thebestvibedev/tromcho.net
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
Files
b9e7d31aa1dbfdc3a8c79e2dccad8229fbda2fae
tromcho.net/blockstore_flush.cpp
T
Vitaliy Filippov 2d9f09dcb6 Attempt forced trim when stopping an overrun flusher 
Fixes a rare hang happening in the event of journal space running out without
new work to do for flushers except the current sector.
The hang could be reproduced more or less consistently with very slow drives.
2021-02-24 01:33:01 +03:00

877 lines
29 KiB
C++
Raw Blame History

// Copyright (c) Vitaliy Filippov, 2019+
// License: VNPL-1.0 (see README.md for details)
#include "blockstore_impl.h"
journal_flusher_t::journal_flusher_t(int flusher_count, blockstore_impl_t *bs)
{
this->bs = bs;
this->flusher_count = flusher_count;
dequeuing = false;
trimming = false;
active_flushers = 0;
syncing_flushers = 0;
// FIXME: allow to configure flusher_start_threshold and journal_trim_interval
flusher_start_threshold = bs->journal_block_size / sizeof(journal_entry_stable);
journal_trim_interval = 512;
journal_trim_counter = 0;
trim_wanted = 0;
journal_superblock = bs->journal.inmemory ? bs->journal.buffer : memalign_or_die(MEM_ALIGNMENT, bs->journal_block_size);
co = new journal_flusher_co[flusher_count];
for (int i = 0; i < flusher_count; i++)
{
co[i].bs = bs;
co[i].flusher = this;
}
}
journal_flusher_co::journal_flusher_co()
{
wait_state = 0;
simple_callback_r = [this](ring_data_t* data)
{
bs->live = true;
if (data->res != data->iov.iov_len)
{
throw std::runtime_error(
"data read operation failed during flush ("+std::to_string(data->res)+" != "+std::to_string(data->iov.iov_len)+
"). can't continue, sorry :-("
);
}
wait_count--;
};
simple_callback_w = [this](ring_data_t* data)
{
bs->live = true;
if (data->res != data->iov.iov_len)
{
throw std::runtime_error(
"write operation failed ("+std::to_string(data->res)+" != "+std::to_string(data->iov.iov_len)+
"). state "+std::to_string(wait_state)+". in-memory state is corrupted. AAAAAAAaaaaaaaaa!!!111"
);
}
wait_count--;
};
}
journal_flusher_t::~journal_flusher_t()
{
if (!bs->journal.inmemory)
free(journal_superblock);
delete[] co;
}
bool journal_flusher_t::is_active()
{
return active_flushers > 0 || dequeuing;
}
void journal_flusher_t::loop()
{
for (int i = 0; (active_flushers > 0 || dequeuing) && i < flusher_count; i++)
{
co[i].loop();
}
}
void journal_flusher_t::enqueue_flush(obj_ver_id ov)
{
#ifdef BLOCKSTORE_DEBUG
printf("enqueue_flush %lx:%lx v%lu\n", ov.oid.inode, ov.oid.stripe, ov.version);
#endif
auto it = flush_versions.find(ov.oid);
if (it != flush_versions.end())
{
if (it->second < ov.version)
it->second = ov.version;
}
else
{
flush_versions[ov.oid] = ov.version;
flush_queue.push_back(ov.oid);
}
if (!dequeuing && (flush_queue.size() >= flusher_start_threshold || trim_wanted > 0))
{
dequeuing = true;
bs->ringloop->wakeup();
}
}
void journal_flusher_t::unshift_flush(obj_ver_id ov, bool force)
{
#ifdef BLOCKSTORE_DEBUG
printf("unshift_flush %lx:%lx v%lu\n", ov.oid.inode, ov.oid.stripe, ov.version);
#endif
auto it = flush_versions.find(ov.oid);
if (it != flush_versions.end())
{
if (it->second < ov.version)
it->second = ov.version;
}
else
{
flush_versions[ov.oid] = ov.version;
if (!force)
flush_queue.push_front(ov.oid);
}
if (force)
flush_queue.push_front(ov.oid);
if (force || !dequeuing && (flush_queue.size() >= flusher_start_threshold || trim_wanted > 0))
{
dequeuing = true;
