Re: [Libvir] PATCH: 10/16: general purpose helper APIs

This patch provides a couple of helper APIs used by the forthcoming driver backends. - virStorageBackendUpdateVolInfo - take a filename and virStorageVolPtr and update the capacity/allocation information based on the file stat() results. Also update the permissions data on owner/mode and SELinux label. - virStorageBackendUpdateVolInfoFD - same as above but with a pre-opened filehandle - virStorageBackendStablePath - given a /dev/XXX node, and a directory of symlinks (eg /dev/disk/by-path), attempts to find a symlink pointing to the desired file. - virStorageBackendRunProgRegex - given one or more regexes and a command line argv[], execute the program and attempt to match its STDOUT against the regex. When complete matches are found invoke a callback. - virStorageBackendRunProgNul - given a command line argv[] and an expected number of fields per record, tokenize the STDOUT into records splitting on NULL, and invoke the callback per record. The SELinux code is optional, and can be replaced with calls to any other library which can provide MAC file labels, or just disabled completely..

+SELINUX_CFLAGS= +SELINUX_LIBS= +if test "$with_selinux" != "no"; then + old_cflags="$CFLAGS" + old_libs="$LIBS" + if test "$with_selinux" = "check"; then + AC_CHECK_HEADER([selinux/selinux.h],[],[with_selinux=no]) + AC_CHECK_LIB(selinux, fgetfilecon,[],[with_selinux=no]) + if test "$with_selinux" != "no"; then + with_selinux="yes" + fi + else + AC_CHECK_HEADER([selinux/selinux.h],[], + [AC_MSG_ERROR([You must install the SELinux development package in order to compile libvirt])]) + AC_CHECK_LIB(selinux, fgetfilecon,[], + [AC_MSG_ERROR([You must install the SELinux development package in order to compile and run libvirt])])

+ if (S_ISREG(sb.st_mode)) { + vol->allocation = (unsigned long long)sb.st_blocks * (unsigned long long)512;

+ /* Regular files may be sparse, so logical size (capacity) is not same + * as actual allocation above + */ + if (withCapacity) + vol->capacity = sb.st_size; + } else { + off_t end; + /* XXX this is POSIX compliant, but doesn't work for for CHAR files, + * only BLOCK. There is a Linux specific ioctl() for getting + * size of both CHAR / BLOCK devices we should check for in + * configure + */ + end = lseek(fd, 0, SEEK_END); + if (end == (off_t)-1) { + virStorageReportError(conn, VIR_ERR_INTERNAL_ERROR, + "cannot seek to end of file '%s': %d (%s)", + vol->target.path, errno, strerror(errno)); + return -1; + } + vol->allocation = end; + if (withCapacity) vol->capacity = end; + }

+/* + * Run an external program. + * + * Read its output and apply a series of regexes to each line + * When the entire set of regexes has matched consequetively + * then run a callback passing in all the matches + */ +int virStorageBackendRunProgRegex(virConnectPtr conn, + virStoragePoolObjPtr pool, + const char **prog, + int nregex, + const char **regex, + int *nvars, + virStorageBackendListVolRegexFunc func, + void *data)

+ +/* + * Run an external program and read from its standard output + * a stream of tokens from IN_STREAM, applying FUNC to + * each successive sequence of N_COLUMNS tokens. + * If FUNC returns < 0, stop processing input and return -1. + * Return -1 if N_COLUMNS == 0. + * Return -1 upon memory allocation error. + * If the number of input tokens is not a multiple of N_COLUMNS, + * then the final FUNC call will specify a number smaller than N_COLUMNS. + * If there are no input tokens (empty input), call FUNC with N_COLUMNS == 0. + */ +int virStorageBackendRunProgNul(virConnectPtr conn, + virStoragePoolObjPtr pool, + const char **prog, + size_t n_columns, + virStorageBackendListVolNulFunc func, + void *data)