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Commit 19e6c1a2 authored by Rusty Russell's avatar Rusty Russell
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tdb2: import TDB1 code. 

We import the entire codebase, putting a "tdb1_" prefix on the files
and changing the "tdb_" prefix to "tdb1_" everywhere.

The next patches will gradually merge it with the TDB2 code where
necessary.
parent 47656743
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ccan/tdb2/tdb1.h 0 → 100644
View file @ 19e6c1a2
#ifndef TDB1_H
#define TDB1_H
/*
Unix SMB/CIFS implementation.
trivial database library (version 1 compat functions)
Copyright (C) Andrew Tridgell 1999-2004
Copyright (C) Rusty Russell 2011
** NOTE! The following LGPL license applies to the tdb
** library. This does NOT imply that all of Samba is released
** under the LGPL
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#ifndef _SAMBA_BUILD_
/* For mode_t */
#include <sys/types.h>
/* For O_* flags. */
#include <sys/stat.h>
/* For sig_atomic_t. */
#include <signal.h>
#endif
/** Flags to tdb1_store() */
#define TDB1_REPLACE 1 /** Unused */
#define TDB1_INSERT 2 /** Don't overwrite an existing entry */
#define TDB1_MODIFY 3 /** Don't create an existing entry */
/** Flags for tdb1_open() */
#define TDB1_DEFAULT 0 /** just a readability place holder */
#define TDB1_CLEAR_IF_FIRST 1 /** If this is the first open, wipe the db */
#define TDB1_INTERNAL 2 /** Don't store on disk */
#define TDB1_NOLOCK 4 /** Don't do any locking */
#define TDB1_NOMMAP 8 /** Don't use mmap */
#define TDB1_CONVERT 16 /** Convert endian (internal use) */
#define TDB1_BIGENDIAN 32 /** Header is big-endian (internal use) */
#define TDB1_NOSYNC 64 /** Don't use synchronous transactions */
#define TDB1_SEQNUM 128 /** Maintain a sequence number */
#define TDB1_VOLATILE 256 /** Activate the per-hashchain freelist, default 5 */
#define TDB1_ALLOW_NESTING 512 /** Allow transactions to nest */
#define TDB1_DISALLOW_NESTING 1024 /** Disallow transactions to nest */
#define TDB1_INCOMPATIBLE_HASH 2048 /** Better hashing: can't be opened by tdb < 1.2.6. */
/** The tdb error codes */
enum TDB1_ERROR {TDB1_SUCCESS=0, TDB1_ERR_CORRUPT, TDB1_ERR_IO, TDB1_ERR_LOCK,
TDB1_ERR_OOM, TDB1_ERR_EXISTS, TDB1_ERR_NOLOCK, TDB1_ERR_LOCK_TIMEOUT,
TDB1_ERR_NOEXIST, TDB1_ERR_EINVAL, TDB1_ERR_RDONLY,
TDB1_ERR_NESTING};
/** Debugging uses one of the following levels */
enum tdb1_debug_level {TDB1_DEBUG_FATAL = 0, TDB1_DEBUG_ERROR,
TDB1_DEBUG_WARNING, TDB1_DEBUG_TRACE};
/** The tdb data structure */
typedef struct TDB1_DATA {
unsigned char *dptr;
size_t dsize;
} TDB1_DATA;
#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 tdb1_context TDB1_CONTEXT;
typedef int (*tdb1_traverse_func)(struct tdb1_context *, TDB1_DATA, TDB1_DATA, void *);
typedef void (*tdb1_log_func)(struct tdb1_context *, enum tdb1_debug_level, const char *, ...) PRINTF_ATTRIBUTE(3, 4);
typedef unsigned int (*tdb1_hash_func)(TDB1_DATA *key);
struct tdb1_logging_context {
tdb1_log_func log_fn;
void *log_private;
};
struct tdb1_context *tdb1_open(const char *name, int hash_size, int tdb1_flags,
int open_flags, mode_t mode);
struct tdb1_context *tdb1_open_ex(const char *name, int hash_size, int tdb1_flags,
int open_flags, mode_t mode,
const struct tdb1_logging_context *log_ctx,
tdb1_hash_func hash_fn);
void tdb1_set_max_dead(struct tdb1_context *tdb, int max_dead);
int tdb1_reopen(struct tdb1_context *tdb);
int tdb1_reopen_all(int parent_longlived);
void tdb1_set_logging_function(struct tdb1_context *tdb, const struct tdb1_logging_context *log_ctx);
enum TDB1_ERROR tdb1_error(struct tdb1_context *tdb);
const char *tdb1_errorstr(struct tdb1_context *tdb);
TDB1_DATA tdb1_fetch(struct tdb1_context *tdb, TDB1_DATA key);
int tdb1_parse_record(struct tdb1_context *tdb, TDB1_DATA key,
int (*parser)(TDB1_DATA key, TDB1_DATA data,
void *private_data),
void *private_data);
int tdb1_delete(struct tdb1_context *tdb, TDB1_DATA key);
int tdb1_store(struct tdb1_context *tdb, TDB1_DATA key, TDB1_DATA dbuf, int flag);
int tdb1_append(struct tdb1_context *tdb, TDB1_DATA key, TDB1_DATA new_dbuf);
int tdb1_close(struct tdb1_context *tdb);
TDB1_DATA tdb1_firstkey(struct tdb1_context *tdb);
TDB1_DATA tdb1_nextkey(struct tdb1_context *tdb, TDB1_DATA key);
int tdb1_traverse(struct tdb1_context *tdb, tdb1_traverse_func fn, void *private_data);
int tdb1_traverse_read(struct tdb1_context *tdb, tdb1_traverse_func fn, void *private_data);
int tdb1_exists(struct tdb1_context *tdb, TDB1_DATA key);
int tdb1_lockall(struct tdb1_context *tdb);
int tdb1_lockall_nonblock(struct tdb1_context *tdb);
int tdb1_unlockall(struct tdb1_context *tdb);
int tdb1_lockall_read(struct tdb1_context *tdb);
int tdb1_lockall_read_nonblock(struct tdb1_context *tdb);
int tdb1_unlockall_read(struct tdb1_context *tdb);
int tdb1_lockall_mark(struct tdb1_context *tdb);
int tdb1_lockall_unmark(struct tdb1_context *tdb);
const char *tdb1_name(struct tdb1_context *tdb);
int tdb1_fd(struct tdb1_context *tdb);
tdb1_log_func tdb1_log_fn(struct tdb1_context *tdb);
void *tdb1_get_logging_private(struct tdb1_context *tdb);
int tdb1_transaction_start(struct tdb1_context *tdb);
int tdb1_transaction_start_nonblock(struct tdb1_context *tdb);
int tdb1_transaction_prepare_commit(struct tdb1_context *tdb);
int tdb1_transaction_commit(struct tdb1_context *tdb);
int tdb1_transaction_cancel(struct tdb1_context *tdb);
int tdb1_get_seqnum(struct tdb1_context *tdb);
int tdb1_hash_size(struct tdb1_context *tdb);
size_t tdb1_map_size(struct tdb1_context *tdb);
int tdb1_get_flags(struct tdb1_context *tdb);
void tdb1_add_flags(struct tdb1_context *tdb, unsigned flag);
void tdb1_remove_flags(struct tdb1_context *tdb, unsigned flag);
void tdb1_enable_seqnum(struct tdb1_context *tdb);
void tdb1_increment_seqnum_nonblock(struct tdb1_context *tdb);
unsigned int tdb1_jenkins_hash(TDB1_DATA *key);
int tdb1_check(struct tdb1_context *tdb,
int (*check) (TDB1_DATA key, TDB1_DATA data, void *private_data),
void *private_data);
/* @} ******************************************************************/
/* Low level locking functions: use with care */
int tdb1_chainlock(struct tdb1_context *tdb, TDB1_DATA key);
int tdb1_chainlock_nonblock(struct tdb1_context *tdb, TDB1_DATA key);
int tdb1_chainunlock(struct tdb1_context *tdb, TDB1_DATA key);
int tdb1_chainlock_read(struct tdb1_context *tdb, TDB1_DATA key);
int tdb1_chainunlock_read(struct tdb1_context *tdb, TDB1_DATA key);
int tdb1_chainlock_mark(struct tdb1_context *tdb, TDB1_DATA key);
int tdb1_chainlock_unmark(struct tdb1_context *tdb, TDB1_DATA key);
void tdb1_setalarm_sigptr(struct tdb1_context *tdb, volatile sig_atomic_t *sigptr);
/* wipe and repack */
int tdb1_wipe_all(struct tdb1_context *tdb);
int tdb1_repack(struct tdb1_context *tdb);
/* Debug functions. Not used in production. */
void tdb1_dump_all(struct tdb1_context *tdb);
int tdb1_printfreelist(struct tdb1_context *tdb);
int tdb1_validate_freelist(struct tdb1_context *tdb, int *pnum_entries);
int tdb1_freelist_size(struct tdb1_context *tdb);
char *tdb1_summary(struct tdb1_context *tdb);
extern TDB1_DATA tdb1_null;
#endif /* tdb1.h */
ccan/tdb2/tdb1_check.c 0 → 100644
View file @ 19e6c1a2
/*
Unix SMB/CIFS implementation.
trivial database library
Copyright (C) Rusty Russell 2009
** NOTE! The following LGPL license applies to the tdb
** library. This does NOT imply that all of Samba is released
** under the LGPL
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "tdb1_private.h"
/* Since we opened it, these shouldn't fail unless it's recent corruption. */
static bool tdb1_check_header(struct tdb1_context *tdb, tdb1_off_t *recovery)
{
struct tdb1_header hdr;
uint32_t h1, h2;
if (tdb->methods->tdb1_read(tdb, 0, &hdr, sizeof(hdr), 0) == -1)
return false;
if (strcmp(hdr.magic_food, TDB1_MAGIC_FOOD) != 0)
goto corrupt;
TDB1_CONV(hdr);
if (hdr.version != TDB1_VERSION)
goto corrupt;
if (hdr.rwlocks != 0 && hdr.rwlocks != TDB1_HASH_RWLOCK_MAGIC)
goto corrupt;
tdb1_header_hash(tdb, &h1, &h2);
if (hdr.magic1_hash && hdr.magic2_hash &&
(hdr.magic1_hash != h1 || hdr.magic2_hash != h2))
goto corrupt;
if (hdr.hash_size == 0)
goto corrupt;
if (hdr.hash_size != tdb->header.hash_size)
goto corrupt;
if (hdr.recovery_start != 0 &&
hdr.recovery_start < TDB1_DATA_START(tdb->header.hash_size))
goto corrupt;
*recovery = hdr.recovery_start;
return true;
corrupt:
tdb->ecode = TDB1_ERR_CORRUPT;
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "Header is corrupt\n"));
return false;
}
/* Generic record header check. */
static bool tdb1_check_record(struct tdb1_context *tdb,
tdb1_off_t off,
const struct tdb1_record *rec)
{
tdb1_off_t tailer;
/* Check rec->next: 0 or points to record offset, aligned. */
if (rec->next > 0 && rec->next < TDB1_DATA_START(tdb->header.hash_size)){
TDB1_LOG((tdb, TDB1_DEBUG_ERROR,
"Record offset %d too small next %d\n",
off, rec->next));
goto corrupt;
}
if (rec->next + sizeof(*rec) < rec->next) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR,
"Record offset %d too large next %d\n",
off, rec->next));
goto corrupt;
}
if ((rec->next % TDB1_ALIGNMENT) != 0) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR,
"Record offset %d misaligned next %d\n",
off, rec->next));
goto corrupt;
}
if (tdb->methods->tdb1_oob(tdb, rec->next+sizeof(*rec), 0))
goto corrupt;
/* Check rec_len: similar to rec->next, implies next record. */
if ((rec->rec_len % TDB1_ALIGNMENT) != 0) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR,
"Record offset %d misaligned length %d\n",
off, rec->rec_len));
goto corrupt;
}
/* Must fit tailer. */
if (rec->rec_len < sizeof(tailer)) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR,
"Record offset %d too short length %d\n",
off, rec->rec_len));
goto corrupt;
}
/* OOB allows "right at the end" access, so this works for last rec. */
if (tdb->methods->tdb1_oob(tdb, off+sizeof(*rec)+rec->rec_len, 0))
goto corrupt;
/* Check tailer. */
if (tdb1_ofs_read(tdb, off+sizeof(*rec)+rec->rec_len-sizeof(tailer),
&tailer) == -1)
goto corrupt;
if (tailer != sizeof(*rec) + rec->rec_len) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR,
"Record offset %d invalid tailer\n", off));
goto corrupt;
}
return true;
corrupt:
tdb->ecode = TDB1_ERR_CORRUPT;
return false;
}
/* Grab some bytes: may copy if can't use mmap.
Caller has already done bounds check. */
static TDB1_DATA get_bytes(struct tdb1_context *tdb,
tdb1_off_t off, tdb1_len_t len)
{
TDB1_DATA d;
d.dsize = len;
if (tdb->transaction == NULL && tdb->map_ptr != NULL)
d.dptr = (unsigned char *)tdb->map_ptr + off;
else
d.dptr = tdb1_alloc_read(tdb, off, d.dsize);
return d;
}
/* Frees data if we're not able to simply use mmap. */
static void put_bytes(struct tdb1_context *tdb, TDB1_DATA d)
{
if (tdb->transaction == NULL && tdb->map_ptr != NULL)
return;
free(d.dptr);
}
/* We use the excellent Jenkins lookup3 hash; this is based on hash_word2.
* See: http://burtleburtle.net/bob/c/lookup3.c
*/
#define rot(x,k) (((x)<<(k)) | ((x)>>(32-(k))))
static void jhash(uint32_t key, uint32_t *pc, uint32_t *pb)
{
uint32_t a,b,c;
/* Set up the internal state */
a = b = c = 0xdeadbeef + *pc;
c += *pb;
a += key;
c ^= b; c -= rot(b,14);
a ^= c; a -= rot(c,11);
b ^= a; b -= rot(a,25);
c ^= b; c -= rot(b,16);
a ^= c; a -= rot(c,4);
b ^= a; b -= rot(a,14);
c ^= b; c -= rot(b,24);
*pc=c; *pb=b;
}
/*
We want to check that all free records are in the free list
(only once), and all free list entries are free records. Similarly
for each hash chain of used records.
Doing that naively (without walking hash chains, since we want to be
linear) means keeping a list of records which have been seen in each
hash chain, and another of records pointed to (ie. next pointers
from records and the initial hash chain heads). These two lists
should be equal. This will take 8 bytes per record, and require
sorting at the end.
So instead, we record each offset in a bitmap such a way that
recording it twice will cancel out. Since each offset should appear
exactly twice, the bitmap should be zero at the end.
The approach was inspired by Bloom Filters (see Wikipedia). For
each value, we flip K bits in a bitmap of size N. The number of
distinct arrangements is:
N! / (K! * (N-K)!)
Of course, not all arrangements are actually distinct, but testing
shows this formula to be close enough.
So, if K == 8 and N == 256, the probability of two things flipping the same
bits is 1 in 409,663,695,276,000.
Given that ldb uses a hash size of 10000, using 32 bytes per hash chain
(320k) seems reasonable.
*/
#define NUM_HASHES 8
#define BITMAP_BITS 256
static void bit_flip(unsigned char bits[], unsigned int idx)
{
bits[idx / CHAR_BIT] ^= (1 << (idx % CHAR_BIT));
}
/* We record offsets in a bitmap for the particular chain it should be in. */
static void record_offset(unsigned char bits[], tdb1_off_t off)
{
uint32_t h1 = off, h2 = 0;
unsigned int i;
/* We get two good hash values out of jhash2, so we use both. Then
* we keep going to produce further hash values. */
for (i = 0; i < NUM_HASHES / 2; i++) {
jhash(off, &h1, &h2);
bit_flip(bits, h1 % BITMAP_BITS);
bit_flip(bits, h2 % BITMAP_BITS);
h2++;
}
}
/* Check that an in-use record is valid. */
static bool tdb1_check_used_record(struct tdb1_context *tdb,
tdb1_off_t off,
const struct tdb1_record *rec,
unsigned char **hashes,
int (*check)(TDB1_DATA, TDB1_DATA, void *),
void *private_data)
{
TDB1_DATA key, data;
if (!tdb1_check_record(tdb, off, rec))
return false;
/* key + data + tailer must fit in record */
if (rec->key_len + rec->data_len + sizeof(tdb1_off_t) > rec->rec_len) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR,
"Record offset %d too short for contents\n", off));
return false;
}
key = get_bytes(tdb, off + sizeof(*rec), rec->key_len);
if (!key.dptr)
return false;
if (tdb->hash_fn(&key) != rec->full_hash) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR,
"Record offset %d has incorrect hash\n", off));
goto fail_put_key;
}
/* Mark this offset as a known value for this hash bucket. */
record_offset(hashes[TDB1_BUCKET(rec->full_hash)+1], off);
/* And similarly if the next pointer is valid. */
if (rec->next)
record_offset(hashes[TDB1_BUCKET(rec->full_hash)+1], rec->next);
/* If they supply a check function and this record isn't dead,
get data and feed it. */
if (check && rec->magic != TDB1_DEAD_MAGIC) {
data = get_bytes(tdb, off + sizeof(*rec) + rec->key_len,
rec->data_len);
if (!data.dptr)
goto fail_put_key;
if (check(key, data, private_data) == -1)
goto fail_put_data;
put_bytes(tdb, data);
}
put_bytes(tdb, key);
return true;
fail_put_data:
put_bytes(tdb, data);
fail_put_key:
put_bytes(tdb, key);
return false;
}
/* Check that an unused record is valid. */
static bool tdb1_check_free_record(struct tdb1_context *tdb,
tdb1_off_t off,
const struct tdb1_record *rec,
unsigned char **hashes)
{
if (!tdb1_check_record(tdb, off, rec))
return false;
/* Mark this offset as a known value for the free list. */
record_offset(hashes[0], off);
/* And similarly if the next pointer is valid. */
if (rec->next)
record_offset(hashes[0], rec->next);
return true;
}
/* Slow, but should be very rare. */
size_t tdb1_dead_space(struct tdb1_context *tdb, tdb1_off_t off)
{
size_t len;
for (len = 0; off + len < tdb->map_size; len++) {
char c;
if (tdb->methods->tdb1_read(tdb, off, &c, 1, 0))
return 0;
if (c != 0 && c != 0x42)
break;
}
return len;
}
_PUBLIC_ int tdb1_check(struct tdb1_context *tdb,
int (*check)(TDB1_DATA key, TDB1_DATA data, void *private_data),
void *private_data)
{
unsigned int h;
unsigned char **hashes;
tdb1_off_t off, recovery_start;
struct tdb1_record rec;
bool found_recovery = false;
tdb1_len_t dead;
bool locked;
/* Read-only databases use no locking at all: it's best-effort.
* We may have a write lock already, so skip that case too. */
if (tdb->read_only || tdb->allrecord_lock.count != 0) {
locked = false;
} else {
if (tdb1_lockall_read(tdb) == -1)
return -1;
locked = true;
}
/* Make sure we know true size of the underlying file. */
tdb->methods->tdb1_oob(tdb, tdb->map_size + 1, 1);
/* Header must be OK: also gets us the recovery ptr, if any. */
if (!tdb1_check_header(tdb, &recovery_start))
goto unlock;
/* We should have the whole header, too. */
if (tdb->map_size < TDB1_DATA_START(tdb->header.hash_size)) {
tdb->ecode = TDB1_ERR_CORRUPT;
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "File too short for hashes\n"));
goto unlock;
}
/* One big malloc: pointers then bit arrays. */
hashes = (unsigned char **)calloc(
1, sizeof(hashes[0]) * (1+tdb->header.hash_size)
+ BITMAP_BITS / CHAR_BIT * (1+tdb->header.hash_size));
if (!hashes) {
tdb->ecode = TDB1_ERR_OOM;
goto unlock;
}
/* Initialize pointers */
hashes[0] = (unsigned char *)(&hashes[1+tdb->header.hash_size]);
for (h = 1; h < 1+tdb->header.hash_size; h++)
hashes[h] = hashes[h-1] + BITMAP_BITS / CHAR_BIT;
/* Freelist and hash headers are all in a row: read them. */
for (h = 0; h < 1+tdb->header.hash_size; h++) {
if (tdb1_ofs_read(tdb, TDB1_FREELIST_TOP + h*sizeof(tdb1_off_t),
&off) == -1)
goto free;
if (off)
record_offset(hashes[h], off);
}
/* For each record, read it in and check it's ok. */
for (off = TDB1_DATA_START(tdb->header.hash_size);
off < tdb->map_size;
off += sizeof(rec) + rec.rec_len) {
if (tdb->methods->tdb1_read(tdb, off, &rec, sizeof(rec),
TDB1_DOCONV()) == -1)
goto free;
switch (rec.magic) {
case TDB1_MAGIC:
case TDB1_DEAD_MAGIC:
if (!tdb1_check_used_record(tdb, off, &rec, hashes,
check, private_data))
goto free;
break;
case TDB1_FREE_MAGIC:
if (!tdb1_check_free_record(tdb, off, &rec, hashes))
goto free;
break;
/* If we crash after ftruncate, we can get zeroes or fill. */
case TDB1_RECOVERY_INVALID_MAGIC:
case 0x42424242:
if (recovery_start == off) {
found_recovery = true;
break;
}
dead = tdb1_dead_space(tdb, off);
if (dead < sizeof(rec))
goto corrupt;
TDB1_LOG((tdb, TDB1_DEBUG_ERROR,
"Dead space at %d-%d (of %u)\n",
off, off + dead, tdb->map_size));
rec.rec_len = dead - sizeof(rec);
break;
case TDB1_RECOVERY_MAGIC:
if (recovery_start != off) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR,
"Unexpected recovery record at offset %d\n",
off));
goto free;
}
found_recovery = true;
break;
default: ;
corrupt:
tdb->ecode = TDB1_ERR_CORRUPT;
TDB1_LOG((tdb, TDB1_DEBUG_ERROR,
"Bad magic 0x%x at offset %d\n",
rec.magic, off));
goto free;
}
}
/* Now, hashes should all be empty: each record exists and is referred
* to by one other. */
for (h = 0; h < 1+tdb->header.hash_size; h++) {
unsigned int i;
for (i = 0; i < BITMAP_BITS / CHAR_BIT; i++) {
if (hashes[h][i] != 0) {
tdb->ecode = TDB1_ERR_CORRUPT;
TDB1_LOG((tdb, TDB1_DEBUG_ERROR,
"Hashes do not match records\n"));
goto free;
}
}
}
/* We must have found recovery area if there was one. */
if (recovery_start != 0 && !found_recovery) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR,
"Expected a recovery area at %u\n",
recovery_start));
goto free;
}
free(hashes);
if (locked) {
tdb1_unlockall_read(tdb);
}
return 0;
free:
free(hashes);
unlock:
if (locked) {
tdb1_unlockall_read(tdb);
}
return -1;
}
ccan/tdb2/tdb1_dump.c 0 → 100644
View file @ 19e6c1a2
/*
Unix SMB/CIFS implementation.
trivial database library
Copyright (C) Andrew Tridgell 1999-2005
Copyright (C) Paul `Rusty' Russell 2000
Copyright (C) Jeremy Allison 2000-2003
** NOTE! The following LGPL license applies to the tdb
** library. This does NOT imply that all of Samba is released
** under the LGPL
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "tdb1_private.h"
static tdb1_off_t tdb1_dump_record(struct tdb1_context *tdb, int hash,
tdb1_off_t offset)
{
struct tdb1_record rec;
tdb1_off_t tailer_ofs, tailer;
if (tdb->methods->tdb1_read(tdb, offset, (char *)&rec,
sizeof(rec), TDB1_DOCONV()) == -1) {
printf("ERROR: failed to read record at %u\n", offset);
return 0;
}
printf(" rec: hash=%d offset=0x%08x next=0x%08x rec_len=%d "
"key_len=%d data_len=%d full_hash=0x%x magic=0x%x\n",
hash, offset, rec.next, rec.rec_len, rec.key_len, rec.data_len,
rec.full_hash, rec.magic);
tailer_ofs = offset + sizeof(rec) + rec.rec_len - sizeof(tdb1_off_t);
if (tdb1_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 tdb1_dump_chain(struct tdb1_context *tdb, int i)
{
tdb1_off_t rec_ptr, top;
top = TDB1_HASH_TOP(i);
if (tdb1_lock(tdb, i, F_WRLCK) != 0)
return -1;
if (tdb1_ofs_read(tdb, top, &rec_ptr) == -1)
return tdb1_unlock(tdb, i, F_WRLCK);
if (rec_ptr)
printf("hash=%d\n", i);
while (rec_ptr) {
rec_ptr = tdb1_dump_record(tdb, i, rec_ptr);
}
return tdb1_unlock(tdb, i, F_WRLCK);
}
_PUBLIC_ void tdb1_dump_all(struct tdb1_context *tdb)
{
int i;
for (i=0;i<tdb->header.hash_size;i++) {
tdb1_dump_chain(tdb, i);
}
printf("freelist:\n");
tdb1_dump_chain(tdb, -1);
}
_PUBLIC_ int tdb1_printfreelist(struct tdb1_context *tdb)
{
int ret;
long total_free = 0;
tdb1_off_t offset, rec_ptr;
struct tdb1_record rec;
if ((ret = tdb1_lock(tdb, -1, F_WRLCK)) != 0)
return ret;
offset = TDB1_FREELIST_TOP;
/* read in the freelist top */
if (tdb1_ofs_read(tdb, offset, &rec_ptr) == -1) {
tdb1_unlock(tdb, -1, F_WRLCK);
return 0;
}
printf("freelist top=[0x%08x]\n", rec_ptr );
while (rec_ptr) {
if (tdb->methods->tdb1_read(tdb, rec_ptr, (char *)&rec,
sizeof(rec), TDB1_DOCONV()) == -1) {
tdb1_unlock(tdb, -1, F_WRLCK);
return -1;
}
if (rec.magic != TDB1_FREE_MAGIC) {
printf("bad magic 0x%08x in free list\n", rec.magic);
tdb1_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 tdb1_unlock(tdb, -1, F_WRLCK);
}
ccan/tdb2/tdb1_error.c 0 → 100644
View file @ 19e6c1a2
/*
Unix SMB/CIFS implementation.
trivial database library
Copyright (C) Andrew Tridgell 1999-2005
Copyright (C) Paul `Rusty' Russell 2000
Copyright (C) Jeremy Allison 2000-2003
** NOTE! The following LGPL license applies to the tdb
** library. This does NOT imply that all of Samba is released
** under the LGPL
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "tdb1_private.h"
_PUBLIC_ enum TDB1_ERROR tdb1_error(struct tdb1_context *tdb)
{
return tdb->ecode;
}
static struct tdb1_errname {
enum TDB1_ERROR ecode; const char *estring;
} emap[] = { {TDB1_SUCCESS, "Success"},
{TDB1_ERR_CORRUPT, "Corrupt database"},
{TDB1_ERR_IO, "IO Error"},
{TDB1_ERR_LOCK, "Locking error"},
{TDB1_ERR_OOM, "Out of memory"},
{TDB1_ERR_EXISTS, "Record exists"},
{TDB1_ERR_NOLOCK, "Lock exists on other keys"},
{TDB1_ERR_EINVAL, "Invalid parameter"},
{TDB1_ERR_NOEXIST, "Record does not exist"},
{TDB1_ERR_RDONLY, "write not permitted"} };
/* Error string for the last tdb error */
_PUBLIC_ const char *tdb1_errorstr(struct tdb1_context *tdb)
{
uint32_t i;
for (i = 0; i < sizeof(emap) / sizeof(struct tdb1_errname); i++)
if (tdb->ecode == emap[i].ecode)
return emap[i].estring;
return "Invalid error code";
}
ccan/tdb2/tdb1_freelist.c 0 → 100644
View file @ 19e6c1a2
/*
Unix SMB/CIFS implementation.
trivial database library
Copyright (C) Andrew Tridgell 1999-2005
Copyright (C) Paul `Rusty' Russell 2000
Copyright (C) Jeremy Allison 2000-2003
** NOTE! The following LGPL license applies to the tdb
** library. This does NOT imply that all of Samba is released
** under the LGPL
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "tdb1_private.h"
/* 'right' merges can involve O(n^2) cost when combined with a
traverse, so they are disabled until we find a way to do them in
O(1) time
*/
#define USE_RIGHT_MERGES 0
/* read a freelist record and check for simple errors */
int tdb1_rec_free_read(struct tdb1_context *tdb, tdb1_off_t off, struct tdb1_record *rec)
{
if (tdb->methods->tdb1_read(tdb, off, rec, sizeof(*rec),TDB1_DOCONV()) == -1)
return -1;
if (rec->magic == TDB1_MAGIC) {
/* this happens when a app is showdown while deleting a record - we should
not completely fail when this happens */
TDB1_LOG((tdb, TDB1_DEBUG_WARNING, "tdb1_rec_free_read non-free magic 0x%x at offset=%d - fixing\n",
rec->magic, off));
rec->magic = TDB1_FREE_MAGIC;
if (tdb->methods->tdb1_write(tdb, off, rec, sizeof(*rec)) == -1)
return -1;
}
if (rec->magic != TDB1_FREE_MAGIC) {
/* Ensure ecode is set for log fn. */
tdb->ecode = TDB1_ERR_CORRUPT;
TDB1_LOG((tdb, TDB1_DEBUG_WARNING, "tdb1_rec_free_read bad magic 0x%x at offset=%d\n",
rec->magic, off));
return -1;
}
if (tdb->methods->tdb1_oob(tdb, rec->next+sizeof(*rec), 0) != 0)
return -1;
return 0;
}
#if USE_RIGHT_MERGES
/* Remove an element from the freelist. Must have alloc lock. */
static int remove_from_freelist(struct tdb1_context *tdb, tdb1_off_t off, tdb1_off_t next)
{
tdb1_off_t last_ptr, i;
/* read in the freelist top */
last_ptr = TDB1_FREELIST_TOP;
while (tdb1_ofs_read(tdb, last_ptr, &i) != -1 && i != 0) {
if (i == off) {
/* We've found it! */
return tdb1_ofs_write(tdb, last_ptr, &next);
}
/* Follow chain (next offset is at start of record) */
last_ptr = i;
}
tdb->ecode = TDB1_ERR_CORRUPT;
TDB1_LOG((tdb, TDB1_DEBUG_FATAL,"remove_from_freelist: not on list at off=%d\n", off));
return -1;
}
#endif
/* update a record tailer (must hold allocation lock) */
static int update_tailer(struct tdb1_context *tdb, tdb1_off_t offset,
const struct tdb1_record *rec)
{
tdb1_off_t totalsize;
/* Offset of tailer from record header */
totalsize = sizeof(*rec) + rec->rec_len;
return tdb1_ofs_write(tdb, offset + totalsize - sizeof(tdb1_off_t),
&totalsize);
}
/* Add an element into the freelist. Merge adjacent records if
necessary. */
int tdb1_free(struct tdb1_context *tdb, tdb1_off_t offset, struct tdb1_record *rec)
{
/* Allocation and tailer lock */
if (tdb1_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) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_free: update_tailer failed!\n"));
goto fail;
}
#if USE_RIGHT_MERGES
/* Look right first (I'm an Australian, dammit) */
if (offset + sizeof(*rec) + rec->rec_len + sizeof(*rec) <= tdb->map_size) {
tdb1_off_t right = offset + sizeof(*rec) + rec->rec_len;
struct tdb1_record r;
if (tdb->methods->tdb1_read(tdb, right, &r, sizeof(r), TDB1_DOCONV()) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_free: right read failed at %u\n", right));
goto left;
}
/* If it's free, expand to include it. */
if (r.magic == TDB1_FREE_MAGIC) {
if (remove_from_freelist(tdb, right, r.next) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_free: right free failed at %u\n", right));
goto left;
}
rec->rec_len += sizeof(r) + r.rec_len;
if (update_tailer(tdb, offset, rec) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_free: update_tailer failed at %u\n", offset));
goto fail;
}
}
}
left:
#endif
/* Look left */
if (offset - sizeof(tdb1_off_t) > TDB1_DATA_START(tdb->header.hash_size)) {
tdb1_off_t left = offset - sizeof(tdb1_off_t);
struct tdb1_record l;
tdb1_off_t leftsize;
/* Read in tailer and jump back to header */
if (tdb1_ofs_read(tdb, left, &leftsize) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_free: left offset read failed at %u\n", left));
goto update;
}
/* it could be uninitialised data */
if (leftsize == 0 || leftsize == TDB1_PAD_U32) {
goto update;
}
left = offset - leftsize;
if (leftsize > offset ||
left < TDB1_DATA_START(tdb->header.hash_size)) {
goto update;
}
/* Now read in the left record */
if (tdb->methods->tdb1_read(tdb, left, &l, sizeof(l), TDB1_DOCONV()) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_free: left read failed at %u (%u)\n", left, leftsize));
goto update;
}
/* If it's free, expand to include it. */
if (l.magic == TDB1_FREE_MAGIC) {
/* we now merge the new record into the left record, rather than the other
way around. This makes the operation O(1) instead of O(n). This change
prevents traverse from being O(n^2) after a lot of deletes */
l.rec_len += sizeof(*rec) + rec->rec_len;
if (tdb1_rec_write(tdb, left, &l) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_free: update_left failed at %u\n", left));
goto fail;
}
if (update_tailer(tdb, left, &l) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_free: update_tailer failed at %u\n", offset));
goto fail;
}
tdb1_unlock(tdb, -1, F_WRLCK);
return 0;
}
}
update:
/* Now, prepend to free list */
rec->magic = TDB1_FREE_MAGIC;
if (tdb1_ofs_read(tdb, TDB1_FREELIST_TOP, &rec->next) == -1 ||
tdb1_rec_write(tdb, offset, rec) == -1 ||
tdb1_ofs_write(tdb, TDB1_FREELIST_TOP, &offset) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_free record write failed at offset=%d\n", offset));
goto fail;
}
/* And we're done. */
tdb1_unlock(tdb, -1, F_WRLCK);
return 0;
fail:
tdb1_unlock(tdb, -1, F_WRLCK);
return -1;
}
/*
the core of tdb1_allocate - called when we have decided which
free list entry to use
Note that we try to allocate by grabbing data from the end of an existing record,
not the beginning. This is so the left merge in a free is more likely to be
able to free up the record without fragmentation
*/
static tdb1_off_t tdb1_allocate_ofs(struct tdb1_context *tdb,
tdb1_len_t length, tdb1_off_t rec_ptr,
struct tdb1_record *rec, tdb1_off_t last_ptr)
{
#define MIN_REC_SIZE (sizeof(struct tdb1_record) + sizeof(tdb1_off_t) + 8)
if (rec->rec_len < length + MIN_REC_SIZE) {
/* we have to grab the whole record */
/* unlink it from the previous record */
if (tdb1_ofs_write(tdb, last_ptr, &rec->next) == -1) {
return 0;
}
/* mark it not free */
rec->magic = TDB1_MAGIC;
if (tdb1_rec_write(tdb, rec_ptr, rec) == -1) {
return 0;
}
return rec_ptr;
}
/* we're going to just shorten the existing record */
rec->rec_len -= (length + sizeof(*rec));
if (tdb1_rec_write(tdb, rec_ptr, rec) == -1) {
return 0;
}
if (update_tailer(tdb, rec_ptr, rec) == -1) {
return 0;
}
/* and setup the new record */
rec_ptr += sizeof(*rec) + rec->rec_len;
memset(rec, '\0', sizeof(*rec));
rec->rec_len = length;
rec->magic = TDB1_MAGIC;
if (tdb1_rec_write(tdb, rec_ptr, rec) == -1) {
return 0;
}
if (update_tailer(tdb, rec_ptr, rec) == -1) {
return 0;
}
return rec_ptr;
}
/* allocate some space from the free list. The offset returned points
to a unconnected tdb1_record within the database with room for at
least length bytes of total data
0 is returned if the space could not be allocated
*/
tdb1_off_t tdb1_allocate(struct tdb1_context *tdb, tdb1_len_t length, struct tdb1_record *rec)
{
tdb1_off_t rec_ptr, last_ptr, newrec_ptr;
struct {
tdb1_off_t rec_ptr, last_ptr;
tdb1_len_t rec_len;
} bestfit;
float multiplier = 1.0;
if (tdb1_lock(tdb, -1, F_WRLCK) == -1)
return 0;
/* over-allocate to reduce fragmentation */
length *= 1.25;
/* Extra bytes required for tailer */
length += sizeof(tdb1_off_t);
length = TDB1_ALIGN(length, TDB1_ALIGNMENT);
again:
last_ptr = TDB1_FREELIST_TOP;
/* read in the freelist top */
if (tdb1_ofs_read(tdb, TDB1_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 (tdb1_rec_free_read(tdb, rec_ptr, rec) == -1) {
goto fail;
}
if (rec->rec_len >= length) {
if (bestfit.rec_ptr == 0 ||
rec->rec_len < bestfit.rec_len) {
bestfit.rec_len = rec->rec_len;
bestfit.rec_ptr = rec_ptr;
bestfit.last_ptr = last_ptr;
}
}
/* move to the next record */
last_ptr = rec_ptr;
rec_ptr = rec->next;
/* if we've found a record that is big enough, then
stop searching if its also not too big. The
definition of 'too big' changes as we scan
through */
if (bestfit.rec_len > 0 &&
bestfit.rec_len < length * multiplier) {
break;
}
/* this multiplier means we only extremely rarely
search more than 50 or so records. At 50 records we
accept records up to 11 times larger than what we
want */
multiplier *= 1.05;
}
if (bestfit.rec_ptr != 0) {
if (tdb1_rec_free_read(tdb, bestfit.rec_ptr, rec) == -1) {
goto fail;
}
newrec_ptr = tdb1_allocate_ofs(tdb, length, bestfit.rec_ptr,
rec, bestfit.last_ptr);
tdb1_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 (tdb1_expand(tdb, length + sizeof(*rec)) == 0)
goto again;
fail:
tdb1_unlock(tdb, -1, F_WRLCK);
return 0;
}
/*
return the size of the freelist - used to decide if we should repack
*/
_PUBLIC_ int tdb1_freelist_size(struct tdb1_context *tdb)
{
tdb1_off_t ptr;
int count=0;
if (tdb1_lock(tdb, -1, F_RDLCK) == -1) {
return -1;
}
ptr = TDB1_FREELIST_TOP;
while (tdb1_ofs_read(tdb, ptr, &ptr) == 0 && ptr != 0) {
count++;
}
tdb1_unlock(tdb, -1, F_RDLCK);
return count;
}
ccan/tdb2/tdb1_freelistcheck.c 0 → 100644
View file @ 19e6c1a2
/*
Unix SMB/CIFS implementation.
trivial database library
Copyright (C) Jeremy Allison 2006
** NOTE! The following LGPL license applies to the tdb
** library. This does NOT imply that all of Samba is released
** under the LGPL
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "tdb1_private.h"
/* Check the freelist is good and contains no loops.
Very memory intensive - only do this as a consistency
checker. Heh heh - uses an in memory tdb as the storage
for the "seen" record list. For some reason this strikes
me as extremely clever as I don't have to write another tree
data structure implementation :-).
*/
static int seen_insert(struct tdb1_context *mem_tdb, tdb1_off_t rec_ptr)
{
TDB1_DATA key, data;
memset(&data, '\0', sizeof(data));
key.dptr = (unsigned char *)&rec_ptr;
key.dsize = sizeof(rec_ptr);
return tdb1_store(mem_tdb, key, data, TDB1_INSERT);
}
_PUBLIC_ int tdb1_validate_freelist(struct tdb1_context *tdb, int *pnum_entries)
{
struct tdb1_context *mem_tdb = NULL;
struct tdb1_record rec;
tdb1_off_t rec_ptr, last_ptr;
int ret = -1;
*pnum_entries = 0;
mem_tdb = tdb1_open("flval", tdb->header.hash_size,
TDB1_INTERNAL, O_RDWR, 0600);
if (!mem_tdb) {
return -1;
}
if (tdb1_lock(tdb, -1, F_WRLCK) == -1) {
tdb1_close(mem_tdb);
return 0;
}
last_ptr = TDB1_FREELIST_TOP;
/* Store the TDB1_FREELIST_TOP record. */
if (seen_insert(mem_tdb, last_ptr) == -1) {
tdb->ecode = TDB1_ERR_CORRUPT;
ret = -1;
goto fail;
}
/* read in the freelist top */
if (tdb1_ofs_read(tdb, TDB1_FREELIST_TOP, &rec_ptr) == -1) {
goto fail;
}
while (rec_ptr) {
/* If we can't store this record (we've seen it
before) then the free list has a loop and must
be corrupt. */
if (seen_insert(mem_tdb, rec_ptr)) {
tdb->ecode = TDB1_ERR_CORRUPT;
ret = -1;
goto fail;
}
if (tdb1_rec_free_read(tdb, rec_ptr, &rec) == -1) {
goto fail;
}
/* move to the next record */
last_ptr = rec_ptr;
rec_ptr = rec.next;
*pnum_entries += 1;
}
ret = 0;
fail:
tdb1_close(mem_tdb);
tdb1_unlock(tdb, -1, F_WRLCK);
return ret;
}
ccan/tdb2/tdb1_hash.c 0 → 100644
View file @ 19e6c1a2
/*
Unix SMB/CIFS implementation.
trivial database library
Copyright (C) Rusty Russell 2010
** NOTE! The following LGPL license applies to the tdb
** library. This does NOT imply that all of Samba is released
** under the LGPL
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "tdb1_private.h"
/* This is based on the hash algorithm from gdbm */
unsigned int tdb1_old_hash(TDB1_DATA *key)
{
uint32_t value; /* Used to compute the hash value. */
uint32_t i; /* Used to cycle through random values. */
/* Set the initial value from the key size. */
for (value = 0x238F13AF * key->dsize, i=0; i < key->dsize; i++)
value = (value + (key->dptr[i] << (i*5 % 24)));
return (1103515243 * value + 12345);
}
#ifndef WORDS_BIGENDIAN
# define HASH_LITTLE_ENDIAN 1
# define HASH_BIG_ENDIAN 0
#else
# define HASH_LITTLE_ENDIAN 0
# define HASH_BIG_ENDIAN 1
#endif
/*
-------------------------------------------------------------------------------
lookup3.c, by Bob Jenkins, May 2006, Public Domain.
These are functions for producing 32-bit hashes for hash table lookup.
hash_word(), hashlittle(), hashlittle2(), hashbig(), mix(), and final()
are externally useful functions. Routines to test the hash are included
if SELF_TEST is defined. You can use this free for any purpose. It's in
the public domain. It has no warranty.
You probably want to use hashlittle(). hashlittle() and hashbig()
hash byte arrays. hashlittle() is is faster than hashbig() on
little-endian machines. Intel and AMD are little-endian machines.
On second thought, you probably want hashlittle2(), which is identical to
hashlittle() except it returns two 32-bit hashes for the price of one.
You could implement hashbig2() if you wanted but I haven't bothered here.
If you want to find a hash of, say, exactly 7 integers, do
a = i1; b = i2; c = i3;
mix(a,b,c);
a += i4; b += i5; c += i6;
mix(a,b,c);
a += i7;
final(a,b,c);
then use c as the hash value. If you have a variable length array of
4-byte integers to hash, use hash_word(). If you have a byte array (like
a character string), use hashlittle(). If you have several byte arrays, or
a mix of things, see the comments above hashlittle().
Why is this so big? I read 12 bytes at a time into 3 4-byte integers,
then mix those integers. This is fast (you can do a lot more thorough
mixing with 12*3 instructions on 3 integers than you can with 3 instructions
on 1 byte), but shoehorning those bytes into integers efficiently is messy.
*/
#define hashsize(n) ((uint32_t)1<<(n))
#define hashmask(n) (hashsize(n)-1)
#define rot(x,k) (((x)<<(k)) | ((x)>>(32-(k))))
/*
-------------------------------------------------------------------------------
mix -- mix 3 32-bit values reversibly.
This is reversible, so any information in (a,b,c) before mix() is
still in (a,b,c) after mix().
If four pairs of (a,b,c) inputs are run through mix(), or through
mix() in reverse, there are at least 32 bits of the output that
are sometimes the same for one pair and different for another pair.
This was tested for:
* pairs that differed by one bit, by two bits, in any combination
of top bits of (a,b,c), or in any combination of bottom bits of
(a,b,c).
* "differ" is defined as +, -, ^, or ~^. For + and -, I transformed
the output delta to a Gray code (a^(a>>1)) so a string of 1's (as
is commonly produced by subtraction) look like a single 1-bit
difference.
* the base values were pseudorandom, all zero but one bit set, or
all zero plus a counter that starts at zero.
Some k values for my "a-=c; a^=rot(c,k); c+=b;" arrangement that
satisfy this are
4 6 8 16 19 4
9 15 3 18 27 15
14 9 3 7 17 3
Well, "9 15 3 18 27 15" didn't quite get 32 bits diffing
for "differ" defined as + with a one-bit base and a two-bit delta. I
used http://burtleburtle.net/bob/hash/avalanche.html to choose
the operations, constants, and arrangements of the variables.
This does not achieve avalanche. There are input bits of (a,b,c)
that fail to affect some output bits of (a,b,c), especially of a. The
most thoroughly mixed value is c, but it doesn't really even achieve
avalanche in c.
This allows some parallelism. Read-after-writes are good at doubling
the number of bits affected, so the goal of mixing pulls in the opposite
direction as the goal of parallelism. I did what I could. Rotates
seem to cost as much as shifts on every machine I could lay my hands
on, and rotates are much kinder to the top and bottom bits, so I used
rotates.
-------------------------------------------------------------------------------
*/
#define mix(a,b,c) \
{ \
a -= c; a ^= rot(c, 4); c += b; \
b -= a; b ^= rot(a, 6); a += c; \
c -= b; c ^= rot(b, 8); b += a; \
a -= c; a ^= rot(c,16); c += b; \
b -= a; b ^= rot(a,19); a += c; \
c -= b; c ^= rot(b, 4); b += a; \
}
/*
-------------------------------------------------------------------------------
final -- final mixing of 3 32-bit values (a,b,c) into c
Pairs of (a,b,c) values differing in only a few bits will usually
produce values of c that look totally different. This was tested for
* pairs that differed by one bit, by two bits, in any combination
of top bits of (a,b,c), or in any combination of bottom bits of
(a,b,c).
* "differ" is defined as +, -, ^, or ~^. For + and -, I transformed
the output delta to a Gray code (a^(a>>1)) so a string of 1's (as
is commonly produced by subtraction) look like a single 1-bit
difference.
* the base values were pseudorandom, all zero but one bit set, or
all zero plus a counter that starts at zero.
These constants passed:
14 11 25 16 4 14 24
12 14 25 16 4 14 24
and these came close:
4 8 15 26 3 22 24
10 8 15 26 3 22 24
11 8 15 26 3 22 24
-------------------------------------------------------------------------------
*/
#define final(a,b,c) \
{ \
c ^= b; c -= rot(b,14); \
a ^= c; a -= rot(c,11); \
b ^= a; b -= rot(a,25); \
c ^= b; c -= rot(b,16); \
a ^= c; a -= rot(c,4); \
b ^= a; b -= rot(a,14); \
c ^= b; c -= rot(b,24); \
}
/*
-------------------------------------------------------------------------------
hashlittle() -- hash a variable-length key into a 32-bit value
k : the key (the unaligned variable-length array of bytes)
length : the length of the key, counting by bytes
val2 : IN: can be any 4-byte value OUT: second 32 bit hash.
Returns a 32-bit value. Every bit of the key affects every bit of
the return value. Two keys differing by one or two bits will have
totally different hash values. Note that the return value is better
mixed than val2, so use that first.
The best hash table sizes are powers of 2. There is no need to do
mod a prime (mod is sooo slow!). If you need less than 32 bits,
use a bitmask. For example, if you need only 10 bits, do
h = (h & hashmask(10));
In which case, the hash table should have hashsize(10) elements.
If you are hashing n strings (uint8_t **)k, do it like this:
for (i=0, h=0; i<n; ++i) h = hashlittle( k[i], len[i], h);
By Bob Jenkins, 2006. bob_jenkins@burtleburtle.net. You may use this
code any way you wish, private, educational, or commercial. It's free.
Use for hash table lookup, or anything where one collision in 2^^32 is
acceptable. Do NOT use for cryptographic purposes.
-------------------------------------------------------------------------------
*/
static uint32_t hashlittle( const void *key, size_t length )
{
uint32_t a,b,c; /* internal state */
union { const void *ptr; size_t i; } u; /* needed for Mac Powerbook G4 */
/* Set up the internal state */
a = b = c = 0xdeadbeef + ((uint32_t)length);
u.ptr = key;
if (HASH_LITTLE_ENDIAN && ((u.i & 0x3) == 0)) {
const uint32_t *k = (const uint32_t *)key; /* read 32-bit chunks */
const uint8_t *k8;
/*------ all but last block: aligned reads and affect 32 bits of (a,b,c) */
while (length > 12)
{
a += k[0];
b += k[1];
c += k[2];
mix(a,b,c);
length -= 12;
k += 3;
}
/*----------------------------- handle the last (probably partial) block */
k8 = (const uint8_t *)k;
switch(length)
{
case 12: c+=k[2]; b+=k[1]; a+=k[0]; break;
case 11: c+=((uint32_t)k8[10])<<16; /* fall through */
case 10: c+=((uint32_t)k8[9])<<8; /* fall through */
case 9 : c+=k8[8]; /* fall through */
case 8 : b+=k[1]; a+=k[0]; break;
case 7 : b+=((uint32_t)k8[6])<<16; /* fall through */
case 6 : b+=((uint32_t)k8[5])<<8; /* fall through */
case 5 : b+=k8[4]; /* fall through */
case 4 : a+=k[0]; break;
case 3 : a+=((uint32_t)k8[2])<<16; /* fall through */
case 2 : a+=((uint32_t)k8[1])<<8; /* fall through */
case 1 : a+=k8[0]; break;
case 0 : return c;
}
} else if (HASH_LITTLE_ENDIAN && ((u.i & 0x1) == 0)) {
const uint16_t *k = (const uint16_t *)key; /* read 16-bit chunks */
const uint8_t *k8;
/*--------------- all but last block: aligned reads and different mixing */
while (length > 12)
{
a += k[0] + (((uint32_t)k[1])<<16);
b += k[2] + (((uint32_t)k[3])<<16);
c += k[4] + (((uint32_t)k[5])<<16);
mix(a,b,c);
length -= 12;
k += 6;
}
/*----------------------------- handle the last (probably partial) block */
k8 = (const uint8_t *)k;
switch(length)
{
case 12: c+=k[4]+(((uint32_t)k[5])<<16);
b+=k[2]+(((uint32_t)k[3])<<16);
a+=k[0]+(((uint32_t)k[1])<<16);
break;
case 11: c+=((uint32_t)k8[10])<<16; /* fall through */
case 10: c+=k[4];
b+=k[2]+(((uint32_t)k[3])<<16);
a+=k[0]+(((uint32_t)k[1])<<16);
break;
case 9 : c+=k8[8]; /* fall through */
case 8 : b+=k[2]+(((uint32_t)k[3])<<16);
a+=k[0]+(((uint32_t)k[1])<<16);
break;
case 7 : b+=((uint32_t)k8[6])<<16; /* fall through */
case 6 : b+=k[2];
a+=k[0]+(((uint32_t)k[1])<<16);
break;
case 5 : b+=k8[4]; /* fall through */
case 4 : a+=k[0]+(((uint32_t)k[1])<<16);
break;
case 3 : a+=((uint32_t)k8[2])<<16; /* fall through */
case 2 : a+=k[0];
break;
case 1 : a+=k8[0];
break;
case 0 : return c; /* zero length requires no mixing */
}
} else { /* need to read the key one byte at a time */
const uint8_t *k = (const uint8_t *)key;
/*--------------- all but the last block: affect some 32 bits of (a,b,c) */
while (length > 12)
{
a += k[0];
a += ((uint32_t)k[1])<<8;
a += ((uint32_t)k[2])<<16;
a += ((uint32_t)k[3])<<24;
b += k[4];
b += ((uint32_t)k[5])<<8;
b += ((uint32_t)k[6])<<16;
b += ((uint32_t)k[7])<<24;
c += k[8];
c += ((uint32_t)k[9])<<8;
c += ((uint32_t)k[10])<<16;
c += ((uint32_t)k[11])<<24;
mix(a,b,c);
length -= 12;
k += 12;
}
/*-------------------------------- last block: affect all 32 bits of (c) */
switch(length) /* all the case statements fall through */
{
case 12: c+=((uint32_t)k[11])<<24;
case 11: c+=((uint32_t)k[10])<<16;
case 10: c+=((uint32_t)k[9])<<8;
case 9 : c+=k[8];
case 8 : b+=((uint32_t)k[7])<<24;
case 7 : b+=((uint32_t)k[6])<<16;
case 6 : b+=((uint32_t)k[5])<<8;
case 5 : b+=k[4];
case 4 : a+=((uint32_t)k[3])<<24;
case 3 : a+=((uint32_t)k[2])<<16;
case 2 : a+=((uint32_t)k[1])<<8;
case 1 : a+=k[0];
break;
case 0 : return c;
}
}
final(a,b,c);
return c;
}
_PUBLIC_ unsigned int tdb1_jenkins_hash(TDB1_DATA *key)
{
return hashlittle(key->dptr, key->dsize);
}
ccan/tdb2/tdb1_io.c 0 → 100644
View file @ 19e6c1a2
/*
Unix SMB/CIFS implementation.
trivial database library
Copyright (C) Andrew Tridgell 1999-2005
Copyright (C) Paul `Rusty' Russell 2000
Copyright (C) Jeremy Allison 2000-2003
** NOTE! The following LGPL license applies to the tdb
** library. This does NOT imply that all of Samba is released
** under the LGPL
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "tdb1_private.h"
#ifndef MAX
#define MAX(a,b) ((a) > (b) ? (a) : (b))
#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 tdb1_oob(struct tdb1_context *tdb, tdb1_off_t len, int probe)
{
struct stat st;
if (len <= tdb->map_size)
return 0;
if (tdb->flags & TDB1_INTERNAL) {
if (!probe) {
/* Ensure ecode is set for log fn. */
tdb->ecode = TDB1_ERR_IO;
TDB1_LOG((tdb, TDB1_DEBUG_FATAL,"tdb1_oob len %d beyond internal malloc size %d\n",
(int)len, (int)tdb->map_size));
}
return -1;
}
if (fstat(tdb->fd, &st) == -1) {
tdb->ecode = TDB1_ERR_IO;
return -1;
}
if (st.st_size < (size_t)len) {
if (!probe) {
/* Ensure ecode is set for log fn. */
tdb->ecode = TDB1_ERR_IO;
TDB1_LOG((tdb, TDB1_DEBUG_FATAL,"tdb1_oob len %d beyond eof at %d\n",
(int)len, (int)st.st_size));
}
return -1;
}
/* Unmap, update size, remap */
if (tdb1_munmap(tdb) == -1) {
tdb->ecode = TDB1_ERR_IO;
return -1;
}
tdb->map_size = st.st_size;
tdb1_mmap(tdb);
return 0;
}
/* write a lump of data at a specified offset */
static int tdb1_write(struct tdb1_context *tdb, tdb1_off_t off,
const void *buf, tdb1_len_t len)
{
if (len == 0) {
return 0;
}
if (tdb->read_only || tdb->traverse_read) {
tdb->ecode = TDB1_ERR_RDONLY;
return -1;
}
if (tdb->methods->tdb1_oob(tdb, off + len, 0) != 0)
return -1;
if (tdb->map_ptr) {
memcpy(off + (char *)tdb->map_ptr, buf, len);
} else {
ssize_t written = pwrite(tdb->fd, buf, len, off);
if ((written != (ssize_t)len) && (written != -1)) {
/* try once more */
tdb->ecode = TDB1_ERR_IO;
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_write: wrote only "
"%d of %d bytes at %d, trying once more\n",
(int)written, len, off));
written = pwrite(tdb->fd, (const char *)buf+written,
len-written,
off+written);
}
if (written == -1) {
/* Ensure ecode is set for log fn. */
tdb->ecode = TDB1_ERR_IO;
TDB1_LOG((tdb, TDB1_DEBUG_FATAL,"tdb1_write failed at %d "
"len=%d (%s)\n", off, len, strerror(errno)));
return -1;
} else if (written != (ssize_t)len) {
tdb->ecode = TDB1_ERR_IO;
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_write: failed to "
"write %d bytes at %d in two attempts\n",
len, off));
return -1;
}
}
return 0;
}
/* Endian conversion: we only ever deal with 4 byte quantities */
void *tdb1_convert(void *buf, uint32_t size)
{
uint32_t i, *p = (uint32_t *)buf;
for (i = 0; i < size / 4; i++)
p[i] = TDB1_BYTEREV(p[i]);
return buf;
}
/* read a lump of data at a specified offset, maybe convert */
static int tdb1_read(struct tdb1_context *tdb, tdb1_off_t off, void *buf,
tdb1_len_t len, int cv)
{
if (tdb->methods->tdb1_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 = TDB1_ERR_IO;
TDB1_LOG((tdb, TDB1_DEBUG_FATAL,"tdb1_read failed at %d "
"len=%d ret=%d (%s) map_size=%d\n",
(int)off, (int)len, (int)ret, strerror(errno),
(int)tdb->map_size));
return -1;
}
}
if (cv) {
tdb1_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 tdb1_next_hash_chain(struct tdb1_context *tdb, uint32_t *chain)
{
uint32_t h = *chain;
if (tdb->map_ptr) {
for (;h < tdb->header.hash_size;h++) {
if (0 != *(uint32_t *)(TDB1_HASH_TOP(h) + (unsigned char *)tdb->map_ptr)) {
break;
}
}
} else {
uint32_t off=0;
for (;h < tdb->header.hash_size;h++) {
if (tdb1_ofs_read(tdb, TDB1_HASH_TOP(h), &off) != 0 || off != 0) {
break;
}
}
}
(*chain) = h;
}
int tdb1_munmap(struct tdb1_context *tdb)
{
if (tdb->flags & TDB1_INTERNAL)
return 0;
#if HAVE_MMAP
if (tdb->map_ptr) {
int ret;
ret = munmap(tdb->map_ptr, tdb->map_size);
if (ret != 0)
return ret;
}
#endif
tdb->map_ptr = NULL;
return 0;
}
void tdb1_mmap(struct tdb1_context *tdb)
{
if (tdb->flags & TDB1_INTERNAL)
return;
#if HAVE_MMAP
if (!(tdb->flags & TDB1_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;
TDB1_LOG((tdb, TDB1_DEBUG_WARNING, "tdb1_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 tdb1_expand_file(struct tdb1_context *tdb, tdb1_off_t size, tdb1_off_t addition)
{
char buf[8192];
if (tdb->read_only || tdb->traverse_read) {
tdb->ecode = TDB1_ERR_RDONLY;
return -1;
}
if (ftruncate(tdb->fd, size+addition) == -1) {
char b = 0;
ssize_t written = pwrite(tdb->fd, &b, 1, (size+addition) - 1);
if (written == 0) {
/* try once more, potentially revealing errno */
written = pwrite(tdb->fd, &b, 1, (size+addition) - 1);
}
if (written == 0) {
/* again - give up, guessing errno */
errno = ENOSPC;
}
if (written != 1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "expand_file to %d failed (%s)\n",
size+addition, strerror(errno)));
return -1;
}
}
/* now fill the file with something. This ensures that the
file isn't sparse, which would be very bad if we ran out of
disk. This must be done with write, not via mmap */
memset(buf, TDB1_PAD_BYTE, sizeof(buf));
while (addition) {
size_t n = addition>sizeof(buf)?sizeof(buf):addition;
ssize_t written = pwrite(tdb->fd, buf, n, size);
if (written == 0) {
/* prevent infinite loops: try _once_ more */
written = pwrite(tdb->fd, buf, n, size);
}
if (written == 0) {
/* give up, trying to provide a useful errno */
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "expand_file write "
"returned 0 twice: giving up!\n"));
errno = ENOSPC;
return -1;
} else if (written == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "expand_file write of "
"%d bytes failed (%s)\n", (int)n,
strerror(errno)));
return -1;
} else if (written != n) {
TDB1_LOG((tdb, TDB1_DEBUG_WARNING, "expand_file: wrote "
"only %d of %d bytes - retrying\n", (int)written,
(int)n));
}
addition -= written;
size += written;
}
return 0;
}
/* expand the database at least size bytes by expanding the underlying
file and doing the mmap again if necessary */
int tdb1_expand(struct tdb1_context *tdb, tdb1_off_t size)
{
struct tdb1_record rec;
tdb1_off_t offset, new_size, top_size, map_size;
if (tdb1_lock(tdb, -1, F_WRLCK) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "lock failed in tdb1_expand\n"));
return -1;
}
/* must know about any previous expansions by another process */
tdb->methods->tdb1_oob(tdb, tdb->map_size + 1, 1);
/* limit size in order to avoid using up huge amounts of memory for
* in memory tdbs if an oddball huge record creeps in */
if (size > 100 * 1024) {
top_size = tdb->map_size + size * 2;
} else {
top_size = tdb->map_size + size * 100;
}
/* always make room for at least top_size more records, and at
least 25% more space. if the DB is smaller than 100MiB,
otherwise grow it by 10% only. */
if (tdb->map_size > 100 * 1024 * 1024) {
map_size = tdb->map_size * 1.10;
} else {
map_size = tdb->map_size * 1.25;
}
/* Round the database up to a multiple of the page size */
new_size = MAX(top_size, map_size);
size = TDB1_ALIGN(new_size, tdb->page_size) - tdb->map_size;
if (!(tdb->flags & TDB1_INTERNAL))
tdb1_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 & TDB1_INTERNAL)) {
if (tdb->methods->tdb1_expand_file(tdb, tdb->map_size, size) != 0)
goto fail;
}
tdb->map_size += size;
if (tdb->flags & TDB1_INTERNAL) {
char *new_map_ptr = (char *)realloc(tdb->map_ptr,
tdb->map_size);
if (!new_map_ptr) {
tdb->map_size -= size;
goto fail;
}
tdb->map_ptr = new_map_ptr;
} else {
/*
* We must ensure the file is remapped before adding the space
* to ensure consistency with systems like OpenBSD where
* writes and mmaps are not consistent.
*/
/* We're ok if the mmap fails as we'll fallback to read/write */
tdb1_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 (tdb1_free(tdb, offset, &rec) == -1)
goto fail;
tdb1_unlock(tdb, -1, F_WRLCK);
return 0;
fail:
tdb1_unlock(tdb, -1, F_WRLCK);
return -1;
}
/* read/write a tdb1_off_t */
int tdb1_ofs_read(struct tdb1_context *tdb, tdb1_off_t offset, tdb1_off_t *d)
{
return tdb->methods->tdb1_read(tdb, offset, (char*)d, sizeof(*d), TDB1_DOCONV());
}
int tdb1_ofs_write(struct tdb1_context *tdb, tdb1_off_t offset, tdb1_off_t *d)
{
tdb1_off_t off = *d;
return tdb->methods->tdb1_write(tdb, offset, TDB1_CONV(off), sizeof(*d));
}
/* read a lump of data, allocating the space for it */
unsigned char *tdb1_alloc_read(struct tdb1_context *tdb, tdb1_off_t offset, tdb1_len_t len)
{
unsigned char *buf;
/* some systems don't like zero length malloc */
if (!(buf = (unsigned char *)malloc(len ? len : 1))) {
/* Ensure ecode is set for log fn. */
tdb->ecode = TDB1_ERR_OOM;
TDB1_LOG((tdb, TDB1_DEBUG_ERROR,"tdb1_alloc_read malloc failed len=%d (%s)\n",
len, strerror(errno)));
return NULL;
}
if (tdb->methods->tdb1_read(tdb, offset, buf, len, 0) == -1) {
SAFE_FREE(buf);
return NULL;
}
return buf;
}
/* Give a piece of tdb data to a parser */
int tdb1_parse_data(struct tdb1_context *tdb, TDB1_DATA key,
tdb1_off_t offset, tdb1_len_t len,
int (*parser)(TDB1_DATA key, TDB1_DATA data,
void *private_data),
void *private_data)
{
TDB1_DATA data;
int result;
data.dsize = len;
if ((tdb->transaction == NULL) && (tdb->map_ptr != NULL)) {
/*
* Optimize by avoiding the malloc/memcpy/free, point the
* parser directly at the mmap area.
*/
if (tdb->methods->tdb1_oob(tdb, offset+len, 0) != 0) {
return -1;
}
data.dptr = offset + (unsigned char *)tdb->map_ptr;
return parser(key, data, private_data);
}
if (!(data.dptr = tdb1_alloc_read(tdb, offset, len))) {
return -1;
}
result = parser(key, data, private_data);
free(data.dptr);
return result;
}
/* read/write a record */
int tdb1_rec_read(struct tdb1_context *tdb, tdb1_off_t offset, struct tdb1_record *rec)
{
if (tdb->methods->tdb1_read(tdb, offset, rec, sizeof(*rec),TDB1_DOCONV()) == -1)
return -1;
if (TDB1_BAD_MAGIC(rec)) {
/* Ensure ecode is set for log fn. */
tdb->ecode = TDB1_ERR_CORRUPT;
TDB1_LOG((tdb, TDB1_DEBUG_FATAL,"tdb1_rec_read bad magic 0x%x at offset=%d\n", rec->magic, offset));
return -1;
}
return tdb->methods->tdb1_oob(tdb, rec->next+sizeof(*rec), 0);
}
int tdb1_rec_write(struct tdb1_context *tdb, tdb1_off_t offset, struct tdb1_record *rec)
{
struct tdb1_record r = *rec;
return tdb->methods->tdb1_write(tdb, offset, TDB1_CONV(r), sizeof(r));
}
static const struct tdb1_methods io1_methods = {
tdb1_read,
tdb1_write,
tdb1_next_hash_chain,
tdb1_oob,
tdb1_expand_file,
};
/*
initialise the default methods table
*/
void tdb1_io_init(struct tdb1_context *tdb)
{
tdb->methods = &io1_methods;
}
ccan/tdb2/tdb1_lock.c 0 → 100644
View file @ 19e6c1a2
/*
Unix SMB/CIFS implementation.
trivial database library
Copyright (C) Andrew Tridgell 1999-2005
Copyright (C) Paul `Rusty' Russell 2000
Copyright (C) Jeremy Allison 2000-2003
** NOTE! The following LGPL license applies to the tdb
** library. This does NOT imply that all of Samba is released
** under the LGPL
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "tdb1_private.h"
_PUBLIC_ void tdb1_setalarm_sigptr(struct tdb1_context *tdb, volatile sig_atomic_t *ptr)
{
tdb->interrupt_sig_ptr = ptr;
}
static int fcntl_lock(struct tdb1_context *tdb,
int rw, off_t off, off_t len, bool waitflag)
{
struct flock fl;
fl.l_type = rw;
fl.l_whence = SEEK_SET;
fl.l_start = off;
fl.l_len = len;
fl.l_pid = 0;
if (waitflag)
return fcntl(tdb->fd, F_SETLKW, &fl);
else
return fcntl(tdb->fd, F_SETLK, &fl);
}
static int fcntl_unlock(struct tdb1_context *tdb, int rw, off_t off, off_t len)
{
struct flock fl;
#if 0 /* Check they matched up locks and unlocks correctly. */
char line[80];
FILE *locks;
bool found = false;
locks = fopen("/proc/locks", "r");
while (fgets(line, 80, locks)) {
char *p;
int type, start, l;
/* eg. 1: FLOCK ADVISORY WRITE 2440 08:01:2180826 0 EOF */
p = strchr(line, ':') + 1;
if (strncmp(p, " POSIX ADVISORY ", strlen(" POSIX ADVISORY ")))
continue;
p += strlen(" FLOCK ADVISORY ");
if (strncmp(p, "READ ", strlen("READ ")) == 0)
type = F_RDLCK;
else if (strncmp(p, "WRITE ", strlen("WRITE ")) == 0)
type = F_WRLCK;
else
abort();
p += 6;
if (atoi(p) != getpid())
continue;
p = strchr(strchr(p, ' ') + 1, ' ') + 1;
start = atoi(p);
p = strchr(p, ' ') + 1;
if (strncmp(p, "EOF", 3) == 0)
l = 0;
else
l = atoi(p) - start + 1;
if (off == start) {
if (len != l) {
fprintf(stderr, "Len %u should be %u: %s",
(int)len, l, line);
abort();
}
if (type != rw) {
fprintf(stderr, "Type %s wrong: %s",
rw == F_RDLCK ? "READ" : "WRITE", line);
abort();
}
found = true;
break;
}
}
if (!found) {
fprintf(stderr, "Unlock on %u@%u not found!\n",
(int)off, (int)len);
abort();
}
fclose(locks);
#endif
fl.l_type = F_UNLCK;
fl.l_whence = SEEK_SET;
fl.l_start = off;
fl.l_len = len;
fl.l_pid = 0;
return fcntl(tdb->fd, F_SETLKW, &fl);
}
/* list -1 is the alloc list, otherwise a hash chain. */
static tdb1_off_t lock_offset(int list)
{
return TDB1_FREELIST_TOP + 4*list;
}
/* 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 tdb1_open().
note that a len of zero means lock to end of file
*/
int tdb1_brlock(struct tdb1_context *tdb,
int rw_type, tdb1_off_t offset, size_t len,
enum tdb1_lock_flags flags)
{
int ret;
if (tdb->flags & TDB1_NOLOCK) {
return 0;
}
if (flags & TDB1_LOCK_MARK_ONLY) {
return 0;
}
if ((rw_type == F_WRLCK) && (tdb->read_only || tdb->traverse_read)) {
tdb->ecode = TDB1_ERR_RDONLY;
return -1;
}
do {
ret = fcntl_lock(tdb, rw_type, offset, len,
flags & TDB1_LOCK_WAIT);
/* Check for a sigalarm break. */
if (ret == -1 && errno == EINTR &&
tdb->interrupt_sig_ptr &&
*tdb->interrupt_sig_ptr) {
break;
}
} while (ret == -1 && errno == EINTR);
if (ret == -1) {
tdb->ecode = TDB1_ERR_LOCK;
/* Generic lock error. errno set by fcntl.
* EAGAIN is an expected return from non-blocking
* locks. */
if (!(flags & TDB1_LOCK_PROBE) && errno != EAGAIN) {
TDB1_LOG((tdb, TDB1_DEBUG_TRACE,"tdb1_brlock failed (fd=%d) at offset %d rw_type=%d flags=%d len=%d\n",
tdb->fd, offset, rw_type, flags, (int)len));
}
return -1;
}
return 0;
}
int tdb1_brunlock(struct tdb1_context *tdb,
int rw_type, tdb1_off_t offset, size_t len)
{
int ret;
if (tdb->flags & TDB1_NOLOCK) {
return 0;
}
do {
ret = fcntl_unlock(tdb, rw_type, offset, len);
} while (ret == -1 && errno == EINTR);
if (ret == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_TRACE,"tdb1_brunlock failed (fd=%d) at offset %d rw_type=%d len=%d\n",
tdb->fd, offset, rw_type, (int)len));
}
return ret;
}
/*
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 tdb1_allrecord_upgrade(struct tdb1_context *tdb)
{
int count = 1000;
if (tdb->allrecord_lock.count != 1) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR,
"tdb1_allrecord_upgrade failed: count %u too high\n",
tdb->allrecord_lock.count));
return -1;
}
if (tdb->allrecord_lock.off != 1) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR,
"tdb1_allrecord_upgrade failed: already upgraded?\n"));
return -1;
}
while (count--) {
struct timeval tv;
if (tdb1_brlock(tdb, F_WRLCK, TDB1_FREELIST_TOP, 0,
TDB1_LOCK_WAIT|TDB1_LOCK_PROBE) == 0) {
tdb->allrecord_lock.ltype = F_WRLCK;
tdb->allrecord_lock.off = 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);
}
TDB1_LOG((tdb, TDB1_DEBUG_TRACE,"tdb1_allrecord_upgrade failed\n"));
return -1;
}
static struct tdb1_lock_type *tdb1_find_nestlock(struct tdb1_context *tdb,
tdb1_off_t offset)
{
unsigned int i;
for (i=0; i<tdb->num_lockrecs; i++) {
if (tdb->lockrecs[i].off == offset) {
return &tdb->lockrecs[i];
}
}
return NULL;
}
/* lock an offset in the database. */
int tdb1_nest_lock(struct tdb1_context *tdb, uint32_t offset, int ltype,
enum tdb1_lock_flags flags)
{
struct tdb1_lock_type *new_lck;
if (offset >= lock_offset(tdb->header.hash_size)) {
tdb->ecode = TDB1_ERR_LOCK;
TDB1_LOG((tdb, TDB1_DEBUG_ERROR,"tdb1_lock: invalid offset %u for ltype=%d\n",
offset, ltype));
return -1;
}
if (tdb->flags & TDB1_NOLOCK)
return 0;
new_lck = tdb1_find_nestlock(tdb, offset);
if (new_lck) {
/*
* Just increment the in-memory struct, posix locks
* don't stack.
