mirror of
https://github.com/seaweedfs/seaweedfs.git
synced 2024-01-19 02:48:24 +00:00
3a75d7f7aa
See the man page of copy_file_range: https://man7.org/linux/man-pages/man2/copy_file_range.2.html
65 lines
1.6 KiB
Go
65 lines
1.6 KiB
Go
package mount
|
|
|
|
import (
|
|
"io"
|
|
|
|
"github.com/hanwen/go-fuse/v2/fuse"
|
|
|
|
"github.com/seaweedfs/seaweedfs/weed/glog"
|
|
)
|
|
|
|
/**
|
|
* Read data
|
|
*
|
|
* Read should send exactly the number of bytes requested except
|
|
* on EOF or error, otherwise the rest of the data will be
|
|
* substituted with zeroes. An exception to this is when the file
|
|
* has been opened in 'direct_io' mode, in which case the return
|
|
* value of the read system call will reflect the return value of
|
|
* this operation.
|
|
*
|
|
* fi->fh will contain the value set by the open method, or will
|
|
* be undefined if the open method didn't set any value.
|
|
*
|
|
* Valid replies:
|
|
* fuse_reply_buf
|
|
* fuse_reply_iov
|
|
* fuse_reply_data
|
|
* fuse_reply_err
|
|
*
|
|
* @param req request handle
|
|
* @param ino the inode number
|
|
* @param size number of bytes to read
|
|
* @param off offset to read from
|
|
* @param fi file information
|
|
*/
|
|
func (wfs *WFS) Read(cancel <-chan struct{}, in *fuse.ReadIn, buff []byte) (fuse.ReadResult, fuse.Status) {
|
|
fh := wfs.GetHandle(FileHandleId(in.Fh))
|
|
if fh == nil {
|
|
return nil, fuse.ENOENT
|
|
}
|
|
|
|
fh.entryLock.Lock()
|
|
defer fh.entryLock.Unlock()
|
|
|
|
offset := int64(in.Offset)
|
|
fh.lockForRead(offset, len(buff))
|
|
defer fh.unlockForRead(offset, len(buff))
|
|
|
|
totalRead, err := fh.readFromChunks(buff, offset)
|
|
if err == nil || err == io.EOF {
|
|
maxStop := fh.readFromDirtyPages(buff, offset)
|
|
totalRead = max(maxStop-offset, totalRead)
|
|
}
|
|
if err == io.EOF {
|
|
err = nil
|
|
}
|
|
|
|
if err != nil {
|
|
glog.Warningf("file handle read %s %d: %v", fh.FullPath(), totalRead, err)
|
|
return nil, fuse.EIO
|
|
}
|
|
|
|
return fuse.ReadResultData(buff[:totalRead]), fuse.OK
|
|
}
|