diff options
Diffstat (limited to 'tdb/common')
| -rw-r--r-- | tdb/common/dump.c | 137 | ||||
| -rw-r--r-- | tdb/common/error.c | 57 | ||||
| -rw-r--r-- | tdb/common/freelist.c | 382 | ||||
| -rw-r--r-- | tdb/common/freelistcheck.c | 107 | ||||
| -rw-r--r-- | tdb/common/io.c | 473 | ||||
| -rw-r--r-- | tdb/common/lock.c | 553 | ||||
| -rw-r--r-- | tdb/common/open.c | 488 | ||||
| -rw-r--r-- | tdb/common/tdb.c | 891 | ||||
| -rw-r--r-- | tdb/common/tdb_private.h | 213 | ||||
| -rw-r--r-- | tdb/common/transaction.c | 1119 | ||||
| -rw-r--r-- | tdb/common/traverse.c | 348 |
11 files changed, 0 insertions, 4768 deletions
diff --git a/tdb/common/dump.c b/tdb/common/dump.c deleted file mode 100644 index d1c902dd..00000000 --- a/tdb/common/dump.c +++ /dev/null @@ -1,137 +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 <http://www.gnu.org/licenses/>. -*/ - -#include "tdb_private.h" - -static tdb_off_t tdb_dump_record(struct tdb_context *tdb, int hash, - tdb_off_t offset) -{ - struct list_struct rec; - tdb_off_t tailer_ofs, tailer; - - if (tdb->methods->tdb_read(tdb, offset, (char *)&rec, - sizeof(rec), DOCONV()) == -1) { - printf("ERROR: failed to read record at %u\n", offset); - return 0; - } - - printf(" rec: hash=%d offset=0x%08x next=0x%08x rec_len=%d " - "key_len=%d data_len=%d full_hash=0x%x magic=0x%x\n", - hash, offset, rec.next, rec.rec_len, rec.key_len, rec.data_len, - rec.full_hash, rec.magic); - - tailer_ofs = offset + sizeof(rec) + rec.rec_len - sizeof(tdb_off_t); - - if (tdb_ofs_read(tdb, tailer_ofs, &tailer) == -1) { - printf("ERROR: failed to read tailer at %u\n", tailer_ofs); - return rec.next; - } - - if (tailer != rec.rec_len + sizeof(rec)) { - printf("ERROR: tailer does not match record! tailer=%u totalsize=%u\n", - (unsigned int)tailer, (unsigned int)(rec.rec_len + sizeof(rec))); - } - return rec.next; -} - -static int tdb_dump_chain(struct tdb_context *tdb, int i) -{ - tdb_off_t rec_ptr, top; - - top = TDB_HASH_TOP(i); - - if (tdb_lock(tdb, i, F_WRLCK) != 0) - return -1; - - if (tdb_ofs_read(tdb, top, &rec_ptr) == -1) - return tdb_unlock(tdb, i, F_WRLCK); - - if (rec_ptr) - printf("hash=%d\n", i); - - while (rec_ptr) { - rec_ptr = tdb_dump_record(tdb, i, rec_ptr); - } - - return tdb_unlock(tdb, i, F_WRLCK); -} - -void tdb_dump_all(struct tdb_context *tdb) -{ - int i; - for (i=0;i<tdb->header.hash_size;i++) { - tdb_dump_chain(tdb, i); - } - printf("freelist:\n"); - tdb_dump_chain(tdb, -1); -} - -int tdb_printfreelist(struct tdb_context *tdb) -{ - int ret; - long total_free = 0; - tdb_off_t offset, rec_ptr; - struct list_struct rec; - - if ((ret = tdb_lock(tdb, -1, F_WRLCK)) != 0) - return ret; - - offset = FREELIST_TOP; - - /* read in the freelist top */ - if (tdb_ofs_read(tdb, offset, &rec_ptr) == -1) { - tdb_unlock(tdb, -1, F_WRLCK); - return 0; - } - - printf("freelist top=[0x%08x]\n", rec_ptr ); - while (rec_ptr) { - if (tdb->methods->tdb_read(tdb, rec_ptr, (char *)&rec, - sizeof(rec), DOCONV()) == -1) { - tdb_unlock(tdb, -1, F_WRLCK); - return -1; - } - - if (rec.magic != TDB_FREE_MAGIC) { - printf("bad magic 0x%08x in free list\n", rec.magic); - tdb_unlock(tdb, -1, F_WRLCK); - return -1; - } - - printf("entry offset=[0x%08x], rec.rec_len = [0x%08x (%d)] (end = 0x%08x)\n", - rec_ptr, rec.rec_len, rec.rec_len, rec_ptr + rec.rec_len); - total_free += rec.rec_len; - - /* move to the next record */ - rec_ptr = rec.next; - } - printf("total rec_len = [0x%08x (%d)]\n", (int)total_free, - (int)total_free); - - return tdb_unlock(tdb, -1, F_WRLCK); -} - diff --git a/tdb/common/error.c b/tdb/common/error.c deleted file mode 100644 index 195ab238..00000000 --- a/tdb/common/error.c +++ /dev/null @@ -1,57 +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 <http://www.gnu.org/licenses/>. -*/ - -#include "tdb_private.h" - -enum TDB_ERROR tdb_error(struct tdb_context *tdb) -{ - return tdb->ecode; -} - -static struct tdb_errname { - enum TDB_ERROR ecode; const char *estring; -} emap[] = { {TDB_SUCCESS, "Success"}, - {TDB_ERR_CORRUPT, "Corrupt database"}, - {TDB_ERR_IO, "IO Error"}, - {TDB_ERR_LOCK, "Locking error"}, - {TDB_ERR_OOM, "Out of memory"}, - {TDB_ERR_EXISTS, "Record exists"}, - {TDB_ERR_NOLOCK, "Lock exists on other keys"}, - {TDB_ERR_EINVAL, "Invalid parameter"}, - {TDB_ERR_NOEXIST, "Record does not exist"}, - {TDB_ERR_RDONLY, "write not permitted"} }; - -/* Error string for the last tdb error */ -const char *tdb_errorstr(struct tdb_context *tdb) -{ - uint32_t i; - for (i = 0; i < sizeof(emap) / sizeof(struct tdb_errname); i++) - if (tdb->ecode == emap[i].ecode) - return emap[i].estring; - return "Invalid error code"; -} - diff --git a/tdb/common/freelist.c b/tdb/common/freelist.c deleted file mode 100644 index 2f2a4c37..00000000 --- a/tdb/common/freelist.c +++ /dev/null @@ -1,382 +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 <http://www.gnu.org/licenses/>. -*/ - -#include "tdb_private.h" - -/* 'right' merges can involve O(n^2) cost when combined with a - traverse, so they are disabled until we find a way to do them in - O(1) time -*/ -#define USE_RIGHT_MERGES 0 - -/* read a freelist record and check for simple errors */ -int tdb_rec_free_read(struct tdb_context *tdb, tdb_off_t off, struct list_struct *rec) -{ - if (tdb->methods->tdb_read(tdb, off, rec, sizeof(*rec),DOCONV()) == -1) - return -1; - - if (rec->magic == TDB_MAGIC) { - /* this happens when a app is showdown while deleting a record - we should - not completely fail when this happens */ - TDB_LOG((tdb, TDB_DEBUG_WARNING, "tdb_rec_free_read non-free magic 0x%x at offset=%d - fixing\n", - rec->magic, off)); - rec->magic = TDB_FREE_MAGIC; - if (tdb->methods->tdb_write(tdb, off, rec, sizeof(*rec)) == -1) - return -1; - } - - if (rec->magic != TDB_FREE_MAGIC) { - /* Ensure ecode is set for log fn. */ - tdb->ecode = TDB_ERR_CORRUPT; - TDB_LOG((tdb, TDB_DEBUG_WARNING, "tdb_rec_free_read bad magic 0x%x at offset=%d\n", - rec->magic, off)); - return TDB_ERRCODE(TDB_ERR_CORRUPT, -1); - } - if (tdb->methods->tdb_oob(tdb, rec->next+sizeof(*rec), 0) != 0) - return -1; - return 0; -} - - -#if USE_RIGHT_MERGES -/* Remove an element from the freelist. Must have alloc lock. */ -static int remove_from_freelist(struct tdb_context *tdb, tdb_off_t off, tdb_off_t next) -{ - tdb_off_t last_ptr, i; - - /* read in the freelist top */ - last_ptr = FREELIST_TOP; - while (tdb_ofs_read(tdb, last_ptr, &i) != -1 && i != 0) { - if (i == off) { - /* We've found it! */ - return tdb_ofs_write(tdb, last_ptr, &next); - } - /* Follow chain (next offset is at start of record) */ - last_ptr = i; - } - TDB_LOG((tdb, TDB_DEBUG_FATAL,"remove_from_freelist: not on list at off=%d\n", off)); - return TDB_ERRCODE(TDB_ERR_CORRUPT, -1); -} -#endif - - -/* update a record tailer (must hold allocation lock) */ -static int update_tailer(struct tdb_context *tdb, tdb_off_t offset, - const struct list_struct *rec) -{ - tdb_off_t totalsize; - - /* Offset of tailer from record header */ - totalsize = sizeof(*rec) + rec->rec_len; - return tdb_ofs_write(tdb, offset + totalsize - sizeof(tdb_off_t), - &totalsize); -} - -/* Add an element into the freelist. Merge adjacent records if - neccessary. */ -int tdb_free(struct tdb_context *tdb, tdb_off_t offset, struct list_struct *rec) -{ - /* Allocation and tailer lock */ - if (tdb_lock(tdb, -1, F_WRLCK) != 0) - return -1; - - /* set an initial tailer, so if we fail we don't leave a bogus record */ - if (update_tailer(tdb, offset, rec) != 0) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_free: update_tailer failed!\n")); - goto fail; - } - -#if USE_RIGHT_MERGES - /* Look right first (I'm an Australian, dammit) */ - if (offset + sizeof(*rec) + rec->rec_len + sizeof(*rec) <= tdb->map_size) { - tdb_off_t right = offset + sizeof(*rec) + rec->rec_len; - struct list_struct r; - - if (tdb->methods->tdb_read(tdb, right, &r, sizeof(r), DOCONV()) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_free: right read failed at %u\n", right)); - goto left; - } - - /* If it's free, expand to include it. */ - if (r.magic == TDB_FREE_MAGIC) { - if (remove_from_freelist(tdb, right, r.next) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_free: right free failed at %u\n", right)); - goto left; - } - rec->rec_len += sizeof(r) + r.rec_len; - if (update_tailer(tdb, offset, rec) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_free: update_tailer failed at %u\n", offset)); - goto fail; - } - } - } -left: -#endif - - /* Look left */ - if (offset - sizeof(tdb_off_t) > TDB_DATA_START(tdb->header.hash_size)) { - tdb_off_t left = offset - sizeof(tdb_off_t); - struct list_struct l; - tdb_off_t leftsize; - - /* Read in tailer and jump back to header */ - if (tdb_ofs_read(tdb, left, &leftsize) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_free: left offset read failed at %u\n", left)); - goto update; - } - - /* it could be uninitialised data */ - if (leftsize == 0 || leftsize == TDB_PAD_U32) { - goto update; - } - - left = offset - leftsize; - - if (leftsize > offset || - left < TDB_DATA_START(tdb->header.hash_size)) { - goto update; - } - - /* Now read in the left record */ - if (tdb->methods->tdb_read(tdb, left, &l, sizeof(l), DOCONV()) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_free: left read failed at %u (%u)\n", left, leftsize)); - goto update; - } - - /* If it's free, expand to include it. */ - if (l.magic == TDB_FREE_MAGIC) { - /* we now merge the new record into the left record, rather than the other - way around. This makes the operation O(1) instead of O(n). This change - prevents traverse from being O(n^2) after a lot of deletes */ - l.rec_len += sizeof(*rec) + rec->rec_len; - if (tdb_rec_write(tdb, left, &l) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_free: update_left failed at %u\n", left)); - goto fail; - } - if (update_tailer(tdb, left, &l) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_free: update_tailer failed at %u\n", offset)); - goto fail; - } - tdb_unlock(tdb, -1, F_WRLCK); - return 0; - } - } - -update: - - /* Now, prepend to free list */ - rec->magic = TDB_FREE_MAGIC; - - if (tdb_ofs_read(tdb, FREELIST_TOP, &rec->next) == -1 || - tdb_rec_write(tdb, offset, rec) == -1 || - tdb_ofs_write(tdb, FREELIST_TOP, &offset) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_free record write failed at offset=%d\n", offset)); - goto fail; - } - - /* And we're done. */ - tdb_unlock(tdb, -1, F_WRLCK); - return 0; - - fail: - tdb_unlock(tdb, -1, F_WRLCK); - return -1; -} - - - -/* - the core of tdb_allocate - called when we have decided which - free list entry to use - - Note that we try to allocate by grabbing data from the end of an existing record, - not the beginning. This is so the left merge in a free is more likely to be - able to free up the record without fragmentation - */ -static tdb_off_t tdb_allocate_ofs(struct tdb_context *tdb, - tdb_len_t length, tdb_off_t rec_ptr, - struct list_struct *rec, tdb_off_t last_ptr) -{ -#define MIN_REC_SIZE (sizeof(struct list_struct) + sizeof(tdb_off_t) + 8) - - if (rec->rec_len < length + MIN_REC_SIZE) { - /* we have to grab the whole record */ - - /* unlink it from the previous record */ - if (tdb_ofs_write(tdb, last_ptr, &rec->next) == -1) { - return 0; - } - - /* mark it not free */ - rec->magic = TDB_MAGIC; - if (tdb_rec_write(tdb, rec_ptr, rec) == -1) { - return 0; - } - return rec_ptr; - } - - /* we're going to just shorten the existing record */ - rec->rec_len -= (length + sizeof(*rec)); - if (tdb_rec_write(tdb, rec_ptr, rec) == -1) { - return 0; - } - if (update_tailer(tdb, rec_ptr, rec) == -1) { - return 0; - } - - /* and setup the new record */ - rec_ptr += sizeof(*rec) + rec->rec_len; - - memset(rec, '\0', sizeof(*rec)); - rec->rec_len = length; - rec->magic = TDB_MAGIC; - - if (tdb_rec_write(tdb, rec_ptr, rec) == -1) { - return 0; - } - - if (update_tailer(tdb, rec_ptr, rec) == -1) { - return 0; - } - - return rec_ptr; -} - -/* allocate some space from the free list. The offset returned points - to a unconnected list_struct within the database with room for at - least length bytes of total data - - 0 is returned if the space could not be allocated - */ -tdb_off_t tdb_allocate(struct tdb_context *tdb, tdb_len_t length, struct list_struct *rec) -{ - tdb_off_t rec_ptr, last_ptr, newrec_ptr; - struct { - tdb_off_t rec_ptr, last_ptr; - tdb_len_t rec_len; - } bestfit; - float multiplier = 1.0; - - if (tdb_lock(tdb, -1, F_WRLCK) == -1) - return 0; - - /* Extra bytes required for tailer */ - length += sizeof(tdb_off_t); - length = TDB_ALIGN(length, TDB_ALIGNMENT); - - again: - last_ptr = FREELIST_TOP; - - /* read in the freelist top */ - if (tdb_ofs_read(tdb, FREELIST_TOP, &rec_ptr) == -1) - goto fail; - - bestfit.rec_ptr = 0; - bestfit.last_ptr = 0; - bestfit.rec_len = 0; - - /* - this is a best fit allocation strategy. Originally we used - a first fit strategy, but it suffered from massive fragmentation - issues when faced with a slowly increasing record size. - */ - while (rec_ptr) { - if (tdb_rec_free_read(tdb, rec_ptr, rec) == -1) { - goto fail; - } - - if (rec->rec_len >= length) { - if (bestfit.rec_ptr == 0 || - rec->rec_len < bestfit.rec_len) { - bestfit.rec_len = rec->rec_len; - bestfit.rec_ptr = rec_ptr; - bestfit.last_ptr = last_ptr; - } - } - - /* move to the next record */ - last_ptr = rec_ptr; - rec_ptr = rec->next; - - /* if we've found a record that is big enough, then - stop searching if its also not too big. The - definition of 'too big' changes as we scan - through */ - if (bestfit.rec_len > 0 && - bestfit.rec_len < length * multiplier) { - break; - } - - /* this