Use 'mdinfo' instead of special 'sysdev' structure.
[thirdparty/mdadm.git] / mdadm.h
CommitLineData
64c4757e 1/*
9a9dab36 2 * mdadm - manage Linux "md" devices aka RAID arrays.
64c4757e 3 *
4f589ad0 4 * Copyright (C) 2001-2006 Neil Brown <neilb@suse.de>
64c4757e
NB
5 *
6 *
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.
11 *
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.
16 *
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
20 *
21 * Author: Neil Brown
22 * Email: <neilb@cse.unsw.edu.au>
23 * Paper: Neil Brown
24 * School of Computer Science and Engineering
25 * The University of New South Wales
26 * Sydney, 2052
27 * Australia
28 */
29
4ccdb956 30#define _GNU_SOURCE
64c4757e 31#include <unistd.h>
e39b673e 32#if !defined(__dietlibc__) && !defined(__KLIBC__)
64c4757e 33extern __off64_t lseek64 __P ((int __fd, __off64_t __offset, int __whence));
f783ca4f 34#else
fffdbe5e 35# if defined(__NO_STAT64) || __WORDSIZE != 32
f783ca4f
NB
36# define lseek64 lseek
37# endif
98c6faba 38#endif
64c4757e
NB
39
40#include <sys/types.h>
41#include <sys/stat.h>
42#include <stdlib.h>
43#include <time.h>
11018a45 44#include <sys/time.h>
64c4757e
NB
45#include <getopt.h>
46#include <fcntl.h>
47#include <stdio.h>
48#include <errno.h>
49#include <string.h>
773135f5 50#include <syslog.h>
b56c3630
NB
51#ifdef __dietlibc__
52#include <strings.h>
280a927d
NB
53/* dietlibc has deprecated random and srandom!! */
54#define random rand
55#define srandom srand
98c6faba
NB
56#endif
57
64c4757e
NB
58
59#include <linux/kdev_t.h>
e0d19036
NB
60/*#include <linux/fs.h> */
61#include <sys/mount.h>
62#include <asm/types.h>
64c4757e
NB
63#include <sys/ioctl.h>
64#define MD_MAJOR 9
dd0781e5 65#define MdpMinorShift 6
64c4757e 66
e0d19036 67#ifndef BLKGETSIZE64
98c6faba 68#define BLKGETSIZE64 _IOR(0x12,114,size_t) /* return device size in bytes (u64 *arg) */
e0d19036 69#endif
56eb10c0 70
c82f047c
NB
71#define DEFAULT_BITMAP_CHUNK 4096
72#define DEFAULT_BITMAP_DELAY 5
dfd4d8ee 73#define DEFAULT_MAX_WRITE_BEHIND 256
64c4757e
NB
74
75#include "md_u.h"
e0d19036 76#include "md_p.h"
c82f047c 77#include "bitmap.h"
64c4757e 78
1e0d770c 79#include <endian.h>
efd441d1
NB
80/* Redhat don't like to #include <asm/byteorder.h>, and
81 * some time include <linux/byteorder/xxx_endian.h> isn't enough,
82 * and there is no standard conversion function so... */
0ae03b8a
NB
83/* And dietlibc doesn't think byteswap is ok, so.. */
84/* #include <byteswap.h> */
85#define bswap_16(x) (((x) & 0x00ffU) << 8 | \
86 ((x) & 0xff00U) >> 8)
87#define bswap_32(x) (((x) & 0x000000ffU) << 24 | \
88 ((x) & 0xff000000U) >> 24 | \
89 ((x) & 0x0000ff00U) << 8 | \
90 ((x) & 0x00ff0000U) >> 8)
91#define bswap_64(x) (((x) & 0x00000000000000ffULL) << 56 | \
92 ((x) & 0xff00000000000000ULL) >> 56 | \
93 ((x) & 0x000000000000ff00ULL) << 40 | \
94 ((x) & 0x00ff000000000000ULL) >> 40 | \
95 ((x) & 0x0000000000ff0000ULL) << 24 | \
96 ((x) & 0x0000ff0000000000ULL) >> 24 | \
97 ((x) & 0x00000000ff000000ULL) << 8 | \
98 ((x) & 0x000000ff00000000ULL) >> 8)
99
e39b673e 100#if !defined(__KLIBC__)
efd441d1
NB
101#if BYTE_ORDER == LITTLE_ENDIAN
102#define __cpu_to_le16(_x) (_x)
103#define __cpu_to_le32(_x) (_x)
104#define __cpu_to_le64(_x) (_x)
105#define __le16_to_cpu(_x) (_x)
106#define __le32_to_cpu(_x) (_x)
107#define __le64_to_cpu(_x) (_x)
108#elif BYTE_ORDER == BIG_ENDIAN
109#define __cpu_to_le16(_x) bswap_16(_x)
110#define __cpu_to_le32(_x) bswap_32(_x)
111#define __cpu_to_le64(_x) bswap_64(_x)
112#define __le16_to_cpu(_x) bswap_16(_x)
113#define __le32_to_cpu(_x) bswap_32(_x)
114#define __le64_to_cpu(_x) bswap_64(_x)
1e0d770c
NB
115#else
116# error "unknown endianness."
117#endif
e39b673e 118#endif /* __KLIBC__ */
1e0d770c
NB
119
120
121
4b1ac34b
NB
122/* general information that might be extracted from a superblock */
123struct mdinfo {
124 mdu_array_info_t array;
125 mdu_disk_info_t disk;
126 __u64 events;
fbf8a0b7 127 int uuid[4];
31317663 128 char name[33];
353632d9
NB
129 unsigned long long data_offset;
130 unsigned long long component_size;
131 int reshape_active;
132 unsigned long long reshape_progress;
133 int new_level, delta_disks, new_layout, new_chunk;
06c7f68e
NB
134 int errors;
135
136 char sys_name[20];
137 struct mdinfo *next;
4b1ac34b
NB
138};
139
5bbb4842
NB
140struct createinfo {
141 int uid;
142 int gid;
143 int autof;
144 int mode;
38098016 145 int symlinks;
058574b1 146 struct supertype *supertype;
5bbb4842
NB
147};
148
9a9dab36 149#define Name "mdadm"
682c7051 150
e0d19036
NB
151enum mode {
152 ASSEMBLE=1,
153 BUILD,
154 CREATE,
155 MANAGE,
156 MISC,
157 MONITOR,
dd0781e5 158 GROW,
8382f19b 159 INCREMENTAL,
1f48664b 160 AUTODETECT,
e0d19036
NB
161};
162
64c4757e 163extern char short_options[];
024768c4 164extern char short_bitmap_options[];
c06487ce 165extern char short_bitmap_auto_options[];
64c4757e 166extern struct option long_options[];
56eedc1a 167extern char Version[], Usage[], Help[], OptionHelp[],
dd0781e5 168 Help_create[], Help_build[], Help_assemble[], Help_grow[],
8382f19b 169 Help_incr[],
e0d19036 170 Help_manage[], Help_misc[], Help_monitor[], Help_config[];
64c4757e 171
997aed5d
NB
172/* for option that don't have short equivilents, we assign arbitrary
173 * small numbers. '1' means an undecorated option, so we start at '2'.
174 */
175enum special_options {
176 AssumeClean = 2,
177 BitmapChunk,
178 WriteBehind,
179 ReAdd,
180 NoDegraded,
181 Sparc22,
182 BackupFile,
183 HomeHost,
589395d6 184 AutoHomeHost,
38098016 185 Symlinks,
1f48664b 186 AutoDetect,
997aed5d
NB
187};
188
64c4757e 189/* structures read from config file */
52826846
NB
190/* List of mddevice names and identifiers
191 * Identifiers can be:
192 * uuid=128-hex-uuid
193 * super-minor=decimal-minor-number-from-superblock
194 * devices=comma,separated,list,of,device,names,with,wildcards
195 *
196 * If multiple fields are present, the intersection of all matching
197 * devices is considered
198 */
98c6faba 199#define UnSet (0xfffe)
52826846 200typedef struct mddev_ident_s {
dd0781e5 201 char *devname;
aba69144 202
dd0781e5 203 int uuid_set;
3fa06e9d 204 int uuid[4];
947fd4dd 205 char name[33];
52826846 206
98c6faba 207 unsigned int super_minor;
52826846 208
dd0781e5 209 char *devices; /* comma separated list of device
52826846
NB
210 * names with wild cards
211 */
dd0781e5 212 int level;
98c6faba
NB
213 unsigned int raid_disks;
214 unsigned int spare_disks;
82d9eba6 215 struct supertype *st;
dd0781e5
NB
216 int autof; /* 1 for normal, 2 for partitioned */
217 char *spare_group;
7ef02d01 218 char *bitmap_file;
c82f047c 219 int bitmap_fd;
dd0781e5 220
52826846
NB
221 struct mddev_ident_s *next;
222} *mddev_ident_t;
64c4757e
NB
223
224/* List of device names - wildcards expanded */
225typedef struct mddev_dev_s {
226 char *devname;
cd29a5c8
NB
227 char disposition; /* 'a' for add, 'r' for remove, 'f' for fail.
228 * Not set for names read from .config
229 */
dfd4d8ee 230 char writemostly;
fe80f49b 231 char re_add;
811e6cbe 232 char used; /* set when used */
64c4757e
NB
233 struct mddev_dev_s *next;
234} *mddev_dev_t;
235
682c7051
NB
236typedef struct mapping {
237 char *name;
238 int num;
239} mapping_t;
240
e0d19036
NB
241
242struct mdstat_ent {
243 char *dev;
244 int devnum;
245 int active;
246 char *level;
247 char *pattern; /* U or up, _ for down */
248 int percent; /* -1 if no resync */
e5329c37 249 int resync; /* 1 if resync, 0 if recovery */
e0d19036
NB
250 struct mdstat_ent *next;
251};
252
22a88995 253extern struct mdstat_ent *mdstat_read(int hold, int start);
e0d19036 254extern void free_mdstat(struct mdstat_ent *ms);
dd0781e5 255extern void mdstat_wait(int seconds);
8382f19b
NB
256extern int mddev_busy(int devnum);
257
258struct map_ent {
259 struct map_ent *next;
260 int devnum;
261 int major,minor;
262 int uuid[4];
263 char *path;
264};
265extern int map_update(struct map_ent **mpp, int devnum, int major, int minor,
266 int uuid[4], char *path);
267extern struct map_ent *map_by_uuid(struct map_ent **map, int uuid[4]);
268extern void map_read(struct map_ent **melp);
269extern int map_write(struct map_ent *mel);
270extern void map_delete(struct map_ent **mapp, int devnum);
271extern void map_free(struct map_ent *map);
272extern void map_add(struct map_ent **melp,
273 int devnum, int major, int minor, int uuid[4], char *path);
e0d19036 274
e86c9dd6
NB
275struct sysarray {
276 char name[20];
06c7f68e 277 struct mdinfo *devs;
e86c9dd6
NB
278 int chunk;
279 unsigned long long component_size;
280 int layout;
281 int level;
282 int spares;
758d3a8e 283 int cache_size;
37dfc3d6 284 int mismatch_cnt;
8382f19b 285 int major_version, minor_version;
e86c9dd6
NB
286};
287/* various details can be requested */
288#define GET_LEVEL 1
289#define GET_LAYOUT 2
290#define GET_COMPONENT 4
291#define GET_CHUNK 8
758d3a8e 292#define GET_CACHE 16
37dfc3d6 293#define GET_MISMATCH 32
8382f19b 294#define GET_VERSION 64
e86c9dd6
NB
295
296#define GET_DEVS 1024 /* gets role, major, minor */
297#define GET_OFFSET 2048
298#define GET_SIZE 4096
299#define GET_STATE 8192
300#define GET_ERROR 16384
301
302/* If fd >= 0, get the array it is open on,
303 * else use devnum. >=0 -> major9. <0.....
304 */
8382f19b 305extern void sysfs_free(struct sysarray *sra);
e86c9dd6 306extern struct sysarray *sysfs_read(int fd, int devnum, unsigned long options);
06c7f68e 307extern int sysfs_set_str(struct sysarray *sra, struct mdinfo *dev,
e86c9dd6 308 char *name, char *val);
06c7f68e 309extern int sysfs_set_num(struct sysarray *sra, struct mdinfo *dev,
e86c9dd6 310 char *name, unsigned long long val);
06c7f68e 311extern int sysfs_get_ll(struct sysarray *sra, struct mdinfo *dev,
e86c9dd6
NB
312 char *name, unsigned long long *val);
313
314
315extern int save_stripes(int *source, unsigned long long *offsets,
316 int raid_disks, int chunk_size, int level, int layout,
317 int nwrites, int *dest,
318 unsigned long long start, unsigned long long length);
353632d9
NB
319extern int restore_stripes(int *dest, unsigned long long *offsets,
320 int raid_disks, int chunk_size, int level, int layout,
321 int source, unsigned long long read_offset,
322 unsigned long long start, unsigned long long length);
e86c9dd6 323
52826846
NB
324#ifndef Sendmail
325#define Sendmail "/usr/lib/sendmail -t"
326#endif
327
773135f5
NB
328#define SYSLOG_FACILITY LOG_DAEMON
329
682c7051
NB
330extern char *map_num(mapping_t *map, int num);
331extern int map_name(mapping_t *map, char *name);
b5e64645 332extern mapping_t r5layout[], pers[], modes[], faultylayout[];
682c7051 333
16c6fa80 334extern char *map_dev(int major, int minor, int create);
64c4757e
NB
335
336
f9ce90ba 337extern struct superswitch {
3da92f27
NB
338 void (*examine_super)(struct supertype *st, char *homehost);
339 void (*brief_examine_super)(struct supertype *st);
340 void (*detail_super)(struct supertype *st, char *homehost);
341 void (*export_super)(struct supertype *st);
342 void (*brief_detail_super)(struct supertype *st);
343 void (*uuid_from_super)(struct supertype *st, int uuid[4]);
344 void (*getinfo_super)(struct supertype *st, struct mdinfo *info);
345 int (*match_home)(struct supertype *st, char *homehost);
68c7d6d7 346 int (*update_super)(struct supertype *st, struct mdinfo *info,
3da92f27 347 char *update,
e5eac01f
NB
348 char *devname, int verbose,
349 int uuid_set, char *homehost);
3da92f27
NB
350 int (*init_super)(struct supertype *st, mdu_array_info_t *info,
351 unsigned long long size, char *name,
352 char *homehost, int *uuid);
353 void (*add_to_super)(struct supertype *st, mdu_disk_info_t *dinfo);
354 int (*store_super)(struct supertype *st, int fd);
355 int (*write_init_super)(struct supertype *st, mdu_disk_info_t *dinfo,
356 char *devname);
64557c33 357 int (*compare_super)(struct supertype *st, struct supertype *tst);
3da92f27 358 int (*load_super)(struct supertype *st, int fd, char *devname);
82d9eba6 359 struct supertype * (*match_metadata_desc)(char *arg);
1bf4e2d9 360 __u64 (*avail_size)(struct supertype *st, __u64 size);
3da92f27 361 int (*add_internal_bitmap)(struct supertype *st, int *chunkp,
199171a2 362 int delay, int write_behind,
f9c25f1d 363 unsigned long long size, int may_change, int major);
3da92f27
NB
364 void (*locate_bitmap)(struct supertype *st, int fd);
365 int (*write_bitmap)(struct supertype *st, int fd);
366 void (*free_super)(struct supertype *st);
82d9eba6 367 int major;
f277ce36 368 int swapuuid; /* true if uuid is bigending rather than hostendian */
82d9eba6
NB
369} super0, super1, *superlist[];
370
371struct supertype {
372 struct superswitch *ss;
373 int minor_version;
ea329559 374 int max_devs;
64557c33 375 void *sb;
82d9eba6 376};
f9ce90ba 377
1686dc25 378extern struct supertype *super_by_fd(int fd);
82d9eba6 379extern struct supertype *guess_super(int fd);
3da92f27 380extern struct supertype *dup_super(struct supertype *st);
beae1dfe 381extern int get_dev_size(int fd, char *dname, unsigned long long *sizep);
8382f19b
NB
382extern void get_one_disk(int mdfd, mdu_array_info_t *ainf,
383 mdu_disk_info_t *disk);
f9ce90ba 384
838acbc2
NB
385#if __GNUC__ < 3
386struct stat64;
387#endif
388
45e878bb
NB
389#define HAVE_NFTW we assume
390#define HAVE_FTW
391
173fc515 392#ifdef UCLIBC
45e878bb
NB
393# include <features.h>
394# ifndef __UCLIBC_HAS_FTW__
395# undef HAVE_FTW
396# undef HAVE_NFTW
397# endif
398#endif
399
400#ifdef __dietlibc__
401# undef HAVE_NFTW
402#endif
403
e39b673e 404#if defined(__KLIBC__)
405# undef HAVE_NFTW
406# undef HAVE_FTW
407#endif
408
45e878bb 409#ifndef HAVE_NFTW
173fc515 410# define FTW_PHYS 1
45e878bb
NB
411# ifndef HAVE_FTW
412 struct FTW {};
173fc515
NB
413# endif
414#endif
415
45e878bb
NB
416#ifdef HAVE_FTW
417# include <ftw.h>
418#endif
419
173fc515
NB
420extern int add_dev(const char *name, const struct stat *stb, int flag, struct FTW *s);
421
f9ce90ba 422
64c4757e 423extern int Manage_ro(char *devname, int fd, int readonly);
91f068bf 424extern int Manage_runstop(char *devname, int fd, int runstop, int quiet);
dd0781e5 425extern int Manage_resize(char *devname, int fd, long long size, int raid_disks);
b5e64645 426extern int Manage_reconfig(char *devname, int fd, int layout);
64c4757e 427extern int Manage_subdevs(char *devname, int fd,
dab6685f 428 mddev_dev_t devlist, int verbose);
1f48664b 429extern int autodetect(void);
e5329c37 430extern int Grow_Add_device(char *devname, int fd, char *newdev);
8fac0577 431extern int Grow_addbitmap(char *devname, int fd, char *file, int chunk, int delay, int write_behind, int force);
06b0d786 432extern int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
e86c9dd6
NB
433 long long size,
434 int level, int layout, int chunksize, int raid_disks);
06b0d786
NB
435extern int Grow_restart(struct supertype *st, struct mdinfo *info,
436 int *fdlist, int cnt, char *backup_file);
64c4757e
NB
437
438
82d9eba6 439extern int Assemble(struct supertype *st, char *mddev, int mdfd,
52826846 440 mddev_ident_t ident,
06b0d786 441 mddev_dev_t devlist, char *backup_file,
64c4757e 442 int readonly, int runstop,
e5eac01f 443 char *update, char *homehost,
64c4757e
NB
444 int verbose, int force);
445
b5e64645 446extern int Build(char *mddev, int mdfd, int chunk, int level, int layout,
64c4757e 447 int raiddisks,
c82f047c 448 mddev_dev_t devlist, int assume_clean,
dab6685f 449 char *bitmap_file, int bitmap_chunk, int write_behind, int delay, int verbose);
64c4757e
NB
450
451
82d9eba6 452extern int Create(struct supertype *st, char *mddev, int mdfd,
5dd497ee 453 int chunk, int level, int layout, unsigned long long size, int raiddisks, int sparedisks,
3d3dd91e 454 char *name, char *homehost, int *uuid,
cd29a5c8 455 int subdevs, mddev_dev_t devlist,
47d79ef8 456 int runstop, int verbose, int force, int assume_clean,
dfd4d8ee 457 char *bitmap_file, int bitmap_chunk, int write_behind, int delay);
64c4757e 458
54bad364 459extern int Detail(char *dev, int brief, int export, int test, char *homehost);
e0d19036 460extern int Query(char *dev);
82d9eba6 461extern int Examine(mddev_dev_t devlist, int brief, int scan, int SparcAdjust,
a1cbd7d0 462 struct supertype *forcest, char *homehost);
cd29a5c8 463extern int Monitor(mddev_dev_t devlist,
e0d19036 464 char *mailaddr, char *alert_cmd,
aa88f531 465 int period, int daemonise, int scan, int oneshot,
8aec876d 466 int dosyslog, int test, char *pidfile);
64c4757e 467
6409687b 468extern int Kill(char *dev, int force, int quiet);
b90c0e9a 469extern int Wait(char *dev);
9a9dab36 470
8382f19b
NB
471extern int Incremental(char *devname, int verbose, int runstop,
