Files
seaweedFS/weed/command/mount_std.go
Chris Lu 1424fe6ed5 mount: add -writebackCache flag for FUSE writeback caching (#7921)
* mount: add -writebackCache flag for FUSE writeback caching

This adds support for FUSE writeback caching via the -writebackCache flag.

Writeback caching buffers writes in the kernel page cache before flushing
to the filesystem. This significantly improves performance for workloads
with many small writes by reducing the number of write syscalls.

Benefits:
- Improved write performance for small files (2-5x faster)
- Reduced latency for write-heavy workloads
- Better handling of bursty write patterns

Trade-offs:
- Data may be lost if system crashes before kernel flushes
- Not recommended for critical data without proper fsync usage
- Disabled by default for safety

Inspired by JuiceFS implementation which uses the same FUSE option.

Usage:
  weed mount -filer=localhost:8888 -dir=/mnt/seaweedfs -writebackCache

* Apply suggestion from @gemini-code-assist[bot]

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

---------

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
2025-12-30 23:23:02 -08:00

316 lines
9.9 KiB
Go

//go:build linux || darwin || freebsd
// +build linux darwin freebsd
package command
import (
"context"
"fmt"
"net"
"net/http"
"os"
"os/user"
"runtime"
"strconv"
"strings"
"syscall"
"time"
"github.com/seaweedfs/seaweedfs/weed/util/version"
"github.com/hanwen/go-fuse/v2/fuse"
"github.com/seaweedfs/seaweedfs/weed/glog"
"github.com/seaweedfs/seaweedfs/weed/mount"
"github.com/seaweedfs/seaweedfs/weed/mount/meta_cache"
"github.com/seaweedfs/seaweedfs/weed/mount/unmount"
"github.com/seaweedfs/seaweedfs/weed/pb"
"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
"github.com/seaweedfs/seaweedfs/weed/pb/mount_pb"
"github.com/seaweedfs/seaweedfs/weed/security"
"github.com/seaweedfs/seaweedfs/weed/storage/types"
"google.golang.org/grpc/reflection"
"github.com/seaweedfs/seaweedfs/weed/util"
"github.com/seaweedfs/seaweedfs/weed/util/grace"
)
func runMount(cmd *Command, args []string) bool {
if *mountOptions.debug {
go http.ListenAndServe(fmt.Sprintf(":%d", *mountOptions.debugPort), nil)
}
grace.SetupProfiling(*mountCpuProfile, *mountMemProfile)
if *mountReadRetryTime < time.Second {
*mountReadRetryTime = time.Second
}
util.RetryWaitTime = *mountReadRetryTime
umask, umaskErr := strconv.ParseUint(*mountOptions.umaskString, 8, 64)
if umaskErr != nil {
fmt.Printf("can not parse umask %s", *mountOptions.umaskString)
return false
}
if len(args) > 0 {
return false
}
return RunMount(&mountOptions, os.FileMode(umask))
}
func RunMount(option *MountOptions, umask os.FileMode) bool {
// basic checks
chunkSizeLimitMB := *mountOptions.chunkSizeLimitMB
if chunkSizeLimitMB <= 0 {
fmt.Printf("Please specify a reasonable buffer size.\n")
return false
}
// try to connect to filer
filerAddresses := pb.ServerAddresses(*option.filer).ToAddresses()
util.LoadSecurityConfiguration()
grpcDialOption := security.LoadClientTLS(util.GetViper(), "grpc.client")
var cipher bool
var err error
for i := 0; i < 10; i++ {
err = pb.WithOneOfGrpcFilerClients(false, filerAddresses, grpcDialOption, func(client filer_pb.SeaweedFilerClient) error {
resp, err := client.GetFilerConfiguration(context.Background(), &filer_pb.GetFilerConfigurationRequest{})
if err != nil {
return fmt.Errorf("get filer grpc address %v configuration: %w", filerAddresses, err)
}
cipher = resp.Cipher
return nil
})
if err != nil {
glog.V(0).Infof("failed to talk to filer %v: %v", filerAddresses, err)
glog.V(0).Infof("wait for %d seconds ...", i+1)
time.Sleep(time.Duration(i+1) * time.Second)
}
}
if err != nil {
glog.Errorf("failed to talk to filer %v: %v", filerAddresses, err)
return true
}
filerMountRootPath := *option.filerMountRootPath
// clean up mount point
dir := util.ResolvePath(*option.dir)
if dir == "" {
fmt.Printf("Please specify the mount directory via \"-dir\"")
return false
}
unmount.Unmount(dir)
// start on local unix socket
if *option.localSocket == "" {
mountDirHash := util.HashToInt32([]byte(dir))
if mountDirHash < 0 {
mountDirHash = -mountDirHash
}
*option.localSocket = fmt.Sprintf("/tmp/seaweedfs-mount-%d.sock", mountDirHash)
}
if err := os.Remove(*option.localSocket); err != nil && !os.IsNotExist(err) {
glog.Fatalf("Failed to remove %s, error: %s", *option.localSocket, err.Error())
}
montSocketListener, err := net.Listen("unix", *option.localSocket)
if err != nil {
glog.Fatalf("Failed to listen on %s: %v", *option.localSocket, err)
}
// detect mount folder mode
if *option.dirAutoCreate {
os.MkdirAll(dir, os.FileMode(0777)&^umask)
}
fileInfo, err := os.Stat(dir)
// collect uid, gid
uid, gid := uint32(0), uint32(0)
mountMode := os.ModeDir | 0777
if err == nil {
mountMode = os.ModeDir | os.FileMode(0777)&^umask
uid, gid = util.GetFileUidGid(fileInfo)
fmt.Printf("mount point owner uid=%d gid=%d mode=%s\n", uid, gid, mountMode)
} else {
fmt.Printf("can not stat %s\n", dir)
return false
}
// detect uid, gid
if uid == 0 {
if u, err := user.Current(); err == nil {
if parsedId, pe := strconv.ParseUint(u.Uid, 10, 32); pe == nil {
uid = uint32(parsedId)
}
if parsedId, pe := strconv.ParseUint(u.Gid, 10, 32); pe == nil {
gid = uint32(parsedId)
}
fmt.Printf("current uid=%d gid=%d\n", uid, gid)
}
}
// mapping uid, gid
uidGidMapper, err := meta_cache.NewUidGidMapper(*option.uidMap, *option.gidMap)
if err != nil {
fmt.Printf("failed to parse %s %s: %v\n", *option.uidMap, *option.gidMap, err)
return false
}
// Ensure target mount point availability
if isValid := checkMountPointAvailable(dir); !isValid {
glog.Fatalf("Target mount point is not available: %s, please check!", dir)
return true
}
serverFriendlyName := strings.ReplaceAll(*option.filer, ",", "+")
// mount fuse
fuseMountOptions := &fuse.MountOptions{
AllowOther: *option.allowOthers,
Options: option.extraOptions,
MaxBackground: 128,
MaxWrite: 1024 * 1024 * 2,
MaxReadAhead: 1024 * 1024 * 2,
IgnoreSecurityLabels: false,
RememberInodes: false,
FsName: serverFriendlyName + ":" + filerMountRootPath,
Name: "seaweedfs",
SingleThreaded: false,
DisableXAttrs: *option.disableXAttr,
Debug: *option.debug,
EnableLocks: false,
ExplicitDataCacheControl: false,
DirectMount: true,
DirectMountFlags: 0,
//SyncRead: false, // set to false to enable the FUSE_CAP_ASYNC_READ capability
EnableAcl: true,
}
if *option.nonempty {
fuseMountOptions.Options = append(fuseMountOptions.Options, "nonempty")
}
if *option.readOnly {
if runtime.GOOS == "darwin" {
fuseMountOptions.Options = append(fuseMountOptions.Options, "rdonly")
} else {
fuseMountOptions.Options = append(fuseMountOptions.Options, "ro")
}
}
if runtime.GOOS == "darwin" {
// https://github-wiki-see.page/m/macfuse/macfuse/wiki/Mount-Options
ioSizeMB := 1
for ioSizeMB*2 <= *option.chunkSizeLimitMB && ioSizeMB*2 <= 32 {
ioSizeMB *= 2
}
fuseMountOptions.Options = append(fuseMountOptions.Options, "daemon_timeout=600")
if runtime.GOARCH == "amd64" {
