osd/ReplicatedPG: greedily take write_lock for copyfrom finish, snapdir

In the cases where we are taking a write lock and are careful
enough that we know we should succeed (i.e, we assert(got)),
use the get_write_greedy() variant that skips the checks for
waiters (be they ops or backfill) that are normally necessary
to avoid starvation.  We don't care about staration here
because our op is already in-progress and can't easily be
aborted, and new ops won't start because they do make those
checks.

Fixes: #8889
Signed-off-by: Sage Weil <sage@redhat.com>

diff --git a/src/osd/ReplicatedPG.cc b/src/osd/ReplicatedPG.cc
index 3933cd0226311d3ef196c7bb0d67cac1e6ce644b..f134830e2ad4ee1a909b6d9a92fc0f1102e67148 100644 (file)
--- a/src/osd/ReplicatedPG.cc
+++ b/src/osd/ReplicatedPG.cc
@@ -4852,7 +4852,7 @@ void ReplicatedPG::make_writeable(OpContext *ctx)
       if (pool.info.require_rollback())
        ctx->clone_obc->attr_cache = ctx->obc->attr_cache;
       snap_oi = &ctx->clone_obc->obs.oi;
-      bool got = ctx->clone_obc->get_write(ctx->op);
+      bool got = ctx->clone_obc->get_write_greedy(ctx->op);
       assert(got);
     } else {
       snap_oi = &static_snap_oi;
@@ -5158,7 +5158,7 @@ void ReplicatedPG::finish_ctx(OpContext *ctx, int log_op_type, bool maintain_ssc
                                        0, osd_reqid_t(), ctx->mtime));
 
       ctx->snapset_obc = get_object_context(snapoid, true);
-      bool got = ctx->snapset_obc->get_write(ctx->op);
+      bool got = ctx->snapset_obc->get_write_greedy(ctx->op);
       assert(got);
       ctx->release_snapset_obc = true;
       if (pool.info.require_rollback() && !ctx->snapset_obc->obs.exists) {