bs->ringloop->wakeup();
}
}
void journal_flusher_t::remove_flush(object_id oid)
{
#ifdef BLOCKSTORE_DEBUG
printf("undo_flush %lx:%lx\n", oid.inode, oid.stripe);
#endif
auto v_it = flush_versions.find(oid);
if (v_it != flush_versions.end())
{
flush_versions.erase(v_it);
for (auto q_it = flush_queue.begin(); q_it != flush_queue.end(); q_it++)
{
if (*q_it == oid)
{
flush_queue.erase(q_it);
break;
}
}
}
}
void journal_flusher_t::request_trim()
{
dequeuing = true;
trim_wanted++;
bs->ringloop->wakeup();
}
void journal_flusher_t::mark_trim_possible()
{
if (trim_wanted > 0)
{
dequeuing = true;
journal_trim_counter++;
bs->ringloop->wakeup();
}
}
void journal_flusher_t::release_trim()
{
trim_wanted--;
}
#define await_sqe(label) \
resume_##label:\
sqe = bs->get_sqe();\
if (!sqe)\
{\
wait_state = label;\
return false;\
}\
data = ((ring_data_t*)sqe->user_data);
// FIXME: Implement batch flushing
bool journal_flusher_co::loop()
{
// This is much better than implementing the whole function as an FSM
// Maybe I should consider a coroutine library like https://github.com/hnes/libaco ...
if (wait_state == 1)
goto resume_1;
else if (wait_state == 2)
goto resume_2;
else if (wait_state == 3)
goto resume_3;
else if (wait_state == 4)
goto resume_4;
else if (wait_state == 5)
goto resume_5;
else if (wait_state == 6)
goto resume_6;
else if (wait_state == 7)
goto resume_7;
else if (wait_state == 8)
goto resume_8;
else if (wait_state == 9)
goto resume_9;
else if (wait_state == 10)
goto resume_10;
else if (wait_state == 12)
goto resume_12;
else if (wait_state == 13)
goto resume_13;
else if (wait_state == 14)
goto resume_14;
else if (wait_state == 15)
goto resume_15;
else if (wait_state == 16)
goto resume_16;
else if (wait_state == 17)
goto resume_17;
else if (wait_state == 18)
goto resume_18;
else if (wait_state == 19)
goto resume_19;
else if (wait_state == 20)
goto resume_20;
else if (wait_state == 21)
goto resume_21;
resume_0:
if (!flusher->flush_queue.size() || !flusher->dequeuing)
{
stop_flusher:
if (flusher->trim_wanted > 0 && flusher->journal_trim_counter > 0)
{
// Attempt forced trim
flusher->active_flushers++;
goto trim_journal;
}
flusher->dequeuing = false;
wait_state = 0;
return true;
}
cur.oid = flusher->flush_queue.front();
cur.version = flusher->flush_versions[cur.oid];
flusher->flush_queue.pop_front();
flusher->flush_versions.erase(cur.oid);
dirty_end = bs->dirty_db.find(cur);
if (dirty_end != bs->dirty_db.end())
{
repeat_it = flusher->sync_to_repeat.find(cur.oid);
if (repeat_it != flusher->sync_to_repeat.end())
{
#ifdef BLOCKSTORE_DEBUG
printf("Postpone %lx:%lx v%lu\n", cur.oid.inode, cur.oid.stripe, cur.version);
#endif
// We don't flush different parts of history of the same object in parallel
// So we check if someone is already flushing this object
// In that case we set sync_to_repeat and pick another object
// Another coroutine will see it and re-queue the object after it finishes
if (repeat_it->second < cur.version)
repeat_it->second = cur.version;
wait_state = 0;
goto resume_0;
}
else
flusher->sync_to_repeat[cur.oid] = 0;
if (dirty_end->second.journal_sector >= bs->journal.dirty_start &&
(bs->journal.dirty_start >= bs->journal.used_start ||
dirty_end->second.journal_sector < bs->journal.used_start))
{
flusher->enqueue_flush(cur);
// We can't flush journal sectors that are still written to
// However, as we group flushes by oid, current oid may have older writes to flush!
