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Bottomley" , "Martin K. Petersen" , xen-devel@lists.xenproject.org, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] scsi: xen-scsifront: add error handling for xenbus_printf Date: Fri, 15 Jun 2018 00:08:34 +0800 Message-Id: <1528992514-53963-1-git-send-email-jiazhouyang09@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1528774962-39173-1-git-send-email-jiazhouyang09@gmail.com> References: <1528774962-39173-1-git-send-email-jiazhouyang09@gmail.com> To: unlisted-recipients:; (no To-header on input) Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP When xenbus_printf fails, the lack of error-handling code may cause unexpected results. This patch adds error-handling code after calling xenbus_printf. Signed-off-by: Zhouyang Jia --- v1->v2: - Fix dereferencing before checking --- drivers/scsi/xen-scsifront.c | 29 ++++++++++++++++++++++------- 1 file changed, 22 insertions(+), 7 deletions(-) diff --git a/drivers/scsi/xen-scsifront.c b/drivers/scsi/xen-scsifront.c index 36f59a1..a7f6111 100644 --- a/drivers/scsi/xen-scsifront.c +++ b/drivers/scsi/xen-scsifront.c @@ -654,10 +654,16 @@ static int scsifront_dev_reset_handler(struct scsi_cmnd *sc) static int scsifront_sdev_configure(struct scsi_device *sdev) { struct vscsifrnt_info *info = shost_priv(sdev->host); + int err; - if (info && current == info->curr) - xenbus_printf(XBT_NIL, info->dev->nodename, + if (info && current == info->curr) { + err = xenbus_printf(XBT_NIL, info->dev->nodename, info->dev_state_path, "%d", XenbusStateConnected); + if (err) { + dev_err(&info->dev->dev, "writing dev_state_path\n"); + return err; + } + } return 0; } @@ -665,10 +671,14 @@ static int scsifront_sdev_configure(struct scsi_device *sdev) static void scsifront_sdev_destroy(struct scsi_device *sdev) { struct vscsifrnt_info *info = shost_priv(sdev->host); + int err; - if (info && current == info->curr) - xenbus_printf(XBT_NIL, info->dev->nodename, + if (info && current == info->curr) { + err = xenbus_printf(XBT_NIL, info->dev->nodename, info->dev_state_path, "%d", XenbusStateClosed); + if (err) + dev_err(&info->dev->dev, "writing dev_state_path\n"); + } } static struct scsi_host_template scsifront_sht = { @@ -1003,9 +1013,11 @@ static void scsifront_do_lun_hotplug(struct vscsifrnt_info *info, int op) if (scsi_add_device(info->host, chn, tgt, lun)) { dev_err(&dev->dev, "scsi_add_device\n"); - xenbus_printf(XBT_NIL, dev->nodename, + err = xenbus_printf(XBT_NIL, dev->nodename, info->dev_state_path, "%d", XenbusStateClosed); + if (err) + dev_err(&dev->dev, "writing dev_state_path\n"); } break; case VSCSIFRONT_OP_DEL_LUN: @@ -1019,10 +1031,13 @@ static void scsifront_do_lun_hotplug(struct vscsifrnt_info *info, int op) } break; case VSCSIFRONT_OP_READD_LUN: - if (device_state == XenbusStateConnected) - xenbus_printf(XBT_NIL, dev->nodename, + if (device_state == XenbusStateConnected) { + err = xenbus_printf(XBT_NIL, dev->nodename, info->dev_state_path, "%d", XenbusStateConnected); + if (err) + dev_err(&dev->dev, "writing dev_state_path\n"); + } break; default: break;