From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from canpmsgout04.his.huawei.com (canpmsgout04.his.huawei.com [113.46.200.219]) (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 916FC20ED; Sat, 30 May 2026 02:51:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=113.46.200.219 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780109507; cv=none; b=P8dBkuc2wis/Pe48UNb0x8HoAa8Lp5uvOY+ME4QgJ2RqwDh+TEFOhSBMNpUr97eXJFBcvIcAio5Vh+TvTYS8BXHX2EZV57ivelm8Ma0ODkJSo0neGad5KVb64T4PFlZetBatWvd2RNH8SqVzsikgnIKINd+/YhrjTeRtw+74rxo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780109507; c=relaxed/simple; bh=EFG/iQaBXXP+DusiWKq81bHf2W4ixTBrCHyUwVzINcQ=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=CIDQo/SBNnmeLxMsm+iBefGN4HDU+PcnkTPVYScLM1St/lWFTC46qpRHEGv5x72Vzkki+LFdWhvjI9AjTupWk9DUx8TlRfTsRBMmF+0wAp4Ubi3xC662y+JddWXvQ2RIsc7nseMs+WaxjDEodyXQuS9Mf2i08Id6k75bYWi3bgs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=h-partners.com; dkim=pass (1024-bit key) header.d=h-partners.com header.i=@h-partners.com header.b=Qg2K+xKC; arc=none smtp.client-ip=113.46.200.219 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=h-partners.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=h-partners.com header.i=@h-partners.com header.b="Qg2K+xKC" dkim-signature: v=1; a=rsa-sha256; d=h-partners.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=RMFOUU7k7mkNvJvM/qymw/jR59axjzjEhPWy9hDZ+t4=; b=Qg2K+xKCvOVeOADnv2/AnDYxY3JAp5Lzb63lgGzkGSz6daXj410i8g+p666JF0Cd6oaAh3i2k 52So2rVIWHkk1yDtRzPx5SBwcRSixMEHZE36weGqeAGYbzteodumnTMm+EqYMOi/XtXbMs7gbuR BtmXwY4e3YJRW5OuHEVNFyw= Received: from mail.maildlp.com (unknown [172.19.162.197]) by canpmsgout04.his.huawei.com (SkyGuard) with ESMTPS id 4gS4Kt0SFGz1prk3; Sat, 30 May 2026 10:43:46 +0800 (CST) Received: from kwepemj100018.china.huawei.com (unknown [7.202.194.12]) by mail.maildlp.com (Postfix) with ESMTPS id DCF6C40569; Sat, 30 May 2026 10:51:35 +0800 (CST) Received: from localhost.localdomain (10.50.163.32) by kwepemj100018.china.huawei.com (7.202.194.12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.36; Sat, 30 May 2026 10:51:35 +0800 From: Xingui Yang To: , , , CC: , , , , , , Subject: [PATCH v5 2/2] scsi: libsas: Add linkrate and sas_addr change detection in rediscover Date: Sat, 30 May 2026 10:49:58 +0800 Message-ID: <20260530024958.3279112-3-yangxingui@huawei.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260530024958.3279112-1-yangxingui@huawei.com> References: <20260530024958.3279112-1-yangxingui@huawei.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: kwepems200002.china.huawei.com (7.221.188.68) To kwepemj100018.china.huawei.com (7.202.194.12) In sas_rediscover_dev(), when detecting a "flutter" condition (same SAS address and compatible device type), the code assumes the device remains unchanged and only handles SATA pending state recovery. However, this approach misses two important scenarios: First, the flutter detection only compares SAS address and device type, ignoring potential linkrate changes that may have already occurred. Second, after sas_ex_phy_discover() re-queries the expander phy, both linkrate and attached SAS address may be updated. The current code does not validate these changes against the existing child device. Additionally, the replace code path (different SAS address detected) has a sysfs duplication issue: sas_unregister_devs_sas_addr() only marks the device as gone, but the actual sysfs cleanup happens later in sas_destruct_devices(). Calling sas_discover_new() immediately after unregister causes sysfs_warn_dup() errors. Introduce sas_dev_is_flutter() to check whether it is a true flutter with validation for linkrate and sas_addr changes. It returns true for normal flutter and false when changes are detected requiring