-/*
+ /*
Unix SMB/Netbios implementation.
Version 3.0
Samba database functions
- Copyright (C) Andrew Tridgell 1999
+ Copyright (C) Andrew Tridgell 1999-2000
+ Copyright (C) Luke Kenneth Casson Leighton 2000
+ Copyright (C) Paul `Rusty' Russell 2000
+ Copyright (C) Jeremy Allison 2000
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
+#ifdef STANDALONE
+#if HAVE_CONFIG_H
+#include <config.h>
+#endif
-#if STANDALONE
#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include "tdb.h"
+#include "spinlock.h"
#else
#include "includes.h"
#endif
-#define TDB_VERSION (0x26011967 + 1)
+#define TDB_MAGIC_FOOD "TDB file\n"
+#define TDB_VERSION (0x26011967 + 6)
#define TDB_MAGIC (0x26011999U)
#define TDB_FREE_MAGIC (~TDB_MAGIC)
-#define TDB_ALIGN 32
-#define MIN_REC_SIZE (2*sizeof(struct list_struct) + TDB_ALIGN)
-#define DEFAULT_HASH_SIZE 512
+#define TDB_DEAD_MAGIC (0xFEE1DEAD)
+#define TDB_ALIGNMENT 4
+#define MIN_REC_SIZE (2*sizeof(struct list_struct) + TDB_ALIGNMENT)
+#define DEFAULT_HASH_SIZE 131
#define TDB_PAGE_SIZE 0x2000
-#define TDB_LEN_MULTIPLIER 10
#define FREELIST_TOP (sizeof(struct tdb_header))
+#define TDB_ALIGN(x,a) (((x) + (a)-1) & ~((a)-1))
+#define TDB_BYTEREV(x) (((((x)&0xff)<<24)|((x)&0xFF00)<<8)|(((x)>>8)&0xFF00)|((x)>>24))
+#define TDB_DEAD(r) ((r)->magic == TDB_DEAD_MAGIC)
+#define TDB_BAD_MAGIC(r) ((r)->magic != TDB_MAGIC && !TDB_DEAD(r))
+#define TDB_HASH_TOP(hash) (FREELIST_TOP + (BUCKET(hash)+1)*sizeof(tdb_off))
+
+/* NB assumes there is a local variable called "tdb" that is the
+ * current context, also takes doubly-parenthesized print-style
+ * argument. */
+#define TDB_LOG(x) (tdb->log_fn?((tdb->log_fn x),0) : 0)
+
+/* lock offsets */
+#define GLOBAL_LOCK 0
+#define ACTIVE_LOCK 4
+
+#ifndef MAP_FILE
+#define MAP_FILE 0
+#endif
+
+#ifndef MAP_FAILED
+#define MAP_FAILED ((void *)-1)
+#endif
+
+/* free memory if the pointer is valid and zero the pointer */
+#ifndef SAFE_FREE
+#define SAFE_FREE(x) do { if ((x) != NULL) {free((x)); (x)=NULL;} } while(0)
+#endif
#define BUCKET(hash) ((hash) % tdb->header.hash_size)
+TDB_DATA tdb_null;
+
+/* all contexts, to ensure no double-opens (fcntl locks don't nest!) */
+static TDB_CONTEXT *tdbs = NULL;
+
+static void tdb_munmap(TDB_CONTEXT *tdb)
+{
+ if (tdb->flags & TDB_INTERNAL)
+ return;
+
+#ifdef HAVE_MMAP
+ if (tdb->map_ptr)
+ munmap(tdb->map_ptr, tdb->map_size);
+#endif
+ tdb->map_ptr = NULL;
+}
+
+static void tdb_mmap(TDB_CONTEXT *tdb)
+{
+ if (tdb->flags & TDB_INTERNAL)
+ return;
+
+#ifdef HAVE_MMAP
+ if (!(tdb->flags & TDB_NOMMAP)) {
+ tdb->map_ptr = mmap(NULL, tdb->map_size,
+ PROT_READ|(tdb->read_only? 0:PROT_WRITE),
+ MAP_SHARED|MAP_FILE, tdb->fd, 0);
+
+ /*
+ * NB. When mmap fails it returns MAP_FAILED *NOT* NULL !!!!
+ */
+
+ if (tdb->map_ptr == MAP_FAILED) {
+ tdb->map_ptr = NULL;
+ TDB_LOG((tdb, 2, "tdb_mmap failed for size %d (%s)\n",
+ tdb->map_size, strerror(errno)));
+ }
+ } else {
+ tdb->map_ptr = NULL;
+ }
+#else
+ tdb->map_ptr = NULL;
+#endif
+}
+
+/* Endian conversion: we only ever deal with 4 byte quantities */
+static void *convert(void *buf, u32 size)
+{
+ u32 i, *p = buf;
+ for (i = 0; i < size / 4; i++)
+ p[i] = TDB_BYTEREV(p[i]);
+ return buf;
+}
+#define DOCONV() (tdb->flags & TDB_CONVERT)
+#define CONVERT(x) (DOCONV() ? convert(&x, sizeof(x)) : &x)
/* the body of the database is made of one list_struct for the free space
plus a separate data list for each hash value */
struct list_struct {
- tdb_len rec_len; /* total byte length of record */
tdb_off next; /* offset of the next record in the list */
+ tdb_len rec_len; /* total byte length of record */
tdb_len key_len; /* byte length of key */
tdb_len data_len; /* byte length of data */
- unsigned full_hash; /* the full 32 bit hash of the key */
- unsigned magic; /* try to catch errors */
- /*
- the following union is implied
- union {
- char record[rec_len];
- struct {
- char key[key_len];
- char data[data_len];
- }
- }
+ u32 full_hash; /* the full 32 bit hash of the key */
+ u32 magic; /* try to catch errors */
+ /* the following union is implied:
+ union {
+ char record[rec_len];
+ struct {
+ char key[key_len];
+ char data[data_len];
+ }
+ u32 totalsize; (tailer)
+ }
*/
};
-/* a null data record - useful for error returns */
-static TDB_DATA null_data;
-
-#if STANDALONE
-/* like strdup but for memory */
-static char *memdup(char *d, int size)
-{
- char *ret;
- ret = (char *)malloc(size);
- if (!ret) return NULL;
- memcpy(ret, d, size);
- return ret;
-}
-#endif
-
-
/* a byte range locking function - return 0 on success
- this functions locks/unlocks 1 byte at the specified offset */
-static int tdb_brlock(TDB_CONTEXT *tdb, tdb_off offset, int set)
+ this functions locks/unlocks 1 byte at the specified offset.
+
+ On error, errno is also set so that errors are passed back properly
+ through tdb_open(). */
+static int tdb_brlock(TDB_CONTEXT *tdb, tdb_off offset,
+ int rw_type, int lck_type, int probe)
{
-#if NOLOCK
- return 0;
-#else
struct flock fl;
- if (tdb->read_only) return -1;
+ if (tdb->flags & TDB_NOLOCK)
+ return 0;
+ if (tdb->read_only) {
+ errno = EACCES;
+ return -1;
+ }
- fl.l_type = set?F_WRLCK:F_UNLCK;
+ fl.l_type = rw_type;
fl.l_whence = SEEK_SET;
fl.l_start = offset;
fl.l_len = 1;
fl.l_pid = 0;
- if (fcntl(tdb->fd, F_SETLKW, &fl) != 0) {
-#if TDB_DEBUG
- printf("lock %d failed at %d (%s)\n",
- set, offset, strerror(errno));
-#endif
- return -1;
+ if (fcntl(tdb->fd,lck_type,&fl) == -1) {
+ if (!probe) {
+ TDB_LOG((tdb, 5,"tdb_brlock failed (fd=%d) at offset %d rw_type=%d lck_type=%d\n",
+ tdb->fd, offset, rw_type, lck_type));
+ }
+ /* errno set by fcntl */
+ return TDB_ERRCODE(TDB_ERR_LOCK, -1);
}
return 0;
-#endif
}
/* lock a list in the database. list -1 is the alloc list */
-static int tdb_lock(TDB_CONTEXT *tdb, int list)
+static int tdb_lock(TDB_CONTEXT *tdb, int list, int ltype)
{
if (list < -1 || list >= (int)tdb->header.hash_size) {
-#if TDB_DEBUG
- printf("bad list %d\n", list);
-#endif
+ TDB_LOG((tdb, 0,"tdb_lock: invalid list %d for ltype=%d\n",
+ list, ltype));
return -1;
}
- if (tdb->locked[list+1] == 0) {
- if (tdb_brlock(tdb, 4*(list+1), 1) != 0) {
+ if (tdb->flags & TDB_NOLOCK)
+ return 0;
+
+ /* Since fcntl locks don't nest, we do a lock for the first one,
+ and simply bump the count for future ones */
+ if (tdb->locked[list+1].count == 0) {
+ if (!tdb->read_only && tdb->header.rwlocks) {
+ if (tdb_spinlock(tdb, list, ltype)) {
+ TDB_LOG((tdb, 0, "tdb_lock spinlock failed on list ltype=%d\n",
+ list, ltype));
+ return -1;
+ }
+ } else if (tdb_brlock(tdb,FREELIST_TOP+4*list,ltype,F_SETLKW, 0)) {
+ TDB_LOG((tdb, 0,"tdb_lock failed on list %d ltype=%d (%s)\n",
+ list, ltype, strerror(errno)));
return -1;
}
+ tdb->locked[list+1].ltype = ltype;
}
- tdb->locked[list+1]++;
+ tdb->locked[list+1].count++;
return 0;
}
-/* unlock the database. */
-static int tdb_unlock(TDB_CONTEXT *tdb, int list)
+/* unlock the database: returns void because it's too late for errors. */
+static void tdb_unlock(TDB_CONTEXT *tdb, int list, int ltype)
{
- if (list < -1 || list >= (int)tdb->header.hash_size) {
-#if TDB_DEBUG
- printf("bad unlock list %d\n", list);
-#endif
- return -1;
+ if (tdb->flags & TDB_NOLOCK)
+ return;
+
+ /* Sanity checks */
+ if (list < -1 || list >= (int)tdb->header.hash_size)
+ return;
+ if (tdb->locked[list+1].count==0)
+ return;
+
+ if (tdb->locked[list+1].count == 1) {
+ /* Down to last nested lock: unlock underneath */
+ if (!tdb->read_only && tdb->header.rwlocks)
+ tdb_spinunlock(tdb, list, ltype);
+ else
+ tdb_brlock(tdb, FREELIST_TOP+4*list, F_UNLCK, F_SETLKW, 0);
}
-
- if (tdb->locked[list+1] == 0) {
-#if TDB_DEBUG
- printf("not locked %d\n", list);
-#endif
- return -1;
- }
- if (tdb->locked[list+1] == 1) {
- if (tdb_brlock(tdb, 4*(list+1), 0) != 0) {
- return -1;
- }
- }
- tdb->locked[list+1]--;
- return 0;
+ tdb->locked[list+1].count--;
}
-/* the hash algorithm - turn a key into an integer
- This is based on the hash agorithm from gdbm */
-static unsigned tdb_hash(TDB_DATA *key)
+/* This is based on the hash agorithm from gdbm */
+static u32 tdb_hash(TDB_DATA *key)
{
- unsigned value; /* Used to compute the hash value. */
- unsigned i; /* Used to cycle through random values. */
+ u32 value; /* Used to compute the hash value. */
+ u32 i; /* Used to cycle through random values. */
/* Set the initial value from the key size. */
- value = 0x238F13AF * key->dsize;
- for (i=0; i < key->dsize; i++) {
+ for (value = 0x238F13AF * key->dsize, i=0; i < key->dsize; i++)
value = (value + (key->dptr[i] << (i*5 % 24)));
- }
-
- value = (1103515243 * value + 12345);
-
- return value;
-}
-/* find the top of the hash chain for an open database */
-static tdb_off tdb_hash_top(TDB_CONTEXT *tdb, unsigned hash)
-{
- tdb_off ret;
- hash = BUCKET(hash);
- ret = FREELIST_TOP + (hash+1)*sizeof(tdb_off);
- return ret;
+ return (1103515243 * value + 12345);
}
-
/* 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 */
-static int tdb_oob(TDB_CONTEXT *tdb, tdb_off offset)
+ if necessary
+ note that "len" is the minimum length needed for the db
+*/
+static int tdb_oob(TDB_CONTEXT *tdb, tdb_off len, int probe)
{
struct stat st;
- if (offset <= tdb->map_size) return 0;
+ if (len <= tdb->map_size)
+ return 0;
+ if (tdb->flags & TDB_INTERNAL) {
+ if (!probe) {
+ TDB_LOG((tdb, 0,"tdb_oob len %d beyond internal malloc size %d\n",
+ (int)len, (int)tdb->map_size));
+ }
+ return TDB_ERRCODE(TDB_ERR_IO, -1);
+ }
- fstat(tdb->fd, &st);
- if (st.st_size <= (ssize_t)tdb->map_size) return -1;
+ if (fstat(tdb->fd, &st) == -1)
+ return TDB_ERRCODE(TDB_ERR_IO, -1);
-#if HAVE_MMAP
- if (tdb->map_ptr) {
- munmap(tdb->map_ptr, tdb->map_size);
- tdb->map_ptr = NULL;
+ if (st.st_size < (size_t)len) {
+ if (!probe) {
+ TDB_LOG((tdb, 0,"tdb_oob len %d beyond eof at %d\n",
+ (int)len, (int)st.st_size));
+ }
+ return TDB_ERRCODE(TDB_ERR_IO, -1);
}
-#endif
+ /* Unmap, update size, remap */
+ tdb_munmap(tdb);
tdb->map_size = st.st_size;
-#if HAVE_MMAP
- tdb->map_ptr = (void *)mmap(NULL, tdb->map_size,
- tdb->read_only?PROT_READ:PROT_READ|PROT_WRITE,
- MAP_SHARED | MAP_FILE, tdb->fd, 0);
-#endif
+ tdb_mmap(tdb);
return 0;
}
-
/* write a lump of data at a specified offset */
-static int tdb_write(TDB_CONTEXT *tdb, tdb_off offset, char *buf, tdb_len len)
+static int tdb_write(TDB_CONTEXT *tdb, tdb_off off, void *buf, tdb_len len)
{
- if (tdb_oob(tdb, offset + len) != 0) {
- /* oops - trying to write beyond the end of the database! */
-#if TDB_DEBUG
- printf("write error of length %u at offset %u (max %u)\n",
- len, offset, tdb->map_size);
-#endif
+ if (tdb_oob(tdb, off + len, 0) != 0)
return -1;
- }
- if (tdb->map_ptr) {
- memcpy(offset + (char *)tdb->map_ptr, buf, len);
- } else {
- lseek(tdb->fd, offset, SEEK_SET);
- if (write(tdb->fd, buf, len) != (ssize_t)len) {
- return -1;
- }
+ if (tdb->map_ptr)
+ memcpy(off + (char *)tdb->map_ptr, buf, len);
+#ifdef HAVE_PWRITE
+ else if (pwrite(tdb->fd, buf, len, off) != (ssize_t)len) {
+#else
+ else if (lseek(tdb->fd, off, SEEK_SET) != off
+ || write(tdb->fd, buf, len) != (ssize_t)len) {
+#endif
+ TDB_LOG((tdb, 0,"tdb_write failed at %d len=%d (%s)\n",
+ off, len, strerror(errno)));
+ return TDB_ERRCODE(TDB_ERR_IO, -1);
}
return 0;
}
-/* read a lump of data at a specified offset */
-static int tdb_read(TDB_CONTEXT *tdb, tdb_off offset, char *buf, tdb_len len)
+/* read a lump of data at a specified offset, maybe convert */
+static int tdb_read(TDB_CONTEXT *tdb,tdb_off off,void *buf,tdb_len len,int cv)
{
- if (tdb_oob(tdb, offset + len) != 0) {
- /* oops - trying to read beyond the end of the database! */
-#if TDB_DEBUG
- printf("read error of length %u at offset %u (max %u)\n",
- len, offset, tdb->map_size);
-#endif
+ if (tdb_oob(tdb, off + len, 0) != 0)
return -1;
- }
- if (tdb->map_ptr) {
- memcpy(buf, offset + (char *)tdb->map_ptr, len);
- } else {
- lseek(tdb->fd, offset, SEEK_SET);
- if (read(tdb->fd, buf, len) != (ssize_t)len) {
- return -1;
- }
+ if (tdb->map_ptr)
+ memcpy(buf, off + (char *)tdb->map_ptr, len);
+#ifdef HAVE_PREAD
+ else if (pread(tdb->fd, buf, len, off) != (ssize_t)len) {
+#else
+ else if (lseek(tdb->fd, off, SEEK_SET) != off
+ || read(tdb->fd, buf, len) != (ssize_t)len) {
+#endif
+ TDB_LOG((tdb, 0,"tdb_read failed at %d len=%d (%s)\n",
+ off, len, strerror(errno)));
+ return TDB_ERRCODE(TDB_ERR_IO, -1);
}
+ if (cv)
+ convert(buf, len);
return 0;
}
-
/* read a lump of data, allocating the space for it */
static char *tdb_alloc_read(TDB_CONTEXT *tdb, tdb_off offset, tdb_len len)
{
char *buf;
- buf = (char *)malloc(len);
-
- if (tdb_read(tdb, offset, buf, len) == -1) {
- free(buf);
+ if (!(buf = malloc(len))) {
+ TDB_LOG((tdb, 0,"tdb_alloc_read malloc failed len=%d (%s)\n",
+ len, strerror(errno)));
+ return TDB_ERRCODE(TDB_ERR_OOM, buf);
+ }
+ if (tdb_read(tdb, offset, buf, len, 0) == -1) {
+ SAFE_FREE(buf);
return NULL;
}
-
return buf;
}
-/* convenience routine for writing a record */
-static int rec_write(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec)
+/* read/write a tdb_off */
+static int ofs_read(TDB_CONTEXT *tdb, tdb_off offset, tdb_off *d)
{
- return tdb_write(tdb, offset, (char *)rec, sizeof(*rec));
+ return tdb_read(tdb, offset, (char*)d, sizeof(*d), DOCONV());
}
-
-/* convenience routine for writing a tdb_off */
static int ofs_write(TDB_CONTEXT *tdb, tdb_off offset, tdb_off *d)
{
- return tdb_write(tdb, offset, (char *)d, sizeof(*d));
+ tdb_off off = *d;
+ return tdb_write(tdb, offset, CONVERT(off), sizeof(*d));
}
-/* read a tdb_off from the store */
-static int ofs_read(TDB_CONTEXT *tdb, tdb_off offset, tdb_off *d)
+/* read/write a record */
+static int rec_read(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec)
+{
+ if (tdb_read(tdb, offset, rec, sizeof(*rec),DOCONV()) == -1)
+ return -1;
+ if (TDB_BAD_MAGIC(rec)) {
+ TDB_LOG((tdb, 0,"rec_read bad magic 0x%x at offset=%d\n", rec->magic, offset));
+ return TDB_ERRCODE(TDB_ERR_CORRUPT, -1);
+ }
+ return tdb_oob(tdb, rec->next+sizeof(*rec), 0);
+}
+static int rec_write(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec)
{
- return tdb_read(tdb, offset, (char *)d, sizeof(*d));
+ struct list_struct r = *rec;
+ return tdb_write(tdb, offset, CONVERT(r), sizeof(r));
}
-/* read a record and check for simple errors */
-static int rec_read(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec)
+/* read a freelist record and check for simple errors */
+static int rec_free_read(TDB_CONTEXT *tdb, tdb_off off, struct list_struct *rec)
{
- if (tdb_read(tdb, offset, (char *)rec, sizeof(*rec)) == -1) return -1;
- if (rec->magic != TDB_MAGIC) {
-#if TDB_DEBUG
- printf("bad magic 0x%08x at offset %d\n",
- rec->magic, offset);
-#endif
+ if (tdb_read(tdb, off, rec, sizeof(*rec),DOCONV()) == -1)
return -1;
+ if (rec->magic != TDB_FREE_MAGIC) {
+ TDB_LOG((tdb, 0,"rec_free_read bad magic 0x%x at offset=%d\n",
+ rec->magic, off));
+ return TDB_ERRCODE(TDB_ERR_CORRUPT, -1);
}
- if (tdb_oob(tdb, rec->next) != 0) {
-#if TDB_DEBUG
- printf("bad next %d at offset %d\n",
- rec->next, offset);
-#endif
+ if (tdb_oob(tdb, rec->next+sizeof(*rec), 0) != 0)
return -1;
- }
return 0;
}
-/* expand the database at least length bytes by expanding the
- underlying file and doing the mmap again if necessary */
-static int tdb_expand(TDB_CONTEXT *tdb, tdb_off length)
+/* update a record tailer (must hold allocation lock) */
+static int update_tailer(TDB_CONTEXT *tdb, tdb_off offset,
+ const struct list_struct *rec)
{
- struct list_struct rec;
- tdb_off offset, ptr;
- char b = 0;
+ tdb_off totalsize;
- tdb_lock(tdb,-1);
-
- /* make sure we know about any previous expansions by another
- process */
- tdb_oob(tdb,tdb->map_size + 1);
+ /* Offset of tailer from record header */
+ totalsize = sizeof(*rec) + rec->rec_len;
+ return ofs_write(tdb, offset + totalsize - sizeof(tdb_off),
+ &totalsize);
+}
- /* always make room for at least 10 more records */
- length *= TDB_LEN_MULTIPLIER;
+static tdb_off tdb_dump_record(TDB_CONTEXT *tdb, tdb_off offset)
+{
+ struct list_struct rec;
+ tdb_off tailer_ofs, tailer;
- /* and round the database up to a multiple of TDB_PAGE_SIZE */
- length = ((tdb->map_size + length + TDB_PAGE_SIZE) & ~(TDB_PAGE_SIZE - 1)) - tdb->map_size;
+ if (tdb_read(tdb, offset, (char *)&rec, sizeof(rec), DOCONV()) == -1) {
+ printf("ERROR: failed to read record at %u\n", offset);
+ return 0;
+ }
- /* expand the file itself */
- lseek(tdb->fd, tdb->map_size + length - 1, SEEK_SET);
- if (write(tdb->fd, &b, 1) != 1) goto fail;
+ printf(" rec: offset=%u next=%d rec_len=%d key_len=%d data_len=%d full_hash=0x%x magic=0x%x\n",
+ offset, rec.next, rec.rec_len, rec.key_len, rec.data_len, rec.full_hash, rec.magic);
- /* form a new freelist record */
- offset = FREELIST_TOP;
- rec.rec_len = length - sizeof(rec);
- rec.magic = TDB_FREE_MAGIC;
- if (ofs_read(tdb, offset, &rec.next) == -1) {
- goto fail;
+ tailer_ofs = offset + sizeof(rec) + rec.rec_len - sizeof(tdb_off);
+ if (ofs_read(tdb, tailer_ofs, &tailer) == -1) {
+ printf("ERROR: failed to read tailer at %u\n", tailer_ofs);
+ return rec.next;
}
-#if HAVE_MMAP
- if (tdb->map_ptr) {
- munmap(tdb->map_ptr, tdb->map_size);
- tdb->map_ptr = NULL;
+ if (tailer != rec.rec_len + sizeof(rec)) {
+ printf("ERROR: tailer does not match record! tailer=%u totalsize=%u\n",
+ (unsigned)tailer, (unsigned)(rec.rec_len + sizeof(rec)));
}
-#endif
+ return rec.next;
+}
- tdb->map_size += length;
+static void tdb_dump_chain(TDB_CONTEXT *tdb, int i)
+{
+ tdb_off rec_ptr, top;
- /* write it out */
- if (rec_write(tdb, tdb->map_size - length, &rec) == -1) {
- goto fail;
- }
+ top = TDB_HASH_TOP(i);
- /* link it into the free list */
- ptr = tdb->map_size - length;
- if (ofs_write(tdb, offset, &ptr) == -1) goto fail;
+ tdb_lock(tdb, i, F_WRLCK);
-#if HAVE_MMAP
- tdb->map_ptr = (void *)mmap(NULL, tdb->map_size,
- PROT_READ|PROT_WRITE,
- MAP_SHARED | MAP_FILE, tdb->fd, 0);
-#endif
- tdb_unlock(tdb, -1);
- return 0;
+ if (ofs_read(tdb, top, &rec_ptr) == -1) {
+ tdb_unlock(tdb, i, F_WRLCK);
+ return;
+ }
- fail:
- tdb_unlock(tdb,-1);
- return -1;
+ if (rec_ptr)
+ printf("hash=%d\n", i);
+
+ while (rec_ptr) {
+ rec_ptr = tdb_dump_record(tdb, rec_ptr);
+ }
+ tdb_unlock(tdb, i, F_WRLCK);
}
-/* allocate some space from the free list. The offset returned points
- to a unconnected list_struct within the database with room for at
- least length bytes of total data
+void tdb_dump_all(TDB_CONTEXT *tdb)
+{
+ int i;
+ for (i=0;i<tdb->header.hash_size;i++) {
+ tdb_dump_chain(tdb, i);
+ }
+ printf("freelist:\n");
+ tdb_dump_chain(tdb, -1);
+}
- 0 is returned if the space could not be allocated
- */
-static tdb_off tdb_allocate(TDB_CONTEXT *tdb, tdb_len length)
+void tdb_printfreelist(TDB_CONTEXT *tdb)
{
- tdb_off offset, rec_ptr, last_ptr;
- struct list_struct rec, lastrec, newrec;
+ long total_free = 0;
+ tdb_off offset, rec_ptr;
+ struct list_struct rec;
- tdb_lock(tdb, -1);
+ tdb_lock(tdb, -1, F_WRLCK);
- again:
- last_ptr = 0;
offset = FREELIST_TOP;
/* read in the freelist top */
if (ofs_read(tdb, offset, &rec_ptr) == -1) {
- goto fail;
+ return;
}
- /* keep looking until we find a freelist record that is big
- enough */
+ printf("freelist top=[0x%08x]\n", rec_ptr );
while (rec_ptr) {
- if (tdb_read(tdb, rec_ptr, (char *)&rec, sizeof(rec)) == -1) {
- goto fail;
+ if (tdb_read(tdb, rec_ptr, (char *)&rec, sizeof(rec), DOCONV()) == -1) {
+ return;
}
if (rec.magic != TDB_FREE_MAGIC) {
-#if TDB_DEBUG
printf("bad magic 0x%08x in free list\n", rec.magic);
-#endif
- goto fail;
+ return;
}
- if (rec.rec_len >= length) {
- /* found it - now possibly split it up */
- if (rec.rec_len > length + MIN_REC_SIZE) {
- length = (length + TDB_ALIGN) & ~(TDB_ALIGN-1);
-
- newrec.rec_len = rec.rec_len - (sizeof(rec) + length);
- newrec.next = rec.next;
- newrec.magic = TDB_FREE_MAGIC;
-
- rec.rec_len = length;
- rec.next = rec_ptr + sizeof(rec) + rec.rec_len;
-
- if (rec_write(tdb, rec.next, &newrec) == -1) {
- goto fail;
- }
-
- if (rec_write(tdb, rec_ptr, &rec) == -1) {
- goto fail;
- }
- }
-
- /* remove it from the list */
- if (last_ptr == 0) {
- offset = FREELIST_TOP;
-
- if (ofs_write(tdb, offset, &rec.next) == -1) {
- goto fail;
- }
- } else {
- lastrec.next = rec.next;
- if (rec_write(tdb, last_ptr, &lastrec) == -1) {
- goto fail;
- }
- }
-
- /* all done - return the new record offset */
- tdb_unlock(tdb, -1);
- return rec_ptr;
- }
+ printf("entry offset=[0x%08x], rec.rec_len = [0x%08x (%d)]\n", rec.next, rec.rec_len, rec.rec_len );
+ total_free += rec.rec_len;
/* move to the next record */
- lastrec = rec;
- last_ptr = rec_ptr;
rec_ptr = rec.next;
}
+ printf("total rec_len = [0x%08x (%d)]\n", (int)total_free,
+ (int)total_free);
- /* we didn't find enough space. See if we can expand the
- database and if we can then try again */
- if (tdb_expand(tdb, length + sizeof(rec)) == 0) goto again;
-
- fail:
-#if TDB_DEBUG
- printf("tdb_allocate failed for size %u\n", length);
-#endif
- tdb_unlock(tdb, -1);
- return 0;
+ tdb_unlock(tdb, -1, F_WRLCK);
}
-/* initialise a new database with a specified hash size */
-static int tdb_new_database(TDB_CONTEXT *tdb, int hash_size)
+/* Remove an element from the freelist. Must have alloc lock. */
+static int remove_from_freelist(TDB_CONTEXT *tdb, tdb_off off, tdb_off next)
{
- struct tdb_header header;
- tdb_off offset;
- int i;
-
- /* create the header */
- header.version = TDB_VERSION;
- header.hash_size = hash_size;
- lseek(tdb->fd, 0, SEEK_SET);
- ftruncate(tdb->fd, 0);
+ tdb_off last_ptr, i;
- if (write(tdb->fd, &header, sizeof(header)) != sizeof(header)) return -1;
-
- /* the freelist and hash pointers */
- offset = 0;
- for (i=0;i<hash_size+1;i++) {
- if (write(tdb->fd, &offset, sizeof(tdb_off)) != sizeof(tdb_off)) return -1;
+ /* read in the freelist top */
+ last_ptr = FREELIST_TOP;
+ while (ofs_read(tdb, last_ptr, &i) != -1 && i != 0) {
+ if (i == off) {
+ /* We've found it! */
+ return ofs_write(tdb, last_ptr, &next);
+ }
+ /* Follow chain (next offset is at start of record) */
+ last_ptr = i;
}
-
-#if TDB_DEBUG
- printf("initialised database of hash_size %u\n",
- hash_size);
-#endif
- return 0;
+ TDB_LOG((tdb, 0,"remove_from_freelist: not on list at off=%d\n", off));
+ return TDB_ERRCODE(TDB_ERR_CORRUPT, -1);
}
-
-/* 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
-*/
-int tdb_update(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf)
+/* Add an element into the freelist. Merge adjacent records if
+ neccessary. */
+static int tdb_free(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec)
{
- unsigned hash;
- tdb_off offset, rec_ptr;
- struct list_struct rec;
- char *data=NULL;
+ tdb_off right, left;
- /* find which hash bucket it is in */
- hash = tdb_hash(&key);
+ /* Allocation and tailer lock */
+ if (tdb_lock(tdb, -1, F_WRLCK) != 0)
+ return -1;
- tdb_lock(tdb, BUCKET(hash));
+ /* set an initial tailer, so if we fail we don't leave a bogus record */
+ update_tailer(tdb, offset, rec);
- /* find the top of the hash chain */
- offset = tdb_hash_top(tdb, hash);
+ /* Look right first (I'm an Australian, dammit) */
+ right = offset + sizeof(*rec) + rec->rec_len;
+ if (right + sizeof(*rec) <= tdb->map_size) {
+ struct list_struct r;
- /* read in the hash top */
- if (ofs_read(tdb, offset, &rec_ptr) == -1) {
- goto fail;
+ if (tdb_read(tdb, right, &r, sizeof(r), DOCONV()) == -1) {
+ TDB_LOG((tdb, 0, "tdb_free: right read failed at %u\n", right));
+ goto left;
+ }
+
+ /* If it's free, expand to include it. */
+ if (r.magic == TDB_FREE_MAGIC) {
+ if (remove_from_freelist(tdb, right, r.next) == -1) {
+ TDB_LOG((tdb, 0, "tdb_free: right free failed at %u\n", right));
+ goto left;
+ }
+ rec->rec_len += sizeof(r) + r.rec_len;
+ }
}
- /* keep looking until we find the right record */
- while (rec_ptr) {
- if (rec_read(tdb, rec_ptr, &rec) == -1) {
- goto fail;
+left:
+ /* Look left */
+ left = offset - sizeof(tdb_off);
+ if (left > TDB_HASH_TOP(tdb->header.hash_size-1)) {
+ struct list_struct l;
+ tdb_off leftsize;
+
+ /* Read in tailer and jump back to header */
+ if (ofs_read(tdb, left, &leftsize) == -1) {
+ TDB_LOG((tdb, 0, "tdb_free: left offset read failed at %u\n", left));
+ goto update;
}
+ left = offset - leftsize;
- if (hash == rec.full_hash && key.dsize == rec.key_len) {
- /* a very likely hit - read the full key */
- data = tdb_alloc_read(tdb, rec_ptr + sizeof(rec),
- rec.key_len);
- if (!data) goto fail;
+ /* Now read in record */
+ if (tdb_read(tdb, left, &l, sizeof(l), DOCONV()) == -1) {
+ TDB_LOG((tdb, 0, "tdb_free: left read failed at %u (%u)\n", left, leftsize));
+ goto update;
+ }
- if (memcmp(key.dptr, data, key.dsize) == 0) {
- /* definate hit */
- if (rec.rec_len < key.dsize + dbuf.dsize) {
- /* the update won't fit! */
- goto fail;
- }
- if (tdb_write(tdb, rec_ptr + sizeof(rec) + rec.key_len,
- dbuf.dptr, dbuf.dsize) == -1) {
- goto fail;
- }
- if (dbuf.dsize != rec.data_len) {
- rec.data_len = dbuf.dsize;
- if (rec_write(tdb, rec_ptr, &rec) == -1) {
- goto fail;
- }
- }
- free(data);
- tdb_unlock(tdb, BUCKET(hash));
- return 0;
+ /* If it's free, expand to include it. */
+ if (l.magic == TDB_FREE_MAGIC) {
+ if (remove_from_freelist(tdb, left, l.next) == -1) {
+ TDB_LOG((tdb, 0, "tdb_free: left free failed at %u\n", left));
+ goto update;
+ } else {
+ offset = left;
+ rec->rec_len += leftsize;
