btrfs-progs: rename and move __strncpy_null to string-utils

Now that there's only __strncpy_null we can drop the underscore and move
it to string-utils as it's a generic string function rather than
something for paths.

Signed-off-by: David Sterba <dsterba@suse.com>

cmds/device.c

@@ -169,7 +169,7 @@ static int cmd_device_add(const struct cmd_struct *cmd,
 		}
 
 		memset(&ioctl_args, 0, sizeof(ioctl_args));
-		__strncpy_null(ioctl_args.name, path, sizeof(ioctl_args.name));
+		strncpy_null(ioctl_args.name, path, sizeof(ioctl_args.name));
 		res = ioctl(fdmnt, BTRFS_IOC_ADD_DEV, &ioctl_args);
 		if (res < 0) {
 			error("error adding device '%s': %m", path);
@@ -287,7 +287,7 @@ static int _cmd_device_remove(const struct cmd_struct *cmd,
 		} else if (strcmp(argv[i], "missing") == 0 ||
 			   cancel ||
 			   path_is_block_device(argv[i]) == 1) {
-			__strncpy_null(argv2.name, argv[i], sizeof(argv2.name));
+			strncpy_null(argv2.name, argv[i], sizeof(argv2.name));
 		} else {
 			error("not a block device: %s", argv[i]);
 			ret++;
@@ -312,7 +312,7 @@ static int _cmd_device_remove(const struct cmd_struct *cmd,
 				continue;
 			}
 			memset(&arg, 0, sizeof(arg));
-			__strncpy_null(arg.name, argv[i], sizeof(arg.name));
+			strncpy_null(arg.name, argv[i], sizeof(arg.name));
 			res = ioctl(fdmnt, BTRFS_IOC_RM_DEV, &arg);
 		}
 
@@ -396,7 +396,7 @@ static int btrfs_forget_devices(const char *path)
 
 	memset(&args, 0, sizeof(args));
 	if (path)
-		__strncpy_null(args.name, path, sizeof(args.name));
+		strncpy_null(args.name, path, sizeof(args.name));
 	ret = ioctl(fd, BTRFS_IOC_FORGET_DEV, &args);
 	if (ret)
 		ret = -errno;
@@ -557,7 +557,7 @@ static int cmd_device_ready(const struct cmd_struct *cmd, int argc, char **argv)
 	}
 
 	memset(&args, 0, sizeof(args));
-	__strncpy_null(args.name, path, sizeof(args.name));
+	strncpy_null(args.name, path, sizeof(args.name));
 	ret = ioctl(fd, BTRFS_IOC_DEVICES_READY, &args);
 	if (ret < 0) {
 		error("unable to determine if device '%s' is ready for mount: %m",

cmds/filesystem.c

@@ -1441,7 +1441,7 @@ static int cmd_filesystem_resize(const struct cmd_struct *cmd,
 	memset(&args, 0, sizeof(args));
 	if (devid == (u64)-1) {
 		/* Ok to copy the string verbatim. */
-		__strncpy_null(args.name, amount, sizeof(args.name));
+		strncpy_null(args.name, amount, sizeof(args.name));
 	} else {
 		/* The implicit devid 1 needs to be adjusted. */
 		snprintf(args.name, sizeof(args.name) - 1, "%llu:%s", devid, amount);

cmds/receive.c

@@ -179,7 +179,7 @@ static int process_subvol(const char *path, const u8 *uuid, u64 ctransid,
 	}
 
 	if (*rctx->dest_dir_path == 0) {
-		__strncpy_null(rctx->cur_subvol_path, path, sizeof(rctx->cur_subvol_path));
+		strncpy_null(rctx->cur_subvol_path, path, sizeof(rctx->cur_subvol_path));
 	} else {
 		ret = path_cat_out(rctx->cur_subvol_path, rctx->dest_dir_path,
 				   path);
@@ -209,7 +209,7 @@ static int process_subvol(const char *path, const u8 *uuid, u64 ctransid,
 	}
 
 	memset(&args_v1, 0, sizeof(args_v1));
-	__strncpy_null(args_v1.name, path, sizeof(args_v1.name));
+	strncpy_null(args_v1.name, path, sizeof(args_v1.name));
 	ret = ioctl(rctx->dest_dir_fd, BTRFS_IOC_SUBVOL_CREATE, &args_v1);
 	if (ret < 0) {
 		ret = -errno;
@@ -249,7 +249,7 @@ static int process_snapshot(const char *path, const u8 *uuid, u64 ctransid,
 	}
 
