X-Git-Url: https://git.ozlabs.org/?a=blobdiff_plain;ds=sidebyside;f=ccan%2Ftdb%2Ftdb.c;fp=ccan%2Ftdb%2Ftdb.c;h=0000000000000000000000000000000000000000;hb=7581be1b694700155dbb0edb91a772babf160545;hp=7317a3aa521554c898d12a5e5b8f57c7dafea36f;hpb=98b8ada203137a324f1712c042f7f6f3a5ef9ea0;p=ccan diff --git a/ccan/tdb/tdb.c b/ccan/tdb/tdb.c deleted file mode 100644 index 7317a3aa..00000000 --- a/ccan/tdb/tdb.c +++ /dev/null @@ -1,1141 +0,0 @@ - /* - 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 . -*/ - -#include "tdb_private.h" - -TDB_DATA tdb_null; - -/* - non-blocking increment of the tdb sequence number if the tdb has been opened using - the TDB_SEQNUM flag -*/ -void tdb_increment_seqnum_nonblock(struct tdb_context *tdb) -{ - tdb_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. - */ - tdb_ofs_read(tdb, TDB_SEQNUM_OFS, &seqnum); - seqnum++; - tdb_ofs_write(tdb, TDB_SEQNUM_OFS, &seqnum); -} - -/* - increment the tdb sequence number if the tdb has been opened using - the TDB_SEQNUM flag -*/ -static void tdb_increment_seqnum(struct tdb_context *tdb) -{ - if (!(tdb->flags & TDB_SEQNUM)) { - return; - } - - if (tdb_nest_lock(tdb, TDB_SEQNUM_OFS, F_WRLCK, - TDB_LOCK_WAIT|TDB_LOCK_PROBE) != 0) { - return; - } - - tdb_increment_seqnum_nonblock(tdb); - - tdb_nest_unlock(tdb, TDB_SEQNUM_OFS, F_WRLCK, false); -} - -static int tdb_key_compare(TDB_DATA key, TDB_DATA data, void *private_data) -{ - return memcmp(data.dptr, key.dptr, data.dsize); -} - -/* Returns 0 on fail. On success, return offset of record, and fills - in rec */ -static tdb_off_t tdb_find(struct tdb_context *tdb, TDB_DATA key, uint32_t hash, - struct tdb_record *r) -{ - tdb_off_t rec_ptr; - - /* read in the hash top */ - if (tdb_ofs_read(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) - return 0; - - /* keep looking until we find the right record */ - while (rec_ptr) { - if (tdb_rec_read(tdb, rec_ptr, r) == -1) - return 0; - - if (!TDB_DEAD(r) && hash==r->full_hash - && key.dsize==r->key_len - && tdb_parse_data(tdb, key, rec_ptr + sizeof(*r), - r->key_len, tdb_key_compare, - NULL) == 0) { - return rec_ptr; - } - /* detect tight infinite loop */ - if (rec_ptr == r->next) { - tdb->ecode = TDB_ERR_CORRUPT; - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_find: loop detected.\n")); - return 0; - } - rec_ptr = r->next; - } - tdb->ecode = TDB_ERR_NOEXIST; - return 0; -} - -/* As tdb_find, but if you succeed, keep the lock */ -tdb_off_t tdb_find_lock_hash(struct tdb_context *tdb, TDB_DATA key, uint32_t hash, int locktype, - struct tdb_record *rec) -{ - uint32_t rec_ptr; - - if (tdb_lock(tdb, BUCKET(hash), locktype) == -1) - return 0; - if (!(rec_ptr = tdb_find(tdb, key, hash, rec))) - tdb_unlock(tdb, BUCKET(hash), locktype); - return rec_ptr; -} - -static TDB_DATA _tdb_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 tdb_update_hash(struct tdb_context *tdb, TDB_DATA key, uint32_t hash, TDB_DATA dbuf) -{ - struct tdb_record rec; - tdb_off_t rec_ptr; - - /* find entry */ - if (!