Remove 'fd' arg from sysfs_add_disk
[thirdparty/mdadm.git] / mdadm.h
1 /*
2 * mdadm - manage Linux "md" devices aka RAID arrays.
3 *
4 * Copyright (C) 2001-2006 Neil Brown <neilb@suse.de>
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
30 #define _GNU_SOURCE
31 #define _FILE_OFFSET_BITS 64
32 #include <unistd.h>
33 #if !defined(__dietlibc__) && !defined(__KLIBC__)
34 extern __off64_t lseek64 __P ((int __fd, __off64_t __offset, int __whence));
35 #else
36 # if defined(__NO_STAT64) || __WORDSIZE != 32
37 # define lseek64 lseek
38 # endif
39 #endif
40
41 #include <sys/types.h>
42 #include <sys/stat.h>
43 #include <stdlib.h>
44 #include <time.h>
45 #include <sys/time.h>
46 #include <getopt.h>
47 #include <fcntl.h>
48 #include <stdio.h>
49 #include <errno.h>
50 #include <string.h>
51 #include <syslog.h>
52 #ifdef __dietlibc__
53 #include <strings.h>
54 /* dietlibc has deprecated random and srandom!! */
55 #define random rand
56 #define srandom srand
57 #endif
58
59
60 #include <linux/kdev_t.h>
61 /*#include <linux/fs.h> */
62 #include <sys/mount.h>
63 #include <asm/types.h>
64 #include <sys/ioctl.h>
65 #define MD_MAJOR 9
66 #define MdpMinorShift 6
67
68 #ifndef BLKGETSIZE64
69 #define BLKGETSIZE64 _IOR(0x12,114,size_t) /* return device size in bytes (u64 *arg) */
70 #endif
71
72 #define DEFAULT_BITMAP_CHUNK 4096
73 #define DEFAULT_BITMAP_DELAY 5
74 #define DEFAULT_MAX_WRITE_BEHIND 256
75
76 #include "md_u.h"
77 #include "md_p.h"
78 #include "bitmap.h"
79 #include "msg.h"
80
81 #include <endian.h>
82 /* Redhat don't like to #include <asm/byteorder.h>, and
83 * some time include <linux/byteorder/xxx_endian.h> isn't enough,
84 * and there is no standard conversion function so... */
85 /* And dietlibc doesn't think byteswap is ok, so.. */
86 /* #include <byteswap.h> */
87 #define bswap_16(x) (((x) & 0x00ffU) << 8 | \
88 ((x) & 0xff00U) >> 8)
89 #define bswap_32(x) (((x) & 0x000000ffU) << 24 | \
90 ((x) & 0xff000000U) >> 24 | \
91 ((x) & 0x0000ff00U) << 8 | \
92 ((x) & 0x00ff0000U) >> 8)
93 #define bswap_64(x) (((x) & 0x00000000000000ffULL) << 56 | \
94 ((x) & 0xff00000000000000ULL) >> 56 | \
95 ((x) & 0x000000000000ff00ULL) << 40 | \
96 ((x) & 0x00ff000000000000ULL) >> 40 | \
97 ((x) & 0x0000000000ff0000ULL) << 24 | \
98 ((x) & 0x0000ff0000000000ULL) >> 24 | \
99 ((x) & 0x00000000ff000000ULL) << 8 | \
100 ((x) & 0x000000ff00000000ULL) >> 8)
101
102 #if !defined(__KLIBC__)
103 #if BYTE_ORDER == LITTLE_ENDIAN
104 #define __cpu_to_le16(_x) (_x)
105 #define __cpu_to_le32(_x) (_x)
106 #define __cpu_to_le64(_x) (_x)
107 #define __le16_to_cpu(_x) (_x)
108 #define __le32_to_cpu(_x) (_x)
109 #define __le64_to_cpu(_x) (_x)
110
111 #define __cpu_to_be16(_x) bswap_16(_x)
112 #define __cpu_to_be32(_x) bswap_32(_x)
113 #define __cpu_to_be64(_x) bswap_64(_x)
114 #define __be16_to_cpu(_x) bswap_16(_x)
115 #define __be32_to_cpu(_x) bswap_32(_x)
116 #define __be64_to_cpu(_x) bswap_64(_x)
117 #elif BYTE_ORDER == BIG_ENDIAN
118 #define __cpu_to_le16(_x) bswap_16(_x)
119 #define __cpu_to_le32(_x) bswap_32(_x)
120 #define __cpu_to_le64(_x) bswap_64(_x)
121 #define __le16_to_cpu(_x) bswap_16(_x)
122 #define __le32_to_cpu(_x) bswap_32(_x)
123 #define __le64_to_cpu(_x) bswap_64(_x)
124
125 #define __cpu_to_be16(_x) (_x)
126 #define __cpu_to_be32(_x) (_x)
127 #define __cpu_to_be64(_x) (_x)
128 #define __be16_to_cpu(_x) (_x)
129 #define __be32_to_cpu(_x) (_x)
130 #define __be64_to_cpu(_x) (_x)
131 #else
132 # error "unknown endianness."
