Hi all, MDS version v14.2.11 Client kernel 3.10.0-1127.19.1.el7.x86_64 We are seeing a strange issue with a dovecot use-case on cephfs. Occasionally we have dovecot reporting a file locked, such as: Nov 09 13:55:00 dovecot-backend-00.cern.ch dovecot[27710]: imap(reguero)<23945><fRA6B6yznq68uE28>: Error: Mailbox Deleted Items: Timeout (180s) while waiting for lock for transaction log file /mail/users/r/reguero//mdbox/mailboxes/Deleted Items/dbox-Mails/dovecot.index.log (WRITE lock held by pid -9605) We checked all hosts that have mounted the cephfs -- there is no pid 9605. Is there any way to see who exactly created the lock? ceph_filelock has a client id, but I didn't find a way to inspect the cephfs_metadata to see the ceph_filelock directly. Otherwise, are other Dovecot/CephFS users seeing this? Did you switch to flock or lockfile instead of fnctlk locks? Thanks! Dan P.S. here is the output from print locks tool from the kernel client: Read lock: Type: 1 (0: Read, 1: Write, 2: Unlocked) Whence: 0 (0: start, 1: current, 2: end) Offset: 0 Len: 1 Pid: -9605 Write lock: Type: 1 (0: Read, 1: Write, 2: Unlocked) Whence: 0 (0: start, 1: current, 2: end) Offset: 0 Len: 1 Pid: -9605 and same file from a 15.2.5 fuse client : Read lock: Type: 1 (0: Read, 1: Write, 2: Unlocked) Whence: 0 (0: start, 1: current, 2: end) Offset: 0 Len: 0 Pid: 0 Write lock: Type: 1 (0: Read, 1: Write, 2: Unlocked) Whence: 0 (0: start, 1: current, 2: end) Offset: 0 Len: 0 Pid: 0