nvpair: Constify string functions

After addressing coverity complaints involving `nvpair_name()`, the
compiler started complaining about dropping const. This lead to a rabbit
hole where not only `nvpair_name()` needed to be constified, but also
`nvpair_value_string()`, `fnvpair_value_string()` and a few other static
functions, plus variable pointers throughout the code. The result became
a fairly big change, so it has been split out into its own patch.

Reviewed-by: Tino Reichardt <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Richard Yao <[email protected]>
Closes #14612

1 files changed, 2 insertions, 2 deletions

diff --git a/lib/libzfs/libzfs_util.c b/lib/libzfs/libzfs_util.c
index 2507bfecd..b0d7b2afa 100644
--- a/lib/libzfs/libzfs_util.c
+++ b/lib/libzfs/libzfs_util.c
@@ -1595,13 +1595,13 @@ zfs_nicestrtonum(libzfs_handle_t *hdl, const char *value, uint64_t *num)
  */
 int
 zprop_parse_value(libzfs_handle_t *hdl, nvpair_t *elem, int prop,
-    zfs_type_t type, nvlist_t *ret, char **svalp, uint64_t *ivalp,
+    zfs_type_t type, nvlist_t *ret, const char **svalp, uint64_t *ivalp,
     const char *errbuf)
 {
 	data_type_t datatype = nvpair_type(elem);
 	zprop_type_t proptype;
 	const char *propname;
-	char *value;
+	const char *value;
 	boolean_t isnone = B_FALSE;
 	boolean_t isauto = B_FALSE;
 	int err = 0;