Problem reported: http://marc.info/?l=dm-devel&m=124585978305866&w=2 This patch fixes the problem: ----------------- scsi_dh does not do a refernce count for attach/detach, and this affects the way it is supposed to work with multipath when a device is not in the dev_list of the hardware handler. This patch adds a reference count that counts each attach. Signed-Off-by: Chandra Seetharaman <sekharan@xxxxxxxxxx> --- drivers/scsi/device_handler/scsi_dh.c | 23 ++++++++++++++++------- include/scsi/scsi_device.h | 2 ++ 2 files changed, 18 insertions(+), 7 deletions(-) Index: linux-2.6.31-rc1/include/scsi/scsi_device.h =================================================================== --- linux-2.6.31-rc1.orig/include/scsi/scsi_device.h +++ linux-2.6.31-rc1/include/scsi/scsi_device.h @@ -191,6 +191,8 @@ struct scsi_device_handler { struct scsi_dh_data { struct scsi_device_handler *scsi_dh; + struct scsi_device *sdev; + struct kref kref; char buf[0]; }; Index: linux-2.6.31-rc1/drivers/scsi/device_handler/scsi_dh.c =================================================================== --- linux-2.6.31-rc1.orig/drivers/scsi/device_handler/scsi_dh.c +++ linux-2.6.31-rc1/drivers/scsi/device_handler/scsi_dh.c @@ -153,12 +153,24 @@ 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 __detach_handler (struct kref *kref) +{ + struct scsi_dh_data *scsi_dh_data = container_of(kref, struct scsi_dh_data, kref); + 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 @@ -180,7 +192,7 @@ static void scsi_dh_handler_detach(struc 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, __detach_handler); } /* @@ -474,7 +486,6 @@ int scsi_dh_attach(struct request_queue if (!err) { err = scsi_dh_handler_attach(sdev, scsi_dh); - put_device(&sdev->sdev_gendev); } return err; @@ -505,10 +516,8 @@ void scsi_dh_detach(struct request_queue return; if (sdev->scsi_dh_data) { - /* if sdev is not on internal list, detach */ scsi_dh = sdev->scsi_dh_data->scsi_dh; - if (!device_handler_match(scsi_dh, sdev)) - scsi_dh_handler_detach(sdev, scsi_dh); + scsi_dh_handler_detach(sdev, scsi_dh); } put_device(&sdev->sdev_gendev); } -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
