Enable -Wwrite-strings

Also, fix leak from ztest_global_vars_to_zdb_args()

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #13348

lib/libspl/include/os/linux/sys/mnttab.h

@@ -74,7 +74,7 @@ extern int getmntany(FILE *fp, struct mnttab *mp, struct mnttab *mpref);
 extern int _sol_getmntent(FILE *fp, struct mnttab *mp);
 extern int getextmntent(const char *path, struct extmnttab *mp,
     struct stat64 *statbuf);
-static inline char *_sol_hasmntopt(struct mnttab *mnt, char *opt)
+static inline char *_sol_hasmntopt(struct mnttab *mnt, const char *opt)
 {
 	struct mntent mnt_new;
 

lib/libspl/include/umem.h

@@ -140,7 +140,7 @@ umem_nofail_callback(umem_nofail_callback_t *cb __maybe_unused)
 
 static inline umem_cache_t *
 umem_cache_create(
-    char *name, size_t bufsize, size_t align,
+    const char *name, size_t bufsize, size_t align,
     umem_constructor_t *constructor,
     umem_destructor_t *destructor,
     umem_reclaim_t *reclaim,

lib/libzfs/libzfs_crypto.c

@@ -849,7 +849,8 @@ encryption_feature_is_enabled(zpool_handle_t *zph)
 static int
 populate_create_encryption_params_nvlists(libzfs_handle_t *hdl,
     zfs_handle_t *zhp, boolean_t newkey, zfs_keyformat_t keyformat,
-    char *keylocation, nvlist_t *props, uint8_t **wkeydata, uint_t *wkeylen)
+    const char *keylocation, nvlist_t *props, uint8_t **wkeydata,
+    uint_t *wkeylen)
 {
 	int ret;
 	uint64_t iters = 0, salt = 0;
@@ -1121,7 +1122,7 @@ zfs_crypto_create(libzfs_handle_t *hdl, char *parent_name, nvlist_t *props,
 
 	/* default to prompt if no keylocation is specified */
 	if (keyformat != ZFS_KEYFORMAT_NONE && keylocation == NULL) {
-		keylocation = "prompt";
+		keylocation = (char *)"prompt";
 		ret = nvlist_add_string(props,
 		    zfs_prop_to_name(ZFS_PROP_KEYLOCATION), keylocation);
 		if (ret != 0)
@@ -1699,7 +1700,7 @@ zfs_crypto_rewrap(zfs_handle_t *zhp, nvlist_t *raw_props, boolean_t inheritkey)
 
 			/* default to prompt if no keylocation is specified */
 			if (keylocation == NULL) {
-				keylocation = "prompt";
+				keylocation = (char *)"prompt";
 				ret = nvlist_add_string(props,
 				    zfs_prop_to_name(ZFS_PROP_KEYLOCATION),
 				    keylocation);

lib/libzfs/libzfs_dataset.c

@@ -882,7 +882,7 @@ libzfs_mnttab_find(libzfs_handle_t *hdl, const char *fsname,
 			return (ENOENT);
 
 		srch.mnt_special = (char *)fsname;
-		srch.mnt_fstype = MNTTYPE_ZFS;
+		srch.mnt_fstype = (char *)MNTTYPE_ZFS;
 		ret = getmntany(mnttab, entry, &srch) ? ENOENT : 0;
 		(void) fclose(mnttab);
 		return (ret);
@@ -2051,7 +2051,7 @@ getprop_uint64(zfs_handle_t *zhp, zfs_prop_t prop, char **source)
 		verify(!zhp->zfs_props_table ||
 		    zhp->zfs_props_table[prop] == B_TRUE);
 		value = zfs_prop_default_numeric(prop);
-		*source = "";
+		*source = (char *)"";
 	}
 
 	return (value);
@@ -2072,7 +2072,7 @@ getprop_string(zfs_handle_t *zhp, zfs_prop_t prop, char **source)
 		verify(!zhp->zfs_props_table ||
 		    zhp->zfs_props_table[prop] == B_TRUE);
 		value = zfs_prop_default_string(prop);
-		*source = "";
+		*source = (char *)"";
 	}
 
