310 lines
9.1 KiB
C++
310 lines
9.1 KiB
C++
#include "blockstore.h"
|
|
|
|
// Stabilize small write:
|
|
// 1) Copy data from the journal to the data device
|
|
// Sync it before writing metadata if we want to keep metadata consistent
|
|
// Overall it's optional because it can be replayed from the journal until
|
|
// it's cleared, and reads are also fulfilled from the journal
|
|
// 2) Increase version on the metadata device and sync it
|
|
// 3) Advance clean_db entry's version, clear previous journal entries
|
|
//
|
|
// This makes 1 4K small write+sync look like:
|
|
// 512b+4K (journal) + sync + 512b (journal) + sync + 4K (data) [+ sync?] + 512b (metadata) + sync.
|
|
// WA = 2.375. It's not the best, SSD FTL-like redirect-write with defragmentation
|
|
// could probably be lower even with defragmentation. But it's fixed and it's still
|
|
// better than in Ceph. :)
|
|
|
|
// Stabilize big write:
|
|
// 1) Copy metadata from the journal to the metadata device
|
|
// 2) Move dirty_db entry to clean_db and clear previous journal entries
|
|
//
|
|
// This makes 1 128K big write+sync look like:
|
|
// 128K (data) + sync + 512b (journal) + sync + 512b (journal) + sync + 512b (metadata) + sync.
|
|
// WA = 1.012. Very good :)
|
|
|
|
// AND We must do it in batches, for the sake of reduced fsync call count
|
|
// AND We must know what we stabilize. Basic workflow is like:
|
|
// 1) primary OSD receives sync request
|
|
// 2) it determines his own unsynced writes from blockstore's information
|
|
// just before submitting fsync
|
|
// 3) it submits syncs to blockstore and peers
|
|
// 4) after everyone acks sync it takes the object list and sends stabilize requests to everyone
|
|
|
|
int blockstore::dequeue_stable(blockstore_operation *op)
|
|
{
|
|
obj_ver_id* v;
|
|
int i, todo = 0;
|
|
for (i = 0, v = (obj_ver_id*)op->buf; i < op->len; i++, v++)
|
|
{
|
|
auto dirty_it = dirty_db.find(*v);
|
|
if (dirty_it == dirty_db.end())
|
|
{
|
|
auto clean_it = clean_db.find(v->oid);
|
|
if (clean_it == clean_db.end() || clean_it->second.version < v->version)
|
|
{
|
|
// No such object version
|
|
op->retval = EINVAL;
|
|
op->callback(op);
|
|
return 1;
|
|
}
|
|
else
|
|
{
|
|
// Already stable
|
|
}
|
|
}
|
|
else if (IS_UNSYNCED(dirty_it->second.state))
|
|
{
|
|
// Object not synced yet. Caller must sync it first
|
|
op->retval = EAGAIN;
|
|
op->callback(op);
|
|
return 1;
|
|
}
|
|
else if (!IS_STABLE(dirty_it->second.state))
|
|
{
|
|
todo++;
|
|
}
|
|
}
|
|
if (!todo)
|
|
{
|
|
// Already stable
|
|
op->retval = 0;
|
|
op->callback(op);
|
|
return 1;
|
|
}
|
|
// Check journal space
|
|
blockstore_journal_check_t space_check(this);
|
|
if (!space_check.check_available(op, todo, sizeof(journal_entry_stable), 0))
|
|
{
|
|
return 0;
|
|
}
|
|
// There is sufficient space. Get SQEs
|
|
struct io_uring_sqe *sqe[space_check.sectors_required];
|
|
for (i = 0; i < space_check.sectors_required; i++)
|
|
{
|
|
