Hi, Can you try the attached patch. chandra PS: I see a problem (not related to this patch) that the dh_state file is not getting recreated, still working on it. ------------- 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 +153,26 @@ 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); + } 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(sdev); +} + /* * scsi_dh_handler_detach - Detach a device handler from a device * @sdev - SCSI device the device handler should be detached from @@ -176,11 +190,7 @@ 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 @@ -191,6 +191,7 @@ struct scsi_device_handler { struct scsi_dh_data { struct scsi_device_handler *scsi_dh; + struct kref kref; char buf[0]; }; -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel