2 * mdadm - manage Linux "md" devices aka RAID arrays.
4 * Copyright (C) 2006-2009 Neil Brown <neilb@suse.de>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 * Email: <neilb@suse.de>
28 /* To restripe, we read from old geometry to a buffer, and
29 * read from buffer to new geometry.
30 * When reading, we might have missing devices and so could need
32 * When writing, we need to create correct parity and Q.
36 int geo_map(int block
, unsigned long long stripe
, int raid_disks
,
37 int level
, int layout
)
39 /* On the given stripe, find which disk in the array will have
40 * block numbered 'block'.
41 * '-1' means the parity block.
42 * '-2' means the Q syndrome.
46 /* layout is not relevant for raid0 and raid4 */
51 switch(level
*100 + layout
) {
54 case 500 + ALGORITHM_PARITY_N
:
55 /* raid 4 isn't messed around by parity blocks */
57 return raid_disks
-1; /* parity block */
59 case 500 + ALGORITHM_LEFT_ASYMMETRIC
:
60 pd
= (raid_disks
-1) - stripe
% raid_disks
;
61 if (block
== -1) return pd
;
66 case 500 + ALGORITHM_RIGHT_ASYMMETRIC
:
67 pd
= stripe
% raid_disks
;
68 if (block
== -1) return pd
;
73 case 500 + ALGORITHM_LEFT_SYMMETRIC
:
74 pd
= (raid_disks
- 1) - stripe
% raid_disks
;
75 if (block
== -1) return pd
;
76 return (pd
+ 1 + block
) % raid_disks
;
78 case 500 + ALGORITHM_RIGHT_SYMMETRIC
:
79 pd
= stripe
% raid_disks
;
80 if (block
== -1) return pd
;
81 return (pd
+ 1 + block
) % raid_disks
;
83 case 500 + ALGORITHM_PARITY_0
:
87 case 600 + ALGORITHM_PARITY_N_6
:
89 return raid_disks
- 1;
91 return raid_disks
- 2; /* parity block */
93 case 600 + ALGORITHM_LEFT_ASYMMETRIC_6
:
95 return raid_disks
- 1;
97 pd
= (raid_disks
-1) - stripe
% raid_disks
;
98 if (block
== -1) return pd
;
103 case 600 + ALGORITHM_RIGHT_ASYMMETRIC_6
:
105 return raid_disks
- 1;
107 pd
= stripe
% raid_disks
;
108 if (block
== -1) return pd
;
113 case 600 + ALGORITHM_LEFT_SYMMETRIC_6
:
115 return raid_disks
- 1;
117 pd
= (raid_disks
- 1) - stripe
% raid_disks
;
118 if (block
== -1) return pd
;
119 return (pd
+ 1 + block
) % raid_disks
;
121 case 600 + ALGORITHM_RIGHT_SYMMETRIC_6
:
123 return raid_disks
- 1;
125 pd
= stripe
% raid_disks
;
126 if (block
== -1) return pd
;
127 return (pd
+ 1 + block
) % raid_disks
;
129 case 600 + ALGORITHM_PARITY_0_6
:
131 return raid_disks
- 1;
135 case 600 + ALGORITHM_PARITY_0
:
142 case 600 + ALGORITHM_LEFT_ASYMMETRIC
:
143 pd
= raid_disks
- 1 - (stripe
% raid_disks
);
144 if (block
== -1) return pd
;
145 if (block
== -2) return (pd
+1) % raid_disks
;
146 if (pd
== raid_disks
- 1)
152 case 600 + ALGORITHM_ROTATING_ZERO_RESTART
:
153 /* Different order for calculating Q, otherwize same as ... */
154 case 600 + ALGORITHM_RIGHT_ASYMMETRIC
:
155 pd
= stripe
% raid_disks
;
156 if (block
== -1) return pd
;
157 if (block
== -2) return (pd
+1) % raid_disks
;
158 if (pd
