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>
(cherry picked from commit 08c422c27f855d27b0b3d9fa30ebd938d4ae6f1f)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index c9f365b6649ed534a5584a2916390bd37ab1121d..d86ebbc6ad2212c630b673d230dbfd4ba27c9bab 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4545,10 +4545,6 @@ 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;
@@ -4610,6 +4606,7 @@ 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;
@@ -4677,6 +4674,7 @@ 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;
@@ -4734,6 +4732,7 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
                struct dentry *parent = dget_parent(dentry);
                err = btrfs_update_inode(trans, root, inode);
                BUG_ON(err);
+               d_instantiate(dentry, inode);
                btrfs_log_new_name(trans, inode, NULL, parent);
                dput(parent);
        }
@@ -7202,6 +7201,8 @@ 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) {