Adding upstream version 4.2.upstream/4.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 714 insertions, 0 deletions

diff --git a/raid6check.c b/raid6check.c
new file mode 100644
index 0000000..a8e6005
--- /dev/null
+++ b/raid6check.c
@@ -0,0 +1,714 @@
+/*
+ * raid6check - extended consistency check for RAID-6
+ *
+ * Copyright (C) 2011 Piergiorgio Sartor
+ *
+ *
+ *    This program is free software; you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation; either version 2 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program; if not, write to the Free Software
+ *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ *    Author: Piergiorgio Sartor
+ *    Based on "restripe.c" from "mdadm" codebase
+ */
+
+#include "mdadm.h"
+#include <stdint.h>
+#include <signal.h>
+#include <sys/mman.h>
+
+#define CHECK_PAGE_BITS (12)
+#define CHECK_PAGE_SIZE (1 << CHECK_PAGE_BITS)
+
+char const Name[] = "raid6check";
+
+enum repair {
+	NO_REPAIR = 0,
+	MANUAL_REPAIR,
+	AUTO_REPAIR
+};
+
+int geo_map(int block, unsigned long long stripe, int raid_disks,
+	    int level, int layout);
+int is_ddf(int layout);
+void qsyndrome(uint8_t *p, uint8_t *q, uint8_t **sources, int disks, int size);
+void make_tables(void);
+void ensure_zero_has_size(int chunk_size);
+void raid6_datap_recov(int disks, size_t bytes, int faila, uint8_t **ptrs,
+		       int neg_offset);
+void raid6_2data_recov(int disks, size_t bytes, int faila, int failb,
+		       uint8_t **ptrs, int neg_offset);
+void xor_blocks(char *target, char **sources, int disks, int size);
+
+/* Collect per stripe consistency information */
+void raid6_collect(int chunk_size, uint8_t *p, uint8_t *q,
+		   char *chunkP, char *chunkQ, int *results)
+{
+	int i;
+	int data_id;
+	uint8_t Px, Qx;
+	extern uint8_t raid6_gflog[];
+
+	for(i = 0; i < chunk_size; i++) {
+		Px = (uint8_t)chunkP[i] ^ (uint8_t)p[i];
+		Qx = (uint8_t)chunkQ[i] ^ (uint8_t)q[i];
+
+		if((Px != 0) && (Qx == 0))
+			results[i] = -1;
+
+		if((Px == 0) && (Qx != 0))
+			results[i] = -2;
+
+		if((Px != 0) && (Qx != 0)) {
+			data_id = (raid6_gflog[Qx] - raid6_gflog[Px]);
+			if(data_id < 0) data_id += 255;
+			results[i] = data_id;
+		}
+
+		if((Px == 0) && (Qx == 0))
+			results[i] = -255;
+	}
+}
+
+/* Try to find out if a specific disk has problems in a CHECK_PAGE_SIZE page size */
+int raid6_stats_blk(int *results, int raid_disks)
+{
+	int i;
+	int curr_broken_disk = -255;
+	int prev_broken_disk = -255;
+	int broken_status = 0;
+
+	for(i = 0; i < CHECK_PAGE_SIZE; i++) {
+
+		if(results[i] != -255)
+			curr_broken_disk = results[i];
+
+		if(curr_broken_disk >= raid_disks)
+			broken_status = 2;
+
+		switch(broken_status) {
+		case 0:
+			if(curr_broken_disk != -255) {
+				prev_broken_disk = curr_broken_disk;
+				broken_status = 1;
+			}
+			break;
+
+		case 1:
+			if(curr_broken_disk != prev_broken_disk)
+				broken_status = 2;
+			break;
+
+		case 2:
+		default:
+			curr_broken_disk = prev_broken_disk = -65535;
+			break;
+		}
+	}
+
+	return curr_broken_disk;
+}
+
+/* Collect disks status for a strip in CHECK_PAGE_SIZE page size blocks */
+void raid6_stats(int *disk, int *results, int raid_disks, int chunk_size)
+{
+	int i, j;
+
+	for(i = 0, j = 0; i < chunk_size; i += CHECK_PAGE_SIZE, j++) {
