Throw const on some strings

In C, const indicates to the reader that mutation will not occur.
It can also serve as a hint about ownership.

Add const in a few places where it makes sense.

Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Ryan Moeller <[email protected]>
Closes #10997 

1 files changed, 15 insertions, 16 deletions

diff --git a/module/zfs/zfs_ioctl.c b/module/zfs/zfs_ioctl.c
index d2550750c..94cd1a3dc 100644
--- a/module/zfs/zfs_ioctl.c
+++ b/module/zfs/zfs_ioctl.c
@@ -270,7 +270,7 @@ static int zfs_ioc_userspace_upgrade(zfs_cmd_t *zc);
 static int zfs_ioc_id_quota_upgrade(zfs_cmd_t *zc);
 static int zfs_check_settable(const char *name, nvpair_t *property,
     cred_t *cr);
-static int zfs_check_clearable(char *dataset, nvlist_t *props,
+static int zfs_check_clearable(const char *dataset, nvlist_t *props,
     nvlist_t **errors);
 static int zfs_fill_zplprops_root(uint64_t, nvlist_t *, nvlist_t *,
     boolean_t *);
@@ -498,7 +498,7 @@ zfs_secpolicy_write_perms(const char *name, const char *perm, cred_t *cr)
  * Returns 0 for success, non-zero for access and other errors.
  */
 static int
-zfs_set_slabel_policy(const char *name, char *strval, cred_t *cr)
+zfs_set_slabel_policy(const char *name, const char *strval, cred_t *cr)
 {
 #ifdef HAVE_MLSLABEL
 	char		ds_hexsl[MAXNAMELEN];
@@ -553,7 +553,7 @@ zfs_set_slabel_policy(const char *name, char *strval, cred_t *cr)
 	 */
 	if (strcasecmp(ds_hexsl, ZFS_MLSLABEL_DEFAULT) != 0) {
 		objset_t *os;
-		static char *setsl_tag = "setsl_tag";
+		static const char *setsl_tag = "setsl_tag";
 
 		/*
 		 * Try to own the dataset; abort if there is any error,
@@ -680,7 +680,7 @@ zfs_secpolicy_send(zfs_cmd_t *zc, nvlist_t *innvl, cred_t *cr)
 {
 	dsl_pool_t *dp;
 	dsl_dataset_t *ds;
-	char *cp;
+	const char *cp;
 	int error;
 
 	/*
@@ -1443,7 +1443,7 @@ zfs_ioc_pool_create(zfs_cmd_t *zc)
 	nvlist_t *rootprops = NULL;
 	nvlist_t *zplprops = NULL;
 	dsl_crypto_params_t *dcp = NULL;
-	char *spa_name = zc->zc_name;
+	const char *spa_name = zc->zc_name;
 	boolean_t unload_wkey = B_TRUE;
 
 	if ((error = get_nvlist(zc->zc_nvlist_conf, zc->zc_nvlist_conf_size,
@@ -1997,7 +1997,7 @@ static int
 zfs_ioc_vdev_setpath(zfs_cmd_t *zc)
 {
 	spa_t *spa;
-	char *path = zc->zc_value;
+	const char *path = zc->zc_value;
 	uint64_t guid = zc->zc_guid;
 	int error;
 
@@ -2014,7 +2014,7 @@ static int
 zfs_ioc_vdev_setfru(zfs_cmd_t *zc)
 {
 	spa_t *spa;
-	char *fru = zc->zc_value;
+	const char *fru = zc->zc_value;
 	uint64_t guid = zc->zc_guid;
 	int error;
 
@@ -2351,8 +2351,7 @@ zfs_prop_set_userquota(const char *dsname, nvpair_t *pair)
 	const char *propname = nvpair_name(pair);
 	uint64_t *valary;
 	unsigned int vallen;
-	const char *domain;
-	char *dash;
+	const char *dash, *domain;
 	zfs_userquota_prop_t type;
 	uint64_t rid;
 	uint64_t quota;
@@ -2405,7 +2404,7 @@ zfs_prop_set_special(const char *dsname, zprop_source_t source,
 	const char *propname = nvpair_name(pair);
 	zfs_prop_t prop = zfs_name_to_prop(propname);
 	uint64_t intval = 0;
-	char *strval = NULL;
+	const char *strval = NULL;
 	int err = -1;
 
 	if (prop == ZPROP_INVAL) {
@@ -2531,7 +2530,7 @@ zfs_set_prop_nvlist(const char *dsname, zprop_source_t source, nvlist_t *nvl,
 	nvpair_t *propval;
 	int rv = 0;
 	uint64_t intval;
-	char *strval;
+	const char *strval;
 
 	nvlist_t *genericnvl = fnvlist_alloc();
 	nvlist_t *retrynvl = fnvlist_alloc();
@@ -3349,7 +3348,7 @@ zfs_ioc_clone(const char *fsname, nvlist_t *innvl, nvlist_t *outnvl)
 {
 	int error = 0;
 	nvlist_t *nvprops = NULL;
-	char *origin_name;
+	const char *origin_name;
 
 	origin_name = fnvlist_lookup_string(innvl, "origin");
 	(void) nvlist_lookup_nvlist(innvl, "props", &nvprops);
@@ -3475,10 +3474,10 @@ static const zfs_ioc_key_t zfs_keys_log_history[] = {
 static int
 zfs_ioc_log_history(const char *unused, nvlist_t *innvl, nvlist_t *outnvl)
 {
-	char *message;
+	const char *message;
+	char *poolname;
 	spa_t *spa;
 	int error;
-	char *poolname;
 
 	/*
 	 * The poolname in the ioctl is not set, we get it from the TSD,
@@ -3574,7 +3573,7 @@ zfs_unmount_snap(const char *snapname)
 	if (strchr(snapname, '@') == NULL)
 		return;
 
-	(void) zfsctl_snapshot_unmount((char *)snapname, MNT_FORCE);
+	(void) zfsctl_snapshot_unmount(snapname, MNT_FORCE);
 }
 
 /* ARGSUSED */
@@ -4617,7 +4616,7 @@ zfs_check_settable(const char *dsname, nvpair_t *pair, cred_t *cr)
  * pointed at by errlist is NULL.
  */
 static int
-zfs_check_clearable(char *dataset, nvlist_t *props, nvlist_t **errlist)
+zfs_check_clearable(const char *dataset, nvlist_t *props, nvlist_t **errlist)
 {
 	zfs_cmd_t *zc;
 	nvpair_t *pair, *next_pair;