thebestvibedev/tromcho.net
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Implement read-modify-write calculation and extract it into a separate file

Browse Source
This commit is contained in:
Vitaliy Filippov
2020-02-23 02:11:43 +03:00
parent 0e177c7a2a
commit d4fd9d982a
11 changed files with 637 additions and 178 deletions
Download Patch File Download Diff File Expand all files Collapse all files
osd_primary.cpp
+111 -171
View File
@@ -1,5 +1,5 @@
#include "osd.h"
#include "xor.h"
#include "osd_rmw.h"
// read: read directly or read paired stripe(s), reconstruct, return
// write: read paired stripe(s), modify, write
@@ -10,19 +10,7 @@
//
// sync: sync peers, get unstable versions from somewhere, stabilize them
struct off_len_t
{
uint64_t offset, len;
};
struct osd_read_stripe_t
{
uint64_t pos;
uint32_t start, end;
uint32_t real_start, real_end;
};
struct osd_primary_read_t
struct osd_primary_op_data_t
{
pg_num_t pg_num;
object_id oid;
@@ -31,6 +19,9 @@ struct osd_primary_read_t
int degraded = 0, pg_size, pg_minsize;
osd_read_stripe_t *stripes;
osd_op_t *subops = NULL;
void *rmw_buf = NULL;
bool should_read_version = false;
};
void osd_t::finish_primary_op(osd_op_t *cur_op, int retval)
@@ -43,35 +34,19 @@ void osd_t::finish_primary_op(osd_op_t *cur_op, int retval)
outbox_push(this->clients[cur_op->peer_fd], cur_op);
}
inline void split_stripes(uint64_t pg_minsize, uint32_t bs_block_size, uint64_t start, uint64_t end, osd_read_stripe_t *stripes)
{
for (int role = 0; role < pg_minsize; role++)
{
if (start < (1+role)*bs_block_size && end > role*bs_block_size)
{
stripes[role].real_start = stripes[role].start
= start < role*bs_block_size ? 0 : start-role*bs_block_size;
stripes[role].real_end = stripes[role].end
= end > (role+1)*bs_block_size ? bs_block_size : end-role*bs_block_size;
}
}
}
void osd_t::exec_primary_read(osd_op_t *cur_op)
bool osd_t::prepare_primary_rw(osd_op_t *cur_op)
{
// PG number is calculated from the offset
// Our EC scheme stores data in fixed chunks equal to (K*block size)
// But we must not use K in the process of calculating the PG number
// So we calculate the PG number using a separate setting which should be per-inode (FIXME)
uint64_t start = cur_op->op.rw.offset;
uint64_t end = cur_op->op.rw.offset + cur_op->op.rw.len;
// FIXME Real pg_num should equal the below expression + 1
pg_num_t pg_num = (cur_op->op.rw.inode + cur_op->op.rw.offset / parity_block_size) % pg_count;
// FIXME: Postpone operations in inactive PGs
if (pg_num > pgs.size() || !(pgs[pg_num].state & PG_ACTIVE))
{
finish_primary_op(cur_op, -EINVAL);
return;
return false;
}
uint64_t pg_parity_size = bs_block_size * pgs[pg_num].pg_minsize;
object_id oid = {
@@ -80,56 +55,72 @@ void osd_t::exec_primary_read(osd_op_t *cur_op)
.stripe = (cur_op->op.rw.offset / parity_block_size) * parity_block_size +
((cur_op->op.rw.offset % parity_block_size) / pg_parity_size) * pg_parity_size
};
if (end > (oid.stripe + pg_parity_size) ||
(start % bs_disk_alignment) != 0 ||
(end % bs_disk_alignment) != 0)
if ((cur_op->op.rw.offset + cur_op->op.rw.len) > (oid.stripe + pg_parity_size) ||
(cur_op->op.rw.offset % bs_disk_alignment) != 0 ||
(cur_op->op.rw.len % bs_disk_alignment) != 0)
{
finish_primary_op(cur_op, -EINVAL);
return;
return false;
}
osd_primary_read_t *op_data = (osd_primary_read_t*)calloc(
sizeof(osd_primary_read_t) + sizeof(osd_read_stripe_t) * pgs[pg_num].pg_size, 1
osd_primary_op_data_t *op_data = (osd_primary_op_data_t*)calloc(
