From: Adam Kupczyk <akupczyk@ibm.com>
Date: Thu, 22 Jan 2026 15:23:56 +0000 (+0000)
Subject: os/bluestore: Add config bluestore_use_ebd
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=71cae2ca72707bf60f5c8d4b44a70e7fcbd44428;p=ceph.git

os/bluestore: Add config bluestore_use_ebd

When EBD(extblkdev) plugin is in use usually it needs to present all the time.
For bluestore deployed with EBD plugin it makes it an error if bluestore tries
to mount and EBD plugin is not present.

Preload of extblkdev plugins was misplaced.
Moved loading plugins into BlueStore.
This way both OSD and tools can load plugins.

Plugins are now loaded only:
- before mkfs
- when extblkdev plugin is signalled in label meta

Signed-off-by: Adam Kupczyk <akupczyk@ibm.com>
(cherry picked from commit addb8388637737c79099bf96e0fe770d6f0dbbf8)
---

diff --git a/src/ceph_osd.cc b/src/ceph_osd.cc
index 34737f29360c..ba784adba57c 100644
--- a/src/ceph_osd.cc
+++ b/src/ceph_osd.cc
@@ -26,7 +26,6 @@
 #include "mon/MonClient.h"
 #include "include/ceph_features.h"
 #include "common/config.h"
-#include "extblkdev/ExtBlkDevPlugin.h"
 
 #include "mon/MonMap.h"
 
@@ -489,14 +488,6 @@ flushjournal_out:
     }
     forker.exit(0);
   }
-  
-  {
-    int r = extblkdev::preload(g_ceph_context);
-    if (r < 0) {
-      derr << "Failed preloading extblkdev plugins, error code: " << r << dendl;
-      forker.exit(1);
-    }
-  }
 
   string magic;
   uuid_d cluster_fsid, osd_fsid;
diff --git a/src/common/options/global.yaml.in b/src/common/options/global.yaml.in
index 947b25113f8e..da1ff5a1009a 100644
--- a/src/common/options/global.yaml.in
+++ b/src/common/options/global.yaml.in
@@ -4491,6 +4491,18 @@ options:
   flags:
   - create
   with_legacy: true
+- name: bluestore_use_ebd
+  type: bool
+  level: advanced
+  desc: EBD plugin used during mkfs is required for mounts.
+  long_desc: The flag has two effects, on mkfs and on mount.
+    If set for mkfs and EBD plugin did attach to the device then save plugin name to OSD metadata.
+    If set when mounting and plugin name is stored in OSD metadata then refuse to mount.
+    The flag has no meaning if the device has no associated EBD plugin.
+  default: true
+  see_also:
+  - osd_extblkdev_plugins
+  with_legacy: true
 - name: bluestore_bdev_label_multi
   type: bool
   level: advanced
diff --git a/src/os/bluestore/BlueStore.cc b/src/os/bluestore/BlueStore.cc
index 6461263d2215..b9efb168763d 100644
--- a/src/os/bluestore/BlueStore.cc
+++ b/src/os/bluestore/BlueStore.cc
@@ -60,6 +60,7 @@
 #include "Writer.h"
 #include "Compression.h"
 #include "BlueAdmin.h"
+#include "extblkdev/ExtBlkDevPlugin.h"
 
 #if defined(WITH_LTTNG)
 #define TRACEPOINT_DEFINE
@@ -7135,7 +7136,15 @@ int BlueStore::_open_bdev(bool create)
   ceph_assert(bdev == NULL);
   string p = path + "/block";
   bdev = BlockDevice::create(cct, p, aio_cb, static_cast<void*>(this), discard_cb, static_cast<void*>(this), "bluestore");
-  int r = bdev->open(p);
+  int r = 0;
+  int plugin_preload_r = 0;
+  if (cct->_conf->bluestore_use_ebd) {
+    //load plugins
+    plugin_preload_r = extblkdev::preload(cct);
+    // do not complain yet. wait until we check "extblkdev" meta.
+  }
+
+  r = bdev->open(p);
   if (r < 0)
     goto fail;
 
@@ -7145,6 +7154,31 @@ int BlueStore::_open_bdev(bool create)
     bdev->try_discard(whole_device, false);
   }
 
+  if (!create && cct->_conf->bluestore_use_ebd) {
+    // for regular bdev opens check if it was deployed with plugin
+    string meta_plugin_id;
+    r = read_meta("extblkdev", &meta_plugin_id);
+    if (r == 0) {
+      // plugin selection fixed to meta, plugins must be loaded
+      if (plugin_preload_r != 0) {
+        // we will complain twice - once generally about not loading plugins,
+        // and later that specific plugin is not ready
+        derr << "Failed preloading extblkdev plugins, error code: " << plugin_preload_r << dendl;
+      }
+      string bdev_plugin_id;
+      r = bdev->get_ebd_id(bdev_plugin_id);
+      if (r != 0) {
+        derr << __func__ << " plugin " << meta_plugin_id << " not loaded" << dendl;
+        goto fail_close;
+      }
+      if (meta_plugin_id != bdev_plugin_id) {
+        derr << __func__ << " plugin '" << meta_plugin_id << "' used on mkfs, "
+          << "but now uses plugin '" << bdev_plugin_id << "'" << dendl;
+        goto fail_close;
+      }
+    }
+  }
+
   if (bdev->supported_bdev_label()) {
     if (create) {
       r = _set_main_bdev_label();
@@ -8609,6 +8643,20 @@ int BlueStore::mkfs()
         return r;
     }
   }
+  if (cct->_conf->bluestore_use_ebd) {
+    // check if EBD plugin is enabled
+    string plugin_id;
+    r = bdev->get_ebd_id(plugin_id);
+    if (r == 0) {
+      // retrieved name, save plugin into bdev metadata
+      r = write_meta("extblkdev", plugin_id);
+      if (r < 0)
+        return r;
+    } else {
+      // Non zero result is not a problem, it just means we do not have EBD plugin.
+      r = 0;
+    }
+  }
 
   freelist_type = "bitmap";
   dout(10) << " freelist_type " << freelist_type << dendl;