On Mon, Dec 03, 2018 at 08:20:30AM -0800, Darrick J. Wong wrote:
> On Mon, Dec 03, 2018 at 07:53:42AM +1100, Dave Chinner wrote:
> > From: Dave Chinner <dchinner@xxxxxxxxxx>
> >
> > So that O_RDONLY open commands (such as from copy_range) do not
> > block forever waiting on a non-existent writer.
> >
> > Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
> > ---
> > io/open.c | 13 +++++++++++++
> > 1 file changed, 13 insertions(+)
> >
> > diff --git a/io/open.c b/io/open.c
> > index 6ea3e9a2019f..b1d9a0fa317c 100644
> > --- a/io/open.c
> > +++ b/io/open.c
> > @@ -56,6 +56,7 @@ openfile(
> > struct fs_path *fs_path)
> > {
> > struct fs_path *fsp;
> > + struct stat st;
> > int fd;
> > int oflags;
> >
> > @@ -79,6 +80,18 @@ openfile(
> > if (flags & IO_NOFOLLOW)
> > oflags |= O_NOFOLLOW;
> >
> > + /*
> > + * if we've been passed a pipe to open, don't block waiting for a
> > + * reader or writer to appear. We want to either succeed or error out
> > + * immediately.
> > + */
> > + if (stat(path, &st) < 0 && errno != ENOENT) {
> > + perror("stat");
> > + return -1;
> > + }
> > + if (S_ISFIFO(st.st_mode))
>
> Hmm... does stat() set st.st_mode even if it returns ENOENT? Or are we
> possibly branching on an uninitialized st here?
>
> struct stat st = { 0 }; ?
Yeah, I'll fix that.
Cheers,
Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
