X-Git-Url: https://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftdb2%2Flock.c;h=4033d0afe813e59bf4dee4b8bcc9e5d34757c298;hp=60ed46379aa7b6960d51e5778c907945614b7c0f;hb=dc9da1e34fe6a9d113fd57e116ebbc6d5bd54819;hpb=49c1b2e371c2fa6c3e74cee8d8222d161454ffe4;ds=sidebyside diff --git a/ccan/tdb2/lock.c b/ccan/tdb2/lock.c index 60ed4637..4033d0af 100644 --- a/ccan/tdb2/lock.c +++ b/ccan/tdb2/lock.c @@ -1,4 +1,4 @@ - /* + /* Unix SMB/CIFS implementation. trivial database library @@ -29,26 +29,90 @@ #include #include -static int fcntl_lock(struct tdb_context *tdb, - int rw, off_t off, off_t len, bool waitflag) +/* If we were threaded, we could wait for unlock, but we're not, so fail. */ +static enum TDB_ERROR owner_conflict(struct tdb_context *tdb, const char *call) +{ + return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_USE_ERROR, + "%s: lock owned by another tdb in this process.", + call); +} + +/* If we fork, we no longer really own locks: preserves errno */ +static bool check_lock_pid(struct tdb_context *tdb, + const char *call, bool log) +{ + /* No locks? No problem! */ + if (tdb->file->allrecord_lock.count == 0 + && tdb->file->num_lockrecs == 0) { + return true; + } + + /* No fork? No problem! */ + if (tdb->file->locker == getpid()) { + return true; + } + + if (log) { + tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_USE_ERROR, + "%s: fork() detected after lock acquisition!" + " (%u vs %u)", call, tdb->file->locker, getpid()); + } + return false; +} + +int tdb_fcntl_lock(int fd, int rw, off_t off, off_t len, bool waitflag, + void *unused) { struct flock fl; + int ret; - fl.l_type = rw; - fl.l_whence = SEEK_SET; - fl.l_start = off; - fl.l_len = len; - fl.l_pid = 0; + do { + fl.l_type = rw; + fl.l_whence = SEEK_SET; + fl.l_start = off; + fl.l_len = len; - if (waitflag) - return fcntl(tdb->fd, F_SETLKW, &fl); - else - return fcntl(tdb->fd, F_SETLK, &fl); + if (waitflag) + ret = fcntl(fd, F_SETLKW, &fl); + else + ret = fcntl(fd, F_SETLK, &fl); + } while (ret != 0 && errno == EINTR); + return ret; } -static int fcntl_unlock(struct tdb_context *tdb, int rw, off_t off, off_t len) +int tdb_fcntl_unlock(int fd, int rw, off_t off, off_t len, void *unused) { struct flock fl; + int ret; + + do { + fl.l_type = F_UNLCK; + fl.l_whence = SEEK_SET; + fl.l_start = off; + fl.l_len = len; + + ret = fcntl(fd, F_SETLKW, &fl); + } while (ret != 0 && errno == EINTR); + return ret; +} + +static int lock(struct tdb_context *tdb, + int rw, off_t off, off_t len, bool waitflag) +{ + if (tdb->file->allrecord_lock.count == 0 + && tdb->file->num_lockrecs == 0) { + tdb->file->locker = getpid(); + } + + tdb->stats.lock_lowlevel++; + if (!waitflag) + tdb->stats.lock_nonblock++; + return tdb->lock_fn(tdb->file->fd, rw, off, len, waitflag, + tdb->lock_data); +} + +static int unlock(struct tdb_context *tdb, int rw, off_t off, off_t len) +{ #if 0 /* Check they matched up locks and unlocks correctly. */ char line[80]; FILE *locks; @@ -99,7 +163,7 @@ static int fcntl_unlock(struct tdb_context *tdb, int rw, off_t off, off_t len) } if (!found) { - fprintf(stderr, "Unlock on %u@%u not found!\n", + fprintf(stderr, "Unlock on %u@%u not found!", (int)off, (int)len); abort(); } @@ -107,122 +171,116 @@ static int fcntl_unlock(struct tdb_context *tdb, int rw, off_t off, off_t len) fclose(locks); #endif - fl.l_type = F_UNLCK; - fl.l_whence = SEEK_SET; - fl.l_start = off; - fl.l_len = len; - fl.l_pid = 0; - - return fcntl(tdb->fd, F_SETLKW, &fl); + return tdb->unlock_fn(tdb->file->fd, rw, off, len, tdb->lock_data); } /* a byte range locking function - return 0 on success - this functions locks/unlocks 1 byte at the specified offset. + this functions locks len bytes at the specified offset. note that a len of zero means lock to end of file */ -static int tdb_brlock(struct tdb_context *tdb, - int rw_type, tdb_off_t offset, tdb_off_t len, - enum tdb_lock_flags flags) +static enum TDB_ERROR tdb_brlock(struct tdb_context *tdb, + int rw_type, tdb_off_t offset, tdb_off_t len, + enum tdb_lock_flags flags) { int ret; if (tdb->flags & TDB_NOLOCK) { - return 0; + return TDB_SUCCESS; } if (rw_type == F_WRLCK && tdb->read_only) { - tdb->ecode = TDB_ERR_RDONLY; - return -1; + return tdb_logerr(tdb, TDB_ERR_RDONLY, TDB_LOG_USE_ERROR, + "Write lock attempted on read-only database"); } /* A 32 bit system cannot open a 64-bit file, but it could have * expanded since then: check here. */ if ((size_t)(offset + len) != offset + len) { - tdb->ecode = TDB_ERR_IO; - tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv, - "tdb_brlock: lock on giant offset %llu\n", - (long long)(offset + len)); - return -1; + return tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR, + "tdb_brlock: lock on giant offset %llu", + (long long)(offset + len)); } - do { - ret = fcntl_lock(tdb, rw_type, offset, len, - flags & TDB_LOCK_WAIT); - } while (ret == -1 && errno == EINTR); - - if (ret == -1) { - tdb->ecode = TDB_ERR_LOCK; + ret = lock(tdb, rw_type, offset, len, flags & TDB_LOCK_WAIT); + if (ret != 0) { /* Generic lock error. errno set by fcntl. * EAGAIN is an expected return from non-blocking * locks. */ - if (!(flags & TDB_LOCK_PROBE) && errno != EAGAIN) { - tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv, - "tdb_brlock failed (fd=%d) at" - " offset %llu rw_type=%d flags=%d len=%llu\n", - tdb->fd, (long long)offset, rw_type, - flags, (long long)len); + if (!(flags & TDB_LOCK_PROBE) + && (errno != EAGAIN && errno != EINTR)) { + tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR, + "tdb_brlock failed (fd=%d) at" + " offset %zu rw_type=%d flags=%d len=%zu:" + " %s", + tdb->file->fd, (size_t)offset, rw_type, + flags, (size_t)len, strerror(errno)); } - return -1; + return TDB_ERR_LOCK; } - return 0; + return TDB_SUCCESS; } -static int tdb_brunlock(struct tdb_context *tdb, - int rw_type, tdb_off_t offset, size_t len) +static enum TDB_ERROR tdb_brunlock(struct tdb_context *tdb, + int rw_type, tdb_off_t offset, size_t len) { int ret; if (tdb->flags & TDB_NOLOCK) { - return 0; + return TDB_SUCCESS; } - do { - ret = fcntl_unlock(tdb, rw_type, offset, len); - } while (ret == -1 && errno == EINTR); + ret = unlock(tdb, rw_type, offset, len); - if (ret == -1) { - tdb->log(tdb, TDB_DEBUG_TRACE, tdb->log_priv, - "tdb_brunlock failed (fd=%d) at offset %llu" - " rw_type=%d len=%llu\n", - tdb->fd, (long long)offset, rw_type, (long long)len); + /* If we fail, *then* we verify that we owned the lock. If not, ok. */ + if (ret == -1 && check_lock_pid(tdb, "tdb_brunlock", false)) { + return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR, + "tdb_brunlock failed (fd=%d) at offset %zu" + " rw_type=%d len=%zu: %s", + tdb->file->fd, (size_t)offset, rw_type, + (size_t)len, strerror(errno)); } - return ret; + return TDB_SUCCESS; } -#if 0 /* upgrade a read lock to a write lock. This needs to be handled in a special way as some OSes (such as solaris) have too conservative deadlock detection and claim a deadlock when progress can be - made. For those OSes we may loop for a while. + made. For those OSes we may loop for a while. */ -int tdb_allrecord_upgrade(struct tdb_context *tdb) +enum TDB_ERROR tdb_allrecord_upgrade(struct tdb_context *tdb) { int count = 1000; - if (tdb->allrecord_lock.count != 1) { - tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv, - "tdb_allrecord_upgrade failed: count %u too high\n", - tdb->allrecord_lock.count); - return -1; + if (!check_lock_pid(tdb, "tdb_transaction_prepare_commit", true)) + return TDB_ERR_LOCK; + + if (tdb->file->allrecord_lock.count != 1) { + return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR, + "tdb_allrecord_upgrade failed:" + " count %u too high", + tdb->file->allrecord_lock.count); } - if (tdb->allrecord_lock.off != 1) { - tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv, - "tdb_allrecord_upgrade failed: already upgraded?\n"); - return -1; + if (tdb->file->allrecord_lock.off != 1) { + return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR, + "tdb_allrecord_upgrade failed:" + " already upgraded?"); + } + + if (tdb->file->allrecord_lock.owner != tdb) { + return owner_conflict(tdb, "tdb_allrecord_upgrade"); } while (count--) { struct timeval tv; if (tdb_brlock(tdb, F_WRLCK, - TDB_HASH_LOCK_START - + (1ULL << tdb->header.v.hash_bits), 0, - TDB_LOCK_WAIT|TDB_LOCK_PROBE) == 0) { - tdb->allrecord_lock.ltype = F_WRLCK; - tdb->allrecord_lock.off = 0; - return 0; + TDB_HASH_LOCK_START, 0, + TDB_LOCK_WAIT|TDB_LOCK_PROBE) == TDB_SUCCESS) { + tdb->file->allrecord_lock.ltype = F_WRLCK; + tdb->file->allrecord_lock.off = 0; + return TDB_SUCCESS; } if (errno != EDEADLK) { break; @@ -232,145 +290,169 @@ int tdb_allrecord_upgrade(struct tdb_context *tdb) tv.tv_usec = 1; select(0, NULL, NULL, NULL, &tv); } - tdb->log(tdb, TDB_DEBUG_WARNING, tdb->log_priv, - "tdb_allrecord_upgrade failed\n"); - return -1; + + if (errno != EAGAIN && errno != EINTR) + tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR, + "tdb_allrecord_upgrade failed"); + return TDB_ERR_LOCK; } -#endif -static struct tdb_lock_type *find_nestlock(struct tdb_context *tdb, - tdb_off_t offset) +static