svn commit: r284025 - head/sys/boot/zfs

[Andriy Gapon]

Author: avg
Date: Fri Jun  5 15:32:04 2015
New Revision: 284025
URL: https://svnweb.freebsd.org/changeset/base/284025

Log:
  dnode_read: handle hole blocks in zfs boot code
  
  A hole block pointer can be encountered at any level and the hole
  can cover multiple data blocks, but we are reading the data blocks
  one by one, so we care only about the current one.
  
  PR:		199804
  Reported by:	Toomas Soome <tsoome at me.com>
  Submitted by:	Toomas Soome <tsoome at me.com> (earlier version)
  Tested by:	Toomas Soome <tsoome at me.com>
  MFC after:	11 days

Modified:
  head/sys/boot/zfs/zfsimpl.c

Modified: head/sys/boot/zfs/zfsimpl.c
==============================================================================
--- head/sys/boot/zfs/zfsimpl.c	Fri Jun  5 15:16:26 2015	(r284024)
+++ head/sys/boot/zfs/zfsimpl.c	Fri Jun  5 15:32:04 2015	(r284025)
@@ -1255,6 +1255,10 @@ dnode_read(const spa_t *spa, const dnode
 			ibn = bn >> ((nlevels - i - 1) * ibshift);
 			ibn &= ((1 << ibshift) - 1);
 			bp = indbp[ibn];
+			if (BP_IS_HOLE(bp)) {
+				memset(dnode_cache_buf, 0, bsize);
+				break;
+			}
 			rc = zio_read(spa, &bp, dnode_cache_buf);
 			if (rc)
 				return (rc);