Re: [libvirt] [PATCH] Adding filesystem mount support for openVZ

Hi everyone, This patch is to allow using the "mount" type in the "filesystem" tag for OpenVZ domains. Example: ... <filesystem type='mount'> <source dir='/path/to/filesystem/directory/' /> <target dir='/path/to/pivot/root/' /> </filesystem> ... This is my first patch to an external project, so don't spare me if I got things wrong :) Also, I'm curious for suggestions as to how I could allow for the target not to be specified in the XML. Because in this case OpenVZ just makes a temporary pivot root in "/var/lib/vz/root/" and that is probably sufficient for most people, who might not want to have to explicitly create a pivot root somewhere, just for mounting the filesystem while it's running.

diff --git a/src/openvz_conf.c b/src/openvz_conf.c index ff3d607..33fb259 100644 --- a/src/openvz_conf.c +++ b/src/openvz_conf.c @@ -314,6 +314,41 @@ error: } +/* utility function to replace 'from' by 'to' in 'str' */ +static char* +openvz_replace(const char* str, + const char* from, + int to) { + char tmp[4096]; + char* offset = tmp; + int len = strlen(str); + int fromLen = strlen(from); + int r,i,maxcmp,left = sizeof(tmp); + + if(!from) + return NULL; + + for(i = 0; i < len && left; ++i) { + /* compare first caracters to limit useless full comparisons */ + if(*from == str[i]) { + maxcmp = (fromLen > len-i) ? len-i : fromLen; + if(strncmp(from, str+i, maxcmp) == 0) { + r = snprintf(offset, left, "%d", to); + offset += r; + i += fromLen - 1; + continue; + } + } + *offset++ = str[i]; + left = sizeof(tmp) - (offset-tmp); + } + + tmp[sizeof(tmp)-left] = '\0'; + + return strdup(tmp); +}

@@ -343,7 +378,42 @@ openvzReadFSConf(virConnectPtr conn, goto no_memory; def->fss[def->nfss++] = fs; fs = NULL; + } else { + /* OSTEMPLATE was not found, VE was booted from a private dir directly */ + ret = openvzReadConfigParam(veid, "VE_PRIVATE", temp, sizeof(temp)); + if (ret <= 0) { + openvzError(conn, VIR_ERR_INTERNAL_ERROR, + _("Cound not read 'VE_PRIVATE' from config for container %d"), + veid); + goto error; + } + + if (VIR_ALLOC(fs) < 0) + goto no_memory; + + fs->type = VIR_DOMAIN_FS_TYPE_MOUNT; + fs->src = openvz_replace(temp, "$VEID", veid); + + if (fs->src == NULL) + goto no_memory; + + ret = openvzReadConfigParam(veid, "VE_ROOT", temp, sizeof(temp)); + if (ret <= 0) { + openvzError(conn, VIR_ERR_INTERNAL_ERROR, + _("Cound not read 'VE_ROOT' from config for container %d"), + veid); + goto error; + } + + fs->dst = openvz_replace(temp, "$VEID", veid); + if (fs->dst == NULL) + goto no_memory; + + if (VIR_REALLOC_N(def->fss, def->nfss + 1) < 0) + goto no_memory; + def->fss[def->nfss++] = fs; + fs = NULL; } return 0; @@ -597,6 +667,81 @@ openvzReadConfigParam(int vpsid ,const char * param, char *value, int maxlen) return ret ; } +static int +openvz_copyfile(char* from_path, char* to_path) +{ + char line[PATH_MAX]; + int fd, copy_fd; + int bytes_read; + + fd = open(from_path, O_RDONLY); + if (fd == -1) + return -1; + copy_fd = open(to_path, O_WRONLY | O_CREAT | O_TRUNC, 0644); + if (copy_fd == -1) { + close(fd); + return -1; + } + + while(1) { + if (openvz_readline(fd, line, sizeof(line)) <= 0) + break; + + bytes_read = strlen(line); + if (safewrite(copy_fd, line, bytes_read) != bytes_read) + goto error; + } + + if (close(fd) < 0) + goto error; + fd = -1; + if (close(copy_fd) < 0) + goto error; + copy_fd = -1; + + return 0; + +error: + if (fd != -1) + close(fd); + if (copy_fd != -1) + close(copy_fd); + return -1; +} + +/* +* Copy the default config to the VE conf file +* return: -1 - error +* 0 - OK +*/ +int +openvzCopyDefaultConfig(int vpsid) +{ + char * confdir; + char default_conf_file[PATH_MAX], conf_file[PATH_MAX]; + + confdir = openvzLocateConfDir(); + if (confdir == NULL) + return -1; + + if (snprintf(default_conf_file, PATH_MAX, "%s/%s", + confdir, VZ_DEFAULT_CONF_FILE) >= PATH_MAX) + { + VIR_FREE(confdir); + return -1; + }

+ + VIR_FREE(confdir); + + if (openvzLocateConfFile(vpsid, conf_file, PATH_MAX, "conf")<0) + return -1; + + if (openvz_copyfile(default_conf_file, conf_file)<0) + return -1; + + return 0; +} + /* Locate config file of container