On 01/20/2018 08:11 PM, Andi Kleen wrote: > Goldwyn Rodrigues <rgoldwyn@xxxxxxx> writes: > >> From: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx> >> >> In case direct I/O encounters an error midway, it returns the error. >> Instead it should be returning the number of bytes transferred so far. > > It's likely there's a lot of code in user space that does > > if (write(..., N) < 0) handle error > > With your change it would need to be > > if (write(..., N) != N) handle error > > How much code is actually doing that? > > I can understand it fixes your artifical test suite, but it seems to me your > change has a high potential to break a lot of existing user code > in subtle ways. So it seems to be a bad idea. > > -Andi > Quoting 'man 2 write': RETURN VALUE On success, the number of bytes written is returned (zero indicates nothing was written). It is not an error if this number is smaller than the number of bytes requested; this may happen for example because the disk device was filled. See also NOTES. -- Goldwyn
