git.sesse.net Git - bcachefs-tools-debian/blob - libbcachefs/journal_types.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _BCACHEFS_JOURNAL_TYPES_H
   3 #define _BCACHEFS_JOURNAL_TYPES_H
   4
   5 #include <linux/cache.h>
   6 #include <linux/workqueue.h>
   7
   8 #include "alloc_types.h"
   9 #include "super_types.h"
  10 #include "fifo.h"
  11
  12 #define JOURNAL_BUF_BITS        2
  13 #define JOURNAL_BUF_NR          (1U << JOURNAL_BUF_BITS)
  14 #define JOURNAL_BUF_MASK        (JOURNAL_BUF_NR - 1)
  15
  16 /*
  17  * We put JOURNAL_BUF_NR of these in struct journal; we used them for writes to
  18  * the journal that are being staged or in flight.
  19  */
  20 struct journal_buf {
  21         struct jset             *data;
  22
  23         __BKEY_PADDED(key, BCH_REPLICAS_MAX);
  24         struct bch_devs_list    devs_written;
  25
  26         struct closure_waitlist wait;
  27         u64                     last_seq;       /* copy of data->last_seq */
  28         long                    expires;
  29         u64                     flush_time;
  30
  31         unsigned                buf_size;       /* size in bytes of @data */
  32         unsigned                sectors;        /* maximum size for current entry */
  33         unsigned                disk_sectors;   /* maximum size entry could have been, if
  34                                                    buf_size was bigger */
  35         unsigned                u64s_reserved;
  36         bool                    noflush;        /* write has already been kicked off, and was noflush */
  37         bool                    must_flush;     /* something wants a flush */
  38         bool                    separate_flush;
  39 };
  40
  41 /*
  42  * Something that makes a journal entry dirty - i.e. a btree node that has to be
  43  * flushed:
  44  */
  45
  46 enum journal_pin_type {
  47         JOURNAL_PIN_btree,
  48         JOURNAL_PIN_key_cache,
  49         JOURNAL_PIN_other,
  50         JOURNAL_PIN_NR,
  51 };
  52
  53 struct journal_entry_pin_list {
  54         struct list_head                list[JOURNAL_PIN_NR];
  55         struct list_head                flushed;
  56         atomic_t                        count;
  57         struct bch_devs_list            devs;
  58 };
  59
  60 struct journal;
  61 struct journal_entry_pin;
  62 typedef int (*journal_pin_flush_fn)(struct journal *j,
  63                                 struct journal_entry_pin *, u64);
  64
  65 struct journal_entry_pin {
  66         struct list_head                list;
  67         journal_pin_flush_fn            flush;
  68         u64                             seq;
  69 };
  70
  71 struct journal_res {
  72         bool                    ref;
  73         u8                      idx;
  74         u16                     u64s;
  75         u32                     offset;
  76         u64                     seq;
  77 };
  78
  79 union journal_res_state {
  80         struct {
  81                 atomic64_t      counter;
  82         };
  83
  84         struct {
  85                 u64             v;
  86         };
  87
  88         struct {
  89                 u64             cur_entry_offset:20,
  90                                 idx:2,
  91                                 unwritten_idx:2,
  92                                 buf0_count:10,
  93                                 buf1_count:10,
  94                                 buf2_count:10,
  95                                 buf3_count:10;
  96         };
  97 };
  98
  99 /* bytes: */
 100 #define JOURNAL_ENTRY_SIZE_MIN          (64U << 10) /* 64k */
 101 #define JOURNAL_ENTRY_SIZE_MAX          (4U  << 20) /* 4M */
 102
 103 /*
 104  * We stash some journal state as sentinal values in cur_entry_offset:
 105  * note - cur_entry_offset is in units of u64s
 106  */
 107 #define JOURNAL_ENTRY_OFFSET_MAX        ((1U << 20) - 1)
 108
 109 #define JOURNAL_ENTRY_CLOSED_VAL        (JOURNAL_ENTRY_OFFSET_MAX - 1)
 110 #define JOURNAL_ENTRY_ERROR_VAL         (JOURNAL_ENTRY_OFFSET_MAX)
 111
 112 struct journal_space {
 113         /* Units of 512 bytes sectors: */
 114         unsigned        next_entry; /* How big the next journal entry can be */
 115         unsigned        total;
 116 };
 117
 118 enum journal_space_from {
 119         journal_space_discarded,
 120         journal_space_clean_ondisk,
 121         journal_space_clean,
 122         journal_space_total,
 123         journal_space_nr,
 124 };
 125
 126 enum journal_flags {
 127         JOURNAL_REPLAY_DONE,
 128         JOURNAL_STARTED,
 129         JOURNAL_MAY_SKIP_FLUSH,
 130         JOURNAL_NEED_FLUSH_WRITE,
 131 };
 132
 133 /* Reasons we may fail to get a journal reservation: */
 134 #define JOURNAL_ERRORS()                \
 135         x(ok)                           \
 136         x(blocked)                      \
 137         x(max_in_flight)                \
 138         x(journal_full)                 \
 139         x(journal_pin_full)             \
 140         x(journal_stuck)                \
 141         x(insufficient_devices)
 142
 143 enum journal_errors {
 144 #define x(n)    JOURNAL_ERR_##n,
 145         JOURNAL_ERRORS()
 146 #undef x
 147 };
 148
 149 typedef DARRAY(u64)             darray_u64;
 150
 151 /* Embedded in struct bch_fs */
 152 struct journal {
 153         /* Fastpath stuff up front: */
 154         struct {
 155
 156         union journal_res_state reservations;
 157         enum bch_watermark      watermark;
 158
 159         } __aligned(SMP_CACHE_BYTES);
 160
 161         unsigned long           flags;
 162
 163         /* Max size of current journal entry */
 164         unsigned                cur_entry_u64s;
 165         unsigned                cur_entry_sectors;
 166
 167         /* Reserved space in journal entry to be used just prior to write */
 168         unsigned                entry_u64s_reserved;
 169
 170
 171         /*
 172          * 0, or -ENOSPC if waiting on journal reclaim, or -EROFS if
 173          * insufficient devices:
 174          */
 175         enum journal_errors     cur_entry_error;
 176
 177         unsigned                buf_size_want;
 178         /*
 179          * We may queue up some things to be journalled (log messages) before
 180          * the journal has actually started - stash them here:
 181          */
 182         darray_u64              early_journal_entries;
 183
 184         /*
 185          * Two journal entries -- one is currently open for new entries, the
 186          * other is possibly being written out.
 187          */
 188         struct journal_buf      buf[JOURNAL_BUF_NR];
 189
 190         spinlock_t              lock;
 191
 192         /* if nonzero, we may not open a new journal entry: */
 193         unsigned                blocked;
 194
 195         /* Used when waiting because the journal was full */
 196         wait_queue_head_t       wait;
 197         struct closure_waitlist async_wait;
 198
 199         struct closure          io;
 200         struct delayed_work     write_work;
 201
 202         /* Sequence number of most recent journal entry (last entry in @pin) */
 203         atomic64_t              seq;
 204
 205         /* seq, last_seq from the most recent journal entry successfully written */
 206         u64                     seq_ondisk;
 207         u64                     flushed_seq_ondisk;
 208         u64                     last_seq_ondisk;
 209         u64                     err_seq;
 210         u64                     last_empty_seq;
 211
 212         /*
 213          * FIFO of journal entries whose btree updates have not yet been
 214          * written out.
 215          *
 216          * Each entry is a reference count. The position in the FIFO is the
 217          * entry's sequence number relative to @seq.
 218          *
 219          * The journal entry itself holds a reference count, put when the
 220          * journal entry is written out. Each btree node modified by the journal
 221          * entry also holds a reference count, put when the btree node is
 222          * written.
 223          *
 224          * When a reference count reaches zero, the journal entry is no longer
 225          * needed. When all journal entries in the oldest journal bucket are no
 226          * longer needed, the bucket can be discarded and reused.
 227          */
 228         struct {
 229                 u64 front, back, size, mask;
 230                 struct journal_entry_pin_list *data;
 231         }                       pin;
 232
 233         struct journal_space    space[journal_space_nr];
 234
 235         u64                     replay_journal_seq;
 236         u64                     replay_journal_seq_end;
 237
 238         struct write_point      wp;
 239         spinlock_t              err_lock;
 240
 241         struct mutex            reclaim_lock;
 242         /*
 243          * Used for waiting until journal reclaim has freed up space in the
 244          * journal:
 245          */
 246         wait_queue_head_t       reclaim_wait;
 247         struct task_struct      *reclaim_thread;
 248         bool                    reclaim_kicked;
 249         unsigned long           next_reclaim;
 250         u64                     nr_direct_reclaim;
 251         u64                     nr_background_reclaim;
 252
 253         unsigned long           last_flushed;
 254         struct journal_entry_pin *flush_in_progress;
 255         bool                    flush_in_progress_dropped;
 256         wait_queue_head_t       pin_flush_wait;
 257
 258         /* protects advancing ja->discard_idx: */
 259         struct mutex            discard_lock;
 260         bool                    can_discard;
 261
 262         unsigned long           last_flush_write;
 263
 264         u64                     write_start_time;
 265
 266         u64                     nr_flush_writes;
 267         u64                     nr_noflush_writes;
 268         u64                     entry_bytes_written;
 269
 270         u64                     low_on_space_start;
 271         u64                     low_on_pin_start;
 272         u64                     max_in_flight_start;
 273
 274         struct bch2_time_stats  *flush_write_time;
 275         struct bch2_time_stats  *noflush_write_time;
 276         struct bch2_time_stats  *flush_seq_time;
 277
 278 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 279         struct lockdep_map      res_map;
 280 #endif
 281 } __aligned(SMP_CACHE_BYTES);
 282
 283 /*
 284  * Embedded in struct bch_dev. First three fields refer to the array of journal
 285  * buckets, in bch_sb.
 286  */
 287 struct journal_device {
 288         /*
 289          * For each journal bucket, contains the max sequence number of the
 290          * journal writes it contains - so we know when a bucket can be reused.
 291          */
 292         u64                     *bucket_seq;
 293
 294         unsigned                sectors_free;
 295
 296         /*
 297          * discard_idx <= dirty_idx_ondisk <= dirty_idx <= cur_idx:
 298          */
 299         unsigned                discard_idx;            /* Next bucket to discard */
 300         unsigned                dirty_idx_ondisk;
 301         unsigned                dirty_idx;
 302         unsigned                cur_idx;                /* Journal bucket we're currently writing to */
 303         unsigned                nr;
 304
 305         u64                     *buckets;
 306
 307         /* Bio for journal reads/writes to this device */
 308         struct bio              *bio;
 309
 310         /* for bch_journal_read_device */
 311         struct closure          read;
 312 };
 313
 314 /*
 315  * journal_entry_res - reserve space in every journal entry:
 316  */
 317 struct journal_entry_res {
 318         unsigned                u64s;
 319 };
 320
 321 #endif /* _BCACHEFS_JOURNAL_TYPES_H */