--- /dev/null
+#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 */
--- /dev/null
+ /*
+ 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;
+}
--- /dev/null
+ /*
+ Unix SMB/CIFS implementation.
+
+ trivial database library
+
+ Copyright (C) Andrew Tridgell 1999-2005
+ Copyright (C) Paul `Rusty' Russell 2000
+ Copyright (C) Jeremy Allison 2000-2003
+
+ ** NOTE! The following LGPL license applies to the tdb
+ ** library. This does NOT imply that all of Samba is released
+ ** under the LGPL
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 3 of the License, or (at your option) any later version.
+
+ This library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with this library; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "tdb1_private.h"
+
+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);
+}
--- /dev/null
+ /*
+ Unix SMB/CIFS implementation.
+
+ trivial database library
+
+ Copyright (C) Andrew Tridgell 1999-2005
+ Copyright (C) Paul `Rusty' Russell 2000
+ Copyright (C) Jeremy Allison 2000-2003
+
+ ** NOTE! The following LGPL license applies to the tdb
+ ** library. This does NOT imply that all of Samba is released
+ ** under the LGPL
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 3 of the License, or (at your option) any later version.
+
+ This library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with this library; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "tdb1_private.h"
+
+_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";
+}
--- /dev/null
+ /*
+ Unix SMB/CIFS implementation.
+
+ trivial database library
+
+ Copyright (C) Andrew Tridgell 1999-2005
+ Copyright (C) Paul `Rusty' Russell 2000
+ Copyright (C) Jeremy Allison 2000-2003
+
+ ** NOTE! The following LGPL license applies to the tdb
+ ** library. This does NOT imply that all of Samba is released
+ ** under the LGPL
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 3 of the License, or (at your option) any later version.
+
+ This library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with this library; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "tdb1_private.h"
+
+/* '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;
+}
--- /dev/null
+/*
+ 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;
+}
--- /dev/null
+ /*
+ 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);
+}
--- /dev/null
+ /*
+ Unix SMB/CIFS implementation.
+
+ trivial database library
+
+ Copyright (C) Andrew Tridgell 1999-2005
+ Copyright (C) Paul `Rusty' Russell 2000
+ Copyright (C) Jeremy Allison 2000-2003
+
+ ** NOTE! The following LGPL license applies to the tdb
+ ** library. This does NOT imply that all of Samba is released
+ ** under the LGPL
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 3 of the License, or (at your option) any later version.
+
+ This library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with this library; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+
+#include "tdb1_private.h"
+#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;
+}
--- /dev/null
+ /*
+ Unix SMB/CIFS implementation.
+
+ trivial database library
+
+ Copyright (C) Andrew Tridgell 1999-2005
+ Copyright (C) Paul `Rusty' Russell 2000
+ Copyright (C) Jeremy Allison 2000-2003
+
+ ** NOTE! The following LGPL license applies to the tdb
+ ** library. This does NOT imply that all of Samba is released
+ ** under the LGPL
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 3 of the License, or (at your option) any later version.
+
+ This library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with this library; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "tdb1_private.h"
+
+_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);
+ }
+}
--- /dev/null
+ /*
+ Unix SMB/CIFS implementation.
+
+ trivial database library
+
+ Copyright (C) Andrew Tridgell 1999-2005
+ Copyright (C) Paul `Rusty' Russell 2000
+ Copyright (C) Jeremy Allison 2000-2003
+
+ ** NOTE! The following LGPL license applies to the tdb
+ ** library. This does NOT imply that all of Samba is released
+ ** under the LGPL
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 3 of the License, or (at your option) any later version.
+
+ This library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with this library; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "tdb1_private.h"
+
+/* 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;
+}
--- /dev/null
+#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 */
--- /dev/null
+ /*
+ 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;
+}
--- /dev/null
+ /*
+ Unix SMB/CIFS implementation.
+
+ trivial database library
+
+ Copyright (C) Andrew Tridgell 1999-2005
+ Copyright (C) Paul `Rusty' Russell 2000
+ Copyright (C) Jeremy Allison 2000-2003
+
+ ** NOTE! The following LGPL license applies to the tdb
+ ** library. This does NOT imply that all of Samba is released
+ ** under the LGPL
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 3 of the License, or (at your option) any later version.
+
+ This library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with this library; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "tdb1_private.h"
+
+_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;
+}
--- /dev/null
+ /*
+ 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);
+}
--- /dev/null
+ /*
+ Unix SMB/CIFS implementation.
+
+ trivial database library
+
+ Copyright (C) Andrew Tridgell 1999-2005
+ Copyright (C) Paul `Rusty' Russell 2000
+ Copyright (C) Jeremy Allison 2000-2003
+
+ ** NOTE! The following LGPL license applies to the tdb
+ ** library. This does NOT imply that all of Samba is released
+ ** under the LGPL
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 3 of the License, or (at your option) any later version.
+
+ This library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with this library; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "tdb1_private.h"
+
+#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;
+}
projects / ccan / commitdiff