6840231 Panic in treeclimb_export()->checkexport4()

6840163 Variable treenode_t *ns_root should be declared as extern in export.h
6840149 "#define EXPTABLESIZE 16" is twice in the source
6834678 typo in /usr/include/nfs/export.h

3 files changed, 25 insertions, 24 deletions

diff --git a/usr/src/uts/common/fs/nfs/nfs4_srv_ns.c b/usr/src/uts/common/fs/nfs/nfs4_srv_ns.c
index 17f13008eb..40ef94e16b 100644
--- a/usr/src/uts/common/fs/nfs/nfs4_srv_ns.c
+++ b/usr/src/uts/common/fs/nfs/nfs4_srv_ns.c
@@ -18,12 +18,10 @@
  *
  * CDDL HEADER END
  *
- * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
+ * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
-#pragma ident	"%Z%%M%	%I%	%E% SMI"
-
 #include <sys/systm.h>
 
 #include <nfs/nfs.h>
@@ -647,18 +645,8 @@ treeclimb_export(struct exportinfo *exip)
 		 */
 		va.va_mask = AT_NODEID;
 		error = VOP_GETATTR(vp, &va, 0, CRED(), NULL);
-		if (error) {
-			if (new_exi && new_exi != exip) {
-				/*
-				 * This exportinfo is not connected with
-				 * treenode yet. Free it here.
-				 */
-				(void) export_unlink(&new_exi->exi_fsid,
-				    &new_exi->exi_fid, new_exi->exi_vp, NULL);
-				exi_rele(new_exi);
-			}
+		if (error)
 			break;
-		}
 
 		/*
 		 *  Add this directory fid to visible list
@@ -714,23 +702,29 @@ treeclimb_export(struct exportinfo *exip)
 	 * 2. pseudo_exportfs() which can fail only in vop_fid_pseudo()
 	 * 3. VOP_GETATTR()
 	 * 4. VOP_LOOKUP()
-	 * To cleanup, free pseudo exportinfos, visibles and treenodes.
+	 * We must free pseudo exportinfos, visibles and treenodes.
+	 * Visibles are referenced from treenode_t::tree_vis and
+	 * exportinfo_t::exi_visible. To avoid double freeing, only
+	 * exi_visible pointer is used, via exi_rele(), for the clean-up.
 	 */
 	if (error) {
+		/* Free unconnected visibles, if there are any. */
+		if (vis_head)
+			free_visible(vis_head);
+
+		/* Connect unconnected exportinfo, if there is any. */
+		if (new_exi && new_exi != exip)
+			tree_head = tree_prepend_node(tree_head, 0, new_exi);
+
 		while (tree_head) {
 			treenode_t *t2 = tree_head;
 			exportinfo_t *e  = tree_head->tree_exi;
-			exp_visible_t *v = tree_head->tree_vis;
 			/* exip will be freed in exportfs() */
 			if (e && e != exip) {
 				(void) export_unlink(&e->exi_fsid, &e->exi_fid,
 				    e->exi_vp, NULL);
 				exi_rele(e);
 			}
-			if (v) {
-				VN_RELE(v->vis_vp);
-				kmem_free(v, sizeof (*v));
-			}
 			tree_head = tree_head->tree_child_first;
 			kmem_free(t2, sizeof (*t2));
 		}
diff --git a/usr/src/uts/common/fs/nfs/nfs_export.c b/usr/src/uts/common/fs/nfs/nfs_export.c
index a2646ce627..6bd69dc5c3 100644
--- a/usr/src/uts/common/fs/nfs/nfs_export.c
+++ b/usr/src/uts/common/fs/nfs/nfs_export.c
@@ -64,7 +64,7 @@
 #include <nfs/lm.h>
 #include <sys/sunddi.h>
 
-#define	EXPTABLESIZE 16
+treenode_t *ns_root;
 
 struct exportinfo *exptable[EXPTABLESIZE];
 
diff --git a/usr/src/uts/common/nfs/export.h b/usr/src/uts/common/nfs/export.h
index 9e06cb5224..b66c00c389 100644
--- a/usr/src/uts/common/nfs/export.h
+++ b/usr/src/uts/common/nfs/export.h
@@ -19,7 +19,7 @@
  * CDDL HEADER END
  */
 /*
- * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
+ * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
@@ -350,7 +350,7 @@ struct exp_visible;
  * treenode_t::tree_exi ---------  exportinfo_t::exi_tree
  * treenode_t::tree_vis ......... exp_visible_t::vis_tree
  */
-/* Access to treenodei_t is under under protection of exported_lock RW_LOCK */
+/* Access to treenode_t is under protection of exported_lock RW_LOCK */
 typedef struct treenode {
 	/* support for generic n-ary trees */
 	struct treenode *tree_parent;
@@ -373,7 +373,7 @@ typedef struct treenode {
 	((t)->tree_exi && !PSEUDO((t)->tree_exi))
 
 /* Root of nfs pseudo namespace */
-treenode_t *ns_root;
+extern treenode_t *ns_root;
 
 #define	EXPTABLESIZE	16
 
@@ -437,6 +437,13 @@ typedef struct secinfo secinfo_t;
  * The vis_count field records the number of paths in this filesystem
  * that use this directory. The vis_exported field is non-zero if the
  * entry is an exported directory (leaf node).
+ *
+ * exp_visible itself is not reference counted. Each exp_visible is
+ * referenced twice:
+ * 1) from treenode::tree_vis
+ * 2) linked from exportinfo::exi_visible
+ * The 'owner' of exp_visible is the exportinfo structure. exp_visible should
+ * be always freed only from exportinfo_t, never from treenode::tree_vis.
  */
 
 struct exp_visible {