server: Move all the top level files into cmd folder. (#2490)

This change brings a change which was done for the 'mc'
package to allow for clean repo and have a cleaner
github drop in experience.

cmd/xl-v1-bucket.go

@@ -0,0 +1,304 @@
+/*
+ * Minio Cloud Storage, (C) 2016 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 (
+	"path"
+	"sort"
+	"sync"
+)
+
+/// Bucket operations
+
+// MakeBucket - make a bucket.
+func (xl xlObjects) MakeBucket(bucket string) error {
+	// Verify if bucket is valid.
+	if !IsValidBucketName(bucket) {
+		return BucketNameInvalid{Bucket: bucket}
+	}
+	// Verify if bucket is found.
+	if xl.isBucketExist(bucket) {
+		return toObjectErr(errVolumeExists, bucket)
+	}
+
+	nsMutex.Lock(bucket, "")
+	defer nsMutex.Unlock(bucket, "")
+
+	// Initialize sync waitgroup.
+	var wg = &sync.WaitGroup{}
+
+	// Initialize list of errors.
+	var dErrs = make([]error, len(xl.storageDisks))
+
+	// Make a volume entry on all underlying storage disks.
+	for index, disk := range xl.storageDisks {
+		if disk == nil {
+			dErrs[index] = errDiskNotFound
+			continue
+		}
+		wg.Add(1)
+		// Make a volume inside a go-routine.
+		go func(index int, disk StorageAPI) {
+			defer wg.Done()
+			err := disk.MakeVol(bucket)
+			if err != nil {
+				dErrs[index] = err
+			}
+		}(index, disk)
+	}
+
+	// Wait for all make vol to finish.
+	wg.Wait()
+
+	// Do we have write quorum?.
+	if !isDiskQuorum(dErrs, xl.writeQuorum) {
+		// Purge successfully created buckets if we don't have writeQuorum.
+		xl.undoMakeBucket(bucket)
+		return toObjectErr(errXLWriteQuorum, bucket)
+	}
+
+	// Verify we have any other errors which should undo make bucket.
+	if reducedErr := reduceErrs(dErrs, []error{
+		errDiskNotFound,
+		errFaultyDisk,
+		errDiskAccessDenied,
+	}); reducedErr != nil {
+		return toObjectErr(reducedErr, bucket)
+	}
+	return nil
+}
+
+func (xl xlObjects) undoDeleteBucket(bucket string) {
+	// Initialize sync waitgroup.
+	var wg = &sync.WaitGroup{}
+	// Undo previous make bucket entry on all underlying storage disks.
+	for index, disk := range xl.storageDisks {
+		if disk == nil {
+			continue
+		}
+		wg.Add(1)
+		// Delete a bucket inside a go-routine.
+		go func(index int, disk StorageAPI) {
+			defer wg.Done()
+			_ = disk.MakeVol(bucket)
+		}(index, disk)
+	}
+
+	// Wait for all make vol to finish.
+	wg.Wait()
+}
+
+// undo make bucket operation upon quorum failure.
+func (xl xlObjects) undoMakeBucket(bucket string) {
+	// Initialize sync waitgroup.
+	var wg = &sync.WaitGroup{}
+	// Undo previous make bucket entry on all underlying storage disks.
+	for index, disk := range xl.storageDisks {
+		if disk == nil {
+			continue
+		}
+		wg.Add(1)
+		// Delete a bucket inside a go-routine.
+		go func(index int, disk StorageAPI) {
+			defer wg.Done()
+			_ = disk.DeleteVol(bucket)
+		}(index, disk)
+	}
+
+	// Wait for all make vol to finish.
+	wg.Wait()
+}
+
+// list all errors that can be ignored in a bucket metadata operation.
+var bucketMetadataOpIgnoredErrs = []error{
+	errDiskNotFound,
+	errDiskAccessDenied,
+	errFaultyDisk,
+	errVolumeNotFound,
+}
+
+// getBucketInfo - returns the BucketInfo from one of the load balanced disks.
+func (xl xlObjects) getBucketInfo(bucketName string) (bucketInfo BucketInfo, err error) {
+	for _, disk := range xl.getLoadBalancedDisks() {
+		if disk == nil {
+			continue
+		}
+		var volInfo VolInfo
+		volInfo, err = disk.StatVol(bucketName)
+		if err == nil {
+			bucketInfo = BucketInfo{
+				Name:    volInfo.Name,
+				Created: volInfo.Created,
+			}
+			return bucketInfo, nil
+		}
+		// For any reason disk went offline continue and pick the next one.
+		if isErrIgnored(err, bucketMetadataOpIgnoredErrs) {
+			continue
+		}
+		break
+	}
+	return BucketInfo{}, err
+}
+
+// Checks whether bucket exists.
+func (xl xlObjects) isBucketExist(bucket string) bool {
+	nsMutex.RLock(bucket, "")
+	defer nsMutex.RUnlock(bucket, "")
+
+	// Check whether bucket exists.
