LCOV - code coverage report
Current view: top level - drivers/md - md.h (source / functions) Hit Total Coverage
Test: combined.info Lines: 3 40 7.5 %
Date: 2022-04-01 14:58:12 Functions: 0 3 0.0 %
Branches: 1 242 0.4 %

           Branch data     Line data    Source code
       1                 :            : /* SPDX-License-Identifier: GPL-2.0-or-later */
       2                 :            : /*
       3                 :            :    md.h : kernel internal structure of the Linux MD driver
       4                 :            :           Copyright (C) 1996-98 Ingo Molnar, Gadi Oxman
       5                 :            : 
       6                 :            : */
       7                 :            : 
       8                 :            : #ifndef _MD_MD_H
       9                 :            : #define _MD_MD_H
      10                 :            : 
      11                 :            : #include <linux/blkdev.h>
      12                 :            : #include <linux/backing-dev.h>
      13                 :            : #include <linux/badblocks.h>
      14                 :            : #include <linux/kobject.h>
      15                 :            : #include <linux/list.h>
      16                 :            : #include <linux/mm.h>
      17                 :            : #include <linux/mutex.h>
      18                 :            : #include <linux/timer.h>
      19                 :            : #include <linux/wait.h>
      20                 :            : #include <linux/workqueue.h>
      21                 :            : #include "md-cluster.h"
      22                 :            : 
      23                 :            : #define MaxSector (~(sector_t)0)
      24                 :            : 
      25                 :            : /*
      26                 :            :  * These flags should really be called "NO_RETRY" rather than
      27                 :            :  * "FAILFAST" because they don't make any promise about time lapse,
      28                 :            :  * only about the number of retries, which will be zero.
      29                 :            :  * REQ_FAILFAST_DRIVER is not included because
      30                 :            :  * Commit: 4a27446f3e39 ("[SCSI] modify scsi to handle new fail fast flags.")
      31                 :            :  * seems to suggest that the errors it avoids retrying should usually
      32                 :            :  * be retried.
      33                 :            :  */
      34                 :            : #define MD_FAILFAST     (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT)
      35                 :            : 
      36                 :            : /*
      37                 :            :  * The struct embedded in rdev is used to serialize IO.
      38                 :            :  */
      39                 :            : struct serial_in_rdev {
      40                 :            :         struct rb_root_cached serial_rb;
      41                 :            :         spinlock_t serial_lock;
      42                 :            :         wait_queue_head_t serial_io_wait;
      43                 :            : };
      44                 :            : 
      45                 :            : /*
      46                 :            :  * MD's 'extended' device
      47                 :            :  */
      48                 :            : struct md_rdev {
      49                 :            :         struct list_head same_set;      /* RAID devices within the same set */
      50                 :            : 
      51                 :            :         sector_t sectors;               /* Device size (in 512bytes sectors) */
      52                 :            :         struct mddev *mddev;            /* RAID array if running */
      53                 :            :         int last_events;                /* IO event timestamp */
      54                 :            : 
      55                 :            :         /*
      56                 :            :          * If meta_bdev is non-NULL, it means that a separate device is
      57                 :            :          * being used to store the metadata (superblock/bitmap) which
      58                 :            :          * would otherwise be contained on the same device as the data (bdev).
      59                 :            :          */
      60                 :            :         struct block_device *meta_bdev;
      61                 :            :         struct block_device *bdev;      /* block device handle */
      62                 :            : 
      63                 :            :         struct page     *sb_page, *bb_page;
      64                 :            :         int             sb_loaded;
      65                 :            :         __u64           sb_events;
      66                 :            :         sector_t        data_offset;    /* start of data in array */
      67                 :            :         sector_t        new_data_offset;/* only relevant while reshaping */
      68                 :            :         sector_t        sb_start;       /* offset of the super block (in 512byte sectors) */
      69                 :            :         int             sb_size;        /* bytes in the superblock */
      70                 :            :         int             preferred_minor;        /* autorun support */
      71                 :            : 
      72                 :            :         struct kobject  kobj;
      73                 :            : 
      74                 :            :         /* A device can be in one of three states based on two flags:
      75                 :            :          * Not working:   faulty==1 in_sync==0
      76                 :            :          * Fully working: faulty==0 in_sync==1
      77                 :            :          * Working, but not
      78                 :            :          * in sync with array
      79                 :            :          *                faulty==0 in_sync==0
      80                 :            :          *
      81                 :            :          * It can never have faulty==1, in_sync==1
      82                 :            :          * This reduces the burden of testing multiple flags in many cases
      83                 :            :          */
      84                 :            : 
      85                 :            :         unsigned long   flags;  /* bit set of 'enum flag_bits' bits. */
      86                 :            :         wait_queue_head_t blocked_wait;
      87                 :            : 
      88                 :            :         int desc_nr;                    /* descriptor index in the superblock */
      89                 :            :         int raid_disk;                  /* role of device in array */
      90                 :            :         int new_raid_disk;              /* role that the device will have in
      91                 :            :                                          * the array after a level-change completes.
      92                 :            :                                          */
      93                 :            :         int saved_raid_disk;            /* role that device used to have in the
      94                 :            :                                          * array and could again if we did a partial
      95                 :            :                                          * resync from the bitmap
      96                 :            :                                          */
      97                 :            :         union {
      98                 :            :                 sector_t recovery_offset;/* If this device has been partially
      99                 :            :                                          * recovered, this is where we were
     100                 :            :                                          * up to.
     101                 :            :                                          */
     102                 :            :                 sector_t journal_tail;  /* If this device is a journal device,
     103                 :            :                                          * this is the journal tail (journal
     104                 :            :                                          * recovery start point)
     105                 :            :                                          */
     106                 :            :         };
     107                 :            : 
     108                 :            :         atomic_t        nr_pending;     /* number of pending requests.
     109                 :            :                                          * only maintained for arrays that
     110                 :            :                                          * support hot removal
     111                 :            :                                          */
     112                 :            :         atomic_t        read_errors;    /* number of consecutive read errors that
     113                 :            :                                          * we have tried to ignore.
     114                 :            :                                          */
     115                 :            :         time64_t        last_read_error;        /* monotonic time since our
     116                 :            :                                                  * last read error
     117                 :            :                                                  */
     118                 :            :         atomic_t        corrected_errors; /* number of corrected read errors,
     119                 :            :                                            * for reporting to userspace and storing
     120                 :            :                                            * in superblock.
     121                 :            :                                            */
     122                 :            : 
     123                 :            :         struct serial_in_rdev *serial;  /* used for raid1 io serialization */
     124                 :            : 
     125                 :            :         struct work_struct del_work;    /* used for delayed sysfs removal */
     126                 :            : 
     127                 :            :         struct kernfs_node *sysfs_state; /* handle for 'state'
     128                 :            :                                            * sysfs entry */
     129                 :            : 
     130                 :            :         struct badblocks badblocks;
     131                 :            : 
     132                 :            :         struct {
     133                 :            :                 short offset;   /* Offset from superblock to start of PPL.
     134                 :            :                                  * Not used by external metadata. */
     135                 :            :                 unsigned int size;      /* Size in sectors of the PPL space */
     136                 :            :                 sector_t sector;        /* First sector of the PPL space */
     137                 :            :         } ppl;
     138                 :            : };
     139                 :            : enum flag_bits {
     140                 :            :         Faulty,                 /* device is known to have a fault */
     141                 :            :         In_sync,                /* device is in_sync with rest of array */
     142                 :            :         Bitmap_sync,            /* ..actually, not quite In_sync.  Need a
     143                 :            :                                  * bitmap-based recovery to get fully in sync.
     144                 :            :                                  * The bit is only meaningful before device
     145                 :            :                                  * has been passed to pers->hot_add_disk.
     146                 :            :                                  */
     147                 :            :         WriteMostly,            /* Avoid reading if at all possible */
     148                 :            :         AutoDetected,           /* added by auto-detect */
     149                 :            :         Blocked,                /* An error occurred but has not yet
     150                 :            :                                  * been acknowledged by the metadata
     151                 :            :                                  * handler, so don't allow writes
     152                 :            :                                  * until it is cleared */
     153                 :            :         WriteErrorSeen,         /* A write error has been seen on this
     154                 :            :                                  * device
     155                 :            :                                  */
     156                 :            :         FaultRecorded,          /* Intermediate state for clearing
     157                 :            :                                  * Blocked.  The Fault is/will-be
     158                 :            :                                  * recorded in the metadata, but that
     159                 :            :                                  * metadata hasn't been stored safely
     160                 :            :                                  * on disk yet.
     161                 :            :                                  */
     162                 :            :         BlockedBadBlocks,       /* A writer is blocked because they
     163                 :            :                                  * found an unacknowledged bad-block.
     164                 :            :                                  * This can safely be cleared at any
     165                 :            :                                  * time, and the writer will re-check.
     166                 :            :                                  * It may be set at any time, and at
     167                 :            :                                  * worst the writer will timeout and
     168                 :            :                                  * re-check.  So setting it as
     169                 :            :                                  * accurately as possible is good, but
     170                 :            :                                  * not absolutely critical.
     171                 :            :                                  */
     172                 :            :         WantReplacement,        /* This device is a candidate to be
     173                 :            :                                  * hot-replaced, either because it has
     174                 :            :                                  * reported some faults, or because
     175                 :            :                                  * of explicit request.
     176                 :            :                                  */
     177                 :            :         Replacement,            /* This device is a replacement for
     178                 :            :                                  * a want_replacement device with same
     179                 :            :                                  * raid_disk number.
     180                 :            :                                  */
     181                 :            :         Candidate,              /* For clustered environments only:
     182                 :            :                                  * This device is seen locally but not
     183                 :            :                                  * by the whole cluster
     184                 :            :                                  */
     185                 :            :         Journal,                /* This device is used as journal for
     186                 :            :                                  * raid-5/6.
     187                 :            :                                  * Usually, this device should be faster
     188                 :            :                                  * than other devices in the array
     189                 :            :                                  */
     190                 :            :         ClusterRemove,
     191                 :            :         RemoveSynchronized,     /* synchronize_rcu() was called after
     192                 :            :                                  * this device was known to be faulty,
     193                 :            :                                  * so it is safe to remove without
     194                 :            :                                  * another synchronize_rcu() call.
     195                 :            :                                  */
     196                 :            :         ExternalBbl,            /* External metadata provides bad
     197                 :            :                                  * block management for a disk
     198                 :            :                                  */
     199                 :            :         FailFast,               /* Minimal retries should be attempted on
     200                 :            :                                  * this device, so use REQ_FAILFAST_DEV.
     201                 :            :                                  * Also don't try to repair failed reads.
     202                 :            :                                  * It is expects that no bad block log
     203                 :            :                                  * is present.
     204                 :            :                                  */
     205                 :            :         LastDev,                /* Seems to be the last working dev as
     206                 :            :                                  * it didn't fail, so don't use FailFast
     207                 :            :                                  * any more for metadata
     208                 :            :                                  */
     209                 :            :         CollisionCheck,         /*
     210                 :            :                                  * check if there is collision between raid1
     211                 :            :                                  * serial bios.
     212                 :            :                                  */
     213                 :            : };
     214                 :            : 
     215                 :            : static inline int is_badblock(struct md_rdev *rdev, sector_t s, int sectors,
     216                 :            :                               sector_t *first_bad, int *bad_sectors)
     217                 :            : {
     218                 :            :         if (unlikely(rdev->badblocks.count)) {
     219                 :            :                 int rv = badblocks_check(&rdev->badblocks, rdev->data_offset + s,
     220                 :            :                                         sectors,
     221                 :            :                                         first_bad, bad_sectors);
     222                 :            :                 if (rv)
     223                 :            :                         *first_bad -= rdev->data_offset;
     224                 :            :                 return rv;
     225                 :            :         }
     226                 :            :         return 0;
     227                 :            : }
     228                 :            : extern int rdev_set_badblocks(struct md_rdev *rdev, sector_t s, int sectors,
     229                 :            :                               int is_new);
     230                 :            : extern int rdev_clear_badblocks(struct md_rdev *rdev, sector_t s, int sectors,
     231                 :            :                                 int is_new);
     232                 :            : struct md_cluster_info;
     233                 :            : 
     234                 :            : /* change UNSUPPORTED_MDDEV_FLAGS for each array type if new flag is added */
     235                 :            : enum mddev_flags {
     236                 :            :         MD_ARRAY_FIRST_USE,     /* First use of array, needs initialization */
     237                 :            :         MD_CLOSING,             /* If set, we are closing the array, do not open
     238                 :            :                                  * it then */
     239                 :            :         MD_JOURNAL_CLEAN,       /* A raid with journal is already clean */
     240                 :            :         MD_HAS_JOURNAL,         /* The raid array has journal feature set */
     241                 :            :         MD_CLUSTER_RESYNC_LOCKED, /* cluster raid only, which means node
     242                 :            :                                    * already took resync lock, need to
     243                 :            :                                    * release the lock */
     244                 :            :         MD_FAILFAST_SUPPORTED,  /* Using MD_FAILFAST on metadata writes is
     245                 :            :                                  * supported as calls to md_error() will
     246                 :            :                                  * never cause the array to become failed.
     247                 :            :                                  */
     248                 :            :         MD_HAS_PPL,             /* The raid array has PPL feature set */
     249                 :            :         MD_HAS_MULTIPLE_PPLS,   /* The raid array has multiple PPLs feature set */
     250                 :            :         MD_ALLOW_SB_UPDATE,     /* md_check_recovery is allowed to update
     251                 :            :                                  * the metadata without taking reconfig_mutex.
     252                 :            :                                  */
     253                 :            :         MD_UPDATING_SB,         /* md_check_recovery is updating the metadata
     254                 :            :                                  * without explicitly holding reconfig_mutex.
     255                 :            :                                  */
     256                 :            :         MD_NOT_READY,           /* do_md_run() is active, so 'array_state'
     257                 :            :                                  * must not report that array is ready yet
     258                 :            :                                  */
     259                 :            :         MD_BROKEN,              /* This is used in RAID-0/LINEAR only, to stop
     260                 :            :                                  * I/O in case an array member is gone/failed.
     261                 :            :                                  */
     262                 :            : };
     263                 :            : 
     264                 :            : enum mddev_sb_flags {
     265                 :            :         MD_SB_CHANGE_DEVS,              /* Some device status has changed */
     266                 :            :         MD_SB_CHANGE_CLEAN,     /* transition to or from 'clean' */
     267                 :            :         MD_SB_CHANGE_PENDING,   /* switch from 'clean' to 'active' in progress */
     268                 :            :         MD_SB_NEED_REWRITE,     /* metadata write needs to be repeated */
     269                 :            : };
     270                 :            : 
     271                 :            : #define NR_SERIAL_INFOS         8
     272                 :            : /* record current range of serialize IOs */
     273                 :            : struct serial_info {
     274                 :            :         struct rb_node node;
     275                 :            :         sector_t start;         /* start sector of rb node */
     276                 :            :         sector_t last;          /* end sector of rb node */
     277                 :            :         sector_t _subtree_last; /* highest sector in subtree of rb node */
     278                 :            : };
     279                 :            : 
     280                 :            : struct mddev {
     281                 :            :         void                            *private;
     282                 :            :         struct md_personality           *pers;
     283                 :            :         dev_t                           unit;
     284                 :            :         int                             md_minor;
     285                 :            :         struct list_head                disks;
     286                 :            :         unsigned long                   flags;
     287                 :            :         unsigned long                   sb_flags;
     288                 :            : 
     289                 :            :         int                             suspended;
     290                 :            :         atomic_t                        active_io;
     291                 :            :         int                             ro;
     292                 :            :         int                             sysfs_active; /* set when sysfs deletes
     293                 :            :                                                        * are happening, so run/
     294                 :            :                                                        * takeover/stop are not safe
     295                 :            :                                                        */
     296                 :            :         struct gendisk                  *gendisk;
     297                 :            : 
     298                 :            :         struct kobject                  kobj;
     299                 :            :         int                             hold_active;
     300                 :            : #define UNTIL_IOCTL     1
     301                 :            : #define UNTIL_STOP      2
     302                 :            : 
     303                 :            :         /* Superblock information */
     304                 :            :         int                             major_version,
     305                 :            :                                         minor_version,
     306                 :            :                                         patch_version;
     307                 :            :         int                             persistent;
     308                 :            :         int                             external;       /* metadata is
     309                 :            :                                                          * managed externally */
     310                 :            :         char                            metadata_type[17]; /* externally set*/
     311                 :            :         int                             chunk_sectors;
     312                 :            :         time64_t                        ctime, utime;
     313                 :            :         int                             level, layout;
     314                 :            :         char                            clevel[16];
     315                 :            :         int                             raid_disks;
     316                 :            :         int                             max_disks;
     317                 :            :         sector_t                        dev_sectors;    /* used size of
     318                 :            :                                                          * component devices */
     319                 :            :         sector_t                        array_sectors; /* exported array size */
     320                 :            :         int                             external_size; /* size managed
     321                 :            :                                                         * externally */
     322                 :            :         __u64                           events;
     323                 :            :         /* If the last 'event' was simply a clean->dirty transition, and
     324                 :            :          * we didn't write it to the spares, then it is safe and simple
     325                 :            :          * to just decrement the event count on a dirty->clean transition.
