2 files changed, 20 insertions, 4 deletions

diff --git a/usr.sbin/extattrctl/extattrctl.8 b/usr.sbin/extattrctl/extattrctl.8
index 60c6009aeb22..52ad1349a64a 100644
--- a/usr.sbin/extattrctl/extattrctl.8
+++ b/usr.sbin/extattrctl/extattrctl.8
@@ -40,6 +40,7 @@
 .Ar path
 .Nm extattrctl
 .Cm initattr
+.Op Fl o
 .Op Fl p Ar path
 .Ar attrsize
 .Ar attrfile
@@ -75,6 +76,7 @@ Stop extended attribute support on the file system named using
 Extended attribute support must previously have been started.
 .It Xo
 .Cm initattr
+.Op Fl o
 .Op Fl p Ar path
 .Ar attrsize attrfile
 .Xc
@@ -85,6 +87,12 @@ as well as the file where the attribute will be stored, using
 .Ar attrfile .
 .Pp
 The
+.Fl o
+argument may be used to indicate that it is alright to overwrite an
+existing attribute backing file; otherwise, if the target file exists,
+an error will be returned.
+.Pp
+The
 .Fl p Ar path
 argument may be used to preallocate space for all attributes rather than
 relying on sparse files to conserve space.
diff --git a/usr.sbin/extattrctl/extattrctl.c b/usr.sbin/extattrctl/extattrctl.c
index 7d34831f007c..2d08926e1869 100644
--- a/usr.sbin/extattrctl/extattrctl.c
+++ b/usr.sbin/extattrctl/extattrctl.c
@@ -54,7 +54,7 @@ usage(void)
 	    "usage:\n"
 	    "  extattrctl start [path]\n"
 	    "  extattrctl stop [path]\n"
-	    "  extattrctl initattr [-p path] [attrsize] [attrfile]\n"
+	    "  extattrctl initattr [-o] [-p path] [attrsize] [attrfile]\n"
 	    "  extattrctl enable [path] [attrname] [attrfile]\n"
 	    "  extattrctl disable [path] [attrname]\n");
 	exit(-1);
@@ -82,11 +82,14 @@ initattr(int argc, char *argv[])
 	char	*fs_path = NULL;
 	char	*zero_buf = NULL;
 	long	loop, num_inodes;
-	int	ch, i, error, chunksize;
+	int	ch, i, error, chunksize, overwrite = 0, flags;
 
 	optind = 0;
-	while ((ch = getopt(argc, argv, "p:r:w:")) != -1)
+	while ((ch = getopt(argc, argv, "op:r:w:")) != -1)
 		switch (ch) {
+		case 'o':
+			overwrite = 1;
+			break;
 		case 'p':
 			fs_path = strdup(optarg);
 			break;
@@ -101,8 +104,13 @@ initattr(int argc, char *argv[])
 	if (argc != 2)
 		usage();
 
+	if (overwrite)
+		flags = O_CREAT | O_WRONLY;
+	else
+		flags = O_CREAT | O_EXCL | O_WRONLY;
+
 	error = 0;
-	if ((i = open(argv[1], O_CREAT | O_EXCL | O_WRONLY, 0600)) != -1) {
+	if ((i = open(argv[1], flags, 0600)) != -1) {
 		uef.uef_magic = UFS_EXTATTR_MAGIC;
 		uef.uef_version = UFS_EXTATTR_VERSION;
 		uef.uef_size = atoi(argv[0]);