From: Igor Fedotov <igor.fedotov@croit.io>
Date: Thu, 12 Dec 2024 05:29:17 +0000 (+0300)
Subject: libcephfs/client: pin inode/dentry for an opened directory
X-Git-Tag: v20.0.0~197^2~2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=7b8a86f105f66eb0d39b6c4920a722eedd88fedd;p=ceph.git

libcephfs/client: pin inode/dentry for an opened directory

Fixes: https://tracker.ceph.com/issues/69092

Signed-off-by: Igor Fedotov <igor.fedotov@croit.io>
---

diff --git a/src/client/Client.cc b/src/client/Client.cc
index c404057b929d..eb35485cc7ea 100644
--- a/src/client/Client.cc
+++ b/src/client/Client.cc
@@ -10431,8 +10431,17 @@ int Client::_open(Inode *in, int flags, mode_t mode, Fh **fhp,
 
   // success?
   if (result >= 0) {
-    if (fhp)
+    if (fhp) {
       *fhp = _create_fh(in, flags, cmode, perms);
+      // ceph_flags_sys2wire/ceph_flags_to_mode() calls above transforms O_DIRECTORY flag
+      // into CEPH_FILE_MODE_PIN mode. Although this mode is used at server size
+      // we [ab]use it here to determine whether we should pin inode to prevent from
+      // undesired cache eviction.
+      if (cmode == CEPH_FILE_MODE_PIN) {
+        ldout(cct, 20) << " pinning ll_get() call for " << *in << dendl;
+        _ll_get(in);
+      }
+    }
   } else {
     in->put_open_ref(cmode);
   }
@@ -10489,6 +10498,10 @@ int Client::_close(int fd)
   Fh *fh = get_filehandle(fd);
   if (!fh)
     return -CEPHFS_EBADF;
+  if (fh->mode == CEPH_FILE_MODE_PIN) {
+    ldout(cct, 20) << " unpinning ll_put() call for " << *(fh->inode.get()) << dendl;
+    _ll_put(fh->inode.get(), 1);
+  }
   int err = _release_fh(fh);
   fd_map.erase(fd);
   put_fd(fd);