mdadm.h

   1 /*
   2  * mdadm - manage Linux "md" devices aka RAID arrays.
   3  *
   4  * Copyright (C) 2001-2009 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@suse.de>
  23  */
  24
  25 #define _GNU_SOURCE
  26 #define _FILE_OFFSET_BITS 64
  27 #include        <unistd.h>
  28 #if !defined(__dietlibc__) && !defined(__KLIBC__)
  29 extern __off64_t lseek64 __P ((int __fd, __off64_t __offset, int __whence));
  30 #else
  31 # if defined(__NO_STAT64) || __WORDSIZE != 32
  32 # define lseek64 lseek
  33 # endif
  34 #endif
  35
  36 #include        <sys/types.h>
  37 #include        <sys/stat.h>
  38 #include        <stdlib.h>
  39 #include        <time.h>
  40 #include        <sys/time.h>
  41 #include        <getopt.h>
  42 #include        <fcntl.h>
  43 #include        <stdio.h>
  44 #include        <errno.h>
  45 #include        <string.h>
  46 #include        <syslog.h>
  47 #ifdef __dietlibc__
  48 #include        <strings.h>
  49 /* dietlibc has deprecated random and srandom!! */
  50 #define random rand
  51 #define srandom srand
  52 #endif
  53
  54
  55 #include        <linux/kdev_t.h>
  56 /*#include      <linux/fs.h> */
  57 #include        <sys/mount.h>
  58 #include        <asm/types.h>
  59 #include        <sys/ioctl.h>
  60 #define MD_MAJOR 9
  61 #define MdpMinorShift 6
  62
  63 #ifndef BLKGETSIZE64
  64 #define BLKGETSIZE64 _IOR(0x12,114,size_t) /* return device size in bytes (u64 *arg) */
  65 #endif
  66
  67 #define DEFAULT_BITMAP_CHUNK 4096
  68 #define DEFAULT_BITMAP_DELAY 5
  69 #define DEFAULT_MAX_WRITE_BEHIND 256
  70
  71 /* VAR_RUN is where pid and socket files used for communicating
  72  * with mdmon normally live.  It should be /var/run, but if
  73  * it is too hard to remount /var/run as read-only rather than
  74  * unmounting it at shutdown time, then it should be
  75  * redefined to some place that comfortably persists until
  76  * final shutdown, possibly in /dev if that is a tmpfs.
  77  * Note: VAR_RUN does not need to be writable at shutdown,
  78  * only during boot when "mdmon --takeover" is run.
  79  */
  80 #ifndef VAR_RUN
  81 #define VAR_RUN "/var/run/mdadm"
  82 #endif /* VAR_RUN */
  83 /* ALT_RUN should be somewhere that persists across the pivotroot
  84  * from early boot to late boot.
  85  * If you don't have /lib/init/rw you might want to use /dev/.something
  86  */
  87 #ifndef ALT_RUN
  88 #define ALT_RUN "/lib/init/rw/mdadm"
  89 #endif /* ALT_RUN */
  90
  91 #include        "md_u.h"
  92 #include        "md_p.h"
  93 #include        "bitmap.h"
  94 #include        "msg.h"
  95
  96 #include <endian.h>
  97 /* Redhat don't like to #include <asm/byteorder.h>, and
  98  * some time include <linux/byteorder/xxx_endian.h> isn't enough,
  99  * and there is no standard conversion function so... */
 100 /* And dietlibc doesn't think byteswap is ok, so.. */
 101 /*  #include <byteswap.h> */
 102 #define bswap_16(x) (((x) & 0x00ffU) << 8 | \
 103                      ((x) & 0xff00U) >> 8)
 104 #define bswap_32(x) (((x) & 0x000000ffU) << 24 | \
 105                      ((x) & 0xff000000U) >> 24 | \
 106                      ((x) & 0x0000ff00U) << 8  | \
 107                      ((x) & 0x00ff0000U) >> 8)
 108 #define bswap_64(x) (((x) & 0x00000000000000ffULL) << 56 | \
 109                      ((x) & 0xff00000000000000ULL) >> 56 | \
 110                      ((x) & 0x000000000000ff00ULL) << 40 | \
 111                      ((x) & 0x00ff000000000000ULL) >> 40 | \
 112                      ((x) & 0x0000000000ff0000ULL) << 24 | \
 113                      ((x) & 0x0000ff0000000000ULL) >> 24 | \
 114                      ((x) & 0x00000000ff000000ULL) << 8 | \
 115                      ((x) & 0x000000ff00000000ULL) >> 8)
 116
 117 #if !defined(__KLIBC__)
 118 #if BYTE_ORDER == LITTLE_ENDIAN
 119 #define __cpu_to_le16(_x) (_x)
 120 #define __cpu_to_le32(_x) (_x)
 121 #define __cpu_to_le64(_x) (_x)
 122 #define __le16_to_cpu(_x) (_x)
 123 #define __le32_to_cpu(_x) (_x)
 124 #define __le64_to_cpu(_x) (_x)
 125
 126 #define __cpu_to_be16(_x) bswap_16(_x)
 127 #define __cpu_to_be32(_x) bswap_32(_x)
 128 #define __cpu_to_be64(_x) bswap_64(_x)
 129 #define __be16_to_cpu(_x) bswap_16(_x)
 130 #define __be32_to_cpu(_x) bswap_32(_x)
 131 #define __be64_to_cpu(_x) bswap_64(_x)
 132 #elif BYTE_ORDER == BIG_ENDIAN
 133 #define __cpu_to_le16(_x) bswap_16(_x)
 134 #define __cpu_to_le32(_x) bswap_32(_x)
 135 #define __cpu_to_le64(_x) bswap_64(_x)
 136 #define __le16_to_cpu(_x) bswap_16(_x)
 137 #define __le32_to_cpu(_x) bswap_32(_x)
 138 #define __le64_to_cpu(_x) bswap_64(_x)
 139
 140 #define __cpu_to_be16(_x) (_x)
 141 #define __cpu_to_be32(_x) (_x)
 142 #define __cpu_to_be64(_x) (_x)
 143 #define __be16_to_cpu(_x) (_x)
 144 #define __be32_to_cpu(_x) (_x)
 145 #define __be64_to_cpu(_x) (_x)
 146 #else
 147 #  error "unknown endianness."