+	_, err := xl.getBucketInfo(bucket)
+	if err != nil {
+		if err == errVolumeNotFound {
+			return false
+		}
+		errorIf(err, "Stat failed on bucket "+bucket+".")
+		return false
+	}
+	return true
+}
+
+// GetBucketInfo - returns BucketInfo for a bucket.
+func (xl xlObjects) GetBucketInfo(bucket string) (BucketInfo, error) {
+	// Verify if bucket is valid.
+	if !IsValidBucketName(bucket) {
+		return BucketInfo{}, BucketNameInvalid{Bucket: bucket}
+	}
+	nsMutex.RLock(bucket, "")
+	defer nsMutex.RUnlock(bucket, "")
+	bucketInfo, err := xl.getBucketInfo(bucket)
+	if err != nil {
+		return BucketInfo{}, toObjectErr(err, bucket)
+	}
+	return bucketInfo, nil
+}
+
+// listBuckets - returns list of all buckets from a disk picked at random.
+func (xl xlObjects) listBuckets() (bucketsInfo []BucketInfo, err error) {
+	for _, disk := range xl.getLoadBalancedDisks() {
+		if disk == nil {
+			continue
+		}
+		var volsInfo []VolInfo
+		volsInfo, err = disk.ListVols()
+		if err == nil {
+			// NOTE: The assumption here is that volumes across all disks in
+			// readQuorum have consistent view i.e they all have same number
+			// of buckets. This is essentially not verified since healing
+			// should take care of this.
+			var bucketsInfo []BucketInfo
+			for _, volInfo := range volsInfo {
+				// StorageAPI can send volume names which are incompatible
+				// with buckets, handle it and skip them.
+				if !IsValidBucketName(volInfo.Name) {
+					continue
+				}
+				// Ignore the volume special bucket.
+				if volInfo.Name == minioMetaBucket {
+					continue
+				}
+				bucketsInfo = append(bucketsInfo, BucketInfo{
+					Name:    volInfo.Name,
+					Created: volInfo.Created,
+				})
+			}
+			// For buckets info empty, loop once again to check
+			// if we have, can happen if disks are down.
+			if len(bucketsInfo) == 0 {
+				continue
+			}
+			return bucketsInfo, nil
+		}
+		// Ignore any disks not found.
+		if isErrIgnored(err, bucketMetadataOpIgnoredErrs) {
+			continue
+		}
+		break
+	}
+	return nil, err
+}
+
+// ListBuckets - lists all the buckets, sorted by its name.
+func (xl xlObjects) ListBuckets() ([]BucketInfo, error) {
+	bucketInfos, err := xl.listBuckets()
+	if err != nil {
+		return nil, toObjectErr(err)
+	}
+	// Sort by bucket name before returning.
+	sort.Sort(byBucketName(bucketInfos))
+	return bucketInfos, nil
+}
+
+// DeleteBucket - deletes a bucket.
+func (xl xlObjects) DeleteBucket(bucket string) error {
+	// Verify if bucket is valid.
+	if !IsValidBucketName(bucket) {
+		return BucketNameInvalid{Bucket: bucket}
+	}
+	// Verify if bucket is found.
+	if !xl.isBucketExist(bucket) {
+		return BucketNotFound{Bucket: bucket}
+	}
+
+	nsMutex.Lock(bucket, "")
+	defer nsMutex.Unlock(bucket, "")
+
+	// Collect if all disks report volume not found.
+	var wg = &sync.WaitGroup{}
+	var dErrs = make([]error, len(xl.storageDisks))
+
+	// Remove a volume entry on all underlying storage disks.
+	for index, disk := range xl.storageDisks {
+		if disk == nil {
+			dErrs[index] = errDiskNotFound
+			continue
+		}
+		wg.Add(1)
+		// Delete volume inside a go-routine.
+		go func(index int, disk StorageAPI) {
+			defer wg.Done()
+			// Attempt to delete bucket.
+			err := disk.DeleteVol(bucket)
+			if err != nil {
+				dErrs[index] = err
+				return
+			}
+			// Cleanup all the previously incomplete multiparts.
+			err = cleanupDir(disk, path.Join(minioMetaBucket, mpartMetaPrefix), bucket)
+			if err != nil && err != errVolumeNotFound {
+				dErrs[index] = err
+			}
+		}(index, disk)
+	}
+
+	// Wait for all the delete vols to finish.
+	wg.Wait()
+
+	if !isDiskQuorum(dErrs, xl.writeQuorum) {
+		xl.undoDeleteBucket(bucket)
+		return toObjectErr(errXLWriteQuorum, bucket)
+	}
+
+	if reducedErr := reduceErrs(dErrs, []error{
+		errFaultyDisk,
+		errDiskNotFound,
+		errDiskAccessDenied,
+	}); reducedErr != nil {
+		return toObjectErr(reducedErr, bucket)
+	}
+	return nil
+}