(rec_ptr = tdb_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 = _tdb_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(tdb_off_t)) { - tdb->ecode = TDB_SUCCESS; /* Not really an error */ - return -1; - } - - if (tdb->methods->tdb_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 tdb_rec_write(tdb, rec_ptr, &rec); - } - - return 0; -} - -/* find an entry in the database given a key */ -/* If an entry doesn't exist tdb_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 _tdb_fetch(struct tdb_context *tdb, TDB_DATA key) -{ - tdb_off_t rec_ptr; - struct tdb_record rec; - TDB_DATA ret; - uint32_t hash; - - /* find which hash bucket it is in */ - hash = tdb->hash_fn(&key); - if (!(rec_ptr = tdb_find_lock_hash(tdb,key,hash,F_RDLCK,&rec))) - return tdb_null; - - ret.dptr = tdb_alloc_read(tdb, rec_ptr + sizeof(rec) + rec.key_len, - rec.data_len); - ret.dsize = rec.data_len; - tdb_unlock(tdb, BUCKET(rec.full_hash), F_RDLCK); - return ret; -} - -TDB_DATA tdb_fetch(struct tdb_context *tdb, TDB_DATA key) -{ - TDB_DATA ret = _tdb_fetch(tdb, key); - - tdb_trace_1rec_retrec(tdb, "tdb_fetch", key, ret); - return ret; -} - -/* - * Find an entry in the database and hand the record's data to a parsing - * function. The parsing function is executed under the chain read lock, so it - * should be fast and should not block on other syscalls. - * - * DON'T CALL OTHER TDB CALLS FROM THE PARSER, THIS MIGHT LEAD TO SEGFAULTS. - * - * For mmapped tdb's that do not have a transaction open it points the parsing - * function directly at the mmap area, it avoids the malloc/memcpy in this - * case. If a transaction is open or no mmap is available, it has to do - * malloc/read/parse/free. - * - * This is interesting for all readers of potentially large data structures in - * the tdb records, ldb indexes being one example. - */ - -int tdb_parse_record(struct tdb_context *tdb, TDB_DATA key, - int (*parser)(TDB_DATA key, TDB_DATA data, - void *private_data), - void *private_data) -{ - tdb_off_t rec_ptr; - struct tdb_record rec; - int ret; - uint32_t hash; - - /* find which hash bucket it is in */ - hash = tdb->hash_fn(&key); - - if (!(rec_ptr = tdb_find_lock_hash(tdb,key,hash,F_RDLCK,&rec))) { - tdb_trace_1rec_ret(tdb, "tdb_parse_record", key, -1); - tdb->ecode = TDB_ERR_NOEXIST; - return 0; - } - tdb_trace_1rec_ret(tdb, "tdb_parse_record", key, 0); - - ret = tdb_parse_data(tdb, key, rec_ptr + sizeof(rec) + rec.key_len, - rec.data_len, parser, private_data); - - tdb_unlock(tdb, 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 tdb_exists_hash(struct tdb_context *tdb, TDB_DATA key, uint32_t hash) -{ - struct tdb_record rec; - - if (tdb_find_lock_hash(tdb, key, hash, F_RDLCK, &rec) == 0) - return 0; - tdb_unlock(tdb, BUCKET(rec.full_hash), F_RDLCK); - return 1; -} - -int tdb_exists(struct tdb_context *tdb, TDB_DATA key) -{ - uint32_t hash = tdb->hash_fn(&key); - int ret; - - ret = tdb_exists_hash(tdb, key, hash); - tdb_trace_1rec_ret(tdb, "tdb_exists", key, ret); - return ret; -} - -/* actually delete an entry in the database given the offset */ -int tdb_do_delete(struct tdb_context *tdb, tdb_off_t rec_ptr, struct tdb_record *rec) -{ - tdb_off_t last_ptr, i; - struct tdb_record lastrec; - - if (tdb->read_only || tdb->traverse_read) return -1; - - if (((tdb->traverse_write != 0) && (!TDB_DEAD(rec))) || - tdb_write_lock_record(tdb, rec_ptr) == -1) { - /* Someone traversing here: mark it as dead */ - rec->magic = TDB_DEAD_MAGIC; - return tdb_rec_write(tdb, rec_ptr, rec); - } - if (tdb_write_unlock_record(tdb, rec_ptr) != 0) - return -1; - - /* find previous record in hash chain */ - if (tdb_ofs_read(tdb, TDB_HASH_TOP(rec->full_hash), &i) == -1) - return -1; - for (last_ptr = 0; i != rec_ptr; last_ptr = i, i = lastrec.next) - if (tdb_rec_read(tdb, i, &lastrec) == -1) - return -1; - - /* unlink it: next ptr is at start of record. */ - if (last_ptr == 0) - last_ptr = TDB_HASH_TOP(rec->full_hash); - if (tdb_ofs_write(tdb, last_ptr, &rec->next) == -1) - return -1; - - /* recover the space */ - if (tdb_free(tdb, rec_ptr, rec) == -1) - return -1; - return 0; -} - -static int tdb_count_dead(struct tdb_context *tdb, uint32_t hash) -{ - int res = 0; - tdb_off_t rec_ptr; - struct tdb_record rec; - - /* read in the hash top */ - if (tdb_ofs_read(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) - return 0; - - while (rec_ptr) { - if (tdb_rec_read(tdb, rec_ptr, &rec) == -1) - return 0; - - if (rec.magic == TDB_DEAD_MAGIC) { - res += 1; - } - rec_ptr = rec.next; - } - return res; -} - -/* - * Purge all DEAD records from a hash chain - */ -static int tdb_purge_dead(struct tdb_context *tdb, uint32_t hash) -{ - int res = -1; - struct tdb_record rec; - tdb_off_t rec_ptr; - - if (tdb_lock(tdb, -1, F_WRLCK) == -1) { - return -1; - } - - /* read in the hash top */ - if (tdb_ofs_read(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) - goto fail; - - while (rec_ptr) { - tdb_off_t next; - - if (tdb_rec_read(tdb, rec_ptr, &rec) == -1) { - goto fail; - } - - next = rec.next; - - if (rec.magic == TDB_DEAD_MAGIC - && tdb_do_delete(tdb, rec_ptr, &rec) == -1) { - goto fail; - } - rec_ptr = next; - } - res = 0; - fail: - tdb_unlock(tdb, -1, F_WRLCK); - return res; -} - -/* delete an entry in the database given a key */ -static int tdb_delete_hash(struct tdb_context *tdb, TDB_DATA key, uint32_t hash) -{ - tdb_off_t rec_ptr; - struct tdb_record rec; - int ret; - - if (tdb->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 (tdb_lock(tdb, BUCKET(hash), F_WRLCK) == -1) - return -1; - - if (tdb_count_dead(tdb, hash) >= tdb->max_dead_records) { - /* - * Don't let the per-chain freelist grow too large, - * delete all existing dead records - */ - tdb_purge_dead(tdb, hash); - } - - if (!(rec_ptr = tdb_find(tdb, key, hash, &rec))) { - tdb_unlock(tdb, BUCKET(hash), F_WRLCK); - return -1; - } - - /* - * Just mark the record as dead. - */ - rec.magic = TDB_DEAD_MAGIC; - ret = tdb_rec_write(tdb, rec_ptr, &rec); - } - else { - if (!(rec_ptr = tdb_find_lock_hash(tdb, key, hash, F_WRLCK, - &rec))) - return -1; - - ret = tdb_do_delete(tdb, rec_ptr, &rec); - } - - if (ret == 0) { - tdb_increment_seqnum(tdb); - } - - if (tdb_unlock(tdb, BUCKET(rec.full_hash), F_WRLCK) != 0) - TDB_LOG((tdb, TDB_DEBUG_WARNING, "tdb_delete: WARNING tdb_unlock failed!