From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from canpmsgout09.his.huawei.com (canpmsgout09.his.huawei.com [113.46.200.224]) (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 5951F4477E8; Tue, 18 Aug 2026 09:42:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=113.46.200.224 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787046128; cv=none; b=YDGMX8+wRicW+vcstZy+RBugKhLgLRP5imQG3iOzlvVRYmX/kzuV39INEEslHcfMAhf4hFUX7ZiTTlAPCZ3yVG9l84Ro9syU2GgsWVqEFCTJPqUDHX8pdR4CZ7E/5QRVuD41BSm23hYT+q1eyWTItvI1lJ+iE03yHSpaaZZVwLg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787046128; c=relaxed/simple; bh=OJ8nXTRKS/39+g45AO8X3MsAHcd/a6wcRxPr0gDMcRk=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=RbfBHpM72buMEevsBPh+Jz/iCjHLhPIZgnAnJvRsFDFyb4D8SqZUBRkioyStei5wOGG2LESWjMMo4Q3VuCIigk1oedeTHpYb9J3zFmY50AR5RLu7L3z2UTjSQp0u7yTuCoPUfd21OURY9Nz3ddNpcwfvFcxk8oup9clh3SCm1Bc= 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=JBkXy81A; arc=none smtp.client-ip=113.46.200.224 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="JBkXy81A" dkim-signature: v=1; a=rsa-sha256; d=h-partners.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=Mfk6kC41flOs9S4tTGuDvyDtZ2MtwDDXuUdpCO4Ql1U=; b=JBkXy81AFcwowDScUzPxoX1OcBLb93daI0ko6Nqern7IzFqYKz4iFr+9MRzNMdeABgBMVLPoM zT9xXRizPf+efZUhnIlwKBJdakwJt1G23HVYzgzAYECfTFu+igANKzkoAZ97GNzQScafr6Jiha6 dutklQT3b+fah09Z3+rxYvE= Received: from mail.maildlp.com (unknown [172.19.163.15]) by canpmsgout09.his.huawei.com (SkyGuard) with ESMTPS id 4hPPbC6kQtz1cyTS; Tue, 18 Aug 2026 17:31:19 +0800 (CST) Received: from kwepemp500012.china.huawei.com (unknown [7.202.195.81]) by mail.maildlp.com (Postfix) with ESMTPS id E1E8240586; Tue, 18 Aug 2026 17:41:59 +0800 (CST) Received: from kwepemp500015.china.huawei.com (7.202.195.9) by kwepemp500012.china.huawei.com (7.202.195.81) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.45; Tue, 18 Aug 2026 17:41:59 +0800 Received: from [10.67.120.108] (10.67.120.108) by kwepemp500015.china.huawei.com (7.202.195.9) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.45; Tue, 18 Aug 2026 17:41:59 +0800 Message-ID: Date: Tue, 18 Aug 2026 17:41:58 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.3.1 Subject: Re: [PATCH v10 2/2] scsi: libsas: Add linkrate and sas_addr change detection in rediscover Content-Language: en-CA To: Jason Yan , , , CC: , , , , References: <20260811040334.4184911-1-yangxingui@huawei.com> <20260811040334.4184911-3-yangxingui@huawei.com> <528a4c8f-f061-4879-9547-73eda8db77b0@huawei.com> From: yangxingui In-Reply-To: <528a4c8f-f061-4879-9547-73eda8db77b0@huawei.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: kwepemh500015.china.huawei.com (7.202.181.149) To kwepemp500015.china.huawei.com (7.202.195.9) On 2026/8/14 14:33, Jason Yan wrote: > 在 2026/8/11 12:03, Xingui Yang 写道: >> Introduce sas_dev_is_flutter() and sas_rediscover_ex_phy() to improve >> flutter and device replace detection during rediscovery. >> >> sas_dev_is_flutter() calls sas_ex_phy_discover() before looking up the >> child device via sas_ex_phy_to_dev(), ensuring the PHY state is always >> updated and avoiding use-after-free since the child device pointer is >> obtained after the sleeping SMP request completes. >> >> It adds validation for linkrate and sas_addr changes. When the SAS >> address changes, phy->attached_sas_addr is restored to the original >> address before returning false, so sas_unregister_devs_sas_addr() can >> properly match and unregister the old device. The sas_addr check is >> ordered before the linkrate check to avoid skipping the restoration >> when both change simultaneously. >> >> sas_rediscover_ex_phy() uses the async discovery pattern >> (sas_discover_event) instead of the synchronous sas_discover_new() to >> ensure proper ordering between device unregistration and rediscovery, >> avoiding sysfs_warn_dup() errors. >> >> Signed-off-by: Xingui Yang >> Suggested-by: John Garry >> --- >>   drivers/scsi/libsas/sas_expander.c | 83 +++++++++++++++++++++++++----- >>   1 file changed, 69 insertions(+), 14 deletions(-) >> >> diff --git a/drivers/scsi/libsas/sas_expander.c >> b/drivers/scsi/libsas/sas_expander.c >> index a5c5327cd0dd..811c9eb4fef1 100644 >> --- a/drivers/scsi/libsas/sas_expander.c >> +++ b/drivers/scsi/libsas/sas_expander.c >> @@ -1963,6 +1963,72 @@ 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; >> + >> +    res = sas_ex_phy_discover(dev, phy_id); >> +    if (res) >> +        return false; >> + >> +    child_dev = sas_ex_phy_to_dev(dev, phy_id); >> +    if (!child_dev) >> +        goto out; >> + >> +    if (dev_is_sata(child_dev) && >> +        phy->attached_dev_type == SAS_SATA_PENDING) { >> +        action = ", needs recovery"; >> +        goto out; >> +    } >> + >> +    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)); >> +        /* >> +         * Device unregistering relies on address matching. Restore >> +         * attached_sas_addr back to the original address so that the >> old >> +         * device can be unregistered later >> +         */ >> +        memcpy(phy->attached_sas_addr, child_dev->sas_addr, >> SAS_ADDR_SIZE); >> +        return false; >> +    } >> + >> +    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; >> +    } >> + >> +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) >>   { >> @@ -2016,27 +2082,16 @@ 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 */ > > Please remove this comment since you are not deleting the old device now. Hi, Jason We will call sas_rediscover_ex_phy(dev, phy_id, last) later to delete the old device, and rediscover the device. Thanks, Xingui