 148 #endif
 149 #endif /* __KLIBC__ */
 150
 151
 152 /*
 153  * min()/max()/clamp() macros that also do
 154  * strict type-checking.. See the
 155  * "unnecessary" pointer comparison.
 156  */
 157 #define min(x, y) ({                            \
 158         typeof(x) _min1 = (x);                  \
 159         typeof(y) _min2 = (y);                  \
 160         (void) (&_min1 == &_min2);              \
 161         _min1 < _min2 ? _min1 : _min2; })
 162
 163 #define max(x, y) ({                            \
 164         typeof(x) _max1 = (x);                  \
 165         typeof(y) _max2 = (y);                  \
 166         (void) (&_max1 == &_max2);              \
 167         _max1 > _max2 ? _max1 : _max2; })
 168
 169 /* general information that might be extracted from a superblock */
 170 struct mdinfo {
 171         mdu_array_info_t        array;
 172         mdu_disk_info_t         disk;
 173         __u64                   events;
 174         int                     uuid[4];
 175         char                    name[33];
 176         unsigned long long      data_offset;
 177         unsigned long long      component_size; /* same as array.size, except in
 178                                                  * sectors and up to 64bits.
 179                                                  */
 180         unsigned long long      custom_array_size; /* size for non-default sized
 181                                                     * arrays (in sectors)
 182                                                     */
 183         int                     reshape_active;
 184         unsigned long long      reshape_progress;
 185         union {
 186                 unsigned long long resync_start; /* per-array resync position */
 187                 unsigned long long recovery_start; /* per-device rebuild position */
 188                 #define MaxSector  (~0ULL) /* resync/recovery complete position */
 189         };
 190         unsigned long           safe_mode_delay; /* ms delay to mark clean */
 191         int                     new_level, delta_disks, new_layout, new_chunk;
 192         int                     errors;
 193         int                     cache_size; /* size of raid456 stripe cache*/
 194         int                     mismatch_cnt;
 195         char                    text_version[50];
 196         void                    *update_private; /* for passing metadata-format
 197                                                   * specific update data
 198                                                   * between successive calls to
 199                                                   * update_super()
 200                                                   */
 201
 202         int container_member; /* for assembling external-metatdata arrays
 203                                * This is to be used internally by metadata
 204                                * handler only */
 205
 206         char            sys_name[20];
 207         struct mdinfo *devs;
 208         struct mdinfo *next;
 209
 210         /* Device info for mdmon: */
 211         int recovery_fd;
 212         int state_fd;
 213         #define DS_FAULTY       1
 214         #define DS_INSYNC       2
 215         #define DS_WRITE_MOSTLY 4
 216         #define DS_SPARE        8
 217         #define DS_BLOCKED      16
 218         #define DS_REMOVE       1024
 219         #define DS_UNBLOCK      2048
 220         int prev_state, curr_state, next_state;
 221
 222 };
 223
 224 struct createinfo {
 225         int     uid;
 226         int     gid;
 227         int     autof;
 228         int     mode;
 229         int     symlinks;
 230         struct supertype *supertype;
 231 };
 232
 233 #define Name "mdadm"
 234
 235 enum mode {
 236         ASSEMBLE=1,
 237         BUILD,
 238         CREATE,
 239         MANAGE,
 240         MISC,
 241         MONITOR,
 242         GROW,
 243         INCREMENTAL,
 244         AUTODETECT,
 245 };
 246
 247 extern char short_options[];
 248 extern char short_bitmap_options[];
 249 extern char short_bitmap_auto_options[];
 250 extern struct option long_options[];
 251 extern char Version[], Usage[], Help[], OptionHelp[],
 252         Help_create[], Help_build[], Help_assemble[], Help_grow[],
 253         Help_incr[],
 254         Help_manage[], Help_misc[], Help_monitor[], Help_config[];
 255
 256 /* for option that don't have short equivilents, we assign arbitrary
 257  * small numbers.  '1' means an undecorated option, so we start at '2'.
 258  */
 259 enum special_options {
 260         AssumeClean = 2,
 261         BitmapChunk,
 262         WriteBehind,
 263         ReAdd,
 264         NoDegraded,
 265         Sparc22,
 266         BackupFile,
 267         HomeHost,
 268         AutoHomeHost,
 269         Symlinks,
 270         AutoDetect,
 271         Waitclean,
 272         DetailPlatform,
 273 };
 274
 275 /* structures read from config file */
 276 /* List of mddevice names and identifiers
 277  * Identifiers can be:
 278  *    uuid=128-hex-uuid
 279  *    super-minor=decimal-minor-number-from-superblock
 280  *    devices=comma,separated,list,of,device,names,with,wildcards
 281  *
 282  * If multiple fields are present, the intersection of all matching
 283  * devices is considered
 284  */
 285 #define UnSet (0xfffe)
 286 typedef struct mddev_ident_s {
 287         char    *devname;
 288
 289         int     uuid_set;
 290         int     uuid[4];
 291         char    name[33];
 292
 293         unsigned int super_minor;
 294
 295         char    *devices;       /* comma separated list of device
 296                                  * names with wild cards
 297                                  */
 298         int     level;
 299         unsigned int raid_disks;
 300         unsigned int spare_disks;
 301         struct supertype *st;
 302         int     autof;          /* 1 for normal, 2 for partitioned */
 303         char    *spare_group;
 304         char    *bitmap_file;
 305         int     bitmap_fd;
 306
 307         char    *container;     /* /dev/whatever name of container, or
 308                                  * uuid of container.  You would expect
 309                                  * this to be the 'devname' or UUID
 310                                  * of some other entry.
