72 lines
1.5 KiB
Go
72 lines
1.5 KiB
Go
//go:build linux
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package file
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import (
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"os"
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"sync"
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"sync/atomic"
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"syscall"
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"github.com/rclone/rclone/fs"
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"golang.org/x/sys/unix"
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)
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var (
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fallocFlags = [...]uint32{
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unix.FALLOC_FL_KEEP_SIZE, // Default
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unix.FALLOC_FL_KEEP_SIZE | unix.FALLOC_FL_PUNCH_HOLE, // for ZFS #3066
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}
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fallocFlagsIndex atomic.Int32
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preAllocateMu sync.Mutex
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)
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// PreallocateImplemented is a constant indicating whether the
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// implementation of Preallocate actually does anything.
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const PreallocateImplemented = true
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// PreAllocate the file for performance reasons
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func PreAllocate(size int64, out *os.File) (err error) {
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if size <= 0 {
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return nil
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}
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preAllocateMu.Lock()
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defer preAllocateMu.Unlock()
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for {
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index := fallocFlagsIndex.Load()
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again:
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if index >= int32(len(fallocFlags)) {
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return nil // Fallocate is disabled
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}
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flags := fallocFlags[index]
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err = unix.Fallocate(int(out.Fd()), flags, 0, size)
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if err == unix.ENOTSUP {
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// Try the next flags combination
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index++
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fallocFlagsIndex.Store(index)
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fs.Debugf(nil, "preAllocate: got error on fallocate, trying combination %d/%d: %v", index, len(fallocFlags), err)
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goto again
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}
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// Wrap important errors
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if err == unix.ENOSPC {
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return ErrDiskFull
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}
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if err != syscall.EINTR {
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break
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}
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}
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return err
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}
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// SetSparseImplemented is a constant indicating whether the
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// implementation of SetSparse actually does anything.
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const SetSparseImplemented = false
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// SetSparse makes the file be a sparse file
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func SetSparse(out *os.File) error {
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return nil
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}
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