struct tdb_lock *find_nestlock(struct tdb_context *tdb, tdb_off_t offset, + const struct tdb_context *owner) { unsigned int i; - for (i=0; inum_lockrecs; i++) { - if (tdb->lockrecs[i].off == offset) { - return &tdb->lockrecs[i]; + for (i=0; ifile->num_lockrecs; i++) { + if (tdb->file->lockrecs[i].off == offset) { + if (owner && tdb->file->lockrecs[i].owner != owner) + return NULL; + return &tdb->file->lockrecs[i]; } } return NULL; } +enum TDB_ERROR tdb_lock_and_recover(struct tdb_context *tdb) +{ + enum TDB_ERROR ecode; + + if (!check_lock_pid(tdb, "tdb_transaction_prepare_commit", true)) + return TDB_ERR_LOCK; + + ecode = tdb_allrecord_lock(tdb, F_WRLCK, TDB_LOCK_WAIT|TDB_LOCK_NOCHECK, + false); + if (ecode != TDB_SUCCESS) { + return ecode; + } + + ecode = tdb_lock_open(tdb, TDB_LOCK_WAIT|TDB_LOCK_NOCHECK); + if (ecode != TDB_SUCCESS) { + tdb_allrecord_unlock(tdb, F_WRLCK); + return ecode; + } + ecode = tdb_transaction_recover(tdb); + tdb_unlock_open(tdb); + tdb_allrecord_unlock(tdb, F_WRLCK); + + return ecode; +} + /* lock an offset in the database. */ -static int tdb_nest_lock(struct tdb_context *tdb, tdb_off_t offset, int ltype, - enum tdb_lock_flags flags) +static enum TDB_ERROR tdb_nest_lock(struct tdb_context *tdb, + tdb_off_t offset, int ltype, + enum tdb_lock_flags flags) { - struct tdb_lock_type *new_lck; + struct tdb_lock *new_lck; + enum TDB_ERROR ecode; - if (offset > TDB_HASH_LOCK_START + TDB_HASH_LOCK_RANGE + tdb->map_size / 8) { - tdb->ecode = TDB_ERR_LOCK; - tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv, - "tdb_nest_lock: invalid offset %llu ltype=%d\n", - (long long)offset, ltype); - return -1; + if (offset > (TDB_HASH_LOCK_START + TDB_HASH_LOCK_RANGE + + tdb->file->map_size / 8)) { + return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR, + "tdb_nest_lock: invalid offset %zu ltype=%d", + (size_t)offset, ltype); } if (tdb->flags & TDB_NOLOCK) - return 0; + return TDB_SUCCESS; - new_lck = find_nestlock(tdb, offset); + if (!check_lock_pid(tdb, "tdb_nest_lock", true)) { + return TDB_ERR_LOCK; + } + + tdb->stats.locks++; + + new_lck = find_nestlock(tdb, offset, NULL); if (new_lck) { + if (new_lck->owner != tdb) { + return owner_conflict(tdb, "tdb_nest_lock"); + } + if (new_lck->ltype == F_RDLCK && ltype == F_WRLCK) { - tdb->ecode = TDB_ERR_LOCK; - tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv, - "tdb_nest_lock: offset %llu has read lock\n", - (long long)offset); - return -1; + return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR, + "tdb_nest_lock:" + " offset %zu has read lock", + (size_t)offset); } /* Just increment the struct, posix locks don't stack. */ new_lck->count++; - return 0; + return TDB_SUCCESS; } - if (tdb->num_lockrecs +#if 0 + if (tdb->file->num_lockrecs && offset >= TDB_HASH_LOCK_START && offset < TDB_HASH_LOCK_START + TDB_HASH_LOCK_RANGE) { - tdb->ecode = TDB_ERR_LOCK; - tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv, - "tdb_nest_lock: already have a hash lock?\n"); - return -1; + return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR, + "tdb_nest_lock: already have a hash lock?"); } +#endif - new_lck = (struct tdb_lock_type *)realloc( - tdb->lockrecs, - sizeof(*tdb->lockrecs) * (tdb->num_lockrecs+1)); + new_lck = (struct tdb_lock *)realloc( + tdb->file->lockrecs, + sizeof(*tdb->file->lockrecs) * (tdb->file->num_lockrecs+1)); if (new_lck == NULL) { - tdb->ecode = TDB_ERR_OOM; - tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv, - "tdb_nest_lock: unable to allocate %llu lock struct", - (long long)(tdb->num_lockrecs + 1)); - errno = ENOMEM; - return -1; + return tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR, + "tdb_nest_lock:" + " unable to allocate %zu lock struct", + tdb->file->num_lockrecs + 1); } - tdb->lockrecs = new_lck; + tdb->file->lockrecs = new_lck; /* Since fcntl locks don't nest, we do a lock for the first one, and simply bump the count for future ones */ - if (tdb_brlock(tdb, ltype, offset, 1, flags)) { - return -1; - } - - tdb->lockrecs[tdb->num_lockrecs].off = offset; - tdb->lockrecs[tdb->num_lockrecs].count = 1; - tdb->lockrecs[tdb->num_lockrecs].ltype = ltype; - tdb->num_lockrecs++; - - return 0; -} - -static int tdb_lock_and_recover(struct tdb_context *tdb) -{ -#if 0 /* FIXME */ - - int ret; - - /* We need to match locking order in transaction commit. */ - if (tdb_brlock(tdb, F_WRLCK, FREELIST_TOP, 0, TDB_LOCK_WAIT)) { - return -1; - } - - if (tdb_brlock(tdb, F_WRLCK, OPEN_LOCK, 1, TDB_LOCK_WAIT)) { - tdb_brunlock(tdb, F_WRLCK, FREELIST_TOP, 0); - return -1; + ecode = tdb_brlock(tdb, ltype, offset, 1, flags); + if (ecode != TDB_SUCCESS) { + return ecode; + } + + /* First time we grab a lock, perhaps someone died in commit? */ + if (!