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Diffstat (limited to 'mm/memfd.c')
-rw-r--r--mm/memfd.c61
1 files changed, 25 insertions, 36 deletions
diff --git a/mm/memfd.c b/mm/memfd.c
index 2bb5e257080e..cf0ddd5fc859 100644
--- a/mm/memfd.c
+++ b/mm/memfd.c
@@ -21,7 +21,7 @@
#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.
*/
@@ -72,9 +72,7 @@ static void memfd_tag_pins(struct address_space *mapping)
*/
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;
@@ -82,7 +80,9 @@ static int memfd_wait_for_pins(struct address_space *mapping)
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 +90,34 @@ static int memfd_wait_for_pins(struct address_space *mapping)
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;
+ 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;