On Mon, Feb 18, 2013 at 15:38:41 +0100, Michal Privoznik wrote:
This is just digging out important implementation from qemu driver's qemuDomainGetDiskBlockInfo() API as this functionality is going to be required in the next patch. --- src/qemu/qemu_domain.c | 127 +++++++++++++++++++++++++++++++++++++++++++++++++ src/qemu/qemu_domain.h | 4 ++ src/qemu/qemu_driver.c | 124 +++-------------------------------------------- 3 files changed, 138 insertions(+), 117 deletions(-)
diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index 482f64a..8df2739 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -40,6 +40,9 @@
#include <sys/time.h> #include <fcntl.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <unistd.h>
#include <libxml/xpathInternals.h>
@@ -1959,3 +1962,127 @@ cleanup: virObjectUnref(cfg); return ret; } + +int +qemuDomainGetDiskBlockInfo(virQEMUDriverPtr driver, + virDomainObjPtr vm, + virDomainDiskDefPtr disk, + virDomainBlockInfoPtr info) +{ + + int ret = -1; + virStorageFileMetadata *meta = NULL; + virQEMUDriverConfigPtr cfg = NULL; + int format; + struct stat sb; + int fd = -1; + off_t end; + const char *path; + + if (!disk->src) { + virReportError(VIR_ERR_INVALID_ARG, + _("disk %s does not currently have a source assigned"), + disk->dst); + goto cleanup; + } + path = disk->src; + cfg = virQEMUDriverGetConfig(driver); + + /* The path is correct, now try to open it and get its size. */ + if ((fd = open(path, O_RDONLY)) < 0) {
This should really check for -1 only, which is what the original code did.
+ virReportSystemError(errno, _("failed to open path '%s'"), path); + goto cleanup; + } + + /* Probe for magic formats */ + if (disk->format) { + format = disk->format; + } else { + if (cfg->allowDiskFormatProbing) { + if ((format = virStorageFileProbeFormat(path, + cfg->user, + cfg->group)) < 0) + goto cleanup; + } else { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("no disk format for %s and probing is disabled"), + path); + goto cleanup; + } + } + + if (!(meta = virStorageFileGetMetadataFromFD(path, fd, format))) + goto cleanup; + + /* Get info for normal formats */ + if (fstat(fd, &sb) < 0) { + virReportSystemError(errno, _("cannot stat file '%s'"), path); + goto cleanup; + } + + if (S_ISREG(sb.st_mode)) { +#ifndef WIN32 + info->physical = (unsigned long long)sb.st_blocks * + (unsigned long long)DEV_BSIZE; +#else + info->physical = sb.st_size; +#endif + /* Regular files may be sparse, so logical size (capacity) is not same + * as actual physical above + */ + info->capacity = sb.st_size; + } else { + /* NB. Because we configure with AC_SYS_LARGEFILE, off_t should + * be 64 bits on all platforms. + */ + end = lseek(fd, 0, SEEK_END); + if (end == (off_t)-1) { + virReportSystemError(errno, _("failed to seek to end of %s"), path); + goto cleanup; + } + info->physical = end; + info->capacity = end; + } + + /* If the file we probed has a capacity set, then override + * what we calculated from file/block extents */ + if (meta->capacity) + info->capacity = meta->capacity; + + /* Set default value .. */ + info->allocation = info->physical; + + /* ..but if guest is running & not using raw + disk format and on a block device, then query + highest allocated extent from QEMU */ + if (disk->type == VIR_DOMAIN_DISK_TYPE_BLOCK && + format != VIR_STORAGE_FILE_RAW && + S_ISBLK(sb.st_mode) && + virDomainObjIsActive(vm)) { + qemuDomainObjPrivatePtr priv = vm->privateData; + + if (qemuDomainObjBeginJob(driver, vm, QEMU_JOB_QUERY) < 0) + goto cleanup; + + if (virDomainObjIsActive(vm)) { + qemuDomainObjEnterMonitor(driver, vm); + ret = qemuMonitorGetBlockExtent(priv->mon, + disk->info.alias, + &info->allocation); + qemuDomainObjExitMonitor(driver, vm); + } else { + ret = 0; + } + + if (qemuDomainObjEndJob(driver, vm) == 0) + vm = NULL;
As already found by John, this would not work. You either need to move setting up the job outside of this function or pass a reference to vm inside.
+ } else { + ret = 0; + } + +cleanup: + VIR_FORCE_CLOSE(fd); + virStorageFileFreeMetadata(meta); + virObjectUnref(cfg); + return ret; +} ...
Jirka