\n")); - return ret; -} - -int tdb_delete(struct tdb_context *tdb, TDB_DATA key) -{ - uint32_t hash = tdb->hash_fn(&key); - int ret; - - ret = tdb_delete_hash(tdb, key, hash); - tdb_trace_1rec_ret(tdb, "tdb_delete", key, ret); - return ret; -} - -/* - * See if we have a dead record around with enough space - */ -static tdb_off_t tdb_find_dead(struct tdb_context *tdb, uint32_t hash, - struct tdb_record *r, tdb_len_t length) -{ - tdb_off_t rec_ptr; - - /* read in the hash top */ - if (tdb_ofs_read(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) - return 0; - - /* keep looking until we find the right record */ - while (rec_ptr) { - if (tdb_rec_read(tdb, rec_ptr, r) == -1) - return 0; - - if (TDB_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 _tdb_store(struct tdb_context *tdb, TDB_DATA key, - TDB_DATA dbuf, int flag, uint32_t hash) -{ - struct tdb_record rec; - tdb_off_t rec_ptr; - char *p = NULL; - int ret = -1; - - /* check for it existing, on insert. */ - if (flag == TDB_INSERT) { - if (tdb_exists_hash(tdb, key, hash)) { - tdb->ecode = TDB_ERR_EXISTS; - goto fail; - } - } else { - /* first try in-place update, on modify or replace. */ - if (tdb_update_hash(tdb, key, hash, dbuf) == 0) { - goto done; - } - if (tdb->ecode == TDB_ERR_NOEXIST && - flag == TDB_MODIFY) { - /* if the record doesn't exist and we are in TDB_MODIFY mode then - we should fail the store */ - goto fail; - } - } - /* reset the error code potentially set by the tdb_update() */ - tdb->ecode = 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) - tdb_delete_hash(tdb, key, hash); - - /* Copy key+value *before* allocating free space in case malloc - fails and we are left with a dead spot in the tdb. */ - - if (!(p = (char *)malloc(key.dsize + dbuf.dsize))) { - tdb->ecode = TDB_ERR_OOM; - goto fail; - } - - memcpy(p, key.dptr, key.dsize); - if (dbuf.dsize) - memcpy(p+key.dsize, dbuf.dptr, dbuf.dsize); - - if (tdb->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 = tdb_find_dead( - tdb, hash, &rec, - key.dsize + dbuf.dsize + sizeof(tdb_off_t)); - - if (rec_ptr != 0) { - rec.key_len = key.dsize; - rec.data_len = dbuf.dsize; - rec.full_hash = hash; - rec.magic = TDB_MAGIC; - if (tdb_rec_write(tdb, rec_ptr, &rec) == -1 - || tdb->methods->tdb_write( - tdb, rec_ptr + sizeof(rec), - p, key.dsize + 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 (tdb_lock(tdb, -1, F_WRLCK) == -1) { - goto fail; - } - - if ((tdb->max_dead_records != 0) - && (tdb_purge_dead(tdb, hash) == -1)) { - tdb_unlock(tdb, -1, F_WRLCK); - goto fail; - } - - /* we have to allocate some space */ - rec_ptr = tdb_allocate(tdb, key.dsize + dbuf.dsize, &rec); - - tdb_unlock(tdb, -1, F_WRLCK); - - if (rec_ptr == 0) { - goto fail; - } - - /* Read hash top into next ptr */ - if (tdb_ofs_read(tdb, TDB_HASH_TOP(hash), &rec.next) == -1) - goto fail; - - rec.key_len = key.dsize; - rec.data_len = dbuf.dsize; - rec.full_hash = hash; - rec.magic = TDB_MAGIC; - - /* write out and point the top of the hash chain at it */ - if (tdb_rec_write(tdb, rec_ptr, &rec) == -1 - || tdb->methods->tdb_write(tdb, rec_ptr+sizeof(rec), p, key.dsize+dbuf.dsize)==-1 - || tdb_ofs_write(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) { - /* Need to tdb_unallocate() here */ - goto fail; - } - - done: - ret = 0; - fail: - if (ret == 0) { - tdb_increment_seqnum(tdb); - } - - SAFE_FREE(p); - return ret; -} - -/* store an element in the database, replacing any existing element - with the same key - - return 0 on success, -1 on failure -*/ -int tdb_store(struct tdb_context *tdb, TDB_DATA key, TDB_DATA dbuf, int flag) -{ - uint32_t hash; - int ret; - - if (tdb->read_only || tdb->traverse_read) { - tdb->ecode = TDB_ERR_RDONLY; - tdb_trace_2rec_flag_ret(tdb, "tdb_store", key, dbuf, flag, -1); - return -1; - } - - /* find which hash bucket it is in */ - hash = tdb->hash_fn(&key); - if (tdb_lock(tdb, BUCKET(hash), F_WRLCK) == -1) - return -1; - - ret = _tdb_store(tdb, key, dbuf, flag, hash); - tdb_trace_2rec_flag_ret(tdb, "tdb_store", key, dbuf, flag, ret); - tdb_unlock(tdb, BUCKET(hash), F_WRLCK); - return ret; -} - -/* Append to an entry. Create if not exist. */ -int tdb_append(struct tdb_context *tdb, TDB_DATA key, TDB_DATA new_dbuf) -{ - uint32_t hash; - TDB_DATA dbuf; - int ret = -1; - - /* find which hash bucket it is in */ - hash = tdb->hash_fn(&key); - if (tdb_lock(tdb, BUCKET(hash), F_WRLCK) == -1) - return -1; - - dbuf = _tdb_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->ecode = TDB_ERR_OOM; - goto failed; - } - - memcpy(dbuf.dptr + dbuf.dsize, new_dbuf.dptr, new_dbuf.dsize); - dbuf.dsize += new_dbuf.dsize; - - ret = _tdb_store(tdb, key, dbuf, 0, hash); - tdb_trace_2rec_retrec(tdb, "tdb_append", key, new_dbuf, dbuf); - -failed: - tdb_unlock(tdb, BUCKET(hash), F_WRLCK); - SAFE_FREE(dbuf.dptr); - return ret; -} - - -/* - return the name of the current tdb file - useful for external logging functions -*/ -const char *tdb_name(struct tdb_context *tdb) -{ - return tdb->name; -} - -/* - return the underlying file descriptor being used by tdb, or -1 - useful for external routines that want to check the device/inode - of the fd -*/ -int tdb_fd(struct tdb_context *tdb) -{ - return tdb->fd; -} - -/* - return the current logging function - useful for external tdb routines that wish to log tdb errors -*/ -tdb_log_func tdb_log_fn(struct tdb_context *tdb) -{ - return tdb->log.log_fn; -} - - -/* - get the tdb sequence number. Only makes sense if the writers opened - with TDB_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 tdb_get_seqnum(struct tdb_context *tdb) -{ - tdb_off_t seqnum=0; - - tdb_ofs_read(tdb, TDB_SEQNUM_OFS, &seqnum); - return seqnum; -} - -int tdb_hash_size(struct tdb_context *tdb) -{ - return tdb->header.hash_size; -} - -size_t tdb_map_size(struct tdb_context *tdb) -{ - return tdb->map_size; -} - -int tdb_get_flags(struct tdb_context *tdb) -{ - return tdb->flags; -} - -void tdb_add_flags(struct tdb_context *tdb, unsigned flags) -{ - if ((flags & TDB_ALLOW_NESTING) && - (flags & TDB_DISALLOW_NESTING)) { - tdb->ecode = TDB_ERR_NESTING; - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_add_flags: " - "allow_nesting and disallow_nesting are not allowed together!")); - return; - } - - if (flags & TDB_ALLOW_NESTING) { - tdb->flags &= ~TDB_DISALLOW_NESTING; - } - if (flags & TDB_DISALLOW_NESTING) { - tdb->flags &= ~TDB_ALLOW_NESTING; - } - - tdb->flags |= flags; -} - -void tdb_remove_flags(struct