[Qemu-devel] [PATCH] qemu-io: Verify read data by patterns

[Kevin Wolf]

This patch adds a -P option to read and readv which allows to compare the read
data to a given pattern. This can be used to verify data written by write -P.

Signed-off-by: Kevin Wolf <address@hidden>
---
 qemu-io.c |   42 ++++++++++++++++++++++++++++++++++++++----
 1 files changed, 38 insertions(+), 4 deletions(-)

diff --git a/qemu-io.c b/qemu-io.c
index 3e5c444..b32c45e 100644
--- a/qemu-io.c
+++ b/qemu-io.c
@@ -192,6 +192,7 @@ read_help(void)
 " Reads a segment of the currently open file, optionally dumping it to the\n"
 " standard output stream (with -v option) for subsequent inspection.\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"
@@ -207,8 +208,10 @@ read_f(int argc, char **argv)
        char *buf;
        int64_t offset;
        int count, total;
+       int pattern = 0;
+       int use_pattern = 0;
 
-       while ((c = getopt(argc, argv, "Cpqv")) != EOF) {
+       while ((c = getopt(argc, argv, "CpP:qv")) != EOF) {
                switch (c) {
                case 'C':
                        Cflag = 1;
@@ -216,6 +219,10 @@ read_f(int argc, char **argv)
                case 'p':
                        pflag = 1;
                        break;
+               case 'P':
+                       use_pattern = 1;
+                       pattern = atoi(optarg);
+                       break;
                case 'q':
                        qflag = 1;
                        break;
@@ -270,6 +277,16 @@ read_f(int argc, char **argv)
                return 0;
        }
 
+       if (use_pattern) {
+               void* cmp_buf = malloc(count);
+               memset(cmp_buf, pattern, count);
+               if (memcmp(buf, cmp_buf, count)) {
+                       printf("Pattern verification failed at offset %lld, %d 
bytes\n",
+                               (long long) offset, count);
+               }
+               free(cmp_buf);
+       }
+
        if (qflag)
                return 0;
 
@@ -291,7 +308,7 @@ static const cmdinfo_t read_cmd = {
        .cfunc          = read_f,
        .argmin         = 2,
        .argmax         = -1,
-       .args           = "[-aCpqv] off len",
+       .args           = "[-aCpqv] [-P pattern ] off len",
        .oneline        = "reads a number of bytes at a specified offset",
        .help           = read_help,
 };
@@ -312,6 +329,7 @@ readv_help(void)
 " standard output stream (with -v option) for subsequent inspection.\n"
 " Uses multiple iovec buffers if more than one byte range is specified.\n"
 " -C, -- report statistics in a machine parsable format\n"
+" -P, -- use a pattern to verify read data\n"
 " -v, -- dump buffer to standard output\n"
 " -q, -- quite mode, do not show I/O statistics\n"
 "\n");
@@ -328,12 +346,18 @@ readv_f(int argc, char **argv)
        int count = 0, total;
        int nr_iov, i;
        QEMUIOVector qiov;
+       int pattern = 0;
+       int use_pattern = 0;
 
-       while ((c = getopt(argc, argv, "Cqv")) != EOF) {
+       while ((c = getopt(argc, argv, "CP:qv")) != EOF) {
                switch (c) {
                case 'C':
                        Cflag = 1;
                        break;
+               case 'P':
+                       use_pattern = 1;
+                       pattern = atoi(optarg);
+                       break;
                case 'q':
                        qflag = 1;
                        break;
@@ -406,6 +430,16 @@ readv_f(int argc, char **argv)
                return 0;
        }
 
+       if (use_pattern) {
+               void* cmp_buf = malloc(count);
+               memset(cmp_buf, pattern, count);
+               if (memcmp(buf, cmp_buf, count)) {
+                       printf("Pattern verification failed at offset %lld, %d 
bytes\n",
+                               (long long) offset, count);
+               }
+               free(cmp_buf);
+       }
+
        if (qflag)
                return 0;
 
@@ -426,7 +460,7 @@ static const cmdinfo_t readv_cmd = {
        .cfunc          = readv_f,
        .argmin         = 2,
        .argmax         = -1,
-       .args           = "[-Cqv] off len [len..]",
+       .args           = "[-Cqv] [-P pattern ] off len [len..]",
        .oneline        = "reads a number of bytes at a specified offset",
        .help           = readv_help,
 };
-- 
1.6.0.6