we succeed to isolate the page, we grabbed another refcount on
+ * the page, so we can safely drop the one we got from get_any_pages().
+ * If we failed to isolate the page, it means that we cannot go further
+ * and we will return an error, so drop the reference we got from
+ * get_any_pages() as well.
*/
- put_hwpoison_page(hpage);
- if (!ret) {
- pr_info("soft offline: %#lx hugepage failed to isolate\n", pfn);
- return -EBUSY;
- }
-
- ret = migrate_pages(&pagelist, new_page, NULL, MPOL_MF_MOVE_ALL,
- MIGRATE_SYNC, MR_MEMORY_FAILURE);
- if (ret) {
- pr_info("soft offline: %#lx: hugepage migration failed %d, type %lx (%pGp)\n",
- pfn, ret, page->flags, &page->flags);
- if (!list_empty(&pagelist))
- putback_movable_pages(&pagelist);
- if (ret > 0)
- ret = -EIO;
- } else {
- /*
- * We set PG_hwpoison only when the migration source hugepage
- * was successfully dissolved, because otherwise hwpoisoned
- * hugepage remains on free hugepage list, then userspace will
- * find it as SIGBUS by allocation failure. That's not expected
- * in soft-offlining.
- */
- ret = dissolve_free_huge_page(page);
- if (!ret) {
- if (set_hwpoison_free_buddy_page(page))
- num_poisoned_pages_inc();
- else
- ret = -EBUSY;
- }
- }
- return ret;
+ put_page(page);
+ return isolated;
}
-static int __soft_offline_page(struct page *page, int flags)
+/*
+ * __soft_offline_page handles hugetlb-pages and non-hugetlb pages.
+ * If the page is a non-dirty unmapped page-cache page, it simply invalidates.
+ * If the page is mapped, it migrates the contents over.
+ */
+static int __soft_offline_page(struct page *page)
{
- int ret;
+ int ret = 0;
unsigned long pfn = page_to_pfn(page);
+ struct page *hpage = compound_head(page);
+ char const *msg_page[] = {"page", "hugepage"};
+ bool huge = PageHuge(page);
+ LIST_HEAD(pagelist);
/*
* Check PageHWPoison again inside page lock because PageHWPoison
@@ -1789,121 +1805,75 @@ static int __soft_offline_page(struct page *page, int flags)
* so there's no race between soft_offline_page() and memory_failure().
*/
lock_page(page);
- wait_on_page_writeback(page);
+ if (!PageHuge(page))
+ wait_on_page_writeback(page);
if (PageHWPoison(page)) {
unlock_page(page);
- put_hwpoison_page(page);
+ put_page(page);
pr_info("soft offline: %#lx page already poisoned\n", pfn);
- return -EBUSY;
+ return 0;
}
- /*
- * Try to invalidate first. This should work for
- * non dirty unmapped page cache pages.
- */
- ret = invalidate_inode_page(page);
+
+ if (!PageHuge(page))
+ /*
+ * Try to invalidate first. This should work for
+ * non dirty unmapped page cache pages.
+ */
+ ret = invalidate_inode_page(page);
unlock_page(page);
+
/*
* RED-PEN would be better to keep it isolated here, but we
* would need to fix isolation locking first.
*/
- if (ret == 1) {
- put_hwpoison_page(page);
+ if (ret) {
pr_info("soft_offline: %#lx: invalidated\n", pfn);
- SetPageHWPoison(page);
- num_poisoned_pages_inc();
+ page_handle_poison(page, false, true);
return 0;
}
- /*
- * Simple invalidation didn't work.
- * Try to migrate to a new page instead. migrate.c
- * handles a large number of cases for us.
- */
- if (PageLRU(page))
- ret = isolate_lru_page(page);
- else
- ret = isolate_movable_page(page, ISOLATE_UNEVICTABLE);
- /*
- * Drop page reference which is came from get_any_page()
- * successful isolate_lru_page() already took another one.
- */
- put_hwpoison_page(page);
- if (!ret) {
- LIST_HEAD(pagelist);
- /*
- * After isolated lru page, the PageLRU will be cleared,
- * so use !__PageMovable instead for LRU page's mapping
- * cannot have PAGE_MAPPING_MOVABLE.