sizeof(osd_primary_op_data_t) + sizeof(osd_read_stripe_t) * pgs[pg_num].pg_size, 1
);
op_data->pg_num = pg_num;
op_data->oid = oid;
op_data->stripes = ((osd_read_stripe_t*)(op_data+1));
cur_op->op_data = op_data;
split_stripes(pgs[pg_num].pg_minsize, bs_block_size, start, end, op_data->stripes);
// Determine version
split_stripes(pgs[pg_num].pg_minsize, bs_block_size, (uint32_t)(cur_op->op.rw.offset - oid.stripe), cur_op->op.rw.len, op_data->stripes);
return true;
}
void osd_t::exec_primary_read(osd_op_t *cur_op)
{
if (!prepare_primary_rw(cur_op))
{
auto vo_it = pgs[pg_num].ver_override.find(oid);
op_data->target_ver = vo_it != pgs[pg_num].ver_override.end() ? vo_it->second : UINT64_MAX;
return;
}
if (pgs[pg_num].state == PG_ACTIVE)
osd_primary_op_data_t *op_data = (osd_primary_op_data_t*)cur_op->op_data;
auto & pg = pgs[op_data->pg_num];
for (int role = 0; role < pg.pg_minsize; role++)
{
op_data->stripes[role].read_start = op_data->stripes[role].req_start;
op_data->stripes[role].read_end = op_data->stripes[role].req_end;
}
// Determine version
auto vo_it = pg.ver_override.find(op_data->oid);
op_data->target_ver = vo_it != pg.ver_override.end() ? vo_it->second : UINT64_MAX;
if (pg.state == PG_ACTIVE)
{
// Fast happy-path
submit_read_subops(pgs[pg_num].pg_minsize, pgs[pg_num].cur_set.data(), cur_op);
cur_op->buf = alloc_read_buffer(op_data->stripes, pg.pg_minsize, 0);
submit_read_subops(pg.pg_minsize, pg.cur_set.data(), cur_op);
cur_op->send_list.push_back(cur_op->buf, cur_op->op.rw.len);
}
else
{
// PG may be degraded or have misplaced objects
spp::sparse_hash_map<object_id, pg_osd_set_state_t*> obj_states;
auto st_it = pgs[pg_num].obj_states.find(oid);
uint64_t* cur_set = (st_it != pgs[pg_num].obj_states.end()
auto st_it = pg.obj_states.find(op_data->oid);
uint64_t* cur_set = (st_it != pg.obj_states.end()
? st_it->second->read_target.data()
: pgs[pg_num].cur_set.data());
if (extend_missing_stripes(op_data->stripes, cur_set, pgs[pg_num].pg_minsize, pgs[pg_num].pg_size) < 0)
: pg.cur_set.data());
if (extend_missing_stripes(op_data->stripes, cur_set, pg.pg_minsize, pg.pg_size) < 0)
{
free(op_data);
finish_primary_op(cur_op, -EIO);
return;
}
// Submit reads
submit_read_subops(pgs[pg_num].pg_size, cur_set, cur_op);
op_data->pg_minsize = pgs[pg_num].pg_minsize;
op_data->pg_size = pgs[pg_num].pg_size;
cur_op->buf = alloc_read_buffer(op_data->stripes, pg.pg_size, 0);
submit_read_subops(pg.pg_size, cur_set, cur_op);
op_data->pg_minsize = pg.pg_minsize;
op_data->pg_size = pg.pg_size;
op_data->degraded = 1;
}
}
void osd_t::handle_primary_read_subop(osd_op_t *cur_op, int ok)
{
osd_primary_read_t *op_data = (osd_primary_read_t*)cur_op->op_data;
osd_primary_op_data_t *op_data = (osd_primary_op_data_t*)cur_op->op_data;
if (!ok)
op_data->errors++;
else
@@ -152,42 +143,15 @@ void osd_t::handle_primary_read_subop(osd_op_t *cur_op, int ok)
osd_read_stripe_t *stripes = op_data->stripes;
for (int role = 0; role < op_data->pg_minsize; role++)
{
if (stripes[role].end != 0 && stripes[role].real_end == 0)
if (stripes[role].read_end != 0 && stripes[role].missing)
{
int prev = -2;
for (int other = 0; other < op_data->pg_size; other++)
{
if (other != role)
{
if (prev == -2)
{
prev = other;
}
else if (prev >= 0)
{
memxor(
cur_op->buf + stripes[prev].pos + (stripes[prev].real_start - stripes[role].start),
cur_op->buf + stripes[other].pos + (stripes[other].real_start - stripes[other].start),
cur_op->buf + stripes[role].pos, stripes[role].end - stripes[role].start
);
prev = -1;
}
else
{
memxor(
cur_op->buf + stripes[role].pos,
cur_op->buf + stripes[other].pos + (stripes[other].real_start - stripes[role].start),
cur_op->buf + stripes[role].pos, stripes[role].end - stripes[role].start
);
}
}
}
reconstruct_stripe(stripes, op_data->pg_size, role);
}
if (stripes[role].end != 0)
if (stripes[role].req_end != 0)
{
// Send buffer in parts to avoid copying
cur_op->send_list.push_back(
cur_op->buf + stripes[role].pos + (stripes[role].real_start - stripes[role].start), stripes[role].end
stripes[role].read_buf + (stripes[role].read_start - stripes[role].req_start), stripes[role].req_end
);
}
}
@@ -198,75 +162,38 @@ void osd_t::handle_primary_read_subop(osd_op_t *cur_op, int ok)
}
}
int osd_t::extend_missing_stripes(osd_read_stripe_t *stripes, osd_num_t *osd_set, int minsize, int size)
{
for (int role = 0; role < minsize; role++)
{
if (stripes[role].end != 0 && osd_set[role] == 0)
{
stripes[role].real_start = stripes[role].real_end = 0;
// Stripe is missing. Extend read to other stripes.
// We need at least pg_minsize stripes to recover the lost part.
int exist = 0;
for (int j = 0; j < size; j++)
{
if (osd_set[j] != 0)
{
if (stripes[j].real_end == 0 || j >= minsize)
{
stripes[j].real_start = stripes[role].start;
stripes[j].real_end = stripes[role].end;
}
else
{
stripes[j].real_start = stripes[j].start < stripes[role].start ? stripes[j].start : stripes[role].start;
stripes[j].real_end = stripes[j].end > stripes[role].end ? stripes[j].end : stripes[role].end;
}
exist++;
if (exist >= minsize)
{
break;
}
}
}
if (exist < minsize)
{
// Less than minsize stripes are available for this object
return -1;
}
}
}
return 0;
}
void osd_t::submit_read_subops(int read_pg_size, const uint64_t* osd_set, osd_op_t *cur_op)
{
osd_primary_read_t *op_data = (osd_primary_read_t*)cur_op->op_data;
osd_primary_op_data_t *op_data = (osd_primary_op_data_t*)cur_op->op_data;
osd_read_stripe_t *stripes = op_data->stripes;
uint64_t buf_size = 0;
int n_subops = 0;
// Allocate subops
int n_subops = 0, force_read = -1;
for (int role = 0; role < read_pg_size; role++)
{
if (stripes[role].real_end != 0)
if (osd_set[role] == this->osd_num || osd_set[role] != 0 && force_read == -1)
{
force_read = role;
}
if (osd_set[role] != 0 && stripes[role].read_end != 0)
{
n_subops++;
stripes[role].pos = buf_size;
buf_size += stripes[role].real_end - stripes[role].real_start;
}
else if (stripes[role].end != 0)
{
stripes[role].pos = buf_size;
buf_size += stripes[role].end - stripes[role].start;
}
}
if (!n_subops && op_data->should_read_version)
{
n_subops = 1;
}
else
{
force_read = -1;
}
osd_op_t *subops = new osd_op_t[n_subops];
cur_op->buf = memalign(MEM_ALIGNMENT, buf_size);
op_data->n_subops = n_subops;
op_data->subops = subops;
int subop = 0;
for (int role = 0; role < read_pg_size; role++)
{
if (stripes[role].real_end == 0)
if (stripes[role].read_end == 0 && force_read != role)
{
continue;
}
@@ -277,7 +204,7 @@ void osd_t::submit_read_subops(int read_pg_size, const uint64_t* osd_set, osd_op
{
subops[subop].bs_op = {
.opcode = BS_OP_READ,
.callback = [this, cur_op](blockstore_op_t *subop)
.callback = [cur_op, this](blockstore_op_t *subop)
{
handle_primary_read_subop(cur_op, subop->retval == subop->len);
},
@@ -286,9 +213,9 @@ void osd_t::submit_read_subops(int read_pg_size, const uint64_t* osd_set, osd_op
.stripe = op_data->oid.stripe | role,
},
.version = op_data->target_ver,
.offset = stripes[role].real_start,
.len = stripes[role].real_end - stripes[role].real_start,
