diff options
Diffstat (limited to 'source3/tdb')
| -rw-r--r-- | source3/tdb/dump.c | 135 | ||||
| -rw-r--r-- | source3/tdb/error.c | 58 | ||||
| -rw-r--r-- | source3/tdb/freelist.c | 331 | ||||
| -rw-r--r-- | source3/tdb/io.c | 412 | ||||
| -rw-r--r-- | source3/tdb/lock.c | 276 | ||||
| -rw-r--r-- | source3/tdb/open.c | 453 | ||||
| -rw-r--r-- | source3/tdb/spinlock.c | 472 | ||||
| -rw-r--r-- | source3/tdb/spinlock.h | 59 | ||||
| -rw-r--r-- | source3/tdb/tdb.c | 1941 | ||||
| -rw-r--r-- | source3/tdb/tdb.h | 146 | ||||
| -rw-r--r-- | source3/tdb/tdb_private.h | 241 | ||||
| -rw-r--r-- | source3/tdb/tdbback.c | 6 | ||||
| -rw-r--r-- | source3/tdb/tdbutil.c | 186 | ||||
| -rw-r--r-- | source3/tdb/tdbutil.h | 38 | ||||
| -rw-r--r-- | source3/tdb/transaction.c | 1043 | ||||
| -rw-r--r-- | source3/tdb/traverse.c | 334 |
16 files changed, 3553 insertions, 2578 deletions
diff --git a/source3/tdb/dump.c b/source3/tdb/dump.c new file mode 100644 index 0000000000..577f23aac6 --- /dev/null +++ b/source3/tdb/dump.c @@ -0,0 +1,135 @@ + /* + 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 2 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, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA +*/ + +#include "tdb_private.h" + +static tdb_off_t tdb_dump_record(struct tdb_context *tdb, 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: offset=0x%08x next=0x%08x rec_len=%d key_len=%d data_len=%d full_hash=0x%x magic=0x%x\n", + 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, 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/source3/tdb/error.c b/source3/tdb/error.c new file mode 100644 index 0000000000..4cf33a29ab --- /dev/null +++ b/source3/tdb/error.c @@ -0,0 +1,58 @@ + /* + 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 2 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, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA +*/ + +#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) +{ + u32 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/source3/tdb/freelist.c b/source3/tdb/freelist.c new file mode 100644 index 0000000000..3483751164 --- /dev/null +++ b/source3/tdb/freelist.c @@ -0,0 +1,331 @@ + /* + 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 2 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, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA +*/ + +#include "tdb_private.h" + +/* read a freelist record and check for simple errors */ +static int 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, 0,"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, 0,"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; +} + + + +/* 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, 0,"remove_from_freelist: not on list at off=%d\n", off)); + return TDB_ERRCODE(TDB_ERR_CORRUPT, -1); +} + + +/* 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) +{ + tdb_off_t right, left; + + /* 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, 0, "tdb_free: upfate_tailer failed!\n")); + goto fail; + } + + /* Look right first (I'm an Australian, dammit) */ + right = offset + sizeof(*rec) + rec->rec_len; + if (right + sizeof(*rec) <= tdb->map_size) { + struct list_struct r; + + if (tdb->methods->tdb_read(tdb, right, &r, sizeof(r), DOCONV()) == -1) { + TDB_LOG((tdb, 0, "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, 0, "tdb_free: right free failed at %u\n", right)); + goto left; + } + rec->rec_len += sizeof(r) + r.rec_len; + } + } + +left: + /* Look left */ + left = offset - sizeof(tdb_off_t); + if (left > TDB_DATA_START(tdb->header.hash_size)) { + 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, 0, "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; + + /* Now read in record */ + if (tdb->methods->tdb_read(tdb, left, &l, sizeof(l), DOCONV()) == -1) { + TDB_LOG((tdb, 0, "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) { + if (remove_from_freelist(tdb, left, l.next) == -1) { + TDB_LOG((tdb, 0, "tdb_free: left free failed at %u\n", left)); + goto update; + } else { + offset = left; + rec->rec_len += leftsize; + } + } + } + +update: + if (update_tailer(tdb, offset, rec) == -1) { + TDB_LOG((tdb, 0, "tdb_free: update_tailer failed at %u\n", offset)); + goto fail; + } + + /* 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, 0, "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 + */ +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) +{ + struct list_struct newrec; + tdb_off_t newrec_ptr; + + memset(&newrec, '\0', sizeof(newrec)); + + /* found it - now possibly split it up */ + if (rec->rec_len > length + MIN_REC_SIZE) { + /* Length of left piece */ + length = TDB_ALIGN(length, TDB_ALIGNMENT); + + /* Right piece to go on free list */ + newrec.rec_len = rec->rec_len - (sizeof(*rec) + length); + newrec_ptr = rec_ptr + sizeof(*rec) + length; + + /* And left record is shortened */ + rec->rec_len = length; + } else { + newrec_ptr = 0; + } + + /* Remove allocated record from the free list */ + if (tdb_ofs_write(tdb, last_ptr, &rec->next) == -1) { + return 0; + } + + /* Update header: do this before we drop alloc + lock, otherwise tdb_free() might try to + merge with us, thinking we're free. + (Thanks Jeremy Allison). */ + rec->magic = TDB_MAGIC; + if (tdb_rec_write(tdb, rec_ptr, rec) == -1) { + return 0; + } + + /* Did we create new block? */ + if (newrec_ptr) { + /* Update allocated record tailer (we + shortened it). */ + if (update_tailer(tdb, rec_ptr, rec) == -1) { + return 0; + } + + /* Free new record */ + if (tdb_free(tdb, newrec_ptr, &newrec) == -1) { + return 0; + } + } + + /* all done - return the new record offset */ + 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; + + if (tdb_lock(tdb, -1, F_WRLCK) == -1) + return 0; + + /* Extra bytes required for tailer */ + length += sizeof(tdb_off_t); + + 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 (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; + /* consider a fit to be good enough if + we aren't wasting more than half + the space */ + if (bestfit.rec_len < 2*length) { + break; + } + } + } + + /* move to the next record */ + last_ptr = rec_ptr; + rec_ptr = rec->next; + } + + if (bestfit.rec_ptr != 0) { + if (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; +} + diff --git a/source3/tdb/io.c b/source3/tdb/io.c new file mode 100644 index 0000000000..ac6f4cdf57 --- /dev/null +++ b/source3/tdb/io.c @@ -0,0 +1,412 @@ + /* + 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 2 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, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA +*/ + + +#include "tdb_private.h" + +#ifndef HAVE_PREAD + static ssize_t pread(int fd, void *buf, size_t count, off_t offset) +{ + if (lseek(fd, offset, SEEK_SET) != offset) { + errno = EIO; + return -1; + } + return read(fd, buf, count); +} +#endif + +#ifndef HAVE_PWRITE + static ssize_t pwrite(int fd, const void *buf, size_t count, off_t offset) +{ + if (lseek(fd, offset, SEEK_SET) != offset) { + errno = EIO; + return -1; + } + return write(fd, buf, count); +} +#endif + +/* 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, 0,"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, 0,"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 if (pwrite(tdb->fd, buf, len, off) != (ssize_t)len) { + /* Ensure ecode is set for log fn. */ + tdb->ecode = TDB_ERR_IO; + TDB_LOG((tdb, 0,"tdb_write failed at %d len=%d (%s)\n", + off, len, strerror(errno))); + return TDB_ERRCODE(TDB_ERR_IO, -1); + } + return 0; +} + +/* Endian conversion: we only ever deal with 4 byte quantities */ +void *tdb_convert(void *buf, u32 size) +{ + u32 i, *p = 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, 0,"tdb_read failed at %d len=%d ret=%d (%s) map_size=%d\n", + off, 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, u32 *chain) +{ + u32 h = *chain; + if (tdb->map_ptr) { + for (;h < tdb->header.hash_size;h++) { + if (0 != *(u32 *)(TDB_HASH_TOP(h) + (unsigned char *)tdb->map_ptr)) { + break; + } + } + } else { + u32 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 = 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, 2, "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[1024]; + + if (tdb->read_only || tdb->traverse_read) { + tdb->ecode = TDB_ERR_RDONLY; + return -1; + } + + if (ftruncate(tdb->fd, size+addition) == -1) { + char b = 0; + if (pwrite(tdb->fd, &b, 1, (size+addition) - 1) != 1) { + TDB_LOG((tdb, 0, "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) { + int n = addition>sizeof(buf)?sizeof(buf):addition; + int ret = pwrite(tdb->fd, buf, n, size); + if (ret != n) { + TDB_LOG((tdb, 0, "expand_file write of %d failed (%s)\n", + n, strerror(errno))); + return -1; + } + addition -= n; + size += n; + } + 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; + + if (tdb_lock(tdb, -1, F_WRLCK) == -1) { + TDB_LOG((tdb, 0, "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 10 more records, and round + the database up to a multiple of the page size */ + size = TDB_ALIGN(tdb->map_size + size*10, 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 = 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 */ +char *tdb_alloc_read(struct tdb_context *tdb, tdb_off_t offset, tdb_len_t len) +{ + char *buf; + + /* some systems don't like zero length malloc */ + if (len == 0) { + len = 1; + } + + if (!(buf = malloc(len))) { + /* Ensure ecode is set for log fn. */ + tdb->ecode = TDB_ERR_OOM; + TDB_LOG((tdb, 0,"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; +} + +/* 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, 0,"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/source3/tdb/lock.c b/source3/tdb/lock.c new file mode 100644 index 0000000000..a96d77a229 --- /dev/null +++ b/source3/tdb/lock.c @@ -0,0 +1,276 @@ + /* + 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 2 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, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA +*/ + +#include "tdb_private.h" + +/* 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_len(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); + } 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, 5,"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_len(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, 5,"tdb_brlock_upgrade failed at offset %d\n", offset)); + return -1; +} + + +/* 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(). */ +int tdb_brlock(struct tdb_context *tdb, tdb_off_t offset, + int rw_type, int lck_type, int probe) +{ + return tdb_brlock_len(tdb, offset, rw_type, lck_type, probe, 1); +} + +/* lock a list in the database. list -1 is the alloc list */ +int tdb_lock(struct tdb_context *tdb, int list, int ltype) +{ + if (list < -1 || list >= (int)tdb->header.hash_size) { + TDB_LOG((tdb, 0,"tdb_lock: invalid list %d for ltype=%d\n", + list, ltype)); + return -1; + } + if (tdb->flags & TDB_NOLOCK) + return 0; + + /* Since fcntl locks don't nest, we do a lock for the first one, + and simply bump the count for future ones */ + if (tdb->locked[list+1].count == 0) { + if (tdb->methods->tdb_brlock(tdb,FREELIST_TOP+4*list,ltype,F_SETLKW, 0)) { + TDB_LOG((tdb, 0,"tdb_lock failed on list %d ltype=%d (%s)\n", + list, ltype, strerror(errno))); + return -1; + } + tdb->locked[list+1].ltype = ltype; + tdb->num_locks++; + } + tdb->locked[list+1].count++; + return 0; +} + +/* 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; + + if (tdb->flags & TDB_NOLOCK) + return 0; + + /* Sanity checks */ + if (list < -1 || list >= (int)tdb->header.hash_size) { + TDB_LOG((tdb, 0, "tdb_unlock: list %d invalid (%d)\n", list, tdb->header.hash_size)); + return ret; + } + + if (tdb->locked[list+1].count==0) { + TDB_LOG((tdb, 0, "tdb_unlock: count is 0\n")); + return ret; + } + + if (tdb->locked[list+1].count == 1) { + /* Down to last nested lock: unlock underneath */ + ret = tdb->methods->tdb_brlock(tdb, FREELIST_TOP+4*list, F_UNLCK, F_SETLKW, 0); + tdb->num_locks--; + } else { + ret = 0; + } + tdb->locked[list+1].count--; + + if (ret) + TDB_LOG((tdb, 0,"tdb_unlock: An error occurred unlocking!\n")); + return ret; +} + + + +/* lock/unlock entire database */ +int tdb_lockall(struct tdb_context *tdb) +{ + u32 i; + + /* There are no locks on read-only dbs */ + if (tdb->read_only || tdb->traverse_read) + return TDB_ERRCODE(TDB_ERR_LOCK, -1); + for (i = 0; i < tdb->header.hash_size; i++) + if (tdb_lock(tdb, i, F_WRLCK)) + break; + + /* If error, release locks we have... */ + if (i < tdb->header.hash_size) { + u32 j; + + for ( j = 0; j < i; j++) + tdb_unlock(tdb, j, F_WRLCK); + return TDB_ERRCODE(TDB_ERR_NOLOCK, -1); + } + + return 0; +} +void tdb_unlockall(struct tdb_context *tdb) +{ + u32 i; + for (i=0; i < tdb->header.hash_size; i++) + tdb_unlock(tdb, i, F_WRLCK); +} + +/* 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); +} + +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) +{ + return off ? tdb->methods->tdb_brlock(tdb, off, F_RDLCK, F_SETLKW, 0) : 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); +} + +/* + 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); +} + +/* 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; + u32 count = 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) : 0); +} diff --git a/source3/tdb/open.c b/source3/tdb/open.c new file mode 100644 index 0000000000..cb4a9cd994 --- /dev/null +++ b/source3/tdb/open.c @@ -0,0 +1,453 @@ + /* + 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 2 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, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA +*/ + +#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) +{ + u32 value; /* Used to compute the hash value. */ + u32 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; + int size, ret = -1; + + /* 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 = 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); + if (write(tdb->fd, newdb, size) != size) { + ret = -1; + } else { + ret = 0; + } + + 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, int 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, + tdb_log_func log_fn, + tdb_hash_func hash_fn) +{ + struct tdb_context *tdb; + struct stat st; + int rev = 0, locked = 0; + unsigned char *vp; + u32 vertest; + + if (!(tdb = 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; + tdb->log_fn = log_fn?log_fn:null_log_fn; + 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; + } + + if ((open_flags & O_ACCMODE) == O_WRONLY) { + TDB_LOG((tdb, 0, "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, 0, "tdb_open_ex: tdb_new_database failed!")); + goto fail; + } + goto internal; + } + + if ((tdb->fd = open(name, open_flags, mode)) == -1) { + TDB_LOG((tdb, 5, "tdb_open_ex: could not open file %s: %s\n", + name, strerror(errno))); + goto fail; /* errno set by open(2) */ + } + + /* ensure there is only one process initialising at once */ + if (tdb->methods->tdb_brlock(tdb, GLOBAL_LOCK, F_WRLCK, F_SETLKW, 0) == -1) { + TDB_LOG((tdb, 0, "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) && + (locked = (tdb->methods->tdb_brlock(tdb, ACTIVE_LOCK, F_WRLCK, F_SETLK, 0) == 0))) { + open_flags |= O_CREAT; + if (ftruncate(tdb->fd, 0) == -1) { + TDB_LOG((tdb, 0, "tdb_open_ex: " + "failed to truncate %s: %s\n", + name, strerror(errno))); + goto fail; /* errno set by ftruncate */ + } + } + + 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) { + errno = EIO; /* ie bad format or something */ + goto fail; + } + rev = (tdb->flags & TDB_CONVERT); + } + vp = (unsigned char *)&tdb->header.version; + vertest = (((u32)vp[0]) << 24) | (((u32)vp[1]) << 16) | + (((u32)vp[2]) << 8) | (u32)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, 5, "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, 2, "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->locked = calloc(tdb->header.hash_size+1, sizeof(tdb->locked[0])); + if (!tdb->locked) { + TDB_LOG((tdb, 2, "tdb_open_ex: " + "failed to allocate lock structure for %s\n", + name)); + errno = ENOMEM; + goto fail; + } + tdb_mmap(tdb); + if (locked) { + if (tdb->methods->tdb_brlock(tdb, ACTIVE_LOCK, F_UNLCK, F_SETLK, 0) == -1) { + TDB_LOG((tdb, 0, "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) + 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) + 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, 5, "tdb_open_ex: failed to close tdb->fd on error!\n")); + SAFE_FREE(tdb->locked); + SAFE_FREE(tdb); + errno = save_errno; + return NULL; + } +} + +/** + * 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->locked); + + /* 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_logging_function(struct tdb_context *tdb, void (*fn)(struct tdb_context *, int , const char *, ...)) +{ + tdb->log_fn = fn?fn:null_log_fn; +} + + +/* 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_LOG((tdb, 0, "tdb_reopen: reopen not allowed with locks held\n")); + goto fail; + } + + if (tdb->transaction != 0) { + TDB_LOG((tdb, 0, "tdb_reopen: reopen not allowed inside a transaction\n")); + goto fail; + } + + if (tdb_munmap(tdb) != 0) { + TDB_LOG((tdb, 0, "tdb_reopen: munmap failed (%s)\n", strerror(errno))); + goto fail; + } + if (close(tdb->fd) != 0) + TDB_LOG((tdb, 0, "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, 0, "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)) { + TDB_LOG((tdb, 0, "tdb_reopen: failed to obtain active lock\n")); + goto fail; + } + if (fstat(tdb->fd, &st) != 0) { + TDB_LOG((tdb, 0, "tdb_reopen: fstat failed (%s)\n", strerror(errno))); + goto fail; + } + if (st.st_ino != tdb->inode || st.st_dev != tdb->device) { + TDB_LOG((tdb, 0, "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/source3/tdb/spinlock.c b/source3/tdb/spinlock.c deleted file mode 100644 index e42a6901c7..0000000000 --- a/source3/tdb/spinlock.c +++ /dev/null @@ -1,472 +0,0 @@ -/* - Unix SMB/CIFS implementation. - - trivial database library - - Copyright (C) Anton Blanchard 2001 - - ** 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 2 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, write to the Free Software - Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA -*/ -#if HAVE_CONFIG_H -#include <config.h> -#endif - -#ifdef STANDALONE -#include <stdlib.h> -#include <stdio.h> -#include <unistd.h> -#include <string.h> -#include <fcntl.h> -#include <errno.h> -#include <sys/stat.h> -#include <time.h> -#include <signal.h> -#include "tdb.h" -#include "spinlock.h" - -#define DEBUG -#else -#include "includes.h" -#endif - -#ifdef USE_SPINLOCKS - -/* - * ARCH SPECIFIC - */ - -#if defined(SPARC_SPINLOCKS) - -static inline int __spin_trylock(spinlock_t *lock) -{ - unsigned int result; - - asm volatile("ldstub [%1], %0" - : "=r" (result) - : "r" (lock) - : "memory"); - - return (result == 0) ? 0 : EBUSY; -} - -static inline void __spin_unlock(spinlock_t *lock) -{ - asm volatile("":::"memory"); - *lock = 0; -} - -static inline void __spin_lock_init(spinlock_t *lock) -{ - *lock = 0; -} - -static inline int __spin_is_locked(spinlock_t *lock) -{ - return (*lock != 0); -} - -#elif defined(POWERPC_SPINLOCKS) - -static inline int __spin_trylock(spinlock_t *lock) -{ - unsigned int result; - - __asm__ __volatile__( -"1: lwarx %0,0,%1\n\ - cmpwi 0,%0,0\n\ - li %0,0\n\ - bne- 2f\n\ - li %0,1\n\ - stwcx. %0,0,%1\n\ - bne- 1b\n\ - isync\n\ -2:" : "=&r"(result) - : "r"(lock) - : "cr0", "memory"); - - return (result == 1) ? 0 : EBUSY; -} - -static inline void __spin_unlock(spinlock_t *lock) -{ - asm volatile("eieio":::"memory"); - *lock = 0; -} - -static inline void __spin_lock_init(spinlock_t *lock) -{ - *lock = 0; -} - -static inline int __spin_is_locked(spinlock_t *lock) -{ - return (*lock != 0); -} - -#elif defined(INTEL_SPINLOCKS) - -static inline int __spin_trylock(spinlock_t *lock) -{ - int oldval; - - asm volatile("xchgl %0,%1" - : "=r" (oldval), "=m" (*lock) - : "0" (0) - : "memory"); - - return oldval > 0 ? 0 : EBUSY; -} - -static inline void __spin_unlock(spinlock_t *lock) -{ - asm volatile("":::"memory"); - *lock = 1; -} - -static inline void __spin_lock_init(spinlock_t *lock) -{ - *lock = 1; -} - -static inline int __spin_is_locked(spinlock_t *lock) -{ - return (*lock != 1); -} - -#elif defined(MIPS_SPINLOCKS) && defined(sgi) && (_COMPILER_VERSION >= 730) - -/* Implement spinlocks on IRIX using the MIPSPro atomic fetch operations. See - * sync(3) for the details of the intrinsic operations. - * - * "sgi" and "_COMPILER_VERSION" are always defined by MIPSPro. - */ - -#ifdef STANDALONE - -/* MIPSPro 7.3 has "__inline" as an extension, but not "inline. */ -#define inline __inline - -#endif /* STANDALONE */ - -/* Returns 0 if the lock is acquired, EBUSY otherwise. */ -static inline int __spin_trylock(spinlock_t *lock) -{ - unsigned int val; - val = __lock_test_and_set(lock, 1); - return val == 0 ? 0 : EBUSY; -} - -static inline void __spin_unlock(spinlock_t *lock) -{ - __lock_release(lock); -} - -static inline void __spin_lock_init(spinlock_t *lock) -{ - __lock_release(lock); -} - -/* Returns 1 if the lock is held, 0 otherwise. */ -static inline int __spin_is_locked(spinlock_t *lock) -{ - unsigned int val; - val = __add_and_fetch(lock, 0); - return val; -} - -#elif defined(MIPS_SPINLOCKS) - -static inline unsigned int load_linked(unsigned long addr) -{ - unsigned int res; - - __asm__ __volatile__("ll\t%0,(%1)" - : "=r" (res) - : "r" (addr)); - - return res; -} - -static inline unsigned int store_conditional(unsigned long addr, unsigned int value) -{ - unsigned int res; - - __asm__ __volatile__("sc\t%0,(%2)" - : "=r" (res) - : "0" (value), "r" (addr)); - return res; -} - -static inline int __spin_trylock(spinlock_t *lock) -{ - unsigned int mw; - - do { - mw = load_linked(lock); - if (mw) - return EBUSY; - } while (!store_conditional(lock, 1)); - - asm volatile("":::"memory"); - - return 0; -} - -static inline void __spin_unlock(spinlock_t *lock) -{ - asm volatile("":::"memory"); - *lock = 0; -} - -static inline void __spin_lock_init(spinlock_t *lock) -{ - *lock = 0; -} - -static inline int __spin_is_locked(spinlock_t *lock) -{ - return (*lock != 0); -} - -#else -#error Need to implement spinlock code in spinlock.c -#endif - -/* - * OS SPECIFIC - */ - -static void yield_cpu(void) -{ - struct timespec tm; - -#ifdef USE_SCHED_YIELD - sched_yield(); -#else - /* Linux will busy loop for delays < 2ms on real time tasks */ - tm.tv_sec = 0; - tm.tv_nsec = 2000000L + 1; - nanosleep(&tm, NULL); -#endif -} - -/* - * GENERIC - */ - -static int smp_machine = 0; - -static inline void __spin_lock(spinlock_t *lock) -{ - int ntries = 0; - - while(__spin_trylock(lock)) { - while(__spin_is_locked(lock)) { - if (smp_machine && ntries++ < MAX_BUSY_LOOPS) - continue; - yield_cpu(); - } - } -} - -static void __read_lock(tdb_rwlock_t *rwlock) -{ - int ntries = 0; - - while(1) { - __spin_lock(&rwlock->lock); - - if (!(rwlock->count & RWLOCK_BIAS)) { - rwlock->count++; - __spin_unlock(&rwlock->lock); - return; - } - - __spin_unlock(&rwlock->lock); - - while(rwlock->count & RWLOCK_BIAS) { - if (smp_machine && ntries++ < MAX_BUSY_LOOPS) - continue; - yield_cpu(); - } - } -} - -static void __write_lock(tdb_rwlock_t *rwlock) -{ - int ntries = 0; - - while(1) { - __spin_lock(&rwlock->lock); - - if (rwlock->count == 0) { - rwlock->count |= RWLOCK_BIAS; - __spin_unlock(&rwlock->lock); - return; - } - - __spin_unlock(&rwlock->lock); - - while(rwlock->count != 0) { - if (smp_machine && ntries++ < MAX_BUSY_LOOPS) - continue; - yield_cpu(); - } - } -} - -static void __write_unlock(tdb_rwlock_t *rwlock) -{ - __spin_lock(&rwlock->lock); - -#ifdef DEBUG - if (!(rwlock->count & RWLOCK_BIAS)) - fprintf(stderr, "bug: write_unlock\n"); -#endif - - rwlock->count &= ~RWLOCK_BIAS; - __spin_unlock(&rwlock->lock); -} - -static void __read_unlock(tdb_rwlock_t *rwlock) -{ - __spin_lock(&rwlock->lock); - -#ifdef DEBUG - if (!rwlock->count) - fprintf(stderr, "bug: read_unlock\n"); - - if (rwlock->count & RWLOCK_BIAS) - fprintf(stderr, "bug: read_unlock\n"); -#endif - - rwlock->count--; - __spin_unlock(&rwlock->lock); -} - -/* TDB SPECIFIC */ - -/* lock a list in the database. list -1 is the alloc list */ -int tdb_spinlock(TDB_CONTEXT *tdb, int list, int rw_type) -{ - tdb_rwlock_t *rwlocks; - - if (!tdb->map_ptr) return -1; - rwlocks = (tdb_rwlock_t *)((char *)tdb->map_ptr + tdb->header.rwlocks); - - switch(rw_type) { - case F_RDLCK: - __read_lock(&rwlocks[list+1]); - break; - - case F_WRLCK: - __write_lock(&rwlocks[list+1]); - break; - - default: - return TDB_ERRCODE(TDB_ERR_LOCK, -1); - } - return 0; -} - -/* unlock the database. */ -int tdb_spinunlock(TDB_CONTEXT *tdb, int list, int rw_type) -{ - tdb_rwlock_t *rwlocks; - - if (!tdb->map_ptr) return -1; - rwlocks = (tdb_rwlock_t *)((char *)tdb->map_ptr + tdb->header.rwlocks); - - switch(rw_type) { - case F_RDLCK: - __read_unlock(&rwlocks[list+1]); - break; - - case F_WRLCK: - __write_unlock(&rwlocks[list+1]); - break; - - default: - return TDB_ERRCODE(TDB_ERR_LOCK, -1); - } - - return 0; -} - -int tdb_create_rwlocks(int fd, unsigned int hash_size) -{ - unsigned size, i; - tdb_rwlock_t *rwlocks; - - size = TDB_SPINLOCK_SIZE(hash_size); - rwlocks = malloc(size); - if (!rwlocks) - return -1; - - for(i = 0; i < hash_size+1; i++) { - __spin_lock_init(&rwlocks[i].lock); - rwlocks[i].count = 0; - } - - /* Write it out (appending to end) */ - if (write(fd, rwlocks, size) != size) { - free(rwlocks); - return -1; - } - smp_machine = this_is_smp(); - free(rwlocks); - return 0; -} - -int tdb_clear_spinlocks(TDB_CONTEXT *tdb) -{ - tdb_rwlock_t *rwlocks; - unsigned i; - - if (tdb->header.rwlocks == 0) return 0; - if (!tdb->map_ptr) return -1; - - /* We're mmapped here */ - rwlocks = (tdb_rwlock_t *)((char *)tdb->map_ptr + tdb->header.rwlocks); - for(i = 0; i < tdb->header.hash_size+1; i++) { - __spin_lock_init(&rwlocks[i].lock); - rwlocks[i].count = 0; - } - return 0; -} -#else -int tdb_create_rwlocks(int fd, unsigned int hash_size) { return 0; } -int tdb_spinlock(TDB_CONTEXT *tdb, int list, int rw_type) { return -1; } -int tdb_spinunlock(TDB_CONTEXT *tdb, int list, int rw_type) { return -1; } - -/* Non-spinlock version: remove spinlock pointer */ -int tdb_clear_spinlocks(TDB_CONTEXT *tdb) -{ - tdb_off off = (tdb_off)((char *)&tdb->header.rwlocks - - (char *)&tdb->header); - - tdb->header.rwlocks = 0; - if (lseek(tdb->fd, off, SEEK_SET) != off - || write(tdb->fd, (void *)&tdb->header.rwlocks, - sizeof(tdb->header.rwlocks)) - != sizeof(tdb->header.rwlocks)) - return -1; - return 0; -} -#endif diff --git a/source3/tdb/spinlock.h b/source3/tdb/spinlock.h deleted file mode 100644 index 967fe37457..0000000000 --- a/source3/tdb/spinlock.h +++ /dev/null @@ -1,59 +0,0 @@ -#ifndef __SPINLOCK_H__ -#define __SPINLOCK_H__ - -#ifdef HAVE_CONFIG_H -#include <config.h> -#endif - -#include "tdb.h" - -#ifdef USE_SPINLOCKS - -#define RWLOCK_BIAS 0x1000UL - -/* OS SPECIFIC */ -#define MAX_BUSY_LOOPS 1000 -#undef USE_SCHED_YIELD - -/* ARCH SPECIFIC */ -/* We should make sure these are padded to a cache line */ -#if defined(SPARC_SPINLOCKS) -typedef volatile char spinlock_t; -#elif defined(POWERPC_SPINLOCKS) -typedef volatile unsigned long spinlock_t; -#elif defined(INTEL_SPINLOCKS) -typedef volatile int spinlock_t; -#elif defined(MIPS_SPINLOCKS) -typedef volatile unsigned long spinlock_t; -#else -#error Need to implement spinlock code in spinlock.h -#endif - -typedef struct { - spinlock_t lock; - volatile int count; -} tdb_rwlock_t; - -int tdb_spinlock(TDB_CONTEXT *tdb, int list, int rw_type); -int tdb_spinunlock(TDB_CONTEXT *tdb, int list, int rw_type); -int tdb_create_rwlocks(int fd, unsigned int hash_size); -int tdb_clear_spinlocks(TDB_CONTEXT *tdb); - -#define TDB_SPINLOCK_SIZE(hash_size) (((hash_size) + 1) * sizeof(tdb_rwlock_t)) - -#else /* !USE_SPINLOCKS */ -#if 0 -#define tdb_create_rwlocks(fd, hash_size) 0 -#define tdb_spinlock(tdb, list, rw_type) (-1) -#define tdb_spinunlock(tdb, list, rw_type) (-1) -#else -int tdb_spinlock(TDB_CONTEXT *tdb, int list, int rw_type); -int tdb_spinunlock(TDB_CONTEXT *tdb, int list, int rw_type); -int tdb_create_rwlocks(int fd, unsigned int hash_size); -#endif -int tdb_clear_spinlocks(TDB_CONTEXT *tdb); -#define TDB_SPINLOCK_SIZE(hash_size) 0 - -#endif - -#endif diff --git a/source3/tdb/tdb.c b/source3/tdb/tdb.c index ad73a1d9aa..1fae6b6de1 100644 --- a/source3/tdb/tdb.c +++ b/source3/tdb/tdb.c @@ -3,7 +3,7 @@ trivial database library - Copyright (C) Andrew Tridgell 1999-2004 + Copyright (C) Andrew Tridgell 1999-2005 Copyright (C) Paul `Rusty' Russell 2000 Copyright (C) Jeremy Allison 2000-2003 @@ -20,1004 +20,57 @@ 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, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ +#include "tdb_private.h" -/* NOTE: If you use tdbs under valgrind, and in particular if you run - * tdbtorture, you may get spurious "uninitialized value" warnings. I - * think this is because valgrind doesn't understand that the mmap'd - * area may be written to by other processes. Memory can, from the - * point of view of the grinded process, spontaneously become - * initialized. - * - * I can think of a few solutions. [mbp 20030311] - * - * 1 - Write suppressions for Valgrind so that it doesn't complain - * about this. Probably the most reasonable but people need to - * remember to use them. - * - * 2 - Use IO not mmap when running under valgrind. Not so nice. - * - * 3 - Use the special valgrind macros to mark memory as valid at the - * right time. Probably too hard -- the process just doesn't know. - */ - -#ifdef STANDALONE -#if HAVE_CONFIG_H -#include <config.h> -#endif - -#include <stdlib.h> -#include <stdio.h> -#include <fcntl.h> -#include <unistd.h> -#include <string.h> -#include <fcntl.h> -#include <errno.h> -#include <sys/mman.h> -#include <sys/stat.h> -#include <signal.h> -#include "tdb.h" -#include "spinlock.h" -#else -#include "includes.h" - -#if defined(PARANOID_MALLOC_CHECKER) -#ifdef malloc -#undef malloc -#endif - -#ifdef realloc -#undef realloc -#endif - -#ifdef calloc -#undef calloc -#endif - -#ifdef strdup -#undef strdup -#endif - -#ifdef strndup -#undef strndup -#endif - -#endif - -#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_ALIGNMENT 4 -#define MIN_REC_SIZE (2*sizeof(struct list_struct) + TDB_ALIGNMENT) -#define DEFAULT_HASH_SIZE 131 -#define TDB_PAGE_SIZE 0x2000 -#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)) -#define TDB_DATA_START(hash_size) (TDB_HASH_TOP(hash_size-1) + TDB_SPINLOCK_SIZE(hash_size)) - - -/* 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_fn?((tdb->log_fn x),0) : 0) - -/* lock offsets */ -#define GLOBAL_LOCK 0 -#define ACTIVE_LOCK 4 - -#ifndef MAP_FILE -#define MAP_FILE 0 -#endif - -#ifndef MAP_FAILED -#define MAP_FAILED ((void *)-1) -#endif - -/* 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) TDB_DATA tdb_null; -/* all contexts, to ensure no double-opens (fcntl locks don't nest!) */ -static TDB_CONTEXT *tdbs = NULL; - -static int tdb_munmap(TDB_CONTEXT *tdb) +/* + 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_INTERNAL) - return 0; - -#ifdef HAVE_MMAP - if (tdb->map_ptr) { - int ret = munmap(tdb->map_ptr, tdb->map_size); - if (ret != 0) - return ret; + tdb_off_t seqnum=0; + + if (!(tdb->flags & TDB_SEQNUM)) { + return; } -#endif - tdb->map_ptr = NULL; - return 0; -} -static void tdb_mmap(TDB_CONTEXT *tdb) -{ - if (tdb->flags & TDB_INTERNAL) + if (tdb_brlock(tdb, TDB_SEQNUM_OFS, F_WRLCK, F_SETLKW, 1) != 0) { 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, 2, "tdb_mmap failed for size %d (%s)\n", - tdb->map_size, strerror(errno))); - } - } else { - tdb->map_ptr = NULL; } -#else - tdb->map_ptr = NULL; -#endif -} -/* Endian conversion: we only ever deal with 4 byte quantities */ -static void *convert(void *buf, u32 size) -{ - u32 i, *p = buf; - for (i = 0; i < size / 4; i++) - p[i] = TDB_BYTEREV(p[i]); - return buf; -} -#define DOCONV() (tdb->flags & TDB_CONVERT) -#define CONVERT(x) (DOCONV() ? 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 next; /* offset of the next record in the list */ - tdb_len rec_len; /* total byte length of record */ - tdb_len key_len; /* byte length of key */ - tdb_len data_len; /* byte length of data */ - u32 full_hash; /* the full 32 bit hash of the key */ - u32 magic; /* try to catch errors */ - /* the following union is implied: - union { - char record[rec_len]; - struct { - char key[key_len]; - char data[data_len]; - } - u32 totalsize; (tailer) - } + /* we ignore errors from this, as we have no sane way of + dealing with them. */ -}; - -/*************************************************************** - Allow a caller to set a "alarm" flag that tdb can check to abort - a blocking lock on SIGALRM. -***************************************************************/ - -static sig_atomic_t *palarm_fired; - -void tdb_set_lock_alarm(sig_atomic_t *palarm) -{ - palarm_fired = palarm; -} - -/* 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(). */ -static int tdb_brlock(TDB_CONTEXT *tdb, tdb_off offset, - int rw_type, int lck_type, int probe) -{ - struct flock fl; - int ret; - - if (tdb->flags & TDB_NOLOCK) - return 0; - if ((rw_type == F_WRLCK) && (tdb->read_only)) { - errno = EACCES; - return -1; - } - - fl.l_type = rw_type; - fl.l_whence = SEEK_SET; - fl.l_start = offset; - fl.l_len = 1; - fl.l_pid = 0; - - do { - ret = fcntl(tdb->fd,lck_type,&fl); - if (ret == -1 && errno == EINTR && palarm_fired && *palarm_fired) - break; - } while (ret == -1 && errno == EINTR); - - if (ret == -1) { - if (!probe && lck_type != F_SETLK) { - /* Ensure error code is set for log fun to examine. */ - if (errno == EINTR && palarm_fired && *palarm_fired) - tdb->ecode = TDB_ERR_LOCK_TIMEOUT; - else - tdb->ecode = TDB_ERR_LOCK; - TDB_LOG((tdb, 5,"tdb_brlock failed (fd=%d) at offset %d rw_type=%d lck_type=%d\n", - tdb->fd, offset, rw_type, lck_type)); - } - /* Was it an alarm timeout ? */ - if (errno == EINTR && palarm_fired && *palarm_fired) { - TDB_LOG((tdb, 5, "tdb_brlock timed out (fd=%d) at offset %d rw_type=%d lck_type=%d\n", - tdb->fd, offset, rw_type, lck_type)); - return TDB_ERRCODE(TDB_ERR_LOCK_TIMEOUT, -1); - } - /* Otherwise - generic lock error. errno set by fcntl. - * EAGAIN is an expected return from non-blocking - * locks. */ - if (errno != EAGAIN) { - TDB_LOG((tdb, 5, "tdb_brlock failed (fd=%d) at offset %d rw_type=%d lck_type=%d: %s\n", - tdb->fd, offset, rw_type, lck_type, - strerror(errno))); - } - return TDB_ERRCODE(TDB_ERR_LOCK, -1); - } - return 0; -} - -/* lock a list in the database. list -1 is the alloc list */ -static int tdb_lock(TDB_CONTEXT *tdb, int list, int ltype) -{ - if (list < -1 || list >= (int)tdb->header.hash_size) { - TDB_LOG((tdb, 0,"tdb_lock: invalid list %d for ltype=%d\n", - list, ltype)); - return -1; - } - if (tdb->flags & TDB_NOLOCK) - return 0; - - /* Since fcntl locks don't nest, we do a lock for the first one, - and simply bump the count for future ones */ - if (tdb->locked[list+1].count == 0) { - if (!tdb->read_only && tdb->header.rwlocks) { - if (tdb_spinlock(tdb, list, ltype)) { - TDB_LOG((tdb, 0, "tdb_lock spinlock failed on list %d ltype=%d\n", - list, ltype)); - return -1; - } - } else if (tdb_brlock(tdb,FREELIST_TOP+4*list,ltype,F_SETLKW, 0)) { - TDB_LOG((tdb, 0,"tdb_lock failed on list %d ltype=%d (%s)\n", - list, ltype, strerror(errno))); - return -1; - } - tdb->locked[list+1].ltype = ltype; - } - tdb->locked[list+1].count++; - return 0; -} - -/* 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 */ -static int tdb_unlock(TDB_CONTEXT *tdb, int list, int ltype) -{ - int ret = -1; - - if (tdb->flags & TDB_NOLOCK) - return 0; - - /* Sanity checks */ - if (list < -1 || list >= (int)tdb->header.hash_size) { - TDB_LOG((tdb, 0, "tdb_unlock: list %d invalid (%d)\n", list, tdb->header.hash_size)); - return ret; - } - - if (tdb->locked[list+1].count==0) { - TDB_LOG((tdb, 0, "tdb_unlock: count is 0\n")); - return ret; - } - - if (tdb->locked[list+1].count == 1) { - /* Down to last nested lock: unlock underneath */ - if (!tdb->read_only && tdb->header.rwlocks) { - ret = tdb_spinunlock(tdb, list, ltype); - } else { - ret = tdb_brlock(tdb, FREELIST_TOP+4*list, F_UNLCK, F_SETLKW, 0); - } - } else { - ret = 0; - } - tdb->locked[list+1].count--; - - if (ret) - TDB_LOG((tdb, 0,"tdb_unlock: An error occurred unlocking!\n")); - return ret; -} - -/* 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(TDB_CONTEXT *tdb, tdb_off 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, 0,"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, 0,"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(TDB_CONTEXT *tdb, tdb_off off, void *buf, tdb_len len) -{ - if (tdb_oob(tdb, off + len, 0) != 0) - return -1; - - if (tdb->map_ptr) - memcpy(off + (char *)tdb->map_ptr, buf, len); -#ifdef HAVE_PWRITE - else if (pwrite(tdb->fd, buf, len, off) != (ssize_t)len) { -#else - else if (lseek(tdb->fd, off, SEEK_SET) != off - || write(tdb->fd, buf, len) != (ssize_t)len) { -#endif - /* Ensure ecode is set for log fn. */ - tdb->ecode = TDB_ERR_IO; - TDB_LOG((tdb, 0,"tdb_write failed at %d len=%d (%s)\n", - off, len, strerror(errno))); - return TDB_ERRCODE(TDB_ERR_IO, -1); - } - return 0; -} - -/* read a lump of data at a specified offset, maybe convert */ -static int tdb_read(TDB_CONTEXT *tdb,tdb_off off,void *buf,tdb_len len,int cv) -{ - if (tdb_oob(tdb, off + len, 0) != 0) - return -1; - - if (tdb->map_ptr) - memcpy(buf, off + (char *)tdb->map_ptr, len); -#ifdef HAVE_PREAD - else if (pread(tdb->fd, buf, len, off) != (ssize_t)len) { -#else - else if (lseek(tdb->fd, off, SEEK_SET) != off - || read(tdb->fd, buf, len) != (ssize_t)len) { -#endif - /* Ensure ecode is set for log fn. */ - tdb->ecode = TDB_ERR_IO; - TDB_LOG((tdb, 0,"tdb_read failed at %d len=%d (%s)\n", - off, len, strerror(errno))); - return TDB_ERRCODE(TDB_ERR_IO, -1); - } - if (cv) - convert(buf, len); - return 0; -} - -/* read a lump of data, allocating the space for it */ -static char *tdb_alloc_read(TDB_CONTEXT *tdb, tdb_off offset, tdb_len len) -{ - char *buf; + tdb_ofs_read(tdb, TDB_SEQNUM_OFS, &seqnum); + seqnum++; + tdb_ofs_write(tdb, TDB_SEQNUM_OFS, &seqnum); - if (!(buf = malloc(len))) { - /* Ensure ecode is set for log fn. */ - tdb->ecode = TDB_ERR_OOM; - TDB_LOG((tdb, 0,"tdb_alloc_read malloc failed len=%d (%s)\n", - len, strerror(errno))); - return TDB_ERRCODE(TDB_ERR_OOM, buf); - } - if (tdb_read(tdb, offset, buf, len, 0) == -1) { - SAFE_FREE(buf); - return NULL; - } - return buf; -} - -/* read/write a tdb_off */ -static int ofs_read(TDB_CONTEXT *tdb, tdb_off offset, tdb_off *d) -{ - return tdb_read(tdb, offset, (char*)d, sizeof(*d), DOCONV()); -} -static int ofs_write(TDB_CONTEXT *tdb, tdb_off offset, tdb_off *d) -{ - tdb_off off = *d; - return tdb_write(tdb, offset, CONVERT(off), sizeof(*d)); + tdb_brlock(tdb, TDB_SEQNUM_OFS, F_UNLCK, F_SETLKW, 1); } -/* read/write a record */ -static int rec_read(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec) -{ - if (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, 0,"rec_read bad magic 0x%x at offset=%d\n", rec->magic, offset)); - return TDB_ERRCODE(TDB_ERR_CORRUPT, -1); - } - return tdb_oob(tdb, rec->next+sizeof(*rec), 0); -} -static int rec_write(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec) -{ - struct list_struct r = *rec; - return tdb_write(tdb, offset, CONVERT(r), sizeof(r)); -} - -/* read a freelist record and check for simple errors */ -static int rec_free_read(TDB_CONTEXT *tdb, tdb_off off, struct list_struct *rec) -{ - if (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, 0,"rec_free_read non-free magic 0x%x at offset=%d - fixing\n", - rec->magic, off)); - rec->magic = TDB_FREE_MAGIC; - if (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, 0,"rec_free_read bad magic 0x%x at offset=%d\n", - rec->magic, off)); - return TDB_ERRCODE(TDB_ERR_CORRUPT, -1); - } - if (tdb_oob(tdb, rec->next+sizeof(*rec), 0) != 0) - return -1; - return 0; -} - -/* update a record tailer (must hold allocation lock) */ -static int update_tailer(TDB_CONTEXT *tdb, tdb_off offset, - const struct list_struct *rec) -{ - tdb_off totalsize; - - /* Offset of tailer from record header */ - totalsize = sizeof(*rec) + rec->rec_len; - return ofs_write(tdb, offset + totalsize - sizeof(tdb_off), - &totalsize); -} - -static tdb_off tdb_dump_record(TDB_CONTEXT *tdb, tdb_off offset) -{ - struct list_struct rec; - tdb_off tailer_ofs, tailer; - - if (tdb_read(tdb, offset, (char *)&rec, sizeof(rec), DOCONV()) == -1) { - printf("ERROR: failed to read record at %u\n", offset); - return 0; - } - - printf(" rec: offset=%u next=%d rec_len=%d key_len=%d data_len=%d full_hash=0x%x magic=0x%x\n", - 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); - if (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)tailer, (unsigned)(rec.rec_len + sizeof(rec))); - } - return rec.next; -} - -static int tdb_dump_chain(TDB_CONTEXT *tdb, int i) -{ - tdb_off rec_ptr, top; - int hash_length = 0; - - top = TDB_HASH_TOP(i); - - if (tdb_lock(tdb, i, F_WRLCK) != 0) - return -1; - - if (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, rec_ptr); - hash_length += 1; - } - - printf("chain %d length %d\n", i, hash_length); - - return tdb_unlock(tdb, i, F_WRLCK); -} - -void tdb_dump_all(TDB_CONTEXT *tdb) -{ - int i; - for (i=0;i<tdb->header.hash_size;i++) { - tdb_dump_chain(tdb, i); - } - tdb_printfreelist(tdb); -} - -int tdb_printfreelist(TDB_CONTEXT *tdb) -{ - int ret; - long total_free = 0; - tdb_off 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 (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_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)]\n", rec.next, rec.rec_len, 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); -} - -/* Remove an element from the freelist. Must have alloc lock. */ -static int remove_from_freelist(TDB_CONTEXT *tdb, tdb_off off, tdb_off next) -{ - tdb_off last_ptr, i; - - /* read in the freelist top */ - last_ptr = FREELIST_TOP; - while (ofs_read(tdb, last_ptr, &i) != -1 && i != 0) { - if (i == off) { - /* We've found it! */ - return ofs_write(tdb, last_ptr, &next); - } - /* Follow chain (next offset is at start of record) */ - last_ptr = i; - } - TDB_LOG((tdb, 0,"remove_from_freelist: not on list at off=%d\n", off)); - return TDB_ERRCODE(TDB_ERR_CORRUPT, -1); -} - -/* Add an element into the freelist. Merge adjacent records if - neccessary. */ -static int tdb_free(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec) -{ - tdb_off right, left; - - /* 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, 0, "tdb_free: upfate_tailer failed!\n")); - goto fail; - } - - /* Look right first (I'm an Australian, dammit) */ - right = offset + sizeof(*rec) + rec->rec_len; - if (right + sizeof(*rec) <= tdb->map_size) { - struct list_struct r; - - if (tdb_read(tdb, right, &r, sizeof(r), DOCONV()) == -1) { - TDB_LOG((tdb, 0, "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, 0, "tdb_free: right free failed at %u\n", right)); - goto left; - } - rec->rec_len += sizeof(r) + r.rec_len; - } - } - -left: - /* Look left */ - left = offset - sizeof(tdb_off); - if (left > TDB_DATA_START(tdb->header.hash_size)) { - struct list_struct l; - tdb_off leftsize; - - /* Read in tailer and jump back to header */ - if (ofs_read(tdb, left, &leftsize) == -1) { - TDB_LOG((tdb, 0, "tdb_free: left offset read failed at %u\n", left)); - goto update; - } - left = offset - leftsize; - - /* Now read in record */ - if (tdb_read(tdb, left, &l, sizeof(l), DOCONV()) == -1) { - TDB_LOG((tdb, 0, "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) { - if (remove_from_freelist(tdb, left, l.next) == -1) { - TDB_LOG((tdb, 0, "tdb_free: left free failed at %u\n", left)); - goto update; - } else { - offset = left; - rec->rec_len += leftsize; - } - } - } - -update: - if (update_tailer(tdb, offset, rec) == -1) { - TDB_LOG((tdb, 0, "tdb_free: update_tailer failed at %u\n", offset)); - goto fail; - } - - /* Now, prepend to free list */ - rec->magic = TDB_FREE_MAGIC; - - if (ofs_read(tdb, FREELIST_TOP, &rec->next) == -1 || - rec_write(tdb, offset, rec) == -1 || - ofs_write(tdb, FREELIST_TOP, &offset) == -1) { - TDB_LOG((tdb, 0, "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; -} - - -/* expand a file. we prefer to use ftruncate, as that is what posix - says to use for mmap expansion */ -static int expand_file(TDB_CONTEXT *tdb, tdb_off size, tdb_off addition) -{ - char buf[1024]; -#if HAVE_FTRUNCATE_EXTEND - if (ftruncate(tdb->fd, size+addition) != 0) { - TDB_LOG((tdb, 0, "expand_file ftruncate to %d failed (%s)\n", - size+addition, strerror(errno))); - return -1; - } -#else - char b = 0; - -#ifdef HAVE_PWRITE - if (pwrite(tdb->fd, &b, 1, (size+addition) - 1) != 1) { -#else - if (lseek(tdb->fd, (size+addition) - 1, SEEK_SET) != (size+addition) - 1 || - write(tdb->fd, &b, 1) != 1) { -#endif - TDB_LOG((tdb, 0, "expand_file to %d failed (%s)\n", - size+addition, strerror(errno))); - return -1; - } -#endif - - /* 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, 0x42, sizeof(buf)); - while (addition) { - int n = addition>sizeof(buf)?sizeof(buf):addition; -#ifdef HAVE_PWRITE - int ret = pwrite(tdb->fd, buf, n, size); -#else - int ret; - if (lseek(tdb->fd, size, SEEK_SET) != size) - return -1; - ret = write(tdb->fd, buf, n); -#endif - if (ret != n) { - TDB_LOG((tdb, 0, "expand_file write of %d failed (%s)\n", - n, strerror(errno))); - return -1; - } - addition -= n; - size += n; - } - return 0; -} - - -/* expand the database at least size bytes by expanding the underlying - file and doing the mmap again if necessary */ -static int tdb_expand(TDB_CONTEXT *tdb, tdb_off size) -{ - struct list_struct rec; - tdb_off offset; - - if (tdb_lock(tdb, -1, F_WRLCK) == -1) { - TDB_LOG((tdb, 0, "lock failed in tdb_expand\n")); - return -1; - } - - /* must know about any previous expansions by another process */ - tdb_oob(tdb, tdb->map_size + 1, 1); - - /* always make room for at least 10 more records, and round - the database up to a multiple of TDB_PAGE_SIZE */ - size = TDB_ALIGN(tdb->map_size + size*10, 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 (expand_file(tdb, tdb->map_size, size) != 0) - goto fail; - } - - tdb->map_size += size; - - if (tdb->flags & TDB_INTERNAL) { - char *new_map_ptr = 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; -} - -/* 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 - */ -static tdb_off tdb_allocate(TDB_CONTEXT *tdb, tdb_len length, - struct list_struct *rec) -{ - tdb_off rec_ptr, last_ptr, newrec_ptr; - struct list_struct newrec; - - memset(&newrec, '\0', sizeof(newrec)); - - if (tdb_lock(tdb, -1, F_WRLCK) == -1) - return 0; - - /* Extra bytes required for tailer */ - length += sizeof(tdb_off); - - again: - last_ptr = FREELIST_TOP; - - /* read in the freelist top */ - if (ofs_read(tdb, FREELIST_TOP, &rec_ptr) == -1) - goto fail; - - /* keep looking until we find a freelist record big enough */ - while (rec_ptr) { - if (rec_free_read(tdb, rec_ptr, rec) == -1) - goto fail; - - if (rec->rec_len >= length) { - /* found it - now possibly split it up */ - if (rec->rec_len > length + MIN_REC_SIZE) { - /* Length of left piece */ - length = TDB_ALIGN(length, TDB_ALIGNMENT); - - /* Right piece to go on free list */ - newrec.rec_len = rec->rec_len - - (sizeof(*rec) + length); - newrec_ptr = rec_ptr + sizeof(*rec) + length; - - /* And left record is shortened */ - rec->rec_len = length; - } else - newrec_ptr = 0; - - /* Remove allocated record from the free list */ - if (ofs_write(tdb, last_ptr, &rec->next) == -1) - goto fail; - - /* Update header: do this before we drop alloc - lock, otherwise tdb_free() might try to - merge with us, thinking we're free. - (Thanks Jeremy Allison). */ - rec->magic = TDB_MAGIC; - if (rec_write(tdb, rec_ptr, rec) == -1) - goto fail; - - /* Did we create new block? */ - if (newrec_ptr) { - /* Update allocated record tailer (we - shortened it). */ - if (update_tailer(tdb, rec_ptr, rec) == -1) - goto fail; - - /* Free new record */ - if (tdb_free(tdb, newrec_ptr, &newrec) == -1) - goto fail; - } - - /* all done - return the new record offset */ - tdb_unlock(tdb, -1, F_WRLCK); - return rec_ptr; - } - /* move to the next record */ - last_ptr = rec_ptr; - rec_ptr = rec->next; - } - /* 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; -} - -/* initialise a new database with a specified hash size */ -static int tdb_new_database(TDB_CONTEXT *tdb, int hash_size) -{ - struct tdb_header *newdb; - int size, ret = -1; - - /* We make it up in memory, then write it out if not internal */ - size = sizeof(struct tdb_header) + (hash_size+1)*sizeof(tdb_off); - if (!(newdb = calloc(size, 1))) - return TDB_ERRCODE(TDB_ERR_OOM, -1); - - /* Fill in the header */ - newdb->version = TDB_VERSION; - newdb->hash_size = hash_size; -#ifdef USE_SPINLOCKS - newdb->rwlocks = size; -#endif - 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); - if (write(tdb->fd, newdb, size) != size) - ret = -1; - else - ret = tdb_create_rwlocks(tdb->fd, hash_size); - - fail: - SAFE_FREE(newdb); - return ret; -} /* Returns 0 on fail. On success, return offset of record, and fills in rec */ -static tdb_off tdb_find(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash, +static tdb_off_t tdb_find(struct tdb_context *tdb, TDB_DATA key, u32 hash, struct list_struct *r) { - tdb_off rec_ptr; + tdb_off_t rec_ptr; /* read in the hash top */ - if (ofs_read(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) + 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 (rec_read(tdb, rec_ptr, r) == -1) + if (tdb_rec_read(tdb, rec_ptr, r) == -1) return 0; if (!TDB_DEAD(r) && hash==r->full_hash && key.dsize==r->key_len) { @@ -1040,8 +93,8 @@ static tdb_off tdb_find(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash, } /* As tdb_find, but if you succeed, keep the lock */ -static tdb_off tdb_find_lock_hash(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash, int locktype, - struct list_struct *rec) +tdb_off_t tdb_find_lock_hash(struct tdb_context *tdb, TDB_DATA key, u32 hash, int locktype, + struct list_struct *rec) { u32 rec_ptr; @@ -1052,60 +105,34 @@ static tdb_off tdb_find_lock_hash(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash, int return rec_ptr; } -enum TDB_ERROR tdb_error(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_NOEXIST, "Record does not exist"} }; - -/* Error string for the last tdb error */ -const char *tdb_errorstr(TDB_CONTEXT *tdb) -{ - u32 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"; -} /* 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(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash, TDB_DATA dbuf) +static int tdb_update_hash(struct tdb_context *tdb, TDB_DATA key, u32 hash, TDB_DATA dbuf) { struct list_struct rec; - tdb_off rec_ptr; + 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)) { + if (rec.rec_len < key.dsize + dbuf.dsize + sizeof(tdb_off_t)) { tdb->ecode = TDB_SUCCESS; /* Not really an error */ return -1; } - if (tdb_write(tdb, rec_ptr + sizeof(rec) + rec.key_len, + 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 rec_write(tdb, rec_ptr, &rec); + return tdb_rec_write(tdb, rec_ptr, &rec); } return 0; @@ -1114,13 +141,12 @@ static int tdb_update_hash(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash, TDB_DATA db /* 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 - * tdb_err will not be set. Both will return a - * zero pptr and zero dsize. + * then the TDB_DATA will have zero length but + * a non-zero pointer */ - -TDB_DATA tdb_fetch(TDB_CONTEXT *tdb, TDB_DATA key) +TDB_DATA tdb_fetch(struct tdb_context *tdb, TDB_DATA key) { - tdb_off rec_ptr; + tdb_off_t rec_ptr; struct list_struct rec; TDB_DATA ret; u32 hash; @@ -1130,11 +156,8 @@ TDB_DATA tdb_fetch(TDB_CONTEXT *tdb, TDB_DATA key) if (!(rec_ptr = tdb_find_lock_hash(tdb,key,hash,F_RDLCK,&rec))) return tdb_null; - if (rec.data_len) - ret.dptr = tdb_alloc_read(tdb, rec_ptr + sizeof(rec) + rec.key_len, - rec.data_len); - else - ret.dptr = 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; @@ -1146,7 +169,7 @@ TDB_DATA tdb_fetch(TDB_CONTEXT *tdb, TDB_DATA key) this doesn't match the conventions in the rest of this module, but is compatible with gdbm */ -static int tdb_exists_hash(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash) +static int tdb_exists_hash(struct tdb_context *tdb, TDB_DATA key, u32 hash) { struct list_struct rec; @@ -1156,82 +179,39 @@ static int tdb_exists_hash(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash) return 1; } -int tdb_exists(TDB_CONTEXT *tdb, TDB_DATA key) +int tdb_exists(struct tdb_context *tdb, TDB_DATA key) { u32 hash = tdb->hash_fn(&key); return tdb_exists_hash(tdb, key, hash); } -/* record lock stops delete underneath */ -static int lock_record(TDB_CONTEXT *tdb, tdb_off off) -{ - return off ? tdb_brlock(tdb, off, F_RDLCK, F_SETLKW, 0) : 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. -*/ - -static int write_lock_record(TDB_CONTEXT *tdb, tdb_off off) -{ - struct tdb_traverse_lock *i; - for (i = &tdb->travlocks; i; i = i->next) - if (i->off == off) - return -1; - return tdb_brlock(tdb, off, F_WRLCK, F_SETLK, 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. -*/ - -static int write_unlock_record(TDB_CONTEXT *tdb, tdb_off off) -{ - return tdb_brlock(tdb, off, F_UNLCK, F_SETLK, 0); -} -/* fcntl locks don't stack: avoid unlocking someone else's */ -static int unlock_record(TDB_CONTEXT *tdb, tdb_off off) -{ - struct tdb_traverse_lock *i; - u32 count = 0; - - if (off == 0) - return 0; - for (i = &tdb->travlocks; i; i = i->next) - if (i->off == off) - count++; - return (count == 1 ? tdb_brlock(tdb, off, F_UNLCK, F_SETLKW, 0) : 0); -} - /* actually delete an entry in the database given the offset */ -static int do_delete(TDB_CONTEXT *tdb, tdb_off rec_ptr, struct list_struct*rec) +int tdb_do_delete(struct tdb_context *tdb, tdb_off_t rec_ptr, struct list_struct*rec) { - tdb_off last_ptr, i; + tdb_off_t last_ptr, i; struct list_struct lastrec; - if (tdb->read_only) return -1; + if (tdb->read_only || tdb->traverse_read) return -1; - if (write_lock_record(tdb, rec_ptr) == -1) { + if (tdb_write_lock_record(tdb, rec_ptr) == -1) { /* Someone traversing here: mark it as dead */ rec->magic = TDB_DEAD_MAGIC; - return rec_write(tdb, rec_ptr, rec); + return tdb_rec_write(tdb, rec_ptr, rec); } - if (write_unlock_record(tdb, rec_ptr) != 0) + if (tdb_write_unlock_record(tdb, rec_ptr) != 0) return -1; /* find previous record in hash chain */ - if (ofs_read(tdb, TDB_HASH_TOP(rec->full_hash), &i) == -1) + 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 (rec_read(tdb, i, &lastrec) == -1) + 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 (ofs_write(tdb, last_ptr, &rec->next) == -1) + if (tdb_ofs_write(tdb, last_ptr, &rec->next) == -1) return -1; /* recover the space */ @@ -1240,283 +220,27 @@ static int do_delete(TDB_CONTEXT *tdb, tdb_off rec_ptr, struct list_struct*rec) return 0; } -/* Uses traverse lock: 0 = finish, -1 = error, other = record offset */ -static int tdb_next_lock(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++) { - - /* 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). - */ - if (!tlock->off && tlock->hash != 0) { - u32 off; - if (tdb->map_ptr) { - for (;tlock->hash < tdb->header.hash_size;tlock->hash++) { - if (0 != *(u32 *)(TDB_HASH_TOP(tlock->hash) + (unsigned char *)tdb->map_ptr)) { - break; - } - } - if (tlock->hash == tdb->header.hash_size) { - continue; - } - } else { - if (ofs_read(tdb, TDB_HASH_TOP(tlock->hash), &off) == 0 && - off == 0) { - continue; - } - } - } - - if (tdb_lock(tdb, tlock->hash, F_WRLCK) == -1) - return -1; - - /* No previous record? Start at top of chain. */ - if (!tlock->off) { - if (ofs_read(tdb, TDB_HASH_TOP(tlock->hash), - &tlock->off) == -1) - goto fail; - } else { - /* Otherwise unlock the previous record. */ - if (unlock_record(tdb, tlock->off) != 0) - goto fail; - } - - if (want_next) { - /* We have offset of old record: grab next */ - if (rec_read(tdb, tlock->off, rec) == -1) - goto fail; - tlock->off = rec->next; - } - - /* Iterate through chain */ - while( tlock->off) { - tdb_off current; - if (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, 0, "tdb_next_lock: loop detected.\n")); - goto fail; - } - - if (!TDB_DEAD(rec)) { - /* Woohoo: we found one! */ - if (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 && - do_delete(tdb, current, rec) != 0) - goto fail; - } - tdb_unlock(tdb, tlock->hash, F_WRLCK); - 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, F_WRLCK) != 0) - TDB_LOG((tdb, 0, "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 - */ -int tdb_traverse(TDB_CONTEXT *tdb, tdb_traverse_func fn, void *private_val) -{ - TDB_DATA key, dbuf; - struct list_struct rec; - struct tdb_traverse_lock tl = { NULL, 0, 0 }; - 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, F_WRLCK) != 0) - goto out; - if (unlock_record(tdb, tl.off) != 0) - TDB_LOG((tdb, 0, "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, F_WRLCK) != 0) { - ret = -1; - SAFE_FREE(key.dptr); - goto out; - } - if (fn && fn(tdb, key, dbuf, private_val)) { - /* They want us to terminate traversal */ - ret = count; - if (unlock_record(tdb, tl.off) != 0) { - TDB_LOG((tdb, 0, "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; -} - -/* find the first entry in the database and return its key */ -TDB_DATA tdb_firstkey(TDB_CONTEXT *tdb) -{ - TDB_DATA key; - struct list_struct rec; - - /* release any old lock */ - if (unlock_record(tdb, tdb->travlocks.off) != 0) - return tdb_null; - tdb->travlocks.off = tdb->travlocks.hash = 0; - - 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); - if (tdb_unlock(tdb, BUCKET(tdb->travlocks.hash), F_WRLCK) != 0) - TDB_LOG((tdb, 0, "tdb_firstkey: error occurred while tdb_unlocking!\n")); - return key; -} - -/* find the next entry in the database, returning its key */ -TDB_DATA tdb_nextkey(TDB_CONTEXT *tdb, TDB_DATA oldkey) -{ - u32 oldhash; - TDB_DATA key = tdb_null; - struct list_struct rec; - 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,F_WRLCK)) - return tdb_null; - if (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 (unlock_record(tdb, tdb->travlocks.off) != 0) { - SAFE_FREE(k); - return tdb_null; - } - if (tdb_unlock(tdb, tdb->travlocks.hash, F_WRLCK) != 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), F_WRLCK, &rec); - if (!tdb->travlocks.off) - return tdb_null; - tdb->travlocks.hash = BUCKET(rec.full_hash); - if (lock_record(tdb, tdb->travlocks.off) != 0) { - TDB_LOG((tdb, 0, "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, F_WRLCK) != 0) - TDB_LOG((tdb, 0, "tdb_nextkey: WARNING tdb_unlock failed!\n")); - } - /* Unlock the chain of old record */ - if (tdb_unlock(tdb, BUCKET(oldhash), F_WRLCK) != 0) - TDB_LOG((tdb, 0, "tdb_nextkey: WARNING tdb_unlock failed!\n")); - return key; -} - /* delete an entry in the database given a key */ -static int tdb_delete_hash(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash) +static int tdb_delete_hash(struct tdb_context *tdb, TDB_DATA key, u32 hash) { - tdb_off rec_ptr; + tdb_off_t rec_ptr; struct list_struct rec; int ret; if (!(rec_ptr = tdb_find_lock_hash(tdb, key, hash, F_WRLCK, &rec))) return -1; - ret = do_delete(tdb, rec_ptr, &rec); + 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, 0, "tdb_delete: WARNING tdb_unlock failed!\n")); return ret; } -int tdb_delete(TDB_CONTEXT *tdb, TDB_DATA key) +int tdb_delete(struct tdb_context *tdb, TDB_DATA key) { u32 hash = tdb->hash_fn(&key); return tdb_delete_hash(tdb, key, hash); @@ -1527,14 +251,19 @@ int tdb_delete(TDB_CONTEXT *tdb, TDB_DATA key) return 0 on success, -1 on failure */ -int tdb_store(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, int flag) +int tdb_store(struct tdb_context *tdb, TDB_DATA key, TDB_DATA dbuf, int flag) { struct list_struct rec; u32 hash; - tdb_off rec_ptr; + tdb_off_t rec_ptr; char *p = NULL; int ret = 0; + 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) @@ -1555,7 +284,7 @@ int tdb_store(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, int flag) /* 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; @@ -1583,7 +312,7 @@ int tdb_store(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, int flag) goto fail; /* Read hash top into next ptr */ - if (ofs_read(tdb, TDB_HASH_TOP(hash), &rec.next) == -1) + if (tdb_ofs_read(tdb, TDB_HASH_TOP(hash), &rec.next) == -1) goto fail; rec.key_len = key.dsize; @@ -1592,12 +321,15 @@ int tdb_store(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, int flag) rec.magic = TDB_MAGIC; /* write out and point the top of the hash chain at it */ - if (rec_write(tdb, rec_ptr, &rec) == -1 - || tdb_write(tdb, rec_ptr+sizeof(rec), p, key.dsize+dbuf.dsize)==-1 - || ofs_write(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) { + 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; } + + tdb_increment_seqnum(tdb); + out: SAFE_FREE(p); tdb_unlock(tdb, BUCKET(hash), F_WRLCK); @@ -1607,521 +339,92 @@ fail: goto out; } -/* Attempt to append data to 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. Record must be locked before calling. -*/ -static int tdb_append_inplace(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash, TDB_DATA new_dbuf) -{ - struct list_struct rec; - tdb_off rec_ptr; - - /* find entry */ - if (!(rec_ptr = tdb_find(tdb, key, hash, &rec))) - return -1; - - /* Append of 0 is always ok. */ - if (new_dbuf.dsize == 0) - return 0; - - /* must be long enough for key, old data + new data and tailer */ - if (rec.rec_len < key.dsize + rec.data_len + new_dbuf.dsize + sizeof(tdb_off)) { - /* No room. */ - tdb->ecode = TDB_SUCCESS; /* Not really an error */ - return -1; - } - - if (tdb_write(tdb, rec_ptr + sizeof(rec) + rec.key_len + rec.data_len, - new_dbuf.dptr, new_dbuf.dsize) == -1) - return -1; - - /* update size */ - rec.data_len += new_dbuf.dsize; - return rec_write(tdb, rec_ptr, &rec); -} /* Append to an entry. Create if not exist. */ - -int tdb_append(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA new_dbuf) +int tdb_append(struct tdb_context *tdb, TDB_DATA key, TDB_DATA new_dbuf) { - struct list_struct rec; u32 hash; - tdb_off rec_ptr; - char *p = NULL; - int ret = 0; - size_t new_data_size = 0; + 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; - /* first try in-place. */ - if (tdb_append_inplace(tdb, key, hash, new_dbuf) == 0) - goto out; + dbuf = tdb_fetch(tdb, key); - /* reset the error code potentially set by the tdb_append_inplace() */ - tdb->ecode = TDB_SUCCESS; - - /* find entry */ - if (!(rec_ptr = tdb_find(tdb, key, hash, &rec))) { - if (tdb->ecode != TDB_ERR_NOEXIST) - goto fail; - - /* Not found - create. */ - - ret = tdb_store(tdb, key, new_dbuf, TDB_INSERT); - goto out; + if (dbuf.dptr == NULL) { + dbuf.dptr = malloc(new_dbuf.dsize); + } else { + dbuf.dptr = realloc(dbuf.dptr, dbuf.dsize + new_dbuf.dsize); } - new_data_size = rec.data_len + new_dbuf.dsize; - - /* Copy key+old_value+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 + new_data_size))) { + if (dbuf.dptr == NULL) { tdb->ecode = TDB_ERR_OOM; - goto fail; - } - - /* Copy the key in place. */ - memcpy(p, key.dptr, key.dsize); - - /* Now read the old data into place. */ - if (rec.data_len && - tdb_read(tdb, rec_ptr + sizeof(rec) + rec.key_len, p + key.dsize, rec.data_len, 0) == -1) - goto fail; - - /* Finally append the new data. */ - if (new_dbuf.dsize) - memcpy(p+key.dsize+rec.data_len, new_dbuf.dptr, new_dbuf.dsize); - - /* 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. */ - - tdb_delete_hash(tdb, key, hash); - - if (!(rec_ptr = tdb_allocate(tdb, key.dsize + new_data_size, &rec))) - goto fail; - - /* Read hash top into next ptr */ - if (ofs_read(tdb, TDB_HASH_TOP(hash), &rec.next) == -1) - goto fail; - - rec.key_len = key.dsize; - rec.data_len = new_data_size; - rec.full_hash = hash; - rec.magic = TDB_MAGIC; - - /* write out and point the top of the hash chain at it */ - if (rec_write(tdb, rec_ptr, &rec) == -1 - || tdb_write(tdb, rec_ptr+sizeof(rec), p, key.dsize+new_data_size)==-1 - || ofs_write(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) { - /* Need to tdb_unallocate() here */ - goto fail; + goto failed; } - out: - SAFE_FREE(p); - tdb_unlock(tdb, BUCKET(hash), F_WRLCK); - return ret; - -fail: - ret = -1; - goto out; -} + memcpy(dbuf.dptr + dbuf.dsize, new_dbuf.dptr, new_dbuf.dsize); + dbuf.dsize += new_dbuf.dsize; -static int tdb_already_open(dev_t device, - ino_t ino) -{ - TDB_CONTEXT *i; + ret = tdb_store(tdb, key, dbuf, 0); - for (i = tdbs; i; i = i->next) { - if (i->device == device && i->inode == ino) { - return 1; - } - } - - return 0; -} - -/* This is based on the hash algorithm from gdbm */ -static u32 default_tdb_hash(TDB_DATA *key) -{ - u32 value; /* Used to compute the hash value. */ - u32 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); -} - -/* 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. */ -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); -} - - -TDB_CONTEXT *tdb_open_ex(const char *name, int hash_size, int tdb_flags, - int open_flags, mode_t mode, - tdb_log_func log_fn, - tdb_hash_func hash_fn) -{ - TDB_CONTEXT *tdb; - struct stat st; - int rev = 0, locked = 0; - unsigned char *vp; - u32 vertest; - - if (!(tdb = calloc(1, sizeof *tdb))) { - /* Can't log this */ - errno = ENOMEM; - goto fail; - } - tdb->fd = -1; - tdb->name = NULL; - tdb->map_ptr = NULL; - tdb->flags = tdb_flags; - tdb->open_flags = open_flags; - tdb->log_fn = log_fn; - tdb->hash_fn = hash_fn ? hash_fn : default_tdb_hash; - - if ((open_flags & O_ACCMODE) == O_WRONLY) { - TDB_LOG((tdb, 0, "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, 0, "tdb_open_ex: tdb_new_database failed!")); - goto fail; - } - goto internal; - } - - if ((tdb->fd = open(name, open_flags, mode)) == -1) { - TDB_LOG((tdb, 5, "tdb_open_ex: could not open file %s: %s\n", - name, strerror(errno))); - goto fail; /* errno set by open(2) */ - } - - /* ensure there is only one process initialising at once */ - if (tdb_brlock(tdb, GLOBAL_LOCK, F_WRLCK, F_SETLKW, 0) == -1) { - TDB_LOG((tdb, 0, "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) && - (locked = (tdb_brlock(tdb, ACTIVE_LOCK, F_WRLCK, F_SETLK, 0) == 0))) { - open_flags |= O_CREAT; - if (ftruncate(tdb->fd, 0) == -1) { - TDB_LOG((tdb, 0, "tdb_open_ex: " - "failed to truncate %s: %s\n", - name, strerror(errno))); - goto fail; /* errno set by ftruncate */ - } - } - - 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) { - errno = EIO; /* ie bad format or something */ - goto fail; - } - rev = (tdb->flags & TDB_CONVERT); - } - vp = (unsigned char *)&tdb->header.version; - vertest = (((u32)vp[0]) << 24) | (((u32)vp[1]) << 16) | - (((u32)vp[2]) << 8) | (u32)vp[3]; - tdb->flags |= (vertest==TDB_VERSION) ? TDB_BIGENDIAN : 0; - if (!rev) - tdb->flags &= ~TDB_CONVERT; - else { - tdb->flags |= TDB_CONVERT; - convert(&tdb->header, sizeof(tdb->header)); - } - if (fstat(tdb->fd, &st) == -1) - 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, 2, "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->locked = calloc(tdb->header.hash_size+1, sizeof(tdb->locked[0])); - if (!tdb->locked) { - TDB_LOG((tdb, 2, "tdb_open_ex: " - "failed to allocate lock structure for %s\n", - name)); - errno = ENOMEM; - goto fail; - } - tdb_mmap(tdb); - if (locked) { - if (!tdb->read_only) - if (tdb_clear_spinlocks(tdb) != 0) { - TDB_LOG((tdb, 0, "tdb_open_ex: " - "failed to clear spinlock\n")); - goto fail; - } - if (tdb_brlock(tdb, ACTIVE_LOCK, F_UNLCK, F_SETLK, 0) == -1) { - TDB_LOG((tdb, 0, "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_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0) == -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_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0) == -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, 5, "tdb_open_ex: failed to close tdb->fd on error!