svn commit: r307691 - head/sys/geom/mirror

[Mark Johnston]

Author: markj
Date: Thu Oct 20 23:02:30 2016
New Revision: 307691
URL: https://svnweb.freebsd.org/changeset/base/307691

Log:
  gmirror: Release pending regular requests when synchronization stops.
  
  Normally gmirror allows colliding requests to proceed whenever a
  synchronization request completes and advances to the next offset. However
  if an I/O request collides with one of the final g_mirror_syncreqs, nothing
  releases it once synchronization completes, resulting in an apparent I/O
  hang. The same problem can occur if synchronization is aborted by an
  I/O error. Therefore, be sure to requeue pending requests when
  mirror synchronization is stopped for any reason.
  
  While here, remove some dead code from g_mirror_regular_release().
  
  MFC after:	2 weeks
  Sponsored by:	Dell EMC Isilon

Modified:
  head/sys/geom/mirror/g_mirror.c

Modified: head/sys/geom/mirror/g_mirror.c
==============================================================================
--- head/sys/geom/mirror/g_mirror.c	Thu Oct 20 21:29:59 2016	(r307690)
+++ head/sys/geom/mirror/g_mirror.c	Thu Oct 20 23:02:30 2016	(r307691)
@@ -1252,13 +1252,6 @@ g_mirror_regular_release(struct g_mirror
 		G_MIRROR_LOGREQ(2, bp, "Releasing delayed request (%p).", bp);
 		mtx_lock(&sc->sc_queue_mtx);
 		bioq_insert_head(&sc->sc_queue, bp);
-#if 0
-		/*
-		 * wakeup() is not needed, because this function is called from
-		 * the worker thread.
-		 */
-		wakeup(&sc->sc_queue);
-#endif
 		mtx_unlock(&sc->sc_queue_mtx);
 	}
 }
@@ -2065,6 +2058,7 @@ g_mirror_sync_stop(struct g_mirror_disk 
 		G_MIRROR_DEBUG(0, "Device %s: rebuilding provider %s stopped.",
 		    sc->sc_name, g_mirror_get_diskname(disk));
 	}
+	g_mirror_regular_release(sc);
 	free(disk->d_sync.ds_bios, M_MIRROR);
 	disk->d_sync.ds_bios = NULL;
 	cp = disk->d_sync.ds_consumer;