Btrfs: call d_instantiate after all ops are setup

This closes races where btrfs is calling d_instantiate too soon during
inode creation.  All of the callers of btrfs_add_nondir are updated to
instantiate after the inode is fully setup in memory.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 5 insertions, 4 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 740e67bbe249..13b0542015ff 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4590,10 +4590,6 @@ static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
         int err = btrfs_add_link(trans, dir, inode,
                                  dentry->d_name.name, dentry->d_name.len,
                                  backref, index);
-        if (!err) {
-                d_instantiate(dentry, inode);
-                return 0;
-        }
         if (err > 0)
                 err = -EEXIST;
         return err;
@@ -4655,6 +4651,7 @@ static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
         else {
                 init_special_inode(inode, inode->i_mode, rdev);
                 btrfs_update_inode(trans, root, inode);
+                d_instantiate(dentry, inode);
         }
 out_unlock:
         nr = trans->blocks_used;
@@ -4722,6 +4719,7 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry,
                 inode->i_mapping->a_ops = &btrfs_aops;
                 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
                 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
+                d_instantiate(dentry, inode);
         }
 out_unlock:
         nr = trans->blocks_used;
@@ -4779,6 +4777,7 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
                 struct dentry *parent = dentry->d_parent;
                 err = btrfs_update_inode(trans, root, inode);
                 BUG_ON(err);
+                d_instantiate(dentry, inode);
                 btrfs_log_new_name(trans, inode, NULL, parent);
         }
 
@@ -7245,6 +7244,8 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
                 drop_inode = 1;
 
 out_unlock:
+        if (!err)
+                d_instantiate(dentry, inode);
         nr = trans->blocks_used;
         btrfs_end_transaction_throttle(trans, root);
         if (drop_inode) {