     326                 :            :          * So we record that possibility here.
     327                 :            :          */
     328                 :            :         int                             can_decrease_events;
     329                 :            : 
     330                 :            :         char                            uuid[16];
     331                 :            : 
     332                 :            :         /* If the array is being reshaped, we need to record the
     333                 :            :          * new shape and an indication of where we are up to.
     334                 :            :          * This is written to the superblock.
     335                 :            :          * If reshape_position is MaxSector, then no reshape is happening (yet).
     336                 :            :          */
     337                 :            :         sector_t                        reshape_position;
     338                 :            :         int                             delta_disks, new_level, new_layout;
     339                 :            :         int                             new_chunk_sectors;
     340                 :            :         int                             reshape_backwards;
     341                 :            : 
     342                 :            :         struct md_thread                *thread;        /* management thread */
     343                 :            :         struct md_thread                *sync_thread;   /* doing resync or reconstruct */
     344                 :            : 
     345                 :            :         /* 'last_sync_action' is initialized to "none".  It is set when a
     346                 :            :          * sync operation (i.e "data-check", "requested-resync", "resync",
     347                 :            :          * "recovery", or "reshape") is started.  It holds this value even
     348                 :            :          * when the sync thread is "frozen" (interrupted) or "idle" (stopped
     349                 :            :          * or finished).  It is overwritten when a new sync operation is begun.
     350                 :            :          */
     351                 :            :         char                            *last_sync_action;
     352                 :            :         sector_t                        curr_resync;    /* last block scheduled */
     353                 :            :         /* As resync requests can complete out of order, we cannot easily track
     354                 :            :          * how much resync has been completed.  So we occasionally pause until
     355                 :            :          * everything completes, then set curr_resync_completed to curr_resync.
     356                 :            :          * As such it may be well behind the real resync mark, but it is a value
     357                 :            :          * we are certain of.
     358                 :            :          */
     359                 :            :         sector_t                        curr_resync_completed;
     360                 :            :         unsigned long                   resync_mark;    /* a recent timestamp */
     361                 :            :         sector_t                        resync_mark_cnt;/* blocks written at resync_mark */
     362                 :            :         sector_t                        curr_mark_cnt; /* blocks scheduled now */
     363                 :            : 
     364                 :            :         sector_t                        resync_max_sectors; /* may be set by personality */
     365                 :            : 
     366                 :            :         atomic64_t                      resync_mismatches; /* count of sectors where
     367                 :            :                                                             * parity/replica mismatch found
     368                 :            :                                                             */
     369                 :            : 
     370                 :            :         /* allow user-space to request suspension of IO to regions of the array */
     371                 :            :         sector_t                        suspend_lo;
     372                 :            :         sector_t                        suspend_hi;
     373                 :            :         /* if zero, use the system-wide default */
     374                 :            :         int                             sync_speed_min;
     375                 :            :         int                             sync_speed_max;
     376                 :            : 
     377                 :            :         /* resync even though the same disks are shared among md-devices */
     378                 :            :         int                             parallel_resync;
     379                 :            : 
     380                 :            :         int                             ok_start_degraded;
     381                 :            : 
     382                 :            :         unsigned long                   recovery;
     383                 :            :         /* If a RAID personality determines that recovery (of a particular
     384                 :            :          * device) will fail due to a read error on the source device, it
     385                 :            :          * takes a copy of this number and does not attempt recovery again
     386                 :            :          * until this number changes.
     387                 :            :          */
     388                 :            :         int                             recovery_disabled;
     389                 :            : 
     390                 :            :         int                             in_sync;        /* know to not need resync */
     391                 :            :         /* 'open_mutex' avoids races between 'md_open' and 'do_md_stop', so
     392                 :            :          * that we are never stopping an array while it is open.
     393                 :            :          * 'reconfig_mutex' protects all other reconfiguration.
     394                 :            :          * These locks are separate due to conflicting interactions
     395                 :            :          * with bdev->bd_mutex.
     396                 :            :          * Lock ordering is:
     397                 :            :          *  reconfig_mutex -> bd_mutex : e.g. do_md_run -> revalidate_disk
     398                 :            :          *  bd_mutex -> open_mutex:  e.g. __blkdev_get -> md_open
     399                 :            :          */
     400                 :            :         struct mutex                    open_mutex;
     401                 :            :         struct mutex                    reconfig_mutex;
     402                 :            :         atomic_t                        active;         /* general refcount */
     403                 :            :         atomic_t                        openers;        /* number of active opens */
     404                 :            : 
     405                 :            :         int                             changed;        /* True if we might need to
     406                 :            :                                                          * reread partition info */
     407                 :            :         int                             degraded;       /* whether md should consider
     408                 :            :                                                          * adding a spare
     409                 :            :                                                          */
     410                 :            : 
     411                 :            :         atomic_t                        recovery_active; /* blocks scheduled, but not written */
     412                 :            :         wait_queue_head_t               recovery_wait;
     413                 :            :         sector_t                        recovery_cp;
     414                 :            :         sector_t                        resync_min;     /* user requested sync
     415                 :            :                                                          * starts here */
     416                 :            :         sector_t                        resync_max;     /* resync should pause
     417                 :            :                                                          * when it gets here */
     418                 :            : 
     419                 :            :         struct kernfs_node              *sysfs_state;   /* handle for 'array_state'
     420                 :            :                                                          * file in sysfs.
