qemu-io: Optionally verify only part of read data
There are reasonable test cases where a read must span areas that are not
uniformly filled with one pattern but contains several parts. This makes -P
useless for them currently.
Introducing additional options which determine the part of the read data that
should be verified with the given pattern allows to check such reads.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/qemu-io.c b/qemu-io.c
index 405b6c5..60464e6 100644
--- a/qemu-io.c
+++ b/qemu-io.c
@@ -191,11 +191,13 @@
"\n"
" Reads a segment of the currently open file, optionally dumping it to the\n"
" standard output stream (with -v option) for subsequent inspection.\n"
+" -C, -- report statistics in a machine parsable format\n"
+" -l, -- length for pattern verification (only with -P)\n"
" -p, -- use bdrv_pread to read the file\n"
" -P, -- use a pattern to verify read data\n"
-" -C, -- report statistics in a machine parsable format\n"
-" -v, -- dump buffer to standard output\n"
" -q, -- quite mode, do not show I/O statistics\n"
+" -s, -- start offset for pattern verification (only with -P)\n"
+" -v, -- dump buffer to standard output\n"
"\n");
}
@@ -204,18 +206,26 @@
{
struct timeval t1, t2;
int Cflag = 0, pflag = 0, qflag = 0, vflag = 0;
+ int Pflag = 0, sflag = 0, lflag = 0;
int c, cnt;
char *buf;
int64_t offset;
int count, total;
- int pattern = 0;
- int Pflag = 0;
+ int pattern = 0, pattern_offset = 0, pattern_count = 0;
- while ((c = getopt(argc, argv, "CpP:qv")) != EOF) {
+ while ((c = getopt(argc, argv, "Cl:pP:qs:v")) != EOF) {
switch (c) {
case 'C':
Cflag = 1;
break;
+ case 'l':
+ lflag = 1;
+ pattern_count = cvtnum(optarg);
+ if (pattern_count < 0) {
+ printf("non-numeric length argument -- %s\n", optarg);
+ return 0;
+ }
+ break;
case 'p':
pflag = 1;
break;
@@ -226,6 +236,14 @@
case 'q':
qflag = 1;
break;
+ case 's':
+ sflag = 1;
+ pattern_offset = cvtnum(optarg);
+ if (pattern_offset < 0) {
+ printf("non-numeric length argument -- %s\n", optarg);
+ return 0;
+ }
+ break;
case 'v':
vflag = 1;
break;
@@ -250,6 +268,19 @@
return 0;
}
+ if (!Pflag && (lflag || sflag)) {
+ return command_usage(&read_cmd);
+ }
+
+ if (!lflag) {
+ pattern_count = count - pattern_offset;
+ }
+
+ if ((pattern_count < 0) || (pattern_count + pattern_offset > count)) {
+ printf("pattern verfication range exceeds end of read data\n");
+ return 0;
+ }
+
if (!pflag)
if (offset & 0x1ff) {
printf("offset %lld is not sector aligned\n",
@@ -278,12 +309,12 @@
}
if (Pflag) {
- void* cmp_buf = malloc(count);
- memset(cmp_buf, pattern, count);
- if (memcmp(buf, cmp_buf, count)) {
+ void* cmp_buf = malloc(pattern_count);
+ memset(cmp_buf, pattern, pattern_count);
+ if (memcmp(buf + pattern_offset, cmp_buf, pattern_count)) {
printf("Pattern verification failed at offset %lld, "
"%d bytes\n",
- (long long) offset, count);
+ (long long) offset + pattern_offset, pattern_count);
}
free(cmp_buf);
}
@@ -309,7 +340,7 @@
.cfunc = read_f,
.argmin = 2,
.argmax = -1,
- .args = "[-aCpqv] [-P pattern ] off len",
+ .args = "[-aCpqv] [-P pattern [-s off] [-l len]] off len",
.oneline = "reads a number of bytes at a specified offset",
.help = read_help,
};
