diff options
Diffstat (limited to 'source3/tdb')
| -rw-r--r-- | source3/tdb/Makefile | 10 | ||||
| -rw-r--r-- | source3/tdb/spinlock.c | 403 | ||||
| -rw-r--r-- | source3/tdb/spinlock.h | 55 | ||||
| -rw-r--r-- | source3/tdb/tdb.c | 1730 | ||||
| -rw-r--r-- | source3/tdb/tdb.h | 111 | ||||
| -rw-r--r-- | source3/tdb/tdbutil.c | 4 |
6 files changed, 1255 insertions, 1058 deletions
diff --git a/source3/tdb/Makefile b/source3/tdb/Makefile index d9b0e05f4d..01de7d244b 100644 --- a/source3/tdb/Makefile +++ b/source3/tdb/Makefile @@ -8,14 +8,14 @@ PROGS = tdbtest tdbtool tdbtorture default: $(PROGS) -tdbtest: tdbtest.o tdb.o - $(CC) $(CFLAGS) -o tdbtest tdbtest.o tdb.o -lgdbm +tdbtest: tdbtest.o tdb.o spinlock.o + $(CC) $(CFLAGS) -o tdbtest tdbtest.o tdb.o spinlock.o -lgdbm -tdbtool: tdbtool.o tdb.o - $(CC) $(CFLAGS) -o tdbtool tdbtool.o tdb.o +tdbtool: tdbtool.o tdb.o spinlock.o + $(CC) $(CFLAGS) -o tdbtool tdbtool.o tdb.o spinlock.o tdbtorture: tdbtorture.o tdb.o - $(CC) $(CFLAGS) -o tdbtorture tdbtorture.o tdb.o + $(CC) $(CFLAGS) -o tdbtorture tdbtorture.o tdb.o spinlock.o clean: rm -f $(PROGS) *.o *~ *% core test.db test.tdb test.gdbm diff --git a/source3/tdb/spinlock.c b/source3/tdb/spinlock.c new file mode 100644 index 0000000000..731188a153 --- /dev/null +++ b/source3/tdb/spinlock.c @@ -0,0 +1,403 @@ +#if STANDALONE +#if HAVE_CONFIG_H +#include <config.h> +#endif + +#include <stdlib.h> +#include <stdio.h> +#include <unistd.h> +#include <string.h> +#include <fcntl.h> +#include <errno.h> +#include <sys/stat.h> +#include <time.h> +#include "tdb.h" +#include "spinlock.h" + +#define DEBUG +#else +#include "includes.h" +#endif + +#ifdef USE_SPINLOCKS + +/* + * ARCH SPECIFIC + */ + +#if defined(SPARC_SPINLOCKS) + +static inline int __spin_trylock(spinlock_t *lock) +{ + unsigned int result; + + asm volatile("ldstub [%1], %0" + : "=r" (result) + : "r" (lock) + : "memory"); + + return (result == 0) ? 0 : EBUSY; +} + +static inline void __spin_unlock(spinlock_t *lock) +{ + *lock = 0; +} + +static inline void __spin_lock_init(spinlock_t *lock) +{ + *lock = 0; +} + +static inline int __spin_is_locked(spinlock_t *lock) +{ + return (*lock != 0); +} + +#elif defined(POWERPC_SPINLOCKS) + +static inline int __spin_trylock(spinlock_t *lock) +{ + int result; + + __asm__ __volatile__ ( + " eieio;" + "0: lwarx %0,0,%1;" + " cmpwi 0,%0,0;" + " bne- 1f;" + " stwcx. %2,0,%1;" + " bne- 0b;" + " sync;" + "1:" + : "=&r"(result) + : "r"(lock), "r"(1) + : "cr0", "memory"); + + return (result == 0) ? 0 : EBUSY; +} + +static inline void __spin_unlock(spinlock_t *lock) +{ + asm volatile("sync"); + *lock = 0; +} + +static inline void __spin_lock_init(spinlock_t *lock) +{ + *lock = 0; +} + +static inline int __spin_is_locked(spinlock_t *lock) +{ + return (*lock != 0); +} + +#elif defined(INTEL_SPINLOCKS) + +static inline int __spin_trylock(spinlock_t *lock) +{ + int oldval; + + asm volatile("xchgl %0,%1" + : "=r" (oldval), "=m" (*lock) + : "0" (0)); + return oldval > 0 ? 0 : EBUSY; +} + +static inline void __spin_unlock(spinlock_t *lock) +{ + *lock = 1; +} + +static inline void __spin_lock_init(spinlock_t *lock) +{ + *lock = 1; +} + +static inline int __spin_is_locked(spinlock_t *lock) +{ + return (*lock != 1); +} + +#elif defined(MIPS_SPINLOCKS) + +static inline unsigned int load_linked(unsigned long addr) +{ + unsigned int res; + + __asm__ __volatile__("ll\t%0,(%1)" + : "=r" (res) + : "r" (addr)); + + return res; +} + +static inline unsigned int store_conditional(unsigned long addr, unsigned int value) +{ + unsigned int res; + + __asm__ __volatile__("sc\t%0,(%2)" + : "=r" (res) + : "0" (value), "r" (addr)); + return res; +} + +static inline int __spin_trylock(spinlock_t *lock) +{ + unsigned int mw; + + do { + mw = load_linked(lock); + if (mw) + return EBUSY; + } while (!store_conditional(lock, 1)); + + return 0; +} + +static inline void __spin_unlock(spinlock_t *lock) +{ + *lock = 0; +} + +static inline void __spin_lock_init(spinlock_t *lock) +{ + *lock = 0; +} + +static inline int __spin_is_locked(spinlock_t *lock) +{ + return (*lock != 0); +} + +#else +#error Need to implement spinlock code in spinlock.c +#endif + +/* + * OS SPECIFIC + */ + +static void yield_cpu(void) +{ + struct timespec tm; + +#ifdef USE_SCHED_YIELD + sched_yield(); +#else + /* Linux will busy loop for delays < 2ms on real time tasks */ + tm.tv_sec = 0; + tm.tv_nsec = 2000000L + 1; + nanosleep(&tm, NULL); +#endif +} + +static int this_is_smp(void) +{ + return 0; +} + +/* + * GENERIC + */ + +static int smp_machine = 0; + +static inline void __spin_lock(spinlock_t *lock) +{ + int ntries = 0; + + while(__spin_trylock(lock)) { + while(__spin_is_locked(lock)) { + if (smp_machine && ntries++ < MAX_BUSY_LOOPS) + continue; + yield_cpu(); + } + } +} + +static void __read_lock(rwlock_t *rwlock) +{ + int ntries = 0; + + while(1) { + __spin_lock(&rwlock->lock); + + if (!(rwlock->count & RWLOCK_BIAS)) { + rwlock->count++; + __spin_unlock(&rwlock->lock); + return; + } + + __spin_unlock(&rwlock->lock); + + while(rwlock->count & RWLOCK_BIAS) { + if (smp_machine && ntries++ < MAX_BUSY_LOOPS) + continue; + yield_cpu(); + } + } +} + +static void __write_lock(rwlock_t *rwlock) +{ + int ntries = 0; + + while(1) { + __spin_lock(&rwlock->lock); + + if (rwlock->count == 0) { + rwlock->count |= RWLOCK_BIAS; + __spin_unlock(&rwlock->lock); + return; + } + + __spin_unlock(&rwlock->lock); + + while(rwlock->count != 0) { + if (smp_machine && ntries++ < MAX_BUSY_LOOPS) + continue; + yield_cpu(); + } + } +} + +static void __write_unlock(rwlock_t *rwlock) +{ + __spin_lock(&rwlock->lock); + +#ifdef DEBUG + if (!(rwlock->count & RWLOCK_BIAS)) + fprintf(stderr, "bug: write_unlock\n"); +#endif + + rwlock->count &= ~RWLOCK_BIAS; + __spin_unlock(&rwlock->lock); +} + +static void __read_unlock(rwlock_t *rwlock) +{ + __spin_lock(&rwlock->lock); + +#ifdef DEBUG + if (!rwlock->count) + fprintf(stderr, "bug: read_unlock\n"); + + if (rwlock->count & RWLOCK_BIAS) + fprintf(stderr, "bug: read_unlock\n"); +#endif + + rwlock->count--; + __spin_unlock(&rwlock->lock); +} + +/* TDB SPECIFIC */ + +/* lock a list in the database. list -1 is the alloc list */ +int tdb_spinlock(TDB_CONTEXT *tdb, int list, int rw_type) +{ + rwlock_t *rwlocks; + + if (!tdb->map_ptr) return -1; + rwlocks = (rwlock_t *)((char *)tdb->map_ptr + tdb->header.rwlocks); + + switch(rw_type) { + case F_RDLCK: + __read_lock(&rwlocks[list+1]); + break; + + case F_WRLCK: + __write_lock(&rwlocks[list+1]); + break; + + default: + return TDB_ERRCODE(TDB_ERR_LOCK, -1); + } + return 0; +} + +/* unlock the database. */ +int tdb_spinunlock(TDB_CONTEXT *tdb, int list, int rw_type) +{ + rwlock_t *rwlocks; + + if (!tdb->map_ptr) return -1; + rwlocks = (rwlock_t *)((char *)tdb->map_ptr + tdb->header.rwlocks); + + switch(rw_type) { + case F_RDLCK: + __read_unlock(&rwlocks[list+1]); + break; + + case F_WRLCK: + __write_unlock(&rwlocks[list+1]); + break; + + default: + return TDB_ERRCODE(TDB_ERR_LOCK, -1); + } + + return 0; +} + +int tdb_create_rwlocks(int fd, unsigned int hash_size) +{ + unsigned size, i; + rwlock_t *rwlocks; + + size = (hash_size + 1) * sizeof(rwlock_t); + rwlocks = malloc(size); + if (!rwlocks) + return -1; + + for(i = 0; i < hash_size+1; i++) { + __spin_lock_init(&rwlocks[i].lock); + rwlocks[i].count = 0; + } + + /* Write it out (appending to end) */ + if (write(fd, rwlocks, size) != size) { + free(rwlocks); + return -1; + } + smp_machine = this_is_smp(); + free(rwlocks); + return 0; +} + +int tdb_clear_spinlocks(TDB_CONTEXT *tdb) +{ + rwlock_t *rwlocks; + unsigned i; + + if (tdb->header.rwlocks == 0) return 0; + if (!tdb->map_ptr) return -1; + + /* We're mmapped here */ + rwlocks = (rwlock_t *)((char *)tdb->map_ptr + tdb->header.rwlocks); + for(i = 0; i < tdb->header.hash_size+1; i++) { + __spin_lock_init(&rwlocks[i].lock); + rwlocks[i].count = 0; + } + return 0; +} +#else +int tdb_create_rwlocks(int fd, unsigned int hash_size) { return 0; } +int tdb_spinlock(TDB_CONTEXT *tdb, int list, int rw_type) { return -1; } +int tdb_spinunlock(TDB_CONTEXT *tdb, int list, int rw_type) { return -1; } + +/* Non-spinlock version: remove spinlock pointer */ +int tdb_clear_spinlocks(TDB_CONTEXT *tdb) +{ + tdb_off off = (tdb_off)((char *)&tdb->header.rwlocks + - (char *)&tdb->header); + + tdb->header.rwlocks = 0; + if (lseek(tdb->fd, off, SEEK_SET) != off + || write(tdb->fd, (void *)&tdb->header.rwlocks, + sizeof(tdb->header.rwlocks)) + != sizeof(tdb->header.rwlocks)) + return -1; + return 0; +} +#endif diff --git a/source3/tdb/spinlock.h b/source3/tdb/spinlock.h new file mode 100644 index 0000000000..a0dd9cbca5 --- /dev/null +++ b/source3/tdb/spinlock.h @@ -0,0 +1,55 @@ +#ifndef __SPINLOCK_H__ +#define __SPINLOCK_H__ + +#if HAVE_CONFIG_H +#include <config.h> +#endif + +#include "tdb.h" + +#ifdef USE_SPINLOCKS + +#define RWLOCK_BIAS 0x1000UL + +/* OS SPECIFIC */ +#define MAX_BUSY_LOOPS 1000 +#undef USE_SCHED_YIELD + +/* ARCH SPECIFIC */ +/* We should make sure these are padded to a cache line */ +#if defined(SPARC_SPINLOCKS) +typedef volatile char spinlock_t; +#elif defined(POWERPC_SPINLOCKS) +typedef volatile unsigned long spinlock_t; +#elif defined(INTEL_SPINLOCKS) +typedef volatile int spinlock_t; +#elif defined(MIPS_SPINLOCKS) +typedef volatile unsigned long spinlock_t; +#else +#error Need to implement spinlock code in spinlock.h +#endif + +typedef struct { + spinlock_t lock; + volatile int count; +} rwlock_t; + +int tdb_spinlock(TDB_CONTEXT *tdb, int list, int rw_type); +int tdb_spinunlock(TDB_CONTEXT *tdb, int list, int rw_type); +int tdb_create_rwlocks(int fd, unsigned int hash_size); +int tdb_clear_spinlocks(TDB_CONTEXT *tdb); + +#else /* !USE_SPINLOCKS */ +#if 0 +#define tdb_create_rwlocks(fd, hash_size) 0 +#define tdb_spinlock(tdb, list, rw_type) (-1) +#define tdb_spinunlock(tdb, list, rw_type) (-1) +#else +int tdb_spinlock(TDB_CONTEXT *tdb, int list, int rw_type); +int tdb_spinunlock(TDB_CONTEXT *tdb, int list, int rw_type); +int tdb_create_rwlocks(int fd, unsigned int hash_size); +#endif +int tdb_clear_spinlocks(TDB_CONTEXT *tdb); +#endif + +#endif diff --git a/source3/tdb/tdb.c b/source3/tdb/tdb.c index d142649adf..1e66fe1419 100644 --- a/source3/tdb/tdb.c +++ b/source3/tdb/tdb.c @@ -4,7 +4,8 @@ Samba database functions Copyright (C) Andrew Tridgell 1999-2000 Copyright (C) Luke Kenneth Casson Leighton 2000 - Copyright (C) Jeremy Allison 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 @@ -22,6 +23,10 @@ */ #if STANDALONE +#if HAVE_CONFIG_H +#include <config.h> +#endif + #include <stdlib.h> #include <stdio.h> #include <fcntl.h> @@ -32,55 +37,88 @@ #include <sys/mman.h> #include <sys/stat.h> #include "tdb.h" +#include "spinlock.h" #else #include "includes.h" #endif -#define TDB_VERSION (0x26011967 + 3) +#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 4 -#define MIN_REC_SIZE (2*sizeof(struct list_struct) + 200) +#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)) & ~((a)-1)) +#define TDB_BYTEREV(x) (((x<<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)) /* lock offsets */ #define GLOBAL_LOCK 0 #define ACTIVE_LOCK 4 -#define LIST_LOCK_BASE 1024 - -#define BUCKET(hash) ((hash) % tdb->header.hash_size) #ifndef MAP_FILE #define MAP_FILE 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(void *ptr, tdb_len size) +{ +#ifdef HAVE_MMAP + munmap(ptr, size); +#endif + return NULL; +} + +static void *tdb_mmap(tdb_len size, int readonly, int fd) +{ + void *ret = NULL; +#ifdef HAVE_MMAP + ret = mmap(NULL, size, PROT_READ | (readonly ? 0 : PROT_WRITE), MAP_SHARED|MAP_FILE, fd, 0); +#endif + return ret; +} + +/* 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 + 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; - /* 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, @@ -89,7 +127,6 @@ static int tdb_brlock(TDB_CONTEXT *tdb, tdb_off offset, struct flock fl; if (tdb->flags & TDB_NOLOCK) return 0; - if (tdb->read_only) return -1; fl.l_type = rw_type; @@ -98,102 +135,59 @@ static int tdb_brlock(TDB_CONTEXT *tdb, tdb_off offset, fl.l_len = 1; fl.l_pid = 0; - if (fcntl(tdb->fd, lck_type, &fl) != 0) { -#if TDB_DEBUG - if (lck_type == F_SETLKW) { - printf("lock failed at %d (%s)\n", - offset, strerror(errno)); - } -#endif - tdb->ecode = TDB_ERR_LOCK; - return -1; - } + if (fcntl(tdb->fd,lck_type,&fl)) return TDB_ERRCODE(TDB_ERR_LOCK, -1); return 0; } /* lock a list in the database. list -1 is the alloc list */ -static int tdb_lock(TDB_CONTEXT *tdb, int list, int locktype) +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 - return -1; - } - + if (list < -1 || list >= (int)tdb->header.hash_size) return -1; if (tdb->flags & TDB_NOLOCK) return 0; - if (tdb->locked[list+1].count == 0 || - (tdb->locked[list+1].ltype == F_RDLCK && - locktype == F_WRLCK)) { - if (tdb_brlock(tdb, LIST_LOCK_BASE + 4*list, - locktype, F_SETLKW) != 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->header.rwlocks) { + if (tdb_spinlock(tdb, list, ltype)) return -1; + } else if (tdb_brlock(tdb,FREELIST_TOP+4*list,ltype,F_SETLKW)) return -1; - } - tdb->locked[list+1].ltype = locktype; + tdb->locked[list+1].ltype = ltype; } - 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; - if (tdb->flags & TDB_NOLOCK) return 0; + /* 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 == 0) { -#if TDB_DEBUG - printf("not locked %d\n", list); -#endif - tdb->ecode = TDB_ERR_LOCK; - return -1; - } if (tdb->locked[list+1].count == 1) { - if (tdb_brlock(tdb, LIST_LOCK_BASE + 4*list, - F_UNLCK, F_SETLKW) != 0) { - return -1; - } + /* Down to last nested lock: unlock underneath */ + if (tdb->header.rwlocks) tdb_spinunlock(tdb, list, ltype); + else tdb_brlock(tdb, FREELIST_TOP+4*list, F_UNLCK, F_SETLKW); } tdb->locked[list+1].count--; - return 0; } -/* 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 */ @@ -201,372 +195,274 @@ static int tdb_oob(TDB_CONTEXT *tdb, tdb_off offset) { struct stat st; if (offset <= tdb->map_size) return 0; - if (tdb->flags & TDB_INTERNAL) return 0; fstat(tdb->fd, &st); - if (st.st_size <= (size_t)offset) { - tdb->ecode = TDB_ERR_IO; - return -1; - } - -#if HAVE_MMAP - if (tdb->map_ptr) { - munmap(tdb->map_ptr, tdb->map_size); - tdb->map_ptr = NULL; - } -#endif + if (st.st_size <= (size_t)offset) return TDB_ERRCODE(TDB_ERR_IO, -1); + /* Unmap, update size, remap */ + if (tdb->map_ptr) tdb->map_ptr=tdb_munmap(tdb->map_ptr, tdb->map_size); tdb->map_size = st.st_size; -#if HAVE_MMAP - if (!(tdb->flags & TDB_NOMMAP)) { - 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 + if (!