diff options
| -rw-r--r-- | qemu-nbd.c | 18 | ||||
| -rw-r--r-- | qemu-nbd.texi | 4 |
2 files changed, 19 insertions, 3 deletions
diff --git a/qemu-nbd.c b/qemu-nbd.c index 0a6091b6a8..e7268d0a9f 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -33,9 +33,10 @@ #include <libgen.h> #include <pthread.h> -#define SOCKET_PATH "/var/lock/qemu-nbd-%s" -#define QEMU_NBD_OPT_CACHE 1 -#define QEMU_NBD_OPT_AIO 2 +#define SOCKET_PATH "/var/lock/qemu-nbd-%s" +#define QEMU_NBD_OPT_CACHE 1 +#define QEMU_NBD_OPT_AIO 2 +#define QEMU_NBD_OPT_DISCARD 3 static NBDExport *exp; static int verbose; @@ -330,6 +331,7 @@ int main(int argc, char **argv) #ifdef CONFIG_LINUX_AIO { "aio", 1, NULL, QEMU_NBD_OPT_AIO }, #endif + { "discard", 1, NULL, QEMU_NBD_OPT_DISCARD }, { "shared", 1, NULL, 'e' }, { "persistent", 0, NULL, 't' }, { "verbose", 0, NULL, 'v' }, @@ -344,6 +346,7 @@ int main(int argc, char **argv) int ret; int fd; bool seen_cache = false; + bool seen_discard = false; #ifdef CONFIG_LINUX_AIO bool seen_aio = false; #endif @@ -389,6 +392,15 @@ int main(int argc, char **argv) } break; #endif + case QEMU_NBD_OPT_DISCARD: + if (seen_discard) { + errx(EXIT_FAILURE, "--discard can only be specified once"); + } + seen_discard = true; + if (bdrv_parse_discard_flags(optarg, &flags) == -1) { + errx(EXIT_FAILURE, "Invalid discard mode `%s'", optarg); + } + break; case 'b': bindto = optarg; break; diff --git a/qemu-nbd.texi b/qemu-nbd.texi index 3e57200e76..5f3f3e3276 100644 --- a/qemu-nbd.texi +++ b/qemu-nbd.texi @@ -35,6 +35,10 @@ Export QEMU disk image using NBD protocol. @item --aio=@var{aio} choose asynchronous I/O mode between @samp{threads} (the default) and @samp{native} (Linux only). +@item --discard=@var{discard} + toggles whether @dfn{discard} (also known as @dfn{trim} or @dfn{unmap}) + requests are ignored or passed to the filesystem. The default is no + (@samp{--discard=ignore}). @item -c, --connect=@var{dev} connect @var{filename} to NBD device @var{dev} @item -d, --disconnect |