search for: lock_connection

...tion, run a single connection, free the backend, and then try to unlock the connection. Unfortunately the unlock operation has to check the thread model again which fails because the backend has gone away: Program terminated with signal SIGSEGV, Segmentation fault. #0 0x00000000004070ce in unlock_connection () at locks.c:59 59 int thread_model = backend->thread_model (backend); [Current thread is 1 (Thread 0x7fab43243700 (LWP 6676))] (gdb) bt #0 0x00000000004070ce in unlock_connection () at locks.c:59 #1 0x00000000004061b1 in handle_single_connection (sockin=<optimized out>,...

...--- > src/internal.h | 14 ++++--- > src/locks.c | 115 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ > src/plugins.c | 77 +++++------------------------------- > 5 files changed, 142 insertions(+), 79 deletions(-) > > +++ b/src/locks.c > +void > +lock_connection (void) > +{ > + int thread_model = plugin_thread_model (); > + > + if (thread_model <= NBDKIT_THREAD_MODEL_SERIALIZE_CONNECTIONS) { > +++ b/src/plugins.c > +int > +plugin_thread_model (void) > +{ > + assert (dl); > + > + return plugin._thread_model; > +}...

...in_is_parallel() || nworkers == 1) + if (plugin_thread_model () < NBDKIT_THREAD_MODEL_PARALLEL || nworkers == 1) nworkers = 0; conn = new_connection (sockin, sockout, nworkers); if (!conn) @@ -287,9 +287,9 @@ handle_single_connection (int sockin, int 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 (...

...in_is_parallel() || nworkers == 1) + if (plugin_thread_model () < NBDKIT_THREAD_MODEL_PARALLEL || nworkers == 1) nworkers = 0; conn = new_connection (sockin, sockout, nworkers); if (!conn) @@ -287,9 +287,9 @@ handle_single_connection (int sockin, int 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 (...

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.

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

This fixes the long-standing crash on close when nbdkit exits. I did try first to fix threads so we're using a proper thread pool, but that's difficult to implement. So this does the minimal change needed to fix the crash instead. There are still two segfaults that happen during running the test suite. One is deliberately caused (tests/test-captive.sh). The other appears to be an

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

--- src/locks.c | 26 ++++++-------------------- 1 file changed, 6 insertions(+), 20 deletions(-) diff --git a/src/locks.c b/src/locks.c index bd8fd99..1724b5a 100644 --- a/src/locks.c +++ b/src/locks.c @@ -56,53 +56,39 @@ lock_init_thread_model (void) void lock_connection (void) { - if (thread_model <= NBDKIT_THREAD_MODEL_SERIALIZE_CONNECTIONS) { - debug ("acquire connection lock"); + if (thread_model <= NBDKIT_THREAD_MODEL_SERIALIZE_CONNECTIONS) pthread_mutex_lock (&connection_lock); - } } void unlock_connection (void) { - if...

...if (conn->nworkers && + pthread_mutex_unlock (&conn->status_lock)) + abort (); return value; } diff --git a/server/locks.c b/server/locks.c index f4d6497..d70baf2 100644 --- a/server/locks.c +++ b/server/locks.c @@ -55,49 +55,59 @@ lock_init_thread_model (void) void lock_connection (void) { - if (thread_model <= NBDKIT_THREAD_MODEL_SERIALIZE_CONNECTIONS) - pthread_mutex_lock (&connection_lock); + if (thread_model <= NBDKIT_THREAD_MODEL_SERIALIZE_CONNECTIONS && + pthread_mutex_lock (&connection_lock)) + abort (); } void unlock_connection...

..., uint32_t count, uint64_t offset); + int (*zero) (struct backend *, struct connection *conn, uint32_t count, uint64_t offset, int may_trim); +}; + +extern struct backend *plugin_register (const char *_filename, void *_dl, struct nbdkit_plugin *(*plugin_init) (void)); /* locks.c */ extern void lock_connection (void); diff --git a/src/locks.c b/src/locks.c index 6021356..62b2dd0 100644 --- a/src/locks.c +++ b/src/locks.c @@ -45,7 +45,7 @@ static pthread_rwlock_t unload_prevention_lock = PTHREAD_RWLOCK_INITIALIZER; void lock_connection (void) { - int thread_model = plugin_thread_model (); + int threa...