(tdb->flags & TDB_NOMMAP)) + tdb->map_ptr = tdb_mmap(tdb->map_size, tdb->read_only,tdb->fd); return 0; } - /* write a lump of data at a specified offset */ -static int tdb_write(TDB_CONTEXT *tdb, tdb_off offset, const 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! */ - return -1; - } + if (tdb_oob(tdb, off + len) != 0) return -1; - if (tdb->map_ptr) { - memcpy(offset + (char *)tdb->map_ptr, buf, len); - } else { - if (lseek(tdb->fd, offset, SEEK_SET) != offset || - write(tdb->fd, buf, len) != (ssize_t)len) { - tdb->ecode = TDB_ERR_IO; - return -1; - } - } + if (tdb->map_ptr) memcpy(off + (char *)tdb->map_ptr, buf, len); + else if (lseek(tdb->fd, off, SEEK_SET) != off + || write(tdb->fd, buf, len) != (ssize_t)len) + 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! */ - return -1; - } + if (tdb_oob(tdb, off + len) != 0) return -1; - if (tdb->map_ptr) { - memcpy(buf, offset + (char *)tdb->map_ptr, len); - } else { - if (lseek(tdb->fd, offset, SEEK_SET) != offset || - read(tdb->fd, buf, len) != (ssize_t)len) { - tdb->ecode = TDB_ERR_IO; - return -1; - } - } + if (tdb->map_ptr) memcpy(buf, off + (char *)tdb->map_ptr, len); + else if (lseek(tdb->fd, off, SEEK_SET) != off + || read(tdb->fd, buf, len) != (ssize_t)len) + 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 (!buf) { - tdb->ecode = TDB_ERR_OOM; - return NULL; - } - - if (tdb_read(tdb, offset, buf, len) == -1) { + if (!(buf = malloc(len))) return TDB_ERRCODE(TDB_ERR_OOM, buf); + if (tdb_read(tdb, offset, buf, len, 0) == -1) { 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) { - return tdb_read(tdb, offset, (char *)d, sizeof(*d)); + if (tdb_read(tdb, offset, rec, sizeof(*rec),DOCONV()) == -1) return -1; + if (TDB_BAD_MAGIC(rec)) return TDB_ERRCODE(TDB_ERR_CORRUPT, -1); + return tdb_oob(tdb, rec->next); } - -/* read a record and check for simple errors */ -static int rec_read(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec) +static int rec_write(TDB_CONTEXT *tdb, tdb_off offset, 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 - tdb->ecode = TDB_ERR_CORRUPT; - return -1; - } - if (tdb_oob(tdb, rec->next) != 0) { - return -1; - } - return 0; + struct list_struct r = *rec; + return tdb_write(tdb, offset, CONVERT(r), sizeof(r)); } /* read a freelist record and check for simple errors */ -static int rec_free_read(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec) +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 (tdb_read(tdb, off, rec, sizeof(*rec),DOCONV()) == -1) return -1; if (rec->magic != TDB_FREE_MAGIC) { -#if TDB_DEBUG +#ifdef TDB_DEBUG printf("bad magic 0x%08x at offset %d\n", - rec->magic, offset); + rec->magic, off); #endif - tdb->ecode = TDB_ERR_CORRUPT; - return -1; - } - if (tdb_oob(tdb, rec->next) != 0) { - return -1; + return TDB_ERRCODE(TDB_ERR_CORRUPT, -1); } + if (tdb_oob(tdb, rec->next) != 0) return -1; return 0; } -/* Add an element into the (sorted) freelist. Merge adjacent records - if neccessary. */ - -static int tdb_free(TDB_CONTEXT *tdb, tdb_off rec_offset, struct list_struct *rec) +/* update a record tailer (must hold allocation lock) */ +static int update_tailer(TDB_CONTEXT *tdb, tdb_off offset, + const struct list_struct *rec) { - tdb_off curr_offset = 0; - struct list_struct curr_rec; + tdb_off totalsize; - /* Set rec as free. */ - rec->magic = TDB_FREE_MAGIC; - rec->next = 0; - - tdb_lock(tdb, -1, F_WRLCK); - - /* Find the correct place for this offset in the freelist. */ - - if (ofs_read(tdb, FREELIST_TOP, &curr_offset) == -1) { - goto fail; - } + /* Offset of tailer from record header */ + totalsize = sizeof(*rec) + rec->rec_len; + return ofs_write(tdb, offset + totalsize - sizeof(tdb_off), + &totalsize); +} - /* Special case 1 - no freelist. */ - if (curr_offset == 0) { - if (rec_write(tdb, rec_offset, rec) == -1) - goto fail; +#ifdef TDB_DEBUG +void tdb_printfreelist(TDB_CONTEXT *tdb) +{ + tdb_off offset, rec_ptr, last_ptr; + struct list_struct rec, lastrec, newrec; - if (ofs_write(tdb, FREELIST_TOP, &rec_offset) == -1) { - tdb->ecode = TDB_ERR_CORRUPT; - goto fail; - } + tdb_lock(tdb, -1, F_WRLCK); -#if TDB_DEBUG_FREE - { - extern void tdb_printfreelist(TDB_CONTEXT *); + last_ptr = 0; + offset = FREELIST_TOP; - tdb_printfreelist(tdb); - } -#endif - tdb_unlock(tdb, -1); - return 0; + /* read in the freelist top */ + if (ofs_read(tdb, offset, &rec_ptr) == -1) { + return; } - - /* Special case 2 - rec should be inserted at start of freelist. */ - if (rec_offset < curr_offset) { - - /* Link the record being freed into the freelist. */ - rec->next = curr_offset; - - /* Check for merge with first record. */ - if (rec_offset + rec->rec_len + sizeof(struct list_struct) == curr_offset ) { - - /* Read the first freelist record. */ - if (rec_free_read(tdb, curr_offset, &curr_rec) == -1) { - goto fail; - } - rec->rec_len += (curr_rec.rec_len + sizeof(struct list_struct)); - rec->next = curr_rec.next; + printf("freelist top=[0x%08x]\n", rec_ptr ); + while (rec_ptr) { + if (tdb_read(tdb, rec_ptr, (char *)&rec, sizeof(rec), DOCONV()) == -1) { + return; } - /* Write out the new record. */ - if (rec_write(tdb, rec_offset, rec) == -1) - goto fail; - - /* Insert at the start of the freelist. */ - if (ofs_write(tdb, FREELIST_TOP, &rec_offset) == -1) { - tdb->ecode = TDB_ERR_CORRUPT; - goto fail; + if (rec.magic != TDB_FREE_MAGIC) { + printf("bad magic 0x%08x in free list\n", rec.magic); + return; } -#if TDB_DEBUG_FREE - { - extern void tdb_printfreelist(TDB_CONTEXT *); - - tdb_printfreelist(tdb); - } -#endif - tdb_unlock(tdb, -1); - return 0; - } - - /* Find the correct place to insert into the freelist. */ + printf("entry offset=[0x%08x], rec.rec_len = [0x%08x]\n", rec.next, rec.rec_len ); - /* Read the first freelist record. */ - if (rec_free_read(tdb, curr_offset, &curr_rec) == -1) { - goto fail; + /* move to the next record */ + rec_ptr = rec.next; } - while ( curr_rec.next && (rec_offset > curr_rec.next)) { + tdb_unlock(tdb, -1, F_WRLCK); +} +#endif - curr_offset = curr_rec.next; +/* Remove an element from the freelist. Must have alloc lock. */ +static int remove_from_freelist(TDB_CONTEXT *tdb, tdb_off off, tdb_off next) +{ + tdb_off last_ptr, i; - if (rec_free_read(tdb, curr_offset, &curr_rec) == -1) { - goto fail; + /* 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; } + return TDB_ERRCODE(TDB_ERR_CORRUPT, -1); +} - /* Link the record being freed into the freelist. */ - rec->next = curr_rec.next; - curr_rec.next = rec_offset; - - /* Check for merge with previous record. */ - - if (curr_offset + curr_rec.rec_len + sizeof(struct list_struct) == rec_offset) { - /* Merge with previous. */ - curr_rec.rec_len += (rec->rec_len + sizeof(struct list_struct)); - curr_rec.next = rec->next; - rec_offset = curr_offset; - *rec = curr_rec; - } +/* Add an element into the freelist. Merge adjacent records if + neccessary. */ +static int tdb_free(TDB_CONTEXT *tdb, tdb_off offset, struct list_struct *rec) +{ + tdb_off right, left; + /* Allocation and tailer lock */ + if (tdb_lock(tdb, -1, F_WRLCK) != 0) return -1; - /* Check for merge with next record. */ - if (rec_offset + rec->rec_len + sizeof(struct list_struct) == rec->next ) { - struct list_struct next_rec; + /* Look right first (I'm an Australian, dammit) */ + right = offset + sizeof(*rec) + rec->rec_len; + if (tdb_oob(tdb, right + sizeof(*rec)) == 0) { + struct list_struct r; - if (rec_free_read(tdb, rec->next, &next_rec) == -1) { + if (tdb_read(tdb, right, &r, sizeof(r), DOCONV()) == -1) goto fail; - } - /* Merge with next. */ - rec->rec_len += (next_rec.rec_len + sizeof(struct list_struct)); - rec->next = next_rec.next; + /* If it's free, expand