Chris Lalancette <clalance@xxxxxxxxxx> wrote:
...
> test suite. As far as the error reporting goes, I won't argue that my patch
> gives slightly less information. However, that being said, I have to believe
> that the most likely use of block statistics is something like:
>
> virsh dumpxml <dom>
> ...see what devices are listed there
> virsh domblkstats <dom> <device>
>
> In which case the slightly less verbose error reporting won't matter a whole lot.
Hi Chris,
...
> Index: src/stats_linux.c
> ===================================================================
...
> +static int
> +disk_re_match(const char *regex, const char *path, int *part)
> +{
> + regex_t myreg;
> + int err;
> + int retval;
> + regmatch_t pmatch[2];
> +
> + retval = 0;
> +
> + err = regcomp(&myreg, regex, REG_EXTENDED);
> + if (err != 0)
> + return 0;
> +
> + err = regexec(&myreg, path, 2, pmatch, 0);
> +
> + if (err == 0) {
> + /* OK, we have a match; see if we have a partition */
> + *part = 0;
> + if (pmatch[1].rm_so != -1) {
> + if (virStrToLong_i(path + pmatch[1].rm_so, NULL, 10, part) < 0)
> + retval = 0;
> + else
> + retval = 1;
> + }
> + else
> + retval = 1;
> + }
How about dropping both "else" blocks and initializing "retval=1" above:
if (err == 0) {
/* OK, we have a match; see if we have a partition */
*part = 0;
retval = 1;
if (pmatch[1].rm_so != -1) {
if (virStrToLong_i(path + pmatch[1].rm_so, NULL, 10, part) < 0)
retval = 0;
}
}
You could even reduce the retval-setting part to a single statement:
if (err == 0) {
/* OK, we have a match; see if we have a partition */
*part = 0;
retval = (pmatch[1].rm_so == -1
|| virStrToLong_i(path + pmatch[1].rm_so,
NULL, 10, part) == 0);
}
> int
> xenLinuxDomainDeviceID(virConnectPtr conn, int domid, const char *path)
> {
> - int disk, part = 0;
> -
> - /* Strip leading path if any */
> - if (strlen(path) > 5 &&
> - STRPREFIX(path, "/dev/"))
> - path += 5;
> + int major, minor;
> + int part;
> + int retval;
> + char *mod_path;
> +
> + int scsi_majors[] = { SCSI_DISK0_MAJOR, SCSI_DISK1_MAJOR,
I know you just moved these, but they can be const:
int const scsi_majors[] = {...
...
> + int ide_majors[] = { IDE0_MAJOR, IDE1_MAJOR, IDE2_MAJOR, IDE3_MAJOR,
int const ide_majors[] = { ...
...
> + if (strlen(path) > 5 && STRPREFIX(path, "/dev/"))
Maybe use ">= 5", so that this code will preserve /dev/,
rather than turn it into "/dev//dev/" ?
> + retval = asprintf(&mod_path, "%s", path);
> + else
> + retval = asprintf(&mod_path, "/dev/%s", path);
...
> + if (disk_re_match("/dev/sd[a-z]([1-9]|1[0-5])?$", mod_path, &part)) {
> + major = scsi_majors[(mod_path[7] - 'a') / 16];
> + minor = ((mod_path[7] - 'a') % 16) * 16 + part;
> + retval = major * 256 + minor;
> + }
> + else if (disk_re_match("/dev/sd[a-h][a-z]([1-9]|1[0-5])?$",
> + mod_path, &part) ||
> + disk_re_match("/dev/sdi[a-v]([1-9]|1[0-5])?$",
> + mod_path, &part)) {
> + major = scsi_majors[((mod_path[7] - 'a' + 1) * 26 + (mod_path[8] - 'a')) / 16];
> + minor = (((mod_path[7] - 'a' + 1) * 26 + (mod_path[8] - 'a')) % 16)
> + * 16 + part;
> + retval = major * 256 + minor;
> + }
> + else if (disk_re_match("/dev/hd[a-t]([1-9]|[1-5][0-9]|6[0-3])?$",
> + mod_path, &part)) {
> + major = ide_majors[(mod_path[7] - 'a') / 2];
> + minor = ((mod_path[7] - 'a') % 2) * 64 + part;
> + retval = major * 256 + minor;
> }
> + else if (disk_re_match("/dev/xvd[a-p]([1-9]|1[0-5])?$", mod_path, &part))
> + retval = (202 << 8) + ((mod_path[8] - 'a') << 4) + part;
> + else if (disk_re_match("/dev/xvd[q-z]([1-9]|1[0-5])?$", mod_path, &part))
> + retval = (1 << 28) + ((mod_path[8] - 'a') << 8) + part;
> + else if (disk_re_match("/dev/xvd[a-i][a-z]([1-9]|1[0-5])?$",
> + mod_path, &part))
> + retval = (1 << 28) + (((mod_path[8] - 'a' + 1) * 26 + (mod_path[9] - 'a')) << 8) + part;
To retain the diagnostic Dan mentioned, you should be able to
insert something like this just before the final "else":
else if (disk_re_match("/dev/sd[a-z]([0-9])+$", mod_path, &part)) {
> + else
> + statsErrorFunc (conn, VIR_ERR_INVALID_ARG, __FUNCTION__,
> + "unsupported path, use xvdN, hdN, or sdN", domid);
--
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