mount/shell: bucket allow-empty-folders toggle, mount keeps explicit false (#11370)

* mount: keep a deliberate bucket allow-empty-folders setting * shell: s3.bucket.allowEmptyFolders toggles the empty folder cleaner * shell: guard allow-empty-folders toggle with expected extended attrs * filer: drop cached empty-folder policy on bucket entry update * mount: guard allow-empty-folders write with expected extended attrs * filer: skip caching a stale cleanup policy read across an update * mount, shell: snapshot the full extended attributes for update preconditions * filer: fail closed and invalidate on all bucket entry events for cleanup policy * filer: key the cleanup policy generation by bucket * filer: requeue cleanup when the bucket policy cannot be loaded * filer: expire idle cleanup policy generations * filer: skip requeueing cleanup after the cleaner stops * filer: bound cleanup retries on repeated policy failures * filer: cover cleanup requeue on repeated policy failures * filer: keep cleanup policy generations while reads are in flight * filer: exercise the cleanup queue lifecycle in the retry-cap test
2026-09-28 18:55:49 +00:00 · 2026-09-17 20:30:53 -07:00
parent 2d2619f0b4
commit bdc37a1e86
7 changed files with 569 additions and 53 deletions
@@ -0,0 +1,130 @@
+package shell
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"io"
+	"strings"
+
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+
+	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
+	"github.com/seaweedfs/seaweedfs/weed/s3api/s3_constants"
+	"github.com/seaweedfs/seaweedfs/weed/s3api/s3bucket"
+)
+
+func init() {
+	Commands = append(Commands, &commandS3BucketAllowEmptyFolders{})
+}
+
+type commandS3BucketAllowEmptyFolders struct {
+}
+
+func (c *commandS3BucketAllowEmptyFolders) Name() string {
+	return "s3.bucket.allowEmptyFolders"
+}
+
+func (c *commandS3BucketAllowEmptyFolders) Help() string {
+	return `view or toggle whether a bucket keeps empty folders
+
+	When enabled, the empty folder cleaner skips this bucket, so empty
+	directories persist (POSIX semantics). weed mount sets this when
+	mounting a bucket root.
+
+	When disabled, folders emptied by object deletes are removed
+	asynchronously and stop appearing as CommonPrefix in S3 listings.
+	The explicit "false" marker is kept by weed mount.
+
+	Example:
+		# Show the current setting
+		s3.bucket.allowEmptyFolders -name <bucket_name>
+
+		# Keep empty folders (skip the cleaner for this bucket)
+		s3.bucket.allowEmptyFolders -name <bucket_name> -enable
+
+		# Let the cleaner remove empty folders
+		s3.bucket.allowEmptyFolders -name <bucket_name> -disable
+`
+}
+
+func (c *commandS3BucketAllowEmptyFolders) HasTag(CommandTag) bool {
+	return false
+}
+
+func (c *commandS3BucketAllowEmptyFolders) Do(args []string, commandEnv *CommandEnv, writer io.Writer) (err error) {
+	bucketCommand := flag.NewFlagSet(c.Name(), flag.ContinueOnError)
+	bucketName := bucketCommand.String("name", "", "bucket name")
+	enable := bucketCommand.Bool("enable", false, "keep empty folders in the bucket")
+	disable := bucketCommand.Bool("disable", false, "remove empty folders asynchronously")
+	if err = bucketCommand.Parse(args); err != nil {
+		return err
+	}
+
+	if *bucketName == "" {
+		return fmt.Errorf("empty bucket name")
+	}
+	if err := s3bucket.VerifyS3BucketName(*bucketName); err != nil {
+		return fmt.Errorf("invalid bucket name %q: %w", *bucketName, err)
+	}
+	if *enable && *disable {
+		return fmt.Errorf("only one of -enable or -disable can be set")
+	}
+
+	filerBucketsPath, err := readFilerBucketsPath(commandEnv)
+	if err != nil {
+		return fmt.Errorf("read buckets: %w", err)
+	}
+
+	return commandEnv.WithFilerClient(false, func(client filer_pb.SeaweedFilerClient) error {
+		for attempt := 0; attempt < 5; attempt++ {
+			lookupResp, err := client.LookupDirectoryEntry(context.Background(), &filer_pb.LookupDirectoryEntryRequest{
+				Directory: filerBucketsPath,
+				Name:      *bucketName,
+			})
+			if err != nil {
+				return fmt.Errorf("lookup bucket %s: %w", *bucketName, err)
+			}
+			entry := lookupResp.Entry
+
+			if !*enable && !*disable {
+				state := "disabled"
+				if strings.EqualFold(strings.TrimSpace(string(entry.Extended[s3_constants.ExtAllowEmptyFolders])), "true") {
+					state = "enabled"
+				}
+				fmt.Fprintf(writer, "Bucket: %s\n", *bucketName)
+				fmt.Fprintf(writer, "Allow empty folders: %s\n", state)
+				return nil
+			}
+
+			expected := filer_pb.SnapshotExtended(entry.Extended, s3_constants.ExtAllowEmptyFolders)
+
+			if entry.Extended == nil {
+				entry.Extended = make(map[string][]byte)
+			}
+			state := "disabled"
+			if *enable {
+				entry.Extended[s3_constants.ExtAllowEmptyFolders] = []byte("true")
+				state = "enabled"
+			} else {
+				entry.Extended[s3_constants.ExtAllowEmptyFolders] = []byte("false")
+			}
+
+			if _, err := client.UpdateEntry(context.Background(), &filer_pb.UpdateEntryRequest{
+				Directory:        filerBucketsPath,
+				Entry:            entry,
+				ExpectedExtended: expected,
+			}); err != nil {
+				if status.Code(err) == codes.FailedPrecondition {
+					continue
+				}
+				return fmt.Errorf("failed to update bucket: %w", err)
+			}
+
+			fmt.Fprintf(writer, "Bucket %s allow empty folders %s\n", *bucketName, state)
+			return nil
+		}
+		return fmt.Errorf("bucket %s changed concurrently; please retry", *bucketName)
+	})
+}