search for: plugin_close

$ ./nbdkit -s memory 1M < fuzzing/testcase_dir/newstyle-cflags NBDMAGICIHAVEOPTnbdkit: plugins.c:274: plugin_close: Assertion `connection_get_handle (conn, 0)' failed. Aborted (core dumped) git bisect implicates this patch: 2f80ce1209d5898cb9a567c0b29e7736ff4d03eb is the first bad commit Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtu...

..., the following calls are neither locked against each other nor are they locked against client requests: plugin_register (const char *_filename, plugin_cleanup (void) plugin_config (const char *key, const char *value) plugin_config_complete (void) plugin_open (struct connection *conn, int readonly) plugin_close (struct connection *conn) plugin_get_size (struct connection *conn) plugin_can_write (struct connection *conn) plugin_can_flush (struct connection *conn) plugin_is_rotational (struct connection *conn) plugin_can_trim (struct connection *conn) That means dumping the plugin-internal data on connecti...

...#7 0x00007ffff6fbad43 in PyObject_Call () from /usr/lib/x86_64-linux-gnu/libpython2.7.so.1.0 #8 0x00007ffff7033577 in PyEval_CallObjectWithKeywords () from /usr/lib/x86_64-linux-gnu/libpython2.7.so.1.0 #9 0x00007ffff73f0af0 in py_close (handle=0x625338) at python.c:234 #10 0x0000000000405803 in plugin_close (conn=conn@entry=0x7fffe8000910) at plugins.c:377 #11 0x00000000004037ec in free_connection (conn=0x7fffe8000910) at connections.c:147 #12 0x0000000000404476 in _handle_single_connection (sockout=<optimized out>, sockin=<optimized out>) at connections.c:99 #13 handle_single_connection (...

...n strlen () from /lib64/libc.so.6 #1 0x00007f67a884f465 in fputs () from /lib64/libc.so.6 #2 0x0000000000406715 in prologue (type=0x409928 "debug") at errors.c:54 #3 0x000000000040685d in nbdkit_debug (fs=fs@entry=0x40ace6 "close") at errors.c:91 #4 0x00000000004077d9 in plugin_close (conn=conn@entry=0x7f679c000910) at plugins.c:386 #5 0x0000000000404de3 in free_connection (conn=0x7f679c000910) at connections.c:228 #6 0x00000000004059fd in _handle_single_connection (sockout=<optimized out>, sockin=<optimized out>) at connections.c:179 #7 handle_singl...

...+), 9 deletions(-) diff --git a/src/connections.c b/src/connections.c index 46609f0..0cbf54a 100644 --- a/src/connections.c +++ b/src/connections.c @@ -224,8 +224,14 @@ free_connection (struct connection *conn) pthread_mutex_destroy (&conn->request_lock); - if (conn->handle) - plugin_close (conn); + /* Don't call the plugin again if quit has been set because the main + * thread will be in the process of unloading it. The plugin.unload + * callback should always be called. + */ + if (!quit) { + if (conn->handle) + plugin_close (conn); + } free (conn); }...

...[open $file $flags] + + # Stop Tcl from trying to convert to and from UTF-8. + fconfigure $fh -translation binary + + # We can return any Tcl object as the handle. In this + # plugin it's convenient to return the file handle. + return $fh +} + +# Close a client connection. +proc plugin_close {fh} { + close $fh +} + +proc get_size {fh} { + global file + + return [file size $file] +} + +proc pread {fh count offset} { + seek $fh $offset + return [read $fh $count] +} + +proc pwrite {fh buf offset} { + seek $fh $offset + puts -nonewline $fh $buf +} diff --git a/plugins/...

..."%s.%d", backend->name (backend), nworkers) < 0) { perror ("asprintf"); set_status (conn, -1); free (worker); @@ -340,7 +342,7 @@ free_connection (struct connection *conn) */ if (!quit) { if (conn->handle) - plugin_close (conn); + backend->close (backend, conn); } free (conn); @@ -352,7 +354,7 @@ compute_eflags (struct connection *conn, uint16_t *flags) uint16_t eflags = NBD_FLAG_HAS_FLAGS; int fl; - fl = plugin_can_write (conn); + fl = backend->can_write (backend, conn); if (fl == -...

..."%s.%d", backend->name (backend), nworkers) < 0) { perror ("asprintf"); set_status (conn, -1); free (worker); @@ -340,7 +342,7 @@ free_connection (struct connection *conn) */ if (!quit) { if (conn->handle) - plugin_close (conn); + backend->close (backend, conn); } free (conn); @@ -352,7 +354,7 @@ compute_eflags (struct connection *conn, uint16_t *flags) uint16_t eflags = NBD_FLAG_HAS_FLAGS; int fl; - fl = plugin_can_write (conn); + fl = backend->can_write (backend, conn); if (fl == -...

..."%s.%d", backend->name (backend), nworkers) < 0) { perror ("asprintf"); set_status (conn, -1); free (worker); @@ -340,7 +342,7 @@ free_connection (struct connection *conn) */ if (!quit) { if (conn->handle) - plugin_close (conn); + backend->close (backend, conn); } free (conn); @@ -352,7 +354,7 @@ compute_eflags (struct connection *conn, uint16_t *flags) uint16_t eflags = NBD_FLAG_HAS_FLAGS; int fl; - fl = plugin_can_write (conn); + fl = backend->can_write (backend, conn); if (fl == -...