     421                 :            :                                                          */
     422                 :            :         struct kernfs_node              *sysfs_action;  /* handle for 'sync_action' */
     423                 :            : 
     424                 :            :         struct work_struct del_work;    /* used for delayed sysfs removal */
     425                 :            : 
     426                 :            :         /* "lock" protects:
     427                 :            :          *   flush_bio transition from NULL to !NULL
     428                 :            :          *   rdev superblocks, events
     429                 :            :          *   clearing MD_CHANGE_*
     430                 :            :          *   in_sync - and related safemode and MD_CHANGE changes
     431                 :            :          *   pers (also protected by reconfig_mutex and pending IO).
     432                 :            :          *   clearing ->bitmap
     433                 :            :          *   clearing ->bitmap_info.file
     434                 :            :          *   changing ->resync_{min,max}
     435                 :            :          *   setting MD_RECOVERY_RUNNING (which interacts with resync_{min,max})
     436                 :            :          */
     437                 :            :         spinlock_t                      lock;
     438                 :            :         wait_queue_head_t               sb_wait;        /* for waiting on superblock updates */
     439                 :            :         atomic_t                        pending_writes; /* number of active superblock writes */
     440                 :            : 
     441                 :            :         unsigned int                    safemode;       /* if set, update "clean" superblock
     442                 :            :                                                          * when no writes pending.
     443                 :            :                                                          */
     444                 :            :         unsigned int                    safemode_delay;
     445                 :            :         struct timer_list               safemode_timer;
     446                 :            :         struct percpu_ref               writes_pending;
     447                 :            :         int                             sync_checkers;  /* # of threads checking writes_pending */
     448                 :            :         struct request_queue            *queue; /* for plugging ... */
     449                 :            : 
     450                 :            :         struct bitmap                   *bitmap; /* the bitmap for the device */
     451                 :            :         struct {
     452                 :            :                 struct file             *file; /* the bitmap file */
     453                 :            :                 loff_t                  offset; /* offset from superblock of
     454                 :            :                                                  * start of bitmap. May be
     455                 :            :                                                  * negative, but not '0'
     456                 :            :                                                  * For external metadata, offset
     457                 :            :                                                  * from start of device.
     458                 :            :                                                  */
     459                 :            :                 unsigned long           space; /* space available at this offset */
     460                 :            :                 loff_t                  default_offset; /* this is the offset to use when
     461                 :            :                                                          * hot-adding a bitmap.  It should
     462                 :            :                                                          * eventually be settable by sysfs.
     463                 :            :                                                          */
     464                 :            :                 unsigned long           default_space; /* space available at
     465                 :            :                                                         * default offset */
     466                 :            :                 struct mutex            mutex;
     467                 :            :                 unsigned long           chunksize;
     468                 :            :                 unsigned long           daemon_sleep; /* how many jiffies between updates? */
     469                 :            :                 unsigned long           max_write_behind; /* write-behind mode */
     470                 :            :                 int                     external;
     471                 :            :                 int                     nodes; /* Maximum number of nodes in the cluster */
     472                 :            :                 char                    cluster_name[64]; /* Name of the cluster */
     473                 :            :         } bitmap_info;
     474                 :            : 
     475                 :            :         atomic_t                        max_corr_read_errors; /* max read retries */
     476                 :            :         struct list_head                all_mddevs;
     477                 :            : 
     478                 :            :         struct attribute_group          *to_remove;
     479                 :            : 
     480                 :            :         struct bio_set                  bio_set;
     481                 :            :         struct bio_set                  sync_set; /* for sync operations like
     482                 :            :                                                    * metadata and bitmap writes
     483                 :            :                                                    */
     484                 :            : 
     485                 :            :         /* Generic flush handling.
     486                 :            :          * The last to finish preflush schedules a worker to submit
     487                 :            :          * the rest of the request (without the REQ_PREFLUSH flag).
     488                 :            :          */
     489                 :            :         struct bio *flush_bio;
     490                 :            :         atomic_t flush_pending;
     491                 :            :         ktime_t start_flush, last_flush; /* last_flush is when the last completed
     492                 :            :                                           * flush was started.
     493                 :            :                                           */
     494                 :            :         struct work_struct flush_work;
     495                 :            :         struct work_struct event_work;  /* used by dm to report failure event */
     496                 :            :         mempool_t *serial_info_pool;
     497                 :            :         void (*sync_super)(struct mddev *mddev, struct md_rdev *rdev);
     498                 :            :         struct md_cluster_info          *cluster_info;
     499                 :            :         unsigned int                    good_device_nr; /* good device num within cluster raid */
     500                 :            : 
     501                 :            :         bool    has_superblocks:1;
     502                 :            :         bool    fail_last_dev:1;
     503                 :            :         bool    serialize_policy:1;
     504                 :            : };
     505                 :            : 
     506                 :            : enum recovery_flags {
     507                 :            :         /*
     508                 :            :          * If neither SYNC or RESHAPE are set, then it is a recovery.
     509                 :            :          */
     510                 :            :         MD_RECOVERY_RUNNING,    /* a thread is running, or about to be started */
     511                 :            :         MD_RECOVERY_SYNC,       /* actually doing a resync, not a recovery */
     512                 :            :         MD_RECOVERY_RECOVER,    /* doing recovery, or need to try it. */
     513                 :            :         MD_RECOVERY_INTR,       /* resync needs to be aborted for some reason */
     514                 :            :         MD_RECOVERY_DONE,       /* thread is done and is waiting to be reaped */
     515                 :            :         MD_RECOVERY_NEEDED,     /* we might need to start a resync/recover */
     516                 :            :         MD_RECOVERY_REQUESTED,  /* user-space has requested a sync (used with SYNC) */
     517                 :            :         MD_RECOVERY_CHECK,      /* user-space request for check-only, no repair */
     518                 :            :         MD_RECOVERY_RESHAPE,    /* A reshape is happening */
     519                 :            :         MD_RECOVERY_FROZEN,     /* User request to abort, and not restart, any action */
     520                 :            :         MD_RECOVERY_ERROR,      /* sync-action interrupted because io-error */
     521                 :            :         MD_RECOVERY_WAIT,       /* waiting for pers->start() to finish */
     522                 :            :         MD_RESYNCING_REMOTE,    /* remote node is running resync thread */
     523                 :            : };
     524                 :            : 
     525                 :          0 : static inline int __must_check mddev_lock(struct mddev *mddev)
     526                 :            : {
     527                 :          0 :         return mutex_lock_interruptible(&mddev->reconfig_mutex);
     528                 :            : }
     529                 :            : 
     530                 :            : /* Sometimes we need to take the lock in a situation where
     531                 :            :  * failure due to interrupts is not acceptable.
