s3-talloc Change TALLOC_REALLOC_ARRAY() to talloc_realloc()
[ira/wip.git] / source3 / lib / util_tdb.c
index 2dbdd5794787df11ab76fec59aa8a94d1699a279..5c3dc3a07dc3aad87e494242028e03e04eec4de4 100644 (file)
@@ -4,22 +4,25 @@
    Copyright (C) Andrew Tridgell   1992-1998
    Copyright (C) Rafal Szczesniak  2002
    Copyright (C) Michael Adam      2007
-   
+
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.
-   
+
    This program 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 General Public License for more details.
-   
+
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
 #include "includes.h"
+#include "system/filesys.h"
+#include "util_tdb.h"
+
 #undef malloc
 #undef realloc
 #undef calloc
@@ -34,7 +37,7 @@ static SIG_ATOMIC_T gotalarm;
  Signal function to tell us we timed out.
 ****************************************************************/
 
-static void gotalarm_sig(void)
+static void gotalarm_sig(int signum)
 {
        gotalarm = 1;
 }
@@ -50,7 +53,7 @@ static int tdb_chainlock_with_timeout_internal( TDB_CONTEXT *tdb, TDB_DATA key,
        gotalarm = 0;
 
        if (timeout) {
-               CatchSignal(SIGALRM, SIGNAL_CAST gotalarm_sig);
+               CatchSignal(SIGALRM, gotalarm_sig);
                tdb_setalarm_sigptr(tdb, &gotalarm);
                alarm(timeout);
        }
@@ -63,7 +66,7 @@ static int tdb_chainlock_with_timeout_internal( TDB_CONTEXT *tdb, TDB_DATA key,
        if (timeout) {
                alarm(0);
                tdb_setalarm_sigptr(tdb, NULL);
-               CatchSignal(SIGALRM, SIGNAL_CAST SIG_IGN);
+               CatchSignal(SIGALRM, SIG_IGN);
                if (gotalarm && (ret == -1)) {
                        DEBUG(0,("tdb_chainlock_with_timeout_internal: alarm (%u) timed out for key %s in tdb %s\n",
                                timeout, key.dptr, tdb_name(tdb)));
@@ -91,7 +94,7 @@ int tdb_lock_bystring_with_timeout(TDB_CONTEXT *tdb, const char *keyval,
                                   int timeout)
 {
        TDB_DATA key = string_term_tdb_data(keyval);
-       
+
        return tdb_chainlock_with_timeout(tdb, key, timeout);
 }
 
@@ -102,7 +105,7 @@ int tdb_lock_bystring_with_timeout(TDB_CONTEXT *tdb, const char *keyval,
 int tdb_read_lock_bystring_with_timeout(TDB_CONTEXT *tdb, const char *keyval, unsigned int timeout)
 {
        TDB_DATA key = string_term_tdb_data(keyval);
-       
+
        return tdb_chainlock_with_timeout_internal(tdb, key, timeout, F_RDLCK);
 }
 
@@ -113,7 +116,7 @@ int tdb_trans_store_bystring(TDB_CONTEXT *tdb, const char *keystr,
                             TDB_DATA data, int flags)
 {
        TDB_DATA key = string_term_tdb_data(keystr);
-       
+
        return tdb_trans_store(tdb, key, data, flags);
 }
 
@@ -202,7 +205,7 @@ static size_t tdb_pack_va(uint8 *buf, int bufsize, const char *fmt, va_list ap)
 
        DEBUG(18,("tdb_pack_va(%s, %d) -> %d\n", 
                 fmt0, bufsize0, (int)PTR_DIFF(buf, buf0)));
-       
+
        return PTR_DIFF(buf, buf0);
 }
 
@@ -228,7 +231,7 @@ bool tdb_pack_append(TALLOC_CTX *mem_ctx, uint8 **buf, size_t *len,
        va_end(ap);
 
        if (mem_ctx != NULL) {
-               *buf = TALLOC_REALLOC_ARRAY(mem_ctx, *buf, uint8,
+               *buf = talloc_realloc(mem_ctx, *buf, uint8,
                                            (*len) + len1);
        } else {
                *buf = SMB_REALLOC_ARRAY(*buf, uint8, (*len) + len1);
@@ -481,636 +484,75 @@ int tdb_trans_delete(struct tdb_context *tdb, TDB_DATA key)
        return res;
 }
 