// And it may even block writes if we don't flush the older version
// (if it's in the beginning of the journal)...
// So first try to find an older version of the same object to flush.
bool found = false;
while (dirty_end != bs->dirty_db.begin())
{
dirty_end--;
if (dirty_end->first.oid != cur.oid)
{
break;
}
if (!(dirty_end->second.journal_sector >= bs->journal.dirty_start &&
(bs->journal.dirty_start >= bs->journal.used_start ||
dirty_end->second.journal_sector < bs->journal.used_start)))
{
found = true;
cur.version = dirty_end->first.version;
break;
}
}
if (!found)
{
// Try other objects
flusher->sync_to_repeat.erase(cur.oid);
int search_left = flusher->flush_queue.size() - 1;
#ifdef BLOCKSTORE_DEBUG
printf("Flusher overran writers (dirty_start=%08lx) - searching for older flushes (%d left)\n", bs->journal.dirty_start, search_left);
#endif
while (search_left > 0)
{
cur.oid = flusher->flush_queue.front();
cur.version = flusher->flush_versions[cur.oid];
flusher->flush_queue.pop_front();
flusher->flush_versions.erase(cur.oid);
dirty_end = bs->dirty_db.find(cur);
if (dirty_end != bs->dirty_db.end())
{
if (dirty_end->second.journal_sector >= bs->journal.dirty_start &&
(bs->journal.dirty_start >= bs->journal.used_start ||
dirty_end->second.journal_sector < bs->journal.used_start))
{
#ifdef BLOCKSTORE_DEBUG
printf("Write %lx:%lx v%lu is too new: offset=%08lx\n", cur.oid.inode, cur.oid.stripe, cur.version, dirty_end->second.journal_sector);
#endif
flusher->enqueue_flush(cur);
}
else
{
repeat_it = flusher->sync_to_repeat.find(cur.oid);
if (repeat_it == flusher->sync_to_repeat.end())
{
flusher->sync_to_repeat[cur.oid] = 0;
break;
}
}
}
search_left--;
}
if (search_left <= 0)
{
#ifdef BLOCKSTORE_DEBUG
printf("No older flushes, stopping\n");
#endif
goto stop_flusher;
}
}
}
#ifdef BLOCKSTORE_DEBUG
printf("Flushing %lx:%lx v%lu\n", cur.oid.inode, cur.oid.stripe, cur.version);
#endif
flusher->active_flushers++;
resume_1:
// Find it in clean_db
clean_it = bs->clean_db.find(cur.oid);
old_clean_loc = (clean_it != bs->clean_db.end() ? clean_it->second.location : UINT64_MAX);
// Scan dirty versions of the object
if (!scan_dirty(1))
{
wait_state += 1;
return false;
}
// Writes and deletes shouldn't happen at the same time
assert(!has_writes || !has_delete);
if (!has_writes && !has_delete || has_delete && old_clean_loc == UINT64_MAX)
{
// Nothing to flush
bs->erase_dirty(dirty_start, std::next(dirty_end), clean_loc);
goto release_oid;
}
if (clean_loc == UINT64_MAX)
{
if (old_clean_loc == UINT64_MAX)
{
// Object not allocated. This is a bug.
char err[1024];
snprintf(
err, 1024, "BUG: Object %lx:%lx v%lu that we are trying to flush is not allocated on the data device",
cur.oid.inode, cur.oid.stripe, cur.version
);
throw std::runtime_error(err);
}
else
{
clean_loc = old_clean_loc;
}
}
// Also we need to submit metadata read(s). We do read-modify-write cycle(s) for every operation.
