From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Matthew Wilcox To: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Matthew Wilcox , Jan Kara , Jeff Layton , Lukas Czerner , Ross Zwisler , Christoph Hellwig , Goldwyn Rodrigues , Nicholas Piggin , Ryusuke Konishi , linux-nilfs@vger.kernel.org, Jaegeuk Kim , Chao Yu , linux-f2fs-devel@lists.sourceforge.net Subject: [PATCH v14 60/74] nilfs2: Convert to XArray Date: Sat, 16 Jun 2018 19:00:38 -0700 Message-Id: <20180617020052.4759-61-willy@infradead.org> In-Reply-To: <20180617020052.4759-1-willy@infradead.org> References: <20180617020052.4759-1-willy@infradead.org> Sender: owner-linux-mm@kvack.org List-ID: This is close to a 1:1 replacement of radix tree APIs with their XArray equivalents. It would be possible to optimise nilfs_copy_back_pages(), but that doesn't seem to be in the performance path. Also, I think it has a pre-existing bug, and I've added a note to that effect in the source code. Signed-off-by: Matthew Wilcox --- fs/nilfs2/btnode.c | 26 +++++++++----------------- fs/nilfs2/page.c | 29 +++++++++++++---------------- 2 files changed, 22 insertions(+), 33 deletions(-) diff --git a/fs/nilfs2/btnode.c b/fs/nilfs2/btnode.c index dec98cab729d..e9fcffb3a15c 100644 --- a/fs/nilfs2/btnode.c +++ b/fs/nilfs2/btnode.c @@ -177,24 +177,18 @@ int nilfs_btnode_prepare_change_key(struct address_space *btnc, ctxt->newbh = NULL; if (inode->i_blkbits == PAGE_SHIFT) { - lock_page(obh->b_page); - /* - * We cannot call radix_tree_preload for the kernels older - * than 2.6.23, because it is not exported for modules. - */ + struct page *opage = obh->b_page; + lock_page(opage); retry: - err = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM); - if (err) - goto failed_unlock; /* BUG_ON(oldkey != obh->b_page->index); */ - if (unlikely(oldkey != obh->b_page->index)) - NILFS_PAGE_BUG(obh->b_page, + if (unlikely(oldkey != opage->index)) + NILFS_PAGE_BUG(opage, "invalid oldkey %lld (newkey=%lld)", (unsigned long long)oldkey, (unsigned long long)newkey); xa_lock_irq(&btnc->i_pages); - err = radix_tree_insert(&btnc->i_pages, newkey, obh->b_page); + err = __xa_insert(&btnc->i_pages, newkey, opage, GFP_NOFS); xa_unlock_irq(&btnc->i_pages); /* * Note: page->index will not change to newkey until @@ -202,7 +196,6 @@ int nilfs_btnode_prepare_change_key(struct address_space *btnc, * To protect the page in intermediate state, the page lock * is held. */ - radix_tree_preload_end(); if (!err) return 0; else if (err != -EEXIST) @@ -212,7 +205,7 @@ int nilfs_btnode_prepare_change_key(struct address_space *btnc, if (!err) goto retry; /* fallback to copy mode */ - unlock_page(obh->b_page); + unlock_page(opage); } nbh = nilfs_btnode_create_block(btnc, newkey); @@ -252,9 +245,8 @@ void nilfs_btnode_commit_change_key(struct address_space *btnc, mark_buffer_dirty(obh); xa_lock_irq(&btnc->i_pages); - radix_tree_delete(&btnc->i_pages, oldkey); - radix_tree_tag_set(&btnc->i_pages, newkey, - PAGECACHE_TAG_DIRTY); + __xa_erase(&btnc->i_pages, oldkey); + __xa_set_tag(&btnc->i_pages, newkey, PAGECACHE_TAG_DIRTY); xa_unlock_irq(&btnc->i_pages); opage->index = obh->b_blocknr = newkey; @@ -284,7 +276,7 @@ void nilfs_btnode_abort_change_key(struct address_space *btnc, if (nbh == NULL) { /* blocksize == pagesize */ xa_lock_irq(&btnc->i_pages); - radix_tree_delete(&btnc->i_pages, newkey); + __xa_erase(&btnc->i_pages, newkey); xa_unlock_irq(&btnc->i_pages); unlock_page(ctxt->bh->b_page); } else diff --git a/fs/nilfs2/page.c b/fs/nilfs2/page.c index 4cb850a6f1c2..8384473b98b8 100644 --- a/fs/nilfs2/page.c +++ b/fs/nilfs2/page.c @@ -298,7 +298,7 @@ int nilfs_copy_dirty_pages(struct address_space *dmap, * @dmap: destination page cache * @smap: source page cache * - * No pages must no be added to the cache during this process. + * No pages must be added to the cache during this process. * This must be ensured by the caller. */ void nilfs_copy_back_pages(struct address_space *dmap, @@ -307,7 +307,6 @@ void nilfs_copy_back_pages(struct address_space *dmap, struct pagevec pvec; unsigned int i, n; pgoff_t index = 0; - int err; pagevec_init(&pvec); repeat: @@ -322,35 +321,34 @@ void nilfs_copy_back_pages(struct address_space *dmap, lock_page(page); dpage = find_lock_page(dmap, offset); if (dpage) { - /* override existing page on the destination cache */ + /* overwrite existing page in the destination cache */ WARN_ON(PageDirty(dpage)); nilfs_copy_page(dpage, page, 0); unlock_page(dpage); put_page(dpage); + /* Do we not need to remove page from smap here? */ } else { - struct page *page2; + struct page *p; /* move the page to the destination cache */ xa_lock_irq(&smap->i_pages); - page2 = radix_tree_delete(&smap->i_pages, offset); - WARN_ON(page2 != page); - + p = __xa_erase(&smap->i_pages, offset); + WARN_ON(page != p); smap->nrpages--; xa_unlock_irq(&smap->i_pages); xa_lock_irq(&dmap->i_pages); - err = radix_tree_insert(&dmap->i_pages, offset, page); - if (unlikely(err < 0)) { - WARN_ON(err == -EEXIST); + p = __xa_store(&dmap->i_pages, offset, page, GFP_NOFS); + if (unlikely(p)) { + /* Probably -ENOMEM */ page->mapping = NULL; - put_page(page); /* for cache */ + put_page(page); } else { page->mapping = dmap; dmap->nrpages++; if (PageDirty(page)) - radix_tree_tag_set(&dmap->i_pages, - offset, - PAGECACHE_TAG_DIRTY); + __xa_set_tag(&dmap->i_pages, offset, + PAGECACHE_TAG_DIRTY); } xa_unlock_irq(&dmap->i_pages); } @@ -476,8 +474,7 @@ int __nilfs_clear_page_dirty(struct page *page) if (mapping) { xa_lock_irq(&mapping->i_pages); if (test_bit(PG_dirty, &page->flags)) { - radix_tree_tag_clear(&mapping->i_pages, - page_index(page), + __xa_clear_tag(&mapping->i_pages, page_index(page), PAGECACHE_TAG_DIRTY); xa_unlock_irq(&mapping->i_pages); return clear_page_dirty_for_io(page); -- 2.17.1