From mboxrd@z Thu Jan 1 00:00:00 1970 From: wangyijing Subject: Re: [PATCH v2 1/2] libsas: Don't process sas events in static works Date: Wed, 14 Jun 2017 17:28:34 +0800 Message-ID: <594101C2.702@huawei.com> References: <1497425597-18799-1-git-send-email-wangyijing@huawei.com> <1497425597-18799-2-git-send-email-wangyijing@huawei.com> <692abe7a-149f-c1bf-5f28-3e36cad81b5a@suse.de> <5940FC1C.5050000@huawei.com> <3c713ab7-c958-ab1a-0a12-cdd5e876e845@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <3c713ab7-c958-ab1a-0a12-cdd5e876e845@suse.de> Sender: linux-kernel-owner@vger.kernel.org To: Johannes Thumshirn , jejb@linux.vnet.ibm.com, martin.petersen@oracle.com Cc: chenqilin2@huawei.com, hare@suse.com, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, chenxiang66@hisilicon.com, huangdaode@hisilicon.com, wangkefeng.wang@huawei.com, zhaohongjiang@huawei.com, dingtianhong@huawei.com, guohanjun@huawei.com, yanaijie@huawei.com, hch@lst.de, dan.j.williams@intel.com, emilne@redhat.com, thenzl@redhat.com, wefu@redhat.com, charles.chenxin@huawei.com, chenweilong@huawei.com, Yousong He List-Id: linux-scsi@vger.kernel.org 在 2017/6/14 17:18, Johannes Thumshirn 写道: > On 06/14/2017 11:04 AM, wangyijing wrote: >>>> static void notify_ha_event(struct sas_ha_struct *sas_ha, enum ha_event event) >>>> { >>>> + struct sas_ha_event *ev; >>>> + >>>> BUG_ON(event >= HA_NUM_EVENTS); >>>> >>>> - sas_queue_event(event, &sas_ha->pending, >>>> - &sas_ha->ha_events[event].work, sas_ha); >>>> + ev = kzalloc(sizeof(*ev), GFP_ATOMIC); >>>> + if (!ev) >>>> + return; >>> GFP_ATOMIC allocations can fail and then no events will be queued *and* we >>> don't report the error back to the caller. >>> >> >> Yes, it's really a problem, but I don't find a better solution, do you have some suggestion ? > > Something like this? > > diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c > b/drivers/scsi/hisi_sas/hisi_sas_main.c > index d622db502ec9..27cd7307d308 100644 > --- a/drivers/scsi/hisi_sas/hisi_sas_main.c > +++ b/drivers/scsi/hisi_sas/hisi_sas_main.c > @@ -894,7 +894,11 @@ static int hisi_sas_controller_reset(struct > hisi_hba *hisi_hba) > hisi_sas_release_tasks(hisi_hba); > spin_unlock_irqrestore(&hisi_hba->lock, flags); > > - sas_ha->notify_ha_event(sas_ha, HAE_RESET); > + rc = sas_ha->notify_ha_event(sas_ha, HAE_RESET); > + if (rc) { > + dev_warn(dev, "failed to queue HA event (%d)\n", > rc); > + goto out; > + } > dev_dbg(dev, "controller reset successful!\n"); > } else > return -1; > diff --git a/drivers/scsi/libsas/sas_event.c > b/drivers/scsi/libsas/sas_event.c > index aadbd5314c5c..6c91fb31f891 100644 > --- a/drivers/scsi/libsas/sas_event.c > +++ b/drivers/scsi/libsas/sas_event.c > @@ -116,7 +116,7 @@ void sas_enable_revalidation(struct sas_ha_struct *ha) > mutex_unlock(&ha->disco_mutex); > } > > -static void notify_ha_event(struct sas_ha_struct *sas_ha, enum ha_event > event) > +static int notify_ha_event(struct sas_ha_struct *sas_ha, enum ha_event > event) > { > BUG_ON(event >= HA_NUM_EVENTS); > > diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h > index dd0f72c95abe..5d9cd6d20855 100644 > --- a/include/scsi/libsas.h > +++ b/include/scsi/libsas.h > @@ -415,7 +415,7 @@ struct sas_ha_struct { > * their siblings when forming wide ports */ > > /* LLDD calls these to notify the class of an event. */ > - void (*notify_ha_event)(struct sas_ha_struct *, enum ha_event); > + int (*notify_ha_event)(struct sas_ha_struct *, enum ha_event); > void (*notify_port_event)(struct asd_sas_phy *, enum port_event); > void (*notify_phy_event)(struct asd_sas_phy *, enum phy_event); This make sense, return a fail status and report it to the callers. > >