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-rw-r--r--mm/filemap.c83
1 files changed, 83 insertions, 0 deletions
diff --git a/mm/filemap.c b/mm/filemap.c
index a11b42189436..a470dd8cd05b 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -304,6 +304,89 @@ void delete_from_page_cache(struct page *page)
}
EXPORT_SYMBOL(delete_from_page_cache);
+/*
+ * page_cache_tree_delete_batch - delete several pages from page cache
+ * @mapping: the mapping to which pages belong
+ * @pvec: pagevec with pages to delete
+ *
+ * The function walks over mapping->page_tree and removes pages passed in @pvec
+ * from the radix tree. The function expects @pvec to be sorted by page index.
+ * It tolerates holes in @pvec (radix tree entries at those indices are not
+ * modified). The function expects only THP head pages to be present in the
+ * @pvec and takes care to delete all corresponding tail pages from the radix
+ * tree as well.
+ *
+ * The function expects mapping->tree_lock to be held.
+ */
+static void
+page_cache_tree_delete_batch(struct address_space *mapping,
+ struct pagevec *pvec)
+{
+ struct radix_tree_iter iter;
+ void **slot;
+ int total_pages = 0;
+ int i = 0, tail_pages = 0;
+ struct page *page;
+ pgoff_t start;
+
+ start = pvec->pages[0]->index;
+ radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) {
+ if (i >= pagevec_count(pvec) && !tail_pages)
+ break;
+ page = radix_tree_deref_slot_protected(slot,
+ &mapping->tree_lock);
+ if (radix_tree_exceptional_entry(page))
+ continue;
+ if (!tail_pages) {
+ /*
+ * Some page got inserted in our range? Skip it. We
+ * have our pages locked so they are protected from
+ * being removed.
+ */
+ if (page != pvec->pages[i])
+ continue;
+ WARN_ON_ONCE(!PageLocked(page));
+ if (PageTransHuge(page) && !PageHuge(page))
+ tail_pages = HPAGE_PMD_NR - 1;
+ page->mapping = NULL;
+ /*
+ * Leave page->index set: truncation lookup relies
+ * upon it
+ */
+ i++;
+ } else {
+ tail_pages--;
+ }
+ radix_tree_clear_tags(&mapping->page_tree, iter.node, slot);
+ __radix_tree_replace(&mapping->page_tree, iter.node, slot, NULL,
+ workingset_update_node, mapping);
+ total_pages++;
+ }
+ mapping->nrpages -= total_pages;
+}
+
+void delete_from_page_cache_batch(struct address_space *mapping,
+ struct pagevec *pvec)
+{
+ int i;
+ unsigned long flags;
+
+ if (!pagevec_count(pvec))
+ return;
+
+ spin_lock_irqsave(&mapping->tree_lock, flags);
+ for (i = 0; i < pagevec_count(pvec); i++) {
+ trace_mm_filemap_delete_from_page_cache(pvec->pages[i]);
+
+ unaccount_page_cache_page(mapping, pvec->pages[i]);
+ }
+ page_cache_tree_delete_batch(mapping, pvec);
+ spin_unlock_irqrestore(&mapping->tree_lock, flags);
+
+ for (i = 0; i < pagevec_count(pvec); i++)
+ page_cache_free_page(mapping, pvec->pages[i]);
+}
+
int filemap_check_errors(struct address_space *mapping)
{
int ret = 0;