\n")); - SAFE_FREE(tdb->locked); - SAFE_FREE(tdb); - errno = save_errno; - return NULL; - } -} - -/** - * Close a database. - * - * @returns -1 for error; 0 for success. - **/ -int tdb_close(TDB_CONTEXT *tdb) -{ - TDB_CONTEXT **i; - int ret = 0; - - 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->locked); - - /* 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); - +failed: + tdb_unlock(tdb, BUCKET(hash), F_WRLCK); + SAFE_FREE(dbuf.dptr); return ret; } -/* lock/unlock entire database */ -int tdb_lockall(TDB_CONTEXT *tdb) -{ - u32 i; - - /* There are no locks on read-only dbs */ - if (tdb->read_only) - return TDB_ERRCODE(TDB_ERR_LOCK, -1); - for (i = 0; i < tdb->header.hash_size; i++) - if (tdb_lock(tdb, i, F_WRLCK)) - break; - - /* If error, release locks we have... */ - if (i < tdb->header.hash_size) { - u32 j; - - for ( j = 0; j < i; j++) - tdb_unlock(tdb, j, F_WRLCK); - return TDB_ERRCODE(TDB_ERR_NOLOCK, -1); - } - - return 0; -} -void tdb_unlockall(TDB_CONTEXT *tdb) -{ - u32 i; - for (i=0; i < tdb->header.hash_size; i++) - tdb_unlock(tdb, i, F_WRLCK); -} - -/* 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(TDB_CONTEXT *tdb, TDB_DATA key) -{ - return tdb_lock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK); -} -int tdb_chainunlock(TDB_CONTEXT *tdb, TDB_DATA key) +/* + return the name of the current tdb file + useful for external logging functions +*/ +const char *tdb_name(struct tdb_context *tdb) { - return tdb_unlock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK); + return tdb->name; } -int tdb_chainlock_read(TDB_CONTEXT *tdb, TDB_DATA key) +/* + 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_lock(tdb, BUCKET(tdb->hash_fn(&key)), F_RDLCK); + return tdb->fd; } -int tdb_chainunlock_read(TDB_CONTEXT *tdb, TDB_DATA key) +/* + 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_unlock(tdb, BUCKET(tdb->hash_fn(&key)), F_RDLCK); + return tdb->log_fn; } -/* register a loging function */ -void tdb_logging_function(TDB_CONTEXT *tdb, void (*fn)(TDB_CONTEXT *, int , const char *, ...)) -{ - tdb->log_fn = fn; -} - -/* 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(TDB_CONTEXT *tdb) +/* + 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) { - struct stat st; + tdb_off_t seqnum=0; - if (tdb->flags & TDB_INTERNAL) - return 0; /* Nothing to do. */ - if (tdb_munmap(tdb) != 0) { - TDB_LOG((tdb, 0, "tdb_reopen: munmap failed (%s)\n", strerror(errno))); - goto fail; - } - if (close(tdb->fd) != 0) - TDB_LOG((tdb, 0, "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, 0, "tdb_reopen: open failed (%s)\n", strerror(errno))); - goto fail; - } - if ((tdb->flags & TDB_CLEAR_IF_FIRST) && - (tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0) == -1)) { - TDB_LOG((tdb, 0, "tdb_reopen: failed to obtain active lock\n")); - goto fail; - } - if (fstat(tdb->fd, &st) != 0) { - TDB_LOG((tdb, 0, "tdb_reopen: fstat failed (%s)\n", strerror(errno))); - goto fail; - } - if (st.st_ino != tdb->inode || st.st_dev != tdb->device) { - TDB_LOG((tdb, 0, "tdb_reopen: file dev/inode has changed!\n")); - goto fail; - } - tdb_mmap(tdb); - - return 0; - -fail: - tdb_close(tdb); - return -1; + tdb_ofs_read(tdb, TDB_SEQNUM_OFS, &seqnum); + return seqnum; } -/* reopen all tdb's */ -int tdb_reopen_all(int parent_longlived) +int tdb_hash_size(struct tdb_context *tdb) { - 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; + return tdb->header.hash_size; } diff --git a/source3/tdb/tdb.h b/source3/tdb/tdb.h index b5b87ee5a5..82f8828c89 100644 --- a/source3/tdb/tdb.h +++ b/source3/tdb/tdb.h @@ -3,9 +3,9 @@ /* Unix SMB/CIFS implementation. - + trivial database library - + Copyright (C) Andrew Tridgell 1999-2004 ** NOTE! The following LGPL license applies to the tdb @@ -21,7 +21,7 @@ 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, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA @@ -31,17 +31,6 @@ extern "C" { #endif -#ifndef PRINTF_ATTRIBUTE -/** Use gcc attribute to check printf fns. a1 is the 1-based index of - * the parameter containing the format, and a2 the index of the first - * argument. Note that some gcc 2.x versions don't handle this - * properly **/ -#if (__GNUC__ >= 3) && (__GNUC_MINOR__ >= 1 ) -#define PRINTF_ATTRIBUTE(a1, a2) __attribute__ ((format (__printf__, a1, a2))) -#else -#define PRINTF_ATTRIBUTE(a1, a2) -#endif -#endif /* flags to tdb_store() */ #define TDB_REPLACE 1 @@ -56,102 +45,83 @@ extern "C" { #define TDB_NOMMAP 8 /* don't use mmap */ #define TDB_CONVERT 16 /* convert endian (internal use) */ #define TDB_BIGENDIAN 32 /* header is big-endian (internal use) */ +#define TDB_NOSYNC 64 /* don't use synchronous transactions */ +#define TDB_SEQNUM 128 /* maintain a sequence number */ #define TDB_ERRCODE(code, ret) ((tdb->ecode = (code)), ret) /* error codes */ enum TDB_ERROR {TDB_SUCCESS=0, TDB_ERR_CORRUPT, TDB_ERR_IO, TDB_ERR_LOCK, TDB_ERR_OOM, TDB_ERR_EXISTS, TDB_ERR_NOLOCK, TDB_ERR_LOCK_TIMEOUT, - TDB_ERR_NOEXIST}; - -#ifndef u32 -#define u32 unsigned -#endif + TDB_ERR_NOEXIST, TDB_ERR_EINVAL, TDB_ERR_RDONLY}; -typedef struct { +typedef struct TDB_DATA { char *dptr; size_t dsize; } TDB_DATA; -typedef u32 tdb_len; -typedef u32 tdb_off; - -/* this is stored at the front of every database */ -struct tdb_header { - char magic_food[32]; /* for /etc/magic */ - u32 version; /* version of the code */ - u32 hash_size; /* number of hash entries */ - tdb_off rwlocks; - tdb_off reserved[31]; -}; - -struct tdb_lock_type { - u32 count; - u32 ltype; -}; - -struct tdb_traverse_lock { - struct tdb_traverse_lock *next; - u32 off; - u32 hash; -}; +#ifndef PRINTF_ATTRIBUTE +#if (__GNUC__ >= 3) +/** Use gcc attribute to check printf fns. a1 is the 1-based index of + * the parameter containing the format, and a2 the index of the first + * argument. Note that some gcc 2.x versions don't handle this + * properly **/ +#define PRINTF_ATTRIBUTE(a1, a2) __attribute__ ((format (__printf__, a1, a2))) +#else +#define PRINTF_ATTRIBUTE(a1, a2) +#endif +#endif /* this is the context structure that is returned from a db open */ -typedef 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 map_size; /* how much space has been mapped */ - int read_only; /* opened read-only */ - struct tdb_lock_type *locked; /* array of chain locks */ - enum TDB_ERROR ecode; /* error code for last tdb error */ - struct tdb_header header; /* a cached copy of the header */ - u32 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 */ - void (*log_fn)(struct tdb_context *tdb, int level, const char *, ...) PRINTF_ATTRIBUTE(3,4); /* logging function */ - u32 (*hash_fn)(TDB_DATA *key); - int open_flags; /* flags used in the open - needed by reopen */ -} TDB_CONTEXT; - -typedef int (*tdb_traverse_func)(TDB_CONTEXT *, TDB_DATA, TDB_DATA, void *); -typedef void (*tdb_log_func)(TDB_CONTEXT *, int , const char *, ...); -typedef u32 (*tdb_hash_func)(TDB_DATA *key); - -TDB_CONTEXT *tdb_open(const char *name, int hash_size, int tdb_flags, +typedef struct tdb_context TDB_CONTEXT; + +typedef int (*tdb_traverse_func)(struct tdb_context *, TDB_DATA, TDB_DATA, void *); +typedef void (*tdb_log_func)(struct tdb_context *, int , const char *, ...); +typedef unsigned int (*tdb_hash_func)(TDB_DATA *key); + +struct tdb_context *tdb_open(const char *name, int hash_size, int tdb_flags, int open_flags, mode_t mode); -TDB_CONTEXT *tdb_open_ex(const char *name, int hash_size, int tdb_flags, +struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags, int open_flags, mode_t mode, tdb_log_func log_fn, tdb_hash_func hash_fn); -int tdb_reopen(TDB_CONTEXT *tdb); -int tdb_reopen_all(int); -void tdb_logging_function(TDB_CONTEXT *tdb, tdb_log_func); -enum TDB_ERROR tdb_error(TDB_CONTEXT *tdb); -const char *tdb_errorstr(TDB_CONTEXT *tdb); -TDB_DATA tdb_fetch(TDB_CONTEXT *tdb, TDB_DATA key); -int tdb_delete(TDB_CONTEXT *tdb, TDB_DATA key); -int tdb_store(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, int flag); -int tdb_append(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA new_dbuf); -int tdb_close(TDB_CONTEXT *tdb); -TDB_DATA tdb_firstkey(TDB_CONTEXT *tdb); -TDB_DATA tdb_nextkey(TDB_CONTEXT *tdb, TDB_DATA key); -int tdb_traverse(TDB_CONTEXT *tdb, tdb_traverse_func fn, void *); -int tdb_exists(TDB_CONTEXT *tdb, TDB_DATA key); -int tdb_lockall(TDB_CONTEXT *tdb); -void tdb_unlockall(TDB_CONTEXT *tdb); +int tdb_reopen(struct tdb_context *tdb); +int tdb_reopen_all(int parent_longlived); +void tdb_logging_function(struct tdb_context *tdb, tdb_log_func); +enum TDB_ERROR tdb_error(struct tdb_context *tdb); +const char *tdb_errorstr(struct tdb_context *tdb); +TDB_DATA tdb_fetch(struct tdb_context *tdb, TDB_DATA key); +int tdb_delete(struct tdb_context *tdb, TDB_DATA key); +int tdb_store(struct tdb_context *tdb, TDB_DATA key, TDB_DATA dbuf, int flag); +int tdb_append(struct tdb_context *tdb, TDB_DATA key, TDB_DATA new_dbuf); +int tdb_close(struct tdb_context *tdb); +TDB_DATA tdb_firstkey(struct tdb_context *tdb); +TDB_DATA tdb_nextkey(struct tdb_context *tdb, TDB_DATA key); +int tdb_traverse(struct tdb_context *tdb, tdb_traverse_func fn, void *); +int tdb_traverse_read(struct tdb_context *tdb, tdb_traverse_func fn, void *); +int tdb_exists(struct tdb_context *tdb, TDB_DATA key); +int tdb_lockall(struct tdb_context *tdb); +void tdb_unlockall(struct tdb_context *tdb); +const char *tdb_name(struct tdb_context *tdb); +int tdb_fd(struct tdb_context *tdb); +tdb_log_func tdb_log_fn(struct tdb_context *tdb); +int tdb_transaction_start(struct tdb_context *tdb); +int tdb_transaction_commit(struct tdb_context *tdb); +int tdb_transaction_cancel(struct tdb_context *tdb); +int tdb_transaction_recover(struct tdb_context *tdb); +int tdb_get_seqnum(struct tdb_context *tdb); +int tdb_hash_size(struct tdb_context *tdb); /* Low level locking functions: use with care */ -void tdb_set_lock_alarm(sig_atomic_t *palarm); -int tdb_chainlock(TDB_CONTEXT *tdb, TDB_DATA key); -int tdb_chainunlock(TDB_CONTEXT *tdb, TDB_DATA key); +int tdb_chainlock(struct tdb_context *tdb, TDB_DATA key); +int tdb_chainunlock(struct tdb_context *tdb, TDB_DATA key); +int tdb_chainlock_read(struct tdb_context *tdb, TDB_DATA key); +int tdb_chainunlock_read(struct tdb_context *tdb, TDB_DATA key); /* Debug functions. Not used in production. */ -void tdb_dump_all(TDB_CONTEXT *tdb); -int tdb_printfreelist(TDB_CONTEXT *tdb); +void tdb_dump_all(struct tdb_context *tdb); +int tdb_printfreelist(struct tdb_context *tdb); extern TDB_DATA tdb_null; diff --git a/source3/tdb/tdb_private.h b/source3/tdb/tdb_private.h new file mode 100644 index 0000000000..d10c1c46bf --- /dev/null +++ b/source3/tdb/tdb_private.h @@ -0,0 +1,241 @@ + /* + 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 2 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, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA +*/ + +#ifndef _SAMBA_BUILD_ +#include "config.h" +#include <stdlib.h> +#include <stdio.h> +#ifdef HAVE_STDINT_H +#include <stdint.h> +#endif +#include <fcntl.h> +#include <unistd.h> +#include <string.h> +#include <fcntl.h> +#include <errno.h> +#include <sys/mman.h> +#include <sys/stat.h> +#ifdef HAVE_SYS_SELECT_H +#include <sys/select.h> +#endif +#ifdef HAVE_SYS_TIME_H +#include <sys/time.h> +#endif +#include "tdb.h" + +#ifndef HAVE_PREAD_DECL +ssize_t pread(int fd, void *buf, size_t count, off_t offset); +#endif +#ifndef HAVE_PWRITE_DECL +ssize_t pwrite(int fd, const void *buf, size_t count, off_t offset); +#endif + +#else +#include "includes.h" +#undef malloc +#undef realloc +#undef calloc +#undef strdup +#endif + +#ifndef u32 +#define u32 unsigned +#endif + +#ifndef HAVE_GETPAGESIZE +#define getpagesize() 0x2000 +#endif + +typedef u32 tdb_len_t; +typedef u32 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 MIN_REC_SIZE (2*sizeof(struct list_struct) + TDB_ALIGNMENT) +#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) +#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_fn x + +/* lock offsets */ +#define GLOBAL_LOCK 0 +#define ACTIVE_LOCK 4 +#define TRANSACTION_LOCK 8 + +#ifndef MAP_FILE +#define MAP_FILE 0 +#endif + +#ifndef MAP_FAILED +#define MAP_FAILED ((void *)-1) +#endif + +/* 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 */ + u32 full_hash; /* the full 32 bit hash of the key */ + u32 magic; /* try to catch errors */ + /* the following union is implied: + union { + char record[rec_len]; + struct { + char key[key_len]; + char data[data_len]; + } + u32 totalsize; (tailer) + } + */ +}; + + +/* this is stored at the front of every database */ +struct tdb_header { + char magic_food[32]; /* for /etc/magic */ + u32 version; /* version of the code */ + u32 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 { + u32 count; + u32 ltype; +}; + +struct tdb_traverse_lock { + struct tdb_traverse_lock *next; + u32 off; + u32 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 *, u32 *); + 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); +}; + +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 */ + struct tdb_lock_type *locked; /* array of chain locks */ + enum TDB_ERROR ecode; /* error code for last tdb error */ + struct tdb_header header; /* a cached copy of the header */ + u32 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 */ + void (*log_fn)(struct tdb_context *tdb, int level, const char *, ...) PRINTF_ATTRIBUTE(3,4); /* logging function */ + 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; +}; + + +/* + 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_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); +int tdb_brlock_upgrade(struct tdb_context *tdb, tdb_off_t offset, size_t len); +int tdb_brlock_len(struct tdb_context *tdb, tdb_off_t offset, + int rw_type, int lck_type, int probe, 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, u32 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); +char *tdb_alloc_read(struct tdb_context *tdb, tdb_off_t offset, tdb_len_t len); +tdb_off_t tdb_find_lock_hash(struct tdb_context *tdb, TDB_DATA key, u32 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); + + diff --git a/source3/tdb/tdbback.c b/source3/tdb/tdbback.c index 7967a6bbf5..c337924d6c 100644 --- a/source3/tdb/tdbback.c +++ b/source3/tdb/tdbback.c @@ -77,7 +77,7 @@ static int copy_fn(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, void *state) TDB_CONTEXT *tdb_new = (TDB_CONTEXT *)state; if (tdb_store(tdb_new, key, dbuf, TDB_INSERT) != 0) { - fprintf(stderr,"Failed to insert into %s\n", tdb_new->name); + fprintf(stderr,"Failed to insert into %s\n", tdb_name(tdb)); failed = 1; return 1; } @@ -122,7 +122,7 @@ int backup_tdb(const char *old_name, const char *new_name) /* create the new tdb */ unlink(tmp_name); - tdb_new = tdb_open(tmp_name, tdb->header.hash_size, + tdb_new = tdb_open(tmp_name, tdb_hash_size(tdb), TDB_DEFAULT, O_RDWR|O_CREAT|O_EXCL, st.st_mode & 0777); if (!tdb_new) { @@ -179,7 +179,7 @@ int backup_tdb(const char *old_name, const char *new_name) } /* make sure the new tdb has reached stable storage */ - fsync(tdb_new->fd); + fsync(tdb_fd(tdb_new)); /* close the new tdb and rename it to .bak */ tdb_close(tdb_new); diff --git a/source3/tdb/tdbutil.c b/source3/tdb/tdbutil.c index fc45fa9360..e13f7e3e67 100644 --- a/source3/tdb/tdbutil.c +++ b/source3/tdb/tdbutil.c @@ -19,9 +19,21 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ -#include "includes.h" +#include "tdb_private.h" #include <fnmatch.h> +/*************************************************************** + Allow a caller to set a "alarm" flag that tdb can check to abort + a blocking lock on SIGALRM. +***************************************************************/ + +static sig_atomic_t *palarm_fired; + +static void tdb_set_lock_alarm(sig_atomic_t *palarm) +{ + palarm_fired = palarm; +} + /* these are little tdb utility functions that are meant to make dealing with a tdb database a little less cumbersome in Samba */ @@ -641,129 +653,6 @@ int tdb_unpack(char *buf, int bufsize, const char *fmt, ...) } -/** - * Pack SID passed by pointer - * - * @param pack_buf pointer to buffer which is to be filled with packed data - * @param bufsize size of packing buffer - * @param sid pointer to sid to be packed - * - * @return length of the packed representation of the whole structure - **/ -size_t tdb_sid_pack(char* pack_buf, int bufsize, DOM_SID* sid) -{ - int idx; - size_t len = 0; - - if (!sid || !pack_buf) return -1; - - len += tdb_pack(pack_buf + len, bufsize - len, "bb", sid->sid_rev_num, - sid->num_auths); - - for (idx = 0; idx < 6; idx++) { - len += tdb_pack(pack_buf + len, bufsize - len, "b", sid->id_auth[idx]); - } - - for (idx = 0; idx < MAXSUBAUTHS; idx++) { - len += tdb_pack(pack_buf + len, bufsize - len, "d", sid->sub_auths[idx]); - } - - return len; -} - - -/** - * Unpack SID into a pointer - * - * @param pack_buf pointer to buffer with packed representation - * @param bufsize size of the buffer - * @param sid pointer to sid structure to be filled with unpacked data - * - * @return size of structure unpacked from buffer - **/ -size_t tdb_sid_unpack(char* pack_buf, int bufsize, DOM_SID* sid) -{ - int idx, len = 0; - - if (!sid || !pack_buf) return -1; - - len += tdb_unpack(pack_buf + len, bufsize - len, "bb", - &sid->sid_rev_num, &sid->num_auths); - - for (idx = 0; idx < 6; idx++) { - len += tdb_unpack(pack_buf + len, bufsize - len, "b", &sid->id_auth[idx]); - } - - for (idx = 0; idx < MAXSUBAUTHS; idx++) { - len += tdb_unpack(pack_buf + len, bufsize - len, "d", &sid->sub_auths[idx]); - } - - return len; -} - - -/** - * Pack TRUSTED_DOM_PASS passed by pointer - * - * @param pack_buf pointer to buffer which is to be filled with packed data - * @param bufsize size of the buffer - * @param pass pointer to trusted domain password to be packed - * - * @return length of the packed representation of the whole structure - **/ -size_t tdb_trusted_dom_pass_pack(char* pack_buf, int bufsize, TRUSTED_DOM_PASS* pass) -{ - int idx, len = 0; - - if (!pack_buf || !pass) return -1; - - /* packing unicode domain name and password */ - len += tdb_pack(pack_buf + len, bufsize - len, "d", pass->uni_name_len); - - for (idx = 0; idx < 32; idx++) - len += tdb_pack(pack_buf + len, bufsize - len, "w", pass->uni_name[idx]); - - len += tdb_pack(pack_buf + len, bufsize - len, "dPd", pass->pass_len, - pass->pass, pass->mod_time); - - /* packing SID structure */ - len += tdb_sid_pack(pack_buf + len, bufsize - len, &pass->domain_sid); - - return len; -} - - -/** - * Unpack TRUSTED_DOM_PASS passed by pointer - * - * @param pack_buf pointer to buffer with packed representation - * @param bufsize size of the buffer - * @param pass pointer to trusted domain password to be filled with unpacked data - * - * @return size of structure unpacked from buffer - **/ -size_t tdb_trusted_dom_pass_unpack(char* pack_buf, int bufsize, TRUSTED_DOM_PASS* pass) -{ - int idx, len = 0; - - if (!pack_buf || !pass) return -1; - - /* unpack unicode domain name and plaintext password */ - len += tdb_unpack(pack_buf, bufsize - len, "d", &pass->uni_name_len); - - for (idx = 0; idx < 32; idx++) - len += tdb_unpack(pack_buf + len, bufsize - len, "w", &pass->uni_name[idx]); - - len += tdb_unpack(pack_buf + len, bufsize - len, "dPd", &pass->pass_len, &pass->pass, - &pass->mod_time); - - /* unpack domain sid */ - len += tdb_sid_unpack(pack_buf + len, bufsize - len, &pass->domain_sid); - - return len; -} - - /**************************************************************************** Log tdb messages via DEBUG(). ****************************************************************************/ @@ -806,15 +695,6 @@ TDB_CONTEXT *tdb_open_log(const char *name, int hash_size, int tdb_flags, } /**************************************************************************** - return the name of the current tdb file useful for external logging - functions -****************************************************************************/ -const char *tdb_name(struct tdb_context *tdb) -{ - return tdb->name; -} - -/**************************************************************************** Allow tdb_delete to be used as a tdb_traversal_fn. ****************************************************************************/ @@ -893,3 +773,43 @@ void tdb_search_list_free(TDB_LIST_NODE* node) node = next_node; }; } + +size_t tdb_map_size(struct tdb_context *tdb) +{ + return tdb->map_size; +} + +int tdb_get_flags(struct tdb_context *tdb) +{ + return tdb->flags; +} + +/**************************************************************************** + tdb_store, wrapped in a transaction. This way we make sure that a process + that dies within writing does not leave a corrupt tdb behind. +****************************************************************************/ + +int tdb_trans_store(struct tdb_context *tdb, TDB_DATA key, TDB_DATA dbuf, + int flag) +{ + int res; + + if ((res = tdb_transaction_start(tdb)) != 0) { + DEBUG(5, ("tdb_transaction_start failed\n")); + return res; + } + + if ((res = tdb_store(tdb, key, dbuf, flag)) != 0) { + DEBUG(10, ("tdb_store failed\n")); + if (tdb_transaction_cancel(tdb) != 0) { + smb_panic("Cancelling transaction failed\n"); + } + return res; + } + + if ((res = tdb_transaction_commit(tdb)) != 0) { + DEBUG(5, ("tdb_transaction_commit failed\n")); + } + + return res; +} diff --git a/source3/tdb/tdbutil.h b/source3/tdb/tdbutil.h index 1a181a962f..44351619f4 100644 --- a/source3/tdb/tdbutil.h +++ b/source3/tdb/tdbutil.h @@ -1,8 +1,7 @@ /* Unix SMB/CIFS implementation. tdb utility functions - Copyright (C) Andrew Tridgell 1999 - Copyright (C) Rafal Szczesniak 2002 + Copyright (C) Andrew Tridgell 1999 This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -22,6 +21,7 @@ #ifndef __TDBUTIL_H__ #define __TDBUTIL_H__ +#include "tdb.h" /* single node of a list returned by tdb_search_keys */ typedef struct keys_node @@ -31,8 +31,38 @@ typedef struct keys_node } TDB_LIST_NODE; -TDB_LIST_NODE *tdb_search_keys(TDB_CONTEXT*, const char*); +TDB_LIST_NODE *tdb_search_keys(struct tdb_context*, const char*); void tdb_search_list_free(TDB_LIST_NODE*); - +int32_t tdb_change_int32_atomic(struct tdb_context *tdb, const char *keystr, int32_t *oldval, int32_t change_val); +int tdb_lock_bystring(struct tdb_context *tdb, const char *keyval); +int tdb_lock_bystring_with_timeout(TDB_CONTEXT *tdb, const char *keyval, + int timeout); +void tdb_unlock_bystring(struct tdb_context *tdb, const char *keyval); +int tdb_read_lock_bystring_with_timeout(TDB_CONTEXT *tdb, const char *keyval, + unsigned int timeout); +void tdb_read_unlock_bystring(TDB_CONTEXT *tdb, const char *keyval); +int32_t tdb_fetch_int32(struct tdb_context *tdb, const char *keystr); +BOOL tdb_store_uint32(struct tdb_context *tdb, const char *keystr, uint32_t value); +int tdb_store_int32(struct tdb_context *tdb, const char *keystr, int32_t v); +BOOL tdb_fetch_uint32(struct tdb_context *tdb, const char *keystr, uint32_t *value); +int tdb_traverse_delete_fn(struct tdb_context *the_tdb, TDB_DATA key, TDB_DATA dbuf, + void *state); +int tdb_store_bystring(struct tdb_context *tdb, const char *keystr, TDB_DATA data, int flags); +TDB_DATA tdb_fetch_bystring(struct tdb_context *tdb, const char *keystr); +int tdb_delete_bystring(struct tdb_context *tdb, const char *keystr); +struct tdb_context *tdb_open_log(const char *name, int hash_size, + int tdb_flags, int open_flags, mode_t mode); +int tdb_unpack(char *buf, int bufsize, const char *fmt, ...); +size_t tdb_pack(char *buf, int bufsize, const char *fmt, ...); +TDB_DATA make_tdb_data(const char *dptr, size_t dsize); +TDB_DATA string_tdb_data(const char *string); +int tdb_trans_store(struct tdb_context *tdb, TDB_DATA key, TDB_DATA dbuf, + int flag); +BOOL tdb_change_uint32_atomic(TDB_CONTEXT *tdb, const char *keystr, + uint32 *oldval, uint32 change_val); +int tdb_chainlock_with_timeout( TDB_CONTEXT *tdb, TDB_DATA key, + unsigned int timeout); +int tdb_get_flags(struct tdb_context *tdb); +size_t tdb_map_size(struct tdb_context *tdb); #endif /* __TDBUTIL_H__ */ diff --git a/source3/tdb/transaction.c b/source3/tdb/transaction.c new file mode 100644 index 0000000000..aa54c4ae3c --- /dev/null +++ b/source3/tdb/transaction.c @@ -0,0 +1,1043 @@ + /* + 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 2 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, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA +*/ + +#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 + + - dymacially 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 */ + u32 *hash_heads; + + /* the original io methods - used to do IOs to the real db */ + const struct tdb_methods *io_methods; + + /* the list of transaction elements. We use a doubly linked + list with a last pointer to allow us to keep the list + ordered, with first element at the front of the list. It + needs to be doubly linked as the read/write traversals need + to be backwards, while the commit needs to be forwards */ + struct tdb_transaction_el { + struct tdb_transaction_el *next, *prev; + tdb_off_t offset; + tdb_len_t length; + unsigned char *data; + } *elements, *elements_last; + + /* 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) +{ + struct tdb_transaction_el *el; + + /* we need to walk the list backwards to get the most recent data */ + for (el=tdb->transaction->elements_last;el;el=el->prev) { + tdb_len_t partial; + + if (off+len <= el->offset) { + continue; + } + if (off >= el->offset + el->length) { + continue; + } + + /* an overlapping read - needs to be split into up to + 2 reads and a memcpy */ + if (off < el->offset) { + partial = el->offset - off; + if (transaction_read(tdb, off, buf, partial, cv) != 0) { + goto fail; + } + len -= partial; + off += partial; + buf = (void *)(partial + (char *)buf); + } + if (off + len <= el->offset + el->length) { + partial = len; + } else { + partial = el->offset + el->length - off; + } + memcpy(buf, el->data + (off - el->offset), partial); + if (cv) { + tdb_convert(buf, len); + } + len -= partial; + off += partial; + buf = (void *)(partial + (char *)buf); + + if (len != 0 && transaction_read(tdb, off, buf, len, cv) != 0) { + goto