}
-
- /* a miss - drat */
- free(data);
- data = NULL;
}
+ }
- /* move to the next record */
- rec_ptr = rec.next;
+update:
+ if (update_tailer(tdb, offset, rec) == -1) {
+ TDB_LOG((tdb, 0, "tdb_free: update_tailer failed at %u\n", offset));
+ goto fail;
+ }
+
+ /* Now, prepend to free list */
+ rec->magic = TDB_FREE_MAGIC;
+
+ if (ofs_read(tdb, FREELIST_TOP, &rec->next) == -1 ||
+ rec_write(tdb, offset, rec) == -1 ||
+ ofs_write(tdb, FREELIST_TOP, &offset) == -1) {
+ TDB_LOG((tdb, 0, "tdb_free record write failed at offset=%d\n", offset));
+ goto fail;
}
- /* we didn't find it */
+ /* And we're done. */
+ tdb_unlock(tdb, -1, F_WRLCK);
+ return 0;
+
fail:
- tdb_unlock(tdb, BUCKET(hash));
- if (data) free(data);
+ tdb_unlock(tdb, -1, F_WRLCK);
return -1;
}
-/* find an entry in the database given a key */
-TDB_DATA tdb_fetch(TDB_CONTEXT *tdb, TDB_DATA key)
+/* expand a file. we prefer to use ftruncate, as that is what posix
+ says to use for mmap expansion */
+static int expand_file(TDB_CONTEXT *tdb, tdb_off size, tdb_off addition)
{
- unsigned hash;
- tdb_off offset, rec_ptr;
- struct list_struct rec;
- char *data;
- TDB_DATA ret;
+ char buf[1024];
+#if HAVE_FTRUNCATE_EXTEND
+ if (ftruncate(tdb->fd, size+addition) != 0) {
+ TDB_LOG((tdb, 0, "expand_file ftruncate to %d failed (%s)\n",
+ size+addition, strerror(errno)));
+ return -1;
+ }
+#else
+ char b = 0;
- /* find which hash bucket it is in */
- hash = tdb_hash(&key);
+#ifdef HAVE_PWRITE
+ if (pwrite(tdb->fd, &b, 1, (size+addition) - 1) != 1) {
+#else
+ if (lseek(tdb->fd, (size+addition) - 1, SEEK_SET) != (size+addition) - 1 ||
+ write(tdb->fd, &b, 1) != 1) {
+#endif
+ TDB_LOG((tdb, 0, "expand_file to %d failed (%s)\n",
+ size+addition, strerror(errno)));
+ return -1;
+ }
+#endif
- tdb_lock(tdb, BUCKET(hash));
+ /* now fill the file with something. This ensures that the file isn't sparse, which would be
+ very bad if we ran out of disk. This must be done with write, not via mmap */
+ memset(buf, 0x42, sizeof(buf));
+ while (addition) {
+ int n = addition>sizeof(buf)?sizeof(buf):addition;
+#ifdef HAVE_PWRITE
+ int ret = pwrite(tdb->fd, buf, n, size);
+#else
+ int ret;
+ if (lseek(tdb->fd, size, SEEK_SET) != size)
+ return -1;
+ ret = write(tdb->fd, buf, n);
+#endif
+ if (ret != n) {
+ TDB_LOG((tdb, 0, "expand_file write of %d failed (%s)\n",
+ n, strerror(errno)));
+ return -1;
+ }
+ addition -= n;
+ size += n;
+ }
+ return 0;
+}
- /* find the top of the hash chain */
- offset = tdb_hash_top(tdb, hash);
- /* read in the hash top */
- if (ofs_read(tdb, offset, &rec_ptr) == -1) {
- goto fail;
+/* expand the database at least size bytes by expanding the underlying
+ file and doing the mmap again if necessary */
+static int tdb_expand(TDB_CONTEXT *tdb, tdb_off size)
+{
+ struct list_struct rec;
+ tdb_off offset;
+
+ if (tdb_lock(tdb, -1, F_WRLCK) == -1) {
+ TDB_LOG((tdb, 0, "lock failed in tdb_expand\n"));
+ return -1;
}
- /* keep looking until we find the right record */
- while (rec_ptr) {
- if (rec_read(tdb, rec_ptr, &rec) == -1) {
- goto fail;
- }
+ /* must know about any previous expansions by another process */
+ tdb_oob(tdb, tdb->map_size + 1, 1);
- if (hash == rec.full_hash && key.dsize == rec.key_len) {
- /* a very likely hit - read the full record */
- data = tdb_alloc_read(tdb, rec_ptr + sizeof(rec),
- rec.key_len + rec.data_len);
- if (!data) {
- goto fail;
- }
+ /* always make room for at least 10 more records, and round
+ the database up to a multiple of TDB_PAGE_SIZE */
+ size = TDB_ALIGN(tdb->map_size + size*10, TDB_PAGE_SIZE) - tdb->map_size;
- if (memcmp(key.dptr, data, key.dsize) == 0) {
- /* a definate match */
- ret.dptr = (char *)memdup(data + rec.key_len, rec.data_len);
- ret.dsize = rec.data_len;
- free(data);
- tdb_unlock(tdb, BUCKET(hash));
- return ret;
- }
+ if (!(tdb->flags & TDB_INTERNAL))
+ tdb_munmap(tdb);
- /* a miss - drat */
- free(data);
- }
+ /*
+ * We must ensure the file is unmapped before doing this
+ * to ensure consistency with systems like OpenBSD where
+ * writes and mmaps are not consistent.
+ */
- /* move to the next record */
- rec_ptr = rec.next;
+ /* expand the file itself */
+ if (!(tdb->flags & TDB_INTERNAL)) {
+ if (expand_file(tdb, tdb->map_size, size) != 0)
+ goto fail;
+ }
+
+ tdb->map_size += size;
+
+ if (tdb->flags & TDB_INTERNAL)
+ tdb->map_ptr = realloc(tdb->map_ptr, tdb->map_size);
+ else {
+ /*
+ * We must ensure the file is remapped before adding the space
+ * to ensure consistency with systems like OpenBSD where
+ * writes and mmaps are not consistent.
+ */
+
+ /* We're ok if the mmap fails as we'll fallback to read/write */
+ tdb_mmap(tdb);
}
- /* we didn't find it */
+ /* form a new freelist record */
+ memset(&rec,'\0',sizeof(rec));
+ rec.rec_len = size - sizeof(rec);
+
+ /* link it into the free list */
+ offset = tdb->map_size - size;
+ if (tdb_free(tdb, offset, &rec) == -1)
+ goto fail;
+
+ tdb_unlock(tdb, -1, F_WRLCK);
+ return 0;
fail:
- tdb_unlock(tdb, BUCKET(hash));
- return null_data;
+ tdb_unlock(tdb, -1, F_WRLCK);
+ return -1;
}
-/* check if an entry in the database exists
+/* allocate some space from the free list. The offset returned points
+ to a unconnected list_struct within the database with room for at
+ least length bytes of total data
- 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
-*/
-int tdb_exists(TDB_CONTEXT *tdb, TDB_DATA key)
+ 0 is returned if the space could not be allocated
+ */
+static tdb_off tdb_allocate(TDB_CONTEXT *tdb, tdb_len length,
+ struct list_struct *rec)
{
- unsigned hash;
- tdb_off offset, rec_ptr;
- struct list_struct rec;
- char *data;
+ tdb_off rec_ptr, last_ptr, newrec_ptr;
+ struct list_struct newrec;
- /* find which hash bucket it is in */
- hash = tdb_hash(&key);
+ if (tdb_lock(tdb, -1, F_WRLCK) == -1)
+ return 0;
- tdb_lock(tdb, BUCKET(hash));
+ /* Extra bytes required for tailer */
+ length += sizeof(tdb_off);
- /* find the top of the hash chain */
- offset = tdb_hash_top(tdb, hash);
+ again:
+ last_ptr = FREELIST_TOP;
- /* read in the hash top */
- if (ofs_read(tdb, offset, &rec_ptr) == -1) {
+ /* read in the freelist top */
+ if (ofs_read(tdb, FREELIST_TOP, &rec_ptr) == -1)
goto fail;
- }
- /* keep looking until we find the right record */
+ /* keep looking until we find a freelist record big enough */
while (rec_ptr) {
- if (rec_read(tdb, rec_ptr, &rec) == -1) {
+ if (rec_free_read(tdb, rec_ptr, rec) == -1)
goto fail;
- }
- if (hash == rec.full_hash && key.dsize == rec.key_len) {
- /* a very likely hit - read the full record */
- data = tdb_alloc_read(tdb, rec_ptr + sizeof(rec),
- rec.key_len + rec.data_len);
- if (!data) {
+ if (rec->rec_len >= length) {
+ /* found it - now possibly split it up */
+ if (rec->rec_len > length + MIN_REC_SIZE) {
+ /* Length of left piece */
+ length = TDB_ALIGN(length, TDB_ALIGNMENT);
+
+ /* Right piece to go on free list */
+ newrec.rec_len = rec->rec_len
+ - (sizeof(*rec) + length);
+ newrec_ptr = rec_ptr + sizeof(*rec) + length;
+
+ /* And left record is shortened */
+ rec->rec_len = length;
+ } else
+ newrec_ptr = 0;
+
+ /* Remove allocated record from the free list */
+ if (ofs_write(tdb, last_ptr, &rec->next) == -1)
goto fail;
- }
- if (memcmp(key.dptr, data, key.dsize) == 0) {
- /* a definate match */
- free(data);
- tdb_unlock(tdb, BUCKET(hash));
- return 1;
+ /* Update header: do this before we drop alloc
+ lock, otherwise tdb_free() might try to
+ merge with us, thinking we're free.
+ (Thanks Jeremy Allison). */
+ rec->magic = TDB_MAGIC;
+ if (rec_write(tdb, rec_ptr, rec) == -1)
+ goto fail;
+
+ /* Did we create new block? */
+ if (newrec_ptr) {
+ /* Update allocated record tailer (we
+ shortened it). */
+ if (update_tailer(tdb, rec_ptr, rec) == -1)
+ goto fail;
+
+ /* Free new record */
+ if (tdb_free(tdb, newrec_ptr, &newrec) == -1)
+ goto fail;
}
- /* a miss - drat */
- free(data);
+ /* all done - return the new record offset */
+ tdb_unlock(tdb, -1, F_WRLCK);
+ return rec_ptr;
}
-
/* move to the next record */
- rec_ptr = rec.next;
+ last_ptr = rec_ptr;
+ rec_ptr = rec->next;
}
-
- /* we didn't find it */
+ /* we didn't find enough space. See if we can expand the
+ database and if we can then try again */
+ if (tdb_expand(tdb, length + sizeof(*rec)) == 0)
+ goto again;
fail:
- tdb_unlock(tdb, BUCKET(hash));
+ tdb_unlock(tdb, -1, F_WRLCK);
return 0;
}
-
-/* traverse the entire database - calling fn(tdb, key, data) on each element.
