From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 81FE41D6A5; Tue, 13 Feb 2024 16:38:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707842311; cv=none; b=tGgkmglv3wfMGwIhmmSEMFoow73KsrEkC3FbfEgJuTZm2JggeEkLcQeHxjw+l3QC1oUjWl/QoC3bX9irh3dcRyEkfR+DBzERuUME+3eJMm98KzoDRUncOC4M0tDaGd3YbIYHBW/rjqGpXcwhXoqIogcKnEulv0inByjfR18W+1s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707842311; c=relaxed/simple; bh=tj+7TbENZG51WqSKyLxJxlrP3jkogejbHEm7mQelHao=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=S23uhwVPevB0tLqQ5sxIoihGsjbx0J4cm9iQsGsKC6vIwhhcAjORbnv00a+hYoXwn5pmJvYD50vz/8TsiJcHdZFEyiISamJn/2aN02sJVMMMnkH2U6MUhl/WgRikJj+hD/zgueokoyf6iP5DbSywXtlV0D9PJxQudfmHDFW03sI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=SVd+B4Na; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="SVd+B4Na" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 17282C433C7; Tue, 13 Feb 2024 16:38:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1707842310; bh=tj+7TbENZG51WqSKyLxJxlrP3jkogejbHEm7mQelHao=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=SVd+B4NaowQbDyPchjA4D5BZ2fZXSB/eV8rxFnFB3SswALTWYWgzH5KEmwVCvK0D/ eA0cvi+/fgWFrqPJ5Zdy8MO4sQRU1TMSJcM3AJxeudTlYhJkN0CRW9WBLmQYWpg6K9 i9RpproerpQzgm296HmhVFNSY9AO3eSY6a4G6bg5o/BjhyaGTgnEmtToT9UQf+qt2a muBEzsGZjUb7NDtQ4ZuGwhBI6oNusHtYxlzP+ojZ7OKyWuc8ie6+fuNjNq4Pu7yzX1 +oFvewXLVKtunQ/90YrkIVyZYJ6OPO2S9l4/EQTkCuXh4AVIf2eyIwZY2ZbsE7IOk8 MMi8XP+hnZJFQ== Date: Tue, 13 Feb 2024 08:38:29 -0800 From: "Darrick J. Wong" To: "Pankaj Raghav (Samsung)" Cc: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, mcgrof@kernel.org, gost.dev@samsung.com, akpm@linux-foundation.org, kbusch@kernel.org, chandan.babu@oracle.com, p.raghav@samsung.com, linux-kernel@vger.kernel.org, hare@suse.de, willy@infradead.org, linux-mm@kvack.org, david@fromorbit.com Subject: Re: [RFC v2 03/14] filemap: use mapping_min_order while allocating folios Message-ID: <20240213163829.GT6184@frogsfrogsfrogs> References: <20240213093713.1753368-1-kernel@pankajraghav.com> <20240213093713.1753368-4-kernel@pankajraghav.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240213093713.1753368-4-kernel@pankajraghav.com> On Tue, Feb 13, 2024 at 10:37:02AM +0100, Pankaj Raghav (Samsung) wrote: > From: Pankaj Raghav > > filemap_create_folio() and do_read_cache_folio() were always allocating > folio of order 0. __filemap_get_folio was trying to allocate higher > order folios when fgp_flags had higher order hint set but it will default > to order 0 folio if higher order memory allocation fails. > > As we bring the notion of mapping_min_order, make sure these functions > allocate at least folio of mapping_min_order as we need to guarantee it > in the page cache. > > Add some additional VM_BUG_ON() in page_cache_delete[batch] and > __filemap_add_folio to catch errors where we delete or add folios that > has order less than min_order. > > Signed-off-by: Pankaj Raghav > Signed-off-by: Luis Chamberlain Looks good to me, Acked-by: Darrick J. Wong --D > --- > mm/filemap.c | 25 +++++++++++++++++++++---- > 1 file changed, 21 insertions(+), 4 deletions(-) > > diff --git a/mm/filemap.c b/mm/filemap.c > index 323a8e169581..7a6e15c47150 100644 > --- a/mm/filemap.c > +++ b/mm/filemap.c > @@ -127,6 +127,7 @@ > static void page_cache_delete(struct address_space *mapping, > struct folio *folio, void *shadow) > { > + unsigned int min_order = mapping_min_folio_order(mapping); > XA_STATE(xas, &mapping->i_pages, folio->index); > long nr = 1; > > @@ -135,6 +136,7 @@ static void