Re: [Qemu-devel] [PATCH v7] qemu-io: add pattern file for write command

[Denis Plotnikov]

Ping!

On Jul 5 2019, at 1:21 pm, Denis Plotnikov <address@hidden> wrote:
The patch allows to provide a pattern file for write
command. There was no similar ability before.

Signed-off-by: Denis Plotnikov <address@hidden>
---
v7:
* fix variable naming
* make code more readable
* extend help for write command

v6:
* the pattern file is read once to reduce io

v5:
* file name initiated with null to make compilers happy

v4:
* missing signed-off clause added

v3:
* missing file closing added
* exclusive flags processing changed
* buffer void* converted to char* to fix pointer arithmetics
* file reading error processing added
---
qemu-io-cmds.c | 86 ++++++++++++++++++++++++++++++++++++++++++++++----
1 file changed, 80 insertions(+), 6 deletions(-)

diff --git a/qemu-io-cmds.c b/qemu-io-cmds.c
index 09750a23ce..495170380a 100644
--- a/qemu-io-cmds.c
+++ b/qemu-io-cmds.c
@@ -343,6 +343,66 @@ static void *qemu_io_alloc(BlockBackend *blk, size_t len, 
int pattern)
return buf;
}

+static void *qemu_io_alloc_from_file(BlockBackend *blk, size_t len,
+ char *file_name)
+{
+ char *buf, *buf_origin;
+ FILE *f = fopen(file_name, "r");
+ int pattern_len;
+
+ if (!f) {
+ printf("'%s': %s\n", file_name, strerror(errno));
+ return NULL;
+ }
+
+ if (qemuio_misalign) {
+ len += MISALIGN_OFFSET;
+ }
+
+ buf_origin = buf = blk_blockalign(blk, len);
+
+ pattern_len = fread(buf, sizeof(char), len, f);
+
+ if (ferror(f)) {
+ printf("'%s': %s\n", file_name, strerror(errno));
+ goto error;
+ }
+
+ if (pattern_len == 0) {
+ printf("'%s' is empty\n", file_name);
+ goto error;
+ }
+
+ fclose(f);
+
+ if (len > pattern_len) {
+ char *file_buf = g_malloc(sizeof(char) * pattern_len);
+ memcpy(file_buf, buf, pattern_len);
+ len -= pattern_len;
+ buf += pattern_len;
+
+ while (len > 0) {
+ size_t len_to_copy = MIN(pattern_len, len);
+
+ memcpy(buf, file_buf, len_to_copy);
+
+ len -= len_to_copy;
+ buf += len_to_copy;
+ }
+ qemu_vfree(file_buf);
+ }
+
+ if (qemuio_misalign) {
+ buf_origin += MISALIGN_OFFSET;
+ }
+
+ return buf_origin;
+
+error:
+ qemu_vfree(buf_origin);
+ return NULL;
+}
+
static void qemu_io_free(void *p)
{
if (qemuio_misalign) {
@@ -949,6 +1009,7 @@ static void write_help(void)
" -n, -- with -z, don't allow slow fallback\n"
" -p, -- ignored for backwards compatibility\n"
" -P, -- use different pattern to fill file\n"
+" -s, -- use a pattern file to fill the write buffer\n"
" -C, -- report statistics in a machine parsable format\n"
" -q, -- quiet mode, do not show I/O statistics\n"
" -u, -- with -z, allow unmapping\n"
@@ -965,7 +1026,7 @@ static const cmdinfo_t write_cmd = {
.perm = BLK_PERM_WRITE,
.argmin = 2,
.argmax = -1,
- .args = "[-bcCfnquz] [-P pattern] off len",
+ .args = "[-bcCfnquz] [-P pattern | -s source_file] off len",
.oneline = "writes a number of bytes at a specified offset",
.help = write_help,
};
@@ -974,7 +1035,7 @@ static int write_f(BlockBackend *blk, int argc, char 
**argv)
{
struct timeval t1, t2;
bool Cflag = false, qflag = false, bflag = false;
- bool Pflag = false, zflag = false, cflag = false;
+ bool Pflag = false, zflag = false, cflag = false, sflag = false;
int flags = 0;
int c, cnt, ret;
char *buf = NULL;
@@ -983,8 +1044,9 @@ static int write_f(BlockBackend *blk, int argc, char 
**argv)
/* Some compilers get confused and warn if this is not initialized. */
int64_t total = 0;
int pattern = 0xcd;
+ char *file_name = NULL;

- while ((c = getopt(argc, argv, "bcCfnpP:quz")) != -1) {
+ while ((c = getopt(argc, argv, "bcCfnpP:quzs:")) != -1) {
switch (c) {
case 'b':
bflag = true;
@@ -1020,6 +1082,10 @@ static int write_f(BlockBackend *blk, int argc, char 
**argv)
case 'z':
zflag = true;
break;
+ case 's':
+ sflag = true;
+ file_name = g_strdup(optarg);
+ break;
default:
qemuio_command_usage(&write_cmd);
return -EINVAL;
@@ -1051,8 +1117,9 @@ static int write_f(BlockBackend *blk, int argc, char 
**argv)
return -EINVAL;
}

- if (zflag && Pflag) {
- printf("-z and -P cannot be specified at the same time\n");
+ if ((int)zflag + (int)Pflag + (int)sflag > 1) {
+ printf("Only one of -z, -P, and -s"
+ "can be specified at the same time\n");
return -EINVAL;
}

@@ -1088,7 +1155,14 @@ static int write_f(BlockBackend *blk, int argc, char 
**argv)
}

if (!zflag) {
- buf = qemu_io_alloc(blk, count, pattern);
+ if (sflag) {
+ buf = qemu_io_alloc_from_file(blk, count, file_name);
+ if (!buf) {
+ return -EINVAL;
+ }
+ } else {
+ buf = qemu_io_alloc(blk, count, pattern);
+ }
}

gettimeofday(&t1, NULL);
--
2.17.0