smbd: Fix an uninitalized variable
[samba.git] / source3 / locking / share_mode_lock.c
index 90723fb4243f3463a29bb1538fb61caad7f208c8..92289404468ac3031cc0c09b0c9d51076d90d36a 100644 (file)
@@ -59,6 +59,7 @@
 
 /* the locking database handle */
 static struct db_context *lock_db;
+static struct db_context *share_entries_db;
 
 static bool locking_init_internal(bool read_only)
 {
@@ -77,7 +78,11 @@ static bool locking_init_internal(bool read_only)
 
        backend = db_open(NULL, db_path,
                          SMB_OPEN_DATABASE_TDB_HASH_SIZE,
-                         TDB_DEFAULT|TDB_VOLATILE|TDB_CLEAR_IF_FIRST|TDB_INCOMPATIBLE_HASH,
+                         TDB_DEFAULT|
+                         TDB_VOLATILE|
+                         TDB_CLEAR_IF_FIRST|
+                         TDB_INCOMPATIBLE_HASH|
+                         TDB_SEQNUM,
                          read_only?O_RDONLY:O_RDWR|O_CREAT, 0644,
                          DBWRAP_LOCK_ORDER_1, DBWRAP_FLAG_NONE);
        TALLOC_FREE(db_path);
@@ -86,14 +91,36 @@ static bool locking_init_internal(bool read_only)
                return False;
        }
 
-       lock_db = db_open_watched(NULL, &backend, server_messaging_context());
+       lock_db = db_open_watched(NULL, &backend, global_messaging_context());
        if (lock_db == NULL) {
                DBG_ERR("db_open_watched failed\n");
                TALLOC_FREE(backend);
                return false;
        }
 
+       db_path = lock_path(talloc_tos(), "share_entries.tdb");
+       if (db_path == NULL) {
+               return false;
+       }
+
+       share_entries_db = db_open(
+               NULL, db_path,
+               SMB_OPEN_DATABASE_TDB_HASH_SIZE,
+               TDB_DEFAULT|
+               TDB_VOLATILE|
+               TDB_CLEAR_IF_FIRST|
+               TDB_INCOMPATIBLE_HASH,
+               read_only?O_RDONLY:O_RDWR|O_CREAT, 0644,
+               DBWRAP_LOCK_ORDER_3, DBWRAP_FLAG_NONE);
+       TALLOC_FREE(db_path);
+
+       if (share_entries_db == NULL) {
+               TALLOC_FREE(lock_db);
+               return false;
+       }
+
        if (!posix_locking_init(read_only)) {
+               TALLOC_FREE(share_entries_db);
                TALLOC_FREE(lock_db);
                return False;
        }
@@ -142,33 +169,19 @@ static TDB_DATA locking_key(const struct file_id *id)
  necessary we can always make this a separate (smaller) cache.
 ******************************************************************/
 
-static const DATA_BLOB memcache_key(const struct file_id *id)
+static DATA_BLOB memcache_key(const struct file_id *id)
 {
        return data_blob_const((const void *)id, sizeof(*id));
 }
 
-static void share_mode_memcache_delete(struct share_mode_data *d)
-{
-       const DATA_BLOB key = memcache_key(&d->id);
-
-       DEBUG(10,("deleting entry for file %s seq 0x%llu key %s\n",
-               d->base_name,
-               (unsigned long long) d->sequence_number,
-               file_id_string(talloc_tos(), &d->id)));
-
-       memcache_delete(NULL,
-                       SHARE_MODE_LOCK_CACHE,
-                       key);
-}
-
 static void share_mode_memcache_store(struct share_mode_data *d)
 {
        const DATA_BLOB key = memcache_key(&d->id);
 
-       DEBUG(10,("stored entry for file %s seq 0x%llu key %s\n",
-               d->base_name,
-               (unsigned long long) d->sequence_number,
-               file_id_string(talloc_tos(), &d->id)));
+       DBG_DEBUG("stored entry for file %s seq %"PRIx64" key %s\n",
+                 d->base_name,
+                 d->sequence_number,
+                 file_id_string(talloc_tos(), &d->id));
 
        /* Ensure everything stored in the cache is pristine. */
        d->modified = false;
@@ -177,7 +190,8 @@ static void share_mode_memcache_store(struct share_mode_data *d)
        /*
         * Ensure the memory going into the cache
         * doesn't have a destructor so it can be
-        * cleanly freed by share_mode_memcache_delete().
+        * cleanly evicted by the memcache LRU
+        * mechanism.
         */
        talloc_set_destructor(d, NULL);
 
@@ -192,17 +206,78 @@ static void share_mode_memcache_store(struct share_mode_data *d)
  * NB. We use ndr_pull_hyper on a stack-created
  * struct ndr_pull with no talloc allowed, as we
  * need this to be really fast as an ndr-peek into
- * the first 8 bytes of the blob.
+ * the first 9 bytes of the blob.
  */
 
-static enum ndr_err_code get_blob_sequence_number(DATA_BLOB *blob,
-                                               uint64_t *pseq)
+static enum ndr_err_code get_share_mode_blob_header(
+       DATA_BLOB *blob, uint64_t *pseq, uint16_t *pflags)
 {
        struct ndr_pull ndr = {.data = blob->data, .data_size = blob->length};
        NDR_CHECK(ndr_pull_hyper(&ndr, NDR_SCALARS, pseq));
+       NDR_CHECK(ndr_pull_uint16(&ndr, NDR_SCALARS, pflags));
        return NDR_ERR_SUCCESS;
 }
 
+struct fsp_update_share_mode_flags_state {
+       enum ndr_err_code ndr_err;
+       uint16_t share_mode_flags;
+};
+
+static void fsp_update_share_mode_flags_fn(
+       struct db_record *rec, bool *modified_dependent, void *private_data)
+{
+       struct fsp_update_share_mode_flags_state *state = private_data;
+       TDB_DATA value = dbwrap_record_get_value(rec);
+       DATA_BLOB blob = { .data = value.dptr, .length = value.dsize };
+       uint64_t seq;
+
+       state->ndr_err = get_share_mode_blob_header(
+               &blob, &seq, &state->share_mode_flags);
+}
+
+static NTSTATUS fsp_update_share_mode_flags(struct files_struct *fsp)
+{
+       struct fsp_update_share_mode_flags_state state = {0};
+       int seqnum = dbwrap_get_seqnum(lock_db);
+       NTSTATUS status;
+
+       if (seqnum == fsp->share_mode_flags_seqnum) {
+               return NT_STATUS_OK;
+       }
+
+       status = share_mode_do_locked(
+               fsp->file_id, fsp_update_share_mode_flags_fn, &state);
+       if (!NT_STATUS_IS_OK(status)) {
+               DBG_DEBUG("share_mode_do_locked returned %s\n",
+                         nt_errstr(status));
+               return status;
+       }
+
+       if (!NDR_ERR_CODE_IS_SUCCESS(state.ndr_err)) {
+               DBG_DEBUG("get_share_mode_blob_header returned %s\n",
+                         ndr_errstr(state.ndr_err));
+               return ndr_map_error2ntstatus(state.ndr_err);
+       }
+
+       fsp->share_mode_flags_seqnum = seqnum;
+       fsp->share_mode_flags = state.share_mode_flags;
+
+       return NT_STATUS_OK;
+}
+
+bool file_has_read_lease(struct files_struct *fsp)
+{
+       NTSTATUS status;
+
+       status = fsp_update_share_mode_flags(fsp);
+       if (!NT_STATUS_IS_OK(status)) {
+               /* Safe default for leases */
+               return true;
+       }
+
+       return (fsp->share_mode_flags & SHARE_MODE_LEASE_READ) != 0;
+}
+
 static int share_mode_data_nofree_destructor(struct share_mode_data *d)
 {
        return -1;
@@ -215,6 +290,7 @@ static struct share_mode_data *share_mode_memcache_fetch(TALLOC_CTX *mem_ctx,
        enum ndr_err_code ndr_err;
        struct share_mode_data *d;
        uint64_t sequence_number;
+       uint16_t flags;
        void *ptr;
        struct file_id id;
        DATA_BLOB key;
@@ -236,7 +312,7 @@ static struct share_mode_data *share_mode_memcache_fetch(TALLOC_CTX *mem_ctx,
                return NULL;
        }
        /* sequence number key is at start of blob. */
-       ndr_err = get_blob_sequence_number(blob, &sequence_number);
+       ndr_err = get_share_mode_blob_header(blob, &sequence_number, &flags);
        if (ndr_err != NDR_ERR_SUCCESS) {
                /* Bad blob. Remove entry. */
                DEBUG(10,("bad blob %u key %s\n",
@@ -250,11 +326,11 @@ static struct share_mode_data *share_mode_memcache_fetch(TALLOC_CTX *mem_ctx,
 