 	if (*rctx->dest_dir_path == 0) {
-		__strncpy_null(rctx->cur_subvol_path, path, sizeof(rctx->cur_subvol_path));
+		strncpy_null(rctx->cur_subvol_path, path, sizeof(rctx->cur_subvol_path));
 	} else {
 		ret = path_cat_out(rctx->cur_subvol_path, rctx->dest_dir_path,
 				   path);
@@ -281,7 +281,7 @@ static int process_snapshot(const char *path, const u8 *uuid, u64 ctransid,
 	}
 
 	memset(&args_v2, 0, sizeof(args_v2));
-	__strncpy_null(args_v2.name, path, sizeof(args_v2.name));
+	strncpy_null(args_v2.name, path, sizeof(args_v2.name));
 
 	parent_subvol = subvol_uuid_search(rctx->mnt_fd, 0, parent_uuid,
 					   parent_ctransid, NULL,
@@ -663,7 +663,7 @@ static int open_inode_for_write(struct btrfs_receive *rctx, const char *path)
 		error("cannot open %s: %m", path);
 		goto out;
 	}
-	__strncpy_null(rctx->write_path, path, sizeof(rctx->write_path));
+	strncpy_null(rctx->write_path, path, sizeof(rctx->write_path));
 
 out:
 	return ret;

cmds/subvolume.c

@@ -197,7 +197,7 @@ static int create_one_subvolume(const char *dst, struct btrfs_qgroup_inherit *in
 		char dstdir_dup[PATH_MAX];
 		char *token;
 
-		__strncpy_null(dstdir_dup, dstdir, sizeof(dstdir_dup));
+		strncpy_null(dstdir_dup, dstdir, sizeof(dstdir_dup));
 		if (dstdir_dup[0] == '/')
 			strcat(p, "/");
 
@@ -233,7 +233,7 @@ static int create_one_subvolume(const char *dst, struct btrfs_qgroup_inherit *in
 		struct btrfs_ioctl_vol_args_v2	args;
 
 		memset(&args, 0, sizeof(args));
-		__strncpy_null(args.name, newname, sizeof(args.name));
+		strncpy_null(args.name, newname, sizeof(args.name));
 		args.flags |= BTRFS_SUBVOL_QGROUP_INHERIT;
 		args.size = btrfs_qgroup_inherit_size(inherit);
 		args.qgroup_inherit = inherit;
@@ -243,7 +243,7 @@ static int create_one_subvolume(const char *dst, struct btrfs_qgroup_inherit *in
 		struct btrfs_ioctl_vol_args	args;
 
 		memset(&args, 0, sizeof(args));
-		__strncpy_null(args.name, newname, sizeof(args.name));
+		strncpy_null(args.name, newname, sizeof(args.name));
 		ret = ioctl(fddst, BTRFS_IOC_SUBVOL_CREATE, &args);
 	}
 
@@ -737,7 +737,7 @@ static int cmd_subvolume_snapshot(const struct cmd_struct *cmd, int argc, char *
 		args.size = btrfs_qgroup_inherit_size(inherit);
 		args.qgroup_inherit = inherit;
 	}
-	__strncpy_null(args.name, newname, sizeof(args.name));
+	strncpy_null(args.name, newname, sizeof(args.name));
 
 	res = ioctl(fddst, BTRFS_IOC_SNAP_CREATE_V2, &args);
 	if (res < 0) {

common/device-scan.c

@@ -51,6 +51,7 @@
 #include "common/utils.h"
 #include "common/defs.h"
 #include "common/open-utils.h"
+#include "common/string-utils.h"
 #include "common/units.h"
 
 static int btrfs_scan_done = 0;
@@ -237,7 +238,7 @@ int btrfs_register_one_device(const char *fname)
 		return -errno;
 	}
 	memset(&args, 0, sizeof(args));
-	__strncpy_null(args.name, fname, sizeof(args.name));
+	strncpy_null(args.name, fname, sizeof(args.name));
 	ret = ioctl(fd, BTRFS_IOC_SCAN_DEV, &args);
 	if (ret < 0) {
 		error("device scan failed on '%s': %m", fname);
@@ -468,7 +469,7 @@ int btrfs_scan_devices(int verbose)
 		if (!dev)
 			continue;
 		/* if we are here its definitely a btrfs disk*/
-		__strncpy_null(path, blkid_dev_devname(dev), sizeof(path));
+		strncpy_null(path, blkid_dev_devname(dev), sizeof(path));
 
 		if (stat(path, &dev_stat) < 0)
 			continue;

common/filesystem-utils.c

@@ -28,6 +28,7 @@
 #include "common/filesystem-utils.h"
 #include "common/messages.h"
 #include "common/open-utils.h"
+#include "common/string-utils.h"
 #include "common/path-utils.h"
 
