No, this sentence is not correct. This is a conditional sentence [if sentence] and there are three basic types of if sentences, not counting mixed conditionals. Type 1: If John has his way, he will play tennis all afternoon. Type 2: If John had his way, he would play tennis all afternoon. Type 3: If John had had his way, he would have played tennis all afternoon. Leaving aside type 1, which is straightforward, let's look at the difference between type 2 and type 3. Look at type 2 and ask yourself 'when?': If John had his own way ..... when? Then supply one of the following answers: now, in the future, in the past. The answer could be now or in the future, but definitely not in the past. Therefore we choose if type 2, because if type 2 sentences refer to the present or the future, whether they are improbable or impossible events. The structure of the if type 2 sentence is: If + Past Simple, would + infinitive without to [Note the comma!] or: would + infinitive without to if + Past Simple. [No comma!] Type 3 sentences refer only to the past: If John had had his way ....... when? In the past. Type 3 if sentences: If + past perfect, would have + past participle. or: would have + past participle if + past perfect Now back to your original sentence. If John had had his way, he would have spent all his time playing tennis. This is now correct because it is a type 3 if sentence and refers to the past. BTW: You can use elements from if sentences type 2 and 3 as in the following example: If I hadn't sworn at my boss [but unfortunately I did], I wouldn't be out of work now. The sentence shows that you swore [in the past] at your boss and as a consequence of this unfortunate action, you are now unemployed. Therefore we need If + past perfect - to show the action refers to a past event, but we also need would + infinitive without to - to show that the consequence of the action refers to the present. That is why this is called a mixed conditional because we have elements of if type 3 and if type 2 together. And finally ...! You might even say: Had John had his way, he would have spent all his time playing tennis. 'If' has been dropped and the auxiliary verb 'had' precedes the subject. This phenomenon is known as inversion.

The part "would have spent all his time" tells us this is an unreal past. To match the context, you need a phrase constructed of "if + [past perfect]". "If John had had his way, he would have spent all his time playing tennis." If you use "if John had his way", then you are imagining unlikely possibilities in the present or future: "if + [past simple]".

If anything, I would say 'John had had his way'.