[Qemu-devel] [PATCH] qemu-io: Add multiwrite command

[Kevin Wolf]

The new multiwrite commands allows to use qemu-io for testing
bdrv_aio_multiwrite.

Signed-off-by: Kevin Wolf <address@hidden>
---
 qemu-io.c |  192 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 192 insertions(+), 0 deletions(-)

diff --git a/qemu-io.c b/qemu-io.c
index 8517b90..e99c040 100644
--- a/qemu-io.c
+++ b/qemu-io.c
@@ -267,6 +267,47 @@ static int do_aio_writev(QEMUIOVector *qiov, int64_t 
offset, int *total)
        return async_ret < 0 ? async_ret : 1;
 }
 
+struct multiwrite_async_ret {
+       int num_done;
+       int error;
+};
+
+static void multiwrite_cb(void *opaque, int ret)
+{
+       struct multiwrite_async_ret *async_ret = opaque;
+
+       async_ret->num_done++;
+       if (ret < 0) {
+               async_ret->error = ret;
+       }
+}
+
+static int do_aio_multiwrite(BlockRequest* reqs, int num_reqs, int *total)
+{
+       int i, ret;
+       struct multiwrite_async_ret async_ret = {
+               .num_done = 0,
+               .error = 0,
+       };
+
+       *total = 0;
+       for (i = 0; i < num_reqs; i++) {
+               reqs[i].cb = multiwrite_cb;
+               reqs[i].opaque = &async_ret;
+               *total += reqs[i].qiov->size;
+       }
+
+       ret = bdrv_aio_multiwrite(bs, reqs, num_reqs);
+       if (ret < 0) {
+               return ret;
+       }
+
+       while (async_ret.num_done < num_reqs) {
+               qemu_aio_wait();
+       }
+
+       return async_ret.error < 0 ? async_ret.error : 1;
+}
 
 static void
 read_help(void)
@@ -811,6 +852,156 @@ out:
        return 0;
 }
 
+static void
+multiwrite_help(void)
+{
+       printf(
+"\n"
+" writes a range of bytes from the given offset source from multiple 
buffers,\n"
+" in a batch of requests that may be merged by qemu\n"
+"\n"
+" Example:\n"
+" 'multiwrite 512 1k 1k ; 4k 1k' \n"
+"  writes 2 kB at 512 bytes and 1 kB at 4 kB into the open file\n"
+"\n"
+" Writes into a segment of the currently open file, using a buffer\n"
+" filled with a set pattern (0xcdcdcdcd). The pattern byte is increased\n"
+" by one for each request contained in the multiwrite command.\n"
+" -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"
+"\n");
+}
+
+static int multiwrite_f(int argc, char **argv);
+
+static const cmdinfo_t multiwrite_cmd = {
+       .name           = "multiwrite",
+       .cfunc          = multiwrite_f,
+       .argmin         = 2,
+       .argmax         = -1,
+       .args           = "[-Cq] [-P pattern ] off len [len..] [; off len 
[len..]..]",
+       .oneline        = "issues multiple write requests at once",
+       .help           = multiwrite_help,
+};
+
+static int
+multiwrite_f(int argc, char **argv)
+{
+       struct timeval t1, t2;
+       int Cflag = 0, qflag = 0;
+       int c, cnt;
+       char **buf;
+       int64_t offset, first_offset = 0;
+       /* Some compilers get confused and warn if this is not initialized.  */
+       int total = 0;
+       int nr_iov;
+       int nr_reqs;
+       int pattern = 0xcd;
+       QEMUIOVector *qiovs;
+       int i;
+       BlockRequest *reqs;
+
+       while ((c = getopt(argc, argv, "CqP:")) != EOF) {
+               switch (c) {
+               case 'C':
+                       Cflag = 1;
+                       break;
+               case 'q':
+                       qflag = 1;
+                       break;
+               case 'P':
+                       pattern = parse_pattern(optarg);
+                       if (pattern < 0)
+                               return 0;
+                       break;
+               default:
+                       return command_usage(&writev_cmd);
+               }
+       }
+
+       if (optind > argc - 2)
+               return command_usage(&writev_cmd);
+
+       nr_reqs = 1;
+       for (i = optind; i < argc; i++) {
+               if (!strcmp(argv[i], ";")) {
+                       nr_reqs++;
+               }
+       }
+
+       reqs = qemu_malloc(nr_reqs * sizeof(*reqs));
+       buf = qemu_malloc(nr_reqs * sizeof(*buf));
+       qiovs = qemu_malloc(nr_reqs * sizeof(*qiovs));
+
+       for (i = 0; i < nr_reqs; i++) {
+               int j;
+
+               /* Read the offset of the request */
+               offset = cvtnum(argv[optind]);
+               if (offset < 0) {
+                       printf("non-numeric offset argument -- %s\n", 
argv[optind]);
+                       return 0;
+               }
+               optind++;
+
+               if (offset & 0x1ff) {
+                       printf("offset %lld is not sector aligned\n",
+                               (long long)offset);
+                       return 0;
+               }
+
+        if (i == 0) {
+            first_offset = offset;
+        }
+
+               /* Read lengths for qiov entries */
+               for (j = optind; j < argc; j++) {
+                       if (!strcmp(argv[j], ";")) {
+                               break;
+                       }
+               }
+
+               nr_iov = j - optind;
+
+               /* Build request */
+               reqs[i].qiov = &qiovs[i];
+               buf[i] = create_iovec(reqs[i].qiov, &argv[optind], nr_iov, 
pattern);
+               reqs[i].sector = offset >> 9;
+               reqs[i].nb_sectors = reqs[i].qiov->size >> 9;
+
+               optind = j + 1;
+
+               offset += reqs[i].qiov->size;
+               pattern++;
+       }
+
+       gettimeofday(&t1, NULL);
+       cnt = do_aio_multiwrite(reqs, nr_reqs, &total);
+       gettimeofday(&t2, NULL);
+
+       if (cnt < 0) {
+               printf("aio_multiwrite failed: %s\n", strerror(-cnt));
+               goto out;
+       }
+
+       if (qflag)
+               goto out;
+
+       /* Finally, report back -- -C gives a parsable format */
+       t2 = tsub(t2, t1);
+       print_report("wrote", &t2, first_offset, total, total, cnt, Cflag);
+out:
+       for (i = 0; i < nr_reqs; i++) {
+               qemu_io_free(buf[i]);
+               qemu_iovec_destroy(&qiovs[i]);
+       }
+       qemu_free(buf);
+       qemu_free(reqs);
+       qemu_free(qiovs);
+       return 0;
+}
+
 struct aio_ctx {
        QEMUIOVector qiov;
        int64_t offset;
@@ -1483,6 +1674,7 @@ int main(int argc, char **argv)
        add_command(&readv_cmd);
        add_command(&write_cmd);
        add_command(&writev_cmd);
+       add_command(&multiwrite_cmd);
        add_command(&aio_read_cmd);
        add_command(&aio_write_cmd);
        add_command(&aio_flush_cmd);
-- 
1.6.6.1