rediscovery. Introduce sas_rediscover_ex_phy() to handle async rediscovery for both flutter and replace cases. When invoked: - Set phy_change_count and ex_change_count to -1 to force revalidation - Unregister the device via sas_unregister_devs_sas_addr() - Queue DISCE_REVALIDATE_DOMAIN event The old device sysfs is cleaned up by sas_destruct_devices() at the end of current revalidation work. The new event triggers discovery via sas_discover_new() since attached_sas_addr is cleared, avoiding the sysfs duplication issue. Signed-off-by: Xingui Yang Suggested-by: John Garry --- drivers/scsi/libsas/sas_expander.c | 71 ++++++++++++++++++++++++------ 1 file changed, 57 insertions(+), 14 deletions(-) diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c index f55ae9a979cd..7246e41aee12 100644 --- a/drivers/scsi/libsas/sas_expander.c +++ b/drivers/scsi/libsas/sas_expander.c @@ -1962,6 +1962,60 @@ static bool dev_type_flutter(enum sas_device_type new, enum sas_device_type old) return false; } +static void sas_rediscover_ex_phy(struct domain_device *dev, int phy_id, + bool last) +{ + struct expander_device *ex = &dev->ex_dev; + struct ex_phy *phy = &ex->ex_phy[phy_id]; + + phy->phy_change_count = -1; + ex->ex_change_count = -1; + sas_unregister_devs_sas_addr(dev, phy_id, last); + sas_discover_event(dev->port, DISCE_REVALIDATE_DOMAIN); +} + +static bool sas_dev_is_flutter(struct domain_device *dev, int phy_id, + u8 *sas_addr, enum sas_device_type type) +{ + struct expander_device *ex = &dev->ex_dev; + struct ex_phy *phy = &ex->ex_phy[phy_id]; + struct domain_device *child_dev; + char *action = ""; + int res; + + if (SAS_ADDR(sas_addr) != SAS_ADDR(phy->attached_sas_addr) || + !dev_type_flutter(type, phy->attached_dev_type)) + return false; + + child_dev = sas_ex_to_dev(dev, phy_id); + if (!child_dev) + goto out; + + res = sas_ex_phy_discover(dev, phy_id); + if (res) + return false; + + if (dev_is_sata(child_dev) && + phy->attached_dev_type == SAS_SATA_PENDING) { + action = ", needs recovery"; + } else if (child_dev->linkrate != phy->linkrate) { + pr_info("ex %016llx phy%02d linkrate changed from %d to %d\n", + SAS_ADDR(dev->sas_addr), phy_id, + child_dev->linkrate, phy->linkrate); + return false; + } else if (SAS_ADDR(child_dev->sas_addr) != SAS_ADDR(phy->attached_sas_addr)) { + pr_info("ex %016llx phy%02d sas_addr changed from %016llx to %016llx\n", + SAS_ADDR(dev->sas_addr), phy_id, + SAS_ADDR(child_dev->sas_addr), + SAS_ADDR(phy->attached_sas_addr)); + return false; + } +out: + pr_debug("ex %016llx phy%02d broadcast flutter%s\n", + SAS_ADDR(dev->sas_addr), phy_id, action); + return true; +} + static int sas_rediscover_dev(struct domain_device *dev, int phy_id, bool last, int sibling) { @@ -2015,27 +2069,16 @@ static int sas_rediscover_dev(struct domain_device *dev, int phy_id, if (res == 0) sas_set_ex_phy(dev, phy_id, disc_resp); goto out_free_resp; - } else if (SAS_ADDR(sas_addr) == SAS_ADDR(phy->attached_sas_addr) && - dev_type_flutter(type, phy->attached_dev_type)) { - struct domain_device *ata_dev = sas_ex_to_ata(dev, phy_id); - char *action = ""; - - sas_ex_phy_discover(dev, phy_id); + } - if (ata_dev && phy->attached_dev_type == SAS_SATA_PENDING) - action = ", needs recovery"; - pr_debug("ex %016llx phy%02d broadcast flutter%s\n", - SAS_ADDR(dev->sas_addr), phy_id, action); + if (sas_dev_is_flutter(dev, phy_id, sas_addr, type)) goto out_free_resp; - } /* we always have to delete the old device when we went here */ pr_info("ex %016llx phy%02d replace %016llx\n", SAS_ADDR(dev->sas_addr), phy_id, SAS_ADDR(phy->attached_sas_addr)); - sas_unregister_devs_sas_addr(dev, phy_id, last); - - res = sas_discover_new(dev, phy_id); + sas_rediscover_ex_phy(dev, phy_id, last); out_free_resp: kfree(disc_resp); return res; -- 2.43.0