From db9ec690e6d7d173d978884d7a4cbd1f0bf3cf18 Mon Sep 17 00:00:00 2001
From: Sage Weil <sage@redhat.com>
Date: Tue, 1 Dec 2015 17:21:00 -0500
Subject: [PATCH] osd: mark osd backend type in osd_data dir

When we create an osd, mark the type of the backend in the
osd_data dir in the 'type' file.  On startup, if this file is
present, us this to decide which ObjectStore to instantiate.  If
it is not present, use the osd_objectstore option as before.

Signed-off-by: Sage Weil <sage@redhat.com>
---
 src/ceph_osd.cc         | 17 ++++++++++++++++-
 src/os/FileStore.cc     |  4 ++++
 src/os/KeyValueStore.cc |  4 ++++
 src/os/MemStore.cc      |  4 ++++
 4 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/src/ceph_osd.cc b/src/ceph_osd.cc
index aad4307d2e50..fb5de3688a58 100644
--- a/src/ceph_osd.cc
+++ b/src/ceph_osd.cc
@@ -240,8 +240,23 @@ int main(int argc, const char **argv)
   }
 
   // the store
+  string store_type = g_conf->osd_objectstore;
+  {
+    char fn[PATH_MAX];
+    snprintf(fn, sizeof(fn), "%s/type", g_conf->osd_data.c_str());
+    int fd = ::open(fn, O_RDONLY);
+    if (fd >= 0) {
+      bufferlist bl;
+      bl.read_fd(fd, 64);
+      if (bl.length()) {
+	store_type = string(bl.c_str(), bl.length() - 1);  // drop \n
+	dout(5) << "object store type is " << store_type << dendl;
+      }
+      ::close(fd);
+    }
+  }
   ObjectStore *store = ObjectStore::create(g_ceph_context,
-					   g_conf->osd_objectstore,
+					   store_type,
 					   g_conf->osd_data,
 					   g_conf->osd_journal);
   if (!store) {
diff --git a/src/os/FileStore.cc b/src/os/FileStore.cc
index 24653164ff31..d58fa5ffe4cf 100644
--- a/src/os/FileStore.cc
+++ b/src/os/FileStore.cc
@@ -926,6 +926,10 @@ int FileStore::mkfs()
   if (ret)
     goto close_fsid_fd;
 
+  ret = write_meta("type", "filestore");
+  if (ret)
+    goto close_fsid_fd;
+
   dout(1) << "mkfs done in " << basedir << dendl;
   ret = 0;
 
diff --git a/src/os/KeyValueStore.cc b/src/os/KeyValueStore.cc
index 1d715222a875..481a8ac6f2c4 100644
--- a/src/os/KeyValueStore.cc
+++ b/src/os/KeyValueStore.cc
@@ -718,6 +718,10 @@ int KeyValueStore::mkfs()
     delete store;
   }
 
+  ret = write_meta("type", "keyvaluestore");
+  if (ret < 0)
+    goto close_fsid_fd;
+
   dout(1) << "mkfs done in " << basedir << dendl;
   ret = 0;
 
diff --git a/src/os/MemStore.cc b/src/os/MemStore.cc
index 678b16d2138f..f87e6287fb69 100644
--- a/src/os/MemStore.cc
+++ b/src/os/MemStore.cc
@@ -224,6 +224,10 @@ int MemStore::mkfs()
   if (r < 0)
     return r;
 
+  r = write_meta("type", "memstore");
+  if (r < 0)
+    return r;
+
   return 0;
 }
 
-- 
2.47.3