From: Jianpeng Ma <jianpeng.ma@intel.com>
Date: Wed, 10 Jun 2015 07:56:59 +0000 (+0800)
Subject: osdc: Make librbd cache handle NOCACHE fadvise flag.
X-Git-Tag: v9.0.3~166^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=e68ea2c9421160acdcaa7e8bcee7d46a5b46ceed;p=ceph.git

osdc: Make librbd cache handle NOCACHE fadvise flag.

Signed-off-by: Jianpeng Ma <jianpeng.ma@intel.com>
---

diff --git a/src/osdc/ObjectCacher.cc b/src/osdc/ObjectCacher.cc
index db6779c7dbf0..daff1052020b 100644
--- a/src/osdc/ObjectCacher.cc
+++ b/src/osdc/ObjectCacher.cc
@@ -34,6 +34,7 @@ ObjectCacher::BufferHead *ObjectCacher::Object::split(BufferHead *left, loff_t o
 
   //inherit and if later access, this auto clean.
   right->set_dontneed(left->get_dontneed());
+  right->set_nocache(left->get_nocache());
 
   right->last_write_tid = left->last_write_tid;
   right->last_read_tid = left->last_read_tid;
@@ -103,6 +104,7 @@ void ObjectCacher::Object::merge_left(BufferHead *left, BufferHead *right)
   left->last_write = MAX( left->last_write, right->last_write );
 
   left->set_dontneed(right->get_dontneed() ? left->get_dontneed() : false);
+  left->set_nocache(right->get_nocache() ? left->get_nocache() : false);
 
   // waiters
   for (map<loff_t, list<Context*> >::iterator p = right->waitfor_read.begin();
@@ -918,6 +920,8 @@ void ObjectCacher::bh_write_commit(int64_t poolid, sobject_t oid, loff_t start,
       if (r >= 0) {
 	// ok!  mark bh clean and error-free
 	mark_clean(bh);
+	if (bh->get_nocache())
+	  bh_lru_rest.lru_bottouch(bh);
 	hit.push_back(bh);
 	ldout(cct, 10) << "bh_write_commit clean " << *bh << dendl;
       } else {
@@ -1068,6 +1072,7 @@ int ObjectCacher::_readx(OSDRead *rd, ObjectSet *oset, Context *onfinish,
   uint64_t total_bytes_read = 0;
   map<uint64_t, bufferlist> stripe_map;  // final buffer offset -> substring
   bool dontneed = rd->fadvise_flags & LIBRADOS_OP_FLAG_FADVISE_DONTNEED;
+  bool nocache = rd->fadvise_flags & LIBRADOS_OP_FLAG_FADVISE_NOCACHE;
 
   /*
    * WARNING: we can only meaningfully return ENOENT if the read request
@@ -1172,6 +1177,7 @@ int ObjectCacher::_readx(OSDRead *rd, ObjectSet *oset, Context *onfinish,
 	  bh_remove(o, bh_it->second);
 	  delete bh_it->second;
 	} else {
+	  bh_it->second->set_nocache(nocache);
 	  bh_read(bh_it->second, rd->fadvise_flags);
 	  if ((success && onfinish) || last != missing.end())
 	    last = bh_it;
@@ -1218,7 +1224,10 @@ int ObjectCacher::_readx(OSDRead *rd, ObjectSet *oset, Context *onfinish,
 	  error = bh->error;
         bytes_in_cache += bh->length();
 
-	touch_bh(bh);
+	if (bh->get_nocache() && bh->is_clean())
+	  bh_lru_rest.lru_bottouch(bh);
+	else
+	  touch_bh(bh);
 	//must be after touch_bh because touch_bh set dontneed false
 	if (dontneed &&
 	    ((loff_t)ex_it->offset <= bh->start() && (bh->end() <= (loff_t)(ex_it->offset + ex_it->length)))) {
@@ -1361,6 +1370,7 @@ int ObjectCacher::writex(OSDWrite *wr, ObjectSet *oset, Context *onfreespace)
   uint64_t bytes_written = 0;
   uint64_t bytes_written_in_flush = 0;
   bool dontneed = wr->fadvise_flags & LIBRADOS_OP_FLAG_FADVISE_DONTNEED;
+  bool nocache = wr->fadvise_flags & LIBRADOS_OP_FLAG_FADVISE_NOCACHE;
   
   for (vector<ObjectExtent>::iterator ex_it = wr->extents.begin();
        ex_it != wr->extents.end();
@@ -1372,6 +1382,7 @@ int ObjectCacher::writex(OSDWrite *wr, ObjectSet *oset, Context *onfreespace)
 
     // map it all into a single bufferhead.
     BufferHead *bh = o->map_write(wr);
+    bool missing = bh->is_missing();
     bh->snapc = wr->snapc;
     
     bytes_written += bh->length();
@@ -1411,6 +1422,8 @@ int ObjectCacher::writex(OSDWrite *wr, ObjectSet *oset, Context *onfreespace)
     mark_dirty(bh);
     if (dontneed)
       bh->set_dontneed(true);
+    else if (nocache && missing)
+      bh->set_nocache(true);
     else
       touch_bh(bh);
 
diff --git a/src/osdc/ObjectCacher.h b/src/osdc/ObjectCacher.h
index 0bef597fdf65..eeed83a52313 100644
--- a/src/osdc/ObjectCacher.h
+++ b/src/osdc/ObjectCacher.h
@@ -102,6 +102,7 @@ class ObjectCacher {
       loff_t start, length;   // bh extent in object
     } ex;
     bool dontneed; //indicate bh don't need by anyone
+    bool nocache; //indicate bh don't need by this caller
 
   public:
     Object *ob;
@@ -119,6 +120,7 @@ class ObjectCacher {
       state(STATE_MISSING),
       ref(0),
       dontneed(false),
+      nocache(false),
       ob(o),
       last_write_tid(0),
       last_read_tid(0),
@@ -169,6 +171,13 @@ class ObjectCacher {
     bool get_dontneed() {
       return dontneed;
     }
+
+    void set_nocache(bool v) {
+      nocache = v;
+    }
+    bool get_nocache() {
+      return nocache;
+    }
   };
 
   // ******* Object *********
@@ -422,6 +431,7 @@ class ObjectCacher {
       bh_lru_rest.lru_touch(bh);
 
     bh->set_dontneed(false);
+    bh->set_nocache(false);
     touch_ob(bh->ob);
   }
   void touch_ob(Object *ob) {