H版本ceph修改superblock中oldest_map字段工具

基于H版本ceph修改：

diff --git a/src/test/encoding/ceph_dencoder.cc b/src/test/encoding/ceph_dencoder.cc
index 7e10565..129d399 100644
--- a/src/test/encoding/ceph_dencoder.cc
+++ b/src/test/encoding/ceph_dencoder.cc
@@ -46,9 +46,12 @@ void usage(ostream &amp;out)
   out &lt; &lt; "\n";
   out &lt;&lt; "  count_tests         print number of generated test objects (to stdout)\n";
   out &lt;&lt; "  select_test &lt;n&gt;     select generated test object as in-memory object\n";
+  out &lt; &lt; "  editsb &lt;oldest_map&gt; &lt;input sb file/&gt; &lt;output sb file&gt;    edit OSDSuperblock oldest_map section\n";
 }
 struct Dencoder {
   virtual ~Dencoder() {}
+  virtual void editsb(epoch_t oldest) {}
   virtual string decode(bufferlist bl, uint64_t seek) = 0;
   virtual void encode(bufferlist&amp; out, uint64_t features) = 0;
   virtual void dump(ceph::Formatter *f) = 0;
@@ -147,6 +150,15 @@ public:
   }
 };

+class DencoderOSDSuperblock : public DencoderImplNoFeature&lt;osdsuperblock&gt; {
+public:
+  DencoderOSDSuperblock()
+    : DencoderImplNoFeature&lt;/osdsuperblock&gt;&lt;osdsuperblock&gt;(false) {}
+  void editsb(epoch_t oldest) { m_object-&gt;oldest_map = oldest; }
+};
+
 template&lt;class T&gt;
 class DencoderImplFeatureful : public DencoderBase&lt;t&gt; {
 public:
@@ -401,6 +413,49 @@ int main(int argc, const char **argv)
       }
       int n = atoi(*i);
       err = den-&gt;select_generated(n);      
+    } else if (*i++ == string("editsb")) {
+      if (args.size() &lt; 4) {
+        usage(cerr);
+        exit(1);
+      }
+      // new oldest_map epoch value
+      epoch_t oldest(atoi(*i++));
+      // input file
+      int r = encbl.read_file(*i++, &amp;err);
+      if (r &lt; 0) {
+        cerr &lt;&lt; "error reading " &lt;&lt; *i &lt;&lt; ": " &lt;&lt; err &lt;&lt; std::endl;
+        exit(1);
+      }
+
+      // edit oldest_map value
+      den = new DencoderOSDSuperblock();
+      den-&gt;generate();
+      err = den-&gt;decode(encbl, 0);
+      den-&gt;editsb(oldest);
+      den-&gt;encode(encbl, features | CEPH_FEATURE_RESERVED);
+
+      // output file
+      int fd = ::open(*i, O_WRONLY|O_CREAT|O_TRUNC, 0644);
+      if (fd &lt; 0) {
+        cerr &lt;&lt; "error opening " &lt;&lt; *i &lt;&lt; " for write: " &lt;&lt; cpp_strerror(errno) &lt;&lt; std::endl;
+        exit(1);
+      }
+      r = encbl.write_fd(fd);
+      if (r &lt; 0) {
+        cerr &lt;&lt; "error writing " &lt;&lt; *i &lt;&lt; ": " &lt;&lt; cpp_strerror(errno) &lt;&lt; std::endl;
+        exit(1);
+      }
+      ::close(fd);
+
+      // dump json
+      JSONFormatter jf(true);
+      jf.open_object_section("object");
+      den-&gt;dump(&amp;jf);
+      jf.close_section();
+      jf.flush(cout);
+      cout &lt;&lt; std::endl;
     } else {
       cerr &lt;&lt; "unknown option '" &lt;&lt; *i &lt;&lt; "'" &lt;&lt; std::endl;
       usage(cerr);

diff --git a/src/test/encoding/ceph_dencoder.cc b/src/test/encoding/ceph_dencoder.cc

index 7e10565..129d399 100644

--- a/src/test/encoding/ceph_dencoder.cc

+++ b/src/test/encoding/ceph_dencoder.cc

@@ -46,9 +46,12 @@ void usage(ostream &out)

out < < "\n";

out << " count_tests print number of generated test objects (to stdout)\n";

out << " select_test <n> select generated test object as in-memory object\n";

+ out < < " editsb <oldest_map> <input sb file/> <output sb file> edit OSDSuperblock oldest_map section\n";

}

struct Dencoder {

virtual ~Dencoder() {}

+ virtual void editsb(epoch_t oldest) {}

virtual string decode(bufferlist bl, uint64_t seek) = 0;

virtual void encode(bufferlist& out, uint64_t features) = 0;

virtual void dump(ceph::Formatter *f) = 0;

@@ -147,6 +150,15 @@ public:

}

};

+class DencoderOSDSuperblock : public DencoderImplNoFeature<osdsuperblock> {

+public:

+ DencoderOSDSuperblock()

+ : DencoderImplNoFeature</osdsuperblock><osdsuperblock>(false) {}

+ void editsb(epoch_t oldest) { m_object->oldest_map = oldest; }

+};

template<class T>

class DencoderImplFeatureful : public DencoderBase<t> {

public:

@@ -401,6 +413,49 @@ int main(int argc, const char **argv)

}

int n = atoi(*i);

err = den->select_generated(n);

+ } else if (*i++ == string("editsb")) {

+ if (args.size() < 4) {

+ usage(cerr);

+ exit(1);

+ }

+ // new oldest_map epoch value

+ epoch_t oldest(atoi(*i++));

+ // input file

+ int r = encbl.read_file(*i++, &err);

+ if (r < 0) {

+ cerr << "error reading " << *i << ": " << err << std::endl;

+ exit(1);

+ }

+ // edit oldest_map value

+ den = new DencoderOSDSuperblock();

+ den->generate();

+ err = den->decode(encbl, 0);

+ den->editsb(oldest);

+ den->encode(encbl, features | CEPH_FEATURE_RESERVED);

+ // output file

+ int fd = ::open(*i, O_WRONLY|O_CREAT|O_TRUNC, 0644);

+ if (fd < 0) {

+ cerr << "error opening " << *i << " for write: " << cpp_strerror(errno) << std::endl;

+ exit(1);

+ }

+ r = encbl.write_fd(fd);

+ if (r < 0) {

+ cerr << "error writing " << *i << ": " << cpp_strerror(errno) << std::endl;

+ exit(1);

+ }

+ ::close(fd);

+ // dump json

+ JSONFormatter jf(true);

+ jf.open_object_section("object");

+ den->dump(&jf);

+ jf.close_section();

+ jf.flush(cout);

+ cout << std::endl;

} else {

cerr << "unknown option '" << *i << "'" << std::endl;

usage(cerr);

改动原因，查询线上环境OSD使用容量信息，发现osdmap占用了大量空间：
OLDEST MAP: 16986
NEWEST MAP: 235999

可以看到osd保存了235999-16986=219013左右的osdmap，占用了大量空间，200~300G可能

社区相关的tracker：

http://tracker.ceph.com/issues/13990

临时清理方案：
清理方案
1.ceph pg query $pgid确认osd上的最老的pg epoch版本

2.停止osd

3.find和读取superblock

find $OSDPATH/current/meta -name “osd\usuperblock*”

ceph-dencoder import $superblock type OSDSuperblock decode dump_json

确认oldestmap和newestmap

4.使用修改过的ceph-dencoder工具修改oldestmap

5.更新superblock，启动osd

6.观察一会儿无问题，清理老的osdmap

完整解决方案：合入社区修复补丁