2 files changed, 14 insertions, 9 deletions

diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
index 9194e274f849..dbd95512808c 100644
--- a/fs/autofs4/root.c
+++ b/fs/autofs4/root.c
@@ -36,7 +36,7 @@ static long autofs4_root_compat_ioctl(struct file *,unsigned int,unsigned long);
 static int autofs4_dir_open(struct inode *inode, struct file *file);
 static struct dentry *autofs4_lookup(struct inode *,struct dentry *, struct nameidata *);
 static struct vfsmount *autofs4_d_automount(struct path *);
-static int autofs4_d_manage(struct dentry *, bool);
+static int autofs4_d_manage(struct dentry *, bool, bool);
 
 const struct file_operations autofs4_root_operations = {
         .open           = dcache_dir_open,
@@ -450,7 +450,7 @@ done:
         return NULL;
 }
 
-int autofs4_d_manage(struct dentry *dentry, bool mounting_here)
+int autofs4_d_manage(struct dentry *dentry, bool mounting_here, bool rcu_walk)
 {
         struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 
@@ -464,6 +464,10 @@ int autofs4_d_manage(struct dentry *dentry, bool mounting_here)
                 return 0;
         }
 
+        /* We need to sleep, so we need pathwalk to be in ref-mode */
+        if (rcu_walk)
+                return -ECHILD;
+
         /* Wait for pending expires */
         do_expire_wait(dentry);
 
diff --git a/fs/namei.c b/fs/namei.c
index 373852012713..5c89695ae1e4 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -987,7 +987,8 @@ static int follow_managed(struct path *path, unsigned flags)
                 if (managed & DCACHE_MANAGE_TRANSIT) {
                         BUG_ON(!path->dentry->d_op);
                         BUG_ON(!path->dentry->d_op->d_manage);
-                        ret = path->dentry->d_op->d_manage(path->dentry, false);
+                        ret = path->dentry->d_op->d_manage(path->dentry,
+                                                           false, false);
                         if (ret < 0)
                                 return ret == -EISDIR ? 0 : ret;
                 }
@@ -1048,13 +1049,12 @@ int follow_down_one(struct path *path)
 static bool __follow_mount_rcu(struct nameidata *nd, struct path *path,
                                struct inode **inode, bool reverse_transit)
 {
-        unsigned abort_mask =
-                reverse_transit ? 0 : DCACHE_MANAGE_TRANSIT;
-
         while (d_mountpoint(path->dentry)) {
                 struct vfsmount *mounted;
-                if (path->dentry->d_flags & abort_mask)
-                        return true;
+                if (unlikely(path->dentry->d_flags & DCACHE_MANAGE_TRANSIT) &&
+                    !reverse_transit &&
+                    path->dentry->d_op->d_manage(path->dentry, false, true) < 0)
+                        return false;
                 mounted = __lookup_mnt(path->mnt, path->dentry, 1);
                 if (!mounted)
                         break;
@@ -1132,7 +1132,8 @@ int follow_down(struct path *path, bool mounting_here)
                 if (managed & DCACHE_MANAGE_TRANSIT) {
                         BUG_ON(!path->dentry->d_op);
                         BUG_ON(!path->dentry->d_op->d_manage);
-                        ret = path->dentry->d_op->d_manage(path->dentry, mounting_here);
+                        ret = path->dentry->d_op->d_manage(
+                                path->dentry, mounting_here, false);
                         if (ret < 0)
                                 return ret == -EISDIR ? 0 : ret;
                 }