nothing in do_follow_link() is going to see RCU

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

nothing in do_follow_link() is going to see RCU
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Al Viro
1 parent 795abaf1e4
Showing 1 changed file with 7 additions and 8 deletions Side-by-side Diff
fs/namei.c
@@ -668,9 +668,6 @@
 		return 0;
  
 	if (!status) {
-		/* Don't d_invalidate in rcu-walk mode */
-		if (nameidata_drop_rcu(nd))
-			return -ECHILD;
 		d_invalidate(dentry);
 		status = -ESTALE;
 	}
@@ -777,6 +774,8 @@
 	int error;
 	struct dentry *dentry = link->dentry;
  
+	BUG_ON(nd->flags & LOOKUP_RCU);
+
 	touch_atime(link->mnt, dentry);
 	nd_set_link(nd, NULL);
  
@@ -811,6 +810,11 @@
 {
 	void *cookie;
 	int err = -ELOOP;
+
+	/* We drop rcu-walk here */
+	if (nameidata_dentry_drop_rcu_maybe(nd, path->dentry))
+		return -ECHILD;
+
 	if (current->link_count >= MAX_NESTED_LINKS)
 		goto loop;
 	if (current->total_link_count >= 40)
@@ -1419,9 +1423,6 @@
 			goto out_dput;
  
 		if (inode->i_op->follow_link) {
-			/* We commonly drop rcu-walk here */
-			if (nameidata_dentry_drop_rcu_maybe(nd, next.dentry))
-				return -ECHILD;
 			BUG_ON(inode != next.dentry->d_inode);
 			err = do_follow_link(&next, nd);
 			if (err)
@@ -1467,8 +1468,6 @@
 			break;
 		if (inode && unlikely(inode->i_op->follow_link) &&
 		    (lookup_flags & LOOKUP_FOLLOW)) {
-			if (nameidata_dentry_drop_rcu_maybe(nd, next.dentry))
-				return -ECHILD;
 			BUG_ON(inode != next.dentry->d_inode);
 			err = do_follow_link(&next, nd);
 			if (err)
...	...	@@ -668,9 +668,6 @@
668	668	return 0;
669	669
670	670	if (!status) {
671		- /* Don't d_invalidate in rcu-walk mode */
672		- if (nameidata_drop_rcu(nd))
673		- return -ECHILD;
674	671	d_invalidate(dentry);
675	672	status = -ESTALE;
676	673	}
...	...	@@ -777,6 +774,8 @@
777	774	int error;
778	775	struct dentry *dentry = link->dentry;
779	776
	777	+ BUG_ON(nd->flags & LOOKUP_RCU);
	778	+
780	779	touch_atime(link->mnt, dentry);
781	780	nd_set_link(nd, NULL);
782	781
...	...	@@ -811,6 +810,11 @@
811	810	{
812	811	void *cookie;
813	812	int err = -ELOOP;
	813	+
	814	+ /* We drop rcu-walk here */
	815	+ if (nameidata_dentry_drop_rcu_maybe(nd, path->dentry))
	816	+ return -ECHILD;
	817	+
814	818	if (current->link_count >= MAX_NESTED_LINKS)
815	819	goto loop;
816	820	if (current->total_link_count >= 40)
...	...	@@ -1419,9 +1423,6 @@
1419	1423	goto out_dput;
1420	1424
1421	1425	if (inode->i_op->follow_link) {
1422		- /* We commonly drop rcu-walk here */
1423		- if (nameidata_dentry_drop_rcu_maybe(nd, next.dentry))
1424		- return -ECHILD;
1425	1426	BUG_ON(inode != next.dentry->d_inode);
1426	1427	err = do_follow_link(&next, nd);
1427	1428	if (err)
...	...	@@ -1467,8 +1468,6 @@
1467	1468	break;
1468	1469	if (inode && unlikely(inode->i_op->follow_link) &&
1469	1470	(lookup_flags & LOOKUP_FOLLOW)) {
1470		- if (nameidata_dentry_drop_rcu_maybe(nd, next.dentry))
1471		- return -ECHILD;
1472	1471	BUG_ON(inode != next.dentry->d_inode);
1473	1472	err = do_follow_link(&next, nd);
1474	1473	if (err)