orangefs-debugfs.c 25.3 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058
/*
 * What:		/sys/kernel/debug/orangefs/debug-help
 * Date:		June 2015
 * Contact:		Mike Marshall <hubcap@omnibond.com>
 * Description:
 * 			List of client and kernel debug keywords.
 *
 *
 * What:		/sys/kernel/debug/orangefs/client-debug
 * Date:		June 2015
 * Contact:		Mike Marshall <hubcap@omnibond.com>
 * Description:
 * 			Debug setting for "the client", the userspace
 * 			helper for the kernel module.
 *
 *
 * What:		/sys/kernel/debug/orangefs/kernel-debug
 * Date:		June 2015
 * Contact:		Mike Marshall <hubcap@omnibond.com>
 * Description:
 * 			Debug setting for the orangefs kernel module.
 *
 * 			Any of the keywords, or comma-separated lists
 * 			of keywords, from debug-help can be catted to
 * 			client-debug or kernel-debug.
 *
 * 			"none", "all" and "verbose" are special keywords
 * 			for client-debug. Setting client-debug to "all"
 * 			is kind of like trying to drink water from a
 * 			fire hose, "verbose" triggers most of the same
 * 			output except for the constant flow of output
 * 			from the main wait loop.
 *
 * 			"none" and "all" are similar settings for kernel-debug
 * 			no need for a "verbose".
 */
#include <linux/debugfs.h>
#include <linux/slab.h>

#include <linux/uaccess.h>

#include "orangefs-debugfs.h"
#include "protocol.h"
#include "orangefs-kernel.h"

#define DEBUG_HELP_STRING_SIZE 4096
#define HELP_STRING_UNINITIALIZED \
	"Client Debug Keywords are unknown until the first time\n" \
	"the client is started after boot.\n"
#define ORANGEFS_KMOD_DEBUG_HELP_FILE "debug-help"
#define ORANGEFS_KMOD_DEBUG_FILE "kernel-debug"
#define ORANGEFS_CLIENT_DEBUG_FILE "client-debug"
#define ORANGEFS_VERBOSE "verbose"
#define ORANGEFS_ALL "all"

/*
 * An array of client_debug_mask will be built to hold debug keyword/mask
 * values fetched from userspace.
 */
struct client_debug_mask {
	char *keyword;
	__u64 mask1;
	__u64 mask2;
};

static int orangefs_kernel_debug_init(void);

static int orangefs_debug_help_open(struct inode *, struct file *);
static void *help_start(struct seq_file *, loff_t *);
static void *help_next(struct seq_file *, void *, loff_t *);
static void help_stop(struct seq_file *, void *);
static int help_show(struct seq_file *, void *);

static int orangefs_debug_open(struct inode *, struct file *);

static ssize_t orangefs_debug_read(struct file *,
				 char __user *,
				 size_t,
				 loff_t *);

static ssize_t orangefs_debug_write(struct file *,
				  const char __user *,
				  size_t,
				  loff_t *);

static int orangefs_prepare_cdm_array(char *);
static void debug_mask_to_string(void *, int);
static void do_k_string(void *, int);
static void do_c_string(void *, int);
static int keyword_is_amalgam(char *);
static int check_amalgam_keyword(void *, int);
static void debug_string_to_mask(char *, void *, int);
static void do_c_mask(int, char *, struct client_debug_mask **);
static void do_k_mask(int, char *, __u64 **);

static char kernel_debug_string[ORANGEFS_MAX_DEBUG_STRING_LEN] = "none";
static char *debug_help_string;
static char client_debug_string[ORANGEFS_MAX_DEBUG_STRING_LEN];
static char client_debug_array_string[ORANGEFS_MAX_DEBUG_STRING_LEN];

static struct dentry *help_file_dentry;
static struct dentry *client_debug_dentry;
static struct dentry *debug_dir;

static unsigned int kernel_mask_set_mod_init;
static int orangefs_debug_disabled = 1;
static int help_string_initialized;

static const struct seq_operations help_debug_ops = {
	.start	= help_start,
	.next	= help_next,
	.stop	= help_stop,
	.show	= help_show,
};