multiplier means we only extremely rarely - search more than 50 or so records. At 50 records we - accept records up to 11 times larger than what we - want */ - multiplier *= 1.05; - } - - if (bestfit.rec_ptr != 0) { - if (tdb_rec_free_read(tdb, bestfit.rec_ptr, rec) == -1) { - goto fail; - } - - newrec_ptr = tdb_allocate_ofs(tdb, length, bestfit.rec_ptr, - rec, bestfit.last_ptr); - tdb_unlock(tdb, -1, F_WRLCK); - return newrec_ptr; - } - - /* we didn't find enough space. See if we can expand the - database and if we can then try again */ - if (tdb_expand(tdb, length + sizeof(*rec)) == 0) - goto again; - fail: - tdb_unlock(tdb, -1, F_WRLCK); - return 0; -} - - - -/* - return the size of the freelist - used to decide if we should repack -*/ -int tdb_freelist_size(struct tdb_context *tdb) -{ - tdb_off_t ptr; - int count=0; - - if (tdb_lock(tdb, -1, F_RDLCK) == -1) { - return -1; - } - - ptr = FREELIST_TOP; - while (tdb_ofs_read(tdb, ptr, &ptr) == 0 && ptr != 0) { - count++; - } - - tdb_unlock(tdb, -1, F_RDLCK); - return count; -} diff --git a/tdb/common/freelistcheck.c b/tdb/common/freelistcheck.c deleted file mode 100644 index efc050df..00000000 --- a/tdb/common/freelistcheck.c +++ /dev/null @@ -1,107 +0,0 @@ -/* - 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 "tdb_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 tdb_context *mem_tdb, tdb_off_t rec_ptr) -{ - TDB_DATA key, data; - - memset(&data, '\0', sizeof(data)); - key.dptr = (unsigned char *)&rec_ptr; - key.dsize = sizeof(rec_ptr); - return tdb_store(mem_tdb, key, data, TDB_INSERT); -} - -int tdb_validate_freelist(struct tdb_context *tdb, int *pnum_entries) -{ - struct tdb_context *mem_tdb = NULL; - struct list_struct rec; - tdb_off_t rec_ptr, last_ptr; - int ret = -1; - - *pnum_entries = 0; - - mem_tdb = tdb_open("flval", tdb->header.hash_size, - TDB_INTERNAL, O_RDWR, 0600); - if (!mem_tdb) { - return -1; - } - - if (tdb_lock(tdb, -1, F_WRLCK) == -1) { - tdb_close(mem_tdb); - return 0; - } - - last_ptr = FREELIST_TOP; - - /* Store the FREELIST_TOP record. */ - if (seen_insert(mem_tdb, last_ptr) == -1) { - ret = TDB_ERRCODE(TDB_ERR_CORRUPT, -1); - goto fail; - } - - /* read in the freelist top */ - if (tdb_ofs_read(tdb, 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)) { - ret = TDB_ERRCODE(TDB_ERR_CORRUPT, -1); - goto fail; - } - - if (tdb_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: - - tdb_close(mem_tdb); - tdb_unlock(tdb, -1, F_WRLCK); - return ret; -} diff --git a/tdb/common/io.c b/tdb/common/io.c deleted file mode 100644 index 661f7614..00000000 --- a/tdb/common/io.c +++ /dev/null @@ -1,473 +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 <http://www.gnu.org/licenses/>. -*/ - - -#include "tdb_private.h" - -/* check for an out of bounds access - if it is out of bounds then - see if the database has been expanded by someone else and expand - if necessary - note that "len" is the minimum length needed for the db -*/ -static int tdb_oob(struct tdb_context *tdb, tdb_off_t len, int probe) -{ - struct stat st; - if (len <= tdb->map_size) - return 0; - if (tdb->flags & TDB_INTERNAL) { - if (!probe) { - /* Ensure ecode is set for log fn. */ - tdb->ecode = TDB_ERR_IO; - TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_oob len %d beyond internal malloc size %d\n", - (int)len, (int)tdb->map_size)); - } - return TDB_ERRCODE(TDB_ERR_IO, -1); - } - - if (fstat(tdb->fd, &st) == -1) { - return TDB_ERRCODE(TDB_ERR_IO, -1); - } - - if (st.st_size < (size_t)len) { - if (!probe) { - /* Ensure ecode is set for log fn. */ - tdb->ecode = TDB_ERR_IO; - TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_oob len %d beyond eof at %d\n", - (int)len, (int)st.st_size)); - } - return TDB_ERRCODE(TDB_ERR_IO, -1); - } - - /* Unmap, update size, remap */ - if (tdb_munmap(tdb) == -1) - return TDB_ERRCODE(TDB_ERR_IO, -1); - tdb->map_size = st.st_size; - tdb_mmap(tdb); - return 0; -} - -/* write a lump of data at a specified offset */ -static int tdb_write(struct tdb_context *tdb, tdb_off_t off, - const void *buf, tdb_len_t len) -{ - if (len == 0) { - return 0; - } - - if (tdb->read_only || tdb->traverse_read) { - tdb->ecode = TDB_ERR_RDONLY; - return -1; - } - - if (tdb->methods->tdb_oob(tdb, off + len, 0) != 0) - return -1; - - if (tdb->map_ptr) { - memcpy(off + (char *)tdb->map_ptr, buf, len); - } else { - ssize_t written = pwrite(tdb->fd, buf, len, off); - if ((written != (ssize_t)len) && (written != -1)) { - /* try once more */ - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_write: wrote only " - "%d of %d bytes at %d, trying once more\n", - (int)written, len, off)); - errno = ENOSPC; - written = pwrite(tdb->fd, (const void *)((const char *)buf+written), - len-written, - off+written); - } - if (written == -1) { - /* Ensure ecode is set for log fn. */ - tdb->ecode = TDB_ERR_IO; - TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_write failed at %d " - "len=%d (%s)\n", off, len, strerror(errno))); - return TDB_ERRCODE(TDB_ERR_IO, -1); - } else if (written != (ssize_t)len) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_write: failed to " - "write %d bytes at %d in two attempts\n", - len, off)); - errno = ENOSPC; - return TDB_ERRCODE(TDB_ERR_IO, -1); - } - } - return 0; -} - -/* Endian conversion: we only ever deal with 4 byte quantities */ -void *tdb_convert(void *buf, uint32_t size) -{ - uint32_t i, *p = (uint32_t *)buf; - for (i = 0; i < size / 4; i++) - p[i] = TDB_BYTEREV(p[i]); - return buf; -} - - -/* read a lump of data at a specified offset, maybe convert */ -static int tdb_read(struct tdb_context *tdb, tdb_off_t off, void *buf, - tdb_len_t len, int cv) -{ - if (tdb->methods->tdb_oob(tdb, off + len, 0) != 0) { - return -1; - } - - if (tdb->map_ptr) { - memcpy(buf, off + (char *)tdb->map_ptr, len); - } else { - ssize_t ret = pread(tdb->fd, buf, len, off); - if (ret != (ssize_t)len) { - /* Ensure ecode is set for log fn. */ - tdb->ecode = TDB_ERR_IO; - TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_read failed at %d " - "len=%d ret=%d (%s) map_size=%d\n", - (int)off, (int)len, (int)ret, strerror(errno), - (int)tdb->map_size)); - return TDB_ERRCODE(TDB_ERR_IO, -1); - } - } - if (cv) { - tdb_convert(buf, len); - } - return 0; -} - - - -/* - do an unlocked scan of the hash table heads to find the next non-zero head. The value - will then be confirmed with the lock held -*/ -static void tdb_next_hash_chain(struct tdb_context *tdb, uint32_t *chain) -{ - uint32_t h = *chain; - if (tdb->map_ptr) { - for (;h < tdb->header.hash_size;h++) { - if (0 != *(uint32_t *)(TDB_HASH_TOP(h) + (unsigned char *)tdb->map_ptr)) { - break; - } - } - } else { - uint32_t off=0; - for (;h < tdb->header.hash_size;h++) { - if (tdb_ofs_read(tdb, TDB_HASH_TOP(h), &off) != 0 || off != 0) { - break; - } - } - } - (*chain) = h; -} - - -int tdb_munmap(struct tdb_context *tdb) -{ - if (tdb->flags & TDB_INTERNAL) - return 0; - -#ifdef HAVE_MMAP - if (tdb->map_ptr) { - int ret; - - ret = munmap(tdb->map_ptr, tdb->map_size); - if (ret != 0) - return ret; - } -#endif - tdb->map_ptr = NULL; - return 0; -} - -void tdb_mmap(struct tdb_context *tdb) -{ - if (tdb->flags & TDB_INTERNAL) - return; - -#ifdef HAVE_MMAP - if (!(tdb->flags & TDB_NOMMAP)) { - tdb->map_ptr = mmap(NULL, tdb->map_size, - PROT_READ|(tdb->read_only? 0:PROT_WRITE), - MAP_SHARED|MAP_FILE, tdb->fd, 0); - - /* - * NB. When mmap fails it returns MAP_FAILED *NOT* NULL !!!! - */ - - if (tdb->map_ptr == MAP_FAILED) { - tdb->map_ptr = NULL; - TDB_LOG((tdb, TDB_DEBUG_WARNING, "tdb_mmap failed for size %d (%s)\n", - tdb->map_size, strerror(errno))); - } - } else { - tdb->map_ptr = NULL; - } -#else - tdb->map_ptr = NULL; -#endif -} - -/* expand a file. we prefer to use ftruncate, as that is what posix - says to use for mmap expansion */ -static int tdb_expand_file(struct tdb_context *tdb, tdb_off_t size, tdb_off_t addition) -{ - char buf[8192]; - - if (tdb->read_only || tdb->traverse_read) { - tdb->ecode = TDB_ERR_RDONLY; - return -1; - } - - if (ftruncate(tdb->fd, size+addition) == -1) { - char b = 0; - ssize_t written = pwrite(tdb->fd, &b, 1, (size+addition) - 1); - if (written == 0) { - /* try once more, potentially revealing errno */ - written = pwrite(tdb->fd, &b, 1, (size+addition) - 1); - } - if (written == 0) { - /* again - give up, guessing errno */ - errno = ENOSPC; - } - if (written != 1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "expand_file to %d failed (%s)\n", - size+addition, strerror(errno))); - return -1; - } - } - - /* now fill the file with something. This ensures that the - file isn't sparse, which would be very bad if we ran out of - disk. This must be done with write, not via mmap */ - memset(buf, TDB_PAD_BYTE, sizeof(buf)); - while (addition) { - size_t n = addition>sizeof(buf)?sizeof(buf):addition; - ssize_t written = pwrite(tdb->fd, buf, n, size); - if (written == 0) { - /* prevent infinite loops: try _once_ more */ - written = pwrite(tdb->fd, buf, n, size); - } - if (written == 0) { - /* give up, trying to provide a useful errno */ - TDB_LOG((tdb, TDB_DEBUG_FATAL, "expand_file write " - "returned 0 twice: giving up!\n")); - errno = ENOSPC; - return -1; - } else if (written == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "expand_file write of " - "%d bytes failed (%s)\n", (int)n, - strerror(errno))); - return -1; - } else if (written != n) { - TDB_LOG((tdb, TDB_DEBUG_WARNING, "expand_file: wrote " - "only %d of %d bytes - retrying\n", (int)written, - (int)n)); - } - addition -= written; - size += written; - } - return 0; -} - - -/* expand the database at least size bytes by expanding the underlying - file and doing the mmap again if necessary */ -int tdb_expand(struct tdb_context *tdb, tdb_off_t size) -{ - struct list_struct rec; - tdb_off_t offset, new_size; - - if (tdb_lock(tdb, -1, F_WRLCK) == -1) { - TDB_LOG((tdb, TDB_DEBUG_ERROR, "lock failed in tdb_expand\n")); - return -1; - } - - /* must know about any previous expansions by another process */ - tdb->methods->tdb_oob(tdb, tdb->map_size + 1, 1); - - /* always make room for at least 100 more records, and at - least 25% more space. Round the database up to a multiple - of the page size */ - new_size = MAX(tdb->map_size + size*100, tdb->map_size * 1.25); - size = TDB_ALIGN(new_size, tdb->page_size) - tdb->map_size; - - if (!(tdb->flags & TDB_INTERNAL)) - tdb_munmap(tdb); - - /* - * We must ensure the file is unmapped before doing this - * to ensure consistency with systems like OpenBSD where - * writes and mmaps are not consistent. - */ - - /* expand the file itself */ - if (!(tdb->flags & TDB_INTERNAL)) { - if (tdb->methods->tdb_expand_file(tdb, tdb->map_size, size) != 0) - goto fail; - } - - tdb->map_size += size; - - if (tdb->flags & TDB_INTERNAL) { - char *new_map_ptr = (char *)realloc(tdb->map_ptr, - tdb->map_size); - if (!new_map_ptr) { - tdb->map_size -= size; - goto fail; - } - tdb->map_ptr = new_map_ptr; - } else { - /* - * We must ensure the file is remapped before adding the space - * to ensure consistency with systems like OpenBSD where - * writes and mmaps are not consistent. - */ - - /* We're ok if the mmap fails as we'll fallback to read/write */ - tdb_mmap(tdb); - } - - /* form a new freelist record */ - memset(&rec,'\0',sizeof(rec)); - rec.rec_len = size - sizeof(rec); - - /* link it into the free list */ - offset = tdb->map_size - size; - if (tdb_free(tdb, offset, &rec) == -1) - goto fail; - - tdb_unlock(tdb, -1, F_WRLCK); - return 0; - fail: - tdb_unlock(tdb, -1, F_WRLCK); - return -1; -} - -/* read/write a tdb_off_t */ -int tdb_ofs_read(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d) -{ - return tdb->methods->tdb_read(tdb, offset, (char*)d, sizeof(*d), DOCONV()); -} - -int tdb_ofs_write(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d) -{ - tdb_off_t off = *d; - return tdb->methods->tdb_write(tdb, offset, CONVERT(off), sizeof(*d)); -} - - -/* read a lump of data, allocating the space for it */ -unsigned char *tdb_alloc_read(struct tdb_context *tdb, tdb_off_t offset, tdb_len_t len) -{ - unsigned char *buf; - - /* some systems don't like zero length malloc */ - if (len == 0) { - len = 1; - } - - if (!(buf = (unsigned char *)malloc(len))) { - /* Ensure ecode is set for log fn. */ - tdb->ecode = TDB_ERR_OOM; - TDB_LOG((tdb, TDB_DEBUG_ERROR,"tdb_alloc_read malloc failed len=%d (%s)\n", - len, strerror(errno))); - return TDB_ERRCODE(TDB_ERR_OOM, buf); - } - if (tdb->methods->tdb_read(tdb, offset, buf, len, 0) == -1) { - SAFE_FREE(buf); - return NULL; - } - return buf; -} - -/* Give a piece of tdb data to a parser */ - -int tdb_parse_data(struct tdb_context *tdb, TDB_DATA key, - tdb_off_t offset, tdb_len_t len, - int (*parser)(TDB_DATA key, TDB_DATA data, - void *private_data), - void *private_data) -{ - TDB_DATA data; - int result; - - data.dsize = len; - - if ((tdb->transaction == NULL) && (tdb->map_ptr != NULL)) { - /* - * Optimize by avoiding the malloc/memcpy/free, point the - * parser directly at the mmap area. - */ - if (tdb->methods->tdb_oob(tdb, offset+len, 0) != 0) { - return -1; - } - data.dptr = offset + (unsigned char *)tdb->map_ptr; - return parser(key, data, private_data); - } - - if (!(data.dptr = tdb_alloc_read(tdb, offset, len))) { - return -1; - } - - result = parser(key, data, private_data); - free(data.dptr); - return result; -} - -/* read/write a record */ -int tdb_rec_read(struct tdb_context *tdb, tdb_off_t offset, struct list_struct *rec) -{ - if (tdb->methods->tdb_read(tdb, offset, rec, sizeof(*rec),DOCONV()) == -1) - return -1; - if (TDB_BAD_MAGIC(rec)) { - /* Ensure ecode is set for log fn. */ - tdb->ecode = TDB_ERR_CORRUPT; - TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_rec_read bad magic 0x%x at offset=%d\n", rec->magic, offset)); - return TDB_ERRCODE(TDB_ERR_CORRUPT, -1); - } - return tdb->methods->tdb_oob(tdb, rec->next+sizeof(*rec), 0); -} - -int tdb_rec_write(struct tdb_context *tdb, tdb_off_t offset, struct list_struct *rec) -{ - struct list_struct r = *rec; - return tdb->methods->tdb_write(tdb, offset, CONVERT(r), sizeof(r)); -} - -static const struct tdb_methods io_methods = { - tdb_read, - tdb_write, - tdb_next_hash_chain, - tdb_oob, - tdb_expand_file, - tdb_brlock -}; - -/* - initialise the default methods table -*/ -void tdb_io_init(struct tdb_context *tdb) -{ - tdb->methods = &io_methods; -} diff --git a/tdb/common/lock.c b/tdb/common/lock.c deleted file mode 100644 index f156c0fa..00000000 --- a/tdb/common/lock.c +++ /dev/null @@ -1,553 +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 <http://www.gnu.org/licenses/>. -*/ - -#include "tdb_private.h" - -#define TDB_MARK_LOCK 0x80000000 - -void tdb_setalarm_sigptr(struct tdb_context *tdb, volatile sig_atomic_t *ptr) -{ - tdb->interrupt_sig_ptr = ptr; -} - -/* a byte range locking function - return 0 on success - this functions locks/unlocks 1 byte at the specified offset. - - On error, errno is also set so that errors are passed back properly - through tdb_open(). - - note that a len of zero means lock to end of file -*/ -int tdb_brlock(struct tdb_context *tdb, tdb_off_t offset, - int rw_type, int lck_type, int probe, size_t len) -{ - struct flock fl; - int ret; - - if (tdb->flags & TDB_NOLOCK) { - return 0; - } - - if ((rw_type == F_WRLCK) && (tdb->read_only || tdb->traverse_read)) { - tdb->ecode = TDB_ERR_RDONLY; - return -1; - } - - fl.l_type = rw_type; - fl.l_whence = SEEK_SET; - fl.l_start = offset; - fl.l_len = len; - fl.l_pid = 0; - - do { - ret = fcntl(tdb->fd,lck_type,&fl); - - /* Check for a sigalarm break. */ - if (ret == -1 && errno == EINTR && - tdb->interrupt_sig_ptr && - *tdb->interrupt_sig_ptr) { - break; - } - } while (ret == -1 && errno == EINTR); - - if (ret == -1) { - /* Generic lock error. errno set by fcntl. - * EAGAIN is an expected return from non-blocking - * locks. */ - if (!probe && lck_type != F_SETLK) { - /* Ensure error code is set for log fun to examine. */ - tdb->ecode = TDB_ERR_LOCK; - TDB_LOG((tdb, TDB_DEBUG_TRACE,"tdb_brlock failed (fd=%d) at offset %d rw_type=%d lck_type=%d len=%d\n", - tdb->fd, offset, rw_type, lck_type, (int)len)); - } - return TDB_ERRCODE(TDB_ERR_LOCK, -1); - } - return 0; -} - - -/* - upgrade a read lock to a write lock. This needs to be handled in a - special way as some OSes (such as solaris) have too conservative - deadlock detection and claim a deadlock when progress can be - made. For those OSes we may loop for a while. -*/ -int tdb_brlock_upgrade(struct tdb_context *tdb, tdb_off_t offset, size_t len) -{ - int count = 1000; - while (count--) { - struct timeval tv; - if (tdb_brlock(tdb, offset, F_WRLCK, F_SETLKW, 1, len) == 0) { - return 0; - } - if (errno != EDEADLK) { - break; - } - /* sleep for as short a time as we can - more portable than usleep() */ - tv.tv_sec = 0; - tv.tv_usec = 1; - select(0, NULL, NULL, NULL, &tv); - } - TDB_LOG((tdb, TDB_DEBUG_TRACE,"tdb_brlock_upgrade failed at offset %d\n", offset)); - return -1; -} - - -/* lock a list in the database. list -1 is the alloc list */ -static int _tdb_lock(struct tdb_context *tdb, int list, int ltype, int op) -{ - struct tdb_lock_type *new_lck; - int i; - bool mark_lock = ((ltype & TDB_MARK_LOCK) == TDB_MARK_LOCK); - - ltype &= ~TDB_MARK_LOCK; - - /* a global lock allows us to avoid per chain locks */ - if (tdb->global_lock.count && - (ltype == tdb->global_lock.ltype || ltype == F_RDLCK)) { - return 0; - } - - if (tdb->global_lock.count) { - return TDB_ERRCODE(TDB_ERR_LOCK, -1); - } - - if (list < -1 || list >= (int)tdb->header.hash_size) { - TDB_LOG((tdb, TDB_DEBUG_ERROR,"tdb_lock: invalid list %d for ltype=%d\n", - list, ltype)); - return -1; - } - if (tdb->flags & TDB_NOLOCK) - return 0; - - for (i=0; i<tdb->num_lockrecs; i++) { - if (tdb->lockrecs[i].list == list) { - if (tdb->lockrecs[i].count == 0) { - /* - * Can't happen, see tdb_unlock(). It should - * be an assert. - */ - TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_lock: " - "lck->count == 0 for list %d", list)); - } - /* - * Just increment the in-memory struct, posix locks - * don't stack. - */ - tdb->lockrecs[i].count++; - return 0; - } - } - - new_lck = (struct tdb_lock_type *)realloc( - tdb->lockrecs, - sizeof(*tdb->lockrecs) * (tdb->num_lockrecs+1)); - if (new_lck == NULL) { - errno = ENOMEM; - return -1; - } - tdb->lockrecs = new_lck; - - /* Since fcntl locks don't nest, we do a lock for the first one, - and simply bump the count for future ones */ - if (!mark_lock && - tdb->methods->tdb_brlock(tdb,FREELIST_TOP+4*list, ltype, op, - 0, 1)) { - return -1; - } - - tdb->num_locks++; - - tdb->lockrecs[tdb->num_lockrecs].list = list; - tdb->lockrecs[tdb->num_lockrecs].count = 1; - tdb->lockrecs[tdb->num_lockrecs].ltype = ltype; - tdb->num_lockrecs += 1; - - return 0; -} - -/* lock a list in the database. list -1 is the alloc list */ -int tdb_lock(struct tdb_context *tdb, int list, int ltype) -{ - int ret; - ret = _tdb_lock(tdb, list, ltype, F_SETLKW); - if (ret) { - TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_lock failed on list %d " - "ltype=%d (%s)\n", list, ltype, strerror(errno))); - } - return ret; -} - -/* lock a list in the database. list -1 is the alloc list. non-blocking lock */ -int tdb_lock_nonblock(struct tdb_context *tdb, int list, int ltype) -{ - return _tdb_lock(tdb, list, ltype, F_SETLK); -} - - -/* unlock the database: returns void because it's too late for errors. */ - /* changed to return int it may be interesting to know there - has been an error --simo */ -int tdb_unlock(struct tdb_context *tdb, int list, int ltype) -{ - int ret = -1; - int i; - struct tdb_lock_type *lck = NULL; - bool mark_lock = ((ltype & TDB_MARK_LOCK) == TDB_MARK_LOCK); - - ltype &= ~TDB_MARK_LOCK; - - /* a global lock allows us to avoid per chain locks */ - if (tdb->global_lock.count && - (ltype == tdb->global_lock.ltype || ltype == F_RDLCK)) { - return 0; - } - - if (tdb->global_lock.count) { - return TDB_ERRCODE(TDB_ERR_LOCK, -1); - } - - if (tdb->flags & TDB_NOLOCK) - return 0; - - /* Sanity checks */ - if (list < -1 || list >= (int)tdb->header.hash_size) { - TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_unlock: list %d invalid (%d)\n", list, tdb->header.hash_size)); - return ret; - } - - for (i=0; i<tdb->num_lockrecs; i++) { - if (tdb->lockrecs[i].list == list) { - lck = &tdb->lockrecs[i]; - break; - } - } - - if ((lck == NULL) || (lck->count == 0)) { - TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_unlock: count is 0\n")); - return -1; - } - - if (lck->count > 1) { - lck->count--; - return 0; - } - - /* - * This lock has count==1 left, so we need to unlock it in the - * kernel. We don't bother with decrementing the in-memory array - * element, we're about to overwrite it with the last array element - * anyway. - */ - - if (mark_lock) { - ret = 0; - } else { - ret = tdb->methods->tdb_brlock(tdb, FREELIST_TOP+4*list, F_UNLCK, - F_SETLKW, 0, 1); - } - tdb->num_locks--; - - /* - * Shrink the array by overwriting the element just unlocked with the - * last array element. - */ - - if (tdb->num_lockrecs > 1) { - *lck = tdb->lockrecs[tdb->num_lockrecs-1]; - } - tdb->num_lockrecs -= 1; - - /* - * We don't bother with realloc when the array shrinks, but if we have - * a completely idle tdb we should get rid of the locked array. - */ - - if (tdb->num_lockrecs == 0) { - SAFE_FREE(tdb->lockrecs); - } - - if (ret) - TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_unlock: An error occurred unlocking!\n")); - return ret; -} - -/* - get the transaction lock - */ -int tdb_transaction_lock(struct tdb_context *tdb, int ltype) -{ - if (tdb->have_transaction_lock || tdb->global_lock.count) { - return 0; - } - if (tdb->methods->tdb_brlock(tdb, TRANSACTION_LOCK, ltype, - F_SETLKW, 0, 1) == -1) { - TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_lock: failed to get transaction lock\n")); - tdb->ecode = TDB_ERR_LOCK; - return -1; - } - tdb->have_transaction_lock = 1; - return 0; -} - -/* - release the transaction lock - */ -int tdb_transaction_unlock(struct tdb_context *tdb) -{ - int ret; - if (!tdb->have_transaction_lock) { - return 0; - } - ret = tdb->methods->tdb_brlock(tdb, TRANSACTION_LOCK, F_UNLCK, F_SETLKW, 0, 1); - if (ret == 0) { - tdb->have_transaction_lock = 0; - } - return ret; -} - - - - -/* lock/unlock entire database */ -static int _tdb_lockall(struct tdb_context *tdb, int ltype, int op) -{ - bool mark_lock = ((ltype & TDB_MARK_LOCK) == TDB_MARK_LOCK); - - ltype &= ~TDB_MARK_LOCK; - - /* There are no locks on read-only dbs */ - if (tdb->read_only || tdb->traverse_read) - return TDB_ERRCODE(TDB_ERR_LOCK, -1); - - if (tdb->global_lock.count && tdb->global_lock.ltype == ltype) { - tdb->global_lock.count++; - return 0; - } - - if (tdb->global_lock.count) { - /* a global lock of a different type exists */ - return TDB_ERRCODE(TDB_ERR_LOCK, -1); - } - - if (tdb->num_locks != 0) { - /* can't combine global and chain locks */ - return TDB_ERRCODE(TDB_ERR_LOCK, -1); - } - - if (!mark_lock && - tdb->methods->tdb_brlock(tdb, FREELIST_TOP, ltype, op, - 0, 4*tdb->header.hash_size)) { - if (op == F_SETLKW) { - TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_lockall failed (%s)\n", strerror(errno))); - } - return -1; - } - - tdb->global_lock.count = 1; - tdb->global_lock.ltype = ltype; - - return 0; -} - - - -/* unlock entire db */ -static int _tdb_unlockall(struct tdb_context *tdb, int ltype) -{ - bool mark_lock = ((ltype & TDB_MARK_LOCK) == TDB_MARK_LOCK); - - ltype &= ~TDB_MARK_LOCK; - - /* There are no locks on read-only dbs */ - if (tdb->read_only || tdb->traverse_read) { - return TDB_ERRCODE(TDB_ERR_LOCK, -1); - } - - if (tdb->global_lock.ltype != ltype || tdb->global_lock.count == 0) { - return TDB_ERRCODE(TDB_ERR_LOCK, -1); - } - - if (tdb->global_lock.count > 1) { - tdb->global_lock.count--; - return 0; - } - - if (!mark_lock && - tdb->methods->tdb_brlock(tdb, FREELIST_TOP, F_UNLCK, F_SETLKW, - 0, 4*tdb->header.hash_size)) { - TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_unlockall failed (%s)\n", strerror(errno))); - return -1; - } - - tdb->global_lock.count = 0; - tdb->global_lock.ltype = 0; - - return 0; -} - -/* lock entire database with write lock */ -int tdb_lockall(struct tdb_context *tdb) -{ - return _tdb_lockall(tdb, F_WRLCK, F_SETLKW); -} - -/* lock entire database with write lock - mark only */ -int tdb_lockall_mark(struct tdb_context *tdb) -{ - return _tdb_lockall(tdb, F_WRLCK | TDB_MARK_LOCK, F_SETLKW); -} - -/* unlock entire database with write lock - unmark only */ -int tdb_lockall_unmark(struct tdb_context *tdb) -{ - return _tdb_unlockall(tdb, F_WRLCK | TDB_MARK_LOCK); -} - -/* lock entire database with write lock - nonblocking varient */ -int tdb_lockall_nonblock(struct tdb_context *tdb) -{ - return _tdb_lockall(tdb, F_WRLCK, F_SETLK); -} - -/* unlock entire database with write lock */ -int tdb_unlockall(struct tdb_context *tdb) -{ - return _tdb_unlockall(tdb, F_WRLCK); -} - -/* lock entire database with read lock */ -int tdb_lockall_read(struct tdb_context *tdb) -{ - return _tdb_lockall(tdb, F_RDLCK, F_SETLKW); -} - -/* lock entire database with read lock - nonblock varient */ -int tdb_lockall_read_nonblock(struct tdb_context *tdb) -{ - return _tdb_lockall(tdb, F_RDLCK, F_SETLK); -} - -/* unlock entire database with read lock */ -int tdb_unlockall_read(struct tdb_context *tdb) -{ - return _tdb_unlockall(tdb, F_RDLCK); -} - -/* lock/unlock one hash chain. This is meant to be used to reduce - contention - it cannot guarantee how many records will be locked */ -int tdb_chainlock(struct tdb_context *tdb, TDB_DATA key) -{ - return tdb_lock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK); -} - -/* lock/unlock one hash chain, non-blocking. This is meant to be used - to reduce contention - it cannot guarantee how many records will be - locked */ -int tdb_chainlock_nonblock(struct tdb_context *tdb, TDB_DATA key) -{ - return tdb_lock_nonblock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK); -} - -/* mark a chain as locked without actually locking it. Warning! use with great caution! */ -int tdb_chainlock_mark(struct tdb_context *tdb, TDB_DATA key) -{ - return tdb_lock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK | TDB_MARK_LOCK); -} - -/* unmark a chain as locked without actually locking it. Warning! use with great caution! */ -int tdb_chainlock_unmark(struct tdb_context *tdb, TDB_DATA key) -{ - return tdb_unlock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK | TDB_MARK_LOCK); -} - -int tdb_chainunlock(struct tdb_context *tdb, TDB_DATA key) -{ - return tdb_unlock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK); -} - -int tdb_chainlock_read(struct tdb_context *tdb, TDB_DATA key) -{ - return tdb_lock(tdb, BUCKET(tdb->hash_fn(&key)), F_RDLCK); -} - -int tdb_chainunlock_read(struct tdb_context *tdb, TDB_DATA key) -{ - return tdb_unlock(tdb, BUCKET(tdb->hash_fn(&key)), F_RDLCK); -} - - - -/* record lock stops delete underneath */ -int tdb_lock_record(struct tdb_context *tdb, tdb_off_t off) -{ - if (tdb->global_lock.count) { - return 0; - } - return off ? tdb->methods->tdb_brlock(tdb, off, F_RDLCK, F_SETLKW, 0, 1) : 0; -} - -/* - Write