[Libvir] [PATCH] write(2) may write less than the total requested

[Daniel Veillard]

On Wed, Feb 20, 2008 at 02:53:49PM +0100, Jim Meyering wrote:
> Use safewrite in place of write, in many cases.
> And add "make syntax-check" rules to ensure no new uses sneak in.
> 
> There are many uses of write like this:
> 
>     if (write (fd, xml, towrite) != towrite)
>         return -1;
> 
> The problem is that the syscall can succeed, yet write less than
> the requested number of bytes, so the caller should retry
> rather than simply failing.

  agreed using safewrite is a good idea, +1

> This patch changes most of them to use util.c's safewrite wrapper,
> which encapsulates the process.  Also, there were a few cases in
> which the retry loop was open-coded, and I replaced those, too.

> However, there remain invalid uses of write in both virsh.c and
> console.c.  I would have replaced those, too, but util.c isn't
> linked with them, so it would have made this change more involved.
> xend_internal.c has one use, but it's ok, and not easily replaced.

  maybe for case outside of the library adding a copy of safewrite
in virsh.c would be a good way to do this while keeping the code
consistent. The duplication of that small function whould not
be a real problem IMHO

Daniel

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