search for: lock_request

On Haiku tests/test-socket-activation failed with: nbdkit: locks.c:96:lock_request: conn != NULL called from server/sockets.c: accept_connection in the fallback path which does: lock_request (); thread_data->sock = set_cloexec (accept (listen_sock, NULL, NULL)); unlock_request () Because there is no current connection in this thread this code fails. However it should...

Patch itself is not controversial. However I do wonder if we want to change all these constructs so that instead of using #ifdef we use something like: if (HAVE_PIPE2) { // normal path } else { // fallback } (It wouldn't actually work as written above because HAVE_PIPE2 is not always defined, but you get the idea.) This would allow us to test that the fallback paths still

On Haiku which doesn't have pipe2 we were using the fallback path. However a previous change to remove the conn parameter of lock_request and unlock_request had not been made to this code and so it failed to compile. Fixes: commit 91023f269d4cea56f573a1aa0d880b12052f6e1e --- server/connections.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/server/connections.c b/server/connections.c index c7b55ca1....

On 4/28/20 11:45 AM, Richard W.M. Jones wrote: > On Haiku tests/test-socket-activation failed with: > > nbdkit: locks.c:96:lock_request: conn != NULL > > called from server/sockets.c: accept_connection > in the fallback path which does: > lock_request (); > thread_data->sock = set_cloexec (accept (listen_sock, NULL, NULL)); > unlock_request () > > Because there is no current connection in this...

...nt sockout) { int r; - plugin_lock_connection (); + lock_connection (); r = _handle_single_connection (sockin, sockout); - plugin_unlock_connection (); + unlock_connection (); return r; } @@ -740,12 +740,12 @@ negotiate_handshake (struct connection *conn) { int r; - plugin_lock_request (conn); + lock_request (conn); if (!newstyle) r = _negotiate_handshake_oldstyle (conn); else r = _negotiate_handshake_newstyle (conn); - plugin_unlock_request (conn); + unlock_request (conn); return r; } @@ -1057,9 +1057,9 @@ recv_request_send_reply (struct connection *conn...

...6 +181,7 @@ struct backend { extern struct backend *plugin_register (const char *_filename, void *_dl, struct nbdkit_plugin *(*plugin_init) (void)); /* locks.c */ +extern void lock_init_thread_model (void); extern void lock_connection (void); extern void unlock_connection (void); extern void lock_request (struct connection *conn); diff --git a/src/locks.c b/src/locks.c index 62b2dd0..bd8fd99 100644 --- a/src/locks.c +++ b/src/locks.c @@ -38,15 +38,24 @@ #include "internal.h" +/* Note that the plugin's thread model cannot change after being + * loaded, so caching it here is safe....

...nt sockout) { int r; - plugin_lock_connection (); + lock_connection (); r = _handle_single_connection (sockin, sockout); - plugin_unlock_connection (); + unlock_connection (); return r; } @@ -740,12 +740,12 @@ negotiate_handshake (struct connection *conn) { int r; - plugin_lock_request (conn); + lock_request (conn); if (!newstyle) r = _negotiate_handshake_oldstyle (conn); else r = _negotiate_handshake_newstyle (conn); - plugin_unlock_request (conn); + unlock_request (conn); return r; } @@ -1057,9 +1057,9 @@ recv_request_send_reply (struct connection *conn...

The third patch is a large but mechanical change which gets rid of passing around struct connection * entirely within the server, preferring instead to reference the connection through thread-local storage. I hope this is a gateway to simplifying other parts of the code. Rich.

.../* plugins.c */ extern struct backend *plugin_register (size_t index, const char *filename, @@ -465,8 +446,8 @@ extern void lock_init_thread_model (void); extern const char *name_of_thread_model (int model); extern void lock_connection (void); extern void unlock_connection (void); -extern void lock_request (struct connection *conn); -extern void unlock_request (struct connection *conn); +extern void lock_request (void); +extern void unlock_request (void); extern void lock_unload (void); extern void unlock_unload (void); diff --git a/server/backend.c b/server/backend.c index 208c07b1..7a9a7ec8 100...

v1 was here: https://www.redhat.com/archives/libguestfs/2020-February/msg00081.html v2 replaces struct connection *conn = GET_CONN; with GET_CONN; which sets conn implicitly and asserts that it is non-NULL. If we actually want to test if conn is non-NULL or behave differently, then you must use threadlocal_get_conn() instead, and some existing uses do that. Rich.

v1 -> v2: - Fixed everything mentioned in the review. Rich.

