Glusterfs session #11 locks xlator entrylks

Glusterfs session #11 locks xlator entrylks

• 1.
  Glusterfs Session #11 Locksxlator entrylks
• 2.
  Scope - What isthe behavior of entrylks - Code walk through of entrylks - Dependency of entrylk, inodelk - Optimization of the interaction
• 3.
  Behavior of entrylks -To recap, entrylks are used to synchronize entry operations on directories. - In inodelks range(offset, length) is what we synchronize on. In entrylks we synchronize on the name. - In entrylks NULL name represents full directory lock
• 4.
  Behavior of entrylks Ifnames are different they are granted irrespective of the lk-owner/client Directory dir1 Name1 Name2 Directory: dir1
• 5.
  Behavior of entrylks Ifnames are conflicting they are not granted if the lk-owner/client differs Directory dir1 Name1 Name1 Directory: dir1
• 6.
  Behavior of entrylks Ifnames are conflicting they are not granted if the lk-owner/client differs Directory dir1 Name1 NULL(value) Directory: dir1
• 7.
  Behavior of entrylks Ifnames are not conflicting they are granted if the lk-owner, client matches Directory dir1 Name1 Name1 Directory: dir1
• 8.
  Behavior of entrylks Ifnames are same they are granted if the lk-owner, client matches Directory dir1 Name1 NULL(value) Directory: dir1
• 9.
  Code walk through
• 10.
  Dependency of entrylk,inodelk - When doing parallel operations on EC, we sometimes faced this issue where by the time inode is going to be unlocked, entry is already removed leading to issues while doing operations on the inode - https://github.com/gluster/glusterfs/issues/990 - There was no synchronization between entry operations and inode operations
• 11.
  Solution - Block entrydeletion until inodelk is unlocked. - Code walkthrough
• 12.
  Q & A