From: Xiubo Li <xiubli@redhat.com>
Date: Mon, 8 Jul 2024 07:53:28 +0000 (+0800)
Subject: mds: avoid acquiring the wrlock twice for a single request
X-Git-Tag: testing/wip-vshankar-testing-20250523.134245-squid-debug~60^2
X-Git-Url: http://git.apps.os.sepia.ceph.com/?a=commitdiff_plain;h=d5d623382da886a008f87a570e631b4ba4a6b7f5;p=ceph-ci.git

mds: avoid acquiring the wrlock twice for a single request

In case the current request has lock cache attached and then the
lock cache must have already acquired the wrlock of filelock. So
currently the path_traverse() will acquire the wrlock twice and
possibly caused deadlock by itself.

Fixes: https://tracker.ceph.com/issues/65607
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Sunnatillo <sunnat.samadov@est.tech>
(cherry picked from commit 276b81a55d391b52f9772fc76b86b845eb3854a6)

Conflicts:
    src/mds/MDSRank.cc

This commit moves around the config `mds_allow_async_dirops` in
the tracked keys which caused the conflict - avoid the move.
---

diff --git a/src/mds/MDCache.cc b/src/mds/MDCache.cc
index f00e588c7a2..ead3868520e 100644
--- a/src/mds/MDCache.cc
+++ b/src/mds/MDCache.cc
@@ -8509,8 +8509,11 @@ int MDCache::path_traverse(const MDRequestRef& mdr, MDSContextFactory& cf,
 	  lov.add_xlock(&dn->lock);
 	} else {
 	  // force client to flush async dir operation if necessary
-	  if (cur->filelock.is_cached())
+	  if (cur->filelock.is_cached() &&
+	      !(mdr->lock_cache &&
+		static_cast<const MutationImpl*>(mdr->lock_cache)->is_wrlocked(&cur->filelock))) {
 	    lov.add_wrlock(&cur->filelock);
+	  }
 	  lov.add_rdlock(&dn->lock);
 	}
 	if (!mds->locker->acquire_locks(mdr, lov)) {
@@ -8630,8 +8633,11 @@ int MDCache::path_traverse(const MDRequestRef& mdr, MDSContextFactory& cf,
 		lov.add_xlock(&dn->lock);
 	      } else {
 		// force client to flush async dir operation if necessary
-		if (cur->filelock.is_cached())
+		if (cur->filelock.is_cached() &&
+		    !(mdr->lock_cache &&
+		      static_cast<const MutationImpl*>(mdr->lock_cache)->is_wrlocked(&cur->filelock))) {
 		  lov.add_wrlock(&cur->filelock);
+		}
 		lov.add_rdlock(&dn->lock);
 	      }
 	      if (!mds->locker->acquire_locks(mdr, lov)) {