locks override our own fcntl readlocks, so check it here. - Note this is meant to be F_SETLK, *not* F_SETLKW, as it's not - an error to fail to get the lock here. -*/ -int tdb_write_lock_record(struct tdb_context *tdb, tdb_off_t off) -{ - struct tdb_traverse_lock *i; - for (i = &tdb->travlocks; i; i = i->next) - if (i->off == off) - return -1; - return tdb->methods->tdb_brlock(tdb, off, F_WRLCK, F_SETLK, 1, 1); -} - -/* - Note this is meant to be F_SETLK, *not* F_SETLKW, as it's not - an error to fail to get the lock here. -*/ -int tdb_write_unlock_record(struct tdb_context *tdb, tdb_off_t off) -{ - return tdb->methods->tdb_brlock(tdb, off, F_UNLCK, F_SETLK, 0, 1); -} - -/* fcntl locks don't stack: avoid unlocking someone else's */ -int tdb_unlock_record(struct tdb_context *tdb, tdb_off_t off) -{ - struct tdb_traverse_lock *i; - uint32_t count = 0; - - if (tdb->global_lock.count) { - return 0; - } - - if (off == 0) - return 0; - for (i = &tdb->travlocks; i; i = i->next) - if (i->off == off) - count++; - return (count == 1 ? tdb->methods->tdb_brlock(tdb, off, F_UNLCK, F_SETLKW, 0, 1) : 0); -} diff --git a/tdb/common/open.c b/tdb/common/open.c deleted file mode 100644 index b19e4cea..00000000 --- a/tdb/common/open.c +++ /dev/null @@ -1,488 +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 <http://www.gnu.org/licenses/>. -*/ - -#include "tdb_private.h" - -/* all contexts, to ensure no double-opens (fcntl locks don't nest!) */ -static struct tdb_context *tdbs = NULL; - - -/* This is based on the hash algorithm from gdbm */ -static unsigned int default_tdb_hash(TDB_DATA *key) -{ - uint32_t value; /* Used to compute the hash value. */ - uint32_t i; /* Used to cycle through random values. */ - - /* Set the initial value from the key size. */ - for (value = 0x238F13AF * key->dsize, i=0; i < key->dsize; i++) - value = (value + (key->dptr[i] << (i*5 % 24))); - - return (1103515243 * value + 12345); -} - - -/* initialise a new database with a specified hash size */ -static int tdb_new_database(struct tdb_context *tdb, int hash_size) -{ - struct tdb_header *newdb; - size_t size; - int ret = -1; - ssize_t written; - - /* We make it up in memory, then write it out if not internal */ - size = sizeof(struct tdb_header) + (hash_size+1)*sizeof(tdb_off_t); - if (!(newdb = (struct tdb_header *)calloc(size, 1))) - return TDB_ERRCODE(TDB_ERR_OOM, -1); - - /* Fill in the header */ - newdb->version = TDB_VERSION; - newdb->hash_size = hash_size; - if (tdb->flags & TDB_INTERNAL) { - tdb->map_size = size; - tdb->map_ptr = (char *)newdb; - memcpy(&tdb->header, newdb, sizeof(tdb->header)); - /* Convert the `ondisk' version if asked. */ - CONVERT(*newdb); - return 0; - } - if (lseek(tdb->fd, 0, SEEK_SET) == -1) - goto fail; - - if (ftruncate(tdb->fd, 0) == -1) - goto fail; - - /* This creates an endian-converted header, as if read from disk */ - CONVERT(*newdb); - memcpy(&tdb->header, newdb, sizeof(tdb->header)); - /* Don't endian-convert the magic food! */ - memcpy(newdb->magic_food, TDB_MAGIC_FOOD, strlen(TDB_MAGIC_FOOD)+1); - /* we still have "ret == -1" here */ - written = write(tdb->fd, newdb, size); - if (written == size) { - ret = 0; - } else if (written != -1) { - /* call write once again, this usually should return -1 and - * set errno appropriately */ - size -= written; - written = write(tdb->fd, newdb+written, size); - if (written == size) { - ret = 0; - } else if (written >= 0) { - /* a second incomplete write - we give up. - * guessing the errno... */ - errno = ENOSPC; - } - } - - fail: - SAFE_FREE(newdb); - return ret; -} - - - -static int tdb_already_open(dev_t device, - ino_t ino) -{ - struct tdb_context *i; - - for (i = tdbs; i; i = i->next) { - if (i->device == device && i->inode == ino) { - return 1; - } - } - - return 0; -} - -/* open the database, creating it if necessary - - The open_flags and mode are passed straight to the open call on the - database file. A flags value of O_WRONLY is invalid. The hash size - is advisory, use zero for a default value. - - Return is NULL on error, in which case errno is also set. Don't - try to call tdb_error or tdb_errname, just do strerror(errno). - - @param name may be NULL for internal databases. */ -struct tdb_context *tdb_open(const char *name, int hash_size, int tdb_flags, - int open_flags, mode_t mode) -{ - return tdb_open_ex(name, hash_size, tdb_flags, open_flags, mode, NULL, NULL); -} - -/* a default logging function */ -static void null_log_fn(struct tdb_context *tdb, enum tdb_debug_level level, const char *fmt, ...) PRINTF_ATTRIBUTE(3, 4); -static void null_log_fn(struct tdb_context *tdb, enum tdb_debug_level level, const char *fmt, ...) -{ -} - - -struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags, - int open_flags, mode_t mode, - const struct tdb_logging_context *log_ctx, - tdb_hash_func hash_fn) -{ - struct tdb_context *tdb; - struct stat st; - int rev = 0, locked = 0; - unsigned char *vp; - uint32_t vertest; - unsigned v; - - if (!(tdb = (struct tdb_context *)calloc(1, sizeof *tdb))) { - /* Can't log this */ - errno = ENOMEM; - goto fail; - } - tdb_io_init(tdb); - tdb->fd = -1; - tdb->name = NULL; - tdb->map_ptr = NULL; - tdb->flags = tdb_flags; - tdb->open_flags = open_flags; - if (log_ctx) { - tdb->log = *log_ctx; - } else { - tdb->log.log_fn = null_log_fn; - tdb->log.log_private = NULL; - } - tdb->hash_fn = hash_fn ? hash_fn : default_tdb_hash; - - /* cache the page size */ - tdb->page_size = getpagesize(); - if (tdb->page_size <= 0) { - tdb->page_size = 0x2000; - } - - tdb->max_dead_records = (tdb_flags & TDB_VOLATILE) ? 5 : 0; - - if ((open_flags & O_ACCMODE) == O_WRONLY) { - TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: can't open tdb %s write-only\n", - name)); - errno = EINVAL; - goto fail; - } - - if (hash_size == 0) - hash_size = DEFAULT_HASH_SIZE; - if ((open_flags & O_ACCMODE) == O_RDONLY) { - tdb->read_only = 1; - /* read only databases don't do locking or clear if first */ - tdb->flags |= TDB_NOLOCK; - tdb->flags &= ~TDB_CLEAR_IF_FIRST; - } - - /* internal databases don't mmap or lock, and start off cleared */ - if (tdb->flags & TDB_INTERNAL) { - tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP); - tdb->flags &= ~TDB_CLEAR_IF_FIRST; - if (tdb_new_database(tdb, hash_size) != 0) { - TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: tdb_new_database failed!")); - goto fail; - } - goto internal; - } - - if ((tdb->fd = open(name, open_flags, mode)) == -1) { - TDB_LOG((tdb, TDB_DEBUG_WARNING, "tdb_open_ex: could not open file %s: %s\n", - name, strerror(errno))); - goto fail; /* errno set by open(2) */ - } - - /* on exec, don't inherit the fd */ - v = fcntl(tdb->fd, F_GETFD, 0); - fcntl(tdb->fd, F_SETFD, v | FD_CLOEXEC); - - /* ensure there is only one process initialising at once */ - if (tdb->methods->tdb_brlock(tdb, GLOBAL_LOCK, F_WRLCK, F_SETLKW, 0, 1) == -1) { - TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to get global lock on %s: %s\n", - name, strerror(errno))); - goto fail; /* errno set by tdb_brlock */ - } - - /* we need to zero database if we are the only one with it open */ - if ((tdb_flags & TDB_CLEAR_IF_FIRST) && - (!tdb->read_only) && - (locked = (tdb->methods->tdb_brlock(tdb, ACTIVE_LOCK, F_WRLCK, F_SETLK, 0, 1) == 0))) { - open_flags |= O_CREAT; - if (ftruncate(tdb->fd, 0) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: " - "failed to truncate %s: %s\n", - name, strerror(errno))); - goto fail; /* errno set by ftruncate */ - } - } - - errno = 0; - if (read(tdb->fd, &tdb->header, sizeof(tdb->header)) != sizeof(tdb->header) - || strcmp(tdb->header.magic_food, TDB_MAGIC_FOOD) != 0 - || (tdb->header.version != TDB_VERSION - && !(rev = (tdb->header.version==TDB_BYTEREV(TDB_VERSION))))) { - /* its not a valid database - possibly initialise it */ - if (!(open_flags & O_CREAT) || tdb_new_database(tdb, hash_size) == -1) { - if (errno == 0) { - errno = EIO; /* ie bad format or something */ - } - goto fail; - } - rev = (tdb->flags & TDB_CONVERT); - } - vp = (unsigned char *)&tdb->header.version; - vertest = (((uint32_t)vp[0]) << 24) | (((uint32_t)vp[1]) << 16) | - (((uint32_t)vp[2]) << 8) | (uint32_t)vp[3]; - tdb->flags |= (vertest==TDB_VERSION) ? TDB_BIGENDIAN : 0; - if (!rev) - tdb->flags &= ~TDB_CONVERT; - else { - tdb->flags |= TDB_CONVERT; - tdb_convert(&tdb->header, sizeof(tdb->header)); - } - if (fstat(tdb->fd, &st) == -1) - goto fail; - - if (tdb->header.rwlocks != 0) { - TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: spinlocks no longer supported\n")); - goto fail; - } - - /* Is it already in the open list? If so, fail. */ - if (tdb_already_open(st.st_dev, st.st_ino)) { - TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: " - "%s (%d,%d) is already open in this process\n", - name, (int)st.st_dev, (int)st.st_ino)); - errno = EBUSY; - goto fail; - } - - if (!(tdb->name = (char *)strdup(name))) { - errno = ENOMEM; - goto fail; - } - - tdb->map_size = st.st_size; - tdb->device = st.st_dev; - tdb->inode = st.st_ino; - tdb_mmap(tdb); - if (locked) { - if (tdb->methods->tdb_brlock(tdb, ACTIVE_LOCK, F_UNLCK, F_SETLK, 0, 1) == -1) { - TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: " - "failed to take ACTIVE_LOCK on %s: %s\n", - name, strerror(errno))); - goto fail; - } - - } - - /* We always need to do this if the CLEAR_IF_FIRST flag is set, even if - we didn't get the initial exclusive lock as we need to let all other - users know we're using it. */ - - if (tdb_flags & TDB_CLEAR_IF_FIRST) { - /* leave this lock in place to indicate it's in use */ - if (tdb->methods->tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0, 1) == -1) - goto fail; - } - - /* if needed, run recovery */ - if (tdb_transaction_recover(tdb) == -1) { - goto fail; - } - - internal: - /* Internal (memory-only) databases skip all the code above to - * do with disk files, and resume here by releasing their - * global lock and hooking into the active list. */ - if (tdb->methods->tdb_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0, 1) == -1) - goto fail; - tdb->next = tdbs; - tdbs = tdb; - return tdb; - - fail: - { int save_errno = errno; - - if (!tdb) - return NULL; - - if (tdb->map_ptr) { - if (tdb->flags & TDB_INTERNAL) - SAFE_FREE(tdb->map_ptr); - else - tdb_munmap(tdb); - } - SAFE_FREE(tdb->name); - if (tdb->fd != -1) - if (close(tdb->fd) != 0) - TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to close tdb->fd on error!\n")); - SAFE_FREE(tdb); - errno = save_errno; - return NULL; - } -} - -/* - * Set the maximum number of dead records per hash chain - */ - -void tdb_set_max_dead(struct tdb_context *tdb, int max_dead) -{ - tdb->max_dead_records = max_dead; -} - -/** - * Close a database. - * - * @returns -1 for error; 0 for success. - **/ -int tdb_close(struct tdb_context *tdb) -{ - struct tdb_context **i; - int ret = 0; - - if (tdb->transaction) { - tdb_transaction_cancel(tdb); - } - - if (tdb->map_ptr) { - if (tdb->flags & TDB_INTERNAL) - SAFE_FREE(tdb->map_ptr); - else - tdb_munmap(tdb); - } - SAFE_FREE(tdb->name); - if (tdb->fd != -1) - ret = close(tdb->fd); - SAFE_FREE(tdb->lockrecs); - - /* Remove from contexts list */ - for (i = &tdbs; *i; i = &(*i)->next) { - if (*i == tdb) { - *i = tdb->next; - break; - } - } - - memset(tdb, 0, sizeof(*tdb)); - SAFE_FREE(tdb); - - return ret; -} - -/* register a loging function */ -void tdb_set_logging_function(struct tdb_context *tdb, - const struct tdb_logging_context *log_ctx) -{ - tdb->log = *log_ctx; -} - -void *tdb_get_logging_private(struct tdb_context *tdb) -{ - return tdb->log.log_private; -} - -/* reopen a tdb - this can be used after a fork to ensure that we have an independent - seek pointer from our parent and to re-establish locks */ -int tdb_reopen(struct tdb_context *tdb) -{ - struct stat st; - - if (tdb->flags & TDB_INTERNAL) { - return 0; /* Nothing to do. */ - } - - if (tdb->num_locks != 0 || tdb->global_lock.count) { - TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_reopen: reopen not allowed with locks held\n")); - goto fail; - } - - if (tdb->transaction != 0) { - TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_reopen: reopen not allowed inside a transaction\n")); - goto fail; - } - - if (tdb_munmap(tdb) != 0) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: munmap failed (%s)\n", strerror(errno))); - goto fail; - } - if (close(tdb->fd) != 0) - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: WARNING closing tdb->fd failed!\n")); - tdb->fd = open(tdb->name, tdb->open_flags & ~(O_CREAT|O_TRUNC), 0); - if (tdb->fd == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: open failed (%s)\n", strerror(errno))); - goto fail; - } - if ((tdb->flags & TDB_CLEAR_IF_FIRST) && - (tdb->methods->tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0, 1) == -1)) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: failed to obtain active lock\n")); - goto fail; - } - if (fstat(tdb->fd, &st) != 0) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: fstat failed (%s)\n", strerror(errno))); - goto fail; - } - if (st.st_ino != tdb->inode || st.st_dev != tdb->device) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: file dev/inode has changed!