git.sesse.net Git - bcachefs-tools-debian/blob - c_src/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         bool                    need_flush_to_write_buffer;
  40 };
  41
  42 /*
  43  * Something that makes a journal entry dirty - i.e. a btree node that has to be
  44  * flushed:
  45  */
  46
  47 enum journal_pin_type {
  48         JOURNAL_PIN_btree,
  49         JOURNAL_PIN_key_cache,
  50         JOURNAL_PIN_other,
  51         JOURNAL_PIN_NR,
  52 };
  53
  54 struct journal_entry_pin_list {
  55         struct list_head                list[JOURNAL_PIN_NR];
  56         struct list_head                flushed;
  57         atomic_t                        count;
  58         struct bch_devs_list            devs;
  59 };
  60
  61 struct journal;
  62 struct journal_entry_pin;
  63 typedef int (*journal_pin_flush_fn)(struct journal *j,
  64                                 struct journal_entry_pin *, u64);
  65
  66 struct journal_entry_pin {
  67         struct list_head                list;
  68         journal_pin_flush_fn            flush;
  69         u64                             seq;
  70 };
  71
  72 struct journal_res {
  73         bool                    ref;
  74         u8                      idx;
  75         u16                     u64s;
  76         u32                     offset;
  77         u64                     seq;
  78 };
  79
  80 union journal_res_state {
  81         struct {
  82                 atomic64_t      counter;
  83         };
  84
  85         struct {
  86                 u64             v;
  87         };
  88
  89         struct {
  90                 u64             cur_entry_offset:20,
  91                                 idx:2,
  92                                 unwritten_idx:2,
  93                                 buf0_count:10,
  94                                 buf1_count:10,
  95                                 buf2_count:10,
  96                                 buf3_count:10;
  97         };
  98 };
  99
 100 /* bytes: */
 101 #define JOURNAL_ENTRY_SIZE_MIN          (64U << 10) /* 64k */
 102 #define JOURNAL_ENTRY_SIZE_MAX          (4U  << 20) /* 4M */
 103
 104 /*
 105  * We stash some journal state as sentinal values in cur_entry_offset:
 106  * note - cur_entry_offset is in units of u64s
 107  */
 108 #define JOURNAL_ENTRY_OFFSET_MAX        ((1U << 20) - 1)
 109
 110 #define JOURNAL_ENTRY_CLOSED_VAL        (JOURNAL_ENTRY_OFFSET_MAX - 1)
 111 #define JOURNAL_ENTRY_ERROR_VAL         (JOURNAL_ENTRY_OFFSET_MAX)
 112
 113 struct journal_space {
 114         /* Units of 512 bytes sectors: */
 115         unsigned        next_entry; /* How big the next journal entry can be */
 116         unsigned        total;
 117 };
 118
 119 enum journal_space_from {
 120         journal_space_discarded,
 121         journal_space_clean_ondisk,
 122         journal_space_clean,
 123         journal_space_total,
 124         journal_space_nr,
 125 };
 126
 127 enum journal_flags {
 128         JOURNAL_REPLAY_DONE,
 129         JOURNAL_STARTED,
 130         JOURNAL_MAY_SKIP_FLUSH,
 131         JOURNAL_NEED_FLUSH_WRITE,
 132 };
 133
 134 /* Reasons we may fail to get a journal reservation: */
 135 #define JOURNAL_ERRORS()                \
 136         x(ok)                           \
 137         x(blocked)                      \
 138         x(max_in_flight)                \
 139         x(journal_full)                 \
 140         x(journal_pin_full)             \
 141         x(journal_stuck)                \
 142         x(insufficient_devices)
 143
 144 enum journal_errors {
 145 #define x(n)    JOURNAL_ERR_##n,
 146         JOURNAL_ERRORS()
 147 #undef x
 148 };
 149
 150 typedef DARRAY(u64)             darray_u64;
 151
 152 /* Embedded in struct bch_fs */
 153 struct journal {
 154         /* Fastpath stuff up front: */
 155         struct {
 156
 157         union journal_res_state reservations;
 158         enum bch_watermark      watermark;
 159
 160         } __aligned(SMP_CACHE_BYTES);
 161
 162         unsigned long           flags;
 163
 164         /* Max size of current journal entry */
 165         unsigned                cur_entry_u64s;
 166         unsigned                cur_entry_sectors;
 167
 168         /* Reserved space in journal entry to be used just prior to write */
 169         unsigned                entry_u64s_reserved;
 170
 171
 172         /*
 173          * 0, or -ENOSPC if waiting on journal reclaim, or -EROFS if
 174          * insufficient devices:
 175          */
 176         enum journal_errors     cur_entry_error;
 177
 178         unsigned                buf_size_want;
 179         /*
 180          * We may queue up some things to be journalled (log messages) before
 181          * the journal has actually started - stash them here:
 182          */
 183         darray_u64              early_journal_entries;
 184
 185         /*
 186          * Protects journal_buf->data, when accessing without a jorunal
 187          * reservation: for synchronization between the btree write buffer code
 188          * and the journal write path:
 189          */
 190         struct mutex            buf_lock;
 191         /*
 192          * Two journal entries -- one is currently open for new entries, the
 193          * other is possibly being written out.