to include it. */ + if (r.magic == TDB_FREE_MAGIC) { + if (remove_from_freelist(tdb, right, r.next) == -1) + goto fail; + rec->rec_len += sizeof(r) + r.rec_len; + } } - /* At this point rec_offset is the offset of the - new free record, and rec points at the new record to write. */ - -#if TDB_DEBUG_FREE - printf("tdb free: writing record of size %x at offset %x\n", - rec->rec_len, rec_offset ); -#endif + /* Look left */ + left = offset - 4; + if (left > TDB_HASH_TOP(tdb->header.hash_size-1)) { + struct list_struct l; + tdb_off leftsize; - /* Write the new record. */ - if (rec_write(tdb, rec_offset, rec) == -1) { - tdb->ecode = TDB_ERR_CORRUPT; - goto fail; - } + /* Read in tailer and jump back to header */ + if (ofs_read(tdb, left, &leftsize) == -1) goto fail; + left = offset - leftsize; - /* Now link into the freelist. */ - if (rec_offset != curr_offset) { - if (rec_write(tdb, curr_offset, &curr_rec) == -1) { - tdb->ecode = TDB_ERR_CORRUPT; + /* Now read in record */ + if (tdb_read(tdb, left, &l, sizeof(l), DOCONV()) == -1) goto fail; + + /* If it's free, expand to include it. */ + if (l.magic == TDB_FREE_MAGIC) { + if (remove_from_freelist(tdb, left, l.next) == -1) + goto fail; + offset = left; + rec->rec_len += leftsize; } } + if (update_tailer(tdb, offset, rec) == -1) goto fail; -#if TDB_DEBUG_FREE - { - extern void tdb_printfreelist(TDB_CONTEXT *); + /* Now, prepend to free list */ + rec->magic = TDB_FREE_MAGIC; - tdb_printfreelist(tdb); - } -#endif + if (ofs_read(tdb, FREELIST_TOP, &rec->next) == -1) goto fail; + if (rec_write(tdb, offset, rec) == -1) goto fail; + if (ofs_write(tdb, FREELIST_TOP, &offset) == -1) goto fail; - tdb_unlock(tdb, -1); + /* And we're done. */ + tdb_unlock(tdb, -1, F_WRLCK); return 0; - fail: - - tdb_unlock(tdb, -1); + fail: + tdb_unlock(tdb, -1, F_WRLCK); return -1; } -/* 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) +/* 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, ptr; + tdb_off offset; char b = 0; - tdb_lock(tdb,-1, F_WRLCK); + if (tdb_lock(tdb, -1, F_WRLCK) == -1) return 0; - /* make sure we know about any previous expansions by another - process */ - tdb_oob(tdb,tdb->map_size + 1); + /* must know about any previous expansions by another process */ + tdb_oob(tdb, tdb->map_size + 1); - /* always make room for at least 10 more records */ - length *= TDB_LEN_MULTIPLIER; - - /* 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; + /* 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; /* expand the file itself */ - if (!(tdb->flags & TDB_INTERNAL)) { - lseek(tdb->fd, tdb->map_size + length - 1, SEEK_SET); + if (!(tdb->flags & TDB_INTERNAL)) { + lseek(tdb->fd, tdb->map_size + size - 1, SEEK_SET); if (write(tdb->fd, &b, 1) != 1) goto fail; - } + } -#if HAVE_MMAP - if (!(tdb->flags & TDB_INTERNAL) && tdb->map_ptr) { - munmap(tdb->map_ptr, tdb->map_size); - tdb->map_ptr = NULL; - } -#endif + if (!(tdb->flags & TDB_INTERNAL) && tdb->map_ptr) + tdb->map_ptr = tdb_munmap(tdb->map_ptr, tdb->map_size); - tdb->map_size += length; + tdb->map_size += size; - if (tdb->flags & TDB_INTERNAL) { + if (tdb->flags & TDB_INTERNAL) tdb->map_ptr = realloc(tdb->map_ptr, tdb->map_size); - } /* form a new freelist record */ memset(&rec,'\0',sizeof(rec)); - rec.rec_len = length - sizeof(rec); + rec.rec_len = size - sizeof(rec); /* link it into the free list */ - offset = tdb->map_size - length; + offset = tdb->map_size - size; if (tdb_free(tdb, offset, &rec) == -1) goto fail; -#if HAVE_MMAP - if (!(tdb->flags & TDB_NOMMAP)) { - tdb->map_ptr = (void *)mmap(NULL, tdb->map_size, - PROT_READ|PROT_WRITE, - MAP_SHARED | MAP_FILE, tdb->fd, 0); - } -#endif + if (!(tdb->flags & TDB_NOMMAP)) + tdb->map_ptr = tdb_mmap(tdb->map_size, 0, tdb->fd); - tdb_unlock(tdb, -1); + tdb_unlock(tdb, -1, F_WRLCK); return 0; - fail: - tdb_unlock(tdb,-1); + tdb_unlock(tdb, -1, F_WRLCK); return -1; } @@ -578,189 +474,125 @@ static int tdb_expand(TDB_CONTEXT *tdb, tdb_off length) */ static tdb_off tdb_allocate(TDB_CONTEXT *tdb, tdb_len length) { - tdb_off offset, rec_ptr, last_ptr; - struct list_struct rec, lastrec, newrec; + tdb_off rec_ptr, last_ptr; + struct list_struct rec, newrec; - tdb_lock(tdb, -1, F_WRLCK); + if (tdb_lock(tdb, -1, F_WRLCK) == -1) return 0; + + /* Extra bytes required for tailer */ + length += sizeof(tdb_off); again: - last_ptr = 0; - offset = FREELIST_TOP; + last_ptr = FREELIST_TOP; /* read in the freelist top */ - if (ofs_read(tdb, offset, &rec_ptr) == -1) { - goto fail; - } + if (ofs_read(tdb, FREELIST_TOP, &rec_ptr) == -1) goto fail; - /* keep looking until we find a freelist record that is big - enough */ + /* keep looking until we find a freelist record big enough */ while (rec_ptr) { - if (tdb_read(tdb, rec_ptr, (char *)&rec, sizeof(rec)) == -1) { - goto fail; - } - - if (rec.magic != TDB_FREE_MAGIC) { -#if TDB_DEBUG - printf("bad magic 0x%08x in free list\n", rec.magic); -#endif - goto fail; - } + if (rec_free_read(tdb, rec_ptr, &rec) == -1) goto fail; if (rec.rec_len >= length) { /* found it - now possibly split it up */ if (rec.rec_len > length + MIN_REC_SIZE) { - length = (length + TDB_ALIGN) & ~(TDB_ALIGN-1); + length = TDB_ALIGN(length, TDB_ALIGNMENT); - newrec.rec_len = rec.rec_len - (sizeof(rec) + length); + 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) { + /* Update split-off record */ + if (rec_write(tdb, rec.next, &newrec) == -1 + || update_tailer(tdb,rec.next,&newrec)==-1) + goto fail; + /* Update record we're about to allocate */ + if (rec_write(tdb, rec_ptr, &rec) == -1 + || update_tailer(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) { + if (ofs_write(tdb, last_ptr, &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); - -#if TDB_DEBUG_FREE - { - extern void tdb_printfreelist(TDB_CONTEXT *); - printf("tdb_allocate: offset %x, size %x\n", rec_ptr, rec.rec_len); - - tdb_printfreelist(tdb); - } -#endif + tdb_unlock(tdb, -1, F_WRLCK); return rec_ptr; } - /* move to the next record */ - lastrec = rec; last_ptr = rec_ptr; rec_ptr = rec.next; } - /* we didn't find enough space. See if we can expand the database and if we can then try again */ if (tdb_expand(tdb, length + sizeof(rec)) == 0) goto again; - fail: -#if TDB_DEBUG - printf("tdb_allocate failed for size %u\n", length); -#endif - tdb_unlock(tdb, -1); + tdb_unlock(tdb, -1, F_WRLCK); return 0; } /* initialise a new database with a specified hash size */ static int tdb_new_database(TDB_CONTEXT *tdb, int hash_size) { - struct tdb_header header; - tdb_off offset; - int i, size = 0; - tdb_off buf[16]; - - /* create the header */ - memset(&header, 0, sizeof(header)); - memcpy(header.magic_food, TDB_MAGIC_FOOD, strlen(TDB_MAGIC_FOOD)+1); - header.version = TDB_VERSION; - header.hash_size = hash_size; - if (tdb->fd != -1) { - lseek(tdb->fd, 0, SEEK_SET); - ftruncate(tdb->fd, 0); - } - - if (tdb->fd != -1 && write(tdb->fd, &header, sizeof(header)) != - sizeof(header)) { - tdb->ecode = TDB_ERR_IO; - return -1; - } else size += sizeof(header); - - /* the freelist and hash pointers */ - offset = 0; - memset(buf, 0, sizeof(buf)); - - for (i=0;(hash_size+1)-i >= 16; i += 16) { - if (tdb->fd != -1 && write(tdb->fd, buf, sizeof(buf)) != - sizeof(buf)) { - tdb->ecode = TDB_ERR_IO; - return -1; - } else size += sizeof(buf); - } - - for (;i<hash_size+1; i++) { - if (tdb->fd != -1 && write(tdb->fd, buf, sizeof(tdb_off)) != - sizeof(tdb_off)) { - tdb->ecode = TDB_ERR_IO; - return -1; - } else size += sizeof(tdb_off); - } - - if (tdb->flags & TDB_INTERNAL) { - tdb->map_ptr = calloc(size,1); - tdb->map_size = size; - if (tdb->map_ptr == NULL) { - tdb->ecode = TDB_ERR_IO; - return -1; - } - memcpy(&tdb->header, &header, sizeof(header)); - } - -#if TDB_DEBUG - printf("initialised database of hash_size %u\n", - hash_size); + struct tdb_header *newdb; + int size, ret; + + /* 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 - return 0; + 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; + } + lseek(tdb->fd, 0, SEEK_SET); + ftruncate(tdb->fd, 0); + /* 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); + + free(newdb); + return ret; } /* Returns 0 on fail. On success, return offset of record, and fills in rec */ -static tdb_off tdb_find(TDB_CONTEXT *tdb, TDB_DATA key, unsigned int hash, - struct list_struct *rec) +static tdb_off tdb_find(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash, + struct list_struct *r) { - tdb_off offset, rec_ptr; + tdb_off rec_ptr; - /* 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) - return 0; + if (ofs_read(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) return 0; /* keep looking until we find the right record */ while (rec_ptr) { - if (rec_read(tdb, rec_ptr, rec) == -1) - return 0; + if (rec_read(tdb, rec_ptr, r) == -1) return 0; - if (hash == rec->full_hash && key.dsize == rec->key_len) { + 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(*rec), - rec->key_len); - - if (!k) - return 0; + k = tdb_alloc_read(tdb, rec_ptr + sizeof(*r), + r->key_len); + if (!k) return 0; if (memcmp(key.dptr, k, key.dsize) == 0) { free(k); @@ -768,77 +600,75 @@ static tdb_off tdb_find(TDB_CONTEXT *tdb, TDB_DATA key, unsigned int hash, } free(k); } - - /* move to the next record */ - rec_ptr = rec->next; + rec_ptr = r->next; } - return 0; + return TDB_ERRCODE(TDB_ERR_NOEXIST, 0); } -/* - return an error string for the last tdb error -*/ -char *tdb_error(TDB_CONTEXT *tdb) +/* If they do lockkeys, check that this hash is one they locked */ +static int tdb_keylocked(TDB_CONTEXT *tdb, u32 hash) +{ + 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); +} + +/* 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; + + 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; +} + +enum TDB_ERROR tdb_error(TDB_CONTEXT *tdb) { - int i; - static struct { - enum TDB_ERROR ecode; - 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_NOEXIST, "Record does not exist"}, - {(enum TDB_ERROR)-1, NULL}}; - if (tdb != NULL) { - for (i=0;emap[i].estring;i++) { + return tdb->ecode; +} + +static struct tdb_errname { + enum TDB_ERROR ecode; const char *estring; +} emap[] = { {TDB_SUCCESS, "Success"}, + {TDB_ERR_CORRUPT, "Corrupt database"}, + {TDB_ERR_IO, "IO Error"}, + {TDB_ERR_LOCK, "Locking error"}, + {TDB_ERR_OOM, "Out of memory"}, + {TDB_ERR_EXISTS, "Record exists"}, + {TDB_ERR_NOLOCK, "Lock exists on other keys"}, + {TDB_ERR_NOEXIST, "Record does not exist"} }; + +/* Error string for the last tdb error */ +const char *tdb_errorstr(TDB_CONTEXT *tdb) +{ + u32 i; + for (i = 0; i < sizeof(emap) / sizeof(struct tdb_errname); i++) if (tdb->ecode == emap[i].ecode) return emap[i].estring; - } - } else { - return "Invalid tdb context"; - } return "Invalid error code"; } - /* update an entry in place - this only works if the new data size is <= the old data size and the key exists. on failure return -1 */ -int tdb_update(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf) +static int tdb_update(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf) { - unsigned hash; struct list_struct rec; tdb_off rec_ptr; int ret = -1; - if (tdb == NULL) { -#ifdef TDB_DEBUG - printf("tdb_update() called with null context\n"); -#endif - return -1; - } + /* find entry */ + if (!(rec_ptr = tdb_find_lock(tdb, key, F_WRLCK, &rec))) return -1; - /* initialise error code to ok, first */ - tdb->ecode = 0; - - /* find which hash bucket it is in */ - hash = tdb_hash(&key); - - tdb_lock(tdb, BUCKET(hash), F_WRLCK); - rec_ptr = tdb_find(tdb, key, hash, &rec); - - if (!rec_ptr) { - tdb->ecode = TDB_ERR_NOEXIST; - goto out; - } - - /* must be long enough */ - if (rec.rec_len < key.dsize + dbuf.dsize) - goto out; + /* must be long enough key, data and tailer */ + if (rec.rec_len < key.dsize + dbuf.dsize + sizeof(tdb_off)) goto out; if (tdb_write(tdb, rec_ptr + sizeof(rec) + rec.key_len, dbuf.dptr, dbuf.dsize) == -1) @@ -848,46 +678,27 @@ int tdb_update(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf) /* update size */ rec.data_len = dbuf.dsize; ret = rec_write(tdb, rec_ptr, &rec); - } else - ret = 0; - + } + else ret = 0; out: - tdb_unlock(tdb, BUCKET(hash)); + tdb_unlock(tdb, BUCKET(rec.full_hash), F_WRLCK); return ret; } /* find an entry in the database given a key */ TDB_DATA tdb_fetch(TDB_CONTEXT *tdb, TDB_DATA key) { - unsigned hash; tdb_off rec_ptr; struct list_struct rec; - TDB_DATA ret = null_data; - - if (tdb == NULL) { -#ifdef TDB_DEBUG - printf("tdb_fetch() called with null context\n"); -#endif - return null_data; - } + TDB_DATA ret; /* find which hash bucket it is in */ - hash = tdb_hash(&key); + if (!(rec_ptr = tdb_find_lock(tdb,key,F_RDLCK,&rec))) return tdb_null; - tdb_lock(tdb, BUCKET(hash), F_RDLCK); - rec_ptr = tdb_find(tdb, key, hash, &rec); - - if (rec_ptr) { - if (rec.data_len) - ret.dptr = tdb_alloc_read(tdb, - rec_ptr + sizeof(rec) + rec.key_len, - rec.data_len); - else - ret.dptr = NULL; - ret.dsize = rec.data_len; - } - - tdb_unlock(tdb, BUCKET(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; } @@ -899,299 +710,245 @@ TDB_DATA tdb_fetch(TDB_CONTEXT *tdb, TDB_DATA key) */ int tdb_exists(TDB_CONTEXT *tdb, TDB_DATA key) { - unsigned hash; - tdb_off rec_ptr; struct list_struct rec; - if (tdb == NULL) { -#ifdef TDB_DEBUG - printf("tdb_exists() called with null context\n"); -#endif - return 0; - } - - /* find which hash bucket it is in */ - hash = tdb_hash(&key); + if (tdb_find_lock(tdb, key, F_RDLCK, &rec) == 0) return 0; + tdb_unlock(tdb, BUCKET(rec.full_hash), F_RDLCK); + return 1; +} - tdb_lock(tdb, BUCKET(hash), F_RDLCK); - rec_ptr = tdb_find(tdb, key, hash, &rec); - tdb_unlock(tdb, BUCKET(hash)); +/* record lock stops delete underneath */ +static int lock_record(TDB_CONTEXT *tdb, tdb_off off) +{ + return off ? tdb_brlock(tdb, off, F_RDLCK, F_SETLKW) : 0; +} +/* write locks override our own fcntl readlocks, so check it 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); +} +static int write_unlock_record(TDB_CONTEXT *tdb, tdb_off off) +{ + return tdb_brlock(tdb, off, F_UNLCK, F_SETLK); +} +/* 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; - return rec_ptr != 0; + if (off == 0) return 0; + for (i = &tdb->travlocks; i; i = i->next) if (i->off == off) count++; + return (count == 1 ? tdb_brlock(tdb, off, F_UNLCK, F_SETLKW) : 0); } -/* 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, void* state), void* state) +/* actually delete an entry in the database given the offset */ +static int do_delete(TDB_CONTEXT *tdb, tdb_off rec_ptr, struct list_struct*rec) { - int count = 0; - unsigned h; - tdb_off offset, rec_ptr; - struct list_struct rec; - char *data; - TDB_DATA key, dbuf; + tdb_off last_ptr, i; + struct list_struct lastrec; - if (tdb == NULL) { -#ifdef TDB_DEBUG - printf("tdb_traverse() called with null context\n"); -#endif - return -1; - } + 