mds: add alternate_name feature support for dentries

This will support the "alternate_name" filename support, and will save
an alternate name for each dentry. This alternate name is not used in
path lookup or for any other usual file system purpose. The name is
simply an added blob of metadata on the dentry that is distributed to
clients so that "long" file names may be supported for clients which
require them. In the case of an fscrypt enhanced kernel mount driver,
the long name may be the cyphertext (exceeding FILENAME_MAX) of a long
file name.

Because this affects only files with long file names, the use of this
feature should be rare but could be common for some unusual
applications.

The client mount should check the CEPHFS_FEATURE_ALTERNATE_NAME feature
bit first to check whether the MDS has support for this feature or not.
The alternate_name is transmitted as part of the message payload in
MClientRequest when setting the alternate_name. The LeaseStat structure
in MClientReply contains the alternate_name.

When executing a metadata mutation RPC, the client will set the
alternate_name (if it exists) as part of the operation. The MDS will
pick that up and set it on the new or mutated dentry.

Fixes: https://tracker.ceph.com/issues/47162
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Patrick Donnelly <pdonnell@redhat.com>

diff --git a/src/client/Client.cc b/src/client/Client.cc
index a21e65ec6dd9791db482b86cf7407e67662a455e..01e130037a256aac844d273b07939ab90b3e9a1f 100644 (file)
--- a/src/client/Client.cc
+++ b/src/client/Client.cc
@@ -1061,6 +1061,7 @@ Dentry *Client::insert_dentry_inode(Dir *dir, const string& dname, LeaseStat *dl
   }
 
   update_dentry_lease(dn, dlease, from, session);
+  dn->alternate_name = std::move(dlease->alternate_name);
   return dn;
 }
 
@@ -1247,6 +1248,7 @@ void Client::insert_readdir_results(MetaRequest *request, MetaSession *session,
        // new dn
        dn = link(dir, dname, in, NULL);
       }
+      dn->alternate_name = std::move(dlease.alternate_name);
 
       update_dentry_lease(dn, &dlease, request->sent_stamp, session);
       if (hash_order) {

diff --git a/src/client/Dentry.h b/src/client/Dentry.h
index 7559c45f49b59e293a0a5fbd744b30504d2ee783..483a31eccb324b56dd704f1931dbe1a68cea26e6 100644 (file)
--- a/src/client/Dentry.h
+++ b/src/client/Dentry.h
@@ -90,6 +90,7 @@ public:
   uint64_t lease_gen = 0;
   ceph_seq_t lease_seq = 0;
   int cap_shared_gen = 0;
+  std::string alternate_name;
 
 private:
   xlist<Dentry *>::item inode_xlist_link;

diff --git a/src/mds/CDentry.cc b/src/mds/CDentry.cc
index b674f8ba0d42852b59bc85193ebd514c044038c2..9831b3dc9a488c70d2ee31cc00ceb5a555234f50 100644 (file)
--- a/src/mds/CDentry.cc
+++ b/src/mds/CDentry.cc
@@ -235,6 +235,12 @@ void CDentry::make_path(filepath& fp, bool projected) const
   fp.push_dentry(get_name());
 }
 
+void CDentry::set_alternate_name(std::string_view _alternate_name)
+{
+  dout(10) << "setting alternate_name on " << *this << dendl;
+  alternate_name = _alternate_name;
+}
+
 /*
  * we only add ourselves to remote_parents when the linkage is
  * active (no longer projected).  if the passed dnl is projected,
@@ -530,24 +536,30 @@ void CDentry::_put()
   }
 }
 
-void CDentry::encode_remote(inodeno_t& ino, unsigned char d_type, bufferlist &bl)
+void CDentry::encode_remote(inodeno_t& ino, unsigned char d_type,
+                            std::string_view alternate_name,
+                            bufferlist &bl)
 {
-  bl.append("l", 1);  // remote link
+  bl.append('l');  // remote link
 