472 struct supertype *st, char *homehost, int autof);
473extern void RebuildMap(void);
474extern int IncrementalScan(int verbose);
475
c82f047c
NB
476extern int CreateBitmap(char *filename, int force, char uuid[16],
477 unsigned long chunksize, unsigned long daemon_sleep,
dfd4d8ee 478 unsigned long write_behind,
dcec9ee5
NB
479 unsigned long long array_size,
480 int major);
55935d51 481extern int ExamineBitmap(char *filename, int brief, struct supertype *st);
bf4fb153 482extern int bitmap_update_uuid(int fd, int *uuid, int swap);
c82f047c 483
64c4757e 484extern int md_get_version(int fd);
e0d19036 485extern int get_linux_version(void);
64c4757e 486extern int parse_uuid(char *str, int uuid[4]);
682c7051
NB
487extern int check_ext2(int fd, char *name);
488extern int check_reiser(int fd, char *name);
489extern int check_raid(int fd, char *name);
64c4757e 490
dd0781e5 491extern int get_mdp_major(void);
8b0dabea 492extern int dev_open(char *dev, int flags);
8d80900b 493extern int is_standard(char *dev, int *nump);
dd0781e5 494
f1ae21c4 495extern int parse_auto(char *str, char *msg, int config);
8aec876d
NB
496extern mddev_ident_t conf_get_ident(char *dev);
497extern mddev_dev_t conf_get_devs(void);
8382f19b 498extern int conf_test_dev(char *devname);
8aec876d
NB
499extern struct createinfo *conf_get_create_info(void);
500extern void set_conffile(char *file);
501extern char *conf_get_mailaddr(void);
502extern char *conf_get_mailfrom(void);
503extern char *conf_get_program(void);
504extern char *conf_get_homehost(void);
e0d19036 505extern char *conf_line(FILE *file);
98c6faba 506extern char *conf_word(FILE *file, int allow_key);
e0d19036
NB
507extern void free_line(char *line);
508extern int match_oneof(char *devices, char *devname);
e0d19036 509extern void uuid_from_super(int uuid[4], mdp_super_t *super);
f277ce36 510extern int same_uuid(int a[4], int b[4], int swapuuid);
350f29f9 511extern void copy_uuid(void *a, int b[4], int swapuuid);
4b1ac34b 512extern unsigned long calc_csum(void *super, int bytes);
583315d9 513extern int enough(int level, int raid_disks, int layout, int clean,
265e0f17 514 char *avail, int avail_disks);
e0d19036 515extern int ask(char *mesg);
8fac0577 516extern unsigned long long get_component_size(int fd);
0430ed48 517extern void remove_partitions(int fd);
e0d19036 518
cd29a5c8 519
56eb10c0 520extern char *human_size(long long bytes);
e0d19036
NB
521char *human_size_brief(long long bytes);
522
523extern void put_md_name(char *name);
524extern char *get_md_name(int dev);
525
c913b90e 526extern char DefaultConfFile[];
b5e64645
NB
527
528extern int open_mddev(char *dev, int autof);
8382f19b
NB
529extern int open_mddev_devnum(char *devname, int devnum, char *name,
530 char *chosen_name);
b5e64645
NB
531
532
533#define LEVEL_MULTIPATH (-4)
534#define LEVEL_LINEAR (-1)
535#define LEVEL_FAULTY (-5)
536
537
538/* faulty stuff */
539
540#define WriteTransient 0
541#define ReadTransient 1
542#define WritePersistent 2
543#define ReadPersistent 3
544#define WriteAll 4 /* doesn't go to device */
545#define ReadFixable 5
546#define Modes 6
547
548#define ClearErrors 31
549#define ClearFaults 30
550
551#define AllPersist 100 /* internal use only */
552#define NoPersist 101
553
554#define ModeMask 0x1f
555#define ModeShift 5
fe6729fa
NB
556
557
558#ifdef __TINYC__
559#undef minor
560#undef major
561#undef makedev
562#define minor(x) ((x)&0xff)
563#define major(x) (((x)>>8)&0xff)
564#define makedev(M,m) (((M)<<8) | (m))
565#endif
566
e86c9dd6
NB
567/* for raid5 */
568#define ALGORITHM_LEFT_ASYMMETRIC 0
569#define ALGORITHM_RIGHT_ASYMMETRIC 1
570#define ALGORITHM_LEFT_SYMMETRIC 2
571#define ALGORITHM_RIGHT_SYMMETRIC 3