tdb_context *tdb, unsigned flags) -{ - if ((flags & TDB_ALLOW_NESTING) && - (flags & TDB_DISALLOW_NESTING)) { - tdb->ecode = TDB_ERR_NESTING; - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_remove_flags: " - "allow_nesting and disallow_nesting are not allowed together!")); - return; - } - - if (flags & TDB_ALLOW_NESTING) { - tdb->flags |= TDB_DISALLOW_NESTING; - } - if (flags & TDB_DISALLOW_NESTING) { - tdb->flags |= TDB_ALLOW_NESTING; - } - - tdb->flags &= ~flags; -} - - -/* - enable sequence number handling on an open tdb -*/ -void tdb_enable_seqnum(struct tdb_context *tdb) -{ - tdb->flags |= TDB_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 tdb_free_region(struct tdb_context *tdb, tdb_off_t offset, ssize_t length) -{ - struct tdb_record rec; - if (length <= sizeof(rec)) { - /* the region is not worth adding */ - return 0; - } - if (length + offset > tdb->map_size) { - TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_free_region: adding region beyond end of file\n")); - return -1; - } - memset(&rec,'\0',sizeof(rec)); - rec.rec_len = length - sizeof(rec); - if (tdb_free(tdb, offset, &rec) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_free_region: failed to add free record\n")); - 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 tdb_wipe_all(struct tdb_context *tdb) -{ - int i; - tdb_off_t offset = 0; - ssize_t data_len; - tdb_off_t recovery_head; - tdb_len_t recovery_size = 0; - - if (tdb_lockall(tdb) != 0) { - return -1; - } - - tdb_trace(tdb, "tdb_wipe_all"); - - /* see if the tdb has a recovery area, and remember its size - if so. We don't want to lose this as otherwise each - tdb_wipe_all() in a transaction will increase the size of - the tdb by the size of the recovery area */ - if (tdb_ofs_read(tdb, TDB_RECOVERY_HEAD, &recovery_head) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_wipe_all: failed to read recovery head\n")); - goto failed; - } - - if (recovery_head != 0) { - struct tdb_record rec; - if (tdb->methods->tdb_read(tdb, recovery_head, &rec, sizeof(rec), DOCONV()) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_wipe_all: failed to read recovery record\n")); - return -1; - } - recovery_size = rec.rec_len + sizeof(rec); - } - - /* wipe the hashes */ - for (i=0;iheader.hash_size;i++) { - if (tdb_ofs_write(tdb, TDB_HASH_TOP(i), &offset) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_wipe_all: failed to write hash %d\n", i)); - goto failed; - } - } - - /* wipe the freelist */ - if (tdb_ofs_write(tdb, FREELIST_TOP, &offset) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_wipe_all: failed to write freelist\n")); - 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->map_size - TDB_DATA_START(tdb->header.hash_size)); - if (tdb_free_region(tdb, TDB_DATA_START(tdb->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 - TDB_DATA_START(tdb->header.hash_size)); - if (tdb_free_region(tdb, TDB_DATA_START(tdb->header.hash_size), data_len) != 0) { - goto failed; - } - /* and the 2nd free list entry after the recovery area - if any */ - data_len = tdb->map_size - (recovery_head+recovery_size); - if (tdb_free_region(tdb, recovery_head+recovery_size, data_len) != 