Re: [Qemu-devel] [PATCH v0] qemu-io: add pattern file for write command

[Denis Plotnikov]

On 29.05.2019 11:11, Vladimir Sementsov-Ogievskiy wrote:
> 29.05.2019 9:48, 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 <address@hidden>
>> ---
>>    qemu-io-cmds.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++----
>>    1 file changed, 54 insertions(+), 4 deletions(-)
>>
>> diff --git a/qemu-io-cmds.c b/qemu-io-cmds.c
>> index 09750a23ce..b93955116f 100644
>> --- a/qemu-io-cmds.c
>> +++ b/qemu-io-cmds.c
>> @@ -21,6 +21,7 @@
>>    #include "qemu/option.h"
>>    #include "qemu/timer.h"
>>    #include "qemu/cutils.h"
>> +#include "string.h"
>>    
>>    #define CMD_NOFILE_OK   0x01
>>    
>> @@ -343,6 +344,35 @@ 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)
>> +{
>> +    void *buf;
>> +    FILE *f = fopen(file_name, "r");
>> +
>> +    if (!f) {
>> +        printf("cannot open file '%s'\n", file_name);
> 
> I see, printf fro errors is preexisting in qemu-io-cmds.c, but error_report 
> is used here too,
> I think it's better to use error_report.
write_f don't use error_report. I think it's worth to go with printf in 
this case - not to mix up printf-s with error_report
> 
>> +        return NULL;
>> +    }
>> +
>> +    if (qemuio_misalign) {
>> +        len += MISALIGN_OFFSET;
>> +    }
>> +    buf = blk_blockalign(blk, len);
>> +    memset(buf, 0, len);
>> +
>> +    if (!fread(buf, sizeof(char), len, f)) {
>> +        printf("file '%s' is empty\n", file_name);
>> +        free(buf);
>> +        return NULL;
>> +    }
>> +
>> +    if (qemuio_misalign) {
>> +        buf += MISALIGN_OFFSET;
> 
> hmm, preexisting in qemu_io_alloc and qemu_io_free, but If I remember 
> correctly, pointer arithmetic
> on void* is not guaranteed to work as expected here..
will change to g_malloc/g_free
> 
>> +    }
>> +    return buf;
>> +}
>> +
>>    static void qemu_io_free(void *p)
>>    {
>>        if (qemuio_misalign) {
>> @@ -965,7 +995,7 @@ 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 +1004,7 @@ 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 +1013,9 @@ 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[255] = { 0 };
>>    
>> -    while ((c = getopt(argc, argv, "bcCfnpP:quz")) != -1) {
>> +    while ((c = getopt(argc, argv, "bcCfnpP:quzs:")) != -1) {
>>            switch (c) {
>>            case 'b':
>>                bflag = true;
>> @@ -1020,6 +1051,10 @@ static int write_f(BlockBackend *blk, int argc, char 
>> **argv)
>>            case 'z':
>>                zflag = true;
>>                break;
>> +        case 's':
>> +            sflag = true;
>> +            strncpy(file_name, optarg, sizeof(file_name) - 1);
> 
> Maybe, g_strdup and don't care about file_name length?
yeah, that would be better
> 
>> +            break;
>>            default:
>>                qemuio_command_usage(&write_cmd);
>>                return -EINVAL;
>> @@ -1056,6 +1091,14 @@ static int write_f(BlockBackend *blk, int argc, char 
>> **argv)
>>            return -EINVAL;
>>        }
>>    
>> +    if (sflag && Pflag) {
>> +        printf("-s and -P cannot be specified at the same time\n");
>> +    }
>> +
>> +    if (zflag && Pflag) {
>> +        printf("-z and -P cannot be specified at the same time\n");
>> +    }
yes, this is an error. Here should be zflag && sflag
> 
> strange, that you add this last check.. I see it in master branch already.
> 
>> +
>>        offset = cvtnum(argv[optind]);
>>        if (offset < 0) {
>>            print_cvtnum_err(offset, argv[optind]);
>> @@ -1088,7 +1131,14 @@ 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);
>>
> 
> 

-- 
Best,
Denis