nfsstat: Add -S/--since flag.

	Read statistics from the file given with -S/--since and display
the difference between those and the current statistics.  Valid stat files
are those in the form of /proc/net/rpc/nfs, /proc/net/rpc/nfsd, or any
"pretty" output from nfsstat itself.  Statistics that are missing from a
"pretty" stat file are treated as zeroes.

	Similar to Neil Brown's suggestion, one might use this in
conjunction with watch(1) like this:

$ watch "nfsstat --since /tmp/stats; nfsstat >/tmp/stats"

Signed-off-by: David M. Richter <richterd@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>

diff --git a/utils/nfsstat/nfsstat.c b/utils/nfsstat/nfsstat.c
index c6f2ace0032a0500a2f6f70ce884d5f66ed0761f..828119b724d17a440fbe5ddb013dff2b76314a35 100644 (file)
--- a/utils/nfsstat/nfsstat.c
+++ b/utils/nfsstat/nfsstat.c
@@ -171,7 +171,8 @@ static void         print_numbers(const char *, unsigned int *,
                                        unsigned int);
 static void            print_callstats(const char *, const char **,
                                        unsigned int *, unsigned int);
-static int             parse_statfile(const char *, struct statinfo *);
+static int             parse_raw_statfile(const char *, struct statinfo *);
+static int             parse_pretty_statfile(const char *, struct statinfo *);
 
 static statinfo                *get_stat_info(const char *, struct statinfo *);
 
@@ -222,7 +223,8 @@ void usage(char *name)
   -v, --verbose, --all\tSame as '-o all'\n\
   -r, --rpc\t\tShow RPC statistics\n\
   -n, --nfs\t\tShow NFS statistics\n\
-  -Z, --sleep\tSaves stats, pauses, diffs current and saved\n\
+  -Z, --sleep\t\tSaves stats, pauses, diffs current and saved\n\
+  -S, --since file\tShows difference between current stats and those in 'file'\n\
   --version\t\tShow program version\n\
   --help\t\tWhat you just did\n\
 \n", name);
@@ -244,6 +246,7 @@ static struct option longopts[] =
        { "help", 0, 0, '\1' },
        { "version", 0, 0, '\2' },
        { "sleep", 0, 0, 'Z' },
+       { "since", 1, 0, 'S' },
        { NULL, 0, 0, 0 }
 };
 
@@ -254,9 +257,12 @@ main(int argc, char **argv)
                        opt_srv = 0,
                        opt_clt = 0,
                        opt_prt = 0,
-                       opt_sleep = 0;
+                       opt_sleep = 0,
+                       opt_since = 0;
        int             c;
-       char           *progname;
+       char           *progname,
+                      *serverfile = NFSSRVSTAT,
+                      *clientfile = NFSCLTSTAT;
 
        struct statinfo *serverinfo = srvinfo,
                        *serverinfo_tmp = srvinfo_old,
@@ -273,7 +279,7 @@ main(int argc, char **argv)
        else
                progname = argv[0];
 
-       while ((c = getopt_long(argc, argv, "234acmno:Zvrsz\1\2", longopts, NULL)) != EOF) {
+       while ((c = getopt_long(argc, argv, "234acmno:ZS:vrsz\1\2", longopts, NULL)) != EOF) {
                switch (c) {
                case 'a':
                        fprintf(stderr, "nfsstat: nfs acls are not yet supported.\n");
@@ -306,6 +312,11 @@ main(int argc, char **argv)
                case 'Z':
                        opt_sleep = 1;
                        break;
+               case 'S':
+                       opt_since = 1;
+                       serverfile = optarg;
+                       clientfile = optarg;
+                       break;
                case '2':
                case '3':
                case '4':
@@ -361,7 +372,7 @@ main(int argc, char **argv)
                        "server.\n");
        }
 
-       if (opt_sleep) {
+       if (opt_since || opt_sleep) {
                serverinfo = srvinfo_old;
                serverinfo_tmp = srvinfo;
                clientinfo = cltinfo_old;
@@ -369,11 +380,10 @@ main(int argc, char **argv)
        }
 
        if (opt_srv)
-               get_stats(NFSSRVSTAT, serverinfo, &opt_srv, opt_clt, 1);
+               get_stats(serverfile, serverinfo, &opt_srv, opt_clt, 1);
        if (opt_clt)
-               get_stats(NFSCLTSTAT, clientinfo, &opt_clt, opt_srv, 0);
+               get_stats(clientfile, clientinfo, &opt_clt, opt_srv, 0);
 
-       /* save stat snapshots; wait for signal; then diff current and saved stats */
        if (opt_sleep) {
                starttime = time(NULL);
                printf("Collecting statistics; press CTRL-C to view results from interval (i.e., from pause to CTRL-C).\n");
@@ -382,6 +392,9 @@ main(int argc, char **argv)
                        return 1;
                }
                pause();
+       }
+
+       if (opt_since || opt_sleep) {
                if (opt_srv) {
                        get_stats(NFSSRVSTAT, serverinfo_tmp, &opt_srv, opt_clt, 1);
                        diff_stats(serverinfo_tmp, serverinfo, 1);
@@ -556,9 +569,9 @@ print_callstats(const char *hdr, const char **names,
        printf("\n");
 }
 
-
+/* returns 0 on success, 1 otherwise */
 static int
-parse_statfile(const char *name, struct statinfo *statp)
+parse_raw_statfile(const char *name, struct statinfo *statp)
 {
        char    buffer[4096], *next;
        FILE    *fp;
@@ -568,7 +581,7 @@ parse_statfile(const char *name, struct statinfo *statp)
         */
        if ((fp = fopen(name, "r")) == NULL) {
                // fprintf(stderr, "Warning: %s: %m\n", name);
-               return 0;
+               return 1;
        }
 
        while (fgets(buffer, sizeof(buffer), fp) != NULL) {
@@ -598,7 +611,79 @@ parse_statfile(const char *name, struct statinfo *statp)
        }
 
        fclose(fp);
-       return 1;
+       return 0;
+}
+
+/* returns 0 on success, 1 otherwise */
+static int
+parse_pretty_statfile(const char *filename, struct statinfo *info)
+{
+       int numvals, curindex, numconsumed, n, sum, err = 1;
+       char buf[4096], *bufp, *fmt, is_proc;
+       FILE *fp = NULL;
+       struct statinfo *ip;
+
+       if ((fp = fopen(filename, "r")) == NULL)
+               //err(2, "Unable to open statfile '%s'.\n", filename);
+               goto out;
+
+       while (fgets(buf, sizeof(buf), fp) != NULL) {
+               for (ip = info; ip->tag; ip++) {
+                       if (strcmp(buf, ip->label))
+                               continue;
+
+                       sum = 0;
+                       numvals = ip->nrvals - 1;
+                       is_proc = strncmp("proc", ip->tag, 4) ? 0 : 1;
+                       if (is_proc) {
+                               fmt = " %u %*u%% %n";
+                               curindex = 1;
+                               ip->valptr[0] = 0;
+                       } else {
+                               fmt = " %u %n";
+                               curindex = 0;
+                       }
+more_stats:
+                       /* get (and skip) header */
+                       if (fgets(buf, sizeof(buf), fp) == NULL) {
+                               fprintf(stderr, "Failed to locate header after "
+                                               "label for '%s' in %s.\n",
+                                               ip->tag, filename);
+                               goto out;
+                       }
+                       /* no header -- done with this "tag" */
+                       if (*buf == '\n') {
+                               ip->valptr[numvals] = sum;
+                               break;
+                       }
+                       /* get stats */
+                       if (fgets(buf, sizeof(buf), fp) == NULL) {
+                               fprintf(stderr, "Failed to locate stats after "
+                                               "header for '%s' in %s.\n",
+                                               ip->tag, filename);
+                               goto out;
+                       }
+                       bufp = buf;
+                       for (; curindex < numvals; curindex++) {
+                               n = sscanf(bufp, fmt, &ip->valptr[curindex],
+                                               &numconsumed);
+                               if (n != 1)
+                                       break;
+                               if (is_proc) {
+                                       ip->valptr[0]++;
+                                       sum++;
+                               }
+                               sum += ip->valptr[curindex];
+                               bufp += numconsumed;
+                       }
+                       goto more_stats;
+               }
+       }
+       err = 0;
+out:
+       if (fp)
+               fclose(fp);
+       return err;
 }
 
 static int
@@ -653,11 +738,42 @@ static void
 get_stats(const char *file, struct statinfo *info, int *opt, int other_opt,
                int is_srv)
 {
-       const char *label = is_srv ? "Server" : "Client";
-
-       if (!parse_statfile(file, info)) {
+       FILE *fp;
+       char buf[10];
+       int err = 1;
+       char *label = is_srv ? "Server" : "Client";
+
+       /* try to guess what type of stat file we're dealing with */
+       if ((fp = fopen(file, "r")) == NULL)
+               goto out;
+       if (fgets(buf, 10, fp) == NULL)
+               goto out;
+       if (!strncmp(buf, "net ", 4)) {
+               /* looks like raw client stats */
+               if (is_srv) {
+                       fprintf(stderr, "Warning: no server info present in "
+                                       "raw client stats file.\n");
+                       *opt = 0;
+               } else
+                       err = parse_raw_statfile(file, info);
+       } else if (!strncmp(buf, "rc ", 3)) {
+               /* looks like raw server stats */
+               if (!is_srv) {
+                       fprintf(stderr, "Warning: no client info present in "
+                                       "raw server stats file.\n");
+                       *opt = 0;
+               } else
+                       err = parse_raw_statfile(file, info);
+       } else
+               /* looks like pretty client and server stats */
+               err = parse_pretty_statfile(file, info);
+out:
+       if (fp)
+               fclose(fp);
+       if (err) {
                if (!other_opt) {
-                       fprintf(stderr, "Warning: No %s Stats (%s: %m). \n", label, file);
+                       fprintf(stderr, "Error: No %s Stats (%s: %m). \n",
+                                       label, file);
                        exit(2);
                }
                *opt = 0;
@@ -711,7 +827,7 @@ diff_stats(struct statinfo *new, struct statinfo *old, int is_srv)
                 * diff -- i.e., it should always be included in the
                 * total.
                 */
-               if (!strncmp("proc", new[i].tag, 4))
+               if (!strncmp("proc", new[i].tag, 4) && old[i].valptr[0])
                        new[i].valptr[new[i].nrvals - 1] += new[i].valptr[0];
        }
 }