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   1 /*
   2    md_k.h : kernel internal structure of the Linux MD driver
   3           Copyright (C) 1996-98 Ingo Molnar, Gadi Oxman
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 2, or (at your option)
   8    any later version.
   9
  10    You should have received a copy of the GNU General Public License
  11    (for example /usr/src/linux/COPYING); if not, write to the Free
  12    Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  13 */
  14
  15 #ifndef _MD_K_H
  16 #define _MD_K_H
  17
  18 /* and dm-bio-list.h is not under include/linux because.... ??? */
  19 #include "../../../drivers/md/dm-bio-list.h"
  20
  21 #ifdef CONFIG_BLOCK
  22
  23 #define MaxSector (~(sector_t)0)
  24
  25 typedef struct mddev_s mddev_t;
  26 typedef struct mdk_rdev_s mdk_rdev_t;
  27
  28 /*
  29  * options passed in raidrun:
  30  */
  31
  32 /* Currently this must fit in an 'int' */
  33 #define MAX_CHUNK_SIZE (1<<30)
  34
  35 /*
  36  * MD's 'extended' device
  37  */
  38 struct mdk_rdev_s
  39 {
  40         struct list_head same_set;      /* RAID devices within the same set */
  41
  42         sector_t size;                  /* Device size (in blocks) */
  43         mddev_t *mddev;                 /* RAID array if running */
  44         int last_events;                /* IO event timestamp */
  45
  46         struct block_device *bdev;      /* block device handle */
  47
  48         struct page     *sb_page;
  49         int             sb_loaded;
  50         __u64           sb_events;
  51         sector_t        data_offset;    /* start of data in array */
  52         sector_t        sb_start;       /* offset of the super block (in 512byte sectors) */
  53         int             sb_size;        /* bytes in the superblock */
  54         int             preferred_minor;        /* autorun support */
  55
  56         struct kobject  kobj;
  57
  58         /* A device can be in one of three states based on two flags:
  59          * Not working:   faulty==1 in_sync==0
  60          * Fully working: faulty==0 in_sync==1
  61          * Working, but not
  62          * in sync with array
  63          *                faulty==0 in_sync==0
  64          *
  65          * It can never have faulty==1, in_sync==1
  66          * This reduces the burden of testing multiple flags in many cases
  67          */
  68
  69         unsigned long   flags;
  70 #define Faulty          1               /* device is known to have a fault */
  71 #define In_sync         2               /* device is in_sync with rest of array */
  72 #define WriteMostly     4               /* Avoid reading if at all possible */
  73 #define BarriersNotsupp 5               /* BIO_RW_BARRIER is not supported */
  74 #define AllReserved     6               /* If whole device is reserved for
  75                                          * one array */
  76 #define AutoDetected    7               /* added by auto-detect */
  77 #define Blocked         8               /* An error occured on an externally
  78                                          * managed array, don't allow writes
  79                                          * until it is cleared */
  80 #define StateChanged    9               /* Faulty or Blocked has changed during
  81                                          * interrupt, so it needs to be
  82                                          * notified by the thread */
  83         wait_queue_head_t blocked_wait;
  84
  85         int desc_nr;                    /* descriptor index in the superblock */
  86         int raid_disk;                  /* role of device in array */
  87         int saved_raid_disk;            /* role that device used to have in the
  88                                          * array and could again if we did a partial
  89                                          * resync from the bitmap
  90                                          */
  91         sector_t        recovery_offset;/* If this device has been partially
  92                                          * recovered, this is where we were
  93                                          * up to.
  94                                          */
  95
  96         atomic_t        nr_pending;     /* number of pending requests.
  97                                          * only maintained for arrays that
  98                                          * support hot removal
  99                                          */
 100         atomic_t        read_errors;    /* number of consecutive read errors that
 101                                          * we have tried to ignore.
 102                                          */
 103         atomic_t        corrected_errors; /* number of corrected read errors,
 104                                            * for reporting to userspace and storing
 105                                            * in superblock.