BS_SUBMIT_GET_SQE_DECL(sqe[i]);
|
|
}
|
|
// Prepare and submit journal entries
|
|
int s = 0, cur_sector = -1;
|
|
for (i = 0, v = (obj_ver_id*)op->buf; i < op->len; i++, v++)
|
|
{
|
|
journal_entry_stable *je = (journal_entry_stable*)
|
|
prefill_single_journal_entry(journal, JE_STABLE, sizeof(journal_entry_stable));
|
|
je->oid = v->oid;
|
|
je->version = v->version;
|
|
je->crc32 = je_crc32((journal_entry*)je);
|
|
journal.crc32_last = je->crc32;
|
|
if (cur_sector != journal.cur_sector)
|
|
{
|
|
if (cur_sector == -1)
|
|
op->min_used_journal_sector = 1 + journal.cur_sector;
|
|
cur_sector = journal.cur_sector;
|
|
prepare_journal_sector_write(op, journal, sqe[s++]);
|
|
}
|
|
}
|
|
op->max_used_journal_sector = 1 + journal.cur_sector;
|
|
op->pending_ops = s;
|
|
return 1;
|
|
}
|
|
|
|
int blockstore::continue_stable(blockstore_operation *op)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
void blockstore::handle_stable_event(ring_data_t *data, blockstore_operation *op)
|
|
{
|
|
if (data->res < 0)
|
|
{
|
|
// sync error
|
|
// FIXME: our state becomes corrupted after a write error. maybe do something better than just die
|
|
throw new std::runtime_error("write operation failed. in-memory state is corrupted. AAAAAAAaaaaaaaaa!!!111");
|
|
}
|
|
op->pending_ops--;
|
|
if (op->pending_ops == 0)
|
|
{
|
|
// First step: mark dirty_db entries as stable, acknowledge op completion
|
|
obj_ver_id* v;
|
|
int i;
|
|
for (i = 0, v = (obj_ver_id*)op->buf; i < op->len; i++, v++)
|
|
{
|
|
// Mark all dirty_db entries up to op->version as stable
|
|
auto dirty_it = dirty_db.find(*v);
|
|
if (dirty_it != dirty_db.end())
|
|
{
|
|
do
|
|
{
|
|
if (dirty_it->second.state == ST_J_SYNCED)
|
|
{
|
|
dirty_it->second.state = ST_J_STABLE;
|
|
}
|
|
else if (dirty_it->second.state == ST_D_META_SYNCED)
|
|
{
|
|
dirty_it->second.state = ST_D_STABLE;
|
|
}
|
|
else if (IS_STABLE(dirty_it->second.state))
|
|
{
|
|
break;
|
|
}
|
|
dirty_it--;
|
|
} while (dirty_it != dirty_db.begin() && dirty_it->first.oid == v->oid);
|
|
flusher.flush_queue.push_back(*v);
|
|
}
|
|
}
|
|
// Acknowledge op
|
|
op->retval = 0;
|
|
op->callback(op);
|
|
}
|
|
}
|
|
|
|
struct offset_len
|
|
{
|
|
uint64_t offset, len;
|
|
};
|
|
|
|
class journal_flusher_t
|
|
{
|
|
blockstore *bs;
|
|
int state;
|
|
obj_ver_id cur;
|
|
std::map<obj_ver_id, dirty_entry>::iterator dirty_it;
|
|
std::vector<offset_len> v;
|
|
std::vector<offset_len>::iterator it;
|
|
uint64_t offset, len;
|
|
|
|
public:
|
|
journal_flusher_t();
|
|
std::deque<obj_ver_id> flush_queue;
|
|
void stabilize_object_loop();
|
|
};
|
|
|
|
#define F_NEXT_OBJ 0
|
|
#define F_NEXT_VER 1
|
|
#define F_FIND_POS 2
|
|
#define F_SUBMIT_FULL 3
|
|
#define F_SUBMIT_PART 4
|
|
#define F_CUT_OFFSET 5
|
|
#define F_FINISH_VER 6
|
|
|
|
journal_flusher_t::journal_flusher_t()
|
|
{
|
|
state = F_NEXT_OBJ;
|
|
}
|
|
|
|
// It would be prettier as a coroutine (maybe https://github.com/hnes/libaco ?)
