ceph-csi/internal/journal/omap.go
John Mulligan 8a41cd03a5 journal: fix reading omaps from objects with large key counts
The implementation of getOMapValues assumed that the number of key-value
pairs assigned to the object would be close to the number of keys
being requested. When the number of keys on the object exceeded the
"listExcess" value the function would fail to read additional keys
even if they existed in the omap.
This change sets a large fixed "chunk size" value and keeps reading
key-value pairs as long as the callback gets called and increments
the numKeys counter.

Signed-off-by: John Mulligan <jmulligan@redhat.com>
2020-11-06 06:42:22 +00:00

159 lines
4.1 KiB
Go

/*
Copyright 2020 The Ceph-CSI Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package journal
import (
"context"
"errors"
"github.com/ceph/ceph-csi/internal/util"
"github.com/ceph/go-ceph/rados"
)
// chunkSize is the number of key-value pairs that will be fetched in
// one call. This is set fairly large to avoid calling into ceph APIs
// over and over.
const chunkSize int64 = 512
func getOMapValues(
ctx context.Context,
conn *Connection,
poolName, namespace, oid, prefix string, keys []string) (map[string]string, error) {
// fetch and configure the rados ioctx
ioctx, err := conn.conn.GetIoctx(poolName)
if err != nil {
return nil, omapPoolError(err)
}
defer ioctx.Destroy()
if namespace != "" {
ioctx.SetNamespace(namespace)
}
results := map[string]string{}
// want is our "lookup map" that ensures O(1) checks for keys
// while iterating, without needing to complicate the caller.
want := make(map[string]bool, len(keys))
for i := range keys {
want[keys[i]] = true
}
numKeys := uint64(0)
startAfter := ""
for {
prevNumKeys := numKeys
err = ioctx.ListOmapValues(
oid, startAfter, prefix, chunkSize,
func(key string, value []byte) {
numKeys++
startAfter = key
if want[key] {
results[key] = string(value)
}
},
)
// if we hit an error, or no new keys were seen, exit the loop
if err != nil || numKeys == prevNumKeys {
break
}
}
if err != nil {
if errors.Is(err, rados.ErrNotFound) {
util.ErrorLog(ctx, "omap not found (pool=%q, namespace=%q, name=%q): %v",
poolName, namespace, oid, err)
return nil, util.JoinErrors(util.ErrKeyNotFound, err)
}
return nil, err
}
util.DebugLog(ctx, "got omap values: (pool=%q, namespace=%q, name=%q): %+v",
poolName, namespace, oid, results)
return results, nil
}
func removeMapKeys(
ctx context.Context,
conn *Connection,
poolName, namespace, oid string, keys []string) error {
// fetch and configure the rados ioctx
ioctx, err := conn.conn.GetIoctx(poolName)
if err != nil {
return omapPoolError(err)
}
defer ioctx.Destroy()
if namespace != "" {
ioctx.SetNamespace(namespace)
}
err = ioctx.RmOmapKeys(oid, keys)
if err != nil {
if errors.Is(err, rados.ErrNotFound) {
// the previous implementation of removing omap keys (via the cli)
// treated failure to find the omap as a non-error. Do so here to
// mimic the previous behavior.
util.DebugLog(ctx, "when removing omap keys, omap not found (pool=%q, namespace=%q, name=%q): %+v",
poolName, namespace, oid, keys)
} else {
util.ErrorLog(ctx, "failed removing omap keys (pool=%q, namespace=%q, name=%q): %v",
poolName, namespace, oid, err)
return err
}
}
util.DebugLog(ctx, "removed omap keys (pool=%q, namespace=%q, name=%q): %+v",
poolName, namespace, oid, keys)
return nil
}
func setOMapKeys(
ctx context.Context,
conn *Connection,
poolName, namespace, oid string, pairs map[string]string) error {
// fetch and configure the rados ioctx
ioctx, err := conn.conn.GetIoctx(poolName)
if err != nil {
return omapPoolError(err)
}
defer ioctx.Destroy()
if namespace != "" {
ioctx.SetNamespace(namespace)
}
bpairs := make(map[string][]byte, len(pairs))
for k, v := range pairs {
bpairs[k] = []byte(v)
}
err = ioctx.SetOmap(oid, bpairs)
if err != nil {
util.ErrorLog(ctx, "failed setting omap keys (pool=%q, namespace=%q, name=%q, pairs=%+v): %v",
poolName, namespace, oid, pairs, err)
return err
}
util.DebugLog(ctx, "set omap keys (pool=%q, namespace=%q, name=%q): %+v)",
poolName, namespace, oid, pairs)
return nil
}
func omapPoolError(err error) error {
if errors.Is(err, rados.ErrNotFound) {
return util.JoinErrors(util.ErrPoolNotFound, err)
}
return err
}