os/bluestore: fix duplicate allocations in bmap allocator

Fixes: http://tracker.ceph.com/issues/40080
Signed-off-by: Igor Fedotov <ifedotov@suse.com>
(cherry picked from commit eac81bc85970287fce60178e80c37628b3df0e7d)

 Conflicts:
	src/os/bluestore/fastbmap_allocator_impl.cc
        ceph_assert vs. assert mismatch

diff --git a/src/os/bluestore/fastbmap_allocator_impl.cc b/src/os/bluestore/fastbmap_allocator_impl.cc
index 1eff326d4f4a2409b13fdea9bec419d08fdaa3ba..a46cbc79a7e45268f98aacb28054de06998639c5 100755 (executable)
--- a/src/os/bluestore/fastbmap_allocator_impl.cc
+++ b/src/os/bluestore/fastbmap_allocator_impl.cc
@@ -363,7 +363,7 @@ interval_t AllocatorLevel01Loose::_allocate_l1_contiguous(uint64_t length,
     if (ctx.affordable_len) {
       assert(ctx.affordable_len >= length);
       assert((length % l0_granularity) == 0);
-      auto pos_start = ctx.affordable_offs + length / l0_granularity;
+      auto pos_start = ctx.affordable_offs / l0_granularity;
       auto pos_end = (ctx.affordable_offs + length) / l0_granularity;
       _mark_alloc_l1_l0(pos_start, pos_end);
       res = interval_t(ctx.affordable_offs, length);