ceph/src/cls_rbd.cc
2010-07-19 10:20:43 -07:00

378 lines
9.9 KiB
C++

#include <iostream>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include "include/types.h"
#include "objclass/objclass.h"
#include "include/rbd_types.h"
CLS_VER(1,2)
CLS_NAME(rbd)
cls_handle_t h_class;
cls_method_handle_t h_snapshots_list;
cls_method_handle_t h_snapshot_add;
cls_method_handle_t h_snapshot_remove;
cls_method_handle_t h_snapshot_revert;
cls_method_handle_t h_assign_bid;
static int snap_read_header(cls_method_context_t hctx, bufferlist& bl)
{
unsigned snap_count = 0;
uint64_t snap_names_len = 0;
int rc;
struct rbd_obj_header_ondisk *header;
cls_log("snapshots_list");
while (1) {
int len = sizeof(*header) +
snap_count * sizeof(struct rbd_obj_snap_ondisk) +
snap_names_len;
rc = cls_cxx_read(hctx, 0, len, &bl);
if (rc < 0)
return rc;
header = (struct rbd_obj_header_ondisk *)bl.c_str();
if ((snap_count != header->snap_count) ||
(snap_names_len != header->snap_names_len)) {
snap_count = header->snap_count;
snap_names_len = header->snap_names_len;
bl.clear();
continue;
}
break;
}
return 0;
}
int snapshots_list(cls_method_context_t hctx, bufferlist *in, bufferlist *out)
{
bufferlist bl;
struct rbd_obj_header_ondisk *header;
int rc = snap_read_header(hctx, bl);
if (rc < 0)
return rc;
header = (struct rbd_obj_header_ondisk *)bl.c_str();
bufferptr p(header->snap_names_len);
char *buf = (char *)header;
char *name = buf + sizeof(*header) + header->snap_count * sizeof(struct rbd_obj_snap_ondisk);
char *end = name + header->snap_names_len;
memcpy(p.c_str(),
buf + sizeof(*header) + header->snap_count * sizeof(struct rbd_obj_snap_ondisk),
header->snap_names_len);
::encode(header->snap_seq, *out);
::encode(header->snap_count, *out);
for (unsigned i = 0; i < header->snap_count; i++) {
string s = name;
::encode(header->snaps[i].id, *out);
::encode(header->snaps[i].image_size, *out);
::encode(s, *out);
name += strlen(name) + 1;
if (name > end)
return -EIO;
}
return 0;
}
int snapshot_add(cls_method_context_t hctx, bufferlist *in, bufferlist *out)
{
bufferlist bl;
struct rbd_obj_header_ondisk *header;
bufferlist newbl;
bufferptr header_bp(sizeof(*header));
struct rbd_obj_snap_ondisk *new_snaps;
int rc = snap_read_header(hctx, bl);
if (rc < 0)
return rc;
header = (struct rbd_obj_header_ondisk *)bl.c_str();
int snaps_id_ofs = sizeof(*header);
int len = snaps_id_ofs;
int names_ofs = snaps_id_ofs + sizeof(*new_snaps) * header->snap_count;
const char *snap_name;
const char *snap_names = ((char *)header) + names_ofs;
const char *end = snap_names + header->snap_names_len;
bufferlist::iterator iter = in->begin();
string s;
uint64_t snap_id;
try {
::decode(s, iter);
::decode(snap_id, iter);
} catch (buffer::error *err) {
return -EINVAL;
}
snap_name = s.c_str();
const char *cur_snap_name;
for (cur_snap_name = snap_names; cur_snap_name < end; cur_snap_name += strlen(cur_snap_name) + 1) {
if (strncmp(cur_snap_name, snap_name, end - cur_snap_name) == 0)
return -EEXIST;
}
if (cur_snap_name > end)
return -EIO;
int snap_name_len = strlen(snap_name);
bufferptr new_names_bp(header->snap_names_len + snap_name_len + 1);