+		disk[j] = raid6_stats_blk(&results[i], raid_disks);
+	}
+}
+
+int lock_stripe(struct mdinfo *info, unsigned long long start,
+		int chunk_size, int data_disks, sighandler_t *sig) {
+	int rv;
+	if(mlockall(MCL_CURRENT | MCL_FUTURE) != 0) {
+		return 2;
+	}
+
+	sig[0] = signal(SIGTERM, SIG_IGN);
+	sig[1] = signal(SIGINT, SIG_IGN);
+	sig[2] = signal(SIGQUIT, SIG_IGN);
+
+	rv = sysfs_set_num(info, NULL, "suspend_lo", start * chunk_size * data_disks);
+	rv |= sysfs_set_num(info, NULL, "suspend_hi", (start + 1) * chunk_size * data_disks);
+	return rv * 256;
+}
+
+int unlock_all_stripes(struct mdinfo *info, sighandler_t *sig) {
+	int rv;
+	rv = sysfs_set_num(info, NULL, "suspend_lo", 0x7FFFFFFFFFFFFFFFULL);
+	rv |= sysfs_set_num(info, NULL, "suspend_hi", 0);
+	rv |= sysfs_set_num(info, NULL, "suspend_lo", 0);
+
+	signal(SIGQUIT, sig[2]);
+	signal(SIGINT, sig[1]);
+	signal(SIGTERM, sig[0]);
+
+	if(munlockall() != 0)
+		return 3;
+	return rv * 256;
+}
+
+/* Autorepair */
+int autorepair(int *disk, unsigned long long start, int chunk_size,
+		char *name[], int raid_disks, int syndrome_disks, char **blocks_page,
+		char **blocks, uint8_t *p, int *block_index_for_slot,
+		int *source, unsigned long long *offsets)
+{
+	int i, j;
+	int pages_to_write_count = 0;
+	int page_to_write[chunk_size >> CHECK_PAGE_BITS];
+	for(j = 0; j < (chunk_size >> CHECK_PAGE_BITS); j++) {
+		if (disk[j] >= -2 && block_index_for_slot[disk[j]] >= 0) {
+			int slot = block_index_for_slot[disk[j]];
+			printf("Auto-repairing slot %d (%s)\n", slot, name[slot]);
+			pages_to_write_count++;
+			page_to_write[j] = 1;
+			for(i = -2; i < syndrome_disks; i++) {
+				blocks_page[i] = blocks[i] + j * CHECK_PAGE_SIZE;
+			}
+			if (disk[j] == -2) {
+				qsyndrome(p, (uint8_t*)blocks_page[-2],
+					  (uint8_t**)blocks_page,
+					  syndrome_disks, CHECK_PAGE_SIZE);
+			}
+			else {
+				char *all_but_failed_blocks[syndrome_disks];
+				for(i = 0; i < syndrome_disks; i++) {
+					if (i == disk[j])
+						all_but_failed_blocks[i] = blocks_page[-1];
+					else
+						all_but_failed_blocks[i] = blocks_page[i];
+				}
+				xor_blocks(blocks_page[disk[j]],
+					   all_but_failed_blocks, syndrome_disks,
+					   CHECK_PAGE_SIZE);
+			}
+		}
+		else {
+			page_to_write[j] = 0;
+		}
+	}
+
+	if(pages_to_write_count > 0) {
+		int write_res = 0;
+		for(j = 0; j < (chunk_size >> CHECK_PAGE_BITS); j++) {
+			if(page_to_write[j] == 1) {
+				int slot = block_index_for_slot[disk[j]];
+				lseek64(source[slot], offsets[slot] + start * chunk_size + j * CHECK_PAGE_SIZE, SEEK_SET);
+				write_res += write(source[slot],
+						   blocks[disk[j]] + j * CHECK_PAGE_SIZE,
+						   CHECK_PAGE_SIZE);
+			}
+		}
+
+		if (write_res != (CHECK_PAGE_SIZE * pages_to_write_count)) {
+			fprintf(stderr, "Failed to write a full chunk.\n");
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+/* Manual repair */
+int manual_repair(int chunk_size, int syndrome_disks,
+		  int failed_slot1, int failed_slot2,
+		  unsigned long long start, int *block_index_for_slot,
+		  char *name[], char **stripes, char **blocks, uint8_t *p,
+		  int *source, unsigned long long *offsets)
+{
+	int i;
+	int fd1 = block_index_for_slot[failed_slot1];
+	int fd2 = block_index_for_slot[failed_slot2];
