From e30b2577d94fec4e74feeecd940569880bc883a5 Mon Sep 17 00:00:00 2001
From: Matt Benjamin <mbenjamin@redhat.com>
Date: Thu, 6 Jun 2019 16:54:43 -0400
Subject: [PATCH] rgw_file: permit lookup_handle to lookup root_fh

Originally, root_fh was reachable from RGWLibFS::fh_cache, but
this was problematic as it has infinite lifetime and so is not
present in RGWLibFS::fs_lru.

To fix the above, RGWLibFS::root_fh came to live unhooked from the
handle caches which works because nfs-ganesha/the application
always has an instance handle.  However, this silently breaks
READDIR event invalidation.

Fixes: https://tracker.ceph.com/issues/40196

Signed-off-by: Matt Benjamin <mbenjamin@redhat.com>
(cherry picked from commit 547cb9f87b72440cb8a1d496ac5cfb37b2d83cc7)
---
 src/rgw/rgw_file.cc | 22 +++++++++++++++-------
 src/rgw/rgw_file.h  |  9 ++++++---
 2 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/src/rgw/rgw_file.cc b/src/rgw/rgw_file.cc
index 5c0a4d3beffbd..301322223dbc4 100644
--- a/src/rgw/rgw_file.cc
+++ b/src/rgw/rgw_file.cc
@@ -993,7 +993,12 @@ namespace rgw {
 	<< dendl;
       {
 	lock_guard guard(state.mtx); /* LOCKED */
-	/* just return if no events */
+	lsubdout(get_context(), rgw, 15)
+	  << "GC: processing"
+	  << " count=" << events.size()
+	  << " events"
+	  << dendl;
+        /* just return if no events */
 	if (events.empty()) {
 	  return;
 	}
@@ -1189,6 +1194,11 @@ namespace rgw {
     struct timespec now;
     CephContext* cct = fs->get_context();
 
+    lsubdout(cct, rgw, 10)
+      << __func__ << " readdir called on "
+      << object_name()
+      << dendl;
+
     directory* d = get<directory>(&variant_type);
     if (d) {
       (void) clock_gettime(CLOCK_MONOTONIC_COARSE, &now); /* !LOCKED */
@@ -1215,9 +1225,6 @@ namespace rgw {
 	  set_nlink(2);
 	inc_nlink(req.d_count);
 	*eof = req.eof();
-	event ev(event::type::READDIR, get_key(), state.atime);
-	lock_guard sguard(fs->state.mtx);
-	fs->state.push_event(ev);
       }
     } else {
       RGWReaddirRequest req(cct, fs->get_user(), this, rcb, cb_arg, offset);
@@ -1230,12 +1237,13 @@ namespace rgw {
 	  set_nlink(2);
 	inc_nlink(req.d_count);
 	*eof = req.eof();
-	event ev(event::type::READDIR, get_key(), state.atime);
-	lock_guard sguard(fs->state.mtx);
-	fs->state.push_event(ev);
       }
     }
 
+    event ev(event::type::READDIR, get_key(), state.atime);
+    lock_guard sguard(fs->state.mtx);
+    fs->state.push_event(ev);
+
     lsubdout(fs->get_context(), rgw, 15)
       << __func__
       << " final link count=" << state.nlink
diff --git a/src/rgw/rgw_file.h b/src/rgw/rgw_file.h
index 1bd9433240370..e45aa58cb61ad 100644
--- a/src/rgw/rgw_file.h
+++ b/src/rgw/rgw_file.h
@@ -1205,10 +1205,13 @@ namespace rgw {
 			    RGWFileHandle::FHCache::FLAG_LOCK);
       /* LATCHED */
       if (! fh) {
+	if (unlikely(fhk == root_fh.fh.fh_hk)) {
+	  /* lookup for root of this fs */
+	  fh = &root_fh;
+	  goto out;
+	}
 	lsubdout(get_context(), rgw, 0)
-	  << __func__ << " handle lookup failed <"
-	  << fhk.fh_hk.bucket << "," << fhk.fh_hk.object << ">"
-	  << "(need persistent handles)"
+	  << __func__ << " handle lookup failed " << fhk
 	  << dendl;
 	goto out;
       }
-- 
2.39.5