From: xie xingguo <xie.xingguo@zte.com.cn>
Date: Thu, 22 Sep 2016 11:59:05 +0000 (+0800)
Subject: os/bluestore: fix race condition of global csum setting
X-Git-Tag: v11.0.1~126^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=07f697799bd9ffc865ff776a33ab7f6c6df72da9;p=ceph.git

os/bluestore: fix race condition of global csum setting

The global csum_type option can be changed dynamically and
can be fixed by upgrading into std::atomic.

Signed-off-by: xie xingguo <xie.xingguo@zte.com.cn>
---

diff --git a/src/os/bluestore/BlueStore.cc b/src/os/bluestore/BlueStore.cc
index 0ec048f6f29..43eb9d7d45c 100644
--- a/src/os/bluestore/BlueStore.cc
+++ b/src/os/bluestore/BlueStore.cc
@@ -4728,8 +4728,7 @@ int BlueStore::_do_read(
     } else {
       for (auto reg : b2r_it->second) {
 	// determine how much of the blob to read
-	uint64_t chunk_size = bptr->get_blob().get_chunk_size(
-	  csum_type != bluestore_blob_t::CSUM_NONE, block_size);
+	uint64_t chunk_size = bptr->get_blob().get_chunk_size(true, block_size);
 	uint64_t r_off = reg.blob_xoffset;
 	uint64_t r_len = reg.length;
 	unsigned front = r_off % chunk_size;
@@ -7337,8 +7336,9 @@ int BlueStore::_do_alloc_write(
 	     << dendl;
 
     // checksum
-    if (csum_type) {
-      b->dirty_blob().init_csum(csum_type, csum_order, csum_length);
+    int csum = csum_type.load();
+    if (csum) {
+      b->dirty_blob().init_csum(csum, csum_order, csum_length);
       b->dirty_blob().calc_csum(b_off, *l);
     }
     if (wi.mark_unused) {
diff --git a/src/os/bluestore/BlueStore.h b/src/os/bluestore/BlueStore.h
index 5e5253d5cc9..b206bb087b1 100644
--- a/src/os/bluestore/BlueStore.h
+++ b/src/os/bluestore/BlueStore.h
@@ -1336,7 +1336,7 @@ private:
   set<ghobject_t, ghobject_t::BitwiseComparator> debug_data_error_objects;
   set<ghobject_t, ghobject_t::BitwiseComparator> debug_mdata_error_objects;
 
-  int csum_type;
+  std::atomic<int> csum_type;
 
   uint64_t block_size;     ///< block size of block device (power of 2)
   uint64_t block_mask;     ///< mask to get just the block offset