+	printf("Repairing stripe %llu\n", start);
+	printf("Assuming slots %d (%s) and %d (%s) are incorrect\n",
+	       fd1, name[fd1],
+	       fd2, name[fd2]);
+
+	if (failed_slot1 == -2 || failed_slot2 == -2) {
+		char *all_but_failed_blocks[syndrome_disks];
+		int failed_data_or_p;
+
+		if (failed_slot1 == -2)
+			failed_data_or_p = failed_slot2;
+		else
+			failed_data_or_p = failed_slot1;
+
+		printf("Repairing D/P(%d) and Q\n", failed_data_or_p);
+
+		for (i = 0; i < syndrome_disks; i++) {
+			if (i == failed_data_or_p)
+				all_but_failed_blocks[i] = blocks[-1];
+			else
+				all_but_failed_blocks[i] = blocks[i];
+		}
+		xor_blocks(blocks[failed_data_or_p],
+			   all_but_failed_blocks, syndrome_disks, chunk_size);
+		qsyndrome(p, (uint8_t*)blocks[-2], (uint8_t**)blocks,
+			  syndrome_disks, chunk_size);
+	} else {
+		ensure_zero_has_size(chunk_size);
+		if (failed_slot1 == -1 || failed_slot2 == -1) {
+			int failed_data;
+			if (failed_slot1 == -1)
+				failed_data = failed_slot2;
+			else
+				failed_data = failed_slot1;
+
+			printf("Repairing D(%d) and P\n", failed_data);
+			raid6_datap_recov(syndrome_disks+2, chunk_size,
+					  failed_data, (uint8_t**)blocks, 1);
+		} else {
+			printf("Repairing D and D\n");
+			raid6_2data_recov(syndrome_disks+2, chunk_size,
+					  failed_slot1, failed_slot2,
+					  (uint8_t**)blocks, 1);
+		}
+	}
+
+	int write_res1, write_res2;
+	off64_t seek_res;
+
+	seek_res = lseek64(source[fd1],
+			   offsets[fd1] + start * chunk_size, SEEK_SET);
+	if (seek_res < 0) {
+		fprintf(stderr, "lseek failed for failed_disk1\n");
+		return -1;
+	}
+	write_res1 = write(source[fd1], blocks[failed_slot1], chunk_size);
+
+	seek_res = lseek64(source[fd2],
+			   offsets[fd2] + start * chunk_size, SEEK_SET);
+	if (seek_res < 0) {
+		fprintf(stderr, "lseek failed for failed_disk2\n");
+		return -1;
+	}
+	write_res2 = write(source[fd2], blocks[failed_slot2], chunk_size);
+
+	if (write_res1 != chunk_size || write_res2 != chunk_size) {
+		fprintf(stderr, "Failed to write a complete chunk.\n");
+		return -2;
+	}
+
+	return 0;
+}
+
+int check_stripes(struct mdinfo *info, int *source, unsigned long long *offsets,
+		  int raid_disks, int chunk_size, int level, int layout,
+		  unsigned long long start, unsigned long long length, char *name[],
+		  enum repair repair, int failed_disk1, int failed_disk2)
+{
+	/* read the data and p and q blocks, and check we got them right */
+	int data_disks = raid_disks - 2;
+	int syndrome_disks = data_disks + is_ddf(layout) * 2;
+	char *stripe_buf;
+
+	/* stripes[] is indexed by raid_disk and holds chunks from each device */
+	char **stripes = xmalloc(raid_disks * sizeof(char*));
+
+	/* blocks[] is indexed by syndrome number and points to either one of the
+	 * chunks from 'stripes[]', or to a chunk of zeros. -1 and -2 are
+	 * P and Q */
+	char **blocks = xmalloc((syndrome_disks + 2) * sizeof(char*));
+
+	/* blocks_page[] is a temporary index to just one page of the chunks
+	 * that blocks[] points to. */
+	char **blocks_page = xmalloc((syndrome_disks + 2) * sizeof(char*));
+
+	/* block_index_for_slot[] provides the reverse mapping from blocks to stripes.
+	 * The index is a syndrome position, the content is a raid_disk number.