const struct file_operations debug_help_fops = {
	.owner		= THIS_MODULE,
	.open           = orangefs_debug_help_open,
	.read           = seq_read,
	.release        = seq_release,
	.llseek         = seq_lseek,
};

static const struct file_operations kernel_debug_fops = {
	.owner		= THIS_MODULE,
	.open           = orangefs_debug_open,
	.read           = orangefs_debug_read,
	.write		= orangefs_debug_write,
	.llseek         = generic_file_llseek,
};

static int client_all_index;
static int client_verbose_index;

static struct client_debug_mask *cdm_array;
static int cdm_element_count;

static struct client_debug_mask client_debug_mask;

/*
 * Used to protect data in ORANGEFS_KMOD_DEBUG_FILE and
 * ORANGEFS_KMOD_DEBUG_FILE.
 */
static DEFINE_MUTEX(orangefs_debug_lock);

/* Used to protect data in ORANGEFS_KMOD_DEBUG_HELP_FILE */
static DEFINE_MUTEX(orangefs_help_file_lock);

/*
 * initialize kmod debug operations, create orangefs debugfs dir and
 * ORANGEFS_KMOD_DEBUG_HELP_FILE.
 */
int orangefs_debugfs_init(int debug_mask)
{
	int rc = -ENOMEM;

	/* convert input debug mask to a 64-bit unsigned integer */
        orangefs_gossip_debug_mask = (unsigned long long)debug_mask;

	/*
	 * set the kernel's gossip debug string; invalid mask values will
	 * be ignored.
	 */
	debug_mask_to_string(&orangefs_gossip_debug_mask, 0);

	/* remove any invalid values from the mask */
	debug_string_to_mask(kernel_debug_string, &orangefs_gossip_debug_mask,
	    0);

	/*
	 * if the mask has a non-zero value, then indicate that the mask
	 * was set when the kernel module was loaded.  The orangefs dev ioctl
	 * command will look at this boolean to determine if the kernel's
	 * debug mask should be overwritten when the client-core is started.
	 */
	if (orangefs_gossip_debug_mask != 0)
		kernel_mask_set_mod_init = true;

	pr_info("%s: called with debug mask: :%s: :%llx:\n",
		__func__,
		kernel_debug_string,
		(unsigned long long)orangefs_gossip_debug_mask);

	debug_dir = debugfs_create_dir("orangefs", NULL);
	if (!debug_dir) {
		pr_info("%s: debugfs_create_dir failed.\n", __func__);
		goto out;
	}

	help_file_dentry = debugfs_create_file(ORANGEFS_KMOD_DEBUG_HELP_FILE,
				  0444,
				  debug_dir,
				  debug_help_string,
				  &debug_help_fops);
	if (!help_file_dentry) {
		pr_info("%s: debugfs_create_file failed.\n", __func__);
		goto out;
	}

	orangefs_debug_disabled = 0;

	rc = orangefs_kernel_debug_init();

out:

	return rc;
}

/*
 * initialize the kernel-debug file.
 */
static int orangefs_kernel_debug_init(void)
{
	int rc = -ENOMEM;
	struct dentry *ret;
	char *k_buffer = NULL;

	gossip_debug(GOSSIP_DEBUGFS_DEBUG, "%s: start\n", __func__);

	k_buffer = kzalloc(ORANGEFS_MAX_DEBUG_STRING_LEN, GFP_KERNEL);
	if (!k_buffer)
		goto out;

	if (strlen(kernel_debug_string) + 1 < ORANGEFS_MAX_DEBUG_STRING_LEN) {
		strcpy(k_buffer, kernel_debug_string);
		strcat(k_buffer, "\n");
	} else {
		strcpy(k_buffer, "none\n");
		pr_info("%s: overflow 1!\n", __func__);
	}

	ret = debugfs_create_file(ORANGEFS_KMOD_DEBUG_FILE,
				  0444,
				  debug_dir,
				  k_buffer,
				  &kernel_debug_fops);
	if (!ret) {
		pr_info("%s: failed to create %s.\n",
			__func__,
			ORANGEFS_KMOD_DEBUG_FILE);
		goto out;
	}

