Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/mm/swap_state.c b/mm/swap_state.c
index ecee9c6..8e7ce9a 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -73,23 +73,24 @@
unsigned int i, j, nr;
unsigned long ret = 0;
struct address_space *spaces;
+ struct swap_info_struct *si;
- rcu_read_lock();
for (i = 0; i < MAX_SWAPFILES; i++) {
- /*
- * The corresponding entries in nr_swapper_spaces and
- * swapper_spaces will be reused only after at least
- * one grace period. So it is impossible for them
- * belongs to different usage.
- */
- nr = nr_swapper_spaces[i];
- spaces = rcu_dereference(swapper_spaces[i]);
- if (!nr || !spaces)
+ swp_entry_t entry = swp_entry(i, 1);
+
+ /* Avoid get_swap_device() to warn for bad swap entry */
+ if (!swp_swap_info(entry))
continue;
+ /* Prevent swapoff to free swapper_spaces */
+ si = get_swap_device(entry);
+ if (!si)
+ continue;
+ nr = nr_swapper_spaces[i];
+ spaces = swapper_spaces[i];
for (j = 0; j < nr; j++)
ret += spaces[j].nrpages;
+ put_swap_device(si);
}
- rcu_read_unlock();
return ret;
}
@@ -107,14 +108,15 @@
}
/*
- * __add_to_swap_cache resembles add_to_page_cache_locked on swapper_space,
+ * add_to_swap_cache resembles add_to_page_cache_locked on swapper_space,
* but sets SwapCache flag and private instead of mapping and index.
*/
-int __add_to_swap_cache(struct page *page, swp_entry_t entry)
+int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp)
{
- int error, i, nr = hpage_nr_pages(page);
- struct address_space *address_space;
+ struct address_space *address_space = swap_address_space(entry);
pgoff_t idx = swp_offset(entry);
+ XA_STATE_ORDER(xas, &address_space->i_pages, idx, compound_order(page));
+ unsigned long i, nr = compound_nr(page);
VM_BUG_ON_PAGE(!PageLocked(page), page);
VM_BUG_ON_PAGE(PageSwapCache(page), page);
@@ -123,73 +125,52 @@
page_ref_add(page, nr);
SetPageSwapCache(page);
- address_space = swap_address_space(entry);
- xa_lock_irq(&address_space->i_pages);
- for (i = 0; i < nr; i++) {
- set_page_private(page + i, entry.val + i);
- error = radix_tree_insert(&address_space->i_pages,
- idx + i, page + i);
- if (unlikely(error))
- break;
- }
- if (likely(!error)) {
+ do {
+ xas_lock_irq(&xas);
+ xas_create_range(&xas);
+ if (xas_error(&xas))
+ goto unlock;
+ for (i = 0; i < nr; i++) {
+ VM_BUG_ON_PAGE(xas.xa_index != idx + i, page);
+ set_page_private(page + i, entry.val + i);
+ xas_store(&xas, page);
+ xas_next(&xas);
+ }
address_space->nrpages += nr;
__mod_node_page_state(page_pgdat(page), NR_FILE_PAGES, nr);
ADD_CACHE_INFO(add_total, nr);
- } else {
- /*
- * Only the context which have set SWAP_HAS_CACHE flag
- * would call add_to_swap_cache().
- * So add_to_swap_cache() doesn't returns -EEXIST.
- */
- VM_BUG_ON(error == -EEXIST);
- set_page_private(page + i, 0UL);
- while (i--) {
- radix_tree_delete(&address_space->i_pages, idx + i);
- set_page_private(page + i, 0UL);
- }
- ClearPageSwapCache(page);
- page_ref_sub(page, nr);
- }
- xa_unlock_irq(&address_space->i_pages);
+unlock:
+ xas_unlock_irq(&xas);
+ } while (xas_nomem(&xas, gfp));
- return error;
-}
+ if (!xas_error(&xas))
+ return 0;
-
-int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp_mask)
-{
- int error;
-
- error = radix_tree_maybe_preload_order(gfp_mask, compound_order(page));
- if (!error) {
- error = __add_to_swap_cache(page, entry);
- radix_tree_preload_end();
- }
- return error;
+ ClearPageSwapCache(page);
+ page_ref_sub(page, nr);
+ return xas_error(&xas);
}
/*
* This must be called only on pages that have
* been verified to be in the swap cache.