-/*
- Log tdb messages via DEBUG().
-*/
-static void tdb_wrap_log(TDB_CONTEXT *tdb, enum tdb_debug_level level, 
-                        const char *format, ...) PRINTF_ATTRIBUTE(3,4);
-
-static void tdb_wrap_log(TDB_CONTEXT *tdb, enum tdb_debug_level level, 
-                        const char *format, ...)
+NTSTATUS map_nt_error_from_tdb(enum TDB_ERROR err)
 {
-       va_list ap;
-       char *ptr = NULL;
-       int debuglevel = 0;
-       int ret;
+       NTSTATUS result = NT_STATUS_INTERNAL_ERROR;
 
-       switch (level) {
-       case TDB_DEBUG_FATAL:
-               debuglevel = 0;
+       switch (err) {
+       case TDB_SUCCESS:
+               result = NT_STATUS_OK;
                break;
-       case TDB_DEBUG_ERROR:
-               debuglevel = 1;
+       case TDB_ERR_CORRUPT:
+               result = NT_STATUS_INTERNAL_DB_CORRUPTION;
                break;
-       case TDB_DEBUG_WARNING:
-               debuglevel = 2;
+       case TDB_ERR_IO:
+               result = NT_STATUS_UNEXPECTED_IO_ERROR;
                break;
-       case TDB_DEBUG_TRACE:
-               debuglevel = 5;
+       case TDB_ERR_OOM:
+               result = NT_STATUS_NO_MEMORY;
+               break;
+       case TDB_ERR_EXISTS:
+               result = NT_STATUS_OBJECT_NAME_COLLISION;
                break;
-       default:
-               debuglevel = 0;
-       }               
-
-       va_start(ap, format);
-       ret = vasprintf(&ptr, format, ap);
-       va_end(ap);
-
-       if (ret != -1) {
-               const char *name = tdb_name(tdb);
-               DEBUG(debuglevel, ("tdb(%s): %s", name ? name : "unnamed", ptr));
-               free(ptr);
-       }
-}
-
-static struct tdb_wrap *tdb_list;
-
-/* destroy the last connection to a tdb */
-static int tdb_wrap_destructor(struct tdb_wrap *w)
-{
-       tdb_close(w->tdb);
-       DLIST_REMOVE(tdb_list, w);
-       return 0;
-}                               
-
-/*
-  wrapped connection to a tdb database
-  to close just talloc_free() the tdb_wrap pointer
- */
-struct tdb_wrap *tdb_wrap_open(TALLOC_CTX *mem_ctx,
-                              const char *name, int hash_size, int tdb_flags,
-                              int open_flags, mode_t mode)
-{
-       struct tdb_wrap *w;
-       struct tdb_logging_context log_ctx;
-       log_ctx.log_fn = tdb_wrap_log;
-
-       if (!lp_use_mmap())
-               tdb_flags |= TDB_NOMMAP;
-
-       for (w=tdb_list;w;w=w->next) {
-               if (strcmp(name, w->name) == 0) {
-                       /*
-                        * Yes, talloc_reference is exactly what we want
-                        * here. Otherwise we would have to implement our own
-                        * reference counting.
-                        */
-                       return talloc_reference(mem_ctx, w);
-               }
-       }
-
-       w = talloc(mem_ctx, struct tdb_wrap);
-       if (w == NULL) {
-               return NULL;
-       }
-
-       if (!(w->name = talloc_strdup(w, name))) {
-               talloc_free(w);
-               return NULL;
-       }
-
-       if ((hash_size == 0) && (name != NULL)) {
-               const char *base = strrchr_m(name, '/');
-               if (base != NULL) {
-                       base += 1;
-               }
-               else {
-                       base = name;
-               }
-               hash_size = lp_parm_int(-1, "tdb_hashsize", base, 0);
-       }
-
-       w->tdb = tdb_open_ex(name, hash_size, tdb_flags, 
-                            open_flags, mode, &log_ctx, NULL);
-       if (w->tdb == NULL) {
-               talloc_free(w);
-               return NULL;
-       }
-
-       talloc_set_destructor(w, tdb_wrap_destructor);
-
-       DLIST_ADD(tdb_list, w);
-
-       return w;
-}
-
-NTSTATUS map_nt_error_from_tdb(enum TDB_ERROR err)
-{
-       struct { enum TDB_ERROR err; NTSTATUS status; } map[] =
-               { { TDB_SUCCESS,        NT_STATUS_OK },
-                 { TDB_ERR_CORRUPT,    NT_STATUS_INTERNAL_DB_CORRUPTION },
-                 { TDB_ERR_IO,         NT_STATUS_UNEXPECTED_IO_ERROR },
-                 { TDB_ERR_OOM,        NT_STATUS_NO_MEMORY },
-                 { TDB_ERR_EXISTS,     NT_STATUS_OBJECT_NAME_COLLISION },
-
-                 /*
-                  * TDB_ERR_LOCK is very broad, we could for example
-                  * distinguish between fcntl locks and invalid lock
-                  * sequences. So NT_STATUS_FILE_LOCK_CONFLICT is a
-                  * compromise.
-                  */
-                 { TDB_ERR_LOCK,       NT_STATUS_FILE_LOCK_CONFLICT },
-                 /*
-                  * The next two ones in the enum are not actually used
-                  */
-                 { TDB_ERR_NOLOCK,     NT_STATUS_FILE_LOCK_CONFLICT },
-                 { TDB_ERR_LOCK_TIMEOUT, NT_STATUS_FILE_LOCK_CONFLICT },
-                 { TDB_ERR_NOEXIST,    NT_STATUS_NOT_FOUND },
-                 { TDB_ERR_EINVAL,     NT_STATUS_INVALID_PARAMETER },
-                 { TDB_ERR_RDONLY,     NT_STATUS_ACCESS_DENIED }
-               };
-
-       int i;
-
-       for (i=0; i < sizeof(map) / sizeof(map[0]); i++) {
-               if (err == map[i].err) {
-                       return map[i].status;
-               }
-       }
-
-       return NT_STATUS_INTERNAL_ERROR;
-}
-
-
-/*********************************************************************
- * the following is a generic validation mechanism for tdbs.
- *********************************************************************/
-
-/* 
- * internal validation function, executed by the child.  
- */
-static int tdb_validate_child(struct tdb_context *tdb,
-                             tdb_validate_data_func validate_fn)
-{
-       int ret = 1;
-       int num_entries = 0;
-       struct tdb_validation_status v_status;
-
-       v_status.tdb_error = False;
-       v_status.bad_freelist = False;
-       v_status.bad_entry = False;
-       v_status.unknown_key = False;
-       v_status.success = True;
-
-       if (!tdb) {
-               v_status.tdb_error = True;
-               v_status.success = False;
-               goto out;
-       }
-
-       /* Check if the tdb's freelist is good. */
-       if (tdb_validate_freelist(tdb, &num_entries) == -1) {
-               v_status.bad_freelist = True;
-               v_status.success = False;
-               goto out;
-       }
-
-       DEBUG(10,("tdb_validate_child: tdb %s freelist has %d entries\n",
-                 tdb_name(tdb), num_entries));
-
-       /* Now traverse the tdb to validate it. */
-       num_entries = tdb_traverse(tdb, validate_fn, (void *)&v_status);
-       if (!v_status.success) {
-               goto out;
-       } else if (num_entries == -1) {
-               v_status.tdb_error = True;
-               v_status.success = False;
-               goto out;
-       }
-
-       DEBUG(10,("tdb_validate_child: tdb %s is good with %d entries\n",
-                 tdb_name(tdb), num_entries));
-       ret = 0; /* Cache is good. */
-
-out:
-       DEBUG(10,   ("tdb_validate_child: summary of validation status:\n"));
-       DEBUGADD(10,(" * tdb error: %s\n", v_status.tdb_error ? "yes" : "no"));
-       DEBUGADD(10,(" * bad freelist: %s\n",v_status.bad_freelist?"yes":"no"));
-       DEBUGADD(10,(" * bad entry: %s\n", v_status.bad_entry ? "yes" : "no"));
-       DEBUGADD(10,(" * unknown key: %s\n", v_status.unknown_key?"yes":"no"));
-       DEBUGADD(10,(" => overall success: %s\n", v_status.success?"yes":"no"));
-
-       return ret;
-}
-
-/*
- * tdb validation function.
- * returns 0 if tdb is ok, != 0 if it isn't.
- * this function expects an opened tdb.
- */
-int tdb_validate(struct tdb_context *tdb, tdb_validate_data_func validate_fn)
-{
-       pid_t child_pid = -1;
-       int child_status = 0;
-       int wait_pid = 0;
-       int ret = 1;
-
-       if (tdb == NULL) {
-               DEBUG(1, ("Error: tdb_validate called with tdb == NULL\n"));
-               return ret;
-       }
-
-       DEBUG(5, ("tdb_validate called for tdb '%s'\n", tdb_name(tdb)));
-
-       /* fork and let the child do the validation.
-        * benefit: no need to twist signal handlers and panic functions.
-        * just let the child panic. we catch the signal. */
-
-       DEBUG(10, ("tdb_validate: forking to let child do validation.\n"));
-       child_pid = sys_fork();
-       if (child_pid == 0) {
-               /* child code */
-               DEBUG(10, ("tdb_validate (validation child): created\n"));
-               DEBUG(10, ("tdb_validate (validation child): "
-                          "calling tdb_validate_child\n"));
-               exit(tdb_validate_child(tdb, validate_fn));
-       }
-       else if (child_pid < 0) {
-               DEBUG(1, ("tdb_validate: fork for validation failed.\n"));
-               goto done;
-       }
-
-       /* parent */
-
-       DEBUG(10, ("tdb_validate: fork succeeded, child PID = %d\n",child_pid));
-
-       DEBUG(10, ("tdb_validate: waiting for child to finish...\n"));
-       while  ((wait_pid = sys_waitpid(child_pid, &child_status, 0)) < 0) {
-               if (errno == EINTR) {
-                       DEBUG(10, ("tdb_validate: got signal during waitpid, "
-                                  "retrying\n"));
-                       errno = 0;
-                       continue;
-               }
-               DEBUG(1, ("tdb_validate: waitpid failed with error '%s'.\n",
-                         strerror(errno)));
-               goto done;
-       }
-       if (wait_pid != child_pid) {
-               DEBUG(1, ("tdb_validate: waitpid returned pid %d, "
-                         "but %d was expected\n", wait_pid, child_pid));
-               goto done;
-       }
-
-       DEBUG(10, ("tdb_validate: validating child returned.\n"));
-       if (WIFEXITED(child_status)) {
-               DEBUG(10, ("tdb_validate: child exited, code %d.\n",
-                          WEXITSTATUS(child_status)));
-               ret = WEXITSTATUS(child_status);
-       }
-       if (WIFSIGNALED(child_status)) {
-               DEBUG(10, ("tdb_validate: child terminated by signal %d\n",
-                          WTERMSIG(child_status)));
-#ifdef WCOREDUMP
-               if (WCOREDUMP(child_status)) {
-                       DEBUGADD(10, ("core dumped\n"));
-               }
-#endif
-               ret = WTERMSIG(child_status);
-       }
-       if (WIFSTOPPED(child_status)) {
-               DEBUG(10, ("tdb_validate: child was stopped by signal %d\n",
-                          WSTOPSIG(child_status)));
-               ret = WSTOPSIG(child_status);
-       }
-
-done:
-       DEBUG(5, ("tdb_validate returning code '%d' for tdb '%s'\n", ret,
-                 tdb_name(tdb)));
-
-       return ret;
-}
-
-/*
- * tdb validation function.
- * returns 0 if tdb is ok, != 0 if it isn't.
- * this is a wrapper around the actual validation function that opens and closes
- * the tdb.
- */
-int tdb_validate_open(const char *tdb_path, tdb_validate_data_func validate_fn)
-{
-       TDB_CONTEXT *tdb = NULL;
-       int ret = 1;
-
-       DEBUG(5, ("tdb_validate_open called for tdb '%s'\n", tdb_path));
-
-       tdb = tdb_open_log(tdb_path, 0, TDB_DEFAULT, O_RDONLY, 0);
-       if (!tdb) {
-               DEBUG(1, ("Error opening tdb %s\n", tdb_path));
-               return ret;
-       }
-
-       ret = tdb_validate(tdb, validate_fn);
-       tdb_close(tdb);
-       return ret;
-}
-
-/*
- * tdb backup function and helpers for tdb_validate wrapper with backup
- * handling.
- */
-
-/* this structure eliminates the need for a global overall status for
- * the traverse-copy */
-struct tdb_copy_data {
-       struct tdb_context *dst;
-       bool success;
-};
 
