1 files changed, 67 insertions, 11 deletions

diff --git a/fs/afs/dir.c b/fs/afs/dir.c
index 81207dc3c997..5c794f4b051a 100644
--- a/fs/afs/dir.c
+++ b/fs/afs/dir.c
@@ -803,7 +803,12 @@ success:
 			continue;
 
 		if (cookie->inodes[i]) {
-			afs_vnode_commit_status(&fc, AFS_FS_I(cookie->inodes[i]),
+			struct afs_vnode *iv = AFS_FS_I(cookie->inodes[i]);
+
+			if (test_bit(AFS_VNODE_UNSET, &iv->flags))
+				continue;
+
+			afs_vnode_commit_status(&fc, iv,
 						scb->cb_break, NULL, scb);
 			continue;
 		}
@@ -903,6 +908,7 @@ static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
 				 unsigned int flags)
 {
 	struct afs_vnode *dvnode = AFS_FS_I(dir);
+	struct afs_fid fid = {};
 	struct inode *inode;
 	struct dentry *d;
 	struct key *key;
@@ -946,25 +952,75 @@ static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
 	afs_stat_v(dvnode, n_lookup);
 	inode = afs_do_lookup(dir, dentry, key);
 	key_put(key);
-	if (inode == ERR_PTR(-ENOENT)) {
+	if (inode == ERR_PTR(-ENOENT))
 		inode = afs_try_auto_mntpt(dentry, dir);
-	} else {
-		dentry->d_fsdata =
-			(void *)(unsigned long)dvnode->status.data_version;
-	}
+
+	if (!IS_ERR_OR_NULL(inode))
+		fid = AFS_FS_I(inode)->fid;
+
 	d = d_splice_alias(inode, dentry);
 	if (!IS_ERR_OR_NULL(d)) {
 		d->d_fsdata = dentry->d_fsdata;
-		trace_afs_lookup(dvnode, &d->d_name,
-				 inode ? AFS_FS_I(inode) : NULL);
+		trace_afs_lookup(dvnode, &d->d_name, &fid);
 	} else {
-		trace_afs_lookup(dvnode, &dentry->d_name,
-				 inode ? AFS_FS_I(inode) : NULL);
+		trace_afs_lookup(dvnode, &dentry->d_name, &fid);
 	}
 	return d;
 }
 
 /*
+ * Check the validity of a dentry under RCU conditions.
+ */
+static int afs_d_revalidate_rcu(struct dentry *dentry)
+{
+	struct afs_vnode *dvnode, *vnode;
+	struct dentry *parent;
+	struct inode *dir, *inode;
+	long dir_version, de_version;
+
+	_enter("%p", dentry);
+
+	/* Check the parent directory is still valid first. */
+	parent = READ_ONCE(dentry->d_parent);
+	dir = d_inode_rcu(parent);
+	if (!dir)
+		return -ECHILD;
+	dvnode = AFS_FS_I(dir);
+	if (test_bit(AFS_VNODE_DELETED, &dvnode->flags))
+		return -ECHILD;
+
+	if (!afs_check_validity(dvnode))
+		return -ECHILD;
+
+	/* We only need to invalidate a dentry if the server's copy changed
+	 * behind our back.  If we made the change, it's no problem.  Note that
+	 * on a 32-bit system, we only have 32 bits in the dentry to store the
+	 * version.
+	 */
+	dir_version = (long)READ_ONCE(dvnode->status.data_version);
+	de_version = (long)READ_ONCE(dentry->d_fsdata);
+	if (de_version != dir_version) {
+		dir_version = (long)READ_ONCE(dvnode->invalid_before);
+		if (de_version - dir_version < 0)
+			return -ECHILD;
+	}
+
+	/* Check to see if the vnode referred to by the dentry still
+	 * has a callback.
+	 */
+	if (d_really_is_positive(dentry)) {
+		inode = d_inode_rcu(dentry);
+		if (inode) {
+			vnode = AFS_FS_I(inode);
+			if (!afs_check_validity(vnode))
+				return -ECHILD;
+		}
+	}
+
+	return 1; /* Still valid */
+}
+
+/*
  * check that a dentry lookup hit has found a valid entry
  * - NOTE! the hit can be a negative hit too, so we can't assume we have an
  *   inode
@@ -981,7 +1037,7 @@ static int afs_d_revalidate(struct dentry *dentry, unsigned int flags)
 	int ret;
 
 	if (flags & LOOKUP_RCU)
-		return -ECHILD;
+		return afs_d_revalidate_rcu(dentry);
 
 	if (d_really_is_positive(dentry)) {
 		vnode = AFS_FS_I(d_inode(dentry));