libzfs_sendrecv: Style pass on send_iterate_prop

* Add a high level comment.
* Move locals closer to point of use.
* Use fnv* routines rather than explicit verification of success.
* Factor out duplicated code by introducing isspacelimit to clarify
  behavior.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <freqlabs@FreeBSD.org>
Closes #12967

diff --git a/lib/libzfs/libzfs_sendrecv.c b/lib/libzfs/libzfs_sendrecv.c
index 8e037cde66a8cce90bcbee16b3cdc248be70d2c1..d271db30311a33307afd5453d394ace345e2209d 100644 (file)
--- a/lib/libzfs/libzfs_sendrecv.c
+++ b/lib/libzfs/libzfs_sendrecv.c
@@ -364,21 +364,23 @@ send_iterate_snap(zfs_handle_t *zhp, void *arg)
        return (0);
 }
 
+/*
+ * Collect all valid props from the handle snap into an nvlist.
+ */
 static void
 send_iterate_prop(zfs_handle_t *zhp, boolean_t received_only, nvlist_t *nv)
 {
-       nvlist_t *props = NULL;
-       nvpair_t *elem = NULL;
+       nvlist_t *props;
 
        if (received_only)
                props = zfs_get_recvd_props(zhp);
        else
                props = zhp->zfs_props;
 
+       nvpair_t *elem = NULL;
        while ((elem = nvlist_next_nvpair(props, elem)) != NULL) {
                char *propname = nvpair_name(elem);
                zfs_prop_t prop = zfs_name_to_prop(propname);
-               nvlist_t *propnv;
 
                if (!zfs_prop_user(propname)) {
                        /*
@@ -396,34 +398,26 @@ send_iterate_prop(zfs_handle_t *zhp, boolean_t received_only, nvlist_t *nv)
                                continue;
                }
 
-               verify(nvpair_value_nvlist(elem, &propnv) == 0);
-               if (prop == ZFS_PROP_QUOTA || prop == ZFS_PROP_RESERVATION ||
+               nvlist_t *propnv = fnvpair_value_nvlist(elem);
+
+               boolean_t isspacelimit = (prop == ZFS_PROP_QUOTA ||
+                   prop == ZFS_PROP_RESERVATION ||
                    prop == ZFS_PROP_REFQUOTA ||
-                   prop == ZFS_PROP_REFRESERVATION) {
-                       char *source;
-                       uint64_t value;
-                       verify(nvlist_lookup_uint64(propnv,
-                           ZPROP_VALUE, &value) == 0);
-                       if (zhp->zfs_type == ZFS_TYPE_SNAPSHOT)
+                   prop == ZFS_PROP_REFRESERVATION);
+               if (isspacelimit && zhp->zfs_type == ZFS_TYPE_SNAPSHOT)
+                       continue;
+
+               char *source;
+               if (nvlist_lookup_string(propnv, ZPROP_SOURCE, &source) == 0) {
+                       if (strcmp(source, zhp->zfs_name) != 0 &&
+                           strcmp(source, ZPROP_SOURCE_VAL_RECVD) != 0)
                                continue;
+               } else {
                        /*
                         * May have no source before SPA_VERSION_RECVD_PROPS,
                         * but is still modifiable.
                         */
-                       if (nvlist_lookup_string(propnv,
-                           ZPROP_SOURCE, &source) == 0) {
-                               if ((strcmp(source, zhp->zfs_name) != 0) &&
-                                   (strcmp(source,
-                                   ZPROP_SOURCE_VAL_RECVD) != 0))
-                                       continue;
-                       }
-               } else {
-                       char *source;
-                       if (nvlist_lookup_string(propnv,
-                           ZPROP_SOURCE, &source) != 0)
-                               continue;
-                       if ((strcmp(source, zhp->zfs_name) != 0) &&
-                           (strcmp(source, ZPROP_SOURCE_VAL_RECVD) != 0))
+                       if (!isspacelimit)
                                continue;
                }