Allow removal of bad direntries in VitastorFS (direntries referring non-existent inodes)

src/nfs/nfs_kv_getattr.cpp

@@ -13,6 +13,12 @@ void kv_read_inode(nfs_proxy_t *proxy, uint64_t ino,
     std::function<void(int res, const std::string & value, json11::Json ientry)> cb,
     bool allow_cache)
 {
+    if (!ino)
+    {
+        // Zero value can not exist
+        cb(-ENOENT, "", json11::Json());
+        return;
+    }
     auto key = kv_inode_key(ino);
     proxy->db->get(key, [=](int res, const std::string & value)
     {
@@ -49,7 +55,7 @@ int kv_nfs3_getattr_proc(void *opaque, rpc_op_t *rop)
     auto ino = kv_fh_inode(fh);
     if (self->parent->trace)
         fprintf(stderr, "[%d] GETATTR %ju\n", self->nfs_fd, ino);
-    if (!kv_fh_valid(fh))
+    if (!kv_fh_valid(fh) || !ino)
     {
         *reply = (GETATTR3res){ .status = NFS3ERR_INVAL };
         rpc_queue_reply(rop);

src/nfs/nfs_kv_lookup.cpp

@@ -43,9 +43,30 @@ int kv_nfs3_lookup_proc(void *opaque, rpc_op_t *rop)
         uint64_t ino = direntry["ino"].uint64_value();
         kv_read_inode(self->parent, ino, [=](int res, const std::string & value, json11::Json ientry)
         {
-            if (res < 0)
+            if (res == -ENOENT)
             {
-                *reply = (LOOKUP3res){ .status = vitastor_nfs_map_err(res == -ENOENT ? -EIO : res) };
+                *reply = (LOOKUP3res){
+                    .status = NFS3_OK,
+                    .resok = (LOOKUP3resok){
+                        .object = xdr_copy_string(rop->xdrs, kv_fh(ino)),
+                        .obj_attributes = {
+                            .attributes_follow = 1,
+                            .attributes = (fattr3){
+                                .type = (ftype3)0,
+                                .mode = 0666,
+                                .nlink = 1,
+                                .fsid = self->parent->fsid,
+                                .fileid = ino,
+                            },
+                        },
+                    },
+                };
+                rpc_queue_reply(rop);
+                return;
+            }
+            else if (res < 0)
+            {
+                *reply = (LOOKUP3res){ .status = vitastor_nfs_map_err(res) };
                 rpc_queue_reply(rop);
                 return;
             }

src/nfs/nfs_kv_remove.cpp

@@ -89,12 +89,23 @@ resume_1:
 resume_2:
     if (st->res < 0)
     {
-        fprintf(stderr, "error reading inode %s: %s (code %d)\n",
-            kv_inode_key(st->ino).c_str(), strerror(-st->res), st->res);
-        auto cb = std::move(st->cb);
-        cb(st->res);
-        return;
+        if (st->res == -ENOENT)
+        {
+            // Just delete direntry and skip inode
+            fprintf(stderr, "direntry %s references a non-existing inode %ju, deleting\n",
+                kv_direntry_key(st->dir_ino, st->filename).c_str(), st->ino);
+            st->ino = 0;
+        }
+        else
+        {
+            fprintf(stderr, "error reading inode %s: %s (code %d)\n",
+                kv_inode_key(st->ino).c_str(), strerror(-st->res), st->res);
+            auto cb = std::move(st->cb);
+            cb(st->res);
+            return;
+        }
     }
+    else
     {
         std::string err;
         st->ientry = json11::Json::parse(st->ientry_text, err);

tests/test_nfs.sh

@@ -165,4 +165,24 @@ if ls ./testdata/nfs | grep over1; then false; fi
 [[ "`cat ./testdata/nfs/linked1`" = "BABABA" ]]
 format_green "rename over existing file ok"
 
+# check listing and removal of a bad direntry
+sudo umount ./testdata/nfs/
+build/src/kv/vitastor-kv --etcd_address $ETCD_URL fsmeta set d11/settings.jsonLGNmGn '{"ino": 123}'
+sudo mount localhost:/ ./testdata/nfs -o port=2050,mountport=2050,nfsvers=3,soft,nolock,tcp
+ls -l ./testdata/nfs
+ls -l ./testdata/nfs/settings.jsonLGNmGn
+rm ./testdata/nfs/settings.jsonLGNmGn
+build/src/kv/vitastor-kv --etcd_address $ETCD_URL fsmeta get d11/settings.jsonLGNmGn 2>&1 | grep '(code -2)'
+ls -l ./testdata/nfs
+
+# repeat with ino=0
+sudo umount ./testdata/nfs/
+build/src/kv/vitastor-kv --etcd_address $ETCD_URL fsmeta set d11/settings.jsonLGNmGn '{"ino": 0}'
+sudo mount localhost:/ ./testdata/nfs -o port=2050,mountport=2050,nfsvers=3,soft,nolock,tcp
+ls -l ./testdata/nfs
+ls -l ./testdata/nfs/settings.jsonLGNmGn
+rm ./testdata/nfs/settings.jsonLGNmGn
+build/src/kv/vitastor-kv --etcd_address $ETCD_URL fsmeta get d11/settings.jsonLGNmGn 2>&1 | grep '(code -2)'
+ls -l ./testdata/nfs
+
 format_green OK