 311                                  */
 312         char    *member;        /* subarray within a container */
 313
 314         struct mddev_ident_s *next;
 315         union {
 316                 /* fields needed by different users of this structure */
 317                 int assembled;  /* set when assembly succeeds */
 318         };
 319 } *mddev_ident_t;
 320
 321 /* List of device names - wildcards expanded */
 322 typedef struct mddev_dev_s {
 323         char *devname;
 324         char disposition;       /* 'a' for add, 'r' for remove, 'f' for fail.
 325                                  * Not set for names read from .config
 326                                  */
 327         char writemostly;       /* 1 for 'set writemostly', 2 for 'clear writemostly' */
 328         char re_add;
 329         char used;              /* set when used */
 330         struct mdinfo *content; /* If devname is a container, this might list
 331                                  * the remaining member arrays. */
 332         struct mddev_dev_s *next;
 333 } *mddev_dev_t;
 334
 335 typedef struct mapping {
 336         char *name;
 337         int num;
 338 } mapping_t;
 339
 340
 341 struct mdstat_ent {
 342         char            *dev;
 343         int             devnum;
 344         int             active;
 345         char            *level;
 346         char            *pattern; /* U or up, _ for down */
 347         int             percent; /* -1 if no resync */
 348         int             resync; /* 1 if resync, 0 if recovery */
 349         int             devcnt;
 350         int             raid_disks;
 351         int             chunk_size;
 352         char *          metadata_version;
 353         struct mdstat_ent *next;
 354 };
 355
 356 extern struct mdstat_ent *mdstat_read(int hold, int start);
 357 extern void free_mdstat(struct mdstat_ent *ms);
 358 extern void mdstat_wait(int seconds);
 359 extern void mdstat_wait_fd(int fd, const sigset_t *sigmask);
 360 extern int mddev_busy(int devnum);
 361
 362 struct map_ent {
 363         struct map_ent *next;
 364         int     devnum;
 365         char    metadata[20];
 366         int     uuid[4];
 367         int     bad;
 368         char    *path;
 369 };
 370 extern int map_update(struct map_ent **mpp, int devnum, char *metadata,
 371                       int uuid[4], char *path);
 372 extern struct map_ent *map_by_uuid(struct map_ent **map, int uuid[4]);
 373 extern struct map_ent *map_by_devnum(struct map_ent **map, int devnum);
 374 extern struct map_ent *map_by_name(struct map_ent **map, char *name);
 375 extern void map_read(struct map_ent **melp);
 376 extern int map_write(struct map_ent *mel);
 377 extern void map_delete(struct map_ent **mapp, int devnum);
 378 extern void map_free(struct map_ent *map);
 379 extern void map_add(struct map_ent **melp,
 380                     int devnum, char *metadata, int uuid[4], char *path);
 381 extern int map_lock(struct map_ent **melp);
 382 extern void map_unlock(struct map_ent **melp);
 383
 384 /* various details can be requested */
 385 enum sysfs_read_flags {
 386         GET_LEVEL       = (1 << 0),
 387         GET_LAYOUT      = (1 << 1),
 388         GET_COMPONENT   = (1 << 2),
 389         GET_CHUNK       = (1 << 3),
 390         GET_CACHE       = (1 << 4),
 391         GET_MISMATCH    = (1 << 5),
 392         GET_VERSION     = (1 << 6),
 393         GET_DISKS       = (1 << 7),
 394         GET_DEGRADED    = (1 << 8),
 395         GET_SAFEMODE    = (1 << 9),
 396         GET_DEVS        = (1 << 10), /* gets role, major, minor */
 397         GET_OFFSET      = (1 << 11),
 398         GET_SIZE        = (1 << 12),
 399         GET_STATE       = (1 << 13),
 400         GET_ERROR       = (1 << 14),
 401         SKIP_GONE_DEVS  = (1 << 15),
 402 };
 403
 404 /* If fd >= 0, get the array it is open on,
 405  * else use devnum. >=0 -> major9. <0.....
