This file displays the files currently locked by the kernel. The contents of this file contain internal kernel debugging data and can vary tremendously, depending on the use of the system. A sample
/proc/locksfile for a lightly loaded system looks similar to the following:
1: POSIX ADVISORY WRITE 3568 fd:00:2531452 0 EOF 2: FLOCK ADVISORY WRITE 3517 fd:00:2531448 0 EOF 3: POSIX ADVISORY WRITE 3452 fd:00:2531442 0 EOF 4: POSIX ADVISORY WRITE 3443 fd:00:2531440 0 EOF 5: POSIX ADVISORY WRITE 3326 fd:00:2531430 0 EOF 6: POSIX ADVISORY WRITE 3175 fd:00:2531425 0 EOF 7: POSIX ADVISORY WRITE 3056 fd:00:2548663 0 EOF
Each lock has its own line which starts with a unique number. The second column refers to the class of lock used, with
FLOCKsignifying the older-style UNIX file locks from a
flocksystem call and
POSIXrepresenting the newer POSIX locks from the
The third column can have two values:
ADVISORYmeans that the lock does not prevent other people from accessing the data; it only prevents other attempts to lock it.
MANDATORYmeans that no other access to the data is permitted while the lock is held. The fourth column reveals whether the lock is allowing the holder
WRITEaccess to the file. The fifth column shows the ID of the process holding the lock. The sixth column shows the ID of the file being locked, in the format of
MAJOR-DEVICE:MINOR-DEVICE:INODE-NUMBER. The seventh and eighth column shows the start and end of the file's locked region.