.buf = cur_op->buf + stripes[role].pos,
.offset = stripes[role].read_start,
.len = stripes[role].read_end - stripes[role].read_start,
.buf = stripes[role].read_buf,
};
bs->enqueue_op(&subops[subop].bs_op);
}
@@ -307,11 +234,11 @@ void osd_t::submit_read_subops(int read_pg_size, const uint64_t* osd_set, osd_op
.stripe = op_data->oid.stripe | role,
},
.version = op_data->target_ver,
.offset = stripes[role].real_start,
.len = stripes[role].real_end - stripes[role].real_start,
.offset = stripes[role].read_start,
.len = stripes[role].read_end - stripes[role].read_start,
};
subops[subop].buf = cur_op->buf + stripes[role].pos;
subops[subop].callback = [this, cur_op](osd_op_t *subop)
subops[subop].buf = stripes[role].read_buf;
subops[subop].callback = [cur_op, this](osd_op_t *subop)
{
// so it doesn't get freed. FIXME: do it better
subop->buf = NULL;
@@ -326,31 +253,44 @@ void osd_t::submit_read_subops(int read_pg_size, const uint64_t* osd_set, osd_op
void osd_t::exec_primary_write(osd_op_t *cur_op)
{
// "RAID5" EC(k+1) parity modification variants (Px = previous, Nx = new):
// 1,2,3 write N1 -> read P2 -> write N3 = N1^P2
// _,2,3 write N1 -> read P2 -> write N3 = N1^P2
// 1,_,3 write N1 -> read P1,P3 -> write N3 = N1^P3^P1
// 1,2,_ write N1 -> read nothing
// 1,2,3,4 write N1 -> read P2,P3 -> write N4 = N1^P2^P3
// (or read P1,P4 -> write N4 = N1^P4^P1)
// 1,_,3,4 write N1 -> read P1,P4 -> write N4 = N1^P4^P1
// _,2,3,4 write N1 -> read P2,P3 -> write N4 = N1^P3^P2
// 1,2,3,4,5 write N1 -> read P1,P5 -> write N5 = N1^P5^P1
// 1,_,3,4,5 write N1 -> read P1,P5 -> write N5 = N1^P5^P1
// _,2,3,4,5 write N1 -> read P2,P3,P4 -> write N5 = N1^P2^P3^P4
//
// I.e, when we write a part:
// 1) If parity is missing and all other parts are available:
// just overwrite the part
// 2) If the modified part is missing and all other parts are available:
// read all other parts except parity, xor them all with the new data
// 3) If all parts are available and size=3:
// read the paired data stripe, xor it with the new data
// 4) Otherwise:
// read old parity and old data of the modified part, xor them both with the new data
// Ouсh. Scary. But faster than the generic variant.
//
// Generic variant for jerasure is a simple RMW process: read all -> decode -> modify -> encode -> write
if (!prepare_primary_rw(cur_op))
{
return;
}
osd_primary_op_data_t *op_data = (osd_primary_op_data_t*)cur_op->op_data;
auto & pg = pgs[op_data->pg_num];
// Check if actions are pending for this object
auto act_it = pg.obj_stab_actions.lower_bound((obj_piece_id_t){
.oid = op_data->oid,
.osd_num = 0,
});
if (act_it != pg.obj_stab_actions.end() &&
act_it->first.oid.inode == op_data->oid.inode &&
(act_it->first.oid.stripe & ~STRIPE_MASK) == op_data->oid.stripe)
{
// FIXME postpone the request until actions are done
free(op_data);
finish_primary_op(cur_op, -EIO);
return;
}
// Check if there are other write requests to the same object
// Determine blocks to read
op_data->rmw_buf = calc_rmw_reads(cur_op->buf, op_data->stripes, pg.cur_set.data(), pg.pg_size, pg.pg_minsize, pg.pg_cursize);
op_data->should_read_version = true;
// Read required blocks
submit_read_subops(pg.pg_size, pg.cur_set.data(), cur_op);
// ->>>>> Continue from the callback
// Calculate parity
calc_rmw_parity(op_data->stripes, op_data->pg_size);
// Save version override if degraded
// Send writes
// ->>>>> Continue from the callback
// Remember version as unstable
// Remove version override if degraded
}