-static int traverse_copy_fn(struct tdb_context *tdb, TDB_DATA key,
-                           TDB_DATA dbuf, void *private_data)
-{
-       struct tdb_copy_data *data = (struct tdb_copy_data *)private_data;
+       case TDB_ERR_LOCK:
+               /*
+                * TDB_ERR_LOCK is very broad, we could for example
+                * distinguish between fcntl locks and invalid lock
+                * sequences. So NT_STATUS_FILE_LOCK_CONFLICT is a
+                * compromise.
+                */
+               result = NT_STATUS_FILE_LOCK_CONFLICT;
+               break;
 
-       if (tdb_store(data->dst, key, dbuf, TDB_INSERT) != 0) {
-               DEBUG(4, ("Failed to insert into %s: %s\n", tdb_name(data->dst),
-                         strerror(errno)));
-               data->success = False;
-               return 1;
-       }
-       return 0;
+       case TDB_ERR_NOLOCK:
+       case TDB_ERR_LOCK_TIMEOUT:
+               /*
+                * These two ones in the enum are not actually used
+                */
+               result = NT_STATUS_FILE_LOCK_CONFLICT;
+               break;
+       case TDB_ERR_NOEXIST:
+               result = NT_STATUS_NOT_FOUND;
+               break;
+       case TDB_ERR_EINVAL:
+               result = NT_STATUS_INVALID_PARAMETER;
+               break;
+       case TDB_ERR_RDONLY:
+               result = NT_STATUS_ACCESS_DENIED;
+               break;
+       case TDB_ERR_NESTING:
+               result = NT_STATUS_INTERNAL_ERROR;
+               break;
+       };
+       return result;
 }
 
-static int tdb_copy(struct tdb_context *src, struct tdb_context *dst)
+int tdb_data_cmp(TDB_DATA t1, TDB_DATA t2)
 {
-       struct tdb_copy_data data;
-       int count;
-
-       data.dst = dst;
-       data.success = True;
-
-       count = tdb_traverse(src, traverse_copy_fn, (void *)(&data));
-       if ((count < 0) || (data.success == False)) {
+       int ret;
+       if (t1.dptr == NULL && t2.dptr != NULL) {
                return -1;
        }
-       return count;
-}
-
-static int tdb_verify_basic(struct tdb_context *tdb)
-{
-       return tdb_traverse(tdb, NULL, NULL);
-}
-
-/* this backup function is essentially taken from lib/tdb/tools/tdbbackup.tdb
- */
-static int tdb_backup(TALLOC_CTX *ctx, const char *src_path,
-                     const char *dst_path, int hash_size)
-{
-       struct tdb_context *src_tdb = NULL;
-       struct tdb_context *dst_tdb = NULL;
-       char *tmp_path = NULL;
-       struct stat st;
-       int count1, count2;
-       int saved_errno = 0;
-       int ret = -1;
-
-       if (stat(src_path, &st) != 0) {
-               DEBUG(3, ("Could not stat '%s': %s\n", src_path,
-                         strerror(errno)));
-               goto done;
-       }
-
-       /* open old tdb RDWR - so we can lock it */
-       src_tdb = tdb_open_log(src_path, 0, TDB_DEFAULT, O_RDWR, 0);
-       if (src_tdb == NULL) {
-               DEBUG(3, ("Failed to open tdb '%s'\n", src_path));
-               goto done;
-       }
-
-       if (tdb_lockall(src_tdb) != 0) {
-               DEBUG(3, ("Failed to lock tdb '%s'\n", src_path));
-               goto done;
-       }
-
-       tmp_path = talloc_asprintf(ctx, "%s%s", dst_path, ".tmp");
-       unlink(tmp_path);
-       dst_tdb = tdb_open_log(tmp_path,
-                              hash_size ? hash_size : tdb_hash_size(src_tdb),
-                              TDB_DEFAULT, O_RDWR | O_CREAT | O_EXCL,
-                              st.st_mode & 0777);
-       if (dst_tdb == NULL) {
-               DEBUG(3, ("Error creating tdb '%s': %s\n", tmp_path,
-                         strerror(errno)));
-               saved_errno = errno;
-               unlink(tmp_path);
-               goto done;
-       }
-
-       count1 = tdb_copy(src_tdb, dst_tdb);
-       if (count1 < 0) {
-               DEBUG(3, ("Failed to copy tdb '%s': %s\n", src_path,
-                         strerror(errno)));
-               tdb_close(dst_tdb);
-               goto done;
-       }
-
-       /* reopen ro and do basic verification */
-       tdb_close(dst_tdb);
-       dst_tdb = tdb_open_log(tmp_path, 0, TDB_DEFAULT, O_RDONLY, 0);
-       if (!dst_tdb) {
-               DEBUG(3, ("Failed to reopen tdb '%s': %s\n", tmp_path,
-                         strerror(errno)));
-               goto done;
-       }
-       count2 = tdb_verify_basic(dst_tdb);
-       if (count2 != count1) {
-               DEBUG(3, ("Failed to verify result of copying tdb '%s'.\n",
-                         src_path));
-               tdb_close(dst_tdb);
-               goto done;
-       }
-
-       DEBUG(10, ("tdb_backup: successfully copied %d entries\n", count1));
-
-       /* make sure the new tdb has reached stable storage
-        * then rename it to its destination */
-       fsync(tdb_fd(dst_tdb));
-       tdb_close(dst_tdb);
-       unlink(dst_path);
-       if (rename(tmp_path, dst_path) != 0) {
-               DEBUG(3, ("Failed to rename '%s' to '%s': %s\n",
-                         tmp_path, dst_path, strerror(errno)));
-               goto done;
-       }
-
-       /* success */
-       ret = 0;
-
-done:
-       if (src_tdb != NULL) {
-               tdb_close(src_tdb);
-       }
-       if (tmp_path != NULL) {
-               unlink(tmp_path);
-               TALLOC_FREE(tmp_path);
-       }
-       if (saved_errno != 0) {
-               errno = saved_errno;
-       }
-       return ret;
-}
-
-static int rename_file_with_suffix(TALLOC_CTX *ctx, const char *path,
-                                  const char *suffix)
-{
-       int ret = -1;
-       char *dst_path;
-
-       dst_path = talloc_asprintf(ctx, "%s%s", path, suffix);
-
-       ret = (rename(path, dst_path) != 0);
-
-       if (ret == 0) {
-               DEBUG(5, ("moved '%s' to '%s'\n", path, dst_path));
-       } else if (errno == ENOENT) {
-               DEBUG(3, ("file '%s' does not exist - so not moved\n", path));
-               ret = 0;
-       } else {
-               DEBUG(3, ("error renaming %s to %s: %s\n", path, dst_path,
-                         strerror(errno)));
-       }
-
-       TALLOC_FREE(dst_path);
-       return ret;
-}
-
-/*
- * do a backup of a tdb, moving the destination out of the way first
- */
-static int tdb_backup_with_rotate(TALLOC_CTX *ctx, const char *src_path,
-                                 const char *dst_path, int hash_size,
-                                 const char *rotate_suffix,
-                                 bool retry_norotate_if_nospc,
-                                 bool rename_as_last_resort_if_nospc)
-{
-       int ret;
-
-        rename_file_with_suffix(ctx, dst_path, rotate_suffix);
-
-        ret = tdb_backup(ctx, src_path, dst_path, hash_size);
-
-       if (ret != 0) {
-               DEBUG(10, ("backup of %s failed: %s\n", src_path, strerror(errno)));
+       if (t1.dptr != NULL && t2.dptr == NULL) {
+               return 1;
        }
-        if ((ret != 0) && (errno == ENOSPC) && retry_norotate_if_nospc)
-        {
-                char *rotate_path = talloc_asprintf(ctx, "%s%s", dst_path,
-                                                    rotate_suffix);
-                DEBUG(10, ("backup of %s failed due to lack of space\n",
-                          src_path));
-                DEBUGADD(10, ("trying to free some space by removing rotated "
-                             "dst %s\n", rotate_path));
-                if (unlink(rotate_path) == -1) {
-                        DEBUG(10, ("unlink of %s failed: %s\n", rotate_path,
-                                  strerror(errno)));
-                } else {
-                        ret = tdb_backup(ctx, src_path, dst_path, hash_size);
-                }
-                TALLOC_FREE(rotate_path);
-        }
-
-        if ((ret != 0) && (errno == ENOSPC) && rename_as_last_resort_if_nospc)
-        {
-                DEBUG(10, ("backup of %s failed due to lack of space\n", 
-                          src_path));
-                DEBUGADD(10, ("using 'rename' as a last resort\n"));
-                ret = rename(src_path, dst_path);
-        }
-
-        return ret;
-}
-
-/*
- * validation function with backup handling:
- *
- *  - calls tdb_validate
- *  - if the tdb is ok, create a backup "name.bak", possibly moving
- *    existing backup to name.bak.old,
- *    return 0 (success) even if the backup fails
- *  - if the tdb is corrupt:
- *    - move the tdb to "name.corrupt"
- *    - check if there is valid backup.
- *      if so, restore the backup.
- *      if restore is successful, return 0 (success),
- *    - otherwise return -1 (failure)
- */
-int tdb_validate_and_backup(const char *tdb_path,
-                           tdb_validate_data_func validate_fn)
-{
-       int ret = -1;
-       const char *backup_suffix = ".bak";
-       const char *corrupt_suffix = ".corrupt";
-       const char *rotate_suffix = ".old";
-       char *tdb_path_backup;
-       struct stat st;
-       TALLOC_CTX *ctx = NULL;
-
-       ctx = talloc_new(NULL);
-       if (ctx == NULL) {
-               DEBUG(0, ("tdb_validate_and_backup: out of memory\n"));
-               goto done;
+       if (t1.dptr == t2.dptr) {
+               return t1.dsize - t2.dsize;
        }
-
-       tdb_path_backup = talloc_asprintf(ctx, "%s%s", tdb_path, backup_suffix);
-
-       ret = tdb_validate_open(tdb_path, validate_fn);
-
+       ret = memcmp(t1.dptr, t2.dptr, MIN(t1.dsize, t2.dsize));
        if (ret == 0) {
-               DEBUG(1, ("tdb '%s' is valid\n", tdb_path));
-               ret = tdb_backup_with_rotate(ctx, tdb_path, tdb_path_backup, 0,
-                                            rotate_suffix, True, False);
-               if (ret != 0) {
-                       DEBUG(1, ("Error creating backup of tdb '%s'\n",
-                                 tdb_path));
-                       /* the actual validation was successful: */
-                       ret = 0;
-               } else {
-                       DEBUG(1, ("Created backup '%s' of tdb '%s'\n",
-                                 tdb_path_backup, tdb_path));
-               }
-       } else {
-               DEBUG(1, ("tdb '%s' is invalid\n", tdb_path));
-
-               ret =stat(tdb_path_backup, &st);
-               if (ret != 0) {
-                       DEBUG(5, ("Could not stat '%s': %s\n", tdb_path_backup,
-                                 strerror(errno)));
-                       DEBUG(1, ("No backup found.\n"));
-               } else {
-                       DEBUG(1, ("backup '%s' found.\n", tdb_path_backup));
-                       ret = tdb_validate_open(tdb_path_backup, validate_fn);
-                       if (ret != 0) {
-                               DEBUG(1, ("Backup '%s' is invalid.\n",
-                                         tdb_path_backup));
-                       }
-               }
-
-               if (ret != 0) {
-                       int renamed = rename_file_with_suffix(ctx, tdb_path,
-                                                             corrupt_suffix);
-                       if (renamed != 0) {
-                               DEBUG(1, ("Error moving tdb to '%s%s'\n",
-                                         tdb_path, corrupt_suffix));
-                       } else {
-                               DEBUG(1, ("Corrupt tdb stored as '%s%s'\n",
-                                         tdb_path, corrupt_suffix));
-                       }
-                       goto done;
-               }
-
-               DEBUG(1, ("valid backup '%s' found\n", tdb_path_backup));
-               ret = tdb_backup_with_rotate(ctx, tdb_path_backup, tdb_path, 0,
-                                            corrupt_suffix, True, True);
-               if (ret != 0) {
-                       DEBUG(1, ("Error restoring backup from '%s'\n",
-                                 tdb_path_backup));
-               } else {
-                       DEBUG(1, ("Restored tdb backup from '%s'\n",
-                                 tdb_path_backup));
-               }
+               return t1.dsize - t2.dsize;
        }
-
-done:
-       TALLOC_FREE(ctx);
        return ret;
 }