*/
-void __delete_from_swap_cache(struct page *page)
+void __delete_from_swap_cache(struct page *page, swp_entry_t entry)
{
- struct address_space *address_space;
+ struct address_space *address_space = swap_address_space(entry);
int i, nr = hpage_nr_pages(page);
- swp_entry_t entry;
- pgoff_t idx;
+ pgoff_t idx = swp_offset(entry);
+ XA_STATE(xas, &address_space->i_pages, idx);
VM_BUG_ON_PAGE(!PageLocked(page), page);
VM_BUG_ON_PAGE(!PageSwapCache(page), page);
VM_BUG_ON_PAGE(PageWriteback(page), page);
- entry.val = page_private(page);
- address_space = swap_address_space(entry);
- idx = swp_offset(entry);
for (i = 0; i < nr; i++) {
- radix_tree_delete(&address_space->i_pages, idx + i);
+ void *entry = xas_store(&xas, NULL);
+ VM_BUG_ON_PAGE(entry != page, entry);
set_page_private(page + i, 0);
+ xas_next(&xas);
}
ClearPageSwapCache(page);
address_space->nrpages -= nr;
@@ -217,7 +198,7 @@
return 0;
/*
- * Radix-tree node allocations from PF_MEMALLOC contexts could
+ * XArray node allocations from PF_MEMALLOC contexts could
* completely exhaust the page allocator. __GFP_NOMEMALLOC
* stops emergency reserves from being allocated.
*
@@ -229,7 +210,6 @@
*/
err = add_to_swap_cache(page, entry,
__GFP_HIGH|__GFP_NOMEMALLOC|__GFP_NOWARN);
- /* -ENOMEM radix-tree allocation failure */
if (err)
/*
* add_to_swap_cache() doesn't return -EEXIST, so we can safely
@@ -263,14 +243,11 @@
*/
void delete_from_swap_cache(struct page *page)
{
- swp_entry_t entry;
- struct address_space *address_space;
+ swp_entry_t entry = { .val = page_private(page) };
+ struct address_space *address_space = swap_address_space(entry);
- entry.val = page_private(page);
-
- address_space = swap_address_space(entry);
xa_lock_irq(&address_space->i_pages);
- __delete_from_swap_cache(page);
+ __delete_from_swap_cache(page, entry);
xa_unlock_irq(&address_space->i_pages);
put_swap_page(page, entry);
@@ -334,8 +311,13 @@
unsigned long addr)
{
struct page *page;
+ struct swap_info_struct *si;
+ si = get_swap_device(entry);
+ if (!si)
+ return NULL;
page = find_get_page(swap_address_space(entry), swp_offset(entry));
+ put_swap_device(si);
INC_CACHE_INFO(find_total);
if (page) {
@@ -378,8 +360,8 @@
struct vm_area_struct *vma, unsigned long addr,
bool *new_page_allocated)
{
- struct page *found_page, *new_page = NULL;
- struct address_space *swapper_space = swap_address_space(entry);
+ struct page *found_page = NULL, *new_page = NULL;
+ struct swap_info_struct *si;
int err;
*new_page_allocated = false;
@@ -389,7 +371,12 @@
* called after lookup_swap_cache() failed, re-calling
* that would confuse statistics.
*/
- found_page = find_get_page(swapper_space, swp_offset(entry));
+ si = get_swap_device(entry);
+ if (!si)
+ break;
+ found_page = find_get_page(swap_address_space(entry),
+ swp_offset(entry));
+ put_swap_device(si);
if (found_page)
break;
@@ -414,18 +401,10 @@
}
/*
- * call radix_tree_preload() while we can wait.
- */
- err = radix_tree_maybe_preload(gfp_mask & GFP_KERNEL);
- if (err)
- break;
-
- /*
* Swap entry may have been freed since our caller observed it.
