Files
tromcho.net/blockstore_journal.cpp
T
Vitaliy Filippov 4a2dcf7b6b Update the license to VNPL 1.1
VNPL 1.1 is slightly reworded to make it clear that proprietary software
interacting with Vitastor and providing some kind of service to end users isn't
a "Proxy Program" if it's not specially designed to be used with Vitastor.

For example, Windows OS running in a virtual machine stored in a Vitastor
cluster clearly isn't.
2021-02-25 23:55:33 +03:00

221 lines
7.8 KiB
C++

// Copyright (c) Vitaliy Filippov, 2019+
// License: VNPL-1.1 (see README.md for details)
#include "blockstore_impl.h"
blockstore_journal_check_t::blockstore_journal_check_t(blockstore_impl_t *bs)
{
this->bs = bs;
sectors_to_write = 0;
next_pos = bs->journal.next_free;
next_sector = bs->journal.cur_sector;
first_sector = -1;
next_in_pos = bs->journal.in_sector_pos;
right_dir = next_pos >= bs->journal.used_start;
}
// Check if we can write <required> entries of <size> bytes and <data_after> data bytes after them to the journal
int blockstore_journal_check_t::check_available(blockstore_op_t *op, int entries_required, int size, int data_after)
{
int required = entries_required;
while (1)
{
int fits = bs->journal.no_same_sector_overwrites && next_pos == bs->journal.next_free && bs->journal.sector_info[next_sector].written
? 0
: (bs->journal.block_size - next_in_pos) / size;
if (fits > 0)
{
if (fits > required)
{
fits = required;
}
if (first_sector == -1)
{
first_sector = next_sector;
}
required -= fits;
next_in_pos += fits * size;
sectors_to_write++;
}
else if (bs->journal.sector_info[next_sector].dirty)
{
sectors_to_write++;
}
if (required <= 0)
{
break;
}
next_pos = next_pos + bs->journal.block_size;
if (next_pos >= bs->journal.len)
{
next_pos = bs->journal.block_size;
right_dir = false;
}
next_in_pos = 0;
next_sector = ((next_sector + 1) % bs->journal.sector_count);
if (next_sector == first_sector)
{
// next_sector may wrap when all sectors are flushed and the incoming batch is too big
// This is an error condition, we can't wait for anything in this case
throw std::runtime_error(
"Blockstore journal_sector_buffer_count="+std::to_string(bs->journal.sector_count)+
" is too small for a batch of "+std::to_string(entries_required)+" entries of "+std::to_string(size)+" bytes"
);
}
if (bs->journal.sector_info[next_sector].flush_count > 0 ||
bs->journal.sector_info[next_sector].dirty)
{
// No memory buffer available. Wait for it.
int used = 0, dirty = 0;
for (int i = 0; i < bs->journal.sector_count; i++)
{
if (bs->journal.sector_info[i].dirty)
{
dirty++;
used++;
}
if (bs->journal.sector_info[i].flush_count > 0)
{
used++;
}
}
// In fact, it's even more rare than "ran out of journal space", so print a warning
printf(
"Ran out of journal sector buffers: %d/%lu buffers used (%d dirty), next buffer (%ld)"
" is %s and flushed %lu times. Consider increasing \'journal_sector_buffer_count\'\n",
used, bs->journal.sector_count, dirty, next_sector,
bs->journal.sector_info[next_sector].dirty ? "dirty" : "not dirty",
bs->journal.sector_info[next_sector].flush_count
);
PRIV(op)->wait_for = WAIT_JOURNAL_BUFFER;
return 0;
}
}
if (data_after > 0)
{
next_pos = next_pos + data_after;
if (next_pos > bs->journal.len)
{
next_pos = bs->journal.block_size + data_after;
right_dir = false;
}
}
if (!right_dir && next_pos >= bs->journal.used_start-bs->journal.block_size)
{
// No space in the journal. Wait until used_start changes.
printf(
"Ran out of journal space (used_start=%08lx, next_free=%08lx, dirty_start=%08lx)\n",
bs->journal.used_start, bs->journal.next_free, bs->journal.dirty_start
);
PRIV(op)->wait_for = WAIT_JOURNAL;
bs->flusher->request_trim();
PRIV(op)->wait_detail = bs->journal.used_start;
return 0;
}
return 1;
}
journal_entry* prefill_single_journal_entry(journal_t & journal, uint16_t type, uint32_t size)
{
if (!journal.entry_fits(size))
{
assert(!journal.sector_info[journal.cur_sector].dirty);
// Move to the next journal sector
if (journal.sector_info[journal.cur_sector].flush_count > 0)
{
// Also select next sector buffer in memory
journal.cur_sector = ((journal.cur_sector + 1) % journal.sector_count);
assert(!journal.sector_info[journal.cur_sector].flush_count);
}
else
{
journal.dirty_start = journal.next_free;
}
journal.sector_info[journal.cur_sector].written = false;
journal.sector_info[journal.cur_sector].offset = journal.next_free;
journal.in_sector_pos = 0;
journal.next_free = (journal.next_free+journal.block_size) < journal.len ? journal.next_free + journal.block_size : journal.block_size;
memset(journal.inmemory
? journal.buffer + journal.sector_info[journal.cur_sector].offset
: journal.sector_buf + journal.block_size*journal.cur_sector, 0, journal.block_size);
}
journal_entry *je = (struct journal_entry*)(
(journal.inmemory
? journal.buffer + journal.sector_info[journal.cur_sector].offset
: journal.sector_buf + journal.block_size*journal.cur_sector) + journal.in_sector_pos
);
journal.in_sector_pos += size;
je->magic = JOURNAL_MAGIC;
je->type = type;
je->size = size;
je->crc32_prev = journal.crc32_last;
journal.sector_info[journal.cur_sector].dirty = true;
return je;
}
void prepare_journal_sector_write(journal_t & journal, int cur_sector, io_uring_sqe *sqe, std::function<void(ring_data_t*)> cb)
{
journal.sector_info[cur_sector].dirty = false;
journal.sector_info[cur_sector].written = true;
journal.sector_info[cur_sector].flush_count++;
ring_data_t *data = ((ring_data_t*)sqe->user_data);
data->iov = (struct iovec){
(journal.inmemory
? journal.buffer + journal.sector_info[cur_sector].offset
: journal.sector_buf + journal.block_size*cur_sector),
journal.block_size
};
data->callback = cb;
my_uring_prep_writev(
sqe, journal.fd, &data->iov, 1, journal.offset + journal.sector_info[cur_sector].offset
);
}
journal_t::~journal_t()
{
if (sector_buf)
free(sector_buf);
if (sector_info)
free(sector_info);
if (buffer)
free(buffer);
sector_buf = NULL;
sector_info = NULL;
buffer = NULL;
}
uint64_t journal_t::get_trim_pos()
{
auto journal_used_it = used_sectors.lower_bound(used_start);
#ifdef BLOCKSTORE_DEBUG
printf(
"Trimming journal (used_start=%08lx, next_free=%08lx, dirty_start=%08lx, new_start=%08lx, new_refcount=%ld)\n",
used_start, next_free, dirty_start,
journal_used_it == used_sectors.end() ? 0 : journal_used_it->first,
journal_used_it == used_sectors.end() ? 0 : journal_used_it->second
);
#endif
if (journal_used_it == used_sectors.end())
{
// Journal is cleared to its end, restart from the beginning
journal_used_it = used_sectors.begin();
if (journal_used_it == used_sectors.end())
{
// Journal is empty
return next_free;
}
else
{
// next_free does not need updating during trim
return journal_used_it->first;
}
}
else if (journal_used_it->first > used_start)
{
// Journal is cleared up to <journal_used_it>
return journal_used_it->first;
}
// Can't trim journal
return used_start;
}