*/
new_lck->count++;
return 0;
}
new_lck = (struct tdb1_lock_type *)realloc(
tdb->lockrecs,
sizeof(*tdb->lockrecs) * (tdb->num_lockrecs+1));
if (new_lck == NULL) {
errno = ENOMEM;
return -1;
}
tdb->lockrecs = new_lck;
/* Since fcntl locks don't nest, we do a lock for the first one,
and simply bump the count for future ones */
if (tdb1_brlock(tdb, ltype, offset, 1, flags)) {
return -1;
}
tdb->lockrecs[tdb->num_lockrecs].off = offset;
tdb->lockrecs[tdb->num_lockrecs].count = 1;
tdb->lockrecs[tdb->num_lockrecs].ltype = ltype;
tdb->num_lockrecs++;
return 0;
}
static int tdb1_lock_and_recover(struct tdb1_context *tdb)
{
int ret;
/* We need to match locking order in transaction commit. */
if (tdb1_brlock(tdb, F_WRLCK, TDB1_FREELIST_TOP, 0, TDB1_LOCK_WAIT)) {
return -1;
}
if (tdb1_brlock(tdb, F_WRLCK, TDB1_OPEN_LOCK, 1, TDB1_LOCK_WAIT)) {
tdb1_brunlock(tdb, F_WRLCK, TDB1_FREELIST_TOP, 0);
return -1;
}
ret = tdb1_transaction_recover(tdb);
tdb1_brunlock(tdb, F_WRLCK, TDB1_OPEN_LOCK, 1);
tdb1_brunlock(tdb, F_WRLCK, TDB1_FREELIST_TOP, 0);
return ret;
}
static bool have_data_locks(const struct tdb1_context *tdb)
{
unsigned int i;
for (i = 0; i < tdb->num_lockrecs; i++) {
if (tdb->lockrecs[i].off >= lock_offset(-1))
return true;
}
return false;
}
static int tdb1_lock_list(struct tdb1_context *tdb, int list, int ltype,
enum tdb1_lock_flags waitflag)
{
int ret;
bool check = false;
/* a allrecord lock allows us to avoid per chain locks */
if (tdb->allrecord_lock.count &&
(ltype == tdb->allrecord_lock.ltype || ltype == F_RDLCK)) {
return 0;
}
if (tdb->allrecord_lock.count) {
tdb->ecode = TDB1_ERR_LOCK;
ret = -1;
} else {
/* Only check when we grab first data lock. */
check = !have_data_locks(tdb);
ret = tdb1_nest_lock(tdb, lock_offset(list), ltype, waitflag);
if (ret == 0 && check && tdb1_needs_recovery(tdb)) {
tdb1_nest_unlock(tdb, lock_offset(list), ltype, false);
if (tdb1_lock_and_recover(tdb) == -1) {
return -1;
}
return tdb1_lock_list(tdb, list, ltype, waitflag);
}
}
return ret;
}
/* lock a list in the database. list -1 is the alloc list */
int tdb1_lock(struct tdb1_context *tdb, int list, int ltype)
{
int ret;
ret = tdb1_lock_list(tdb, list, ltype, TDB1_LOCK_WAIT);
if (ret) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "tdb1_lock failed on list %d "
"ltype=%d (%s)\n", list, ltype, strerror(errno)));
}
return ret;
}
/* lock a list in the database. list -1 is the alloc list. non-blocking lock */
int tdb1_lock_nonblock(struct tdb1_context *tdb, int list, int ltype)
{
return tdb1_lock_list(tdb, list, ltype, TDB1_LOCK_NOWAIT);
}
int tdb1_nest_unlock(struct tdb1_context *tdb, uint32_t offset, int ltype,
bool mark_lock)
{
int ret = -1;
struct tdb1_lock_type *lck;
if (tdb->flags & TDB1_NOLOCK)
return 0;
/* Sanity checks */
if (offset >= lock_offset(tdb->header.hash_size)) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "tdb1_unlock: offset %u invalid (%d)\n", offset, tdb->header.hash_size));
return ret;
}
lck = tdb1_find_nestlock(tdb, offset);
if ((lck == NULL) || (lck->count == 0)) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "tdb1_unlock: count is 0\n"));
return -1;
}
if (lck->count > 1) {
lck->count--;
return 0;
}
/*
* This lock has count==1 left, so we need to unlock it in the
* kernel. We don't bother with decrementing the in-memory array
* element, we're about to overwrite it with the last array element
* anyway.
*/
if (mark_lock) {
ret = 0;
} else {
ret = tdb1_brunlock(tdb, ltype, offset, 1);
}
/*
* Shrink the array by overwriting the element just unlocked with the
* last array element.
*/
*lck = tdb->lockrecs[--tdb->num_lockrecs];
/*
* We don't bother with realloc when the array shrinks, but if we have
* a completely idle tdb we should get rid of the locked array.
*/
if (tdb->num_lockrecs == 0) {
SAFE_FREE(tdb->lockrecs);
}
if (ret)
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "tdb1_unlock: An error occurred unlocking!\n"));
return ret;
}
int tdb1_unlock(struct tdb1_context *tdb, int list, int ltype)
{
/* a global lock allows us to avoid per chain locks */
if (tdb->allrecord_lock.count &&
(ltype == tdb->allrecord_lock.ltype || ltype == F_RDLCK)) {
return 0;
}
if (tdb->allrecord_lock.count) {
tdb->ecode = TDB1_ERR_LOCK;
return -1;
}
return tdb1_nest_unlock(tdb, lock_offset(list), ltype, false);
}
/*
get the transaction lock
*/
int tdb1_transaction_lock(struct tdb1_context *tdb, int ltype,
enum tdb1_lock_flags lockflags)
{
return tdb1_nest_lock(tdb, TDB1_TRANSACTION_LOCK, ltype, lockflags);
}
/*
release the transaction lock
*/
int tdb1_transaction_unlock(struct tdb1_context *tdb, int ltype)
{
return tdb1_nest_unlock(tdb, TDB1_TRANSACTION_LOCK, ltype, false);
}
/* Returns 0 if all done, -1 if error, 1 if ok. */
static int tdb1_allrecord_check(struct tdb1_context *tdb, int ltype,
enum tdb1_lock_flags flags, bool upgradable)
{
/* There are no locks on read-only dbs */
if (tdb->read_only || tdb->traverse_read) {
tdb->ecode = TDB1_ERR_LOCK;
return -1;
}
if (tdb->allrecord_lock.count && tdb->allrecord_lock.ltype == ltype) {
tdb->allrecord_lock.count++;
return 0;
}
if (tdb->allrecord_lock.count) {
/* a global lock of a different type exists */
tdb->ecode = TDB1_ERR_LOCK;
return -1;
}
if (tdb1_have_extra_locks(tdb)) {
/* can't combine global and chain locks */
tdb->ecode = TDB1_ERR_LOCK;
return -1;
}
if (upgradable && ltype != F_RDLCK) {
/* tdb error: you can't upgrade a write lock! */
tdb->ecode = TDB1_ERR_LOCK;
return -1;
}
return 1;
}
/* We only need to lock individual bytes, but Linux merges consecutive locks
* so we lock in contiguous ranges. */
static int tdb1_chainlock_gradual(struct tdb1_context *tdb,
int ltype, enum tdb1_lock_flags flags,
size_t off, size_t len)
{
int ret;
enum tdb1_lock_flags nb_flags = (flags & ~TDB1_LOCK_WAIT);
if (len <= 4) {
/* Single record. Just do blocking lock. */
return tdb1_brlock(tdb, ltype, off, len, flags);
}
/* First we try non-blocking. */
ret = tdb1_brlock(tdb, ltype, off, len, nb_flags);
if (ret == 0) {
return 0;
}
/* Try locking first half, then second. */
ret = tdb1_chainlock_gradual(tdb, ltype, flags, off, len / 2);
if (ret == -1)
return -1;
ret = tdb1_chainlock_gradual(tdb, ltype, flags,
off + len / 2, len - len / 2);
if (ret == -1) {
tdb1_brunlock(tdb, ltype, off, len / 2);
return -1;
}
return 0;
}
/* lock/unlock entire database. It can only be upgradable if you have some
* other way of guaranteeing exclusivity (ie. transaction write lock).
* We do the locking gradually to avoid being starved by smaller locks. */
int tdb1_allrecord_lock(struct tdb1_context *tdb, int ltype,
enum tdb1_lock_flags flags, bool upgradable)
{
switch (tdb1_allrecord_check(tdb, ltype, flags, upgradable)) {
case -1:
return -1;
case 0:
return 0;
}
/* We cover two kinds of locks:
* 1) Normal chain locks. Taken for almost all operations.
* 3) Individual records locks. Taken after normal or free
* chain locks.
*
* It is (1) which cause the starvation problem, so we're only
* gradual for that. */
if (tdb1_chainlock_gradual(tdb, ltype, flags, TDB1_FREELIST_TOP,
tdb->header.hash_size * 4) == -1) {
return -1;
}
/* Grab individual record locks. */
if (tdb1_brlock(tdb, ltype, lock_offset(tdb->header.hash_size), 0,
flags) == -1) {
tdb1_brunlock(tdb, ltype, TDB1_FREELIST_TOP,
tdb->header.hash_size * 4);
return -1;
}
tdb->allrecord_lock.count = 1;
/* If it's upgradable, it's actually exclusive so we can treat
* it as a write lock. */
tdb->allrecord_lock.ltype = upgradable ? F_WRLCK : ltype;
tdb->allrecord_lock.off = upgradable;
if (tdb1_needs_recovery(tdb)) {
bool mark = flags & TDB1_LOCK_MARK_ONLY;
tdb1_allrecord_unlock(tdb, ltype, mark);
if (mark) {
tdb->ecode = TDB1_ERR_LOCK;
TDB1_LOG((tdb, TDB1_DEBUG_ERROR,
"tdb1_lockall_mark cannot do recovery\n"));
return -1;
}
if (tdb1_lock_and_recover(tdb) == -1) {
return -1;
}
return tdb1_allrecord_lock(tdb, ltype, flags, upgradable);
}
return 0;
}
/* unlock entire db */
int tdb1_allrecord_unlock(struct tdb1_context *tdb, int ltype, bool mark_lock)
{
/* There are no locks on read-only dbs */
if (tdb->read_only || tdb->traverse_read) {
tdb->ecode = TDB1_ERR_LOCK;
return -1;
}
if (tdb->allrecord_lock.count == 0) {
tdb->ecode = TDB1_ERR_LOCK;
return -1;
}
/* Upgradable locks are marked as write locks. */
if (tdb->allrecord_lock.ltype != ltype
&& (!tdb->allrecord_lock.off || ltype != F_RDLCK)) {
tdb->ecode = TDB1_ERR_LOCK;
return -1;
}
if (tdb->allrecord_lock.count > 1) {
tdb->allrecord_lock.count--;
return 0;
}
if (!mark_lock && tdb1_brunlock(tdb, ltype, TDB1_FREELIST_TOP, 0)) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "tdb1_unlockall failed (%s)\n", strerror(errno)));
return -1;
}
tdb->allrecord_lock.count = 0;
tdb->allrecord_lock.ltype = 0;
return 0;
}
/* lock entire database with write lock */
_PUBLIC_ int tdb1_lockall(struct tdb1_context *tdb)
{
return tdb1_allrecord_lock(tdb, F_WRLCK, TDB1_LOCK_WAIT, false);
}
/* lock entire database with write lock - mark only */
_PUBLIC_ int tdb1_lockall_mark(struct tdb1_context *tdb)
{
return tdb1_allrecord_lock(tdb, F_WRLCK, TDB1_LOCK_MARK_ONLY, false);
}
/* unlock entire database with write lock - unmark only */
_PUBLIC_ int tdb1_lockall_unmark(struct tdb1_context *tdb)
{
return tdb1_allrecord_unlock(tdb, F_WRLCK, true);
}
/* lock entire database with write lock - nonblocking varient */
_PUBLIC_ int tdb1_lockall_nonblock(struct tdb1_context *tdb)
{
int ret = tdb1_allrecord_lock(tdb, F_WRLCK, TDB1_LOCK_NOWAIT, false);
return ret;
}
/* unlock entire database with write lock */
_PUBLIC_ int tdb1_unlockall(struct tdb1_context *tdb)
{
return tdb1_allrecord_unlock(tdb, F_WRLCK, false);
}
/* lock entire database with read lock */
_PUBLIC_ int tdb1_lockall_read(struct tdb1_context *tdb)
{
return tdb1_allrecord_lock(tdb, F_RDLCK, TDB1_LOCK_WAIT, false);
}
/* lock entire database with read lock - nonblock varient */
_PUBLIC_ int tdb1_lockall_read_nonblock(struct tdb1_context *tdb)
{
int ret = tdb1_allrecord_lock(tdb, F_RDLCK, TDB1_LOCK_NOWAIT, false);
return ret;
}
/* unlock entire database with read lock */
_PUBLIC_ int tdb1_unlockall_read(struct tdb1_context *tdb)
{
return tdb1_allrecord_unlock(tdb, F_RDLCK, false);
}
/* lock/unlock one hash chain. This is meant to be used to reduce
contention - it cannot guarantee how many records will be locked */
_PUBLIC_ int tdb1_chainlock(struct tdb1_context *tdb, TDB1_DATA key)
{
int ret = tdb1_lock(tdb, TDB1_BUCKET(tdb->hash_fn(&key)), F_WRLCK);
return ret;
}
/* lock/unlock one hash chain, non-blocking. This is meant to be used
to reduce contention - it cannot guarantee how many records will be
locked */
_PUBLIC_ int tdb1_chainlock_nonblock(struct tdb1_context *tdb, TDB1_DATA key)
{
int ret = tdb1_lock_nonblock(tdb, TDB1_BUCKET(tdb->hash_fn(&key)), F_WRLCK);
return ret;
}
/* mark a chain as locked without actually locking it. Warning! use with great caution! */
_PUBLIC_ int tdb1_chainlock_mark(struct tdb1_context *tdb, TDB1_DATA key)
{
int ret = tdb1_nest_lock(tdb, lock_offset(TDB1_BUCKET(tdb->hash_fn(&key))),
F_WRLCK, TDB1_LOCK_MARK_ONLY);
return ret;
}
/* unmark a chain as locked without actually locking it. Warning! use with great caution! */
_PUBLIC_ int tdb1_chainlock_unmark(struct tdb1_context *tdb, TDB1_DATA key)
{
return tdb1_nest_unlock(tdb, lock_offset(TDB1_BUCKET(tdb->hash_fn(&key))),
F_WRLCK, true);
}
_PUBLIC_ int tdb1_chainunlock(struct tdb1_context *tdb, TDB1_DATA key)
{
return tdb1_unlock(tdb, TDB1_BUCKET(tdb->hash_fn(&key)), F_WRLCK);
}
_PUBLIC_ int tdb1_chainlock_read(struct tdb1_context *tdb, TDB1_DATA key)
{
int ret;
ret = tdb1_lock(tdb, TDB1_BUCKET(tdb->hash_fn(&key)), F_RDLCK);
return ret;
}
_PUBLIC_ int tdb1_chainunlock_read(struct tdb1_context *tdb, TDB1_DATA key)
{
return tdb1_unlock(tdb, TDB1_BUCKET(tdb->hash_fn(&key)), F_RDLCK);
}
/* record lock stops delete underneath */
int tdb1_lock_record(struct tdb1_context *tdb, tdb1_off_t off)
{
if (tdb->allrecord_lock.count) {
return 0;
}
return off ? tdb1_brlock(tdb, F_RDLCK, off, 1, TDB1_LOCK_WAIT) : 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 tdb1_write_lock_record(struct tdb1_context *tdb, tdb1_off_t off)
{
struct tdb1_traverse_lock *i;
for (i = &tdb->travlocks; i; i = i->next)
if (i->off == off)
return -1;
if (tdb->allrecord_lock.count) {
if (tdb->allrecord_lock.ltype == F_WRLCK) {
return 0;
}
return -1;
}
return tdb1_brlock(tdb, F_WRLCK, off, 1, TDB1_LOCK_NOWAIT|TDB1_LOCK_PROBE);
}
int tdb1_write_unlock_record(struct tdb1_context *tdb, tdb1_off_t off)
{
if (tdb->allrecord_lock.count) {
return 0;
}
return tdb1_brunlock(tdb, F_WRLCK, off, 1);
}
/* fcntl locks don't stack: avoid unlocking someone else's */
int tdb1_unlock_record(struct tdb1_context *tdb, tdb1_off_t off)
{
struct tdb1_traverse_lock *i;
uint32_t count = 0;
if (tdb->allrecord_lock.count) {
return 0;
}
if (off == 0)
return 0;
for (i = &tdb->travlocks; i; i = i->next)
if (i->off == off)
count++;
return (count == 1 ? tdb1_brunlock(tdb, F_RDLCK, off, 1) : 0);
}
bool tdb1_have_extra_locks(struct tdb1_context *tdb)
{
unsigned int extra = tdb->num_lockrecs;
/* A transaction holds the lock for all records. */
if (!tdb->transaction && tdb->allrecord_lock.count) {
return true;
}
/* We always hold the active lock if CLEAR_IF_FIRST. */
if (tdb1_find_nestlock(tdb, TDB1_ACTIVE_LOCK)) {
extra--;
}
/* In a transaction, we expect to hold the transaction lock */
if (tdb->transaction
&& tdb1_find_nestlock(tdb, TDB1_TRANSACTION_LOCK)) {
extra--;
}
return extra;
}
/* The transaction code uses this to remove all locks. */
void tdb1_release_transaction_locks(struct tdb1_context *tdb)
{
unsigned int i, active = 0;
if (tdb->allrecord_lock.count != 0) {
tdb1_brunlock(tdb, tdb->allrecord_lock.ltype, TDB1_FREELIST_TOP, 0);
tdb->allrecord_lock.count = 0;
}
for (i=0;i<tdb->num_lockrecs;i++) {
struct tdb1_lock_type *lck = &tdb->lockrecs[i];
/* Don't release the active lock! Copy it to first entry. */
if (lck->off == TDB1_ACTIVE_LOCK) {
tdb->lockrecs[active++] = *lck;
} else {
tdb1_brunlock(tdb, lck->ltype, lck->off, 1);
}
}
tdb->num_lockrecs = active;
if (tdb->num_lockrecs == 0) {
SAFE_FREE(tdb->lockrecs);
}
}
ccan/tdb2/tdb1_open.c 0 → 100644
View file @ 19e6c1a2
/*
Unix SMB/CIFS implementation.
trivial database library
Copyright (C) Andrew Tridgell 1999-2005
Copyright (C) Paul `Rusty' Russell 2000
Copyright (C) Jeremy Allison 2000-2003
** NOTE! The following LGPL license applies to the tdb
** library. This does NOT imply that all of Samba is released
** under the LGPL
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "tdb1_private.h"
/* all contexts, to ensure no double-opens (fcntl locks don't nest!) */
static struct tdb1_context *tdb1s = NULL;
/* We use two hashes to double-check they're using the right hash function. */
void tdb1_header_hash(struct tdb1_context *tdb,
uint32_t *magic1_hash, uint32_t *magic2_hash)
{
TDB1_DATA hash_key;
uint32_t tdb1_magic = TDB1_MAGIC;
hash_key.dptr = (unsigned char *)TDB1_MAGIC_FOOD;
hash_key.dsize = sizeof(TDB1_MAGIC_FOOD);
*magic1_hash = tdb->hash_fn(&hash_key);
hash_key.dptr = (unsigned char *)TDB1_CONV(tdb1_magic);
hash_key.dsize = sizeof(tdb1_magic);
*magic2_hash = tdb->hash_fn(&hash_key);
/* Make sure at least one hash is non-zero! */
if (*magic1_hash == 0 && *magic2_hash == 0)
*magic1_hash = 1;
}
/* initialise a new database with a specified hash size */
static int tdb1_new_database(struct tdb1_context *tdb, int hash_size)
{
struct tdb1_header *newdb;
size_t size;
int ret = -1;
/* We make it up in memory, then write it out if not internal */
size = sizeof(struct tdb1_header) + (hash_size+1)*sizeof(tdb1_off_t);
if (!(newdb = (struct tdb1_header *)calloc(size, 1))) {
tdb->ecode = TDB1_ERR_OOM;
return -1;
}
/* Fill in the header */
newdb->version = TDB1_VERSION;
newdb->hash_size = hash_size;
tdb1_header_hash(tdb, &newdb->magic1_hash, &newdb->magic2_hash);
/* Make sure older tdbs (which don't check the magic hash fields)
* will refuse to open this TDB. */
if (tdb->flags & TDB1_INCOMPATIBLE_HASH)
newdb->rwlocks = TDB1_HASH_RWLOCK_MAGIC;
if (tdb->flags & TDB1_INTERNAL) {
tdb->map_size = size;
tdb->map_ptr = (char *)newdb;
memcpy(&tdb->header, newdb, sizeof(tdb->header));
/* Convert the `ondisk' version if asked. */
TDB1_CONV(*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 */
TDB1_CONV(*newdb);
memcpy(&tdb->header, newdb, sizeof(tdb->header));
/* Don't endian-convert the magic food! */
memcpy(newdb->magic_food, TDB1_MAGIC_FOOD, strlen(TDB1_MAGIC_FOOD)+1);
/* we still have "ret == -1" here */
if (tdb1_write_all(tdb->fd, newdb, size))
ret = 0;
fail:
SAFE_FREE(newdb);
return ret;
}
static int tdb1_already_open(dev_t device,
ino_t ino)
{
struct tdb1_context *i;
for (i = tdb1s; 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 tdb1_error or tdb1_errname, just do strerror(errno).
@param name may be NULL for internal databases. */
_PUBLIC_ struct tdb1_context *tdb1_open(const char *name, int hash_size, int tdb1_flags,
int open_flags, mode_t mode)
{
return tdb1_open_ex(name, hash_size, tdb1_flags, open_flags, mode, NULL, NULL);
}
/* a default logging function */
static void null_log_fn(struct tdb1_context *tdb, enum tdb1_debug_level level, const char *fmt, ...) PRINTF_ATTRIBUTE(3, 4);
static void null_log_fn(struct tdb1_context *tdb, enum tdb1_debug_level level, const char *fmt, ...)
{
}
static bool check_header_hash(struct tdb1_context *tdb,
bool default_hash, uint32_t *m1, uint32_t *m2)
{
tdb1_header_hash(tdb, m1, m2);
if (tdb->header.magic1_hash == *m1 &&
tdb->header.magic2_hash == *m2) {
return true;
}
/* If they explicitly set a hash, always respect it. */
if (!default_hash)
return false;
/* Otherwise, try the other inbuilt hash. */
if (tdb->hash_fn == tdb1_old_hash)
tdb->hash_fn = tdb1_jenkins_hash;
else
tdb->hash_fn = tdb1_old_hash;
return check_header_hash(tdb, false, m1, m2);
}
_PUBLIC_ struct tdb1_context *tdb1_open_ex(const char *name, int hash_size, int tdb1_flags,
int open_flags, mode_t mode,
const struct tdb1_logging_context *log_ctx,
tdb1_hash_func hash_fn)
{
struct tdb1_context *tdb;
struct stat st;
int rev = 0, locked = 0;
unsigned char *vp;
uint32_t vertest;
unsigned v;
const char *hash_alg;
uint32_t magic1, magic2;
if (!(tdb = (struct tdb1_context *)calloc(1, sizeof *tdb))) {
/* Can't log this */
errno = ENOMEM;
goto fail;
}
tdb1_io_init(tdb);
tdb->fd = -1;
tdb->name = NULL;
tdb->map_ptr = NULL;
tdb->flags = tdb1_flags;
tdb->open_flags = open_flags;
if (log_ctx) {
tdb->log = *log_ctx;
} else {
tdb->log.log_fn = null_log_fn;
tdb->log.log_private = NULL;
}
if (name == NULL && (tdb1_flags & TDB1_INTERNAL)) {
name = "__TDB1_INTERNAL__";
}
if (name == NULL) {
tdb->name = (char *)"__NULL__";
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_open_ex: called with name == NULL\n"));
tdb->name = NULL;
errno = EINVAL;
goto fail;
}
/* now make a copy of the name, as the caller memory might went away */
if (!(tdb->name = (char *)strdup(name))) {
/*
* set the name as the given string, so that tdb1_name() will
* work in case of an error.
*/
tdb->name = (char *)name;
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "tdb1_open_ex: can't strdup(%s)\n",
name));
tdb->name = NULL;
errno = ENOMEM;
goto fail;
}
if (hash_fn) {
tdb->hash_fn = hash_fn;
hash_alg = "the user defined";
} else {
/* This controls what we use when creating a tdb. */
if (tdb->flags & TDB1_INCOMPATIBLE_HASH) {
tdb->hash_fn = tdb1_jenkins_hash;
} else {
tdb->hash_fn = tdb1_old_hash;
}
hash_alg = "either default";
}
/* cache the page size */
tdb->page_size = getpagesize();
if (tdb->page_size <= 0) {
tdb->page_size = 0x2000;
}
tdb->max_dead_records = (tdb1_flags & TDB1_VOLATILE) ? 5 : 0;
if ((open_flags & O_ACCMODE) == O_WRONLY) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "tdb1_open_ex: can't open tdb %s write-only\n",
name));
errno = EINVAL;
goto fail;
}
if (hash_size == 0)
hash_size = TDB1_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 |= TDB1_NOLOCK;
tdb->flags &= ~TDB1_CLEAR_IF_FIRST;
}
if ((tdb->flags & TDB1_ALLOW_NESTING) &&
(tdb->flags & TDB1_DISALLOW_NESTING)) {
tdb->ecode = TDB1_ERR_NESTING;
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_open_ex: "
"allow_nesting and disallow_nesting are not allowed together!"));
errno = EINVAL;
goto fail;
}
if (getenv("TDB_NO_FSYNC")) {
tdb->flags |= TDB1_NOSYNC;
}
/*
* TDB1_ALLOW_NESTING is the default behavior.
* Note: this may change in future versions!
*/
if (!(tdb->flags & TDB1_DISALLOW_NESTING)) {
tdb->flags |= TDB1_ALLOW_NESTING;
}
/* internal databases don't mmap or lock, and start off cleared */
if (tdb->flags & TDB1_INTERNAL) {
tdb->flags |= (TDB1_NOLOCK | TDB1_NOMMAP);
tdb->flags &= ~TDB1_CLEAR_IF_FIRST;
if (tdb1_new_database(tdb, hash_size) != 0) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "tdb1_open_ex: tdb1_new_database failed!"));
goto fail;
}
goto internal;
}
if ((tdb->fd = open(name, open_flags, mode)) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_WARNING, "tdb1_open_ex: could not open file %s: %s\n",
name, strerror(errno)));
goto fail; /* errno set by open(2) */
}
/* on exec, don't inherit the fd */
v = fcntl(tdb->fd, F_GETFD, 0);
fcntl(tdb->fd, F_SETFD, v | FD_CLOEXEC);
/* ensure there is only one process initialising at once */
if (tdb1_nest_lock(tdb, TDB1_OPEN_LOCK, F_WRLCK, TDB1_LOCK_WAIT) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "tdb1_open_ex: failed to get open lock on %s: %s\n",
name, strerror(errno)));
goto fail; /* errno set by tdb1_brlock */
}
/* we need to zero database if we are the only one with it open */
if ((tdb1_flags & TDB1_CLEAR_IF_FIRST) &&
(!tdb->read_only) &&
(locked = (tdb1_nest_lock(tdb, TDB1_ACTIVE_LOCK, F_WRLCK, TDB1_LOCK_NOWAIT|TDB1_LOCK_PROBE) == 0))) {
open_flags |= O_CREAT;
if (ftruncate(tdb->fd, 0) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_open_ex: "
"failed to truncate %s: %s\n",
name, strerror(errno)));
goto fail; /* errno set by ftruncate */
}
}
errno = 0;
if (read(tdb->fd, &tdb->header, sizeof(tdb->header)) != sizeof(tdb->header)
|| strcmp(tdb->header.magic_food, TDB1_MAGIC_FOOD) != 0) {
if (!(open_flags & O_CREAT) || tdb1_new_database(tdb, hash_size) == -1) {
if (errno == 0) {
errno = EIO; /* ie bad format or something */
}
goto fail;
}
rev = (tdb->flags & TDB1_CONVERT);
} else if (tdb->header.version != TDB1_VERSION
&& !(rev = (tdb->header.version==TDB1_BYTEREV(TDB1_VERSION)))) {
/* wrong version */
errno = EIO;
goto fail;
}
vp = (unsigned char *)&tdb->header.version;
vertest = (((uint32_t)vp[0]) << 24) | (((uint32_t)vp[1]) << 16) |
(((uint32_t)vp[2]) << 8) | (uint32_t)vp[3];
tdb->flags |= (vertest==TDB1_VERSION) ? TDB1_BIGENDIAN : 0;
if (!rev)
tdb->flags &= ~TDB1_CONVERT;
else {
tdb->flags |= TDB1_CONVERT;
tdb1_convert(&tdb->header, sizeof(tdb->header));
}
if (fstat(tdb->fd, &st) == -1)
goto fail;
if (tdb->header.rwlocks != 0 &&
tdb->header.rwlocks != TDB1_HASH_RWLOCK_MAGIC) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "tdb1_open_ex: spinlocks no longer supported\n"));
goto fail;
}
if ((tdb->header.magic1_hash == 0) && (tdb->header.magic2_hash == 0)) {
/* older TDB without magic hash references */
tdb->hash_fn = tdb1_old_hash;
} else if (!check_header_hash(tdb, !hash_fn, &magic1, &magic2)) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_open_ex: "
"%s was not created with %s hash function we are using\n"
"magic1_hash[0x%08X %s 0x%08X] "
"magic2_hash[0x%08X %s 0x%08X]\n",
name, hash_alg,
tdb->header.magic1_hash,
(tdb->header.magic1_hash == magic1) ? "==" : "!=",
magic1,
tdb->header.magic2_hash,
(tdb->header.magic2_hash == magic2) ? "==" : "!=",
magic2));
errno = EINVAL;
goto fail;
}
/* Is it already in the open list? If so, fail. */
if (tdb1_already_open(st.st_dev, st.st_ino)) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "tdb1_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;
}
tdb->map_size = st.st_size;
tdb->device = st.st_dev;
tdb->inode = st.st_ino;
tdb1_mmap(tdb);
if (locked) {
if (tdb1_nest_unlock(tdb, TDB1_ACTIVE_LOCK, F_WRLCK, false) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "tdb1_open_ex: "
"failed to release 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 (tdb1_flags & TDB1_CLEAR_IF_FIRST) {
/* leave this lock in place to indicate it's in use */
if (tdb1_nest_lock(tdb, TDB1_ACTIVE_LOCK, F_RDLCK, TDB1_LOCK_WAIT) == -1) {
goto fail;
}
}
/* if needed, run recovery */
if (tdb1_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
* open lock and hooking into the active list. */
if (tdb1_nest_unlock(tdb, TDB1_OPEN_LOCK, F_WRLCK, false) == -1) {
goto fail;
}
tdb->next = tdb1s;
tdb1s = tdb;
return tdb;
fail:
{ int save_errno = errno;
if (!tdb)
return NULL;
if (tdb->map_ptr) {
if (tdb->flags & TDB1_INTERNAL)
SAFE_FREE(tdb->map_ptr);
else
tdb1_munmap(tdb);
}
if (tdb->fd != -1)
if (close(tdb->fd) != 0)
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "tdb1_open_ex: failed to close tdb->fd on error!\n"));
SAFE_FREE(tdb->lockrecs);
SAFE_FREE(tdb->name);
SAFE_FREE(tdb);
errno = save_errno;
return NULL;
}
}
/*
* Set the maximum number of dead records per hash chain
*/
_PUBLIC_ void tdb1_set_max_dead(struct tdb1_context *tdb, int max_dead)
{
tdb->max_dead_records = max_dead;
}
/**
* Close a database.
*
* @returns -1 for error; 0 for success.
**/
_PUBLIC_ int tdb1_close(struct tdb1_context *tdb)
{
struct tdb1_context **i;
int ret = 0;
if (tdb->transaction) {
tdb1_transaction_cancel(tdb);
}
if (tdb->map_ptr) {
if (tdb->flags & TDB1_INTERNAL)
SAFE_FREE(tdb->map_ptr);
else
tdb1_munmap(tdb);
}
SAFE_FREE(tdb->name);
if (tdb->fd != -1) {
ret = close(tdb->fd);
tdb->fd = -1;
}
SAFE_FREE(tdb->lockrecs);
/* Remove from contexts list */
for (i = &tdb1s; *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 */
_PUBLIC_ void tdb1_set_logging_function(struct tdb1_context *tdb,
const struct tdb1_logging_context *log_ctx)
{
tdb->log = *log_ctx;
}
_PUBLIC_ void *tdb1_get_logging_private(struct tdb1_context *tdb)
{
return tdb->log.log_private;
}
static int tdb1_reopen_internal(struct tdb1_context *tdb, bool active_lock)
{
#if !defined(LIBREPLACE_PREAD_NOT_REPLACED) || \
!defined(LIBREPLACE_PWRITE_NOT_REPLACED)
struct stat st;
#endif
if (tdb->flags & TDB1_INTERNAL) {
return 0; /* Nothing to do. */
}
if (tdb1_have_extra_locks(tdb)) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "tdb1_reopen: reopen not allowed with locks held\n"));
goto fail;
}
if (tdb->transaction != 0) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "tdb1_reopen: reopen not allowed inside a transaction\n"));
goto fail;
}
/* If we have real pread & pwrite, we can skip reopen. */
#if !defined(LIBREPLACE_PREAD_NOT_REPLACED) || \
!defined(LIBREPLACE_PWRITE_NOT_REPLACED)
if (tdb1_munmap(tdb) != 0) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_reopen: munmap failed (%s)\n", strerror(errno)));
goto fail;
}
if (close(tdb->fd) != 0)
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_reopen: WARNING closing tdb->fd failed!\n"));
tdb->fd = open(tdb->name, tdb->open_flags & ~(O_CREAT|O_TRUNC), 0);
if (tdb->fd == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_reopen: open failed (%s)\n", strerror(errno)));
goto fail;
}
if (fstat(tdb->fd, &st) != 0) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_reopen: fstat failed (%s)\n", strerror(errno)));
goto fail;
}
if (st.st_ino != tdb->inode || st.st_dev != tdb->device) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_reopen: file dev/inode has changed!\n"));
goto fail;
}
tdb1_mmap(tdb);
#endif /* fake pread or pwrite */
/* We may still think we hold the active lock. */
tdb->num_lockrecs = 0;
SAFE_FREE(tdb->lockrecs);
if (active_lock && tdb1_nest_lock(tdb, TDB1_ACTIVE_LOCK, F_RDLCK, TDB1_LOCK_WAIT) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_reopen: failed to obtain active lock\n"));
goto fail;
}
return 0;
fail:
tdb1_close(tdb);
return -1;
}
/* 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 */
_PUBLIC_ int tdb1_reopen(struct tdb1_context *tdb)
{
return tdb1_reopen_internal(tdb, tdb->flags & TDB1_CLEAR_IF_FIRST);
}
/* reopen all tdb's */
_PUBLIC_ int tdb1_reopen_all(int parent_longlived)
{
struct tdb1_context *tdb;
for (tdb=tdb1s; tdb; tdb = tdb->next) {
bool active_lock = (tdb->flags & TDB1_CLEAR_IF_FIRST);
/*
* 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. */
active_lock = false;
}
if (tdb1_reopen_internal(tdb, active_lock) != 0)
return -1;
}
return 0;
}
ccan/tdb2/tdb1_private.h 0 → 100644
View file @ 19e6c1a2
#ifndef CCAN_TDB2_TDB1_PRIVATE_H
#define CCAN_TDB2_TDB1_PRIVATE_H
/*
Unix SMB/CIFS implementation.
trivial database library - private includes
Copyright (C) Andrew Tridgell 2005
** NOTE! The following LGPL license applies to the tdb
** library. This does NOT imply that all of Samba is released
** under the LGPL
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#ifndef _SAMBA_BUILD_
#include "config.h"
/* This keeps us consistent with TDB2 code. */
#if HAVE_FILE_OFFSET_BITS
#define _FILE_OFFSET_BITS 64
#endif
#include <stdint.h>
#include <stdbool.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <sys/time.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <stdlib.h>
#include <limits.h>
#include <stdio.h>
#include <utime.h>
#ifndef _PUBLIC_
#define _PUBLIC_
#endif
#else
#include "replace.h"
#include "system/filesys.h"
#include "system/time.h"
#include "system/shmem.h"
#include "system/select.h"
#include "system/wait.h"
#endif
#include "tdb1.h"
/* #define TDB_TRACE 1 */
#ifndef HAVE_GETPAGESIZE
#define getpagesize() 0x2000
#endif
#ifndef __STRING
#define __STRING(x) #x
#endif
#ifndef __STRINGSTRING
#define __STRINGSTRING(x) __STRING(x)
#endif
#ifndef __location__
#define __location__ __FILE__ ":" __STRINGSTRING(__LINE__)
#endif
typedef uint32_t tdb1_len_t;
typedef uint32_t tdb1_off_t;
#ifndef offsetof
#define offsetof(t,f) ((unsigned int)&((t *)0)->f)
#endif
#define TDB1_MAGIC_FOOD "TDB file\n"
#define TDB1_VERSION (0x26011967 + 6)
#define TDB1_MAGIC (0x26011999U)
#define TDB1_FREE_MAGIC (~TDB1_MAGIC)
#define TDB1_DEAD_MAGIC (0xFEE1DEAD)
#define TDB1_RECOVERY_MAGIC (0xf53bc0e7U)
#define TDB1_RECOVERY_INVALID_MAGIC (0x0)
#define TDB1_HASH_RWLOCK_MAGIC (0xbad1a51U)
#define TDB1_ALIGNMENT 4
#define TDB1_DEFAULT_HASH_SIZE 131
#define TDB1_FREELIST_TOP (sizeof(struct tdb1_header))
#define TDB1_ALIGN(x,a) (((x) + (a)-1) & ~((a)-1))
#define TDB1_BYTEREV(x) (((((x)&0xff)<<24)|((x)&0xFF00)<<8)|(((x)>>8)&0xFF00)|((x)>>24))
#define TDB1_DEAD(r) ((r)->magic == TDB1_DEAD_MAGIC)
#define TDB1_BAD_MAGIC(r) ((r)->magic != TDB1_MAGIC && !TDB1_DEAD(r))
#define TDB1_HASH_TOP(hash) (TDB1_FREELIST_TOP + (TDB1_BUCKET(hash)+1)*sizeof(tdb1_off_t))
#define TDB1_HASHTABLE_SIZE(tdb) ((tdb->header.hash_size+1)*sizeof(tdb1_off_t))
#define TDB1_DATA_START(hash_size) (TDB1_HASH_TOP(hash_size-1) + sizeof(tdb1_off_t))
#define TDB1_RECOVERY_HEAD offsetof(struct tdb1_header, recovery_start)
#define TDB1_SEQNUM_OFS offsetof(struct tdb1_header, sequence_number)
#define TDB1_PAD_BYTE 0x42
#define TDB1_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 TDB1_LOG(x) tdb->log.log_fn x
/* lock offsets */
#define TDB1_OPEN_LOCK 0
#define TDB1_ACTIVE_LOCK 4
#define TDB1_TRANSACTION_LOCK 8
/* free memory if the pointer is valid and zero the pointer */
#ifndef SAFE_FREE
#define SAFE_FREE(x) do { if ((x) != NULL) {free(x); (x)=NULL;} } while(0)
#endif
#define TDB1_BUCKET(hash) ((hash) % tdb->header.hash_size)
#define TDB1_DOCONV() (tdb->flags & TDB1_CONVERT)
#define TDB1_CONV(x) (TDB1_DOCONV() ? tdb1_convert(&x, sizeof(x)) : &x)
/* the body of the database is made of one tdb1_record for the free space
plus a separate data list for each hash value */
struct tdb1_record {
tdb1_off_t next; /* offset of the next record in the list */
tdb1_len_t rec_len; /* total byte length of record */
tdb1_len_t key_len; /* byte length of key */
tdb1_len_t data_len; /* byte length of data */
uint32_t full_hash; /* the full 32 bit hash of the key */
uint32_t magic; /* try to catch errors */
/* the following union is implied:
union {
char record[rec_len];
struct {
char key[key_len];
char data[data_len];
}
uint32_t totalsize; (tailer)
}
*/
};
/* this is stored at the front of every database */
struct tdb1_header {
char magic_food[32]; /* for /etc/magic */
uint32_t version; /* version of the code */
uint32_t hash_size; /* number of hash entries */
tdb1_off_t rwlocks; /* obsolete - kept to detect old formats */
tdb1_off_t recovery_start; /* offset of transaction recovery region */
tdb1_off_t sequence_number; /* used when TDB1_SEQNUM is set */
uint32_t magic1_hash; /* hash of TDB1_MAGIC_FOOD. */
uint32_t magic2_hash; /* hash of TDB1_MAGIC. */
tdb1_off_t reserved[27];
};
struct tdb1_lock_type {
uint32_t off;
uint32_t count;
uint32_t ltype;
};
struct tdb1_traverse_lock {
struct tdb1_traverse_lock *next;
uint32_t off;
uint32_t hash;
int lock_rw;
};
enum tdb1_lock_flags {
/* WAIT == F_SETLKW, NOWAIT == F_SETLK */
TDB1_LOCK_NOWAIT = 0,
TDB1_LOCK_WAIT = 1,
/* If set, don't log an error on failure. */
TDB1_LOCK_PROBE = 2,
/* If set, don't actually lock at all. */
TDB1_LOCK_MARK_ONLY = 4,
};
struct tdb1_context;
struct tdb1_methods {
int (*tdb1_read)(struct tdb1_context *, tdb1_off_t , void *, tdb1_len_t , int );
int (*tdb1_write)(struct tdb1_context *, tdb1_off_t, const void *, tdb1_len_t);
void (*next_hash_chain)(struct tdb1_context *, uint32_t *);
int (*tdb1_oob)(struct tdb1_context *, tdb1_off_t , int );
int (*tdb1_expand_file)(struct tdb1_context *, tdb1_off_t , tdb1_off_t );
};
struct tdb1_context {
char *name; /* the name of the database */
void *map_ptr; /* where it is currently mapped */
int fd; /* open file descriptor for the database */
tdb1_len_t map_size; /* how much space has been mapped */
int read_only; /* opened read-only */
int traverse_read; /* read-only traversal */
int traverse_write; /* read-write traversal */
struct tdb1_lock_type allrecord_lock; /* .offset == upgradable */
int num_lockrecs;
struct tdb1_lock_type *lockrecs; /* only real locks, all with count>0 */
enum TDB1_ERROR ecode; /* error code for last tdb error */
struct tdb1_header header; /* a cached copy of the header */
uint32_t flags; /* the flags passed to tdb1_open */
struct tdb1_traverse_lock travlocks; /* current traversal locks */
struct tdb1_context *next; /* all tdbs to avoid multiple opens */
dev_t device; /* uniquely identifies this tdb */
ino_t inode; /* uniquely identifies this tdb */
struct tdb1_logging_context log;
unsigned int (*hash_fn)(TDB1_DATA *key);
int open_flags; /* flags used in the open - needed by reopen */
const struct tdb1_methods *methods;
struct tdb1_transaction *transaction;
int page_size;
int max_dead_records;
#ifdef TDB1_TRACE
int tracefd;
#endif
volatile sig_atomic_t *interrupt_sig_ptr;
};
/*
internal prototypes
*/
int tdb1_munmap(struct tdb1_context *tdb);
void tdb1_mmap(struct tdb1_context *tdb);
int tdb1_lock(struct tdb1_context *tdb, int list, int ltype);
int tdb1_lock_nonblock(struct tdb1_context *tdb, int list, int ltype);
int tdb1_nest_lock(struct tdb1_context *tdb, uint32_t offset, int ltype,
enum tdb1_lock_flags flags);
int tdb1_nest_unlock(struct tdb1_context *tdb, uint32_t offset, int ltype,
bool mark_lock);
int tdb1_unlock(struct tdb1_context *tdb, int list, int ltype);
int tdb1_brlock(struct tdb1_context *tdb,
int rw_type, tdb1_off_t offset, size_t len,
enum tdb1_lock_flags flags);
int tdb1_brunlock(struct tdb1_context *tdb,
int rw_type, tdb1_off_t offset, size_t len);
bool tdb1_have_extra_locks(struct tdb1_context *tdb);
void tdb1_release_transaction_locks(struct tdb1_context *tdb);
int tdb1_transaction_lock(struct tdb1_context *tdb, int ltype,
enum tdb1_lock_flags lockflags);
int tdb1_transaction_unlock(struct tdb1_context *tdb, int ltype);
int tdb1_recovery_area(struct tdb1_context *tdb,
const struct tdb1_methods *methods,
tdb1_off_t *recovery_offset,
struct tdb1_record *rec);
int tdb1_allrecord_lock(struct tdb1_context *tdb, int ltype,
enum tdb1_lock_flags flags, bool upgradable);
int tdb1_allrecord_unlock(struct tdb1_context *tdb, int ltype, bool mark_lock);
int tdb1_allrecord_upgrade(struct tdb1_context *tdb);
int tdb1_write_lock_record(struct tdb1_context *tdb, tdb1_off_t off);
int tdb1_write_unlock_record(struct tdb1_context *tdb, tdb1_off_t off);
int tdb1_ofs_read(struct tdb1_context *tdb, tdb1_off_t offset, tdb1_off_t *d);
int tdb1_ofs_write(struct tdb1_context *tdb, tdb1_off_t offset, tdb1_off_t *d);
void *tdb1_convert(void *buf, uint32_t size);
int tdb1_free(struct tdb1_context *tdb, tdb1_off_t offset, struct tdb1_record *rec);
tdb1_off_t tdb1_allocate(struct tdb1_context *tdb, tdb1_len_t length, struct tdb1_record *rec);
int tdb1_ofs_read(struct tdb1_context *tdb, tdb1_off_t offset, tdb1_off_t *d);
int tdb1_ofs_write(struct tdb1_context *tdb, tdb1_off_t offset, tdb1_off_t *d);
int tdb1_lock_record(struct tdb1_context *tdb, tdb1_off_t off);
int tdb1_unlock_record(struct tdb1_context *tdb, tdb1_off_t off);
bool tdb1_needs_recovery(struct tdb1_context *tdb);
int tdb1_rec_read(struct tdb1_context *tdb, tdb1_off_t offset, struct tdb1_record *rec);
int tdb1_rec_write(struct tdb1_context *tdb, tdb1_off_t offset, struct tdb1_record *rec);
int tdb1_do_delete(struct tdb1_context *tdb, tdb1_off_t rec_ptr, struct tdb1_record *rec);
unsigned char *tdb1_alloc_read(struct tdb1_context *tdb, tdb1_off_t offset, tdb1_len_t len);
int tdb1_parse_data(struct tdb1_context *tdb, TDB1_DATA key,
tdb1_off_t offset, tdb1_len_t len,
int (*parser)(TDB1_DATA key, TDB1_DATA data,
void *private_data),
void *private_data);
tdb1_off_t tdb1_find_lock_hash(struct tdb1_context *tdb, TDB1_DATA key, uint32_t hash, int locktype,
struct tdb1_record *rec);
void tdb1_io_init(struct tdb1_context *tdb);
int tdb1_expand(struct tdb1_context *tdb, tdb1_off_t size);
int tdb1_rec_free_read(struct tdb1_context *tdb, tdb1_off_t off,
struct tdb1_record *rec);
bool tdb1_write_all(int fd, const void *buf, size_t count);
int tdb1_transaction_recover(struct tdb1_context *tdb);
void tdb1_header_hash(struct tdb1_context *tdb,
uint32_t *magic1_hash, uint32_t *magic2_hash);
unsigned int tdb1_old_hash(TDB1_DATA *key);
size_t tdb1_dead_space(struct tdb1_context *tdb, tdb1_off_t off);
#endif /* CCAN_TDB2_TDB1_PRIVATE_H */
ccan/tdb2/tdb1_summary.c 0 → 100644
View file @ 19e6c1a2
/*
Trivial Database: human-readable summary code
Copyright (C) Rusty Russell 2010
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "tdb1_private.h"
#define SUMMARY_FORMAT1 \
"Size of file/data: %u/%zu\n" \
"Number of records: %zu\n" \
"Smallest/average/largest keys: %zu/%zu/%zu\n" \
"Smallest/average/largest data: %zu/%zu/%zu\n" \
"Smallest/average/largest padding: %zu/%zu/%zu\n" \
"Number of dead records: %zu\n" \
"Smallest/average/largest dead records: %zu/%zu/%zu\n" \
"Number of free records: %zu\n" \
"Smallest/average/largest free records: %zu/%zu/%zu\n" \
"Number of hash chains: %zu\n" \
"Smallest/average/largest hash chains: %zu/%zu/%zu\n" \
"Number of uncoalesced records: %zu\n" \
"Smallest/average/largest uncoalesced runs: %zu/%zu/%zu\n" \
"Percentage keys/data/padding/free/dead/rechdrs&tailers/hashes: %.0f/%.0f/%.0f/%.0f/%.0f/%.0f/%.0f\n"
/* We don't use tally module, to keep upstream happy. */
struct tally {
size_t min, max, total;
size_t num;
};
static void tally1_init(struct tally *tally)
{
tally->total = 0;
tally->num = 0;
tally->min = tally->max = 0;
}
static void tally1_add(struct tally *tally, size_t len)
{
if (tally->num == 0)
tally->max = tally->min = len;
else if (len > tally->max)
tally->max = len;
else if (len < tally->min)
tally->min = len;
tally->num++;
tally->total += len;
}
static size_t tally1_mean(const struct tally *tally)
{
if (!tally->num)
return 0;
return tally->total / tally->num;
}
static size_t get_hash_length(struct tdb1_context *tdb, unsigned int i)
{
tdb1_off_t rec_ptr;
size_t count = 0;
if (tdb1_ofs_read(tdb, TDB1_HASH_TOP(i), &rec_ptr) == -1)
return 0;
/* keep looking until we find the right record */
while (rec_ptr) {
struct tdb1_record r;
++count;
if (tdb1_rec_read(tdb, rec_ptr, &r) == -1)
return 0;
rec_ptr = r.next;
}
return count;
}
_PUBLIC_ char *tdb1_summary(struct tdb1_context *tdb)
{
tdb1_off_t off, rec_off;
struct tally freet, keys, data, dead, extra, hash, uncoal;
struct tdb1_record rec;
char *ret = NULL;
bool locked;
size_t len, unc = 0;
struct tdb1_record recovery;
/* Read-only databases use no locking at all: it's best-effort.
