search for: filter_prepare

...filters when you layer multiple filters in front of a plugin. --- src/filters.c | 27 +++++++++++++++++++-------- 1 file changed, 19 insertions(+), 8 deletions(-) diff --git a/src/filters.c b/src/filters.c index 18948bc..67f06d6 100644 --- a/src/filters.c +++ b/src/filters.c @@ -367,10 +367,17 @@ filter_prepare (struct backend *b, struct connection *conn) debug ("prepare"); - if (f->filter.prepare) - return f->filter.prepare (&next_ops, &nxdata, handle); - else - return f->backend.next->prepare (f->backend.next, conn); + /* Call these in order starting from...

...lter *f = container_of (b, struct backend_filter, backend); void *handle = connection_get_handle (conn, b->i); + /* outer-to-inner order, opposite .open */ if (handle && f->filter.close) f->filter.close (handle); backend_close (b->next, conn); @@ -409,7 +413,7 @@ filter_prepare (struct backend *b, struct connection *conn, int readonly) struct b_conn nxdata = { .b = b->next, .conn = conn }; /* Call these in order starting from the filter closest to the - * plugin. + * plugin, similar to typical .open order. */ if (backend_prepare (b->next, conn) ==...

...uct backend_filter *f = container_of (b, struct backend_filter, backend); void *handle = connection_get_handle (conn, f->backend.i); - debug ("close"); + debug ("%s: close", f->name); if (f->filter.close) f->filter.close (handle); @@ -365,7 +365,7 @@ filter_prepare (struct backend *b, struct connection *conn) void *handle = connection_get_handle (conn, f->backend.i); struct b_conn nxdata = { .b = f->backend.next, .conn = conn }; - debug ("prepare"); + debug ("%s: prepare", f->name); /* Call these in order starting f...

...(void *nxdata, int readonly) { @@ -668,6 +691,7 @@ static struct backend filter_functions = { .config = filter_config, .config_complete = filter_config_complete, .magic_config_key = plugin_magic_config_key, + .ready_to_serve = filter_ready_to_serve, .open = filter_open, .prepare = filter_prepare, .finalize = filter_finalize, diff --git a/server/internal.h b/server/internal.h index 167da59..4c9419d 100644 --- a/server/internal.h +++ b/server/internal.h @@ -312,6 +312,7 @@ struct backend { void (*config) (struct backend *, const char *key, const char *value); void (*config_complete)...

I still don't have .prepare/.finalize working cleanly across reopen, but did find a nasty bug where a botched assertion means we failed to notice reads beyond EOF in both the xz and retry filter. Refactoring backend.c will make .finalize work easier. Eric Blake (5): xz: Avoid reading beyond EOF retry: Check size before transactions tests: Test retry when get_size values change

...r.close (handle); + if (handle && f->filter.close) { + assert (nxdata->b == b->next && nxdata->conn == conn); + f->filter.close (nxdata->handle); + free (nxdata); + } } /* The next_functions structure contains pointers to backend @@ -421,10 +441,11 @@ filter_prepare (struct backend *b, struct connection *conn, void *handle, int readonly) { struct backend_filter *f = container_of (b, struct backend_filter, backend); - struct b_conn nxdata = { .b = b->next, .conn = conn }; + struct b_conn *nxdata = handle; + assert (nxdata->b == b-...

...int32_t flags, int *err) { - struct b_h *b_h = nxdata; - return backend_cache (b_h->b, count, offset, flags, err); + struct backend *b_next = nxdata; + return backend_cache (b_next, count, offset, flags, err); } static struct nbdkit_next_ops next_ops = { @@ -439,11 +408,9 @@ static int filter_prepare (struct backend *b, void *handle, int readonly) { struct backend_filter *f = container_of (b, struct backend_filter, backend); - struct b_h *nxdata = handle; - assert (nxdata->b == b->next); if (f->filter.prepare && - f->filter.prepare (&next_ops, nxdata, nxd...

Eric: Did you want to take this one any further? It might be one that we save for > 1.18: https://www.redhat.com/archives/libguestfs/2020-February/thread.html#00206 Another thing I've been thinking about for some time is splitting .config_complete into .config_complete + .get_ready (new name TBD). At the moment .config_complete is both the place where we finish processing config, and

...ly) { @@ -493,6 +515,7 @@ static struct backend filter_functions = { .config = filter_config, .config_complete = filter_config_complete, .magic_config_key = plugin_magic_config_key, + .get_ready = filter_get_ready, .preconnect = filter_preconnect, .open = filter_open, .prepare = filter_prepare, diff --git a/server/main.c b/server/main.c index 3bc59781..b3d8e5bf 100644 --- a/server/main.c +++ b/server/main.c @@ -691,6 +691,11 @@ main (int argc, char *argv[]) exit (EXIT_FAILURE); } + /* Tell the plugin that we are about to start serving. This must be + * called before we chan...

