svn commit: r296613 - head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs

[Alexander Motin]

Author: mav
Date: Thu Mar 10 14:18:14 2016
New Revision: 296613
URL: https://svnweb.freebsd.org/changeset/base/296613

Log:
  Make ZFS more picky to GEOM stripe sizes and offsets.
  
  Use of misaligned or non-power-of-2 stripes is not really useful for ZFS,
  since increased ashift won't help to avoid read-modify-write cycles, and
  only reduce pool space efficiency and compression rates.

Modified:
  head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_geom.c

Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_geom.c
==============================================================================
--- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_geom.c	Thu Mar 10 14:17:24 2016	(r296612)
+++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_geom.c	Thu Mar 10 14:18:14 2016	(r296613)
@@ -811,7 +811,8 @@ vdev_geom_open(vdev_t *vd, uint64_t *psi
 	 */
 	*logical_ashift = highbit(MAX(pp->sectorsize, SPA_MINBLOCKSIZE)) - 1;
 	*physical_ashift = 0;
-	if (pp->stripesize)
+	if (pp->stripesize > (1 << *logical_ashift) && ISP2(pp->stripesize) &&
+	    pp->stripeoffset == 0)
 		*physical_ashift = highbit(pp->stripesize) - 1;
 
 	/*