autofs_lookup(): hold ->d_lock over playing with ->d_flags

... as well as setting ->d_fsdata, etc.  Make all of that
atomic.

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

1 files changed, 7 insertions, 6 deletions

diff --git a/fs/autofs/root.c b/fs/autofs/root.c
index 64f974c61068..29abafc0ce31 100644
--- a/fs/autofs/root.c
+++ b/fs/autofs/root.c
@@ -504,21 +504,22 @@ static struct dentry *autofs_lookup(struct inode *dir,
                 if (!autofs_oz_mode(sbi) && !IS_ROOT(dentry->d_parent))
                         return ERR_PTR(-ENOENT);
 
-                /* Mark entries in the root as mount triggers */
-                if (IS_ROOT(dentry->d_parent) &&
-                    autofs_type_indirect(sbi->type))
-                        __managed_dentry_set_managed(dentry);
-
                 ino = autofs_new_ino(sbi);
                 if (!ino)
                         return ERR_PTR(-ENOMEM);
 
+                spin_lock(&sbi->lookup_lock);
+                spin_lock(&dentry->d_lock);
+                /* Mark entries in the root as mount triggers */
+                if (IS_ROOT(dentry->d_parent) &&
+                    autofs_type_indirect(sbi->type))
+                        __managed_dentry_set_managed(dentry);
                 dentry->d_fsdata = ino;
                 ino->dentry = dentry;
 
-                spin_lock(&sbi->lookup_lock);
                 list_add(&ino->active, &sbi->active_list);
                 spin_unlock(&sbi->lookup_lock);
+                spin_unlock(&dentry->d_lock);
         }
         return NULL;
 }