I'm still working on another set of patches to have reopen call .finalize/.prepare (so that another filter can safely appear between retry and the plugin), but for tonight, these are the patches I think are ready to go. Eric Blake (4): retry: Handle can_fua and can_fast_zero changes tests: Test retry with different fua/fast-zero flags server: Close backends if a filter's .open fails

...uot;%s: close", f->name); if (f->filter.close) f->filter.close (handle); - f->backend.next->close (f->backend.next, conn); + b->next->close (b->next, conn); } /* The next_functions structure contains pointers to backend @@ -459,15 +453,15 @@ static int filter_prepare (struct backend *b, struct connection *conn) { struct backend_filter *f = container_of (b, struct backend_filter, backend); - void *handle = connection_get_handle (conn, f->backend.i); - struct b_conn nxdata = { .b = f->backend.next, .conn = conn }; + void *handle = connection_get_hand...

...har *exportname, int is_tls) @@ -555,6 +566,7 @@ static struct backend filter_functions = { .after_fork = filter_after_fork, .preconnect = filter_preconnect, .list_exports = filter_list_exports, + .default_export = filter_default_export, .open = filter_open, .prepare = filter_prepare, .finalize = filter_finalize, diff --git a/server/plugins.c b/server/plugins.c index 218764da..924533cb 100644 --- a/server/plugins.c +++ b/server/plugins.c @@ -162,6 +162,7 @@ plugin_dump_fields (struct backend *b) HAS (after_fork); HAS (preconnect); HAS (list_exports); + HAS (default...

...tion) + return f->filter.export_description (&next_ops, b->next, handle); + else + return backend_export_description (b->next); +} + static int64_t filter_get_size (struct backend *b, void *handle) { @@ -571,6 +583,7 @@ static struct backend filter_functions = { .prepare = filter_prepare, .finalize = filter_finalize, .close = filter_close, + .export_description = filter_export_description, .get_size = filter_get_size, .can_write = filter_can_write, .can_flush = filter_can_flush, diff --git a/server/plugins.c b/server/plugins.c index 69835d32..010595c7 100644 --- a/s...

...ckend_filter *f = container_of (b, struct backend_filter, backend); void *handle = connection_get_handle (conn, b->i); - debug ("%s: close", f->name); + debug ("%s: close", b->name); if (f->filter.close) f->filter.close (handle); @@ -456,7 +430,7 @@ filter_prepare (struct backend *b, struct connection *conn) void *handle = connection_get_handle (conn, b->i); struct b_conn nxdata = { .b = b->next, .conn = conn }; - debug ("%s: prepare", f->name); + debug ("%s: prepare", b->name); /* Call these in order starting fro...

I have dropped the map filter from this series for now while I try to get it working. However I think the truncate filter is in a good shape. This incorporates all feedback from Eric's review. Also there are three small fixes to the filter code, all revealed when I was testing using multiple filters which we'd not done much of before. Rich.

....get_size = next_get_size, + .can_write = next_can_write, + .can_flush = next_can_flush, + .is_rotational = next_is_rotational, + .can_trim = next_can_trim, + .pread = next_pread, + .pwrite = next_pwrite, + .flush = next_flush, + .trim = next_trim, + .zero = next_zero, +}; + +static int +filter_prepare (struct backend *b, struct connection *conn) +{ + struct backend_filter *f = container_of (b, struct backend_filter, backend); + void *handle = connection_get_handle (conn, f->backend.i); + struct b_conn nxdata = { .b = f->backend.next, .conn = conn }; + + debug ("prepare"); + +...

....get_size = next_get_size, + .can_write = next_can_write, + .can_flush = next_can_flush, + .is_rotational = next_is_rotational, + .can_trim = next_can_trim, + .pread = next_pread, + .pwrite = next_pwrite, + .flush = next_flush, + .trim = next_trim, + .zero = next_zero, +}; + +static int +filter_prepare (struct backend *b, struct connection *conn) +{ + struct backend_filter *f = container_of (b, struct backend_filter, backend); + void *handle = connection_get_handle (conn, f->backend.i); + struct b_conn nxdata = { .b = f->backend.next, .conn = conn }; + + debug ("prepare"); + +...

...backend_cache (b_conn->b, b_conn->conn, count, offset, flags, err); + struct b_h *b_h = nxdata; + return backend_cache (b_h->b, count, offset, flags, err); } static struct nbdkit_next_ops next_ops = { @@ -437,13 +436,12 @@ static struct nbdkit_next_ops next_ops = { }; static int -filter_prepare (struct backend *b, struct connection *conn, void *handle, - int readonly) +filter_prepare (struct backend *b, void *handle, int readonly) { struct backend_filter *f = container_of (b, struct backend_filter, backend); - struct b_conn *nxdata = handle; + struct b_h *nxdata = han...

...truct backend filter_functions = { @@ -567,7 +589,6 @@ static struct backend filter_functions = { .dump_fields = filter_dump_fields, .config = filter_config, .config_complete = filter_config_complete, - .errno_is_preserved = plugin_errno_is_preserved, .open = filter_open, .prepare = filter_prepare, .finalize = filter_finalize, diff --git a/src/plugins.c b/src/plugins.c index dba3e24..c49c0f0 100644 --- a/src/plugins.c +++ b/src/plugins.c @@ -227,14 +227,6 @@ plugin_config_complete (struct backend *b) exit (EXIT_FAILURE); } -static int -plugin_errno_is_preserved (struct backend *b)...

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.