*/
err = swapcache_prepare(entry);
if (err == -EEXIST) {
- radix_tree_preload_end();
/*
* We might race against get_swap_page() and stumble
* across a SWAP_HAS_CACHE swap_map entry whose page
@@ -433,26 +412,20 @@
*/
cond_resched();
continue;
- }
- if (err) { /* swp entry is obsolete ? */
- radix_tree_preload_end();
+ } else if (err) /* swp entry is obsolete ? */
break;
- }
- /* May fail (-ENOMEM) if radix-tree node allocation failed. */
+ /* May fail (-ENOMEM) if XArray node allocation failed. */
__SetPageLocked(new_page);
__SetPageSwapBacked(new_page);
- err = __add_to_swap_cache(new_page, entry);
+ err = add_to_swap_cache(new_page, entry, gfp_mask & GFP_KERNEL);
if (likely(!err)) {
- radix_tree_preload_end();
- /*
- * Initiate read into locked page and return.
- */
+ /* Initiate read into locked page */
+ SetPageWorkingset(new_page);
lru_cache_add_anon(new_page);
*new_page_allocated = true;
return new_page;
}
- radix_tree_preload_end();
__ClearPageLocked(new_page);
/*
* add_to_swap_cache() doesn't return -EEXIST, so we can safely
@@ -561,7 +534,7 @@
* This has been extended to use the NUMA policies from the mm triggering
* the readahead.
*
- * Caller must hold down_read on the vma->vm_mm if vmf->vma is not NULL.
+ * Caller must hold read mmap_sem if vmf->vma is not NULL.
*/
struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t gfp_mask,
struct vm_fault *vmf)
@@ -581,6 +554,13 @@
if (!mask)
goto skip;
+ /* Test swap type to make sure the dereference is safe */
+ if (likely(si->flags & (SWP_BLKDEV | SWP_FS))) {
+ struct inode *inode = si->swap_file->f_mapping->host;
+ if (inode_read_congested(inode))
+ goto skip;
+ }
+
do_poll = false;
/* Read a page_cluster sized and aligned cluster around offset. */
start_offset = offset & ~mask;
@@ -625,27 +605,23 @@
return -ENOMEM;
for (i = 0; i < nr; i++) {
space = spaces + i;
- INIT_RADIX_TREE(&space->i_pages, GFP_ATOMIC|__GFP_NOWARN);
+ xa_init_flags(&space->i_pages, XA_FLAGS_LOCK_IRQ);
atomic_set(&space->i_mmap_writable, 0);
space->a_ops = &swap_aops;
/* swap cache doesn't use writeback related tags */
mapping_set_no_writeback_tags(space);
}
nr_swapper_spaces[type] = nr;
- rcu_assign_pointer(swapper_spaces[type], spaces);
+ swapper_spaces[type] = spaces;
return 0;
}
void exit_swap_address_space(unsigned int type)
{
- struct address_space *spaces;
-
- spaces = swapper_spaces[type];
+ kvfree(swapper_spaces[type]);
nr_swapper_spaces[type] = 0;
- rcu_assign_pointer(swapper_spaces[type], NULL);
- synchronize_rcu();
- kvfree(spaces);
+ swapper_spaces[type] = NULL;
}
static inline void swap_ra_clamp_pfn(struct vm_area_struct *vma,
@@ -729,6 +705,20 @@
pte_unmap(orig_pte);
}
+/**
+ * swap_vma_readahead - swap in pages in hope we need them soon
+ * @entry: swap entry of this memory
+ * @gfp_mask: memory allocation flags
+ * @vmf: fault information
+ *
+ * Returns the struct page for entry and addr, after queueing swapin.
+ *
+ * Primitive swap readahead code. We simply read in a few pages whoes
+ * virtual addresses are around the fault address in the same vma.
+ *
+ * Caller must hold read mmap_sem if vmf->vma is not NULL.
+ *
+ */
static struct page *swap_vma_readahead(swp_entry_t fentry, gfp_t gfp_mask,
struct vm_fault *vmf)
{