+++ /dev/null
- /*
- Unix SMB/CIFS implementation.
-
- trivial database library
-
- Copyright (C) Andrew Tridgell 1999-2005
- Copyright (C) Paul `Rusty' Russell 2000
- Copyright (C) Jeremy Allison 2000-2003
-
- ** 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"
-#include <assert.h>
-
-/*
- non-blocking increment of the tdb sequence number if the tdb has been opened using
- the TDB_SEQNUM flag
-*/
-void tdb1_increment_seqnum_nonblock(struct tdb_context *tdb)
-{
- tdb1_off_t seqnum=0;
-
- if (!(tdb->flags & TDB_SEQNUM)) {
- return;
- }
-
- /* we ignore errors from this, as we have no sane way of
- dealing with them.
- */
- tdb1_ofs_read(tdb, TDB1_SEQNUM_OFS, &seqnum);
- seqnum++;
- tdb1_ofs_write(tdb, TDB1_SEQNUM_OFS, &seqnum);
-}
-
-/*
- increment the tdb sequence number if the tdb has been opened using
- the TDB_SEQNUM flag
-*/
-static void tdb1_increment_seqnum(struct tdb_context *tdb)
-{
- if (!(tdb->flags & TDB_SEQNUM)) {
- return;
- }
-
- if (tdb1_nest_lock(tdb, TDB1_SEQNUM_OFS, F_WRLCK,
- TDB_LOCK_WAIT|TDB_LOCK_PROBE) != 0) {
- return;
- }
-
- tdb1_increment_seqnum_nonblock(tdb);
-
- tdb1_nest_unlock(tdb, TDB1_SEQNUM_OFS, F_WRLCK);
-}
-
-static enum TDB_ERROR tdb1_key_compare(TDB_DATA key, TDB_DATA data,
- void *matches_)
-{
- bool *matches = matches_;
- *matches = (memcmp(data.dptr, key.dptr, data.dsize) == 0);
- return TDB_SUCCESS;
-}
-
-/* Returns 0 on fail; last_error will be TDB_ERR_NOEXIST if it simply
- * wasn't there, otherwise a real error.
- * On success, return offset of record, and fills in rec */
-static tdb1_off_t tdb1_find(struct tdb_context *tdb, TDB_DATA key, uint32_t hash,
- struct tdb1_record *r)
-{
- tdb1_off_t rec_ptr;
-
- /* read in the hash top */
- if (tdb1_ofs_read(tdb, TDB1_HASH_TOP(hash), &rec_ptr) == -1)
- return 0;
-
- /* keep looking until we find the right record */
- while (rec_ptr) {
- if (tdb1_rec_read(tdb, rec_ptr, r) == -1)
- return 0;
-
- tdb->stats.compares++;
- if (TDB1_DEAD(r)) {
- tdb->stats.compare_wrong_bucket++;
- } else if (key.dsize != r->key_len) {
- tdb->stats.compare_wrong_keylen++;
- } else if (hash != r->full_hash) {
- tdb->stats.compare_wrong_rechash++;
- } else {
- enum TDB_ERROR ecode;
- bool matches;
- ecode = tdb1_parse_data(tdb, key, rec_ptr + sizeof(*r),
- r->key_len, tdb1_key_compare,
- &matches);
-
- if (ecode != TDB_SUCCESS) {
- tdb->last_error = ecode;
- return 0;
- }
-
- if (!matches) {
- tdb->stats.compare_wrong_keycmp++;
- } else {
- return rec_ptr;
- }
- }
- /* detect tight infinite loop */
- if (rec_ptr == r->next) {
- tdb->last_error = tdb_logerr(tdb, TDB_ERR_CORRUPT,
- TDB_LOG_ERROR,
- "tdb1_find: loop detected.");
- return 0;
- }
- rec_ptr = r->next;
- }
- tdb->last_error = TDB_ERR_NOEXIST;
- return 0;
-}
-
-/* As tdb1_find, but if you succeed, keep the lock */
-tdb1_off_t tdb1_find_lock_hash(struct tdb_context *tdb, TDB_DATA key, uint32_t hash, int locktype,
- struct tdb1_record *rec)
-{
- uint32_t rec_ptr;
-
- if (tdb1_lock(tdb, TDB1_BUCKET(hash), locktype) == -1)
- return 0;
- if (!(rec_ptr = tdb1_find(tdb, key, hash, rec)))
- tdb1_unlock(tdb, TDB1_BUCKET(hash), locktype);
- return rec_ptr;
-}
-
-static TDB_DATA _tdb1_fetch(struct tdb_context *tdb, TDB_DATA key);
-
-/* update an entry in place - this only works if the new data size
- is <= the old data size and the key exists.
- on failure return -1.
-*/
-static int tdb1_update_hash(struct tdb_context *tdb, TDB_DATA key, uint32_t hash, TDB_DATA dbuf)
-{
- struct tdb1_record rec;
- tdb1_off_t rec_ptr;
-
- /* find entry */
- if (!(rec_ptr = tdb1_find(tdb, key, hash, &rec)))
- return -1;
-
- /* it could be an exact duplicate of what is there - this is
- * surprisingly common (eg. with a ldb re-index). */
- if (rec.key_len == key.dsize &&
- rec.data_len == dbuf.dsize &&
- rec.full_hash == hash) {
- TDB_DATA data = _tdb1_fetch(tdb, key);
- if (data.dsize == dbuf.dsize &&
- memcmp(data.dptr, dbuf.dptr, data.dsize) == 0) {
- if (data.dptr) {
- free(data.dptr);
- }
- return 0;
- }
- if (data.dptr) {
- free(data.dptr);
- }
- }
-
- /* must be long enough key, data and tailer */
- if (rec.rec_len < key.dsize + dbuf.dsize + sizeof(tdb1_off_t)) {
- tdb->last_error = TDB_SUCCESS; /* Not really an error */
- return -1;
- }
-
- if (tdb->tdb1.io->tdb1_write(tdb, rec_ptr + sizeof(rec) + rec.key_len,
- dbuf.dptr, dbuf.dsize) == -1)
- return -1;
-
- if (dbuf.dsize != rec.data_len) {
- /* update size */
- rec.data_len = dbuf.dsize;
- return tdb1_rec_write(tdb, rec_ptr, &rec);
- }
-
- return 0;
-}
-
-/* find an entry in the database given a key */
-/* If an entry doesn't exist tdb1_err will be set to
- * TDB_ERR_NOEXIST. If a key has no data attached
- * then the TDB_DATA will have zero length but
- * a non-zero pointer
- */
-static TDB_DATA _tdb1_fetch(struct tdb_context *tdb, TDB_DATA key)
-{
- tdb1_off_t rec_ptr;
- struct tdb1_record rec;
- TDB_DATA ret;
- uint32_t hash;
-
- /* find which hash bucket it is in */
- hash = tdb_hash(tdb, key.dptr, key.dsize);
- if (!(rec_ptr = tdb1_find_lock_hash(tdb,key,hash,F_RDLCK,&rec))) {
- ret.dptr = NULL;
- ret.dsize = 0;
- return ret;
- }
-
- ret.dptr = tdb1_alloc_read(tdb, rec_ptr + sizeof(rec) + rec.key_len,
- rec.data_len);
- ret.dsize = rec.data_len;
- tdb1_unlock(tdb, TDB1_BUCKET(rec.full_hash), F_RDLCK);
- return ret;
-}
-
-enum TDB_ERROR tdb1_fetch(struct tdb_context *tdb, TDB_DATA key, TDB_DATA *data)
-{
- *data = _tdb1_fetch(tdb, key);
- if (data->dptr == NULL)
- return tdb->last_error;
- return TDB_SUCCESS;
-}
-
-enum TDB_ERROR tdb1_parse_record(struct tdb_context *tdb, TDB_DATA key,
- enum TDB_ERROR (*parser)(TDB_DATA key,
- TDB_DATA data,
- void *private_data),
- void *private_data)
-{
- tdb1_off_t rec_ptr;
- struct tdb1_record rec;
- enum TDB_ERROR ret;
- uint32_t hash;
-
- /* find which hash bucket it is in */
- hash = tdb_hash(tdb, key.dptr, key.dsize);
-
- if (!(rec_ptr = tdb1_find_lock_hash(tdb,key,hash,F_RDLCK,&rec))) {
- return tdb->last_error;
- }
-
- ret = tdb1_parse_data(tdb, key, rec_ptr + sizeof(rec) + rec.key_len,
- rec.data_len, parser, private_data);
-
- tdb1_unlock(tdb, TDB1_BUCKET(rec.full_hash), F_RDLCK);
-
- return ret;
-}
-
-/* check if an entry in the database exists
-
- note that 1 is returned if the key is found and 0 is returned if not found
- this doesn't match the conventions in the rest of this module, but is
- compatible with gdbm
-*/
-static int tdb1_exists_hash(struct tdb_context *tdb, TDB_DATA key, uint32_t hash)
-{
- struct tdb1_record rec;
-
- if (tdb1_find_lock_hash(tdb, key, hash, F_RDLCK, &rec) == 0)
- return 0;
- tdb1_unlock(tdb, TDB1_BUCKET(rec.full_hash), F_RDLCK);
- return 1;
-}
-
-int tdb1_exists(struct tdb_context *tdb, TDB_DATA key)
-{
- uint32_t hash = tdb_hash(tdb, key.dptr, key.dsize);
- int ret;
-
- assert(tdb->flags & TDB_VERSION1);
- ret = tdb1_exists_hash(tdb, key, hash);
- return ret;
-}
-
-/* actually delete an entry in the database given the offset */
-int tdb1_do_delete(struct tdb_context *tdb, tdb1_off_t rec_ptr, struct tdb1_record *rec)
-{
- tdb1_off_t last_ptr, i;
- struct tdb1_record lastrec;
-
- if ((tdb->flags & TDB_RDONLY) || tdb->tdb1.traverse_read) return -1;
-
- if (((tdb->tdb1.traverse_write != 0) && (!TDB1_DEAD(rec))) ||
- tdb1_write_lock_record(tdb, rec_ptr) == -1) {
- /* Someone traversing here: mark it as dead */
- rec->magic = TDB1_DEAD_MAGIC;
- return tdb1_rec_write(tdb, rec_ptr, rec);
- }
- if (tdb1_write_unlock_record(tdb, rec_ptr) != 0)
- return -1;
-
- /* find previous record in hash chain */
- if (tdb1_ofs_read(tdb, TDB1_HASH_TOP(rec->full_hash), &i) == -1)
- return -1;
- for (last_ptr = 0; i != rec_ptr; last_ptr = i, i = lastrec.next)
- if (tdb1_rec_read(tdb, i, &lastrec) == -1)
- return -1;
-
- /* unlink it: next ptr is at start of record. */
- if (last_ptr == 0)
- last_ptr = TDB1_HASH_TOP(rec->full_hash);
- if (tdb1_ofs_write(tdb, last_ptr, &rec->next) == -1)
- return -1;
-
- /* recover the space */
- if (tdb1_free(tdb, rec_ptr, rec) == -1)
- return -1;
- return 0;
-}
-
-static int tdb1_count_dead(struct tdb_context *tdb, uint32_t hash)
-{
- int res = 0;
- tdb1_off_t rec_ptr;
- struct tdb1_record rec;
-
- /* read in the hash top */
- if (tdb1_ofs_read(tdb, TDB1_HASH_TOP(hash), &rec_ptr) == -1)
- return 0;
-
- while (rec_ptr) {
- if (tdb1_rec_read(tdb, rec_ptr, &rec) == -1)
- return 0;
-
- if (rec.magic == TDB1_DEAD_MAGIC) {
- res += 1;
- }
- rec_ptr = rec.next;
- }
- return res;
-}
-
-/*
- * Purge all DEAD records from a hash chain
- */
-static int tdb1_purge_dead(struct tdb_context *tdb, uint32_t hash)
-{
- int res = -1;
- struct tdb1_record rec;
- tdb1_off_t rec_ptr;
-
- if (tdb1_lock(tdb, -1, F_WRLCK) == -1) {
- return -1;
- }
-
- /* read in the hash top */
- if (tdb1_ofs_read(tdb, TDB1_HASH_TOP(hash), &rec_ptr) == -1)
- goto fail;
-
- while (rec_ptr) {
- tdb1_off_t next;
-
- if (tdb1_rec_read(tdb, rec_ptr, &rec) == -1) {
- goto fail;
- }
-
- next = rec.next;
-
- if (rec.magic == TDB1_DEAD_MAGIC
- && tdb1_do_delete(tdb, rec_ptr, &rec) == -1) {
- goto fail;
- }
- rec_ptr = next;
- }
- res = 0;
- fail:
- tdb1_unlock(tdb, -1, F_WRLCK);
- return res;
-}
-
-/* delete an entry in the database given a key */
-static int tdb1_delete_hash(struct tdb_context *tdb, TDB_DATA key, uint32_t hash)
-{
- tdb1_off_t rec_ptr;
- struct tdb1_record rec;
- int ret;
-
- if (tdb->tdb1.max_dead_records != 0) {
-
- /*
- * Allow for some dead records per hash chain, mainly for
- * tdb's with a very high create/delete rate like locking.tdb.
- */
-
- if (tdb1_lock(tdb, TDB1_BUCKET(hash), F_WRLCK) == -1)
- return -1;
-
- if (tdb1_count_dead(tdb, hash) >= tdb->tdb1.max_dead_records) {
- /*
- * Don't let the per-chain freelist grow too large,
- * delete all existing dead records
- */
- tdb1_purge_dead(tdb, hash);
- }
-
- if (!(rec_ptr = tdb1_find(tdb, key, hash, &rec))) {
- tdb1_unlock(tdb, TDB1_BUCKET(hash), F_WRLCK);
- return -1;
- }
-
- /*
- * Just mark the record as dead.
- */
- rec.magic = TDB1_DEAD_MAGIC;
- ret = tdb1_rec_write(tdb, rec_ptr, &rec);
- }
- else {
- if (!(rec_ptr = tdb1_find_lock_hash(tdb, key, hash, F_WRLCK,
- &rec)))
- return -1;
-
- ret = tdb1_do_delete(tdb, rec_ptr, &rec);
- }
-
- if (ret == 0) {
- tdb1_increment_seqnum(tdb);
- }
-
- if (tdb1_unlock(tdb, TDB1_BUCKET(rec.full_hash), F_WRLCK) != 0)
- tdb_logerr(tdb, tdb->last_error, TDB_LOG_ERROR,
- "tdb1_delete: WARNING tdb1_unlock failed!");
- return ret;
-}
-
-int tdb1_delete(struct tdb_context *tdb, TDB_DATA key)
-{
- uint32_t hash = tdb_hash(tdb, key.dptr, key.dsize);
- int ret;
-
- assert(tdb->flags & TDB_VERSION1);
- ret = tdb1_delete_hash(tdb, key, hash);
- return ret;
-}
-
-/*
- * See if we have a dead record around with enough space
- */
-static tdb1_off_t tdb1_find_dead(struct tdb_context *tdb, uint32_t hash,
- struct tdb1_record *r, tdb1_len_t length)
-{
- tdb1_off_t rec_ptr;
-
- /* read in the hash top */
- if (tdb1_ofs_read(tdb, TDB1_HASH_TOP(hash), &rec_ptr) == -1)
- return 0;
-
- /* keep looking until we find the right record */
- while (rec_ptr) {
- if (tdb1_rec_read(tdb, rec_ptr, r) == -1)
- return 0;
-
- if (TDB1_DEAD(r) && r->rec_len >= length) {
- /*
- * First fit for simple coding, TODO: change to best
- * fit
- */
- return rec_ptr;
- }
- rec_ptr = r->next;
- }
- return 0;
-}
-
-static int _tdb1_store(struct tdb_context *tdb, TDB_DATA key,
- TDB_DATA dbuf, int flag, uint32_t hash)
-{
- struct tdb1_record rec;
- tdb1_off_t rec_ptr;
- int ret = -1;
-
- /* check for it existing, on insert. */
- if (flag == TDB_INSERT) {
- if (tdb1_exists_hash(tdb, key, hash)) {
- tdb->last_error = TDB_ERR_EXISTS;
- goto fail;
- }
- if (tdb->last_error != TDB_ERR_NOEXIST) {
- goto fail;
- }
- } else {
- /* first try in-place update, on modify or replace. */
- if (tdb1_update_hash(tdb, key, hash, dbuf) == 0) {
- goto done;
- }
- if (tdb->last_error != TDB_SUCCESS) {
- if (tdb->last_error != TDB_ERR_NOEXIST) {
- goto fail;
- }
- if (flag == TDB_MODIFY) {
- /* if the record doesn't exist and we are in TDB1_MODIFY mode then
- we should fail the store */
- goto fail;
- }
- }
- }
- /* reset the error code potentially set by the tdb1_update() */
- tdb->last_error = TDB_SUCCESS;
-
- /* delete any existing record - if it doesn't exist we don't
- care. Doing this first reduces fragmentation, and avoids
- coalescing with `allocated' block before it's updated. */
- if (flag != TDB_INSERT)
- tdb1_delete_hash(tdb, key, hash);
-
- if (tdb->tdb1.max_dead_records != 0) {
- /*
- * Allow for some dead records per hash chain, look if we can
- * find one that can hold the new record. We need enough space
- * for key, data and tailer. If we find one, we don't have to
- * consult the central freelist.
- */
- rec_ptr = tdb1_find_dead(
- tdb, hash, &rec,
- key.dsize + dbuf.dsize + sizeof(tdb1_off_t));
-
- if (rec_ptr != 0) {
- rec.key_len = key.dsize;
- rec.data_len = dbuf.dsize;
- rec.full_hash = hash;
- rec.magic = TDB1_MAGIC;
- if (tdb1_rec_write(tdb, rec_ptr, &rec) == -1
- || tdb->tdb1.io->tdb1_write(
- tdb, rec_ptr + sizeof(rec),
- key.dptr, key.dsize) == -1
- || tdb->tdb1.io->tdb1_write(
- tdb, rec_ptr + sizeof(rec) + key.dsize,
- dbuf.dptr, dbuf.dsize) == -1) {
- goto fail;
- }
- goto done;
- }
- }
-
- /*
- * We have to allocate some space from the freelist, so this means we
- * have to lock it. Use the chance to purge all the DEAD records from
- * the hash chain under the freelist lock.
- */
-
- if (tdb1_lock(tdb, -1, F_WRLCK) == -1) {
- goto fail;
- }
-
- if ((tdb->tdb1.max_dead_records != 0)
- && (tdb1_purge_dead(tdb, hash) == -1)) {
- tdb1_unlock(tdb, -1, F_WRLCK);
- goto fail;
- }
-
- /* we have to allocate some space */
- rec_ptr = tdb1_allocate(tdb, key.dsize + dbuf.dsize, &rec);
-
- tdb1_unlock(tdb, -1, F_WRLCK);
-
- if (rec_ptr == 0) {
- goto fail;
- }
-
- /* Read hash top into next ptr */
- if (tdb1_ofs_read(tdb, TDB1_HASH_TOP(hash), &rec.next) == -1)
- goto fail;
-
- rec.key_len = key.dsize;
- rec.data_len = dbuf.dsize;
- rec.full_hash = hash;
- rec.magic = TDB1_MAGIC;
-
- /* write out and point the top of the hash chain at it */
- if (tdb1_rec_write(tdb, rec_ptr, &rec) == -1
- || tdb->tdb1.io->tdb1_write(tdb, rec_ptr + sizeof(rec),
- key.dptr, key.dsize) == -1
- || tdb->tdb1.io->tdb1_write(tdb, rec_ptr + sizeof(rec) + key.dsize,
- dbuf.dptr, dbuf.dsize) == -1
- || tdb1_ofs_write(tdb, TDB1_HASH_TOP(hash), &rec_ptr) == -1) {
- /* Need to tdb1_unallocate() here */
- goto fail;
- }
-
- done:
- ret = 0;
- fail:
- if (ret == 0) {
- tdb1_increment_seqnum(tdb);
- }
- return ret;
-}
-
-/* store an element in the database, replacing any existing element
- with the same key
-
- return 0 on success, -1 on failure
-*/
-int tdb1_store(struct tdb_context *tdb, TDB_DATA key, TDB_DATA dbuf, int flag)
-{
- uint32_t hash;
- int ret;
-
- assert(tdb->flags & TDB_VERSION1);
-
- if ((tdb->flags & TDB_RDONLY) || tdb->tdb1.traverse_read) {
- tdb->last_error = tdb_logerr(tdb, TDB_ERR_RDONLY,
- TDB_LOG_USE_ERROR,
- "tdb_store: read-only tdb");
- return -1;
- }
-
- /* find which hash bucket it is in */
- hash = tdb_hash(tdb, key.dptr, key.dsize);
- if (tdb1_lock(tdb, TDB1_BUCKET(hash), F_WRLCK) == -1)
- return -1;
-
- ret = _tdb1_store(tdb, key, dbuf, flag, hash);
- tdb1_unlock(tdb, TDB1_BUCKET(hash), F_WRLCK);
- return ret;
-}
-
-/* Append to an entry. Create if not exist. */
-int tdb1_append(struct tdb_context *tdb, TDB_DATA key, TDB_DATA new_dbuf)
-{
- uint32_t hash;
- TDB_DATA dbuf;
- int ret = -1;
-
- assert(tdb->flags & TDB_VERSION1);
-
- /* find which hash bucket it is in */
- hash = tdb_hash(tdb, key.dptr, key.dsize);
- if (tdb1_lock(tdb, TDB1_BUCKET(hash), F_WRLCK) == -1)
- return -1;
-
- dbuf = _tdb1_fetch(tdb, key);
-
- if (dbuf.dptr == NULL) {
- dbuf.dptr = (unsigned char *)malloc(new_dbuf.dsize);
- } else {
- unsigned int new_len = dbuf.dsize + new_dbuf.dsize;
- unsigned char *new_dptr;
-
- /* realloc '0' is special: don't do that. */
- if (new_len == 0)
- new_len = 1;
- new_dptr = (unsigned char *)realloc(dbuf.dptr, new_len);
- if (new_dptr == NULL) {
- free(dbuf.dptr);
- }
- dbuf.dptr = new_dptr;
- }
-
- if (dbuf.dptr == NULL) {
- tdb->last_error = TDB_ERR_OOM;
- goto failed;
- }
-
- memcpy(dbuf.dptr + dbuf.dsize, new_dbuf.dptr, new_dbuf.dsize);
- dbuf.dsize += new_dbuf.dsize;
-
- ret = _tdb1_store(tdb, key, dbuf, 0, hash);
-
-failed:
- tdb1_unlock(tdb, TDB1_BUCKET(hash), F_WRLCK);
- SAFE_FREE(dbuf.dptr);
- return ret;
-}
-
-
-/*
- get the tdb sequence number. Only makes sense if the writers opened
- with TDB1_SEQNUM set. Note that this sequence number will wrap quite
- quickly, so it should only be used for a 'has something changed'
- test, not for code that relies on the count of the number of changes
- made. If you want a counter then use a tdb record.
-
- The aim of this sequence number is to allow for a very lightweight
- test of a possible tdb change.
-*/
-int tdb1_get_seqnum(struct tdb_context *tdb)
-{
- tdb1_off_t seqnum=0;
-
- tdb1_ofs_read(tdb, TDB1_SEQNUM_OFS, &seqnum);
- return seqnum;
-}
-
-
-/*
- add a region of the file to the freelist. Length is the size of the region in bytes,
- which includes the free list header that needs to be added
- */
-static int tdb1_free_region(struct tdb_context *tdb, tdb1_off_t offset, ssize_t length)
-{
- struct tdb1_record rec;
- if (length <= sizeof(rec)) {
- /* the region is not worth adding */
- return 0;
- }
- if (length + offset > tdb->file->map_size) {
- tdb->last_error = tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
- "tdb1_free_region: adding region beyond"
- " end of file");
- return -1;
- }
- memset(&rec,'\0',sizeof(rec));
- rec.rec_len = length - sizeof(rec);
- if (tdb1_free(tdb, offset, &rec) == -1) {
- tdb_logerr(tdb, tdb->last_error, TDB_LOG_ERROR,
- "tdb1_free_region: failed to add free record");
- return -1;
- }
- return 0;
-}
-
-/*
- wipe the entire database, deleting all records. This can be done
- very fast by using a allrecord lock. The entire data portion of the
- file becomes a single entry in the freelist.
