search for: backend_can_multi_conn

...tents (b_next); } static int next_can_fua (void *nxdata) { - struct b_h *b_h = nxdata; - return backend_can_fua (b_h->b); + struct backend *b_next = nxdata; + return backend_can_fua (b_next); } static int next_can_multi_conn (void *nxdata) { - struct b_h *b_h = nxdata; - return backend_can_multi_conn (b_h->b); + struct backend *b_next = nxdata; + return backend_can_multi_conn (b_next); } static int next_can_cache (void *nxdata) { - struct b_h *b_h = nxdata; - return backend_can_cache (b_h->b); + struct backend *b_next = nxdata; + return backend_can_cache (b_next); } static...

...return -1; if (fl) eflags |= NBD_FLAG_SEND_FLUSH; - fl = backend_is_rotational (backend); + fl = backend_is_rotational (top); if (fl == -1) return -1; if (fl) eflags |= NBD_FLAG_ROTATIONAL; /* multi-conn is useless if parallel connections are not allowed. */ - fl = backend_can_multi_conn (backend); + fl = backend_can_multi_conn (top); if (fl == -1) return -1; - if (fl && (backend->thread_model (backend) > + if (fl && (top->thread_model (top) > NBDKIT_THREAD_MODEL_SERIALIZE_CONNECTIONS)) eflags |= NBD_FLAG_CAN_MULTI_CONN; -...

...an_fua", b->name); - return b->can_fua (b, conn); + if (h->can_fua == -1) { + r = backend_can_write (b, conn); + if (r != 1) { + h->can_fua = NBDKIT_FUA_NONE; + return r; + } + h->can_fua = b->can_fua (b, conn); + } + return h->can_fua; } int backend_can_multi_conn (struct backend *b, struct connection *conn) { + struct b_conn_handle *h = &conn->handles[b->i]; + debug ("%s: can_multi_conn", b->name); - return b->can_multi_conn (b, conn); + if (h->can_multi_conn == -1) + h->can_multi_conn = b->can_multi_conn (b, co...

...connection *conn) - __attribute__((__nonnull__ (1, 2))); -extern int backend_can_extents (struct backend *b, struct connection *conn) - __attribute__((__nonnull__ (1, 2))); -extern int backend_can_fua (struct backend *b, struct connection *conn) - __attribute__((__nonnull__ (1, 2))); -extern int backend_can_multi_conn (struct backend *b, struct connection *conn) - __attribute__((__nonnull__ (1, 2))); -extern int backend_can_cache (struct backend *b, struct connection *conn) - __attribute__((__nonnull__ (1, 2))); +extern int backend_reopen (struct backend *b, int readonly) + __attribute__((__nonnull__ (1))); +...

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.

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.

...- struct backend *b_next = nxdata; - return backend_can_extents (b_next); -} - -static int -next_can_fua (void *nxdata) -{ - struct backend *b_next = nxdata; - return backend_can_fua (b_next); -} - -static int -next_can_multi_conn (void *nxdata) -{ - struct backend *b_next = nxdata; - return backend_can_multi_conn (b_next); -} - -static int -next_can_cache (void *nxdata) -{ - struct backend *b_next = nxdata; - return backend_can_cache (b_next); -} - -static int -next_pread (void *nxdata, void *buf, uint32_t count, uint64_t offset, - uint32_t flags, int *err) -{ - struct backend *b_next = nxdata...

This is a subset of the last half of the larger 9-patch series. The uncontroversial first half of that series is pushed, but here, I tried to reduce the size of the patches by splitting out some of the more complex changes, so that the rest of the changes remaining in the series are more mechanical. In turn, it forced me to write timing tests, which let me spot another spot where we are wasting

...b->name); @@ -424,7 +424,7 @@ int backend_can_fua (struct backend *b) { GET_CONN; - struct b_conn_handle *h = &conn->handles[b->i]; + struct handle *h = get_handle (conn, b->i); int r; controlpath_debug ("%s: can_fua", b->name); @@ -445,7 +445,7 @@ int backend_can_multi_conn (struct backend *b) { GET_CONN; - struct b_conn_handle *h = &conn->handles[b->i]; + struct handle *h = get_handle (conn, b->i); assert (h->handle && (h->state & HANDLE_CONNECTED)); controlpath_debug ("%s: can_multi_conn", b->name); @@ -459,7...

It's easy to use the sh script to demonstrate that nbdkit is inefficiently calling into .get_size, .can_fua, and friends more than necessary. We've also commented on the list in the past that it would be nice to ensure that when filters call into next_ops, they are not violating constraints (as we've have to fix several bugs in the past where we did not have such checking to protect

...ndle; + assert (nxdata->b == b->next && nxdata->conn == conn); if (f->filter.can_multi_conn) - return f->filter.can_multi_conn (&next_ops, &nxdata, handle); + return f->filter.can_multi_conn (&next_ops, nxdata, nxdata->handle); else return backend_can_multi_conn (b->next, conn); } @@ -566,10 +598,11 @@ static int filter_can_cache (struct backend *b, struct connection *conn, void *handle) { struct backend_filter *f = container_of (b, struct backend_filter, backend); - struct b_conn nxdata = { .b = b->next, .conn = conn }; + struct b_conn *nxda...

I think this is my last round of patches for issues I identified with the retry filter. With this in place, it should be safe to interject another filter in between retry and the plugin. Eric Blake (5): retry: Don't call into closed plugin tests: Refactor test-retry-reopen-fail.sh tests: Enhance retry test to cover failed reopen server: Move prepare/finalize/close recursion to

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 immediate reason for this patch is to reduce the amount of debugging in virt-v2v with using the virt-v2v -v option (because this implies running nbdkit in verbose mode too). Most of the messages are datapath ones about pread/pwrite requests, and in fact as we've added more filters on top of nbdkit these messages have got more and more verbose. However they are not particularly

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

I will be following up to this email with four separate threads each addressed to the appropriate single list, with proposed changes to: - the NBD protocol - qemu: both server and client - libnbd: client - nbdkit: server The feature in question adds a new optional NBD_INFO_ packet to the NBD_OPT_GO portion of handshake, adding up to 16 bits of information that the server can advertise to the