(flags & TDB_LOCK_NOCHECK) + && tdb->file->num_lockrecs == 0) { + tdb_bool_err berr = tdb_needs_recovery(tdb); + if (berr != false) { + tdb_brunlock(tdb, ltype, offset, 1); + + if (berr < 0) + return berr; + ecode = tdb_lock_and_recover(tdb); + if (ecode == TDB_SUCCESS) { + ecode = tdb_brlock(tdb, ltype, offset, 1, + flags); + } + if (ecode != TDB_SUCCESS) { + return ecode; + } + } } - ret = tdb_transaction_recover(tdb); - - tdb_brunlock(tdb, F_WRLCK, OPEN_LOCK, 1); - tdb_brunlock(tdb, F_WRLCK, FREELIST_TOP, 0); + tdb->file->lockrecs[tdb->file->num_lockrecs].owner = tdb; + tdb->file->lockrecs[tdb->file->num_lockrecs].off = offset; + tdb->file->lockrecs[tdb->file->num_lockrecs].count = 1; + tdb->file->lockrecs[tdb->file->num_lockrecs].ltype = ltype; + tdb->file->num_lockrecs++; - return ret; -#else - abort(); - return -1; -#endif -} - -static bool tdb_needs_recovery(struct tdb_context *tdb) -{ - /* FIXME */ - return false; + return TDB_SUCCESS; } -static int tdb_nest_unlock(struct tdb_context *tdb, tdb_off_t off, int ltype) +static enum TDB_ERROR tdb_nest_unlock(struct tdb_context *tdb, + tdb_off_t off, int ltype) { - int ret = -1; - struct tdb_lock_type *lck; + struct tdb_lock *lck; + enum TDB_ERROR ecode; if (tdb->flags & TDB_NOLOCK) - return 0; + return TDB_SUCCESS; - lck = find_nestlock(tdb, off); + lck = find_nestlock(tdb, off, tdb); if ((lck == NULL) || (lck->count == 0)) { - tdb->ecode = TDB_ERR_LOCK; - tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv, - "tdb_nest_unlock: no lock for %llu\n", (long long)off); - return -1; + return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR, + "tdb_nest_unlock: no lock for %zu", + (size_t)off); } if (lck->count > 1) { lck->count--; - return 0; + return TDB_SUCCESS; } /* @@ -379,43 +461,40 @@ static int tdb_nest_unlock(struct tdb_context *tdb, tdb_off_t off, int ltype) * element, we're about to overwrite it with the last array element * anyway. */ - ret = tdb_brunlock(tdb, ltype, off, 1); + ecode = tdb_brunlock(tdb, ltype, off, 1); /* * Shrink the array by overwriting the element just unlocked with the * last array element. */ - *lck = tdb->lockrecs[--tdb->num_lockrecs]; + *lck = tdb->file->lockrecs[--tdb->file->num_lockrecs]; - return ret; + return ecode; } -#if 0 /* get the transaction lock */ -int tdb_transaction_lock(struct tdb_context *tdb, int ltype, - enum tdb_lock_flags lockflags) +enum TDB_ERROR tdb_transaction_lock(struct tdb_context *tdb, int ltype) { - return tdb_nest_lock(tdb, TRANSACTION_LOCK, ltype, lockflags); + return tdb_nest_lock(tdb, TDB_TRANSACTION_LOCK, ltype, TDB_LOCK_WAIT); } /* release the transaction lock */ -int tdb_transaction_unlock(struct tdb_context *tdb, int ltype) +void tdb_transaction_unlock(struct tdb_context *tdb, int ltype) { - return tdb_nest_unlock(tdb, TRANSACTION_LOCK, ltype, false); + tdb_nest_unlock(tdb, TDB_TRANSACTION_LOCK, ltype); } -#endif /* We only need to lock individual bytes, but Linux merges consecutive locks * so we lock in contiguous ranges. */ -static int tdb_lock_gradual(struct tdb_context *tdb, - int ltype, enum tdb_lock_flags flags, - tdb_off_t off, tdb_off_t len) +static enum TDB_ERROR tdb_lock_gradual(struct tdb_context *tdb, + int ltype, enum tdb_lock_flags flags, + tdb_off_t off, tdb_off_t len) { - int ret; + enum TDB_ERROR ecode; enum tdb_lock_flags nb_flags = (flags & ~TDB_LOCK_WAIT); if (len <= 1) { @@ -426,116 +505,116 @@ static int tdb_lock_gradual(struct tdb_context *tdb, } /* First we try non-blocking. */ - ret = tdb_brlock(tdb, ltype, off, len, nb_flags); - if (ret == 0) { - return 0; + if (tdb_brlock(tdb, ltype, off, len, nb_flags) == TDB_SUCCESS) { + return TDB_SUCCESS; } /* Try locking first half, then second. */ - ret = tdb_lock_gradual(tdb, ltype, flags, off, len / 2); - if (ret == -1) - return -1; + ecode = tdb_lock_gradual(tdb, ltype, flags, off, len / 2); + if (ecode != TDB_SUCCESS) + return ecode; - ret = tdb_lock_gradual(tdb, ltype, flags, - off + len / 2, len - len / 2); - if (ret == -1) { + ecode = tdb_lock_gradual(tdb, ltype, flags, + off + len / 2, len - len / 2); + if (ecode != TDB_SUCCESS) { tdb_brunlock(tdb, ltype, off, len / 2); - return -1; } - return 0; + return ecode; } /* lock/unlock entire database. It can only be upgradable if you have some * other way of guaranteeing exclusivity (ie. transaction write lock). */ -int tdb_allrecord_lock(struct tdb_context *tdb, int