On 29/02/2016 21:08, Jeff Cody wrote:
> From: Vasiliy Tolstov <v.tols...@selfip.ru>
>
> This patch implements a blockdriver function bdrv_snapshot_delete() in
> the sheepdog driver. With the new function, snapshots of sheepdog can
> be deleted from libvirt.
>
> Cc: Jeff Cody <jc...@redhat.com>
> Signed-off-by: Hitoshi Mitake <mitake.hito...@lab.ntt.co.jp>
> Signed-off-by: Vasiliy Tolstov <v.tols...@selfip.ru>
> Message-id: 1450873346-22334-1-git-send-email-mitake.hito...@lab.ntt.co.jp
> Signed-off-by: Jeff Cody <jc...@redhat.com>
> ---
> block/sheepdog.c | 125
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 123 insertions(+), 2 deletions(-)
>
> diff --git a/block/sheepdog.c b/block/sheepdog.c
> index a0098c1..8739acc 100644
> --- a/block/sheepdog.c
> +++ b/block/sheepdog.c
> @@ -284,6 +284,12 @@ static inline bool is_snapshot(struct SheepdogInode
> *inode)
> return !!inode->snap_ctime;
> }
>
> +static inline size_t count_data_objs(const struct SheepdogInode *inode)
> +{
> + return DIV_ROUND_UP(inode->vdi_size,
> + (1UL << inode->block_size_shift));
> +}
> +
> #undef DPRINTF
> #ifdef DEBUG_SDOG
> #define DPRINTF(fmt, args...) \
> @@ -2478,13 +2484,128 @@ out:
> return ret;
> }
>
> +#define NR_BATCHED_DISCARD 128
> +
> +static bool remove_objects(BDRVSheepdogState *s)
> +{
> + int fd, i = 0, nr_objs = 0;
> + Error *local_err = NULL;
> + int ret = 0;
> + bool result = true;
> + SheepdogInode *inode = &s->inode;
> +
> + fd = connect_to_sdog(s, &local_err);
> + if (fd < 0) {
> + error_report_err(local_err);
> + return false;
> + }
> +
> + nr_objs = count_data_objs(inode);
> + while (i < nr_objs) {
> + int start_idx, nr_filled_idx;
> +
> + while (i < nr_objs && !inode->data_vdi_id[i]) {
> + i++;
> + }
> + start_idx = i;
> +
> + nr_filled_idx = 0;
> + while (i < nr_objs && nr_filled_idx < NR_BATCHED_DISCARD) {
> + if (inode->data_vdi_id[i]) {
> + inode->data_vdi_id[i] = 0;
> + nr_filled_idx++;
> + }
> +
> + i++;
> + }
> +
> + ret = write_object(fd, s->aio_context,
> + (char *)&inode->data_vdi_id[start_idx],
> + vid_to_vdi_oid(s->inode.vdi_id), inode->nr_copies,
> + (i - start_idx) * sizeof(uint32_t),
> + offsetof(struct SheepdogInode,
> + data_vdi_id[start_idx]),
> + false, s->cache_flags);
> + if (ret < 0) {
> + error_report("failed to discard snapshot inode.");
> + result = false;
> + goto out;
> + }
> + }
> +
> +out:
> + closesocket(fd);
> + return result;
> +}
> +
> static int sd_snapshot_delete(BlockDriverState *bs,
> const char *snapshot_id,
> const char *name,
> Error **errp)
> {
> - /* FIXME: Delete specified snapshot id. */
> - return 0;
> + uint32_t snap_id = 0;
> + char snap_tag[SD_MAX_VDI_TAG_LEN];
> + Error *local_err = NULL;
> + int fd, ret;
> + char buf[SD_MAX_VDI_LEN + SD_MAX_VDI_TAG_LEN];
> + BDRVSheepdogState *s = bs->opaque;
> + unsigned int wlen = SD_MAX_VDI_LEN + SD_MAX_VDI_TAG_LEN, rlen = 0;
> + uint32_t vid;
> + SheepdogVdiReq hdr = {
> + .opcode = SD_OP_DEL_VDI,
> + .data_length = wlen,
> + .flags = SD_FLAG_CMD_WRITE,
> + };
> + SheepdogVdiRsp *rsp = (SheepdogVdiRsp *)&hdr;
> +
> + if (!remove_objects(s)) {
> + return -1;
> + }
> +
> + memset(buf, 0, sizeof(buf));
> + memset(snap_tag, 0, sizeof(snap_tag));
> + pstrcpy(buf, SD_MAX_VDI_LEN, s->name);
> + if (qemu_strtoul(snapshot_id, NULL, 10, (unsigned long *)&snap_id)) {
This cast seems like a very bad idea, and in fact it is. qemu_strtoul
will access 8 bytes on 64-bit machines. Please change snap_id to be an
unsigned long instead.
Paolo
