crimson/os/seastore/cache: do seperated add_to_read_set steps for

initial pending and stable writing extents

Fixes: https://tracker.ceph.com/issues/70976
Signed-off-by: Xuehan Xu <[email protected]>
Signed-off-by: Yingxin Cheng <[email protected]>

Author: xxhdx1985126

src/crimson/os/seastore/cache.h

@@ -471,11 +471,19 @@ class Cache : public ExtentTransViewRetriever {
 
     const auto t_src = t.get_src();
     auto ext_type = extent->get_type();
+    // FIXME: retired-placeholder isn't linked in the lba tree yet.
+    //   We think it's still working because:
+    //   1. A retired-placeholder must be an ObjectDataBlock
+    //   2. Per rados object, no read is possible during write,
+    //      and write cannot be parallel
+    assert(!is_retired_placeholder_type(ext_type));
     cache_access_stats_t& access_stats = get_by_ext(
       get_by_src(stats.access_by_src_ext, t_src),
       ext_type);
 
     CachedExtent* p_extent;
+    bool needs_step_2 = false;
+    bool needs_touch = false;
     if (extent->is_stable()) {
       p_extent = extent->get_transactional_view(t);
       if (p_extent != extent.get()) {
@@ -495,16 +503,22 @@ class Cache : public ExtentTransViewRetriever {
       } else {
         // stable from trans-view
         assert(!p_extent->is_pending_in_trans(t.get_trans_id()));
-        if (t.maybe_add_to_read_set(p_extent)) {
+        auto ret = t.maybe_add_to_read_set(p_extent);
+        if (ret.added) {
           if (p_extent->is_dirty()) {
             ++access_stats.cache_dirty;
             ++stats.access.cache_dirty;
           } else {
             ++access_stats.cache_lru;
             ++stats.access.cache_lru;
           }
-          touch_extent(*p_extent, &t_src, t.get_cache_hint());
+          if (ret.is_paddr_known) {
+            touch_extent(*p_extent, &t_src, t.get_cache_hint());
+          } else {
+            needs_touch = true;
+          }
         } else {
+          // already exists
           if (p_extent->is_dirty()) {
             ++access_stats.trans_dirty;
             ++stats.access.trans_dirty;
@@ -513,6 +527,9 @@ class Cache : public ExtentTransViewRetriever {
             ++stats.access.trans_lru;
           }
         }
+        // step 2 maybe reordered after wait_io(),
+        // always try step 2 if paddr unknown
+        needs_step_2 = !ret.is_paddr_known;
       }
     } else {
       assert(!extent->is_stable_writting());
@@ -538,7 +555,13 @@ class Cache : public ExtentTransViewRetriever {
 
     return trans_intr::make_interruptible(
       p_extent->wait_io()
-    ).then_interruptible([p_extent] {
+    ).then_interruptible([p_extent, needs_touch, needs_step_2, &t, this, &t_src] {
+      if (needs_step_2) {
+	t.maybe_add_to_read_set_step_2(p_extent);
+      }
+      if (needs_touch) {
+	touch_extent(*p_extent, &t_src, t.get_cache_hint());
+      }
       return get_extent_iertr::make_ready_future<CachedExtentRef>(
         CachedExtentRef(p_extent));
     });