- Broaden the scope of locking in aac_command_thread() again to catch some

  edge cases in the loop.

- Try to grab a command before dequeueing the bio from the bioq.  The old
  behaviour of requeuing deferred bios to the end of the bioq is arguably
  wrong.  This should be fixed in the future to check the bioq head without
  automatically dequeueing the bio.

1 files changed, 17 insertions, 11 deletions

diff --git a/sys/dev/aac/aac.c b/sys/dev/aac/aac.c
index 9d6e115bfdfd..b799808eac70 100644
--- a/sys/dev/aac/aac.c
+++ b/sys/dev/aac/aac.c
@@ -632,7 +632,7 @@ aac_intr(void *arg)
 
 		/*
 		 * This might miss doing the actual wakeup.  However, the
-		 * tsleep that this is waking up has a timeout, so it will
+		 * msleep that this is waking up has a timeout, so it will
 		 * wake up eventually.  AIFs and printfs are low enough
 		 * priority that they can handle hanging out for a few seconds
 		 * if needed.
@@ -731,11 +731,15 @@ aac_command_thread(struct aac_softc *sc)
 
 	debug_called(2);
 
-	sc->aifflags |= AAC_AIFFLAGS_RUNNING;
+	AAC_LOCK_ACQUIRE(&sc->aac_io_lock);
+	sc->aifflags = AAC_AIFFLAGS_RUNNING;
+
+	while ((sc->aifflags & AAC_AIFFLAGS_EXIT) == 0) {
 
-	while (!(sc->aifflags & AAC_AIFFLAGS_EXIT)) {
-		retval = tsleep(sc->aifthread, PRIBIO, "aifthd",
-				AAC_PERIODIC_INTERVAL * hz);
+		retval = 0;
+		if ((sc->aifflags & AAC_AIFFLAGS_PENDING) == 0)
+			retval = msleep(sc->aifthread, &sc->aac_io_lock, PRIBIO,
+					"aifthd", AAC_PERIODIC_INTERVAL * hz);
 
 		/*
 		 * First see if any FIBs need to be allocated.  This needs
@@ -743,12 +747,13 @@ aac_command_thread(struct aac_softc *sc)
 		 * will grab Giant, and would result in an LOR.
 		 */
 		if ((sc->aifflags & AAC_AIFFLAGS_ALLOCFIBS) != 0) {
-			aac_alloc_commands(sc);
 			sc->aifflags &= ~AAC_AIFFLAGS_ALLOCFIBS;
+			AAC_LOCK_RELEASE(&sc->aac_io_lock);
+			aac_alloc_commands(sc);
+			AAC_LOCK_ACQUIRE(&sc->aac_io_lock);
+			aac_startio(sc);
 		}
 
-		AAC_LOCK_ACQUIRE(&sc->aac_io_lock);
-
 		/*
 		 * While we're here, check to see if any commands are stuck.
 		 * This is pretty low-priority, so it's ok if it doesn't
@@ -802,9 +807,9 @@ aac_command_thread(struct aac_softc *sc)
 						     fib);
 			}
 		}
-		AAC_LOCK_RELEASE(&sc->aac_io_lock);
 	}
 	sc->aifflags &= ~AAC_AIFFLAGS_RUNNING;
+	AAC_LOCK_RELEASE(&sc->aac_io_lock);
 	wakeup(sc->aac_dev);
 
 	mtx_lock(&Giant);
@@ -896,10 +901,11 @@ aac_bio_command(struct aac_softc *sc, struct aac_command **cmp)
 
 	/* get the resources we will need */
 	cm = NULL;
-	if ((bp = aac_dequeue_bio(sc)) == NULL)
-		goto fail;
+	bp = NULL;
 	if (aac_alloc_command(sc, &cm))	/* get a command */
 		goto fail;
+	if ((bp = aac_dequeue_bio(sc)) == NULL)
+		goto fail;
 
 	/* fill out the command */
 	cm->cm_data = (void *)bp->bio_data;