Merge remote branch 'origin/wip-rbd-watch'

Reviewed-by: Dan Mick <dan.mick@inktank.com>

4 files changed, 15 insertions, 60 deletions

diff --git a/qa/workunits/rbd/watch_correct_version.sh b/qa/workunits/rbd/watch_correct_version.sh
deleted file mode 100755
index 602cf619b67..00000000000
--- a/qa/workunits/rbd/watch_correct_version.sh
+++ /dev/null
@@ -1,31 +0,0 @@
-#!/bin/bash -ex
-
-resize_image() {
-    for i in $(seq 1 1000)
-    do
-        rbd resize --size $i test
-    done
-}
-
-rm -f test.exported || true
-rbd rm test || true
-rbd create -s 1 --order 25 test
-resize_image &
-
-for i in $(seq 1 1000)
-do
-    rbd export test test.exported --debug-rbd 20 2>export.log
-    rm -f test.exported
-    MATCHED=`cat export.log | tr -d '\n' | (grep -c 'watching header object returned -34.*watching header object returned 0' || true)`
-    rm -f export.log
-    if [ "$MATCHED" == "1" ]
-    then
-        echo OK
-        exit 0
-    fi
-done
-rbd rm test
-
-echo "No race detected"
-echo OK
-exit 0
diff --git a/src/librbd/ImageCtx.cc b/src/librbd/ImageCtx.cc
index 80f19d23550..7a44a6a53e8 100644
--- a/src/librbd/ImageCtx.cc
+++ b/src/librbd/ImageCtx.cc
@@ -39,7 +39,6 @@ namespace librbd {
       wctx(NULL),
       refresh_seq(0),
       last_refresh(0),
-      last_header_version(0),
       md_lock("librbd::ImageCtx::md_lock"),
       cache_lock("librbd::ImageCtx::cache_lock"),
       snap_lock("librbd::ImageCtx::snap_lock"),
@@ -556,20 +555,7 @@ namespace librbd {
   int ImageCtx::register_watch() {
     assert(!wctx);
     wctx = new WatchCtx(this);
-
-    int r = 0;
-    do {
-      md_lock.Lock();
-      if (r == -ERANGE)
-	ictx_refresh(this);
-      uint64_t last_read = last_header_version;
-      md_lock.Unlock();
-
-      md_ctx.set_assert_version(last_read);
-      r = md_ctx.watch(header_oid, 0, &(wctx->cookie), wctx);
-      ldout(cct, 20) << "watching header object returned " << r << dendl;
-    } while (r == -ERANGE);
-    return r;
+    return md_ctx.watch(header_oid, 0, &(wctx->cookie), wctx);
   }
 
   void ImageCtx::unregister_watch() {
diff --git a/src/librbd/ImageCtx.h b/src/librbd/ImageCtx.h
index bd0ba87862c..ed03846fcde 100644
--- a/src/librbd/ImageCtx.h
+++ b/src/librbd/ImageCtx.h
@@ -54,8 +54,6 @@ namespace librbd {
     WatchCtx *wctx;
     int refresh_seq;    ///< sequence for refresh requests
     int last_refresh;   ///< last completed refresh
-    uint64_t last_header_version; ///< last version of the header object
-                                  ///< read from librados
 
     /**
      * Lock ordering:
diff --git a/src/librbd/internal.cc b/src/librbd/internal.cc
index ee8966cb40e..0b788136b0d 100644
--- a/src/librbd/internal.cc
+++ b/src/librbd/internal.cc
@@ -1601,7 +1601,6 @@ reprotect_and_return_err:
 	    lderr(cct) << "Error reading header: " << cpp_strerror(r) << dendl;
 	    return r;
 	  }
-	  ictx->last_header_version = ictx->md_ctx.get_last_version();
 	  r = cls_client::old_snapshot_list(&ictx->md_ctx, ictx->header_oid,
 					    &snap_names, &snap_sizes, &new_snapc);
 	  if (r < 0) {
@@ -1639,7 +1638,6 @@ reprotect_and_return_err:
 			 << dendl;
 	      return r;
 	    }
-	    ictx->last_header_version = ictx->md_ctx.get_last_version();
 
 	    uint64_t unsupported = incompatible_features & ~RBD_FEATURES_ALL;
 	    if (unsupported) {
@@ -1915,25 +1913,29 @@ reprotect_and_return_err:
     if (r < 0)
       return r;
 
-    ictx->md_lock.Lock();
-    r = ictx_refresh(ictx);
-    ictx->md_lock.Unlock();
-    if (r < 0)
-      return r;
-
-    _snap_set(ictx, ictx->snap_name.c_str());
-
     if (!ictx->read_only) {
       r = ictx->register_watch();
       if (r < 0) {
 	lderr(ictx->cct) << "error registering a watch: " << cpp_strerror(r)
 			 << dendl;
-	close_image(ictx);
-	return r;
+	goto err_close;
       }
     }
 
+    ictx->md_lock.Lock();
+    r = ictx_refresh(ictx);
+    ictx->md_lock.Unlock();
+    if (r < 0)
+      goto err_close;
+
+    if ((r = _snap_set(ictx, ictx->snap_name.c_str())) < 0)
+      goto err_close;
+
     return 0;
+
+  err_close:
+    close_image(ictx);
+    return r;
   }
 
   void close_image(ImageCtx *ictx)