From: Karel Zak <kzak@redhat.com>
Date: Fri, 13 Apr 2018 09:22:21 +0000 (+0200)
Subject: lslocks: add info about OFD
X-Git-Tag: v2.32.1~17
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=88b630f71de5f91bb6ea504c5bb0cffd222f0de5;p=thirdparty%2Futil-linux.git

lslocks: add info about OFD

It seems users are confused by PID -1 and missing path. This patch add
more information about OFD locks to the man page and "undefined" to
the COMMAND column.

References: http://austingroupbugs.net/view.php?id=768
Addresses: https://bugzilla.redhat.com/show_bug.cgi?id=1527102
Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/misc-utils/lslocks.8 b/misc-utils/lslocks.8
index 09b8d41814..5c7fb6f9e7 100644
--- a/misc-utils/lslocks.8
+++ b/misc-utils/lslocks.8
@@ -12,6 +12,11 @@ lslocks \- list local system locks
 .SH DESCRIPTION
 .B lslocks
 lists information about all the currently held file locks in a Linux system.
+.sp
+Note that lslocks also lists OFD (Open File Description) locks, these locks are
+not associated with any process (PID is -1).  OFD locks are associated with the
+open file description on which they are acquired.  This lock type is available
+since Linux 3.15, see \fBfcntl\fR(2) for more details.
 
 .SH OPTIONS
 .TP
@@ -51,7 +56,7 @@ Display help text and exit.
 .IP "COMMAND"
 The command name of the process holding the lock.
 .IP "PID"
-The process ID of the process which holds the lock.
+The process ID of the process which holds the lock or -1 for OFDLCK.
 .IP "TYPE"
 The type of lock; can be FLOCK (created with \fBflock\fR(2)), POSIX
 (created with \fBfcntl\fR(2) and \fBlockf\fR(3)) or OFDLCK (created with fcntl(2).
diff --git a/misc-utils/lslocks.c b/misc-utils/lslocks.c
index a1a7ab676c..fe15ff5304 100644
--- a/misc-utils/lslocks.c
+++ b/misc-utils/lslocks.c
@@ -276,12 +276,15 @@ static int get_local_locks(struct list_head *locks)
 			case 4: /* PID */
 				/*
 				 * If user passed a pid we filter it later when adding
-				 * to the list, no need to worry now.
+				 * to the list, no need to worry now. OFD locks use -1 PID.
 				 */
 				l->pid = strtos32_or_err(tok, _("failed to parse pid"));
-				l->cmdname = proc_get_command_name(l->pid);
-				if (!l->cmdname)
-					l->cmdname = xstrdup(_("(unknown)"));
+				if (l->pid > 0) {
+					l->cmdname = proc_get_command_name(l->pid);
+					if (!l->cmdname)
+						l->cmdname = xstrdup(_("(unknown)"));
+				} else
+					l->cmdname = xstrdup(_("(undefined)"));
 				break;
 
 			case 5: /* device major:minor and inode number */