From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 074B9C433EF for ; Thu, 26 May 2022 18:25:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233606AbiEZSZr (ORCPT ); Thu, 26 May 2022 14:25:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52648 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349685AbiEZSZl (ORCPT ); Thu, 26 May 2022 14:25:41 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0A9CB62A35; Thu, 26 May 2022 11:25:39 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id 6DDEBCE22CE; Thu, 26 May 2022 18:25:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A5F89C385A9; Thu, 26 May 2022 18:25:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1653589536; bh=MYNWgivGhGmmsbjTVz5uPvg0gyA0R4dUrcZQM07Dcqo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=dc2AjXmO9dHGIz24yuTGtdzntHWgcM+7HyGWa2sDUjyNeGJZy2sGhlFvT04MalrpT qCxXjnTw565MQduk8+DLqbaeIclS5wGPfdnWlxJ4RI9ltkfrQJ20JtGAlsaI9ombVF GDF9+ImAlgHlmLYUOhGIMy+FLo1MunRPsZ4CXwrYpBqPQ+TQOBlwgrawyNdS4neP/Y cxAqdYmqc8NebWW5lT1DvAXOoPinUb5KGGqesQjs6+2iOt2RpEwOGi5AemRsAHRnA+ DcwmTS7tfAu7idBI9MyAxXVlB8ay3LE7QJnu02RirfkZCpxVJsQalwoIRY0UBsLab1 1uQHcrubSEK7g== Date: Thu, 26 May 2022 11:25:36 -0700 From: "Darrick J. Wong" To: Stefan Roesch Cc: io-uring@vger.kernel.org, kernel-team@fb.com, linux-mm@kvack.org, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, david@fromorbit.com, jack@suse.cz, hch@infradead.org Subject: Re: [PATCH v6 04/16] iomap: Add flags parameter to iomap_page_create() Message-ID: References: <20220526173840.578265-1-shr@fb.com> <20220526173840.578265-5-shr@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220526173840.578265-5-shr@fb.com> Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On Thu, May 26, 2022 at 10:38:28AM -0700, Stefan Roesch wrote: > Add the kiocb flags parameter to the function iomap_page_create(). > Depending on the value of the flags parameter it enables different gfp > flags. > > No intended functional changes in this patch. > > Signed-off-by: Stefan Roesch > Reviewed-by: Jan Kara > --- > fs/iomap/buffered-io.c | 19 +++++++++++++------ > 1 file changed, 13 insertions(+), 6 deletions(-) > > diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c > index 8ce8720093b9..d6ddc54e190e 100644 > --- a/fs/iomap/buffered-io.c > +++ b/fs/iomap/buffered-io.c > @@ -44,16 +44,21 @@ static inline struct iomap_page *to_iomap_page(struct folio *folio) > static struct bio_set iomap_ioend_bioset; > > static struct iomap_page * > -iomap_page_create(struct inode *inode, struct folio *folio) > +iomap_page_create(struct inode *inode, struct folio *folio, unsigned int flags) > { > struct iomap_page *iop = to_iomap_page(folio); > unsigned int nr_blocks = i_blocks_per_folio(inode, folio); > + gfp_t gfp = GFP_NOFS | __GFP_NOFAIL; > > if (iop || nr_blocks <= 1) > return iop; > > + if (flags & IOMAP_NOWAIT) > + gfp = GFP_NOWAIT; Hmm. GFP_NOWAIT means we don't wait for reclaim or IO or filesystem callbacks, and NOFAIL means we retry indefinitely. What happens in the NOWAIT|NOFAIL case? Does that imply that the kzalloc loops without triggering direct reclaim until someone else frees enough memory? --D > + > iop = kzalloc(struct_size(iop, uptodate, BITS_TO_LONGS(nr_blocks)), > - GFP_NOFS | __GFP_NOFAIL); > + gfp); > + > spin_lock_init(&iop->uptodate_lock); > if (folio_test_uptodate(folio)) > bitmap_fill(iop->uptodate, nr_blocks); > @@ -226,7 +231,7 @@ static int iomap_read_inline_data(const struct iomap_iter *iter, > if (WARN_ON_ONCE(size > iomap->length)) > return -EIO; > if (offset > 0) > - iop = iomap_page_create(iter->inode, folio); > + iop = iomap_page_create(iter->inode, folio, iter->flags); > else > iop = to_iomap_page(folio); > > @@ -264,7 +269,7 @@ static loff_t iomap_readpage_iter(const struct iomap_iter *iter, > return iomap_read_inline_data(iter, folio); > > /* zero post-eof blocks as the page may be mapped */ > - iop = iomap_page_create(iter->inode, folio); > + iop = iomap_page_create(iter->inode, folio, iter->flags); > iomap_adjust_read_range(iter->inode, folio, &pos, length, &poff, &plen); > if (plen == 0) > goto done; > @@ -550,7 +555,7 @@ static int __iomap_write_begin(const struct iomap_iter *iter, loff_t pos, > size_t len, struct folio *folio) > { > const struct iomap *srcmap = iomap_iter_srcmap(iter); > - struct iomap_page *iop = iomap_page_create(iter->inode, folio); > + struct iomap_page *iop; > loff_t block_size = i_blocksize(iter->inode); > loff_t block_start = round_down(pos, block_size); > loff_t block_end = round_up(pos + len, block_size); > @@ -561,6 +566,8 @@ static int __iomap_write_begin(const struct iomap_iter *iter, loff_t pos, > return 0; > folio_clear_error(folio); > > + iop = iomap_page_create(iter->inode, folio, iter->flags); > + > do { > iomap_adjust_read_range(iter->inode, folio, &block_start, > block_end - block_start, &poff, &plen); > @@ -1332,7 +1339,7 @@ iomap_writepage_map(struct iomap_writepage_ctx *wpc, > struct writeback_control *wbc, struct inode *inode, > struct folio *folio, u64 end_pos) > { > - struct iomap_page *iop = iomap_page_create(inode, folio); > + struct iomap_page *iop = iomap_page_create(inode, folio, 0); > struct iomap_ioend *ioend, *next; > unsigned len = i_blocksize(inode); > unsigned nblocks = i_blocks_per_folio(inode, folio); > -- > 2.30.2 >