 406  */
 407 extern int sysfs_open(int devnum, char *devname, char *attr);
 408 extern void sysfs_init(struct mdinfo *mdi, int fd, int devnum);
 409 extern void sysfs_free(struct mdinfo *sra);
 410 extern struct mdinfo *sysfs_read(int fd, int devnum, unsigned long options);
 411 extern int sysfs_attr_match(const char *attr, const char *str);
 412 extern int sysfs_match_word(const char *word, char **list);
 413 extern int sysfs_set_str(struct mdinfo *sra, struct mdinfo *dev,
 414                          char *name, char *val);
 415 extern int sysfs_set_num(struct mdinfo *sra, struct mdinfo *dev,
 416                          char *name, unsigned long long val);
 417 extern int sysfs_uevent(struct mdinfo *sra, char *event);
 418 extern int sysfs_get_fd(struct mdinfo *sra, struct mdinfo *dev,
 419                         char *name);
 420 extern int sysfs_fd_get_ll(int fd, unsigned long long *val);
 421 extern int sysfs_get_ll(struct mdinfo *sra, struct mdinfo *dev,
 422                         char *name, unsigned long long *val);
 423 extern int sysfs_fd_get_str(int fd, char *val, int size);
 424 extern int sysfs_get_str(struct mdinfo *sra, struct mdinfo *dev,
 425                          char *name, char *val, int size);
 426 extern int sysfs_set_safemode(struct mdinfo *sra, unsigned long ms);
 427 extern int sysfs_set_array(struct mdinfo *info, int vers);
 428 extern int sysfs_add_disk(struct mdinfo *sra, struct mdinfo *sd, int resume);
 429 extern int sysfs_disk_to_scsi_id(int fd, __u32 *id);
 430 extern int sysfs_unique_holder(int devnum, long rdev);
 431 extern int load_sys(char *path, char *buf);
 432
 433
 434 extern int save_stripes(int *source, unsigned long long *offsets,
 435                         int raid_disks, int chunk_size, int level, int layout,
 436                         int nwrites, int *dest,
 437                         unsigned long long start, unsigned long long length,
 438                         char *buf);
 439 extern int restore_stripes(int *dest, unsigned long long *offsets,
 440                            int raid_disks, int chunk_size, int level, int layout,
 441                            int source, unsigned long long read_offset,
 442                            unsigned long long start, unsigned long long length);
 443
 444 #ifndef Sendmail
 445 #define Sendmail "/usr/lib/sendmail -t"
 446 #endif
 447
 448 #define SYSLOG_FACILITY LOG_DAEMON
 449
 450 extern char *map_num(mapping_t *map, int num);
 451 extern int map_name(mapping_t *map, char *name);
 452 extern mapping_t r5layout[], r6layout[], pers[], modes[], faultylayout[];
 453
 454 extern char *map_dev(int major, int minor, int create);
 455
 456 struct active_array;
 457 struct metadata_update;
 458
 459 /* A superswitch provides entry point the a metadata handler.
 460  *
 461  * The super_switch primarily operates on some "metadata" that
 462  * is accessed via the 'supertype'.
 463  * This metadata has one of three possible sources.
 464  * 1/ It is read from a single device.  In this case it may not completely
 465  *    describe the array or arrays as some information might be on other
 466  *    devices.
 467  * 2/ It is read from all devices in a container.  In this case all
 468  *    information is present.
 469  * 3/ It is created by ->init_super / ->add_to_super.  In this case it will
 470  *    be complete once enough ->add_to_super calls have completed.
 471  *
 472  * When creating an array inside a container, the metadata will be
 473  * formed by a combination of 2 and 3.  The metadata or the array is read,
 474  * then new information is added.
 475  *
 476  * The metadata must sometimes have a concept of a 'current' array
 477  * and a 'current' device.
 478  * The 'current' array is set by init_super to be the newly created array,
 479  * or is set by super_by_fd when it finds it is looking at an array inside
 480  * a container.
 481  *
 482  * The 'current' device is either the device that the metadata was read from
 483  * in case 1, or the last device added by add_to_super in case 3.
 484  * Case 2 does not identify a 'current' device.
 485  */
 486 extern struct superswitch {
 487
 488         /* Used to report details of metadata read from a component
 489          * device. ->load_super has been called.
 490          */
 491         void (*examine_super)(struct supertype *st, char *homehost);
 492         void (*brief_examine_super)(struct supertype *st, int verbose);
 493         void (*brief_examine_subarrays)(struct supertype *st, int verbose);
 494         void (*export_examine_super)(struct supertype *st);
 495
 496         /* Used to report details of an active array.
 497          * ->load_super was possibly given a 'component' string.
 498          */
 499         void (*detail_super)(struct supertype *st, char *homehost);
 500         void (*brief_detail_super)(struct supertype *st);
 501         void (*export_detail_super)(struct supertype *st);
 502
 503         /* Optional: platform hardware / firmware details */
 504         int (*detail_platform)(int verbose, int enumerate_only);
 505
 506         /* Used:
 507          *   to get uuid to storing in bitmap metadata
 508          *   and 'reshape' backup-data metadata
 509          *   To see if a device is being re-added to an array it was part of.
 510          */
 511         void (*uuid_from_super)(struct supertype *st, int uuid[4]);
 512
 513         /* Extract generic details from metadata.  This could be details about
 514          * the container, or about an individual array within the container.
 515          * The determination is made either by:
 516          *   load_super being given a 'component' string.
 517          *   validate_geometry determining what to create.
 518          * The info includes both array information and device information.
 519          * The particular device should be:
 520          *   The last device added by add_to_super
 521          *   The device the metadata was loaded from by load_super
 522          */
 523         void (*getinfo_super)(struct supertype *st, struct mdinfo *info);
 524
 525         /* Check if the given metadata is flagged as belonging to "this"
 526          * host.  0 for 'no', 1 for 'yes', -1 for "Don't record homehost"
 527          */
 528         int (*match_home)(struct supertype *st, char *homehost);
 529
 530         /* Make one of several generic modifications to metadata
 531          * prior to assembly (or other times).
 532          *   sparc2.2  - first bug in early 0.90 metadata
 533          *   super-minor - change name of 0.90 metadata
 534          *   summaries - 'correct' any redundant data
 535          *   resync - mark array as dirty to trigger a resync.
 536          *   uuid - set new uuid - only 0.90 or 1.x
 537          *   name - change the name of the array (where supported)
 538          *   homehost - change which host this array is tied to.
 539          *   devicesize - If metadata is at start of device, change recorded
 540          *               device size to match actual device size
 541          *   byteorder - swap bytes for 0.90 metadata
 542          *
 543          *   force-one  - mark that device as uptodate, not old or failed.