- */
- if (!__PageMovable(page))
- inc_node_page_state(page, NR_ISOLATED_ANON +
- page_is_file_lru(page));
- list_add(&page->lru, &pagelist);
+ if (isolate_page(hpage, &pagelist)) {
ret = migrate_pages(&pagelist, new_page, NULL, MPOL_MF_MOVE_ALL,
MIGRATE_SYNC, MR_MEMORY_FAILURE);
- if (ret) {
+ if (!ret) {
+ bool release = !huge;
+
+ if (!page_handle_poison(page, huge, release))
+ ret = -EBUSY;
+ } else {
if (!list_empty(&pagelist))
putback_movable_pages(&pagelist);
- pr_info("soft offline: %#lx: migration failed %d, type %lx (%pGp)\n",
- pfn, ret, page->flags, &page->flags);
+ pr_info("soft offline: %#lx: %s migration failed %d, type %lx (%pGp)\n",
+ pfn, msg_page[huge], ret, page->flags, &page->flags);
if (ret > 0)
ret = -EIO;
}
} else {
- pr_info("soft offline: %#lx: isolation failed: %d, page count %d, type %lx (%pGp)\n",
- pfn, ret, page_count(page), page->flags, &page->flags);
+ pr_info("soft offline: %#lx: %s isolation failed: %d, page count %d, type %lx (%pGp)\n",
+ pfn, msg_page[huge], ret, page_count(page), page->flags, &page->flags);
+ ret = -EBUSY;
}
return ret;
}
-static int soft_offline_in_use_page(struct page *page, int flags)
+static int soft_offline_in_use_page(struct page *page)
{
- int ret;
- int mt;
struct page *hpage = compound_head(page);
- if (!PageHuge(page) && PageTransHuge(hpage)) {
- lock_page(page);
- if (!PageAnon(page) || unlikely(split_huge_page(page))) {
- unlock_page(page);
- if (!PageAnon(page))
- pr_info("soft offline: %#lx: non anonymous thp\n", page_to_pfn(page));
- else
- pr_info("soft offline: %#lx: thp split failed\n", page_to_pfn(page));
- put_hwpoison_page(page);
+ if (!PageHuge(page) && PageTransHuge(hpage))
+ if (try_to_split_thp_page(page, "soft offline") < 0)
return -EBUSY;
- }
- unlock_page(page);
- }
-
- /*
- * Setting MIGRATE_ISOLATE here ensures that the page will be linked
- * to free list immediately (not via pcplist) when released after
- * successful page migration. Otherwise we can't guarantee that the
- * page is really free after put_page() returns, so
- * set_hwpoison_free_buddy_page() highly likely fails.
- */
- mt = get_pageblock_migratetype(page);
- set_pageblock_migratetype(page, MIGRATE_ISOLATE);
- if (PageHuge(page))
- ret = soft_offline_huge_page(page, flags);
- else
- ret = __soft_offline_page(page, flags);
- set_pageblock_migratetype(page, mt);
- return ret;
+ return __soft_offline_page(page);
}
static int soft_offline_free_page(struct page *page)
{
- int rc = dissolve_free_huge_page(page);
+ int rc = 0;
+
+ if (!page_handle_poison(page, true, false))
+ rc = -EBUSY;
- if (!rc) {
- if (set_hwpoison_free_buddy_page(page))
- num_poisoned_pages_inc();
- else
- rc = -EBUSY;
- }
return rc;
}
@@ -1933,6 +1903,7 @@ int soft_offline_page(unsigned long pfn, int flags)
{
int ret;
struct page *page;
+ bool try_again = true;
if (!pfn_valid(pfn))
return -ENXIO;
@@ -1944,18 +1915,22 @@ int soft_offline_page(unsigned long pfn, int flags)
if (PageHWPoison(page)) {
pr_info("soft offline: %#lx page already poisoned\n", pfn);
if (flags & MF_COUNT_INCREASED)
- put_hwpoison_page(page);
- return -EBUSY;
+ put_page(page);
+ return 0;
}
+retry:
get_online_mems();
ret = get_any_page(page, pfn, flags);
put_online_mems();
if (ret > 0)
- ret = soft_offline_in_use_page(page, flags);
+ ret = soft_offline_in_use_page(page);
else if (ret == 0)
- ret = soft_offline_free_page(page);
+ if (soft_offline_free_page(page) && try_again) {
+ try_again = false;
+ goto retry;
+ }
return ret;
}