The patch allows to provide a pattern file for write
command. There was no similar ability before.

Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com>
---
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

Ping!

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

Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com>
---
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

On 05.07.19 12:21, Denis Plotnikov wrote:
> The patch allows to provide a pattern file for write
> command. There was no similar ability before.
> 
> Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com>
> ---
> 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)

Wouldn’t a const char * suffice?

> +{
> +    char *buf, *buf_origin;
> +    FILE *f = fopen(file_name, "r");
> +    int pattern_len;
> +
> +    if (!f) {
> +        printf("'%s': %s\n", file_name, strerror(errno));

(1) Why stdout and not stderr?

(2) Why not just perror()?

> +        return NULL;
> +    }
> +
> +    if (qemuio_misalign) {
> +        len += MISALIGN_OFFSET;
> +    }
> +
> +    buf_origin = buf = blk_blockalign(blk, len);
> +
> +    pattern_len = fread(buf, sizeof(char), len, f);

I know I pointed out already that the C standard defines sizeof(char) to
be 1, but I just want to add that “sizeof(char)” does not appear
anywhere in qemu so far.

That doesn’t make it wrong, but here it looks a bit weird...

> +
> +    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);

...and here you’d actually have to check that the multiplication doesn’t
overflow if you actually consider it a possibility that
sizeof(char) != 1.

But actually, this allocation is just unnecessary altogether, as
Vladimir has said for v6.  You can drop this line,...

> +        memcpy(file_buf, buf, pattern_len);

...this line,...

> +        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);

...make this a memcpy(buf, buf_origin, len_to_copy);,...

> +
> +            len -= len_to_copy;
> +            buf += len_to_copy;
> +        }
> +        qemu_vfree(file_buf);

...and drop this line, too.

> +    }
> +
> +    if (qemuio_misalign) {
> +        buf_origin += MISALIGN_OFFSET;

This will change the pattern, though, because now you’re skipping the
first MISALIGN_OFFSET bytes.  Should the fread() above read to
buf_origin + MISALIGN_OFFSET in that case?

[...]

> @@ -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);

Why does file_name need to be a char * and duplicated here?  (optarg
always points into argv, so as long as that doesn’t change, the optarg
pointer stays valid.)

Max

> +            break;
>          default:
>              qemuio_command_usage(&write_cmd);
>              return -EINVAL;