seaweedfs/weed/mount/weedfs_dir_read.go
2022-05-24 18:52:04 -07:00

241 lines
6.8 KiB
Go

package mount
import (
"context"
"github.com/chrislusf/seaweedfs/weed/filer"
"github.com/chrislusf/seaweedfs/weed/glog"
"github.com/chrislusf/seaweedfs/weed/mount/meta_cache"
"github.com/hanwen/go-fuse/v2/fuse"
"math"
"sync"
)
type DirectoryHandleId uint64
const (
directoryStreamBaseOffset = 2 // . & ..
)
type DirectoryHandle struct {
isFinished bool
entryStream []*filer.Entry
entryStreamOffset uint64
}
func (dh *DirectoryHandle) reset() {
*dh = DirectoryHandle{
isFinished: false,
entryStream: []*filer.Entry{},
entryStreamOffset: directoryStreamBaseOffset,
}
}
type DirectoryHandleToInode struct {
// shares the file handle id sequencer with FileHandleToInode{nextFh}
sync.Mutex
dir2inode map[DirectoryHandleId]*DirectoryHandle
}
func NewDirectoryHandleToInode() *DirectoryHandleToInode {
return &DirectoryHandleToInode{
dir2inode: make(map[DirectoryHandleId]*DirectoryHandle),
}
}
func (wfs *WFS) AcquireDirectoryHandle() (DirectoryHandleId, *DirectoryHandle) {
wfs.fhmap.Lock()
fh := wfs.fhmap.nextFh
wfs.fhmap.nextFh++
wfs.fhmap.Unlock()
wfs.dhmap.Lock()
defer wfs.dhmap.Unlock()
dh := new(DirectoryHandle)
dh.reset()
wfs.dhmap.dir2inode[DirectoryHandleId(fh)] = dh
return DirectoryHandleId(fh), dh
}
func (wfs *WFS) GetDirectoryHandle(dhid DirectoryHandleId) *DirectoryHandle {
wfs.dhmap.Lock()
defer wfs.dhmap.Unlock()
if dh, found := wfs.dhmap.dir2inode[dhid]; found {
return dh
}
dh := new(DirectoryHandle)
dh.reset()
wfs.dhmap.dir2inode[dhid] = dh
return dh
}
func (wfs *WFS) ReleaseDirectoryHandle(dhid DirectoryHandleId) {
wfs.dhmap.Lock()
defer wfs.dhmap.Unlock()
delete(wfs.dhmap.dir2inode, dhid)
}
// Directory handling
/** Open directory
*
* Unless the 'default_permissions' mount option is given,
* this method should check if opendir is permitted for this
* directory. Optionally opendir may also return an arbitrary
* filehandle in the fuse_file_info structure, which will be
* passed to readdir, releasedir and fsyncdir.
*/
func (wfs *WFS) OpenDir(cancel <-chan struct{}, input *fuse.OpenIn, out *fuse.OpenOut) (code fuse.Status) {
if !wfs.inodeToPath.HasInode(input.NodeId) {
return fuse.ENOENT
}
dhid, _ := wfs.AcquireDirectoryHandle()
out.Fh = uint64(dhid)
return fuse.OK
}
/** Release directory
*
* If the directory has been removed after the call to opendir, the
* path parameter will be NULL.
*/
func (wfs *WFS) ReleaseDir(input *fuse.ReleaseIn) {
wfs.ReleaseDirectoryHandle(DirectoryHandleId(input.Fh))
}
/** Synchronize directory contents
*
* If the directory has been removed after the call to opendir, the
* path parameter will be NULL.
*
* If the datasync parameter is non-zero, then only the user data
* should be flushed, not the meta data
*/
func (wfs *WFS) FsyncDir(cancel <-chan struct{}, input *fuse.FsyncIn) (code fuse.Status) {
return fuse.OK
}
/** Read directory
*
* The filesystem may choose between two modes of operation:
*
* 1) The readdir implementation ignores the offset parameter, and
* passes zero to the filler function's offset. The filler
* function will not return '1' (unless an error happens), so the
* whole directory is read in a single readdir operation.
*
* 2) The readdir implementation keeps track of the offsets of the
* directory entries. It uses the offset parameter and always
* passes non-zero offset to the filler function. When the buffer
* is full (or an error happens) the filler function will return
* '1'.