\n")); - goto fail; - } - tdb_mmap(tdb); - - return 0; - -fail: - tdb_close(tdb); - return -1; -} - -/* reopen all tdb's */ -int tdb_reopen_all(int parent_longlived) -{ - struct tdb_context *tdb; - - for (tdb=tdbs; tdb; tdb = tdb->next) { - /* - * If the parent is longlived (ie. a - * parent daemon architecture), we know - * it will keep it's active lock on a - * tdb opened with CLEAR_IF_FIRST. Thus - * for child processes we don't have to - * add an active lock. This is essential - * to improve performance on systems that - * keep POSIX locks as a non-scalable data - * structure in the kernel. - */ - if (parent_longlived) { - /* Ensure no clear-if-first. */ - tdb->flags &= ~TDB_CLEAR_IF_FIRST; - } - - if (tdb_reopen(tdb) != 0) - return -1; - } - - return 0; -} diff --git a/tdb/common/tdb.c b/tdb/common/tdb.c deleted file mode 100644 index 8c61ec1a..00000000 --- a/tdb/common/tdb.c +++ /dev/null @@ -1,891 +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 <http://www.gnu.org/licenses/>. -*/ - -#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_brlock(tdb, TDB_SEQNUM_OFS, F_WRLCK, F_SETLKW, 1, 1) != 0) { - return; - } - - tdb_increment_seqnum_nonblock(tdb); - - tdb_brlock(tdb, TDB_SEQNUM_OFS, F_UNLCK, F_SETLKW, 1, 1); -} - -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 list_struct *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; - } - rec_ptr = r->next; - } - return TDB_ERRCODE(TDB_ERR_NOEXIST, 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 list_struct *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; -} - - -/* 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 list_struct rec; - tdb_off_t rec_ptr; - - /* find entry */ - if (!(rec_ptr = tdb_find(tdb, key, hash, &rec))) - return -1; - - /* 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 - */ -TDB_DATA tdb_fetch(struct tdb_context *tdb, TDB_DATA key) -{ - tdb_off_t rec_ptr; - struct list_struct 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; -} - -/* - * 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. - * - * DONT 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 list_struct 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))) { - return TDB_ERRCODE(TDB_ERR_NOEXIST, 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 list_struct 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); - return tdb_exists_hash(tdb, key, hash); -} - -/* actually delete an entry in the database given the offset */ -int tdb_do_delete(struct tdb_context *tdb, tdb_off_t rec_ptr, struct list_struct *rec) -{ - tdb_off_t last_ptr, i; - struct list_struct 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 list_struct 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 list_struct 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 list_struct 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); - return tdb_delete_hash(tdb, key, hash); -} - -/* - * 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 list_struct *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; -} - -/* 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) -{ - struct list_struct rec; - uint32_t hash; - tdb_off_t rec_ptr; - char *p = NULL; - int ret = -1; - - if (tdb->read_only || tdb->traverse_read) { - tdb->ecode = TDB_ERR_RDONLY; - 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; - - /* 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); - 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 char *new_dptr = (unsigned char *)realloc(dbuf.dptr, - dbuf.dsize + new_dbuf.dsize); - 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); - -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) -{ - tdb->flags |= flags; -} - -void tdb_remove_flags(struct tdb_context *tdb, unsigned flags) -{ - 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 list_struct 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 global 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; - } - - /* 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 list_struct 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;i<tdb->header.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) -{ - struct traverse_state *state = (struct traverse_state *)private; - 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; - - 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; -} diff --git a/tdb/common/tdb_private.h b/tdb/common/tdb_private.h deleted file mode 100644 index ffac89ff..00000000 --- a/tdb/common/tdb_private.h +++ /dev/null @@ -1,213 +0,0 @@ - /* - Unix SMB/CIFS implementation. - - trivial database library - private includes - - Copyright (C) Andrew Tridgell 2005 - - ** 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 "replace.h" -#include "system/filesys.h" -#include "system/time.h" -#include "system/shmem.h" -#include "system/select.h" -#include "system/wait.h" -#include "tdb.h" - -#ifndef HAVE_GETPAGESIZE -#define getpagesize() 0x2000 -#endif - -typedef uint32_t tdb_len_t; -typedef uint32_t tdb_off_t; - -#ifndef offsetof -#define offsetof(t,f) ((unsigned int)&((t *)0)->f) -#endif - -#define TDB_MAGIC_FOOD "TDB file\n" -#define TDB_VERSION (0x26011967 + 6) -#define TDB_MAGIC (0x26011999U) -#define TDB_FREE_MAGIC (~TDB_MAGIC) -#define TDB_DEAD_MAGIC (0xFEE1DEAD) -#define TDB_RECOVERY_MAGIC (0xf53bc0e7U) -#define TDB_ALIGNMENT 4 -#define DEFAULT_HASH_SIZE 131 -#define FREELIST_TOP (sizeof(struct tdb_header)) -#define TDB_ALIGN(x,a) (((x) + (a)-1) & ~((a)-1)) -#define TDB_BYTEREV(x) (((((x)&0xff)<<24)|((x)&0xFF00)<<8)|(((x)>>8)&0xFF00)|((x)>>24)) -#define TDB_DEAD(r) ((r)->magic == TDB_DEAD_MAGIC) -#define TDB_BAD_MAGIC(r) ((r)->magic != TDB_MAGIC && !TDB_DEAD(r)) -#define TDB_HASH_TOP(hash) (FREELIST_TOP + (BUCKET(hash)+1)*sizeof(tdb_off_t)) -#define TDB_HASHTABLE_SIZE(tdb) ((tdb->header.hash_size+1)*sizeof(tdb_off_t)) -#define TDB_DATA_START(hash_size) (TDB_HASH_TOP(hash_size-1) + sizeof(tdb_off_t)) -#define TDB_RECOVERY_HEAD offsetof(struct tdb_header, recovery_start) -#define TDB_SEQNUM_OFS offsetof(struct tdb_header, sequence_number) -#define TDB_PAD_BYTE 0x42 -#define TDB_PAD_U32 0x42424242 - -/* NB assumes there is a local variable called "tdb" that is the - * current context, also takes doubly-parenthesized print-style - * argument. */ -#define TDB_LOG(x) tdb->log.log_fn x - -/* lock offsets */ -#define GLOBAL_LOCK 0 -#define ACTIVE_LOCK 4 -#define TRANSACTION_LOCK 8 - -/* free memory if the pointer is valid and zero the pointer */ -#ifndef SAFE_FREE -#define SAFE_FREE(x) do { if ((x) != NULL) {free(x); (x)=NULL;} } while(0) -#endif - -#define BUCKET(hash) ((hash) % tdb->header.hash_size) - -#define DOCONV() (tdb->flags & TDB_CONVERT) -#define CONVERT(x) (DOCONV() ? tdb_convert(&x, sizeof(x)) : &x) - - -/* the body of the database is made of one list_struct for the free space - plus a separate data list for each hash value */ -struct list_struct { - tdb_off_t next; /* offset of the next record in the list */ - tdb_len_t rec_len; /* total byte length of record */ - tdb_len_t key_len; /* byte length of key */ - tdb_len_t data_len; /* byte length of data */ - uint32_t full_hash; /* the full 32 bit hash of the key */ - uint32_t magic; /* try to catch errors */ - /* the following union is implied: - union { - char record[rec_len]; - struct { - char key[key_len]; - char data[data_len]; - } - uint32_t totalsize; (tailer) - } - */ -}; - - -/* this is stored at the front of every database */ -struct tdb_header { - char magic_food[32]; /* for /etc/magic */ - uint32_t version; /* version of the code */ - uint32_t hash_size; /* number of hash entries */ - tdb_off_t rwlocks; /* obsolete - kept to detect old formats */ - tdb_off_t recovery_start; /* offset of transaction recovery region */ - tdb_off_t sequence_number; /* used when TDB_SEQNUM is set */ - tdb_off_t reserved[29]; -}; - -struct tdb_lock_type { - int list; - uint32_t count; - uint32_t ltype; -}; - -struct tdb_traverse_lock { - struct tdb_traverse_lock *next; - uint32_t off; - uint32_t hash; - int lock_rw; -}; - - -struct tdb_methods { - int (*tdb_read)(struct tdb_context *, tdb_off_t , void *, tdb_len_t , int ); - int (*tdb_write)(struct tdb_context *, tdb_off_t, const void *, tdb_len_t); - void (*next_hash_chain)(struct tdb_context *, uint32_t *); - int (*tdb_oob)(struct tdb_context *, tdb_off_t , int ); - int (*tdb_expand_file)(struct tdb_context *, tdb_off_t , tdb_off_t ); - int (*tdb_brlock)(struct tdb_context *, tdb_off_t , int, int, int, size_t); -}; - -struct tdb_context { - char *name; /* the name of the database */ - void *map_ptr; /* where it is currently mapped */ - int fd; /* open file descriptor for the database */ - tdb_len_t map_size; /* how much space has been mapped */ - int read_only; /* opened read-only */ - int traverse_read; /* read-only traversal */ - int traverse_write; /* read-write traversal */ - struct tdb_lock_type global_lock; - int num_lockrecs; - struct tdb_lock_type *lockrecs; /* only real locks, all with count>0 */ - enum TDB_ERROR ecode; /* error code for last tdb error */ - struct tdb_header header; /* a cached copy of the header */ - uint32_t flags; /* the flags passed to tdb_open */ - struct tdb_traverse_lock travlocks; /* current traversal locks */ - struct tdb_context *next; /* all tdbs to avoid multiple opens */ - dev_t device; /* uniquely identifies this tdb */ - ino_t inode; /* uniquely identifies this tdb */ - struct tdb_logging_context log; - unsigned int (*hash_fn)(TDB_DATA *key); - int open_flags; /* flags used in the open - needed by reopen */ - unsigned int num_locks; /* number of chain locks held */ - const struct tdb_methods *methods; - struct tdb_transaction *transaction; - int page_size; - int max_dead_records; - bool have_transaction_lock; - volatile sig_atomic_t *interrupt_sig_ptr; -}; - - -/* - internal prototypes -*/ -int tdb_munmap(struct tdb_context *tdb); -void tdb_mmap(struct tdb_context *tdb); -int tdb_lock(struct tdb_context *tdb, int list, int ltype); -int tdb_lock_nonblock(struct tdb_context *tdb, int list, int ltype); -int tdb_unlock(struct tdb_context *tdb, int list, int ltype); -int tdb_brlock(struct tdb_context *tdb, tdb_off_t offset, int rw_type, int lck_type, int probe, size_t len); -int tdb_transaction_lock(struct tdb_context *tdb, int ltype); -int tdb_transaction_unlock(struct tdb_context *tdb); -int tdb_brlock_upgrade(struct tdb_context *tdb, tdb_off_t offset, size_t len); -int tdb_write_lock_record(struct tdb_context *tdb, tdb_off_t off); -int tdb_write_unlock_record(struct tdb_context *tdb, tdb_off_t off); -int tdb_ofs_read(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d); -int tdb_ofs_write(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d); -void *tdb_convert(void *buf, uint32_t size); -int tdb_free(struct tdb_context *tdb, tdb_off_t offset, struct list_struct *rec); -tdb_off_t tdb_allocate(struct tdb_context *tdb, tdb_len_t length, struct list_struct *rec); -int tdb_ofs_read(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d); -int tdb_ofs_write(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d); -int tdb_lock_record(struct tdb_context *tdb, tdb_off_t off); -int tdb_unlock_record(struct tdb_context *tdb, tdb_off_t off); -int tdb_rec_read(struct tdb_context *tdb, tdb_off_t offset, struct list_struct *rec); -int tdb_rec_write(struct tdb_context *tdb, tdb_off_t offset, struct list_struct *rec); -int tdb_do_delete(struct tdb_context *tdb, tdb_off_t rec_ptr, struct list_struct *rec); -unsigned char *tdb_alloc_read(struct tdb_context *tdb, tdb_off_t offset, tdb_len_t len); -int tdb_parse_data(struct tdb_context *tdb, TDB_DATA key, - tdb_off_t offset, tdb_len_t len, - int (*parser)(TDB_DATA key, TDB_DATA data, - void *private_data), - void *private_data); -tdb_off_t tdb_find_lock_hash(struct tdb_context *tdb, TDB_DATA key, uint32_t hash, int locktype, - struct list_struct *rec); -void tdb_io_init(struct tdb_context *tdb); -int tdb_expand(struct tdb_context *tdb, tdb_off_t size); -int tdb_rec_free_read(struct tdb_context *tdb, tdb_off_t off, - struct list_struct *rec); - - diff --git a/tdb/common/transaction.c b/tdb/common/transaction.c deleted file mode 100644 index 7acda640..00000000 --- a/tdb/common/transaction.c +++ /dev/null @@ -1,1119 +0,0 @@ - /* - Unix SMB/CIFS implementation. - - trivial database library - - Copyright (C) Andrew Tridgell 2005 - - ** 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 "tdb_private.h" - -/* - transaction design: - - - only allow a single transaction at a time per database. This makes - using the transaction API simpler, as otherwise the caller would - have to cope with temporary failures in transactions that conflict - with other current transactions - - - keep the transaction recovery information in the same file as the - database, using a special 'transaction recovery' record pointed at - by the header. This removes the need for extra journal files as - used by some other databases - - - dynamically allocated the transaction recover record, re-using it - for subsequent transactions. If a larger record is needed then - tdb_free() the old record to place it on the normal tdb freelist - before allocating the new record - - - during transactions, keep a linked list of writes all that have - been performed by intercepting all tdb_write() calls. The hooked - transaction versions of tdb_read() and tdb_write() check this - linked list and try to use the elements of the list in preference - to the real database. - - - don't allow any locks to be held when a transaction starts, - otherwise we can end up with deadlock (plus lack of lock nesting - in posix locks would mean the lock is lost) - - - if the caller gains a lock during the transaction but doesn't - release it then fail the commit - - - allow for nested calls to tdb_transaction_start(), re-using the - existing transaction record. If the inner transaction is cancelled - then a subsequent commit will fail - - - keep a mirrored copy of the tdb hash chain heads to allow for the - fast hash heads scan