page_cache_delete(struct address_space *mapping, > xas_set_order(&xas, folio->index, folio_order(folio)); > nr = folio_nr_pages(folio); > > + VM_BUG_ON_FOLIO(folio_order(folio) < min_order, folio); > VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio); > > xas_store(&xas, shadow); > @@ -277,6 +279,7 @@ void filemap_remove_folio(struct folio *folio) > static void page_cache_delete_batch(struct address_space *mapping, > struct folio_batch *fbatch) > { > + unsigned int min_order = mapping_min_folio_order(mapping); > XA_STATE(xas, &mapping->i_pages, fbatch->folios[0]->index); > long total_pages = 0; > int i = 0; > @@ -305,6 +308,7 @@ static void page_cache_delete_batch(struct address_space *mapping, > > WARN_ON_ONCE(!folio_test_locked(folio)); > > + VM_BUG_ON_FOLIO(folio_order(folio) < min_order, folio); > folio->mapping = NULL; > /* Leave folio->index set: truncation lookup relies on it */ > > @@ -846,6 +850,7 @@ noinline int __filemap_add_folio(struct address_space *mapping, > int huge = folio_test_hugetlb(folio); > bool charged = false; > long nr = 1; > + unsigned int min_order = mapping_min_folio_order(mapping); > > VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio); > VM_BUG_ON_FOLIO(folio_test_swapbacked(folio), folio); > @@ -896,6 +901,7 @@ noinline int __filemap_add_folio(struct address_space *mapping, > } > } > > + VM_BUG_ON_FOLIO(folio_order(folio) < min_order, folio); > xas_store(&xas, folio); > if (xas_error(&xas)) > goto unlock; > @@ -1847,6 +1853,10 @@ struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index, > fgf_t fgp_flags, gfp_t gfp) > { > struct folio *folio; > + unsigned int min_order = mapping_min_folio_order(mapping); > + unsigned int min_nrpages = mapping_min_folio_nrpages(mapping); > + > + index = round_down(index, min_nrpages); > > repeat: > folio = filemap_get_entry(mapping, index); > @@ -1886,7 +1896,7 @@ struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index, > folio_wait_stable(folio); > no_page: > if (!folio && (fgp_flags & FGP_CREAT)) { > - unsigned order = FGF_GET_ORDER(fgp_flags); > + unsigned int order = max(min_order, FGF_GET_ORDER(fgp_flags)); > int err; > > if ((fgp_flags & FGP_WRITE) && mapping_can_writeback(mapping)) > @@ -1914,8 +1924,13 @@ struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index, > err = -ENOMEM; > if (order == 1) > order = 0; > + if (order < min_order) > + order = min_order; > if (order > 0) > alloc_gfp |= __GFP_NORETRY | __GFP_NOWARN; > + > + VM_BUG_ON(index & ((1UL << order) - 1)); > + > folio = filemap_alloc_folio(alloc_gfp, order); > if (!folio) > continue; > @@ -1929,7 +1944,7 @@ struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index, > break; > folio_put(folio); > folio = NULL; > - } while (order-- > 0); > + } while (order-- > min_order); > > if (err == -EEXIST) > goto repeat; > @@ -2424,7 +2439,8 @@ static int filemap_create_folio(struct file *file, > struct folio *folio; > int error; > > - folio = filemap_alloc_folio(mapping_gfp_mask(mapping), 0); > + folio = filemap_alloc_folio(mapping_gfp_mask(mapping), > + mapping_min_folio_order(mapping)); > if (!folio) > return -ENOMEM; > > @@ -3682,7 +3698,8 @@ static struct folio *do_read_cache_folio(struct address_space *mapping, > repeat: > folio = filemap_get_folio(mapping, index); > if (IS_ERR(folio)) { > - folio = filemap_alloc_folio(gfp, 0); > + folio = filemap_alloc_folio(gfp, > + mapping_min_folio_order(mapping)); > if (!folio) > return ERR_PTR(-ENOMEM); > err = filemap_add_folio(mapping, folio, index, gfp); > -- > 2.43.0 > >