	rc = 0;

out:

	gossip_debug(GOSSIP_DEBUGFS_DEBUG, "%s: rc:%d:\n", __func__, rc);
	return rc;
}


void orangefs_debugfs_cleanup(void)
{
	debugfs_remove_recursive(debug_dir);
}

/* open ORANGEFS_KMOD_DEBUG_HELP_FILE */
static int orangefs_debug_help_open(struct inode *inode, struct file *file)
{
	int rc = -ENODEV;
	int ret;

	gossip_debug(GOSSIP_DEBUGFS_DEBUG,
		     "orangefs_debug_help_open: start\n");

	if (orangefs_debug_disabled)
		goto out;

	ret = seq_open(file, &help_debug_ops);
	if (ret)
		goto out;

	((struct seq_file *)(file->private_data))->private = inode->i_private;

	rc = 0;

out:
	gossip_debug(GOSSIP_DEBUGFS_DEBUG,
		     "orangefs_debug_help_open: rc:%d:\n",
		     rc);
	return rc;
}

/*
 * I think start always gets called again after stop. Start
 * needs to return NULL when it is done. The whole "payload"
 * in this case is a single (long) string, so by the second
 * time we get to start (pos = 1), we're done.
 */
static void *help_start(struct seq_file *m, loff_t *pos)
{
	void *payload = NULL;

	gossip_debug(GOSSIP_DEBUGFS_DEBUG, "help_start: start\n");

	mutex_lock(&orangefs_help_file_lock);

	if (*pos == 0)
		payload = m->private;

	return payload;
}

static void *help_next(struct seq_file *m, void *v, loff_t *pos)
{
	gossip_debug(GOSSIP_DEBUGFS_DEBUG, "help_next: start\n");

	return NULL;
}

static void help_stop(struct seq_file *m, void *p)
{
	gossip_debug(GOSSIP_DEBUGFS_DEBUG, "help_stop: start\n");
	mutex_unlock(&orangefs_help_file_lock);
}

static int help_show(struct seq_file *m, void *v)
{
	gossip_debug(GOSSIP_DEBUGFS_DEBUG, "help_show: start\n");

	seq_puts(m, v);

	return 0;
}

/*
 * initialize the client-debug file.
 */
int orangefs_client_debug_init(void)
{

	int rc = -ENOMEM;
	char *c_buffer = NULL;

	gossip_debug(GOSSIP_DEBUGFS_DEBUG, "%s: start\n", __func__);

	c_buffer = kzalloc(ORANGEFS_MAX_DEBUG_STRING_LEN, GFP_KERNEL);
	if (!c_buffer)
		goto out;

	if (strlen(client_debug_string) + 1 < ORANGEFS_MAX_DEBUG_STRING_LEN) {
		strcpy(c_buffer, client_debug_string);
		strcat(c_buffer, "\n");
	} else {
		strcpy(c_buffer, "none\n");
		pr_info("%s: overflow! 2\n", __func__);
	}

	client_debug_dentry = debugfs_create_file(ORANGEFS_CLIENT_DEBUG_FILE,
						  0444,
						  debug_dir,
						  c_buffer,
						  &kernel_debug_fops);
	if (!client_debug_dentry) {
		pr_info("%s: failed to create updated %s.\n",
			__func__,
			ORANGEFS_CLIENT_DEBUG_FILE);
		goto out;
	}

	rc = 0;

out:

	gossip_debug(GOSSIP_DEBUGFS_DEBUG, "%s: rc:%d:\n", __func__, rc);
	return rc;
}

/* open ORANGEFS_KMOD_DEBUG_FILE or ORANGEFS_CLIENT_DEBUG_FILE.*/
static int orangefs_debug_open(struct inode *inode, struct file *file)
{
	int rc = -ENODEV;

	gossip_debug(GOSSIP_DEBUGFS_DEBUG,
		     "%s: orangefs_debug_disabled: %d\n",
		     __func__,
		     orangefs_debug_disabled);

	if (orangefs_debug_disabled)
		goto out;

	rc = 0;
	mutex_lock(&orangefs_debug_lock);
	file->private_data = inode->i_private;
	mutex_unlock(&orangefs_debug_lock);