resume_2:
if (!modify_meta_read(clean_loc, meta_new, 2))
{
wait_state += 2;
return false;
}
if (old_clean_loc != UINT64_MAX && old_clean_loc != clean_loc)
{
resume_14:
if (!modify_meta_read(old_clean_loc, meta_old, 14))
{
wait_state += 14;
return false;
}
}
else
meta_old.submitted = false;
resume_3:
if (wait_count > 0)
{
wait_state = 3;
return false;
}
if (meta_new.submitted)
{
meta_new.it->second.state = 1;
bs->ringloop->wakeup();
}
if (meta_old.submitted)
{
meta_old.it->second.state = 1;
bs->ringloop->wakeup();
}
// Reads completed, submit writes and set bitmap bits
if (bs->clean_entry_bitmap_size)
{
new_clean_bitmap = (bs->inmemory_meta
? meta_new.buf + meta_new.pos*bs->clean_entry_size + sizeof(clean_disk_entry)
: bs->clean_bitmap + (clean_loc >> bs->block_order)*bs->clean_entry_bitmap_size);
if (clean_init_bitmap)
{
memset(new_clean_bitmap, 0, bs->clean_entry_bitmap_size);
bitmap_set(new_clean_bitmap, clean_bitmap_offset, clean_bitmap_len);
}
}
for (it = v.begin(); it != v.end(); it++)
{
if (new_clean_bitmap)
{
bitmap_set(new_clean_bitmap, it->offset, it->len);
}
await_sqe(4);
data->iov = (struct iovec){ it->buf, (size_t)it->len };
data->callback = simple_callback_w;
my_uring_prep_writev(
sqe, bs->data_fd, &data->iov, 1, bs->data_offset + clean_loc + it->offset
);
wait_count++;
}
// Sync data before writing metadata
resume_16:
resume_17:
resume_18:
if (copy_count && !fsync_batch(false, 16))
{
wait_state += 16;
return false;
}
resume_5:
// And metadata writes, but only after data writes complete
if (!bs->inmemory_meta && meta_new.it->second.state == 0 || wait_count > 0)
{
// metadata sector is still being read or data is still being written, wait for it
wait_state = 5;
return false;
}
if (old_clean_loc != UINT64_MAX && old_clean_loc != clean_loc)
{
if (!bs->inmemory_meta && meta_old.it->second.state == 0)
{
wait_state = 5;
return false;
}
memset(meta_old.buf + meta_old.pos*bs->clean_entry_size, 0, bs->clean_entry_size);
await_sqe(15);
data->iov = (struct iovec){ meta_old.buf, bs->meta_block_size };
data->callback = simple_callback_w;
my_uring_prep_writev(
sqe, bs->meta_fd, &data->iov, 1, bs->meta_offset + meta_old.sector
);
wait_count++;
}
if (has_delete)
{
memset(meta_new.buf + meta_new.pos*bs->clean_entry_size, 0, bs->clean_entry_size);
}
else
{
clean_disk_entry *new_entry = (clean_disk_entry*)(meta_new.buf + meta_new.pos*bs->clean_entry_size);
if (new_entry->oid.inode != 0 && new_entry->oid != cur.oid)
{
printf("Fatal error (metadata corruption or bug): tried to overwrite non-zero metadata entry %lu (%lx:%lx) with %lx:%lx\n",
clean_loc >> bs->block_order, new_entry->oid.inode, new_entry->oid.stripe, cur.oid.inode, cur.oid.stripe);
exit(1);
}
new_entry->oid = cur.oid;
new_entry->version = cur.version;
if (!bs->inmemory_meta)
{
memcpy(&new_entry->bitmap, new_clean_bitmap, bs->clean_entry_bitmap_size);
}
}
await_sqe(6);
data->iov = (struct iovec){ meta_new.buf, bs->meta_block_size };
data->callback = simple_callback_w;
my_uring_prep_writev(
sqe, bs->meta_fd, &data->iov, 1, bs->meta_offset + meta_new.sector
);
wait_count++;
resume_7:
if (wait_count > 0)
{
wait_state = 7;
return false;
}
// Done, free all buffers
if (!bs->inmemory_meta)
{
meta_new.it->second.usage_count--;
if (meta_new.it->second.usage_count == 0)
{
free(meta_new.it->second.buf);
flusher->meta_sectors.erase(meta_new.it);
}
if (old_clean_loc != UINT64_MAX && old_clean_loc != clean_loc)
{
meta_old.it->second.usage_count--;
if (meta_old.it->second.usage_count == 0)
{
free(meta_old.it->second.buf);
flusher->meta_sectors.erase(meta_old.it);
}
}
}
for (it = v.begin(); it != v.end(); it++)
{
free(it->buf);
}
v.clear();
// And sync metadata (in batches - not per each operation!)