== raid_disks
- 1)
164 case 600 + ALGORITHM_LEFT_SYMMETRIC
:
165 pd
= raid_disks
- 1 - (stripe
% raid_disks
);
166 if (block
== -1) return pd
;
167 if (block
== -2) return (pd
+1) % raid_disks
;
168 return (pd
+ 2 + block
) % raid_disks
;
170 case 600 + ALGORITHM_RIGHT_SYMMETRIC
:
171 pd
= stripe
% raid_disks
;
172 if (block
== -1) return pd
;
173 if (block
== -2) return (pd
+1) % raid_disks
;
174 return (pd
+ 2 + block
) % raid_disks
;
177 case 600 + ALGORITHM_ROTATING_N_RESTART
:
178 /* Same a left_asymmetric, by first stripe is
179 * D D D P Q rather than
182 pd
= raid_disks
- 1 - ((stripe
+ 1) % raid_disks
);
183 if (block
== -1) return pd
;
184 if (block
== -2) return (pd
+1) % raid_disks
;
185 if (pd
== raid_disks
- 1)
191 case 600 + ALGORITHM_ROTATING_N_CONTINUE
:
192 /* Same as left_symmetric but Q is before P */
193 pd
= raid_disks
- 1 - (stripe
% raid_disks
);
194 if (block
== -1) return pd
;
195 if (block
== -2) return (pd
+raid_disks
-1) % raid_disks
;
196 return (pd
+ 1 + block
) % raid_disks
;
200 static int is_ddf(int layout
)
206 case ALGORITHM_ROTATING_N_CONTINUE
:
207 case ALGORITHM_ROTATING_N_RESTART
:
208 case ALGORITHM_ROTATING_ZERO_RESTART
:
214 static void xor_blocks(char *target
, char **sources
, int disks
, int size
)
217 /* Amazingly inefficient... */
218 for (i
=0; i
<size
; i
++) {
220 for (j
=0 ; j
<disks
; j
++)
226 void qsyndrome(uint8_t *p
, uint8_t *q
, uint8_t **sources
, int disks
, int size
)
229 uint8_t wq0
, wp0
, wd0
, w10
, w20
;
230 for ( d
= 0; d
< size
; d
++) {
231 wq0
= wp0
= sources
[disks
-1][d
];
232 for ( z
= disks
-2 ; z
>= 0 ; z
-- ) {
235 w20
= (wq0
&0x80) ? 0xff : 0x00;
236 w10
= (wq0
<< 1) & 0xff;
248 * The following was taken from linux/drivers/md/mktables.c, and modified
249 * to create in-memory tables rather than C code
251 static uint8_t gfmul(uint8_t a
, uint8_t b
)
258 a
= (a
<< 1) ^ (a
& 0x80 ? 0x1d : 0);
265 static uint8_t gfpow(uint8_t a
, int b
)
283 int tables_ready
= 0;
284 uint8_t raid6_gfmul
[256][256];
285 uint8_t raid6_gfexp
[256];
286 uint8_t raid6_gfinv
[256];
287 uint8_t raid6_gfexi
[256];
288 uint8_t raid6_gflog
[256];
289 uint8_t raid6_gfilog
[256];
290 void make_tables(void)
296 /* Compute multiplication table */
297 for (i
= 0; i
< 256; i
++)
298 for (j
= 0; j
< 256; j
++)
299 raid6_gfmul
[i
][j
] = gfmul(i
, j
);
301 /* Compute power-of-2 table (exponent) */
303 for (i
= 0; i
< 256; i
++) {
307 v
= 0; /* For entry 255, not a real entry */
310 /* Compute inverse table x^-1 == x^254 */
311 for (i
= 0; i
< 256; i
++)
312 raid6_gfinv
[i
] = gfpow(i
, 254);
314 /* Compute inv(2^x + 1) (exponent-xor-inverse) table */
315 for (i
= 0; i
< 256; i
++)
316 raid6_gfexi
[i
] = raid6_gfinv
[raid6_gfexp
[i
] ^ 1];
318 /* Compute log and inverse log */
319 /* Modified code from:
320 * http://web.eecs.utk.edu/~plank/plank/papers/CS-96-332.html