 106                                            */
 107         struct work_struct del_work;    /* used for delayed sysfs removal */
 108
 109         struct sysfs_dirent *sysfs_state; /* handle for 'state'
 110                                            * sysfs entry */
 111 };
 112
 113 struct mddev_s
 114 {
 115         void                            *private;
 116         struct mdk_personality          *pers;
 117         dev_t                           unit;
 118         int                             md_minor;
 119         struct list_head                disks;
 120         unsigned long                   flags;
 121 #define MD_CHANGE_DEVS  0       /* Some device status has changed */
 122 #define MD_CHANGE_CLEAN 1       /* transition to or from 'clean' */
 123 #define MD_CHANGE_PENDING 2     /* superblock update in progress */
 124
 125         int                             ro;
 126
 127         struct gendisk                  *gendisk;
 128
 129         struct kobject                  kobj;
 130         int                             hold_active;
 131 #define UNTIL_IOCTL     1
 132 #define UNTIL_STOP      2
 133
 134         /* Superblock information */
 135         int                             major_version,
 136                                         minor_version,
 137                                         patch_version;
 138         int                             persistent;
 139         int                             external;       /* metadata is
 140                                                          * managed externally */
 141         char                            metadata_type[17]; /* externally set*/
 142         int                             chunk_size;
 143         time_t                          ctime, utime;
 144         int                             level, layout;
 145         char                            clevel[16];
 146         int                             raid_disks;
 147         int                             max_disks;
 148         sector_t                        size; /* used size of component devices */
 149         sector_t                        array_sectors; /* exported array size */
 150         __u64                           events;
 151
 152         char                            uuid[16];
 153
 154         /* If the array is being reshaped, we need to record the
 155          * new shape and an indication of where we are up to.
 156          * This is written to the superblock.
 157          * If reshape_position is MaxSector, then no reshape is happening (yet).
 158          */
 159         sector_t                        reshape_position;
 160         int                             delta_disks, new_level, new_layout, new_chunk;
 161
 162         struct mdk_thread_s             *thread;        /* management thread */
 163         struct mdk_thread_s             *sync_thread;   /* doing resync or reconstruct */
 164         sector_t                        curr_resync;    /* last block scheduled */
 165         unsigned long                   resync_mark;    /* a recent timestamp */
 166         sector_t                        resync_mark_cnt;/* blocks written at resync_mark */
 167         sector_t                        curr_mark_cnt; /* blocks scheduled now */
 168
 169         sector_t                        resync_max_sectors; /* may be set by personality */
 170
 171         sector_t                        resync_mismatches; /* count of sectors where
 172                                                             * parity/replica mismatch found
 173                                                             */
 174
 175         /* allow user-space to request suspension of IO to regions of the array */
 176         sector_t                        suspend_lo;
 177         sector_t                        suspend_hi;
 178         /* if zero, use the system-wide default */
 179         int                             sync_speed_min;
 180         int                             sync_speed_max;
 181
 182         /* resync even though the same disks are shared among md-devices */
 183         int                             parallel_resync;
 184
 185         int                             ok_start_degraded;
 186         /* recovery/resync flags
 187          * NEEDED:   we might need to start a resync/recover
 188          * RUNNING:  a thread is running, or about to be started
 189          * SYNC:     actually doing a resync, not a recovery
 190          * RECOVER:  doing recovery, or need to try it.
 191          * INTR:     resync needs to be aborted for some reason
 192          * DONE:     thread is done and is waiting to be reaped
 193          * REQUEST:  user-space has requested a sync (used with SYNC)
 194          * CHECK:    user-space request for for check-only, no repair
 195          * RESHAPE:  A reshape is happening
 196          *
 197          * If neither SYNC or RESHAPE are set, then it is a recovery.