ltype, - enum tdb_lock_flags flags, bool upgradable) +enum TDB_ERROR tdb_allrecord_lock(struct tdb_context *tdb, int ltype, + enum tdb_lock_flags flags, bool upgradable) { - /* FIXME: There are no locks on read-only dbs */ - if (tdb->read_only) { - tdb->ecode = TDB_ERR_LOCK; - tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv, - "tdb_allrecord_lock: read-only\n"); - return -1; - } + enum TDB_ERROR ecode; + tdb_bool_err berr; - if (tdb->allrecord_lock.count - && (ltype == F_RDLCK || tdb->allrecord_lock.ltype == F_WRLCK)) { - tdb->allrecord_lock.count++; - return 0; + if (tdb->flags & TDB_NOLOCK) + return TDB_SUCCESS; + + if (!check_lock_pid(tdb, "tdb_allrecord_lock", true)) { + return TDB_ERR_LOCK; } - if (tdb->allrecord_lock.count) { + if (tdb->file->allrecord_lock.count) { + if (tdb->file->allrecord_lock.owner != tdb) { + return owner_conflict(tdb, "tdb_allrecord_lock"); + } + + if (ltype == F_RDLCK + || tdb->file->allrecord_lock.ltype == F_WRLCK) { + tdb->file->allrecord_lock.count++; + return TDB_SUCCESS; + } + /* a global lock of a different type exists */ - tdb->ecode = TDB_ERR_LOCK; - tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv, - "tdb_allrecord_lock: already have %s lock\n", - tdb->allrecord_lock.ltype == F_RDLCK - ? "read" : "write"); - return -1; + return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_USE_ERROR, + "tdb_allrecord_lock: already have %s lock", + tdb->file->allrecord_lock.ltype == F_RDLCK + ? "read" : "write"); } - if (tdb_has_locks(tdb)) { + if (tdb_has_hash_locks(tdb)) { /* can't combine global and chain locks */ - tdb->ecode = TDB_ERR_LOCK; - tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv, - "tdb_allrecord_lock: already have chain lock\n"); - return -1; + return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_USE_ERROR, + "tdb_allrecord_lock:" + " already have chain lock"); } if (upgradable && ltype != F_RDLCK) { /* tdb error: you can't upgrade a write lock! */ - tdb->ecode = TDB_ERR_LOCK; - tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv, - "tdb_allrecord_lock: can't upgrade a write lock\n"); - return -1; + return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR, + "tdb_allrecord_lock:" + " can't upgrade a write lock"); } + tdb->stats.locks++; again: /* Lock hashes, gradually. */ - if (tdb_lock_gradual(tdb, ltype, flags, TDB_HASH_LOCK_START, - TDB_HASH_LOCK_RANGE)) { - if (!(flags & TDB_LOCK_PROBE)) { - tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv, - "tdb_allrecord_lock hashes failed (%s)\n", - strerror(errno)); - } - return -1; - } - - /* Lock free lists: there to end of file. */ - if (tdb_brlock(tdb, ltype, TDB_HASH_LOCK_START + TDB_HASH_LOCK_RANGE, - 0, flags)) { - if (!(flags & TDB_LOCK_PROBE)) { - tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv, - "tdb_allrecord_lock freelist failed (%s)\n", - strerror(errno)); - } - tdb_brunlock(tdb, ltype, TDB_HASH_LOCK_START, + ecode = tdb_lock_gradual(tdb, ltype, flags, TDB_HASH_LOCK_START, + TDB_HASH_LOCK_RANGE); + if (ecode != TDB_SUCCESS) + return ecode; + + /* Lock free tables: there to end of file. */ + ecode = tdb_brlock(tdb, ltype, + TDB_HASH_LOCK_START + TDB_HASH_LOCK_RANGE, + 0, flags); + if (ecode != TDB_SUCCESS) { + tdb_brunlock(tdb, ltype, TDB_HASH_LOCK_START, TDB_HASH_LOCK_RANGE); - return -1; + return ecode; } - tdb->allrecord_lock.count = 1; + tdb->file->allrecord_lock.owner = tdb; + tdb->file->allrecord_lock.count = 1; /* If it's upgradable, it's actually exclusive so we can treat * it as a write lock. */ - tdb->allrecord_lock.ltype = upgradable ? F_WRLCK : ltype; - tdb->allrecord_lock.off = upgradable; + tdb->file->allrecord_lock.ltype = upgradable ? F_WRLCK : ltype; + tdb->file->allrecord_lock.off = upgradable; /* Now check for needing recovery. */ - if (unlikely(tdb_needs_recovery(tdb))) { - tdb_allrecord_unlock(tdb, ltype); - if (tdb_lock_and_recover(tdb) == -1) { - return -1; - } - goto again; - } + if (flags & TDB_LOCK_NOCHECK) + return TDB_SUCCESS; + + berr = tdb_needs_recovery(tdb); + if (likely(berr == false)) + return TDB_SUCCESS; - return 0; + tdb_allrecord_unlock(tdb, ltype); + if (berr < 0) + return berr; + ecode = tdb_lock_and_recover(tdb); + if (ecode != TDB_SUCCESS) { + return ecode; + } + goto again; } -int tdb_lock_open(struct tdb_context *tdb) +enum TDB_ERROR tdb_lock_open(struct tdb_context *tdb, enum tdb_lock_flags flags) { - return tdb_nest_lock(tdb, TDB_OPEN_LOCK, F_WRLCK, TDB_LOCK_WAIT); + return tdb_nest_lock(tdb, TDB_OPEN_LOCK, F_WRLCK, flags); } void tdb_unlock_open(struct tdb_context *tdb) @@ -543,9 +622,17 @@ void tdb_unlock_open(struct tdb_context *tdb) tdb_nest_unlock(tdb, TDB_OPEN_LOCK, F_WRLCK); } -int tdb_lock_expand(struct tdb_context *tdb, int ltype) +bool tdb_has_open_lock(struct tdb_context *tdb) +{ + return !