0) { - goto failed; - } - } - - if (tdb_unlockall(tdb) != 0) { - TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_wipe_all: failed to unlock\n")); - goto failed; - } - - return 0; - -failed: - tdb_unlockall(tdb); - return -1; -} - -struct traverse_state { - bool error; - struct tdb_context *dest_db; -}; - -/* - traverse function for repacking - */ -static int repack_traverse(struct tdb_context *tdb, TDB_DATA key, TDB_DATA data, void *private_data) -{ - struct traverse_state *state = (struct traverse_state *)private_data; - if (tdb_store(state->dest_db, key, data, TDB_INSERT) != 0) { - state->error = true; - return -1; - } - return 0; -} - -/* - repack a tdb - */ -int tdb_repack(struct tdb_context *tdb) -{ - struct tdb_context *tmp_db; - struct traverse_state state; - - tdb_trace(tdb, "tdb_repack"); - - if (tdb_transaction_start(tdb) != 0) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, __location__ " Failed to start transaction\n")); - return -1; - } - - tmp_db = tdb_open("tmpdb", tdb_hash_size(tdb), TDB_INTERNAL, O_RDWR|O_CREAT, 0); - if (tmp_db == NULL) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, __location__ " Failed to create tmp_db\n")); - tdb_transaction_cancel(tdb); - return -1; - } - - state.error = false; - state.dest_db = tmp_db; - - if (tdb_traverse_read(tdb, repack_traverse, &state) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, __location__ " Failed to traverse copying out\n")); - tdb_transaction_cancel(tdb); - tdb_close(tmp_db); - return -1; - } - - if (state.error) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, __location__ " Error during traversal\n")); - tdb_transaction_cancel(tdb); - tdb_close(tmp_db); - return -1; - } - - if (tdb_wipe_all(tdb) != 0) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, __location__ " Failed to wipe database\n")); - tdb_transaction_cancel(tdb); - tdb_close(tmp_db); - return -1; - } - - state.error = false; - state.dest_db = tdb; - - if (tdb_traverse_read(tmp_db, repack_traverse, &state) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, __location__ " Failed to traverse copying back\n")); - tdb_transaction_cancel(tdb); - tdb_close(tmp_db); - return -1; - } - - if (state.error) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, __location__ " Error during second traversal\n")); - tdb_transaction_cancel(tdb); - tdb_close(tmp_db); - return -1; - } - - tdb_close(tmp_db); - - if (tdb_transaction_commit(tdb) != 0) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, __location__ " Failed to commit\n")); - return -1; - } - - return 0; -} - -#ifdef TDB_TRACE -static void tdb_trace_write(struct tdb_context *tdb, const char *str) -{ - if (write(tdb->tracefd, str, strlen(str)) != strlen(str)) { - close(tdb->tracefd); - tdb->tracefd = -1; - } -} - -static void tdb_trace_start(struct tdb_context *tdb) -{ - tdb_off_t seqnum=0; - char msg[sizeof(tdb_off_t) * 4 + 1]; - - tdb_ofs_read(tdb, TDB_SEQNUM_OFS, &seqnum); - snprintf(msg, sizeof(msg), "%u ", seqnum); - tdb_trace_write(tdb, msg); -} - -static void tdb_trace_end(struct tdb_context *tdb) -{ - tdb_trace_write(tdb, "\n"); -} - -static