bufferptr new_snaps_bp(sizeof(*new_snaps) * (header->snap_count + 1));
/* copy snap names and append to new snap name */
char *new_snap_names = new_names_bp.c_str();
strcpy(new_snap_names, snap_name);
memcpy(new_snap_names + snap_name_len + 1, snap_names, header->snap_names_len);
/* append new snap id */
new_snaps = (struct rbd_obj_snap_ondisk *)new_snaps_bp.c_str();
memcpy(new_snaps + 1, header->snaps, sizeof(*new_snaps) * header->snap_count);
header->snap_count = header->snap_count + 1;
header->snap_names_len = header->snap_names_len + snap_name_len + 1;
header->snap_seq = snap_id;
new_snaps[0].id = snap_id;
new_snaps[0].image_size = header->image_size;
len += sizeof(*new_snaps) * header->snap_count + header->snap_names_len;
memcpy(header_bp.c_str(), header, sizeof(*header));
newbl.push_back(header_bp);
newbl.push_back(new_snaps_bp);
newbl.push_back(new_names_bp);
rc = cls_cxx_write_full(hctx, &newbl);
if (rc < 0)
return rc;
return 0;
}
int snapshot_revert(cls_method_context_t hctx, bufferlist *in, bufferlist *out)
{
bufferlist bl;
struct rbd_obj_header_ondisk *header;
bufferlist newbl;
bufferptr header_bp(sizeof(*header));
struct rbd_obj_snap_ondisk *new_snaps;
int rc = snap_read_header(hctx, bl);
if (rc < 0)
return rc;
header = (struct rbd_obj_header_ondisk *)bl.c_str();
int snaps_id_ofs = sizeof(*header);
int names_ofs = snaps_id_ofs + sizeof(*new_snaps) * header->snap_count;
const char *snap_name;
const char *snap_names = ((char *)header) + names_ofs;
const char *end = snap_names + header->snap_names_len;
bufferlist::iterator iter = in->begin();
string s;
int i;
bool found = false;
struct rbd_obj_snap_ondisk snap;
try {
::decode(s, iter);
} catch (buffer::error *err) {
return -EINVAL;
}
snap_name = s.c_str();
for (i = 0; snap_names < end; i++) {
if (strcmp(snap_names, snap_name) == 0) {
snap = header->snaps[i];
found = true;
break;
}
snap_names += strlen(snap_names) + 1;
}
if (!found) {
CLS_LOG("couldn't find snap %s\n",snap_name);
return -ENOENT;
}
header->image_size = snap.image_size;
header->snap_seq = header->snap_seq + 1;
snap_names += strlen(snap_names) + 1;
i++;
header->snap_count = header->snap_count - i;
bufferptr new_names_bp(end - snap_names);
bufferptr new_snaps_bp(sizeof(header->snaps[0]) * header->snap_count);
memcpy(header_bp.c_str(), header, sizeof(*header));
newbl.push_back(header_bp);
if (header->snap_count) {
memcpy(new_snaps_bp.c_str(), header->snaps + i, sizeof(header->snaps[0]) * header->snap_count);
memcpy(new_names_bp.c_str(), snap_names, end - snap_names);
newbl.push_back(new_snaps_bp);
newbl.push_back(new_names_bp);
}
rc = cls_cxx_write_full(hctx, &newbl);
if (rc < 0)
return rc;
::encode(snap.id, *out);
return out->length();
}
int snapshot_remove(cls_method_context_t hctx, bufferlist *in, bufferlist *out)
{
bufferlist bl;
struct rbd_obj_header_ondisk *header;
bufferlist newbl;
bufferptr header_bp(sizeof(*header));
struct rbd_obj_snap_ondisk *new_snaps;
int rc = snap_read_header(hctx, bl);
if (rc < 0)
return rc;
header = (struct rbd_obj_header_ondisk *)bl.c_str();
int snaps_id_ofs = sizeof(*header);
