Implement property overriding (-o) and filtering (-x) in zfs receive

This allows a user to specify "-o property=value" to override and "-x property"
to exclude properties when receiving a stream. This is useful when using
zfs send/recv for periodic backup/replication because it allows a user to
change properties such as canmount, mountpoint, or compression without
modifying the source dataset.

Signed-off-by: loli10K <ezomori.nozomu@gmail.com>

cmd/zfs/zfs_main.c

@@ -248,10 +248,13 @@ get_usage(zfs_help_t idx)
 	case HELP_PROMOTE:
 		return (gettext("\tpromote <clone-filesystem>\n"));
 	case HELP_RECEIVE:
-		return (gettext("\treceive [-vnsFu] <filesystem|volume|"
-		    "snapshot>\n"
-		    "\treceive [-vnsFu] [-o origin=<snapshot>] [-d | -e] "
-		    "<filesystem>\n"
+		return (gettext("\treceive [-vnsFu] [[-o property=<value>] | "
+		    "[-x property]] ...\n"
+		    "\t    [-o origin=<snapshot>] "
+		    "<filesystem|volume|snapshot>\n"
+		    "\treceive [-vnsFu] [[-o property=<value>] | "
+		    "[-x property]] ... \n"
+		    "\t    [-d | -e] [-o origin=<snapshot>] <filesystem>\n"
 		    "\treceive -A <filesystem|volume>\n"));
 	case HELP_RENAME:
 		return (gettext("\trename [-f] <filesystem|volume|snapshot> "
@@ -489,7 +492,7 @@ usage(boolean_t requested)
 static int
 parseprop(nvlist_t *props, char *propname)
 {
-	char *propval, *strval;
+	char *propval;
 
 	if ((propval = strchr(propname, '=')) == NULL) {
 		(void) fprintf(stderr, gettext("missing "
@@ -498,7 +501,7 @@ parseprop(nvlist_t *props, char *propname)
 	}
 	*propval = '\0';
 	propval++;
-	if (nvlist_lookup_string(props, propname, &strval) == 0) {
+	if (nvlist_exists(props, propname)) {
 		(void) fprintf(stderr, gettext("property '%s' "
 		    "specified multiple times\n"), propname);
 		return (-1);
@@ -508,6 +511,28 @@ parseprop(nvlist_t *props, char *propname)
 	return (0);
 }
 
+/*
+ * Take a property name argument and add it to the given nvlist.
+ * Modifies the argument inplace.
+ */
+static int
+parsepropname(nvlist_t *props, char *propname)
+{
+	if (strchr(propname, '=') != NULL) {
+		(void) fprintf(stderr, gettext("invalid character "
+		    "'=' in property argument\n"));
+		return (-1);
+	}
+	if (nvlist_exists(props, propname)) {
+		(void) fprintf(stderr, gettext("property '%s' "
+		    "specified multiple times\n"), propname);
+		return (-1);
+	}
+	if (nvlist_add_boolean(props, propname) != 0)
+		nomem();
+	return (0);
+}
+
 static int
 parse_depth(char *opt, int *flags)
 {
@@ -3983,20 +4008,24 @@ zfs_do_receive(int argc, char **argv)
 	int c, err;
 	recvflags_t flags = { 0 };
 	boolean_t abort_resumable = B_FALSE;
-
 	nvlist_t *props;
-	nvpair_t *nvp = NULL;
 
 	if (nvlist_alloc(&props, NV_UNIQUE_NAME, 0) != 0)
 		nomem();
 
 	/* check options */
-	while ((c = getopt(argc, argv, ":o:denuvFsA")) != -1) {
+	while ((c = getopt(argc, argv, ":o:x:denuvFsA")) != -1) {
 		switch (c) {
 		case 'o':
 			if (parseprop(props, optarg) != 0) {
 				nvlist_free(props);
-				return (1);
+				usage(B_FALSE);
+			}
+			break;
+		case 'x':
+			if (parsepropname(props, optarg) != 0) {
+				nvlist_free(props);
+				usage(B_FALSE);
 			}
 			break;
 		case 'd':
@@ -4049,13 +4078,6 @@ zfs_do_receive(int argc, char **argv)
 		usage(B_FALSE);
 	}
 
-	while ((nvp = nvlist_next_nvpair(props, nvp))) {
-		if (strcmp(nvpair_name(nvp), "origin") != 0) {
-			(void) fprintf(stderr, gettext("invalid option"));
-			usage(B_FALSE);
-		}
-	}
-
 	if (abort_resumable) {
 		if (flags.isprefix || flags.istail || flags.dryrun ||
 		    flags.resumable || flags.nomount) {

include/libzfs_core.h

@@ -70,9 +70,9 @@ int lzc_receive_resumable(const char *, nvlist_t *, const char *,
     boolean_t, int);
 int lzc_receive_with_header(const char *, nvlist_t *, const char *, boolean_t,
     boolean_t, int, const struct dmu_replay_record *);
-int lzc_receive_one(const char *, nvlist_t *, const char *, boolean_t,
-    boolean_t, int, const struct dmu_replay_record *, int, uint64_t *,
-    uint64_t *, uint64_t *, nvlist_t **);
+int lzc_receive_one(const char *, nvlist_t *, nvlist_t *, const char *,
+    boolean_t, boolean_t, int, const struct dmu_replay_record *, int,
+    uint64_t *, uint64_t *, uint64_t *, nvlist_t **);
 
 boolean_t lzc_exists(const char *);