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

Implement CAS writes

Browse Source 
From now on, reads will return the server-side object version numbers
and writes and deletes will have an additional "version" parameter
which, if set to a non-zero value, will be atomically compared with
the current version of the object plus 1 and the modification will
fail if it doesn't match.

This feature opens the road to correct online flattening of snapshot
layers and other interesting things.
This commit is contained in:
Vitaliy Filippov
2021-06-15 00:12:35 +03:00
parent f9fe72d40a
commit 891250d355
7 changed files with 55 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/osd_primary.cpp
+10 -1
View File
@@ -222,6 +222,7 @@ resume_2:
finish_op(cur_op, op_data->epipe > 0 ? -EPIPE : -EIO);
return;
}
cur_op->reply.rw.version = op_data->fact_ver;
cur_op->reply.rw.bitmap_len = op_data->pg_data_size * clean_entry_bitmap_size;
if (op_data->degraded)
{
@@ -343,6 +344,12 @@ resume_3:
pg_cancel_write_queue(pg, cur_op, op_data->oid, op_data->epipe > 0 ? -EPIPE : -EIO);
return;
}
// Check CAS version
if (cur_op->req.rw.version && op_data->fact_ver != (cur_op->req.rw.version-1))
{
cur_op->reply.hdr.retval = -EINTR;
goto continue_others;
}
// Save version override for parallel reads
pg.ver_override[op_data->oid] = op_data->fact_ver;
// Submit deletes
@@ -370,6 +377,8 @@ resume_5:
free_object_state(pg, &op_data->object_state);
}
pg.total_count--;
cur_op->reply.hdr.retval = 0;
continue_others:
osd_op_t *next_op = NULL;
auto next_it = pg.write_queue.find(op_data->oid);
if (next_it != pg.write_queue.end() && next_it->second == cur_op)
@@ -378,7 +387,7 @@ resume_5:
if (next_it != pg.write_queue.end() && next_it->first == op_data->oid)
next_op = next_it->second;
}
finish_op(cur_op, cur_op->req.rw.len);
finish_op(cur_op, cur_op->reply.hdr.retval);
if (next_op)
{
// Continue next write to the same object