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 X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 382F1C1B08C for ; Wed, 14 Jul 2021 21:15:05 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C237A613CC for ; Wed, 14 Jul 2021 21:15:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C237A613CC Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 08A4A8D0002; Wed, 14 Jul 2021 17:15:05 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 012B86B009C; Wed, 14 Jul 2021 17:15:04 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DF5638D0002; Wed, 14 Jul 2021 17:15:04 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0135.hostedemail.com [216.40.44.135]) by kanga.kvack.org (Postfix) with ESMTP id B25656B009B for ; Wed, 14 Jul 2021 17:15:04 -0400 (EDT) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 92ECF18478D93 for ; Wed, 14 Jul 2021 21:15:03 +0000 (UTC) X-FDA: 78362448486.28.2D55C17 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf09.hostedemail.com (Postfix) with ESMTP id 38BAC3000108 for ; Wed, 14 Jul 2021 21:15:03 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 3F22661396; Wed, 14 Jul 2021 21:15:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1626297302; bh=HdjPomaxvCXL59JuOmncCPcxQ7NoSFrX8DjsY+VkF1w=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=lAKVruPEySQQPZHbiRW8jb8FMSzGLWQRJXnG9/Qt70/iBjrqt6XHHdffqlDqjSgvG iWGQ5rbtukNJsVkcDOvjaRVQdP9ZAu8NIzxw/qTx489oZ+oVKEVl1gVWlML7wxN9T8 nvjcMhflYr6mkiIwNRqixRiLXqeppXGouQe21w1+tO91fM4ezlYN77T1kiu0ONl2yK 3ebaFw92LRH6QV5JACphj8D0uYEcR+MJXBZpmIz3i56kxaBpj/+R/lvLqvKgg0LUAE ljv/Pi78MCgM7jvHjr6WHyoMoVCm6w83FjzSudLESJxSm7/AkMKhhMVb9vKmhoIaqJ UlV+6TIsSpq3w== Date: Wed, 14 Jul 2021 14:15:01 -0700 From: "Darrick J. Wong" To: Dave Chinner Cc: linux-xfs@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 1/3] mm: Add kvrealloc() Message-ID: <20210714211501.GJ22402@magnolia> References: <20210714023440.2608690-1-david@fromorbit.com> <20210714023440.2608690-2-david@fromorbit.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210714023440.2608690-2-david@fromorbit.com> X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 38BAC3000108 X-Stat-Signature: xcwxr8iogogagzbsq43qw8wdq1as58ng Authentication-Results: imf09.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=lAKVruPE; spf=pass (imf09.hostedemail.com: domain of djwong@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=djwong@kernel.org; dmarc=pass (policy=none) header.from=kernel.org X-HE-Tag: 1626297303-718526 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Jul 14, 2021 at 12:34:38PM +1000, Dave Chinner wrote: > From: Dave Chinner > > During log recovery of an XFS filesystem with 64kB directory > buffers, rebuilding a buffer split across two log records results > in a memory allocation warning from krealloc like this: > > xfs filesystem being mounted at /mnt/scratch supports timestamps until 2038 (0x7fffffff) > XFS (dm-0): Unmounting Filesystem > XFS (dm-0): Mounting V5 Filesystem > XFS (dm-0): Starting recovery (logdev: internal) > ------------[ cut here ]------------ > WARNING: CPU: 5 PID: 3435170 at mm/page_alloc.c:3539 get_page_from_freelist+0xdee/0xe40 > ..... > RIP: 0010:get_page_from_freelist+0xdee/0xe40 > Call Trace: > ? complete+0x3f/0x50 > __alloc_pages+0x16f/0x300 > alloc_pages+0x87/0x110 > kmalloc_order+0x2c/0x90 > kmalloc_order_trace+0x1d/0x90 > __kmalloc_track_caller+0x215/0x270 > ? xlog_recover_add_to_cont_trans+0x63/0x1f0 > krealloc+0x54/0xb0 > xlog_recover_add_to_cont_trans+0x63/0x1f0 > xlog_recovery_process_trans+0xc1/0xd0 > xlog_recover_process_ophdr+0x86/0x130 > xlog_recover_process_data+0x9f/0x160 > xlog_recover_process+0xa2/0x120 > xlog_do_recovery_pass+0x40b/0x7d0 > ? __irq_work_queue_local+0x4f/0x60 > ? irq_work_queue+0x3a/0x50 > xlog_do_log_recovery+0x70/0x150 > xlog_do_recover+0x38/0x1d0 > xlog_recover+0xd8/0x170 > xfs_log_mount+0x181/0x300 > xfs_mountfs+0x4a1/0x9b0 > xfs_fs_fill_super+0x3c0/0x7b0 > get_tree_bdev+0x171/0x270 > ? suffix_kstrtoint.constprop.0+0xf0/0xf0 > xfs_fs_get_tree+0x15/0x20 > vfs_get_tree+0x24/0xc0 > path_mount+0x2f5/0xaf0 > __x64_sys_mount+0x108/0x140 > do_syscall_64+0x3a/0x70 > entry_SYSCALL_64_after_hwframe+0x44/0xae > > Essentially, we are taking a multi-order allocation from kmem_alloc() > (which has an open coded no fail, no warn loop) and then > reallocating it out to 64kB using krealloc(__GFP_NOFAIL) and that is > then triggering the above warning. > > This is a regression caused by converting this code from an open > coded no fail/no warn reallocation loop to using __GFP_NOFAIL. > > What we actually need here is kvrealloc(), so that if contiguous > page allocation fails we fall back to vmalloc() and we don't > get nasty warnings happening in XFS. > > Fixes: 771915c4f688 ("xfs: remove kmem_realloc()") > Signed-off-by: Dave Chinner Looks good now, Reviewed-by: Darrick J. Wong --D > --- > fs/xfs/xfs_log_recover.c | 4 +++- > include/linux/mm.h | 2 ++ > mm/util.c | 15 +++++++++++++++ > 3 files changed, 20 insertions(+), 1 deletion(-) > > diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c > index 1721fce2ec94..3c08d495844d 100644 > --- a/fs/xfs/xfs_log_recover.c > +++ b/fs/xfs/xfs_log_recover.c > @@ -2062,7 +2062,9 @@ xlog_recover_add_to_cont_trans( > old_ptr = item->ri_buf[item->ri_cnt-1].i_addr; > old_len = item->ri_buf[item->ri_cnt-1].i_len; > > - ptr = krealloc(old_ptr, len + old_len, GFP_KERNEL | __GFP_NOFAIL); > + ptr = kvrealloc(old_ptr, old_len, len + old_len, GFP_KERNEL); > + if (!ptr) > + return -ENOMEM; > memcpy(&ptr[old_len], dp, len); > item->ri_buf[item->ri_cnt-1].i_len += len; > item->ri_buf[item->ri_cnt-1].i_addr = ptr; > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 57453dba41b9..ff9c00bfb76d 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -829,6 +829,8 @@ static inline void *kvcalloc(size_t n, size_t size, gfp_t flags) > return kvmalloc_array(n, size, flags | __GFP_ZERO); > } > > +extern void *kvrealloc(const void *p, size_t oldsize, size_t newsize, > + gfp_t flags); > extern void kvfree(const void *addr); > extern void kvfree_sensitive(const void *addr, size_t len); > > diff --git a/mm/util.c b/mm/util.c > index 99c6cc77de9e..b7698d6b2226 100644 > --- a/mm/util.c > +++ b/mm/util.c > @@ -635,6 +635,21 @@ void kvfree_sensitive(const void *addr, size_t len) > } > EXPORT_SYMBOL(kvfree_sensitive); > > +void *kvrealloc(const void *p, size_t oldsize, size_t newsize, gfp_t flags) > +{ > + void *newp; > + > + if (oldsize >= newsize) > + return (void *)p; > + newp = kvmalloc(newsize, flags); > + if (!newp) > + return NULL; > + memcpy(newp, p, oldsize); > + kvfree(p); > + return newp; > +} > +EXPORT_SYMBOL(kvrealloc); > + > static inline void *__page_rmapping(struct page *page) > { > unsigned long mapping; > -- > 2.31.1 >