out:
	gossip_debug(GOSSIP_DEBUGFS_DEBUG,
		     "orangefs_debug_open: rc: %d\n",
		     rc);
	return rc;
}

static ssize_t orangefs_debug_read(struct file *file,
				 char __user *ubuf,
				 size_t count,
				 loff_t *ppos)
{
	char *buf;
	int sprintf_ret;
	ssize_t read_ret = -ENOMEM;

	gossip_debug(GOSSIP_DEBUGFS_DEBUG, "orangefs_debug_read: start\n");

	buf = kmalloc(ORANGEFS_MAX_DEBUG_STRING_LEN, GFP_KERNEL);
	if (!buf)
		goto out;

	mutex_lock(&orangefs_debug_lock);
	sprintf_ret = sprintf(buf, "%s", (char *)file->private_data);
	mutex_unlock(&orangefs_debug_lock);

	read_ret = simple_read_from_buffer(ubuf, count, ppos, buf, sprintf_ret);

	kfree(buf);

out:
	gossip_debug(GOSSIP_DEBUGFS_DEBUG,
		     "orangefs_debug_read: ret: %zu\n",
		     read_ret);

	return read_ret;
}

static ssize_t orangefs_debug_write(struct file *file,
				  const char __user *ubuf,
				  size_t count,
				  loff_t *ppos)
{
	char *buf;
	int rc = -EFAULT;
	size_t silly = 0;
	char *debug_string;
	struct orangefs_kernel_op_s *new_op = NULL;
	struct client_debug_mask c_mask = { NULL, 0, 0 };

	gossip_debug(GOSSIP_DEBUGFS_DEBUG,
		"orangefs_debug_write: %pD\n",
		file);

	/*
	 * Thwart users who try to jamb a ridiculous number
	 * of bytes into the debug file...
	 */
	if (count > ORANGEFS_MAX_DEBUG_STRING_LEN + 1) {
		silly = count;
		count = ORANGEFS_MAX_DEBUG_STRING_LEN + 1;
	}

	buf = kzalloc(ORANGEFS_MAX_DEBUG_STRING_LEN, GFP_KERNEL);
	if (!buf)
		goto out;

	if (copy_from_user(buf, ubuf, count - 1)) {
		gossip_debug(GOSSIP_DEBUGFS_DEBUG,
			     "%s: copy_from_user failed!\n",
			     __func__);
		goto out;
	}

	/*
	 * Map the keyword string from userspace into a valid debug mask.
	 * The mapping process involves mapping the human-inputted string
	 * into a valid mask, and then rebuilding the string from the
	 * verified valid mask.
	 *
	 * A service operation is required to set a new client-side
	 * debug mask.
	 */
	if (!strcmp(file->f_path.dentry->d_name.name,
		    ORANGEFS_KMOD_DEBUG_FILE)) {
		debug_string_to_mask(buf, &orangefs_gossip_debug_mask, 0);
		debug_mask_to_string(&orangefs_gossip_debug_mask, 0);
		debug_string = kernel_debug_string;
		gossip_debug(GOSSIP_DEBUGFS_DEBUG,
			     "New kernel debug string is %s\n",
			     kernel_debug_string);
	} else {
		/* Can't reset client debug mask if client is not running. */
		if (is_daemon_in_service()) {
			pr_info("%s: Client not running :%d:\n",
				__func__,
				is_daemon_in_service());
			goto out;
		}

		debug_string_to_mask(buf, &c_mask, 1);
		debug_mask_to_string(&c_mask, 1);
		debug_string = client_debug_string;

		new_op = op_alloc(ORANGEFS_VFS_OP_PARAM);
		if (!new_op) {
			pr_info("%s: op_alloc failed!\n", __func__);
			goto out;
		}

		new_op->upcall.req.param.op =
			ORANGEFS_PARAM_REQUEST_OP_TWO_MASK_VALUES;
		new_op->upcall.req.param.type = ORANGEFS_PARAM_REQUEST_SET;
		memset(new_op->upcall.req.param.s_value,
		       0,
		       ORANGEFS_MAX_DEBUG_STRING_LEN);
		sprintf(new_op->upcall.req.param.s_value,
			"%llx %llx\n",
			c_mask.mask1,
			c_mask.mask2);

