From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751286AbdFEDad (ORCPT ); Sun, 4 Jun 2017 23:30:33 -0400 Received: from ozlabs.org ([103.22.144.67]:49501 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751224AbdFEDaZ (ORCPT ); Sun, 4 Jun 2017 23:30:25 -0400 Date: Mon, 5 Jun 2017 13:30:23 +1000 From: Stephen Rothwell To: David Sterba Cc: Omar Sandoval , Michal Hocko , lkp@01.org, Omar Sandoval , Vinnie Magro , kernel test robot , LKML Subject: Re: [lkp-robot] [btrfs] beeeccca9b: WARNING:at_mm/util.c:#kvmalloc_node Message-ID: <20170605133023.57a82e4d@canb.auug.org.au> In-Reply-To: <20170531145848.GB12135@suse.cz> References: <20170531063033.GC1795@yexl-desktop> <20170531065128.GB3853@dhcp22.suse.cz> <20170531091202.GA769@vader> <20170531091904.GD27783@dhcp22.suse.cz> <20170531092920.GA1418@vader> <20170531145848.GB12135@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi David, On Wed, 31 May 2017 16:58:48 +0200 David Sterba wrote: > > On Wed, May 31, 2017 at 02:29:20AM -0700, Omar Sandoval wrote: > > diff --git a/fs/btrfs/free-space-tree.c b/fs/btrfs/free-space-tree.c > > index fc0bd8406758..5abd3cd71144 100644 > > --- a/fs/btrfs/free-space-tree.c > > +++ b/fs/btrfs/free-space-tree.c > > @@ -153,21 +153,18 @@ static inline u32 free_space_bitmap_size(u64 size, u32 sectorsize) > > > > static u8 *alloc_bitmap(u32 bitmap_size) > > { > > - void *mem; > > + u8 *ret; > > + unsigned int nofs_flag; > > > > /* > > - * The allocation size varies, observed numbers were < 4K up to 16K. > > - * Using vmalloc unconditionally would be too heavy, we'll try > > - * contiguous allocations first. > > + * GFP_NOFS doesn't work with kvmalloc(), but we really can't recurse > > + * into the filesystem as the free space bitmap can be modified in the > > + * critical section of a transaction commit. > > */ > > - if (bitmap_size <= PAGE_SIZE) > > - return kzalloc(bitmap_size, GFP_NOFS); > > - > > - mem = kzalloc(bitmap_size, GFP_NOFS | __GFP_NOWARN); > > - if (mem) > > - return mem; > > - > > - return __vmalloc(bitmap_size, GFP_NOFS | __GFP_ZERO, PAGE_KERNEL); > > + nofs_flag = memalloc_nofs_save(); > > + ret = kvmalloc(bitmap_size, GFP_KERNEL); > > + memalloc_nofs_restore(nofs_flag); > > + return ret; > > } > > > > int convert_free_space_to_bitmaps(struct btrfs_trans_handle *trans, > > > > Dave, would you prefer to replace the patch we have now or do an > > incremental patch on top of it? > > I'll drop the patch "btrfs: Use kvzalloc instead of kzalloc/vmalloc in > alloc_bitmap", please send an updated version. Ping? -- Cheers, Stephen Rothwell