From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Re: [PATCH v8 09/13] libsas: enforce eh strategy handlers only in eh context Date: Wed, 29 Feb 2012 16:05:51 -0600 Message-ID: <1330553151.8846.26.camel@dabdike> References: <20120210084411.25701.94502.stgit@dwillia2-linux.jf.intel.com> <20120210084525.25701.51128.stgit@dwillia2-linux.jf.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from bedivere.hansenpartnership.com ([66.63.167.143]:47867 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964851Ab2B2WFx (ORCPT ); Wed, 29 Feb 2012 17:05:53 -0500 In-Reply-To: <20120210084525.25701.51128.stgit@dwillia2-linux.jf.intel.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Dan Williams Cc: linux-scsi@vger.kernel.org, linux-ide@vger.kernel.org On Fri, 2012-02-10 at 00:45 -0800, Dan Williams wrote: > The strategy handlers may be called in places that are problematic for > libsas (i.e. sata resets outside of domain revalidation filtering / > libata link recovery), or problematic for userspace (non-blocking ioctl > to sleeping reset functions). However, these routines are also called > for eh escalations and recovery of scsi_eh_prep_cmnd(), so permit them > as long as we are running in the host's error handler. > > Signed-off-by: Dan Williams > --- > drivers/scsi/libsas/sas_scsi_host.c | 15 +++++++++++---- > 1 files changed, 11 insertions(+), 4 deletions(-) > > diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c > index f0b9b7b..1cabedc 100644 > --- a/drivers/scsi/libsas/sas_scsi_host.c > +++ b/drivers/scsi/libsas/sas_scsi_host.c > @@ -463,11 +463,14 @@ EXPORT_SYMBOL_GPL(sas_get_local_phy); > /* Attempt to send a LUN reset message to a device */ > int sas_eh_device_reset_handler(struct scsi_cmnd *cmd) > { > - struct domain_device *dev = cmd_to_domain_dev(cmd); > - struct sas_internal *i = > - to_sas_internal(dev->port->ha->core.shost->transportt); > - struct scsi_lun lun; > int res; > + struct scsi_lun lun; > + struct Scsi_Host *host = cmd->device->host; > + struct domain_device *dev = cmd_to_domain_dev(cmd); > + struct sas_internal *i = to_sas_internal(host->transportt); > + > + if (current != host->ehandler) > + return FAILED; Doing this will ensure that SG_SCSI_RESET now fails. I don't mind checking for O_NONBLOCK in the sg handler and failing if it is, but disallowing everything looks a trifle drastic. James