		/* service_operation returns 0 on success... */
		rc = service_operation(new_op,
				       "orangefs_param",
					ORANGEFS_OP_INTERRUPTIBLE);

		if (rc)
			gossip_debug(GOSSIP_DEBUGFS_DEBUG,
				     "%s: service_operation failed! rc:%d:\n",
				     __func__,
				     rc);

		op_release(new_op);
	}

	mutex_lock(&orangefs_debug_lock);
	memset(file->f_inode->i_private, 0, ORANGEFS_MAX_DEBUG_STRING_LEN);
	sprintf((char *)file->f_inode->i_private, "%s\n", debug_string);
	mutex_unlock(&orangefs_debug_lock);

	*ppos += count;
	if (silly)
		rc = silly;
	else
		rc = count;

out:
	gossip_debug(GOSSIP_DEBUGFS_DEBUG,
		     "orangefs_debug_write: rc: %d\n",
		     rc);
	kfree(buf);
	return rc;
}

/*
 * After obtaining a string representation of the client's debug
 * keywords and their associated masks, this function is called to build an
 * array of these values.
 */
static int orangefs_prepare_cdm_array(char *debug_array_string)
{
	int i;
	int rc = -EINVAL;
	char *cds_head = NULL;
	char *cds_delimiter = NULL;
	int keyword_len = 0;

	gossip_debug(GOSSIP_UTILS_DEBUG, "%s: start\n", __func__);

	/*
	 * figure out how many elements the cdm_array needs.
	 */
	for (i = 0; i < strlen(debug_array_string); i++)
		if (debug_array_string[i] == '\n')
			cdm_element_count++;

	if (!cdm_element_count) {
		pr_info("No elements in client debug array string!\n");
		goto out;
	}

	cdm_array =
		kzalloc(cdm_element_count * sizeof(struct client_debug_mask),
			GFP_KERNEL);
	if (!cdm_array) {
		pr_info("malloc failed for cdm_array!\n");
		rc = -ENOMEM;
		goto out;
	}

	cds_head = debug_array_string;

	for (i = 0; i < cdm_element_count; i++) {
		cds_delimiter = strchr(cds_head, '\n');
		*cds_delimiter = '\0';

		keyword_len = strcspn(cds_head, " ");

		cdm_array[i].keyword = kzalloc(keyword_len + 1, GFP_KERNEL);
		if (!cdm_array[i].keyword) {
			rc = -ENOMEM;
			goto out;
		}

		sscanf(cds_head,
		       "%s %llx %llx",
		       cdm_array[i].keyword,
		       (unsigned long long *)&(cdm_array[i].mask1),
		       (unsigned long long *)&(cdm_array[i].mask2));

		if (!strcmp(cdm_array[i].keyword, ORANGEFS_VERBOSE))
			client_verbose_index = i;

		if (!strcmp(cdm_array[i].keyword, ORANGEFS_ALL))
			client_all_index = i;

		cds_head = cds_delimiter + 1;
	}

	rc = cdm_element_count;

	gossip_debug(GOSSIP_UTILS_DEBUG, "%s: rc:%d:\n", __func__, rc);

out:

	return rc;

}

/*
 * /sys/kernel/debug/orangefs/debug-help can be catted to
 * see all the available kernel and client debug keywords.
 *
 * When orangefs.ko initializes, we have no idea what keywords the
 * client supports, nor their associated masks.
 *
 * We pass through this function once at module-load and stamp a
 * boilerplate "we don't know" message for the client in the
 * debug-help file. We pass through here again when the client
 * starts and then we can fill out the debug-help file fully.
 *
 * The client might be restarted any number of times between
 * module reloads, we only build the debug-help file the first time.
 */
int orangefs_prepare_debugfs_help_string(int at_boot)
{
	char *client_title = "Client Debug Keywords:\n";
	char *kernel_title = "Kernel Debug Keywords:\n";
	size_t string_size =  DEBUG_HELP_STRING_SIZE;
	size_t result_size;
	size_t i;
	char *new;
	int rc = -EINVAL;

	gossip_debug(GOSSIP_UTILS_DEBUG, "%s: start\n", __func__);

	if (at_boot)
		client_title = HELP_STRING_UNINITIALIZED;

