[Libguestfs] [PATCH nbdkit v2 10/11] data, memory: Return NBD_FLAG_CAN_MULTI_CONN.

These plugins use NBDKIT_THREAD_MODEL_SERIALIZE_ALL_REQUESTS because of their use of the global sparse array. However since they are both RAM disks, and thus (a) flush is a no-op, and (b) the locked part of each request is short, it is both safe and there may be some performance benefit to using NBD_FLAG_CAN_MULTI_CONN. --- plugins/data/data.c | 8 ++++++++ plugins/memory/memory.c | 8 ++++++++ 2 files changed, 16 insertions(+) diff --git a/plugins/data/data.c b/plugins/data/data.c index f8e91be..11a7b69 100644 --- a/plugins/data/data.c +++ b/plugins/data/data.c @@ -324,6 +324,13 @@ data_get_size (void *handle) return size; } +/* Serves the same data over multiple connections. */ +static int +data_can_multi_conn (void *handle) +{ + return 1; +} + /* Read data. */ static int data_pread (void *handle, void *buf, uint32_t count, uint64_t offset) @@ -366,6 +373,7 @@ static struct nbdkit_plugin plugin = { .dump_plugin = data_dump_plugin, .open = data_open, .get_size = data_get_size, + .can_multi_conn = data_can_multi_conn, .pread = data_pread, .pwrite = data_pwrite, .zero = data_zero, diff --git a/plugins/memory/memory.c b/plugins/memory/memory.c index 4013087..0084401 100644 --- a/plugins/memory/memory.c +++ b/plugins/memory/memory.c @@ -115,6 +115,13 @@ memory_get_size (void *handle) return (int64_t) size; } +/* Serves the same data over multiple connections. */ +static int +memory_can_multi_conn (void *handle) +{ + return 1; +} + /* Read data. */ static int memory_pread (void *handle, void *buf, uint32_t count, uint64_t offset) @@ -156,6 +163,7 @@ static struct nbdkit_plugin plugin = { .config_help = memory_config_help, .open = memory_open, .get_size = memory_get_size, + .can_multi_conn = memory_can_multi_conn, .pread = memory_pread, .pwrite = memory_pwrite, .zero = memory_zero, -- 2.19.2