o Add a ``-o'' argument to initattr, which causes extattrctl to overwrite

  the existing attribute file rather than aborting with an error.
o Useful if you want to reset the state of attributes on the system without
  allocating different disk blocks through deletion and recreation,
  for example, if you're doing benchmarks of extended attribute code. :-)

Obtained from:	TrustedBSD Project

2 files changed, 20 insertions, 4 deletions

diff --git a/usr.sbin/extattrctl/extattrctl.8 b/usr.sbin/extattrctl/extattrctl.8
index 60c6009..52ad134 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 7d34831..2d08926 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]);