        d = (struct share_mode_data *)ptr;
        if (d->sequence_number != sequence_number) {
-               DEBUG(10,("seq changed (cached 0x%llu) (new 0x%llu) "
-                       "for key %s\n",
-                       (unsigned long long)d->sequence_number,
-                       (unsigned long long)sequence_number,
-                       file_id_string(mem_ctx, &id)));
+               DBG_DEBUG("seq changed (cached %"PRIx64") (new %"PRIx64") "
+                         "for key %s\n",
+                         d->sequence_number,
+                         sequence_number,
+                         file_id_string(mem_ctx, &id));
                /* Cache out of date. Remove entry. */
                memcache_delete(NULL,
                        SHARE_MODE_LOCK_CACHE,
@@ -279,10 +355,10 @@ static struct share_mode_data *share_mode_memcache_fetch(TALLOC_CTX *mem_ctx,
        /* And reset the destructor to none. */
        talloc_set_destructor(d, NULL);
 
-       DEBUG(10,("fetched entry for file %s seq 0x%llu key %s\n",
-               d->base_name,
-               (unsigned long long)d->sequence_number,
-               file_id_string(mem_ctx, &id)));
+       DBG_DEBUG("fetched entry for file %s seq %"PRIx64" key %s\n",
+                 d->base_name,
+                 d->sequence_number,
+                 file_id_string(mem_ctx, &id));
 
        return d;
 }
@@ -297,7 +373,6 @@ static struct share_mode_data *parse_share_modes(TALLOC_CTX *mem_ctx,
 {
        struct share_mode_data *d;
        enum ndr_err_code ndr_err;
-       uint32_t i;
        DATA_BLOB blob;
 
        blob.data = dbuf.dptr;
@@ -318,22 +393,11 @@ static struct share_mode_data *parse_share_modes(TALLOC_CTX *mem_ctx,
        ndr_err = ndr_pull_struct_blob_all(
                &blob, d, d, (ndr_pull_flags_fn_t)ndr_pull_share_mode_data);
        if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
-               DEBUG(1, ("ndr_pull_share_mode_lock failed: %s\n",
-                         ndr_errstr(ndr_err)));
+               DBG_WARNING("ndr_pull_share_mode_data failed: %s\n",
+                           ndr_errstr(ndr_err));
                goto fail;
        }
 
-       /*
-        * Initialize the values that are [skip] or [ignore]
-        * in the idl. The NDR code does not initialize them.
-        */
-
-       for (i=0; i<d->num_share_modes; i++) {
-               d->share_modes[i].stale = false;
-       }
-       d->modified = false;
-       d->fresh = false;
-
        if (DEBUGLEVEL >= 10) {
                DEBUG(10, ("parse_share_modes:\n"));
                NDR_PRINT_DEBUG(share_mode_data, d);
@@ -346,113 +410,59 @@ fail:
 }
 
 /*******************************************************************
Create a storable data blob from a modified share_mode_data struct.
If modified, store the share_mode_data back into the database.
 ********************************************************************/
 
-static TDB_DATA unparse_share_modes(struct share_mode_data *d)
+static NTSTATUS share_mode_data_store(struct share_mode_data *d)
 {
        DATA_BLOB blob;
        enum ndr_err_code ndr_err;
+       NTSTATUS status;
+
+       if (!d->modified) {
+               DBG_DEBUG("not modified\n");
+               return NT_STATUS_OK;
+       }
 
        if (DEBUGLEVEL >= 10) {
-               DEBUG(10, ("unparse_share_modes:\n"));
+               DBG_DEBUG("\n");
                NDR_PRINT_DEBUG(share_mode_data, d);
        }
 
-       share_mode_memcache_delete(d);
-
-       /* Update the sequence number. */
        d->sequence_number += 1;
 
-       remove_stale_share_mode_entries(d);
-
        if (d->num_share_modes == 0) {
-               DEBUG(10, ("No used share mode found\n"));
-               return make_tdb_data(NULL, 0);
+               TALLOC_FREE(d->delete_tokens);
+               d->num_delete_tokens = 0;
+
+               if (d->fresh) {
+                       DBG_DEBUG("Ignoring fresh empty record\n");
+                       return NT_STATUS_OK;
+               }
+               status = dbwrap_record_delete(d->record);
+               return status;
        }
 
        ndr_err = ndr_push_struct_blob(
                &blob, d, d, (ndr_push_flags_fn_t)ndr_push_share_mode_data);
        if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
-               smb_panic("ndr_push_share_mode_lock failed");
-       }
-
-       return make_tdb_data(blob.data, blob.length);
-}
-
-/*******************************************************************
- If modified, store the share_mode_data back into the database.
-********************************************************************/
-
-static int share_mode_data_destructor(struct share_mode_data *d)
-{
-       NTSTATUS status;
-       TDB_DATA data;
-
-       if (!d->modified) {
-               return 0;
+               DBG_DEBUG("ndr_push_share_mode_data failed: %s\n",
+                         ndr_errstr(ndr_err));
+               return ndr_map_error2ntstatus(ndr_err);
        }
 
-       data = unparse_share_modes(d);
+       status = dbwrap_record_store(
+               d->record,
+               (TDB_DATA) { .dptr = blob.data, .dsize = blob.length },
+               TDB_REPLACE);
+       TALLOC_FREE(blob.data);
 
-       if (data.dptr == NULL) {
-               if (!d->fresh) {
-                       /* There has been an entry before, delete it */
-
-                       status = dbwrap_record_delete(d->record);
-                       if (!NT_STATUS_IS_OK(status)) {
-                               char *errmsg;
-
-                               DEBUG(0, ("delete_rec returned %s\n",
-                                         nt_errstr(status)));
-
-                               if (asprintf(&errmsg, "could not delete share "
-                                            "entry: %s\n",
-                                            nt_errstr(status)) == -1) {
-                                       smb_panic("could not delete share"
-                                                 "entry");
-                               }
-                               smb_panic(errmsg);
-                       }
-               }
-               /*
-                * Nothing to store in cache - allow the normal
-                * release of record lock and memory free.
-                */
-               return 0;
-       }
-
-       status = dbwrap_record_store(d->record, data, TDB_REPLACE);
        if (!NT_STATUS_IS_OK(status)) {
-               char *errmsg;
-
-               DEBUG(0, ("store returned %s\n", nt_errstr(status)));
-
-               if (asprintf(&errmsg, "could not store share mode entry: %s",
-                            nt_errstr(status)) == -1) {
-                       smb_panic("could not store share mode entry");
-               }
-               smb_panic(errmsg);
+               DBG_DEBUG("dbwrap_record_store failed: %s\n",
+                         nt_errstr(status));
        }
 
-       /*
-        * Release the record lock before putting in the cache.
-        */
-       TALLOC_FREE(d->record);
-
-       /*
-        * Release the dptr as well before reparenting to NULL
-        * (in-memory cache) context.
-        */
-       TALLOC_FREE(data.dptr);
-       /*
-        * Reparent d into the in-memory cache so it can be reused if the
-        * sequence number matches. See parse_share_modes()
-        * for details.
-        */
-
-       share_mode_memcache_store(d);
-       return -1;
+       return status;
 }
 
 /*******************************************************************
@@ -503,76 +513,67 @@ fail:
        return NULL;
 }
 
+/*
+ * We can only ever have one share mode locked. Use a static
+ * share_mode_data pointer that is shared by multiple nested
+ * share_mode_lock structures, explicitly refcounted.
+ */
+static struct share_mode_data *static_share_mode_data = NULL;
+static size_t static_share_mode_data_refcount = 0;
+
+/*
+ * db_record for the above. With dbwrap_do_locked we can get a
+ * db_record on the stack, which we can't TALLOC_FREE but which we
+ * need to share with a nested get_share_mode_lock call.
+ */
+static struct db_record *static_share_mode_record = NULL;
+static bool static_share_mode_record_talloced = false;
+
 /*******************************************************************
  Either fetch a share mode from the database, or allocate a fresh
  one if the record doesn't exist.
 ********************************************************************/
 
-static struct share_mode_lock *get_share_mode_lock_internal(
-       TALLOC_CTX *mem_ctx, struct file_id id,
-       const char *servicepath, const struct smb_filename *smb_fname,
+static NTSTATUS get_static_share_mode_data(
+       struct db_record *rec,
+       struct file_id id,
+       const char *servicepath,
+       const struct smb_filename *smb_fname,
        const struct timespec *old_write_time)
 {
-       struct share_mode_lock *lck;
        struct share_mode_data *d;
-       struct db_record *rec;
-       TDB_DATA key = locking_key(&id);
-       TDB_DATA value;
-
-       rec = dbwrap_fetch_locked(lock_db, mem_ctx, key);
-       if (rec == NULL) {
-               DEBUG(3, ("Could not lock share entry\n"));
-               return NULL;
-       }
+       TDB_DATA value = dbwrap_record_get_value(rec);
 
-       value = dbwrap_record_get_value(rec);
+       SMB_ASSERT(static_share_mode_data == NULL);
 
        if (value.dptr == NULL) {
-               d = fresh_share_mode_lock(mem_ctx, servicepath, smb_fname,
-                                         old_write_time);
+               d = fresh_share_mode_lock(
+                       lock_db, servicepath, smb_fname, old_write_time);
+               if (d == NULL) {
+                       return NT_STATUS_NO_MEMORY;
+               }
        } else {
-               d = parse_share_modes(mem_ctx, key, value);
+               TDB_DATA key = locking_key(&id);
+               d = parse_share_modes(lock_db, key, value);
+               if (d == NULL) {
+                       return NT_STATUS_INTERNAL_DB_CORRUPTION;
+               }
        }
 
-       if (d == NULL) {
-               DEBUG(5, ("get_share_mode_lock_internal: "
-                       "Could not get share mode lock\n"));
-               TALLOC_FREE(rec);
-               return NULL;
-       }
        d->id = id;
-       d->record = talloc_move(d, &rec);
-       talloc_set_destructor(d, share_mode_data_destructor);
-
-       lck = talloc(mem_ctx, struct share_mode_lock);
-       if (lck == NULL) {
-               DEBUG(1, ("talloc failed\n"));
-               TALLOC_FREE(d);
-               return NULL;
-       }
-       lck->data = talloc_move(lck, &d);
-       return lck;
-}
+       d->record = rec;
 
-/*
- * We can only ever have one share mode locked. Users of
- * get_share_mode_lock never see this, it will be refcounted by
- * talloc_reference.
- */
-static struct share_mode_lock *the_lock;
-static struct file_id the_lock_id;
+       static_share_mode_data = d;
 
-static int the_lock_destructor(struct share_mode_lock *l)
-{
-       the_lock = NULL;
-       ZERO_STRUCT(the_lock_id);
-       return 0;
+       return NT_STATUS_OK;
 }
 
 /*******************************************************************
  Get a share_mode_lock, Reference counted to allow nested calls.
 ********************************************************************/
 
+static int share_mode_lock_destructor(struct share_mode_lock *lck);
+
 struct share_mode_lock *get_share_mode_lock(
        TALLOC_CTX *mem_ctx,
        struct file_id id,
@@ -580,7 +581,9 @@ struct share_mode_lock *get_share_mode_lock(
        const struct smb_filename *smb_fname,
        const struct timespec *old_write_time)
 {
-       struct share_mode_lock *lck;
+       TDB_DATA key = locking_key(&id);
+       struct share_mode_lock *lck = NULL;
+       NTSTATUS status;
 
        lck = talloc(mem_ctx, struct share_mode_lock);
        if (lck == NULL) {
@@ -588,32 +591,223 @@ struct share_mode_lock *get_share_mode_lock(
                return NULL;
        }
 
-       if (the_lock == NULL) {
-               the_lock = get_share_mode_lock_internal(
-                       lck, id, servicepath, smb_fname, old_write_time);
-               if (the_lock == NULL) {
-                       goto fail;
-               }
-               talloc_set_destructor(the_lock, the_lock_destructor);
-               the_lock_id = id;
-       } else {
-               if (!file_id_equal(&the_lock_id, &id)) {
+       if (static_share_mode_data != NULL) {
+               if (!file_id_equal(&static_share_mode_data->id, &id)) {
                        DEBUG(1, ("Can not lock two share modes "
                                  "simultaneously\n"));
                        goto fail;
                }
-               if (talloc_reference(lck, the_lock) == NULL) {
-                       DEBUG(1, ("talloc_reference failed\n"));
+               goto done;
+       }
+
+       SMB_ASSERT(static_share_mode_data_refcount == 0);
+
+       if (static_share_mode_record == NULL) {
+               static_share_mode_record = dbwrap_fetch_locked(
+                       lock_db, lock_db, key);
+               if (static_share_mode_record == NULL) {
+                       DEBUG(3, ("Could not lock share entry\n"));
+                       goto fail;
+               }
+               static_share_mode_record_talloced = true;
+
+               status = get_static_share_mode_data(
+                       static_share_mode_record,
+                       id,
+                       servicepath,
+                       smb_fname,
+                       old_write_time);
+               if (!NT_STATUS_IS_OK(status)) {
+                       DBG_DEBUG("get_static_share_mode_data failed: %s\n",
+                                 nt_errstr(status));
+                       TALLOC_FREE(static_share_mode_record);
+                       goto fail;
+               }
+       } else {
+               TDB_DATA static_key;
+               int cmp;
+
+               static_key = dbwrap_record_get_key(static_share_mode_record);
+
+               cmp = tdb_data_cmp(static_key, key);
+               if (cmp != 0) {
+                       DBG_WARNING("Can not lock two share modes "
+                                   "simultaneously\n");
+                       return NULL;
+               }
+
+               status = get_static_share_mode_data(
+                       static_share_mode_record,
+                       id,
+                       servicepath,
+                       smb_fname,
+                       old_write_time);
+               if (!NT_STATUS_IS_OK(status)) {
+                       DBG_WARNING("get_static_share_mode_data failed: %s\n",
+                                   nt_errstr(status));
                        goto fail;
                }
        }
-       lck->data = the_lock->data;
+
+done:
+       static_share_mode_data_refcount += 1;
+       lck->data = static_share_mode_data;
+
+       talloc_set_destructor(lck, share_mode_lock_destructor);
+
        return lck;
 fail:
        TALLOC_FREE(lck);
        return NULL;
 }
 