int names_ofs = snaps_id_ofs + sizeof(*new_snaps) * header->snap_count;
const char *snap_name;
const char *snap_names = ((char *)header) + names_ofs;
const char *orig_names = snap_names;
const char *end = snap_names + header->snap_names_len;
bufferlist::iterator iter = in->begin();
string s;
unsigned i;
bool found = false;
struct rbd_obj_snap_ondisk snap;
try {
::decode(s, iter);
} catch (buffer::error *err) {
return -EINVAL;
}
snap_name = s.c_str();
for (i = 0; snap_names < end; i++) {
if (strcmp(snap_names, snap_name) == 0) {
snap = header->snaps[i];
found = true;
break;
}
snap_names += strlen(snap_names) + 1;
}
if (!found) {
CLS_LOG("couldn't find snap %s\n",snap_name);
return -ENOENT;
}
snap_names += s.length() + 1;
header->snap_names_len = header->snap_names_len - (s.length() + 1);
header->snap_count = header->snap_count - 1;
bufferptr new_names_bp(header->snap_names_len);
bufferptr new_snaps_bp(sizeof(header->snaps[0]) * header->snap_count);
memcpy(header_bp.c_str(), header, sizeof(*header));
newbl.push_back(header_bp);
if (header->snap_count) {
if (i > 0) {
memcpy(new_snaps_bp.c_str(), header->snaps, sizeof(header->snaps[0]) * i);
memcpy(new_names_bp.c_str(), header->snaps, snap_names - orig_names);
}
snap_names += s.length() + 1;
if (i < header->snap_count) {
memcpy(new_snaps_bp.c_str(), header->snaps, sizeof(header->snaps[0]) * i);
memcpy(new_names_bp.c_str(), snap_names , end - snap_names);
}
}
rc = cls_cxx_write_full(hctx, &newbl);
if (rc < 0)
return rc;
return 0;
}
/* assign block id. This method should be called on the rbd_info object */
int rbd_assign_bid(cls_method_context_t hctx, bufferlist *in, bufferlist *out)
{
struct rbd_info info;
int rc;
bufferlist bl;
rc = cls_cxx_read(hctx, 0, sizeof(info), &bl);
if (rc < 0 && rc != -EEXIST)
return rc;
if (rc && rc < (int)sizeof(info)) {
CLS_LOG("bad rbd_info object, read %d bytes, expected %d", rc, sizeof(info));
return -EIO;
}
uint64_t max_id;
if (rc) {
memcpy(&info, bl.c_str(), sizeof(info));
max_id = info.max_id + 1;
info.max_id = max_id;
} else {
memset(&info, 0, sizeof(info));
max_id = 0;
}
bufferlist newbl;
bufferptr bp(sizeof(info));
memcpy(bp.c_str(), &info, sizeof(info));
newbl.push_back(bp);
rc = cls_cxx_write_full(hctx, &newbl);
if (rc < 0) {
CLS_LOG("error writing rbd_info, got rc=%d", rc);
return rc;
}
::encode(max_id, *out);
return out->length();
}
void __cls_init()
{
CLS_LOG("Loaded rbd class!");
cls_register("rbd", &h_class);
cls_register_cxx_method(h_class, "snap_list", CLS_METHOD_RD | CLS_METHOD_PUBLIC, snapshots_list, &h_snapshots_list);
cls_register_cxx_method(h_class, "snap_add", CLS_METHOD_RD | CLS_METHOD_WR | CLS_METHOD_PUBLIC, snapshot_add, &h_snapshot_add);
cls_register_cxx_method(h_class, "snap_remove", CLS_METHOD_RD | CLS_METHOD_WR | CLS_METHOD_PUBLIC, snapshot_remove, &h_snapshot_remove);
cls_register_cxx_method(h_class, "snap_revert", CLS_METHOD_RD | CLS_METHOD_WR | CLS_METHOD_PUBLIC, snapshot_revert, &h_snapshot_revert);
/* assign a unique block id for rbd blocks */
cls_register_cxx_method(h_class, "assign_bid", CLS_METHOD_RD | CLS_METHOD_WR | CLS_METHOD_PUBLIC, rbd_assign_bid, &h_assign_bid);
return;
}