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); - /* loop over all hash chains */ - for (h = 0; h < tdb->header.hash_size; h++) { - tdb_lock(tdb, BUCKET(h), F_WRLCK); + /* 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; - /* read in the hash top */ - offset = tdb_hash_top(tdb, h); - if (ofs_read(tdb, offset, &rec_ptr) == -1) { - goto fail; - } + /* 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; - /* traverse all records for this hash */ - while (rec_ptr) { - if (rec_read(tdb, rec_ptr, &rec) == -1) { - goto fail; - } + /* recover the space */ + if (tdb_free(tdb, rec_ptr, rec) == -1) return -1; + return 0; +} - /* now read the full record */ - data = tdb_alloc_read(tdb, rec_ptr + sizeof(rec), - rec.key_len + rec.data_len); - if (!data) { - goto fail; - } +/* 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) +{ + tdb_off next; + int first = (tlock->off == 0); - key.dptr = data; - key.dsize = rec.key_len; - dbuf.dptr = data + rec.key_len; - dbuf.dsize = rec.data_len; - count++; - - if (fn && fn(tdb, key, dbuf, state) != 0) { - /* they want us to stop traversing */ - free(data); - tdb_unlock(tdb, BUCKET(h)); - return count; - } + /* No traversal allows if you've called tdb_lockkeys() */ + if (tdb->lockedkeys) return TDB_ERRCODE(TDB_ERR_NOLOCK, -1); - /* a miss - drat */ - free(data); + /* 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; - /* move to the next record */ - rec_ptr = rec.next; + /* 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 { + /* Othereisre unlock the previous record. */ + unlock_record(tdb, tlock->off); } - tdb_unlock(tdb, BUCKET(h)); - } - /* return the number traversed */ - return count; + if (!first) { + /* Grab next record */ + if (rec_read(tdb, tlock->off, rec) == -1) goto fail; + tlock->off = rec->next; + first = 0; + } + + /* Iterate through chain */ + for (; tlock->off; tlock->off = next) { + 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 */ + next = rec->next; + do_delete(tdb, tlock->off, rec); + } + tdb_unlock(tdb, tlock->hash, F_WRLCK); + } + /* We finished iteration without finding anything */ + return TDB_ERRCODE(TDB_SUCCESS, 0); fail: - tdb_unlock(tdb, BUCKET(h)); + tlock->off = 0; + tdb_unlock(tdb, tlock->hash, F_WRLCK); return -1; } - -/* find the first entry in the database and return its key */ -TDB_DATA tdb_firstkey(TDB_CONTEXT *tdb) +/* 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_off offset, rec_ptr; + TDB_DATA key, dbuf; struct list_struct rec; - unsigned hash; - TDB_DATA ret; - - if (tdb == NULL) { -#ifdef TDB_DEBUG - printf("tdb_firstkey() called with null context\n"); -#endif - return null_data; - } - - /* 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); - - tdb_lock(tdb, BUCKET(hash), F_RDLCK); - - /* read in the hash top */ - if (ofs_read(tdb, offset, &rec_ptr) == -1) { - goto fail; + struct tdb_traverse_lock tl = { tdb->travlocks.next, 0, 0 }; + int ret, count = 0; + + /* 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; } - - if (rec_ptr) break; - - tdb_unlock(tdb, BUCKET(hash)); + 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; + free(key.dptr); + return count; + } + free(key.dptr); } + tdb->travlocks.next = tl.next; + if (ret < 0) return -1; + else return count; +} - if (rec_ptr == 0) return null_data; - - /* we've found a non-empty chain, now read the record */ - if (rec_read(tdb, rec_ptr, &rec) == -1) { - 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; - /* 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; + /* release any old lock */ + unlock_record(tdb, tdb->travlocks.off); + tdb->travlocks.off = tdb->travlocks.hash = 0; - fail: - tdb_unlock(tdb, BUCKET(hash)); - return null_data; + 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; } /* find the next entry in the database, returning its key */ -TDB_DATA tdb_nextkey(TDB_CONTEXT *tdb, TDB_DATA key) +TDB_DATA tdb_nextkey(TDB_CONTEXT *tdb, TDB_DATA oldkey) { - unsigned hash, hbucket; - tdb_off rec_ptr, offset; + u32 oldhash; + TDB_DATA key = tdb_null; struct list_struct rec; - TDB_DATA ret; - - if (tdb == NULL) { -#ifdef TDB_DEBUG - printf("tdb_nextkey() called with null context\n"); -#endif - return null_data; - } - - /* find which hash bucket it is in */ - hash = tdb_hash(&key); - hbucket = BUCKET(hash); - - tdb_lock(tdb, hbucket, F_RDLCK); - rec_ptr = tdb_find(tdb, key, hash, &rec); - if (rec_ptr) { - /* we want the next record after this one */ - rec_ptr = rec.next; - } - - /* not found or last in hash: look for next non-empty hash chain */ - while (rec_ptr == 0) { - tdb_unlock(tdb, hbucket); - - if (++hbucket >= tdb->header.hash_size - 1) - return null_data; - - offset = tdb_hash_top(tdb, hbucket); - tdb_lock(tdb, hbucket, F_RDLCK); - /* read in the hash top */ - if (ofs_read(tdb, offset, &rec_ptr) == -1) { - tdb_unlock(tdb, hbucket); - return null_data; + 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 */ + free(k); + unlock_record(tdb, tdb->travlocks.off); + tdb_unlock(tdb, tdb->travlocks.hash, F_WRLCK); + tdb->travlocks.off = 0; } } - /* Read the record. */ - if (rec_read(tdb, rec_ptr, &rec) == -1) { - tdb_unlock(tdb, hbucket); - return null_data; + 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); } - /* allocate and read the key */ - ret.dptr = tdb_alloc_read(tdb, rec_ptr + sizeof(rec), rec.key_len); - ret.dsize = rec.key_len; - tdb_unlock(tdb, hbucket); + oldhash = tdb->travlocks.hash; - return ret; + /* 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) { - unsigned hash; - tdb_off offset, rec_ptr, last_ptr; - struct list_struct rec, lastrec; - char *data = NULL; - - if (tdb == NULL) { -#ifdef TDB_DEBUG - printf("tdb_delete() called with null context\n"); -#endif - return -1; - } - - /* find which hash bucket it is in */ - hash = tdb_hash(&key); - - tdb_lock(tdb, BUCKET(hash), F_WRLCK); - - /* 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; - } - - last_ptr = 0; - - /* keep looking until we find the right record */ - while (rec_ptr) { - if (rec_read(tdb, rec_ptr, &rec) == -1) { - goto fail; - } - - 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; - } - - if (memcmp(key.dptr, data, key.dsize) == 0) { - /* a definite 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)); - - /* and recover the space */ - if (tdb_free(tdb, rec_ptr, &rec) == -1) - goto fail2; - - /* yipee - all done */ - free(data); - return 0; - } - - /* a miss - drat */ - free(data); - data = NULL; - } - - /* move to the next record */ - last_ptr = rec_ptr; - lastrec = rec; - rec_ptr = rec.next; - } - - fail: - if (data) free(data); - tdb_unlock(tdb, BUCKET(hash)); - return -1; + tdb_off rec_ptr; + struct list_struct rec; + int ret; - fail2: - if (data) free(data); - return -1; + 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 @@ -1200,318 +957,265 @@ int tdb_delete(TDB_CONTEXT *tdb, TDB_DATA key) int tdb_store(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, int flag) { struct list_struct rec; - unsigned hash; - tdb_off rec_ptr, offset; + u32 hash; + tdb_off rec_ptr; char *p = NULL; - - if (tdb == NULL) { -#ifdef TDB_DEBUG - printf("tdb_store() called with null context\n"); -#endif - return -1; - } + int ret = 0; /* find which hash bucket it is in */ hash = tdb_hash(&key); - + if (!tdb_keylocked(tdb, hash)) return -1; tdb_lock(tdb, BUCKET(hash), F_WRLCK); /* check for it existing, on insert. */ - if (flag == TDB_INSERT && tdb_exists(tdb, key)) { - tdb->ecode = TDB_ERR_EXISTS; - goto fail; - } - - /* first try in-place update, on modify or replace. */ - if (flag != TDB_INSERT && tdb_update(tdb, key, dbuf) == 0) { - tdb_unlock(tdb, BUCKET(hash)); - return 0; - } - - /* check for it _not_ existing, from error code of the update. */ - if (flag == TDB_MODIFY && tdb->ecode == TDB_ERR_NOEXIST) { - goto fail; + 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 = 0; - - /* - * 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). - */ - - rec_ptr = tdb_allocate(tdb, key.dsize + dbuf.dsize); - if (rec_ptr == 0) { - goto fail; - } - - /* delete any existing record - if it doesn't exist we don't care */ - if (flag != TDB_INSERT) { - tdb_delete(tdb, key); - } + tdb->ecode = TDB_SUCCESS; - /* read the newly created record */ - if (tdb_read(tdb, rec_ptr, (char *)&rec, sizeof(rec)) == -1) { - goto fail; - } + /* 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); - if (rec.magic != TDB_FREE_MAGIC) goto fail; + /* 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))) goto fail; - /* find the top of the hash chain */ - offset = tdb_hash_top(tdb, hash); - - /* read in the hash top diretcly into our next pointer */ - if (ofs_read(tdb, offset, &rec.next) == -1) { - goto fail; - } + /* read the newly created record, then read hash top into next ptr */ + if (rec_free_read(tdb, rec_ptr, &rec) == -1) goto fail; + 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; - p = (char *)malloc(sizeof(rec) + key.dsize + dbuf.dsize); - if (!p) { + if (!(p = (char *)malloc(key.dsize + dbuf.dsize))) { tdb->ecode = TDB_ERR_OOM; goto fail; } - memcpy(p, &rec, sizeof(rec)); - memcpy(p+sizeof(rec), key.dptr, key.dsize); - if (dbuf.dsize) - memcpy(p+sizeof(rec)+key.dsize, dbuf.dptr, dbuf.dsize); - - if (tdb_write(tdb, rec_ptr, p, sizeof(rec)+key.dsize+dbuf.dsize) == -1) - goto fail; - + memcpy(p, key.dptr, key.dsize); + memcpy(p+key.dsize, dbuf.dptr, dbuf.dsize); + /* 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: + ret = -1; + } + out: free(p); - p = NULL; - - /* and point the top of the hash chain at it */ - if (ofs_write(tdb, offset, &rec_ptr) == -1) goto fail; - - 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 (p) free(p); - tdb_unlock(tdb, BUCKET(hash)); - return -1; + tdb_unlock(tdb, BUCKET(hash), F_WRLCK); + return ret; } - /* 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 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 -*/ + return is NULL on error */ TDB_CONTEXT *tdb_open(char *name, int hash_size, int tdb_flags, int open_flags, mode_t mode) { - TDB_CONTEXT tdb, *ret; + TDB_CONTEXT tdb, *ret, *i; struct stat st; + int rev = 0, locked; memset(&tdb, 0, sizeof(tdb)); - tdb.fd = -1; tdb.name = NULL; tdb.map_ptr = NULL; + tdb.lockedkeys = NULL; tdb.flags = tdb_flags; - if ((open_flags & O_ACCMODE) == O_WRONLY) { - goto fail; - } - + if ((open_flags & O_ACCMODE) == O_WRONLY) 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 */ + tdb.flags |= TDB_NOLOCK; + } - tdb.read_only = ((open_flags & O_ACCMODE) == O_RDONLY); - - /* internal databases don't use mmap or locking, - and start off cleared */ + /* 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; - } - - /* read only databases don't do locking */ - if (tdb.read_only) tdb.flags |= TDB_NOLOCK; - - if (tdb.flags & TDB_INTERNAL) { tdb_new_database(&tdb, hash_size); goto internal; } - tdb.fd = open(name, open_flags, mode); - if (tdb.fd == -1) { - goto fail; - } + if ((tdb.fd = open(name, open_flags, mode)) == -1) goto fail; /* ensure there is only one process initialising at once */ tdb_brlock(&tdb, GLOBAL_LOCK, F_WRLCK, F_SETLKW); - if (tdb_flags & TDB_CLEAR_IF_FIRST) { - /* we need to zero the database if we are the only - one with it open */ - if (tdb_brlock(&tdb, ACTIVE_LOCK, F_WRLCK, F_SETLK) == 0) { - ftruncate(tdb.fd, 0); - tdb_brlock(&tdb, ACTIVE_LOCK, F_UNLCK, F_SETLK); - } + /* 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)) + && (tdb_flags & TDB_CLEAR_IF_FIRST)) { + open_flags |= O_CREAT; + ftruncate(tdb.fd, 0); } - /* leave this lock in place */ - tdb_brlock(&tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW); - - 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) { + if (read(tdb.fd, &tdb.header, sizeof(tdb.header)) != sizeof(tdb.header) + || strcmp(tdb.header.magic_food, TDB_MAGIC_FOOD) != 0 + || (tdb.header.version != TDB_VERSION + && !(rev = (tdb.header.version==TDB_BYTEREV(TDB_VERSION))))) { /* its not a valid database - possibly initialise it */ - if (!(open_flags & O_CREAT)) { - 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; + if (!(open_flags & O_CREAT) + || tdb_new_database(&tdb, hash_size) == -1) goto fail; + rev = (tdb.flags & TDB_CONVERT); + } + if (!rev) tdb.flags &= ~TDB_CONVERT; + else { + tdb.flags |= TDB_CONVERT; + convert(&tdb.header, sizeof(tdb.header)); } - fstat(tdb.fd, &st); + /* Is it already in the open list? If so, fail. */ + for (i = tdbs; i; i = i->next) { + if (i->device == st.st_dev && i->inode == st.st_ino) { + errno = EBUSY; + close(tdb.fd); + return NULL; + } + } /* map the database and fill in the return structure */ tdb.name = (char *)strdup(name); tdb.map_size = st.st_size; - - tdb.locked = (struct tdb_lock_type *)calloc(tdb.header.hash_size+1, - sizeof(tdb.locked[0])); - if (!tdb.locked) { - goto fail; - } - -#if HAVE_MMAP - if (!(tdb.flags & TDB_NOMMAP)) { - 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 + 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) goto fail; + if (!(tdb.flags & TDB_NOMMAP)) + tdb.map_ptr = tdb_mmap(st.st_size, tdb.read_only, tdb.fd); + if (locked) { + tdb_clear_spinlocks(&tdb); + tdb_brlock(&tdb, ACTIVE_LOCK, F_UNLCK, F_SETLK); + } + /* leave this lock in place to indicate it's in use */ + tdb_brlock(&tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW); internal: - ret = (TDB_CONTEXT *)malloc(sizeof(tdb)); - if (!ret) goto fail; - + if (!(ret = malloc(sizeof(tdb)))) goto fail; *ret = tdb; - -#if TDB_DEBUG - printf("mapped database of hash_size %u map_size=%u\n", - hash_size, tdb.map_size); -#endif - tdb_brlock(&tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW); + ret->next = tdbs; + tdbs = ret; return ret; fail: 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.map_ptr) tdb_munmap(tdb.map_ptr, tdb.map_size); return NULL; } /* close a database */ int tdb_close(TDB_CONTEXT *tdb) { - if (!tdb) return -1; + TDB_CONTEXT **i; + int ret = 0; + if (tdb->map_ptr) { + if (tdb->flags & TDB_INTERNAL) free(tdb->map_ptr); + else tdb_munmap(tdb->map_ptr, tdb->map_size); + } if (tdb->name) free(tdb->name); - if (tdb->fd != -1) close(tdb->fd); + if (tdb->fd != -1) { + ret = close(tdb->fd); + } if (tdb->locked) free(tdb->locked); + if (tdb->lockedkeys) free(tdb->lockedkeys); - if (tdb->map_ptr) { - if (tdb->flags & TDB_INTERNAL) { - free(tdb->map_ptr); - } else { - munmap(tdb->map_ptr, tdb->map_size); + /* 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); - return 0; + return ret; } - -/* lock one hash chain. This is meant to be used to reduce locking - contention - it cannot guarantee how many records will be locked */ -int tdb_lockchain(TDB_CONTEXT *tdb, TDB_DATA key) +/* lock/unlock entire database */ +int tdb_lockall(TDB_CONTEXT *tdb) { - if (tdb == NULL) { -#ifdef TDB_DEBUG - printf("tdb_lockchain() called with null context\n"); -#endif - return -1; - } + u32 i; - return tdb_lock(tdb, BUCKET(tdb_hash(&key)), F_WRLCK); + /* 