client: move readahead ref get/put to obj constr

The readahead context was incrementing the file handle reference count but only
decreasing in finish which is not called if readahead is a no-op.

This fixes a bug caught in testing where readahead was causing inode to become
disconnected:

    2016-06-10 19:46:48.953018 7f2a4351be80  1 client.4125 dump_inode: DISCONNECTED inode 10000000502 #10000000502 ref 110000000502.head(faked_ino=2307 ref=1 ll_ref=0 cap_refs={1024=0,2048=0,4096=0,8192=0} open={1=0,2=0} mode=100666 size=4194304/0 mtime=2016-06-10 19:29:45.107417 caps=-(0=pAsLsXsFscr) objectset[10000000502 ts 2/4012653 objects 0 dirty_or_tx 0] 0x7f2a24300d00)
    2016-06-10 19:46:48.953032 7f2a4351be80  2 client.4125 cache still has 0+155 items, waiting (for caps to release?)

Signed-off-by: Patrick Donnelly <pdonnell@redhat.com>
(cherry picked from commit b5a0773259ce9f2ef44e8e6925ab11dc1a5e55e6)

Signed-off-by: Greg Farnum <gfarnum@redhat.com

diff --git a/src/client/Client.cc b/src/client/Client.cc
index 7ac0b09307f705a1e2ff792a0d6ef0eefc087c95..437ce81872a776b7602dca933fecbab120a069d7 100644 (file)
--- a/src/client/Client.cc
+++ b/src/client/Client.cc
@@ -8053,15 +8053,19 @@ done:
 }
 
 Client::C_Readahead::C_Readahead(Client *c, Fh *f) :
-  client(c), f(f) {
-    f->get();
+    client(c), f(f) {
+  f->get();
+  f->readahead.inc_pending();
+}
+
+Client::C_Readahead::~C_Readahead() {
+  f->readahead.dec_pending();
+  client->_put_fh(f);
 }
 
 void Client::C_Readahead::finish(int r) {
   lgeneric_subdout(client->cct, client, 20) << "client." << client->get_nodeid() << " " << "C_Readahead on " << f->inode << dendl;
   client->put_cap_ref(f->inode.get(), CEPH_CAP_FILE_RD | CEPH_CAP_FILE_CACHE);
-  f->readahead.dec_pending();
-  client->_put_fh(f);
 }
 
 int Client::_read_async(Fh *f, uint64_t off, uint64_t len, bufferlist *bl)
@@ -8113,7 +8117,6 @@ int Client::_read_async(Fh *f, uint64_t off, uint64_t len, bufferlist *bl)
       ldout(cct, 20) << "readahead " << readahead_extent.first << "~" << readahead_extent.second
                     << " (caller wants " << off << "~" << len << ")" << dendl;
       Context *onfinish2 = new C_Readahead(this, f);
-      f->readahead.inc_pending();
       int r2 = objectcacher->file_read(&in->oset, &in->layout, in->snapid,
                                       readahead_extent.first, readahead_extent.second,
                                       NULL, 0, onfinish2);
@@ -8121,7 +8124,6 @@ int Client::_read_async(Fh *f, uint64_t off, uint64_t len, bufferlist *bl)
        ldout(cct, 20) << "readahead initiated, c " << onfinish2 << dendl;
        get_cap_ref(in, CEPH_CAP_FILE_RD | CEPH_CAP_FILE_CACHE);
       } else {
-       f->readahead.dec_pending();
        ldout(cct, 20) << "readahead was no-op, already cached" << dendl;
        delete onfinish2;
       }

diff --git a/src/client/Client.h b/src/client/Client.h
index d912db05c058ee19b4e25db3fc5679974aa11be4..133025949b3c264a661210d08ef76e80be2b3e45 100644 (file)
--- a/src/client/Client.h
+++ b/src/client/Client.h
@@ -713,6 +713,7 @@ private:
     Client *client;
     Fh *f;
     C_Readahead(Client *c, Fh *f);
+    ~C_Readahead();
     void finish(int r);
   };