* [patch] libsas: dereferencing variable before check @ 2010-05-12 22:56 Dan Carpenter 2010-05-12 23:08 ` Tejun Heo 0 siblings, 1 reply; 5+ messages in thread From: Dan Carpenter @ 2010-05-12 22:56 UTC (permalink / raw) To: James E.J. Bottomley; +Cc: Tejun Heo, linux-scsi, linux-kernel The "qc->scsicmd" could be null so I moved the dereference inside the check. This was introduced by 70b25f890: "[SCSI] fix locking around blk_abort_request()" Signed-off-by: Dan Carpenter <error27@gmail.com> diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c index 88f7446..98b1545 100644 --- a/drivers/scsi/libsas/sas_ata.c +++ b/drivers/scsi/libsas/sas_ata.c @@ -395,12 +395,13 @@ int sas_ata_init_host_and_port(struct domain_device *found_dev, void sas_ata_task_abort(struct sas_task *task) { struct ata_queued_cmd *qc = task->uldd_task; - struct request_queue *q = qc->scsicmd->device->request_queue; + struct request_queue *q; struct completion *waiting; unsigned long flags; /* Bounce SCSI-initiated commands to the SCSI EH */ if (qc->scsicmd) { + q = qc->scsicmd->device->request_queue; spin_lock_irqsave(q->queue_lock, flags); blk_abort_request(qc->scsicmd->request); spin_unlock_irqrestore(q->queue_lock, flags); ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [patch] libsas: dereferencing variable before check 2010-05-12 22:56 [patch] libsas: dereferencing variable before check Dan Carpenter @ 2010-05-12 23:08 ` Tejun Heo 2010-05-13 14:31 ` James Bottomley 0 siblings, 1 reply; 5+ messages in thread From: Tejun Heo @ 2010-05-12 23:08 UTC (permalink / raw) To: Dan Carpenter, James E.J. Bottomley; +Cc: linux-scsi, linux-kernel "Dan Carpenter" <error27@gmail.com> wrote: >The "qc->scsicmd" could be null so I moved the dereference inside the >check. This was introduced by 70b25f890: "[SCSI] fix locking around >blk_abort_request()" > >Signed-off-by: Dan Carpenter <error27@gmail.com> Ooh.. right. Asked-by: Tejun Heo <tj@kernel.org> Thanks. -- tejun ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [patch] libsas: dereferencing variable before check 2010-05-12 23:08 ` Tejun Heo @ 2010-05-13 14:31 ` James Bottomley 2010-05-13 14:37 ` Tejun Heo 2010-05-13 18:42 ` Dan Carpenter 0 siblings, 2 replies; 5+ messages in thread From: James Bottomley @ 2010-05-13 14:31 UTC (permalink / raw) To: Tejun Heo; +Cc: Dan Carpenter, linux-scsi, linux-kernel On Thu, 2010-05-13 at 01:08 +0200, Tejun Heo wrote: > > "Dan Carpenter" <error27@gmail.com> wrote: > > >The "qc->scsicmd" could be null so I moved the dereference inside the > >check. This was introduced by 70b25f890: "[SCSI] fix locking around > >blk_abort_request()" > > > >Signed-off-by: Dan Carpenter <error27@gmail.com> > > Ooh.. right. > > Asked-by: Tejun Heo <tj@kernel.org> Well, oops, yes. Two patches to fix one bug is a bit overboard, I think, plus some code rearrangement to fix the locality of the problem and ensure it doesn't happen again might be useful. What about this. James --- diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c index 88f7446..8c496b5 100644 --- a/drivers/scsi/libsas/sas_ata.c +++ b/drivers/scsi/libsas/sas_ata.c @@ -395,12 +395,13 @@ int sas_ata_init_host_and_port(struct domain_device *found_dev, void sas_ata_task_abort(struct sas_task *task) { struct ata_queued_cmd *qc = task->uldd_task; - struct request_queue *q = qc->scsicmd->device->request_queue; struct completion *waiting; - unsigned long flags; /* Bounce SCSI-initiated commands to the SCSI EH */ if (qc->scsicmd) { + struct request_queue *q = qc->scsicmd->device->request_queue; + unsigned long