From: Venky Shankar <vshankar@redhat.com>
Date: Mon, 19 Oct 2020 09:13:01 +0000 (-0400)
Subject: mds: include snap metadata on-disk on snapshot creation
X-Git-Tag: v17.0.0~216^2~4
X-Git-Url: http://git.apps.os.sepia.ceph.com/?a=commitdiff_plain;h=bee70498a55965769d9136d876dc46467b755d02;p=ceph-ci.git

mds: include snap metadata on-disk on snapshot creation

Signed-off-by: Venky Shankar <vshankar@redhat.com>
---

diff --git a/src/client/Client.cc b/src/client/Client.cc
index dd1ca8f7a7b..ec109470a0d 100644
--- a/src/client/Client.cc
+++ b/src/client/Client.cc
@@ -11053,7 +11053,8 @@ int Client::lazyio_synchronize(int fd, loff_t offset, size_t count)
 // =============================
 // snaps
 
-int Client::mksnap(const char *relpath, const char *name, const UserPerm& perm)
+int Client::mksnap(const char *relpath, const char *name, const UserPerm& perm,
+                   mode_t mode, const std::map<std::string, std::string> &metadata)
 {
   RWRef_t mref_reader(mount_state, CLIENT_MOUNTING);
   if (!mref_reader.is_state_satisfied())
@@ -11072,7 +11073,7 @@ int Client::mksnap(const char *relpath, const char *name, const UserPerm& perm)
       return r;
   }
   Inode *snapdir = open_snapdir(in.get());
-  return _mkdir(snapdir, name, 0, perm);
+  return _mkdir(snapdir, name, mode, perm, nullptr, metadata);
 }
 
 int Client::rmsnap(const char *relpath, const char *name, const UserPerm& perms)
@@ -12798,9 +12799,8 @@ int Client::_create(Inode *dir, const char *name, int flags, mode_t mode,
   return res;
 }
 
-
 int Client::_mkdir(Inode *dir, const char *name, mode_t mode, const UserPerm& perm,
-		   InodeRef *inp)
+		   InodeRef *inp, const std::map<std::string, std::string> &metadata)
 {
   ldout(cct, 8) << "_mkdir(" << dir->ino << " " << name << ", 0" << oct
 		<< mode << dec << ", uid " << perm.uid()
@@ -12815,7 +12815,9 @@ int Client::_mkdir(Inode *dir, const char *name, mode_t mode, const UserPerm& pe
   if (is_quota_files_exceeded(dir, perm)) {
     return -EDQUOT;
   }
-  MetaRequest *req = new MetaRequest(dir->snapid == CEPH_SNAPDIR ?
+
+  bool is_snap_op = dir->snapid == CEPH_SNAPDIR;
+  MetaRequest *req = new MetaRequest(is_snap_op ?
 				     CEPH_MDS_OP_MKSNAP : CEPH_MDS_OP_MKDIR);
 
   filepath path;
@@ -12827,13 +12829,23 @@ int Client::_mkdir(Inode *dir, const char *name, mode_t mode, const UserPerm& pe
   req->dentry_unless = CEPH_CAP_FILE_EXCL;
 
   mode |= S_IFDIR;
-  bufferlist xattrs_bl;
-  int res = _posix_acl_create(dir, &mode, xattrs_bl, perm);
+  bufferlist bl;
+  int res = _posix_acl_create(dir, &mode, bl, perm);
   if (res < 0)
     goto fail;
   req->head.args.mkdir.mode = mode;
-  if (xattrs_bl.length() > 0)
-    req->set_data(xattrs_bl);
+  if (is_snap_op) {
+    SnapPayload payload;
+    // clear the bufferlist that may have been populated by the call
+    // to _posix_acl_create(). MDS mksnap does not make use of it.
+    // So, reuse it to pass metadata payload.
+    bl.clear();
+    payload.metadata = metadata;
+    encode(payload, bl);
+  }
+  if (bl.length() > 0) {
+    req->set_data(bl);
+  }
 
   Dentry *de;
   res = get_or_create(dir, name, &de);
diff --git a/src/client/Client.h b/src/client/Client.h
index c61c090485e..a2f3a021aed 100644
--- a/src/client/Client.h
+++ b/src/client/Client.h
@@ -466,7 +466,8 @@ public:
   int enumerate_layout(int fd, vector<ObjectExtent>& result,
 		       loff_t length, loff_t offset);
 
-  int mksnap(const char *path, const char *name, const UserPerm& perm);
+  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);
 
   // Inode permission checking
@@ -1215,7 +1216,7 @@ private:
   int _unlink(Inode *dir, const char *name, const UserPerm& perm);
   int _rename(Inode *olddir, const char *oname, Inode *ndir, const char *nname, const UserPerm& perm);
   int _mkdir(Inode *dir, const char *name, mode_t mode, const UserPerm& perm,
-	     InodeRef *inp = 0);
+	     InodeRef *inp = 0, const std::map<std::string, std::string> &metadata={});
   int _rmdir(Inode *dir, const char *name, const UserPerm& perms);
   int _symlink(Inode *dir, const char *name, const char *target,
 	       const UserPerm& perms, InodeRef *inp = 0);
diff --git a/src/mds/Server.cc b/src/mds/Server.cc
index cbc31013f1f..7b25e4ff981 100644
--- a/src/mds/Server.cc
+++ b/src/mds/Server.cc
@@ -10226,12 +10226,25 @@ void Server::handle_client_mksnap(MDRequestRef& mdr)
 
   ceph_assert(mds->snapclient->get_cached_version() >= stid);
 
+  SnapPayload payload;
+  if (req->get_data().length()) {
+    try {
+      auto iter = req->get_data().cbegin();
+      decode(payload, iter);
+    } catch (const ceph::buffer::error &e) {
+      // backward compat -- client sends xattr bufferlist. however,
+      // that is not used anywhere -- so (log and) ignore.
+      dout(20) << ": no metadata in payload (old client?)" << dendl;
+    }
+  }
+
   // journal
   SnapInfo info;
   info.ino = diri->ino();
   info.snapid = snapid;
   info.name = snapname;
   info.stamp = mdr->get_op_stamp();
+  info.metadata = payload.metadata;
 
   auto pi = diri->project_inode(mdr, false, true);
   pi.inode->ctime = info.stamp;
diff --git a/src/messages/MClientRequest.h b/src/messages/MClientRequest.h
index a1abb8688af..9517126fc68 100644
--- a/src/messages/MClientRequest.h
+++ b/src/messages/MClientRequest.h
@@ -45,6 +45,23 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 
+struct SnapPayload {
+  std::map<std::string, std::string> metadata;
+
+  void encode(ceph::buffer::list &bl) const {
+    ENCODE_START(1, 1, bl);
+    encode(metadata, bl);
+    ENCODE_FINISH(bl);
+  }
+
+  void decode(ceph::buffer::list::const_iterator &iter) {
+    DECODE_START(1, iter);
+    decode(metadata, iter);
+    DECODE_FINISH(iter);
+  }
+};
+
+WRITE_CLASS_ENCODER(SnapPayload)
 
 // metadata ops.