Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/mm/memfd.c b/mm/memfd.c
index 2bb5e25..2647c89 100644
--- a/mm/memfd.c
+++ b/mm/memfd.c
@@ -21,44 +21,37 @@
#include <uapi/linux/memfd.h>
/*
- * We need a tag: a new tag would expand every radix_tree_node by 8 bytes,
+ * We need a tag: a new tag would expand every xa_node by 8 bytes,
* so reuse a tag which we firmly believe is never set or cleared on tmpfs
* or hugetlbfs because they are memory only filesystems.
*/
#define MEMFD_TAG_PINNED PAGECACHE_TAG_TOWRITE
#define LAST_SCAN 4 /* about 150ms max */
-static void memfd_tag_pins(struct address_space *mapping)
+static void memfd_tag_pins(struct xa_state *xas)
{
- struct radix_tree_iter iter;
- void __rcu **slot;
- pgoff_t start;
struct page *page;
+ unsigned int tagged = 0;
lru_add_drain();
- start = 0;
- rcu_read_lock();
- radix_tree_for_each_slot(slot, &mapping->i_pages, &iter, start) {
- page = radix_tree_deref_slot(slot);
- if (!page || radix_tree_exception(page)) {
- if (radix_tree_deref_retry(page)) {
- slot = radix_tree_iter_retry(&iter);
- continue;
- }
- } else if (page_count(page) - page_mapcount(page) > 1) {
- xa_lock_irq(&mapping->i_pages);
- radix_tree_tag_set(&mapping->i_pages, iter.index,
- MEMFD_TAG_PINNED);
- xa_unlock_irq(&mapping->i_pages);
- }
+ xas_lock_irq(xas);
+ xas_for_each(xas, page, ULONG_MAX) {
+ if (xa_is_value(page))
+ continue;
+ page = find_subpage(page, xas->xa_index);
+ if (page_count(page) - page_mapcount(page) > 1)
+ xas_set_mark(xas, MEMFD_TAG_PINNED);
- if (need_resched()) {
- slot = radix_tree_iter_resume(slot, &iter);
- cond_resched_rcu();
- }
+ if (++tagged % XA_CHECK_SCHED)
+ continue;
+
+ xas_pause(xas);
+ xas_unlock_irq(xas);
+ cond_resched();
+ xas_lock_irq(xas);
}
- rcu_read_unlock();
+ xas_unlock_irq(xas);
}
/*
@@ -72,17 +65,17 @@
*/
static int memfd_wait_for_pins(struct address_space *mapping)
{
- struct radix_tree_iter iter;
- void __rcu **slot;
- pgoff_t start;
+ XA_STATE(xas, &mapping->i_pages, 0);
struct page *page;
int error, scan;
- memfd_tag_pins(mapping);
+ memfd_tag_pins(&xas);
error = 0;
for (scan = 0; scan <= LAST_SCAN; scan++) {
- if (!radix_tree_tagged(&mapping->i_pages, MEMFD_TAG_PINNED))
+ unsigned int tagged = 0;
+
+ if (!xas_marked(&xas, MEMFD_TAG_PINNED))
break;
if (!scan)
@@ -90,45 +83,35 @@
else if (schedule_timeout_killable((HZ << scan) / 200))
scan = LAST_SCAN;
- start = 0;
- rcu_read_lock();
- radix_tree_for_each_tagged(slot, &mapping->i_pages, &iter,
- start, MEMFD_TAG_PINNED) {
-
- page = radix_tree_deref_slot(slot);
- if (radix_tree_exception(page)) {
- if (radix_tree_deref_retry(page)) {
- slot = radix_tree_iter_retry(&iter);
- continue;
- }
-
- page = NULL;
- }
-
- if (page &&
- page_count(page) - page_mapcount(page) != 1) {
- if (scan < LAST_SCAN)
- goto continue_resched;
-
+ xas_set(&xas, 0);
+ xas_lock_irq(&xas);
+ xas_for_each_marked(&xas, page, ULONG_MAX, MEMFD_TAG_PINNED) {
+ bool clear = true;
+ if (xa_is_value(page))
+ continue;
+ page = find_subpage(page, xas.xa_index);
+ if (page_count(page) - page_mapcount(page) != 1) {
/*
* On the last scan, we clean up all those tags
* we inserted; but make a note that we still
* found pages pinned.
*/
- error = -EBUSY;
+ if (scan == LAST_SCAN)
+ error = -EBUSY;
+ else
+ clear = false;
}
+ if (clear)
+ xas_clear_mark(&xas, MEMFD_TAG_PINNED);
+ if (++tagged % XA_CHECK_SCHED)
+ continue;
- xa_lock_irq(&mapping->i_pages);
- radix_tree_tag_clear(&mapping->i_pages,
- iter.index, MEMFD_TAG_PINNED);
- xa_unlock_irq(&mapping->i_pages);
-continue_resched:
- if (need_resched()) {
- slot = radix_tree_iter_resume(slot, &iter);
- cond_resched_rcu();
- }
+ xas_pause(&xas);
+ xas_unlock_irq(&xas);
+ cond_resched();
+ xas_lock_irq(&xas);
}
- rcu_read_unlock();
+ xas_unlock_irq(&xas);
}
return error;
@@ -150,7 +133,8 @@
#define F_ALL_SEALS (F_SEAL_SEAL | \
F_SEAL_SHRINK | \
F_SEAL_GROW | \
- F_SEAL_WRITE)
+ F_SEAL_WRITE | \
+ F_SEAL_FUTURE_WRITE)
static int memfd_add_seals(struct file *file, unsigned int seals)
{