mds: Remove scatter_pins.

We used these to prevent freezing a tree during gather-scatter ops,
but now we can just go stale on data when a scatter finishes.
Hurray simpler code that goes into try-undo loops less often!

diff --git a/src/mds/CInode.cc b/src/mds/CInode.cc
index 2f63de82ef0ee8bcc497d12e6099d9685727cb3c..f1a4a511cd12c5648deec66344062d674f6d7f78 100644 (file)
--- a/src/mds/CInode.cc
+++ b/src/mds/CInode.cc
@@ -153,9 +153,6 @@ ostream& operator<<(ostream& out, CInode& in)
     out << " need_snapflush=" << in.client_need_snapflush;
 
 
-  if (in.scatter_pins > 0)
-    out << " scatter_pins=" << in.scatter_pins;
-
   // locks
   if (!in.authlock.is_sync_and_unlocked())
     out << " " << in.authlock;
@@ -1599,20 +1596,6 @@ void CInode::finish_scatter_gather_update_accounted(int type, Mutation *mut, EMe
   }
 }
 
-void CInode::put_scatter_pin(list<Context*>& ls)
-{
-  assert(scatter_pins > 0);
-  scatter_pins--;
-  if (scatter_pins == 0) {
-    dirfragtreelock.take_waiting(SimpleLock::WAIT_ALL, ls);
-    filelock.take_waiting(SimpleLock::WAIT_ALL, ls);
-    nestlock.take_waiting(SimpleLock::WAIT_ALL, ls);
-    ls.push_back(new Locker::C_EvalScatterGathers(mdcache->mds->locker, this));
-  }
-}
-
-
-
 // waiting
 
 bool CInode::is_frozen()

diff --git a/src/mds/CInode.h b/src/mds/CInode.h
index 07d7fd28385af84054e1d0dee1c1645ab6ea49ef..a91cfc7f00b5ef1de94418693a58916e0d486a23 100644 (file)
--- a/src/mds/CInode.h
+++ b/src/mds/CInode.h
@@ -469,7 +469,6 @@ private:
     nestlock(this, &nestlock_type),
     flocklock(this, &flocklock_type),
     policylock(this, &policylock_type),
-    scatter_pins(0),
     loner_cap(-1), want_loner_cap(-1)
   {
     g_num_ino++;
@@ -682,8 +681,6 @@ public:
   SimpleLock flocklock;
   SimpleLock policylock;
 
-  int scatter_pins;
-
   SimpleLock* get_lock(int type) {
     switch (type) {
     case CEPH_LOCK_IFILE: return &filelock;
@@ -709,22 +706,6 @@ public:
   void finish_scatter_gather_update(int type);
   void finish_scatter_gather_update_accounted(int type, Mutation *mut, EMetaBlob *metablob);
 
-  // scatter pins prevent either a scatter or unscatter on _any_
-  // scatterlock for this inode.
-  bool is_scatter_pinned() {
-    return scatter_pins > 0;
-  }
-  bool can_scatter_pin() {
-    return 
-      dirfragtreelock.can_scatter_pin(get_loner()) &&
-      filelock.can_scatter_pin(get_loner()) &&
-      nestlock.can_scatter_pin(get_loner());
-  }
-  void get_scatter_pin() {
-    scatter_pins++;
-  }
-  void put_scatter_pin(list<Context*>& ls);
-
   // -- snap --
   void open_snaprealm(bool no_split=false);
   void close_snaprealm(bool no_join=false);

diff --git a/src/mds/Locker.cc b/src/mds/Locker.cc
index a382433853b87204116b44b9f26e0c8a296fc090..3c1aec9bb65b4e24919f22f92133b3cc0b52ea08 100644 (file)
--- a/src/mds/Locker.cc
+++ b/src/mds/Locker.cc
@@ -476,7 +476,6 @@ void Locker::eval_gather(SimpleLock *lock, bool first, bool *pneed_issue, list<C
       (IS_TRUE_AND_LT_AUTH(lock->get_sm()->states[next].can_wrlock, auth) || !lock->is_wrlocked()) &&
       (IS_TRUE_AND_LT_AUTH(lock->get_sm()->states[next].can_xlock, auth) || !lock->is_xlocked()) &&
       (IS_TRUE_AND_LT_AUTH(lock->get_sm()->states[next].can_lease, auth) || !lock->is_leased()) &&
-      (!in || !in->is_scatter_pinned() || !lock->is_scatterlock()) &&
       (!caps || ((~lock->gcaps_allowed(CAP_ANY, next) & other_issued) == 0 &&
                 (~lock->gcaps_allowed(CAP_LONER, next) & loner_issued) == 0 &&
                 (~lock->gcaps_allowed(CAP_XLOCKER, next) & xlocker_issued) == 0)) &&
@@ -3234,8 +3233,6 @@ void Locker::scatter_writebehind(ScatterLock *lock)
   CInode *in = (CInode*)lock->get_parent();
   dout(10) << "scatter_writebehind " << in->inode.mtime << " on " << *lock << " on " << *in << dendl;
 
