lslocks – list local system locks

lslocks [options]

lslocks lists information about all the currently held file locks in a Linux system.

-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).

-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.

-V, –version

Display version information and exit.

-h, –help

Display help text and exit.

COMMAND

The command name of the process holding the lock.

PID The process ID of the process which holds the lock.

TYPE The type of lock; can be 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.

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.

The lslocks command is meant to replace the lslk(8) command,

originally written by Victor A. Abell <abe@purdue.edu> and unmaintained

since 2001.

Davidlohr Bueso <dave@gnu.org>

flock(1), fcntl(2), lockf(3)

The lslocks command is part of the util-linux package and is available from https://www.kernel.org/pub/linux/utils/util-linux/.