Actually put gfapi to use, by allowing the creation of a gluster pool. Right now, all volumes are treated as raw; further patches will allow peering into files to allow for qcow2 files and backing chains, and reporting proper volume allocation. I've reported a couple of glusterfs bugs; if we were to require a minimum of (not-yet-released) glusterfs 3.5, we could use the new glfs_readdir [1] and not worry about the bogus return value of glfs_fini [2], but for now I'm testing with Fedora 19's glusterfs 3.4.1. [1] http://lists.gnu.org/archive/html/gluster-devel/2013-10/msg00085.html [2] http://lists.gnu.org/archive/html/gluster-devel/2013-10/msg00086.html * src/storage/storage_backend_gluster.c (virStorageBackendGlusterRefreshPool): Initial implementation. (virStorageBackendGlusterOpen, virStorageBackendGlusterClose): New helper functions. Signed-off-by: Eric Blake <eblake(a)redhat.com&gt; --- Depends on these pre-req patches: https://www.redhat.com/archives/libvir-list/2013-October/msg01266.html https://www.redhat.com/archives/libvir-list/2013-October/msg00913.html My next task - figuring out the use of glfs_open() to read metadata from a file and determine backing chains. src/storage/storage_backend_gluster.c | 138 ++++++++++++++++++++++++++++++++-- 1 file changed, 133 insertions(+), 5 deletions(-) diff --git a/src/storage/storage_backend_gluster.c b/src/storage/storage_backend_gluster.c index 2863c73..b0b6ce6 100644 --- a/src/storage/storage_backend_gluster.c +++ b/src/storage/storage_backend_gluster.c @@ -23,20 +23,148 @@ #include <glusterfs/api/glfs.h> -#include "virerror.h" #include "storage_backend_gluster.h" #include "storage_conf.h" +#include "viralloc.h" +#include "virerror.h" +#include "virlog.h" +#include "virstoragefile.h" +#include "virstring.h" #define VIR_FROM_THIS VIR_FROM_STORAGE +struct _virStorageBackendGlusterState { + glfs_t *vol; +}; + +typedef struct _virStorageBackendGlusterState virStorageBackendGlusterState; +typedef virStorageBackendGlusterState *virStorageBackendGlusterStatePtr; + +static void +virStorageBackendGlusterClose(virStorageBackendGlusterStatePtr state) +{ + if (!state || !state->vol) + return; + /* Yuck - glusterfs-api-3.4.1 appears to always return -1 for + * glfs_fini, with errno containing random data, so there's no way + * to tell if it succeeded. 3.4.2 is supposed to fix this.*/ + if (glfs_fini(state->vol) < 0) + VIR_DEBUG("shutdown of gluster failed with errno %d", errno); +} + +static virStorageBackendGlusterStatePtr +virStorageBackendGlusterOpen(virStoragePoolObjPtr pool) +{ + virStorageBackendGlusterStatePtr ret = NULL; + + if (VIR_ALLOC(ret) < 0) + return NULL; + + if (!(ret->vol = glfs_new(pool->def->source.name))) { + virReportOOMError(); + goto error; + } + + /* FIXME: allow alternate transport in the pool xml */ + if (glfs_set_volfile_server(ret->vol, "tcp", + pool->def->source.hosts[0].name, + pool->def->source.hosts[0].port) < 0 || + glfs_init(ret->vol) < 0) { + virReportSystemError(errno, _("failed to connect to gluster %s/%s"), + pool->def->source.hosts[0].name, + pool->def->name); + goto error; + } + + return ret; + +error: + virStorageBackendGlusterClose(ret); + return NULL; +} static int virStorageBackendGlusterRefreshPool(virConnectPtr conn ATTRIBUTE_UNUSED, - virStoragePoolObjPtr pool ATTRIBUTE_UNUSED) + virStoragePoolObjPtr pool) { - virReportError(VIR_ERR_NO_SUPPORT, "%s", - _("gluster pool type not fully supported yet")); - return -1; + int ret = -1; + virStorageBackendGlusterStatePtr state = NULL; + struct { + struct dirent ent; + /* See comment below about readdir_r needing padding */ + char padding[MAX(1, 256 - (int) (sizeof(struct dirent) + - offsetof(struct dirent, d_name)))]; + } de; + struct dirent *ent; + glfs_fd_t *dir = NULL; + virStorageVolDefPtr vol = NULL; + struct statvfs sb; + + if (!(state = virStorageBackendGlusterOpen(pool))) + goto cleanup; + + /* Why oh why did glfs 3.4 decide to expose only readdir_r rather + * than readdir? POSIX admits that readdir_r is inherently a + * flawed design, because systems are not required to define + * NAME_MAX: http://austingroupbugs.net/view.php?id=696 + * http://womble.decadent.org.uk/readdir_r-advisory.html + * + * Fortunately, gluster uses _only_ XFS file systems, and XFS has + * a known NAME_MAX of 255; so we are guaranteed that if we + * provide 256 bytes of tail padding, then we have enough space to + * avoid buffer overflow no matter whether the OS used d_name[], + * d_name[1], or d_name[256] in its 'struct dirent'. + * http://lists.gnu.org/archive/html/gluster-devel/2013-10/msg00083.html + */ + + if (!(dir = glfs_opendir(state->vol, "."))) { + virReportSystemError(errno, _("cannot open path '%s'"), + pool->def->name); + goto cleanup; + } + while (!(errno = glfs_readdir_r(dir, &de.ent, &ent)) && ent) { + if (STREQ(ent->d_name, ".") || STREQ(ent->d_name, "..")) + continue; + if (VIR_ALLOC(vol) < 0 || + VIR_STRDUP(vol->name, ent->d_name) < 0) + goto cleanup; + /* FIXME - must open files to determine if they are non-raw */ + vol->type = VIR_STORAGE_VOL_NETWORK; + vol->target.format = VIR_STORAGE_FILE_RAW; + if (virAsprintf(&vol->key, "%s/%s", + pool->def->name, vol->name) < 0) + goto cleanup; + if (VIR_APPEND_ELEMENT(pool->volumes.objs, pool->volumes.count, + vol) < 0) + goto cleanup; + } + if (errno) { + virReportSystemError(errno, _("failed to read directory '%s'"), + pool->def->name); + goto cleanup; + } + + if (glfs_statvfs(state->vol, ".", &sb) < 0) { + virReportSystemError(errno, _("cannot statvfs path '%s'"), + pool->def->name); + goto cleanup; + } + + pool->def->capacity = ((unsigned long long)sb.f_frsize * + (unsigned long long)sb.f_blocks); + pool->def->available = ((unsigned long long)sb.f_bfree * + (unsigned long long)sb.f_frsize); + pool->def->allocation = pool->def->capacity - pool->def->available; + + ret = 0; +cleanup: + if (dir) + glfs_closedir(dir); + virStorageVolDefFree(vol); + virStorageBackendGlusterClose(state); + if (ret < 0) + virStoragePoolObjClearVols(pool); + return ret; } virStorageBackend virStorageBackendGluster = { -- 1.8.3.1