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-rw-r--r--mm/swapfile.c178
1 files changed, 90 insertions, 88 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 82e62007881d..5fc1237a9f21 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -63,6 +63,10 @@ EXPORT_SYMBOL_GPL(nr_swap_pages);
/* protected with swap_lock. reading in vm_swap_full() doesn't need lock */
long total_swap_pages;
static int least_priority = -1;
+unsigned long swapfile_maximum_size;
+#ifdef CONFIG_MIGRATION
+bool swap_migration_ad_supported;
+#endif /* CONFIG_MIGRATION */
static const char Bad_file[] = "Bad swap file entry ";
static const char Unused_file[] = "Unused swap file entry ";
@@ -128,27 +132,27 @@ static int __try_to_reclaim_swap(struct swap_info_struct *si,
unsigned long offset, unsigned long flags)
{
swp_entry_t entry = swp_entry(si->type, offset);
- struct page *page;
+ struct folio *folio;
int ret = 0;
- page = find_get_page(swap_address_space(entry), offset);
- if (!page)
+ folio = filemap_get_folio(swap_address_space(entry), offset);
+ if (!folio)
return 0;
/*
* When this function is called from scan_swap_map_slots() and it's
- * called by vmscan.c at reclaiming pages. So, we hold a lock on a page,
+ * called by vmscan.c at reclaiming folios. So we hold a folio lock
* here. We have to use trylock for avoiding deadlock. This is a special
- * case and you should use try_to_free_swap() with explicit lock_page()
+ * case and you should use folio_free_swap() with explicit folio_lock()
* in usual operations.
*/
- if (trylock_page(page)) {
+ if (folio_trylock(folio)) {
if ((flags & TTRS_ANYWAY) ||
- ((flags & TTRS_UNMAPPED) && !page_mapped(page)) ||
- ((flags & TTRS_FULL) && mem_cgroup_swap_full(page)))
- ret = try_to_free_swap(page);
- unlock_page(page);
+ ((flags & TTRS_UNMAPPED) && !folio_mapped(folio)) ||
+ ((flags & TTRS_FULL) && mem_cgroup_swap_full(folio)))
+ ret = folio_free_swap(folio);
+ folio_unlock(folio);
}
- put_page(page);
+ folio_put(folio);
return ret;
}
@@ -1328,7 +1332,7 @@ void swap_free(swp_entry_t entry)
/*
* Called after dropping swapcache to decrease refcnt to swap entries.
*/
-void put_swap_page(struct page *page, swp_entry_t entry)
+void put_swap_folio(struct folio *folio, swp_entry_t entry)
{
unsigned long offset = swp_offset(entry);
unsigned long idx = offset / SWAPFILE_CLUSTER;
@@ -1337,7 +1341,7 @@ void put_swap_page(struct page *page, swp_entry_t entry)
unsigned char *map;
unsigned int i, free_entries = 0;
unsigned char val;
- int size = swap_entry_size(thp_nr_pages(page));
+ int size = swap_entry_size(folio_nr_pages(folio));
si = _swap_info_get(entry);
if (!si)
@@ -1427,30 +1431,6 @@ void swapcache_free_entries(swp_entry_t *entries, int n)
spin_unlock(&p->lock);
}
-/*
- * How many references to page are currently swapped out?
- * This does not give an exact answer when swap count is continued,
- * but does include the high COUNT_CONTINUED flag to allow for that.
- */
-static int page_swapcount(struct page *page)
-{
- int count = 0;
- struct swap_info_struct *p;
- struct swap_cluster_info *ci;
- swp_entry_t entry;
- unsigned long offset;
-
- entry.val = page_private(page);
- p = _swap_info_get(entry);
- if (p) {
- offset = swp_offset(entry);
- ci = lock_cluster_or_swap_info(p, offset);
- count = swap_count(p->swap_map[offset]);
- unlock_cluster_or_swap_info(p, ci);
- }
- return count;
-}
-
int __swap_count(swp_entry_t entry)
{
struct swap_info_struct *si;
@@ -1465,11 +1445,16 @@ int __swap_count(swp_entry_t entry)
return count;
}
+/*
+ * How many references to @entry are currently swapped out?
+ * This does not give an exact answer when swap count is continued,
+ * but does include the high COUNT_CONTINUED flag to allow for that.