- return -1 on error or the record count traversed
- if fn is NULL then it is not called
- a non-zero return value from fn() indicates that the traversal should stop
- */
-int tdb_traverse(TDB_CONTEXT *tdb, int (*fn)(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf))
+/* initialise a new database with a specified hash size */
+static int tdb_new_database(TDB_CONTEXT *tdb, int hash_size)
{
- int count = 0;
- unsigned h;
- tdb_off offset, rec_ptr;
- struct list_struct rec;
- char *data;
- TDB_DATA key, dbuf;
-
- /* loop over all hash chains */
- for (h = 0; h < tdb->header.hash_size; h++) {
- tdb_lock(tdb, BUCKET(h));
+ struct tdb_header *newdb;
+ int size, ret = -1;
+
+ /* We make it up in memory, then write it out if not internal */
+ size = sizeof(struct tdb_header) + (hash_size+1)*sizeof(tdb_off);
+ if (!(newdb = calloc(size, 1)))
+ return TDB_ERRCODE(TDB_ERR_OOM, -1);
+
+ /* Fill in the header */
+ newdb->version = TDB_VERSION;
+ newdb->hash_size = hash_size;
+#ifdef USE_SPINLOCKS
+ newdb->rwlocks = size;
+#endif
+ if (tdb->flags & TDB_INTERNAL) {
+ tdb->map_size = size;
+ tdb->map_ptr = (char *)newdb;
+ memcpy(&tdb->header, newdb, sizeof(tdb->header));
+ /* Convert the `ondisk' version if asked. */
+ CONVERT(*newdb);
+ return 0;
+ }
+ if (lseek(tdb->fd, 0, SEEK_SET) == -1)
+ goto fail;
- /* read in the hash top */
- offset = tdb_hash_top(tdb, h);
- if (ofs_read(tdb, offset, &rec_ptr) == -1) {
- goto fail;
- }
+ if (ftruncate(tdb->fd, 0) == -1)
+ goto fail;
- /* traverse all records for this hash */
- while (rec_ptr) {
- if (rec_read(tdb, rec_ptr, &rec) == -1) {
- goto fail;
- }
+ /* This creates an endian-converted header, as if read from disk */
+ CONVERT(*newdb);
+ memcpy(&tdb->header, newdb, sizeof(tdb->header));
+ /* Don't endian-convert the magic food! */
+ memcpy(newdb->magic_food, TDB_MAGIC_FOOD, strlen(TDB_MAGIC_FOOD)+1);
+ if (write(tdb->fd, newdb, size) != size)
+ ret = -1;
+ else
+ ret = tdb_create_rwlocks(tdb->fd, hash_size);
+
+ fail:
+ SAFE_FREE(newdb);
+ return ret;
+}
- /* now read the full record */
- data = tdb_alloc_read(tdb, rec_ptr + sizeof(rec),
- rec.key_len + rec.data_len);
- if (!data) {
- goto fail;
- }
+/* Returns 0 on fail. On success, return offset of record, and fills
+ in rec */
+static tdb_off tdb_find(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash,
+ struct list_struct *r)
+{
+ tdb_off rec_ptr;
+
+ /* read in the hash top */
+ if (ofs_read(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1)
+ return 0;
- key.dptr = data;
- key.dsize = rec.key_len;
- dbuf.dptr = data + rec.key_len;
- dbuf.dsize = rec.data_len;
- count++;
+ /* keep looking until we find the right record */
+ while (rec_ptr) {
+ if (rec_read(tdb, rec_ptr, r) == -1)
+ return 0;
+
+ if (!TDB_DEAD(r) && hash==r->full_hash && key.dsize==r->key_len) {
+ char *k;
+ /* a very likely hit - read the key */
+ k = tdb_alloc_read(tdb, rec_ptr + sizeof(*r),
+ r->key_len);
+ if (!k)
+ return 0;
- if (fn && fn(tdb, key, dbuf) != 0) {
- /* they want us to stop traversing */
- free(data);
- tdb_unlock(tdb, BUCKET(h));
- return count;
+ if (memcmp(key.dptr, k, key.dsize) == 0) {
+ SAFE_FREE(k);
+ return rec_ptr;
}
-
- /* a miss - drat */
- free(data);
-
- /* move to the next record */
- rec_ptr = rec.next;
+ SAFE_FREE(k);
}
- tdb_unlock(tdb, BUCKET(h));
+ rec_ptr = r->next;
}
-
- /* return the number traversed */
- return count;
-
- fail:
- tdb_unlock(tdb, BUCKET(h));
- return -1;
+ return TDB_ERRCODE(TDB_ERR_NOEXIST, 0);
}
-
-/* find the first entry in the database and return its key */
-TDB_DATA tdb_firstkey(TDB_CONTEXT *tdb)
+/* If they do lockkeys, check that this hash is one they locked */
+static int tdb_keylocked(TDB_CONTEXT *tdb, u32 hash)
{
- tdb_off offset, rec_ptr;
- struct list_struct rec;
- unsigned hash;
- TDB_DATA ret;
+ u32 i;
+ if (!tdb->lockedkeys)
+ return 1;
+ for (i = 0; i < tdb->lockedkeys[0]; i++)
+ if (tdb->lockedkeys[i+1] == hash)
+ return 1;
+ return TDB_ERRCODE(TDB_ERR_NOLOCK, 0);
+}
- /* look for a non-empty hash chain */
- for (hash = 0, rec_ptr = 0;
- hash < tdb->header.hash_size;
- hash++) {
- /* find the top of the hash chain */
- offset = tdb_hash_top(tdb, hash);
+/* As tdb_find, but if you succeed, keep the lock */
+static tdb_off tdb_find_lock(TDB_CONTEXT *tdb, TDB_DATA key, int locktype,
+ struct list_struct *rec)
+{
+ u32 hash, rec_ptr;
- tdb_lock(tdb, BUCKET(hash));
+ hash = tdb_hash(&key);
+ if (!tdb_keylocked(tdb, hash))
+ return 0;
+ if (tdb_lock(tdb, BUCKET(hash), locktype) == -1)
+ return 0;
+ if (!(rec_ptr = tdb_find(tdb, key, hash, rec)))
+ tdb_unlock(tdb, BUCKET(hash), locktype);
+ return rec_ptr;
+}
- /* read in the hash top */
- if (ofs_read(tdb, offset, &rec_ptr) == -1) {
- goto fail;
- }
+enum TDB_ERROR tdb_error(TDB_CONTEXT *tdb)
+{
+ return tdb->ecode;
+}
- if (rec_ptr) break;
+static struct tdb_errname {
+ enum TDB_ERROR ecode; const char *estring;
+} emap[] = { {TDB_SUCCESS, "Success"},
+ {TDB_ERR_CORRUPT, "Corrupt database"},
+ {TDB_ERR_IO, "IO Error"},
+ {TDB_ERR_LOCK, "Locking error"},
+ {TDB_ERR_OOM, "Out of memory"},
+ {TDB_ERR_EXISTS, "Record exists"},
+ {TDB_ERR_NOLOCK, "Lock exists on other keys"},
+ {TDB_ERR_NOEXIST, "Record does not exist"} };
+
+/* Error string for the last tdb error */
+const char *tdb_errorstr(TDB_CONTEXT *tdb)
+{
+ u32 i;
+ for (i = 0; i < sizeof(emap) / sizeof(struct tdb_errname); i++)
+ if (tdb->ecode == emap[i].ecode)
+ return emap[i].estring;
+ return "Invalid error code";
+}
- tdb_unlock(tdb, BUCKET(hash));
- }
+/* update an entry in place - this only works if the new data size
+ is <= the old data size and the key exists.
+ on failure return -1
+*/
+static int tdb_update(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf)
+{
+ struct list_struct rec;
+ tdb_off rec_ptr;
+ int ret = -1;
- if (rec_ptr == 0) return null_data;
+ /* find entry */
+ if (!(rec_ptr = tdb_find_lock(tdb, key, F_WRLCK, &rec)))
+ return -1;
- /* we've found a non-empty chain, now read the record */
- if (rec_read(tdb, rec_ptr, &rec) == -1) {
- goto fail;
+ /* must be long enough key, data and tailer */
+ if (rec.rec_len < key.dsize + dbuf.dsize + sizeof(tdb_off)) {
+ tdb->ecode = TDB_SUCCESS; /* Not really an error */
+ goto out;
}
- /* allocate and read the key space */
- ret.dptr = tdb_alloc_read(tdb, rec_ptr + sizeof(rec), rec.key_len);
- ret.dsize = rec.key_len;
- tdb_unlock(tdb, BUCKET(hash));
+ if (tdb_write(tdb, rec_ptr + sizeof(rec) + rec.key_len,
+ dbuf.dptr, dbuf.dsize) == -1)
+ goto out;
+
+ if (dbuf.dsize != rec.data_len) {
+ /* update size */
+ rec.data_len = dbuf.dsize;
+ ret = rec_write(tdb, rec_ptr, &rec);
+ } else
+ ret = 0;
+ out:
+ tdb_unlock(tdb, BUCKET(rec.full_hash), F_WRLCK);
return ret;
-
- fail:
- tdb_unlock(tdb, BUCKET(hash));
- return null_data;
}
-/* find the next entry in the database, returning its key */
-TDB_DATA tdb_nextkey(TDB_CONTEXT *tdb, TDB_DATA key)
+/* find an entry in the database given a key */
+TDB_DATA tdb_fetch(TDB_CONTEXT *tdb, TDB_DATA key)
{
- unsigned hash, h;
- tdb_off offset, rec_ptr;
+ tdb_off rec_ptr;
struct list_struct rec;
- char *data;
TDB_DATA ret;
/* find which hash bucket it is in */
- hash = tdb_hash(&key);
-
- tdb_lock(tdb, BUCKET(hash));
+ if (!(rec_ptr = tdb_find_lock(tdb,key,F_RDLCK,&rec)))
+ return tdb_null;
- /* find the top of the hash chain */
- offset = tdb_hash_top(tdb, hash);
+ ret.dptr = tdb_alloc_read(tdb, rec_ptr + sizeof(rec) + rec.key_len,
+ rec.data_len);
+ ret.dsize = rec.data_len;
+ tdb_unlock(tdb, BUCKET(rec.full_hash), F_RDLCK);
+ return ret;
+}
- /* read in the hash top */
- if (ofs_read(tdb, offset, &rec_ptr) == -1) {
- goto fail;
- }
+/* check if an entry in the database exists
- /* look until we find the right record */
- while (rec_ptr) {
- if (rec_read(tdb, rec_ptr, &rec) == -1) {
- goto fail;
- }
+ 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
+*/
+int tdb_exists(TDB_CONTEXT *tdb, TDB_DATA key)
+{
+ struct list_struct rec;
+
+ if (tdb_find_lock(tdb, key, F_RDLCK, &rec) == 0)
+ return 0;
+ tdb_unlock(tdb, BUCKET(rec.full_hash), F_RDLCK);
+ return 1;
+}
- if (hash == rec.full_hash && key.dsize == rec.key_len) {
- /* a very likely hit - read the full key */
- data = tdb_alloc_read(tdb, rec_ptr + sizeof(rec),
- rec.key_len);
- if (!data) {
- goto fail;
- }
+/* record lock stops delete underneath */
+static int lock_record(TDB_CONTEXT *tdb, tdb_off off)
+{
+ return off ? tdb_brlock(tdb, off, F_RDLCK, F_SETLKW, 0) : 0;
+}
+/*
+ Write locks override our own fcntl readlocks, so check it here.
+ Note this is meant to be F_SETLK, *not* F_SETLKW, as it's not
+ an error to fail to get the lock here.
+*/
+
+static int write_lock_record(TDB_CONTEXT *tdb, tdb_off off)
+{
+ struct tdb_traverse_lock *i;
+ for (i = &tdb->travlocks; i; i = i->next)
+ if (i->off == off)
+ return -1;
+ return tdb_brlock(tdb, off, F_WRLCK, F_SETLK, 1);
+}
- if (memcmp(key.dptr, data, key.dsize) == 0) {
- /* a definate match - we want the next
- record after this one */
- rec_ptr = rec.next;
- free(data);
- if (rec_ptr == 0) goto next_hash;
- goto found_record;
- }
+/*
+ Note this is meant to be F_SETLK, *not* F_SETLKW, as it's not
+ an error to fail to get the lock here.
