Hi Babu, There is an another issue w.r.t non-listed devices (like you tested). The issue is that when the device disappears and reappear, the dh_state file is not created for them. I wanted to send the patch for that also together with this one. That is the reason for delay. chandra On Thu, 2008-10-23 at 08:12 -0600, Moger, Babu wrote: > Hello Chandra, > I have not seen this patch being submitted to mainstream kernel. When are you planning to submit this patch? Should I open a bugzilla for tracking purposes? > > Thanks > Babu Moger > -----Original Message----- > From: Chandra Seetharaman [mailto:sekharan@xxxxxxxxxx] > Sent: Tuesday, October 07, 2008 2:19 PM > To: Moger, Babu > Cc: device-mapper development; linux-scsi@xxxxxxxxxxxxxxx > Subject: RE: failover does not work with rdac device handler > > > Sorry, I sent an imcomplete patch. Here is the correct one. > > BTW, The panic you saw is caused by the line (one of the lines you > added): > > dev = container_of(&scsi_dh_data, struct scsi_device, scsi_dh_data); > > in scsi_dh_release(). We cannot use pointer in a structure to get the > parent structure. > > chandra > > Keep a reference count of attaches, so that same number of detaches are allowed. > ----------- > > Signed-off-by: Chandra Seetharaman <sekharan@xxxxxxxxxx> > --- > Index: linux-2.6.27-rc8-git5/drivers/scsi/device_handler/scsi_dh.c > =================================================================== > --- linux-2.6.27-rc8-git5.orig/drivers/scsi/device_handler/scsi_dh.c > +++ linux-2.6.27-rc8-git5/drivers/scsi/device_handler/scsi_dh.c > @@ -153,12 +153,28 @@ static int scsi_dh_handler_attach(struct > if (sdev->scsi_dh_data) { > if (sdev->scsi_dh_data->scsi_dh != scsi_dh) > err = -EBUSY; > - } else if (scsi_dh->attach) > + else > + kref_get(&sdev->scsi_dh_data->kref); > + } else if (scsi_dh->attach) { > err = scsi_dh->attach(sdev); > + if (!err) { > + kref_init(&sdev->scsi_dh_data->kref); > + sdev->scsi_dh_data->sdev = sdev; > + } > + } > > return err; > } > > +static void scsi_dh_release(struct kref *kref) > +{ > + struct scsi_dh_data *scsi_dh_data; > + scsi_dh_data = container_of(kref, struct scsi_dh_data, kref); > + > + if (scsi_dh_data->scsi_dh && scsi_dh_data->scsi_dh->detach) > + scsi_dh_data->scsi_dh->detach(scsi_dh_data->sdev); > +} > + > /* > * scsi_dh_handler_detach - Detach a device handler from a device > * @sdev - SCSI device the device handler should be detached from > @@ -176,11 +192,7 @@ static void scsi_dh_handler_detach(struc > if (scsi_dh && scsi_dh != sdev->scsi_dh_data->scsi_dh) > return; > > - if (!scsi_dh) > - scsi_dh = sdev->scsi_dh_data->scsi_dh; > - > - if (scsi_dh && scsi_dh->detach) > - scsi_dh->detach(sdev); > + kref_put(&sdev->scsi_dh_data->kref, scsi_dh_release); > } > > /* > Index: linux-2.6.27-rc8-git5/include/scsi/scsi_device.h > =================================================================== > --- linux-2.6.27-rc8-git5.orig/include/scsi/scsi_device.h > +++ linux-2.6.27-rc8-git5/include/scsi/scsi_device.h > @@ -6,6 +6,7 @@ > #include <linux/spinlock.h> > #include <linux/workqueue.h> > #include <linux/blkdev.h> > +#include <linux/kref.h> > #include <scsi/scsi.h> > #include <asm/atomic.h> > > @@ -191,6 +192,8 @@ struct scsi_device_handler { > > struct scsi_dh_data { > struct scsi_device_handler *scsi_dh; > + struct kref kref; > + struct scsi_device *sdev; /* back reference */ > char buf[0]; > }; > > > -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