133 #endif
134 #endif /* __KLIBC__ */
135
136
137
138 /* general information that might be extracted from a superblock */
139 struct mdinfo {
140 mdu_array_info_t array;
141 mdu_disk_info_t disk;
142 __u64 events;
143 int uuid[4];
144 char name[33];
145 unsigned long long data_offset;
146 unsigned long long component_size; /* same as array.size, except in
147 * sectors and up to 64bits.
148 */
149 int reshape_active;
150 unsigned long long reshape_progress;
151 unsigned long long resync_start;
152 int new_level, delta_disks, new_layout, new_chunk;
153 int errors;
154 int cache_size; /* size of raid456 stripe cache*/
155 int mismatch_cnt;
156 char text_version[50];
157 int container_member; /* for assembling external-metatdata arrays */
158
159 char sys_name[20];
160 struct mdinfo *devs;
161 struct mdinfo *next;
162
163 /* Device info for mdmon: */
164 int state_fd;
165 #define DS_FAULTY 1
166 #define DS_INSYNC 2
167 #define DS_WRITE_MOSTLY 4
168 #define DS_SPARE 8
169 #define DS_BLOCKED 16
170 #define DS_REMOVE 1024
171 int prev_state, curr_state, next_state;
172
173 };
174
175 struct createinfo {
176 int uid;
177 int gid;
178 int autof;
179 int mode;
180 int symlinks;
181 struct supertype *supertype;
182 };
183
184 #define Name "mdadm"
185
186 enum mode {
187 ASSEMBLE=1,
188 BUILD,
189 CREATE,
190 MANAGE,
191 MISC,
192 MONITOR,
193 GROW,
194 INCREMENTAL,
195 AUTODETECT,
196 };
197
198 extern char short_options[];
199 extern char short_bitmap_options[];
200 extern char short_bitmap_auto_options[];
201 extern struct option long_options[];
202 extern char Version[], Usage[], Help[], OptionHelp[],
203 Help_create[], Help_build[], Help_assemble[], Help_grow[],
204 Help_incr[],
205 Help_manage[], Help_misc[], Help_monitor[], Help_config[];
206
207 /* for option that don't have short equivilents, we assign arbitrary
208 * small numbers. '1' means an undecorated option, so we start at '2'.
209 */
210 enum special_options {
211 AssumeClean = 2,
212 BitmapChunk,
213 WriteBehind,
214 ReAdd,
215 NoDegraded,
216 Sparc22,
217 BackupFile,
218 HomeHost,
219 AutoHomeHost,
220 Symlinks,
221 AutoDetect,
222 };
223
224 /* structures read from config file */
225 /* List of mddevice names and identifiers
226 * Identifiers can be:
227 * uuid=128-hex-uuid
228 * super-minor=decimal-minor-number-from-superblock
229 * devices=comma,separated,list,of,device,names,with,wildcards
230 *
231 * If multiple fields are present, the intersection of all matching
232 * devices is considered
233 */
234 #define UnSet (0xfffe)
235 typedef struct mddev_ident_s {
236 char *devname;
237
238 int uuid_set;
239 int uuid[4];
240 char name[33];
241
242 unsigned int super_minor;
243
244 char *devices; /* comma separated list of device
245 * names with wild cards
246 */
247 int level;
248 unsigned int raid_disks;
249 unsigned int spare_disks;
250 struct supertype *st;
251 int autof; /* 1 for normal, 2 for partitioned */
252 char *spare_group;
253 char *bitmap_file;
254 int bitmap_fd;
255
256 struct mddev_ident_s *next;
257 } *mddev_ident_t;
258
259 /* List of device names - wildcards expanded */
260 typedef struct mddev_dev_s {
261 char *devname;
262 char disposition; /* 'a' for add, 'r' for remove, 'f' for fail.
