Import NetBSD flock(1)

Also fix the MINIX3 libc flock(3) implementation.

Change-Id: Ia80280029968786d7f029940ec02e942057701bd

distrib/sets/lists/minix/mi

@@ -331,6 +331,7 @@
 ./usr/bin/fix				minix-sys
 ./usr/bin/flex++			minix-sys
 ./usr/bin/flex				minix-sys
+./usr/bin/flock				minix-sys
 ./usr/bin/fold				minix-sys
 ./usr/bin/format			minix-sys
 ./usr/bin/fpr				minix-sys
@@ -2405,6 +2406,7 @@
 ./usr/man/man1/finger.1			minix-sys
 ./usr/man/man1/flex.1			minix-sys
 ./usr/man/man1/flexdoc.1		minix-sys
+./usr/man/man1/flock.1			minix-sys
 ./usr/man/man1/fold.1			minix-sys
 ./usr/man/man1/for.1			minix-sys	obsolete
 ./usr/man/man1/format.1			minix-sys

minix/lib/libc/sys/flock.c

@@ -21,14 +21,15 @@
 int flock(int fd, int mode)
 {
   struct flock lck;
-  register int retcode;
 
   memset((void *) &lck, 0, sizeof(struct flock));
-  lck.l_type = mode & ~LOCK_NB;
+  switch (mode & ~LOCK_NB) {
-  lck.l_pid = getpid();
+  case LOCK_SH: lck.l_type = F_RDLCK; break;
-  if ((retcode = fcntl(fd, mode & LOCK_NB ? F_SETLK : F_SETLKW, &lck)) < 0 && errno == EAGAIN)
+  case LOCK_EX: lck.l_type = F_WRLCK; break;
-	errno = EWOULDBLOCK;
+  case LOCK_UN: lck.l_type = F_UNLCK; break;
-  return retcode;
+  default: errno = EINVAL; return -1;
+  }
+  return fcntl(fd, mode & LOCK_NB ? F_SETLK : F_SETLKW, &lck);
 }
 
 /** flock.c **/

usr.bin/Makefile

@@ -10,7 +10,7 @@ SUBDIR= asa \
 	column comm csplit ctags cut \
 	deroff dirname du \
 	env expand \
-	false find finger fold fpr from \
+	false find finger flock fold fpr from \
 	fsplit ftp genassym getopt \
 	head hexdump id indent infocmp join jot \
 	lam last ldd leave \

usr.bin/flock/Makefile

@@ -0,0 +1,8 @@
+#	$NetBSD: Makefile,v 1.1 2012/11/01 23:30:19 christos Exp $
+#	@(#)Makefile	8.1 (Berkeley) 6/6/93
+
+PROG=	flock
+#LDADD+=	-lutil
+#DPADD+=	${LIBUTIL}
+
+.include <bsd.prog.mk>

usr.bin/flock/flock.1

@@ -0,0 +1,100 @@
+.\"	$NetBSD: flock.1,v 1.9 2013/09/21 15:01:14 khorben Exp $
+.\"
+.\" Copyright (c) 2012 The NetBSD Foundation, Inc.
+.\" All rights reserved.
+.\"
+.\" This code is derived from software contributed to The NetBSD Foundation
+.\" by Christos Zoulas.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+.\" PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+.\" POSSIBILITY OF SUCH DAMAGE.
+.\"
+.\"
+.Dd November 2, 2012
+.Dt FLOCK 1
+.Os
+.Sh NAME
+.Nm flock
+.Nd Provide locking API for shell scripts
+.Sh SYNOPSIS
+.Nm
+.Op Fl dnosvx
+.Op Fl w Ar timeout
+.Ar lockfile|lockdir
+.Op Fl c Ar command
+|
+.Op Ar command ...
+.Nm
+.Op Fl dnsuvx
+.Op Fl w Ar timeout
+.Ar lockfd
+.Sh DESCRIPTION
+The
+.Nm
+utility provides
+.Xr flock 2
+access to the command line or scripts.
+The first form locks a file or directory while the command provided is executed.
+If the file or directory does not exist, then a file is created.
+.Pp
+The second form can use an arbitrary file descriptor that is provided from a
+shell script for example:
+.Bd -literal
+(
+	flock -s 100
+	# commands to be executed under the lock
+) 100> /path/to/lockfile
+.Ed
+.Pp
+The following options are available:
+.Bl -tag -width "XXXXXXXXXXXXXXXXX"
+.It Fl c Ar command
+Pass a command to a the shell.
+.It Fl d , Fl Fl debug
+Provide debugging output.
+.It Fl n , Fl Fl nb , Fl Fl nonblock
+Don't block and fail immediately if the lock could not be obtained.
+.It Fl o , Fl Fl close
+Close the file before executing the command.
+This is useful if the child forks and should not be holding the lock.
+.It Fl s , Fl Fl shared
+Obtain a shared lock.
+.It Fl u , Fl Fl unlock
+Unlock an existing lock.
+This is available only for a file descriptor.
+.It Fl v , Fl Fl verbose
+On error print an explanation of the failure.
+.It Fl w , Fl Fl wait , Fl Fl timeout Ar seconds
+Fail if the lock could not be obtained after
+.Ar seconds .
+.It Fl x , Fl Fl exclusive
+Obtain an exclusive lock.
+.El
+.Sh EXIT STATUS
+.Ex -std
+.Sh SEE ALSO
+.Xr shlock 1 ,
+.Xr flock 2
+.Sh HISTORY
+An
+.Nm
+utility appeared in
+.Nx 6.1 .

