From: plus <plus@localhost.localdomain>
Date: Thu, 13 Oct 2022 08:37:20 +0000 (+0800)
Subject: mkfs.bfs: Support BSD lock
X-Git-Tag: v2.39-rc1~485
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cc4fefc635613252ffd16baf469e8a32129706bf;p=thirdparty%2Futil-linux.git

mkfs.bfs: Support BSD lock

Addresses: #1842 #921
Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/disk-utils/mkfs.bfs.8.adoc b/disk-utils/mkfs.bfs.8.adoc
index 6b04b105f0..198d61f5ef 100644
--- a/disk-utils/mkfs.bfs.8.adoc
+++ b/disk-utils/mkfs.bfs.8.adoc
@@ -35,6 +35,9 @@ Specify the volume _label_. I have no idea if/where this is used.
 *-F*, *--fname* _name_::
 Specify the filesystem _name_. I have no idea if/where this is used.
 
+*--lock*[=_mode_]::
+Use exclusive BSD lock for device or file it operates. The optional argument _mode_ can be *yes*, *no* (or 1 and 0) or *nonblock*. If the _mode_ argument is omitted, it defaults to *yes*. This option overwrites environment variable *$LOCK_BLOCK_DEVICE*. The default is not to use any lock at all, but it's recommended to avoid collisions with *systemd-udevd*(8) or other tools.
+
 *-v*, *--verbose*::
 Explain what is being done.
 
diff --git a/disk-utils/mkfs.bfs.c b/disk-utils/mkfs.bfs.c
index 54d261b293..541aa0315c 100644
--- a/disk-utils/mkfs.bfs.c
+++ b/disk-utils/mkfs.bfs.c
@@ -22,6 +22,7 @@
 #include "strutils.h"
 #include "xalloc.h"
 #include "bitops.h"
+#include "exitcodes.h"
 
 #define BFS_ROOT_INO		2
 #define BFS_NAMELEN		14
@@ -84,6 +85,7 @@ static void __attribute__((__noreturn__)) usage(void)
 		       " -v, --verbose       explain what is being done\n"
 		       " -c                  this option is silently ignored\n"
 		       " -l                  this option is silently ignored\n"
+		       " --lock=[=<mode>]    use exclusive device lock (yes, no or nonblock)\n"
 		       ));
 	printf(USAGE_HELP_OPTIONS(21));
 
@@ -94,6 +96,7 @@ static void __attribute__((__noreturn__)) usage(void)
 int main(int argc, char **argv)
 {
 	char *device, *volume, *fsname;
+	char *lockmode = 0;
 	long inodes;
 	unsigned long long total_blocks, ino_bytes, ino_blocks, data_blocks;
 	unsigned long long user_specified_total_blocks = 0;
@@ -107,7 +110,10 @@ int main(int argc, char **argv)
 	time_t now;
 	int c, i, len;
 
-	enum { VERSION_OPTION = CHAR_MAX + 1 };
+	enum {
+	    VERSION_OPTION = CHAR_MAX + 1,
+	    OPT_LOCK
+	};
 	static const struct option longopts[] = {
 		{"inodes", required_argument, NULL, 'N'},
 		{"vname", required_argument, NULL, 'V'},
@@ -115,6 +121,7 @@ int main(int argc, char **argv)
 		{"verbose", no_argument, NULL, 'v'},
 		{"version", no_argument, NULL, VERSION_OPTION},
 		{"help", no_argument, NULL, 'h'},
+		{"lock", optional_argument, NULL, OPT_LOCK},
 		{NULL, 0, NULL, 0}
 	};
 
@@ -162,6 +169,15 @@ int main(int argc, char **argv)
 			/* when called via mkfs we may get options c,l,v */
 			break;
 
+                case OPT_LOCK:
+			lockmode = "1";
+			if (optarg) {
+				if (*optarg == '=')
+					optarg++;
+				lockmode = optarg;
+			}
+			break;
+
 		case VERSION_OPTION:
 			print_version(EXIT_SUCCESS);
 		case 'h':
@@ -185,6 +201,9 @@ int main(int argc, char **argv)
 	if (fd < 0)
 		err(EXIT_FAILURE, _("cannot open %s"), device);
 
+	if (blkdev_lock(fd, device, lockmode) != 0)
+		exit(MKFS_EX_ERROR);
+
 	if (optind == argc - 1)
 		user_specified_total_blocks =
 			strtou64_or_err(argv[optind], _("invalid block-count"));