+	 * indicies -1 and -2 work, and are P and Q disks */
+	int *block_index_for_slot = xmalloc((syndrome_disks+2) * sizeof(int));
+
+	/* 'p' and 'q' contain calcualted P and Q, to be compared with
+	 * blocks[-1] and blocks[-2];
+	 */
+	uint8_t *p = xmalloc(chunk_size);
+	uint8_t *q = xmalloc(chunk_size);
+	char *zero = xmalloc(chunk_size);
+	int *results = xmalloc(chunk_size * sizeof(int));
+	sighandler_t *sig = xmalloc(3 * sizeof(sighandler_t));
+
+	int i, j;
+	int diskP, diskQ, diskD;
+	int err = 0;
+
+	extern int tables_ready;
+
+	if (!tables_ready)
+		make_tables();
+
+	if (posix_memalign((void**)&stripe_buf, 4096, raid_disks * chunk_size) != 0)
+		exit(4);
+	block_index_for_slot += 2;
+	blocks += 2;
+	blocks_page += 2;
+
+	memset(zero, 0, chunk_size);
+	for ( i = 0 ; i < raid_disks ; i++)
+		stripes[i] = stripe_buf + i * chunk_size;
+
+	while (length > 0) {
+		/* The syndrome number of the broken disk is recorded
+		 * in 'disk[]' which allows a different broken disk for
+		 * each page.
+		 */
+		int disk[chunk_size >> CHECK_PAGE_BITS];
+
+		err = lock_stripe(info, start, chunk_size, data_disks, sig);
+		if(err != 0) {
+			if (err != 2)
+				unlock_all_stripes(info, sig);
+			goto exitCheck;
+		}
+		for (i = 0 ; i < raid_disks ; i++) {
+			off64_t seek_res = lseek64(source[i], offsets[i] + start * chunk_size,
+						   SEEK_SET);
+			if (seek_res < 0) {
+				fprintf(stderr, "lseek to source %d failed\n", i);
+				unlock_all_stripes(info, sig);
+				err = -1;
+				goto exitCheck;
+			}
+			int read_res = read(source[i], stripes[i], chunk_size);
+			if (read_res < chunk_size) {
+				fprintf(stderr, "Failed to read complete chunk disk %d, aborting\n", i);
+				unlock_all_stripes(info, sig);
+				err = -1;
+				goto exitCheck;
+			}
+		}
+
+		diskP = geo_map(-1, start, raid_disks, level, layout);
+		block_index_for_slot[-1] = diskP;
+		blocks[-1] = stripes[diskP];
+
+		diskQ = geo_map(-2, start, raid_disks, level, layout);
+		block_index_for_slot[-2] = diskQ;
+		blocks[-2] = stripes[diskQ];
+
+		if (!is_ddf(layout)) {
+			/* The syndrome-order of disks starts immediately after 'Q',
+			 * but skips P */
+			diskD = diskQ;
+			for (i = 0 ; i < data_disks ; i++) {
+				diskD = diskD + 1;
+				if (diskD >= raid_disks)
+					diskD = 0;
+				if (diskD == diskP)
+					diskD += 1;
+				if (diskD >= raid_disks)
+					diskD = 0;
+				blocks[i] = stripes[diskD];
+				block_index_for_slot[i] = diskD;
+			}
+		} else {
+			/* The syndrome-order exactly follows raid-disk
+			 * numbers, with ZERO in place of P and Q
+			 */
+			for (i = 0 ; i < raid_disks; i++) {
+				if (i == diskP || i == diskQ) {
+					blocks[i] = zero;
+					block_index_for_slot[i] = -1;
+				} else {
+					blocks[i] = stripes[i];
+					block_index_for_slot[i] = i;
+				}
+			}
+		}
+
+		qsyndrome(p, q, (uint8_t**)blocks, syndrome_disks, chunk_size);
+
+		raid6_collect(chunk_size, p, q, stripes[diskP], stripes[diskQ], results);
+		raid6_stats(disk, results, raid_disks, chunk_size);
+
+		for(j = 0; j < (chunk_size >> CHECK_PAGE_BITS); j++) {
+			int role = disk[j];
+			if (role >= -2) {
+				int slot = block_index_for_slot[role];
+				if (slot >= 0)
+					printf("Error detected at stripe %llu, page %d: possible failed disk slot %d: %d --> %s\n",
+					       start, j, role, slot, name[slot]);
+				else
+					printf("Error detected at stripe %llu, page %d: failed slot %d should be zeros\n",
