+#include <inttypes.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
static int get_io_ticks(struct disk_util *du, struct disk_util_stat *dus)
{
- unsigned in_flight;
- unsigned long long sectors[2];
char line[256];
FILE *f;
char *p;
dprint(FD_DISKUTIL, "%s: %s", du->path, p);
- ret = sscanf(p, "%llu %llu %llu %llu %llu %llu %llu %llu %u %llu %llu\n",
- (unsigned long long *) &dus->s.ios[0],
- (unsigned long long *) &dus->s.merges[0],
- §ors[0],
- (unsigned long long *) &dus->s.ticks[0],
- (unsigned long long *) &dus->s.ios[1],
- (unsigned long long *) &dus->s.merges[1],
- §ors[1],
- (unsigned long long *) &dus->s.ticks[1],
- &in_flight,
- (unsigned long long *) &dus->s.io_ticks,
- (unsigned long long *) &dus->s.time_in_queue);
+ ret = sscanf(p, "%"SCNu64" %"SCNu64" %"SCNu64" %"SCNu64" "
+ "%"SCNu64" %"SCNu64" %"SCNu64" %"SCNu64" "
+ "%*u %"SCNu64" %"SCNu64"\n",
+ &dus->s.ios[0], &dus->s.merges[0], &dus->s.sectors[0],
+ &dus->s.ticks[0],
+ &dus->s.ios[1], &dus->s.merges[1], &dus->s.sectors[1],
+ &dus->s.ticks[1],
+ &dus->s.io_ticks, &dus->s.time_in_queue);
fclose(f);
- dprint(FD_DISKUTIL, "%s: stat read ok? %d\n", du->path, ret == 1);
- dus->s.sectors[0] = sectors[0];
- dus->s.sectors[1] = sectors[1];
- return ret != 11;
+ dprint(FD_DISKUTIL, "%s: stat read ok? %d\n", du->path, ret == 10);
+ return ret != 10;
+}
+
+static uint64_t safe_32bit_diff(uint64_t nval, uint64_t oval)
+{
+ /* Linux kernel prints some of the stat fields as 32-bit integers. It is
+ * possible that the value overflows, but since fio uses unsigned 64-bit
+ * arithmetic in update_io_tick_disk(), it instead results in a huge
+ * bogus value being added to the respective accumulating field. Just
+ * in case Linux starts reporting these metrics as 64-bit values in the
+ * future, check that overflow actually happens around the 32-bit
+ * unsigned boundary; assume overflow only happens once between
+ * successive polls.
+ */
+ if (oval <= nval || oval >= (1ull << 32))
+ return nval - oval;
+ else
+ return (1ull << 32) + nval - oval;
}
static void update_io_tick_disk(struct disk_util *du)
dus->s.ios[1] += (__dus.s.ios[1] - ldus->s.ios[1]);
dus->s.merges[0] += (__dus.s.merges[0] - ldus->s.merges[0]);
dus->s.merges[1] += (__dus.s.merges[1] - ldus->s.merges[1]);
- dus->s.ticks[0] += (__dus.s.ticks[0] - ldus->s.ticks[0]);
- dus->s.ticks[1] += (__dus.s.ticks[1] - ldus->s.ticks[1]);
- dus->s.io_ticks += (__dus.s.io_ticks - ldus->s.io_ticks);
- dus->s.time_in_queue += (__dus.s.time_in_queue - ldus->s.time_in_queue);
+ dus->s.ticks[0] += safe_32bit_diff(__dus.s.ticks[0], ldus->s.ticks[0]);
+ dus->s.ticks[1] += safe_32bit_diff(__dus.s.ticks[1], ldus->s.ticks[1]);
+ dus->s.io_ticks += safe_32bit_diff(__dus.s.io_ticks, ldus->s.io_ticks);
+ dus->s.time_in_queue +=
+ safe_32bit_diff(__dus.s.time_in_queue, ldus->s.time_in_queue);
fio_gettime(&t, NULL);
dus->s.msec += mtime_since(&du->time, &t);
- memcpy(&du->time, &t, sizeof(t));
- memcpy(&ldus->s, &__dus.s, sizeof(__dus.s));
+ du->time = t;
+ ldus->s = __dus.s;
}
int update_io_ticks(void)
if (S_ISBLK(st.st_mode)) {
majdev = major(st.st_rdev);
mindev = minor(st.st_rdev);
- } else if (S_ISCHR(st.st_mode)) {
- majdev = major(st.st_rdev);
- mindev = minor(st.st_rdev);
- if (fio_lookup_raw(st.st_rdev, &majdev, &mindev))
- return -1;
- } else if (S_ISFIFO(st.st_mode))
+ } else if (S_ISCHR(st.st_mode) ||
+ S_ISFIFO(st.st_mode)) {
return -1;
- else {
+ } else {
majdev = major(st.st_dev);
mindev = minor(st.st_dev);
}