#include <ccan/build_assert/build_assert.h>
/* If we were threaded, we could wait for unlock, but we're not, so fail. */
-static bool owner_conflict(struct tdb_context *tdb, struct tdb_lock *lock)
+static enum TDB_ERROR owner_conflict(struct tdb_context *tdb, const char *call)
{
- if (lock->owner != tdb) {
- tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_USE_ERROR,
- "Lock already owned by another opener");
+ 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;
}
-static int fcntl_lock(struct tdb_context *tdb,
- int rw, off_t off, off_t len, bool waitflag)
+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;
- add_stat(tdb, lock_lowlevel, 1);
- if (waitflag)
- return fcntl(tdb->file->fd, F_SETLKW, &fl);
- else {
- add_stat(tdb, lock_nonblock, 1);
- return fcntl(tdb->file->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;
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->file->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
(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) {
+ 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) {
+ 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:"
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) {
+ /* 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",
+ " rw_type=%d len=%zu: %s",
tdb->file->fd, (size_t)offset, rw_type,
- (size_t)len);
+ (size_t)len, strerror(errno));
}
return TDB_SUCCESS;
}
{
int count = 1000;
+ 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:"
" 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,
tv.tv_usec = 1;
select(0, NULL, NULL, NULL, &tv);
}
- return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR,
- "tdb_allrecord_upgrade failed");
+
+ if (errno != EAGAIN && errno != EINTR)
+ tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR,
+ "tdb_allrecord_upgrade failed");
+ return TDB_ERR_LOCK;
}
static struct tdb_lock *find_nestlock(struct tdb_context *tdb, tdb_off_t offset,
{
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) {
if (tdb->flags & TDB_NOLOCK)
return TDB_SUCCESS;
- add_stat(tdb, locks, 1);
+ 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 (owner_conflict(tdb, new_lck))
- return -1;
+ if (new_lck->owner != tdb) {
+ return owner_conflict(tdb, "tdb_nest_lock");
+ }
if (new_lck->ltype == F_RDLCK && ltype == F_WRLCK) {
return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR,
return TDB_SUCCESS;
}
+#if 0
if (tdb->file->num_lockrecs
&& offset >= TDB_HASH_LOCK_START
&& offset < TDB_HASH_LOCK_START + TDB_HASH_LOCK_RANGE) {
return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR,
"tdb_nest_lock: already have a hash lock?");
}
+#endif
new_lck = (struct tdb_lock *)realloc(
tdb->file->lockrecs,
enum TDB_ERROR ecode;
tdb_bool_err berr;
- if (tdb->file->allrecord_lock.count
- && (ltype == F_RDLCK
- || tdb->file->allrecord_lock.ltype == F_WRLCK)) {
- tdb->file->allrecord_lock.count++;
+ if (tdb->flags & TDB_NOLOCK)
return TDB_SUCCESS;
+
+ if (!check_lock_pid(tdb, "tdb_allrecord_lock", true)) {
+ return TDB_ERR_LOCK;
}
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 */
return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_USE_ERROR,
"tdb_allrecord_lock: already have %s lock",
" can't upgrade a write lock");
}
- add_stat(tdb, locks, 1);
+ tdb->stats.locks++;
again:
/* Lock hashes, gradually. */
ecode = tdb_lock_gradual(tdb, ltype, flags, TDB_HASH_LOCK_START,
TDB_HASH_LOCK_RANGE);
- if (ecode != TDB_SUCCESS) {
- if (!(flags & TDB_LOCK_PROBE)) {
- tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
- "tdb_allrecord_lock hashes failed");
- }
+ 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) {
- if (!(flags & TDB_LOCK_PROBE)) {
- tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
- "tdb_allrecord_lock freetables failed");
- }
tdb_brunlock(tdb, ltype, TDB_HASH_LOCK_START,
TDB_HASH_LOCK_RANGE);
return ecode;
/* unlock entire db */
void tdb_allrecord_unlock(struct tdb_context *tdb, int ltype)
{
+ 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!");
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->file->allrecord_lock.count &&
- (ltype == tdb->file->allrecord_lock.ltype || ltype == F_RDLCK)) {
- return TDB_SUCCESS;
- }
-
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;
+ }
+
return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_USE_ERROR,
"tdb_lock_hashes:"
" already have %s allrecordlock",
" already have expansion lock");
}
- return tdb_nest_lock(tdb, lock, ltype, waitflag);
+ return tdb_nest_lock(tdb, l, ltype, waitflag);
}
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 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.
/* a allrecord lock allows us to avoid per chain locks */
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;
return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR,
tdb_nest_unlock(tdb, free_lock_off(b_off), F_WRLCK);
}
-void tdb_unlock_all(struct tdb_context *tdb)
+enum TDB_ERROR tdb_lockall(struct tdb_context *tdb)
+{
+ return tdb_allrecord_lock(tdb, F_WRLCK, TDB_LOCK_WAIT, false);
+}
+
+void tdb_unlockall(struct tdb_context *tdb)
+{
+ tdb_allrecord_unlock(tdb, F_WRLCK);
+}
+
+enum TDB_ERROR tdb_lockall_read(struct tdb_context *tdb)
+{
+ return tdb_allrecord_lock(tdb, F_RDLCK, TDB_LOCK_WAIT, false);
+}
+
+void tdb_unlockall_read(struct tdb_context *tdb)
+{
+ tdb_allrecord_unlock(tdb, F_RDLCK);
+}
+
+void tdb_lock_cleanup(struct tdb_context *tdb)
{
unsigned int i;
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