iowatcher: Merge trace dumping functions into one

Now that combine_blktrace_devs() takes a list of traces it's fairly
generic so we might as well merge blktrace_to_dump() into it. The latter
can be replaced with a call using a list with a single entry.

combine_blktrace_devs() is renamed dump_traces() because that's what it
does.

Also eradicate the big global char array 'line' that was being used in a
bunch of places along with some more unnecessary strdup()s.

Signed-off-by: Andrew Price <anprice@redhat.com>

diff --git a/iowatcher/blkparse.c b/iowatcher/blkparse.c
index bf58b453aa3690d67952678a5801ade842f7fd38..1555845f6c98a616dba67c3671e180c607c42b84 100644 (file)
--- a/iowatcher/blkparse.c
+++ b/iowatcher/blkparse.c
@@ -49,9 +49,6 @@ static struct list_head process_hash_table[PROCESS_HASH_TABLE_SIZE];
 extern int plot_io_action;
 extern int io_per_process;
 
-static const int line_len = 1024;
-static char line[1024];
-
 /*
  * Trace categories
  */
@@ -736,27 +733,29 @@ static struct tracelist *traces_list(char *dir_name, int *len)
 {
        int count = 0;
        struct tracelist *traces = NULL;
+       int dlen = strlen(dir_name);
        DIR *dir = opendir(dir_name);
        if (!dir)
                return NULL;
 
        while (1) {
-               int len;
+               int n = 0;
                struct tracelist *tl;
                struct dirent *d = readdir(dir);
                if (!d)
                        break;
 
-               if (!match_trace(d->d_name, &len))
+               if (!match_trace(d->d_name, &n))
                        continue;
 
+               n += dlen + 1; /* dir + '/' + file */
                /* Allocate space for tracelist + filename */
-               tl = calloc(1, sizeof(struct tracelist) + (sizeof(char) * (len + 1)));
+               tl = calloc(1, sizeof(struct tracelist) + (sizeof(char) * (n + 1)));
                if (!tl)
                        return NULL;
                tl->next = traces;
                tl->name = (char *)(tl + 1);
-               strncpy(tl->name, d->d_name, len);
+               snprintf(tl->name, n, "%s/%s", dir_name, d->d_name);
                traces = tl;
                count++;
        }
@@ -778,35 +777,23 @@ static void traces_free(struct tracelist *traces)
        }
 }
 
-static char *combine_blktrace_devs(char *dir_name)
+static int dump_traces(struct tracelist *traces, int count, char *dumpfile)
 {
-       struct tracelist *traces = NULL;
        struct tracelist *tl;
-       char *ret = NULL;
        char **argv = NULL;
-       char *dumpfile;
        int argc = 0;
        int i;
-       int err;
+       int err = 0;
 
-       if (!asprintf(&dumpfile, "%s.dump", dir_name))
-               goto out;
-
-       traces = traces_list(dir_name, &argc);
-       if (!traces)
-               goto out;
-
-       argc *= 2; /* {"-i", trace } */
-       argc += 6; /* See below */
+       argc = count * 2; /* {"-i", trace } */
+       argc += 4; /* See below */
        argv = calloc(argc + 1, sizeof(char *));
        if (!argv)
-               goto out;
+               return -errno;
 
        i = 0;
        argv[i++] = "blkparse";
        argv[i++] = "-O";
-       argv[i++] = "-D";
-       argv[i++] = dir_name;
        argv[i++] = "-d";
        argv[i++] = dumpfile;
        for (tl = traces; tl != NULL; tl = tl->next) {
@@ -816,14 +803,7 @@ static char *combine_blktrace_devs(char *dir_name)
 
        err = run_program2(argc, argv);
        free(argv);
-       if (err) {
-               fprintf(stderr, "blkparse failed with exit code %d\n", err);
-               exit(1);
-       }
-       ret = dumpfile;
-out:
-       traces_free(traces);
-       return ret;
+       return err;
 }
 
 static char *find_trace_file(char *filename)
@@ -831,8 +811,9 @@ static char *find_trace_file(char *filename)
        int ret;
        struct stat st;
        char *dot;
-       char *try;
        int found_dir = 0;
+       char *dumpfile;
+       int len = strlen(filename);
 
        /* look for an exact match of whatever they pass in.
         * If it is a file, assume it is the dump file.
@@ -851,7 +832,7 @@ static char *find_trace_file(char *filename)
        if (found_dir) {
                int i;
                /* Eat up trailing '/'s */
-               for (i = strlen(filename) - 1; filename[i] == '/'; i--)
+               for (i = len - 1; filename[i] == '/'; i--)
                        filename[i] = '\0';
        }
 
@@ -859,43 +840,58 @@ static char *find_trace_file(char *filename)
         * try tacking .dump onto the end and see if that already
         * has been generated
         */
-       snprintf(line, line_len, "%s.%s", filename, "dump");
-       ret = stat(line, &st);
+       ret = asprintf(&dumpfile, "%s.dump", filename);
+       if (ret == -1) {
+               perror("Error building dump file name");
+               return NULL;
+       }
+       ret = stat(dumpfile, &st);
        if (ret == 0)
-               return strdup(line);
+               return dumpfile;
 
        /*
         * try to generate the .dump from all the traces in
         * a single dir.
         */
        if (found_dir) {
-               try = combine_blktrace_devs(filename);
-               if (try)
-                       return try;
+               int count;
+               struct tracelist *traces = traces_list(filename, &count);
+               if (traces) {
+                       ret = dump_traces(traces, count, dumpfile);
+                       traces_free(traces);
+                       if (ret == 0)
+                               return dumpfile;
+               }
        }
+       free(dumpfile);
 
        /*
         * try to generate the .dump from all the blktrace
         * files for a named trace
         */
-       try = strdup(filename);
-       dot = strrchr(try, '.');
+       dot = strrchr(filename, '.');
        if (!dot || strcmp(".dump", dot) != 0) {
-               if (dot && dot != try)
-                       *dot = '\0';
-               snprintf(line, line_len, "%s%s", try, ".blktrace.0");
-               ret = stat(line, &st);
+               struct tracelist trace = {0};
+               if (dot && dot != filename)
+                       len = dot - filename;
+
+               ret = asprintf(&trace.name, "%*s.blktrace.0", len, filename);
+               if (ret == -1)
+                       return NULL;
+               ret = asprintf(&dumpfile, "%*s.dump", len, filename);
+               if (ret == -1) {
+                       free(trace.name);
+                       return NULL;
+               }
+
+               ret = dump_traces(&trace, 1, dumpfile);
                if (ret == 0) {
-                       blktrace_to_dump(try);
-                       snprintf(line, line_len, "%s.%s", try, "dump");
-                       ret = stat(line, &st);
-                       if (ret == 0) {
-                               free(try);
-                               return strdup(line);
-                       }
+                       free(trace.name);
+                       return dumpfile;
                }
+               free(trace.name);
+               free(dumpfile);
        }
-       free(try);
        return NULL;
 }
 struct trace *open_trace(char *filename)

diff --git a/iowatcher/tracers.c b/iowatcher/tracers.c
index ed5efa181aa20f52e2034839f71afa6f5731dbc2..f42958b57f900183bb704ccce4416ca59363eaa4 100644 (file)
--- a/iowatcher/tracers.c
+++ b/iowatcher/tracers.c
@@ -223,22 +223,6 @@ int wait_for_tracers(void)
        return 0;
 }
 
-int blktrace_to_dump(char *trace_name)
-{
-       char *argv[] = {
-               "blkparse", "-O",
-               "-i", NULL,
-               "-d", NULL,
-               NULL
-       };
-
-       argv[3] = trace_name;
-       snprintf(line, line_len, "%s.dump", trace_name);
-       argv[5] = line;
-
-       return run_program2(6, argv);
-}
-
 int start_mpstat(char *trace_name)
 {
        int fd;

diff --git a/iowatcher/tracers.h b/iowatcher/tracers.h
index 48eec45ef4b24993170725042711096b93923fcd..92f349adf4d2dfad6323db3f3d791d26f1c34f05 100644 (file)
--- a/iowatcher/tracers.h
+++ b/iowatcher/tracers.h
@@ -23,7 +23,6 @@ int stop_blktrace(void);
 int start_blktrace(char **devices, int num_devices, char *trace_name, char *dest);
 int start_mpstat(char *trace_name);
 int wait_for_tracers(void);
-int blktrace_to_dump(char *trace_name);
 int start_mpstat(char *trace_name);