diff options
| -rw-r--r-- | include/linux/pagemap.h | 4 | ||||
| -rw-r--r-- | mm/filemap.c | 83 | ||||
| -rw-r--r-- | mm/truncate.c | 20 |
3 files changed, 105 insertions, 2 deletions
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 956d6a8..e0f7181 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -16,6 +16,8 @@ #include <linux/hardirq.h> /* for in_interrupt() */ #include <linux/hugetlb_inline.h> +struct pagevec; + /* * Bits in mapping->flags. */ @@ -624,6 +626,8 @@ int add_to_page_cache_lru(struct page *page, struct address_space *mapping, extern void delete_from_page_cache(struct page *page); extern void __delete_from_page_cache(struct page *page, void *shadow); int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask); +void delete_from_page_cache_batch(struct address_space *mapping, + struct pagevec *pvec); /* * Like add_to_page_cache_locked, but used to add newly allocated pages: diff --git a/mm/filemap.c b/mm/filemap.c index a11b421..a470dd8 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; diff --git a/mm/truncate.c b/mm/truncate.c index 383a530..4a39a31 100644 --- a/mm/truncate.c +++ b/mm/truncate.c @@ -294,6 +294,14 @@ void truncate_inode_pages_range(struct address_space *mapping, while (index < end && pagevec_lookup_entries(&pvec, mapping, index, min(end - index, (pgoff_t)PAGEVEC_SIZE), indices)) { + /* + * Pagevec array has exceptional entries and we may also fail + * to lock some pages. So we store pages that can be deleted + * in a new pagevec. + */ + struct pagevec locked_pvec; + + pagevec_init(&locked_pvec, 0); for (i = 0; i < pagevec_count(&pvec); i++) { struct page *page = pvec.pages[i]; @@ -315,9 +323,17 @@ void truncate_inode_pages_range(struct address_space *mapping, unlock_page(page); continue; } - truncate_inode_page(mapping, page); - unlock_page(page); + if (page->mapping != mapping) { + unlock_page(page); + continue; + } + pagevec_add(&locked_pvec, page); } + for (i = 0; i < pagevec_count(&locked_pvec); i++) + truncate_cleanup_page(mapping, locked_pvec.pages[i]); + delete_from_page_cache_batch(mapping, &locked_pvec); + for (i = 0; i < pagevec_count(&locked_pvec); i++) + unlock_page(locked_pvec.pages[i]); pagevec_remove_exceptionals(&pvec); pagevec_release(&pvec); cond_resched(); |