+					       start, j, role);
+			} else if(disk[j] == -65535) {
+				printf("Error detected at stripe %llu, page %d: disk slot unknown\n", start, j);
+			}
+		}
+
+		if(repair == AUTO_REPAIR) {
+			err = autorepair(disk, start, chunk_size,
+					name, raid_disks, syndrome_disks, blocks_page,
+					blocks, p, block_index_for_slot,
+					source, offsets);
+			if(err != 0) {
+				unlock_all_stripes(info, sig);
+				goto exitCheck;
+			}
+		}
+
+		if(repair == MANUAL_REPAIR) {
+			int failed_slot1 = -1, failed_slot2 = -1;
+			for (i = -2; i < syndrome_disks; i++) {
+				if (block_index_for_slot[i] == failed_disk1)
+					failed_slot1 = i;
+				if (block_index_for_slot[i] == failed_disk2)
+					failed_slot2 = i;
+			}
+			err = manual_repair(chunk_size, syndrome_disks,
+					    failed_slot1, failed_slot2,
+					    start, block_index_for_slot,
+					    name, stripes, blocks, p,
+					    source, offsets);
+			if(err == -1) {
+				unlock_all_stripes(info, sig);
+				goto exitCheck;
+			}
+		}
+
+		err = unlock_all_stripes(info, sig);
+		if(err != 0) {
+			goto exitCheck;
+		}
+
+		length--;
+		start++;
+	}
+
+exitCheck:
+
+	free(stripe_buf);
+	free(stripes);
+	free(blocks-2);
+	free(blocks_page-2);
+	free(block_index_for_slot-2);
+	free(p);
+	free(q);
+	free(results);
+	free(sig);
+
+	return err;
+}
+
+unsigned long long getnum(char *str, char **err)
+{
+	char *e;
+	unsigned long long rv = strtoull(str, &e, 10);
+	if (e==str || *e) {
+		*err = str;
+		return 0;
+	}
+	return rv;
+}
+
+int main(int argc, char *argv[])
+{
+	/* md_device start length */
+	int *fds = NULL;
+	char *buf = NULL;
+	char **disk_name = NULL;
+	unsigned long long *offsets = NULL;
+	int raid_disks = 0;
+	int active_disks;
+	int chunk_size = 0;
+	int layout = -1;
+	int level = 6;
+	enum repair repair = NO_REPAIR;
+	int failed_disk1 = -1;
+	int failed_disk2 = -1;
+	unsigned long long start, length;
+	int i;
+	int mdfd;
+	struct mdinfo *info = NULL, *comp = NULL;
+	char *err = NULL;
+	int exit_err = 0;
+	int close_flag = 0;
+	char *prg = strrchr(argv[0], '/');
+
+	if (prg == NULL)
+		prg = argv[0];
+	else
+		prg++;
+
+	if (argc < 4) {
+		fprintf(stderr, "Usage: %s md_device start_stripe length_stripes [autorepair]\n", prg);
+		fprintf(stderr, "   or: %s md_device repair stripe failed_slot_1 failed_slot_2\n", prg);
+		exit_err = 1;
+		goto exitHere;
+	}
+
+	mdfd = open(argv[1], O_RDONLY);
+	if(mdfd < 0) {
+		perror(argv[1]);
+		fprintf(stderr, "%s: cannot open %s\n", prg, argv[1]);
+		exit_err = 2;
+		goto exitHere;
+	}
+
+	info = sysfs_read(mdfd, NULL,
+			  GET_LEVEL|
+			  GET_LAYOUT|
+			  GET_DISKS|
+			  GET_STATE |
+			  GET_COMPONENT|
+			  GET_CHUNK|
+			  GET_DEVS|
+			  GET_OFFSET|
+			  GET_SIZE);
+
+	if(info == NULL) {
+		fprintf(stderr, "%s: Error reading sysfs information of %s\n", prg, argv[1]);
+		exit_err = 9;
+		goto exitHere;
+	}
+
+	if(info->array.level != level) {
+		fprintf(stderr, "%s: %s not a RAID-6\n", prg, argv[1]);
+		exit_err = 3;
+		goto exitHere;
+	}
+
+	if(info->array.failed_disks > 0) {
+		fprintf(stderr, "%s: %s degraded array\n", prg, argv[1]);
+		exit_err = 8;
+		goto exitHere;
+	}
+
+	printf("layout: %d\n", info->array.layout);
+	printf("disks: %d\n", info->array.raid_disks);
+	printf("component size: %llu\n", info->component_size * 512);
+	printf("total stripes: %llu\n", (info->component_size * 512) / info->array.chunk_size);