324 raid6_gfilog
[255] = 0;
326 for (log
= 0; log
< 255; log
++) {
327 raid6_gflog
[b
] = (uint8_t) log
;
328 raid6_gfilog
[log
] = (uint8_t) b
;
330 if (b
& 256) b
= b
^ 0435;
337 /* Following was taken from linux/drivers/md/raid6recov.c */
339 /* Recover two failed data blocks. */
340 void raid6_2data_recov(int disks
, size_t bytes
, int faila
, int failb
,
343 uint8_t *p
, *q
, *dp
, *dq
;
345 const uint8_t *pbmul
; /* P multiplier table for B data */
346 const uint8_t *qmul
; /* Q multiplier table (for both) */
351 /* Compute syndrome with zero for the missing data pages
352 Use the dead data pages as temporary storage for
353 delta p and delta q */
359 qsyndrome(dp
, dq
, ptrs
, disks
-2, bytes
);
361 /* Restore pointer table */
365 /* Now, pick the proper data tables */
366 pbmul
= raid6_gfmul
[raid6_gfexi
[failb
-faila
]];
367 qmul
= raid6_gfmul
[raid6_gfinv
[raid6_gfexp
[faila
]^raid6_gfexp
[failb
]]];
373 *dq
++ = db
= pbmul
[px
] ^ qx
; /* Reconstructed B */
374 *dp
++ = db
^ px
; /* Reconstructed A */
379 /* Recover failure of one data block plus the P block */
380 void raid6_datap_recov(int disks
, size_t bytes
, int faila
, uint8_t **ptrs
)
383 const uint8_t *qmul
; /* Q multiplier table */
388 /* Compute syndrome with zero for the missing data page
389 Use the dead data page as temporary storage for delta q */
393 qsyndrome(p
, dq
, ptrs
, disks
-2, bytes
);
395 /* Restore pointer table */
398 /* Now, pick the proper data tables */
399 qmul
= raid6_gfmul
[raid6_gfinv
[raid6_gfexp
[faila
]]];
403 *p
++ ^= *dq
= qmul
[*q
^ *dq
];
408 /* Try to find out if a specific disk has a problem */
409 int raid6_check_disks(int data_disks
, int start
, int chunk_size
,
410 int level
, int layout
, int diskP
, int diskQ
,
411 char *p
, char *q
, char **stripes
)
416 int curr_broken_disk
= -1;
417 int prev_broken_disk
= -1;
418 int broken_status
= 0;
420 for(i
= 0; i
< chunk_size
; i
++) {
421 Px
= (uint8_t)stripes
[diskP
][i
] ^ (uint8_t)p
[i
];
422 Qx
= (uint8_t)stripes
[diskQ
][i
] ^ (uint8_t)q
[i
];
424 if((Px
!= 0) && (Qx
== 0))
425 curr_broken_disk
= diskP
;
428 if((Px
== 0) && (Qx
!= 0))
429 curr_broken_disk
= diskQ
;
432 if((Px
!= 0) && (Qx
!= 0)) {
433 data_id
= (raid6_gflog
[Qx
] - raid6_gflog
[Px
]);
434 if(data_id
< 0) data_id
+= 255;
435 diskD
= geo_map(data_id
, start
/chunk_size
,
436 data_disks
+ 2, level
, layout
);
437 curr_broken_disk
= diskD
;
440 if((Px
== 0) && (Qx
== 0))
441 curr_broken_disk
= curr_broken_disk
;
443 if(curr_broken_disk
>= data_disks
+ 2)
446 switch(broken_status
) {
448 if(curr_broken_disk
!= -1) {
449 prev_broken_disk
= curr_broken_disk
;
455 if(curr_broken_disk
!= prev_broken_disk
)
461 curr_broken_disk
= prev_broken_disk
= -2;
466 return curr_broken_disk
;
471 * A list of 'fds' of the active disks. Some may be absent.
472 * A geometry: raid_disks, chunk_size, level, layout
473 * A list of 'fds' for mirrored targets. They are already seeked to
474 * right (Write) location
475 * A start and length which must be stripe-aligned
476 * 'buf' is large enough to hold one stripe, and is aligned
479 int save_stripes(int *source
, unsigned long long *offsets
,
480 int raid_disks
, int chunk_size
, int level
, int layout
,
481 int nwrites
, int *dest
,
482 unsigned long long start
, unsigned long long length
,
486 int data_disks
= raid_disks
- (level
== 0 ? 0 : level
<=5 ? 1 : 2);
494 zero
= malloc(chunk_size
);
495 memset(zero
, 0, chunk_size
);
498 len
= data_disks
* chunk_size
;
501 int fdisk
[3], fblock
[3];
502 for (disk
= 0; disk
< raid_disks
; disk
++) {
503 unsigned long long offset
;
506 offset
= (start
/chunk_size
/data_disks
)*chunk_size
;
507 dnum
= geo_map(disk
< data_disks
? disk
: data_disks
- disk
- 1,
508 start
/chunk_size
/data_disks
,
509 raid_disks
, level
, layout
);
510 if (dnum
< 0) abort();
511 if (source
[dnum
] < 0 ||
512 lseek64(source
[dnum
], offsets
[dnum
]+offset
, 0) < 0 ||
513 read(source
[dnum
], buf
+disk
* chunk_size
, chunk_size
)
516 fdisk
[failed
] = dnum
;
517 fblock
[failed
] = disk
;
521 if (failed
== 0 || fblock
[0] >= data_disks
)
522 /* all data disks are good */
524 else if (failed
== 1 || fblock
[1] >= data_disks
+1) {
525 /* one failed data disk and good parity */
526 char *bufs
[data_disks
];
527 for (i
=0; i
< data_disks
; i
++)
529 bufs
[i
] = buf
+ data_disks
*chunk_size
;
531 bufs
[i
] = buf
+ i
*chunk_size
;
533 xor_blocks(buf
+ fblock
[0]*chunk_size
,
534 bufs
, data_disks
, chunk_size
);
535 } else if (failed
> 2 || level
!= 6)
536 /* too much failure */
539 /* RAID6 computations needed. */
540 uint8_t *bufs
[data_disks
+4];
543 disk
= geo_map(-1, start
/chunk_size
/data_disks
,
544 raid_disks
, level
, layout
);
545 qdisk
= geo_map(-2, start
/chunk_size
/data_disks
,
546 raid_disks
, level
, layout
);
547 if (is_ddf(layout
)) {
548 /* q over 'raid_disks' blocks, in device order.
549 * 'p' and 'q' get to be all zero
551 for (i
= 0; i
< raid_disks
; i
++)
553 for (i
= 0; i
< data_disks
; i
++) {
554 int dnum
= geo_map(i
,
555 start
/chunk_size
/data_disks
,
556 raid_disks
, level
, layout
);
558 /* i is the logical block number, so is index to 'buf'.
559 * dnum is physical disk number
560 * and thus the syndrome number.
563 bufs
[snum
] = (uint8_t*)buf
+ chunk_size
* i
;
565 syndrome_disks
= raid_disks
;
567 /* for md, q is over 'data_disks' blocks,
568 * starting immediately after 'q'
569 * Note that for the '_6' variety, the p block
570 * makes a hole that we need to be careful of.
574 for (j
= 0; j
< raid_disks
; j
++) {
575 int dnum
= (qdisk
+ 1 + j
) % raid_disks
;
576 if (dnum
== disk
|| dnum
== qdisk
)
578 for (i
= 0; i
< data_disks
; i
++)
580 start
/chunk_size
/data_disks
,
581 raid_disks
, level
, layout
) == dnum
)
583 /* i is the logical block number, so is index to 'buf'.
584 * dnum is physical disk number
585 * snum is syndrome disk for which 0 is immediately after Q
587 bufs
[snum
] = (uint8_t*)buf
+ chunk_size
* i
;
596 syndrome_disks
= data_disks
;
599 /* Place P and Q blocks at end of bufs */
600 bufs
[syndrome_disks
] = (uint8_t*)buf
+ chunk_size
* data_disks
;
601 bufs
[syndrome_disks
+1] = (uint8_t*)buf
+ chunk_size
* (data_disks
+1);
603 if (fblock
[1] == data_disks
)
604 /* One data failed, and parity failed */
605 raid6_datap_recov(syndrome_disks
+2, chunk_size
,
608 if (fdisk
[0] > fdisk
[1]) {
613 /* Two data blocks failed, P,Q OK */
614 raid6_2data_recov(syndrome_disks
+2, chunk_size
,
615 fdisk
[0], fdisk
[1], bufs
);
619 for (i
=0; i
<nwrites
; i
++)
620 if (write(dest
[i
], buf
, len
) != len
)
631 * A list of 'fds' of the active disks. Some may be '-1' for not-available.
632 * A geometry: raid_disks, chunk_size, level, layout
633 * An 'fd' to read from. It is already seeked to the right (Read) location.
634 * A start and length.
635 * The length must be a multiple of the stripe size.
637 * We build a full stripe in memory and then write it out.
638 * We assume that there are enough working devices.
640 int restore_stripes(int *dest
, unsigned long long *offsets
,
641 int raid_disks
, int chunk_size
, int level
, int layout
,
642 int source
, unsigned long long read_offset
,
643 unsigned long long start
, unsigned long long length
)
646 char **stripes
= malloc(raid_disks
* sizeof(char*));
647 char **blocks
= malloc(raid_disks
* sizeof(char*));
650 int data_disks
= raid_disks
- (level
== 0 ? 0 : level
<= 5 ? 1 : 2);
652 if (posix_memalign((void**)&stripe_buf
, 4096, raid_disks
* chunk_size
))
655 zero
= malloc(chunk_size
);
657 memset(zero
, 0, chunk_size
);
659 if (stripe_buf
== NULL
|| stripes
== NULL
|| blocks
== NULL
667 for (i
=0; i
<raid_disks
; i
++)
668 stripes
[i
] = stripe_buf
+ i
* chunk_size
;
670 unsigned int len
= data_disks
* chunk_size
;
671 unsigned long long offset
;
676 for (i
=0; i
< data_disks
; i
++) {
677 int disk
= geo_map(i
, start
/chunk_size
/data_disks
,
678 raid_disks
, level
, layout
);
679 if ((unsigned long long)lseek64(source
, read_offset
, 0)
682 if (read(source
, stripes
[disk
],
683 chunk_size
) != chunk_size
)
685 read_offset
+= chunk_size
;
687 /* We have the data, now do the parity */
688 offset
= (start
/chunk_size
/data_disks
) * chunk_size
;
692 disk
= geo_map(-1, start
/chunk_size
/data_disks
,
693 raid_disks
, level
, layout
);
694 for (i
= 0; i
< data_disks
; i
++)
695 blocks
[i
] = stripes
[(disk
+1+i
) % raid_disks
];
696 xor_blocks(stripes
[disk
], blocks
, data_disks
, chunk_size
);
699 disk
= geo_map(-1, start
/chunk_size
/data_disks
,
700 raid_disks
, level
, layout
);
701 qdisk
= geo_map(-2, start
/chunk_size
/data_disks
,
702 raid_disks
, level
, layout
);
703 if (is_ddf(layout
)) {
704 /* q over 'raid_disks' blocks, in device order.
705 * 'p' and 'q' get to be all zero
707 for (i
= 0; i
< raid_disks
; i
++)
708 if (i
== disk
|| i
== qdisk
)
709 blocks
[i
] = (char*)zero
;
711 blocks
[i
] = stripes
[i
];
712 syndrome_disks
= raid_disks
;
714 /* for md, q is over 'data_disks' blocks,
715 * starting immediately after 'q'
717 for (i
= 0; i
< data_disks
; i
++)
718 blocks
[i
] = stripes
[(qdisk
+1+i
) % raid_disks
];
720 syndrome_disks
= data_disks
;
722 qsyndrome((uint8_t*)stripes
[disk
],
723 (uint8_t*)stripes
[qdisk
],
725 syndrome_disks
, chunk_size
);
728 for (i
=0; i
< raid_disks
; i
++)
730 if (lseek64(dest
[i
], offsets
[i
]+offset
, 0) < 0)
732 if (write(dest
[i
], stripes
[i
], chunk_size
) != chunk_size
)
743 int test_stripes(int *source
, unsigned long long *offsets
,
744 int raid_disks
, int chunk_size
, int level
, int layout
,
745 unsigned long long start
, unsigned long long length
)
747 /* ready the data and p (and q) blocks, and check we got them right */
748 char *stripe_buf
= malloc(raid_disks
* chunk_size
);
749 char **stripes
= malloc(raid_disks
* sizeof(char*));
750 char **blocks
= malloc(raid_disks