void tdb_trace_end_ret(struct tdb_context *tdb, int ret) -{ - char msg[sizeof(ret) * 4 + 4]; - snprintf(msg, sizeof(msg), " = %i\n", ret); - tdb_trace_write(tdb, msg); -} - -static void tdb_trace_record(struct tdb_context *tdb, TDB_DATA rec) -{ - char msg[20 + rec.dsize*2], *p; - unsigned int i; - - /* We differentiate zero-length records from non-existent ones. */ - if (rec.dptr == NULL) { - tdb_trace_write(tdb, " NULL"); - return; - } - - /* snprintf here is purely cargo-cult programming. */ - p = msg; - p += snprintf(p, sizeof(msg), " %zu:", rec.dsize); - for (i = 0; i < rec.dsize; i++) - p += snprintf(p, 2, "%02x", rec.dptr[i]); - - tdb_trace_write(tdb, msg); -} - -void tdb_trace(struct tdb_context *tdb, const char *op) -{ - tdb_trace_start(tdb); - tdb_trace_write(tdb, op); - tdb_trace_end(tdb); -} - -void tdb_trace_seqnum(struct tdb_context *tdb, uint32_t seqnum, const char *op) -{ - char msg[sizeof(tdb_off_t) * 4 + 1]; - - snprintf(msg, sizeof(msg), "%u ", seqnum); - tdb_trace_write(tdb, msg); - tdb_trace_write(tdb, op); - tdb_trace_end(tdb); -} - -void tdb_trace_open(struct tdb_context *tdb, const char *op, - unsigned hash_size, unsigned tdb_flags, unsigned open_flags) -{ - char msg[128]; - - snprintf(msg, sizeof(msg), - "%s %u 0x%x 0x%x", op, hash_size, tdb_flags, open_flags); - tdb_trace_start(tdb); - tdb_trace_write(tdb, msg); - tdb_trace_end(tdb); -} - -void tdb_trace_ret(struct tdb_context *tdb, const char *op, int ret) -{ - tdb_trace_start(tdb); - tdb_trace_write(tdb, op); - tdb_trace_end_ret(tdb, ret); -} - -void tdb_trace_retrec(struct tdb_context *tdb, const char *op, TDB_DATA ret) -{ - tdb_trace_start(tdb); - tdb_trace_write(tdb, op); - tdb_trace_write(tdb, " ="); - tdb_trace_record(tdb, ret); - tdb_trace_end(tdb); -} - -void tdb_trace_1rec(struct tdb_context *tdb, const char *op, - TDB_DATA rec) -{ - tdb_trace_start(tdb); - tdb_trace_write(tdb, op); - tdb_trace_record(tdb, rec); - tdb_trace_end(tdb); -} - -void tdb_trace_1rec_ret(struct tdb_context *tdb, const char *op, - TDB_DATA rec, int ret) -{ - tdb_trace_start(tdb); - tdb_trace_write(tdb, op); - tdb_trace_record(tdb, rec); - tdb_trace_end_ret(tdb, ret); -} - -void tdb_trace_1rec_retrec(struct tdb_context *tdb, const char *op, - TDB_DATA rec, TDB_DATA ret) -{ - tdb_trace_start(tdb); - tdb_trace_write(tdb, op); - tdb_trace_record(tdb, rec); - tdb_trace_write(tdb, " ="); - tdb_trace_record(tdb, ret); - tdb_trace_end(tdb); -} - -void tdb_trace_2rec_flag_ret(struct tdb_context *tdb, const char *op, - TDB_DATA rec1, TDB_DATA rec2, unsigned flag, - int ret) -{ - char msg[1 + sizeof(ret) * 4]; - - snprintf(msg, sizeof(msg), " %#x", flag); - tdb_trace_start(tdb); - tdb_trace_write(tdb, op); - tdb_trace_record(tdb, rec1); - tdb_trace_record(tdb, rec2); - tdb_trace_write(tdb, msg); - tdb_trace_end_ret(tdb, ret); -} - -void tdb_trace_2rec_retrec(struct tdb_context *tdb, const char *op, - TDB_DATA rec1, TDB_DATA rec2, TDB_DATA ret) -{ - tdb_trace_start(tdb); - tdb_trace_write(tdb, op); - tdb_trace_record(tdb, rec1); - tdb_trace_record(tdb, rec2); - tdb_trace_write(tdb, " ="); - tdb_trace_record(tdb, ret); - tdb_trace_end(tdb); -} -#endif