 544          *   force-array - mark array as clean if it would not otherwise
 545          *               assemble
 546          *   assemble   - not sure how this is different from force-one...
 547          *   linear-grow-new - add a new device to a linear array, but don't
 548          *                   change the size: so superblock still matches
 549          *   linear-grow-update - now change the size of the array.
 550          */
 551         int (*update_super)(struct supertype *st, struct mdinfo *info,
 552                             char *update,
 553                             char *devname, int verbose,
 554                             int uuid_set, char *homehost);
 555
 556         /* Create new metadata for new array as described.  This could
 557          * be a new container, or an array in a pre-existing container.
 558          * Also used to zero metadata prior to writing it to invalidate old
 559          * metadata.
 560          */
 561         int (*init_super)(struct supertype *st, mdu_array_info_t *info,
 562                           unsigned long long size, char *name,
 563                           char *homehost, int *uuid);
 564
 565         /* update the metadata to include new device, either at create or
 566          * when hot-adding a spare.
 567          */
 568         int (*add_to_super)(struct supertype *st, mdu_disk_info_t *dinfo,
 569                              int fd, char *devname);
 570
 571         /* Write metadata to one device when fixing problems or adding
 572          * a new device.
 573          */
 574         int (*store_super)(struct supertype *st, int fd);
 575
 576         /*  Write all metadata for this array.
 577          */
 578         int (*write_init_super)(struct supertype *st);
 579         int (*compare_super)(struct supertype *st, struct supertype *tst);
 580         int (*load_super)(struct supertype *st, int fd, char *devname);
 581         struct supertype * (*match_metadata_desc)(char *arg);
 582         __u64 (*avail_size)(struct supertype *st, __u64 size);
 583         int (*add_internal_bitmap)(struct supertype *st, int *chunkp,
 584                                    int delay, int write_behind,
 585                                    unsigned long long size, int may_change, int major);
 586         void (*locate_bitmap)(struct supertype *st, int fd);
 587         int (*write_bitmap)(struct supertype *st, int fd);
 588         void (*free_super)(struct supertype *st);
 589
 590         /* validate_geometry is called with an st returned by
 591          * match_metadata_desc.
 592          * It should check that the geometry described in compatible with
 593          * the metadata type.  It will be called repeatedly as devices
 594          * added to validate changing size and new devices.  If there are
 595          * inter-device dependencies, it should record sufficient details
 596          * so these can be validated.
 597          * Both 'size' and '*freesize' are in sectors.  chunk is bytes.
 598          */
 599         int (*validate_geometry)(struct supertype *st, int level, int layout,
 600                                  int raiddisks,
 601                                  int chunk, unsigned long long size,
 602                                  char *subdev, unsigned long long *freesize,
 603                                  int verbose);
 604
 605         struct mdinfo *(*container_content)(struct supertype *st);
 606         /* Allow a metadata handler to override mdadm's default layouts */
 607         int (*default_layout)(int level); /* optional */
 608
 609 /* for mdmon */
 610         int (*open_new)(struct supertype *c, struct active_array *a,
 611                         char *inst);
 612
 613         /* Tell the metadata handler the current state of the array.
 614          * This covers whether it is known to be consistent (no pending writes)
 615          * and how far along a resync is known to have progressed
 616          * (in a->resync_start).
 617          * resync status is really irrelevant if the array is not consistent,
 618          * but some metadata (DDF!) have a place to record the distinction.
 619          * If 'consistent' is '2', then the array can mark it dirty if a
 620          * resync/recovery/whatever is required, or leave it clean if not.
 621          * Return value is 0 dirty (not consistent) and 1 if clean.
 622          * it is only really important if consistent is passed in as '2'.
 623          */
 624         int (*set_array_state)(struct active_array *a, int consistent);
 625
 626         /* When the state of a device might have changed, we call set_disk to
 627          * tell the metadata what the current state is.
 628          * Typically this happens on spare->in_sync and (spare|in_sync)->faulty
 629          * transitions.
 630          * set_disk might be called when the state of the particular disk has
 631          * not in fact changed.
 632          */
 633         void (*set_disk)(struct active_array *a, int n, int state);
 634         void (*sync_metadata)(struct supertype *st);
 635         void (*process_update)(struct supertype *st,
 636                                struct metadata_update *update);
 637         void (*prepare_update)(struct supertype *st,
 638                                struct metadata_update *update);
 639
 640         /* activate_spare will check if the array is degraded and, if it
 641          * is, try to find some spare space in the container.
 642          * On success, it add appropriate updates (For process_update) to
 643          * to the 'updates' list and returns a list of 'mdinfo' identifying
 644          * the device, or devices as there might be multiple missing
 645          * devices and multiple spares available.
 646          */
 647         struct mdinfo *(*activate_spare)(struct active_array *a,
 648                                          struct metadata_update **updates);
 649
 650         int swapuuid; /* true if uuid is bigending rather than hostendian */
 651         int external;
 652         const char *name; /* canonical metadata name */
 653 } super0, super1, super_ddf, *superlist[];
 654
 655 extern struct superswitch super_imsm;
 656
 657 struct metadata_update {
 658         int     len;
 659         char    *buf;
 660         void    *space; /* allocated space that monitor will use */
 661         struct metadata_update *next;
 662 };
 663
 664 /* A supertype holds a particular collection of metadata.
 665  * It identifies the metadata type by the superswitch, and the particular
 666  * sub-version of that metadata type.
 667  * metadata read in or created is stored in 'sb' and 'info'.