|
|
// Now it's a state machine
|
|
void journal_flusher_t::stabilize_object_loop()
|
|
{
|
|
begin:
|
|
if (state == F_NEXT_OBJ)
|
|
{
|
|
// Pick next object
|
|
if (!flush_queue.size())
|
|
return;
|
|
while (1)
|
|
{
|
|
cur = flush_queue.front();
|
|
flush_queue.pop_front();
|
|
dirty_it = bs->dirty_db.find(cur);
|
|
if (dirty_it != bs->dirty_db.end())
|
|
{
|
|
state = F_NEXT_VER;
|
|
v.clear();
|
|
break;
|
|
}
|
|
else if (flush_queue.size() == 0)
|
|
return;
|
|
}
|
|
}
|
|
if (state == F_NEXT_VER)
|
|
{
|
|
if (dirty_it->second.state == ST_J_STABLE)
|
|
{
|
|
offset = dirty_it->second.offset;
|
|
len = dirty_it->second.size;
|
|
it = v.begin();
|
|
state = F_FIND_POS;
|
|
}
|
|
else if (dirty_it->second.state == ST_D_STABLE)
|
|
{
|
|
|
|
state = F_NEXT_OBJ;
|
|
}
|
|
else if (IS_STABLE(dirty_it->second.state))
|
|
{
|
|
state = F_NEXT_OBJ;
|
|
}
|
|
else
|
|
state = F_FINISH_VER;
|
|
}
|
|
if (state == F_FIND_POS)
|
|
{
|
|
for (; it != v.end(); it++)
|
|
if (it->offset >= offset)
|
|
break;
|
|
if (it == v.end() || it->offset >= offset+len)
|
|
{
|
|
state = F_SUBMIT_FULL;
|
|
}
|
|
else
|
|
{
|
|
if (it->offset > offset)
|
|
state = F_SUBMIT_PART;
|
|
else
|
|
state = F_CUT_OFFSET;
|
|
}
|
|
}
|
|
if (state == F_SUBMIT_FULL)
|
|
{
|
|
struct io_uring_sqe *sqe = get_sqe();
|
|
if (!sqe)
|
|
return;
|
|
struct ring_data_t *data = ((ring_data_t*)sqe->user_data);
|
|
data->iov = (struct iovec){ malloc(len), len };
|
|
data->op = op; // FIXME OOPS
|
|
io_uring_prep_readv(
|
|
sqe, journal_fd, &data->iov, 1, journal_offset + dirty_it->second.location + offset
|
|
);
|
|
op->pending_ops = 1;
|
|
v.insert(it, (offset_len){ .offset = offset, .len = len });
|
|
state = F_SUBMIT_FULL_WRITE;
|
|
return;
|
|
}
|
|
if (state == F_SUBMIT_FULL_WRITE)
|
|
{
|
|
struct io_uring_sqe *sqe = get_sqe();
|
|
if (!sqe)
|
|
return;
|
|
struct ring_data_t *data = ((ring_data_t*)sqe->user_data);
|
|
|
|
}
|
|
if (state == F_SUBMIT_PART)
|
|
{
|
|
if (!can_submit)
|
|
{
|
|
return;
|
|
}
|
|
v.insert(it, (offset_len){ .offset = offset, .len = it->offset-offset });
|
|
state = F_CUT_OFFSET;
|
|
}
|
|
if (state == F_CUT_OFFSET)
|
|
{
|
|
if (offset+len > it->offset+it->len)
|
|
{
|
|
len = offset+len - (it->offset+it->len);
|
|
offset = it->offset+it->len;
|
|
state = F_FIND_POS;
|
|
}
|
|
else
|
|
state = F_FINISH_VER;
|
|
}
|
|
if (state == F_FINISH_VER)
|
|
{
|
|
dirty_it--;
|
|
if (dirty_it == bs->dirty_db.begin() || dirty_it->first.oid != cur.oid)
|
|
state = F_NEXT_OBJ;
|
|
else
|
|
state = F_NEXT_VER;
|
|
}
|
|
goto begin;
|
|
}
|