As the new mutex primitive is now in place, I read,it is advised not to use binary semaphore for mutual exclusion. while looking at different place where a binary semaphore is initialized, I came accross bd_mount_sem. I read a thread on LKML few months back related to the bd_mount_sem and realized that there are cases where a binary semaphore can not be replaced by a mutex. The reason being mutex has a sense of ownership, i.e. a mutex can only be unlocked from the context from which it was locked. e.g bd_mount_sem in the block device structure is used to make sure no new mounts happen on bdev in between freeze_bdev and thaw_bdev(). so locking is done in freeze_bdev & unlocking in thaw_bdev these can be from different context i guess.. is my understandig correct.. CMIIW.. would appreciate some pointers on how to identify such cases.. -- Milind Arun Choudhary -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