 198          */
 199 #define MD_RECOVERY_RUNNING     0
 200 #define MD_RECOVERY_SYNC        1
 201 #define MD_RECOVERY_RECOVER     2
 202 #define MD_RECOVERY_INTR        3
 203 #define MD_RECOVERY_DONE        4
 204 #define MD_RECOVERY_NEEDED      5
 205 #define MD_RECOVERY_REQUESTED   6
 206 #define MD_RECOVERY_CHECK       7
 207 #define MD_RECOVERY_RESHAPE     8
 208 #define MD_RECOVERY_FROZEN      9
 209
 210         unsigned long                   recovery;
 211         int                             recovery_disabled; /* if we detect that recovery
 212                                                             * will always fail, set this
 213                                                             * so we don't loop trying */
 214
 215         int                             in_sync;        /* know to not need resync */
 216         struct mutex                    reconfig_mutex;
 217         atomic_t                        active;         /* general refcount */
 218         atomic_t                        openers;        /* number of active opens */
 219
 220         int                             changed;        /* true if we might need to reread partition info */
 221         int                             degraded;       /* whether md should consider
 222                                                          * adding a spare
 223                                                          */
 224         int                             barriers_work;  /* initialised to true, cleared as soon
 225                                                          * as a barrier request to slave
 226                                                          * fails.  Only supported
 227                                                          */
 228         struct bio                      *biolist;       /* bios that need to be retried
 229                                                          * because BIO_RW_BARRIER is not supported
 230                                                          */
 231
 232         atomic_t                        recovery_active; /* blocks scheduled, but not written */
 233         wait_queue_head_t               recovery_wait;
 234         sector_t                        recovery_cp;
 235         sector_t                        resync_min;     /* user requested sync
 236                                                          * starts here */
 237         sector_t                        resync_max;     /* resync should pause
 238                                                          * when it gets here */
 239
 240         struct sysfs_dirent             *sysfs_state;   /* handle for 'array_state'
 241                                                          * file in sysfs.
 242                                                          */
 243         struct sysfs_dirent             *sysfs_action;  /* handle for 'sync_action' */
 244
 245         struct work_struct del_work;    /* used for delayed sysfs removal */
 246
 247         spinlock_t                      write_lock;
 248         wait_queue_head_t               sb_wait;        /* for waiting on superblock updates */
 249         atomic_t                        pending_writes; /* number of active superblock writes */
 250
 251         unsigned int                    safemode;       /* if set, update "clean" superblock
 252                                                          * when no writes pending.
 253                                                          */
 254         unsigned int                    safemode_delay;
 255         struct timer_list               safemode_timer;
 256         atomic_t                        writes_pending;
 257         struct request_queue            *queue; /* for plugging ... */
 258
 259         atomic_t                        write_behind; /* outstanding async IO */
 260         unsigned int                    max_write_behind; /* 0 = sync */
 261
 262         struct bitmap                   *bitmap; /* the bitmap for the device */
 263         struct file                     *bitmap_file; /* the bitmap file */
 264         long                            bitmap_offset; /* offset from superblock of
 265                                                         * start of bitmap. May be
 266                                                         * negative, but not '0'
 267                                                         */
 268         long                            default_bitmap_offset; /* this is the offset to use when
 269                                                                 * hot-adding a bitmap.  It should
 270                                                                 * eventually be settable by sysfs.
