search for: _pwrite_old

...uct backend_plugin, backend); - char *buf; + static const char buf[MAX_REQUEST_SIZE]; uint32_t limit; int r = -1; bool may_trim = flags & NBDKIT_FLAG_MAY_TRIM; @@ -639,12 +639,7 @@ plugin_zero (struct backend *b, struct connection *conn, assert (p->plugin.pwrite || p->plugin._pwrite_old); flags &= ~NBDKIT_FLAG_MAY_TRIM; threadlocal_set_error (0); - limit = count < MAX_REQUEST_SIZE ? count : MAX_REQUEST_SIZE; - buf = calloc (limit, 1); - if (!buf) { - *err = ENOMEM; - return -1; - } + limit = count < sizeof (buf) ? count : sizeof (buf); while (count)...

...const void *buf, uint32_t count, uint64_t offset); int (*flush) (void *handle); int (*trim) (void *handle, uint32_t count, uint64_t offset); int (*zero) (void *handle, uint32_t count, uint64_t offset, int may_trim); +#else + int (*_pread_old) (void *, void *, uint32_t, uint64_t); + int (*_pwrite_old) (void *, const void *, uint32_t, uint64_t); + int (*_flush_old) (void *); + int (*_trim_old) (void *, uint32_t, uint64_t); + int (*_zero_old) (void *, uint32_t, uint64_t, int); +#endif int errno_is_preserved; void (*dump_plugin) (void); + int (*can_fua) (void *handle); +#if NBDKIT_API...

...can_flush: Option<extern fn (*mut c_void) -> c_int>, + pub is_rotational: Option<extern fn (*mut c_void) -> c_int>, + pub can_trim: Option<extern fn (*mut c_void) -> c_int>, + + // Slots for old v1 API functions. + _pread_old: Option<extern fn ()>, + _pwrite_old: Option<extern fn ()>, + _flush_old: Option<extern fn ()>, + _trim_old: Option<extern fn ()>, + _zero_old: Option<extern fn ()>, + + errno_is_preserved: c_int, + + pub dump_plugin: Option<extern fn ()>, + + pub can_zero: Option<extern fn (*mut c_vo...

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

...\ + return (plugin).pread (handle, buf, count, offset, 0); \ + } \ + static int \ + nbdkit_pwrite_old (void *handle, const void *buf, uint32_t count, \ + uint64_t offset) \ + { \ + return (plugin).pwrite (handle, buf, count, offset, 0); \ + }...

This adds very rough support for writing nbdkit plugins in Rust. This is not very idiomatic -- essentially we're handling the direct C calls from nbdkit in Rust. We have to use ‘unsafe’ in a few places because there's no way to tell the Rust code that nbdkit satisfies guarantees (eg. around thread safety, always returning leaked pointers back to the close function, always doing bounds

...plugin.zero (connection_get_handle (conn, 0), count, offset, @@ -658,6 +673,12 @@ plugin_zero (struct backend *b, struct connection *conn, goto done; } + if (fast_zero) { + assert (r == -1); + *err = EOPNOTSUPP; + goto done; + } + assert (p->plugin.pwrite || p->plugin._pwrite_old); flags &= ~NBDKIT_FLAG_MAY_TRIM; threadlocal_set_error (0); @@ -762,6 +783,7 @@ static struct backend plugin_functions = { .is_rotational = plugin_is_rotational, .can_trim = plugin_can_trim, .can_zero = plugin_can_zero, + .can_fast_zero = plugin_can_fast_zero, .can_extents =...

...ection_get_handle (conn, 0), count, offset, + may_trim); + else + emulate = true; + if (r == -1) + *err = emulate ? EOPNOTSUPP : get_error (p); + if (r == 0 || *err != EOPNOTSUPP) + goto done; + } assert (p->plugin.pwrite || p->plugin._pwrite_old); flags &= ~NBDKIT_FLAG_MAY_TRIM; diff --git a/plugins/nbd/nbd.c b/plugins/nbd/nbd.c index dd84b04..51de178 100644 --- a/plugins/nbd/nbd.c +++ b/plugins/nbd/nbd.c @@ -618,6 +618,14 @@ nbd_can_trim (void *handle) return h->flags & NBD_FLAG_SEND_TRIM; } +static int +nbd_can_zero (v...

After more than a month since v2 [1], I've finally got my FUA support series polished. This is all of my outstanding patches, even though some of them were originally posted in separate threads from the original FUA post [2], [3] [1] https://www.redhat.com/archives/libguestfs/2018-January/msg00113.html [2] https://www.redhat.com/archives/libguestfs/2018-January/msg00219.html [3]

This is a cover letter to a series of patches being proposed in tandem to four different projects: - nbd: Document a new NBD_CMD_FLAG_FAST_ZERO command flag - qemu: Implement the flag for both clients and server - libnbd: Implement the flag for clients - nbdkit: Implement the flag for servers, including the nbd passthrough client If you want to test the patches together, I've pushed a