iostats: properly distribute exit status and give usefull error messages

diff --git a/sys/src/cmd/iostats.c b/sys/src/cmd/iostats.c
index b2986efd52fe19bb4fe4c3e5ef96130069b36cf2..be49a11b70e0e16e539ef386ec0daf82f30c6c6d 100644 (file)
--- a/sys/src/cmd/iostats.c
+++ b/sys/src/cmd/iostats.c
@@ -262,10 +262,11 @@ main(int argc, char **argv)
        char *dbfile;
        char buf[64*1024];
        float brpsec, bwpsec, bppsec;
-       int cpid, fspid, rspid, dbg, n, mflag;
+       int cpid, fspid, expid, rspid, dbg, n, mflag;
        char *fds[3];
+       Waitmsg *w;
        File *fs;
-       Req *r, **rr;
+       Req *r;
 
        dbg = 0;
        mflag = MREPL;
@@ -291,7 +292,7 @@ main(int argc, char **argv)
                usage();
 
        if(pipe(pfd) < 0)
-               sysfatal("pipe");
+               sysfatal("pipe: %r");
 
        /* dup std fds to be inherited to exportfs */
        fds[0] = smprint("/fd/%d", dup(0, -1));
@@ -300,7 +301,7 @@ main(int argc, char **argv)
 
        switch(cpid = fork()) {
        case -1:
-               sysfatal("fork");
+               sysfatal("fork: %r");
        case 0:
                close(pfd[1]);
                close(atoi(strrchr(fds[0], '/')+1));
@@ -308,12 +309,12 @@ main(int argc, char **argv)
                close(atoi(strrchr(fds[2], '/')+1));
 
                if(getwd(buf, sizeof(buf)) == 0)
-                       sysfatal("no working directory");
+                       sysfatal("no working directory: %r");
 
                rfork(RFENVG|RFNAMEG);
 
                if(mount(pfd[0], -1, "/", mflag, "") < 0)
-                       sysfatal("mount /");
+                       sysfatal("mount /: %r");
 
                /* replace std fds with the exported ones */
                close(0); open(fds[0], OREAD);
@@ -326,7 +327,7 @@ main(int argc, char **argv)
                bind("#d", "/fd", MREPL);
 
                if(chdir(buf) < 0)
-                       sysfatal("chdir");
+                       sysfatal("chdir: %r");
 
                exec(*argv, argv);
                if(**argv != '/' && strncmp(*argv, "./", 2) != 0 && strncmp(*argv, "../", 3) != 0)
@@ -339,10 +340,10 @@ main(int argc, char **argv)
        /* isolate us from interrupts */
        rfork(RFNOTEG);
        if(pipe(efd) < 0)
-               sysfatal("pipe");
+               sysfatal("pipe: %r");
 
        /* spawn exportfs */
-       switch(fork()) {
+       switch(expid = fork()) {
        default:
                close(efd[0]);
                close(atoi(strrchr(fds[0], '/')+1));
@@ -350,7 +351,7 @@ main(int argc, char **argv)
                close(atoi(strrchr(fds[2], '/')+1));
                break;
        case -1:
-               sysfatal("fork");
+               sysfatal("fork: %r");
        case 0:
                dup(efd[0], 0);
                close(efd[0]);
@@ -361,21 +362,33 @@ main(int argc, char **argv)
                } else {
                        execl("/bin/exportfs", "exportfs", "-r", "/", nil);
                }
-               exits(0);
+               sysfatal("exec: %r");
        }
 
        switch(fspid = fork()) {
        default:
                close(pfd[1]);
                close(efd[1]);
-               while(cpid != waitpid())
-                       ;
-               postnote(PNPROC, fspid, DONESTR);
-               while(fspid != waitpid())
-                       ;
-               exits(0);
+
+               buf[0] = '\0';
+               while((w = wait()) != nil && (cpid != -1 || fspid != -1 || expid != -1)){
+                       if(w->pid == fspid)
+                               fspid = -1;
+                       else if(w->pid == expid)
+                               expid = -1;
+                       else if(w->pid == cpid){
+                               cpid = -1;
+                               strcpy(buf, w->msg);
+                               if(fspid != -1)
+                                       postnote(PNPROC, fspid, DONESTR);
+                       }
+                       if(buf[0] == '\0')
+                               strcpy(buf, w->msg);
+                       free(w);
+               }
+               exits(buf);
        case -1:
-               sysfatal("fork");
+               sysfatal("fork: %r");
        case 0:
                notify(catcher);
                break;
@@ -404,6 +417,7 @@ main(int argc, char **argv)
                while(!done){
                        uchar tmp[sizeof(buf)];
                        Fcall f;
+                       Req **rr;
 
                        n = read(efd[1], buf, sizeof(buf));
                        if(n < 0)
@@ -458,7 +472,7 @@ main(int argc, char **argv)
                        if(write(pfd[1], buf, n) != n)
                                break;
                }
-               exits(0);
+               exits(nil);
        default:
                /* read request from mount and pass to exportfs */
                while(!done){
@@ -556,5 +570,5 @@ main(int argc, char **argv)
                        fs->path);
        }
 
-       exits(0);
+       exits(nil);
 }