   // marker, name, ino
-  ENCODE_START(1, 1, bl);
+  ENCODE_START(2, 1, bl);
   encode(ino, bl);
   encode(d_type, bl);
+  encode(alternate_name, bl);
   ENCODE_FINISH(bl);
 }
 
 void CDentry::decode_remote(char icode, inodeno_t& ino, unsigned char& d_type,
+                            mempool::mds_co::string& alternate_name,
                             ceph::buffer::list::const_iterator& bl)
 {
   if (icode == 'l') {
-    DECODE_START(1, bl);
+    DECODE_START(2, bl);
     decode(ino, bl);
     decode(d_type, bl);
+    if (struct_v >= 2)
+      decode(alternate_name, bl);
     DECODE_FINISH(bl);
   } else if (icode == 'L') {
     decode(ino, bl);

diff --git a/src/mds/CDentry.h b/src/mds/CDentry.h
index a192527dd348fe20d937c0d3cb7aa13aca4662c8..5b60b838155cdf158df200e196ca269b919b936b 100644 (file)
--- a/src/mds/CDentry.h
+++ b/src/mds/CDentry.h
@@ -151,6 +151,9 @@ public:
   const CDir *get_dir() const { return dir; }
   CDir *get_dir() { return dir; }
   std::string_view get_name() const { return std::string_view(name); }
+  void set_alternate_name(std::string_view _alternate_name);
+  std::string_view get_alternate_name() const { return std::string_view(alternate_name); }
+  void decode_alternate_name(bufferlist::const_iterator &bl) { decode(alternate_name, bl); }
 
   __u32 get_hash() const { return hash; }
 
@@ -332,8 +335,11 @@ public:
   void print(std::ostream& out) override;
   void dump(ceph::Formatter *f) const;
 
-  static void encode_remote(inodeno_t& ino, unsigned char d_type, bufferlist &bl);
+  static void encode_remote(inodeno_t& ino, unsigned char d_type,
+                            std::string_view alternate_name,
+                            bufferlist &bl);
   static void decode_remote(char icode, inodeno_t& ino, unsigned char& d_type,
+                            mempool::mds_co::string& alternate_name,
                             ceph::buffer::list::const_iterator& bl);
 
   __u32 hash;
@@ -370,6 +376,7 @@ protected:
 
 private:
   mempool::mds_co::string name;
+  mempool::mds_co::string alternate_name;
 };
 
 std::ostream& operator<<(std::ostream& out, const CDentry& dn);

diff --git a/src/mds/CDir.cc b/src/mds/CDir.cc
index 47834b116282ea8b185f42fa53d362ce763bb085..5458dadcf94f77bd355459f566df337c4ab6c437 100644 (file)
--- a/src/mds/CDir.cc
+++ b/src/mds/CDir.cc
@@ -1766,8 +1766,11 @@ CDentry *CDir::_load_dentry(
     // hard link
     inodeno_t ino;
     unsigned char d_type;
+    mempool::mds_co::string alternate_name;
 
-    CDentry::decode_remote(type, ino, d_type, q);
+    CDentry::decode_remote(type, ino, d_type, alternate_name, q);
+    if (alternate_name.length())
+      dn->set_alternate_name(std::move(alternate_name));
 
     if (stale) {
       if (!dn) {
@@ -1808,7 +1811,9 @@ CDentry *CDir::_load_dentry(
     // inode
     // Load inode data before looking up or constructing CInode
     if (type == 'i') {
-      DECODE_START(1, q);
+      DECODE_START(2, q);
+      if (struct_v >= 2)
+        dn->decode_alternate_name(q);
       inode_data.decode(q);
       DECODE_FINISH(q);
     } else {
@@ -2228,6 +2233,7 @@ void CDir::_encode_primary_inode_base(dentry_commit_item &item, bufferlist &dfts
 
   encode(item.oldest_snap, bl);
   encode(item.damage_flags, bl);
+  encode(item.alternate_name, bl);
   ENCODE_FINISH(bl);
 }
 