usr.bin/flock/flock.c

@@ -0,0 +1,324 @@
+/*	$NetBSD: flock.c,v 1.8 2013/10/29 16:02:15 christos Exp $	*/
+
+/*-
+ * Copyright (c) 2012 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Christos Zoulas.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__RCSID("$NetBSD: flock.c,v 1.8 2013/10/29 16:02:15 christos Exp $");
+
+#include <stdio.h>
+#include <string.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <unistd.h>
+#include <err.h>
+#include <errno.h>
+#include <getopt.h>
+#include <paths.h>
+#include <time.h>
+
+static struct option flock_longopts[] = {
+	{ "debug",		no_argument,		0, 'd' },
+	{ "help",		no_argument,		0, 'h' },
+	{ "nonblock",		no_argument,		0, 'n' },
+	{ "nb",			no_argument,		0, 'n' },
+	{ "close",		no_argument,		0, 'o' },
+	{ "shared",		no_argument,		0, 's' },
+	{ "exclusive",		no_argument,		0, 'x' },
+	{ "unlock",		no_argument,		0, 'u' },
+	{ "verbose",		no_argument,		0, 'v' },
+	{ "command",		required_argument,	0, 'c' },
+	{ "wait",		required_argument,	0, 'w' },
+	{ "timeout",		required_argument,	0, 'w' },
+	{ NULL,			0,			0, 0   },
+};
+
+static sig_atomic_t timeout_expired;
+
+static __dead void
+usage(const char *fmt, ...) 
+{
+	if (fmt) {
+		va_list ap;
+		va_start(ap, fmt);
+		fprintf(stderr, "%s: ", getprogname());
+		vfprintf(stderr, fmt, ap);
+		fputc('\n', stderr);
+		va_end(ap);
+	}
+
+	fprintf(stderr, "Usage: %s [-dnosvx] [-w timeout] lockfile|lockdir "
+	    "[-c command]|command ...\n\t%s [-dnsuvx] [-w timeout] lockfd\n",
+	    getprogname(), getprogname());
+	exit(EXIT_FAILURE);
+}
+
+static void
+sigalrm(int sig)
+{
+	timeout_expired++;
+}
+
+static const char *
+lock2name(int l)
+{
+	static char buf[1024];
+	int nb = l & LOCK_NB;
+
+	l &= ~LOCK_NB;
+	if (nb)
+		strlcpy(buf, "LOCK_NB|", sizeof(buf));
+	else
+		buf[0] = '\0';
+
+	switch (l) {
+	case LOCK_SH:
+		strlcat(buf, "LOCK_SH", sizeof(buf));
+		return buf;
+	case LOCK_EX:
+		strlcat(buf, "LOCK_EX", sizeof(buf));
+		return buf;
+	case LOCK_UN:
+		strlcat(buf, "LOCK_UN", sizeof(buf));
+		return buf;
+	default:
+		snprintf(buf, sizeof(buf), "*%d*", l | nb);
+		return buf;
+	}
+}
+
+static char
+lockchar(int l)
+{
+	switch (l & ~LOCK_NB) {
+	case LOCK_SH:
+		return 's';
+	case LOCK_EX:
+		return 'x';
+	case LOCK_UN:
+		return 'u';
+	default:
+		return '*';
+	}
+}
+
+static char *
+cmdline(char **av)
+{
+	char *v = NULL;
+	while (*av)
+		if (v) {
+			if (asprintf(&v, "%s %s", v, *av++) < 0)
+				err(EXIT_FAILURE, "malloc");
+		} else {
+			if ((v = strdup(*av++)) == NULL)
+				err(EXIT_FAILURE, "strdup");
+		}
+	return v;
+}
+
+int
+main(int argc, char *argv[])
+{
+	int c;
+	int lock = 0;
+	double timeout = 0;
+	int cls = 0;
+	int fd = -1;
+	int debug = 0;
+	int verbose = 0;
+	char *mcargv[] = {
+	    __UNCONST(_PATH_BSHELL), __UNCONST("-c"), NULL, NULL
+	};
+	char **cmdargv = NULL, *v;
+#ifndef __minix
+	timer_t tm;
+#else /* __minix */
+	struct itimerval it;
+#endif /* __minix */
+
+	setprogname(argv[0]);
+
+	while ((c = getopt_long(argc, argv, "+dnosuvw:x", flock_longopts, NULL))
+	    != -1)
+		switch (c) {
+		case 'd':
+			debug++;
+			break;
+		case 'x':
+#define T(l)	(lock & ~LOCK_NB) != (l) && (lock & ~LOCK_NB) != 0
+			if (T(LOCK_EX))
+				goto badlock;
+			lock |= LOCK_EX;
+			break;
+		case 'n':
+			lock |= LOCK_NB;
+			break;