 	return (value);
@@ -2114,8 +2114,8 @@ get_numeric_property(zfs_handle_t *zhp, zfs_prop_t prop, zprop_source_t *src,
 	zfs_cmd_t zc = {"\0"};
 	nvlist_t *zplprops = NULL;
 	struct mnttab mnt;
-	char *mntopt_on = NULL;
-	char *mntopt_off = NULL;
+	const char *mntopt_on = NULL;
+	const char *mntopt_off = NULL;
 	boolean_t received = zfs_is_recvd_props_mode(zhp);
 
 	*source = NULL;
@@ -2194,7 +2194,7 @@ get_numeric_property(zfs_handle_t *zhp, zfs_prop_t prop, zprop_source_t *src,
 	}
 
 	if (zhp->zfs_mntopts == NULL)
-		mnt.mnt_mntopts = "";
+		mnt.mnt_mntopts = (char *)"";
 	else
 		mnt.mnt_mntopts = zhp->zfs_mntopts;
 

lib/libzfs/libzfs_impl.h

@@ -223,7 +223,7 @@ typedef struct differ_info {
 	int datafd;
 } differ_info_t;
 
-extern int do_mount(zfs_handle_t *zhp, const char *mntpt, char *opts,
+extern int do_mount(zfs_handle_t *zhp, const char *mntpt, const char *opts,
     int flags);
 extern int do_unmount(zfs_handle_t *zhp, const char *mntpt, int flags);
 extern int libzfs_load_module(void);

lib/libzfs/libzfs_mount.c

@@ -289,7 +289,7 @@ zfs_is_mountable(zfs_handle_t *zhp, char *buf, size_t buflen,
 
 static int
 zfs_add_option(zfs_handle_t *zhp, char *options, int len,
-    zfs_prop_t prop, char *on, char *off)
+    zfs_prop_t prop, const char *on, const char *off)
 {
 	char *source;
 	uint64_t value;

lib/libzfs/libzfs_pool.c

@@ -119,7 +119,7 @@ zpool_get_prop_string(zpool_handle_t *zhp, zpool_prop_t prop,
     zprop_source_t *src)
 {
 	nvlist_t *nv, *nvl;
-	char *value;
+	const char *value;
 	zprop_source_t source;
 
 	nvl = zhp->zpool_props;
@@ -128,7 +128,7 @@ zpool_get_prop_string(zpool_handle_t *zhp, zpool_prop_t prop,
 		value = fnvlist_lookup_string(nv, ZPROP_VALUE);
 	} else {
 		source = ZPROP_SRC_DEFAULT;
-		if ((value = (char *)zpool_prop_default_string(prop)) == NULL)
+		if ((value = zpool_prop_default_string(prop)) == NULL)
 			value = "-";
 	}
 
@@ -2111,7 +2111,7 @@ zpool_import_props(libzfs_handle_t *hdl, nvlist_t *config, const char *newname,
 		case EREMOTEIO:
 			if (nv != NULL && nvlist_lookup_nvlist(nv,
 			    ZPOOL_CONFIG_LOAD_INFO, &nvinfo) == 0) {
-				char *hostname = "<unknown>";
+				const char *hostname = "<unknown>";
 				uint64_t hostid = 0;
 				mmp_state_t mmp_state;
 
@@ -5029,7 +5029,7 @@ zpool_get_vdev_prop_value(nvlist_t *nvprop, vdev_prop_t prop, char *prop_name,
     char *buf, size_t len, zprop_source_t *srctype, boolean_t literal)
 {
 	nvlist_t *nv;
-	char *strval;
+	const char *strval;
 	uint64_t intval;
 	zprop_source_t src = ZPROP_SRC_NONE;
 
@@ -5059,8 +5059,7 @@ zpool_get_vdev_prop_value(nvlist_t *nvprop, vdev_prop_t prop, char *prop_name,
 			strval = fnvlist_lookup_string(nv, ZPROP_VALUE);
 		} else {
 			src = ZPROP_SRC_DEFAULT;
-			if ((strval = (char *)vdev_prop_default_string(prop))
-			    == NULL)
+			if ((strval = vdev_prop_default_string(prop)) == NULL)
 				strval = "-";
 		}
 		(void) strlcpy(buf, strval, len);

lib/libzfs/libzfs_sendrecv.c

@@ -2065,7 +2065,7 @@ send_prelim_records(zfs_handle_t *zhp, const char *from, int fd,
 	/* name of filesystem/volume that contains snapshot we are sending */
 	char tofs[ZFS_MAX_DATASET_NAME_LEN];
 	/* short name of snap we are sending */
-	char *tosnap = "";
+	const char *tosnap = "";
 
 	char errbuf[ERRBUFLEN];
 	(void) snprintf(errbuf, sizeof (errbuf), dgettext(TEXT_DOMAIN,

lib/libzfs/libzfs_status.c

@@ -56,7 +56,7 @@
  * in include/libzfs.h.  Note that there are some status results which go past
  * the end of this table, and hence have no associated message ID.
  */
-static char *zfs_msgid_table[] = {
+static const char *const zfs_msgid_table[] = {
 	"ZFS-8000-14", /* ZPOOL_STATUS_CORRUPT_CACHE */
 	"ZFS-8000-2Q", /* ZPOOL_STATUS_MISSING_DEV_R */
 	"ZFS-8000-3C", /* ZPOOL_STATUS_MISSING_DEV_NR */
@@ -495,7 +495,8 @@ check_status(nvlist_t *config, boolean_t isimport,
 }
 
 zpool_status_t
-zpool_get_status(zpool_handle_t *zhp, char **msgid, zpool_errata_t *errata)
+zpool_get_status(zpool_handle_t *zhp, const char **msgid,
+    zpool_errata_t *errata)
 {
 	/*
 	 * pass in the desired feature set, as
@@ -519,7 +520,8 @@ zpool_get_status(zpool_handle_t *zhp, char **msgid, zpool_errata_t *errata)
 }
 
 zpool_status_t
-zpool_import_status(nvlist_t *config, char **msgid, zpool_errata_t *errata)
+zpool_import_status(nvlist_t *config, const char **msgid,
+    zpool_errata_t *errata)
 {
 	zpool_status_t ret = check_status(config, B_TRUE, errata, NULL);
 

lib/libzfs/libzfs_util.c

@@ -999,16 +999,13 @@ libzfs_free_str_array(char **strs, int count)
  *
  * Returns 0 otherwise.
  */
-int
-libzfs_envvar_is_set(char *envvar)
+boolean_t
+libzfs_envvar_is_set(const char *envvar)
 {
 	char *env = getenv(envvar);
-	if (env && (strtoul(env, NULL, 0) > 0 ||
+	return (env && (strtoul(env, NULL, 0) > 0 ||
 	    (!strncasecmp(env, "YES", 3) && strnlen(env, 4) == 3) ||
-	    (!strncasecmp(env, "ON", 2) && strnlen(env, 3) == 2)))
-		return (1);
-
-	return (0);
+	    (!strncasecmp(env, "ON", 2) && strnlen(env, 3) == 2)));
 }
 
 libzfs_handle_t *
@@ -2002,22 +1999,22 @@ use_color(void)
  * color_end();
  */
 void
-color_start(char *color)
+color_start(const char *color)
 {
 	if (use_color())
-		printf("%s", color);
+		fputs(color, stdout);
 }
 
 void
 color_end(void)
 {
 	if (use_color())
-		printf(ANSI_RESET);
+		fputs(ANSI_RESET, stdout);
 }
 
