call);
}
-/* If we fork, we no longer really own locks. */
+/* 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)
{
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;
+
+ do {
+ fl.l_type = rw;
+ fl.l_whence = SEEK_SET;
+ fl.l_start = off;
+ fl.l_len = len;
+
+ if (waitflag)
+ ret = fcntl(fd, F_SETLKW, &fl);
+ else
+ ret = fcntl(fd, F_SETLK, &fl);
+ } while (ret != 0 && errno == EINTR);
+ return ret;
+}
+
+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;
- fl.l_type = rw;
- fl.l_whence = SEEK_SET;
- fl.l_start = off;
- fl.l_len = len;
- fl.l_pid = 0;
+ 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();
}
add_stat(tdb, lock_lowlevel, 1);
- if (waitflag)
- return fcntl(tdb->file->fd, F_SETLKW, &fl);
- else {
+ if (!waitflag)
add_stat(tdb, lock_nonblock, 1);
- return fcntl(tdb->file->fd, F_SETLK, &fl);
- }
+ return tdb->lock_fn(tdb->file->fd, rw, off, len, waitflag,
+ tdb->lock_data);
}
-static int fcntl_unlock(struct tdb_context *tdb, int rw, off_t off, off_t len)
+static int unlock(struct tdb_context *tdb, int rw, off_t off, off_t len)
{
- struct flock fl;
#if 0 /* Check they matched up locks and unlocks correctly. */
char line[80];
FILE *locks;
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 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;
}
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,
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 */
" 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.
tdb->access = NULL;
tdb->last_error = TDB_SUCCESS;
tdb->file = NULL;
+ tdb->lock_fn = fcntl_lock;
+ tdb->unlock_fn = fcntl_unlock;
tdb_hash_init(tdb);
tdb_io_init(tdb);
case TDB_ATTRIBUTE_OPENHOOK:
openhook = &attr->openhook;
break;
+ case TDB_ATTRIBUTE_FLOCK:
+ tdb->lock_fn = attr->flock.lock;
+ tdb->unlock_fn = attr->flock.unlock;
+ tdb->lock_data = attr->flock.data;
+ break;
default:
ecode = tdb_logerr(tdb, TDB_ERR_EINVAL,
TDB_LOG_USE_ERROR,
/* ensure there is only one process initialising at once */
ecode = tdb_lock_open(tdb, TDB_LOCK_WAIT|TDB_LOCK_NOCHECK);
if (ecode != TDB_SUCCESS) {
- goto fail;
+ saved_errno = errno;
+ goto fail_errno;
}
/* call their open hook if they gave us one. */
void *hash_data;
uint64_t hash_seed;
+ /* low level (fnctl) lock functions. */
+ int (*lock_fn)(int fd, int rw, off_t off, off_t len, bool w, void *);
+ int (*unlock_fn)(int fd, int rw, off_t off, off_t len, void *);
+ void *lock_data;
+
/* Set if we are in a transaction. */
struct tdb_transaction *transaction;
/* If it needs recovery, grab all the locks and do it. */
enum TDB_ERROR tdb_lock_and_recover(struct tdb_context *tdb);
+/* Default lock and unlock functions. */
+int tdb_fcntl_lock(int fd, int rw, off_t off, off_t len, bool waitflag, void *);
+int tdb_fcntl_unlock(int fd, int rw, off_t off, off_t len, void *);
+
/* transaction.c: */
enum TDB_ERROR tdb_transaction_recover(struct tdb_context *tdb);
tdb_bool_err tdb_needs_recovery(struct tdb_context *tdb);
TDB_ATTRIBUTE_HASH = 1,
TDB_ATTRIBUTE_SEED = 2,
TDB_ATTRIBUTE_STATS = 3,
- TDB_ATTRIBUTE_OPENHOOK = 4
+ TDB_ATTRIBUTE_OPENHOOK = 4,
+ TDB_ATTRIBUTE_FLOCK = 5
};
/**
void *data;
};
+/**
+ * struct tdb_attribute_flock - tdb special effects hook for file locking
+ *
+ * This attribute contains function to call to place locks on a file; it can
+ * be used to support non-blocking operations or lock proxying.