resume_8:
resume_9:
resume_10:
if (!fsync_batch(true, 8))
{
wait_state += 8;
return false;
}
// Update clean_db and dirty_db, free old data locations
update_clean_db();
#ifdef BLOCKSTORE_DEBUG
printf("Flushed %lx:%lx v%lu (%d copies, wr:%d, del:%d), %ld left\n", cur.oid.inode, cur.oid.stripe, cur.version,
copy_count, has_writes, has_delete, flusher->flush_queue.size());
#endif
release_oid:
repeat_it = flusher->sync_to_repeat.find(cur.oid);
if (repeat_it != flusher->sync_to_repeat.end() && repeat_it->second > cur.version)
{
// Requeue version
flusher->unshift_flush({ .oid = cur.oid, .version = repeat_it->second }, false);
}
flusher->sync_to_repeat.erase(repeat_it);
trim_journal:
// Clear unused part of the journal every <journal_trim_interval> flushes
if (!((++flusher->journal_trim_counter) % flusher->journal_trim_interval) || flusher->trim_wanted > 0)
{
flusher->journal_trim_counter = 0;
new_trim_pos = bs->journal.get_trim_pos();
if (new_trim_pos != bs->journal.used_start)
{
resume_19:
// Wait for other coroutines trimming the journal, if any
if (flusher->trimming)
{
wait_state = 19;
return false;
}
flusher->trimming = true;
// First update journal "superblock" and only then update <used_start> in memory
await_sqe(12);
*((journal_entry_start*)flusher->journal_superblock) = {
.crc32 = 0,
.magic = JOURNAL_MAGIC,
.type = JE_START,
.size = sizeof(journal_entry_start),
.reserved = 0,
.journal_start = new_trim_pos,
};
((journal_entry_start*)flusher->journal_superblock)->crc32 = je_crc32((journal_entry*)flusher->journal_superblock);
data->iov = (struct iovec){ flusher->journal_superblock, bs->journal_block_size };
data->callback = simple_callback_w;
my_uring_prep_writev(sqe, bs->journal.fd, &data->iov, 1, bs->journal.offset);
wait_count++;
resume_13:
if (wait_count > 0)
{
wait_state = 13;
return false;
}
if (!bs->disable_journal_fsync)
{
await_sqe(20);
my_uring_prep_fsync(sqe, bs->journal.fd, IORING_FSYNC_DATASYNC);
data->iov = { 0 };
data->callback = simple_callback_w;
resume_21:
if (wait_count > 0)
{
wait_state = 21;
return false;
}
}
bs->journal.used_start = new_trim_pos;
#ifdef BLOCKSTORE_DEBUG
printf("Journal trimmed to %08lx (next_free=%08lx)\n", bs->journal.used_start, bs->journal.next_free);
#endif
flusher->trimming = false;
}
}
// All done
flusher->active_flushers--;
wait_state = 0;
goto resume_0;
}
return true;
}
bool journal_flusher_co::scan_dirty(int wait_base)
{
if (wait_state == wait_base)
{
goto resume_0;
}
dirty_it = dirty_start = dirty_end;
v.clear();
wait_count = 0;
copy_count = 0;
clean_loc = UINT64_MAX;