     532                 :            :  */
     533                 :          0 : static inline void mddev_lock_nointr(struct mddev *mddev)
     534                 :            : {
     535                 :          0 :         mutex_lock(&mddev->reconfig_mutex);
     536                 :          0 : }
     537                 :            : 
     538                 :          0 : static inline int mddev_trylock(struct mddev *mddev)
     539                 :            : {
     540                 :          0 :         return mutex_trylock(&mddev->reconfig_mutex);
     541                 :            : }
     542                 :            : extern void mddev_unlock(struct mddev *mddev);
     543                 :            : 
     544                 :            : static inline void md_sync_acct(struct block_device *bdev, unsigned long nr_sectors)
     545                 :            : {
     546                 :            :         atomic_add(nr_sectors, &bdev->bd_contains->bd_disk->sync_io);
     547                 :            : }
     548                 :            : 
     549                 :            : static inline void md_sync_acct_bio(struct bio *bio, unsigned long nr_sectors)
     550                 :            : {
     551                 :            :         atomic_add(nr_sectors, &bio->bi_disk->sync_io);
     552                 :            : }
     553                 :            : 
     554                 :            : struct md_personality
     555                 :            : {
     556                 :            :         char *name;
     557                 :            :         int level;
     558                 :            :         struct list_head list;
     559                 :            :         struct module *owner;
     560                 :            :         bool __must_check (*make_request)(struct mddev *mddev, struct bio *bio);
     561                 :            :         /*
     562                 :            :          * start up works that do NOT require md_thread. tasks that
     563                 :            :          * requires md_thread should go into start()
     564                 :            :          */
     565                 :            :         int (*run)(struct mddev *mddev);
     566                 :            :         /* start up works that require md threads */
     567                 :            :         int (*start)(struct mddev *mddev);
     568                 :            :         void (*free)(struct mddev *mddev, void *priv);
     569                 :            :         void (*status)(struct seq_file *seq, struct mddev *mddev);
     570                 :            :         /* error_handler must set ->faulty and clear ->in_sync
     571                 :            :          * if appropriate, and should abort recovery if needed
     572                 :            :          */
     573                 :            :         void (*error_handler)(struct mddev *mddev, struct md_rdev *rdev);
     574                 :            :         int (*hot_add_disk) (struct mddev *mddev, struct md_rdev *rdev);
     575                 :            :         int (*hot_remove_disk) (struct mddev *mddev, struct md_rdev *rdev);
     576                 :            :         int (*spare_active) (struct mddev *mddev);
     577                 :            :         sector_t (*sync_request)(struct mddev *mddev, sector_t sector_nr, int *skipped);
     578                 :            :         int (*resize) (struct mddev *mddev, sector_t sectors);
     579                 :            :         sector_t (*size) (struct mddev *mddev, sector_t sectors, int raid_disks);
     580                 :            :         int (*check_reshape) (struct mddev *mddev);
     581                 :            :         int (*start_reshape) (struct mddev *mddev);
     582                 :            :         void (*finish_reshape) (struct mddev *mddev);
     583                 :            :         void (*update_reshape_pos) (struct mddev *mddev);
     584                 :            :         /* quiesce suspends or resumes internal processing.
     585                 :            :          * 1 - stop new actions and wait for action io to complete
     586                 :            :          * 0 - return to normal behaviour
     587                 :            :          */
     588                 :            :         void (*quiesce) (struct mddev *mddev, int quiesce);
     589                 :            :         /* takeover is used to transition an array from one
     590                 :            :          * personality to another.  The new personality must be able
     591                 :            :          * to handle the data in the current layout.
     592                 :            :          * e.g. 2drive raid1 -> 2drive raid5
     593                 :            :          *      ndrive raid5 -> degraded n+1drive raid6 with special layout
     594                 :            :          * If the takeover succeeds, a new 'private' structure is returned.
     595                 :            :          * This needs to be installed and then ->run used to activate the
     596                 :            :          * array.
     597                 :            :          */
     598                 :            :         void *(*takeover) (struct mddev *mddev);
     599                 :            :         /* congested implements bdi.congested_fn().