+ *
+ * They should return 0 on success, -1 on failure and set errno.
+ *
+ * An error will be logged on error if errno is neither EAGAIN nor EINTR
+ * (normally it would only return EAGAIN if waitflag is false, and
+ * loop internally on EINTR).
+ */
+struct tdb_attribute_flock {
+ struct tdb_attribute_base base; /* .attr = TDB_ATTRIBUTE_FLOCK */
+ int (*lock)(int fd,int rw, off_t off, off_t len, bool waitflag, void *);
+ int (*unlock)(int fd, int rw, off_t off, off_t len, void *);
+ void *data;
+};
+
/**
* union tdb_attribute - tdb attributes.
*
* See also:
* struct tdb_attribute_log, struct tdb_attribute_hash,
* struct tdb_attribute_seed, struct tdb_attribute_stats,
- * struct tdb_attribute_openhook.
+ * struct tdb_attribute_openhook, struct tdb_attribute_flock.
*/
union tdb_attribute {
struct tdb_attribute_base base;
struct tdb_attribute_seed seed;
struct tdb_attribute_stats stats;
struct tdb_attribute_openhook openhook;
+ struct tdb_attribute_flock flock;
};
#ifdef __cplusplus
--- /dev/null
+#include <ccan/tdb2/tdb.c>
+#include <ccan/tdb2/open.c>
+#include <ccan/tdb2/free.c>
+#include <ccan/tdb2/lock.c>
+#include <ccan/tdb2/io.c>
+#include <ccan/tdb2/hash.c>
+#include <ccan/tdb2/check.c>
+#include <ccan/tdb2/transaction.c>
+#include <ccan/tdb2/traverse.c>
+#include <ccan/tap/tap.h>
+#include "logging.h"
+
+static int mylock(int fd, int rw, off_t off, off_t len, bool waitflag,
+ void *_err)
+{
+ int *lock_err = _err;
+ struct flock fl;
+ int ret;
+
+ if (*lock_err) {
+ errno = *lock_err;
+ return -1;
+ }
+
+ do {
+ fl.l_type = rw;
+ fl.l_whence = SEEK_SET;
+ fl.l_start = off;
+ fl.l_len = len;
+
+ if (waitflag)
+ ret = fcntl(fd, F_SETLKW, &fl);
+ else
+ ret = fcntl(fd, F_SETLK, &fl);
+ } while (ret != 0 && errno == EINTR);
+
+ return ret;
+}
+
+static int myunlock(int fd, int rw, off_t off, off_t len, void *_err)
+{
+ int *lock_err = _err;
+ struct flock fl;
+ int ret;
+
+ if (*lock_err) {
+ errno = *lock_err;
+ return -1;
+ }
+
+ 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 trav_err;
+static int trav(struct tdb_context *tdb, TDB_DATA k, TDB_DATA d, int *err)
+{
+ *err = trav_err;
+ return 0;
+}
+
+int main(int argc, char *argv[])
+{
+ unsigned int i;
+ struct tdb_context *tdb;
+ int flags[] = { TDB_DEFAULT, TDB_NOMMAP,
+ TDB_CONVERT, TDB_NOMMAP|TDB_CONVERT };
+ union tdb_attribute lock_attr;
+ struct tdb_data key = tdb_mkdata("key", 3);
+ struct tdb_data data = tdb_mkdata("data", 4);
+ int lock_err;
+
+ lock_attr.base.attr = TDB_ATTRIBUTE_FLOCK;
+ lock_attr.base.next = &tap_log_attr;
+ lock_attr.flock.lock = mylock;