fuseMountOptions.Options = append(fuseMountOptions.Options, "noapplexattr")
}
// fuseMountOptions.Options = append(fuseMountOptions.Options, "novncache") // need to test effectiveness
fuseMountOptions.Options = append(fuseMountOptions.Options, "slow_statfs")
fuseMountOptions.Options = append(fuseMountOptions.Options, "volname="+serverFriendlyName)
fuseMountOptions.Options = append(fuseMountOptions.Options, fmt.Sprintf("iosize=%d", ioSizeMB*1024*1024))
}
if *option.writebackCache {
fuseMountOptions.Options = append(fuseMountOptions.Options, "writeback_cache")
}
// find mount point
mountRoot := filerMountRootPath
if mountRoot != "/" && strings.HasSuffix(mountRoot, "/") {
mountRoot = mountRoot[0 : len(mountRoot)-1]
}
cacheDirForWrite := *option.cacheDirForWrite
if cacheDirForWrite == "" {
cacheDirForWrite = *option.cacheDirForRead
}
seaweedFileSystem := mount.NewSeaweedFileSystem(&mount.Option{
MountDirectory: dir,
FilerAddresses: filerAddresses,
GrpcDialOption: grpcDialOption,
FilerMountRootPath: mountRoot,
Collection: *option.collection,
Replication: *option.replication,
TtlSec: int32(*option.ttlSec),
DiskType: types.ToDiskType(*option.diskType),
ChunkSizeLimit: int64(chunkSizeLimitMB) * 1024 * 1024,
ConcurrentWriters: *option.concurrentWriters,
ConcurrentReaders: *option.concurrentReaders,
CacheDirForRead: *option.cacheDirForRead,
CacheSizeMBForRead: *option.cacheSizeMBForRead,
CacheDirForWrite: cacheDirForWrite,
CacheMetaTTlSec: *option.cacheMetaTtlSec,
DataCenter: *option.dataCenter,
Quota: int64(*option.collectionQuota) * 1024 * 1024,
MountUid: uid,
MountGid: gid,
MountMode: mountMode,
MountCtime: fileInfo.ModTime(),
MountMtime: time.Now(),
Umask: umask,
VolumeServerAccess: *mountOptions.volumeServerAccess,
Cipher: cipher,
UidGidMapper: uidGidMapper,
DisableXAttr: *option.disableXAttr,
IsMacOs: runtime.GOOS == "darwin",
MetadataFlushSeconds: *option.metadataFlushSeconds,
// RDMA acceleration options
RdmaEnabled: *option.rdmaEnabled,
RdmaSidecarAddr: *option.rdmaSidecarAddr,
RdmaFallback: *option.rdmaFallback,
RdmaReadOnly: *option.rdmaReadOnly,
RdmaMaxConcurrent: *option.rdmaMaxConcurrent,
RdmaTimeoutMs: *option.rdmaTimeoutMs,
})
// create mount root
mountRootPath := util.FullPath(mountRoot)
mountRootParent, mountDir := mountRootPath.DirAndName()
if err = filer_pb.Mkdir(context.Background(), seaweedFileSystem, mountRootParent, mountDir, nil); err != nil {
fmt.Printf("failed to create dir %s on filer %s: %v\n", mountRoot, filerAddresses, err)
return false
}
server, err := fuse.NewServer(seaweedFileSystem, dir, fuseMountOptions)
if err != nil {
glog.Fatalf("Mount fail: %v", err)
}
grace.OnInterrupt(func() {
unmount.Unmount(dir)
})
if mountOptions.fuseCommandPid != 0 {
// send a signal to the parent process to notify that the mount is ready
err = syscall.Kill(mountOptions.fuseCommandPid, syscall.SIGTERM)
if err != nil {
fmt.Printf("failed to notify parent process: %v\n", err)
return false
}
}
grpcS := pb.NewGrpcServer()
mount_pb.RegisterSeaweedMountServer(grpcS, seaweedFileSystem)
reflection.Register(grpcS)
go grpcS.Serve(montSocketListener)
err = seaweedFileSystem.StartBackgroundTasks()
if err != nil {
fmt.Printf("failed to start background tasks: %v\n", err)
return false
}
glog.V(0).Infof("mounted %s%s to %v", *option.filer, mountRoot, dir)
glog.V(0).Infof("This is SeaweedFS version %s %s %s", version.Version(), runtime.GOOS, runtime.GOARCH)
server.Serve()
seaweedFileSystem.ClearCacheDir()
return true
}