[PATCH] blktrace: fix network support, don't use sendfile() yet

We need relayfs changed for that to work (which I only have half-done)

diff --git a/blktrace.c b/blktrace.c
index 6a7c58a1fda40e308d52262040e223c12cb2f5ba..a79ad6a844075f4fe8e653711c438d8b24588e6a 100644 (file)
--- a/blktrace.c
+++ b/blktrace.c
@@ -154,7 +154,6 @@ struct tip_subbuf {
        void *buf;
        unsigned int len;
        unsigned int max_len;
-       off_t offset;
 };
 
 #define FIFO_SIZE      (1024)  /* should be plenty big! */
@@ -174,10 +173,7 @@ struct thread_information {
        void *fd_buf;
        char fn[MAXPATHLEN + 64];
 
-       char ofname[64];
-
        FILE *ofile;
-       off_t ofile_offset;
        char *ofile_buffer;
        int ofile_stdout;
        int ofile_mmap;
@@ -257,8 +253,9 @@ static void exit_trace(int status);
  */
 struct blktrace_net_hdr {
        u32 magic;              /* same as trace magic */
-       char ofname[64];        /* trace name */
+       char buts_name[32];     /* trace name */
        u32 cpu;                /* for which cpu */
+       u32 max_cpus;
        u32 len;                /* length of following trace data */
 };
 
@@ -522,48 +519,20 @@ static int mmap_subbuf(struct thread_information *tip, unsigned int maxlen)
 }
 
 /*
- * Use the copy approach for pipes
+ * Use the copy approach for pipes and network
  */
 static int get_subbuf(struct thread_information *tip)
 {
        struct tip_subbuf *ts = malloc(sizeof(*ts));
-       int ret = 1;
-
-       /*
-        * for the net client, don't actually read the data in as we will
-        * use sendfile to transmit it. just mark how much data we have
-        */
-       if (net_mode == Net_client) {
-               struct stat sb;
-
-               ts->buf = NULL;
-
-               if (fstat(tip->fd, &sb) < 0) {
-                       perror("trace stat");
-                       goto out;
-               }
-
-               ts->len = sb.st_size - tip->ofile_offset;
-               ts->max_len = ts->len;
-               ts->offset = tip->ofile_offset;
-               tip->ofile_offset += ts->len;
-               ret = subbuf_fifo_queue(tip, ts);
-       } else {
-               ts->buf = malloc(buf_size);
-               ts->max_len = buf_size;
+       int ret;
 
-               ret = read_data(tip, ts->buf, ts->max_len);
-               if (ret > 0) {
-                       ts->len = ret;
-                       ret = subbuf_fifo_queue(tip, ts);
-               }
-       }
+       ts->buf = malloc(buf_size);
+       ts->max_len = buf_size;
 
-out:
-       if (ret) {
-               if (ts->buf)
-                       free(ts->buf);
-               free(ts);
+       ret = read_data(tip, ts->buf, ts->max_len);
+       if (ret > 0) {
+               ts->len = ret;
+               return subbuf_fifo_queue(tip, ts);
        }
 
        return ret;
@@ -663,20 +632,18 @@ static int flush_subbuf_net(struct thread_information *tip,
                            struct tip_subbuf *ts)
 {
        struct blktrace_net_hdr hdr;
-       int ret = 0;
 
        hdr.magic = BLK_IO_TRACE_MAGIC;
-       strcpy(hdr.ofname, tip->ofname);
+       strcpy(hdr.buts_name, tip->device->buts_name);
        hdr.cpu = tip->cpu;
+       hdr.max_cpus = ncpus;
        hdr.len = ts->len;
 
        if (write_data_net(net_out_fd, &hdr, sizeof(hdr)))
                return 1;
 
-       if (sendfile(net_out_fd, tip->fd, &ts->offset, ts->len) < 0) {
-               perror("sendfile");
-               ret = 1;
-       }
+       if (write_data_net(net_out_fd, ts->buf, ts->len))
+               return 1;
 
        free(ts);
        return 0;
@@ -871,6 +838,7 @@ static int start_threads(struct device_information *dip)
        struct thread_information *tip;
        int j, pipeline = output_name && !strcmp(output_name, "-");
        int mode, vbuf_size;
+       char op[64];
 
        for_each_tip(dip, tip, j) {
                tip->cpu = j;
@@ -886,8 +854,8 @@ static int start_threads(struct device_information *dip)
                        mode = _IOLBF;
                        vbuf_size = 512;
                } else {
-                       fill_ofname(tip->ofname, dip->buts_name, tip->cpu);
-                       tip->ofile = fopen(tip->ofname, "w+");
+                       fill_ofname(op, dip->buts_name, tip->cpu);
+                       tip->ofile = fopen(op, "w+");
                        tip->ofile_stdout = 0;
                        tip->ofile_mmap = 1;
                        mode = _IOFBF;
@@ -895,7 +863,7 @@ static int start_threads(struct device_information *dip)
                }
 
                if (tip->ofile == NULL) {
-                       perror(tip->ofname);
+                       perror(op);
                        return 1;
                }
 
