6:30 p.m.
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>
---
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