* We may have a write lock already, so skip that case too. */
if (tdb->read_only || tdb->allrecord_lock.count != 0) {
locked = false;
} else {
if (tdb1_lockall_read(tdb) == -1)
return NULL;
locked = true;
}
if (tdb1_recovery_area(tdb, tdb->methods, &rec_off, &recovery) != 0) {
goto unlock;
}
tally1_init(&freet);
tally1_init(&keys);
tally1_init(&data);
tally1_init(&dead);
tally1_init(&extra);
tally1_init(&hash);
tally1_init(&uncoal);
for (off = TDB1_DATA_START(tdb->header.hash_size);
off < tdb->map_size - 1;
off += sizeof(rec) + rec.rec_len) {
if (tdb->methods->tdb1_read(tdb, off, &rec, sizeof(rec),
TDB1_DOCONV()) == -1)
goto unlock;
switch (rec.magic) {
case TDB1_MAGIC:
tally1_add(&keys, rec.key_len);
tally1_add(&data, rec.data_len);
tally1_add(&extra, rec.rec_len - (rec.key_len
+ rec.data_len));
if (unc > 1)
tally1_add(&uncoal, unc - 1);
unc = 0;
break;
case TDB1_FREE_MAGIC:
tally1_add(&freet, rec.rec_len);
unc++;
break;
/* If we crash after ftruncate, we can get zeroes or fill. */
case TDB1_RECOVERY_INVALID_MAGIC:
case 0x42424242:
unc++;
/* If it's a valid recovery, we can trust rec_len. */
if (off != rec_off) {
rec.rec_len = tdb1_dead_space(tdb, off)
- sizeof(rec);
}
/* Fall through */
case TDB1_DEAD_MAGIC:
tally1_add(&dead, rec.rec_len);
break;
default:
TDB1_LOG((tdb, TDB1_DEBUG_ERROR,
"Unexpected record magic 0x%x at offset %d\n",
rec.magic, off));
goto unlock;
}
}
if (unc > 1)
tally1_add(&uncoal, unc - 1);
for (off = 0; off < tdb->header.hash_size; off++)
tally1_add(&hash, get_hash_length(tdb, off));
/* 20 is max length of a %zu. */
len = strlen(SUMMARY_FORMAT1) + 35*20 + 1;
ret = (char *)malloc(len);
if (!ret)
goto unlock;
snprintf(ret, len, SUMMARY_FORMAT1,
tdb->map_size, keys.total+data.total,
keys.num,
keys.min, tally1_mean(&keys), keys.max,
data.min, tally1_mean(&data), data.max,
extra.min, tally1_mean(&extra), extra.max,
dead.num,
dead.min, tally1_mean(&dead), dead.max,
freet.num,
freet.min, tally1_mean(&freet), freet.max,
hash.num,
hash.min, tally1_mean(&hash), hash.max,
uncoal.total,
uncoal.min, tally1_mean(&uncoal), uncoal.max,
keys.total * 100.0 / tdb->map_size,
data.total * 100.0 / tdb->map_size,
extra.total * 100.0 / tdb->map_size,
freet.total * 100.0 / tdb->map_size,
dead.total * 100.0 / tdb->map_size,
(keys.num + freet.num + dead.num)
* (sizeof(struct tdb1_record) + sizeof(uint32_t))
* 100.0 / tdb->map_size,
tdb->header.hash_size * sizeof(tdb1_off_t)
* 100.0 / tdb->map_size);
unlock:
if (locked) {
tdb1_unlockall_read(tdb);
}
return ret;
}
ccan/tdb2/tdb1_tdb.c 0 → 100644
View file @ 19e6c1a2
/*
Unix SMB/CIFS implementation.
trivial database library
Copyright (C) Andrew Tridgell 1999-2005
Copyright (C) Paul `Rusty' Russell 2000
Copyright (C) Jeremy Allison 2000-2003
** NOTE! The following LGPL license applies to the tdb
** library. This does NOT imply that all of Samba is released
** under the LGPL
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "tdb1_private.h"
_PUBLIC_ TDB1_DATA tdb1_null;
/*
non-blocking increment of the tdb sequence number if the tdb has been opened using
the TDB1_SEQNUM flag
*/
_PUBLIC_ void tdb1_increment_seqnum_nonblock(struct tdb1_context *tdb)
{
tdb1_off_t seqnum=0;
if (!(tdb->flags & TDB1_SEQNUM)) {
return;
}
/* we ignore errors from this, as we have no sane way of
dealing with them.
*/
tdb1_ofs_read(tdb, TDB1_SEQNUM_OFS, &seqnum);
seqnum++;
tdb1_ofs_write(tdb, TDB1_SEQNUM_OFS, &seqnum);
}
/*
increment the tdb sequence number if the tdb has been opened using
the TDB1_SEQNUM flag
*/
static void tdb1_increment_seqnum(struct tdb1_context *tdb)
{
if (!(tdb->flags & TDB1_SEQNUM)) {
return;
}
if (tdb1_nest_lock(tdb, TDB1_SEQNUM_OFS, F_WRLCK,
TDB1_LOCK_WAIT|TDB1_LOCK_PROBE) != 0) {
return;
}
tdb1_increment_seqnum_nonblock(tdb);
tdb1_nest_unlock(tdb, TDB1_SEQNUM_OFS, F_WRLCK, false);
}
static int tdb1_key_compare(TDB1_DATA key, TDB1_DATA data, void *private_data)
{
return memcmp(data.dptr, key.dptr, data.dsize);
}
/* Returns 0 on fail. On success, return offset of record, and fills
in rec */
static tdb1_off_t tdb1_find(struct tdb1_context *tdb, TDB1_DATA key, uint32_t hash,
struct tdb1_record *r)
{
tdb1_off_t rec_ptr;
/* read in the hash top */
if (tdb1_ofs_read(tdb, TDB1_HASH_TOP(hash), &rec_ptr) == -1)
return 0;
/* keep looking until we find the right record */
while (rec_ptr) {
if (tdb1_rec_read(tdb, rec_ptr, r) == -1)
return 0;
if (!TDB1_DEAD(r) && hash==r->full_hash
&& key.dsize==r->key_len
&& tdb1_parse_data(tdb, key, rec_ptr + sizeof(*r),
r->key_len, tdb1_key_compare,
NULL) == 0) {
return rec_ptr;
}
/* detect tight infinite loop */
if (rec_ptr == r->next) {
tdb->ecode = TDB1_ERR_CORRUPT;
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_find: loop detected.\n"));
return 0;
}
rec_ptr = r->next;
}
tdb->ecode = TDB1_ERR_NOEXIST;
return 0;
}
/* As tdb1_find, but if you succeed, keep the lock */
tdb1_off_t tdb1_find_lock_hash(struct tdb1_context *tdb, TDB1_DATA key, uint32_t hash, int locktype,
struct tdb1_record *rec)
{
uint32_t rec_ptr;
if (tdb1_lock(tdb, TDB1_BUCKET(hash), locktype) == -1)
return 0;
if (!(rec_ptr = tdb1_find(tdb, key, hash, rec)))
tdb1_unlock(tdb, TDB1_BUCKET(hash), locktype);
return rec_ptr;
}
static TDB1_DATA _tdb1_fetch(struct tdb1_context *tdb, TDB1_DATA key);
/* update an entry in place - this only works if the new data size
is <= the old data size and the key exists.
on failure return -1.
*/
static int tdb1_update_hash(struct tdb1_context *tdb, TDB1_DATA key, uint32_t hash, TDB1_DATA dbuf)
{
struct tdb1_record rec;
tdb1_off_t rec_ptr;
/* find entry */
if (!(rec_ptr = tdb1_find(tdb, key, hash, &rec)))
return -1;
/* it could be an exact duplicate of what is there - this is
* surprisingly common (eg. with a ldb re-index). */
if (rec.key_len == key.dsize &&
rec.data_len == dbuf.dsize &&
rec.full_hash == hash) {
TDB1_DATA data = _tdb1_fetch(tdb, key);
if (data.dsize == dbuf.dsize &&
memcmp(data.dptr, dbuf.dptr, data.dsize) == 0) {
if (data.dptr) {
free(data.dptr);
}
return 0;
}
if (data.dptr) {
free(data.dptr);
}
}
/* must be long enough key, data and tailer */
if (rec.rec_len < key.dsize + dbuf.dsize + sizeof(tdb1_off_t)) {
tdb->ecode = TDB1_SUCCESS; /* Not really an error */
return -1;
}
if (tdb->methods->tdb1_write(tdb, rec_ptr + sizeof(rec) + rec.key_len,
dbuf.dptr, dbuf.dsize) == -1)
return -1;
if (dbuf.dsize != rec.data_len) {
/* update size */
rec.data_len = dbuf.dsize;
return tdb1_rec_write(tdb, rec_ptr, &rec);
}
return 0;
}
/* find an entry in the database given a key */
/* If an entry doesn't exist tdb1_err will be set to
* TDB1_ERR_NOEXIST. If a key has no data attached
* then the TDB1_DATA will have zero length but
* a non-zero pointer
*/
static TDB1_DATA _tdb1_fetch(struct tdb1_context *tdb, TDB1_DATA key)
{
tdb1_off_t rec_ptr;
struct tdb1_record rec;
TDB1_DATA ret;
uint32_t hash;
/* find which hash bucket it is in */
hash = tdb->hash_fn(&key);
if (!(rec_ptr = tdb1_find_lock_hash(tdb,key,hash,F_RDLCK,&rec)))
return tdb1_null;
ret.dptr = tdb1_alloc_read(tdb, rec_ptr + sizeof(rec) + rec.key_len,
rec.data_len);
ret.dsize = rec.data_len;
tdb1_unlock(tdb, TDB1_BUCKET(rec.full_hash), F_RDLCK);
return ret;
}
_PUBLIC_ TDB1_DATA tdb1_fetch(struct tdb1_context *tdb, TDB1_DATA key)
{
TDB1_DATA ret = _tdb1_fetch(tdb, key);
return ret;
}
/*
* Find an entry in the database and hand the record's data to a parsing
* function. The parsing function is executed under the chain read lock, so it
* should be fast and should not block on other syscalls.
*
* DON'T CALL OTHER TDB CALLS FROM THE PARSER, THIS MIGHT LEAD TO SEGFAULTS.
*
* For mmapped tdb's that do not have a transaction open it points the parsing
* function directly at the mmap area, it avoids the malloc/memcpy in this
* case. If a transaction is open or no mmap is available, it has to do
* malloc/read/parse/free.
*
* This is interesting for all readers of potentially large data structures in
* the tdb records, ldb indexes being one example.
*
* Return -1 if the record was not found.
*/
_PUBLIC_ int tdb1_parse_record(struct tdb1_context *tdb, TDB1_DATA key,
int (*parser)(TDB1_DATA key, TDB1_DATA data,
void *private_data),
void *private_data)
{
tdb1_off_t rec_ptr;
struct tdb1_record rec;
int ret;
uint32_t hash;
/* find which hash bucket it is in */
hash = tdb->hash_fn(&key);
if (!(rec_ptr = tdb1_find_lock_hash(tdb,key,hash,F_RDLCK,&rec))) {
/* record not found */
tdb->ecode = TDB1_ERR_NOEXIST;
return -1;
}
ret = tdb1_parse_data(tdb, key, rec_ptr + sizeof(rec) + rec.key_len,
rec.data_len, parser, private_data);
tdb1_unlock(tdb, TDB1_BUCKET(rec.full_hash), F_RDLCK);
return ret;
}
/* check if an entry in the database exists
note that 1 is returned if the key is found and 0 is returned if not found
this doesn't match the conventions in the rest of this module, but is
compatible with gdbm
*/
static int tdb1_exists_hash(struct tdb1_context *tdb, TDB1_DATA key, uint32_t hash)
{
struct tdb1_record rec;
if (tdb1_find_lock_hash(tdb, key, hash, F_RDLCK, &rec) == 0)
return 0;
tdb1_unlock(tdb, TDB1_BUCKET(rec.full_hash), F_RDLCK);
return 1;
}
_PUBLIC_ int tdb1_exists(struct tdb1_context *tdb, TDB1_DATA key)
{
uint32_t hash = tdb->hash_fn(&key);
int ret;
ret = tdb1_exists_hash(tdb, key, hash);
return ret;
}
/* actually delete an entry in the database given the offset */
int tdb1_do_delete(struct tdb1_context *tdb, tdb1_off_t rec_ptr, struct tdb1_record *rec)
{
tdb1_off_t last_ptr, i;
struct tdb1_record lastrec;
if (tdb->read_only || tdb->traverse_read) return -1;
if (((tdb->traverse_write != 0) && (!TDB1_DEAD(rec))) ||
tdb1_write_lock_record(tdb, rec_ptr) == -1) {
/* Someone traversing here: mark it as dead */
rec->magic = TDB1_DEAD_MAGIC;
return tdb1_rec_write(tdb, rec_ptr, rec);
}
if (tdb1_write_unlock_record(tdb, rec_ptr) != 0)
return -1;
/* find previous record in hash chain */
if (tdb1_ofs_read(tdb, TDB1_HASH_TOP(rec->full_hash), &i) == -1)
return -1;
for (last_ptr = 0; i != rec_ptr; last_ptr = i, i = lastrec.next)
if (tdb1_rec_read(tdb, i, &lastrec) == -1)
return -1;
/* unlink it: next ptr is at start of record. */
if (last_ptr == 0)
last_ptr = TDB1_HASH_TOP(rec->full_hash);
if (tdb1_ofs_write(tdb, last_ptr, &rec->next) == -1)
return -1;
/* recover the space */
if (tdb1_free(tdb, rec_ptr, rec) == -1)
return -1;
return 0;
}
static int tdb1_count_dead(struct tdb1_context *tdb, uint32_t hash)
{
int res = 0;
tdb1_off_t rec_ptr;
struct tdb1_record rec;
/* read in the hash top */
if (tdb1_ofs_read(tdb, TDB1_HASH_TOP(hash), &rec_ptr) == -1)
return 0;
while (rec_ptr) {
if (tdb1_rec_read(tdb, rec_ptr, &rec) == -1)
return 0;
if (rec.magic == TDB1_DEAD_MAGIC) {
res += 1;
}
rec_ptr = rec.next;
}
return res;
}
/*
* Purge all DEAD records from a hash chain
*/
static int tdb1_purge_dead(struct tdb1_context *tdb, uint32_t hash)
{
int res = -1;
struct tdb1_record rec;
tdb1_off_t rec_ptr;
if (tdb1_lock(tdb, -1, F_WRLCK) == -1) {
return -1;
}
/* read in the hash top */
if (tdb1_ofs_read(tdb, TDB1_HASH_TOP(hash), &rec_ptr) == -1)
goto fail;
while (rec_ptr) {
tdb1_off_t next;
if (tdb1_rec_read(tdb, rec_ptr, &rec) == -1) {
goto fail;
}
next = rec.next;
if (rec.magic == TDB1_DEAD_MAGIC
&& tdb1_do_delete(tdb, rec_ptr, &rec) == -1) {
goto fail;
}
rec_ptr = next;
}
res = 0;
fail:
tdb1_unlock(tdb, -1, F_WRLCK);
return res;
}
/* delete an entry in the database given a key */
static int tdb1_delete_hash(struct tdb1_context *tdb, TDB1_DATA key, uint32_t hash)
{
tdb1_off_t rec_ptr;
struct tdb1_record rec;
int ret;
if (tdb->max_dead_records != 0) {
/*
* Allow for some dead records per hash chain, mainly for
* tdb's with a very high create/delete rate like locking.tdb.
*/
if (tdb1_lock(tdb, TDB1_BUCKET(hash), F_WRLCK) == -1)
return -1;
if (tdb1_count_dead(tdb, hash) >= tdb->max_dead_records) {
/*
* Don't let the per-chain freelist grow too large,
* delete all existing dead records
*/
tdb1_purge_dead(tdb, hash);
}
if (!(rec_ptr = tdb1_find(tdb, key, hash, &rec))) {
tdb1_unlock(tdb, TDB1_BUCKET(hash), F_WRLCK);
return -1;
}
/*
* Just mark the record as dead.
*/
rec.magic = TDB1_DEAD_MAGIC;
ret = tdb1_rec_write(tdb, rec_ptr, &rec);
}
else {
if (!(rec_ptr = tdb1_find_lock_hash(tdb, key, hash, F_WRLCK,
&rec)))
return -1;
ret = tdb1_do_delete(tdb, rec_ptr, &rec);
}
if (ret == 0) {
tdb1_increment_seqnum(tdb);
}
if (tdb1_unlock(tdb, TDB1_BUCKET(rec.full_hash), F_WRLCK) != 0)
TDB1_LOG((tdb, TDB1_DEBUG_WARNING, "tdb1_delete: WARNING tdb1_unlock failed!\n"));
return ret;
}
_PUBLIC_ int tdb1_delete(struct tdb1_context *tdb, TDB1_DATA key)
{
uint32_t hash = tdb->hash_fn(&key);
int ret;
ret = tdb1_delete_hash(tdb, key, hash);
return ret;
}
/*
* See if we have a dead record around with enough space
*/
static tdb1_off_t tdb1_find_dead(struct tdb1_context *tdb, uint32_t hash,
struct tdb1_record *r, tdb1_len_t length)
{
tdb1_off_t rec_ptr;
/* read in the hash top */
if (tdb1_ofs_read(tdb, TDB1_HASH_TOP(hash), &rec_ptr) == -1)
return 0;
/* keep looking until we find the right record */
while (rec_ptr) {
if (tdb1_rec_read(tdb, rec_ptr, r) == -1)
return 0;
if (TDB1_DEAD(r) && r->rec_len >= length) {
/*
* First fit for simple coding, TODO: change to best
* fit
*/
return rec_ptr;
}
rec_ptr = r->next;
}
return 0;
}
static int _tdb1_store(struct tdb1_context *tdb, TDB1_DATA key,
TDB1_DATA dbuf, int flag, uint32_t hash)
{
struct tdb1_record rec;
tdb1_off_t rec_ptr;
char *p = NULL;
int ret = -1;
/* check for it existing, on insert. */
if (flag == TDB1_INSERT) {
if (tdb1_exists_hash(tdb, key, hash)) {
tdb->ecode = TDB1_ERR_EXISTS;
goto fail;
}
} else {
/* first try in-place update, on modify or replace. */
if (tdb1_update_hash(tdb, key, hash, dbuf) == 0) {
goto done;
}
if (tdb->ecode == TDB1_ERR_NOEXIST &&
flag == TDB1_MODIFY) {
/* if the record doesn't exist and we are in TDB1_MODIFY mode then
we should fail the store */
goto fail;
}
}
/* reset the error code potentially set by the tdb1_update() */
tdb->ecode = TDB1_SUCCESS;
/* delete any existing record - if it doesn't exist we don't
care. Doing this first reduces fragmentation, and avoids
coalescing with `allocated' block before it's updated. */
if (flag != TDB1_INSERT)
tdb1_delete_hash(tdb, key, hash);
/* Copy key+value *before* allocating free space in case malloc
fails and we are left with a dead spot in the tdb. */
if (!(p = (char *)malloc(key.dsize + dbuf.dsize))) {
tdb->ecode = TDB1_ERR_OOM;
goto fail;
}
memcpy(p, key.dptr, key.dsize);
if (dbuf.dsize)
memcpy(p+key.dsize, dbuf.dptr, dbuf.dsize);
if (tdb->max_dead_records != 0) {
/*
* Allow for some dead records per hash chain, look if we can
* find one that can hold the new record. We need enough space
* for key, data and tailer. If we find one, we don't have to
* consult the central freelist.
*/
rec_ptr = tdb1_find_dead(
tdb, hash, &rec,
key.dsize + dbuf.dsize + sizeof(tdb1_off_t));
if (rec_ptr != 0) {
rec.key_len = key.dsize;
rec.data_len = dbuf.dsize;
rec.full_hash = hash;
rec.magic = TDB1_MAGIC;
if (tdb1_rec_write(tdb, rec_ptr, &rec) == -1
|| tdb->methods->tdb1_write(
tdb, rec_ptr + sizeof(rec),
p, key.dsize + dbuf.dsize) == -1) {
goto fail;
}
goto done;
}
}
/*
* We have to allocate some space from the freelist, so this means we
* have to lock it. Use the chance to purge all the DEAD records from
* the hash chain under the freelist lock.
*/
if (tdb1_lock(tdb, -1, F_WRLCK) == -1) {
goto fail;
}
if ((tdb->max_dead_records != 0)
&& (tdb1_purge_dead(tdb, hash) == -1)) {
tdb1_unlock(tdb, -1, F_WRLCK);
goto fail;
}
/* we have to allocate some space */
rec_ptr = tdb1_allocate(tdb, key.dsize + dbuf.dsize, &rec);
tdb1_unlock(tdb, -1, F_WRLCK);
if (rec_ptr == 0) {
goto fail;
}
/* Read hash top into next ptr */
if (tdb1_ofs_read(tdb, TDB1_HASH_TOP(hash), &rec.next) == -1)
goto fail;
rec.key_len = key.dsize;
rec.data_len = dbuf.dsize;
rec.full_hash = hash;
rec.magic = TDB1_MAGIC;
/* write out and point the top of the hash chain at it */
if (tdb1_rec_write(tdb, rec_ptr, &rec) == -1
|| tdb->methods->tdb1_write(tdb, rec_ptr+sizeof(rec), p, key.dsize+dbuf.dsize)==-1
|| tdb1_ofs_write(tdb, TDB1_HASH_TOP(hash), &rec_ptr) == -1) {
/* Need to tdb1_unallocate() here */
goto fail;
}
done:
ret = 0;
fail:
if (ret == 0) {
tdb1_increment_seqnum(tdb);
}
SAFE_FREE(p);
return ret;
}
/* store an element in the database, replacing any existing element
with the same key
return 0 on success, -1 on failure
*/
_PUBLIC_ int tdb1_store(struct tdb1_context *tdb, TDB1_DATA key, TDB1_DATA dbuf, int flag)
{
uint32_t hash;
int ret;
if (tdb->read_only || tdb->traverse_read) {
tdb->ecode = TDB1_ERR_RDONLY;
return -1;
}
/* find which hash bucket it is in */
hash = tdb->hash_fn(&key);
if (tdb1_lock(tdb, TDB1_BUCKET(hash), F_WRLCK) == -1)
return -1;
ret = _tdb1_store(tdb, key, dbuf, flag, hash);
tdb1_unlock(tdb, TDB1_BUCKET(hash), F_WRLCK);
return ret;
}
/* Append to an entry. Create if not exist. */
_PUBLIC_ int tdb1_append(struct tdb1_context *tdb, TDB1_DATA key, TDB1_DATA new_dbuf)
{
uint32_t hash;
TDB1_DATA dbuf;
int ret = -1;
/* find which hash bucket it is in */
hash = tdb->hash_fn(&key);
if (tdb1_lock(tdb, TDB1_BUCKET(hash), F_WRLCK) == -1)
return -1;
dbuf = _tdb1_fetch(tdb, key);
if (dbuf.dptr == NULL) {
dbuf.dptr = (unsigned char *)malloc(new_dbuf.dsize);
} else {
unsigned int new_len = dbuf.dsize + new_dbuf.dsize;
unsigned char *new_dptr;
/* realloc '0' is special: don't do that. */
if (new_len == 0)
new_len = 1;
new_dptr = (unsigned char *)realloc(dbuf.dptr, new_len);
if (new_dptr == NULL) {
free(dbuf.dptr);
}
dbuf.dptr = new_dptr;
}
if (dbuf.dptr == NULL) {
tdb->ecode = TDB1_ERR_OOM;
goto failed;
}
memcpy(dbuf.dptr + dbuf.dsize, new_dbuf.dptr, new_dbuf.dsize);
dbuf.dsize += new_dbuf.dsize;
ret = _tdb1_store(tdb, key, dbuf, 0, hash);
failed:
tdb1_unlock(tdb, TDB1_BUCKET(hash), F_WRLCK);
SAFE_FREE(dbuf.dptr);
return ret;
}
/*
return the name of the current tdb file
useful for external logging functions
*/
_PUBLIC_ const char *tdb1_name(struct tdb1_context *tdb)
{
return tdb->name;
}
/*
return the underlying file descriptor being used by tdb, or -1
useful for external routines that want to check the device/inode
of the fd
*/
_PUBLIC_ int tdb1_fd(struct tdb1_context *tdb)
{
return tdb->fd;
}
/*
return the current logging function
useful for external tdb routines that wish to log tdb errors
*/
_PUBLIC_ tdb1_log_func tdb1_log_fn(struct tdb1_context *tdb)
{
return tdb->log.log_fn;
}
/*
get the tdb sequence number. Only makes sense if the writers opened
with TDB1_SEQNUM set. Note that this sequence number will wrap quite
quickly, so it should only be used for a 'has something changed'
test, not for code that relies on the count of the number of changes
made. If you want a counter then use a tdb record.
The aim of this sequence number is to allow for a very lightweight
test of a possible tdb change.
