Provided by: util-linux_2.40.2-1ubuntu1_amd64
NAME
lslocks - list local system locks
SYNOPSIS
lslocks [options]
DESCRIPTION
lslocks lists information about all the currently held file locks in a Linux system.
OPTIONS
-b, --bytes Print the sizes in bytes rather than in a human-readable format. By default, the unit, sizes are expressed in, is byte, and unit prefixes are in power of 2^10 (1024). Abbreviations of symbols are exhibited truncated in order to reach a better readability, by exhibiting alone the first letter of them; examples: "1 KiB" and "1 MiB" are respectively exhibited as "1 K" and "1 M", then omitting on purpose the mention "iB", which is part of these abbreviations. -H, --list-columns List the available columns, use with --json or --raw to get output in machine-readable format. -i, --noinaccessible Ignore lock files which are inaccessible for the current user. -J, --json Use JSON output format. -n, --noheadings Do not print a header line. -o, --output list Specify which output columns to print. Use --help to get a list of all supported columns. The default list of columns may be extended if list is specified in the format +list (e.g., lslocks -o +BLOCKER). --output-all Output all available columns. -p, --pid pid Display only the locks held by the process with this pid. -r, --raw Use the raw output format. -u, --notruncate Do not truncate text in columns. -h, --help Display help text and exit. -V, --version Print version and exit.
OUTPUT
COMMAND The command name of the process holding the lock. PID The process ID of the process. TYPE The type of lock; can be LEASE (created with fcntl(2)), FLOCK (created with flock(2)), POSIX (created with fcntl(2) and lockf(3)) or OFDLCK (created with fcntl(2)). SIZE Size of the locked file. INODE The inode number. MAJ:MIN The major:minor device number. MODE The lock’s access permissions (read, write). If the process is blocked and waiting for the lock, then the mode is postfixed with an '*' (asterisk). M Whether the lock is mandatory; 0 means no (meaning the lock is only advisory), 1 means yes. (See fcntl(2).) START Relative byte offset of the lock. END Ending offset of the lock. PATH Full path of the lock. If none is found, or there are no permissions to read the path, it will fall back to the device’s mountpoint and "..." is appended to the path. The path might be truncated; use --notruncate to get the full path. BLOCKER The PID of the process which blocks the lock. HOLDERS The holder(s) of the lock. The format of the holder is PID,COMMAND,FD. If a lock is an open file description-oriented lock, there can be more than one holder for the lock. See the NOTES below.
NOTES
The lslocks command is meant to replace the lslk(8) command, originally written by Victor A. Abell <abe@purdue.edu> and unmaintained since 2001. "The process holding the lock" for leases, FLOCK locks, and OFD locks is a fake-concept. They are associated with the open file description on which they are acquired. With fork(2) and/or cmsg(3), multiple processes can share an open file description. So the holder process of a lease (or a lock) is not uniquely determined. lslocks shows the one of the holder processes in COMMAND and PID columns.
AUTHORS
Davidlohr Bueso <dave@gnu.org>
SEE ALSO
flock(1), fcntl(2), lockf(3)
REPORTING BUGS
For bug reports, use the issue tracker at https://github.com/util-linux/util-linux/issues.
AVAILABILITY
The lslocks command is part of the util-linux package which can be downloaded from Linux Kernel Archive <https://www.kernel.org/pub/linux/utils/util-linux/>.