+*/
- /* a miss - drat */
- free(data);
- }
+static int write_unlock_record(TDB_CONTEXT *tdb, tdb_off off)
+{
+ return tdb_brlock(tdb, off, F_UNLCK, F_SETLK, 0);
+}
+/* fcntl locks don't stack: avoid unlocking someone else's */
+static int unlock_record(TDB_CONTEXT *tdb, tdb_off off)
+{
+ struct tdb_traverse_lock *i;
+ u32 count = 0;
- /* move to the next record */
- rec_ptr = rec.next;
- }
+ if (off == 0)
+ return 0;
+ for (i = &tdb->travlocks; i; i = i->next)
+ if (i->off == off)
+ count++;
+ return (count == 1 ? tdb_brlock(tdb, off, F_UNLCK, F_SETLKW, 0) : 0);
+}
- next_hash:
- tdb_unlock(tdb, BUCKET(hash));
-
- h = BUCKET(hash);
- if (h == tdb->header.hash_size - 1) return null_data;
-
- /* look for a non-empty hash chain */
- for (hash = h+1, rec_ptr = 0;
- hash < tdb->header.hash_size;
- hash++) {
- /* find the top of the hash chain */
- offset = tdb_hash_top(tdb, hash);
-
- tdb_lock(tdb, BUCKET(hash));
- /* read in the hash top */
- if (ofs_read(tdb, offset, &rec_ptr) == -1) {
- goto fail;
- }
+/* actually delete an entry in the database given the offset */
+static int do_delete(TDB_CONTEXT *tdb, tdb_off rec_ptr, struct list_struct*rec)
+{
+ tdb_off last_ptr, i;
+ struct list_struct lastrec;
- if (rec_ptr) break;
+ if (tdb->read_only) return -1;
- tdb_unlock(tdb, BUCKET(hash));
+ if (write_lock_record(tdb, rec_ptr) == -1) {
+ /* Someone traversing here: mark it as dead */
+ rec->magic = TDB_DEAD_MAGIC;
+ return rec_write(tdb, rec_ptr, rec);
}
+ write_unlock_record(tdb, rec_ptr);
- if (rec_ptr == 0) return null_data;
+ /* find previous record in hash chain */
+ if (ofs_read(tdb, TDB_HASH_TOP(rec->full_hash), &i) == -1)
+ return -1;
+ for (last_ptr = 0; i != rec_ptr; last_ptr = i, i = lastrec.next)
+ if (rec_read(tdb, i, &lastrec) == -1)
+ return -1;
- found_record:
-
- /* we've found a non-empty chain, now read the record */
- if (rec_read(tdb, rec_ptr, &rec) == -1) {
- goto fail;
- }
-
- /* allocate and read the key space */
- ret.dptr = tdb_alloc_read(tdb, rec_ptr + sizeof(rec), rec.key_len);
- ret.dsize = rec.key_len;
- tdb_unlock(tdb, BUCKET(hash));
- return ret;
+ /* unlink it: next ptr is at start of record. */
+ if (last_ptr == 0)
+ last_ptr = TDB_HASH_TOP(rec->full_hash);
+ if (ofs_write(tdb, last_ptr, &rec->next) == -1)
+ return -1;
- fail:
- tdb_unlock(tdb, BUCKET(hash));
- return null_data;
+ /* recover the space */
+ if (tdb_free(tdb, rec_ptr, rec) == -1)
+ return -1;
+ return 0;
}
-/* delete an entry in the database given a key */
-int tdb_delete(TDB_CONTEXT *tdb, TDB_DATA key)
+/* Uses traverse lock: 0 = finish, -1 = error, other = record offset */
+static int tdb_next_lock(TDB_CONTEXT *tdb, struct tdb_traverse_lock *tlock,
+ struct list_struct *rec)
{
- unsigned hash;
- tdb_off offset, rec_ptr, last_ptr;
- struct list_struct rec, lastrec;
- char *data;
+ int want_next = (tlock->off != 0);
- /* find which hash bucket it is in */
- hash = tdb_hash(&key);
+ /* No traversal allows if you've called tdb_lockkeys() */
+ if (tdb->lockedkeys)
+ return TDB_ERRCODE(TDB_ERR_NOLOCK, -1);
- tdb_lock(tdb, BUCKET(hash));
+ /* Lock each chain from the start one. */
+ for (; tlock->hash < tdb->header.hash_size; tlock->hash++) {
+ if (tdb_lock(tdb, tlock->hash, F_WRLCK) == -1)
+ return -1;
- /* find the top of the hash chain */
- offset = tdb_hash_top(tdb, hash);
+ /* No previous record? Start at top of chain. */
+ if (!tlock->off) {
+ if (ofs_read(tdb, TDB_HASH_TOP(tlock->hash),
+ &tlock->off) == -1)
+ goto fail;
+ } else {
+ /* Otherwise unlock the previous record. */
+ unlock_record(tdb, tlock->off);
+ }
- /* read in the hash top */
- if (ofs_read(tdb, offset, &rec_ptr) == -1) {
- goto fail;
+ if (want_next) {
+ /* We have offset of old record: grab next */
+ if (rec_read(tdb, tlock->off, rec) == -1)
+ goto fail;
+ tlock->off = rec->next;
+ }
+
+ /* Iterate through chain */
+ while( tlock->off) {
+ tdb_off current;
+ if (rec_read(tdb, tlock->off, rec) == -1)
+ goto fail;
+ if (!TDB_DEAD(rec)) {
+ /* Woohoo: we found one! */
+ lock_record(tdb, tlock->off);
+ return tlock->off;
+ }
+ /* Try to clean dead ones from old traverses */
+ current = tlock->off;
+ tlock->off = rec->next;
+ do_delete(tdb, current, rec);
+ }
+ tdb_unlock(tdb, tlock->hash, F_WRLCK);
+ want_next = 0;
}
+ /* We finished iteration without finding anything */
+ return TDB_ERRCODE(TDB_SUCCESS, 0);
- last_ptr = 0;
+ fail:
+ tlock->off = 0;
+ tdb_unlock(tdb, tlock->hash, F_WRLCK);
+ return -1;
+}
- /* keep looking until we find the right record */
- while (rec_ptr) {
- if (rec_read(tdb, rec_ptr, &rec) == -1) {
- goto fail;
+/* traverse the entire database - calling fn(tdb, key, data) on each element.
+ return -1 on error or the record count traversed
+ if fn is NULL then it is not called
+ a non-zero return value from fn() indicates that the traversal should stop
+ */
+int tdb_traverse(TDB_CONTEXT *tdb, tdb_traverse_func fn, void *state)
+{
+ TDB_DATA key, dbuf;
+ struct list_struct rec;
+ struct tdb_traverse_lock tl = { NULL, 0, 0 };
+ int ret, count = 0;
+
+ /* This was in the initializaton, above, but the IRIX compiler
+ * did not like it. crh
+ */
+ tl.next = tdb->travlocks.next;
+
+ /* fcntl locks don't stack: beware traverse inside traverse */
+ tdb->travlocks.next = &tl;
+
+ /* tdb_next_lock places locks on the record returned, and its chain */
+ while ((ret = tdb_next_lock(tdb, &tl, &rec)) > 0) {
+ count++;
+ /* now read the full record */
+ key.dptr = tdb_alloc_read(tdb, tl.off + sizeof(rec),
+ rec.key_len + rec.data_len);
+ if (!key.dptr) {
+ tdb_unlock(tdb, tl.hash, F_WRLCK);
+ unlock_record(tdb, tl.off);
+ tdb->travlocks.next = tl.next;
+ return -1;
+ }
+ key.dsize = rec.key_len;
+ dbuf.dptr = key.dptr + rec.key_len;
+ dbuf.dsize = rec.data_len;
+
+ /* Drop chain lock, call out */
+ tdb_unlock(tdb, tl.hash, F_WRLCK);
+ if (fn && fn(tdb, key, dbuf, state)) {
+ /* They want us to terminate traversal */
+ unlock_record(tdb, tl.off);
+ tdb->travlocks.next = tl.next;
+ SAFE_FREE(key.dptr);
+ return count;
}
+ SAFE_FREE(key.dptr);
+ }
+ tdb->travlocks.next = tl.next;
+ if (ret < 0)
+ return -1;
+ else
+ return count;
+}
- if (hash == rec.full_hash && key.dsize == rec.key_len) {
- /* a very likely hit - read the record and full key */
- data = tdb_alloc_read(tdb, rec_ptr + sizeof(rec),
- rec.key_len);
- if (!data) {
- goto fail;
- }
+/* find the first entry in the database and return its key */
+TDB_DATA tdb_firstkey(TDB_CONTEXT *tdb)
+{
+ TDB_DATA key;
+ struct list_struct rec;
- if (memcmp(key.dptr, data, key.dsize) == 0) {
- /* a definate match - delete it */
- if (last_ptr == 0) {
- offset = tdb_hash_top(tdb, hash);
- if (ofs_write(tdb, offset, &rec.next) == -1) {
- goto fail;
- }
- } else {
- lastrec.next = rec.next;
- if (rec_write(tdb, last_ptr, &lastrec) == -1) {
- goto fail;
- }
- }
- tdb_unlock(tdb, BUCKET(hash));
- tdb_lock(tdb, -1);
- /* and recover the space */
- offset = FREELIST_TOP;
- if (ofs_read(tdb, offset, &rec.next) == -1) {
- goto fail2;
- }
- rec.magic = TDB_FREE_MAGIC;
- if (rec_write(tdb, rec_ptr, &rec) == -1) {
- goto fail2;
- }
- if (ofs_write(tdb, offset, &rec_ptr) == -1) {
- goto fail2;
- }
-
- /* yipee - all done */
- free(data);
- tdb_unlock(tdb, -1);
- return 0;
- }
+ /* release any old lock */
+ unlock_record(tdb, tdb->travlocks.off);
+ tdb->travlocks.off = tdb->travlocks.hash = 0;
+
+ if (tdb_next_lock(tdb, &tdb->travlocks, &rec) <= 0)
+ return tdb_null;
+ /* now read the key */
+ key.dsize = rec.key_len;
+ key.dptr =tdb_alloc_read(tdb,tdb->travlocks.off+sizeof(rec),key.dsize);
+ tdb_unlock(tdb, BUCKET(tdb->travlocks.hash), F_WRLCK);
+ return key;
+}
- /* a miss - drat */
- free(data);
- data = NULL;
+/* find the next entry in the database, returning its key */
+TDB_DATA tdb_nextkey(TDB_CONTEXT *tdb, TDB_DATA oldkey)
+{
+ u32 oldhash;
+ TDB_DATA key = tdb_null;
+ struct list_struct rec;
+ char *k = NULL;
+
+ /* Is locked key the old key? If so, traverse will be reliable. */
+ if (tdb->travlocks.off) {
+ if (tdb_lock(tdb,tdb->travlocks.hash,F_WRLCK))
+ return tdb_null;
+ if (rec_read(tdb, tdb->travlocks.off, &rec) == -1
+ || !(k = tdb_alloc_read(tdb,tdb->travlocks.off+sizeof(rec),
+ rec.key_len))
+ || memcmp(k, oldkey.dptr, oldkey.dsize) != 0) {
+ /* No, it wasn't: unlock it and start from scratch */