+ */
static int swap_swapcount(struct swap_info_struct *si, swp_entry_t entry)
{
- int count = 0;
pgoff_t offset = swp_offset(entry);
struct swap_cluster_info *ci;
+ int count;
ci = lock_cluster_or_swap_info(si, offset);
count = swap_count(si->swap_map[offset]);
@@ -1570,56 +1555,59 @@ unlock_out:
static bool folio_swapped(struct folio *folio)
{
- swp_entry_t entry;
- struct swap_info_struct *si;
+ swp_entry_t entry = folio_swap_entry(folio);
+ struct swap_info_struct *si = _swap_info_get(entry);
+
+ if (!si)
+ return false;
if (!IS_ENABLED(CONFIG_THP_SWAP) || likely(!folio_test_large(folio)))
- return page_swapcount(&folio->page) != 0;
+ return swap_swapcount(si, entry) != 0;
- entry = folio_swap_entry(folio);
- si = _swap_info_get(entry);
- if (si)
- return swap_page_trans_huge_swapped(si, entry);
- return false;
+ return swap_page_trans_huge_swapped(si, entry);
}
-/*
- * If swap is getting full, or if there are no more mappings of this page,
- * then try_to_free_swap is called to free its swap space.
+/**
+ * folio_free_swap() - Free the swap space used for this folio.
+ * @folio: The folio to remove.
+ *
+ * If swap is getting full, or if there are no more mappings of this folio,
+ * then call folio_free_swap to free its swap space.
+ *
+ * Return: true if we were able to release the swap space.
*/
-int try_to_free_swap(struct page *page)
+bool folio_free_swap(struct folio *folio)
{
- struct folio *folio = page_folio(page);
VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);
if (!folio_test_swapcache(folio))
- return 0;
+ return false;
if (folio_test_writeback(folio))
- return 0;
+ return false;
if (folio_swapped(folio))
- return 0;
+ return false;
/*
* Once hibernation has begun to create its image of memory,
- * there's a danger that one of the calls to try_to_free_swap()
+ * there's a danger that one of the calls to folio_free_swap()
* - most probably a call from __try_to_reclaim_swap() while
* hibernation is allocating its own swap pages for the image,
* but conceivably even a call from memory reclaim - will free
- * the swap from a page which has already been recorded in the
- * image as a clean swapcache page, and then reuse its swap for
+ * the swap from a folio which has already been recorded in the
+ * image as a clean swapcache folio, and then reuse its swap for
* another page of the image. On waking from hibernation, the
- * original page might be freed under memory pressure, then
+ * original folio might be freed under memory pressure, then
* later read back in from swap, now with the wrong data.
*
* Hibernation suspends storage while it is writing the image
* to disk so check that here.
*/
if (pm_suspended_storage())
- return 0;
+ return false;
delete_from_swap_cache(folio);
folio_set_dirty(folio);
- return 1;
+ return true;
}
/*
@@ -1770,8 +1758,9 @@ static inline int pte_same_as_swp(pte_t pte, pte_t swp_pte)
* force COW, vm_page_prot omits write permission from any private vma.
*/
static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd,
- unsigned long addr, swp_entry_t entry, struct page *page)
+ unsigned long addr, swp_entry_t entry, struct folio *folio)
{
+ struct page *page = folio_file_page(folio, swp_offset(entry));
struct page *swapcache;
spinlock_t *ptl;
pte_t *pte, new_pte;
@@ -1843,17 +1832,18 @@ static int unuse_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
unsigned long addr, unsigned long end,
unsigned int type)
{
- struct page *page;
swp_entry_t entry;
pte_t *pte;
struct swap_info_struct *si;
- unsigned long offset;
int ret = 0;
volatile unsigned char *swap_map;
si = swap_info[type];
pte = pte_offset_map(pmd, addr);
do {
+ struct folio *folio;
+ unsigned long offset;
+
if (!is_swap_pte(*pte))
continue;
@@ -1864,8 +1854,9 @@ static int unuse_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
offset = swp_offset(entry);
pte_unmap(pte);
swap_map = &si->swap_map[offset];
- page = lookup_swap_cache(entry, vma, addr);
- if (!page) {
+ folio = swap_cache_get_folio(entry, vma, addr);
+ if (!folio) {
+ struct page *page;
struct vm_fault vmf = {
.vma = vma,
.address = addr,
@@ -1875,25 +1866,27 @@ static int unuse_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
page = swapin_readahead(entry, GFP_HIGHUSER_MOVABLE,
&vmf);
+ if (page)
+ folio = page_folio(page);
}
- if (!page) {
+ if (!folio) {
if (*swap_map == 0 || *swap_map == SWAP_MAP_BAD)
goto try_next;
return -ENOMEM;
}
- lock_page(page);
- wait_on_page_writeback(page);
- ret = unuse_pte(vma, pmd, addr, entry, page);
+ folio_lock(folio);
+ folio_wait_writeback(folio);
+ ret = unuse_pte(vma, pmd, addr, entry, folio);
if (ret < 0) {
- unlock_page(page);
- put_page(page);
+ folio_unlock(folio);
+ folio_put(folio);
goto out;
}
- try_to_free_swap(page);
- unlock_page(page);
- put_page(page);
+ folio_free_swap(folio);
+ folio_unlock(folio);
+ folio_put(folio);
try_next:
pte = pte_offset_map(pmd, addr);
} while (pte++, addr += PAGE_SIZE, addr != end);
@@ -1990,14 +1983,16 @@ static int unuse_mm(struct mm_struct *mm, unsigned int type)
{
struct vm_area_struct *vma;
int ret = 0;
+ VMA_ITERATOR(vmi, mm, 0);
mmap_read_lock(mm);
- for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ for_each_vma(vmi, vma) {
if (vma->anon_vma) {
ret = unuse_vma(vma, type);
if (ret)
break;
}
+
cond_resched();
}
mmap_read_unlock(mm);
@@ -2042,7 +2037,7 @@ static int try_to_unuse(unsigned int type)
struct list_head *p;
int retval = 0;
struct swap_info_struct *si = swap_info[type];
- struct page *page;
+ struct folio *folio;
swp_entry_t entry;
unsigned int i;
@@ -2092,21 +2087,21 @@ retry:
(i = find_next_to_unuse(si, i)) != 0) {
entry = swp_entry(type, i);
- page = find_get_page(swap_address_space(entry), i);
- if (!page)
+ folio = filemap_get_folio(swap_address_space(entry), i);
+ if (!folio)
continue;
/*
- * It is conceivable that a racing task removed this page from
- * swap cache just before we acquired the page lock. The page
+ * It is conceivable that a racing task removed this folio from
+ * swap cache just before we acquired the page lock. The folio
* might even be back in swap cache on another swap area. But
- * that is okay, try_to_free_swap() only removes stale pages.
+ * that is okay, folio_free_swap() only removes stale folios.
*/
- lock_page(page);
- wait_on_page_writeback(page);
- try_to_free_swap(page);
- unlock_page(page);
- put_page(page);
+ folio_lock(folio);
+ folio_wait_writeback(folio);
+ folio_free_swap(folio);
+ folio_unlock(folio);
+ folio_put(folio);
}
/*
@@ -2816,7 +2811,7 @@ unsigned long generic_max_swapfile_size(void)
}
/* Can be overridden by an architecture for additional checks. */
-__weak unsigned long max_swapfile_size(void)
+__weak unsigned long arch_max_swapfile_size(void)
{
return generic_max_swapfile_size();
}
@@ -2856,7 +2851,7 @@ static unsigned long read_swap_header(struct swap_info_struct *p,
p->cluster_next = 1;
p->cluster_nr = 0;
- maxpages = max_swapfile_size();
+ maxpages = swapfile_maximum_size;
last_page = swap_header->info.last_page;
if (!last_page) {
pr_warn("Empty swap-file\n");
@@ -3677,6 +3672,13 @@ static int __init swapfile_init(void)
for_each_node(nid)
plist_head_init(&swap_avail_heads[nid]);
+ swapfile_maximum_size = arch_max_swapfile_size();
+
+#ifdef CONFIG_MIGRATION
+ if (swapfile_maximum_size >= (1UL << SWP_MIG_TOTAL_BITS))
+ swap_migration_ad_supported = true;
+#endif /* CONFIG_MIGRATION */
+
return 0;
}
subsys_initcall(swapfile_init);