[PATCHv2,2/3] qemu-nbd: add option to set detect-zeroes mode

Signed-off-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 qemu-nbd.c |   25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

The Wednesday 13 Aug 2014 à 19:20:18 (+0200), Peter Lieven wrote :
> Signed-off-by: Peter Lieven <pl@kamp.de>
> Reviewed-by: Eric Blake <eblake@redhat.com>
> ---
>  qemu-nbd.c |   25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
> 
> diff --git a/qemu-nbd.c b/qemu-nbd.c
> index 626e584..6ef8b10 100644
> --- a/qemu-nbd.c
> +++ b/qemu-nbd.c
> @@ -18,11 +18,13 @@
>  
>  #include "qemu-common.h"
>  #include "block/block.h"
> +#include "block/block_int.h"
>  #include "block/nbd.h"
>  #include "qemu/main-loop.h"
>  #include "qemu/sockets.h"
>  #include "qemu/error-report.h"
>  #include "block/snapshot.h"
> +#include "qapi/util.h"
>  
>  #include <stdarg.h>
>  #include <stdio.h>
> @@ -41,6 +43,7 @@
>  #define QEMU_NBD_OPT_CACHE   1
>  #define QEMU_NBD_OPT_AIO     2
>  #define QEMU_NBD_OPT_DISCARD 3
> +#define QEMU_NBD_OPT_DETECT_ZEROES 4
>  
>  static NBDExport *exp;
>  static int verbose;
> @@ -96,6 +99,8 @@ static void usage(const char *name)
>  #ifdef CONFIG_LINUX_AIO
>  "      --aio=MODE       set AIO mode (native or threads)\n"
>  #endif
> +"      --discard=MODE        set discard mode (ignore, unmap)\n"
> +"      --detect-zeroes=MODE  set detect-zeroes mode (off, on, discard)\n"
>  "\n"
>  "Report bugs to <qemu-devel@nongnu.org>\n"
>      , name, NBD_DEFAULT_PORT, "DEVICE");
> @@ -410,6 +415,7 @@ int main(int argc, char **argv)
>          { "aio", 1, NULL, QEMU_NBD_OPT_AIO },
>  #endif
>          { "discard", 1, NULL, QEMU_NBD_OPT_DISCARD },
> +        { "detect-zeroes", 1, NULL, QEMU_NBD_OPT_DETECT_ZEROES },
>          { "shared", 1, NULL, 'e' },
>          { "format", 1, NULL, 'f' },
>          { "persistent", 0, NULL, 't' },
> @@ -432,6 +438,7 @@ int main(int argc, char **argv)
>      pthread_t client_thread;
>      const char *fmt = NULL;
>      Error *local_err = NULL;
> +    BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
>  
>      /* The client thread uses SIGTERM to interrupt the server.  A signal
>       * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
> @@ -483,6 +490,23 @@ int main(int argc, char **argv)
>                  errx(EXIT_FAILURE, "Invalid discard mode `%s'", optarg);
>              }
>              break;
> +        case QEMU_NBD_OPT_DETECT_ZEROES:
> +            detect_zeroes =
> +                qapi_enum_parse(BlockdevDetectZeroesOptions_lookup,
> +                                optarg,
> +                                BLOCKDEV_DETECT_ZEROES_OPTIONS_MAX,
> +                                BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
> +                                &local_err);
> +            if (local_err) {
> +                errx(EXIT_FAILURE, "Failed to parse detect_zeroes mode: %s", 
> +                     error_get_pretty(local_err));
> +            }
> +            if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
> +                !(flags & BDRV_O_UNMAP)) {
> +                errx(EXIT_FAILURE, "setting detect-zeroes to unmap is not allowed "
> +                                   "without setting discard operation to unmap"); 
> +            }
> +            break;
>          case 'b':
>              bindto = optarg;
>              break;
> @@ -686,6 +710,7 @@ int main(int argc, char **argv)
>              error_get_pretty(local_err));
>      }
>  
> +    bs->detect_zeroes = detect_zeroes;
>      fd_size = bdrv_getlength(bs);
>  
>      if (partition != -1) {
> -- 
> 1.7.9.5
> 
> 
Reviewed-by: Benoit Canet <benoit.canet@nodalink.com>