os/bluestore: fix assertion in StupidAllocator::get_fragmentation

One might face an assertion (assert(intervals <= max_intervals))
in StupidAllocator::get_fragmentation method for clusters created
by early Luminous releases and before. The root cause is that block
volume size wasn't aligned with min_alloc_size and hence we missed
that last fraction interval during max_interval calculation.

Fixes: https://tracker.ceph.com/issues/43297
Note: This was a clean cherry-pick from master, but p2roundup was
introduced since mimic release, use P2ROUNDUP instead

Signed-off-by: Igor Fedotov <ifedotov@suse.com>
(cherry picked from commit a60b2316ce0bed28c468043cff4cab5e61b1a694)
Signed-off-by: Lei Liu <liulei3@360.cn>

diff --git a/src/os/bluestore/StupidAllocator.cc b/src/os/bluestore/StupidAllocator.cc
index 4ea171e8598170e6baedbd33c87eb691b920771d..d174de471adf81ec07e408926e36d9c774f8c302 100644 (file)
--- a/src/os/bluestore/StupidAllocator.cc
+++ b/src/os/bluestore/StupidAllocator.cc
@@ -258,7 +258,7 @@ double StupidAllocator::get_fragmentation(uint64_t alloc_unit)
   uint64_t intervals = 0;
   {
     std::lock_guard<std::mutex> l(lock);
-    max_intervals = num_free / alloc_unit;
+    max_intervals = P2ROUNDUP(num_free, alloc_unit) / alloc_unit;
     for (unsigned bin = 0; bin < free.size(); ++bin) {
       intervals += free[bin].num_intervals();
     }