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 A7E0BC43217 for ; Tue, 11 Oct 2022 14:54:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230240AbiJKOyI (ORCPT ); Tue, 11 Oct 2022 10:54:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36914 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230241AbiJKOxG (ORCPT ); Tue, 11 Oct 2022 10:53:06 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6FDA29A9E5; Tue, 11 Oct 2022 07:51:17 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 3C14B611B1; Tue, 11 Oct 2022 14:51:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D5BCBC433D7; Tue, 11 Oct 2022 14:51:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1665499870; bh=TQ1Dc96/cVm2pB1sol884Sqey428Yj6pK/JcwcJ4Rlk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pVEc0sGAXMqcywnX6H2ewfsGkImUYI2fVjkqBYRsMrqFI910kRCd72OchCaa4HTSO 2eYfFgYEHwKXy42vp6px58TnRTkZqfM3VMbvgEEjzS1sQpm8FCSBsibKyMUAFfS65z bYFqPHW9bPeVojYeC4TYDFfZ4DzYRkiMs4DmcKJMjRXjGfAbM5ZyRqicqfHt5XlNa5 TSEfedadX57a3VwoZtGuTf49xxGFGQ3koG3t7I5FLK+iyt6w7HWvuh/y0opnqi3V4Y HYQrmCBAkLSGItz1t4+VMbdgCnhjh0Klv6TTksIji31A/e5IbQLW0UKdYrnGRaC1cX s5YhP7fS9VgsA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Josef Bacik , David Sterba , Sasha Levin , clm@fb.com, linux-btrfs@vger.kernel.org Subject: [PATCH AUTOSEL 6.0 35/46] btrfs: call __btrfs_remove_free_space_cache_locked on cache load failure Date: Tue, 11 Oct 2022 10:50:03 -0400 Message-Id: <20221011145015.1622882-35-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221011145015.1622882-1-sashal@kernel.org> References: <20221011145015.1622882-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Josef Bacik [ Upstream commit 8a1ae2781dee9fc21ca82db682d37bea4bd074ad ] Now that lockdep is staying enabled through our entire CI runs I started seeing the following stack in generic/475 ------------[ cut here ]------------ WARNING: CPU: 1 PID: 2171864 at fs/btrfs/discard.c:604 btrfs_discard_update_discardable+0x98/0xb0 CPU: 1 PID: 2171864 Comm: kworker/u4:0 Not tainted 5.19.0-rc8+ #789 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 Workqueue: btrfs-cache btrfs_work_helper RIP: 0010:btrfs_discard_update_discardable+0x98/0xb0 RSP: 0018:ffffb857c2f7bad0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff8c85c605c200 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff86807c5b RDI: ffffffff868a831e RBP: ffff8c85c4c54000 R08: 0000000000000000 R09: 0000000000000000 R10: ffff8c85c66932f0 R11: 0000000000000001 R12: ffff8c85c3899010 R13: ffff8c85d5be4f40 R14: ffff8c85c4c54000 R15: ffff8c86114bfa80 FS: 0000000000000000(0000) GS:ffff8c863bd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2e7f168160 CR3: 000000010289a004 CR4: 0000000000370ee0 Call Trace: __btrfs_remove_free_space_cache+0x27/0x30 load_free_space_cache+0xad2/0xaf0 caching_thread+0x40b/0x650 ? lock_release+0x137/0x2d0 btrfs_work_helper+0xf2/0x3e0 ? lock_is_held_type+0xe2/0x140 process_one_work+0x271/0x590 ? process_one_work+0x590/0x590 worker_thread+0x52/0x3b0 ? process_one_work+0x590/0x590 kthread+0xf0/0x120 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x1f/0x30 This is the code ctl = block_group->free_space_ctl; discard_ctl = &block_group->fs_info->discard_ctl; lockdep_assert_held(&ctl->tree_lock); We have a temporary free space ctl for loading the free space cache in order to avoid having allocations happening while we're loading the cache. When we hit an error we free it all up, however this also calls btrfs_discard_update_discardable, which requires block_group->free_space_ctl->tree_lock to be held. However this is our temporary ctl so this lock isn't held. Fix this by calling __btrfs_remove_free_space_cache_locked instead so that we only clean up the entries and do not mess with the discardable stats. Signed-off-by: Josef Bacik Signed-off-by: David Sterba Signed-off-by: Sasha Levin --- fs/btrfs/free-space-cache.c | 53 +++++++++++++++++++++++-------------- 1 file changed, 33 insertions(+), 20 deletions(-) diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c index 835071fa39a9..2f88053cfc5e 100644 --- a/fs/btrfs/free-space-cache.c +++ b/fs/btrfs/free-space-cache.c @@ -48,6 +48,25 @@ static void bitmap_clear_bits(struct btrfs_free_space_ctl *ctl, struct btrfs_free_space *info, u64 offset, u64 bytes, bool update_stats); +static void __btrfs_remove_free_space_cache_locked( + struct btrfs_free_space_ctl *ctl) +{ + struct btrfs_free_space *info; + struct rb_node *node; + + while ((node = rb_last(&ctl->free_space_offset)) != NULL) { + info = rb_entry(node, struct btrfs_free_space, offset_index); + if (!info->bitmap) { + unlink_free_space(ctl, info, true); + kmem_cache_free(btrfs_free_space_cachep, info); + } else { + free_bitmap(ctl, info); + } + + cond_resched_lock(&ctl->tree_lock); + } +} + static struct inode *__lookup_free_space_inode(struct btrfs_root *root, struct btrfs_path *path, u64 offset) @@ -881,7 +900,14 @@ static int __load_free_space_cache(struct btrfs_root *root, struct inode *inode, return ret; free_cache: io_ctl_drop_pages(&io_ctl); - __btrfs_remove_free_space_cache(ctl); + + /* + * We need to call the _locked variant so we don't try to update the + * discard counters. + */ + spin_lock(&ctl->tree_lock); + __btrfs_remove_free_space_cache_locked(ctl); + spin_unlock(&ctl->tree_lock); goto out; } @@ -1017,7 +1043,13 @@ int load_free_space_cache(struct btrfs_block_group *block_group) if (ret == 0) ret = 1; } else { + /* + * We need to call the _locked variant so we don't try to update + * the discard counters. + */ + spin_lock(&tmp_ctl.tree_lock); __btrfs_remove_free_space_cache(&tmp_ctl); + spin_unlock(&tmp_ctl.tree_lock); btrfs_warn(fs_info, "block group %llu has wrong amount of free space", block_group->start); @@ -2980,25 +3012,6 @@ static void __btrfs_return_cluster_to_free_space( btrfs_put_block_group(block_group); } -static void __btrfs_remove_free_space_cache_locked( - struct btrfs_free_space_ctl *ctl) -{ - struct btrfs_free_space *info; - struct rb_node *node; - - while ((node = rb_last(&ctl->free_space_offset)) != NULL) { - info = rb_entry(node, struct btrfs_free_space, offset_index); - if (!info->bitmap) { - unlink_free_space(ctl, info, true); - kmem_cache_free(btrfs_free_space_cachep, info); - } else { - free_bitmap(ctl, info); - } - - cond_resched_lock(&ctl->tree_lock); - } -} - void __btrfs_remove_free_space_cache(struct btrfs_free_space_ctl *ctl) { spin_lock(&ctl->tree_lock); -- 2.35.1