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=-16.4 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 F0F9CC11F65 for ; Wed, 30 Jun 2021 16:08:48 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 8CB2C6141A for ; Wed, 30 Jun 2021 16:08:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8CB2C6141A 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 9378B8D01B6; Wed, 30 Jun 2021 12:08:47 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8E7638D01A2; Wed, 30 Jun 2021 12:08:47 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7AF1F8D01B6; Wed, 30 Jun 2021 12:08:47 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0065.hostedemail.com [216.40.44.65]) by kanga.kvack.org (Postfix) with ESMTP id 57C3B8D01A2 for ; Wed, 30 Jun 2021 12:08:47 -0400 (EDT) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 672ED231CD for ; Wed, 30 Jun 2021 16:08:46 +0000 (UTC) X-FDA: 78310873452.15.F45AB2E Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf18.hostedemail.com (Postfix) with ESMTP id 069D0400208C for ; Wed, 30 Jun 2021 16:08:44 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 0329861427; Wed, 30 Jun 2021 16:08:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625069324; bh=DssC5lnqu/8RKxluBn7PzCGFgK6R2k2M25rxK3xWP9o=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=SHAsxqF7H8AsdJhBcM5hJF4ULoM8qIKqXrFaCOOnNosDcxUHYeC8BSd3srpLKqoL5 BwwDQ+4Xnpgo1JYhu/bZRCt6zAQNk6lvk+IjhpOEwiQMRam4C7MaCR8lwVB7Fq/OAe 6q1l3xiMzdrmZde9lQnufTb3AecIy+NgIqr8rMK9f5ENXsnMvl3J6PmT0V9W1DyDmK wRYbP9eTIWzjYWOMgWZjXBvpyxgLu31dEdtCIpgxBejW2k7ejY+8YGP6WQXZLqQ3Gq 2Y/IFeias4PELk0KN8Yu220li7/K5/pjpnJpNmqMzFJMrFmnLAtsBrVqu3t/b01VEt EEFJsstXanOGw== Date: Wed, 30 Jun 2021 09:08:43 -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: <20210630160843.GM13784@locust> References: <20210630061431.1750745-1-david@fromorbit.com> <20210630061431.1750745-2-david@fromorbit.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210630061431.1750745-2-david@fromorbit.com> Authentication-Results: imf18.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=SHAsxqF7; spf=pass (imf18.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-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 069D0400208C X-Stat-Signature: rgbaq4ga9r7qihfqamx6rzwst3nf5zwd X-HE-Tag: 1625069324-892198 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, Jun 30, 2021 at 04:14:29PM +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 > --- > fs/xfs/xfs_log_recover.c | 2 +- > include/linux/mm.h | 2 ++ > mm/util.c | 15 +++++++++++++++ > 3 files changed, 18 insertions(+), 1 deletion(-) > > diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c > index 1721fce2ec94..fee4fbadea0a 100644 > --- a/fs/xfs/xfs_log_recover.c > +++ b/fs/xfs/xfs_log_recover.c > @@ -2062,7 +2062,7 @@ 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); kvrealloc can return null, so this needs to check for that and -ENOMEM, right? It'll suck that log recovery fails, but such is life. --D > 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 8ae31622deef..aa720bc0a1d0 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -827,6 +827,8 @@ 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 a8bf17f18a81..1104339ad2ca 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 >