 668  * There are also fields used by mdmon to track containers.
 669  *
 670  * A supertype may refer to:
 671  *   Just an array, possibly in a container
 672  *   A container, not identifying any particular array
 673  *   Info read from just one device, not yet fully describing the array/container.
 674  *
 675  *
 676  * A supertype is created by:
 677  *   super_by_fd
 678  *   guess_super
 679  *   dup_super
 680  */
 681 struct supertype {
 682         struct superswitch *ss;
 683         int minor_version;
 684         int max_devs;
 685         int container_dev;    /* devnum of container */
 686         char subarray[32];      /* name of array inside container */
 687         void *sb;
 688         void *info;
 689         int loaded_container;   /* Set if load_super found a container,
 690                                  * not just one device */
 691
 692         struct metadata_update *updates;
 693         struct metadata_update **update_tail;
 694
 695         /* extra stuff used by mdmon */
 696         struct active_array *arrays;
 697         int sock; /* listen to external programs */
 698         int devnum;
 699         char *devname; /* e.g. md0.  This appears in metadata_verison:
 700                         *  external:/md0/12
 701                         */
 702         int devcnt;
 703
 704         struct mdinfo *devs;
 705
 706 };
 707
 708 extern struct supertype *super_by_fd(int fd);
 709 extern struct supertype *guess_super(int fd);
 710 extern struct supertype *dup_super(struct supertype *st);
 711 extern int get_dev_size(int fd, char *dname, unsigned long long *sizep);
 712 extern void get_one_disk(int mdfd, mdu_array_info_t *ainf,
 713                          mdu_disk_info_t *disk);
 714 void wait_for(char *dev, int fd);
 715
 716 #if __GNUC__ < 3
 717 struct stat64;
 718 #endif
 719
 720 #define HAVE_NFTW  we assume
 721 #define HAVE_FTW
 722
 723 #ifdef __UCLIBC__
 724 # include <features.h>
 725 # ifndef __UCLIBC_HAS_LFS__
 726 #  define lseek64 lseek
 727 # endif
 728 # ifndef  __UCLIBC_HAS_FTW__
 729 #  undef HAVE_FTW
 730 #  undef HAVE_NFTW
 731 # endif
 732 #endif
 733
 734 #ifdef __dietlibc__
 735 # undef HAVE_NFTW
 736 #endif
 737
 738 #if defined(__KLIBC__)
 739 # undef HAVE_NFTW
 740 # undef HAVE_FTW
 741 #endif
 742
 743 #ifndef HAVE_NFTW
 744 # define FTW_PHYS 1
 745 # ifndef HAVE_FTW
 746   struct FTW {};
 747 # endif
 748 #endif
 749
 750 #ifdef HAVE_FTW
 751 # include <ftw.h>
 752 #endif
 753
 754 extern int add_dev(const char *name, const struct stat *stb, int flag, struct FTW *s);
 755
 756
 757 extern int Manage_ro(char *devname, int fd, int readonly);
 758 extern int Manage_runstop(char *devname, int fd, int runstop, int quiet);
 759 extern int Manage_resize(char *devname, int fd, long long size, int raid_disks);
 760 extern int Manage_subdevs(char *devname, int fd,
 761                           mddev_dev_t devlist, int verbose);
 762 extern int autodetect(void);
 763 extern int Grow_Add_device(char *devname, int fd, char *newdev);
 764 extern int Grow_addbitmap(char *devname, int fd, char *file, int chunk, int delay, int write_behind, int force);
 765 extern int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
 766                         long long size,
 767                         int level, char *layout_str, int chunksize, int raid_disks);
 768 extern int Grow_restart(struct supertype *st, struct mdinfo *info,
 769                         int *fdlist, int cnt, char *backup_file, int verbose);
 770 extern int Grow_continue(int mdfd, struct supertype *st,
 771                          struct mdinfo *info, char *backup_file);
 772
 773 extern int Assemble(struct supertype *st, char *mddev,
 774                     mddev_ident_t ident,
 775                     mddev_dev_t devlist, char *backup_file,
 776                     int readonly, int runstop,
 777                     char *update, char *homehost, int require_homehost,
 778                     int verbose, int force);
 779
 780 extern int Build(char *mddev, int chunk, int level, int layout,
 781                  int raiddisks, mddev_dev_t devlist, int assume_clean,
 782                  char *bitmap_file, int bitmap_chunk, int write_behind,
 783                  int delay, int verbose, int autof, unsigned long long size);
 784
 785
 786 extern int Create(struct supertype *st, char *mddev,
 787                   int chunk, int level, int layout, unsigned long long size, int raiddisks, int sparedisks,
 788                   char *name, char *homehost, int *uuid,
 789                   int subdevs, mddev_dev_t devlist,
 790                   int runstop, int verbose, int force, int assume_clean,
 791                   char *bitmap_file, int bitmap_chunk, int write_behind, int delay, int autof);
 792
 793 extern int Detail(char *dev, int brief, int export, int test, char *homehost);
 794 extern int Detail_Platform(struct superswitch *ss, int scan, int verbose);
 795 extern int Query(char *dev);
 796 extern int Examine(mddev_dev_t devlist, int brief, int export, int scan,
 797                    int SparcAdjust, struct supertype *forcest, char *homehost);
 798 extern int Monitor(mddev_dev_t devlist,
 799                    char *mailaddr, char *alert_cmd,
 800                    int period, int daemonise, int scan, int oneshot,
 801                    int dosyslog, int test, char *pidfile, int increments);
 802
 803 extern int Kill(char *dev, struct supertype *st, int force, int quiet, int noexcl);
 804 extern int Wait(char *dev);
 805 extern int WaitClean(char *dev, int sock, int verbose);
 806
 807 extern int Incremental(char *devname, int verbose, int runstop,
 808                        struct supertype *st, char *homehost, int require_homehost,
 809                        int autof);
 810 extern int Incremental_container(struct supertype *st, char *devname,
 811                                  int verbose, int runstop, int autof,