on traverse, updating the mirrored copy in - the transaction version of tdb_write - - - allow callers to mix transaction and non-transaction use of tdb, - although once a transaction is started then an exclusive lock is - gained until the transaction is committed or cancelled - - - the commit stategy involves first saving away all modified data - into a linearised buffer in the transaction recovery area, then - marking the transaction recovery area with a magic value to - indicate a valid recovery record. In total 4 fsync/msync calls are - needed per commit to prevent race conditions. It might be possible - to reduce this to 3 or even 2 with some more work. - - - check for a valid recovery record on open of the tdb, while the - global lock is held. Automatically recover from the transaction - recovery area if needed, then continue with the open as - usual. This allows for smooth crash recovery with no administrator - intervention. - - - if TDB_NOSYNC is passed to flags in tdb_open then transactions are - still available, but no transaction recovery area is used and no - fsync/msync calls are made. - -*/ - - -/* - hold the context of any current transaction -*/ -struct tdb_transaction { - /* we keep a mirrored copy of the tdb hash heads here so - tdb_next_hash_chain() can operate efficiently */ - uint32_t *hash_heads; - - /* the original io methods - used to do IOs to the real db */ - const struct tdb_methods *io_methods; - - /* the list of transaction blocks. When a block is first - written to, it gets created in this list */ - uint8_t **blocks; - uint32_t num_blocks; - uint32_t block_size; /* bytes in each block */ - uint32_t last_block_size; /* number of valid bytes in the last block */ - - /* non-zero when an internal transaction error has - occurred. All write operations will then fail until the - transaction is ended */ - int transaction_error; - - /* when inside a transaction we need to keep track of any - nested tdb_transaction_start() calls, as these are allowed, - but don't create a new transaction */ - int nesting; - - /* old file size before transaction */ - tdb_len_t old_map_size; -}; - - -/* - read while in a transaction. We need to check first if the data is in our list - of transaction elements, then if not do a real read -*/ -static int transaction_read(struct tdb_context *tdb, tdb_off_t off, void *buf, - tdb_len_t len, int cv) -{ - uint32_t blk; - - /* break it down into block sized ops */ - while (len + (off % tdb->transaction->block_size) > tdb->transaction->block_size) { - tdb_len_t len2 = tdb->transaction->block_size - (off % tdb->transaction->block_size); - if (transaction_read(tdb, off, buf, len2, cv) != 0) { - return -1; - } - len -= len2; - off += len2; - buf = (void *)(len2 + (char *)buf); - } - - if (len == 0) { - return 0; - } - - blk = off / tdb->transaction->block_size; - - /* see if we have it in the block list */ - if (tdb->transaction->num_blocks <= blk || - tdb->transaction->blocks[blk] == NULL) { - /* nope, do a real read */ - if (tdb->transaction->io_methods->tdb_read(tdb, off, buf, len, cv) != 0) { - goto fail; - } - return 0; - } - - /* it is in the block list. Now check for the last block */ - if (blk == tdb->transaction->num_blocks-1) { - if (len > tdb->transaction->last_block_size) { - goto fail; - } - } - - /* now copy it out of this block */ - memcpy(buf, tdb->transaction->blocks[blk] + (off % tdb->transaction->block_size), len); - if (cv) { - tdb_convert(buf, len); - } - return 0; - -fail: - TDB_LOG((tdb, TDB_DEBUG_FATAL, "transaction_read: failed at off=%d len=%d\n", off, len)); - tdb->ecode = TDB_ERR_IO; - tdb->transaction->transaction_error = 1; - return -1; -} - - -/* - write while in a transaction -*/ -static int transaction_write(struct tdb_context *tdb, tdb_off_t off, - const void *buf, tdb_len_t len) -{ - uint32_t blk; - - /* if the write is to a hash head, then update the transaction - hash heads */ - if (len == sizeof(tdb_off_t) && off >= FREELIST_TOP && - off < FREELIST_TOP+TDB_HASHTABLE_SIZE(tdb)) { - uint32_t chain = (off-FREELIST_TOP) / sizeof(tdb_off_t); - memcpy(&tdb->transaction->hash_heads[chain], buf, len); - } - - /* break it up into block sized chunks */ - while (len + (off % tdb->transaction->block_size) > tdb->transaction->block_size) { - tdb_len_t len2 = tdb->transaction->block_size - (off % tdb->transaction->block_size); - if (transaction_write(tdb, off, buf, len2) != 0) { - return -1; - } - len -= len2; - off += len2; - if (buf != NULL) { - buf = (const void *)(len2 + (const char *)buf); - } - } - - if (len == 0) { - return 0; - } - - blk = off / tdb->transaction->block_size; - off = off % tdb->transaction->block_size; - - if (tdb->transaction->num_blocks <= blk) { - uint8_t **new_blocks; - /* expand the blocks array */ - if (tdb->transaction->blocks == NULL) { - new_blocks = (uint8_t **)malloc( - (blk+1)*sizeof(uint8_t *)); - } else { - new_blocks = (uint8_t **)realloc( - tdb->transaction->blocks, - (blk+1)*sizeof(uint8_t *)); - } - if (new_blocks == NULL) { - tdb->ecode = TDB_ERR_OOM; - goto fail; - } - memset(&new_blocks[tdb->transaction->num_blocks], 0, - (1+(blk - tdb->transaction->num_blocks))*sizeof(uint8_t *)); - tdb->transaction->blocks = new_blocks; - tdb->transaction->num_blocks = blk+1; - tdb->transaction->last_block_size = 0; - } - - /* allocate and fill a block? */ - if (tdb->transaction->blocks[blk] == NULL) { - tdb->transaction->blocks[blk] = (uint8_t *)calloc(tdb->transaction->block_size, 1); - if (tdb->transaction->blocks[blk] == NULL) { - tdb->ecode = TDB_ERR_OOM; - tdb->transaction->transaction_error = 1; - return -1; - } - if (tdb->transaction->old_map_size > blk * tdb->transaction->block_size) { - tdb_len_t len2 = tdb->transaction->block_size; - if (len2 + (blk * tdb->transaction->block_size) > tdb->transaction->old_map_size) { - len2 = tdb->transaction->old_map_size - (blk * tdb->transaction->block_size); - } - if (tdb->transaction->io_methods->tdb_read(tdb, blk * tdb->transaction->block_size, - tdb->transaction->blocks[blk], - len2, 0) != 0) { - SAFE_FREE(tdb->transaction->blocks[blk]); - tdb->ecode = TDB_ERR_IO; - goto fail; - } - if (blk == tdb->transaction->num_blocks-1) { - tdb->transaction->last_block_size = len2; - } - } - } - - /* overwrite part of an existing block */ - if (buf == NULL) { - memset(tdb->transaction->blocks[blk] + off, 0, len); - } else { - memcpy(tdb->transaction->blocks[blk] + off, buf, len); - } - if (blk == tdb->transaction->num_blocks-1) { - if (len + off > tdb->transaction->last_block_size) { - tdb->transaction->last_block_size = len + off; - } - } - - return 0; - -fail: - TDB_LOG((tdb, TDB_DEBUG_FATAL, "transaction_write: failed at off=%d len=%d\n", - (blk*tdb->transaction->block_size) + off, len)); - tdb->transaction->transaction_error = 1; - return -1; -} - - -/* - write while in a transaction - this varient never expands the transaction blocks, it only - updates existing blocks. This means it cannot change the recovery size -*/ -static int transaction_write_existing(struct tdb_context *tdb, tdb_off_t off, - const void *buf, tdb_len_t len) -{ - uint32_t blk; - - /* break it up into block sized chunks */ - while (len + (off % tdb->transaction->block_size) > tdb->transaction->block_size) { - tdb_len_t len2 = tdb->transaction->block_size - (off % tdb->transaction->block_size); - if (transaction_write_existing(tdb, off, buf, len2) != 0) { - return -1; - } - len -= len2; - off += len2; - if (buf != NULL) { - buf = (const void *)(len2 + (const char *)buf); - } - } - - if (len == 0) { - return 0; - } - - blk = off / tdb->transaction->block_size; - off = off % tdb->transaction->block_size; - - if (tdb->transaction->num_blocks <= blk || - tdb->transaction->blocks[blk] == NULL) { - return 0; - } - - if (blk == tdb->transaction->num_blocks-1 && - off + len > tdb->transaction->last_block_size) { - if (off >= tdb->transaction->last_block_size) { - return 0; - } - len = tdb->transaction->last_block_size - off; - } - - /* overwrite part of an existing block */ - memcpy(tdb->transaction->blocks[blk] + off, buf, len); - - return 0; -} - - -/* - accelerated hash chain head search, using the cached hash heads -*/ -static void transaction_next_hash_chain(struct tdb_context *tdb, uint32_t *chain) -{ - uint32_t h = *chain; - for (;h < tdb->header.hash_size;h++) { - /* the +1 takes account of the freelist */ - if (0 != tdb->transaction->hash_heads[h+1]) { - break; - } - } - (*chain) = h; -} - -/* - out of bounds check during a transaction -*/ -static int transaction_oob(struct tdb_context *tdb, tdb_off_t len, int probe) -{ - if (len <= tdb->map_size) { - return 0; - } - return TDB_ERRCODE(TDB_ERR_IO, -1); -} - -/* - transaction version of tdb_expand(). -*/ -static int transaction_expand_file(struct tdb_context *tdb, tdb_off_t size, - tdb_off_t addition) -{ - /* add a write to the transaction elements, so subsequent - reads see the zero data */ - if (transaction_write(tdb, size, NULL, addition) != 0) { - return -1; - } - - return 0; -} - -/* - brlock during a transaction - ignore them -*/ -static int transaction_brlock(struct tdb_context *tdb, tdb_off_t offset, - int rw_type, int lck_type, int probe, size_t len) -{ - return 0; -} - -static const struct tdb_methods transaction_methods = { - transaction_read, - transaction_write, - transaction_next_hash_chain, - transaction_oob, - transaction_expand_file, - transaction_brlock -}; - - -/* - start a tdb transaction. No token is returned, as only a single - transaction is allowed to be pending per tdb_context -*/ -int tdb_transaction_start(struct tdb_context *tdb) -{ - /* some sanity checks */ - if (tdb->read_only || (tdb->flags & TDB_INTERNAL) || tdb->traverse_read) { - TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_start: cannot start a transaction on a read-only or internal db\n")); - tdb->ecode = TDB_ERR_EINVAL; - return -1; - } - - /* cope with nested tdb_transaction_start() calls */ - if (tdb->transaction != NULL) { - tdb->transaction->nesting++; - TDB_LOG((tdb, TDB_DEBUG_TRACE, "tdb_transaction_start: nesting %d\n", - tdb->transaction->nesting)); - return 0; - } - - if (tdb->num_locks != 0 || tdb->global_lock.count) { - /* the caller must not have any locks when starting a - transaction as otherwise we'll be screwed by lack - of nested locks in posix */ - TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_start: cannot start a transaction with locks held\n")); - tdb->ecode = TDB_ERR_LOCK; - return -1; - } - - if (tdb->travlocks.next != NULL) { - /* you cannot use transactions inside a traverse (although you can use - traverse inside a transaction) as otherwise you can end up with - deadlock */ - TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_start: cannot start a transaction within a traverse\n")); - tdb->ecode = TDB_ERR_LOCK; - return -1; - } - - tdb->transaction = (struct tdb_transaction *) - calloc(sizeof(struct tdb_transaction), 1); - if (tdb->transaction == NULL) { - tdb->ecode = TDB_ERR_OOM; - return -1; - } - - /* a page at a time seems like a reasonable compromise between compactness and efficiency */ - tdb->transaction->block_size = tdb->page_size; - - /* get the transaction write lock. This is a blocking lock. As - discussed with Volker, there are a number of ways we could - make this async, which we will probably do in the future */ - if (tdb_transaction_lock(tdb, F_WRLCK) == -1) { - SAFE_FREE(tdb->transaction->blocks); - SAFE_FREE(tdb->transaction); - return -1; - } - - /* get a read lock from the freelist to the end of file. This - is upgraded to a write lock during the commit */ - if (tdb_brlock(tdb, FREELIST_TOP, F_RDLCK, F_SETLKW, 0, 0) == -1) { - TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_start: failed to get hash locks\n")); - tdb->ecode = TDB_ERR_LOCK; - goto fail; - } - - /* setup a copy of the hash table heads so the hash scan in - traverse can be fast */ - tdb->transaction->hash_heads = (uint32_t *) - calloc(tdb->header.hash_size+1, sizeof(uint32_t)); - if (tdb->transaction->hash_heads == NULL) { - tdb->ecode = TDB_ERR_OOM; - goto fail; - } - if (tdb->methods->tdb_read(tdb, FREELIST_TOP, tdb->transaction->hash_heads, - TDB_HASHTABLE_SIZE(tdb), 0) != 0) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_start: failed to read hash heads\n")); - tdb->ecode = TDB_ERR_IO; - goto fail; - } - - /* make sure we know about any file expansions already done by - anyone else */ - tdb->methods->tdb_oob(tdb, tdb->map_size + 1, 1); - tdb->transaction->old_map_size = tdb->map_size; - - /* finally hook the io methods, replacing them with - transaction specific methods */ - tdb->transaction->io_methods = tdb->methods; - tdb->methods = &transaction_methods; - - return 0; - -fail: - tdb_brlock(tdb, FREELIST_TOP, F_UNLCK, F_SETLKW, 0, 0); - tdb_transaction_unlock(tdb); - SAFE_FREE(tdb->transaction->blocks); - SAFE_FREE(tdb->transaction->hash_heads); - SAFE_FREE(tdb->transaction); - return -1; -} - - -/* - cancel the current transaction -*/ -int tdb_transaction_cancel(struct tdb_context *tdb) -{ - int i; - - if (tdb->transaction == NULL) { - TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_cancel: no transaction\n")); - return -1; - } - - if (tdb->transaction->nesting != 0) { - tdb->transaction->transaction_error = 1; - tdb->transaction->nesting--; - return 0; - } - - tdb->map_size = tdb->transaction->old_map_size; - - /* free all the transaction blocks */ - for (i=0;i<tdb->transaction->num_blocks;i++) { - if (tdb->transaction->blocks[i] != NULL) { - free(tdb->transaction->blocks[i]); - } - } - SAFE_FREE(tdb->transaction->blocks); - - /* remove