From 31d854b7277021c20d6afc8ec03b53d193b37658 Mon Sep 17 00:00:00 2001
From: sageweil <sageweil@29311d96-e01e-0410-9327-a35deaab8ce9>
Date: Wed, 31 Jan 2007 22:51:08 +0000
Subject: [PATCH] ebofs sync() tweaks (untested!); first pass at is_cached
 interface (with half-assed implementation)

git-svn-id: https://ceph.svn.sf.net/svnroot/ceph@1063 29311d96-e01e-0410-9327-a35deaab8ce9
---
 trunk/ceph/ebofs/Ebofs.cc | 86 ++++++++++++++++++++++++++++-----------
 trunk/ceph/ebofs/Ebofs.h  |  4 +-
 2 files changed, 66 insertions(+), 24 deletions(-)

diff --git a/trunk/ceph/ebofs/Ebofs.cc b/trunk/ceph/ebofs/Ebofs.cc
index e6b505435c9..64485b818e2 100644
--- a/trunk/ceph/ebofs/Ebofs.cc
+++ b/trunk/ceph/ebofs/Ebofs.cc
@@ -16,13 +16,7 @@
 #include "Ebofs.h"
 
 #include <errno.h>
-#ifdef DARWIN
-#include <sys/param.h>
-#include <sys/mount.h>
-#include <sys/statvfs.h>
-#else
 #include <sys/vfs.h>
-#endif // DARWIN
 
 // *******************
 
@@ -1218,8 +1212,10 @@ void Ebofs::kick_idle()
 void Ebofs::sync(Context *onsafe)
 {
   ebofs_lock.Lock();
-  if (onsafe) 
+  if (onsafe) {
+    dirty = true;
     commit_waiters[super_epoch].push_back(onsafe);
+  }
   ebofs_lock.Unlock();
 }
 
@@ -1229,22 +1225,14 @@ void Ebofs::sync()
   if (!dirty) {
     dout(7) << "sync in " << super_epoch << ", not dirty" << endl;
   } else {
-    dout(7) << "sync in " << super_epoch << endl;
-    
-    if (!commit_thread_started) {
-      dout(10) << "sync waiting for commit thread to start" << endl;
+    epoch_t start = super_epoch;
+    dout(7) << "sync start in " << start << endl;
+    while (super_epoch == start) {
+      dout(7) << "sync kicking commit in " << super_epoch << endl;
+      dirty = true;
+      commit_cond.Signal();
       sync_cond.Wait(ebofs_lock);
     }
-    
-    if (mid_commit) {
-      dout(10) << "sync waiting for commit in progress" << endl;
-      sync_cond.Wait(ebofs_lock);
-    }
-    
-    commit_cond.Signal();  // trigger a commit
-    
-    sync_cond.Wait(ebofs_lock);  // wait
-    
     dout(10) << "sync finish in " << super_epoch << endl;
   }
   ebofs_lock.Unlock();
@@ -1290,9 +1278,7 @@ int Ebofs::statfs(struct statfs *buf)
   buf->f_files = nodepool.num_total();   /* total file nodes in file system */
   buf->f_ffree = nodepool.num_free();    /* free file nodes in fs */
   //buf->f_fsid = 0;                       /* file system id */
-#ifndef DARWIN
   buf->f_namelen = 8;                    /* maximum length of filenames */
-#endif // DARWIN
 
   return 0;
 }
@@ -1830,6 +1816,60 @@ bool Ebofs::attempt_read(Onode *on, off_t off, size_t len, bufferlist& bl,
   return true;
 }
 
+
+/*
+ * is_cached -- query whether a object extent is in our cache
+ * return value of -1 if onode isn't loaded.  otherwise, the number
+ * of extents that need to be read (i.e. # of seeks)  
+ */
+int Ebofs::is_cached(object_t oid, off_t off, size_t len)
+{
+  ebofs_lock.Lock();
+  int r = _is_cached(oid, off, len);
+  ebofs_lock.Unlock();
+  return r;
+}
+
+int Ebofs::_is_cached(object_t oid, off_t off, size_t len)
+{
+  Onode *on = 0;
+  if (onode_map.count(oid) == 0) {
+    dout(7) << "_is_cached " << oid << " " << off << "~" << len << " ... onode  " << endl;
+    return -1;  // object dne?
+  } 
+  
+  if (!on->have_oc()) {  
+    // nothing is cached.  return # of extents in file.
+    return on->extent_map.size();
+  }
+  
+  // map
+  block_t bstart = off / EBOFS_BLOCK_SIZE;
+  block_t blast = (len+off-1) / EBOFS_BLOCK_SIZE;
+  block_t blen = blast-bstart+1;
+
+  map<block_t, BufferHead*> hits;
+  map<block_t, BufferHead*> missing;  // read these
+  map<block_t, BufferHead*> rx;       // wait for these
+  map<block_t, BufferHead*> partials;  // ??
+  on->get_oc(&bc)->map_read(bstart, blen, hits, missing, rx, partials);
+  return missing.size() + rx.size() + partials.size();
+
+  // FIXME: actually, we should calculate if these extents are contiguous.
+  // and not using map_read, probably...
+  /* hrmpf
+  block_t dpos = 0;
+  block_t opos = bstart;
+  while (opos < blen) {
+    if (hits.begin()->first == opos) {
+    } else {
+      block_t d;
+      if (missing.begin()->first == opos) d = missing.begin()->second.
+    
+  }
+  */
+}
+
 int Ebofs::read(object_t oid, 
                 off_t off, size_t len,
                 bufferlist& bl)
diff --git a/trunk/ceph/ebofs/Ebofs.h b/trunk/ceph/ebofs/Ebofs.h
index a8efe3b6a6b..f19130a1aab 100644
--- a/trunk/ceph/ebofs/Ebofs.h
+++ b/trunk/ceph/ebofs/Ebofs.h
@@ -242,7 +242,8 @@ class Ebofs : public ObjectStore {
   bool exists(object_t);
   int stat(object_t, struct stat*);
   int read(object_t, off_t off, size_t len, bufferlist& bl);
-  //int write(object_t oid, off_t off, size_t len, bufferlist& bl, bool fsync=true);
+  int is_cached(object_t oid, off_t off, size_t len);
+
   int write(object_t oid, off_t off, size_t len, bufferlist& bl, Context *onsafe);
   int truncate(object_t oid, off_t size, Context *onsafe=0);
   int truncate_front(object_t oid, off_t size, Context *onsafe=0);
@@ -298,6 +299,7 @@ class Ebofs : public ObjectStore {
 private:
   // private interface -- use if caller already holds lock
   int _read(object_t oid, off_t off, size_t len, bufferlist& bl);
+  int _is_cached(object_t oid, off_t off, size_t len);
   int _stat(object_t oid, struct stat *st);
   int _getattr(object_t oid, const char *name, void *value, size_t size);
   int _getattrs(object_t oid, map<string,bufferptr> &aset);