 812                                  int trustworthy);
 813 extern void RebuildMap(void);
 814 extern int IncrementalScan(int verbose);
 815
 816 extern int CreateBitmap(char *filename, int force, char uuid[16],
 817                         unsigned long chunksize, unsigned long daemon_sleep,
 818                         unsigned long write_behind,
 819                         unsigned long long array_size,
 820                         int major);
 821 extern int ExamineBitmap(char *filename, int brief, struct supertype *st);
 822 extern int bitmap_update_uuid(int fd, int *uuid, int swap);
 823 extern unsigned long bitmap_sectors(struct bitmap_super_s *bsb);
 824
 825 extern int md_get_version(int fd);
 826 extern int get_linux_version(void);
 827 extern long long parse_size(char *size);
 828 extern int parse_uuid(char *str, int uuid[4]);
 829 extern int parse_layout_10(char *layout);
 830 extern int parse_layout_faulty(char *layout);
 831 extern int check_ext2(int fd, char *name);
 832 extern int check_reiser(int fd, char *name);
 833 extern int check_raid(int fd, char *name);
 834 extern int check_partitions(int fd, char *dname, unsigned long long freesize);
 835
 836 extern int get_mdp_major(void);
 837 extern int dev_open(char *dev, int flags);
 838 extern int open_dev(int devnum);
 839 extern int open_dev_excl(int devnum);
 840 extern int is_standard(char *dev, int *nump);
 841 extern int same_dev(char *one, char *two);
 842
 843 extern int parse_auto(char *str, char *msg, int config);
 844 extern mddev_ident_t conf_get_ident(char *dev);
 845 extern mddev_dev_t conf_get_devs(void);
 846 extern int conf_test_dev(char *devname);
 847 extern int conf_test_metadata(const char *version, int is_homehost);
 848 extern struct createinfo *conf_get_create_info(void);
 849 extern void set_conffile(char *file);
 850 extern char *conf_get_mailaddr(void);
 851 extern char *conf_get_mailfrom(void);
 852 extern char *conf_get_program(void);
 853 extern char *conf_get_homehost(int *require_homehostp);
 854 extern char *conf_line(FILE *file);
 855 extern char *conf_word(FILE *file, int allow_key);
 856 extern int conf_name_is_free(char *name);
 857 extern int devname_matches(char *name, char *match);
 858 extern struct mddev_ident_s *conf_match(struct mdinfo *info, struct supertype *st);
 859
 860 extern void free_line(char *line);
 861 extern int match_oneof(char *devices, char *devname);
 862 extern void uuid_from_super(int uuid[4], mdp_super_t *super);
 863 extern const int uuid_match_any[4];
 864 extern int same_uuid(int a[4], int b[4], int swapuuid);
 865 extern void copy_uuid(void *a, int b[4], int swapuuid);
 866 extern char *__fname_from_uuid(int id[4], int swap, char *buf, char sep);
 867 extern char *fname_from_uuid(struct supertype *st,
 868                              struct mdinfo *info, char *buf, char sep);
 869 extern unsigned long calc_csum(void *super, int bytes);
 870 extern int enough(int level, int raid_disks, int layout, int clean,
 871                    char *avail, int avail_disks);
 872 extern int ask(char *mesg);
 873 extern unsigned long long get_component_size(int fd);
 874 extern void remove_partitions(int fd);
 875 extern unsigned long long calc_array_size(int level, int raid_disks, int layout,
 876                                    int chunksize, unsigned long long devsize);
 877 extern int flush_metadata_updates(struct supertype *st);
 878 extern void append_metadata_update(struct supertype *st, void *buf, int len);
 879 extern int assemble_container_content(struct supertype *st, int mdfd,
 880                                       struct mdinfo *content, int runstop,
 881                                       char *chosen_name, int verbose);
 882
 883 extern int add_disk(int mdfd, struct supertype *st,
 884                     struct mdinfo *sra, struct mdinfo *info);
 885 extern int set_array_info(int mdfd, struct supertype *st, struct mdinfo *info);
 886 unsigned long long min_recovery_start(struct mdinfo *array);
 887
 888 extern char *human_size(long long bytes);
 889 extern char *human_size_brief(long long bytes);
 890 extern void print_r10_layout(int layout);
 891
 892 #define NoMdDev (1<<23)
 893 extern int find_free_devnum(int use_partitions);
 894
 895 extern void put_md_name(char *name);
 896 extern char *get_md_name(int dev);
 897
 898 extern char DefaultConfFile[];
 899
 900 extern int create_mddev(char *dev, char *name, int autof, int trustworthy,
 901                         char *chosen);
 902 /* values for 'trustworthy' */
 903 #define LOCAL   1
 904 #define LOCAL_ANY 10
 905 #define FOREIGN 2
 906 #define METADATA 3
 907 extern int open_mddev(char *dev, int report_errors);
 908 extern int open_container(int fd);
 909
 910 extern char *pid_dir;
 911 extern int mdmon_running(int devnum);
 912 extern int mdmon_pid(int devnum);
 913 extern int check_env(char *name);
 914 extern __u32 random32(void);
 915 extern int start_mdmon(int devnum);
 916
 917 extern char *devnum2devname(int num);
 918 extern int devname2devnum(char *name);
 919 extern int stat2devnum(struct stat *st);
 920 extern int fd2devnum(int fd);
 921
 922 static inline int dev2major(int d)
 923 {
 924         if (d >= 0)
 925                 return MD_MAJOR;
 926         else
 927                 return get_mdp_major();
 928 }
 929
 930 static inline int dev2minor(int d)
 931 {
 932         if (d >= 0)
 933                 return d;
 934         return (-1-d) << MdpMinorShift;
 935 }
 936
 937 static inline int ROUND_UP(int a, int base)
 938 {
 939         return ((a+base-1)/base)*base;
 940 }
 941
 942 static inline int is_subarray(char *vers)
 943 {
 944         /* The version string for a 'subarray' (an array in a container)
 945          * is
 946          *    /containername/componentname    for normal read-write arrays
 947          *    -containername/componentname    for read-only arrays.
