From 62601ef64202a3514cd805936535671eee836448 Mon Sep 17 00:00:00 2001
From: Patrick Donnelly <pdonnell@ibm.com>
Date: Wed, 5 Feb 2025 11:18:34 -0500
Subject: [PATCH] libcephfs: add mds_command2 for asynchronous commands

Signed-off-by: Patrick Donnelly <pdonnell@ibm.com>
---
 src/include/cephfs/libcephfs.h | 11 ++++++++
 src/libcephfs.cc               | 49 ++++++++++++++++++++++++++++++++++
 2 files changed, 60 insertions(+)

diff --git a/src/include/cephfs/libcephfs.h b/src/include/cephfs/libcephfs.h
index f26eabfbd5c..4fc975801fa 100644
--- a/src/include/cephfs/libcephfs.h
+++ b/src/include/cephfs/libcephfs.h
@@ -319,6 +319,17 @@ int ceph_mount(struct ceph_mount_info *cmount, const char *root);
  */
 int64_t ceph_get_fs_cid(struct ceph_mount_info *cmount);
 
+typedef void (*libcephfs_c_completion_t)(int rc, const void* out, size_t outlen, const void* outs, size_t outslen, void* ud);
+
+int ceph_mds_command2(struct ceph_mount_info *cmount,
+    const char *mds_spec,
+    const char **cmd,
+    size_t cmdlen,
+    const char *inbuf, size_t inbuflen,
+    int one_shot,
+    libcephfs_c_completion_t c,
+    void* ud);
+
 /**
  * Execute a management command remotely on an MDS.
  *
diff --git a/src/libcephfs.cc b/src/libcephfs.cc
index 9cc3fee4d8e..ce06ff7eef0 100644
--- a/src/libcephfs.cc
+++ b/src/libcephfs.cc
@@ -517,6 +517,55 @@ extern "C" int ceph_set_mount_timeout(struct ceph_mount_info *cmount, uint32_t t
   return ceph_conf_set(cmount, "client_mount_timeout", timeout_str.c_str());
 }
 
+class CommandCContext : public Context {
+public:
+  CommandCContext(libcephfs_c_completion_t c, void* ud) : c(c), ud(ud) {}
+
+  void finish(int rc) {
+    c(rc, outbl.c_str(), outbl.length(), outs.c_str(), outs.size(), ud);
+  }
+
+  libcephfs_c_completion_t c;
+  void* ud;
+  bufferlist outbl;
+  std::string outs;
+};
+
+extern "C" int ceph_mds_command2(struct ceph_mount_info *cmount,
+    const char *mds_spec,
+    const char **cmd,
+    size_t cmdlen,
+    const char *inbuf, size_t inbuflen,
+    int one_shot,
+    libcephfs_c_completion_t c,
+    void* ud)
+{
+  bufferlist inbl;
+  std::vector<string> cmdv;
+
+  if (!cmount->is_initialized()) {
+    return -ENOTCONN;
+  }
+
+  // Construct inputs
+  for (size_t i = 0; i < cmdlen; ++i) {
+    cmdv.push_back(cmd[i]);
+  }
+  inbl.append(inbuf, inbuflen);
+
+  // Issue remote command
+  auto* ctx = new CommandCContext(c, ud);
+  int r = cmount->get_client()->mds_command(mds_spec, cmdv, inbl, &ctx->outbl, &ctx->outs, ctx, one_shot);
+
+  if (r != 0) {
+    delete ctx;
+    return r;
+  }
+
+  return 0;
+}
+
+
 extern "C" int ceph_mds_command(struct ceph_mount_info *cmount,
     const char *mds_spec,
     const char **cmd,
-- 
2.39.5