*/
_PUBLIC_ int tdb1_get_seqnum(struct tdb1_context *tdb)
{
tdb1_off_t seqnum=0;
tdb1_ofs_read(tdb, TDB1_SEQNUM_OFS, &seqnum);
return seqnum;
}
_PUBLIC_ int tdb1_hash_size(struct tdb1_context *tdb)
{
return tdb->header.hash_size;
}
_PUBLIC_ size_t tdb1_map_size(struct tdb1_context *tdb)
{
return tdb->map_size;
}
_PUBLIC_ int tdb1_get_flags(struct tdb1_context *tdb)
{
return tdb->flags;
}
_PUBLIC_ void tdb1_add_flags(struct tdb1_context *tdb, unsigned flags)
{
if ((flags & TDB1_ALLOW_NESTING) &&
(flags & TDB1_DISALLOW_NESTING)) {
tdb->ecode = TDB1_ERR_NESTING;
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_add_flags: "
"allow_nesting and disallow_nesting are not allowed together!"));
return;
}
if (flags & TDB1_ALLOW_NESTING) {
tdb->flags &= ~TDB1_DISALLOW_NESTING;
}
if (flags & TDB1_DISALLOW_NESTING) {
tdb->flags &= ~TDB1_ALLOW_NESTING;
}
tdb->flags |= flags;
}
_PUBLIC_ void tdb1_remove_flags(struct tdb1_context *tdb, unsigned flags)
{
if ((flags & TDB1_ALLOW_NESTING) &&
(flags & TDB1_DISALLOW_NESTING)) {
tdb->ecode = TDB1_ERR_NESTING;
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_remove_flags: "
"allow_nesting and disallow_nesting are not allowed together!"));
return;
}
if (flags & TDB1_ALLOW_NESTING) {
tdb->flags |= TDB1_DISALLOW_NESTING;
}
if (flags & TDB1_DISALLOW_NESTING) {
tdb->flags |= TDB1_ALLOW_NESTING;
}
tdb->flags &= ~flags;
}
/*
enable sequence number handling on an open tdb
*/
_PUBLIC_ void tdb1_enable_seqnum(struct tdb1_context *tdb)
{
tdb->flags |= TDB1_SEQNUM;
}
/*
add a region of the file to the freelist. Length is the size of the region in bytes,
which includes the free list header that needs to be added
*/
static int tdb1_free_region(struct tdb1_context *tdb, tdb1_off_t offset, ssize_t length)
{
struct tdb1_record rec;
if (length <= sizeof(rec)) {
/* the region is not worth adding */
return 0;
}
if (length + offset > tdb->map_size) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL,"tdb1_free_region: adding region beyond end of file\n"));
return -1;
}
memset(&rec,'\0',sizeof(rec));
rec.rec_len = length - sizeof(rec);
if (tdb1_free(tdb, offset, &rec) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL,"tdb1_free_region: failed to add free record\n"));
return -1;
}
return 0;
}
/*
wipe the entire database, deleting all records. This can be done
very fast by using a allrecord lock. The entire data portion of the
file becomes a single entry in the freelist.
This code carefully steps around the recovery area, leaving it alone
*/
_PUBLIC_ int tdb1_wipe_all(struct tdb1_context *tdb)
{
int i;
tdb1_off_t offset = 0;
ssize_t data_len;
tdb1_off_t recovery_head;
tdb1_len_t recovery_size = 0;
if (tdb1_lockall(tdb) != 0) {
return -1;
}
/* see if the tdb has a recovery area, and remember its size
if so. We don't want to lose this as otherwise each
tdb1_wipe_all() in a transaction will increase the size of
the tdb by the size of the recovery area */
if (tdb1_ofs_read(tdb, TDB1_RECOVERY_HEAD, &recovery_head) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_wipe_all: failed to read recovery head\n"));
goto failed;
}
if (recovery_head != 0) {
struct tdb1_record rec;
if (tdb->methods->tdb1_read(tdb, recovery_head, &rec, sizeof(rec), TDB1_DOCONV()) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_wipe_all: failed to read recovery record\n"));
return -1;
}
recovery_size = rec.rec_len + sizeof(rec);
}
/* wipe the hashes */
for (i=0;i<tdb->header.hash_size;i++) {
if (tdb1_ofs_write(tdb, TDB1_HASH_TOP(i), &offset) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL,"tdb1_wipe_all: failed to write hash %d\n", i));
goto failed;
}
}
/* wipe the freelist */
if (tdb1_ofs_write(tdb, TDB1_FREELIST_TOP, &offset) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL,"tdb1_wipe_all: failed to write freelist\n"));
goto failed;
}
/* add all the rest of the file to the freelist, possibly leaving a gap
for the recovery area */
if (recovery_size == 0) {
/* the simple case - the whole file can be used as a freelist */
data_len = (tdb->map_size - TDB1_DATA_START(tdb->header.hash_size));
if (tdb1_free_region(tdb, TDB1_DATA_START(tdb->header.hash_size), data_len) != 0) {
goto failed;
}
} else {
/* we need to add two freelist entries - one on either
side of the recovery area
Note that we cannot shift the recovery area during
this operation. Only the transaction.c code may
move the recovery area or we risk subtle data
corruption
*/
data_len = (recovery_head - TDB1_DATA_START(tdb->header.hash_size));
if (tdb1_free_region(tdb, TDB1_DATA_START(tdb->header.hash_size), data_len) != 0) {
goto failed;
}
/* and the 2nd free list entry after the recovery area - if any */
data_len = tdb->map_size - (recovery_head+recovery_size);
if (tdb1_free_region(tdb, recovery_head+recovery_size, data_len) != 0) {
goto failed;
}
}
if (tdb1_unlockall(tdb) != 0) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL,"tdb1_wipe_all: failed to unlock\n"));
goto failed;
}
return 0;
failed:
tdb1_unlockall(tdb);
return -1;
}
struct traverse_state {
bool error;
struct tdb1_context *dest_db;
};
/*
traverse function for repacking
*/
static int repack_traverse(struct tdb1_context *tdb, TDB1_DATA key, TDB1_DATA data, void *private_data)
{
struct traverse_state *state = (struct traverse_state *)private_data;
if (tdb1_store(state->dest_db, key, data, TDB1_INSERT) != 0) {
state->error = true;
return -1;
}
return 0;
}
/*
repack a tdb
*/
_PUBLIC_ int tdb1_repack(struct tdb1_context *tdb)
{
struct tdb1_context *tmp_db;
struct traverse_state state;
if (tdb1_transaction_start(tdb) != 0) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, __location__ " Failed to start transaction\n"));
return -1;
}
tmp_db = tdb1_open("tmpdb", tdb1_hash_size(tdb), TDB1_INTERNAL, O_RDWR|O_CREAT, 0);
if (tmp_db == NULL) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, __location__ " Failed to create tmp_db\n"));
tdb1_transaction_cancel(tdb);
return -1;
}
state.error = false;
state.dest_db = tmp_db;
if (tdb1_traverse_read(tdb, repack_traverse, &state) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, __location__ " Failed to traverse copying out\n"));
tdb1_transaction_cancel(tdb);
tdb1_close(tmp_db);
return -1;
}
if (state.error) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, __location__ " Error during traversal\n"));
tdb1_transaction_cancel(tdb);
tdb1_close(tmp_db);
return -1;
}
if (tdb1_wipe_all(tdb) != 0) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, __location__ " Failed to wipe database\n"));
tdb1_transaction_cancel(tdb);
tdb1_close(tmp_db);
return -1;
}
state.error = false;
state.dest_db = tdb;
if (tdb1_traverse_read(tmp_db, repack_traverse, &state) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, __location__ " Failed to traverse copying back\n"));
tdb1_transaction_cancel(tdb);
tdb1_close(tmp_db);
return -1;
}
if (state.error) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, __location__ " Error during second traversal\n"));
tdb1_transaction_cancel(tdb);
tdb1_close(tmp_db);
return -1;
}
tdb1_close(tmp_db);
if (tdb1_transaction_commit(tdb) != 0) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, __location__ " Failed to commit\n"));
return -1;
}
return 0;
}
/* Even on files, we can get partial writes due to signals. */
bool tdb1_write_all(int fd, const void *buf, size_t count)
{
while (count) {
ssize_t ret;
ret = write(fd, buf, count);
if (ret < 0)
return false;
buf = (const char *)buf + ret;
count -= ret;
}
return true;
}
ccan/tdb2/tdb1_transaction.c 0 → 100644
View file @ 19e6c1a2
/*
Unix SMB/CIFS implementation.
trivial database library
Copyright (C) Andrew Tridgell 2005
** NOTE! The following LGPL license applies to the tdb
** library. This does NOT imply that all of Samba is released
** under the LGPL
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "tdb1_private.h"
/*
transaction design:
- only allow a single transaction at a time per database. This makes
using the transaction API simpler, as otherwise the caller would
have to cope with temporary failures in transactions that conflict
with other current transactions
- keep the transaction recovery information in the same file as the
database, using a special 'transaction recovery' record pointed at
by the header. This removes the need for extra journal files as
used by some other databases
- dynamically allocated the transaction recover record, re-using it
for subsequent transactions. If a larger record is needed then
tdb1_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 tdb1_write() calls. The hooked
transaction versions of tdb1_read() and tdb1_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 tdb1_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 tdb1_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
open 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 TDB1_NOSYNC is passed to flags in tdb1_open then transactions are
still available, but no transaction recovery area is used and no
fsync/msync calls are made.
- if TDB1_ALLOW_NESTING is passed to flags in tdb open, or added using
tdb1_add_flags() transaction nesting is enabled.
It resets the TDB1_DISALLOW_NESTING flag, as both cannot be used together.
The default is that transaction nesting is allowed.
Note: this default may change in future versions of tdb.
Beware. when transactions are nested a transaction successfully
completed with tdb1_transaction_commit() can be silently unrolled later.
- if TDB1_DISALLOW_NESTING is passed to flags in tdb open, or added using
tdb1_add_flags() transaction nesting is disabled.
It resets the TDB1_ALLOW_NESTING flag, as both cannot be used together.
An attempt create a nested transaction will fail with TDB1_ERR_NESTING.
The default is that transaction nesting is allowed.
Note: this default may change in future versions of tdb.
*/
/*
hold the context of any current transaction
*/
struct tdb1_transaction {
/* we keep a mirrored copy of the tdb hash heads here so
tdb1_next_hash_chain() can operate efficiently */
uint32_t *hash_heads;
/* the original io methods - used to do IOs to the real db */
const struct tdb1_methods *io_methods;
/* the list of transaction blocks. When a block is first
written to, it gets created in this list */
uint8_t **blocks;
uint32_t num_blocks;
uint32_t block_size; /* bytes in each block */
uint32_t last_block_size; /* number of valid bytes in the last block */
/* non-zero when an internal transaction error has
occurred. All write operations will then fail until the
transaction is ended */
int transaction_error;
/* when inside a transaction we need to keep track of any
nested tdb1_transaction_start() calls, as these are allowed,
but don't create a new transaction */
int nesting;
/* set when a prepare has already occurred */
bool prepared;
tdb1_off_t magic_offset;
/* old file size before transaction */
tdb1_len_t old_map_size;
/* did we expand in this transaction */
bool expanded;
};
/*
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 transaction1_read(struct tdb1_context *tdb, tdb1_off_t off, void *buf,
tdb1_len_t len, int cv)
{
uint32_t blk;
/* break it down into block sized ops */
while (len + (off % tdb->transaction->block_size) > tdb->transaction->block_size) {
tdb1_len_t len2 = tdb->transaction->block_size - (off % tdb->transaction->block_size);
if (transaction1_read(tdb, off, buf, len2, cv) != 0) {
return -1;
}
len -= len2;
off += len2;
buf = (void *)(len2 + (char *)buf);
}
if (len == 0) {
return 0;
}
blk = off / tdb->transaction->block_size;
/* see if we have it in the block list */
if (tdb->transaction->num_blocks <= blk ||
tdb->transaction->blocks[blk] == NULL) {
/* nope, do a real read */
if (tdb->transaction->io_methods->tdb1_read(tdb, off, buf, len, cv) != 0) {
goto fail;
}
return 0;
}
/* it is in the block list. Now check for the last block */
if (blk == tdb->transaction->num_blocks-1) {
if (len > tdb->transaction->last_block_size) {
goto fail;
}
}
/* now copy it out of this block */
memcpy(buf, tdb->transaction->blocks[blk] + (off % tdb->transaction->block_size), len);
if (cv) {
tdb1_convert(buf, len);
}
return 0;
fail:
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "transaction_read: failed at off=%d len=%d\n", off, len));
tdb->ecode = TDB1_ERR_IO;
tdb->transaction->transaction_error = 1;
return -1;
}
/*
write while in a transaction
*/
static int transaction1_write(struct tdb1_context *tdb, tdb1_off_t off,
const void *buf, tdb1_len_t len)
{
uint32_t blk;
/* Only a commit is allowed on a prepared transaction */
if (tdb->transaction->prepared) {
tdb->ecode = TDB1_ERR_EINVAL;
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "transaction_write: transaction already prepared, write not allowed\n"));
tdb->transaction->transaction_error = 1;
return -1;
}
/* if the write is to a hash head, then update the transaction
hash heads */
if (len == sizeof(tdb1_off_t) && off >= TDB1_FREELIST_TOP &&
off < TDB1_FREELIST_TOP+TDB1_HASHTABLE_SIZE(tdb)) {
uint32_t chain = (off-TDB1_FREELIST_TOP) / sizeof(tdb1_off_t);
memcpy(&tdb->transaction->hash_heads[chain], buf, len);
}
/* break it up into block sized chunks */
while (len + (off % tdb->transaction->block_size) > tdb->transaction->block_size) {
tdb1_len_t len2 = tdb->transaction->block_size - (off % tdb->transaction->block_size);
if (transaction1_write(tdb, off, buf, len2) != 0) {
return -1;
}
len -= len2;
off += len2;
if (buf != NULL) {
buf = (const void *)(len2 + (const char *)buf);
}
}
if (len == 0) {
return 0;
}
blk = off / tdb->transaction->block_size;
off = off % tdb->transaction->block_size;
if (tdb->transaction->num_blocks <= blk) {
uint8_t **new_blocks;
/* expand the blocks array */
if (tdb->transaction->blocks == NULL) {
new_blocks = (uint8_t **)malloc(
(blk+1)*sizeof(uint8_t *));
} else {
new_blocks = (uint8_t **)realloc(
tdb->transaction->blocks,
(blk+1)*sizeof(uint8_t *));
}
if (new_blocks == NULL) {
tdb->ecode = TDB1_ERR_OOM;
goto fail;
}
memset(&new_blocks[tdb->transaction->num_blocks], 0,
(1+(blk - tdb->transaction->num_blocks))*sizeof(uint8_t *));
tdb->transaction->blocks = new_blocks;
tdb->transaction->num_blocks = blk+1;
tdb->transaction->last_block_size = 0;
}
/* allocate and fill a block? */
if (tdb->transaction->blocks[blk] == NULL) {
tdb->transaction->blocks[blk] = (uint8_t *)calloc(tdb->transaction->block_size, 1);
if (tdb->transaction->blocks[blk] == NULL) {
tdb->ecode = TDB1_ERR_OOM;
tdb->transaction->transaction_error = 1;
return -1;
}
if (tdb->transaction->old_map_size > blk * tdb->transaction->block_size) {
tdb1_len_t len2 = tdb->transaction->block_size;
if (len2 + (blk * tdb->transaction->block_size) > tdb->transaction->old_map_size) {
len2 = tdb->transaction->old_map_size - (blk * tdb->transaction->block_size);
}
if (tdb->transaction->io_methods->tdb1_read(tdb, blk * tdb->transaction->block_size,
tdb->transaction->blocks[blk],
len2, 0) != 0) {
SAFE_FREE(tdb->transaction->blocks[blk]);
tdb->ecode = TDB1_ERR_IO;
goto fail;
}
if (blk == tdb->transaction->num_blocks-1) {
tdb->transaction->last_block_size = len2;
}
}
}
/* overwrite part of an existing block */
if (buf == NULL) {
memset(tdb->transaction->blocks[blk] + off, 0, len);
} else {
memcpy(tdb->transaction->blocks[blk] + off, buf, len);
}
if (blk == tdb->transaction->num_blocks-1) {
if (len + off > tdb->transaction->last_block_size) {
tdb->transaction->last_block_size = len + off;
}
}
return 0;
fail:
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "transaction_write: failed at off=%d len=%d\n",
(blk*tdb->transaction->block_size) + off, len));
tdb->transaction->transaction_error = 1;
return -1;
}
/*
write while in a transaction - this varient never expands the transaction blocks, it only
updates existing blocks. This means it cannot change the recovery size
*/
static int transaction1_write_existing(struct tdb1_context *tdb, tdb1_off_t off,
const void *buf, tdb1_len_t len)
{
uint32_t blk;
/* break it up into block sized chunks */
while (len + (off % tdb->transaction->block_size) > tdb->transaction->block_size) {
tdb1_len_t len2 = tdb->transaction->block_size - (off % tdb->transaction->block_size);
if (transaction1_write_existing(tdb, off, buf, len2) != 0) {
return -1;
}
len -= len2;
off += len2;
if (buf != NULL) {
buf = (const void *)(len2 + (const char *)buf);
}
}
if (len == 0) {
return 0;
}
blk = off / tdb->transaction->block_size;
off = off % tdb->transaction->block_size;
if (tdb->transaction->num_blocks <= blk ||
tdb->transaction->blocks[blk] == NULL) {
return 0;
}
if (blk == tdb->transaction->num_blocks-1 &&
off + len > tdb->transaction->last_block_size) {
if (off >= tdb->transaction->last_block_size) {
return 0;
}
len = tdb->transaction->last_block_size - off;
}
/* overwrite part of an existing block */
memcpy(tdb->transaction->blocks[blk] + off, buf, len);
return 0;
}
/*
accelerated hash chain head search, using the cached hash heads
*/
static void transaction1_next_hash_chain(struct tdb1_context *tdb, uint32_t *chain)
{
uint32_t h = *chain;
for (;h < tdb->header.hash_size;h++) {
/* the +1 takes account of the freelist */
if (0 != tdb->transaction->hash_heads[h+1]) {
break;
}
}
(*chain) = h;
}
/*
out of bounds check during a transaction
*/
static int transaction1_oob(struct tdb1_context *tdb, tdb1_off_t len, int probe)
{
if (len <= tdb->map_size) {
return 0;
}
tdb->ecode = TDB1_ERR_IO;
return -1;
}
/*
transaction version of tdb1_expand().
*/
static int transaction1_expand_file(struct tdb1_context *tdb, tdb1_off_t size,
tdb1_off_t addition)
{
/* add a write to the transaction elements, so subsequent
reads see the zero data */
if (transaction1_write(tdb, size, NULL, addition) != 0) {
return -1;
}
tdb->transaction->expanded = true;
return 0;
}
static const struct tdb1_methods transaction1_methods = {
transaction1_read,
transaction1_write,
transaction1_next_hash_chain,
transaction1_oob,
transaction1_expand_file,
};
/*
start a tdb transaction. No token is returned, as only a single
transaction is allowed to be pending per tdb1_context
*/
static int _tdb1_transaction_start(struct tdb1_context *tdb,
enum tdb1_lock_flags lockflags)
{
/* some sanity checks */
if (tdb->read_only || (tdb->flags & TDB1_INTERNAL) || tdb->traverse_read) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "tdb1_transaction_start: cannot start a transaction on a read-only or internal db\n"));
tdb->ecode = TDB1_ERR_EINVAL;
return -1;
}
/* cope with nested tdb1_transaction_start() calls */
if (tdb->transaction != NULL) {
if (!(tdb->flags & TDB1_ALLOW_NESTING)) {
tdb->ecode = TDB1_ERR_NESTING;
return -1;
}
tdb->transaction->nesting++;
TDB1_LOG((tdb, TDB1_DEBUG_TRACE, "tdb1_transaction_start: nesting %d\n",
tdb->transaction->nesting));
return 0;
}
if (tdb1_have_extra_locks(tdb)) {
/* the caller must not have any locks when starting a
transaction as otherwise we'll be screwed by lack
of nested locks in posix */
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "tdb1_transaction_start: cannot start a transaction with locks held\n"));
tdb->ecode = TDB1_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 */
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "tdb1_transaction_start: cannot start a transaction within a traverse\n"));
tdb->ecode = TDB1_ERR_LOCK;
return -1;
}
tdb->transaction = (struct tdb1_transaction *)
calloc(sizeof(struct tdb1_transaction), 1);
if (tdb->transaction == NULL) {
tdb->ecode = TDB1_ERR_OOM;
return -1;
}
/* a page at a time seems like a reasonable compromise between compactness and efficiency */
tdb->transaction->block_size = tdb->page_size;
/* get the transaction write lock. This is a blocking lock. As
discussed with Volker, there are a number of ways we could
make this async, which we will probably do in the future */
if (tdb1_transaction_lock(tdb, F_WRLCK, lockflags) == -1) {
SAFE_FREE(tdb->transaction->blocks);
SAFE_FREE(tdb->transaction);
if ((lockflags & TDB1_LOCK_WAIT) == 0) {
tdb->ecode = TDB1_ERR_NOLOCK;
}
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 (tdb1_allrecord_lock(tdb, F_RDLCK, TDB1_LOCK_WAIT, true) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "tdb1_transaction_start: failed to get hash locks\n"));
goto fail_allrecord_lock;
}
/* setup a copy of the hash table heads so the hash scan in
traverse can be fast */
tdb->transaction->hash_heads = (uint32_t *)
calloc(tdb->header.hash_size+1, sizeof(uint32_t));
if (tdb->transaction->hash_heads == NULL) {
tdb->ecode = TDB1_ERR_OOM;
goto fail;
}
if (tdb->methods->tdb1_read(tdb, TDB1_FREELIST_TOP, tdb->transaction->hash_heads,
TDB1_HASHTABLE_SIZE(tdb), 0) != 0) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_transaction_start: failed to read hash heads\n"));
tdb->ecode = TDB1_ERR_IO;
goto fail;
}
/* make sure we know about any file expansions already done by
anyone else */
tdb->methods->tdb1_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 = &transaction1_methods;
return 0;
fail:
tdb1_allrecord_unlock(tdb, F_RDLCK, false);
fail_allrecord_lock:
tdb1_transaction_unlock(tdb, F_WRLCK);
SAFE_FREE(tdb->transaction->blocks);
SAFE_FREE(tdb->transaction->hash_heads);
SAFE_FREE(tdb->transaction);
return -1;
}
_PUBLIC_ int tdb1_transaction_start(struct tdb1_context *tdb)
{
return _tdb1_transaction_start(tdb, TDB1_LOCK_WAIT);
}
_PUBLIC_ int tdb1_transaction_start_nonblock(struct tdb1_context *tdb)
{
return _tdb1_transaction_start(tdb, TDB1_LOCK_NOWAIT|TDB1_LOCK_PROBE);
}
/*
sync to disk
*/
static int transaction1_sync(struct tdb1_context *tdb, tdb1_off_t offset, tdb1_len_t length)
{
if (tdb->flags & TDB1_NOSYNC) {
return 0;
}
#if HAVE_FDATASYNC
if (fdatasync(tdb->fd) != 0) {
#else
if (fsync(tdb->fd) != 0) {
#endif
tdb->ecode = TDB1_ERR_IO;
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_transaction: fsync failed\n"));
return -1;
}
#if HAVE_MMAP
if (tdb->map_ptr) {
tdb1_off_t moffset = offset & ~(tdb->page_size-1);
if (msync(moffset + (char *)tdb->map_ptr,
length + (offset - moffset), MS_SYNC) != 0) {
tdb->ecode = TDB1_ERR_IO;
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_transaction: msync failed - %s\n",
strerror(errno)));
return -1;
}
}
#endif
return 0;
}
static int _tdb1_transaction_cancel(struct tdb1_context *tdb)
{
int i, ret = 0;
if (tdb->transaction == NULL) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "tdb1_transaction_cancel: no transaction\n"));
return -1;
}
if (tdb->transaction->nesting != 0) {
tdb->transaction->transaction_error = 1;
tdb->transaction->nesting--;
return 0;
}
tdb->map_size = tdb->transaction->old_map_size;
/* free all the transaction blocks */
for (i=0;i<tdb->transaction->num_blocks;i++) {
if (tdb->transaction->blocks[i] != NULL) {
free(tdb->transaction->blocks[i]);
}
}
SAFE_FREE(tdb->transaction->blocks);
if (tdb->transaction->magic_offset) {
const struct tdb1_methods *methods = tdb->transaction->io_methods;
const uint32_t invalid = TDB1_RECOVERY_INVALID_MAGIC;
/* remove the recovery marker */
if (methods->tdb1_write(tdb, tdb->transaction->magic_offset, &invalid, 4) == -1 ||
transaction1_sync(tdb, tdb->transaction->magic_offset, 4) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_transaction_cancel: failed to remove recovery magic\n"));
ret = -1;
}
}
/* This also removes the OPEN_LOCK, if we have it. */
tdb1_release_transaction_locks(tdb);
/* restore the normal io methods */
tdb->methods = tdb->transaction->io_methods;
SAFE_FREE(tdb->transaction->hash_heads);
SAFE_FREE(tdb->transaction);
return ret;