has_delete = false;
has_writes = false;
skip_copy = false;
clean_init_bitmap = false;
while (1)
{
if (!IS_STABLE(dirty_it->second.state))
{
char err[1024];
snprintf(
err, 1024, "BUG: Unexpected dirty_entry %lx:%lx v%lu unstable state during flush: %d",
dirty_it->first.oid.inode, dirty_it->first.oid.stripe, dirty_it->first.version, dirty_it->second.state
);
throw std::runtime_error(err);
}
else if (IS_JOURNAL(dirty_it->second.state) && !skip_copy)
{
// First we submit all reads
has_writes = true;
if (dirty_it->second.len != 0)
{
offset = dirty_it->second.offset;
end_offset = dirty_it->second.offset + dirty_it->second.len;
it = v.begin();
while (1)
{
for (; it != v.end(); it++)
if (it->offset >= offset)
break;
if (it == v.end() || it->offset > offset && it->len > 0)
{
submit_offset = dirty_it->second.location + offset - dirty_it->second.offset;
submit_len = it == v.end() || it->offset >= end_offset ? end_offset-offset : it->offset-offset;
it = v.insert(it, (copy_buffer_t){ .offset = offset, .len = submit_len, .buf = memalign_or_die(MEM_ALIGNMENT, submit_len) });
copy_count++;
if (bs->journal.inmemory)
{
// Take it from memory
memcpy(it->buf, bs->journal.buffer + submit_offset, submit_len);
}
else
{
// Read it from disk
await_sqe(0);
data->iov = (struct iovec){ it->buf, (size_t)submit_len };
data->callback = simple_callback_r;
my_uring_prep_readv(
sqe, bs->journal.fd, &data->iov, 1, bs->journal.offset + submit_offset
);
wait_count++;
}
}
offset = it->offset+it->len;
if (it == v.end() || offset >= end_offset)
break;
}
}
}
else if (IS_BIG_WRITE(dirty_it->second.state) && !skip_copy)
{
// There is an unflushed big write. Copy small writes in its position
has_writes = true;
clean_loc = dirty_it->second.location;
clean_init_bitmap = true;
clean_bitmap_offset = dirty_it->second.offset;
clean_bitmap_len = dirty_it->second.len;
skip_copy = true;
}
else if (IS_DELETE(dirty_it->second.state) && !skip_copy)
{
// There is an unflushed delete
has_delete = true;
skip_copy = true;
}
dirty_start = dirty_it;
if (dirty_it == bs->dirty_db.begin())
{
break;
}
dirty_it--;
if (dirty_it->first.oid != cur.oid)
{
break;
}
}
return true;
}
bool journal_flusher_co::modify_meta_read(uint64_t meta_loc, flusher_meta_write_t &wr, int wait_base)
{
if (wait_state == wait_base)
{
goto resume_0;
}
// We must check if the same sector is already in memory if we don't keep all metadata in memory all the time.
// And yet another option is to use LSM trees for metadata, but it sophisticates everything a lot,
// so I'll avoid it as long as I can.