 271                                                                 */
 272
 273         struct list_head                all_mddevs;
 274 };
 275
 276
 277 static inline void rdev_dec_pending(mdk_rdev_t *rdev, mddev_t *mddev)
 278 {
 279         int faulty = test_bit(Faulty, &rdev->flags);
 280         if (atomic_dec_and_test(&rdev->nr_pending) && faulty)
 281                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
 282 }
 283
 284 static inline void md_sync_acct(struct block_device *bdev, unsigned long nr_sectors)
 285 {
 286         atomic_add(nr_sectors, &bdev->bd_contains->bd_disk->sync_io);
 287 }
 288
 289 struct mdk_personality
 290 {
 291         char *name;
 292         int level;
 293         struct list_head list;
 294         struct module *owner;
 295         int (*make_request)(struct request_queue *q, struct bio *bio);
 296         int (*run)(mddev_t *mddev);
 297         int (*stop)(mddev_t *mddev);
 298         void (*status)(struct seq_file *seq, mddev_t *mddev);
 299         /* error_handler must set ->faulty and clear ->in_sync
 300          * if appropriate, and should abort recovery if needed
 301          */
 302         void (*error_handler)(mddev_t *mddev, mdk_rdev_t *rdev);
 303         int (*hot_add_disk) (mddev_t *mddev, mdk_rdev_t *rdev);
 304         int (*hot_remove_disk) (mddev_t *mddev, int number);
 305         int (*spare_active) (mddev_t *mddev);
 306         sector_t (*sync_request)(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster);
 307         int (*resize) (mddev_t *mddev, sector_t sectors);
 308         int (*check_reshape) (mddev_t *mddev);
 309         int (*start_reshape) (mddev_t *mddev);
 310         int (*reconfig) (mddev_t *mddev, int layout, int chunk_size);
 311         /* quiesce moves between quiescence states
 312          * 0 - fully active
 313          * 1 - no new requests allowed
 314          * others - reserved
 315          */
 316         void (*quiesce) (mddev_t *mddev, int state);
 317 };
 318
 319
 320 struct md_sysfs_entry {
 321         struct attribute attr;
 322         ssize_t (*show)(mddev_t *, char *);
 323         ssize_t (*store)(mddev_t *, const char *, size_t);
 324 };
 325
 326
 327 static inline char * mdname (mddev_t * mddev)
 328 {
 329         return mddev->gendisk ? mddev->gendisk->disk_name : "mdX";
 330 }
 331
 332 /*
 333  * iterates through some rdev ringlist. It's safe to remove the
 334  * current 'rdev'. Dont touch 'tmp' though.
 335  */
 336 #define rdev_for_each_list(rdev, tmp, head)                             \
 337         list_for_each_entry_safe(rdev, tmp, head, same_set)
 338
 339 /*
 340  * iterates through the 'same array disks' ringlist
 341  */
 342 #define rdev_for_each(rdev, tmp, mddev)                         \
 343         list_for_each_entry_safe(rdev, tmp, &((mddev)->disks), same_set)
 344
 345 #define rdev_for_each_rcu(rdev, mddev)                          \
 346         list_for_each_entry_rcu(rdev, &((mddev)->disks), same_set)
 347
 348 typedef struct mdk_thread_s {
 349         void                    (*run) (mddev_t *mddev);
 350         mddev_t                 *mddev;
 351         wait_queue_head_t       wqueue;
 352         unsigned long           flags;
 353         struct task_struct      *tsk;
 354         unsigned long           timeout;
 355 } mdk_thread_t;
 356
 357 #define THREAD_WAKEUP  0
 358
 359 #define __wait_event_lock_irq(wq, condition, lock, cmd)                 \
 360 do {                                                                    \
 361         wait_queue_t __wait;                                            \
 362         init_waitqueue_entry(&__wait, current);                         \
 363                                                                         \
 364         add_wait_queue(&wq, &__wait);                                   \
 365         for (;;) {                                                      \
 366                 set_current_state(TASK_UNINTERRUPTIBLE);                \
 367                 if (condition)                                          \
 368                         break;                                          \
 369                 spin_unlock_irq(&lock);                                 \
 370                 cmd;                                                    \
 371                 schedule();                                             \
 372                 spin_lock_irq(&lock);                                   \
 373         }                                                               \
 374         current->state = TASK_RUNNING;                                  \
 375         remove_wait_queue(&wq, &__wait);                                \
 376 } while (0)
 377
 378 #define wait_event_lock_irq(wq, condition, lock, cmd)                   \
 379 do {                                                                    \
 380         if (condition)                                                  \
 381                 break;                                                  \
 382         __wait_event_lock_irq(wq, condition, lock, cmd);                \
 383 } while (0)
 384
 385 static inline void safe_put_page(struct page *p)
 386 {
 387         if (p) put_page(p);
 388 }
 389
 390 #endif /* CONFIG_BLOCK */
 391 #endif
 392