fs/bcachefs/sb-downgrade.c

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 /*
   4  * Superblock section that contains a list of recovery passes to run when
   5  * downgrading past a given version
   6  */
   7
   8 #include "bcachefs.h"
   9 #include "darray.h"
  10 #include "recovery.h"
  11 #include "sb-downgrade.h"
  12 #include "sb-errors.h"
  13 #include "super-io.h"
  14
  15 /*
  16  * Downgrade table:
  17  * When dowgrading past certain versions, we need to run certain recovery passes
  18  * and fix certain errors:
  19  *
  20  * x(version, recovery_passes, errors...)
  21  */
  22
  23 #define DOWNGRADE_TABLE()
  24
  25 struct downgrade_entry {
  26         u64             recovery_passes;
  27         u16             version;
  28         u16             nr_errors;
  29         const u16       *errors;
  30 };
  31
  32 #define x(ver, passes, ...) static const u16 ver_##errors[] = { __VA_ARGS__ };
  33 DOWNGRADE_TABLE()
  34 #undef x
  35
  36 static const struct downgrade_entry downgrade_table[] = {
  37 #define x(ver, passes, ...) {                                   \
  38         .recovery_passes        = passes,                       \
  39         .version                = bcachefs_metadata_version_##ver,\
  40         .nr_errors              = ARRAY_SIZE(ver_##errors),     \
  41         .errors                 = ver_##errors,                 \
  42 },
  43 DOWNGRADE_TABLE()
  44 #undef x
  45 };
  46
  47 static inline const struct bch_sb_field_downgrade_entry *
  48 downgrade_entry_next_c(const struct bch_sb_field_downgrade_entry *e)
  49 {
  50         return (void *) &e->errors[le16_to_cpu(e->nr_errors)];
  51 }
  52
  53 #define for_each_downgrade_entry(_d, _i)                                                \
  54         for (const struct bch_sb_field_downgrade_entry *_i = (_d)->entries;             \
  55              (void *) _i        < vstruct_end(&(_d)->field) &&                          \
  56              (void *) &_i->errors[0] < vstruct_end(&(_d)->field);                       \
  57              _i = downgrade_entry_next_c(_i))
  58
  59 static int bch2_sb_downgrade_validate(struct bch_sb *sb, struct bch_sb_field *f,
  60                                       struct printbuf *err)
  61 {
  62         struct bch_sb_field_downgrade *e = field_to_type(f, downgrade);
  63
  64         for_each_downgrade_entry(e, i) {
  65                 if (BCH_VERSION_MAJOR(le16_to_cpu(i->version)) !=
  66                     BCH_VERSION_MAJOR(le16_to_cpu(sb->version))) {
  67                         prt_printf(err, "downgrade entry with mismatched major version (%u != %u)",
  68                                    BCH_VERSION_MAJOR(le16_to_cpu(i->version)),
  69                                    BCH_VERSION_MAJOR(le16_to_cpu(sb->version)));
  70                         return -BCH_ERR_invalid_sb_downgrade;
  71                 }
  72         }
  73
  74         return 0;
  75 }
  76
  77 static void bch2_sb_downgrade_to_text(struct printbuf *out, struct bch_sb *sb,
  78                                       struct bch_sb_field *f)
  79 {
  80         struct bch_sb_field_downgrade *e = field_to_type(f, downgrade);
  81
  82         if (out->nr_tabstops <= 1)
  83                 printbuf_tabstop_push(out, 16);
  84
  85         for_each_downgrade_entry(e, i) {
  86                 prt_str(out, "version:");
  87                 prt_tab(out);
  88                 bch2_version_to_text(out, le16_to_cpu(i->version));
  89                 prt_newline(out);
  90
  91                 prt_str(out, "recovery passes:");
  92                 prt_tab(out);
  93                 prt_bitflags(out, bch2_recovery_passes,
  94                              bch2_recovery_passes_from_stable(le64_to_cpu(i->recovery_passes[0])));
  95                 prt_newline(out);
  96
  97                 prt_str(out, "errors:");
  98                 prt_tab(out);