 194          */
 195         struct journal_buf      buf[JOURNAL_BUF_NR];
 196
 197         spinlock_t              lock;
 198
 199         /* if nonzero, we may not open a new journal entry: */
 200         unsigned                blocked;
 201
 202         /* Used when waiting because the journal was full */
 203         wait_queue_head_t       wait;
 204         struct closure_waitlist async_wait;
 205
 206         struct closure          io;
 207         struct delayed_work     write_work;
 208
 209         /* Sequence number of most recent journal entry (last entry in @pin) */
 210         atomic64_t              seq;
 211
 212         /* seq, last_seq from the most recent journal entry successfully written */
 213         u64                     seq_ondisk;
 214         u64                     flushed_seq_ondisk;
 215         u64                     last_seq_ondisk;
 216         u64                     err_seq;
 217         u64                     last_empty_seq;
 218
 219         /*
 220          * FIFO of journal entries whose btree updates have not yet been
 221          * written out.
 222          *
 223          * Each entry is a reference count. The position in the FIFO is the
 224          * entry's sequence number relative to @seq.
 225          *
 226          * The journal entry itself holds a reference count, put when the
 227          * journal entry is written out. Each btree node modified by the journal
 228          * entry also holds a reference count, put when the btree node is
 229          * written.
 230          *
 231          * When a reference count reaches zero, the journal entry is no longer
 232          * needed. When all journal entries in the oldest journal bucket are no
 233          * longer needed, the bucket can be discarded and reused.
 234          */
 235         struct {
 236                 u64 front, back, size, mask;
 237                 struct journal_entry_pin_list *data;
 238         }                       pin;
 239
 240         struct journal_space    space[journal_space_nr];
 241
 242         u64                     replay_journal_seq;
 243         u64                     replay_journal_seq_end;
 244
 245         struct write_point      wp;
 246         spinlock_t              err_lock;
 247
 248         struct mutex            reclaim_lock;
 249         /*
 250          * Used for waiting until journal reclaim has freed up space in the
 251          * journal:
 252          */
 253         wait_queue_head_t       reclaim_wait;
 254         struct task_struct      *reclaim_thread;
 255         bool                    reclaim_kicked;
 256         unsigned long           next_reclaim;
 257         u64                     nr_direct_reclaim;
 258         u64                     nr_background_reclaim;
 259
 260         unsigned long           last_flushed;
 261         struct journal_entry_pin *flush_in_progress;
 262         bool                    flush_in_progress_dropped;
 263         wait_queue_head_t       pin_flush_wait;
 264
 265         /* protects advancing ja->discard_idx: */
 266         struct mutex            discard_lock;
 267         bool                    can_discard;
 268
 269         unsigned long           last_flush_write;
 270
 271         u64                     write_start_time;
 272
 273         u64                     nr_flush_writes;
 274         u64                     nr_noflush_writes;
 275         u64                     entry_bytes_written;
 276
 277         u64                     low_on_space_start;
 278         u64                     low_on_pin_start;
 279         u64                     max_in_flight_start;
 280         u64                     write_buffer_full_start;
 281
 282         struct bch2_time_stats  *flush_write_time;
 283         struct bch2_time_stats  *noflush_write_time;
 284         struct bch2_time_stats  *flush_seq_time;
 285
 286 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 287         struct lockdep_map      res_map;
 288 #endif
 289 } __aligned(SMP_CACHE_BYTES);
 290
 291 /*
 292  * Embedded in struct bch_dev. First three fields refer to the array of journal
 293  * buckets, in bch_sb.
 294  */
 295 struct journal_device {
 296         /*
 297          * For each journal bucket, contains the max sequence number of the
 298          * journal writes it contains - so we know when a bucket can be reused.
 299          */
 300         u64                     *bucket_seq;
 301
 302         unsigned                sectors_free;
 303
 304         /*
 305          * discard_idx <= dirty_idx_ondisk <= dirty_idx <= cur_idx:
 306          */
 307         unsigned                discard_idx;            /* Next bucket to discard */
 308         unsigned                dirty_idx_ondisk;
 309         unsigned                dirty_idx;
 310         unsigned                cur_idx;                /* Journal bucket we're currently writing to */
 311         unsigned                nr;
 312
 313         u64                     *buckets;
 314
 315         /* Bio for journal reads/writes to this device */
 316         struct bio              *bio;
 317
 318         /* for bch_journal_read_device */
 319         struct closure          read;
 320 };
 321
 322 /*
 323  * journal_entry_res - reserve space in every journal entry:
 324  */
 325 struct journal_entry_res {
 326         unsigned                u64s;
 327 };
 328
 329 #endif /* _BCACHEFS_JOURNAL_TYPES_H */