tdb2: import TDB1 code.

[ccan] / ccan / tdb2 / tdb1_freelistcheck.c

diff --git a/ccan/tdb2/tdb1_freelistcheck.c b/ccan/tdb2/tdb1_freelistcheck.c
new file mode 100644 (file)
index 0000000..c095ea5
--- /dev/null
+++ b/ccan/tdb2/tdb1_freelistcheck.c
@@ -0,0 +1,109 @@
+/*
+   Unix SMB/CIFS implementation.
+
+   trivial database library
+
+   Copyright (C) Jeremy Allison                    2006
+
+     ** NOTE! The following LGPL license applies to the tdb
+     ** library. This does NOT imply that all of Samba is released
+     ** under the LGPL
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 3 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this library; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "tdb1_private.h"
+
+/* Check the freelist is good and contains no loops.
+   Very memory intensive - only do this as a consistency
+   checker. Heh heh - uses an in memory tdb as the storage
+   for the "seen" record list. For some reason this strikes
+   me as extremely clever as I don't have to write another tree
+   data structure implementation :-).
+ */
+
+static int seen_insert(struct tdb1_context *mem_tdb, tdb1_off_t rec_ptr)
+{
+       TDB1_DATA key, data;
+
+       memset(&data, '\0', sizeof(data));
+       key.dptr = (unsigned char *)&rec_ptr;
+       key.dsize = sizeof(rec_ptr);
+       return tdb1_store(mem_tdb, key, data, TDB1_INSERT);
+}
+
+_PUBLIC_ int tdb1_validate_freelist(struct tdb1_context *tdb, int *pnum_entries)
+{
+       struct tdb1_context *mem_tdb = NULL;
+       struct tdb1_record rec;
+       tdb1_off_t rec_ptr, last_ptr;
+       int ret = -1;
+
+       *pnum_entries = 0;
+
+       mem_tdb = tdb1_open("flval", tdb->header.hash_size,
+                               TDB1_INTERNAL, O_RDWR, 0600);
+       if (!mem_tdb) {
+               return -1;
+       }
+
+       if (tdb1_lock(tdb, -1, F_WRLCK) == -1) {
+               tdb1_close(mem_tdb);
+               return 0;
+       }
+
+       last_ptr = TDB1_FREELIST_TOP;
+
+       /* Store the TDB1_FREELIST_TOP record. */
+       if (seen_insert(mem_tdb, last_ptr) == -1) {
+               tdb->ecode = TDB1_ERR_CORRUPT;
+               ret = -1;
+               goto fail;
+       }
+
+       /* read in the freelist top */
+       if (tdb1_ofs_read(tdb, TDB1_FREELIST_TOP, &rec_ptr) == -1) {
+               goto fail;
+       }
+
+       while (rec_ptr) {
+
+               /* If we can't store this record (we've seen it
+                  before) then the free list has a loop and must
+                  be corrupt. */
+
+               if (seen_insert(mem_tdb, rec_ptr)) {
+                       tdb->ecode = TDB1_ERR_CORRUPT;
+                       ret = -1;
+                       goto fail;
+               }
+
+               if (tdb1_rec_free_read(tdb, rec_ptr, &rec) == -1) {
+                       goto fail;
+               }
+
+               /* move to the next record */
+               last_ptr = rec_ptr;
+               rec_ptr = rec.next;
+               *pnum_entries += 1;
+       }
+
+       ret = 0;
+
+  fail:
+
+       tdb1_close(mem_tdb);
+       tdb1_unlock(tdb, -1, F_WRLCK);
+       return ret;
+}