MySQL Replication: How to restore master FROM slave?
1) Backups:


You can verify if your backup is successful by tailing the mysqldump for "dump completed successfully" to verify the success of a mysqldump.
Invalid backup is as-good-as (or as-bad-as) no backup. It's a good idea employ a backup-validation process by restoring it to a provisioned location as possible. Do it.
If you want to stick to logical backup, try using with myduper/myloader, which will be quicker than mysqldump.
Again physical backups are faster  than logical and this is specifically true for large sizes. If you can giveup on MySQLDump which is slow for restores and especially if you have all-innodb, you should consider using xtrabackup from Percona (for hotbackup). 
Check installing and configuring xtrabackup with holland framework. 


2) Restoring master from slave.

As such there are few questions and articles available but i will quickly notedown steps I can makeout for restoring master from  slave.


Considering your master is M and slave is S. (M --> S)
M is down.
S is promoted to Master ( readonly=false, binlogging is enabled)
M is later fixed and ready to join but need a restore.
Restore M from latest backup, mark it as readonly=true.
Upon restore, make it slave of S. (S --> M)
Once it catches up, you may want to failback to original master.
Stop production traffic, Mark M as readonly=false, S as readonly=true.
Mark S as slave of M (should be simple change master to from present binlog of M)
Thus making them active-passive master-master pair.
Move traffic to M.
You might want to break the master-master but it's fine to keep active-passive.
Making sure nothing writes to Passive master.


Hope this helps.