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mdbx: lookup suitable txnid for rollback to avoid meta-pages clashes.

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This commit is contained in:
Leo Yuriev 2018-03-20 22:15:36 +03:00
parent dd6cb30820
commit 679fb56787
1 changed files with 21 additions and 6 deletions
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27
src/mdbx.c
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@ -5166,15 +5166,30 @@ static int __cold mdbx_setup_dxb(MDBX_env *env, int lck_rc) {
return MDBX_WANNA_RECOVERY /* LY: could not recovery/rollback */; return MDBX_WANNA_RECOVERY /* LY: could not recovery/rollback */;
} }
/* LY: rollback weak checkpoint */ const MDBX_meta *const meta0 = METAPAGE(env, 0);
mdbx_trace("rollback: from %" PRIaTXN ", to %" PRIaTXN, head_txnid, const MDBX_meta *const meta1 = METAPAGE(env, 1);
const MDBX_meta *const meta2 = METAPAGE(env, 2);
txnid_t undo_txnid = 0;
while (
(head != meta0 && mdbx_meta_txnid_fluid(env, meta0) == undo_txnid) ||
(head != meta1 && mdbx_meta_txnid_fluid(env, meta1) == undo_txnid) ||
(head != meta2 && mdbx_meta_txnid_fluid(env, meta2) == undo_txnid))
undo_txnid += 1;
if (unlikely(undo_txnid >= meta.mm_txnid_a)) {
mdbx_fatal("rollback failed: no suitable txnid (0,1,2) < %" PRIaTXN,
meta.mm_txnid_a); meta.mm_txnid_a);
return MDBX_PANIC /* LY: could not recovery/rollback */;
}
/* LY: rollback weak checkpoint */
mdbx_trace("rollback: from %" PRIaTXN ", to %" PRIaTXN " as %" PRIaTXN,
head_txnid, meta.mm_txnid_a, undo_txnid);
mdbx_ensure(env, head_txnid == mdbx_meta_txnid_stable(env, head)); mdbx_ensure(env, head_txnid == mdbx_meta_txnid_stable(env, head));
if (env->me_flags & MDBX_WRITEMAP) { if (env->me_flags & MDBX_WRITEMAP) {
head->mm_txnid_a = 0; head->mm_txnid_a = undo_txnid;
head->mm_datasync_sign = MDBX_DATASIGN_WEAK; head->mm_datasync_sign = MDBX_DATASIGN_WEAK;
head->mm_txnid_b = 0; head->mm_txnid_b = undo_txnid;
const size_t offset = const size_t offset =
((uint8_t *)container_of(head, MDBX_page, mp_meta)) - ((uint8_t *)container_of(head, MDBX_page, mp_meta)) -
env->me_dxb_mmap.dxb; env->me_dxb_mmap.dxb;
@ -5184,7 +5199,7 @@ static int __cold mdbx_setup_dxb(MDBX_env *env, int lck_rc) {
err = mdbx_msync(&env->me_dxb_mmap, paged_offset, paged_length, false); err = mdbx_msync(&env->me_dxb_mmap, paged_offset, paged_length, false);
} else { } else {
MDBX_meta rollback = *head; MDBX_meta rollback = *head;
mdbx_meta_set_txnid(env, &rollback, 0); mdbx_meta_set_txnid(env, &rollback, undo_txnid);
rollback.mm_datasync_sign = MDBX_DATASIGN_WEAK; rollback.mm_datasync_sign = MDBX_DATASIGN_WEAK;
err = mdbx_pwrite(env->me_fd, &rollback, sizeof(MDBX_meta), err = mdbx_pwrite(env->me_fd, &rollback, sizeof(MDBX_meta),
(uint8_t *)head - (uint8_t *)env->me_map); (uint8_t *)head - (uint8_t *)env->me_map);
@ -5193,7 +5208,7 @@ static int __cold mdbx_setup_dxb(MDBX_env *env, int lck_rc) {
return err; return err;
mdbx_invalidate_cache(env->me_map, pgno2bytes(env, NUM_METAS)); mdbx_invalidate_cache(env->me_map, pgno2bytes(env, NUM_METAS));
mdbx_ensure(env, 0 == mdbx_meta_txnid_fluid(env, head)); mdbx_ensure(env, undo_txnid == mdbx_meta_txnid_fluid(env, head));
mdbx_ensure(env, 0 == mdbx_meta_eq_mask(env)); mdbx_ensure(env, 0 == mdbx_meta_eq_mask(env));
continue; continue;
} }