Check setvbuf return value

[blktrace.git] / blktrace.c

diff --git a/blktrace.c b/blktrace.c
index 4cccb7c635f720c89bd3b13696c1e339af31b1bf..49cfca61352ddca5233f669e76edb1bea54f84e2 100644 (file)
--- a/blktrace.c
+++ b/blktrace.c
@@ -93,7 +93,7 @@ struct devpath {
        char *path;                     /* path to device special file */
        char *buts_name;                /* name returned from bt kernel code */
        struct pdc_stats *stats;
-       int fd, idx, ncpus;
+       int fd, ncpus;
        unsigned long long drops;
 
        /*
@@ -460,8 +460,8 @@ static char usage_str[] = "\n\n" \
        "\t-w Stop after defined time, in seconds\n" \
        "\t-a Only trace specified actions. See documentation\n" \
        "\t-A Give trace mask as a single value. See documentation\n" \
-       "\t-b Sub buffer size in KiB\n" \
-       "\t-n Number of sub buffers\n" \
+       "\t-b Sub buffer size in KiB (default 512)\n" \
+       "\t-n Number of sub buffers (default 4)\n" \
        "\t-l Run in network listen mode (blktrace server)\n" \
        "\t-h Run in network client mode, connecting to the given host\n" \
        "\t-p Network port to use (default 8462)\n" \
@@ -721,18 +721,24 @@ static void *my_mmap(void *addr, size_t length, int prot, int flags, int fd,
        return new;
 }
 
-static int my_mlock(const void *addr, size_t len)
+static int my_mlock(struct tracer *tp,
+                   const void *addr, size_t len)
 {
-       int ret;
+       int ret, retry = 0;
 
        do {
                ret = mlock(addr, len);
+               if ((retry >= 10) && tp && tp->is_done)
+                       break;
+               retry++;
        } while (ret < 0 && handle_mem_failure(len));
 
        return ret;
 }
 
-static int setup_mmap(int fd, unsigned int maxlen, struct mmap_info *mip)
+static int setup_mmap(int fd, unsigned int maxlen,
+                     struct mmap_info *mip,
+                     struct tracer *tp)
 {
        if (mip->fs_off + maxlen > mip->fs_buf_len) {
                unsigned long nr = max(16, mip->buf_nr);
@@ -759,7 +765,10 @@ static int setup_mmap(int fd, unsigned int maxlen, struct mmap_info *mip)
                        perror("setup_mmap: mmap");
                        return 1;
                }
-               my_mlock(mip->fs_buf, mip->fs_buf_len);
+               if (my_mlock(tp, mip->fs_buf, mip->fs_buf_len) < 0) {
+                       perror("setup_mlock: mlock");
+                       return 1;
+               }
        }
 
        return 0;
@@ -1239,7 +1248,7 @@ static int add_devpath(char *path)
        memset(dpp, 0, sizeof(*dpp));
        dpp->path = strdup(path);
        dpp->fd = fd;
-       dpp->idx = ndevs++;
+       ndevs++;
        list_add_tail(&dpp->head, &devpaths);
 
        return 0;
@@ -1321,7 +1330,7 @@ static struct trace_buf *tb_combine(struct trace_buf *prev,
                 * the whole structures, as the other fields
                 * are "static".
                 */
-               prev = realloc(prev->buf, sizeof(*prev) + tot_len);
+               prev = realloc(prev, sizeof(*prev) + tot_len);
                prev->buf = (void *)(prev + 1);
        }
 
@@ -1683,7 +1692,7 @@ static int handle_pfds_file(struct tracer *tp, int nevs, int force_read)
                if (pfd->revents & POLLIN || force_read) {
                        mip = &iop->mmap_info;
 
-                       ret = setup_mmap(iop->ofd, buf_size, mip);
+                       ret = setup_mmap(iop->ofd, buf_size, mip, tp);
                        if (ret < 0) {
                                pfd->events = 0;
                                break;
@@ -2146,12 +2155,17 @@ static int handle_args(int argc, char *argv[])
                return 1;
        }
 
-       if (statfs(debugfs_path, &st) < 0 || st.f_type != (long)DEBUGFS_TYPE) {
+       if (statfs(debugfs_path, &st) < 0) {
                fprintf(stderr, "Invalid debug path %s: %d/%s\n",
                        debugfs_path, errno, strerror(errno));
                return 1;
        }
 
+       if (st.f_type != (long)DEBUGFS_TYPE) {
+               fprintf(stderr, "Debugfs is not mounted at %s\n", debugfs_path);
+               return 1;
+       }
+
        if (act_mask_tmp != 0)
                act_mask = act_mask_tmp;
 
@@ -2169,7 +2183,10 @@ static int handle_args(int argc, char *argv[])
                piped_output = 1;
                handle_pfds = handle_pfds_entries;
                pfp = stdout;
-               setvbuf(pfp, NULL, _IONBF, 0);
+               if (setvbuf(pfp, NULL, _IONBF, 0)) {
+                       perror("setvbuf stdout");
+                       return 1;
+               }
        } else
                handle_pfds = handle_pfds_file;
        return 0;
@@ -2381,7 +2398,7 @@ static void net_client_read_data(struct cl_conn *nc, struct devpath *dpp,
        struct io_info *iop = &dpp->ios[bnh->cpu];
        struct mmap_info *mip = &iop->mmap_info;
 
-       if (setup_mmap(iop->ofd, bnh->len, &iop->mmap_info)) {
+       if (setup_mmap(iop->ofd, bnh->len, &iop->mmap_info, NULL)) {
                fprintf(stderr, "ncd(%s:%d): mmap failed\n",
                        nc->ch->hostname, nc->fd);
                exit(1);