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
+ * for example due to racy page allocation, but that's
* acceptable because soft-offlined page is not broken
* and if someone really want to use it, they should
* take it.
*/
static int me_kernel(struct page *p, unsigned long pfn)
{
+ unlock_page(p);
return MF_IGNORED;
}
static int me_unknown(struct page *p, unsigned long pfn)
{
pr_err("Memory failure: %#lx: Unknown page state\n", pfn);
+ unlock_page(p);
return MF_FAILED;
}
*/
static int me_pagecache_clean(struct page *p, unsigned long pfn)
{
+ int ret;
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.
*/
- if (PageAnon(p))
- return MF_RECOVERED;
+ if (PageAnon(p)) {
+ ret = MF_RECOVERED;
+ goto out;
+ }
/*
* Now truncate the page in the page cache. This is really
/*
* Page has been teared down in the meanwhile
*/
- return MF_FAILED;
+ ret = MF_FAILED;
+ goto out;
}
/*
*
* Open: to take i_mutex or not for this? Right now we don't.
*/
- return truncate_error_page(p, pfn, mapping);
+ ret = truncate_error_page(p, pfn, mapping);
+out:
+ unlock_page(p);
+ return ret;
}
/*
*/
static int me_swapcache_dirty(struct page *p, unsigned long pfn)
{
+ int ret;
+
ClearPageDirty(p);
/* Trigger EIO in shmem: */
ClearPageUptodate(p);
- if (!delete_from_lru_cache(p))
- return MF_DELAYED;
- else
- return MF_FAILED;
+ ret = delete_from_lru_cache(p) ? MF_FAILED : MF_DELAYED;
+ unlock_page(p);
+ return ret;
}
static int me_swapcache_clean(struct page *p, unsigned long pfn)
{
+ int ret;
+
delete_from_swap_cache(p);
- if (!delete_from_lru_cache(p))
- return MF_RECOVERED;
- else
- return MF_FAILED;
+ ret = delete_from_lru_cache(p) ? MF_FAILED : MF_RECOVERED;
+ unlock_page(p);
+ return ret;
}
/*
mapping = page_mapping(hpage);
if (mapping) {
res = truncate_error_page(hpage, pfn, mapping);
+ unlock_page(hpage);
} else {
res = MF_FAILED;
unlock_page(hpage);
page_ref_inc(p);
res = MF_RECOVERED;
}
- lock_page(hpage);
}
return res;
unsigned long mask;
unsigned long res;
enum mf_action_page_type type;
+
+ /* Callback ->action() has to unlock the relevant page inside it. */
int (*action)(struct page *p, unsigned long pfn);
} error_states[] = {
{ reserved, reserved, MF_MSG_KERNEL, me_kernel },
int result;
int count;
+ /* page p should be unlocked after returning from ps->action(). */
result = ps->action(p, pfn);
count = page_count(p) - 1;
return (result == MF_RECOVERED || result == MF_DELAYED) ? 0 : -EBUSY;
}
+/*
+ * Return true if a page type of a given page is supported by hwpoison
+ * mechanism (while handling could fail), otherwise false. This function
+ * does not return true for hugetlb or device memory pages, so it's assumed
+ * to be called only in the context where we never have such pages.
+ */
+static inline bool HWPoisonHandlable(struct page *page)
+{
+ return PageLRU(page) || __PageMovable(page);
+}
+
/**
* __get_hwpoison_page() - Get refcount for memory error handling:
* @page: raw error page (hit by memory error)
static int __get_hwpoison_page(struct page *page)
{
struct page *head = compound_head(page);
+ int ret = 0;
+ bool hugetlb = false;
+
+ ret = get_hwpoison_huge_page(head, &hugetlb);
+ if (hugetlb)
+ return ret;
+
+ /*
+ * This check prevents from calling get_hwpoison_unless_zero()
+ * for any unsupported type of page in order to reduce the risk of
+ * unexpected races caused by taking a page refcount.