}
/*
cancel the current transaction
*/
_PUBLIC_ int tdb1_transaction_cancel(struct tdb1_context *tdb)
{
return _tdb1_transaction_cancel(tdb);
}
/*
work out how much space the linearised recovery data will consume
*/
static tdb1_len_t tdb1_recovery_size(struct tdb1_context *tdb)
{
tdb1_len_t recovery_size = 0;
int i;
recovery_size = sizeof(uint32_t);
for (i=0;i<tdb->transaction->num_blocks;i++) {
if (i * tdb->transaction->block_size >= tdb->transaction->old_map_size) {
break;
}
if (tdb->transaction->blocks[i] == NULL) {
continue;
}
recovery_size += 2*sizeof(tdb1_off_t);
if (i == tdb->transaction->num_blocks-1) {
recovery_size += tdb->transaction->last_block_size;
} else {
recovery_size += tdb->transaction->block_size;
}
}
return recovery_size;
}
int tdb1_recovery_area(struct tdb1_context *tdb,
const struct tdb1_methods *methods,
tdb1_off_t *recovery_offset,
struct tdb1_record *rec)
{
if (tdb1_ofs_read(tdb, TDB1_RECOVERY_HEAD, recovery_offset) == -1) {
return -1;
}
if (*recovery_offset == 0) {
rec->rec_len = 0;
return 0;
}
if (methods->tdb1_read(tdb, *recovery_offset, rec, sizeof(*rec),
TDB1_DOCONV()) == -1) {
return -1;
}
/* ignore invalid recovery regions: can happen in crash */
if (rec->magic != TDB1_RECOVERY_MAGIC &&
rec->magic != TDB1_RECOVERY_INVALID_MAGIC) {
*recovery_offset = 0;
rec->rec_len = 0;
}
return 0;
}
/*
allocate the recovery area, or use an existing recovery area if it is
large enough
*/
static int tdb1_recovery_allocate(struct tdb1_context *tdb,
tdb1_len_t *recovery_size,
tdb1_off_t *recovery_offset,
tdb1_len_t *recovery_max_size)
{
struct tdb1_record rec;
const struct tdb1_methods *methods = tdb->transaction->io_methods;
tdb1_off_t recovery_head;
if (tdb1_recovery_area(tdb, methods, &recovery_head, &rec) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_recovery_allocate: failed to read recovery head\n"));
return -1;
}
*recovery_size = tdb1_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
tdb1_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 (tdb1_free(tdb, recovery_head, &rec) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_recovery_allocate: failed to free previous recovery area\n"));
return -1;
}
}
/* the tdb1_free() call might have increased the recovery size */
*recovery_size = tdb1_recovery_size(tdb);
/* round up to a multiple of page size */
*recovery_max_size = TDB1_ALIGN(sizeof(rec) + *recovery_size, tdb->page_size) - sizeof(rec);
*recovery_offset = tdb->map_size;
recovery_head = *recovery_offset;
if (methods->tdb1_expand_file(tdb, tdb->transaction->old_map_size,
(tdb->map_size - tdb->transaction->old_map_size) +
sizeof(rec) + *recovery_max_size) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_recovery_allocate: failed to create recovery area\n"));
return -1;
}
/* remap the file (if using mmap) */
methods->tdb1_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 */
TDB1_CONV(recovery_head);
if (methods->tdb1_write(tdb, TDB1_RECOVERY_HEAD,
&recovery_head, sizeof(tdb1_off_t)) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_recovery_allocate: failed to write recovery head\n"));
return -1;
}
if (transaction1_write_existing(tdb, TDB1_RECOVERY_HEAD, &recovery_head, sizeof(tdb1_off_t)) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_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 transaction1_setup_recovery(struct tdb1_context *tdb,
tdb1_off_t *magic_offset)
{
tdb1_len_t recovery_size;
unsigned char *data, *p;
const struct tdb1_methods *methods = tdb->transaction->io_methods;
struct tdb1_record *rec;
tdb1_off_t recovery_offset, recovery_max_size;
tdb1_off_t old_map_size = tdb->transaction->old_map_size;
uint32_t magic, tailer;
int i;
/*
check that the recovery area has enough space
*/
if (tdb1_recovery_allocate(tdb, &recovery_size,
&recovery_offset, &recovery_max_size) == -1) {
return -1;
}
data = (unsigned char *)malloc(recovery_size + sizeof(*rec));
if (data == NULL) {
tdb->ecode = TDB1_ERR_OOM;
return -1;
}
rec = (struct tdb1_record *)data;
memset(rec, 0, sizeof(*rec));
rec->magic = TDB1_RECOVERY_INVALID_MAGIC;
rec->data_len = recovery_size;
rec->rec_len = recovery_max_size;
rec->key_len = old_map_size;
TDB1_CONV(*rec);
/* build the recovery data into a single blob to allow us to do a single
large write, which should be more efficient */
p = data + sizeof(*rec);
for (i=0;i<tdb->transaction->num_blocks;i++) {
tdb1_off_t offset;
tdb1_len_t length;
if (tdb->transaction->blocks[i] == NULL) {
continue;
}
offset = i * tdb->transaction->block_size;
length = tdb->transaction->block_size;
if (i == tdb->transaction->num_blocks-1) {
length = tdb->transaction->last_block_size;
}
if (offset >= old_map_size) {
continue;
}
if (offset + length > tdb->transaction->old_map_size) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_transaction_setup_recovery: transaction data over new region boundary\n"));
free(data);
tdb->ecode = TDB1_ERR_CORRUPT;
return -1;
}
memcpy(p, &offset, 4);
memcpy(p+4, &length, 4);
if (TDB1_DOCONV()) {
tdb1_convert(p, 8);
}
/* the recovery area contains the old data, not the
new data, so we have to call the original tdb1_read
method to get it */
if (methods->tdb1_read(tdb, offset, p + 8, length, 0) != 0) {
free(data);
tdb->ecode = TDB1_ERR_IO;
return -1;
}
p += 8 + length;
}
/* and the tailer */
tailer = sizeof(*rec) + recovery_max_size;
memcpy(p, &tailer, 4);
if (TDB1_DOCONV()) {
tdb1_convert(p, 4);
}
/* write the recovery data to the recovery area */
if (methods->tdb1_write(tdb, recovery_offset, data, sizeof(*rec) + recovery_size) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_transaction_setup_recovery: failed to write recovery data\n"));
free(data);
tdb->ecode = TDB1_ERR_IO;
return -1;
}
if (transaction1_write_existing(tdb, recovery_offset, data, sizeof(*rec) + recovery_size) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_transaction_setup_recovery: failed to write secondary recovery data\n"));
free(data);
tdb->ecode = TDB1_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 (transaction1_sync(tdb, recovery_offset, sizeof(*rec) + recovery_size) == -1) {
free(data);
return -1;
}
free(data);
magic = TDB1_RECOVERY_MAGIC;
TDB1_CONV(magic);
*magic_offset = recovery_offset + offsetof(struct tdb1_record, magic);
if (methods->tdb1_write(tdb, *magic_offset, &magic, sizeof(magic)) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_transaction_setup_recovery: failed to write recovery magic\n"));
tdb->ecode = TDB1_ERR_IO;
return -1;
}
if (transaction1_write_existing(tdb, *magic_offset, &magic, sizeof(magic)) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_transaction_setup_recovery: failed to write secondary recovery magic\n"));
tdb->ecode = TDB1_ERR_IO;
return -1;
}
/* ensure the recovery magic marker is on disk */
if (transaction1_sync(tdb, *magic_offset, sizeof(magic)) == -1) {
return -1;
}
return 0;
}
static int _tdb1_transaction_prepare_commit(struct tdb1_context *tdb)
{
const struct tdb1_methods *methods;
if (tdb->transaction == NULL) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "tdb1_transaction_prepare_commit: no transaction\n"));
return -1;
}
if (tdb->transaction->prepared) {
tdb->ecode = TDB1_ERR_EINVAL;
_tdb1_transaction_cancel(tdb);
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "tdb1_transaction_prepare_commit: transaction already prepared\n"));
return -1;
}
if (tdb->transaction->transaction_error) {
tdb->ecode = TDB1_ERR_IO;
_tdb1_transaction_cancel(tdb);
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "tdb1_transaction_prepare_commit: transaction error pending\n"));
return -1;
}
if (tdb->transaction->nesting != 0) {
return 0;
}
/* check for a null transaction */
if (tdb->transaction->blocks == NULL) {
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 (tdb1_have_extra_locks(tdb)) {
tdb->ecode = TDB1_ERR_LOCK;
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "tdb1_transaction_prepare_commit: locks pending on commit\n"));
_tdb1_transaction_cancel(tdb);
return -1;
}
/* upgrade the main transaction lock region to a write lock */
if (tdb1_allrecord_upgrade(tdb) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "tdb1_transaction_prepare_commit: failed to upgrade hash locks\n"));
_tdb1_transaction_cancel(tdb);
return -1;
}
/* get the open lock - this prevents new users attaching to the database
during the commit */
if (tdb1_nest_lock(tdb, TDB1_OPEN_LOCK, F_WRLCK, TDB1_LOCK_WAIT) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "tdb1_transaction_prepare_commit: failed to get open lock\n"));
_tdb1_transaction_cancel(tdb);
return -1;
}
if (!(tdb->flags & TDB1_NOSYNC)) {
/* write the recovery data to the end of the file */
if (transaction1_setup_recovery(tdb, &tdb->transaction->magic_offset) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_transaction_prepare_commit: failed to setup recovery data\n"));
_tdb1_transaction_cancel(tdb);
return -1;
}
}
tdb->transaction->prepared = true;
/* expand the file to the new size if needed */
if (tdb->map_size != tdb->transaction->old_map_size) {
if (methods->tdb1_expand_file(tdb, tdb->transaction->old_map_size,
tdb->map_size -
tdb->transaction->old_map_size) == -1) {
tdb->ecode = TDB1_ERR_IO;
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_transaction_prepare_commit: expansion failed\n"));
_tdb1_transaction_cancel(tdb);
return -1;
}
tdb->map_size = tdb->transaction->old_map_size;
methods->tdb1_oob(tdb, tdb->map_size + 1, 1);
}
/* Keep the open lock until the actual commit */
return 0;
}
/*
prepare to commit the current transaction
*/
_PUBLIC_ int tdb1_transaction_prepare_commit(struct tdb1_context *tdb)
{
return _tdb1_transaction_prepare_commit(tdb);
}
/* A repack is worthwhile if the largest is less than half total free. */
static bool repack_worthwhile(struct tdb1_context *tdb)
{
tdb1_off_t ptr;
struct tdb1_record rec;
tdb1_len_t total = 0, largest = 0;
if (tdb1_ofs_read(tdb, TDB1_FREELIST_TOP, &ptr) == -1) {
return false;
}
while (ptr != 0 && tdb1_rec_free_read(tdb, ptr, &rec) == 0) {
total += rec.rec_len;
if (rec.rec_len > largest) {
largest = rec.rec_len;
}
ptr = rec.next;
}
return total > largest * 2;
}
/*
commit the current transaction
*/
_PUBLIC_ int tdb1_transaction_commit(struct tdb1_context *tdb)
{
const struct tdb1_methods *methods;
int i;
bool need_repack = false;
if (tdb->transaction == NULL) {
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "tdb1_transaction_commit: no transaction\n"));
return -1;
}
if (tdb->transaction->transaction_error) {
tdb->ecode = TDB1_ERR_IO;
_tdb1_transaction_cancel(tdb);
TDB1_LOG((tdb, TDB1_DEBUG_ERROR, "tdb1_transaction_commit: transaction error pending\n"));
return -1;
}
if (tdb->transaction->nesting != 0) {
tdb->transaction->nesting--;
return 0;
}
/* check for a null transaction */
if (tdb->transaction->blocks == NULL) {
_tdb1_transaction_cancel(tdb);
return 0;
}
if (!tdb->transaction->prepared) {
int ret = _tdb1_transaction_prepare_commit(tdb);
if (ret)
return ret;
}
methods = tdb->transaction->io_methods;
/* perform all the writes */
for (i=0;i<tdb->transaction->num_blocks;i++) {
tdb1_off_t offset;
tdb1_len_t length;
if (tdb->transaction->blocks[i] == NULL) {
continue;
}
offset = i * tdb->transaction->block_size;
length = tdb->transaction->block_size;
if (i == tdb->transaction->num_blocks-1) {
length = tdb->transaction->last_block_size;
}
if (methods->tdb1_write(tdb, offset, tdb->transaction->blocks[i], length) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_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;
tdb1_transaction_recover(tdb);
_tdb1_transaction_cancel(tdb);
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_transaction_commit: write failed\n"));
return -1;
}
SAFE_FREE(tdb->transaction->blocks[i]);
}
/* Do this before we drop lock or blocks. */
if (tdb->transaction->expanded) {
need_repack = repack_worthwhile(tdb);
}
SAFE_FREE(tdb->transaction->blocks);
tdb->transaction->num_blocks = 0;
/* ensure the new data is on disk */
if (transaction1_sync(tdb, 0, tdb->map_size) == -1) {
return -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 */
#if HAVE_UTIME
utime(tdb->name, NULL);
#endif
/* use a transaction cancel to free memory and remove the
transaction locks */
_tdb1_transaction_cancel(tdb);
if (need_repack) {
return tdb1_repack(tdb);
}
return 0;
}
/*
recover from an aborted transaction. Must be called with exclusive
database write access already established (including the open
lock to prevent new processes attaching)
*/
int tdb1_transaction_recover(struct tdb1_context *tdb)
{
tdb1_off_t recovery_head, recovery_eof;
unsigned char *data, *p;
uint32_t zero = 0;
struct tdb1_record rec;
/* find the recovery area */
if (tdb1_ofs_read(tdb, TDB1_RECOVERY_HEAD, &recovery_head) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_transaction_recover: failed to read recovery head\n"));
tdb->ecode = TDB1_ERR_IO;
return -1;
}
if (recovery_head == 0) {
/* we have never allocated a recovery record */
return 0;
}
/* read the recovery record */
if (tdb->methods->tdb1_read(tdb, recovery_head, &rec,
sizeof(rec), TDB1_DOCONV()) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_transaction_recover: failed to read recovery record\n"));
tdb->ecode = TDB1_ERR_IO;
return -1;
}
if (rec.magic != TDB1_RECOVERY_MAGIC) {
/* there is no valid recovery data */
return 0;
}
if (tdb->read_only) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_transaction_recover: attempt to recover read only database\n"));
tdb->ecode = TDB1_ERR_CORRUPT;
return -1;
}
recovery_eof = rec.key_len;
data = (unsigned char *)malloc(rec.data_len);
if (data == NULL) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_transaction_recover: failed to allocate recovery data\n"));
tdb->ecode = TDB1_ERR_OOM;
return -1;
}
/* read the full recovery data */
if (tdb->methods->tdb1_read(tdb, recovery_head + sizeof(rec), data,
rec.data_len, 0) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_transaction_recover: failed to read recovery data\n"));
tdb->ecode = TDB1_ERR_IO;
return -1;
}
/* recover the file data */
p = data;
while (p+8 < data + rec.data_len) {
uint32_t ofs, len;
if (TDB1_DOCONV()) {
tdb1_convert(p, 8);
}
memcpy(&ofs, p, 4);
memcpy(&len, p+4, 4);
if (tdb->methods->tdb1_write(tdb, ofs, p+8, len) == -1) {
free(data);
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_transaction_recover: failed to recover %d bytes at offset %d\n", len, ofs));
tdb->ecode = TDB1_ERR_IO;
return -1;
}
p += 8 + len;
}
free(data);
if (transaction1_sync(tdb, 0, tdb->map_size) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_transaction_recover: failed to sync recovery\n"));
tdb->ecode = TDB1_ERR_IO;
return -1;
}
/* if the recovery area is after the recovered eof then remove it */
if (recovery_eof <= recovery_head) {
if (tdb1_ofs_write(tdb, TDB1_RECOVERY_HEAD, &zero) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_transaction_recover: failed to remove recovery head\n"));
tdb->ecode = TDB1_ERR_IO;
return -1;
}
}
/* remove the recovery magic */
if (tdb1_ofs_write(tdb, recovery_head + offsetof(struct tdb1_record, magic),
&zero) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_transaction_recover: failed to remove recovery magic\n"));
tdb->ecode = TDB1_ERR_IO;
return -1;
}
if (transaction1_sync(tdb, 0, recovery_eof) == -1) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_transaction_recover: failed to sync2 recovery\n"));
tdb->ecode = TDB1_ERR_IO;
return -1;
}
TDB1_LOG((tdb, TDB1_DEBUG_TRACE, "tdb1_transaction_recover: recovered %d byte database\n",
recovery_eof));
/* all done */
return 0;
}
/* Any I/O failures we say "needs recovery". */
bool tdb1_needs_recovery(struct tdb1_context *tdb)
{
tdb1_off_t recovery_head;
struct tdb1_record rec;
/* find the recovery area */
if (tdb1_ofs_read(tdb, TDB1_RECOVERY_HEAD, &recovery_head) == -1) {
return true;
}
if (recovery_head == 0) {
/* we have never allocated a recovery record */
return false;
}
/* read the recovery record */
if (tdb->methods->tdb1_read(tdb, recovery_head, &rec,
sizeof(rec), TDB1_DOCONV()) == -1) {
return true;
}
return (rec.magic == TDB1_RECOVERY_MAGIC);
}
ccan/tdb2/tdb1_traverse.c 0 → 100644
View file @ 19e6c1a2
/*
Unix SMB/CIFS implementation.
trivial database library
Copyright (C) Andrew Tridgell 1999-2005
Copyright (C) Paul `Rusty' Russell 2000
Copyright (C) Jeremy Allison 2000-2003
** NOTE! The following LGPL license applies to the tdb
** library. This does NOT imply that all of Samba is released
** under the LGPL
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "tdb1_private.h"
#define TDB1_NEXT_LOCK_ERR ((tdb1_off_t)-1)
/* Uses traverse lock: 0 = finish, TDB1_NEXT_LOCK_ERR = error,
other = record offset */
static tdb1_off_t tdb1_next_lock(struct tdb1_context *tdb, struct tdb1_traverse_lock *tlock,
struct tdb1_record *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 tdb1_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 (tdb1_lock(tdb, tlock->hash, tlock->lock_rw) == -1)
return TDB1_NEXT_LOCK_ERR;
/* No previous record? Start at top of chain. */
if (!tlock->off) {
if (tdb1_ofs_read(tdb, TDB1_HASH_TOP(tlock->hash),
&tlock->off) == -1)
goto fail;
} else {
/* Otherwise unlock the previous record. */
if (tdb1_unlock_record(tdb, tlock->off) != 0)
goto fail;
}
if (want_next) {
/* We have offset of old record: grab next */
if (tdb1_rec_read(tdb, tlock->off, rec) == -1)
goto fail;
tlock->off = rec->next;
}
/* Iterate through chain */
while( tlock->off) {
tdb1_off_t current;
if (tdb1_rec_read(tdb, tlock->off, rec) == -1)
goto fail;
/* Detect infinite loops. From "Shlomi Yaakobovich" <Shlomi@exanet.com>. */
if (tlock->off == rec->next) {
tdb->ecode = TDB1_ERR_CORRUPT;
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_next_lock: loop detected.\n"));
goto fail;
}
if (!TDB1_DEAD(rec)) {
/* Woohoo: we found one! */
if (tdb1_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) &&
tdb1_do_delete(tdb, current, rec) != 0)
goto fail;
}
tdb1_unlock(tdb, tlock->hash, tlock->lock_rw);
want_next = 0;
}
/* We finished iteration without finding anything */
tdb->ecode = TDB1_SUCCESS;
return 0;
fail:
tlock->off = 0;
if (tdb1_unlock(tdb, tlock->hash, tlock->lock_rw) != 0)
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_next_lock: On error unlock failed!\n"));
return TDB1_NEXT_LOCK_ERR;
}
/* 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 tdb1_traverse_internal(struct tdb1_context *tdb,
tdb1_traverse_func fn, void *private_data,
struct tdb1_traverse_lock *tl)
{
TDB1_DATA key, dbuf;
struct tdb1_record rec;
int ret = 0, count = 0;
tdb1_off_t off;
/* 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;
/* tdb1_next_lock places locks on the record returned, and its chain */
while ((off = tdb1_next_lock(tdb, tl, &rec)) != 0) {
if (off == TDB1_NEXT_LOCK_ERR) {
ret = -1;
goto out;
}
count++;
/* now read the full record */
key.dptr = tdb1_alloc_read(tdb, tl->off + sizeof(rec),
rec.key_len + rec.data_len);
if (!key.dptr) {
ret = -1;
if (tdb1_unlock(tdb, tl->hash, tl->lock_rw) != 0)
goto out;
if (tdb1_unlock_record(tdb, tl->off) != 0)
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_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 (tdb1_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 */
if (tdb1_unlock_record(tdb, tl->off) != 0) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_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
*/
_PUBLIC_ int tdb1_traverse_read(struct tdb1_context *tdb,
tdb1_traverse_func fn, void *private_data)
{
struct tdb1_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 (tdb1_transaction_lock(tdb, F_RDLCK, TDB1_LOCK_WAIT)) {
return -1;
}
tdb->traverse_read++;
ret = tdb1_traverse_internal(tdb, fn, private_data, &tl);
tdb->traverse_read--;
tdb1_transaction_unlock(tdb, F_RDLCK);
return ret;
}
/*
a write style traverse - needs to get the transaction lock to
prevent deadlocks
WARNING: The data buffer given to the callback fn does NOT meet the
alignment restrictions malloc gives you.
*/
_PUBLIC_ int tdb1_traverse(struct tdb1_context *tdb,
tdb1_traverse_func fn, void *private_data)
{
struct tdb1_traverse_lock tl = { NULL, 0, 0, F_WRLCK };
int ret;
if (tdb->read_only || tdb->traverse_read) {
return tdb1_traverse_read(tdb, fn, private_data);
}
if (tdb1_transaction_lock(tdb, F_WRLCK, TDB1_LOCK_WAIT)) {
return -1;
}
tdb->traverse_write++;
ret = tdb1_traverse_internal(tdb, fn, private_data, &tl);
tdb->traverse_write--;
tdb1_transaction_unlock(tdb, F_WRLCK);
return ret;
}
/* find the first entry in the database and return its key */
_PUBLIC_ TDB1_DATA tdb1_firstkey(struct tdb1_context *tdb)
{
TDB1_DATA key;
struct tdb1_record rec;
tdb1_off_t off;
/* release any old lock */
if (tdb1_unlock_record(tdb, tdb->travlocks.off) != 0)
return tdb1_null;
tdb->travlocks.off = tdb->travlocks.hash = 0;
tdb->travlocks.lock_rw = F_RDLCK;
/* Grab first record: locks chain and returned record. */
off = tdb1_next_lock(tdb, &tdb->travlocks, &rec);
if (off == 0 || off == TDB1_NEXT_LOCK_ERR) {
return tdb1_null;
}
/* now read the key */
key.dsize = rec.key_len;
key.dptr =tdb1_alloc_read(tdb,tdb->travlocks.off+sizeof(rec),key.dsize);
/* Unlock the hash chain of the record we just read. */
if (tdb1_unlock(tdb, tdb->travlocks.hash, tdb->travlocks.lock_rw) != 0)
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_firstkey: error occurred while tdb1_unlocking!\n"));
return key;
}
/* find the next entry in the database, returning its key */
_PUBLIC_ TDB1_DATA tdb1_nextkey(struct tdb1_context *tdb, TDB1_DATA oldkey)
{
uint32_t oldhash;
TDB1_DATA key = tdb1_null;
struct tdb1_record rec;
unsigned char *k = NULL;
tdb1_off_t off;
/* Is locked key the old key? If so, traverse will be reliable. */
if (tdb->travlocks.off) {
if (tdb1_lock(tdb,tdb->travlocks.hash,tdb->travlocks.lock_rw))
return tdb1_null;
if (tdb1_rec_read(tdb, tdb->travlocks.off, &rec) == -1
|| !(k = tdb1_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 (tdb1_unlock_record(tdb, tdb->travlocks.off) != 0) {
SAFE_FREE(k);
return tdb1_null;
}
if (tdb1_unlock(tdb, tdb->travlocks.hash, tdb->travlocks.lock_rw) != 0) {
SAFE_FREE(k);
return tdb1_null;
}
tdb->travlocks.off = 0;
}
SAFE_FREE(k);
}
if (!tdb->travlocks.off) {
/* No previous element: do normal find, and lock record */
tdb->travlocks.off = tdb1_find_lock_hash(tdb, oldkey, tdb->hash_fn(&oldkey), tdb->travlocks.lock_rw, &rec);
if (!tdb->travlocks.off) {
return tdb1_null;
}
tdb->travlocks.hash = TDB1_BUCKET(rec.full_hash);
if (tdb1_lock_record(tdb, tdb->travlocks.off) != 0) {
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_nextkey: lock_record failed (%s)!\n", strerror(errno)));
return tdb1_null;
}
}
oldhash = tdb->travlocks.hash;
/* Grab next record: locks chain and returned record,
unlocks old record */
off = tdb1_next_lock(tdb, &tdb->travlocks, &rec);
if (off != TDB1_NEXT_LOCK_ERR && off != 0) {
key.dsize = rec.key_len;
key.dptr = tdb1_alloc_read(tdb, tdb->travlocks.off+sizeof(rec),
key.dsize);
/* Unlock the chain of this new record */
if (tdb1_unlock(tdb, tdb->travlocks.hash, tdb->travlocks.lock_rw) != 0)
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_nextkey: WARNING tdb1_unlock failed!\n"));
}
/* Unlock the chain of old record */
if (tdb1_unlock(tdb, TDB1_BUCKET(oldhash), tdb->travlocks.lock_rw) != 0)
TDB1_LOG((tdb, TDB1_DEBUG_FATAL, "tdb1_nextkey: WARNING tdb1_unlock failed!\n"));
return key;
}
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