+ unlock_record(tdb, tdb->travlocks.off);
+ tdb_unlock(tdb, tdb->travlocks.hash, F_WRLCK);
+ tdb->travlocks.off = 0;
}
- /* move to the next record */
- last_ptr = rec_ptr;
- lastrec = rec;
- rec_ptr = rec.next;
+ SAFE_FREE(k);
}
- fail:
- if (data) free(data);
- tdb_unlock(tdb, BUCKET(hash));
- return -1;
-
- fail2:
- if (data) free(data);
- tdb_unlock(tdb, -1);
- return -1;
+ if (!tdb->travlocks.off) {
+ /* No previous element: do normal find, and lock record */
+ tdb->travlocks.off = tdb_find_lock(tdb, oldkey, F_WRLCK, &rec);
+ if (!tdb->travlocks.off)
+ return tdb_null;
+ tdb->travlocks.hash = BUCKET(rec.full_hash);
+ lock_record(tdb, tdb->travlocks.off);
+ }
+ oldhash = tdb->travlocks.hash;
+
+ /* Grab next record: locks chain and returned record,
+ unlocks old record */
+ if (tdb_next_lock(tdb, &tdb->travlocks, &rec) > 0) {
+ key.dsize = rec.key_len;
+ key.dptr = tdb_alloc_read(tdb, tdb->travlocks.off+sizeof(rec),
+ key.dsize);
+ /* Unlock the chain of this new record */
+ tdb_unlock(tdb, tdb->travlocks.hash, F_WRLCK);
+ }
+ /* Unlock the chain of old record */
+ tdb_unlock(tdb, BUCKET(oldhash), F_WRLCK);
+ return key;
}
+/* delete an entry in the database given a key */
+int tdb_delete(TDB_CONTEXT *tdb, TDB_DATA key)
+{
+ tdb_off rec_ptr;
+ struct list_struct rec;
+ int ret;
+
+ if (!(rec_ptr = tdb_find_lock(tdb, key, F_WRLCK, &rec)))
+ return -1;
+ ret = do_delete(tdb, rec_ptr, &rec);
+ tdb_unlock(tdb, BUCKET(rec.full_hash), F_WRLCK);
+ return ret;
+}
/* store an element in the database, replacing any existing element
with the same key
int tdb_store(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, int flag)
{
struct list_struct rec;
- char *data = NULL;
- unsigned hash;
- tdb_off rec_ptr, offset;
+ u32 hash;
+ tdb_off rec_ptr;
+ char *p = NULL;
+ int ret = 0;
/* find which hash bucket it is in */
hash = tdb_hash(&key);
-
- /* check for it existing */
- if (flag == TDB_INSERT && tdb_exists(tdb, key)) {
+ if (!tdb_keylocked(tdb, hash))
return -1;
- }
-
- /* first try in-place update */
- if (flag != TDB_INSERT && tdb_update(tdb, key, dbuf) == 0) {
- return 0;
- }
-
- rec_ptr = tdb_allocate(tdb, key.dsize + dbuf.dsize);
- if (rec_ptr == 0) {
+ if (tdb_lock(tdb, BUCKET(hash), F_WRLCK) == -1)
return -1;
- }
- tdb_lock(tdb, BUCKET(hash));
+ /* check for it existing, on insert. */
+ if (flag == TDB_INSERT) {
+ if (tdb_exists(tdb, key)) {
+ tdb->ecode = TDB_ERR_EXISTS;
+ goto fail;
+ }
+ } else {
+ /* first try in-place update, on modify or replace. */
+ if (tdb_update(tdb, key, dbuf) == 0)
+ goto out;
+ if (flag == TDB_MODIFY && tdb->ecode == TDB_ERR_NOEXIST)
+ goto fail;
+ }
+ /* reset the error code potentially set by the tdb_update() */
+ tdb->ecode = TDB_SUCCESS;
- /* delete any existing record - if it doesn't exist we don't care */
- if (flag != TDB_INSERT) {
+ /* delete any existing record - if it doesn't exist we don't
+ care. Doing this first reduces fragmentation, and avoids
+ coalescing with `allocated' block before it's updated. */
+ if (flag != TDB_INSERT)
tdb_delete(tdb, key);
- }
- /* read the newly created record */
- if (tdb_read(tdb, rec_ptr, (char *)&rec, sizeof(rec)) == -1) {
+ /* Copy key+value *before* allocating free space in case malloc
+ fails and we are left with a dead spot in the tdb. */
+
+ if (!(p = (char *)malloc(key.dsize + dbuf.dsize))) {
+ tdb->ecode = TDB_ERR_OOM;
goto fail;
}
- if (rec.magic != TDB_FREE_MAGIC) goto fail;
+ memcpy(p, key.dptr, key.dsize);
+ memcpy(p+key.dsize, dbuf.dptr, dbuf.dsize);
- /* find the top of the hash chain */
- offset = tdb_hash_top(tdb, hash);
+ /* now we're into insert / modify / replace of a record which
+ * we know could not be optimised by an in-place store (for
+ * various reasons). */
+ if (!(rec_ptr = tdb_allocate(tdb, key.dsize + dbuf.dsize, &rec)))
+ goto fail;
- /* read in the hash top diretcly into our next pointer */
- if (ofs_read(tdb, offset, &rec.next) == -1) {
+ /* Read hash top into next ptr */
+ if (ofs_read(tdb, TDB_HASH_TOP(hash), &rec.next) == -1)
goto fail;
- }
rec.key_len = key.dsize;
rec.data_len = dbuf.dsize;
rec.full_hash = hash;
rec.magic = TDB_MAGIC;
- /* write the new record */
- if (rec_write(tdb, rec_ptr, &rec) == -1) goto fail;
- if (tdb_write(tdb, rec_ptr + sizeof(rec), key.dptr, key.dsize) == -1) goto fail;
- if (tdb_write(tdb, rec_ptr + sizeof(rec) + key.dsize, dbuf.dptr, dbuf.dsize) == -1) goto fail;
+ /* write out and point the top of the hash chain at it */
+ if (rec_write(tdb, rec_ptr, &rec) == -1
+ || tdb_write(tdb, rec_ptr+sizeof(rec), p, key.dsize+dbuf.dsize)==-1
+ || ofs_write(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) {
+ fail:
+ /* Need to tdb_unallocate() here */
+ ret = -1;
+ }
+ out:
+ SAFE_FREE(p);
+ tdb_unlock(tdb, BUCKET(hash), F_WRLCK);
+ return ret;
+}
- /* and point the top of the hash chain at it */
- if (ofs_write(tdb, offset, &rec_ptr) == -1) goto fail;
+static int tdb_already_open(dev_t device,
+ ino_t ino)
+{
+ TDB_CONTEXT *i;
+
+ for (i = tdbs; i; i = i->next) {
+ if (i->device == device && i->inode == ino) {
+ return 1;
+ }
+ }
- tdb_unlock(tdb, BUCKET(hash));
return 0;
-
- fail:
-#if TDB_DEBUG
- printf("store failed for hash 0x%08x in bucket %u\n", hash, BUCKET(hash));
-#endif
- if (data) free(data);
- tdb_unlock(tdb, BUCKET(hash));
- return -1;
}
-
/* open the database, creating it if necessary
- The flags and mode are passed straight to the open call on the database
- file. A flags value of O_WRONLY is invalid
+ 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.
- The hash size is advisory, use zero for a default value.
+ Return is NULL on error, in which case errno is also set. Don't
+ try to call tdb_error or tdb_errname, just do strerror(errno).
- return is NULL on error
-*/
-TDB_CONTEXT *tdb_open(char *name, int hash_size, int flags, mode_t mode)
+ @param name may be NULL for internal databases. */
+TDB_CONTEXT *tdb_open(const char *name, int hash_size, int tdb_flags,
+ int open_flags, mode_t mode)
{
- TDB_CONTEXT tdb, *ret;
- struct stat st;
+ return tdb_open_ex(name, hash_size, tdb_flags, open_flags, mode, NULL);
+}
- tdb.fd = -1;
- tdb.name = NULL;
- tdb.map_ptr = NULL;
- if ((flags & O_ACCMODE) == O_WRONLY) goto fail;
+TDB_CONTEXT *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
+ int open_flags, mode_t mode,
+ tdb_log_func log_fn)
+{
+ TDB_CONTEXT *tdb;
+ struct stat st;
+ int rev = 0, locked;
- if (hash_size == 0) hash_size = DEFAULT_HASH_SIZE;
+ if (!(tdb = calloc(1, sizeof *tdb))) {
+ /* Can't log this */
+ errno = ENOMEM;
+ goto fail;
+ }
+ tdb->fd = -1;
+ tdb->name = NULL;
+ tdb->map_ptr = NULL;
+ tdb->lockedkeys = NULL;
+ tdb->flags = tdb_flags;
+ tdb->open_flags = open_flags;
+ tdb->log_fn = log_fn;
+
+ if ((open_flags & O_ACCMODE) == O_WRONLY) {
+ TDB_LOG((tdb, 0, "tdb_open_ex: can't open tdb %s write-only\n",
+ name));
+ errno = EINVAL;
+ goto fail;
+ }
+
+ if (hash_size == 0)
+ hash_size = DEFAULT_HASH_SIZE;
+ if ((open_flags & O_ACCMODE) == O_RDONLY) {
+ tdb->read_only = 1;
+ /* read only databases don't do locking or clear if first */
+ tdb->flags |= TDB_NOLOCK;
+ tdb->flags &= ~TDB_CLEAR_IF_FIRST;
+ }
- memset(&tdb, 0, sizeof(tdb));
+ /* internal databases don't mmap or lock, and start off cleared */
+ if (tdb->flags & TDB_INTERNAL) {
+ tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP);
+ tdb->flags &= ~TDB_CLEAR_IF_FIRST;
+ tdb_new_database(tdb, hash_size);
+ goto internal;
+ }
- tdb.fd = open(name, flags, mode);
- if (tdb.fd == -1) goto fail;
+ if ((tdb->fd = open(name, open_flags, mode)) == -1) {
+ TDB_LOG((tdb, 0, "tdb_open_ex: could not open file %s: %s\n",
+ name, strerror(errno)));
+ goto fail; /* errno set by open(2) */
+ }
- tdb_brlock(&tdb, 0, 1);
+ /* ensure there is only one process initialising at once */
+ if (tdb_brlock(tdb, GLOBAL_LOCK, F_WRLCK, F_SETLKW, 0) == -1) {
+ TDB_LOG((tdb, 0, "tdb_open_ex: failed to get global lock on %s: %s\n",
+ name, strerror(errno)));
+ goto fail; /* errno set by tdb_brlock */
+ }
+
+ /* we need to zero database if we are the only one with it open */
+ if ((locked = (tdb_brlock(tdb, ACTIVE_LOCK, F_WRLCK, F_SETLK, 0) == 0))
+ && (tdb_flags & TDB_CLEAR_IF_FIRST)) {
+ open_flags |= O_CREAT;
+ if (ftruncate(tdb->fd, 0) == -1) {
+ TDB_LOG((tdb, 0, "tdb_open_ex: "
+ "failed to truncate %s: %s\n",