@@ -2317,12 +2323,13 @@ void CDir::_omap_commit_ops(int r, int op_prio, int64_t metapool, version_t vers
   for (auto &item : to_set) {
     encode(item.first, bl);
     if (item.is_remote) {
-      CDentry::encode_remote(item.ino, item.d_type, bl); // remote link
+      // remote link
+      CDentry::encode_remote(item.ino, item.d_type, item.alternate_name, bl);
     } else {
       // marker, name, inode, [symlink string]
       bl.append('i');         // inode
 
-      ENCODE_START(1, 1, bl);
+      ENCODE_START(2, 1, bl);
       _encode_primary_inode_base(item, dfts, bl);
       ENCODE_FINISH(bl);
     }
@@ -2378,6 +2385,7 @@ void CDir::_omap_commit(int op_prio)
   // reverve enough memories, which maybe larger than the actually needed
   to_set.reserve(count);
 
+  // for dir fragtrees
   bufferlist dfts(CEPH_PAGE_SIZE);
 
   auto write_one = [&](CDentry *dn) {
@@ -2442,6 +2450,10 @@ void CDir::_parse_dentry(CDentry *dn, dentry_commit_item &item,
 
   item.first = dn->first;
 
+  // Only in very rare case the dn->alternate_name not empty,
+  // so it won't cost much to copy it here
+  item.alternate_name = dn->get_alternate_name();
+
   // primary or remote?
   if (dn->linkage.is_remote()) {
     item.is_remote = true;

diff --git a/src/mds/CDir.h b/src/mds/CDir.h
index 030d9c949cbddee0e62efdbfa0cf0c2411c094b0..985f94cb062963a8231a103204669a1570ee3ee1 100644 (file)
--- a/src/mds/CDir.h
+++ b/src/mds/CDir.h
@@ -64,6 +64,7 @@ public:
 
     inodeno_t ino;
     unsigned char d_type;
+    mempool::mds_co::string alternate_name;
 
     bool snaprealm = false;
     sr_t srnode;

diff --git a/src/mds/Locker.cc b/src/mds/Locker.cc
index 8d2740ad7eead28cf96288669c04b7b23ba9ff7d..dc112871d892635dfe5f8b75f31a7fbf8b4eb5ea 100644 (file)
--- a/src/mds/Locker.cc
+++ b/src/mds/Locker.cc
@@ -4252,6 +4252,7 @@ void Locker::issue_client_lease(CDentry *dn, MDRequestRef &mdr, int mask,
     lstat.mask = CEPH_LEASE_VALID | mask;
     lstat.duration_ms = (uint32_t)(1000 * mdcache->client_lease_durations[pool]);
     lstat.seq = ++l->seq;
+    lstat.alternate_name = mempool::mds_co::string(dn->get_alternate_name());
     encode_lease(bl, session->info, lstat);
     dout(20) << "issue_client_lease seq " << lstat.seq << " dur " << lstat.duration_ms << "ms "
             << " on " << *dn << dendl;
@@ -4259,6 +4260,7 @@ void Locker::issue_client_lease(CDentry *dn, MDRequestRef &mdr, int mask,
     // null lease
     LeaseStat lstat;
     lstat.mask = mask;
+    lstat.alternate_name = mempool::mds_co::string(dn->get_alternate_name());
     encode_lease(bl, session->info, lstat);
     dout(20) << "issue_client_lease no/null lease on " << *dn << dendl;
   }
@@ -4291,10 +4293,11 @@ void Locker::encode_lease(bufferlist& bl, const session_info_t& info,
                          const LeaseStat& ls)
 {
   if (info.has_feature(CEPHFS_FEATURE_REPLY_ENCODING)) {
-    ENCODE_START(1, 1, bl);
+    ENCODE_START(2, 1, bl);
     encode(ls.mask, bl);
     encode(ls.duration_ms, bl);
     encode(ls.seq, bl);
+    encode(ls.alternate_name, bl);
     ENCODE_FINISH(bl);
   }
   else {

diff --git a/src/mds/Migrator.cc b/src/mds/Migrator.cc
index 36a8dc0712fee32d2b93e6f03d0d89d90f72941f..f3b653dd47b4f3a0174bd240fe34fab27fe21449 100644 (file)
--- a/src/mds/Migrator.cc
+++ b/src/mds/Migrator.cc
@@ -1793,7 +1793,8 @@ void Migrator::encode_export_dir(bufferlist& exportbl,
     if (dn->get_linkage()->is_remote()) {
       inodeno_t ino = dn->get_linkage()->get_remote_ino();
       unsigned char d_type = dn->get_linkage()->get_remote_d_type();
-      CDentry::encode_remote(ino, d_type, exportbl); // remote link
+      // remote link
+      CDentry::encode_remote(ino, d_type, dn->get_alternate_name(), exportbl);
       continue;
     }
 
@@ -1801,8 +1802,9 @@ void Migrator::encode_export_dir(bufferlist& exportbl,
     // -- inode
     exportbl.append("i", 1);    // inode dentry
 
-    ENCODE_START(1, 1, exportbl);
+    ENCODE_START(2, 1, exportbl);
     encode_export_inode(in, exportbl, exported_client_map, exported_client_metadata_map);  // encode, and (update state for) export
+    encode(dn->get_alternate_name(), exportbl);
     ENCODE_FINISH(exportbl);
 
     // directory?
@@ -3445,7 +3447,12 @@ void Migrator::decode_import_dir(bufferlist::const_iterator& blp,
       // remote link
       inodeno_t ino;
       unsigned char d_type;
-      CDentry::decode_remote(icode, ino, d_type, blp);
+      mempool::mds_co::string alternate_name;
+
+      CDentry::decode_remote(icode, ino, d_type, alternate_name, blp);
+      if (alternate_name.length())
+        dn->set_alternate_name(std::move(alternate_name));
+
       if (dn->get_linkage()->is_remote()) {
        ceph_assert(dn->get_linkage()->get_remote_ino() == ino);
       } else {
@@ -3456,9 +3463,11 @@ void Migrator::decode_import_dir(bufferlist::const_iterator& blp,
       // inode
       ceph_assert(le);
       if (icode == 'i') {
-        DECODE_START(1, blp);
+        DECODE_START(2, blp);
         decode_import_inode(dn, blp, oldauth, ls,
                             peer_exports, updated_scatterlocks);
+       if (struct_v >= 2)
+          dn->decode_alternate_name(blp);
         DECODE_FINISH(blp);
       } else {
         decode_import_inode(dn, blp, oldauth, ls,

diff --git a/src/mds/Server.cc b/src/mds/Server.cc
index 4fc87db91242ce0eb91ce3974547f6f8fb5c9ffe..fb7c74f8ed345fee88bcb40f483b3868c382ff2f 100644 (file)
--- a/src/mds/Server.cc
+++ b/src/mds/Server.cc
@@ -4390,6 +4390,8 @@ void Server::handle_client_openc(MDRequestRef& mdr)
                                   req->head.args.open.mode | S_IFREG, &layout);
   ceph_assert(newi);
 
+  dn->set_alternate_name(req->get_alternate_name());
+
   // it's a file.
   dn->push_projected_linkage(newi);
 
@@ -6269,6 +6271,7 @@ void Server::handle_client_mknod(MDRequestRef& mdr)
   CInode *newi = prepare_new_inode(mdr, dn->get_dir(), inodeno_t(req->head.ino), mode, &layout);
   ceph_assert(newi);
 
+  dn->set_alternate_name(req->get_alternate_name());
   dn->push_projected_linkage(newi);
 
   auto _inode = newi->_get_inode();
@@ -6357,6 +6360,8 @@ void Server::handle_client_mkdir(MDRequestRef& mdr)
   CInode *newi = prepare_new_inode(mdr, dir, inodeno_t(req->head.ino), mode);
   ceph_assert(newi);
 
+  dn->set_alternate_name(req->get_alternate_name());
+
   // it's a directory.
   dn->push_projected_linkage(newi);
 
@@ -6433,6 +6438,8 @@ void Server::handle_client_symlink(MDRequestRef& mdr)
 
   const cref_t<MClientRequest> &req = mdr->client_request;
 
+  dn->set_alternate_name(req->get_alternate_name());
+
   unsigned mode = S_IFLNK | 0777;
   CInode *newi = prepare_new_inode(mdr, dir, inodeno_t(req->head.ino), mode);
   ceph_assert(newi);
@@ -6519,6 +6526,8 @@ void Server::handle_client_link(MDRequestRef& mdr)
       return;
     }
 
+    destdn->set_alternate_name(req->get_alternate_name());
+
     targeti = ret.second->get_projected_linkage()->get_inode();
   }
 
@@ -7946,6 +7955,8 @@ void Server::handle_client_rename(MDRequestRef& mdr)
     return;
   }
 
+  destdn->set_alternate_name(req->get_alternate_name());
+
   // is this a stray migration, reintegration or merge? (sanity checks!)
   if (mdr->reqid.name.is_mds() &&
       !(MDS_INO_IS_STRAY(srcpath.get_ino()) &&

diff --git a/src/mds/cephfs_features.cc b/src/mds/cephfs_features.cc
index 71554d60fd8fa8d8efdf92938030bcb0c7c1ff38..deec59a286045f0bd8f2a7cffff11aadc6f83a42 100644 (file)
--- a/src/mds/cephfs_features.cc
+++ b/src/mds/cephfs_features.cc
@@ -22,6 +22,7 @@ static const std::array feature_names
   "multi_reconnect",
   "deleg_ino",
   "metric_collect",
+  "alternate_name",
 };
 static_assert(feature_names.size() == CEPHFS_FEATURE_MAX + 1);
 

diff --git a/src/mds/cephfs_features.h b/src/mds/cephfs_features.h
index c959e281f83379a6ab0e73b64989c1c7cc417776..ca27c12132c9afbc4d6768bf62e16b7d8d8448a6 100644 (file)
--- a/src/mds/cephfs_features.h
+++ b/src/mds/cephfs_features.h
@@ -42,7 +42,8 @@ namespace ceph {
 #define CEPHFS_FEATURE_DELEG_INO        13
 #define CEPHFS_FEATURE_OCTOPUS          13
 #define CEPHFS_FEATURE_METRIC_COLLECT   14
-#define CEPHFS_FEATURE_MAX             14
+#define CEPHFS_FEATURE_ALTERNATE_NAME   15
+#define CEPHFS_FEATURE_MAX              15
 
 #define CEPHFS_FEATURES_ALL {          \
   0, 1, 2, 3, 4,                       \
@@ -58,6 +59,7 @@ namespace ceph {
   CEPHFS_FEATURE_DELEG_INO,             \
   CEPHFS_FEATURE_OCTOPUS,               \
   CEPHFS_FEATURE_METRIC_COLLECT,        \
+  CEPHFS_FEATURE_ALTERNATE_NAME,        \
 }
 
 #define CEPHFS_METRIC_FEATURES_ALL {           \

diff --git a/src/messages/MClientReply.h b/src/messages/MClientReply.h
index dca000a59bff473e400b5e5821ef9834f5e42e5d..bb20a83b779a77c59c137b35ca440008ee6bd4e5 100644 (file)
--- a/src/messages/MClientReply.h
+++ b/src/messages/MClientReply.h
@@ -18,6 +18,7 @@
 
 #include "include/types.h"
 #include "include/fs_types.h"
+#include "include/mempool.h"
 #include "MClientRequest.h"
 