+		case 's':
+			if (T(LOCK_SH))
+				goto badlock;
+			lock |= LOCK_SH;
+			break;
+		case 'u':
+			if (T(LOCK_UN))
+				goto badlock;
+			lock |= LOCK_UN;
+			break;
+		case 'w':
+			timeout = strtod(optarg, NULL);
+			break;
+		case 'v':
+			verbose = 1;
+			break;
+		case 'o':
+			cls = 1;
+			break;
+		default:
+			usage("Invalid option '%c'", c);
+		badlock:
+			usage("-%c can't be used with -%c", c, lockchar(lock));
+		}
+
+	argc -= optind;
+	argv += optind;
+
+	if ((lock & ~LOCK_NB) == 0)
+		usage("Missing lock type flag");
+
+	switch (argc) {
+	case 0:
+		usage("Missing lock file argument");
+	case 1:
+		if (cls)
+			usage("Close is valid only for descriptors");
+		fd = strtol(argv[0], NULL, 0);	// XXX: error checking
+		if (debug) {
+			fprintf(stderr, "descriptor %s lock %s\n",
+			    argv[0], lock2name(lock));
+		}
+		break;
+
+	default:
+		if ((lock & LOCK_NB) == LOCK_UN)
+			usage("Unlock is only valid for descriptors");
+		if (strcmp(argv[1], "-c") == 0 ||
+		    strcmp(argv[1], "--command") == 0) {
+			if (argc == 2)
+				usage("Missing argument to %s", strcmp(argv[1],
+				    "-c") == 0 ? "-c" : "--command");
+			mcargv[2] = argv[2];
+			cmdargv = mcargv;
+		} else
+			cmdargv = argv + 1;
+			
+		if ((fd = open(argv[0], O_RDONLY)) == -1) {
+			if (errno != ENOENT || 
+			    (fd = open(argv[0], O_RDWR|O_CREAT, 0600)) == -1)
+				err(EXIT_FAILURE, "Cannot open `%s'", argv[0]);
+		}
+		if (debug) {
+			fprintf(stderr, "file %s lock %s command %s ...\n",
+			    argv[0], lock2name(lock), v = cmdline(cmdargv));
+			free(v);
+		}
+		break;
+	}
+
+	if (timeout) {
+#ifndef __minix
+		struct sigevent ev;
+		struct itimerspec it;
+#endif /* !__minix */
+		struct sigaction sa;
+
+#ifndef __minix
+		timespecclear(&it.it_interval);
+		it.it_value.tv_sec = timeout;
+		it.it_value.tv_nsec = (timeout - it.it_value.tv_sec) *
+			1000000000;
+
+		memset(&ev, 0, sizeof(ev));
+		ev.sigev_notify = SIGEV_SIGNAL;
+		ev.sigev_signo = SIGALRM;
+
+		if (timer_create(CLOCK_REALTIME, &ev, &tm) == -1)
+			err(EXIT_FAILURE, "timer_create");
+
+		if (timer_settime(tm, TIMER_RELTIME, &it, NULL) == -1)
+			err(EXIT_FAILURE, "timer_settime");
+#else /* __minix */
+		memset(&it.it_interval, 0, sizeof(it.it_interval));
+		it.it_value.tv_sec = timeout;
+		it.it_value.tv_usec = (timeout - it.it_value.tv_sec) * 1000000;
+
+		if (setitimer(ITIMER_REAL, &it, NULL) == -1)
+			err(EXIT_FAILURE, "setitimer");
+
+		memset(&it, 0, sizeof(it)); /* for the reset later */
+#endif /* __minix */
+
+		memset(&sa, 0, sizeof(sa));
+		sa.sa_handler = sigalrm;
+		sigemptyset(&sa.sa_mask);
+		sa.sa_flags = 0;
+		if (sigaction(SIGALRM, &sa, NULL) == -1)
+			err(EXIT_FAILURE, "sigaction");
+
+		if (debug)
+			fprintf(stderr, "alarm %g\n", timeout);
+	}
+
+	while (flock(fd, lock) == -1) {
+		if (errno == EINTR && timeout_expired == 0)
+			continue;
+		if (verbose)
+			err(EXIT_FAILURE, "flock(%d, %s)", fd, lock2name(lock));
+		else
+			return EXIT_FAILURE;
+	}
+
+	if (timeout)
+#ifndef __minix
+		timer_delete(tm);
+#else /* __minix */
+		setitimer(ITIMER_REAL, &it, NULL);
+#endif /* __minix */
+
+	if (cls)
+		(void)close(fd);
+
+	if (cmdargv != NULL) {
+		execvp(cmdargv[0], cmdargv);
+		err(EXIT_FAILURE, "execvp '%s'", v = cmdline(cmdargv));
+		free(v);
+	}
+	return 0;
+}