*/
func (wfs *WFS) ReadDir(cancel <-chan struct{}, input *fuse.ReadIn, out *fuse.DirEntryList) (code fuse.Status) {
return wfs.doReadDirectory(input, out, false)
}
func (wfs *WFS) ReadDirPlus(cancel <-chan struct{}, input *fuse.ReadIn, out *fuse.DirEntryList) (code fuse.Status) {
return wfs.doReadDirectory(input, out, true)
}
func (wfs *WFS) doReadDirectory(input *fuse.ReadIn, out *fuse.DirEntryList, isPlusMode bool) fuse.Status {
dh := wfs.GetDirectoryHandle(DirectoryHandleId(input.Fh))
if input.Offset == 0 {
dh.reset()
} else if dh.isFinished && input.Offset >= dh.entryStreamOffset {
entryCurrentIndex := input.Offset - dh.entryStreamOffset
if uint64(len(dh.entryStream)) <= entryCurrentIndex {
return fuse.OK
}
}
isEarlyTerminated := false
dirPath, code := wfs.inodeToPath.GetPath(input.NodeId)
if code != fuse.OK {
return code
}
var dirEntry fuse.DirEntry
processEachEntryFn := func(entry *filer.Entry) bool {
dirEntry.Name = entry.Name()
dirEntry.Mode = toSyscallMode(entry.Mode)
inode := wfs.inodeToPath.Lookup(dirPath.Child(dirEntry.Name), entry.Crtime.Unix(), entry.IsDirectory(), len(entry.HardLinkId) > 0, entry.Inode, isPlusMode)
dirEntry.Ino = inode
if !isPlusMode {
if !out.AddDirEntry(dirEntry) {
isEarlyTerminated = true
return false
}
} else {
entryOut := out.AddDirLookupEntry(dirEntry)
if entryOut == nil {
isEarlyTerminated = true
return false
}
if fh, found := wfs.fhmap.FindFileHandle(inode); found {
glog.V(4).Infof("readdir opened file %s", dirPath.Child(dirEntry.Name))
entry = filer.FromPbEntry(string(dirPath), fh.entry)
}
wfs.outputFilerEntry(entryOut, inode, entry)
}
return true
}
if input.Offset < directoryStreamBaseOffset {
if !isPlusMode {
if input.Offset == 0 {
out.AddDirEntry(fuse.DirEntry{Mode: fuse.S_IFDIR, Name: "."})
}
out.AddDirEntry(fuse.DirEntry{Mode: fuse.S_IFDIR, Name: ".."})
} else {
if input.Offset == 0 {
out.AddDirLookupEntry(fuse.DirEntry{Mode: fuse.S_IFDIR, Name: "."})
}
out.AddDirLookupEntry(fuse.DirEntry{Mode: fuse.S_IFDIR, Name: ".."})
}
input.Offset = directoryStreamBaseOffset
}
var lastEntryName string
if input.Offset >= dh.entryStreamOffset {
if input.Offset > dh.entryStreamOffset {
entryPreviousIndex := (input.Offset - dh.entryStreamOffset) - 1
if uint64(len(dh.entryStream)) > entryPreviousIndex {
lastEntryName = dh.entryStream[entryPreviousIndex].Name()
dh.entryStream = dh.entryStream[entryPreviousIndex:]
dh.entryStreamOffset = input.Offset - 1
}
}
entryCurrentIndex := input.Offset - dh.entryStreamOffset
for uint64(len(dh.entryStream)) > entryCurrentIndex {
entry := dh.entryStream[entryCurrentIndex]
if processEachEntryFn(entry) {
lastEntryName = entry.Name()
entryCurrentIndex++
} else {
// early terminated
return fuse.OK
}
}
}
var err error
if err = meta_cache.EnsureVisited(wfs.metaCache, wfs, dirPath); err != nil {
glog.Errorf("dir ReadDirAll %s: %v", dirPath, err)
return fuse.EIO
}
listErr := wfs.metaCache.ListDirectoryEntries(context.Background(), dirPath, lastEntryName, false, int64(math.MaxInt32), func(entry *filer.Entry) bool {
dh.entryStream = append(dh.entryStream, entry)
return processEachEntryFn(entry)
})
if listErr != nil {
glog.Errorf("list meta cache: %v", listErr)
return fuse.EIO
}
if !isEarlyTerminated {
dh.isFinished = true
}
return fuse.OK
}