From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B80FB55769 for ; Thu, 11 Jan 2024 19:25:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="IBMLR1cp" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:In-Reply-To:References; bh=1aClPF8NFde6vj1p83d9fRStlmOrQyle/sYQxH/POPg=; b=IBMLR1cpiXkGWSgkFTw9i6+m38 A5qacrSg1XbR1AxZmIXtcccXLpbpKHm81e9Aq/tmZ68otUHYOFaSWsfC0afg71SZklPAgCximC78t BHGZ823T7vliTInEVC7HSDyNPJJn3+MNJhJh7NJpboQAhQvLhCnMWCzA10B304Ge6bNqOb0t/D9qu 5898eQyrlo3PjqcH8k4O64h6AZz1/f7K30BlHkFW0HEqzgpOJlEakZKFsbazAQa04j+7ftw5kcNhv vJbYDq9kjIRR5GLX7csPhNEUOFffVD625Lt1z8CExGwC//FdDwjVIM+jkEOyeieOOWNEdPr+mKaFS ZYGM2C4Q==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1rO0fy-00Ei2l-UJ; Thu, 11 Jan 2024 19:25:14 +0000 From: "Matthew Wilcox (Oracle)" To: David Howells , linux-fsdevel@vger.kernel.org Cc: "Matthew Wilcox (Oracle)" Subject: [PATCH] filemap: Convert generic_perform_write() to support large folios Date: Thu, 11 Jan 2024 19:25:13 +0000 Message-Id: <20240111192513.3505769-1-willy@infradead.org> X-Mailer: git-send-email 2.37.1 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Modelled after the loop in iomap_write_iter(), copy larger chunks from userspace if the filesystem has created large folios. Signed-off-by: Matthew Wilcox (Oracle) --- mm/filemap.c | 40 +++++++++++++++++++++++++--------------- 1 file changed, 25 insertions(+), 15 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index 750e779c23db..964d5d7b9721 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -3893,6 +3893,7 @@ EXPORT_SYMBOL(generic_file_direct_write); ssize_t generic_perform_write(struct kiocb *iocb, struct iov_iter *i) { struct file *file = iocb->ki_filp; + size_t chunk = PAGE_SIZE << MAX_PAGECACHE_ORDER; loff_t pos = iocb->ki_pos; struct address_space *mapping = file->f_mapping; const struct address_space_operations *a_ops = mapping->a_ops; @@ -3901,16 +3902,18 @@ ssize_t generic_perform_write(struct kiocb *iocb, struct iov_iter *i) do { struct page *page; - unsigned long offset; /* Offset into pagecache page */ - unsigned long bytes; /* Bytes to write to page */ + struct folio *folio; + size_t offset; /* Offset into folio */ + size_t bytes; /* Bytes to write to folio */ size_t copied; /* Bytes copied from user */ void *fsdata = NULL; - offset = (pos & (PAGE_SIZE - 1)); - bytes = min_t(unsigned long, PAGE_SIZE - offset, - iov_iter_count(i)); + bytes = iov_iter_count(i); +retry: + offset = pos & (chunk - 1); + bytes = min(chunk - offset, bytes); + balance_dirty_pages_ratelimited(mapping); -again: /* * Bring in the user page that we will copy from _first_. * Otherwise there's a nasty deadlock on copying from the @@ -3932,11 +3935,16 @@ ssize_t generic_perform_write(struct kiocb *iocb, struct iov_iter *i) if (unlikely(status < 0)) break; + folio = page_folio(page); + offset = offset_in_folio(folio, pos); + if (bytes > folio_size(folio) - offset) + bytes = folio_size(folio) - offset; + if (mapping_writably_mapped(mapping)) - flush_dcache_page(page); + flush_dcache_folio(folio); - copied = copy_page_from_iter_atomic(page, offset, bytes, i); - flush_dcache_page(page); + copied = copy_folio_from_iter_atomic(folio, offset, bytes, i); + flush_dcache_folio(folio); status = a_ops->write_end(file, mapping, pos, bytes, copied, page, fsdata); @@ -3954,14 +3962,16 @@ ssize_t generic_perform_write(struct kiocb *iocb, struct iov_iter *i) * halfway through, might be a race with munmap, * might be severe memory pressure. */ - if (copied) + if (chunk > PAGE_SIZE) + chunk /= 2; + if (copied) { bytes = copied; - goto again; + goto retry; + } + } else { + pos += status; + written += status; } - pos += status; - written += status; - - balance_dirty_pages_ratelimited(mapping); } while (iov_iter_count(i)); if (!written) -- 2.43.0