+static int share_mode_lock_destructor(struct share_mode_lock *lck)
+{
+       NTSTATUS status;
+
+       SMB_ASSERT(static_share_mode_data_refcount > 0);
+       static_share_mode_data_refcount -= 1;
+
+       if (static_share_mode_data_refcount > 0) {
+               return 0;
+       }
+
+       status = share_mode_data_store(static_share_mode_data);
+       if (!NT_STATUS_IS_OK(status)) {
+               DBG_ERR("share_mode_data_store failed: %s\n",
+                       nt_errstr(status));
+               smb_panic("Could not store share mode data\n");
+       }
+
+       /*
+        * Drop the locking.tdb lock before moving the share_mode_data
+        * to memcache
+        */
+       SMB_ASSERT(static_share_mode_data->record == static_share_mode_record);
+       static_share_mode_data->record = NULL;
+
+       if (static_share_mode_record_talloced) {
+               TALLOC_FREE(static_share_mode_record);
+       }
+
+       if (static_share_mode_data->num_share_modes != 0) {
+               /*
+                * This is worth keeping. Without share modes,
+                * share_mode_data_store above has left nothing in the
+                * database.
+                */
+               share_mode_memcache_store(static_share_mode_data);
+               static_share_mode_data = NULL;
+       } else {
+               /*
+                * The next opener of this file will find an empty
+                * locking.tdb record. Don't store the share_mode_data
+                * in the memcache, fresh_share_mode_lock() will
+                * generate a fresh seqnum anyway, obsoleting the
+                * cache entry.
+                */
+               TALLOC_FREE(static_share_mode_data);
+       }
+
+       return 0;
+}
+
+struct share_mode_do_locked_state {
+       void (*fn)(struct db_record *rec,
+                  bool *modified_dependent,
+                  void *private_data);
+       void *private_data;
+};
+
+static void share_mode_do_locked_fn(struct db_record *rec,
+                                   void *private_data)
+{
+       struct share_mode_do_locked_state *state = private_data;
+       bool modified_dependent = false;
+       bool reset_static_share_mode_record = false;
+
+       if (static_share_mode_record == NULL) {
+               static_share_mode_record = rec;
+               static_share_mode_record_talloced = false;
+               reset_static_share_mode_record = true;
+       } else {
+               SMB_ASSERT(static_share_mode_record == rec);
+       }
+
+       state->fn(rec, &modified_dependent, state->private_data);
+
+       if (modified_dependent) {
+               dbwrap_watched_wakeup(rec);
+       }
+
+       if (reset_static_share_mode_record) {
+               static_share_mode_record = NULL;
+       }
+}
+
+NTSTATUS share_mode_do_locked(
+       struct file_id id,
+       void (*fn)(struct db_record *rec,
+                  bool *modified_dependent,
+                  void *private_data),
+       void *private_data)
+{
+       TDB_DATA key = locking_key(&id);
+       size_t refcount = static_share_mode_data_refcount;
+
+       if (static_share_mode_record != NULL) {
+               bool modified_dependent = false;
+               TDB_DATA static_key;
+               int cmp;
+
+               static_key = dbwrap_record_get_key(static_share_mode_record);
+
+               cmp = tdb_data_cmp(static_key, key);
+               if (cmp != 0) {
+                       DBG_WARNING("Can not lock two share modes "
+                                   "simultaneously\n");
+                       return NT_STATUS_INVALID_LOCK_SEQUENCE;
+               }
+
+               fn(static_share_mode_record,
+                  &modified_dependent,
+                  private_data);
+
+               if (modified_dependent) {
+                       dbwrap_watched_wakeup(static_share_mode_record);
+               }
+       } else {
+               struct share_mode_do_locked_state state = {
+                       .fn = fn, .private_data = private_data,
+               };
+               NTSTATUS status;
+
+               status = dbwrap_do_locked(
+                       lock_db, key, share_mode_do_locked_fn, &state);
+               if (!NT_STATUS_IS_OK(status)) {
+                       DBG_WARNING("dbwrap_do_locked failed: %s\n",
+                                   nt_errstr(status));
+                       return status;
+               }
+       }
+
+       SMB_ASSERT(refcount == static_share_mode_data_refcount);
+
+       return NT_STATUS_OK;
+}
+
+static void share_mode_wakeup_waiters_fn(struct db_record *rec,
+                                        bool *modified_dependent,
+                                        void *private_data)
+{
+       *modified_dependent = true;
+}
+
+NTSTATUS share_mode_wakeup_waiters(struct file_id id)
+{
+       return share_mode_do_locked(id, share_mode_wakeup_waiters_fn, NULL);
+}
+
 struct fetch_share_mode_unlocked_state {
        TALLOC_CTX *mem_ctx;
        struct share_mode_lock *lck;
@@ -789,7 +983,6 @@ static int share_mode_traverse_fn(struct db_record *rec, void *_state)
 {
        struct share_mode_forall_state *state =
                (struct share_mode_forall_state *)_state;
-       uint32_t i;
        TDB_DATA key;
        TDB_DATA value;
        DATA_BLOB blob;
@@ -822,10 +1015,6 @@ static int share_mode_traverse_fn(struct db_record *rec, void *_state)
                return 0;
        }
 
-       for (i=0; i<d->num_share_modes; i++) {
-               d->share_modes[i].stale = false;
-       }
-
        if (DEBUGLEVEL > 10) {
                DEBUG(11, ("parse_share_modes:\n"));
                NDR_PRINT_DEBUG(share_mode_data, d);
@@ -863,33 +1052,49 @@ int share_mode_forall(int (*fn)(struct file_id fid,
 }
 
 struct share_entry_forall_state {
+       struct file_id fid;
+       const struct share_mode_data *data;
        int (*fn)(struct file_id fid,
                  const struct share_mode_data *data,
                  const struct share_mode_entry *entry,
                  void *private_data);
        void *private_data;
+       int ret;
 };
 
+static bool share_entry_traverse_walker(
+       struct share_mode_entry *e,
+       bool *modified,
+       void *private_data)
+{
+       struct share_entry_forall_state *state = private_data;
+
+       state->ret = state->fn(
+               state->fid, state->data, e, state->private_data);
+       return (state->ret != 0);
+}
+
 static int share_entry_traverse_fn(struct file_id fid,
                                   const struct share_mode_data *data,
                                   void *private_data)
 {
        struct share_entry_forall_state *state = private_data;
-       uint32_t i;
+       struct share_mode_lock lck = {
+               .data = discard_const_p(struct share_mode_data, data)
+       };
+       bool ok;
 
-       for (i=0; i<data->num_share_modes; i++) {
-               int ret;
+       state->fid = fid;
+       state->data = data;
 
-               ret = state->fn(fid,
-                               data,
-                               &data->share_modes[i],
-                               state->private_data);
-               if (ret != 0) {
-                       return ret;
-               }
+       ok = share_mode_forall_entries(
+               &lck, share_entry_traverse_walker, state);
+       if (!ok) {
+               DBG_DEBUG("share_mode_forall_entries failed\n");
+               return false;
        }
 
-       return 0;
+       return state->ret;
 }
 
 /*******************************************************************
@@ -909,109 +1114,160 @@ int share_entry_forall(int (*fn)(struct file_id fid,
        return share_mode_forall(share_entry_traverse_fn, &state);
 }
 
-bool share_mode_cleanup_disconnected(struct file_id fid,
-                                    uint64_t open_persistent_id)
-{
-       bool ret = false;
-       TALLOC_CTX *frame = talloc_stackframe();
-       unsigned n;
-       struct share_mode_data *data;
+struct cleanup_disconnected_state {
        struct share_mode_lock *lck;
-       bool ok;
+       uint64_t open_persistent_id;
+       bool found_connected;
+};
 
-       lck = get_existing_share_mode_lock(frame, fid);
-       if (lck == NULL) {
-               DEBUG(5, ("share_mode_cleanup_disconnected: "
-                         "Could not fetch share mode entry for %s\n",
-                         file_id_string(frame, &fid)));
-               goto done;
-       }
-       data = lck->data;
-
-       for (n=0; n < data->num_share_modes; n++) {
-               struct share_mode_entry *entry = &data->share_modes[n];
-
-               if (!server_id_is_disconnected(&entry->pid)) {
-                       struct server_id_buf tmp;
-                       DEBUG(5, ("share_mode_cleanup_disconnected: "
-                                 "file (file-id='%s', servicepath='%s', "
-                                 "base_name='%s%s%s') "
-                                 "is used by server %s ==> do not cleanup\n",
-                                 file_id_string(frame, &fid),
-                                 data->servicepath,
-                                 data->base_name,
-                                 (data->stream_name == NULL)
-                                 ? "" : "', stream_name='",
-                                 (data->stream_name == NULL)
-                                 ? "" : data->stream_name,
-                                 server_id_str_buf(entry->pid, &tmp)));
-                       goto done;
-               }
-               if (open_persistent_id != entry->share_file_id) {
-                       DEBUG(5, ("share_mode_cleanup_disconnected: "
-                                 "entry for file "
-                                 "(file-id='%s', servicepath='%s', "
-                                 "base_name='%s%s%s') "
-                                 "has share_file_id %llu but expected %llu"
-                                 "==> do not cleanup\n",
-                                 file_id_string(frame, &fid),
-                                 data->servicepath,
-                                 data->base_name,
-                                 (data->stream_name == NULL)
-                                 ? "" : "', stream_name='",
-                                 (data->stream_name == NULL)
-                                 ? "" : data->stream_name,
-                                 (unsigned long long)entry->share_file_id,
-                                 (unsigned long long)open_persistent_id));
-                       goto done;
-               }
-       }
+static bool cleanup_disconnected_lease(struct share_mode_entry *e,
+                                      void *private_data)
+{
+       struct cleanup_disconnected_state *state = private_data;
+       NTSTATUS status;
 
-       for (n=0; n < data->num_leases; n++) {
-               struct share_mode_lease *l = &data->leases[n];
-               NTSTATUS status;
+       status = leases_db_del(
+               &e->client_guid, &e->lease_key, &state->lck->data->id);
+
+       if (!NT_STATUS_IS_OK(status)) {
+               DBG_DEBUG("leases_db_del failed: %s\n",
+                         nt_errstr(status));
+       }
 
