search for: vhost_scsi_mutex

We don't need the vhost_scsi_mutex in vhost_scsi_port_link and vhost_scsi_port_unlink because LIO has a refcount on the se_tpg for us, so it can't be removed while these functions are called. This removes the vhost_scsi_mutex from those functions to avoid cases where we are adding or removing LUNs to vhost-deviceA but are stuck...

The following patches were made over Linus tree and also apply over mst tree's vhost branch. The patches fix an issue where management operations like LUN mapping/unmapping and device addition hang for 30 seconds or up to N minutes depending on the device. The problem is that we use a global mutex to protect the list of tpgs but we hold that mutex during those management operations. So if you

...se refcounts and how often the global mutex is used so we don't need to always hold it v2: 1. Added fix for possible use after free and merge with a locking cleanup patch. 2. Added fix for LIO LUN unmap during TMF execution bug. 3. Fixed bug where we needed to hold the tpg mutex instead of the vhost_scsi_mutex when calling vhost_scsi_do_plug.

At this point, vs_tpg is not public at all; tv_tpg_vhost_count is accessed under tpg->tv_tpg_mutex; tpg->vhost_scsi is accessed under vhost_scsi_mutex. Therefor there are no atomic operations involved at all here, just remove the barrier. Reported-by: Andrea Parri <andrea.parri at amarulasolutions.com> Signed-off-by: Paolo Bonzini <pbonzini at redhat.com> --- drivers/vhost/scsi.c | 1 - 1 file changed, 1 deletion(-) diff --git a/d...

...T_SCSI_MAX_TARGET; i++) { > + tpg = vs_tpg[i]; > + if (tpg) { > + tpg->tv_tpg_vhost_count--; > + target_undepend_item(&tpg->se_tpg.tpg_group.cg_item); > + } > + } > + kfree(vs_tpg); > out: > mutex_unlock(&vs->dev.mutex); > mutex_unlock(&vhost_scsi_mutex); > @@ -1549,6 +1653,12 @@ static void vhost_scsi_flush(struct vhost_scsi *vs) > mutex_lock(&vq->mutex); > vhost_vq_set_backend(vq, NULL); > mutex_unlock(&vq->mutex); > + /* > + * Make sure cmds are not running before tearing them > + * down. &...