On 12/14/2017 11:11 AM, Hannes Reinecke wrote:
Implement the 'rescan' virtio-scsi feature. Rescanning works by
sending a 'rescan' virtio-scsi command with the next requested
target id to the backend. The backend will respond with the next
used target id or '-1' if no more targets are found.
This avoids scanning all possible targets.
Signed-off-by: Hannes Reinecke <hare@xxxxxxxx>
---
drivers/scsi/virtio_scsi.c | 239 ++++++++++++++++++++++++++++++++++++++-
include/uapi/linux/virtio_scsi.h | 15 +++
2 files changed, 250 insertions(+), 4 deletions(-)
diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index 7c28e8d..a561e90 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
+static void virtscsi_rescan_work(struct work_struct *work)
+{
+ if (target_id == -1) {
+ shost_printk(KERN_INFO, sh, "rescan: terminated\n");
+ spin_unlock_irq(&vscsi->rescan_lock);
+ return;
+ }
+ spin_unlock_irq(&vscsi->rescan_lock);
+
+ cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
+ if (!cmd) {
+ shost_printk(KERN_INFO, sh, "rescan: no memory\n");
+ goto scan_host;
+ }
+ shost_printk(KERN_INFO, sh, "rescan: next target %d\n", target_id);
+ shost_printk(KERN_INFO, sh,
+ "rescan: no more targets\n");
+ shost_printk(KERN_INFO, sh, "rescan: scan host\n");
+ scsi_scan_host(sh);
+}
+
+static void virtscsi_scan_host(struct virtio_scsi *vscsi)
+{
+ struct Scsi_Host *sh = virtio_scsi_host(vscsi->vdev);
+ int ret;
+ struct virtio_scsi_cmd *cmd;
+ DECLARE_COMPLETION_ONSTACK(comp);
+
+ cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
+ if (!cmd) {
+ shost_printk(KERN_INFO, sh, "rescan: no memory\n");
If shost_printk does not add any info about calling function, this
cannot be distinguished from a message with the same format string above
in virtscsi_rescan_work()?
+ return;
+ }
+ shost_printk(KERN_INFO, sh, "rescan: scan host\n");
dito
+static void virtscsi_scan_start(struct Scsi_Host *sh)
+{
+ struct virtio_scsi *vscsi = shost_priv(sh);
+
+ virtscsi_scan_host(vscsi);
+ spin_lock_irq(&vscsi->rescan_lock);
+ if (vscsi->next_target_id != -1) {
+ shost_printk(KERN_INFO, sh, "rescan: already running\n");
+ spin_unlock_irq(&vscsi->rescan_lock);
+ return;
+ }
+ vscsi->next_target_id = 0;
+ shost_printk(KERN_INFO, sh, "rescan: start\n");
+ spin_unlock_irq(&vscsi->rescan_lock);
+ queue_work(system_freezable_wq, &vscsi->rescan_work);
+}
+
+int virtscsi_scan_finished(struct Scsi_Host *sh, unsigned long time)
+ shost_printk(KERN_INFO, sh, "rescan: %s finished\n",
+ ret ? "" : "not");
+ return ret;
+}
--
Mit freundlichen Grüßen / Kind regards
Steffen Maier
Linux on z Systems Development
IBM Deutschland Research & Development GmbH
Vorsitzende des Aufsichtsrats: Martina Koederitz
Geschaeftsfuehrung: Dirk Wittkopp
Sitz der Gesellschaft: Boeblingen
Registergericht: Amtsgericht Stuttgart, HRB 243294