 /* printf() with a color.  If color is NULL, then do a normal printf. */
 int
-printf_color(char *color, char *format, ...)
+printf_color(const char *color, const char *format, ...)
 {
 	va_list aptr;
 	int rc;

lib/libzfs/os/freebsd/libzfs_zmount.c

@@ -74,7 +74,7 @@ build_iovec(struct iovec **iov, int *iovlen, const char *name, void *val,
 }
 
 static int
-do_mount_(const char *spec, const char *dir, int mflag, char *fstype,
+do_mount_(const char *spec, const char *dir, int mflag,
     char *dataptr, int datalen, char *optptr, int optlen)
 {
 	struct iovec *iov;
@@ -83,8 +83,6 @@ do_mount_(const char *spec, const char *dir, int mflag, char *fstype,
 
 	assert(spec != NULL);
 	assert(dir != NULL);
-	assert(fstype != NULL);
-	assert(strcmp(fstype, MNTTYPE_ZFS) == 0);
 	assert(dataptr == NULL), (void) dataptr;
 	assert(datalen == 0), (void) datalen;
 	assert(optptr != NULL);
@@ -99,7 +97,8 @@ do_mount_(const char *spec, const char *dir, int mflag, char *fstype,
 		build_iovec(&iov, &iovlen, "update", NULL, 0);
 	if (mflag & MS_RDONLY)
 		build_iovec(&iov, &iovlen, "ro", NULL, 0);
-	build_iovec(&iov, &iovlen, "fstype", fstype, (size_t)-1);
+	build_iovec(&iov, &iovlen, "fstype", __DECONST(char *, MNTTYPE_ZFS),
+	    (size_t)-1);
 	build_iovec(&iov, &iovlen, "fspath", __DECONST(char *, dir),
 	    (size_t)-1);
 	build_iovec(&iov, &iovlen, "from", __DECONST(char *, spec), (size_t)-1);
@@ -113,10 +112,10 @@ do_mount_(const char *spec, const char *dir, int mflag, char *fstype,
 }
 
 int
-do_mount(zfs_handle_t *zhp, const char *mntpt, char *opts, int flags)
+do_mount(zfs_handle_t *zhp, const char *mntpt, const char *opts, int flags)
 {
 
-	return (do_mount_(zfs_get_name(zhp), mntpt, flags, MNTTYPE_ZFS, NULL, 0,
+	return (do_mount_(zfs_get_name(zhp), mntpt, flags, NULL, 0,
 	    opts, sizeof (mntpt)));
 }
 

lib/libzfs/os/linux/libzfs_mount_os.c

@@ -180,7 +180,7 @@ out:
  * otherwise they are considered fatal are copied in to badopt.
  */
 int
-zfs_parse_mount_options(char *mntopts, unsigned long *mntflags,
+zfs_parse_mount_options(const char *mntopts, unsigned long *mntflags,
     unsigned long *zfsflags, int sloppy, char *badopt, char *mtabopt)
 {
 	int error = 0, quote = 0, flag = 0, count = 0;
@@ -320,7 +320,7 @@ zfs_adjust_mount_options(zfs_handle_t *zhp, const char *mntpoint,
  * make due with return value from the mount process.
  */
 int
-do_mount(zfs_handle_t *zhp, const char *mntpt, char *opts, int flags)
+do_mount(zfs_handle_t *zhp, const char *mntpt, const char *opts, int flags)
 {
 	const char *src = zfs_get_name(zhp);
 	int error = 0;
@@ -341,10 +341,10 @@ do_mount(zfs_handle_t *zhp, const char *mntpt, char *opts, int flags)
 		}
 	} else {
 		char *argv[9] = {
-		    "/bin/mount",
-		    "--no-canonicalize",
-		    "-t", MNTTYPE_ZFS,
-		    "-o", opts,
+		    (char *)"/bin/mount",
+		    (char *)"--no-canonicalize",
+		    (char *)"-t", (char *)MNTTYPE_ZFS,
+		    (char *)"-o", (char *)opts,
 		    (char *)src,
 		    (char *)mntpt,
 		    (char *)NULL };
@@ -384,23 +384,17 @@ do_unmount(zfs_handle_t *zhp, const char *mntpt, int flags)
 		return (rv < 0 ? errno : 0);
 	}
 
