Commit eab8eb8d authored by Vasiliy Tolstov's avatar Vasiliy Tolstov Committed by Jeff Cody
Browse files

sheepdog: allow to delete snapshot 



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 <jcody@redhat.com>
Signed-off-by: default avatarHitoshi Mitake <mitake.hitoshi@lab.ntt.co.jp>
Signed-off-by: default avatarVasiliy Tolstov <v.tolstov@selfip.ru>
Message-id: 1450873346-22334-1-git-send-email-mitake.hitoshi@lab.ntt.co.jp
Signed-off-by: default avatarJeff Cody <jcody@redhat.com>
parent 7725b8bf

block/sheepdog.c

+123 −2
Original line number Diff line number Diff line
@@ -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)) {

        return -1;

    }



    if (snap_id) {

        hdr.snapid = snap_id;

    } else {

        pstrcpy(snap_tag, sizeof(snap_tag), snapshot_id);

        pstrcpy(buf + SD_MAX_VDI_LEN, SD_MAX_VDI_TAG_LEN, snap_tag);

    }



    ret = find_vdi_name(s, s->name, snap_id, snap_tag, &vid, true,

                        &local_err);

    if (ret) {

        return ret;

    }



    fd = connect_to_sdog(s, &local_err);

    if (fd < 0) {

        error_report_err(local_err);

        return -1;

    }



    ret = do_req(fd, s->aio_context, (SheepdogReq *)&hdr,

                 buf, &wlen, &rlen);

    closesocket(fd);

    if (ret) {

        return ret;

    }



    switch (rsp->result) {

    case SD_RES_NO_VDI:

        error_report("%s was already deleted", s->name);

    case SD_RES_SUCCESS:

        break;

    default:

        error_report("%s, %s", sd_strerror(rsp->result), s->name);

        return -1;

    }



    return ret;

}



static int sd_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab)