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 1658F1A0DF2; Thu, 6 Jun 2024 14:12:56 +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=1717683177; cv=none; b=YXqGM7LXan+6C3USZ6T+ZPNZBc3IGnGjCl2qSVGND93qXq73Xp7HvNm6jQcvIkFwU8KosUJCOyb3zXQv12zq9RQ8LPjCKqrAj2CnWs1mCPM0Gdc6d+SRHBlhpNjcIlbdyAKW0M2mBX5c69dYys5K4x9POVccVakrYN9yoQYP8Ck= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717683177; c=relaxed/simple; bh=r/QiWUFvWisaNynEAtQwcgcQxDVPRjrnJLqqlfmbEkw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Zlik4lZE88UoXlixkmmVsbZsEZeUcnDGQP1krH4pRWfPxW0MEnY26b7jbwzCn4wo42puxm9iZzQJrWFHu/M0iTrtq4QZj/GOOFmGl9hNHfj4goczKym2KONfvIr07ampwJrMjGMMffyeoxr/2f6x9JmHZPzO8vYBm0Lh35jTNUc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=gmDmR1wz; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="gmDmR1wz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A7125C32781; Thu, 6 Jun 2024 14:12:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1717683176; bh=r/QiWUFvWisaNynEAtQwcgcQxDVPRjrnJLqqlfmbEkw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gmDmR1wzU2GNRITKeXmqQkjiPwPLOy3X7hSFGc/VSEmCW+YtcU889yRkLVqzZJz5h HbZ/Mr2y4xW2+ZZVxl8FXjT9X8O4sWLcOvRL5qI5MyaC1B7XKeMovRdOLesMVPglGg 69x93SNzF5mZo+T63+X5OTK6x3JOv5mbUgiVswSY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yu Kuai , Song Liu , Sasha Levin , Nigel Croxon Subject: [PATCH 6.6 121/744] md: fix resync softlockup when bitmap size is less than array size Date: Thu, 6 Jun 2024 15:56:33 +0200 Message-ID: <20240606131736.291501869@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240606131732.440653204@linuxfoundation.org> References: <20240606131732.440653204@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yu Kuai [ Upstream commit f0e729af2eb6bee9eb58c4df1087f14ebaefe26b ] Is is reported that for dm-raid10, lvextend + lvchange --syncaction will trigger following softlockup: kernel:watchdog: BUG: soft lockup - CPU#3 stuck for 26s! [mdX_resync:6976] CPU: 7 PID: 3588 Comm: mdX_resync Kdump: loaded Not tainted 6.9.0-rc4-next-20240419 #1 RIP: 0010:_raw_spin_unlock_irq+0x13/0x30 Call Trace: md_bitmap_start_sync+0x6b/0xf0 raid10_sync_request+0x25c/0x1b40 [raid10] md_do_sync+0x64b/0x1020 md_thread+0xa7/0x170 kthread+0xcf/0x100 ret_from_fork+0x30/0x50 ret_from_fork_asm+0x1a/0x30 And the detailed process is as follows: md_do_sync j = mddev->resync_min while (j < max_sectors) sectors = raid10_sync_request(mddev, j, &skipped) if (!md_bitmap_start_sync(..., &sync_blocks)) // md_bitmap_start_sync set sync_blocks to 0 return sync_blocks + sectors_skippe; // sectors = 0; j += sectors; // j never change Root cause is that commit 301867b1c168 ("md/raid10: check slab-out-of-bounds in md_bitmap_get_counter") return early from md_bitmap_get_counter(), without setting returned blocks. Fix this problem by always set returned blocks from md_bitmap_get_counter"(), as it used to be. Noted that this patch just fix the softlockup problem in kernel, the case that bitmap size doesn't match array size still need to be fixed. Fixes: 301867b1c168 ("md/raid10: check slab-out-of-bounds in md_bitmap_get_counter") Reported-and-tested-by: Nigel Croxon Closes: https://lore.kernel.org/all/71ba5272-ab07-43ba-8232-d2da642acb4e@redhat.com/ Signed-off-by: Yu Kuai Link: https://lore.kernel.org/r/20240422065824.2516-1-yukuai1@huaweicloud.com Signed-off-by: Song Liu Signed-off-by: Sasha Levin --- drivers/md/md-bitmap.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c index 42d4c38ba54d5..d9235ee7dcc46 100644 --- a/drivers/md/md-bitmap.c +++ b/drivers/md/md-bitmap.c @@ -1427,7 +1427,7 @@ __acquires(bitmap->lock) sector_t chunk = offset >> bitmap->chunkshift; unsigned long page = chunk >> PAGE_COUNTER_SHIFT; unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT; - sector_t csize; + sector_t csize = ((sector_t)1) << bitmap->chunkshift; int err; if (page >= bitmap->pages) { @@ -1436,6 +1436,7 @@ __acquires(bitmap->lock) * End-of-device while looking for a whole page or * user set a huge number to sysfs bitmap_set_bits. */ + *blocks = csize - (offset & (csize - 1)); return NULL; } err = md_bitmap_checkpage(bitmap, page, create, 0); @@ -1444,8 +1445,7 @@ __acquires(bitmap->lock) bitmap->bp[page].map == NULL) csize = ((sector_t)1) << (bitmap->chunkshift + PAGE_COUNTER_SHIFT); - else - csize = ((sector_t)1) << bitmap->chunkshift; + *blocks = csize - (offset & (csize - 1)); if (err < 0) -- 2.43.0