Messages in this thread |  | | Date | Fri, 5 Jan 2001 00:02:43 +0100 | From | Andi Kleen <> | Subject | Re: generic_file_write code segment in 2.2.18 |
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On Thu, Jan 04, 2001 at 02:58:58PM -0800, Asang K Dani wrote: > --- Andi Kleen <ak@suse.de> wrote: > > On Thu, Jan 04, 2001 at 10:42:34PM +0000, Stephen C. Tweedie wrote: > > > No, because then you'd be skipping the updatepage() call if we > > took a > > > fault mid-copy after copying some data. That would imply you had > > > dirtied the page cache without an updatepage(). > > > > > > The current behaviour should just result in a short IO, which > > should > > > be fine. > > > > The problem is that the short write is not reported to the caller, > > even when only zero bytes are copied (the page is corrupted anyways > > though because cfu zeros the uncopied rest). > > I think it will be reported to caller, because when cfu copies 0 > bytes, > > bytes -= copy_from_user(dest, buf, bytes); > > will make 'bytes' zero. Since 'bytes' is 'zero' updatepage will not > be called and status retains value '-EFAULT' and it breaks out of > the while loop immediately.
Right for zero it is handled, but not for 1 byte copied but the rest zeroed (which is a severe IO error)
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