263 * Not set for names read from .config
264 */
265 char writemostly;
266 char re_add;
267 char used; /* set when used */
268 struct mddev_dev_s *next;
269 } *mddev_dev_t;
270
271 typedef struct mapping {
272 char *name;
273 int num;
274 } mapping_t;
275
276
277 struct mdstat_ent {
278 char *dev;
279 int devnum;
280 int active;
281 char *level;
282 char *pattern; /* U or up, _ for down */
283 int percent; /* -1 if no resync */
284 int resync; /* 1 if resync, 0 if recovery */
285 int devcnt;
286 int raid_disks;
287 int chunk_size;
288 char * metadata_version;
289 struct mdstat_ent *next;
290 };
291
292 extern struct mdstat_ent *mdstat_read(int hold, int start);
293 extern void free_mdstat(struct mdstat_ent *ms);
294 extern void mdstat_wait(int seconds);
295 extern void mdstat_wait_fd(int fd);
296 extern int mddev_busy(int devnum);
297
298 struct map_ent {
299 struct map_ent *next;
300 int devnum;
301 int major,minor;
302 int uuid[4];
303 char *path;
304 };
305 extern int map_update(struct map_ent **mpp, int devnum, int major, int minor,
306 int uuid[4], char *path);
307 extern struct map_ent *map_by_uuid(struct map_ent **map, int uuid[4]);
308 extern void map_read(struct map_ent **melp);
309 extern int map_write(struct map_ent *mel);
310 extern void map_delete(struct map_ent **mapp, int devnum);
311 extern void map_free(struct map_ent *map);
312 extern void map_add(struct map_ent **melp,
313 int devnum, int major, int minor, int uuid[4], char *path);
314
315 /* various details can be requested */
316 #define GET_LEVEL 1
317 #define GET_LAYOUT 2
318 #define GET_COMPONENT 4
319 #define GET_CHUNK 8
320 #define GET_CACHE 16
321 #define GET_MISMATCH 32
322 #define GET_VERSION 64
323 #define GET_DISKS 128
324
325 #define GET_DEVS 1024 /* gets role, major, minor */
326 #define GET_OFFSET 2048
327 #define GET_SIZE 4096
328 #define GET_STATE 8192
329 #define GET_ERROR 16384
330
331 /* If fd >= 0, get the array it is open on,
332 * else use devnum. >=0 -> major9. <0.....
333 */
334 extern int sysfs_open(int devnum, char *devname, char *attr);
335 extern void sysfs_free(struct mdinfo *sra);
336 extern struct mdinfo *sysfs_read(int fd, int devnum, unsigned long options);
337 extern int sysfs_set_str(struct mdinfo *sra, struct mdinfo *dev,
338 char *name, char *val);
339 extern int sysfs_set_num(struct mdinfo *sra, struct mdinfo *dev,
340 char *name, unsigned long long val);
341 extern int sysfs_get_ll(struct mdinfo *sra, struct mdinfo *dev,
342 char *name, unsigned long long *val);
343 extern int sysfs_set_array(struct mdinfo *sra,
344 struct mdinfo *info);
345 extern int sysfs_add_disk(struct mdinfo *sra, struct mdinfo *sd);
346
347
348
349
350 extern int save_stripes(int *source, unsigned long long *offsets,
351 int raid_disks, int chunk_size, int level, int layout,
352 int nwrites, int *dest,
353 unsigned long long start, unsigned long long length);
354 extern int restore_stripes(int *dest, unsigned long long *offsets,
355 int raid_disks, int chunk_size, int level, int layout,
356 int source, unsigned long long read_offset,
357 unsigned long long start, unsigned long long length);
358
359 #ifndef Sendmail
360 #define Sendmail "/usr/lib/sendmail -t"
361 #endif
362
363 #define SYSLOG_FACILITY LOG_DAEMON
364
365 extern char *map_num(mapping_t *map, int num);
366 extern int map_name(mapping_t *map, char *name);
367 extern mapping_t r5layout[], pers[], modes[], faultylayout[];
368
369 extern char *map_dev(int major, int minor, int create);
370
371 struct active_array;
372
373 extern struct superswitch {
