librbd: start perf counters after id is initialized

[trociny]

So the perf counters section name has non-empty id.

Fixes: #13720
Signed-off-by: Mykola Golub mgolub@mirantis.com

[dillaman]

lgtm

[trociny]

Unfortunately, it looks this change causes crush when opening e.g. nonexistent image, because ictx->init() returns earlier than perf counters are started, and on unsuccessful init() we still do close_image(), which calls flush():

#0  PerfCounters::inc (this=0x0, idx=26010, amt=1) at common/perf_counters.cc:142
#1  0x00007ffff5437912 in librbd::flush (ictx=0x555557887630) at librbd/internal.cc:3814
#2  0x00007ffff5437fa5 in librbd::close_image (ictx=ictx@entry=0x555557887630) at librbd/internal.cc:3119
#3  0x00007ffff543ffb7 in librbd::open_image (ictx=0x555557887630) at librbd/internal.cc:3094
#4  0x00007ffff53c72b0 in librbd::RBD::open_read_only (this=0x7fffffffcd6b, io_ctx=..., image=..., name=0x555557879350 "xxx", 
    snap_name=0x0) at librbd/librbd.cc:265

It looks like we have some problems with loic-bot because I don't see it was running for this pr?

[dillaman]

@trociny This should have been fixed on master -- see ticket 13740 / PR #6523

[trociny]

@dillaman thanks!