X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=diskutil.c;h=ace7af3d5b5bb7368584a1369a0872cbe79c92ee;hp=0051a7a035875b3a51493ac527125b413ad1bb7d;hb=HEAD;hpb=e7e536b665bd6a9d3e936e0847dbbb6957101da4

diff --git a/diskutil.c b/diskutil.c
index 0051a7a0..69b3dd26 100644
--- a/diskutil.c
+++ b/diskutil.c
@@ -1,3 +1,4 @@
+#include <inttypes.h>
 #include <stdio.h>
 #include <string.h>
 #include <sys/types.h>
@@ -44,8 +45,6 @@ static void disk_util_free(struct disk_util *du)
 
 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;
@@ -65,23 +64,34 @@ static int get_io_ticks(struct disk_util *du, struct disk_util_stat *dus)
 
 	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],
-				&sectors[0],
-				(unsigned long long *) &dus->s.ticks[0],
-				(unsigned long long *) &dus->s.ios[1],
-				(unsigned long long *) &dus->s.merges[1],
-				&sectors[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)
@@ -103,15 +113,16 @@ 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)
@@ -166,14 +177,10 @@ static int get_device_numbers(char *file_name, int *maj, int *min)
 		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);
 		}