+ */
+ if (!HWPoisonHandlable(head))
+ return 0;
- if (!PageHuge(head) && PageTransHuge(head)) {
+ if (PageTransHuge(head)) {
/*
* Non anonymous thp exists only in allocation/free time. We
* can't handle such a case correctly, so let's give it up.
ret = -EIO;
}
} else {
- if (PageHuge(p) || PageLRU(p) || __PageMovable(p)) {
+ if (PageHuge(p) || HWPoisonHandlable(p)) {
ret = 1;
} else {
/*
if (TestSetPageHWPoison(head)) {
pr_err("Memory failure: %#lx: already hardware poisoned\n",
pfn);
- return 0;
+ return -EHWPOISON;
}
num_poisoned_pages_inc();
goto out;
}
- res = identify_page_state(pfn, p, page_flags);
+ return identify_page_state(pfn, p, page_flags);
out:
unlock_page(head);
return res;
struct page *hpage;
struct page *orig_head;
struct dev_pagemap *pgmap;
- int res;
+ int res = 0;
unsigned long page_flags;
bool retry = true;
+ static DEFINE_MUTEX(mf_mutex);
if (!sysctl_memory_failure_recovery)
panic("Memory failure on page %lx", pfn);
return -ENXIO;
}
+ mutex_lock(&mf_mutex);
+
try_again:
- if (PageHuge(p))
- return memory_failure_hugetlb(pfn, flags);
+ if (PageHuge(p)) {
+ res = memory_failure_hugetlb(pfn, flags);
+ goto unlock_mutex;
+ }
+
if (TestSetPageHWPoison(p)) {
pr_err("Memory failure: %#lx: already hardware poisoned\n",
pfn);
- return 0;
+ res = -EHWPOISON;
+ goto unlock_mutex;
}
orig_head = hpage = compound_head(p);
res = MF_FAILED;
}
action_result(pfn, MF_MSG_BUDDY, res);
- return res == MF_RECOVERED ? 0 : -EBUSY;
+ res = res == MF_RECOVERED ? 0 : -EBUSY;
} else {
action_result(pfn, MF_MSG_KERNEL_HIGH_ORDER, MF_IGNORED);
- return -EBUSY;
+ res = -EBUSY;
}
+ goto unlock_mutex;
}
if (PageTransHuge(hpage)) {
if (try_to_split_thp_page(p, "Memory Failure") < 0) {
action_result(pfn, MF_MSG_UNSPLIT_THP, MF_IGNORED);
- return -EBUSY;
+ res = -EBUSY;
+ goto unlock_mutex;
}
VM_BUG_ON_PAGE(!page_count(p), p);
}
if (PageCompound(p) && compound_head(p) != orig_head) {
action_result(pfn, MF_MSG_DIFFERENT_COMPOUND, MF_IGNORED);
res = -EBUSY;
- goto out;
+ goto unlock_page;
}
/*
num_poisoned_pages_dec();
unlock_page(p);
put_page(p);
- return 0;
+ goto unlock_mutex;
}
if (hwpoison_filter(p)) {
if (TestClearPageHWPoison(p))
num_poisoned_pages_dec();
unlock_page(p);
put_page(p);
- return 0;
+ goto unlock_mutex;
}
- if (!PageTransTail(p) && !PageLRU(p))
+ /*
+ * __munlock_pagevec may clear a writeback page's LRU flag without
+ * page_lock. We need wait writeback completion for this page or it
+ * may trigger vfs BUG while evict inode.
+ */
+ if (!PageTransTail(p) && !PageLRU(p) && !PageWriteback(p))
goto identify_page_state;
/*
if (!hwpoison_user_mappings(p, pfn, flags, &p)) {
action_result(pfn, MF_MSG_UNMAP_FAILED, MF_IGNORED);
res = -EBUSY;
- goto out;
+ goto unlock_page;
}
/*
if (PageLRU(p) && !PageSwapCache(p) && p->mapping == NULL) {
action_result(pfn, MF_MSG_TRUNCATED_LRU, MF_IGNORED);
res = -EBUSY;
- goto out;
+ goto unlock_page;
}
identify_page_state:
res = identify_page_state(pfn, p, page_flags);
-out:
+ mutex_unlock(&mf_mutex);
+ return res;
+unlock_page:
unlock_page(p);
+unlock_mutex:
+ mutex_unlock(&mf_mutex);
return res;
}
EXPORT_SYMBOL_GPL(memory_failure);
git.samba.org / sfrench / cifs-2.6.git / blobdiff