* sizeof(char*));
751 char *p
= malloc(chunk_size
);
752 char *q
= malloc(chunk_size
);
756 int data_disks
= raid_disks
- (level
== 5 ? 1: 2);
761 for ( i
= 0 ; i
< raid_disks
; i
++)
762 stripes
[i
] = stripe_buf
+ i
* chunk_size
;
767 for (i
= 0 ; i
< raid_disks
; i
++) {
768 lseek64(source
[i
], offsets
[i
]+start
, 0);
769 read(source
[i
], stripes
[i
], chunk_size
);
771 for (i
= 0 ; i
< data_disks
; i
++) {
772 int disk
= geo_map(i
, start
/chunk_size
, raid_disks
,
774 blocks
[i
] = stripes
[disk
];
775 printf("%d->%d\n", i
, disk
);
779 qsyndrome(p
, q
, (uint8_t**)blocks
, data_disks
, chunk_size
);
780 diskP
= geo_map(-1, start
/chunk_size
, raid_disks
,
782 if (memcmp(p
, stripes
[diskP
], chunk_size
) != 0) {
783 printf("P(%d) wrong at %llu\n", diskP
,
786 diskQ
= geo_map(-2, start
/chunk_size
, raid_disks
,
788 if (memcmp(q
, stripes
[diskQ
], chunk_size
) != 0) {
789 printf("Q(%d) wrong at %llu\n", diskQ
,
792 disk
= raid6_check_disks(data_disks
, start
, chunk_size
,
793 level
, layout
, diskP
, diskQ
,
796 printf("Possible failed disk: %d\n", disk
);
799 printf("Failure detected, but disk unknown\n");
803 length
-= chunk_size
;
809 unsigned long long getnum(char *str
, char **err
)
812 unsigned long long rv
= strtoull(str
, &e
, 10);
820 main(int argc
, char *argv
[])
822 /* save/restore file raid_disks chunk_size level layout start length devices...
829 unsigned long long *offsets
;
830 int raid_disks
, chunk_size
, level
, layout
;
831 unsigned long long start
, length
;
836 fprintf(stderr
, "Usage: test_stripe save/restore file raid_disks"
837 " chunk_size level layout start length devices...\n");
840 if (strcmp(argv
[1], "save")==0)
842 else if (strcmp(argv
[1], "restore") == 0)
844 else if (strcmp(argv
[1], "test") == 0)
847 fprintf(stderr
, "test_stripe: must give 'save' or 'restore'.\n");
852 raid_disks
= getnum(argv
[3], &err
);
853 chunk_size
= getnum(argv
[4], &err
);
854 level
= getnum(argv
[5], &err
);
855 layout
= getnum(argv
[6], &err
);
856 start
= getnum(argv
[7], &err
);
857 length
= getnum(argv
[8], &err
);
859 fprintf(stderr
, "test_stripe: Bad number: %s\n", err
);
862 if (argc
!= raid_disks
+ 9) {
863 fprintf(stderr
, "test_stripe: wrong number of devices: want %d found %d\n",
867 fds
= malloc(raid_disks
* sizeof(*fds
));
868 offsets
= malloc(raid_disks
* sizeof(*offsets
));
869 memset(offsets
, 0, raid_disks
* sizeof(*offsets
));
871 storefd
= open(file
, O_RDWR
);
874 fprintf(stderr
, "test_stripe: could not open %s.\n", file
);
877 for (i
=0; i
<raid_disks
; i
++) {
878 fds
[i
] = open(argv
[9+i
], O_RDWR
);
881 fprintf(stderr
,"test_stripe: cannot open %s.\n", argv
[9+i
]);
886 buf
= malloc(raid_disks
* chunk_size
);
889 int rv
= save_stripes(fds
, offsets
,
890 raid_disks
, chunk_size
, level
, layout
,
895 "test_stripe: save_stripes returned %d\n", rv
);
898 } else if (save
== 2) {
899 int rv
= test_stripes(fds
, offsets
,
900 raid_disks
, chunk_size
, level
, layout
,
904 "test_stripe: test_stripes returned %d\n", rv
);
908 int rv
= restore_stripes(fds
, offsets
,
909 raid_disks
, chunk_size
, level
, layout
,
914 "test_stripe: restore_stripes returned %d\n",