374 void (*examine_super)(struct supertype *st, char *homehost);
375 void (*brief_examine_super)(struct supertype *st);
376 void (*export_examine_super)(struct supertype *st);
377 void (*detail_super)(struct supertype *st, char *homehost);
378 void (*brief_detail_super)(struct supertype *st);
379 void (*export_detail_super)(struct supertype *st);
380 void (*uuid_from_super)(struct supertype *st, int uuid[4]);
381 void (*getinfo_super)(struct supertype *st, struct mdinfo *info);
382 void (*getinfo_super_n)(struct supertype *st, struct mdinfo *info);
383 int (*match_home)(struct supertype *st, char *homehost);
384 int (*update_super)(struct supertype *st, struct mdinfo *info,
385 char *update,
386 char *devname, int verbose,
387 int uuid_set, char *homehost);
388 int (*init_super)(struct supertype *st, mdu_array_info_t *info,
389 unsigned long long size, char *name,
390 char *homehost, int *uuid);
391 void (*add_to_super)(struct supertype *st, mdu_disk_info_t *dinfo,
392 int fd, char *devname);
393 int (*store_super)(struct supertype *st, int fd);
394 int (*write_init_super)(struct supertype *st);
395 int (*compare_super)(struct supertype *st, struct supertype *tst);
396 int (*load_super)(struct supertype *st, int fd, char *devname);
397 struct supertype * (*match_metadata_desc)(char *arg);
398 __u64 (*avail_size)(struct supertype *st, __u64 size);
399 int (*add_internal_bitmap)(struct supertype *st, int *chunkp,
400 int delay, int write_behind,
401 unsigned long long size, int may_change, int major);
402 void (*locate_bitmap)(struct supertype *st, int fd);
403 int (*write_bitmap)(struct supertype *st, int fd);
404 void (*free_super)(struct supertype *st);
405 int (*validate_geometry)(struct supertype *st, int level, int layout,
406 int raiddisks,
407 int chunk, unsigned long long size,
408 char *subdev, unsigned long long *freesize);
409
410 struct mdinfo *(*container_content)(struct supertype *st);
411
412 /* for mdmon */
413 int (*open_new)(struct supertype *c, struct active_array *a, int inst);
414 void (*mark_clean)(struct active_array *a, unsigned long long sync_pos);
415 void (*mark_dirty)(struct active_array *a);
416 void (*mark_sync)(struct active_array *a, unsigned long long resync);
417 void (*set_disk)(struct active_array *a, int n, int state);
418 void (*sync_metadata)(struct active_array *a);
419
420
421 int major;
422 char *text_version;
423 int swapuuid; /* true if uuid is bigending rather than hostendian */
424 int external;
425 } super0, super1, super_ddf, super_ddf_bvd, super_ddf_svd, *superlist[];
426
427 extern struct superswitch super_imsm, super_imsm_raid;
428
429 struct supertype {
430 struct superswitch *ss;
431 int minor_version;
432 int max_devs;
433 int container_dev; /* devnum of container */
434 int container_member; /* numerical position in container */
435 void *sb;
436 void *info;
437
438 /* extra stuff used by mdmon */
439 struct active_array *arrays;
440 int devfd;
441 int sock; /* listen to external programs */
442 int mgr_pipe[2]; /* communicate between threads */
443 int mon_pipe[2]; /* communicate between threads */
444 int devnum;
445 char *devname; /* e.g. md0. This appears in metadata_verison:
446 * external:/md0/12
447 */
448 int devcnt;
449
450 struct mdinfo *devs;
451
452 };
453
454 extern struct supertype supertype_container_member;
455 extern struct supertype *super_by_fd(int fd);
456 extern struct supertype *guess_super(int fd);
457 extern struct supertype *dup_super(struct supertype *st);