 #include "msg/Message.h"
@@ -50,6 +51,7 @@ struct LeaseStat {
   __u16 mask;
   __u32 duration_ms;  
   __u32 seq;
+  std::string alternate_name;
 
   LeaseStat() : mask(0), duration_ms(0), seq(0) {}
   LeaseStat(__u16 msk, __u32 dur, __u32 sq) : mask{msk}, duration_ms{dur}, seq{sq} {}
@@ -57,10 +59,12 @@ struct LeaseStat {
   void decode(ceph::buffer::list::const_iterator &bl, const uint64_t features) {
     using ceph::decode;
     if (features == (uint64_t)-1) {
-      DECODE_START(1, bl);
+      DECODE_START(2, bl);
       decode(mask, bl);
       decode(duration_ms, bl);
       decode(seq, bl);
+      if (struct_v >= 2)
+        decode(alternate_name, bl);
       DECODE_FINISH(bl);
     }
     else {

diff --git a/src/messages/MClientRequest.h b/src/messages/MClientRequest.h
index 9517126fc68930aaea4031a7f78bff9ee1b8eb88..1463e26194febf415a39003cb08c9c4475f5a811 100644 (file)
--- a/src/messages/MClientRequest.h
+++ b/src/messages/MClientRequest.h
@@ -67,7 +67,7 @@ WRITE_CLASS_ENCODER(SnapPayload)
 
 class MClientRequest final : public MMDSOp {
 private:
-  static constexpr int HEAD_VERSION = 4;
+  static constexpr int HEAD_VERSION = 5;
   static constexpr int COMPAT_VERSION = 1;
 
 public:
@@ -98,6 +98,7 @@ public:
 
   // path arguments
   filepath path, path2;
+  std::string alternate_name;
   std::vector<uint64_t> gid_list;
 
   /* XXX HACK */
@@ -179,6 +180,13 @@ public:
     head.flags = head.flags | CEPH_MDS_FLAG_ASYNC;
   }
 
+  void set_alternate_name(std::string&& _alternate_name) {
+    alternate_name = std::move(_alternate_name);
+  }
+  void set_alternate_name(bufferptr&& cipher) {
+    alternate_name = std::move(cipher.c_str());
+  }
+
   utime_t get_stamp() const { return stamp; }
   ceph_tid_t get_oldest_client_tid() const { return head.oldest_client_tid; }
   int get_num_fwd() const { return head.num_fwd; }
@@ -192,6 +200,7 @@ public:
   const filepath& get_filepath() const { return path; }
   const std::string& get_path2() const { return path2.get_path(); }
   const filepath& get_filepath2() const { return path2; }
+  std::string_view get_alternate_name() const { return std::string_view(alternate_name); }
 
   int get_dentry_wanted() const { return get_flags() & CEPH_MDS_FLAG_WANT_DENTRY; }
 
@@ -229,6 +238,8 @@ public:
       decode(stamp, p);
     if (header.version >= 4) // epoch 3 was for a ceph_mds_request_args change
       decode(gid_list, p);
+    if (header.version >= 5)
+      decode(alternate_name, p);
   }
 
   void encode_payload(uint64_t features) override {
@@ -250,6 +261,7 @@ public:
     ceph::encode_nohead(releases, payload);
     encode(stamp, payload);
     encode(gid_list, payload);
+    encode(alternate_name, payload);
   }
 
   std::string_view get_type_name() const override { return "creq"; }

diff --git a/src/tools/cephfs/DataScan.cc b/src/tools/cephfs/DataScan.cc
index 52ff67a4601950eb3fab87fabec9e97a7ef6ab16..34504fd4dca9eb6044d627469446d84b57e9edb8 100644 (file)
--- a/src/tools/cephfs/DataScan.cc
+++ b/src/tools/cephfs/DataScan.cc
@@ -20,6 +20,7 @@
 