any global lock created during the transaction */ - if (tdb->global_lock.count != 0) { - tdb_brlock(tdb, FREELIST_TOP, F_UNLCK, F_SETLKW, 0, 4*tdb->header.hash_size); - tdb->global_lock.count = 0; - } - - /* remove any locks created during the transaction */ - if (tdb->num_locks != 0) { - for (i=0;i<tdb->num_lockrecs;i++) { - tdb_brlock(tdb,FREELIST_TOP+4*tdb->lockrecs[i].list, - F_UNLCK,F_SETLKW, 0, 1); - } - tdb->num_locks = 0; - tdb->num_lockrecs = 0; - SAFE_FREE(tdb->lockrecs); - } - - /* restore the normal io methods */ - tdb->methods = tdb->transaction->io_methods; - - tdb_brlock(tdb, FREELIST_TOP, F_UNLCK, F_SETLKW, 0, 0); - tdb_transaction_unlock(tdb); - SAFE_FREE(tdb->transaction->hash_heads); - SAFE_FREE(tdb->transaction); - - return 0; -} - -/* - sync to disk -*/ -static int transaction_sync(struct tdb_context *tdb, tdb_off_t offset, tdb_len_t length) -{ - if (fsync(tdb->fd) != 0) { - tdb->ecode = TDB_ERR_IO; - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction: fsync failed\n")); - return -1; - } -#ifdef HAVE_MMAP - if (tdb->map_ptr) { - tdb_off_t moffset = offset & ~(tdb->page_size-1); - if (msync(moffset + (char *)tdb->map_ptr, - length + (offset - moffset), MS_SYNC) != 0) { - tdb->ecode = TDB_ERR_IO; - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction: msync failed - %s\n", - strerror(errno))); - return -1; - } - } -#endif - return 0; -} - - -/* - work out how much space the linearised recovery data will consume -*/ -static tdb_len_t tdb_recovery_size(struct tdb_context *tdb) -{ - tdb_len_t recovery_size = 0; - int i; - - recovery_size = sizeof(uint32_t); - for (i=0;i<tdb->transaction->num_blocks;i++) { - if (i * tdb->transaction->block_size >= tdb->transaction->old_map_size) { - break; - } - if (tdb->transaction->blocks[i] == NULL) { - continue; - } - recovery_size += 2*sizeof(tdb_off_t); - if (i == tdb->transaction->num_blocks-1) { - recovery_size += tdb->transaction->last_block_size; - } else { - recovery_size += tdb->transaction->block_size; - } - } - - return recovery_size; -} - -/* - allocate the recovery area, or use an existing recovery area if it is - large enough -*/ -static int tdb_recovery_allocate(struct tdb_context *tdb, - tdb_len_t *recovery_size, - tdb_off_t *recovery_offset, - tdb_len_t *recovery_max_size) -{ - struct list_struct rec; - const struct tdb_methods *methods = tdb->transaction->io_methods; - tdb_off_t recovery_head; - - if (tdb_ofs_read(tdb, TDB_RECOVERY_HEAD, &recovery_head) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_recovery_allocate: failed to read recovery head\n")); - return -1; - } - - rec.rec_len = 0; - - if (recovery_head != 0 && - methods->tdb_read(tdb, recovery_head, &rec, sizeof(rec), DOCONV()) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_recovery_allocate: failed to read recovery record\n")); - return -1; - } - - *recovery_size = tdb_recovery_size(tdb); - - if (recovery_head != 0 && *recovery_size <= rec.rec_len) { - /* it fits in the existing area */ - *recovery_max_size = rec.rec_len; - *recovery_offset = recovery_head; - return 0; - } - - /* we need to free up the old recovery area, then allocate a - new one at the end of the file. Note that we cannot use - tdb_allocate() to allocate the new one as that might return - us an area that is being currently used (as of the start of - the transaction) */ - if (recovery_head != 0) { - if (tdb_free(tdb, recovery_head, &rec) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_recovery_allocate: failed to free previous recovery area\n")); - return -1; - } - } - - /* the tdb_free() call might have increased the recovery size */ - *recovery_size = tdb_recovery_size(tdb); - - /* round up to a multiple of page size */ - *recovery_max_size = TDB_ALIGN(sizeof(rec) + *recovery_size, tdb->page_size) - sizeof(rec); - *recovery_offset = tdb->map_size; - recovery_head = *recovery_offset; - - if (methods->tdb_expand_file(tdb, tdb->transaction->old_map_size, - (tdb->map_size - tdb->transaction->old_map_size) + - sizeof(rec) + *recovery_max_size) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_recovery_allocate: failed to create recovery area\n")); - return -1; - } - - /* remap the file (if using mmap) */ - methods->tdb_oob(tdb, tdb->map_size + 1, 1); - - /* we have to reset the old map size so that we don't try to expand the file - again in the transaction commit, which would destroy the recovery area */ - tdb->transaction->old_map_size = tdb->map_size; - - /* write the recovery header offset and sync - we can sync without a race here - as the magic ptr in the recovery record has not been set */ - CONVERT(recovery_head); - if (methods->tdb_write(tdb, TDB_RECOVERY_HEAD, - &recovery_head, sizeof(tdb_off_t)) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_recovery_allocate: failed to write recovery head\n")); - return -1; - } - if (transaction_write_existing(tdb, TDB_RECOVERY_HEAD, &recovery_head, sizeof(tdb_off_t)) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_recovery_allocate: failed to write recovery head\n")); - return -1; - } - - return 0; -} - - -/* - setup the recovery data that will be used on a crash during commit -*/ -static int transaction_setup_recovery(struct tdb_context *tdb, - tdb_off_t *magic_offset) -{ - tdb_len_t recovery_size; - unsigned char *data, *p; - const struct tdb_methods *methods = tdb->transaction->io_methods; - struct list_struct *rec; - tdb_off_t recovery_offset, recovery_max_size; - tdb_off_t old_map_size = tdb->transaction->old_map_size; - uint32_t magic, tailer; - int i; - - /* - check that the recovery area has enough space - */ - if (tdb_recovery_allocate(tdb, &recovery_size, - &recovery_offset, &recovery_max_size) == -1) { - return -1; - } - - data = (unsigned char *)malloc(recovery_size + sizeof(*rec)); - if (data == NULL) { - tdb->ecode = TDB_ERR_OOM; - return -1; - } - - rec = (struct list_struct *)data; - memset(rec, 0, sizeof(*rec)); - - rec->magic = 0; - rec->data_len = recovery_size; - rec->rec_len = recovery_max_size; - rec->key_len = old_map_size; - CONVERT(rec); - - /* build the recovery data into a single blob to allow us to do a single - large write, which should be more efficient */ - p = data + sizeof(*rec); - for (i=0;i<tdb->transaction->num_blocks;i++) { - tdb_off_t offset; - tdb_len_t length; - - if (tdb->transaction->blocks[i] == NULL) { - continue; - } - - offset = i * tdb->transaction->block_size; - length = tdb->transaction->block_size; - if (i == tdb->transaction->num_blocks-1) { - length = tdb->transaction->last_block_size; - } - - if (offset >= old_map_size) { - continue; - } - if (offset + length > tdb->transaction->old_map_size) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_setup_recovery: transaction data over new region boundary\n")); - free(data); - tdb->ecode = TDB_ERR_CORRUPT; - return -1; - } - memcpy(p, &offset, 4); - memcpy(p+4, &length, 4); - if (DOCONV()) { - tdb_convert(p, 8); - } - /* the recovery area contains the old data, not the - new data, so we have to call the original tdb_read - method to get it */ - if (methods->tdb_read(tdb, offset, p + 8, length, 0) != 0) { - free(data); - tdb->ecode = TDB_ERR_IO; - return -1; - } - p += 8 + length; - } - - /* and the tailer */ - tailer = sizeof(*rec) + recovery_max_size; - memcpy(p, &tailer, 4); - CONVERT(p); - - /* write the recovery data to the recovery area */ - if (methods->tdb_write(tdb, recovery_offset, data, sizeof(*rec) + recovery_size) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_setup_recovery: failed to write recovery data\n")); - free(data); - tdb->ecode = TDB_ERR_IO; - return -1; - } - if (transaction_write_existing(tdb, recovery_offset, data, sizeof(*rec) + recovery_size) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_setup_recovery: failed to write secondary recovery data\n")); - free(data); - tdb->ecode = TDB_ERR_IO; - return -1; - } - - /* as we don't have ordered writes, we have to sync the recovery - data before we update the magic to indicate that the recovery - data is present */ - if (transaction_sync(tdb, recovery_offset, sizeof(*rec) + recovery_size) == -1) { - free(data); - return -1; - } - - free(data); - - magic = TDB_RECOVERY_MAGIC; - CONVERT(magic); - - *magic_offset = recovery_offset + offsetof(struct list_struct, magic); - - if (methods->tdb_write(tdb, *magic_offset, &magic, sizeof(magic)) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_setup_recovery: failed to write recovery magic\n")); - tdb->ecode = TDB_ERR_IO; - return -1; - } - if (transaction_write_existing(tdb, *magic_offset, &magic, sizeof(magic)) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_setup_recovery: failed to write secondary recovery magic\n")); - tdb->ecode = TDB_ERR_IO; - return -1; - } - - /* ensure the recovery magic marker is on disk */ - if (transaction_sync(tdb, *magic_offset, sizeof(magic)) == -1) { - return -1; - } - - return 0; -} - -/* - commit the current transaction -*/ -int tdb_transaction_commit(struct tdb_context *tdb) -{ - const struct tdb_methods *methods; - tdb_off_t magic_offset = 0; - uint32_t zero = 0; - int i; - - if (tdb->transaction == NULL) { - TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_commit: no transaction\n")); - return -1; - } - - if (tdb->transaction->transaction_error) { - tdb->ecode = TDB_ERR_IO; - tdb_transaction_cancel(tdb); - TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_commit: transaction error pending\n")); - return -1; - } - - - if (tdb->transaction->nesting != 0) { - tdb->transaction->nesting--; - return 0; - } - - /* check for a null transaction */ - if (tdb->transaction->blocks == NULL) { - tdb_transaction_cancel(tdb); - return 0; - } - - methods = tdb->transaction->io_methods; - - /* if there are any locks pending then the caller has not - nested their locks properly, so fail the transaction */ - if (tdb->num_locks || tdb->global_lock.count) { - tdb->ecode = TDB_ERR_LOCK; - TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_commit: locks pending on commit\n")); - tdb_transaction_cancel(tdb); - return -1; - } - - /* upgrade the main transaction lock region to a write lock */ - if (tdb_brlock_upgrade(tdb, FREELIST_TOP, 0) == -1) { - TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_start: failed to upgrade hash locks\n")); - tdb->ecode = TDB_ERR_LOCK; - tdb_transaction_cancel(tdb); - return -1; - } - - /* get the global lock - this prevents new users attaching to the database - during the commit */ - if (tdb_brlock(tdb, GLOBAL_LOCK, F_WRLCK, F_SETLKW, 0, 1) == -1) { - TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_commit: failed to get global lock\n")); - tdb->ecode = TDB_ERR_LOCK; - tdb_transaction_cancel(tdb); - return -1; - } - - if (!(tdb->flags & TDB_NOSYNC)) { - /* write the recovery data to the end of the file */ - if (transaction_setup_recovery(tdb, &magic_offset) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_commit: failed to setup recovery data\n")); - tdb_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0, 1); - tdb_transaction_cancel(tdb); - return -1; - } - } - - /* expand the file to the new size if needed */ - if (tdb->map_size != tdb->transaction->old_map_size) { - if (methods->tdb_expand_file(tdb, tdb->transaction->old_map_size, - tdb->map_size - - tdb->transaction->old_map_size) == -1) { - tdb->ecode = TDB_ERR_IO; - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_commit: expansion failed\n")); - tdb_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0, 1); - tdb_transaction_cancel(tdb); - return -1; - } - tdb->map_size = tdb->transaction->old_map_size; - methods->tdb_oob(tdb, tdb->map_size + 1, 1); - } - - /* perform all the writes */ - for (i=0;i<tdb->transaction->num_blocks;i++) { - tdb_off_t offset; - tdb_len_t length; - - if (tdb->transaction->blocks[i] == NULL) { - continue; - } - - offset = i * tdb->transaction->block_size; - length = tdb->transaction->block_size; - if (i == tdb->transaction->num_blocks-1) { - length = tdb->transaction->last_block_size; - } - - if (methods->tdb_write(tdb, offset, tdb->transaction->blocks[i], length) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_commit: write failed during commit\n")); - - /* we've overwritten part of the data and - possibly expanded the file, so we need to - run the crash recovery code */ - tdb->methods = methods; - tdb_transaction_recover(tdb); - - tdb_transaction_cancel(tdb); - tdb_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0, 1); - - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_commit: write failed\n")); - return -1; - } - SAFE_FREE(tdb->transaction->blocks[i]); - } - - SAFE_FREE(tdb->transaction->blocks); - tdb->transaction->num_blocks = 0; - - if (!