From 73beb7f9378182cc3901fe86c4f1f5d5d98169a6 Mon Sep 17 00:00:00 2001
From: "Yan, Zheng" <zyan@redhat.com>
Date: Mon, 26 Oct 2015 20:34:42 +0800
Subject: [PATCH] client: don't invalidate page cache when inode is no longer
 used

libcephfs does not keep cached data when inode is not used by any
open file. This behaviour is not friendly for workload hat repeatly
read files.

Signed-off-by: Yan, Zheng <zyan@redhat.com>
---
 src/client/Client.cc | 29 +++++++++++++----------------
 1 file changed, 13 insertions(+), 16 deletions(-)

diff --git a/src/client/Client.cc b/src/client/Client.cc
index 3c1acf9c94d..99e9e706834 100644
--- a/src/client/Client.cc
+++ b/src/client/Client.cc
@@ -2857,16 +2857,9 @@ void Client::put_cap_ref(Inode *in, int cap)
     if (last & CEPH_CAP_FILE_CACHE) {
       ldout(cct, 5) << "put_cap_ref dropped last FILE_CACHE ref on " << *in << dendl;
       ++put_nref;
-      // release clean pages too, if we dont want RDCACHE
-      if (!(in->caps_wanted() & CEPH_CAP_FILE_CACHE))
-	drop |= CEPH_CAP_FILE_CACHE;
     }
-    if (drop) {
-      if (drop & CEPH_CAP_FILE_CACHE)
-	_invalidate_inode_cache(in);
-      else
+    if (drop)
 	check_caps(in, false);
-    }
     if (put_nref)
       put_inode(in, put_nref);
   }
@@ -3087,6 +3080,10 @@ void Client::check_caps(Inode *in, bool is_delayed)
     wanted |= CEPH_CAP_FILE_EXCL;
   }
 
+  int implemented;
+  int issued = in->caps_issued(&implemented);
+  int revoking = implemented & ~issued;
+
   int retain = wanted | used | CEPH_CAP_PIN;
   if (!unmounting) {
     if (wanted)
@@ -3098,6 +3095,8 @@ void Client::check_caps(Inode *in, bool is_delayed)
   ldout(cct, 10) << "check_caps on " << *in
 	   << " wanted " << ccap_string(wanted)
 	   << " used " << ccap_string(used)
+	   << " issued " << ccap_string(issued)
+	   << " revoking " << ccap_string(revoking)
 	   << " is_delayed=" << is_delayed
 	   << dendl;
 
@@ -3107,6 +3106,10 @@ void Client::check_caps(Inode *in, bool is_delayed)
   if (in->caps.empty())
     return;   // guard if at end of func
 
+  if ((revoking & (CEPH_CAP_FILE_CACHE | CEPH_CAP_FILE_LAZYIO)) &&
+      (used & CEPH_CAP_FILE_CACHE) && !(used & CEPH_CAP_FILE_BUFFER))
+    _release(in);
+
   if (!in->cap_snaps.empty())
     flush_snaps(in);
 
@@ -3130,7 +3133,7 @@ void Client::check_caps(Inode *in, bool is_delayed)
     if (in->auth_cap && cap != in->auth_cap)
       cap_used &= ~in->auth_cap->issued;
 
-    int revoking = cap->implemented & ~cap->issued;
+    revoking = cap->implemented & ~cap->issued;
     
     ldout(cct, 10) << " cap mds." << mds
 	     << " issued " << ccap_string(cap->issued)
@@ -7132,13 +7135,7 @@ int Client::_release_fh(Fh *f)
   if (in->snapid == CEPH_NOSNAP) {
     if (in->put_open_ref(f->mode)) {
       _flush(in, new C_Client_FlushComplete(this, in));
-      // release clean pages too, if we dont want RDCACHE
-      if (in->cap_refs[CEPH_CAP_FILE_CACHE] == 0 &&
-	  !(in->caps_wanted() & CEPH_CAP_FILE_CACHE) &&
-	  !objectcacher->set_is_empty(&in->oset))
-	_invalidate_inode_cache(in);
-      else
-	check_caps(in, false);
+      check_caps(in, false);
     }
   } else {
     assert(in->snap_cap_refs > 0);