wr.submitted = false;
wr.sector = ((meta_loc >> bs->block_order) / (bs->meta_block_size / bs->clean_entry_size)) * bs->meta_block_size;
wr.pos = ((meta_loc >> bs->block_order) % (bs->meta_block_size / bs->clean_entry_size));
if (bs->inmemory_meta)
{
wr.buf = bs->metadata_buffer + wr.sector;
return true;
}
wr.it = flusher->meta_sectors.find(wr.sector);
if (wr.it == flusher->meta_sectors.end())
{
// Not in memory yet, read it
wr.buf = memalign_or_die(MEM_ALIGNMENT, bs->meta_block_size);
wr.it = flusher->meta_sectors.emplace(wr.sector, (meta_sector_t){
.offset = wr.sector,
.len = bs->meta_block_size,
.state = 0, // 0 = not read yet
.buf = wr.buf,
.usage_count = 1,
}).first;
await_sqe(0);
data->iov = (struct iovec){ wr.it->second.buf, bs->meta_block_size };
data->callback = simple_callback_r;
wr.submitted = true;
my_uring_prep_readv(
sqe, bs->meta_fd, &data->iov, 1, bs->meta_offset + wr.sector
);
wait_count++;
}
else
{
wr.buf = wr.it->second.buf;
wr.it->second.usage_count++;
}
return true;
}
void journal_flusher_co::update_clean_db()
{
if (old_clean_loc != UINT64_MAX && old_clean_loc != clean_loc)
{
#ifdef BLOCKSTORE_DEBUG
printf("Free block %lu (new location is %lu)\n", old_clean_loc >> bs->block_order, clean_loc >> bs->block_order);
#endif
bs->data_alloc->set(old_clean_loc >> bs->block_order, false);
}
if (has_delete)
{
auto clean_it = bs->clean_db.find(cur.oid);
bs->clean_db.erase(clean_it);
bs->data_alloc->set(clean_loc >> bs->block_order, false);
clean_loc = UINT64_MAX;
}
else
{
bs->clean_db[cur.oid] = {
.version = cur.version,
.location = clean_loc,
};
}
bs->erase_dirty(dirty_start, std::next(dirty_end), clean_loc);
}
bool journal_flusher_co::fsync_batch(bool fsync_meta, int wait_base)
{
if (wait_state == wait_base)
goto resume_0;
else if (wait_state == wait_base+1)
goto resume_1;
else if (wait_state == wait_base+2)
goto resume_2;
if (!(fsync_meta ? bs->disable_meta_fsync : bs->disable_journal_fsync))
{
cur_sync = flusher->syncs.end();
while (cur_sync != flusher->syncs.begin())
{
cur_sync--;
if (cur_sync->fsync_meta == fsync_meta && cur_sync->state == 0)
{
goto sync_found;
}
}
cur_sync = flusher->syncs.emplace(flusher->syncs.end(), (flusher_sync_t){
.fsync_meta = fsync_meta,
.ready_count = 0,
.state = 0,
});
sync_found:
cur_sync->ready_count++;
flusher->syncing_flushers++;
if (flusher->syncing_flushers >= flusher->flusher_count || !flusher->flush_queue.size())
{
// Sync batch is ready. Do it.
await_sqe(0);
data->iov = { 0 };
data->callback = simple_callback_w;
my_uring_prep_fsync(sqe, fsync_meta ? bs->meta_fd : bs->data_fd, IORING_FSYNC_DATASYNC);
cur_sync->state = 1;
wait_count++;
resume_1:
if (wait_count > 0)
{
wait_state = 1;
return false;
}
// Sync completed. All previous coroutines waiting for it must be resumed
cur_sync->state = 2;
bs->ringloop->wakeup();
}
// Wait until someone else sends and completes a sync.
resume_2:
if (!cur_sync->state)
{
wait_state = 2;
return false;
}
flusher->syncing_flushers--;
cur_sync->ready_count--;
if (cur_sync->ready_count == 0)
{
flusher->syncs.erase(cur_sync);
}
}
return true;
}
void journal_flusher_co::bitmap_set(void *bitmap, uint64_t start, uint64_t len)
{
if (start == 0)
{
if (len == 32*bs->bitmap_granularity)
{
*((uint32_t*)bitmap) = UINT32_MAX;
return;
}
else if (len == 64*bs->bitmap_granularity)
{
*((uint64_t*)bitmap) = UINT64_MAX;
return;
}
}
unsigned bit_start = start / bs->bitmap_granularity;
unsigned bit_end = ((start + len) + bs->bitmap_granularity - 1) / bs->bitmap_granularity;
while (bit_start < bit_end)
{
if (!(bit_start & 7) && bit_end >= bit_start+8)
{
((uint8_t*)bitmap)[bit_start / 8] = UINT8_MAX;
bit_start += 8;
}
else
{
((uint8_t*)bitmap)[bit_start / 8] |= 1 << (bit_start % 8);
bit_start++;
}
}
}
Reference in New Issue View Git Blame Copy Permalink