-	char force_opt[] = "-f";
-	char lazy_opt[] = "-l";
 	char *argv[7] = {
-	    "/bin/umount",
-	    "-t", MNTTYPE_ZFS,
+	    (char *)"/bin/umount",
+	    (char *)"-t", (char *)MNTTYPE_ZFS,
 	    NULL, NULL, NULL, NULL };
 	int rc, count = 3;
 
-	if (flags & MS_FORCE) {
-		argv[count] = force_opt;
-		count++;
-	}
+	if (flags & MS_FORCE)
+		argv[count++] = (char *)"-f";
 
-	if (flags & MS_DETACH) {
-		argv[count] = lazy_opt;
-		count++;
-	}
+	if (flags & MS_DETACH)
+		argv[count++] = (char *)"-l";
 
 	argv[count] = (char *)mntpt;
 	rc = libzfs_run_process(argv[0], argv, STDOUT_VERBOSE|STDERR_VERBOSE);

lib/libzfs/os/linux/libzfs_util_os.c

@@ -99,7 +99,7 @@ libzfs_load_module(void)
 		return (0);
 
 	if (access(ZFS_SYSFS_DIR, F_OK) != 0) {
-		char *argv[] = {"modprobe", "zfs", NULL};
+		char *argv[] = {(char *)"modprobe", (char *)"zfs", NULL};
 		if (libzfs_run_process("modprobe", argv, 0))
 			return (ENOEXEC);
 

lib/libzpool/kernel.c

@@ -1002,8 +1002,6 @@ kmem_cache_reap_active(void)
 	return (0);
 }
 
-void *zvol_tag = "zvol_tag";
-
 void
 zvol_create_minor(const char *name)
 {

lib/libzpool/util.c

@@ -64,7 +64,8 @@ show_vdev_stats(const char *desc, const char *ctype, nvlist_t *nv, int indent)
 	}
 
 	if (desc != NULL) {
-		char *suffix = "", *bias = NULL;
+		const char *suffix = "";
+		char *bias = NULL;
 		char bias_suffix[32];
 
 		(void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_IS_LOG, &is_log);
@@ -117,7 +118,7 @@ show_vdev_stats(const char *desc, const char *ctype, nvlist_t *nv, int indent)
 		int len;
 		if (nvlist_lookup_string(cnv, ZPOOL_CONFIG_PATH, &cname) &&
 		    nvlist_lookup_string(cnv, ZPOOL_CONFIG_TYPE, &cname))
-			cname = "<unknown>";
+			cname = (char *)"<unknown>";
 		len = strlen(cname) + 2;
 		tname = umem_zalloc(len, UMEM_NOFAIL);
 		(void) strlcpy(tname, cname, len);

lib/libzutil/os/linux/zutil_import_os.c

@@ -328,7 +328,9 @@ zpool_find_import_blkid(libpc_handle_t *hdl, pthread_mutex_t *lock,
 		return (EINVAL);
 	}
 
-	error = blkid_dev_set_search(iter, "TYPE", "zfs_member");
+	/* Only const char *s since 2.32 */
+	error = blkid_dev_set_search(iter,
+	    (char *)"TYPE", (char *)"zfs_member");
 	if (error != 0) {
 		blkid_dev_iterate_end(iter);
 		blkid_put_cache(cache);

lib/libzutil/zutil_import.c

@@ -1543,7 +1543,7 @@ discover_cached_paths(libpc_handle_t *hdl, nvlist_t *nv,
 	 */
 	if (nvlist_lookup_string(nv, ZPOOL_CONFIG_PATH, &path) == 0) {
 		if ((dl = zfs_dirnamelen(path)) == -1)
-			path = ".";
+			path = (char *)".";
 		else
 			path[dl] = '\0';
 		return (zpool_find_import_scan_dir(hdl, lock, cache,