(tdb->flags & TDB_NOLOCK) + && find_nestlock(tdb, TDB_OPEN_LOCK, tdb) != NULL; +} + +enum TDB_ERROR tdb_lock_expand(struct tdb_context *tdb, int ltype) { - return tdb_nest_lock(tdb, TDB_EXPANSION_LOCK, ltype, TDB_LOCK_WAIT); + /* Lock doesn't protect data, so don't check (we recurse if we do!) */ + return tdb_nest_lock(tdb, TDB_EXPANSION_LOCK, ltype, + TDB_LOCK_WAIT | TDB_LOCK_NOCHECK); } void tdb_unlock_expand(struct tdb_context *tdb, int ltype) @@ -554,174 +641,140 @@ void tdb_unlock_expand(struct tdb_context *tdb, int ltype) } /* unlock entire db */ -int tdb_allrecord_unlock(struct tdb_context *tdb, int ltype) +void tdb_allrecord_unlock(struct tdb_context *tdb, int ltype) { - /* FIXME: There are no locks on read-only dbs */ - if (tdb->read_only) { - tdb->ecode = TDB_ERR_LOCK; - tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv, - "tdb_allrecord_unlock: read-only\n"); - return -1; + if (tdb->flags & TDB_NOLOCK) + return; + + if (tdb->file->allrecord_lock.count == 0) { + tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_USE_ERROR, + "tdb_allrecord_unlock: not locked!"); + return; } - if (tdb->allrecord_lock.count == 0) { - tdb->ecode = TDB_ERR_LOCK; - tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv, - "tdb_allrecord_unlock: not locked!\n"); - return -1; + if (tdb->file->allrecord_lock.owner != tdb) { + tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_USE_ERROR, + "tdb_allrecord_unlock: not locked by us!"); + return; } /* Upgradable locks are marked as write locks. */ - if (tdb->allrecord_lock.ltype != ltype - && (!tdb->allrecord_lock.off || ltype != F_RDLCK)) { - tdb->ecode = TDB_ERR_LOCK; - tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv, - "tdb_allrecord_unlock: have %s lock\n", - tdb->allrecord_lock.ltype == F_RDLCK - ? "read" : "write"); - return -1; - } - - if (tdb->allrecord_lock.count > 1) { - tdb->allrecord_lock.count--; - return 0; + if (tdb->file->allrecord_lock.ltype != ltype + && (!tdb->file->allrecord_lock.off || ltype != F_RDLCK)) { + tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR, + "tdb_allrecord_unlock: have %s lock", + tdb->file->allrecord_lock.ltype == F_RDLCK + ? "read" : "write"); + return; } - tdb->allrecord_lock.count = 0; - tdb->allrecord_lock.ltype = 0; - - return tdb_brunlock(tdb, ltype, TDB_HASH_LOCK_START, 0); -} - -bool tdb_has_expansion_lock(struct tdb_context *tdb) -{ - return find_nestlock(tdb, TDB_EXPANSION_LOCK) != NULL; -} - -bool tdb_has_locks(struct tdb_context *tdb) -{ - return tdb->allrecord_lock.count || tdb->num_lockrecs; -} - -#if 0 -/* lock entire database with write lock */ -int tdb_lockall(struct tdb_context *tdb) -{ - tdb_trace(tdb, "tdb_lockall"); - return tdb_allrecord_lock(tdb, F_WRLCK, TDB_LOCK_WAIT, false); -} + if (tdb->file->allrecord_lock.count > 1) { + tdb->file->allrecord_lock.count--; + return; + } -/* lock entire database with write lock - nonblocking varient */ -int tdb_lockall_nonblock(struct tdb_context *tdb) -{ - int ret = tdb_allrecord_lock(tdb, F_WRLCK, TDB_LOCK_NOWAIT, false); - tdb_trace_ret(tdb, "tdb_lockall_nonblock", ret); - return ret; -} + tdb->file->allrecord_lock.count = 0; + tdb->file->allrecord_lock.ltype = 0; -/* unlock entire database with write lock */ -int tdb_unlockall(struct tdb_context *tdb) -{ - tdb_trace(tdb, "tdb_unlockall"); - return tdb_allrecord_unlock(tdb, F_WRLCK); + tdb_brunlock(tdb, ltype, TDB_HASH_LOCK_START, 0); } -/* lock entire database with read lock */ -int tdb_lockall_read(struct tdb_context *tdb) +bool tdb_has_expansion_lock(struct tdb_context *tdb) { - tdb_trace(tdb, "tdb_lockall_read"); - return tdb_allrecord_lock(tdb, F_RDLCK, TDB_LOCK_WAIT, false); + return find_nestlock(tdb, TDB_EXPANSION_LOCK, tdb) != NULL; } -/* lock entire database with read lock - nonblock varient */ -int tdb_lockall_read_nonblock(struct tdb_context *tdb) +bool tdb_has_hash_locks(struct tdb_context *tdb) { - int ret = tdb_allrecord_lock(tdb, F_RDLCK, TDB_LOCK_NOWAIT, false); - tdb_trace_ret(tdb, "tdb_lockall_read_nonblock", ret); - return ret; -} + unsigned int i; -/* unlock entire database with read lock */ -int tdb_unlockall_read(struct tdb_context *tdb) -{ - tdb_trace(tdb, "tdb_unlockall_read"); - return tdb_allrecord_unlock(tdb, F_RDLCK); + for (i=0; ifile->num_lockrecs; i++) { + if (tdb->file->lockrecs[i].off >= TDB_HASH_LOCK_START + && tdb->file->lockrecs[i].off < (TDB_HASH_LOCK_START + + TDB_HASH_LOCK_RANGE)) + return true; + } + return false; } -#endif static bool tdb_has_free_lock(struct tdb_context *tdb) { unsigned int i; - for (i=0; inum_lockrecs; i++) { - if (tdb->lockrecs[i].off + if (tdb->flags & TDB_NOLOCK) + return false; + + for (i=0; ifile->num_lockrecs; i++) { + if (tdb->file->lockrecs[i].off > TDB_HASH_LOCK_START + TDB_HASH_LOCK_RANGE) return true; } return false; } -int tdb_lock_hashes(struct tdb_context *tdb, - tdb_off_t hash_lock, - tdb_len_t hash_range, - int ltype, enum tdb_lock_flags waitflag) +enum TDB_ERROR tdb_lock_hashes(struct tdb_context *tdb, + tdb_off_t hash_lock, + tdb_len_t hash_range, + int ltype, enum tdb_lock_flags waitflag) { /* FIXME: Do this properly, using hlock_range */ - unsigned lock = TDB_HASH_LOCK_START + unsigned l = TDB_HASH_LOCK_START + (hash_lock >> (64 - TDB_HASH_LOCK_RANGE_BITS)); /* a allrecord lock allows us to avoid per chain locks */ - if (tdb->allrecord_lock.count && - (ltype == tdb->allrecord_lock.ltype || ltype == F_RDLCK)) { - return 0; - } + if (tdb->file->allrecord_lock.count) { + if (!check_lock_pid(tdb, "tdb_lock_hashes", true)) + return TDB_ERR_LOCK; + + if (tdb->file->allrecord_lock.owner != tdb) + return owner_conflict(tdb, "tdb_lock_hashes"); + if (ltype == tdb->file->allrecord_lock.ltype + || ltype == F_RDLCK) { + return TDB_SUCCESS; + } - if (tdb->allrecord_lock.count) { - tdb->ecode = TDB_ERR_LOCK; - tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv, - "tdb_lock_hashes: have %s allrecordlock\n", - tdb->allrecord_lock.ltype == F_RDLCK - ? "read" : "write"); - return -1; + return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_USE_ERROR, + "tdb_lock_hashes:" + " already have %s allrecordlock", + tdb->file->allrecord_lock.ltype == F_RDLCK + ? "read" : "write"); } if (tdb_has_free_lock(tdb)) { - tdb->ecode = TDB_ERR_LOCK; - tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv, - "tdb_lock_hashes: have free lock already\n"); - return -1; + return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR, + "tdb_lock_hashes: already have free lock"); } if (tdb_has_expansion_lock(tdb)) { - tdb->ecode = TDB_ERR_LOCK; - tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv, - "tdb_lock_hashes: have expansion lock already\n"); - return -1; + return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR, + "tdb_lock_hashes:" + " already have expansion lock"); } - return tdb_nest_lock(tdb, lock, ltype, waitflag); + return tdb_nest_lock(tdb, l, ltype, waitflag); } -int tdb_unlock_hashes(struct tdb_context *tdb, - tdb_off_t hash_lock, - tdb_len_t hash_range, int ltype) +enum TDB_ERROR tdb_unlock_hashes(struct tdb_context *tdb, + tdb_off_t hash_lock, + tdb_len_t hash_range, int ltype) { - unsigned lock = TDB_HASH_LOCK_START + unsigned l = TDB_HASH_LOCK_START + (hash_lock >> (64 - TDB_HASH_LOCK_RANGE_BITS)); + if (tdb->flags & TDB_NOLOCK) + return 0; + /* a allrecord lock allows us to avoid per chain locks */ - if (tdb->allrecord_lock.count) { - if (tdb->allrecord_lock.ltype == F_RDLCK + if (tdb->file->allrecord_lock.count) { + if (tdb->file->allrecord_lock.ltype == F_RDLCK && ltype == F_WRLCK) { - tdb->ecode = TDB_ERR_LOCK; - tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv, - "tdb_unlock_hashes RO allrecord!\n"); - return -1; + return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR, + "tdb_unlock_hashes RO allrecord!"); } - return 0; + return TDB_SUCCESS; } - return tdb_nest_unlock(tdb, lock, ltype); + return tdb_nest_unlock(tdb, l, ltype); } /* Hash locks use TDB_HASH_LOCK_START + the next 30 bits. @@ -735,27 +788,31 @@ static tdb_off_t free_lock_off(tdb_off_t b_off) + b_off / sizeof(tdb_off_t); } -int tdb_lock_free_bucket(struct tdb_context *tdb, tdb_off_t b_off, - enum tdb_lock_flags waitflag) +enum TDB_ERROR tdb_lock_free_bucket(struct tdb_context *tdb, tdb_off_t b_off, + enum tdb_lock_flags waitflag) { assert(b_off >= sizeof(struct tdb_header)); + if (tdb->flags & TDB_NOLOCK) + return 0; + /* a allrecord lock allows us to avoid per chain locks */ - if (tdb->allrecord_lock.count) { - if (tdb->allrecord_lock.ltype == F_WRLCK) + if (tdb->file->allrecord_lock.count) { + if (!check_lock_pid(tdb, "tdb_lock_free_bucket", true)) + return TDB_ERR_LOCK; + + if (tdb->file->allrecord_lock.ltype == F_WRLCK) return 0; - tdb->ecode = TDB_ERR_LOCK; - tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv, - "tdb_lock_free_bucket with RO allrecordlock!