+	printf("chunk size: %d\n", info->array.chunk_size);
+	printf("\n");
+
+	comp = info->devs;
+	for(i = 0, active_disks = 0; active_disks < info->array.raid_disks; i++) {
+		printf("disk: %d - offset: %llu - size: %llu - name: %s - slot: %d\n",
+			i, comp->data_offset * 512, comp->component_size * 512,
+			map_dev(comp->disk.major, comp->disk.minor, 0),
+			comp->disk.raid_disk);
+		if(comp->disk.raid_disk >= 0)
+			active_disks++;
+		comp = comp->next;
+	}
+	printf("\n");
+
+	close(mdfd);
+
+	raid_disks = info->array.raid_disks;
+	chunk_size = info->array.chunk_size;
+	layout = info->array.layout;
+	if (strcmp(argv[2], "repair")==0) {
+		if (argc < 6) {
+			fprintf(stderr, "For repair mode, call %s md_device repair stripe failed_slot_1 failed_slot_2\n", prg);
+			exit_err = 1;
+			goto exitHere;
+		}
+		repair = MANUAL_REPAIR;
+		start = getnum(argv[3], &err);
+		length = 1;
+		failed_disk1 = getnum(argv[4], &err);
+		failed_disk2 = getnum(argv[5], &err);
+
+		if(failed_disk1 >= info->array.raid_disks) {
+			fprintf(stderr, "%s: failed_slot_1 index is higher than number of devices in raid\n", prg);
+			exit_err = 4;
+			goto exitHere;
+		}
+		if(failed_disk2 >= info->array.raid_disks) {
+			fprintf(stderr, "%s: failed_slot_2 index is higher than number of devices in raid\n", prg);
+			exit_err = 4;
+			goto exitHere;
+		}
+		if(failed_disk1 == failed_disk2) {
+			fprintf(stderr, "%s: failed_slot_1 and failed_slot_2 are the same\n", prg);
+			exit_err = 4;
+			goto exitHere;
+		}
+	}
+	else {
+		start = getnum(argv[2], &err);
+		length = getnum(argv[3], &err);
+		if (argc >= 5 && strcmp(argv[4], "autorepair")==0)
+			repair = AUTO_REPAIR;
+	}
+
+	if (err) {
+		fprintf(stderr, "%s: Bad number: %s\n", prg, err);
+		exit_err = 4;
+		goto exitHere;
+	}
+
+	if(start > ((info->component_size * 512) / chunk_size)) {
+		start = (info->component_size * 512) / chunk_size;
+		fprintf(stderr, "%s: start beyond disks size\n", prg);
+	}
+
+	if((length == 0) ||
+	   ((length + start) > ((info->component_size * 512) / chunk_size))) {
+		length = (info->component_size * 512) / chunk_size - start;
+	}
+
+	disk_name = xmalloc(raid_disks * sizeof(*disk_name));
+	fds = xmalloc(raid_disks * sizeof(*fds));
+	offsets = xcalloc(raid_disks, sizeof(*offsets));
+	buf = xmalloc(raid_disks * chunk_size);
+
+	for(i=0; i<raid_disks; i++) {
+		fds[i] = -1;
+	}
+	close_flag = 1;
+
+	comp = info->devs;
+	for (i=0, active_disks=0; active_disks<raid_disks; i++) {
+		int disk_slot = comp->disk.raid_disk;
+		if(disk_slot >= 0) {
+			disk_name[disk_slot] = map_dev(comp->disk.major, comp->disk.minor, 0);
+			offsets[disk_slot] = comp->data_offset * 512;
+			fds[disk_slot] = open(disk_name[disk_slot], O_RDWR | O_DIRECT);
+			if (fds[disk_slot] < 0) {
+				perror(disk_name[disk_slot]);
+				fprintf(stderr,"%s: cannot open %s\n", prg, disk_name[disk_slot]);
+				exit_err = 6;
+				goto exitHere;
+			}
+			active_disks++;
+		}
+		comp = comp->next;
+	}
+
+	int rv = check_stripes(info, fds, offsets,
+			       raid_disks, chunk_size, level, layout,
+			       start, length, disk_name, repair, failed_disk1, failed_disk2);
+	if (rv != 0) {
+		fprintf(stderr,	"%s: check_stripes returned %d\n", prg, rv);
+		exit_err = 7;
+		goto exitHere;
+	}
+
+exitHere:
+
+	if (close_flag)
+		for(i = 0; i < raid_disks; i++)
+			close(fds[i]);
+
+	free(disk_name);
+	free(fds);
+	free(offsets);
+	free(buf);
+
+	exit(exit_err);
+}