-               status = leases_db_del(&l->client_guid, &l->lease_key, &fid);
+       return false;
+}
+
+static bool share_mode_cleanup_disconnected_fn(
+       struct share_mode_entry *e,
+       bool *modified,
+       void *private_data)
+{
+       struct cleanup_disconnected_state *state = private_data;
+       struct share_mode_data *d = state->lck->data;
+       bool disconnected;
+
+       disconnected = server_id_is_disconnected(&e->pid);
+       if (!disconnected) {
+               struct file_id_buf tmp1;
+               struct server_id_buf tmp2;
+               DBG_INFO("file (file-id='%s', servicepath='%s', "
+                        "base_name='%s%s%s') "
+                        "is used by server %s ==> do not cleanup\n",
+                        file_id_str_buf(d->id, &tmp1),
+                        d->servicepath,
+                        d->base_name,
+                        (d->stream_name == NULL)
+                        ? "" : "', stream_name='",
+                        (d->stream_name == NULL)
+                        ? "" : d->stream_name,
+                        server_id_str_buf(e->pid, &tmp2));
+               state->found_connected = true;
+               return true;
+       }
 
-               DEBUG(10, ("%s: leases_db_del returned %s\n", __func__,
-                          nt_errstr(status)));
+       if (state->open_persistent_id != e->share_file_id) {
+               struct file_id_buf tmp;
+               DBG_INFO("entry for file "
+                        "(file-id='%s', servicepath='%s', "
+                        "base_name='%s%s%s') "
+                        "has share_file_id %"PRIu64" but expected "
+                        "%"PRIu64"==> do not cleanup\n",
+                        file_id_str_buf(d->id, &tmp),
+                        d->servicepath,
+                        d->base_name,
+                        (d->stream_name == NULL)
+                        ? "" : "', stream_name='",
+                        (d->stream_name == NULL)
+                        ? "" : d->stream_name,
+                        e->share_file_id,
+                        state->open_persistent_id);
+               state->found_connected = true;
+               return true;
+       }
+
+       return false;
+}
+
+bool share_mode_cleanup_disconnected(struct file_id fid,
+                                    uint64_t open_persistent_id)
+{
+       struct cleanup_disconnected_state state = {
+               .open_persistent_id = open_persistent_id
+       };
+       struct share_mode_data *data;
+       bool ret = false;
+       TALLOC_CTX *frame = talloc_stackframe();
+       bool ok;
+
+       state.lck = get_existing_share_mode_lock(frame, fid);
+       if (state.lck == NULL) {
+               DEBUG(5, ("share_mode_cleanup_disconnected: "
+                         "Could not fetch share mode entry for %s\n",
+                         file_id_string(frame, &fid)));
+               goto done;
+       }
+       data = state.lck->data;
+
+       ok = share_mode_forall_entries(
+               state.lck, share_mode_cleanup_disconnected_fn, &state);
+       if (!ok) {
+               DBG_DEBUG("share_mode_forall_entries failed\n");
+               goto done;
+       }
+       if (state.found_connected) {
+               DBG_DEBUG("Found connected entry\n");
+               goto done;
+       }
+
+       ok = share_mode_forall_leases(
+               state.lck, cleanup_disconnected_lease, &state);
+       if (!ok) {
+               DBG_DEBUG("failed to clean up leases associated "
+                         "with file (file-id='%s', servicepath='%s', "
+                         "base_name='%s%s%s') and open_persistent_id %"PRIu64" "
+                         "==> do not cleanup\n",
+                         file_id_string(frame, &fid),
+                         data->servicepath,
+                         data->base_name,
+                         (data->stream_name == NULL)
+                         ? "" : "', stream_name='",
+                         (data->stream_name == NULL)
+                         ? "" : data->stream_name,
+                         open_persistent_id);
        }
 
        ok = brl_cleanup_disconnected(fid, open_persistent_id);
        if (!ok) {
-               DEBUG(10, ("share_mode_cleanup_disconnected: "
-                          "failed to clean up byte range locks associated "
-                          "with file (file-id='%s', servicepath='%s', "
-                          "base_name='%s%s%s') and open_persistent_id %llu "
-                          "==> do not cleanup\n",
-                          file_id_string(frame, &fid),
-                          data->servicepath,
-                          data->base_name,
-                          (data->stream_name == NULL)
-                          ? "" : "', stream_name='",
-                          (data->stream_name == NULL)
-                          ? "" : data->stream_name,
-                          (unsigned long long)open_persistent_id));
+               DBG_DEBUG("failed to clean up byte range locks associated "
+                         "with file (file-id='%s', servicepath='%s', "
+                         "base_name='%s%s%s') and open_persistent_id %"PRIu64" "
+                         "==> do not cleanup\n",
+                         file_id_string(frame, &fid),
+                         data->servicepath,
+                         data->base_name,
+                         (data->stream_name == NULL)
+                         ? "" : "', stream_name='",
+                         (data->stream_name == NULL)
+                         ? "" : data->stream_name,
+                         open_persistent_id);
                goto done;
        }
 
-       DEBUG(10, ("share_mode_cleanup_disconnected: "
-                  "cleaning up %u entries for file "
-                  "(file-id='%s', servicepath='%s', "
-                  "base_name='%s%s%s') "
-                  "from open_persistent_id %llu\n",
-                  data->num_share_modes,
-                  file_id_string(frame, &fid),
-                  data->servicepath,
-                  data->base_name,
-                  (data->stream_name == NULL)
-                  ? "" : "', stream_name='",
-                  (data->stream_name == NULL)
-                  ? "" : data->stream_name,
-                  (unsigned long long)open_persistent_id));
+       DBG_DEBUG("cleaning up %u entries for file "
+                 "(file-id='%s', servicepath='%s', "
+                 "base_name='%s%s%s') "
+                 "from open_persistent_id %"PRIu64"\n",
+                 data->num_share_modes,
+                 file_id_string(frame, &fid),
+                 data->servicepath,
+                 data->base_name,
+                 (data->stream_name == NULL)
+                 ? "" : "', stream_name='",
+                 (data->stream_name == NULL)
+                 ? "" : data->stream_name,
+                 open_persistent_id);
 
        data->num_share_modes = 0;
-       data->num_leases = 0;
        data->modified = true;
 
        ret = true;
@@ -1019,3 +1275,864 @@ done:
        talloc_free(frame);
        return ret;
 }
+
+static int share_mode_entry_cmp(
+       struct server_id pid1,
+       uint64_t share_file_id1,
+       struct server_id pid2,
+       uint64_t share_file_id2)
+{
+       int cmp;
+
+       cmp = server_id_cmp(&pid1, &pid2);
+       if (cmp != 0) {
+               return cmp;
+       }
+       if (share_file_id1 != share_file_id2) {
+               return (share_file_id1 < share_file_id2) ? -1 : 1;
+       }
+       return 0;
+}
+
+/*
+ * 132 is the sizeof an ndr-encoded struct share_mode_entry_buf.
+ * Reading/writing entries will immediately error out if this
+ * size differs (push/pull is done without allocs).
+ */
+
+struct share_mode_entry_buf {
+       uint8_t buf[132];
+};
+#define SHARE_MODE_ENTRY_SIZE (sizeof(struct share_mode_entry_buf))
+
+static bool share_mode_entry_put(
+       const struct share_mode_entry *e,
+       struct share_mode_entry_buf *dst)
+{
+       DATA_BLOB blob = { .data = dst->buf, .length = sizeof(dst->buf) };
+       enum ndr_err_code ndr_err;
+
+       if (DEBUGLEVEL>=10) {
+               DBG_DEBUG("share_mode_entry:\n");
+               NDR_PRINT_DEBUG(share_mode_entry, discard_const_p(void, e));
+       }
+
+       ndr_err = ndr_push_struct_into_fixed_blob(
+               &blob,
+               e,
+               (ndr_push_flags_fn_t)ndr_push_share_mode_entry);
+       if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+               DBG_WARNING("ndr_push_share_mode_entry failed: %s\n",
+                           ndr_errstr(ndr_err));
+               return false;
+       }
+
+       return true;
+}
+
+static bool share_mode_entry_get(
+       DATA_BLOB blob, struct share_mode_entry *e)
+{
+       enum ndr_err_code ndr_err = NDR_ERR_SUCCESS;
+
+       ndr_err = ndr_pull_struct_blob_all_noalloc(
+               &blob, e, (ndr_pull_flags_fn_t)ndr_pull_share_mode_entry);
+       if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+               DBG_WARNING("ndr_pull_share_mode_entry failed\n");
+               return false;
+       }
+       return true;
+}
+
+static size_t share_mode_entry_find(
+       uint8_t *data,
+       size_t num_share_modes,
+       struct server_id pid,
+       uint64_t share_file_id,
+       struct share_mode_entry *e,
+       bool *match)
+{
+       ssize_t left, right, middle;
+
+       if (num_share_modes == 0) {
+               *match = false;
+               return 0;
+       }
+
+       left = 0;
+       right = (num_share_modes-1);
+
+       while (left <= right) {
+               DATA_BLOB blob;
+               int cmp;
+               bool ok;
+
+               middle = left + ((right - left) / 2);
+
+               DBG_DEBUG("left=%zu, right=%zu, middle=%zu\n",
+                         left,
+                         right,
+                         middle);
+
+               blob = (DATA_BLOB) {
+                       .data = data + middle * SHARE_MODE_ENTRY_SIZE,
+                       .length = SHARE_MODE_ENTRY_SIZE,
+               };
+
+               DBG_DEBUG("blob.data=%p, blob.length=%zu\n",
+                         blob.data,
+                         blob.length);
+
+               ok = share_mode_entry_get(blob, e);
+               if (!ok) {
+                       DBG_DEBUG("share_mode_entry_get failed\n");
+                       return false;
+               }
+
+               cmp = share_mode_entry_cmp(
+                       e->pid, e->share_file_id, pid, share_file_id);
+               if (cmp == 0) {
+                       *match = true;
+                       return middle;
+               }
+
+               if (cmp < 0) {
+                       right = middle-1;
+               } else {
+                       left = middle+1;
+               }
+       }
+
+       *match = false;
+       return left;
+}
+
+struct set_share_mode_state {
+       struct share_mode_entry e;
+       uint32_t num_share_modes;
+       NTSTATUS status;
+};
+
+static void set_share_mode_fn(struct db_record *rec, void *private_data)
+{
+       struct set_share_mode_state *state = private_data;
+       TDB_DATA data = dbwrap_record_get_value(rec);
+       size_t idx, num_share_modes;
+       struct share_mode_entry tmp;
+       struct share_mode_entry_buf buf;
+       bool ok, found;
+
+       TDB_DATA dbufs[3];
+       size_t num_dbufs = 0;
+
+       if ((data.dsize % SHARE_MODE_ENTRY_SIZE) != 0) {
+               DBG_WARNING("Got invalid record size %zu\n", data.dsize);
+               state->status = NT_STATUS_INTERNAL_DB_CORRUPTION;
+               return;
+       }
+       num_share_modes = data.dsize / SHARE_MODE_ENTRY_SIZE;
+
+       ok = share_mode_entry_put(&state->e, &buf);
+       if (!ok) {
+               DBG_DEBUG("share_mode_entry_put failed\n");
+               state->status = NT_STATUS_INTERNAL_ERROR;
+               return;
+       }
+
+       DBG_DEBUG("num_share_modes=%zu\n", num_share_modes);
+
+       idx = share_mode_entry_find(
+               data.dptr,
+               num_share_modes,
+               state->e.pid,
+               state->e.share_file_id,
+               &tmp,
+               &found);
+       if (found) {
+               DBG_WARNING("Found duplicate share mode\n");
+               state->status = NT_STATUS_INTERNAL_DB_CORRUPTION;
+               return;
+       }
+
+       DBG_DEBUG("idx=%zu, found=%d\n", idx, (int)found);
+
+       if (idx > 0) {
+               dbufs[num_dbufs] = (TDB_DATA) {
+                       .dptr = data.dptr,
+                       .dsize = idx * SHARE_MODE_ENTRY_SIZE,
+               };
+               num_dbufs += 1;
+       }
+
+       dbufs[num_dbufs] = (TDB_DATA) {
+               .dptr = buf.buf, .dsize = SHARE_MODE_ENTRY_SIZE,
+       };
+       num_dbufs += 1;
+
+       if (idx < num_share_modes) {
+               dbufs[num_dbufs] = (TDB_DATA) {
+                       .dptr = data.dptr + idx * SHARE_MODE_ENTRY_SIZE,
+                       .dsize = (num_share_modes-idx) * SHARE_MODE_ENTRY_SIZE,
+               };
+               num_dbufs += 1;
+       }
+
+       {
+               size_t i;
+               for (i=0; i<num_dbufs; i++) {
+                       DBG_DEBUG("dbufs[%zu]=(%p, %zu)\n",
+                                 i,
+                                 dbufs[i].dptr,
+                                 dbufs[i].dsize);
+               }
+       }
+
+       state->num_share_modes = num_share_modes+1;
+       state->status = dbwrap_record_storev(rec, dbufs, num_dbufs, 0);
+}
+
+bool set_share_mode(struct share_mode_lock *lck,
+                   struct files_struct *fsp,
+                   uid_t uid,
+                   uint64_t mid,
+                   uint16_t op_type,
+                   uint32_t share_access,
+                   uint32_t access_mask)
+{
+       struct share_mode_data *d = lck->data;
+       struct set_share_mode_state state = {
+               .status = NT_STATUS_OK,
+               .e.pid = messaging_server_id(fsp->conn->sconn->msg_ctx),
+               .e.share_access = share_access,
+               .e.private_options = fsp->fh->private_options,
+               .e.access_mask = access_mask,
+               .e.op_mid = mid,
+               .e.op_type = op_type,
+               .e.time.tv_sec = fsp->open_time.tv_sec,
+               .e.time.tv_usec = fsp->open_time.tv_usec,
+               .e.share_file_id = fsp->fh->gen_id,
+               .e.uid = (uint32_t)uid,
+               .e.flags = (fsp->posix_flags & FSP_POSIX_FLAGS_OPEN) ?
+               SHARE_MODE_FLAG_POSIX_OPEN : 0,
+               .e.name_hash = fsp->name_hash,
+       };
+       NTSTATUS status;
+
+       if (op_type == LEASE_OPLOCK) {
+               const struct GUID *client_guid = fsp_client_guid(fsp);
+               state.e.client_guid = *client_guid;
+               state.e.lease_key = fsp->lease->lease.lease_key;
+       }
+
+       status = dbwrap_do_locked(
+               share_entries_db,
+               locking_key(&d->id),
+               set_share_mode_fn,
+               &state);
+       if (!NT_STATUS_IS_OK(status)) {
+               DBG_WARNING("dbwrap_do_locked failed: %s\n",
+                           nt_errstr(status));
+               return false;
+       }
+       if (!NT_STATUS_IS_OK(state.status)) {
+               DBG_WARNING("set_share_mode_fn failed: %s\n",
+                           nt_errstr(state.status));
+               return false;
+       }
+
+       d->num_share_modes = state.num_share_modes;
+       d->modified = true;
+
+       return true;
+}
+
+struct share_mode_forall_entries_state {
+       struct share_mode_lock *lck;
+       bool (*fn)(struct share_mode_entry *e,
+                  bool *modified,
