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minio/cmd/metacache-server-pool.go

225 lines
6.2 KiB

/*
* MinIO Cloud Storage, (C) 2020 MinIO, Inc.
*
* 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 cmd
import (
"context"
"errors"
"io"
"path"
"sync"
"time"
"github.com/minio/minio/cmd/logger"
)
// listPath will return the requested entries.
// If no more entries are in the listing io.EOF is returned,
// otherwise nil or an unexpected error is returned.
// The listPathOptions given will be checked and modified internally.
// Required important fields are Bucket, Prefix, Separator.
// Other important fields are Limit, Marker.
// List ID always derived from the Marker.
func (z *erasureServerPools) listPath(ctx context.Context, o listPathOptions) (entries metaCacheEntriesSorted, err error) {
if err := checkListObjsArgs(ctx, o.Bucket, o.Prefix, o.Marker, z); err != nil {
return entries, err
}
// Marker is set validate pre-condition.
if o.Marker != "" && o.Prefix != "" {
// Marker not common with prefix is not implemented. Send an empty response
if !HasPrefix(o.Marker, o.Prefix) {
return entries, io.EOF
}
}
// With max keys of zero we have reached eof, return right here.
if o.Limit == 0 {
return entries, io.EOF
}
// For delimiter and prefix as '/' we do not list anything at all
// since according to s3 spec we stop at the 'delimiter'
// along // with the prefix. On a flat namespace with 'prefix'
// as '/' we don't have any entries, since all the keys are
// of form 'keyName/...'
if o.Separator == SlashSeparator && o.Prefix == SlashSeparator {
return entries, io.EOF
}
// Over flowing count - reset to maxObjectList.
if o.Limit < 0 || o.Limit > maxObjectList {
o.Limit = maxObjectList
}
// If delimiter is slashSeparator we must return directories of
// the non-recursive scan unless explicitly requested.
o.IncludeDirectories = o.Separator == slashSeparator
if (o.Separator == slashSeparator || o.Separator == "") && !o.Recursive {
o.Recursive = o.Separator != slashSeparator
o.Separator = slashSeparator
} else {
// Default is recursive, if delimiter is set then list non recursive.
o.Recursive = true
}
// Decode and get the optional list id from the marker.
o.Marker, o.ID = parseMarker(o.Marker)
o.Create = o.ID == ""
if o.ID == "" {
o.ID = mustGetUUID()
}
o.BaseDir = baseDirFromPrefix(o.Prefix)
if o.discardResult {
// Override for single object.
o.BaseDir = o.Prefix
}
// For very small recursive listings, don't same cache.
// Attempts to avoid expensive listings to run for a long
// while when clients aren't interested in results.
// If the client DOES resume the listing a full cache
// will be generated due to the marker without ID and this check failing.
if o.Limit < 10 && o.Marker == "" && o.Create && o.Recursive {
o.discardResult = true
o.Transient = true
}
var cache metacache
// If we don't have a list id we must ask the server if it has a cache or create a new.
if o.Create {
o.CurrentCycle = intDataUpdateTracker.current()
o.OldestCycle = globalNotificationSys.findEarliestCleanBloomFilter(ctx, path.Join(o.Bucket, o.BaseDir))
var cache metacache
rpc := globalNotificationSys.restClientFromHash(o.Bucket)
if isReservedOrInvalidBucket(o.Bucket, false) {
rpc = nil
o.Transient = true
}
// Apply prefix filter if enabled.
o.SetFilter()
if rpc == nil || o.Transient {
// Local
cache = localMetacacheMgr.findCache(ctx, o)
} else {
ctx, cancel := context.WithTimeout(ctx, 5*time.Second)
defer cancel()
c, err := rpc.GetMetacacheListing(ctx, o)
if err != nil {
if errors.Is(err, context.Canceled) {
// Context is canceled, return at once.
// request canceled, no entries to return
return entries, io.EOF
}
if !errors.Is(err, context.DeadlineExceeded) {
logger.LogIf(ctx, err)
}
o.Transient = true
cache = localMetacacheMgr.findCache(ctx, o)
} else {
cache = *c
}
}
if cache.fileNotFound {
// No cache found, no entries found.
return entries, io.EOF
}
// Only create if we created a new.
o.Create = o.ID == cache.id
o.ID = cache.id
}
var mu sync.Mutex
var wg sync.WaitGroup
var errs []error
allAtEOF := true
mu.Lock()
// Ask all sets and merge entries.
for _, zone := range z.serverPools {
for _, set := range zone.sets {
wg.Add(1)
go func(i int, set *erasureObjects) {
defer wg.Done()
e, err := set.listPath(ctx, o)
mu.Lock()
defer mu.Unlock()
if err == nil {
allAtEOF = false
}
errs[i] = err
entries.merge(e, -1)
// Resolve non-trivial conflicts
entries.deduplicate(func(existing, other *metaCacheEntry) (replace bool) {
if existing.isDir() {
return false
}
eFIV, err := existing.fileInfo(o.Bucket)
if err != nil {
return true
}
oFIV, err := existing.fileInfo(o.Bucket)
if err != nil {
return false
}
return oFIV.ModTime.After(eFIV.ModTime)
})
if entries.len() > o.Limit {
allAtEOF = false
entries.truncate(o.Limit)
}
}(len(errs), set)
errs = append(errs, nil)
}
}
mu.Unlock()
wg.Wait()
if isAllNotFound(errs) {
// All sets returned not found.
go func() {
// Update master cache with that information.
cache.status = scanStateSuccess
cache.fileNotFound = true
o.updateMetacacheListing(cache, globalNotificationSys.restClientFromHash(o.Bucket))
}()
// cache returned not found, entries truncated.
return entries, io.EOF
}
for _, err := range errs {
if err == nil {
allAtEOF = false
continue
}
if err.Error() == io.EOF.Error() {
continue
}
logger.LogIf(ctx, err)
return entries, err
}
truncated := entries.len() > o.Limit || !allAtEOF
entries.truncate(o.Limit)
if !o.discardResult {
entries.listID = o.ID
}
if !truncated {
return entries, io.EOF
}
return entries, nil
}