| Message ID | 1443047877-16929-1-git-send-email-johnzzpcrystal@gmail.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c index 207d6a7..5251d6d 100644 --- a/drivers/scsi/scsi.c +++ b/drivers/scsi/scsi.c @@ -1118,6 +1118,8 @@ struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost, struct scsi_device *sdev; list_for_each_entry(sdev, &shost->__devices, siblings) { + if (sdev->sdev_state == SDEV_DEL) + continue; if (sdev->channel == channel && sdev->id == id && sdev->lun ==lun) return sdev;
when a scsi_device is unpluged from scsi controller, if the scsi_device is still be used by application layer,it won't be released until users release it. In this case, scsi_device_remove just set the scsi_device's state to be SDEV_DEL. But if you plug the disk just before the old scsi_device is released, then there will be two scsi_device structures in scsi_host->__devices. when the next unpluging event happens,some low-level drivers will check whether the scsi_device has been added to host (for example, the megaraid sas series controller) by calling scsi_device_lookup(call __scsi_device_lookup). __scsi_device_lookup will return the first scsi_device. Because its state is SDEV_DEL, the scsi_device_lookup will return NULL finally, making the low-level driver assume that the scsi_device has been removed,and won't call scsi_device_remove,which will lead the failure of hot swap. Signed-off-by: Zhengping Zhou <johnzzpcrystal@gmail.com> --- Hi all: I find a bug about the failure of hot swap when I am using megaraid sas series controller. Finally I have found that when controller receives the event of hot swap, it will firstly check whether the device is added to the system/host by calling scsi_device_lookup.The logics in function megasas_aen_polling is as follows: case MR_EVT_PD_REMOVED: if (megasas_get_pd_list(instance) == 0) { for (i = 0; i < MEGASAS_MAX_PD_CHANNELS; i++) { for (j = 0; j < MEGASAS_MAX_DEV_PER_CHANNEL; j++) { pd_index = (i * MEGASAS_MAX_DEV_PER_CHANNEL) + j; sdev1 = scsi_device_lookup(host, i, j, 0); if (instance->pd_list[pd_index].driveState == MR_PD_STATE_SYSTEM) { if (sdev1) scsi_device_put(sdev1); } else { if (sdev1) { scsi_remove_device(sdev1); scsi_device_put(sdev1); } } } } } If the previous scsi_device is not released, this will lead the appearance of two scsi_devices which correspond with the same disk. And when the disk is unpluged afterwards, the controller will assume that this disk has never been added into the system/host. Thus it won't call scsi_device_remove. When I finish this modification, this problem is fixed.So far, I have successfully test PCI_DEVICE_ID_LSI_SAS0073SKINNY and PCI_DEVICE_ID_LSI_FURY. Thanks Zhengping --- drivers/scsi/scsi.c | 2 ++ 1 file changed, 2 insertions(+)