svn commit: r269431 - in head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs: . sys

[Xin LI]

Author: delphij
Date: Sat Aug  2 08:34:22 2014
New Revision: 269431
URL: http://svnweb.freebsd.org/changeset/base/269431

Log:
  MFV r269427:
  
  In dnode_children_t, use C99's "[]" idiom for declaring the variable
  sized array dnc_children at the end of the structure.
  
  This prevents the compiler from mistakenly optimizing away accesses
  beyond the array's defined size.
  
  Illumos issue:
      5038 Remove "old-style" flexible array usage in ZFS.
      Author: Justin T. Gibbs <justing at spectralogic.com>
  
  MFC after:	2 weeks

Modified:
  head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dnode.c
  head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dnode.h
Directory Properties:
  head/sys/cddl/contrib/opensolaris/   (props changed)

Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dnode.c
==============================================================================
--- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dnode.c	Sat Aug  2 07:47:52 2014	(r269430)
+++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dnode.c	Sat Aug  2 08:34:22 2014	(r269431)
@@ -1026,7 +1026,7 @@ dnode_buf_pageout(dmu_buf_t *db, void *a
 		dnh->dnh_dnode = NULL;
 	}
 	kmem_free(children_dnodes, sizeof (dnode_children_t) +
-	    (epb - 1) * sizeof (dnode_handle_t));
+	    epb * sizeof (dnode_handle_t));
 }
 
 /*
@@ -1111,7 +1111,7 @@ dnode_hold_impl(objset_t *os, uint64_t o
 		int i;
 		dnode_children_t *winner;
 		children_dnodes = kmem_zalloc(sizeof (dnode_children_t) +
-		    (epb - 1) * sizeof (dnode_handle_t), KM_SLEEP);
+		    epb * sizeof (dnode_handle_t), KM_SLEEP);
 		children_dnodes->dnc_count = epb;
 		dnh = &children_dnodes->dnc_children[0];
 		for (i = 0; i < epb; i++) {
@@ -1126,7 +1126,7 @@ dnode_hold_impl(objset_t *os, uint64_t o
 			}
 
 			kmem_free(children_dnodes, sizeof (dnode_children_t) +
-			    (epb - 1) * sizeof (dnode_handle_t));
+			    epb * sizeof (dnode_handle_t));
 			children_dnodes = winner;
 		}
 	}

Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dnode.h
==============================================================================
--- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dnode.h	Sat Aug  2 07:47:52 2014	(r269430)
+++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dnode.h	Sat Aug  2 08:34:22 2014	(r269431)
@@ -245,7 +245,7 @@ typedef struct dnode_handle {
 
 typedef struct dnode_children {
 	size_t dnc_count;		/* number of children */
-	dnode_handle_t dnc_children[1];	/* sized dynamically */
+	dnode_handle_t dnc_children[];	/* sized dynamically */
 } dnode_children_t;
 
 typedef struct free_range {