     600                 :            :          * Will not be called while array is 'suspended' */
     601                 :            :         int (*congested)(struct mddev *mddev, int bits);
     602                 :            :         /* Changes the consistency policy of an active array. */
     603                 :            :         int (*change_consistency_policy)(struct mddev *mddev, const char *buf);
     604                 :            : };
     605                 :            : 
     606                 :            : struct md_sysfs_entry {
     607                 :            :         struct attribute attr;
     608                 :            :         ssize_t (*show)(struct mddev *, char *);
     609                 :            :         ssize_t (*store)(struct mddev *, const char *, size_t);
     610                 :            : };
     611                 :            : extern struct attribute_group md_bitmap_group;
     612                 :            : 
     613                 :          3 : static inline struct kernfs_node *sysfs_get_dirent_safe(struct kernfs_node *sd, char *name)
     614                 :            : {
     615   [ -  -  +  -  :          3 :         if (sd)
                   -  - ]
     616                 :          3 :                 return sysfs_get_dirent(sd, name);
     617                 :            :         return sd;
     618                 :            : }
     619                 :          0 : static inline void sysfs_notify_dirent_safe(struct kernfs_node *sd)
     620                 :            : {
     621   [ #  #  #  #  :          0 :         if (sd)
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
             #  #  #  # ]
     622                 :          0 :                 sysfs_notify_dirent(sd);
     623                 :          0 : }
     624                 :            : 
     625                 :          0 : static inline char * mdname (struct mddev * mddev)
     626                 :            : {
     627   [ #  #  #  #  :          0 :         return mddev->gendisk ? mddev->gendisk->disk_name : "mdX";
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
                   #  # ]
     628                 :            : }
     629                 :            : 
     630                 :          0 : static inline int sysfs_link_rdev(struct mddev *mddev, struct md_rdev *rdev)
     631                 :            : {
     632                 :          0 :         char nm[20];
     633   [ #  #  #  # ]:          0 :         if (!test_bit(Replacement, &rdev->flags) &&
     634                 :          0 :             !test_bit(Journal, &rdev->flags) &&
     635         [ #  # ]:          0 :             mddev->kobj.sd) {
     636                 :          0 :                 sprintf(nm, "rd%d", rdev->raid_disk);
     637                 :          0 :                 return sysfs_create_link(&mddev->kobj, &rdev->kobj, nm);
     638                 :            :         } else
     639                 :          0 :                 return 0;
     640                 :            : }
     641                 :            : 
     642                 :          0 : static inline void sysfs_unlink_rdev(struct mddev *mddev, struct md_rdev *rdev)
     643                 :            : {
     644                 :          0 :         char nm[20];
     645   [ #  #  #  # ]:          0 :         if (!test_bit(Replacement, &rdev->flags) &&
     646                 :          0 :             !test_bit(Journal, &rdev->flags) &&
     647         [ #  # ]:          0 :             mddev->kobj.sd) {
     648                 :          0 :                 sprintf(nm, "rd%d", rdev->raid_disk);
     649                 :          0 :                 sysfs_remove_link(&mddev->kobj, nm);
     650                 :            :         }
     651                 :          0 : }
     652                 :            : 
     653                 :            : /*
     654                 :            :  * iterates through some rdev ringlist. It's safe to remove the
     655                 :            :  * current 'rdev'. Dont touch 'tmp' though.
     656                 :            :  */
     657                 :            : #define rdev_for_each_list(rdev, tmp, head)                             \
     658                 :            :         list_for_each_entry_safe(rdev, tmp, head, same_set)
     659                 :            : 
     660                 :            : /*
     661                 :            :  * iterates through the 'same array disks' ringlist
     662                 :            :  */
     663                 :            : #define rdev_for_each(rdev, mddev)                              \
     664                 :            :         list_for_each_entry(rdev, &((mddev)->disks), same_set)
     665                 :            : 
     666                 :            : #define rdev_for_each_safe(rdev, tmp, mddev)                            \
     667                 :            :         list_for_each_entry_safe(rdev, tmp, &((mddev)->disks), same_set)
     668                 :            : 
     669                 :            : #define rdev_for_each_rcu(rdev, mddev)                          \
     670                 :            :         list_for_each_entry_rcu(rdev, &((mddev)->disks), same_set)
     671                 :            : 
     672                 :            : struct md_thread {
     673                 :            :         void                    (*run) (struct md_thread *thread);
     674                 :            :         struct mddev            *mddev;
     675                 :            :         wait_queue_head_t       wqueue;
     676                 :            :         unsigned long           flags;
     677                 :            :         struct task_struct      *tsk;
     678                 :            :         unsigned long           timeout;
     679                 :            :         void                    *private;
     680                 :            : };
     681                 :            : 
     682                 :            : #define THREAD_WAKEUP  0
     683                 :            : 
     684                 :            : static inline void safe_put_page(struct page *p)
     685                 :            : {
     686                 :            :         if (p) put_page(p);
     687                 :            : }
     688                 :            : 
     689                 :            : extern int register_md_personality(struct md_personality *p);
     690                 :            : extern int unregister_md_personality(struct md_personality *p);
     691                 :            : extern int register_md_cluster_operations(struct md_cluster_operations *ops,
     692                 :            :                 struct module *module);
     693                 :            : extern int unregister_md_cluster_operations(void);
     694                 :            : extern int md_setup_cluster(struct mddev *mddev, int nodes);
     695                 :            : extern void md_cluster_stop(struct mddev *mddev);
     696                 :            : extern struct md_thread *md_register_thread(
     697                 :            :         void (*run)(struct md_thread *thread),
     698                 :            :         struct mddev *mddev,
     699                 :            :         const char *name);
     700                 :            : extern void md_unregister_thread(struct md_thread **threadp);
     701                 :            : extern void md_wakeup_thread(struct md_thread *thread);
     702                 :            : extern void md_check_recovery(struct mddev *mddev);
     703                 :            : extern void md_reap_sync_thread(struct mddev *mddev);
     704                 :            : extern int mddev_init_writes_pending(struct mddev *mddev);
     705                 :            : extern bool md_write_start(struct mddev *mddev, struct bio *bi);
     706                 :            : extern void md_write_inc(struct mddev *mddev, struct bio *bi);
