diff options
Diffstat (limited to 'mm/filemap.c')
| -rw-r--r-- | mm/filemap.c | 146 |
1 files changed, 88 insertions, 58 deletions
diff --git a/mm/filemap.c b/mm/filemap.c index df2006ba0cfa..6dd9a2274c80 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -281,11 +281,11 @@ EXPORT_SYMBOL(delete_from_page_cache); * @pvec: pagevec with pages to delete * * The function walks over mapping->i_pages and removes pages passed in @pvec - * from the mapping. The function expects @pvec to be sorted by page index - * and is optimised for it to be dense. + * from the mapping. The function expects @pvec to be sorted by page index. * It tolerates holes in @pvec (mapping entries at those indices are not * modified). The function expects only THP head pages to be present in the - * @pvec. + * @pvec and takes care to delete all corresponding tail pages from the + * mapping as well. * * The function expects the i_pages lock to be held. */ @@ -294,44 +294,40 @@ static void page_cache_delete_batch(struct address_space *mapping, { XA_STATE(xas, &mapping->i_pages, pvec->pages[0]->index); int total_pages = 0; - int i = 0; + int i = 0, tail_pages = 0; struct page *page; mapping_set_update(&xas, mapping); xas_for_each(&xas, page, ULONG_MAX) { - if (i >= pagevec_count(pvec)) + if (i >= pagevec_count(pvec) && !tail_pages) break; - - /* A swap/dax/shadow entry got inserted? Skip it. */ if (xa_is_value(page)) continue; - /* - * A page got inserted in our range? Skip it. We have our - * pages locked so they are protected from being removed. - * If we see a page whose index is higher than ours, it - * means our page has been removed, which shouldn't be - * possible because we're holding the PageLock. - */ - if (page != pvec->pages[i]) { - VM_BUG_ON_PAGE(page->index > pvec->pages[i]->index, - page); - continue; - } - - WARN_ON_ONCE(!PageLocked(page)); - - if (page->index == xas.xa_index) + 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]) { + VM_BUG_ON_PAGE(page->index > + pvec->pages[i]->index, page); + 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 on it */ - - /* - * Move to the next page in the vector if this is a regular - * page or the index is of the last sub-page of this compound - * page. - */ - if (page->index + (1UL << compound_order(page)) - 1 == - xas.xa_index) + /* + * Leave page->index set: truncation lookup relies + * upon it + */ i++; + } else { + VM_BUG_ON_PAGE(page->index + HPAGE_PMD_NR - tail_pages + != pvec->pages[i]->index, page); + tail_pages--; + } xas_store(&xas, NULL); total_pages++; } @@ -1498,7 +1494,7 @@ EXPORT_SYMBOL(page_cache_prev_miss); struct page *find_get_entry(struct address_space *mapping, pgoff_t offset) { XA_STATE(xas, &mapping->i_pages, offset); - struct page *page; + struct page *head, *page; rcu_read_lock(); repeat: @@ -1513,19 +1509,25 @@ repeat: if (!page || xa_is_value(page)) goto out; - if (!page_cache_get_speculative(page)) + head = compound_head(page); + if (!page_cache_get_speculative(head)) + goto repeat; + + /* The page was split under us? */ + if (compound_head(page) != head) { + put_page(head); goto repeat; + } /* - * Has the page moved or been split? + * Has the page moved? * This is part of the lockless pagecache protocol. See * include/linux/pagemap.h for details. */ if (unlikely(page != xas_reload(&xas))) { - put_page(page); + put_page(head); goto repeat; } - page = find_subpage(page, offset); out: rcu_read_unlock(); @@ -1707,6 +1709,7 @@ unsigned find_get_entries(struct address_space *mapping, rcu_read_lock(); xas_for_each(&xas, page, ULONG_MAX) { + struct page *head; if (xas_retry(&xas, page)) continue; /* @@ -1717,13 +1720,17 @@ unsigned find_get_entries(struct address_space *mapping, if (xa_is_value(page)) goto export; - if (!page_cache_get_speculative(page)) + head = compound_head(page); + if (!page_cache_get_speculative(head)) goto retry; - /* Has the page moved or been split? */ + /* The page was split under us? */ + if (compound_head(page) != head) + goto put_page; + + /* Has the page moved? */ if (unlikely(page != xas_reload(&xas))) goto put_page; - page = find_subpage(page, xas.xa_index); export: indices[ret] = xas.xa_index; @@ -1732,7 +1739,7 @@ export: break; continue; put_page: - put_page(page); + put_page(head); retry: xas_reset(&xas); } @@ -1774,27 +1781,33 @@ unsigned find_get_pages_range(struct address_space *mapping, pgoff_t *start, rcu_read_lock(); xas_for_each(&xas, page, end) { + struct page *head; if (xas_retry(&xas, page)) continue; /* Skip over shadow, swap and DAX entries */ if (xa_is_value(page)) continue; - if (!page_cache_get_speculative(page)) + head = compound_head(page); + if (!page_cache_get_speculative(head)) goto retry; - /* Has the page moved or been split? */ + /* The page was split under us? */ + if (compound_head(page) != head) + goto put_page; + + /* Has the page moved? */ if (unlikely(page != xas_reload(&xas))) goto put_page; - pages[ret] = find_subpage(page, xas.xa_index); + pages[ret] = page; if (++ret == nr_pages) { *start = xas.xa_index + 1; goto out; } continue; put_page: - put_page(page); + put_page(head); retry: xas_reset(&xas); } @@ -1839,6 +1852,7 @@ unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t index, rcu_read_lock(); for (page = xas_load(&xas); page; page = xas_next(&xas)) { + struct page *head; if (xas_retry(&xas, page)) continue; /* @@ -1848,19 +1862,24 @@ unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t index, if (xa_is_value(page)) break; - if (!page_cache_get_speculative(page)) + head = compound_head(page); + if (!page_cache_get_speculative(head)) goto retry; - /* Has the page moved or been split? */ + /* The page was split under us? */ + if (compound_head(page) != head) + goto put_page; + + /* Has the page moved? */ if (unlikely(page != xas_reload(&xas))) goto put_page; - pages[ret] = find_subpage(page, xas.xa_index); + pages[ret] = page; if (++ret == nr_pages) break; continue; put_page: - put_page(page); + put_page(head); retry: xas_reset(&xas); } @@ -1896,6 +1915,7 @@ unsigned find_get_pages_range_tag(struct address_space *mapping, pgoff_t *index, rcu_read_lock(); xas_for_each_marked(&xas, page, end, tag) { + struct page *head; if (xas_retry(&xas, page)) continue; /* @@ -1906,21 +1926,26 @@ unsigned find_get_pages_range_tag(struct address_space *mapping, pgoff_t *index, if (xa_is_value(page)) continue; - if (!page_cache_get_speculative(page)) + head = compound_head(page); + if (!page_cache_get_speculative(head)) goto retry; - /* Has the page moved or been split? */ + /* The page was split under us? */ + if (compound_head(page) != head) + goto put_page; + + /* Has the page moved? */ if (unlikely(page != xas_reload(&xas))) goto put_page; - pages[ret] = find_subpage(page, xas.xa_index); + pages[ret] = page; if (++ret == nr_pages) { *index = xas.xa_index + 1; goto out; } continue; put_page: - put_page(page); + put_page(head); retry: xas_reset(&xas); } @@ -2603,7 +2628,7 @@ void filemap_map_pages(struct vm_fault *vmf, pgoff_t last_pgoff = start_pgoff; unsigned long max_idx; XA_STATE(xas, &mapping->i_pages, start_pgoff); - struct page *page; + struct page *head, *page; rcu_read_lock(); xas_for_each(&xas, page, end_pgoff) { @@ -2612,19 +2637,24 @@ void filemap_map_pages(struct vm_fault *vmf, if (xa_is_value(page)) goto next; + head = compound_head(page); + /* * Check for a locked page first, as a speculative * reference may adversely influence page migration. */ - if (PageLocked(page)) + if (PageLocked(head)) goto next; - if (!page_cache_get_speculative(page)) + if (!page_cache_get_speculative(head)) goto next; - /* Has the page moved or been split? */ + /* The page was split under us? */ + if (compound_head(page) != head) + goto skip; + + /* Has the page moved? */ if (unlikely(page != xas_reload(&xas))) goto skip; - page = find_subpage(page, xas.xa_index); if (!PageUptodate(page) || PageReadahead(page) || |