Re: [PATCH 4/8] vhost scsi: fix cmd completion race
From: Bart Van Assche <bvanassche@acm.org>
Date: 2020-09-22 02:51:20
Also in:
linux-scsi, target-devel
From: Bart Van Assche <bvanassche@acm.org>
Date: 2020-09-22 02:51:20
Also in:
linux-scsi, target-devel
On 2020-09-21 19:48, Bart Van Assche wrote:
On 2020-09-21 11:23, Mike Christie wrote:quoted
We might not do the final se_cmd put from vhost_scsi_complete_cmd_work. If the last put happens a little later then we could race where vhost_scsi_complete_cmd_work does vhost_signal, the guest runs and sends more IO, and vhost_scsi_handle_vq runs but does not find any free cmds. This patch has us delay completing the cmd until the last lio core ref is dropped. We then know that once we signal to the guest that the cmd is completed that if it queues a new command it will find a free cmd.It seems weird to me to see a reference to LIO in the description of a vhost patch? Since this driver supports more backends than LIO, shouldn't the patch description be made more generic?
Please ignore the above comment. Bart. _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization