From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:35706) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SrU8W-0002No-I5 for qemu-devel@nongnu.org; Wed, 18 Jul 2012 09:17:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SrU8Q-0005rH-Rx for qemu-devel@nongnu.org; Wed, 18 Jul 2012 09:17:52 -0400 Received: from mail-bk0-f45.google.com ([209.85.214.45]:39032) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SrU8Q-0005qo-LA for qemu-devel@nongnu.org; Wed, 18 Jul 2012 09:17:46 -0400 Received: by mail-bk0-f45.google.com with SMTP id ji1so1221796bkc.4 for ; Wed, 18 Jul 2012 06:17:46 -0700 (PDT) Sender: Paolo Bonzini From: Paolo Bonzini Date: Wed, 18 Jul 2012 15:17:36 +0200 Message-Id: <1342617456-21725-3-git-send-email-pbonzini@redhat.com> In-Reply-To: <1342617456-21725-1-git-send-email-pbonzini@redhat.com> References: <1342617456-21725-1-git-send-email-pbonzini@redhat.com> Subject: [Qemu-devel] [PATCH 2/2] qemu-nbd: add --cache and --aio options List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Add two options to tune the I/O implementation of qemu-nbd, matching the possibilities given by the QEMU -drive option. Signed-off-by: Paolo Bonzini --- qemu-nbd.c | 42 ++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 40 insertions(+), 2 deletions(-) diff --git a/qemu-nbd.c b/qemu-nbd.c index 1c32290..1c1cf6a 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -33,7 +33,9 @@ #include #include -#define SOCKET_PATH "/var/lock/qemu-nbd-%s" +#define SOCKET_PATH "/var/lock/qemu-nbd-%s" +#define QEMU_NBD_OPT_CACHE 1 +#define QEMU_NBD_OPT_AIO 2 static NBDExport *exp; static int verbose; @@ -77,6 +79,10 @@ static void usage(const char *name) " -r, --read-only export read-only\n" " -s, --snapshot use snapshot file\n" " -n, --nocache disable host cache\n" +" --cache=MODE set cache mode (none, writeback, ...)\n" +#ifdef CONFIG_LINUX_AIO +" --aio=MODE set AIO mode (native or threads)\n" +#endif "\n" "Report bugs to \n" , name, NBD_DEFAULT_PORT, "DEVICE"); @@ -306,6 +312,10 @@ int main(int argc, char **argv) { "disconnect", 0, NULL, 'd' }, { "snapshot", 0, NULL, 's' }, { "nocache", 0, NULL, 'n' }, + { "cache", 1, NULL, QEMU_NBD_OPT_CACHE }, +#ifdef CONFIG_LINUX_AIO + { "aio", 1, NULL, QEMU_NBD_OPT_AIO }, +#endif { "shared", 1, NULL, 'e' }, { "persistent", 0, NULL, 't' }, { "verbose", 0, NULL, 'v' }, @@ -320,6 +330,10 @@ int main(int argc, char **argv) int ret; int fd; int persistent = 0; + bool seen_cache = false; +#ifdef CONFIG_LINUX_AIO + bool seen_aio = false; +#endif pthread_t client_thread; /* The client thread uses SIGTERM to interrupt the server. A signal @@ -336,8 +350,32 @@ int main(int argc, char **argv) flags |= BDRV_O_SNAPSHOT; break; case 'n': - flags |= BDRV_O_NOCACHE | BDRV_O_CACHE_WB; + optarg = (char *) "none"; + /* fallthrough */ + case QEMU_NBD_OPT_CACHE: + if (seen_cache) { + errx(EXIT_FAILURE, "-n and --cache can only be specified once"); + } + seen_cache = true; + if (bdrv_parse_cache_flags(optarg, &flags) == -1) { + errx(EXIT_FAILURE, "Invalid cache mode `%s'", optarg); + } break; +#ifdef CONFIG_LINUX_AIO + case QEMU_NBD_OPT_AIO: + if (seen_aio) { + errx(EXIT_FAILURE, "--aio can only be specified once"); + } + seen_aio = true; + if (!strcmp(optarg, "native")) { + flags |= BDRV_O_NATIVE_AIO; + } else if (!strcmp(optarg, "threads")) { + /* this is the default */ + } else { + errx(EXIT_FAILURE, "invalid aio mode `%s'", optarg); + } + break; +#endif case 'b': bindto = optarg; break; -- 1.7.10.4