smbd: Add share_mode_forall_leases()
authorVolker Lendecke <vl@samba.org>
Mon, 17 Sep 2018 11:14:22 +0000 (13:14 +0200)
committerChristof Schmitt <cs@samba.org>
Sun, 14 Apr 2019 04:01:32 +0000 (04:01 +0000)
Function to walk all leases for a file exactly once. This used to be simpler
with the leases[] array, thus this function that encapsulates the complexity.

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Christof Schmitt <cs@samba.org>
source3/locking/locking.c
source3/locking/proto.h

index ddae920..0c08a2d 100644 (file)
@@ -1296,3 +1296,77 @@ bool file_has_open_streams(files_struct *fsp)
        TALLOC_FREE(lock);
        return false;
 }
+
+/*
+ * Walk share mode entries, looking at every lease only once
+ */
+
+bool share_mode_forall_leases(
+       struct share_mode_lock *lck,
+       bool (*fn)(struct share_mode_lock *lck,
+                  struct share_mode_entry *e,
+                  void *private_data),
+       void *private_data)
+{
+       struct share_mode_data *d = lck->data;
+       uint32_t *leases = NULL;
+       uint32_t num_leases = 0;
+       uint32_t i;
+
+       leases = talloc_array(talloc_tos(), uint32_t, d->num_share_modes);
+       if (leases == NULL) {
+               return false;
+       }
+
+       for (i=0; i<d->num_share_modes; i++) {
+               struct share_mode_entry *e = &d->share_modes[i];
+               uint32_t j;
+               bool ok, stop;
+
+               ok = is_valid_share_mode_entry(e);
+               if (!ok) {
+                       continue;
+               }
+
+               if (e->op_type != LEASE_OPLOCK) {
+                       continue;
+               }
+
+               /*
+                * See if we have already seen "e"'s lease. This is
+                * O(n^2). If we sort "leases", we can get this down
+                * to O(n).
+                */
+
+               for (j=0; j<num_leases; j++) {
+                       uint32_t idx = leases[j];
+                       struct share_mode_entry *l = &d->share_modes[idx];
+
+                       if (smb2_lease_equal(&e->client_guid,
+                                            &e->lease_key,
+                                            &l->client_guid,
+                                            &l->lease_key)) {
+                               break;
+                       }
+               }
+               if (j < num_leases) {
+                       /*
+                        * Don't look at "e"'s lease, we've already
+                        * seen it.
+                        */
+                       continue;
+               }
+
+               stop = fn(lck, e, private_data);
+               if (stop) {
+                       TALLOC_FREE(leases);
+                       return true;
+               }
+
+               leases[num_leases] = i;
+               num_leases += 1;
+       }
+
+       TALLOC_FREE(leases);
+       return true;
+}
index c021d97..9a9feff 100644 (file)
@@ -217,6 +217,12 @@ int share_entry_forall(int (*fn)(struct file_id fid,
                      void *private_data);
 bool share_mode_cleanup_disconnected(struct file_id id,
                                     uint64_t open_persistent_id);
+bool share_mode_forall_leases(
+       struct share_mode_lock *lck,
+       bool (*fn)(struct share_mode_lock *lck,
+                  struct share_mode_entry *e,
+                  void *private_data),
+       void *private_data);
 
 
 /* The following definitions come from locking/posix.c  */