+ name, strerror(errno)));
+ goto fail; /* errno set by ftruncate */
+ }
+ }
- if (read(tdb.fd, &tdb.header, sizeof(tdb.header)) != sizeof(tdb.header) ||
- tdb.header.version != TDB_VERSION) {
+ if (read(tdb->fd, &tdb->header, sizeof(tdb->header)) != sizeof(tdb->header)
+ || strcmp(tdb->header.magic_food, TDB_MAGIC_FOOD) != 0
+ || (tdb->header.version != TDB_VERSION
+ && !(rev = (tdb->header.version==TDB_BYTEREV(TDB_VERSION))))) {
/* its not a valid database - possibly initialise it */
- if (!(flags & O_CREAT)) {
+ if (!(open_flags & O_CREAT) || tdb_new_database(tdb, hash_size) == -1) {
+ errno = EIO; /* ie bad format or something */
goto fail;
}
- if (tdb_new_database(&tdb, hash_size) == -1) goto fail;
-
- lseek(tdb.fd, 0, SEEK_SET);
- if (read(tdb.fd, &tdb.header, sizeof(tdb.header)) != sizeof(tdb.header)) goto fail;
+ rev = (tdb->flags & TDB_CONVERT);
}
+ if (!rev)
+ tdb->flags &= ~TDB_CONVERT;
+ else {
+ tdb->flags |= TDB_CONVERT;
+ convert(&tdb->header, sizeof(tdb->header));
+ }
+ if (fstat(tdb->fd, &st) == -1)
+ goto fail;
- fstat(tdb.fd, &st);
-
- /* map the database and fill in the return structure */
- tdb.name = (char *)strdup(name);
- tdb.locked = (int *)calloc(tdb.header.hash_size+1,
- sizeof(tdb.locked[0]));
- if (!tdb.locked) goto fail;
- tdb.map_size = st.st_size;
- tdb.read_only = ((flags & O_ACCMODE) == O_RDONLY);
-#if HAVE_MMAP
- tdb.map_ptr = (void *)mmap(NULL, st.st_size,
- tdb.read_only? PROT_READ : PROT_READ|PROT_WRITE,
- MAP_SHARED | MAP_FILE, tdb.fd, 0);
-#endif
-
- ret = (TDB_CONTEXT *)malloc(sizeof(tdb));
- if (!ret) goto fail;
+ /* Is it already in the open list? If so, fail. */
+ if (tdb_already_open(st.st_dev, st.st_ino)) {
+ TDB_LOG((tdb, 2, "tdb_open_ex: "
+ "%s (%d,%d) is already open in this process\n",
+ name, st.st_dev, st.st_ino));
+ errno = EBUSY;
+ goto fail;
+ }
- *ret = tdb;
+ if (!(tdb->name = (char *)strdup(name))) {
+ errno = ENOMEM;
+ goto fail;
+ }
-#if TDB_DEBUG
- printf("mapped database of hash_size %u map_size=%u\n",
- hash_size, tdb.map_size);
-#endif
+ tdb->map_size = st.st_size;
+ tdb->device = st.st_dev;
+ tdb->inode = st.st_ino;
+ tdb->locked = calloc(tdb->header.hash_size+1, sizeof(tdb->locked[0]));
+ if (!tdb->locked) {
+ TDB_LOG((tdb, 2, "tdb_open_ex: "
+ "failed to allocate lock structure for %s\n",
+ name));
+ errno = ENOMEM;
+ goto fail;
+ }
+ tdb_mmap(tdb);
+ if (locked) {
+ if (!tdb->read_only)
+ tdb_clear_spinlocks(tdb);
+ if (tdb_brlock(tdb, ACTIVE_LOCK, F_UNLCK, F_SETLK, 0) == -1) {
+ TDB_LOG((tdb, 0, "tdb_open_ex: "
+ "failed to take ACTIVE_LOCK on %s: %s\n",
+ name, strerror(errno)));
+ goto fail;
+ }
+ }
+ /* leave this lock in place to indicate it's in use */
+ if (tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0) == -1)
+ goto fail;
- tdb_brlock(&tdb, 0, 0);
- return ret;
+ internal:
+ /* Internal (memory-only) databases skip all the code above to
+ * do with disk files, and resume here by releasing their
+ * global lock and hooking into the active list. */
+ if (tdb_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0) == -1)
+ goto fail;
+ tdb->next = tdbs;
+ tdbs = tdb;
+ return tdb;
fail:
- tdb_brlock(&tdb, 0, 0);
- if (tdb.name) free(tdb.name);
- if (tdb.fd != -1) close(tdb.fd);
- if (tdb.map_ptr) munmap(tdb.map_ptr, tdb.map_size);
+ { int save_errno = errno;
+ if (!tdb)
+ return NULL;
+
+ if (tdb->map_ptr) {
+ if (tdb->flags & TDB_INTERNAL)
+ SAFE_FREE(tdb->map_ptr);
+ else
+ tdb_munmap(tdb);
+ }
+ SAFE_FREE(tdb->name);
+ if (tdb->fd != -1)
+ close(tdb->fd);
+ SAFE_FREE(tdb->locked);
+ errno = save_errno;
return NULL;
+ }
}
/* close a database */
int tdb_close(TDB_CONTEXT *tdb)
{
- if (!tdb) return -1;
+ TDB_CONTEXT **i;
+ int ret = 0;
- if (tdb->name) free(tdb->name);
- if (tdb->fd != -1) close(tdb->fd);
- if (tdb->map_ptr) munmap(tdb->map_ptr, tdb->map_size);
- if (tdb->locked) free(tdb->locked);
+ if (tdb->map_ptr) {
+ if (tdb->flags & TDB_INTERNAL)
+ SAFE_FREE(tdb->map_ptr);
+ else
+ tdb_munmap(tdb);
+ }
+ SAFE_FREE(tdb->name);
+ if (tdb->fd != -1)
+ ret = close(tdb->fd);
+ SAFE_FREE(tdb->locked);
+ SAFE_FREE(tdb->lockedkeys);
+
+ /* Remove from contexts list */
+ for (i = &tdbs; *i; i = &(*i)->next) {
+ if (*i == tdb) {
+ *i = tdb->next;
+ break;
+ }
+ }
memset(tdb, 0, sizeof(*tdb));
- free(tdb);
+ SAFE_FREE(tdb);
+
+ return ret;
+}
+
+/* lock/unlock entire database */
+int tdb_lockall(TDB_CONTEXT *tdb)
+{
+ u32 i;
+
+ /* There are no locks on read-only dbs */
+ if (tdb->read_only)
+ return TDB_ERRCODE(TDB_ERR_LOCK, -1);
+ if (tdb->lockedkeys)
+ return TDB_ERRCODE(TDB_ERR_NOLOCK, -1);
+ for (i = 0; i < tdb->header.hash_size; i++)
+ if (tdb_lock(tdb, i, F_WRLCK))
+ break;
+
+ /* If error, release locks we have... */
+ if (i < tdb->header.hash_size) {
+ u32 j;
+
+ for ( j = 0; j < i; j++)
+ tdb_unlock(tdb, j, F_WRLCK);
+ return TDB_ERRCODE(TDB_ERR_NOLOCK, -1);
+ }
return 0;
}
+void tdb_unlockall(TDB_CONTEXT *tdb)
+{
+ u32 i;
+ for (i=0; i < tdb->header.hash_size; i++)
+ tdb_unlock(tdb, i, F_WRLCK);
+}
-/* lock the database. If we already have it locked then don't do anything */
-int tdb_writelock(TDB_CONTEXT *tdb)
+int tdb_lockkeys(TDB_CONTEXT *tdb, u32 number, TDB_DATA keys[])
{
- return tdb_lock(tdb, -1);
+ u32 i, j, hash;
+
+ /* Can't lock more keys if already locked */
+ if (tdb->lockedkeys)
+ return TDB_ERRCODE(TDB_ERR_NOLOCK, -1);
+ if (!(tdb->lockedkeys = malloc(sizeof(u32) * (number+1))))
+ return TDB_ERRCODE(TDB_ERR_OOM, -1);
+ /* First number in array is # keys */
+ tdb->lockedkeys[0] = number;
+
+ /* Insertion sort by bucket */
+ for (i = 0; i < number; i++) {
+ hash = tdb_hash(&keys[i]);
+ for (j = 0; j < i && BUCKET(tdb->lockedkeys[j+1]) < BUCKET(hash); j++);
+ memmove(&tdb->lockedkeys[j+2], &tdb->lockedkeys[j+1], sizeof(u32) * (i-j));
+ tdb->lockedkeys[j+1] = hash;
+ }
+ /* Finally, lock in order */
+ for (i = 0; i < number; i++)
+ if (tdb_lock(tdb, i, F_WRLCK))
+ break;
+
+ /* If error, release locks we have... */
+ if (i < number) {
+ for ( j = 0; j < i; j++)
+ tdb_unlock(tdb, j, F_WRLCK);
+ SAFE_FREE(tdb->lockedkeys);
+ return TDB_ERRCODE(TDB_ERR_NOLOCK, -1);
+ }
+ return 0;
}
-/* unlock the database. */
-int tdb_writeunlock(TDB_CONTEXT *tdb)
+/* Unlock the keys previously locked by tdb_lockkeys() */
+void tdb_unlockkeys(TDB_CONTEXT *tdb)
{
- return tdb_unlock(tdb, -1);
+ u32 i;
+ for (i = 0; i < tdb->lockedkeys[0]; i++)
+ tdb_unlock(tdb, tdb->lockedkeys[i+1], F_WRLCK);
+ SAFE_FREE(tdb->lockedkeys);
}
-/* lock one hash chain. This is meant to be used to reduce locking
+/* lock/unlock one hash chain. This is meant to be used to reduce
contention - it cannot guarantee how many records will be locked */
-int tdb_lockchain(TDB_CONTEXT *tdb, TDB_DATA key)
+int tdb_chainlock(TDB_CONTEXT *tdb, TDB_DATA key)
{
- return tdb_lock(tdb, BUCKET(tdb_hash(&key)));
+ return tdb_lock(tdb, BUCKET(tdb_hash(&key)), F_WRLCK);
+}
+void tdb_chainunlock(TDB_CONTEXT *tdb, TDB_DATA key)
+{
+ tdb_unlock(tdb, BUCKET(tdb_hash(&key)), F_WRLCK);
}
-/* unlock one hash chain */
-int tdb_unlockchain(TDB_CONTEXT *tdb, TDB_DATA key)
+/* register a loging function */
+void tdb_logging_function(TDB_CONTEXT *tdb, void (*fn)(TDB_CONTEXT *, int , const char *, ...))
{
- return tdb_unlock(tdb, BUCKET(tdb_hash(&key)));
+ tdb->log_fn = fn;
+}
+
+
+/* reopen a tdb - this is used after a fork to ensure that we have an independent
+ seek pointer from our parent and to re-establish locks */
+int tdb_reopen(TDB_CONTEXT *tdb)
+{
+ struct stat st;
+
+ tdb_munmap(tdb);
+ close(tdb->fd);
+ tdb->fd = open(tdb->name, tdb->open_flags & ~(O_CREAT|O_TRUNC), 0);
+ if (tdb->fd == -1) {
+ TDB_LOG((tdb, 0, "tdb_reopen: open failed (%s)\n", strerror(errno)));
+ goto fail;
+ }
+ fstat(tdb->fd, &st);
+ if (st.st_ino != tdb->inode || st.st_dev != tdb->device) {
+ TDB_LOG((tdb, 0, "tdb_reopen: file dev/inode has changed!\n"));
+ goto fail;
+ }
+ tdb_mmap(tdb);
+ if (tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0) == -1) {
+ TDB_LOG((tdb, 0, "tdb_reopen: failed to obtain active lock\n"));
+ goto fail;
+ }
+
+ return 0;
+
+fail:
+ tdb_close(tdb);
+ return -1;
+}
+
+/* reopen all tdb's */
+int tdb_reopen_all(void)
+{
+ TDB_CONTEXT *tdb;
+
+ for (tdb=tdbs; tdb; tdb = tdb->next) {
+ if (tdb_reopen(tdb) != 0) return -1;
+ }
+
+ return 0;
}
git.samba.org / ira / wip.git / blobdiff