+                  void *private_data);
+       void *private_data;
+       size_t num_share_modes;
+       bool ok;
+};
+
+static bool share_mode_for_one_entry(
+       struct share_mode_forall_entries_state *state,
+       size_t *i,
+       size_t *num_share_modes,
+       TDB_DATA data,
+       bool *writeback)
+{
+       DATA_BLOB blob = {
+               .data = data.dptr + (*i) * SHARE_MODE_ENTRY_SIZE,
+               .length = SHARE_MODE_ENTRY_SIZE,
+       };
+       struct share_mode_entry e = {.pid.pid=0};
+       enum ndr_err_code ndr_err = NDR_ERR_SUCCESS;
+       bool modified = false;
+       bool stop = false;
+       struct server_id e_pid;
+       uint64_t e_share_file_id;
+
+       ndr_err = ndr_pull_struct_blob_all_noalloc(
+               &blob,
+               &e,
+               (ndr_pull_flags_fn_t)ndr_pull_share_mode_entry);
+       if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+               DBG_WARNING("ndr_pull_share_mode_entry failed\n");
+               *i += 1;
+               return false;
+       }
+       if (DEBUGLEVEL >= 10) {
+               DBG_DEBUG("entry[%zu]:\n", *i);
+               NDR_PRINT_DEBUG(share_mode_entry, &e);
+       }
+
+       e_pid = e.pid;
+       e_share_file_id = e.share_file_id;
+
+       stop = state->fn(&e, &modified, state->private_data);
+
+       DBG_DEBUG("entry[%zu]: modified=%d, e.stale=%d\n",
+                 *i,
+                 (int)modified,
+                 (int)e.stale);
+
+       if (modified) {
+               if (DEBUGLEVEL>=10) {
+                       DBG_DEBUG("share_mode_entry:\n");
+                       NDR_PRINT_DEBUG(share_mode_entry, &e);
+               }
+
+               /*
+                * Make sure sorting order is kept intact
+                */
+               SMB_ASSERT(server_id_equal(&e_pid, &e.pid));
+               SMB_ASSERT(e_share_file_id == e.share_file_id);
+
+               ndr_err = ndr_push_struct_into_fixed_blob(
+                       &blob,
+                       &e,
+                       (ndr_push_flags_fn_t)
+                       ndr_push_share_mode_entry);
+               if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+                       DBG_WARNING("ndr_push_share_mode_entry "
+                                   "failed: %s\n",
+                                   ndr_errstr(ndr_err));
+                       /*
+                        * Not much we can do, just ignore it
+                        */
+               }
+               *i += 1;
+               *writeback = true;
+               return stop;
+       }
+
+       if (e.stale) {
+               if (*i < *num_share_modes) {
+                       memmove(blob.data,
+                               blob.data + SHARE_MODE_ENTRY_SIZE,
+                               (*num_share_modes - *i - 1) *
+                               SHARE_MODE_ENTRY_SIZE);
+               }
+               *num_share_modes -= 1;
+               *writeback = true;
+               return stop;
+       }
+
+       if (stop) {
+               return true;
+       }
+
+       *i += 1;
+       return false;
+}
+
+static void share_mode_forall_entries_fn(
+       struct db_record *rec, void *private_data)
+{
+       struct share_mode_forall_entries_state *state = private_data;
+       struct share_mode_data *d = state->lck->data;
+       struct TDB_DATA data = dbwrap_record_get_value(rec);
+       size_t num_share_modes;
+       bool writeback = false;
+       NTSTATUS status;
+       bool stop = false;
+       size_t i;
+
+       if ((data.dsize % SHARE_MODE_ENTRY_SIZE) != 0) {
+               DBG_WARNING("Invalid data size %zu\n", data.dsize);
+               return;
+       }
+       num_share_modes = data.dsize / SHARE_MODE_ENTRY_SIZE;
+
+       DBG_DEBUG("num_share_modes=%zu\n", num_share_modes);
+
+       i = 0;
+       while (i<num_share_modes) {
+               stop = share_mode_for_one_entry(
+                       state, &i, &num_share_modes, data, &writeback);
+               if (stop) {
+                       break;
+               }
+       }
+
+       DBG_DEBUG("num_share_modes=%zu, writeback=%d\n",
+                 num_share_modes,
+                 (int)writeback);
+
+       if (!writeback) {
+               state->ok = true;
+               return;
+       }
+
+       if (num_share_modes != d->num_share_modes) {
+               d->num_share_modes = num_share_modes;
+               d->modified = true;
+       }
+
+       if (num_share_modes == 0) {
+               status = dbwrap_record_delete(rec);
+       } else {
+               TDB_DATA value = {
+                       .dptr = data.dptr,
+                       .dsize = num_share_modes * SHARE_MODE_ENTRY_SIZE,
+               };
+               status = dbwrap_record_store(rec, value, 0);
+       }
+
+       if (!NT_STATUS_IS_OK(status)) {
+               DBG_DEBUG("Storing record with %zu entries failed: %s\n",
+                         num_share_modes,
+                         nt_errstr(status));
+               return;
+       }
+
+
+       state->ok = true;
+}
+
+bool share_mode_forall_entries(
+       struct share_mode_lock *lck,
+       bool (*fn)(struct share_mode_entry *e,
+                  bool *modified,
+                  void *private_data),
+       void *private_data)
+{
+       struct share_mode_forall_entries_state state = {
+               .lck = lck,
+               .fn = fn,
+               .private_data = private_data,
+       };
+       NTSTATUS status;
+
+       status = dbwrap_do_locked(
+               share_entries_db,
+               locking_key(&lck->data->id),
+               share_mode_forall_entries_fn,
+               &state);
+       if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
+               status = NT_STATUS_OK;
+               state.ok = true;
+       }
+       if (!NT_STATUS_IS_OK(status)) {
+               DBG_DEBUG("dbwrap_parse_record returned %s\n",
+                         nt_errstr(status));
+               return false;
+       }
+
+       return state.ok;
+}
+
+struct share_mode_entry_do_state {
+       struct server_id pid;
+       uint64_t share_file_id;
+       void (*fn)(struct share_mode_entry *e,
+                  bool *modified,
+                  void *private_data);
+       void *private_data;
+       size_t num_share_modes;
+       NTSTATUS status;
+};
+
+static void share_mode_entry_do_fn(struct db_record *rec, void *private_data)
+{
+       struct share_mode_entry_do_state *state = private_data;
+       struct TDB_DATA data = dbwrap_record_get_value(rec);
+       size_t idx;
+       bool found = false;
+       bool modified;
+       struct share_mode_entry e;
+       struct share_mode_entry_buf buf;
+       TDB_DATA dbufs[3];
+       size_t num_dbufs = 0;
+
+       if ((data.dsize % SHARE_MODE_ENTRY_SIZE) != 0) {
+               DBG_WARNING("Invalid data size %zu\n", data.dsize);
+               state->status = NT_STATUS_INTERNAL_DB_CORRUPTION;
+               return;
+       }
+       state->num_share_modes = data.dsize / SHARE_MODE_ENTRY_SIZE;
+
+       DBG_DEBUG("state->num_share_modes=%zu\n", state->num_share_modes);
+
+       idx = share_mode_entry_find(
+               data.dptr,
+               state->num_share_modes,
+               state->pid,
+               state->share_file_id,
+               &e,
+               &found);
+       if (!found) {
+               DBG_WARNING("Did not find share mode entry for %"PRIu64"\n",
+                           state->share_file_id);
+               state->status = NT_STATUS_NOT_FOUND;
+               return;
+       }
+
+       state->fn(&e, &modified, state->private_data);
+
+       if (!e.stale && !modified) {
+               state->status = NT_STATUS_OK;
+               return;
+       }
+
+       if (idx > 0) {
+               dbufs[num_dbufs] = (TDB_DATA) {
+                       .dptr = data.dptr,
+                       .dsize = idx * SHARE_MODE_ENTRY_SIZE,
+               };
+               num_dbufs += 1;
+       }
+
+       if (!e.stale) {
+               bool ok = share_mode_entry_put(&e, &buf);
+               if (!ok) {
+                       DBG_DEBUG("share_mode_entry_put failed\n");
+                       state->status = NT_STATUS_INTERNAL_ERROR;
+                       return;
+               }
+
+               dbufs[num_dbufs] = (TDB_DATA) {
+                       .dptr = buf.buf, .dsize = SHARE_MODE_ENTRY_SIZE,
+               };
+               num_dbufs += 1;
+       }
+
+       idx += 1;
+
+       if (idx < state->num_share_modes) {
+               size_t behind = state->num_share_modes - idx;
+               dbufs[num_dbufs] = (TDB_DATA) {
+                       .dptr = data.dptr + idx * SHARE_MODE_ENTRY_SIZE,