(tdb->flags & TDB_NOSYNC)) { - /* ensure the new data is on disk */ - if (transaction_sync(tdb, 0, tdb->map_size) == -1) { - return -1; - } - - /* remove the recovery marker */ - if (methods->tdb_write(tdb, magic_offset, &zero, 4) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_commit: failed to remove recovery magic\n")); - return -1; - } - - /* ensure the recovery marker has been removed on disk */ - if (transaction_sync(tdb, magic_offset, 4) == -1) { - return -1; - } - } - - tdb_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0, 1); - - /* - TODO: maybe write to some dummy hdr field, or write to magic - offset without mmap, before the last sync, instead of the - utime() call - */ - - /* on some systems (like Linux 2.6.x) changes via mmap/msync - don't change the mtime of the file, this means the file may - not be backed up (as tdb rounding to block sizes means that - file size changes are quite rare too). The following forces - mtime changes when a transaction completes */ -#ifdef HAVE_UTIME - utime(tdb->name, NULL); -#endif - - /* use a transaction cancel to free memory and remove the - transaction locks */ - tdb_transaction_cancel(tdb); - - return 0; -} - - -/* - recover from an aborted transaction. Must be called with exclusive - database write access already established (including the global - lock to prevent new processes attaching) -*/ -int tdb_transaction_recover(struct tdb_context *tdb) -{ - tdb_off_t recovery_head, recovery_eof; - unsigned char *data, *p; - uint32_t zero = 0; - struct list_struct rec; - - /* find the recovery area */ - if (tdb_ofs_read(tdb, TDB_RECOVERY_HEAD, &recovery_head) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to read recovery head\n")); - tdb->ecode = TDB_ERR_IO; - return -1; - } - - if (recovery_head == 0) { - /* we have never allocated a recovery record */ - return 0; - } - - /* read the recovery record */ - if (tdb->methods->tdb_read(tdb, recovery_head, &rec, - sizeof(rec), DOCONV()) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to read recovery record\n")); - tdb->ecode = TDB_ERR_IO; - return -1; - } - - if (rec.magic != TDB_RECOVERY_MAGIC) { - /* there is no valid recovery data */ - return 0; - } - - if (tdb->read_only) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: attempt to recover read only database\n")); - tdb->ecode = TDB_ERR_CORRUPT; - return -1; - } - - recovery_eof = rec.key_len; - - data = (unsigned char *)malloc(rec.data_len); - if (data == NULL) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to allocate recovery data\n")); - tdb->ecode = TDB_ERR_OOM; - return -1; - } - - /* read the full recovery data */ - if (tdb->methods->tdb_read(tdb, recovery_head + sizeof(rec), data, - rec.data_len, 0) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to read recovery data\n")); - tdb->ecode = TDB_ERR_IO; - return -1; - } - - /* recover the file data */ - p = data; - while (p+8 < data + rec.data_len) { - uint32_t ofs, len; - if (DOCONV()) { - tdb_convert(p, 8); - } - memcpy(&ofs, p, 4); - memcpy(&len, p+4, 4); - - if (tdb->methods->tdb_write(tdb, ofs, p+8, len) == -1) { - free(data); - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to recover %d bytes at offset %d\n", len, ofs)); - tdb->ecode = TDB_ERR_IO; - return -1; - } - p += 8 + len; - } - - free(data); - - if (transaction_sync(tdb, 0, tdb->map_size) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to sync recovery\n")); - tdb->ecode = TDB_ERR_IO; - return -1; - } - - /* if the recovery area is after the recovered eof then remove it */ - if (recovery_eof <= recovery_head) { - if (tdb_ofs_write(tdb, TDB_RECOVERY_HEAD, &zero) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to remove recovery head\n")); - tdb->ecode = TDB_ERR_IO; - return -1; - } - } - - /* remove the recovery magic */ - if (tdb_ofs_write(tdb, recovery_head + offsetof(struct list_struct, magic), - &zero) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to remove recovery magic\n")); - tdb->ecode = TDB_ERR_IO; - return -1; - } - - /* reduce the file size to the old size */ - tdb_munmap(tdb); - if (ftruncate(tdb->fd, recovery_eof) != 0) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to reduce to recovery size\n")); - tdb->ecode = TDB_ERR_IO; - return -1; - } - tdb->map_size = recovery_eof; - tdb_mmap(tdb); - - if (transaction_sync(tdb, 0, recovery_eof) == -1) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to sync2 recovery\n")); - tdb->ecode = TDB_ERR_IO; - return -1; - } - - TDB_LOG((tdb, TDB_DEBUG_TRACE, "tdb_transaction_recover: recovered %d byte database\n", - recovery_eof)); - - /* all done */ - return 0; -} diff --git a/tdb/common/traverse.c b/tdb/common/traverse.c deleted file mode 100644 index 69c81e6e..00000000 --- a/tdb/common/traverse.c +++ /dev/null @@ -1,348 +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 <http://www.gnu.org/licenses/>. -*/ - -#include "tdb_private.h" - -/* Uses traverse lock: 0 = finish, -1 = error, other = record offset */ -static int tdb_next_lock(struct tdb_context *tdb, struct tdb_traverse_lock *tlock, - struct list_struct *rec) -{ - int want_next = (tlock->off != 0); - - /* Lock each chain from the start one. */ - for (; tlock->hash < tdb->header.hash_size; tlock->hash++) { - if (!tlock->off && tlock->hash != 0) { - /* this is an optimisation for the common case where - the hash chain is empty, which is particularly - common for the use of tdb with ldb, where large - hashes are used. In that case we spend most of our - time in tdb_brlock(), locking empty hash chains. - - To avoid this, we do an unlocked pre-check to see - if the hash chain is empty before starting to look - inside it. If it is empty then we can avoid that - hash chain. If it isn't empty then we can't believe - the value we get back, as we read it without a - lock, so instead we get the lock and re-fetch the - value below. - - Notice that not doing this optimisation on the - first hash chain is critical. We must guarantee - that we have done at least one fcntl lock at the - start of a search to guarantee that memory is - coherent on SMP systems. If records are added by - others during the search then thats OK, and we - could possibly miss those with this trick, but we - could miss them anyway without this trick, so the - semantics don't change. - - With a non-indexed ldb search this trick gains us a - factor of around 80 in speed on a linux 2.6.x - system (testing using ldbtest). - */ - tdb->methods->next_hash_chain(tdb, &tlock->hash); - if (tlock->hash == tdb->header.hash_size) { - continue; - } - } - - if (tdb_lock(tdb, tlock->hash, tlock->lock_rw) == -1) - return -1; - - /* No previous record? Start at top of chain. */ - if (!tlock->off) { - if (tdb_ofs_read(tdb, TDB_HASH_TOP(tlock->hash), - &tlock->off) == -1) - goto fail; - } else { - /* Otherwise unlock the previous record. */ - if (tdb_unlock_record(tdb, tlock->off) != 0) - goto fail; - } - - if (want_next) { - /* We have offset of old record: grab next */ - if (tdb_rec_read(tdb, tlock->off, rec) == -1) - goto fail; - tlock->off = rec->next; - } - - /* Iterate through chain */ - while( tlock->off) { - tdb_off_t current; - if (tdb_rec_read(tdb, tlock->off, rec) == -1) - goto fail; - - /* Detect infinite loops. From "Shlomi Yaakobovich" <Shlomi@exanet.com>. */ - if (tlock->off == rec->next) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_next_lock: loop detected.\n")); - goto fail; - } - - if (!TDB_DEAD(rec)) { - /* Woohoo: we found one! */ - if (tdb_lock_record(tdb, tlock->off) != 0) - goto fail; - return tlock->off; - } - - /* Try to clean dead ones from old traverses */ - current = tlock->off; - tlock->off = rec->next; - if (!(tdb->read_only || tdb->traverse_read) && - tdb_do_delete(tdb, current, rec) != 0) - goto fail; - } - tdb_unlock(tdb, tlock->hash, tlock->lock_rw); - want_next = 0; - } - /* We finished iteration without finding anything */ - return TDB_ERRCODE(TDB_SUCCESS, 0); - - fail: - tlock->off = 0; - if (tdb_unlock(tdb, tlock->hash, tlock->lock_rw) != 0) - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_next_lock: On error unlock failed!\n")); - return -1; -} - -/* traverse the entire database - calling fn(tdb, key, data) on each element. - return -1 on error or the record count traversed - if fn is NULL then it is not called - a non-zero return value from fn() indicates that the traversal should stop - */ -static int tdb_traverse_internal(struct tdb_context *tdb, - tdb_traverse_func fn, void *private_data, - struct tdb_traverse_lock *tl) -{ - TDB_DATA key, dbuf; - struct list_struct rec; - int ret, count = 0; - - /* This was in the initializaton, above, but the IRIX compiler - * did not like it. crh - */ - tl->next = tdb->travlocks.next; - - /* fcntl locks don't stack: beware traverse inside traverse */ - tdb->travlocks.next = tl; - - /* tdb_next_lock places locks on the record returned, and its chain */ - while ((ret = tdb_next_lock(tdb, tl, &rec)) > 0) { - count++; - /* now read the full record */ - key.dptr = tdb_alloc_read(tdb, tl->off + sizeof(rec), - rec.key_len + rec.data_len); - if (!key.dptr) { - ret = -1; - if (tdb_unlock(tdb, tl->hash, tl->lock_rw) != 0) - goto out; - if (tdb_unlock_record(tdb, tl->off) != 0) - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_traverse: key.dptr == NULL and unlock_record failed!\n")); - goto out; - } - key.dsize = rec.key_len; - dbuf.dptr = key.dptr + rec.key_len; - dbuf.dsize = rec.data_len; - - /* Drop chain lock, call out */ - if (tdb_unlock(tdb, tl->hash, tl->lock_rw) != 0) { - ret = -1; - SAFE_FREE(key.dptr); - goto out; - } - if (fn && fn(tdb, key, dbuf, private_data)) { - /* They want us to terminate traversal */ - ret = count; - if (tdb_unlock_record(tdb, tl->off) != 0) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_traverse: unlock_record failed!\n"));; - ret = -1; - } - SAFE_FREE(key.dptr); - goto out; - } - SAFE_FREE(key.dptr); - } -out: - tdb->travlocks.next = tl->next; - if (ret < 0) - return -1; - else - return count; -} - - -/* - a write style traverse - temporarily marks the db read only -*/ -int tdb_traverse_read(struct tdb_context *tdb, - tdb_traverse_func fn, void *private_data) -{ - struct tdb_traverse_lock tl = { NULL, 0, 0, F_RDLCK }; - int ret; - bool in_transaction = (tdb->transaction != NULL); - - /* we need to get a read lock on the transaction lock here to - cope with the lock ordering semantics of solaris10 */ - if (!in_transaction) { - if (tdb_transaction_lock(tdb, F_RDLCK)) { - return -1; - } - } - - tdb->traverse_read++; - ret = tdb_traverse_internal(tdb, fn, private_data, &tl); - tdb->traverse_read--; - - if (!in_transaction) { - tdb_transaction_unlock(tdb); - } - - return ret; -} - -/* - a write style traverse - needs to get the transaction lock to - prevent deadlocks - - WARNING: The data buffer given to the callback fn does NOT meet the - alignment restrictions malloc gives you. -*/ -int tdb_traverse(struct tdb_context *tdb, - tdb_traverse_func fn, void *private_data) -{ - struct tdb_traverse_lock tl = { NULL, 0, 0, F_WRLCK }; - int ret; - bool in_transaction = (tdb->transaction != NULL); - - if (tdb->read_only || tdb->traverse_read) { - return tdb_traverse_read(tdb, fn, private_data); - } - - if (!in_transaction) { - if (tdb_transaction_lock(tdb, F_WRLCK)) { - return -1; - } - } - - tdb->traverse_write++; - ret = tdb_traverse_internal(tdb, fn, private_data, &tl); - tdb->traverse_write--; - - if (!in_transaction) { - tdb_transaction_unlock(tdb); - } - - return ret; -} - - -/* find the first entry in the database and return its key */ -TDB_DATA tdb_firstkey(struct tdb_context *tdb) -{ - TDB_DATA key; - struct list_struct rec; - - /* release any old lock */ - if (tdb_unlock_record(tdb, tdb->travlocks.off) != 0) - return tdb_null; - tdb->travlocks.off = tdb->travlocks.hash = 0; - tdb->travlocks.lock_rw = F_RDLCK; - - /* Grab first record: locks chain and returned record. */ - if (tdb_next_lock(tdb, &tdb->travlocks, &rec) <= 0) - return tdb_null; - /* now read the key */ - key.dsize = rec.key_len; - key.dptr =tdb_alloc_read(tdb,tdb->travlocks.off+sizeof(rec),key.dsize); - - /* Unlock the hash chain of the record we just read. */ - if (tdb_unlock(tdb, tdb->travlocks.hash, tdb->travlocks.lock_rw) != 0) - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_firstkey: error occurred while tdb_unlocking!\n")); - return key; -} - -/* find the next entry in the database, returning its key */ -TDB_DATA tdb_nextkey(struct tdb_context *tdb, TDB_DATA oldkey) -{ - uint32_t oldhash; - TDB_DATA key = tdb_null; - struct list_struct rec; - unsigned char *k = NULL; - - /* Is locked key the old key? If so, traverse will be reliable. */ - if (tdb->travlocks.off) { - if (tdb_lock(tdb,tdb->travlocks.hash,tdb->travlocks.lock_rw)) - return tdb_null; - if (tdb_rec_read(tdb, tdb->travlocks.off, &rec) == -1 - || !(k = tdb_alloc_read(tdb,tdb->travlocks.off+sizeof(rec), - rec.key_len)) - || memcmp(k, oldkey.dptr, oldkey.dsize) != 0) { - /* No, it wasn't: unlock it and start from scratch */ - if (tdb_unlock_record(tdb, tdb->travlocks.off) != 0) { - SAFE_FREE(k); - return tdb_null; - } - if (tdb_unlock(tdb, tdb->travlocks.hash, tdb->travlocks.lock_rw) != 0) { - SAFE_FREE(k); - return tdb_null; - } - tdb->travlocks.off = 0; - } - - SAFE_FREE(k); - } - - if (!tdb->travlocks.off) { - /* No previous element: do normal find, and lock record */ - tdb->travlocks.off = tdb_find_lock_hash(tdb, oldkey, tdb->hash_fn(&oldkey), tdb->travlocks.lock_rw, &rec); - if (!tdb->travlocks.off) - return tdb_null; - tdb->travlocks.hash = BUCKET(rec.full_hash); - if (tdb_lock_record(tdb, tdb->travlocks.off) != 0) { - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_nextkey: lock_record failed (%s)!\n", strerror(errno))); - return tdb_null; - } - } - oldhash = tdb->travlocks.hash; - - /* Grab next record: locks chain and returned record, - unlocks old record */ - if (tdb_next_lock(tdb, &tdb->travlocks, &rec) > 0) { - key.dsize = rec.key_len; - key.dptr = tdb_alloc_read(tdb, tdb->travlocks.off+sizeof(rec), - key.dsize); - /* Unlock the chain of this new record */ - if (tdb_unlock(tdb, tdb->travlocks.hash, tdb->travlocks.lock_rw) != 0) - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_nextkey: WARNING tdb_unlock failed!\n")); - } - /* Unlock the chain of old record */ - if (tdb_unlock(tdb, BUCKET(oldhash), tdb->travlocks.lock_rw) != 0) - TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_nextkey: WARNING tdb_unlock failed!\n")); - return key; -} - |