On 10/15/2015 10:38 AM, Wido den Hollander wrote:
When a RBD volume has snapshots it can not be removed.
This patch introduces a new flag to force volume removal, VIR_STORAGE_VOL_DELETE_WITH_SNAPSHOTS.
With this flag any existing snapshots will be removed prior to removing the volume.
No existing mechanism in libvirt allowed us to pass such information, so that's why a new flag was introduced.
Signed-off-by: Wido den Hollander <wido@widodh.nl> --- include/libvirt/libvirt-storage.h | 1 + src/storage/storage_backend_rbd.c | 59 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 60 insertions(+)
diff --git a/include/libvirt/libvirt-storage.h b/include/libvirt/libvirt-storage.h index 453089e..80da5a3 100644 --- a/include/libvirt/libvirt-storage.h +++ b/include/libvirt/libvirt-storage.h @@ -115,6 +115,7 @@ typedef enum { typedef enum { VIR_STORAGE_VOL_DELETE_NORMAL = 0, /* Delete metadata only (fast) */ VIR_STORAGE_VOL_DELETE_ZEROED = 1 << 0, /* Clear all data to zeros (slow) */ + VIR_STORAGE_VOL_DELETE_WITH_SNAPSHOTS = 2, /* Force removal of volume, even if in use */
s/2/(1 << 1)
} virStorageVolDeleteFlags;
typedef enum { diff --git a/src/storage/storage_backend_rbd.c b/src/storage/storage_backend_rbd.c index 5ae4713..71f7d10 100644 --- a/src/storage/storage_backend_rbd.c +++ b/src/storage/storage_backend_rbd.c @@ -428,9 +428,13 @@ static int virStorageBackendRBDDeleteVol(virConnectPtr conn, { int ret = -1; int r = 0; + int max_snaps = 128; + int i, snap_count, protected;
fail syntax-check - must use "size_t i;" since it's a loop counter
virStorageBackendRBDState ptr; ptr.cluster = NULL; ptr.ioctx = NULL; + rbd_snap_info_t *snaps; + rbd_image_t image = NULL;
VIR_DEBUG("Removing RBD image %s/%s", pool->def->source.name, vol->name);
@@ -443,6 +447,60 @@ static int virStorageBackendRBDDeleteVol(virConnectPtr conn, if (virStorageBackendRBDOpenIoCTX(&ptr, pool) < 0) goto cleanup;
Is any of this useful without VIR_STORAGE_VOL_DELETE_WITH_SNAPSHOTS? I also think you'd leak whatever rbd_snap_list places into the 'snaps' entries since rbd_snap_list_end would only be called if the bit was set. Can this be turned into a helper routine instead, e.g. if (flags & VIR_STORAGE_VOL_DELETE_WITH_SNAPSHOTS) { if (virStorageBackendRBDCleanupSnapshots(...args...) < 0) goto cleanup; } Your new helper should set some kind of error on failure; otherwise, you'll get a generic libvirt failed for some reason type error which could be confusing. IOW: Anywhere you 'goto cleanup;' will need some sort of message. I'm assuming 'failure' means the rbd_remove() was going to fail anyway, so going to cleanup on failure to cleanup is "ok"
+ r = rbd_open(ptr.ioctx, vol->name, &image, NULL); + if (r < 0) { + virReportSystemError(-r, _("failed to open the RBD image '%s'"), + vol->name); + goto cleanup; + } + + do { + if (VIR_ALLOC_N(snaps, max_snaps)) + goto cleanup; + + snap_count = rbd_snap_list(image, snaps, &max_snaps); + if (snap_count <= 0) { + VIR_FREE(snaps); + }
^^ fails syntax-check (the extra { } for one-liner)
+ } while (snap_count == -ERANGE);
Too bad there wasn't a way to pass (image, NULL, &max_snaps); where max_snaps = 0 to start out with in order to get the number to use for max_snaps. Although I assume the loop would only need to be executed at most 2 times. So no big deal.
+ + VIR_DEBUG("Found %d snapshots for volume %s/%s", snap_count, + pool->def->source.name, vol->name); + + if (snap_count > 0 && (flags & VIR_STORAGE_VOL_DELETE_WITH_SNAPSHOTS)) { + for (i = 0; i < snap_count; i++) { + if (rbd_snap_is_protected(image, snaps[i].name, &protected)) + goto cleanup;
No error message?
+ + if (protected == 1) { + VIR_DEBUG("Snapshot %s/%s@%s is protected needs to be " + "unprotected", pool->def->source.name, vol->name, + snaps[i].name); + + if (rbd_snap_unprotect(image, snaps[i].name) < 0) + goto cleanup;
No error message?
+ } + + VIR_DEBUG("Removing snapshot %s/%s@%s", pool->def->source.name, + vol->name, snaps[i].name); + + r = rbd_snap_remove(image, snaps[i].name); + if (r < 0) { + virReportSystemError(-r, _("failed to remove snapshot '%s/%s@%s'"), + pool->def->source.name, vol->name, + snaps[i].name); + goto cleanup; + } + } + + rbd_snap_list_end(snaps); + } + + if (rbd_close(image) < 0) + goto cleanup;
perhaps this should be moved to cleanup and changed to: if (image) rbd_close(image); because all those goto's inside your "if" condition will not close image. Also does rbd_snap_list_end need to be called if any of the goto cleanup's happen? Can I assume that will run through the list of snaps and free the snaps[i].name? and anything else - so yes, I think it needs to be in cleanup as well (lots easier when this code is a helper). John
+ + VIR_DEBUG("Removing volume %s/%s", pool->def->source.name, vol->name); + r = rbd_remove(ptr.ioctx, vol->name); if (r < 0 && (-r) != ENOENT) { virReportSystemError(-r, _("failed to remove volume '%s/%s'"), @@ -453,6 +511,7 @@ static int virStorageBackendRBDDeleteVol(virConnectPtr conn, ret = 0;
cleanup: + VIR_FREE(snaps); virStorageBackendRBDCloseRADOSConn(&ptr); return ret; }