restic/internal/fs/preallocate_linux.go

29 lines
624 B
Go

package fs
import (
"os"
"syscall"
"golang.org/x/sys/unix"
)
func PreallocateFile(wr *os.File, size int64) error {
if size <= 0 {
return nil
}
// int fallocate(int fd, int mode, off_t offset, off_t len)
// use mode = 0 to also change the file size
return ignoringEINTR(func() error { return unix.Fallocate(int(wr.Fd()), 0, 0, size) })
}
// ignoringEINTR makes a function call and repeats it if it returns
// an EINTR error.
// copied from /usr/lib/go/src/internal/poll/fd_posix.go of go 1.23.1
func ignoringEINTR(fn func() error) error {
for {
err := fn()
if err != syscall.EINTR {
return err
}
}
}