-  assert(!in->is_scatter_pinned());
-
   // journal
   Mutation *mut = new Mutation;
   mut->ls = mds->mdlog->get_current_segment();
@@ -3345,15 +3342,6 @@ void Locker::scatter_nudge(ScatterLock *lock, Context *c, bool forcelockchange)
 {
   CInode *p = (CInode *)lock->get_parent();
 
-  if (p->is_scatter_pinned()) {
-    dout(10) << "scatter_nudge waiting for scatter pin release on " << *p << dendl;
-    if (c) 
-      p->filelock.add_waiter(SimpleLock::WAIT_RD, c);
-    else
-      // just requeue.  not ideal.. starvation prone..
-      updated_scatterlocks.push_back(lock->get_updated_item());
-    return;
-  }
   if (p->is_frozen() || p->is_freezing()) {
     dout(10) << "scatter_nudge waiting for unfreeze on " << *p << dendl;
     if (c) 

diff --git a/src/mds/Migrator.cc b/src/mds/Migrator.cc
index 3829679cd715bdc3871e52705779090abb96e006..cdb971f29bf881d11d1472ecbdbe8272aa541dd9 100644 (file)
--- a/src/mds/Migrator.cc
+++ b/src/mds/Migrator.cc
@@ -587,15 +587,6 @@ void Migrator::export_dir(CDir *dir, int dest)
     dout(7) << "export_dir couldn't pin path, failing." << dendl;
     return;
   }
-  // pin parent scatterlocks?
-  CInode *diri = dir->inode;
-  if (!diri->can_scatter_pin()) {
-    dout(7) << "export_dir couldn't pin parent inode scatterlocks, failing. " << *diri << dendl;
-
-    // XXX we should make some effort to move lock(s) to a state where we _can_ export!
-
-    return;
-  }
 
   // ok.
   assert(export_state.count(dir) == 0);
@@ -662,8 +653,7 @@ void Migrator::export_frozen(CDir *dir)
   cache->make_trace(trace, dir->inode);
 
   CInode *diri = dir->inode;
-  if (!mds->locker->dentry_can_rdlock_trace(trace) ||
-      !diri->can_scatter_pin()) {
+  if (!mds->locker->dentry_can_rdlock_trace(trace)) {
     dout(7) << "export_dir couldn't rdlock path or rd|wrlock parent inode file+nest+dftlock, failing. " 
            << *diri << dendl;
 
@@ -684,11 +674,6 @@ void Migrator::export_frozen(CDir *dir)
   // rdlock path
   mds->locker->dentry_anon_rdlock_trace_start(trace);
   
-  // pin scatterlocks
-  diri->get_scatter_pin();
-  dout(10) << " dir inode now scatter pinned " << *diri << dendl;
-
-
   cache->show_subtrees();
 
   // note the bounds.
@@ -1380,7 +1365,6 @@ void Migrator::export_unlock(CDir *dir)
   mds->locker->dentry_anon_rdlock_trace_finish(trace);
 
   list<Context*> ls;
-  dir->inode->put_scatter_pin(ls);
   mds->queue_waiters(ls);
 }
 
@@ -1699,9 +1683,6 @@ void Migrator::handle_export_prep(MExportDirPrep *m)
   // freeze.
   dir->_freeze_tree();
 
-  // pin parent scatterlocks (sloppily!)
-  dir->inode->get_scatter_pin();
-  
   // ok!
   dout(7) << " sending export_prep_ack on " << *dir << dendl;
   mds->send_message(new MExportDirPrepAck(dir->dirfrag()), m->get_connection());
@@ -1961,7 +1942,6 @@ void Migrator::import_reverse_unfreeze(CDir *dir)
   dout(7) << "import_reverse_unfreeze " << *dir << dendl;
   dir->unfreeze_tree();
   list<Context*> ls;
-  dir->inode->put_scatter_pin(ls);
   mds->queue_waiters(ls);
   cache->discard_delayed_expire(dir);
   import_reverse_final(dir);
@@ -2072,7 +2052,6 @@ void Migrator::import_finish(CDir *dir)
   //audit();  // this fails, bc we munge up the subtree map during handle_import_map (resolve phase)
 
   list<Context*> ls;
-  dir->inode->put_scatter_pin(ls);
   mds->queue_waiters(ls);
 
   // re-eval imported caps