qemu-io: Support 'aio_write -z'

This allows testing blk_aio_write_zeroes().
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>

qemu-io-cmds.c

@@ -1416,6 +1416,7 @@ struct aio_ctx {
     int vflag;
     int Cflag;
     int Pflag;
+    int zflag;
     BlockAcctCookie acct;
     int pattern;
     struct timeval t1;
@@ -1446,8 +1447,10 @@ static void aio_write_done(void *opaque, int ret)
     print_report("wrote", &t2, ctx->offset, ctx->qiov.size,
                  ctx->qiov.size, 1, ctx->Cflag);
 out:
-    qemu_io_free(ctx->buf);
-    qemu_iovec_destroy(&ctx->qiov);
+    if (!ctx->zflag) {
+        qemu_io_free(ctx->buf);
+        qemu_iovec_destroy(&ctx->qiov);
+    }
     g_free(ctx);
 }
 
@@ -1612,6 +1615,7 @@ static void aio_write_help(void)
 " -P, -- use different pattern to fill file\n"
 " -C, -- report statistics in a machine parsable format\n"
 " -q, -- quiet mode, do not show I/O statistics\n"
+" -z, -- write zeroes using blk_aio_write_zeroes\n"
 "\n");
 }
 
@@ -1622,7 +1626,7 @@ static const cmdinfo_t aio_write_cmd = {
     .cfunc      = aio_write_f,
     .argmin     = 2,
     .argmax     = -1,
-    .args       = "[-Cq] [-P pattern ] off len [len..]",
+    .args       = "[-Cqz] [-P pattern ] off len [len..]",
     .oneline    = "asynchronously writes a number of bytes",
     .help       = aio_write_help,
 };
@@ -1634,7 +1638,7 @@ static int aio_write_f(BlockBackend *blk, int argc, char **argv)
     struct aio_ctx *ctx = g_new0(struct aio_ctx, 1);
 
     ctx->blk = blk;
-    while ((c = getopt(argc, argv, "CqP:")) != -1) {
+    while ((c = getopt(argc, argv, "CqP:z")) != -1) {
         switch (c) {
         case 'C':
             ctx->Cflag = 1;
@@ -1649,6 +1653,9 @@ static int aio_write_f(BlockBackend *blk, int argc, char **argv)
                 return 0;
             }
             break;
+        case 'z':
+            ctx->zflag = 1;
+            break;
         default:
             g_free(ctx);
             return qemuio_command_usage(&aio_write_cmd);
@@ -1660,6 +1667,18 @@ static int aio_write_f(BlockBackend *blk, int argc, char **argv)
         return qemuio_command_usage(&aio_write_cmd);
     }
 
+    if (ctx->zflag && optind != argc - 2) {
+        printf("-z supports only a single length parameter\n");
+        g_free(ctx);
+        return 0;
+    }
+
+    if (ctx->zflag && ctx->Pflag) {
+        printf("-z and -P cannot be specified at the same time\n");
+        g_free(ctx);
+        return 0;
+    }
+
     ctx->offset = cvtnum(argv[optind]);
     if (ctx->offset < 0) {
         print_cvtnum_err(ctx->offset, argv[optind]);
@@ -1676,19 +1695,33 @@ static int aio_write_f(BlockBackend *blk, int argc, char **argv)
         return 0;
     }
 
-    nr_iov = argc - optind;
-    ctx->buf = create_iovec(blk, &ctx->qiov, &argv[optind], nr_iov, pattern);
-    if (ctx->buf == NULL) {
-        block_acct_invalid(blk_get_stats(blk), BLOCK_ACCT_WRITE);
-        g_free(ctx);
-        return 0;
-    }
+    if (ctx->zflag) {
+        int64_t count = cvtnum(argv[optind]);
+        if (count < 0) {
+            print_cvtnum_err(count, argv[optind]);
+            return 0;
+        }
 
-    gettimeofday(&ctx->t1, NULL);
-    block_acct_start(blk_get_stats(blk), &ctx->acct, ctx->qiov.size,
-                     BLOCK_ACCT_WRITE);
-    blk_aio_writev(blk, ctx->offset >> 9, &ctx->qiov,
-                   ctx->qiov.size >> 9, aio_write_done, ctx);
+        ctx->qiov.size = count;
+        blk_aio_write_zeroes(blk, ctx->offset >> 9, count >> 9, 0,
+                             aio_write_done, ctx);
+    } else {
+        nr_iov = argc - optind;
+        ctx->buf = create_iovec(blk, &ctx->qiov, &argv[optind], nr_iov,
+                                pattern);
+        if (ctx->buf == NULL) {
+            block_acct_invalid(blk_get_stats(blk), BLOCK_ACCT_WRITE);
+            g_free(ctx);
+            return 0;
+        }
+
+        gettimeofday(&ctx->t1, NULL);
+        block_acct_start(blk_get_stats(blk), &ctx->acct, ctx->qiov.size,
+                         BLOCK_ACCT_WRITE);
+
+        blk_aio_writev(blk, ctx->offset >> 9, &ctx->qiov,
+                       ctx->qiov.size >> 9, aio_write_done, ctx);
+    }
     return 0;
 }