458 extern int get_dev_size(int fd, char *dname, unsigned long long *sizep);
459 extern void get_one_disk(int mdfd, mdu_array_info_t *ainf,
460 mdu_disk_info_t *disk);
461
462 #if __GNUC__ < 3
463 struct stat64;
464 #endif
465
466 #define HAVE_NFTW we assume
467 #define HAVE_FTW
468
469 #ifdef UCLIBC
470 # include <features.h>
471 # ifndef __UCLIBC_HAS_FTW__
472 # undef HAVE_FTW
473 # undef HAVE_NFTW
474 # endif
475 #endif
476
477 #ifdef __dietlibc__
478 # undef HAVE_NFTW
479 #endif
480
481 #if defined(__KLIBC__)
482 # undef HAVE_NFTW
483 # undef HAVE_FTW
484 #endif
485
486 #ifndef HAVE_NFTW
487 # define FTW_PHYS 1
488 # ifndef HAVE_FTW
489 struct FTW {};
490 # endif
491 #endif
492
493 #ifdef HAVE_FTW
494 # include <ftw.h>
495 #endif
496
497 extern int add_dev(const char *name, const struct stat *stb, int flag, struct FTW *s);
498
499
500 extern int Manage_ro(char *devname, int fd, int readonly);
501 extern int Manage_runstop(char *devname, int fd, int runstop, int quiet);
502 extern int Manage_resize(char *devname, int fd, long long size, int raid_disks);
503 extern int Manage_reconfig(char *devname, int fd, int layout);
504 extern int Manage_subdevs(char *devname, int fd,
505 mddev_dev_t devlist, int verbose);
506 extern int autodetect(void);
507 extern int Grow_Add_device(char *devname, int fd, char *newdev);
508 extern int Grow_addbitmap(char *devname, int fd, char *file, int chunk, int delay, int write_behind, int force);
509 extern int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
510 long long size,
511 int level, int layout, int chunksize, int raid_disks);
512 extern int Grow_restart(struct supertype *st, struct mdinfo *info,
513 int *fdlist, int cnt, char *backup_file);
514
515
516 extern int Assemble(struct supertype *st, char *mddev, int mdfd,
517 mddev_ident_t ident,
518 mddev_dev_t devlist, char *backup_file,
519 int readonly, int runstop,
520 char *update, char *homehost,
521 int verbose, int force);
522
523 extern int Build(char *mddev, int mdfd, int chunk, int level, int layout,
524 int raiddisks,
525 mddev_dev_t devlist, int assume_clean,
526 char *bitmap_file, int bitmap_chunk, int write_behind, int delay, int verbose);
527
528
529 extern int Create(struct supertype *st, char *mddev, int mdfd,
530 int chunk, int level, int layout, unsigned long long size, int raiddisks, int sparedisks,
531 char *name, char *homehost, int *uuid,
532 int subdevs, mddev_dev_t devlist,
533 int runstop, int verbose, int force, int assume_clean,
534 char *bitmap_file, int bitmap_chunk, int write_behind, int delay);
535
536 extern int Detail(char *dev, int brief, int export, int test, char *homehost);
537 extern int Query(char *dev);
538 extern int Examine(mddev_dev_t devlist, int brief, int export, int scan,
539 int SparcAdjust, struct supertype *forcest, char *homehost);
540 extern int Monitor(mddev_dev_t devlist,
541 char *mailaddr, char *alert_cmd,
542 int period, int daemonise, int scan, int oneshot,
543 int dosyslog, int test, char *pidfile);
544
545 extern int Kill(char *dev, int force, int quiet, int noexcl);
546 extern int Wait(char *dev);
547
548 extern int Incremental(char *devname, int verbose, int runstop,
549 struct supertype *st, char *homehost, int autof);
550 extern int Incremental_container(struct supertype *st, char *devname,
551 int verbose, int runstop, int autof);
552 extern void RebuildMap(void);
553 extern int IncrementalScan(int verbose);
554
555 extern int CreateBitmap(char *filename, int force, char uuid[16],
556 unsigned long chunksize, unsigned long daemon_sleep,
557 unsigned long write_behind,