+                       .dsize = behind * SHARE_MODE_ENTRY_SIZE,
+               };
+               num_dbufs += 1;
+       }
+
+       if (e.stale) {
+               state->num_share_modes -= 1;
+       }
+
+       state->status = dbwrap_record_storev(rec, dbufs, num_dbufs, 0);
+       if (!NT_STATUS_IS_OK(state->status)) {
+               DBG_DEBUG("dbwrap_record_storev failed: %s\n",
+                         nt_errstr(state->status));
+               return;
+       }
+}
+
+static bool share_mode_entry_do(
+       struct share_mode_lock *lck,
+       struct server_id pid,
+       uint64_t share_file_id,
+       void (*fn)(struct share_mode_entry *e,
+                  bool *modified,
+                  void *private_data),
+       void *private_data)
+{
+       struct share_mode_data *d = lck->data;
+       struct share_mode_entry_do_state state = {
+               .pid = pid,
+               .share_file_id = share_file_id,
+               .fn = fn,
+               .private_data = private_data,
+       };
+       NTSTATUS status;
+
+       status = dbwrap_do_locked(
+               share_entries_db,
+               locking_key(&d->id),
+               share_mode_entry_do_fn,
+               &state);
+       if (!NT_STATUS_IS_OK(status)) {
+               DBG_DEBUG("share_mode_forall_entries failed: %s\n",
+                         nt_errstr(status));
+               return false;
+       }
+       if (!NT_STATUS_IS_OK(state.status)) {
+               DBG_DEBUG("share_mode_entry_do_fn failed: %s\n",
+                         nt_errstr(status));
+               return false;
+       }
+
+       if (d->num_share_modes != state.num_share_modes) {
+               d->num_share_modes = state.num_share_modes;
+               d->modified = true;
+       }
+
+       return true;
+}
+
+struct del_share_mode_state {
+       bool ok;
+};
+
+static void del_share_mode_fn(
+       struct share_mode_entry *e,
+       bool *modified,
+       void *private_data)
+{
+       struct del_share_mode_state *state = private_data;
+       e->stale = true;
+       state->ok = true;
+}
+
+bool del_share_mode(struct share_mode_lock *lck, files_struct *fsp)
+{
+       struct del_share_mode_state state = { .ok = false };
+       bool ok;
+
+       ok = share_mode_entry_do(
+               lck,
+               messaging_server_id(fsp->conn->sconn->msg_ctx),
+               fsp->fh->gen_id,
+               del_share_mode_fn,
+               &state);
+       if (!ok) {
+               DBG_DEBUG("share_mode_entry_do failed\n");
+               return false;
+       }
+       if (!state.ok) {
+               DBG_DEBUG("del_share_mode_fn failed\n");
+               return false;
+       }
+       return true;
+}
+
+struct remove_share_oplock_state {
+       bool ok;
+};
+
+static void remove_share_oplock_fn(
+       struct share_mode_entry *e,
+       bool *modified,
+       void *private_data)
+{
+       struct remove_share_oplock_state *state = private_data;
+
+       e->op_type = NO_OPLOCK;
+       *modified = true;
+       state->ok = true;
+}
+
+bool remove_share_oplock(struct share_mode_lock *lck, files_struct *fsp)
+{
+       struct remove_share_oplock_state state = { .ok = false };
+       bool ok;
+
+       ok = share_mode_entry_do(
+               lck,
+               messaging_server_id(fsp->conn->sconn->msg_ctx),
+               fsp->fh->gen_id,
+               remove_share_oplock_fn,
+               &state);
+       if (!ok) {
+               DBG_DEBUG("share_mode_entry_do failed\n");
+               return false;
+       }
+       if (!state.ok) {
+               DBG_DEBUG("remove_share_oplock_fn failed\n");
+               return false;
+       }
+
+       if (fsp->oplock_type == LEASE_OPLOCK) {
+               remove_lease_if_stale(
+                       lck,
+                       fsp_client_guid(fsp),
+                       &fsp->lease->lease.lease_key);
+       }
+
+       lck->data->modified = true; /* signal watchers */
+
+       return true;
+}
+
+struct downgrade_share_oplock_state {
+       bool ok;
+};
+
+static void downgrade_share_oplock_fn(
+       struct share_mode_entry *e,
+       bool *modified,
+       void *private_data)
+{
+       struct downgrade_share_oplock_state *state = private_data;
+
+       e->op_type = LEVEL_II_OPLOCK;
+       *modified = true;
+       state->ok = true;
+}
+
+bool downgrade_share_oplock(struct share_mode_lock *lck, files_struct *fsp)
+{
+       struct downgrade_share_oplock_state state = { .ok = false };
+       bool ok;
+
+       ok = share_mode_entry_do(
+               lck,
+               messaging_server_id(fsp->conn->sconn->msg_ctx),
+               fsp->fh->gen_id,
+               downgrade_share_oplock_fn,
+               &state);
+       if (!ok) {
+               DBG_DEBUG("share_mode_entry_do failed\n");
+               return false;
+       }
+       if (!state.ok) {
+               DBG_DEBUG("downgrade_share_oplock_fn failed\n");
+               return false;
+       }
+
+       lck->data->flags |= SHARE_MODE_LEASE_READ;
+       lck->data->modified = true;
+
+       return true;
+}
+
+struct mark_share_mode_disconnected_state {
+       uint64_t open_persistent_id;
+       bool ok;
+};
+
+static void mark_share_mode_disconnected_fn(
+       struct share_mode_entry *e,
+       bool *modified,
+       void *private_data)
+{
+       struct mark_share_mode_disconnected_state *state = private_data;
+       server_id_set_disconnected(&e->pid);
+       e->share_file_id = state->open_persistent_id;
+       *modified = true;
+       state->ok = true;
+}
+
+bool mark_share_mode_disconnected(struct share_mode_lock *lck,
+                                 struct files_struct *fsp)
+{
+       struct mark_share_mode_disconnected_state state;
+       bool ok;
+
+       if (lck->data->num_share_modes != 1) {
+               return false;
+       }
+
+       if (fsp->op == NULL) {
+               return false;
+       }
+       if (!fsp->op->global->durable) {
+               return false;
+       }
+
+       state = (struct mark_share_mode_disconnected_state) {
+               .open_persistent_id = fsp->op->global->open_persistent_id,
+       };
+
+       ok = share_mode_entry_do(
+               lck,
+               messaging_server_id(fsp->conn->sconn->msg_ctx),
+               fsp->fh->gen_id,
+               mark_share_mode_disconnected_fn,
+               &state);
+       if (!ok) {
+               DBG_DEBUG("share_mode_entry_do failed\n");
+               return false;
+       }
+       if (!state.ok) {
+               DBG_DEBUG("mark_share_mode_disconnected_fn failed\n");
+               return false;
+       }
+
+       lck->data->modified = true;
+       return true;
+}
+
+static void reset_share_mode_entry_del_fn(
+       struct share_mode_entry *e,
+       bool *modified,
+       void *private_data)
+{
+       struct set_share_mode_state *state = private_data;
+
+       state->e = *e;
+       e->stale = true;
+       state->status = NT_STATUS_OK;
+}
+
+bool reset_share_mode_entry(
+       struct share_mode_lock *lck,
+       struct server_id old_pid,
+       uint64_t old_share_file_id,
+       struct server_id new_pid,
+       uint64_t new_mid,
+       uint64_t new_share_file_id)
+{
+       struct share_mode_data *d = lck->data;
+       struct set_share_mode_state state = {
+               .status = NT_STATUS_INTERNAL_ERROR,
+       };
+       NTSTATUS status;
+       bool ok;
+
+       ok = share_mode_entry_do(
+               lck,
+               old_pid,
+               old_share_file_id,
+               reset_share_mode_entry_del_fn,
+               &state);
+       if (!ok) {
+               DBG_DEBUG("share_mode_entry_do failed\n");
+               return false;
+       }
+       if (!NT_STATUS_IS_OK(state.status)) {
+               DBG_DEBUG("reset_share_mode_entry_del_fn failed: %s\n",
+                         nt_errstr(state.status));
+               return false;
+       }
+
+       state.status = NT_STATUS_INTERNAL_ERROR;
+       state.e.pid = new_pid;
+       state.e.op_mid = new_mid;
+       state.e.share_file_id = new_share_file_id;
+
+       status = dbwrap_do_locked(
+               share_entries_db,
+               locking_key(&d->id),
+               set_share_mode_fn,
+               &state);
+       if (!NT_STATUS_IS_OK(status)) {
+               DBG_WARNING("dbwrap_do_locked failed: %s\n",
+                           nt_errstr(status));
+               return false;
+       }
+       if (!NT_STATUS_IS_OK(state.status)) {
+               DBG_WARNING("set_share_mode_fn failed: %s\n",
+                           nt_errstr(state.status));
+               return false;
+       }
+
+       d->num_share_modes = state.num_share_modes;
+       d->modified = true;
+
+       return true;
+}