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

...f6fbad43 in PyObject_Call () from /usr/lib/x86_64-linux-gnu/libpython2.7.so.1.0 > #8 0x00007ffff7033577 in PyEval_CallObjectWithKeywords () from /usr/lib/x86_64-linux-gnu/libpython2.7.so.1.0 > #9 0x00007ffff73f0af0 in py_close (handle=0x625338) at python.c:234 > #10 0x0000000000405803 in plugin_close (conn=conn@entry=0x7fffe8000910) at plugins.c:377 > #11 0x00000000004037ec in free_connection (conn=0x7fffe8000910) at connections.c:147 > #12 0x0000000000404476 in _handle_single_connection (sockout=<optimized out>, sockin=<optimized out>) at connections.c:99 > #13 handle_sing...

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.

On 10/3/19 2:38 PM, Richard W.M. Jones wrote: > > $ ./nbdkit -s memory 1M < fuzzing/testcase_dir/newstyle-cflags > NBDMAGICIHAVEOPTnbdkit: plugins.c:274: plugin_close: Assertion `connection_get_handle (conn, 0)' failed. > Aborted (core dumped) > > git bisect implicates this patch: > > 2f80ce1209d5898cb9a567c0b29e7736ff4d03eb is the first bad commit Yep, I see it. More patches coming (we need to better track when .open and .prepare have su...

This fixes the race conditions for me, using the test described here: https://www.redhat.com/archives/libguestfs/2017-September/msg00226.html Rich.

Hi, I've written an ao plugin for aRts, the soundserver that comes with KDE. Any chance of including this in the ao distribution ? Pretty please ? :) Sources and patches attached. This is a very simple plugin because it uses the easy-to-use 'artsc' C wrapper that aRts installs. configure.in.diff is for ao/configure.in Makefile.am.diff is for ao/src/plugins/Makefile.am Makefile.am

...LL); - b->next->close (b->next, conn); + backend_close (b->next, conn); } /* The next_functions structure contains pointers to backend diff --git a/server/plugins.c b/server/plugins.c index 9b44c548..727fb0e0 100644 --- a/server/plugins.c +++ b/server/plugins.c @@ -273,12 +273,8 @@ plugin_close (struct backend *b, struct connection *conn) assert (connection_get_handle (conn, 0)); - debug ("close"); - if (p->plugin.close) p->plugin.close (connection_get_handle (conn, 0)); - - backend_set_handle (b, conn, NULL); } static int64_t diff --git a/server/protocol...

...ction (void); -extern void plugin_lock_request (struct connection *conn); -extern void plugin_unlock_request (struct connection *conn); -extern bool plugin_is_parallel (void); extern int plugin_errno_is_preserved (void); extern int plugin_open (struct connection *conn, int readonly); extern void plugin_close (struct connection *conn); @@ -169,6 +165,14 @@ extern int plugin_flush (struct connection *conn); extern int plugin_trim (struct connection *conn, uint32_t count, uint64_t offset); extern int plugin_zero (struct connection *conn, uint32_t count, uint64_t offset, int may_trim); +/* locks.c */ +...

...ction (void); -extern void plugin_lock_request (struct connection *conn); -extern void plugin_unlock_request (struct connection *conn); -extern bool plugin_is_parallel (void); extern int plugin_errno_is_preserved (void); extern int plugin_open (struct connection *conn, int readonly); extern void plugin_close (struct connection *conn); @@ -169,6 +165,14 @@ extern int plugin_flush (struct connection *conn); extern int plugin_trim (struct connection *conn, uint32_t count, uint64_t offset); extern int plugin_zero (struct connection *conn, uint32_t count, uint64_t offset, int may_trim); +/* locks.c */ +...

....c b/server/plugins.c index 69835d32..010595c7 100644 --- a/server/plugins.c +++ b/server/plugins.c @@ -170,6 +170,7 @@ plugin_dump_fields (struct backend *b) HAS (open); HAS (close); + HAS (export_description); HAS (get_size); HAS (can_write); HAS (can_flush); @@ -369,6 +370,17 @@ plugin_close (struct backend *b, void *handle) conn->exportname = NULL; } +static const char * +plugin_export_description (struct backend *b, void *handle) +{ + struct backend_plugin *p = container_of (b, struct backend_plugin, backend); + + if (p->plugin.export_description) + return p->plugi...

...ction (void); extern void plugin_lock_request (struct connection *conn); extern void plugin_unlock_request (struct connection *conn); +extern bool plugin_is_parallel (void); extern int plugin_errno_is_preserved (void); extern int plugin_open (struct connection *conn, int readonly); extern void plugin_close (struct connection *conn); diff --git a/src/main.c b/src/main.c index c9f08ab..cc5e9e3 100644 --- a/src/main.c +++ b/src/main.c @@ -84,6 +84,7 @@ int readonly; /* -r */ char *run; /* --run */ int listen_stdin; /* -s */ const char *selinux_labe...