-
- This code carefully steps around the recovery area, leaving it alone
- */
-int tdb1_wipe_all(struct tdb_context *tdb)
-{
- int i;
- tdb1_off_t offset = 0;
- ssize_t data_len;
- tdb1_off_t recovery_head;
- tdb1_len_t recovery_size = 0;
-
- if (tdb_lockall(tdb) != TDB_SUCCESS) {
- return -1;
- }
-
-
- /* see if the tdb has a recovery area, and remember its size
- if so. We don't want to lose this as otherwise each
- tdb1_wipe_all() in a transaction will increase the size of
- the tdb by the size of the recovery area */
- if (tdb1_ofs_read(tdb, TDB1_RECOVERY_HEAD, &recovery_head) == -1) {
- tdb_logerr(tdb, tdb->last_error, TDB_LOG_ERROR,
- "tdb1_wipe_all: failed to read recovery head");
- goto failed;
- }
-
- if (recovery_head != 0) {
- struct tdb1_record rec;
- if (tdb->tdb1.io->tdb1_read(tdb, recovery_head, &rec, sizeof(rec), TDB1_DOCONV()) == -1) {
- tdb_logerr(tdb, tdb->last_error, TDB_LOG_ERROR,
- "tdb1_wipe_all: failed to read recovery record");
- return -1;
- }
- recovery_size = rec.rec_len + sizeof(rec);
- }
-
- /* wipe the hashes */
- for (i=0;i<tdb->tdb1.header.hash_size;i++) {
- if (tdb1_ofs_write(tdb, TDB1_HASH_TOP(i), &offset) == -1) {
- tdb_logerr(tdb, tdb->last_error, TDB_LOG_ERROR,
- "tdb1_wipe_all: failed to write hash %d", i);
- goto failed;
- }
- }
-
- /* wipe the freelist */
- if (tdb1_ofs_write(tdb, TDB1_FREELIST_TOP, &offset) == -1) {
- tdb_logerr(tdb, tdb->last_error, TDB_LOG_ERROR,
- "tdb1_wipe_all: failed to write freelist");
- goto failed;
- }
-
- /* add all the rest of the file to the freelist, possibly leaving a gap
- for the recovery area */
- if (recovery_size == 0) {
- /* the simple case - the whole file can be used as a freelist */
- data_len = (tdb->file->map_size - TDB1_DATA_START(tdb->tdb1.header.hash_size));
- if (tdb1_free_region(tdb, TDB1_DATA_START(tdb->tdb1.header.hash_size), data_len) != 0) {
- goto failed;
- }
- } else {
- /* we need to add two freelist entries - one on either
- side of the recovery area
-
- Note that we cannot shift the recovery area during
- this operation. Only the transaction.c code may
- move the recovery area or we risk subtle data
- corruption
- */
- data_len = (recovery_head - TDB1_DATA_START(tdb->tdb1.header.hash_size));
- if (tdb1_free_region(tdb, TDB1_DATA_START(tdb->tdb1.header.hash_size), data_len) != 0) {
- goto failed;
- }
- /* and the 2nd free list entry after the recovery area - if any */
- data_len = tdb->file->map_size - (recovery_head+recovery_size);
- if (tdb1_free_region(tdb, recovery_head+recovery_size, data_len) != 0) {
- goto failed;
- }
- }
-
- tdb1_increment_seqnum_nonblock(tdb);
- tdb_unlockall(tdb);
- return 0;
-
-failed:
- tdb_unlockall(tdb);
- return -1;
-}
-
-/* Even on files, we can get partial writes due to signals. */
-bool tdb1_write_all(int fd, const void *buf, size_t count)
-{
- while (count) {
- ssize_t ret;
- ret = write(fd, buf, count);
- if (ret < 0)
- return false;
- buf = (const char *)buf + ret;
- count -= ret;
- }
- return true;
-}
projects / ccan / blobdiff