flags; + spin_lock_irqsave(q->queue_lock, flags); blk_abort_request(qc->scsicmd->request); spin_unlock_irqrestore(q->queue_lock, flags); diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c index 8228350..53849f2 100644 --- a/drivers/scsi/libsas/sas_scsi_host.c +++ b/drivers/scsi/libsas/sas_scsi_host.c @@ -1030,8 +1030,6 @@ int __sas_task_abort(struct sas_task *task) void sas_task_abort(struct sas_task *task) { struct scsi_cmnd *sc = task->uldd_task; - struct request_queue *q = sc->device->request_queue; - unsigned long flags; /* Escape for libsas internal commands */ if (!sc) { @@ -1043,13 +1041,15 @@ void sas_task_abort(struct sas_task *task) if (dev_is_sata(task->dev)) { sas_ata_task_abort(task); - return; - } + } else { + struct request_queue *q = sc->device->request_queue; + unsigned long flags; - spin_lock_irqsave(q->queue_lock, flags); - blk_abort_request(sc->request); - spin_unlock_irqrestore(q->queue_lock, flags); - scsi_schedule_eh(sc->device->host); + spin_lock_irqsave(q->queue_lock, flags); + blk_abort_request(sc->request); + spin_unlock_irqrestore(q->queue_lock, flags); + scsi_schedule_eh(sc->device->host); + } } int sas_slave_alloc(struct scsi_device *scsi_dev) ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [patch] libsas: dereferencing variable before check 2010-05-13 14:31 ` James Bottomley @ 2010-05-13 14:37 ` Tejun Heo 2010-05-13 18:42 ` Dan Carpenter 1 sibling, 0 replies; 5+ messages in thread From: Tejun Heo @ 2010-05-13 14:37 UTC (permalink / raw) To: James Bottomley; +Cc: Dan Carpenter, linux-scsi, linux-kernel Hello, On 05/13/2010 04:31 PM, James Bottomley wrote: >> Ooh.. right. >> >> Asked-by: Tejun Heo <tj@kernel.org> That was my first mail from android and of course I typed Asked instead of Acked. :-) > Well, oops, yes. Two patches to fix one bug is a bit overboard, I > think, plus some code rearrangement to fix the locality of the problem > and ensure it doesn't happen again might be useful. What about this. Yeap, as long as the silly bug is fixed. Thank you. -- tejun ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [patch] libsas: dereferencing variable before check 2010-05-13 14:31 ` James Bottomley 2010-05-13 14:37 ` Tejun Heo @ 2010-05-13 18:42 ` Dan Carpenter 1 sibling, 0 replies; 5+ messages in thread From: Dan Carpenter @ 2010-05-13 18:42 UTC (permalink / raw) To: James Bottomley; +Cc: Tejun Heo, linux-scsi, linux-kernel On Thu, May 13, 2010 at 09:31:54AM -0500, James Bottomley wrote: > On Thu, 2010-05-13 at 01:08 +0200, Tejun Heo wrote: > > > > "Dan Carpenter" <error27@gmail.com> wrote: > > > > >The "qc->scsicmd" could be null so I moved the dereference inside the > > >check. This was introduced by 70b25f890: "[SCSI] fix locking around > > >blk_abort_request()" > > > > > >Signed-off-by: Dan Carpenter <error27@gmail.com> > > > > Ooh.. right. > > > > Asked-by: Tejun Heo <tj@kernel.org> > > Well, oops, yes. Two patches to fix one bug is a bit overboard, I > think, plus some code rearrangement to fix the locality of the problem > and ensure it doesn't happen again might be useful. What about this. > Looks good. Acked-by: Dan Carpenter <error27@gmail.com> regards, dan carpenter ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2010-05-13 18:42 UTC | newest] Thread overview: 5+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2010-05-12 22:56 [patch] libsas: dereferencing variable before check Dan Carpenter 2010-05-12 23:08 ` Tejun Heo 2010-05-13 14:31 ` James Bottomley 2010-05-13 14:37 ` Tejun Heo 2010-05-13 18:42 ` Dan Carpenter
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).