+ lock_attr.flock.unlock = myunlock;
+ lock_attr.flock.data = &lock_err;
+
+ plan_tests(sizeof(flags) / sizeof(flags[0]) * 80);
+
+ for (i = 0; i < sizeof(flags) / sizeof(flags[0]); i++) {
+ struct tdb_data d;
+
+ /* Nonblocking open; expect no error message. */
+ lock_err = EAGAIN;
+ tdb = tdb_open("run-82-lockattr.tdb", flags[i],
+ O_RDWR|O_CREAT|O_TRUNC, 0600, &lock_attr);
+ ok(errno == lock_err, "Errno is %u", errno);
+ ok1(!tdb);
+ ok1(tap_log_messages == 0);
+
+ lock_err = EINTR;
+ tdb = tdb_open("run-82-lockattr.tdb", flags[i],
+ O_RDWR|O_CREAT|O_TRUNC, 0600, &lock_attr);
+ ok(errno == lock_err, "Errno is %u", errno);
+ ok1(!tdb);
+ ok1(tap_log_messages == 0);
+
+ /* Forced fail open. */
+ lock_err = ENOMEM;
+ tdb = tdb_open("run-82-lockattr.tdb", flags[i],
+ O_RDWR|O_CREAT|O_TRUNC, 0600, &lock_attr);
+ ok1(errno == lock_err);
+ ok1(!tdb);
+ ok1(tap_log_messages == 1);
+ tap_log_messages = 0;
+
+ lock_err = 0;
+ tdb = tdb_open("run-82-lockattr.tdb", flags[i],
+ O_RDWR|O_CREAT|O_TRUNC, 0600, &lock_attr);
+ if (!ok1(tdb))
+ continue;
+ ok1(tap_log_messages == 0);
+
+ /* Nonblocking store. */
+ lock_err = EAGAIN;
+ ok1(tdb_store(tdb, key, data, TDB_REPLACE) == TDB_ERR_LOCK);
+ ok1(tap_log_messages == 0);
+ lock_err = EINTR;
+ ok1(tdb_store(tdb, key, data, TDB_REPLACE) == TDB_ERR_LOCK);
+ ok1(tap_log_messages == 0);
+ lock_err = ENOMEM;
+ ok1(tdb_store(tdb, key, data, TDB_REPLACE) == TDB_ERR_LOCK);
+ ok1(tap_log_messages == 1);
+ tap_log_messages = 0;
+
+ /* Nonblocking fetch. */
+ lock_err = EAGAIN;
+ ok1(!tdb_exists(tdb, key));
+ ok1(tap_log_messages == 0);
+ lock_err = EINTR;
+ ok1(!tdb_exists(tdb, key));
+ ok1(tap_log_messages == 0);
+ lock_err = ENOMEM;
+ ok1(!tdb_exists(tdb, key));
+ ok1(tap_log_messages == 1);
+ tap_log_messages = 0;
+
+ lock_err = EAGAIN;
+ ok1(tdb_fetch(tdb, key, &d) == TDB_ERR_LOCK);
+ ok1(tap_log_messages == 0);
+ lock_err = EINTR;
+ ok1(tdb_fetch(tdb, key, &d) == TDB_ERR_LOCK);
+ ok1(tap_log_messages == 0);
+ lock_err = ENOMEM;
+ ok1(tdb_fetch(tdb, key, &d) == TDB_ERR_LOCK);
+ ok1(tap_log_messages == 1);
+ tap_log_messages = 0;
+
+ /* Nonblocking delete. */
+ lock_err = EAGAIN;
+ ok1(tdb_delete(tdb, key) == TDB_ERR_LOCK);
+ ok1(tap_log_messages == 0);
+ lock_err = EINTR;
+ ok1(tdb_delete(tdb, key) == TDB_ERR_LOCK);
+ ok1(tap_log_messages == 0);
+ lock_err = ENOMEM;
+ ok1(tdb_delete(tdb, key) == TDB_ERR_LOCK);
+ ok1(tap_log_messages == 1);
+ tap_log_messages = 0;
+
+ /* Nonblocking locks. */
+ lock_err = EAGAIN;
+ ok1(tdb_chainlock(tdb, key) == TDB_ERR_LOCK);
+ ok1(tap_log_messages == 0);
+ lock_err = EINTR;
+ ok1(tdb_chainlock(tdb, key) == TDB_ERR_LOCK);