fail; + } + + return 0; + } + + /* its not in the transaction elements - do a real read */ + return tdb->transaction->io_methods->tdb_read(tdb, off, buf, len, cv); + +fail: + TDB_LOG((tdb, 0, "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) +{ + struct tdb_transaction_el *el, *best_el=NULL; + + if (len == 0) { + return 0; + } + + /* 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)) { + u32 chain = (off-FREELIST_TOP) / sizeof(tdb_off_t); + memcpy(&tdb->transaction->hash_heads[chain], buf, len); + } + + /* first see if we can replace an existing entry */ + for (el=tdb->transaction->elements_last;el;el=el->prev) { + tdb_len_t partial; + + if (best_el == NULL && off == el->offset+el->length) { + best_el = el; + } + + if (off+len <= el->offset) { + continue; + } + if (off >= el->offset + el->length) { + continue; + } + + /* an overlapping write - needs to be split into up to + 2 writes and a memcpy */ + if (off < el->offset) { + partial = el->offset - off; + if (transaction_write(tdb, off, buf, partial) != 0) { + goto fail; + } + len -= partial; + off += partial; + buf = (const void *)(partial + (const char *)buf); + } + if (off + len <= el->offset + el->length) { + partial = len; + } else { + partial = el->offset + el->length - off; + } + memcpy(el->data + (off - el->offset), buf, partial); + len -= partial; + off += partial; + buf = (const void *)(partial + (const char *)buf); + + if (len != 0 && transaction_write(tdb, off, buf, len) != 0) { + goto fail; + } + + return 0; + } + + /* see if we can append the new entry to an existing entry */ + if (best_el && best_el->offset + best_el->length == off && + (off+len < tdb->transaction->old_map_size || + off > tdb->transaction->old_map_size)) { + unsigned char *data = best_el->data; + el = best_el; + el->data = realloc(el->data, el->length + len); + if (el->data == NULL) { + tdb->ecode = TDB_ERR_OOM; + tdb->transaction->transaction_error = 1; + el->data = data; + return -1; + } + if (buf) { + memcpy(el->data + el->length, buf, len); + } else { + memset(el->data + el->length, TDB_PAD_BYTE, len); + } + el->length += len; + return 0; + } + + /* add a new entry at the end of the list */ + el = malloc(sizeof(*el)); + if (el == NULL) { + tdb->ecode = TDB_ERR_OOM; + tdb->transaction->transaction_error = 1; + return -1; + } + el->next = NULL; + el->prev = tdb->transaction->elements_last; + el->offset = off; + el->length = len; + el->data = malloc(len); + if (el->data == NULL) { + free(el); + tdb->ecode = TDB_ERR_OOM; + tdb->transaction->transaction_error = 1; + return -1; + } + if (buf) { + memcpy(el->data, buf, len); + } else { + memset(el->data, TDB_PAD_BYTE, len); + } + if (el->prev) { + el->prev->next = el; + } else { + tdb->transaction->elements = el; + } + tdb->transaction->elements_last = el; + return 0; + +fail: + TDB_LOG((tdb, 0, "transaction_write: failed at off=%d len=%d\n", off, len)); + tdb->ecode = TDB_ERR_IO; + tdb->transaction->transaction_error = 1; + return -1; +} + +/* + accelerated hash chain head search, using the cached hash heads +*/ +static void transaction_next_hash_chain(struct tdb_context *tdb, u32 *chain) +{ + u32 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 +*/ +int transaction_brlock(struct tdb_context *tdb, tdb_off_t offset, + int rw_type, int lck_type, int probe) +{ + 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, 0, "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, 0, "tdb_transaction_start: nesting %d\n", + tdb->transaction->nesting)); + return 0; + } + + if (tdb->num_locks != 0) { + /* 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, 0, "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, 0, "tdb_transaction_start: cannot start a transaction within a traverse\n")); + tdb->ecode = TDB_ERR_LOCK; + return -1; + } + + tdb->transaction = calloc(sizeof(struct tdb_transaction), 1); + if (tdb->transaction == NULL) { + tdb->ecode = TDB_ERR_OOM; + return -1; + } + + /* 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_brlock_len(tdb, TRANSACTION_LOCK, F_WRLCK, F_SETLKW, 0, 1) == -1) { + TDB_LOG((tdb, 0, "tdb_transaction_start: failed to get transaction lock\n")); + tdb->ecode = TDB_ERR_LOCK; + 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_len(tdb, FREELIST_TOP, F_RDLCK, F_SETLKW, 0, 0) == -1) { + TDB_LOG((tdb, 0, "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 = calloc(tdb->header.hash_size+1, sizeof(tdb_off_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, 0, "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; + + /* by calling this transaction write here, we ensure that we don't grow the + transaction linked list due to hash table updates */ + if (transaction_write(tdb, FREELIST_TOP, tdb->transaction->hash_heads, + TDB_HASHTABLE_SIZE(tdb)) != 0) { + TDB_LOG((tdb, 0, "tdb_transaction_start: failed to prime hash table\n")); + tdb->ecode = TDB_ERR_IO; + goto fail; + } + + return 0; + +fail: + tdb_brlock_len(tdb, FREELIST_TOP, F_UNLCK, F_SETLKW, 0, 0); + tdb_brlock_len(tdb, TRANSACTION_LOCK, F_UNLCK, F_SETLKW, 0, 1); + SAFE_FREE(tdb->transaction->hash_heads); + SAFE_FREE(tdb->transaction); + return -1; +} + + +/* + cancel the current transaction +*/ +int tdb_transaction_cancel(struct tdb_context *tdb) +{ + if (tdb->transaction == NULL) { + TDB_LOG((tdb, 0, "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 elements */ + while (tdb->transaction->elements) { + struct tdb_transaction_el *el = tdb->transaction->elements; + tdb->transaction->elements = el->next; + free(el->data); + free(el); + } + + /* remove any locks created during the transaction */ + if (tdb->num_locks != 0) { + int h; + for (h=0;h<tdb->header.hash_size+1;h++) { + if (tdb->locked[h].count != 0) { + tdb_brlock_len(tdb,FREELIST_TOP+4*h,F_UNLCK,F_SETLKW, 0, 1); + tdb->locked[h].count = 0; + } + } + tdb->num_locks = 0; + } + + /* restore the normal io methods */ + tdb->methods = tdb->transaction->io_methods; + + tdb_brlock_len(tdb, FREELIST_TOP, F_UNLCK, F_SETLKW, 0, 0); + tdb_brlock_len(tdb, TRANSACTION_LOCK, F_UNLCK, F_SETLKW, 0, 1); + 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, 0, "tdb_transaction: fsync failed\n")); + return -1; + } +#ifdef MS_SYNC + 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, 0, "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) +{ + struct tdb_transaction_el *el; + tdb_len_t recovery_size = 0; + + recovery_size = sizeof(u32); + for (el=tdb->transaction->elements;el;el=el->next) { + if (el->offset >= tdb->transaction->old_map_size) { + continue; + } + recovery_size += 2*sizeof(tdb_off_t) + el->length; + } + + 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, 0, "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, 0, "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, 0, "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, 0, "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, 0, "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) +{ + struct tdb_transaction_el *el; + 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; + u32 magic, tailer; + + /* + check that the recovery area has enough space + */ + if (tdb_recovery_allocate(tdb, &recovery_size, + &recovery_offset, &recovery_max_size) == -1) { + return -1; + } + + data = 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 (el=tdb->transaction->elements;el;el=el->next) { + if (el->offset >= old_map_size) { + continue; + } + if (el->offset + el->length > tdb->transaction->old_map_size) { + TDB_LOG((tdb, 0, "tdb_transaction_commit: transaction data over new region boundary\n")); + free(data); + tdb->ecode = TDB_ERR_CORRUPT; + return -1; + } + memcpy(p, &el->offset, 4); + memcpy(p+4, &el->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, el->offset, p + 8, el->length, 0) != 0) { + free(data); + tdb->ecode = TDB_ERR_IO; + return -1; + } + p += 8 + el->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, 0, "tdb_transaction_commit: failed to write 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, 0, "tdb_transaction_commit: failed to write 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; + u32 zero = 0; + + if (tdb->transaction == NULL) { + TDB_LOG((tdb, 0, "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, 0, "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->elements == 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->ecode = TDB_ERR_LOCK; + TDB_LOG((tdb, 0, "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, 0, "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_len(tdb, GLOBAL_LOCK, F_WRLCK, F_SETLKW, 0, 1) == -1) { + TDB_LOG((tdb, 0, "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, 0, "tdb_transaction_commit: failed to setup recovery data\n")); + tdb_brlock_len(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, 0, "tdb_transaction_commit: expansion failed\n")); + tdb_brlock_len(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 */ + while (tdb->transaction->elements) { + struct tdb_transaction_el *el = tdb->transaction->elements; + + if (methods->tdb_write(tdb, el->offset, el->data, el->length) == -1) { + TDB_LOG((tdb, 0, "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_len(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0, 1); + + TDB_LOG((tdb, 0, "tdb_transaction_commit: write failed\n")); + return -1; + } + tdb->transaction->elements = el->next; + free(el->data); + free(el); + } + + 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, 0, "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_len(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; + u32 zero = 0; + struct list_struct rec; + + /* find the recovery area */ + if (tdb_ofs_read(tdb, TDB_RECOVERY_HEAD, &recovery_head) == -1) { + TDB_LOG((tdb, 0, "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, 0, "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, 0, "tdb_transaction_recover: attempt to recover read only database\n")); + tdb->ecode = TDB_ERR_CORRUPT; + return -1; + } + + recovery_eof = rec.key_len; + + data = malloc(rec.data_len); + if (data == NULL) { + TDB_LOG((tdb, 0, "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, 0, "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) { + u32 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, 0, "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, 0, "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, 0, "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, 0, "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, 0, "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, 0, "tdb_transaction_recover: failed to sync2 recovery\n")); + tdb->ecode = TDB_ERR_IO; + return -1; + } + + TDB_LOG((tdb, 0, "tdb_transaction_recover: recovered %d byte database\n", + recovery_eof)); + + /* all done */ + return 0; +} diff --git a/source3/tdb/traverse.c b/source3/tdb/traverse.c new file mode 100644 index 0000000000..d070e0a766 --- /dev/null +++ b/source3/tdb/traverse.c @@ -0,0 +1,334 @@ + /* + 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 2 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, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA +*/ + +#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, 0, "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, 0, "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, 0, "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, 0, "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; + + /* we need to get a read lock on the transaction lock here to + cope with the lock ordering semantics of solaris10 */ + if (tdb->methods->tdb_brlock(tdb, TRANSACTION_LOCK, F_RDLCK, F_SETLKW, 0) == -1) { + TDB_LOG((tdb, 0, "tdb_traverse_read: failed to get transaction lock\n")); + tdb->ecode = TDB_ERR_LOCK; + return -1; + } + + tdb->traverse_read++; + ret = tdb_traverse_internal(tdb, fn, private_data, &tl); + tdb->traverse_read--; + + tdb->methods->tdb_brlock(tdb, TRANSACTION_LOCK, F_UNLCK, F_SETLKW, 0); + + return ret; +} + +/* + a write style traverse - needs to get the transaction lock to + prevent deadlocks +*/ +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; + + if (tdb->read_only || tdb->traverse_read) { + return tdb_traverse_read(tdb, fn, private_data); + } + + if (tdb->methods->tdb_brlock(tdb, TRANSACTION_LOCK, F_WRLCK, F_SETLKW, 0) == -1) { + TDB_LOG((tdb, 0, "tdb_traverse: failed to get transaction lock\n")); + tdb->ecode = TDB_ERR_LOCK; + return -1; + } + + ret = tdb_traverse_internal(tdb, fn, private_data, &tl); + + tdb->methods->tdb_brlock(tdb, TRANSACTION_LOCK, F_UNLCK, F_SETLKW, 0); + + 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; + + 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); + if (tdb_unlock(tdb, BUCKET(tdb->travlocks.hash), F_WRLCK) != 0) + TDB_LOG((tdb, 0, "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) +{ + u32 oldhash; + TDB_DATA key = tdb_null; + struct list_struct rec; + 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,F_WRLCK)) + 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, F_WRLCK) != 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), F_WRLCK, &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, 0, "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, F_WRLCK) != 0) + TDB_LOG((tdb, 0, "tdb_nextkey: WARNING tdb_unlock failed!\n")); + } + /* Unlock the chain of old record */ + if (tdb_unlock(tdb, BUCKET(oldhash), F_WRLCK) != 0) + TDB_LOG((tdb, 0, "tdb_nextkey: WARNING tdb_unlock failed!\n")); + return key; +} + |