	/* build a new debug_help_string. */
	new = kzalloc(DEBUG_HELP_STRING_SIZE, GFP_KERNEL);
	if (!new) {
		rc = -ENOMEM;
		goto out;
	}

	/*
	 * strlcat(dst, src, size) will append at most
	 * "size - strlen(dst) - 1" bytes of src onto dst,
	 * null terminating the result, and return the total
	 * length of the string it tried to create.
	 *
	 * We'll just plow through here building our new debug
	 * help string and let strlcat take care of assuring that
	 * dst doesn't overflow.
	 */
	strlcat(new, client_title, string_size);

	if (!at_boot) {

                /*
		 * fill the client keyword/mask array and remember
		 * how many elements there were.
		 */
		cdm_element_count =
			orangefs_prepare_cdm_array(client_debug_array_string);
		if (cdm_element_count <= 0)
			goto out;

		for (i = 0; i < cdm_element_count; i++) {
			strlcat(new, "\t", string_size);
			strlcat(new, cdm_array[i].keyword, string_size);
			strlcat(new, "\n", string_size);
		}
	}

	strlcat(new, "\n", string_size);
	strlcat(new, kernel_title, string_size);

	for (i = 0; i < num_kmod_keyword_mask_map; i++) {
		strlcat(new, "\t", string_size);
		strlcat(new, s_kmod_keyword_mask_map[i].keyword, string_size);
		result_size = strlcat(new, "\n", string_size);
	}

	/* See if we tried to put too many bytes into "new"... */
	if (result_size >= string_size) {
		kfree(new);
		goto out;
	}

	if (at_boot) {
		debug_help_string = new;
	} else {
		mutex_lock(&orangefs_help_file_lock);
		memset(debug_help_string, 0, DEBUG_HELP_STRING_SIZE);
		strlcat(debug_help_string, new, string_size);
		mutex_unlock(&orangefs_help_file_lock);
	}

	rc = 0;

out:	return rc;

}

/*
 * kernel = type 0
 * client = type 1
 */
static void debug_mask_to_string(void *mask, int type)
{
	int i;
	int len = 0;
	char *debug_string;
	int element_count = 0;

	gossip_debug(GOSSIP_UTILS_DEBUG, "%s: start\n", __func__);

	if (type) {
		debug_string = client_debug_string;
		element_count = cdm_element_count;
	} else {
		debug_string = kernel_debug_string;
		element_count = num_kmod_keyword_mask_map;
	}

	memset(debug_string, 0, ORANGEFS_MAX_DEBUG_STRING_LEN);

	/*
	 * Some keywords, like "all" or "verbose", are amalgams of
	 * numerous other keywords. Make a special check for those
	 * before grinding through the whole mask only to find out
	 * later...
	 */
	if (check_amalgam_keyword(mask, type))
		goto out;

	/* Build the debug string. */
	for (i = 0; i < element_count; i++)
		if (type)
			do_c_string(mask, i);
		else
			do_k_string(mask, i);

	len = strlen(debug_string);

	if ((len) && (type))
		client_debug_string[len - 1] = '\0';
	else if (len)
		kernel_debug_string[len - 1] = '\0';
	else if (type)
		strcpy(client_debug_string, "none");
	else
		strcpy(kernel_debug_string, "none");

out:
gossip_debug(GOSSIP_UTILS_DEBUG, "%s: string:%s:\n", __func__, debug_string);

	return;