..., uint32_t count, uint64_t offset); + int (*zero) (struct backend *, struct connection *conn, uint32_t count, uint64_t offset, int may_trim); +}; + +extern struct backend *plugin_register (const char *_filename, void *_dl, struct nbdkit_plugin *(*plugin_init) (void)); /* locks.c */ extern void lock_connection (void); diff --git a/src/locks.c b/src/locks.c index 6021356..62b2dd0 100644 --- a/src/locks.c +++ b/src/locks.c @@ -45,7 +45,7 @@ static pthread_rwlock_t unload_prevention_lock = PTHREAD_RWLOCK_INITIALIZER; void lock_connection (void) { - int thread_model = plugin_thread_model (); + int threa...

..., uint32_t count, uint64_t offset); + int (*zero) (struct backend *, struct connection *conn, uint32_t count, uint64_t offset, int may_trim); +}; + +extern struct backend *plugin_register (const char *_filename, void *_dl, struct nbdkit_plugin *(*plugin_init) (void)); /* locks.c */ extern void lock_connection (void); diff --git a/src/locks.c b/src/locks.c index 6021356..62b2dd0 100644 --- a/src/locks.c +++ b/src/locks.c @@ -45,7 +45,7 @@ static pthread_rwlock_t unload_prevention_lock = PTHREAD_RWLOCK_INITIALIZER; void lock_connection (void) { - int thread_model = plugin_thread_model (); + int threa...

When I added .can_FOO caching in 1.16, I missed the case that the sh plugin itself was calling .can_flush twice in some situations (in order to default .can_fua). Then right after, I regressed it to call .can_zero twice (in order to default .can_fast_zero). I also missed that .thread_model could use better caching, because at the time, I did not add testsuite coverage. Fix that now. Eric Blake

The first three patches are identical to: https://www.redhat.com/archives/libguestfs/2018-January/msg00079.html "[PATCH nbdkit v2 0/3] Refactor plugin_* functions into a backend" The rest of the patches add filters using the new filter API previously described here: https://www.redhat.com/archives/libguestfs/2018-January/msg00073.html This needs a lot more testing -- and tests --

I do have a question about whether patch 2 is right, or whether I've exposed a bigger problem in the truncate (and possibly other) filter, but the rest seem fairly straightforward. Eric Blake (4): server: Check for pthread lock failures truncate: Factor out reading real_size under mutex plugins: Check for mutex failures filters: Check for mutex failures filters/cache/cache.c

...*next, size_t index, + const char *filename, void *dl, + struct nbdkit_filter *(*filter_init) (void)) + __attribute__((__nonnull__ (1, 3, 4, 5))); /* 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); -extern void unlock_request (struct connection *conn); +extern void lock_request (struct connection *conn) + __attribute__((__nonnull__ (1))); +extern void unlock_request (struct connection *conn) +...

A combination of the work that both Rich and I have been doing lately, where filters use only the new API with flags on every command that the client can send over the wire (we can then add support for more flags in nbdkit without having to add new callbacks, as NBD adds more flags upstream). Eric Blake (4): protocol: Split flags from cmd field in requests backend: Pass flags argument through

v1 was here: https://www.redhat.com/archives/libguestfs/2019-January/msg00008.html In v2 I have provided two patches: The first patch extends attribute((nonnull)) to most internal functions, but not to the external API. The second patch uses a macro so that attribute((format)) is only used in the public API on GCC or Clang. At least in theory these headers could be used by a C compiler which

...er (size_t index, const char *filename, void *dl, struct nbdkit_plugin *(*plugin_init) (void)); + +/* filters.c */ +extern struct backend *filter_register (struct backend *next, size_t index, const char *filename, void *dl, struct nbdkit_filter *(*filter_init) (void)); /* locks.c */ extern void lock_connection (void); diff --git a/src/main.c b/src/main.c index 4790c46..38691c9 100644 --- a/src/main.c +++ b/src/main.c @@ -64,7 +64,8 @@ static int is_short_name (const char *); static char *make_random_fifo (void); -static struct backend *open_plugin_so (const char *filename, int short_name); +static st...