@@ -1076,39 +1044,56 @@ static void show_stats(void)
                fprintf(stderr, "You have dropped events, consider using a larger buffer size (-b)\n");
 }
 
-static struct thread_information *net_tip_list;
-static int net_tip_len;
-
-static struct thread_information *net_get_tip(struct blktrace_net_hdr *bnh)
+static struct device_information *net_get_dip(char *buts_name)
 {
-       struct thread_information *tip;
+       struct device_information *dip;
        int i;
 
-       for (i = 0; i < net_tip_len; i++) {
-               tip = &net_tip_list[i];
+       for (i = 0; i < ndevs; i++) {
+               dip = &device_information[i];
 
-               if (!strcmp(bnh->ofname, tip->ofname))
-                       return tip;
+               if (!strcmp(dip->buts_name, buts_name))
+                       return dip;
        }
 
-       net_tip_list = realloc(net_tip_list, (net_tip_len + 1) * sizeof(*tip));
-       tip = &net_tip_list[net_tip_len];
-       net_tip_len++;
+       device_information = realloc(device_information, (ndevs + 1) * sizeof(*dip));
+       dip = &device_information[ndevs];
+       strcpy(dip->buts_name, buts_name);
+       ndevs++;
+       dip->threads = malloc(ncpus * sizeof(struct thread_information));
+       memset(dip->threads, 0, ncpus * sizeof(struct thread_information));
+
+       /*
+        * open all files
+        */
+       for (i = 0; i < ncpus; i++) {
+               struct thread_information *tip = &dip->threads[i];
+               char op[64];
 
-       memset(tip, 0, sizeof(*tip));
+               tip->cpu = i;
+               tip->ofile_stdout = 0;
+               tip->ofile_mmap = 1;
+               tip->device = dip;
 
-       tip->cpu = bnh->cpu;
-       strcpy(tip->ofname, bnh->ofname);
+               fill_ofname(op, dip->buts_name, tip->cpu);
 
-       tip->ofile = fopen(tip->ofname, "w+");
-       if (!tip->ofile) {
-               perror("fopen");
-               return NULL;
+               tip->ofile = fopen(op, "w+");
+               if (!tip->ofile) {
+                       perror("fopen");
+                       return NULL;
+               }
        }
 
-       tip->ofile_stdout = 0;
-       tip->ofile_mmap = 1;
-       return tip;
+       return dip;
+}
+
+static struct thread_information *net_get_tip(struct blktrace_net_hdr *bnh)
+{
+       struct device_information *dip;
+
+       ncpus = bnh->max_cpus;
+       dip = net_get_dip(bnh->buts_name);
+       return &dip->threads[bnh->cpu];
 }
 
 static int net_get_header(struct blktrace_net_hdr *bnh)
@@ -1176,7 +1161,7 @@ static int net_server(void)
 {
        struct sockaddr_in addr;
        socklen_t socklen;
-       int fd, opt, i;
+       int fd, opt, i, j;
 
        fd = socket(AF_INET, SOCK_STREAM, 0);
        if (fd < 0) {
@@ -1226,8 +1211,12 @@ static int net_server(void)
                        break;
        }
 
-       for (i = 0; i < net_tip_len; i++)
-               tip_ftrunc_final(&net_tip_list[i]);
+       for (i = 0; i < ndevs; i++) {
+               struct device_information *dip = &device_information[i];
+
+               for (j = 0; j < ncpus; j++)
+                       tip_ftrunc_final(&dip->threads[j]);
+       }
 
        return 0;
 }
@@ -1387,11 +1376,6 @@ int main(int argc, char *argv[])
                }
        }
 
-       while (optind < argc) {
-               if (resize_devices(argv[optind++]) != 0)
-                       return 1;
-       }
-
        setlocale(LC_NUMERIC, "en_US");
 
        page_size = getpagesize();
@@ -1399,6 +1383,11 @@ int main(int argc, char *argv[])
        if (net_mode == Net_server)
                return net_server();
 
+       while (optind < argc) {
+               if (resize_devices(argv[optind++]) != 0)
+                       return 1;
+       }
+
        if (ndevs == 0) {
                show_usage(argv[0]);
                return 1;