 /*
@@ -102,7 +103,7 @@ static int set_label_unmounted(const char *dev, const char *label)
 		error_msg(ERROR_MSG_START_TRANS, "set label");
 		return PTR_ERR(trans);
 	}
-	__strncpy_null(root->fs_info->super_copy->label, label, BTRFS_LABEL_SIZE);
+	strncpy_null(root->fs_info->super_copy->label, label, BTRFS_LABEL_SIZE);
 
 	btrfs_commit_transaction(trans, root);
 
@@ -123,7 +124,7 @@ static int set_label_mounted(const char *mount_path, const char *labelp)
 	}
 
 	memset(label, 0, sizeof(label));
-	__strncpy_null(label, labelp, BTRFS_LABEL_SIZE);
+	strncpy_null(label, labelp, BTRFS_LABEL_SIZE);
 	if (ioctl(fd, BTRFS_IOC_SET_FSLABEL, label) < 0) {
 		error("unable to set label of %s: %m", mount_path);
 		close(fd);
@@ -152,8 +153,7 @@ int get_label_unmounted(const char *dev, char *label)
 	if(!root)
 		return -1;
 
-	__strncpy_null(label, root->fs_info->super_copy->label,
+	strncpy_null(label, root->fs_info->super_copy->label, BTRFS_LABEL_SIZE);
-			BTRFS_LABEL_SIZE);
 
 	/* Now we close it since we are done. */
 	close_ctree(root);
@@ -187,7 +187,7 @@ int get_label_mounted(const char *mount_path, char *labelp)
 		return ret;
 	}
 
-	__strncpy_null(labelp, label, BTRFS_LABEL_SIZE);
+	strncpy_null(labelp, label, BTRFS_LABEL_SIZE);
 	close(fd);
 	return 0;
 }

common/path-utils.c

@@ -35,6 +35,7 @@
  */
 #include <libgen.h>
 #include <limits.h>
+#include "common/string-utils.h"
 #include "common/path-utils.h"
 
 /*
@@ -193,10 +194,10 @@ static int is_same_blk_file(const char* a, const char* b)
 	char real_b[PATH_MAX];
 
 	if (!realpath(a, real_a))
-		__strncpy_null(real_a, a, sizeof(real_a));
+		strncpy_null(real_a, a, sizeof(real_a));
 
 	if (!realpath(b, real_b))
-		__strncpy_null(real_b, b, sizeof(real_b));
+		strncpy_null(real_b, b, sizeof(real_b));
 
 	/* Identical path? */
 	if (strcmp(real_a, real_b) == 0)
@@ -345,26 +346,6 @@ char *path_canonicalize(const char *path)
 	return canonical;
 }
 
-/*
- * __strncpy_null - strncpy with null termination
- * @dest:	the target array
- * @src:	the source string
- * @n:		maximum bytes to copy (size of *dest)
- *
- * Like strncpy, but ensures destination is null-terminated.
- *
- * Copies the string pointed to by src, including the terminating null
- * byte ('\0'), to the buffer pointed to by dest, up to a maximum
- * of n bytes.  Then ensure that dest is null-terminated.
- */
-char *__strncpy_null(char *dest, const char *src, size_t n)
-{
-	strncpy(dest, src, n);
-	if (n > 0)
-		dest[n - 1] = '\0';
-	return dest;
-}
-
 /*
  * Test if path is a directory
  * Returns:
@@ -403,7 +384,7 @@ int path_is_in_dir(const char *parent, const char *path)
 	char *curr_dir = tmp;
 	int ret;
 
-	__strncpy_null(tmp, path, sizeof(tmp));
+	strncpy_null(tmp, path, sizeof(tmp));
 
 	while (strcmp(parent, curr_dir) != 0) {
 		if (strcmp(curr_dir, "/") == 0) {
@@ -432,7 +413,7 @@ int arg_copy_path(char *dest, const char *src, int destlen)
 	if (len >= PATH_MAX || len >= destlen)
 		return -ENAMETOOLONG;
 
-	__strncpy_null(dest, src, destlen);
+	strncpy_null(dest, src, destlen);
 
 	return 0;
 }

common/path-utils.h

@@ -26,11 +26,6 @@ char *path_canonicalize(const char *path);
 int arg_copy_path(char *dest, const char *src, int destlen);
 int path_cat_out(char *out, const char *p1, const char *p2);
 int path_cat3_out(char *out, const char *p1, const char *p2, const char *p3);
-
-char *__strncpy_null(char *dest, const char *src, size_t n);
-/* Helper to always get proper size of the destination string */
-#define strncpy_null(dest, src) __strncpy_null(dest, src, sizeof(dest))
-
 int path_is_block_device(const char *file);
 int path_is_a_mount_point(const char *file);
 int path_exists(const char *file);

common/string-utils.c

@@ -44,6 +44,26 @@ int string_has_prefix(const char *str, const char *prefix)
 			return (unsigned char)*prefix - (unsigned char)*str;
 }
 
+/*
+ * strncpy_null - strncpy with null termination
+ * @dest:	the target array
+ * @src:	the source string
+ * @n:		maximum bytes to copy (size of *dest)
+ *
+ * Like strncpy, but ensures destination is null-terminated.
+ *
+ * Copies the string pointed to by src, including the terminating null
+ * byte ('\0'), to the buffer pointed to by dest, up to a maximum
+ * of n bytes.  Then ensure that dest is null-terminated.
+ */
+char *strncpy_null(char *dest, const char *src, size_t n)
+{
+	strncpy(dest, src, n);
+	if (n > 0)
+		dest[n - 1] = '\0';
+	return dest;
+}
+
 /*
  * This function should be only used when parsing command arg, it won't return
  * error to its caller and rather exit directly just like usage().

common/string-utils.h

@@ -22,6 +22,8 @@
 int string_is_numerical(const char *str);
 int string_has_prefix(const char *str, const char *prefix);
 
+char *strncpy_null(char *dest, const char *src, size_t n);
+
 /*
  * Helpers prefixed by arg_* can exit if the argument is invalid and are supposed
  * to be used when parsing command line options where the immediate exit is valid

convert/common.c

@@ -30,6 +30,7 @@
 #include "kernel-shared/uapi/btrfs_tree.h"
 #include "common/path-utils.h"
 #include "common/messages.h"
+#include "common/string-utils.h"
 #include "common/fsfeatures.h"
 #include "mkfs/common.h"
 #include "convert/common.h"
@@ -148,7 +149,7 @@ static int setup_temp_super(int fd, struct btrfs_mkfs_config *cfg,
 	btrfs_set_super_cache_generation(&super, -1);
 	btrfs_set_super_incompat_flags(&super, cfg->features.incompat_flags);
 	if (cfg->label)
-		__strncpy_null(super.label, cfg->label, BTRFS_LABEL_SIZE);
+		strncpy_null(super.label, cfg->label, BTRFS_LABEL_SIZE);
 
 	/* Sys chunk array will be re-initialized at chunk tree init time */
 	super.sys_chunk_array_size = 0;

convert/main.c

@@ -1322,8 +1322,7 @@ static int do_convert(const char *devname, u32 convert_flags, u32 nodesize,
 
 	memset(root->fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
 	if (convert_flags & CONVERT_FLAG_COPY_LABEL) {
-		__strncpy_null(root->fs_info->super_copy->label,
+		strncpy_null(root->fs_info->super_copy->label, cctx.label, BTRFS_LABEL_SIZE);
-				cctx.label, BTRFS_LABEL_SIZE);
 		printf("Copy label '%s'\n", root->fs_info->super_copy->label);
 	} else if (convert_flags & CONVERT_FLAG_SET_LABEL) {
 		strcpy(root->fs_info->super_copy->label, fslabel);
@@ -1938,7 +1937,7 @@ int BOX_MAIN(convert)(int argc, char *argv[])
 					"label too long, trimmed to %d bytes",
 						BTRFS_LABEL_SIZE - 1);
 				}
-				__strncpy_null(fslabel, optarg, BTRFS_LABEL_SIZE);
+				strncpy_null(fslabel, optarg, BTRFS_LABEL_SIZE);
 				break;
 			case 'L':
 				copylabel = CONVERT_FLAG_COPY_LABEL;

mkfs/common.c

@@ -38,6 +38,7 @@
 #include "common/path-utils.h"
 #include "common/device-utils.h"
 #include "common/open-utils.h"
+#include "common/string-utils.h"
 #include "mkfs/common.h"
 
 static u64 reference_root_table[] = {
@@ -476,7 +477,7 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
 		btrfs_set_super_nr_global_roots(&super, 1);
 
 	if (cfg->label)
-		__strncpy_null(super.label, cfg->label, BTRFS_LABEL_SIZE);
+		strncpy_null(super.label, cfg->label, BTRFS_LABEL_SIZE);
 
 	/* create the tree of root objects */
 	memset(buf->data, 0, cfg->nodesize);