}

static void do_k_string(void *k_mask, int index)
{
	__u64 *mask = (__u64 *) k_mask;

	if (keyword_is_amalgam((char *) s_kmod_keyword_mask_map[index].keyword))
		goto out;

	if (*mask & s_kmod_keyword_mask_map[index].mask_val) {
		if ((strlen(kernel_debug_string) +
		     strlen(s_kmod_keyword_mask_map[index].keyword))
			< ORANGEFS_MAX_DEBUG_STRING_LEN - 1) {
				strcat(kernel_debug_string,
				       s_kmod_keyword_mask_map[index].keyword);
				strcat(kernel_debug_string, ",");
			} else {
				gossip_err("%s: overflow!\n", __func__);
				strcpy(kernel_debug_string, ORANGEFS_ALL);
				goto out;
			}
	}

out:

	return;
}

static void do_c_string(void *c_mask, int index)
{
	struct client_debug_mask *mask = (struct client_debug_mask *) c_mask;

	if (keyword_is_amalgam(cdm_array[index].keyword))
		goto out;

	if ((mask->mask1 & cdm_array[index].mask1) ||
	    (mask->mask2 & cdm_array[index].mask2)) {
		if ((strlen(client_debug_string) +
		     strlen(cdm_array[index].keyword) + 1)
			< ORANGEFS_MAX_DEBUG_STRING_LEN - 2) {
				strcat(client_debug_string,
				       cdm_array[index].keyword);
				strcat(client_debug_string, ",");
			} else {
				gossip_err("%s: overflow!\n", __func__);
				strcpy(client_debug_string, ORANGEFS_ALL);
				goto out;
			}
	}
out:
	return;
}

static int keyword_is_amalgam(char *keyword)
{
	int rc = 0;

	if ((!strcmp(keyword, ORANGEFS_ALL)) || (!strcmp(keyword, ORANGEFS_VERBOSE)))
		rc = 1;

	return rc;
}

/*
 * kernel = type 0
 * client = type 1
 *
 * return 1 if we found an amalgam.
 */
static int check_amalgam_keyword(void *mask, int type)
{
	__u64 *k_mask;
	struct client_debug_mask *c_mask;
	int k_all_index = num_kmod_keyword_mask_map - 1;
	int rc = 0;

	if (type) {
		c_mask = (struct client_debug_mask *) mask;

		if ((c_mask->mask1 == cdm_array[client_all_index].mask1) &&
		    (c_mask->mask2 == cdm_array[client_all_index].mask2)) {
			strcpy(client_debug_string, ORANGEFS_ALL);
			rc = 1;
			goto out;
		}

		if ((c_mask->mask1 == cdm_array[client_verbose_index].mask1) &&
		    (c_mask->mask2 == cdm_array[client_verbose_index].mask2)) {
			strcpy(client_debug_string, ORANGEFS_VERBOSE);
			rc = 1;
			goto out;
		}

	} else {
		k_mask = (__u64 *) mask;

		if (*k_mask >= s_kmod_keyword_mask_map[k_all_index].mask_val) {
			strcpy(kernel_debug_string, ORANGEFS_ALL);
			rc = 1;
			goto out;
		}
	}

out:

	return rc;
}

/*
 * kernel = type 0
 * client = type 1
 */
static void debug_string_to_mask(char *debug_string, void *mask, int type)
{
	char *unchecked_keyword;
	int i;
	char *strsep_fodder = kstrdup(debug_string, GFP_KERNEL);
	char *original_pointer;
	int element_count = 0;
	struct client_debug_mask *c_mask = NULL;
	__u64 *k_mask = NULL;

	gossip_debug(GOSSIP_UTILS_DEBUG, "%s: start\n", __func__);

	if (type) {
		c_mask = (struct client_debug_mask *)mask;
		element_count = cdm_element_count;
	} else {
		k_mask = (__u64 *)mask;
		*k_mask = 0;
		element_count = num_kmod_keyword_mask_map;
	}

	original_pointer = strsep_fodder;
	while ((unchecked_keyword = strsep(&strsep_fodder, ",")))
		if (strlen(unchecked_keyword)) {
			for (i = 0; i < element_count; i++)
				if (type)
					do_c_mask(i,
						  unchecked_keyword,
						  &c_mask);
				else
					do_k_mask(i,
						  unchecked_keyword,
						  &k_mask);
		}

	kfree(original_pointer);
}

static void do_c_mask(int i, char *unchecked_keyword,
    struct client_debug_mask **sane_mask)
{

