zfs send -p send properties only for snapshots that are actually sent

... as opposed to sending properties of all snapshots of the relevant
filesystem.  The previous behavior results in properties being set on
all snapshots on the receiving side, which is quite slow.

Behavior of zfs send -R is not changed.

References:
  http://thread.gmane.org/gmane.comp.file-systems.openzfs.devel/346

Ported-by: Richard Yao <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Issue #2729
Issue #2210

1 files changed, 25 insertions, 4 deletions

diff --git a/lib/libzfs/libzfs_sendrecv.c b/lib/libzfs/libzfs_sendrecv.c
index 3b4acc956..ef5747f64 100644
--- a/lib/libzfs/libzfs_sendrecv.c
+++ b/lib/libzfs/libzfs_sendrecv.c
@@ -577,6 +577,8 @@ typedef struct send_data {
 	const char *fromsnap;
 	const char *tosnap;
 	boolean_t recursive;
+	boolean_t seenfrom;
+	boolean_t seento;
 
 	/*
 	 * The header nvlist is of the following format:
@@ -611,20 +613,39 @@ send_iterate_snap(zfs_handle_t *zhp, void *arg)
 	uint64_t guid = zhp->zfs_dmustats.dds_guid;
 	char *snapname;
 	nvlist_t *nv;
+	boolean_t isfromsnap, istosnap;
 
 	snapname = strrchr(zhp->zfs_name, '@')+1;
+	isfromsnap = (sd->fromsnap != NULL &&
+	    strcmp(sd->fromsnap, snapname) == 0);
+	istosnap = (sd->tosnap != NULL && (strcmp(sd->tosnap, snapname) == 0));
 
-	VERIFY(0 == nvlist_add_uint64(sd->parent_snaps, snapname, guid));
 	/*
 	 * NB: if there is no fromsnap here (it's a newly created fs in
 	 * an incremental replication), we will substitute the tosnap.
 	 */
-	if ((sd->fromsnap && strcmp(snapname, sd->fromsnap) == 0) ||
-	    (sd->parent_fromsnap_guid == 0 && sd->tosnap &&
-	    strcmp(snapname, sd->tosnap) == 0)) {
+	if (isfromsnap || (sd->parent_fromsnap_guid == 0 && istosnap)) {
 		sd->parent_fromsnap_guid = guid;
 	}
 
+	if (!sd->recursive) {
+		if (!sd->seenfrom && isfromsnap) {
+			sd->seenfrom = B_TRUE;
+			zfs_close(zhp);
+			return (0);
+		}
+
+		if (sd->seento || !sd->seenfrom) {
+			zfs_close(zhp);
+			return (0);
+		}
+
+		if (istosnap)
+			sd->seento = B_TRUE;
+	}
+
+	VERIFY(0 == nvlist_add_uint64(sd->parent_snaps, snapname, guid));
+
 	VERIFY(0 == nvlist_alloc(&nv, NV_UNIQUE_NAME, 0));
 	send_iterate_prop(zhp, nv);
 	VERIFY(0 == nvlist_add_nvlist(sd->snapprops, snapname, nv));