From: Rishabh Dave <ridave@redhat.com>
Date: Thu, 27 Nov 2025 14:10:27 +0000 (+0530)
Subject: client: add client code to allow snap metadata mutations
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=bf5080c08cd86fe39976ebd5310506d7059dbfc6;p=ceph.git

client: add client code to allow snap metadata mutations

Fixes: https://tracker.ceph.com/issues/66293
Signed-off-by: Rishabh Dave <ridave@redhat.com>
---

diff --git a/ceph.spec.in b/ceph.spec.in
index b0fba106c2ce..7bb56a985a83 100644
--- a/ceph.spec.in
+++ b/ceph.spec.in
@@ -2996,6 +2996,7 @@ fi
 %{_includedir}/cephfs/dump.h
 %{_includedir}/cephfs/json.h
 %{_includedir}/cephfs/keys_and_values.h
+%{_includedir}/cephfs/snap_types.h
 %{_libdir}/libcephfs.so
 %{_libdir}/libcephfs_proxy.so
 %{_libdir}/pkgconfig/cephfs.pc
diff --git a/src/client/Client.cc b/src/client/Client.cc
index 3e0135a024fc..3a2041a87537 100644
--- a/src/client/Client.cc
+++ b/src/client/Client.cc
@@ -14245,6 +14245,56 @@ int Client::rmsnap(const char *relpath, const char *name, const UserPerm& perms,
   return _rmdir(snapdir.get(), name, perms, check_perms);
 }
 
+int Client::do_snap_md_op(const char* path, const string& md_key,
+                          const string& md_val, const unsigned int op_flag,
+                          const UserPerm &perms)
+{
+  if (op_flag != CEPH_SNAP_MD_OP_CREATE &&
+      op_flag != (CEPH_SNAP_MD_OP_CREATE | CEPH_SNAP_MD_OP_EXCL) &&
+      op_flag != CEPH_SNAP_MD_OP_REMOVE) {
+    return -EINVAL;
+  }
+
+  RWRef_t mref_reader(mount_state, CLIENT_MOUNTING);
+  if (!mref_reader.is_state_satisfied())
+    return -ENOTCONN;
+
+  std::scoped_lock l(client_lock);
+
+  walk_dentry_result wdr;
+  if (int rc = path_walk(cwd, filepath(path), &wdr, perms, {}); rc < 0) {
+    return rc;
+  }
+
+  if (wdr.target->snapid == CEPH_NOSNAP) {
+    return -EINVAL;
+  }
+
+  MetaRequest *req = new MetaRequest(CEPH_MDS_OP_SNAP_METADATA);
+  req->set_filepath(wdr.getpath());
+  req->set_inode(wdr.diri);
+  req->set_dentry(wdr.dn);
+  req->dentry_drop = CEPH_CAP_FILE_SHARED;
+  req->dentry_unless = CEPH_CAP_FILE_EXCL;
+
+  bufferlist bl;
+  encode(md_key, bl);
+  encode(md_val, bl);
+  encode(op_flag, bl);
+  req->set_data(bl);
+
+  ldout(cct, 10) << __func__ << ": making request" << dendl;
+  int res = make_request(req, perms, &wdr.target);
+  ldout(cct, 10) << __func__ << ": result is " << res << dendl;
+
+  trim_cache();
+
+  ldout(cct, 8) << __func__ << "(" << wdr.getpath() << ", " << perms
+                << ") = " << res << dendl;
+
+  return res;
+}
+
 // =============================
 // expose caps
 
diff --git a/src/client/Client.h b/src/client/Client.h
index 42459f40a599..99c33fe534cf 100644
--- a/src/client/Client.h
+++ b/src/client/Client.h
@@ -633,6 +633,9 @@ public:
   int mksnap(const char *path, const char *name, const UserPerm& perm,
              mode_t mode=0, const std::map<std::string, std::string> &metadata={});
   int rmsnap(const char *path, const char *name, const UserPerm& perm, bool check_perms=false);
+  int do_snap_md_op(const char* path, const std::string& md_key,
+                    const std::string& md_val, const unsigned int op_flag,
+                    const UserPerm &perms);
 
   // cephx mds auth caps checking
   int mds_check_access(std::string& path, const UserPerm& perms, int mask);
diff --git a/src/include/ceph_fs.h b/src/include/ceph_fs.h
index 9c0b67004cc2..b3aca9075068 100644
--- a/src/include/ceph_fs.h
+++ b/src/include/ceph_fs.h
@@ -15,6 +15,7 @@
 #include "msgr.h"
 #include "rados.h"
 #include "include/buffer.h" // for ceph::buffer::list
+#include "include/cephfs/snap_types.h"
 
 /*
  * The data structures defined here are shared between Linux kernel and
diff --git a/src/include/cephfs/snap_types.h b/src/include/cephfs/snap_types.h
new file mode 100644
index 000000000000..755b3e6f5620
--- /dev/null
+++ b/src/include/cephfs/snap_types.h
@@ -0,0 +1,25 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:nil -*-
+// vim: ts=8 sw=2 sts=2 expandtab
+
+/*
+ * snap_types.h - Contains types associated with CephFS snapshots that needs
+ * to be imported in Cython (Python bindings). Placing these types in ceph_fs.h
+ * (where it was initially place) causes an Cython import error.
+ *
+ * LGPL-2.1 or LGPL-3.0
+ */
+
+
+/*
+ * snapshot metadata operations
+ *
+ * XXX: DON'T FORGET to update cephfs.pyx if any changes are made to this enum.
+ */
+enum {
+        // allows both, snap MD create and update
+	CEPH_SNAP_MD_OP_CREATE    = (1 << 0),
+        // when passed with CREATE, allows only snap MD create and rejects
+        // update
+	CEPH_SNAP_MD_OP_EXCL      = (1 << 1),
+	CEPH_SNAP_MD_OP_REMOVE    = (1 << 2),
+};