558 unsigned long long array_size,
559 int major);
560 extern int ExamineBitmap(char *filename, int brief, struct supertype *st);
561 extern int bitmap_update_uuid(int fd, int *uuid, int swap);
562
563 extern int md_get_version(int fd);
564 extern int get_linux_version(void);
565 extern int parse_uuid(char *str, int uuid[4]);
566 extern int check_ext2(int fd, char *name);
567 extern int check_reiser(int fd, char *name);
568 extern int check_raid(int fd, char *name);
569
570 extern int get_mdp_major(void);
571 extern int dev_open(char *dev, int flags);
572 extern int is_standard(char *dev, int *nump);
573
574 extern int parse_auto(char *str, char *msg, int config);
575 extern mddev_ident_t conf_get_ident(char *dev);
576 extern mddev_dev_t conf_get_devs(void);
577 extern int conf_test_dev(char *devname);
578 extern struct createinfo *conf_get_create_info(void);
579 extern void set_conffile(char *file);
580 extern char *conf_get_mailaddr(void);
581 extern char *conf_get_mailfrom(void);
582 extern char *conf_get_program(void);
583 extern char *conf_get_homehost(void);
584 extern char *conf_line(FILE *file);
585 extern char *conf_word(FILE *file, int allow_key);
586 extern void free_line(char *line);
587 extern int match_oneof(char *devices, char *devname);
588 extern void uuid_from_super(int uuid[4], mdp_super_t *super);
589 extern int same_uuid(int a[4], int b[4], int swapuuid);
590 extern void copy_uuid(void *a, int b[4], int swapuuid);
591 extern unsigned long calc_csum(void *super, int bytes);
592 extern int enough(int level, int raid_disks, int layout, int clean,
593 char *avail, int avail_disks);
594 extern int ask(char *mesg);
595 extern unsigned long long get_component_size(int fd);
596 extern void remove_partitions(int fd);
597 extern unsigned long long calc_array_size(int level, int raid_disks, int layout,
598 int chunksize, unsigned long long devsize);
599
600
601 extern char *human_size(long long bytes);
602 char *human_size_brief(long long bytes);
603
604 #define NoMdDev (1<<23)
605 extern int find_free_devnum(int use_partitions);
606
607 extern void put_md_name(char *name);
608 extern char *get_md_name(int dev);
609
610 extern char DefaultConfFile[];
611
612 extern int open_mddev(char *dev, int autof);
613 extern int open_mddev_devnum(char *devname, int devnum, char *name,
614 char *chosen_name, int parts);
615 extern int open_container(int fd);
616
617 extern char *devnum2devname(int num);
618 extern int fd2devnum(int fd);
619
620 #define LEVEL_MULTIPATH (-4)
621 #define LEVEL_LINEAR (-1)
622 #define LEVEL_FAULTY (-5)
623
624 /* kernel module doesn't know about these */
625 #define LEVEL_CONTAINER (-100)
626 #define LEVEL_UNSUPPORTED (-200)
627
628
629 /* faulty stuff */
630
631 #define WriteTransient 0
632 #define ReadTransient 1
633 #define WritePersistent 2
634 #define ReadPersistent 3
635 #define WriteAll 4 /* doesn't go to device */
636 #define ReadFixable 5
637 #define Modes 6
638
639 #define ClearErrors 31
640 #define ClearFaults 30
641
642 #define AllPersist 100 /* internal use only */
643 #define NoPersist 101
644
645 #define ModeMask 0x1f
646 #define ModeShift 5
647
648
649 #ifdef __TINYC__
650 #undef minor
651 #undef major
652 #undef makedev
653 #define minor(x) ((x)&0xff)
654 #define major(x) (((x)>>8)&0xff)
655 #define makedev(M,m) (((M)<<8) | (m))
656 #endif
657
658 /* for raid5 */
659 #define ALGORITHM_LEFT_ASYMMETRIC 0
660 #define ALGORITHM_RIGHT_ASYMMETRIC 1
661 #define ALGORITHM_LEFT_SYMMETRIC 2
662 #define ALGORITHM_RIGHT_SYMMETRIC 3