 #include "mds/CDentry.h"
 #include "mds/CInode.h"
+#include "mds/CDentry.h"
 #include "mds/InoTable.h"
 #include "mds/SnapServer.h"
 #include "cls/cephfs/cls_cephfs_client.h"
@@ -990,10 +991,13 @@ int DataScan::scan_links()
          }
          char dentry_type;
          decode(dentry_type, q);
+         mempool::mds_co::string alternate_name;
          if (dentry_type == 'I' || dentry_type == 'i') {
            InodeStore inode;
             if (dentry_type == 'i') {
-             DECODE_START(1, q);
+             DECODE_START(2, q);
+              if (struct_v >= 2)
+                decode(alternate_name, q);
              inode.decode(q);
              DECODE_FINISH(q);
            } else {
@@ -1059,7 +1063,7 @@ int DataScan::scan_links()
          } else if (dentry_type == 'L' || dentry_type == 'l') {
            inodeno_t ino;
            unsigned char d_type;
-            CDentry::decode_remote(dentry_type, ino, d_type, q);
+            CDentry::decode_remote(dentry_type, ino, d_type, alternate_name, q);
 
            if (step == SCAN_INOS) {
              remote_links[ino]++;
@@ -1481,7 +1485,11 @@ int MetadataTool::read_dentry(inodeno_t parent_ino, frag_t frag,
     decode(dentry_type, q);
     if (dentry_type == 'I' || dentry_type == 'i') {
       if (dentry_type == 'i') {
-        DECODE_START(1, q);
+        mempool::mds_co::string alternate_name;
+
+        DECODE_START(2, q);
+        if (struct_v >= 2)
+          decode(alternate_name, q);
         inode->decode(q);
         DECODE_FINISH(q);
       } else {

diff --git a/src/tools/cephfs/JournalTool.cc b/src/tools/cephfs/JournalTool.cc
index f4598a44029509e8dcf0773d17d7bac0f86a6cfa..ec98609803a46a3998f44efae380440a2f9592aa 100644 (file)
--- a/src/tools/cephfs/JournalTool.cc
+++ b/src/tools/cephfs/JournalTool.cc
@@ -837,7 +837,11 @@ int JournalTool::recover_dentries(
           // Read out inode version to compare with backing store
           InodeStore inode;
           if (dentry_type == 'i') {
-            DECODE_START(1, q);
+            mempool::mds_co::string alternate_name;
+
+            DECODE_START(2, q);
+            if (struct_v >= 2)
+              decode(alternate_name, q);
             inode.decode(q);
             DECODE_FINISH(q);
          } else {

diff --git a/src/tools/cephfs/MetaTool.cc b/src/tools/cephfs/MetaTool.cc
index fc45dc85ae8cd3e0803864d224b5170c914cb8fd..527ae636fc0ffd247fb9788ba761cb391a788795 100644 (file)
--- a/src/tools/cephfs/MetaTool.cc
+++ b/src/tools/cephfs/MetaTool.cc
@@ -926,8 +926,9 @@ int MetaTool::show_child(std::string_view key,
     // hard link
     inodeno_t ino;
     unsigned char d_type;
+    mempool::mds_co::string alternate_name;
 
-    CDentry::decode_remote(type, ino, d_type, q);
+    CDentry::decode_remote(type, ino, d_type, alternate_name, q);
 
     if (sp_ino > 0) {
       if (sp_ino == ino) {
@@ -942,7 +943,11 @@ int MetaTool::show_child(std::string_view key,
     // load inode data before lookuping up or constructing CInode
     InodeStore& inode_data = *(new InodeStore);
     if (type == 'i') {
-      DECODE_START(1, q);
+      mempool::mds_co::string alternate_name;
+
+      DECODE_START(2, q);
+      if (struct_v >= 2)
+        decode(alternate_name, q);
       inode_data.decode(q);
       DECODE_FINISH(q);
     } else {