     707                 :            : extern void md_write_end(struct mddev *mddev);
     708                 :            : extern void md_done_sync(struct mddev *mddev, int blocks, int ok);
     709                 :            : extern void md_error(struct mddev *mddev, struct md_rdev *rdev);
     710                 :            : extern void md_finish_reshape(struct mddev *mddev);
     711                 :            : 
     712                 :            : extern int mddev_congested(struct mddev *mddev, int bits);
     713                 :            : extern bool __must_check md_flush_request(struct mddev *mddev, struct bio *bio);
     714                 :            : extern void md_super_write(struct mddev *mddev, struct md_rdev *rdev,
     715                 :            :                            sector_t sector, int size, struct page *page);
     716                 :            : extern int md_super_wait(struct mddev *mddev);
     717                 :            : extern int sync_page_io(struct md_rdev *rdev, sector_t sector, int size,
     718                 :            :                         struct page *page, int op, int op_flags,
     719                 :            :                         bool metadata_op);
     720                 :            : extern void md_do_sync(struct md_thread *thread);
     721                 :            : extern void md_new_event(struct mddev *mddev);
     722                 :            : extern void md_allow_write(struct mddev *mddev);
     723                 :            : extern void md_wait_for_blocked_rdev(struct md_rdev *rdev, struct mddev *mddev);
     724                 :            : extern void md_set_array_sectors(struct mddev *mddev, sector_t array_sectors);
     725                 :            : extern int md_check_no_bitmap(struct mddev *mddev);
     726                 :            : extern int md_integrity_register(struct mddev *mddev);
     727                 :            : extern int md_integrity_add_rdev(struct md_rdev *rdev, struct mddev *mddev);
     728                 :            : extern int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale);
     729                 :            : 
     730                 :            : extern void mddev_init(struct mddev *mddev);
     731                 :            : extern int md_run(struct mddev *mddev);
     732                 :            : extern int md_start(struct mddev *mddev);
     733                 :            : extern void md_stop(struct mddev *mddev);
     734                 :            : extern void md_stop_writes(struct mddev *mddev);
     735                 :            : extern int md_rdev_init(struct md_rdev *rdev);
     736                 :            : extern void md_rdev_clear(struct md_rdev *rdev);
     737                 :            : 
     738                 :            : extern void md_handle_request(struct mddev *mddev, struct bio *bio);
     739                 :            : extern void mddev_suspend(struct mddev *mddev);
     740                 :            : extern void mddev_resume(struct mddev *mddev);
     741                 :            : extern struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs,
     742                 :            :                                    struct mddev *mddev);
     743                 :            : 
     744                 :            : extern void md_reload_sb(struct mddev *mddev, int raid_disk);
     745                 :            : extern void md_update_sb(struct mddev *mddev, int force);
     746                 :            : extern void md_kick_rdev_from_array(struct md_rdev * rdev);
     747                 :            : extern void mddev_create_serial_pool(struct mddev *mddev, struct md_rdev *rdev,
     748                 :            :                                      bool is_suspend);
     749                 :            : extern void mddev_destroy_serial_pool(struct mddev *mddev, struct md_rdev *rdev,
     750                 :            :                                       bool is_suspend);
     751                 :            : struct md_rdev *md_find_rdev_nr_rcu(struct mddev *mddev, int nr);
     752                 :            : struct md_rdev *md_find_rdev_rcu(struct mddev *mddev, dev_t dev);
     753                 :            : 
     754                 :            : static inline bool is_mddev_broken(struct md_rdev *rdev, const char *md_type)
     755                 :            : {
     756                 :            :         int flags = rdev->bdev->bd_disk->flags;
     757                 :            : 
     758                 :            :         if (!(flags & GENHD_FL_UP)) {
     759                 :            :                 if (!test_and_set_bit(MD_BROKEN, &rdev->mddev->flags))
     760                 :            :                         pr_warn("md: %s: %s array has a missing/failed member\n",
     761                 :            :                                 mdname(rdev->mddev), md_type);
     762                 :            :                 return true;
     763                 :            :         }
     764                 :            :         return false;
     765                 :            : }
     766                 :            : 
     767                 :          0 : static inline void rdev_dec_pending(struct md_rdev *rdev, struct mddev *mddev)
     768                 :            : {
     769                 :          0 :         int faulty = test_bit(Faulty, &rdev->flags);
     770   [ #  #  #  # ]:          0 :         if (atomic_dec_and_test(&rdev->nr_pending) && faulty) {
     771                 :          0 :                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
     772                 :          0 :                 md_wakeup_thread(mddev->thread);
     773                 :            :         }
     774                 :          0 : }
     775                 :            : 
     776                 :            : extern struct md_cluster_operations *md_cluster_ops;
     777                 :          0 : static inline int mddev_is_clustered(struct mddev *mddev)
     778                 :            : {
     779   [ #  #  #  #  :          0 :         return mddev->cluster_info && mddev->bitmap_info.nodes > 1;
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
          #  #  #  #  #  
                   #  # ]
     780                 :            : }
     781                 :            : 
     782                 :            : /* clear unsupported mddev_flags */
     783                 :            : static inline void mddev_clear_unsupported_flags(struct mddev *mddev,
     784                 :            :         unsigned long unsupported_flags)
     785                 :            : {
     786                 :            :         mddev->flags &= ~unsupported_flags;
     787                 :            : }
     788                 :            : 
     789                 :            : static inline void mddev_check_writesame(struct mddev *mddev, struct bio *bio)
     790                 :            : {
     791                 :            :         if (bio_op(bio) == REQ_OP_WRITE_SAME &&
     792                 :            :             !bio->bi_disk->queue->limits.max_write_same_sectors)
     793                 :            :                 mddev->queue->limits.max_write_same_sectors = 0;
     794                 :            : }
     795                 :            : 
     796                 :            : static inline void mddev_check_write_zeroes(struct mddev *mddev, struct bio *bio)
     797                 :            : {
     798                 :            :         if (bio_op(bio) == REQ_OP_WRITE_ZEROES &&
     799                 :            :             !bio->bi_disk->queue->limits.max_write_zeroes_sectors)
     800                 :            :                 mddev->queue->limits.max_write_zeroes_sectors = 0;
     801                 :            : }
     802                 :            : #endif /* _MD_MD_H */

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