\n"); - return -1; + return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR, + "tdb_lock_free_bucket with" + " read-only allrecordlock!"); } #if 0 /* FIXME */ if (tdb_has_expansion_lock(tdb)) { - tdb->ecode = TDB_ERR_LOCK; - tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv, - "tdb_lock_free_bucket: have expansion lock already\n"); - return -1; + return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR, + "tdb_lock_free_bucket:" + " already have expansion lock"); } #endif @@ -764,126 +821,47 @@ int tdb_lock_free_bucket(struct tdb_context *tdb, tdb_off_t b_off, void tdb_unlock_free_bucket(struct tdb_context *tdb, tdb_off_t b_off) { - if (tdb->allrecord_lock.count) + if (tdb->file->allrecord_lock.count) return; tdb_nest_unlock(tdb, free_lock_off(b_off), F_WRLCK); } -#if 0 -/* lock/unlock one hash chain, non-blocking. This is meant to be used - to reduce contention - it cannot guarantee how many records will be - locked */ -int tdb_chainlock_nonblock(struct tdb_context *tdb, TDB_DATA key) -{ - return chainlock(tdb, &key, F_WRLCK, TDB_LOCK_NOWAIT, - "tdb_chainlock_nonblock"); -} - -int tdb_chainlock_read(struct tdb_context *tdb, TDB_DATA key) -{ - return chainlock(tdb, &key, F_RDLCK, TDB_LOCK_WAIT, - "tdb_chainlock_read"); -} - -int tdb_chainunlock_read(struct tdb_context *tdb, TDB_DATA key) +enum TDB_ERROR tdb_lockall(struct tdb_context *tdb) { - uint64_t h = tdb_hash(tdb, key.dptr, key.dsize); - tdb_trace_1rec(tdb, "tdb_chainunlock_read", key); - return tdb_unlock_list(tdb, h & ((1ULL << tdb->header.v.hash_bits)-1), - F_RDLCK); + return tdb_allrecord_lock(tdb, F_WRLCK, TDB_LOCK_WAIT, false); } -/* record lock stops delete underneath */ -int tdb_lock_record(struct tdb_context *tdb, tdb_off_t off) +void tdb_unlockall(struct tdb_context *tdb) { - if (tdb->allrecord_lock.count) { - return 0; - } - return off ? tdb_brlock(tdb, F_RDLCK, off, 1, TDB_LOCK_WAIT) : 0; -} - -/* - Write locks override our own fcntl readlocks, so check it here. - Note this is meant to be F_SETLK, *not* F_SETLKW, as it's not - an error to fail to get the lock here. -*/ -int tdb_write_lock_record(struct tdb_context *tdb, tdb_off_t off) -{ - struct tdb_traverse_lock *i; - for (i = &tdb->travlocks; i; i = i->next) - if (i->off == off) - return -1; - if (tdb->allrecord_lock.count) { - if (tdb->allrecord_lock.ltype == F_WRLCK) { - return 0; - } - return -1; - } - return tdb_brlock(tdb, F_WRLCK, off, 1, TDB_LOCK_NOWAIT|TDB_LOCK_PROBE); + tdb_allrecord_unlock(tdb, F_WRLCK); } -int tdb_write_unlock_record(struct tdb_context *tdb, tdb_off_t off) +enum TDB_ERROR tdb_lockall_read(struct tdb_context *tdb) { - if (tdb->allrecord_lock.count) { - return 0; - } - return tdb_brunlock(tdb, F_WRLCK, off, 1); + return tdb_allrecord_lock(tdb, F_RDLCK, TDB_LOCK_WAIT, false); } -/* fcntl locks don't stack: avoid unlocking someone else's */ -int tdb_unlock_record(struct tdb_context *tdb, tdb_off_t off) +void tdb_unlockall_read(struct tdb_context *tdb) { - struct tdb_traverse_lock *i; - uint32_t count = 0; - - if (tdb->allrecord_lock.count) { - return 0; - } - - if (off == 0) - return 0; - for (i = &tdb->travlocks; i; i = i->next) - if (i->off == off) - count++; - return (count == 1 ? tdb_brunlock(tdb, F_RDLCK, off, 1) : 0); + tdb_allrecord_unlock(tdb, F_RDLCK); } -/* The transaction code uses this to remove all locks. */ -void tdb_release_transaction_locks(struct tdb_context *tdb) +void tdb_lock_cleanup(struct tdb_context *tdb) { unsigned int i; - if (tdb->allrecord_lock.count != 0) { - tdb_off_t hash_size, free_size; - - hash_size = (1ULL << tdb->header.v.hash_bits) - * sizeof(tdb_off_t); - free_size = tdb->header.v.free_zones - * (tdb->header.v.free_buckets + 1) * sizeof(tdb_off_t); - - tdb_brunlock(tdb, tdb->allrecord_lock.ltype, - tdb->header.v.hash_off, hash_size); - tdb_brunlock(tdb, tdb->allrecord_lock.ltype, - tdb->header.v.free_off, free_size); - tdb->allrecord_lock.count = 0; - tdb->allrecord_lock.ltype = 0; + while (tdb->file->allrecord_lock.count + && tdb->file->allrecord_lock.owner == tdb) { + tdb_allrecord_unlock(tdb, tdb->file->allrecord_lock.ltype); } - for (i = 0; inum_lockrecs; i++) { - struct tdb_lock_type *lck = &tdb->lockrecs[i]; - - tdb_brunlock(tdb, lck->ltype, lck->off, 1); + for (i=0; ifile->num_lockrecs; i++) { + if (tdb->file->lockrecs[i].owner == tdb) { + tdb_nest_unlock(tdb, + tdb->file->lockrecs[i].off, + tdb->file->lockrecs[i].ltype); + i--; + } } - tdb->num_lockrecs = 0; - SAFE_FREE(tdb->lockrecs); - tdb->header_uptodate = false; -} -#endif - -void tdb_lock_init(struct tdb_context *tdb) -{ - tdb->num_lockrecs = 0; - tdb->lockrecs = NULL; - tdb->allrecord_lock.count = 0; }