// LOCKS_EXCLUDED(fs.mu)
func (fs *fileSystem) CreateSymlink(
op *fuseops.CreateSymlinkOp) (err error) {
// Find the parent.
fs.mu.Lock()
parent := fs.inodes[op.Parent].(inode.DirInode)
fs.mu.Unlock()
// Create the object in GCS, failing if it already exists.
parent.Lock()
o, err := parent.CreateChildSymlink(op.Context(), op.Name, op.Target)
parent.Unlock()
// Special case: *gcs.PreconditionError means the name already exists.
if _, ok := err.(*gcs.PreconditionError); ok {
err = fuse.EEXIST
return
}
// Propagate other errors.
if err != nil {
err = fmt.Errorf("CreateChildSymlink: %v", err)
return
}
// Attempt to create a child inode using the object we created. If we fail to
// do so, it means someone beat us to the punch with a newer generation
// (unlikely, so we're probably okay with failing here).
fs.mu.Lock()
child := fs.lookUpOrCreateInodeIfNotStale(o.Name, o)
if child == nil {
err = fmt.Errorf("Newly-created record is already stale")
return
}
defer fs.unlockAndMaybeDisposeOfInode(child, &err)
// Fill out the response.
op.Entry.Child = child.ID()
op.Entry.Attributes, err = child.Attributes(op.Context())
if err != nil {
err = fmt.Errorf("Attributes: %v", err)
return
}
return
}