+ ok1(tap_log_messages == 0);
+ lock_err = ENOMEM;
+ ok1(tdb_chainlock(tdb, key) == TDB_ERR_LOCK);
+ ok1(tap_log_messages == 1);
+ tap_log_messages = 0;
+
+ lock_err = EAGAIN;
+ ok1(tdb_chainlock_read(tdb, key) == TDB_ERR_LOCK);
+ ok1(tap_log_messages == 0);
+ lock_err = EINTR;
+ ok1(tdb_chainlock_read(tdb, key) == TDB_ERR_LOCK);
+ ok1(tap_log_messages == 0);
+ lock_err = ENOMEM;
+ ok1(tdb_chainlock_read(tdb, key) == TDB_ERR_LOCK);
+ ok1(tap_log_messages == 1);
+ tap_log_messages = 0;
+
+ lock_err = EAGAIN;
+ ok1(tdb_lockall(tdb) == TDB_ERR_LOCK);
+ ok1(tap_log_messages == 0);
+ lock_err = EINTR;
+ ok1(tdb_lockall(tdb) == TDB_ERR_LOCK);
+ ok1(tap_log_messages == 0);
+ lock_err = ENOMEM;
+ ok1(tdb_lockall(tdb) == TDB_ERR_LOCK);
+ /* This actually does divide and conquer. */
+ ok1(tap_log_messages > 0);
+ tap_log_messages = 0;
+
+ lock_err = EAGAIN;
+ ok1(tdb_lockall_read(tdb) == TDB_ERR_LOCK);
+ ok1(tap_log_messages == 0);
+ lock_err = EINTR;
+ ok1(tdb_lockall_read(tdb) == TDB_ERR_LOCK);
+ ok1(tap_log_messages == 0);
+ lock_err = ENOMEM;
+ ok1(tdb_lockall_read(tdb) == TDB_ERR_LOCK);
+ ok1(tap_log_messages > 0);
+ tap_log_messages = 0;
+
+ /* Nonblocking traverse; go nonblock partway through. */
+ lock_err = 0;
+ ok1(tdb_store(tdb, key, data, TDB_REPLACE) == 0);
+ trav_err = EAGAIN;
+ ok1(tdb_traverse(tdb, trav, &lock_err) == TDB_ERR_LOCK);
+ ok1(tap_log_messages == 0);
+ trav_err = EINTR;
+ lock_err = 0;
+ ok1(tdb_traverse(tdb, trav, &lock_err) == TDB_ERR_LOCK);
+ ok1(tap_log_messages == 0);
+ trav_err = ENOMEM;
+ lock_err = 0;
+ ok1(tdb_traverse(tdb, trav, &lock_err) == TDB_ERR_LOCK);
+ ok1(tap_log_messages == 1);
+ tap_log_messages = 0;
+
+ /* Nonblocking transactions. */
+ lock_err = EAGAIN;
+ ok1(tdb_transaction_start(tdb) == TDB_ERR_LOCK);
+ ok1(tap_log_messages == 0);
+ lock_err = EINTR;
+ ok1(tdb_transaction_start(tdb) == TDB_ERR_LOCK);
+ ok1(tap_log_messages == 0);
+ lock_err = ENOMEM;
+ ok1(tdb_transaction_start(tdb) == TDB_ERR_LOCK);
+ ok1(tap_log_messages == 1);
+ tap_log_messages = 0;
+
+ /* Nonblocking transaction prepare. */
+ lock_err = 0;
+ ok1(tdb_transaction_start(tdb) == 0);
+ ok1(tdb_delete(tdb, key) == 0);
+
+ lock_err = EAGAIN;
+ ok1(tdb_transaction_prepare_commit(tdb) == TDB_ERR_LOCK);
+ ok1(tap_log_messages == 0);
+
+ lock_err = 0;
+ ok1(tdb_transaction_prepare_commit(tdb) == 0);
+ ok1(tdb_transaction_commit(tdb) == 0);
+
+ /* And the transaction was committed, right? */
+ ok1(!tdb_exists(tdb, key));
+ tdb_close(tdb);
+ ok1(tap_log_messages == 0);
+ }
+ return exit_status();
+}
projects / ccan / commitdiff