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sheepdog: allow to delete snapshot

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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: Hitoshi Mitake <mitake.hitoshi@lab.ntt.co.jp>
Signed-off-by: Vasiliy Tolstov <v.tolstov@selfip.ru>
Message-id: 1450873346-22334-1-git-send-email-mitake.hitoshi@lab.ntt.co.jp
Signed-off-by: Jeff Cody <jcody@redhat.com>
This commit is contained in:
Vasiliy Tolstov 2015-12-23 21:22:26 +09:00 committed by Jeff Cody
parent 7725b8bf12
commit eab8eb8db3
1 changed files with 123 additions and 2 deletions
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125
block/sheepdog.c
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@ -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)