Re: [libvirt] [PATCH 1/4] rbd: Add wiping RBD volumes by using rbd_discard() or rbd_write()

This allows user to use the volume wiping functionality of the libvirt storage driver. This patch also adds a new wiping algorithm VIR_STORAGE_VOL_WIPE_ALG_DISCARD By default the VIR_STORAGE_VOL_WIPE_ALG_ZERO algorithm is used and with RBD this will called rbd_write() in chunks of the underlying object size to completely zero out the volume. With VIR_STORAGE_VOL_WIPE_ALG_DISCARD it will call rbd_discard() in the same object size chunks which will trim/discard all underlying RADOS objects in the Ceph cluster. Signed-off-by: Wido den Hollander <wido(a)widodh.nl&gt; --- include/libvirt/libvirt-storage.h | 4 + src/storage/storage_backend_rbd.c | 157 +++++++++++++++++++++++++++++++++++++- tools/virsh-volume.c | 2 +- 3 files changed, 161 insertions(+), 2 deletions(-)

diff --git a/include/libvirt/libvirt-storage.h b/include/libvirt/libvirt-storage.h index 2c55c93..139add3 100644 --- a/include/libvirt/libvirt-storage.h +++ b/include/libvirt/libvirt-storage.h @@ -153,6 +153,10 @@ typedef enum { VIR_STORAGE_VOL_WIPE_ALG_RANDOM = 8, /* 1-pass random */ + VIR_STORAGE_VOL_WIPE_ALG_DISCARD = 9, /* 1-pass, discard all data on the + volume by using TRIM or + DISCARD */ + # ifdef VIR_ENUM_SENTINELS VIR_STORAGE_VOL_WIPE_ALG_LAST /* diff --git a/src/storage/storage_backend_rbd.c b/src/storage/storage_backend_rbd.c index e20a54d..c0001d0 100644 --- a/src/storage/storage_backend_rbd.c +++ b/src/storage/storage_backend_rbd.c @@ -32,6 +32,7 @@ #include "base64.h" #include "viruuid.h" #include "virstring.h" +#include "virutil.h" #include "rados/librados.h" #include "rbd/librbd.h" @@ -730,6 +731,159 @@ static int virStorageBackendRBDResizeVol(virConnectPtr conn ATTRIBUTE_UNUSED, return ret; } +static int virStorageBackendRBDVolWipeZero(rbd_image_t image, + char *imgname, + rbd_image_info_t info, + uint64_t stripe_count) +{ + int r = -1; + size_t offset = 0; + uint64_t length; + char *writebuf; + + if (VIR_ALLOC_N(writebuf, info.obj_size * stripe_count) < 0) + goto cleanup; + + while (offset < info.size) { + length = MIN((info.size - offset), (info.obj_size * stripe_count)); + + r = rbd_write(image, offset, length, writebuf); + if (r < 0) { + virReportSystemError(-r, _("writing %llu bytes failed on " + " RBD image %s at offset %llu"), + (unsigned long long)length, + imgname, + (unsigned long long)offset); + goto cleanup; + } + + VIR_DEBUG("Wrote %llu bytes to RBD image %s at offset %llu", + (unsigned long long)length, + imgname, (unsigned long long)offset); + + offset += length; + } + + cleanup: + VIR_FREE(writebuf); + + return r; +} + +static int virStorageBackendRBDVolWipeDiscard(rbd_image_t image, + char *imgname, + rbd_image_info_t info, + uint64_t stripe_count) +{ + int r = -1; + size_t offset = 0; + uint64_t length; + + VIR_DEBUG("Wiping RBD %s volume using discard)", imgname); + + while (offset < info.size) { + length = MIN((info.size - offset), (info.obj_size * stripe_count)); + + r = rbd_discard(image, offset, length); + if (r < 0) { + virReportSystemError(-r, _("discarding %llu bytes failed on " + " RBD image %s at offset %llu"), + (unsigned long long)length, + imgname, + (unsigned long long)offset); + goto cleanup; + } + + VIR_DEBUG("Discarded %llu bytes of RBD image %s at offset %llu", + (unsigned long long)length, + imgname, (unsigned long long)offset); + + offset += length; + } + + cleanup: + return r; +} + +static int virStorageBackendRBDVolWipe(virConnectPtr conn, + virStoragePoolObjPtr pool, + virStorageVolDefPtr vol, + unsigned int algorithm, + unsigned int flags) +{ + virStorageBackendRBDState ptr; + ptr.cluster = NULL; + ptr.ioctx = NULL; + rbd_image_t image = NULL; + rbd_image_info_t info; + uint64_t stripe_count; + int r = -1; + + virCheckFlags(VIR_STORAGE_VOL_WIPE_ALG_ZERO | + VIR_STORAGE_VOL_WIPE_ALG_DISCARD, -1); + + VIR_DEBUG("Wiping RBD image %s/%s", pool->def->source.name, vol->name); + + if (virStorageBackendRBDOpenRADOSConn(&ptr, conn, &pool->def->source) < 0) + goto cleanup; + + if (virStorageBackendRBDOpenIoCTX(&ptr, pool) < 0) + goto cleanup; + + 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; + } + + r = rbd_stat(image, &info, sizeof(info)); + if (r < 0) { + virReportSystemError(-r, _("failed to stat the RBD image %s"), + vol->name); + goto cleanup; + } + + r = rbd_get_stripe_count(image, &stripe_count); + if (r < 0) { + virReportSystemError(-r, _("failed to get stripe count of RBD image %s"), + vol->name); + goto cleanup; + } + + VIR_DEBUG("Need to wipe %llu bytes from RBD image %s/%s", + (unsigned long long)info.size, pool->def->source.name, vol->name); + + switch (algorithm) { + case VIR_STORAGE_VOL_WIPE_ALG_ZERO: + r = virStorageBackendRBDVolWipeZero(image, vol->name, + info, stripe_count); + break; + case VIR_STORAGE_VOL_WIPE_ALG_DISCARD: + r = virStorageBackendRBDVolWipeDiscard(image, vol->name, + info, stripe_count); + break; + default: + virReportError(VIR_ERR_INVALID_ARG, _("unsupported algorithm %d"), + algorithm); + r = -VIR_ERR_INVALID_ARG; + goto cleanup; + } + + if (r < 0) { + virReportSystemError(-r, _("failed to wipe RBD image %s"), + vol->name); + goto cleanup; + } + + cleanup: + if (image) + rbd_close(image); + + virStorageBackendRBDCloseRADOSConn(&ptr); + return r; +} + virStorageBackend virStorageBackendRBD = { .type = VIR_STORAGE_POOL_RBD, @@ -738,5 +892,6 @@ virStorageBackend virStorageBackendRBD = { .buildVol = virStorageBackendRBDBuildVol, .refreshVol = virStorageBackendRBDRefreshVol, .deleteVol = virStorageBackendRBDDeleteVol, - .resizeVol = virStorageBackendRBDResizeVol, + .wipeVol = virStorageBackendRBDVolWipe, + .resizeVol = virStorageBackendRBDResizeVol }; diff --git a/tools/virsh-volume.c b/tools/virsh-volume.c index 661c876..f86980f 100644 --- a/tools/virsh-volume.c +++ b/tools/virsh-volume.c @@ -906,7 +906,7 @@ static const vshCmdOptDef opts_vol_wipe[] = { VIR_ENUM_DECL(virStorageVolWipeAlgorithm) VIR_ENUM_IMPL(virStorageVolWipeAlgorithm, VIR_STORAGE_VOL_WIPE_ALG_LAST, "zero", "nnsa", "dod", "bsi", "gutmann", "schneier", - "pfitzner7", "pfitzner33", "random"); + "pfitzner7", "pfitzner33", "random", "discard"); static bool cmdVolWipe(vshControl *ctl, const vshCmd *cmd)