  99                 bool first = true;
 100                 for (unsigned j = 0; j < le16_to_cpu(i->nr_errors); j++) {
 101                         if (!first)
 102                                 prt_char(out, ',');
 103                         first = false;
 104                         unsigned e = le16_to_cpu(i->errors[j]);
 105                         prt_str(out, e < BCH_SB_ERR_MAX ? bch2_sb_error_strs[e] : "(unknown)");
 106                 }
 107                 prt_newline(out);
 108         }
 109 }
 110
 111 const struct bch_sb_field_ops bch_sb_field_ops_downgrade = {
 112         .validate       = bch2_sb_downgrade_validate,
 113         .to_text        = bch2_sb_downgrade_to_text,
 114 };
 115
 116 int bch2_sb_downgrade_update(struct bch_fs *c)
 117 {
 118         darray_char table = {};
 119         int ret = 0;
 120
 121         for (const struct downgrade_entry *src = downgrade_table;
 122              src < downgrade_table + ARRAY_SIZE(downgrade_table);
 123              src++) {
 124                 if (BCH_VERSION_MAJOR(src->version) != BCH_VERSION_MAJOR(le16_to_cpu(c->disk_sb.sb->version)))
 125                         continue;
 126
 127                 struct bch_sb_field_downgrade_entry *dst;
 128                 unsigned bytes = sizeof(*dst) + sizeof(dst->errors[0]) * src->nr_errors;
 129
 130                 ret = darray_make_room(&table, bytes);
 131                 if (ret)
 132                         goto out;
 133
 134                 dst = (void *) &darray_top(table);
 135                 dst->version = cpu_to_le16(src->version);
 136                 dst->recovery_passes[0] = cpu_to_le64(src->recovery_passes);
 137                 dst->recovery_passes[1] = 0;
 138                 dst->nr_errors          = cpu_to_le16(src->nr_errors);
 139                 for (unsigned i = 0; i < src->nr_errors; i++)
 140                         dst->errors[i] = cpu_to_le16(src->errors[i]);
 141
 142                 table.nr += bytes;
 143         }
 144
 145         struct bch_sb_field_downgrade *d = bch2_sb_field_get(c->disk_sb.sb, downgrade);
 146
 147         unsigned sb_u64s = DIV_ROUND_UP(sizeof(*d) + table.nr, sizeof(u64));
 148
 149         if (d && le32_to_cpu(d->field.u64s) > sb_u64s)
 150                 goto out;
 151
 152         d = bch2_sb_field_resize(&c->disk_sb, downgrade, sb_u64s);
 153         if (!d) {
 154                 ret = -BCH_ERR_ENOSPC_sb_downgrade;
 155                 goto out;
 156         }
 157
 158         memcpy(d->entries, table.data, table.nr);
 159         memset_u64s_tail(d->entries, 0, table.nr);
 160 out:
 161         darray_exit(&table);
 162         return ret;
 163 }
 164
 165 void bch2_sb_set_downgrade(struct bch_fs *c, unsigned new_minor, unsigned old_minor)
 166 {
 167         struct bch_sb_field_downgrade *d = bch2_sb_field_get(c->disk_sb.sb, downgrade);
 168         if (!d)
 169                 return;
 170
 171         struct bch_sb_field_ext *ext = bch2_sb_field_get(c->disk_sb.sb, ext);
 172
 173         for_each_downgrade_entry(d, i) {
 174                 unsigned minor = BCH_VERSION_MINOR(le16_to_cpu(i->version));
 175                 if (new_minor < minor && minor <= old_minor) {
 176                         ext->recovery_passes_required[0] |= i->recovery_passes[0];
 177                         ext->recovery_passes_required[1] |= i->recovery_passes[1];
 178
 179                         for (unsigned j = 0; j < le16_to_cpu(i->nr_errors); j++) {
 180                                 unsigned e = le16_to_cpu(i->errors[j]);
 181                                 if (e < BCH_SB_ERR_MAX)
 182                                         __set_bit(e, c->sb.errors_silent);
 183                                 if (e < sizeof(ext->errors_silent) * 8)
 184                                         ext->errors_silent[e / 64] |= cpu_to_le64(BIT_ULL(e % 64));
 185                         }
 186                 }
 187         }
 188 }