[Qemu-devel] [PATCH 1/7] scsi-generic: Handle queue full

[Hannes Reinecke]

The sg driver currently has a hardcoded limit of commands it
can handle simultaneously. When this limit is reached the
driver will return -EDOM. So we need to capture this to
enable proper return values here.
And we shouldn't forget we're using linux-style status codes,
which are shift by one.

Signed-off-by: Hannes Reinecke <address@hidden>
---
 hw/scsi-generic.c |   20 +++++++++++++-------
 1 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/hw/scsi-generic.c b/hw/scsi-generic.c
index 6c58742..af76826 100644
--- a/hw/scsi-generic.c
+++ b/hw/scsi-generic.c
@@ -96,13 +96,19 @@ static void scsi_command_complete(void *opaque, int ret)
         s->senselen = r->io_header.sb_len_wr;
 
     if (ret != 0) {
-        scsi_req_print(&r->req);
-        fprintf(stderr, "%s: ret %d (%s)\n", __FUNCTION__,
-                ret, strerror(-ret));
-        s->senselen = scsi_build_sense(SENSE_CODE(INVALID_FIELD),
-                                      s->sensebuf, SCSI_SENSE_BUF_SIZE, 0);
-        s->driver_status = SG_ERR_DRIVER_SENSE;
-        r->req.status = CHECK_CONDITION;
+       if (ret == -EDOM) {
+           /* sg driver uses EDOM to signal queue busy */
+           fprintf(stderr, "%s: sg queue busy\n", __FUNCTION__);
+           r->req.status = QUEUE_FULL << 1;
+       } else {
+           scsi_req_print(&r->req);
+           fprintf(stderr, "%s: ret %d (%s)\n", __FUNCTION__,
+                   ret, strerror(-ret));
+           s->senselen = scsi_build_sense(SENSE_CODE(INVALID_FIELD),
+                                          s->sensebuf, SCSI_SENSE_BUF_SIZE, 0);
+           s->driver_status = SG_ERR_DRIVER_SENSE;
+           r->req.status = CHECK_CONDITION << 1;
+       }
     } else {
         if (s->driver_status & SG_ERR_DRIVER_TIMEOUT) {
             scsi_req_print(&r->req);
-- 
1.6.6.1