	if (!strcmp(cdm_array[i].keyword, unchecked_keyword)) {
		(**sane_mask).mask1 = (**sane_mask).mask1 | cdm_array[i].mask1;
		(**sane_mask).mask2 = (**sane_mask).mask2 | cdm_array[i].mask2;
	}
}

static void do_k_mask(int i, char *unchecked_keyword, __u64 **sane_mask)
{

	if (!strcmp(s_kmod_keyword_mask_map[i].keyword, unchecked_keyword))
		**sane_mask = (**sane_mask) |
				s_kmod_keyword_mask_map[i].mask_val;
}

int orangefs_debugfs_new_client_mask(void __user *arg)
{
	struct dev_mask2_info_s mask2_info = {0};
	int ret;

	ret = copy_from_user(&mask2_info,
			     (void __user *)arg,
			     sizeof(struct dev_mask2_info_s));

	if (ret != 0)
		return -EIO;

	client_debug_mask.mask1 = mask2_info.mask1_value;
	client_debug_mask.mask2 = mask2_info.mask2_value;

	pr_info("%s: client debug mask has been been received "
		":%llx: :%llx:\n",
		__func__,
		(unsigned long long)client_debug_mask.mask1,
		(unsigned long long)client_debug_mask.mask2);

	return ret;
}

int orangefs_debugfs_new_client_string(void __user *arg) 
{
	int ret;

	ret = copy_from_user(&client_debug_array_string,
                                     (void __user *)arg,
                                     ORANGEFS_MAX_DEBUG_STRING_LEN);

	if (ret != 0) {
		pr_info("%s: CLIENT_STRING: copy_from_user failed\n",
			__func__);
		return -EIO;
	}

	/*
	 * The real client-core makes an effort to ensure
	 * that actual strings that aren't too long to fit in
	 * this buffer is what we get here. We're going to use
	 * string functions on the stuff we got, so we'll make
	 * this extra effort to try and keep from
	 * flowing out of this buffer when we use the string
	 * functions, even if somehow the stuff we end up
	 * with here is garbage.
	 */
	client_debug_array_string[ORANGEFS_MAX_DEBUG_STRING_LEN - 1] =
		'\0';
	
	pr_info("%s: client debug array string has been received.\n",
		__func__);

	if (!help_string_initialized) {

		/* Build a proper debug help string. */
		if (orangefs_prepare_debugfs_help_string(0)) {
			gossip_err("%s: no debug help string \n",
				   __func__);
			return -EIO;
		}

	}

	debug_mask_to_string(&client_debug_mask, 1);

	debugfs_remove(client_debug_dentry);

	orangefs_client_debug_init();

	help_string_initialized++;

	return ret;
}

int orangefs_debugfs_new_debug(void __user *arg) 
{
	struct dev_mask_info_s mask_info = {0};
	int ret;

	ret = copy_from_user(&mask_info,
			     (void __user *)arg,
			     sizeof(mask_info));

	if (ret != 0)
		return -EIO;

	if (mask_info.mask_type == KERNEL_MASK) {
		if ((mask_info.mask_value == 0)
		    && (kernel_mask_set_mod_init)) {
			/*
			 * the kernel debug mask was set when the
			 * kernel module was loaded; don't override
			 * it if the client-core was started without
			 * a value for ORANGEFS_KMODMASK.
			 */
			return 0;
		}
		debug_mask_to_string(&mask_info.mask_value,
				     mask_info.mask_type);
		orangefs_gossip_debug_mask = mask_info.mask_value;
		pr_info("%s: kernel debug mask has been modified to "
			":%s: :%llx:\n",
			__func__,
			kernel_debug_string,
			(unsigned long long)orangefs_gossip_debug_mask);
	} else if (mask_info.mask_type == CLIENT_MASK) {
		debug_mask_to_string(&mask_info.mask_value,
				     mask_info.mask_type);
		pr_info("%s: client debug mask has been modified to"
			":%s: :%llx:\n",
			__func__,
			client_debug_string,
			llu(mask_info.mask_value));
	} else {
		gossip_lerr("Invalid mask type....\n");
		return -EINVAL;
	}

	return ret;
}