nmeter: fix block i/o count on newer Linux kernels

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 38 insertions, 12 deletions

diff --git a/procps/nmeter.c b/procps/nmeter.c
index 999955982..ed5479024 100644
--- a/procps/nmeter.c
+++ b/procps/nmeter.c
@@ -274,30 +274,56 @@ static int rdval_loadavg(const char* p, ullong *vec, ...)
 //   1  2 3   4  5        6(rd)  7      8     9     10(wr) 11     12 13     14
 //   3  0 hda 51292 14441 841783 926052 25717 79650 843256 3029804 0 148459 3956933
 //   3  1 hda1 0 0 0 0 <- ignore if only 4 fields
+// Linux 3.0 (maybe earlier) started printing full stats for hda1 too.
+// Had to add code which skips such devices.
 static int rdval_diskstats(const char* p, ullong *vec)
 {
-        ullong rd = rd; // for compiler
-        int indexline = 0;
+        char devname[32];
+        unsigned devname_len = 0;
+        int value_idx = 0;
+
         vec[0] = 0;
         vec[1] = 0;
         while (1) {
-                indexline++;
-                while (*p == ' ' || *p == '\t') p++;
-                if (*p == '\0') break;
+                value_idx++;
+                while (*p == ' ' || *p == '\t')
+                        p++;
+                if (*p == '\0')
+                        break;
                 if (*p == '\n') {
-                        indexline = 0;
+                        value_idx = 0;
                         p++;
                         continue;
                 }
-                if (indexline == 6) {
-                        rd = strtoull(p, NULL, 10);
-                } else if (indexline == 10) {
-                        vec[0] += rd;  // TODO: *sectorsize (don't know how to find out sectorsize)
+                if (value_idx == 3) {
+                        char *end = strchrnul(p, ' ');
+                        /* If this a hda1-like device (same prefix as last one + digit)? */
+                        if (devname_len && strncmp(devname, p, devname_len) == 0 && isdigit(p[devname_len])) {
+                                p = end;
+                                goto skip_line; /* skip entire line */
+                        }
+                        /* It is not. Remember the name for future checks */
+                        devname_len = end - p;
+                        if (devname_len > sizeof(devname)-1)
+                                devname_len = sizeof(devname)-1;
+                        strncpy(devname, p, devname_len);
+                        /* devname[devname_len] = '\0'; - not really needed */
+                        p = end;
+                } else
+                if (value_idx == 6) {
+                        // TODO: *sectorsize (don't know how to find out sectorsize)
+                        vec[0] += strtoull(p, NULL, 10);
+                } else
+                if (value_idx == 10) {
+                        // TODO: *sectorsize (don't know how to find out sectorsize)
                         vec[1] += strtoull(p, NULL, 10);
-                        while (*p != '\n' && *p != '\0') p++;
+ skip_line:
+                        while (*p != '\n' && *p != '\0')
+                                p++;
                         continue;
                 }
-                while (*p > ' ') p++; // skip over value
+                while ((unsigned char)(*p) > ' ') // skip over value
+                        p++;
         }
         return 0;
 }