 948          * containername is e.g. md0, md_d1
 949          * componentname is dependant on the metadata. e.g. '1' 'S1' ...
 950          */
 951         return (*vers == '/' || *vers == '-');
 952 }
 953
 954 #ifdef DEBUG
 955 #define dprintf(fmt, arg...) \
 956         fprintf(stderr, fmt, ##arg)
 957 #else
 958 #define dprintf(fmt, arg...) \
 959         ({ if (0) fprintf(stderr, fmt, ##arg); 0; })
 960 #endif
 961 #include <assert.h>
 962 #include <stdarg.h>
 963 static inline int xasprintf(char **strp, const char *fmt, ...) {
 964         va_list ap;
 965         int ret;
 966         va_start(ap, fmt);
 967         ret = vasprintf(strp, fmt, ap);
 968         va_end(ap);
 969         assert(ret >= 0);
 970         return ret;
 971 }
 972
 973 #define LEVEL_MULTIPATH         (-4)
 974 #define LEVEL_LINEAR            (-1)
 975 #define LEVEL_FAULTY            (-5)
 976
 977 /* kernel module doesn't know about these */
 978 #define LEVEL_CONTAINER         (-100)
 979 #define LEVEL_UNSUPPORTED       (-200)
 980
 981
 982 /* faulty stuff */
 983
 984 #define WriteTransient  0
 985 #define ReadTransient   1
 986 #define WritePersistent 2
 987 #define ReadPersistent  3
 988 #define WriteAll        4 /* doesn't go to device */
 989 #define ReadFixable     5
 990 #define Modes   6
 991
 992 #define ClearErrors     31
 993 #define ClearFaults     30
 994
 995 #define AllPersist      100 /* internal use only */
 996 #define NoPersist       101
 997
 998 #define ModeMask        0x1f
 999 #define ModeShift       5
1000
1001
1002 #ifdef __TINYC__
1003 #undef minor
1004 #undef major
1005 #undef makedev
1006 #define minor(x) ((x)&0xff)
1007 #define major(x) (((x)>>8)&0xff)
1008 #define makedev(M,m) (((M)<<8) | (m))
1009 #endif
1010
1011 /* for raid4/5/6 */
1012 #define ALGORITHM_LEFT_ASYMMETRIC       0
1013 #define ALGORITHM_RIGHT_ASYMMETRIC      1
1014 #define ALGORITHM_LEFT_SYMMETRIC        2
1015 #define ALGORITHM_RIGHT_SYMMETRIC       3
1016
1017 /* Define non-rotating (raid4) algorithms.  These allow
1018  * conversion of raid4 to raid5.
1019  */
1020 #define ALGORITHM_PARITY_0              4 /* P or P,Q are initial devices */
1021 #define ALGORITHM_PARITY_N              5 /* P or P,Q are final devices. */
1022
1023 /* DDF RAID6 layouts differ from md/raid6 layouts in two ways.
1024  * Firstly, the exact positioning of the parity block is slightly
1025  * different between the 'LEFT_*' modes of md and the "_N_*" modes
1026  * of DDF.
1027  * Secondly, or order of datablocks over which the Q syndrome is computed
1028  * is different.
1029  * Consequently we have different layouts for DDF/raid6 than md/raid6.
1030  * These layouts are from the DDFv1.2 spec.
1031  * Interestingly DDFv1.2-Errata-A does not specify N_CONTINUE but
1032  * leaves RLQ=3 as 'Vendor Specific'
1033  */
1034
1035 #define ALGORITHM_ROTATING_ZERO_RESTART 8 /* DDF PRL=6 RLQ=1 */
1036 #define ALGORITHM_ROTATING_N_RESTART    9 /* DDF PRL=6 RLQ=2 */
1037 #define ALGORITHM_ROTATING_N_CONTINUE   10 /*DDF PRL=6 RLQ=3 */
1038
1039
1040 /* For every RAID5 algorithm we define a RAID6 algorithm
1041  * with exactly the same layout for data and parity, and
1042  * with the Q block always on the last device (N-1).
1043  * This allows trivial conversion from RAID5 to RAID6
1044  */
1045 #define ALGORITHM_LEFT_ASYMMETRIC_6     16
1046 #define ALGORITHM_RIGHT_ASYMMETRIC_6    17
1047 #define ALGORITHM_LEFT_SYMMETRIC_6      18
1048 #define ALGORITHM_RIGHT_SYMMETRIC_6     19
1049 #define ALGORITHM_PARITY_0_6            20
1050 #define ALGORITHM_PARITY_N_6            ALGORITHM_PARITY_N
1051
1052 /* Define PATH_MAX in case we don't use glibc or standard library does
1053  * not have PATH_MAX defined. Assume max path length is 4K characters.
1054  */
1055 #ifndef PATH_MAX
1056 #define PATH_MAX        4096
1057 #endif
1058