diff options
Diffstat (limited to 'mm/swap_state.c')
| -rw-r--r-- | mm/swap_state.c | 90 |
1 files changed, 49 insertions, 41 deletions
diff --git a/mm/swap_state.c b/mm/swap_state.c index 013856004825..b9e4ed2e90bf 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -23,6 +23,7 @@ #include <linux/huge_mm.h> #include <linux/shmem_fs.h> #include "internal.h" +#include "swap.h" /* * swapper_space is a fiction, retained to simplify the path through @@ -30,7 +31,7 @@ */ static const struct address_space_operations swap_aops = { .writepage = swap_writepage, - .dirty_folio = swap_dirty_folio, + .dirty_folio = noop_dirty_folio, #ifdef CONFIG_MIGRATION .migratepage = migrate_page, #endif @@ -175,23 +176,26 @@ void __delete_from_swap_cache(struct page *page, } /** - * add_to_swap - allocate swap space for a page - * @page: page we want to move to swap + * add_to_swap - allocate swap space for a folio + * @folio: folio we want to move to swap * - * Allocate swap space for the page and add the page to the - * swap cache. Caller needs to hold the page lock. + * Allocate swap space for the folio and add the folio to the + * swap cache. + * + * Context: Caller needs to hold the folio lock. + * Return: Whether the folio was added to the swap cache. */ -int add_to_swap(struct page *page) +bool add_to_swap(struct folio *folio) { swp_entry_t entry; int err; - VM_BUG_ON_PAGE(!PageLocked(page), page); - VM_BUG_ON_PAGE(!PageUptodate(page), page); + VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio); + VM_BUG_ON_FOLIO(!folio_test_uptodate(folio), folio); - entry = get_swap_page(page); + entry = folio_alloc_swap(folio); if (!entry.val) - return 0; + return false; /* * XArray node allocations from PF_MEMALLOC contexts could @@ -204,7 +208,7 @@ int add_to_swap(struct page *page) /* * Add it to the swap cache. */ - err = add_to_swap_cache(page, entry, + err = add_to_swap_cache(&folio->page, entry, __GFP_HIGH|__GFP_NOMEMALLOC|__GFP_NOWARN, NULL); if (err) /* @@ -213,22 +217,23 @@ int add_to_swap(struct page *page) */ goto fail; /* - * Normally the page will be dirtied in unmap because its pte should be - * dirty. A special case is MADV_FREE page. The page's pte could have - * dirty bit cleared but the page's SwapBacked bit is still set because - * clearing the dirty bit and SwapBacked bit has no lock protected. For - * such page, unmap will not set dirty bit for it, so page reclaim will - * not write the page out. This can cause data corruption when the page - * is swap in later. Always setting the dirty bit for the page solves - * the problem. + * Normally the folio will be dirtied in unmap because its + * pte should be dirty. A special case is MADV_FREE page. The + * page's pte could have dirty bit cleared but the folio's + * SwapBacked flag is still set because clearing the dirty bit + * and SwapBacked flag has no lock protected. For such folio, + * unmap will not set dirty bit for it, so folio reclaim will + * not write the folio out. This can cause data corruption when + * the folio is swapped in later. Always setting the dirty flag + * for the folio solves the problem. */ - set_page_dirty(page); + folio_mark_dirty(folio); - return 1; + return true; fail: - put_swap_page(page, entry); - return 0; + put_swap_page(&folio->page, entry); + return false; } /* @@ -519,14 +524,16 @@ fail_unlock: * the swap entry is no longer in use. */ struct page *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, - struct vm_area_struct *vma, unsigned long addr, bool do_poll) + struct vm_area_struct *vma, + unsigned long addr, bool do_poll, + struct swap_iocb **plug) { bool page_was_allocated; struct page *retpage = __read_swap_cache_async(entry, gfp_mask, vma, addr, &page_was_allocated); if (page_was_allocated) - swap_readpage(retpage, do_poll); + swap_readpage(retpage, do_poll, plug); return retpage; } @@ -620,6 +627,7 @@ struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t gfp_mask, unsigned long mask; struct swap_info_struct *si = swp_swap_info(entry); struct blk_plug plug; + struct swap_iocb *splug = NULL; bool do_poll = true, page_allocated; struct vm_area_struct *vma = vmf->vma; unsigned long addr = vmf->address; @@ -646,7 +654,7 @@ struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t gfp_mask, if (!page) continue; if (page_allocated) { - swap_readpage(page, false); + swap_readpage(page, false, &splug); if (offset != entry_offset) { SetPageReadahead(page); count_vm_event(SWAP_RA); @@ -655,10 +663,12 @@ struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t gfp_mask, put_page(page); } blk_finish_plug(&plug); + swap_read_unplug(splug); lru_add_drain(); /* Push any new pages onto the LRU now */ skip: - return read_swap_cache_async(entry, gfp_mask, vma, addr, do_poll); + /* The page was likely read above, so no need for plugging here */ + return read_swap_cache_async(entry, gfp_mask, vma, addr, do_poll, NULL); } int init_swap_address_space(unsigned int type, unsigned long nr_pages) @@ -789,6 +799,7 @@ static struct page *swap_vma_readahead(swp_entry_t fentry, gfp_t gfp_mask, struct vm_fault *vmf) { struct blk_plug plug; + struct swap_iocb *splug = NULL; struct vm_area_struct *vma = vmf->vma; struct page *page; pte_t *pte, pentry; @@ -807,9 +818,7 @@ static struct page *swap_vma_readahead(swp_entry_t fentry, gfp_t gfp_mask, for (i = 0, pte = ra_info.ptes; i < ra_info.nr_pte; i++, pte++) { pentry = *pte; - if (pte_none(pentry)) - continue; - if (pte_present(pentry)) + if (!is_swap_pte(pentry)) continue; entry = pte_to_swp_entry(pentry); if (unlikely(non_swap_entry(entry))) @@ -819,7 +828,7 @@ static struct page *swap_vma_readahead(swp_entry_t fentry, gfp_t gfp_mask, if (!page) continue; if (page_allocated) { - swap_readpage(page, false); + swap_readpage(page, false, &splug); if (i != ra_info.offset) { SetPageReadahead(page); count_vm_event(SWAP_RA); @@ -828,10 +837,12 @@ static struct page *swap_vma_readahead(swp_entry_t fentry, gfp_t gfp_mask, put_page(page); } blk_finish_plug(&plug); + swap_read_unplug(splug); lru_add_drain(); skip: + /* The page was likely read above, so no need for plugging here */ return read_swap_cache_async(fentry, gfp_mask, vma, vmf->address, - ra_info.win == 1); + ra_info.win == 1, NULL); } /** @@ -865,18 +876,15 @@ static ssize_t vma_ra_enabled_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t count) { - if (!strncmp(buf, "true", 4) || !strncmp(buf, "1", 1)) - enable_vma_readahead = true; - else if (!strncmp(buf, "false", 5) || !strncmp(buf, "0", 1)) - enable_vma_readahead = false; - else - return -EINVAL; + ssize_t ret; + + ret = kstrtobool(buf, &enable_vma_readahead); + if (ret) + return ret; return count; } -static struct kobj_attribute vma_ra_enabled_attr = - __ATTR(vma_ra_enabled, 0644, vma_ra_enabled_show, - vma_ra_enabled_store); +static struct kobj_attribute vma_ra_enabled_attr = __ATTR_RW(vma_ra_enabled); static struct attribute *swap_attrs[] = { &vma_ra_enabled_attr.attr, |