I'm fairly sure that these bugs which appear in the Python plugin: https://bugzilla.redhat.com/show_bug.cgi?id=1566516 https://bugzilla.redhat.com/show_bug.cgi?id=1566522 are really bugs in the SERIALIZE_ALL_REQUESTS thread model. See the first patch for the full explanation. The second patch is a fix for a race condition which is probably nudged into being by the first patch. Now this

...is fine. > } > > static struct backend filter_functions = { > diff --git a/server/locks.c b/server/locks.c > index ef6726d8..d187b422 100644 > --- a/server/locks.c > +++ b/server/locks.c > @@ -91,8 +91,12 @@ unlock_connection (void) > } > > void > -lock_request (struct connection *conn) > +lock_request (void) > { > + struct connection *conn = GET_CONN; > + > + assert (conn != NULL); > + Here's a site where we could exploit the macro guaranteeing a non-null result. -- Eric Blake, Principal Software Engineer Red Hat, Inc....

Somewhat invasive but mostly mechanical change to how plugins are called. This patch is in preparation for adding a second backend subtype for filters. Rich.

The messages are not really useful to us, but they do bloat the debugging output of virt-v2v massively: nbdkit: python[1]: debug: acquire global request lock nbdkit: python[1]: debug: acquire per-connection request lock nbdkit: python[1]: debug: acquire unload prevention lock nbdkit: python[1]: debug: pwrite count=2097152 offset=4628414464 fua=0 nbdkit: python[1]: debug: release unload prevention

...} } void unlock_connection (void) { - if (thread_model <= NBDKIT_THREAD_MODEL_SERIALIZE_CONNECTIONS) { - debug ("release connection lock"); + if (thread_model <= NBDKIT_THREAD_MODEL_SERIALIZE_CONNECTIONS) pthread_mutex_unlock (&connection_lock); - } } void lock_request (struct connection *conn) { - if (thread_model <= NBDKIT_THREAD_MODEL_SERIALIZE_ALL_REQUESTS) { - debug ("acquire global request lock"); + if (thread_model <= NBDKIT_THREAD_MODEL_SERIALIZE_ALL_REQUESTS) pthread_mutex_lock (&all_requests_lock); - } - if (thread_mod...

...ck_connection (void) { - if (thread_model <= NBDKIT_THREAD_MODEL_SERIALIZE_CONNECTIONS) - pthread_mutex_unlock (&connection_lock); + if (thread_model <= NBDKIT_THREAD_MODEL_SERIALIZE_CONNECTIONS && + pthread_mutex_unlock (&connection_lock)) + abort (); } void lock_request (struct connection *conn) { - if (thread_model <= NBDKIT_THREAD_MODEL_SERIALIZE_ALL_REQUESTS) - pthread_mutex_lock (&all_requests_lock); + if (thread_model <= NBDKIT_THREAD_MODEL_SERIALIZE_ALL_REQUESTS && + pthread_mutex_lock (&all_requests_lock)) + abort (); -...

...nnections.c +++ b/server/connections.c @@ -360,7 +360,7 @@ free_connection (struct connection *conn) * thread will be in the process of unloading it. The plugin.unload * callback should always be called. */ - if (!quit && connection_get_handle (conn, 0)) { + if (!quit) { lock_request (conn); backend_close (backend, conn); unlock_request (conn); -- 2.21.0

dlm_request_all_locks() should deal with the status sent from target node if DLM_LOCK_REQUEST_MSG is sent successfully, or recovery master will fall into endless loop, waiting for other nodes to send locks and DLM_RECO_DATA_DONE_MSG to me. NodeA NodeB selected as recovery master...

From: Xue jiufei <xuejiufei at huawei.com> Subject: ocfs2: dlm_request_all_locks() should deal with the status sent from target node dlm_request_all_locks() should deal with the status sent from target node if DLM_LOCK_REQUEST_MSG is sent successfully, or recovery master will fall into endless loop, waiting for other nodes to send locks and DLM_RECO_DATA_DONE_MSG to me. NodeA NodeB selected as recovery master...