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++) tdb_lock(tdb, i, F_WRLCK); + return 0; } - - -/* unlock one hash chain */ -int tdb_unlockchain(TDB_CONTEXT *tdb, TDB_DATA key) +void tdb_unlockall(TDB_CONTEXT *tdb) { - if (tdb == NULL) { -#ifdef TDB_DEBUG - printf("tdb_unlockchain() called with null context\n"); -#endif - return -1; - } - - return tdb_unlock(tdb, BUCKET(tdb_hash(&key))); + u32 i; + for (i=0; i < tdb->header.hash_size; i++) tdb_unlock(tdb, i, F_WRLCK); } - -#if TDB_DEBUG -void tdb_printfreelist(TDB_CONTEXT *tdb) +int tdb_lockkeys(TDB_CONTEXT *tdb, u32 number, TDB_DATA keys[]) { - tdb_off offset, rec_ptr, last_ptr; - struct list_struct rec, lastrec, newrec; - - tdb_lock(tdb, -1, F_WRLCK); - - last_ptr = 0; - offset = FREELIST_TOP; - - /* read in the freelist top */ - if (ofs_read(tdb, offset, &rec_ptr) == -1) { - return; - } - - printf("freelist top=[0x%08x]\n", rec_ptr ); - while (rec_ptr) { - if (tdb_read(tdb, rec_ptr, (char *)&rec, sizeof(rec)) == -1) { - return; - } - - if (rec.magic != TDB_FREE_MAGIC) { - printf("bad magic 0x%08x in free list\n", rec.magic); - return; - } - - printf("entry offset=[0x%08x], rec.rec_len = [0x%08x]\n", rec.next, rec.rec_len ); + 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++) tdb_lock(tdb, i, F_WRLCK); + return 0; +} - /* move to the next record */ - rec_ptr = rec.next; - } +/* Unlock the keys previously locked by tdb_lockkeys() */ +void tdb_unlockkeys(TDB_CONTEXT *tdb) +{ + u32 i; + for (i = 0; i < tdb->lockedkeys[0]; i++) + tdb_unlock(tdb, tdb->lockedkeys[i+1], F_WRLCK); + free(tdb->lockedkeys); + tdb->lockedkeys = NULL; +} - tdb_unlock(tdb, -1); +/* lock/unlock one hash chain. This is meant to be used to reduce + contention - it cannot guarantee how many records will be locked */ +int tdb_chainlock(TDB_CONTEXT *tdb, TDB_DATA key) +{ + return tdb_lock(tdb, BUCKET(tdb_hash(&key)), F_WRLCK); +} +void tdb_chainunlock(TDB_CONTEXT *tdb, TDB_DATA key) +{ + tdb_unlock(tdb, BUCKET(tdb_hash(&key)), F_WRLCK); } -#endif diff --git a/source3/tdb/tdb.h b/source3/tdb/tdb.h index fd770cc5b9..f09c6453b5 100644 --- a/source3/tdb/tdb.h +++ b/source3/tdb/tdb.h @@ -1,3 +1,6 @@ +#ifndef __TDB_H__ +#define __TDB_H__ + /* Unix SMB/Netbios implementation. Version 3.0 @@ -19,73 +22,105 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ -typedef unsigned tdb_len; -typedef unsigned tdb_off; +#ifdef __cplusplus +extern "C" { +#endif -#define TDB_MAGIC_FOOD "TDB file\n" -/* this is stored at the front of every database */ -struct tdb_header { - char magic_food[32]; /* for /etc/magic */ - unsigned version; /* version of the code */ - unsigned hash_size; /* number of hash entries */ - tdb_off reserved[32]; -}; +/* flags to tdb_store() */ +#define TDB_REPLACE 1 +#define TDB_INSERT 2 +#define TDB_MODIFY 3 + +/* flags for tdb_open() */ +#define TDB_DEFAULT 0 /* just a readability place holder */ +#define TDB_CLEAR_IF_FIRST 1 +#define TDB_INTERNAL 2 /* don't store on disk */ +#define TDB_NOLOCK 4 /* don't do any locking */ +#define TDB_NOMMAP 8 /* don't use mmap */ +#define TDB_CONVERT 16 /* convert endian (internal use) */ + +#define TDB_ERRCODE(code, ret) ((tdb->ecode = (code)), ret) + +/* error codes */ +enum TDB_ERROR {TDB_SUCCESS=0, TDB_ERR_CORRUPT, TDB_ERR_IO, TDB_ERR_LOCK, + TDB_ERR_OOM, TDB_ERR_EXISTS, TDB_ERR_NOEXIST, TDB_ERR_NOLOCK }; + +#ifndef u32 +#define u32 unsigned +#endif typedef struct { char *dptr; size_t dsize; } TDB_DATA; +typedef u32 tdb_len; +typedef u32 tdb_off; + +/* this is stored at the front of every database */ +struct tdb_header { + char magic_food[32]; /* for /etc/magic */ + u32 version; /* version of the code */ + u32 hash_size; /* number of hash entries */ + tdb_off rwlocks; + tdb_off reserved[31]; +}; + struct tdb_lock_type { - unsigned count; - unsigned ltype; + u32 count; + u32 ltype; +}; + +struct tdb_traverse_lock { + struct tdb_traverse_lock *next; + u32 off; + u32 hash; }; /* this is the context structure that is returned from a db open */ -typedef struct { +typedef struct tdb_context { char *name; /* the name of the database */ void *map_ptr; /* where it is currently mapped */ int fd; /* open file descriptor for the database */ tdb_len map_size; /* how much space has been mapped */ int read_only; /* opened read-only */ - struct tdb_lock_type *locked; /* set if we have a chain locked */ - int ecode; /* error code for last tdb error */ + struct tdb_lock_type *locked; /* array of chain locks */ + enum TDB_ERROR ecode; /* error code for last tdb error */ struct tdb_header header; /* a cached copy of the header */ - unsigned flags; /* the flags passed to tdb_open */ + u32 flags; /* the flags passed to tdb_open */ + u32 *lockedkeys; /* array of locked keys: first is #keys */ + struct tdb_traverse_lock travlocks; /* current traversal locks */ + struct tdb_context *next; /* all tdbs to avoid multiple opens */ + dev_t device; /* uniquely identifies this tdb */ + ino_t inode; /* uniquely identifies this tdb */ } TDB_CONTEXT; -/* flags to tdb_store() */ -#define TDB_REPLACE 1 -#define TDB_INSERT 2 -#define TDB_MODIFY 3 - -/* flags for tdb_open() */ -#define TDB_CLEAR_IF_FIRST 1 -#define TDB_INTERNAL 2 /* don't store on disk */ -#define TDB_NOLOCK 4 /* don't do any locking */ -#define TDB_NOMMAP 8 /* don't use mmap */ - -/* error codes */ -enum TDB_ERROR {TDB_SUCCESS=0, TDB_ERR_CORRUPT, TDB_ERR_IO, TDB_ERR_LOCK, - TDB_ERR_OOM, TDB_ERR_EXISTS, TDB_ERR_NOEXIST }; - typedef int (*tdb_traverse_func)(TDB_CONTEXT *, TDB_DATA, TDB_DATA, void *); -#if STANDALONE TDB_CONTEXT *tdb_open(char *name, int hash_size, int tdb_flags, int open_flags, mode_t mode); -char *tdb_error(TDB_CONTEXT *tdb); -int tdb_writelock(TDB_CONTEXT *tdb); -int tdb_writeunlock(TDB_CONTEXT *tdb); +enum TDB_ERROR tdb_error(TDB_CONTEXT *tdb); +const char *tdb_errorstr(TDB_CONTEXT *tdb); TDB_DATA tdb_fetch(TDB_CONTEXT *tdb, TDB_DATA key); int tdb_delete(TDB_CONTEXT *tdb, TDB_DATA key); int tdb_store(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, int flag); int tdb_close(TDB_CONTEXT *tdb); TDB_DATA tdb_firstkey(TDB_CONTEXT *tdb); TDB_DATA tdb_nextkey(TDB_CONTEXT *tdb, TDB_DATA key); -int tdb_traverse(TDB_CONTEXT *tdb, - int (*fn)(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, void *state), - void *state); +int tdb_traverse(TDB_CONTEXT *tdb, tdb_traverse_func fn, void *state); int tdb_exists(TDB_CONTEXT *tdb, TDB_DATA key); +int tdb_lockkeys(TDB_CONTEXT *tdb, u32 number, TDB_DATA keys[]); +void tdb_unlockkeys(TDB_CONTEXT *tdb); +int tdb_lockall(TDB_CONTEXT *tdb); +void tdb_unlockall(TDB_CONTEXT *tdb); + +/* Low level locking functions: use with care */ +int tdb_chainlock(TDB_CONTEXT *tdb, TDB_DATA key); +void tdb_chainunlock(TDB_CONTEXT *tdb, TDB_DATA key); +extern TDB_DATA tdb_null; +#ifdef __cplusplus +} #endif + +#endif /* tdb.h */ diff --git a/source3/tdb/tdbutil.c b/source3/tdb/tdbutil.c index 92b8f9cbfb..3f17c0274e 100644 --- a/source3/tdb/tdbutil.c +++ b/source3/tdb/tdbutil.c @@ -32,7 +32,7 @@ int tdb_lock_bystring(TDB_CONTEXT *tdb, char *keyval) key.dptr = keyval; key.dsize = strlen(keyval)+1; - return tdb_lockchain(tdb, key); + return tdb_chainlock(tdb, key); } /* unlock a chain by string */ @@ -43,7 +43,7 @@ int tdb_unlock_bystring(TDB_CONTEXT *tdb, char *keyval) key.dptr = keyval; key.dsize = strlen(keyval)+1; - return tdb_unlockchain(tdb, key); + return tdb_chainunlock(tdb, key); } /* lock a chain by string key */ |