Messages in this thread | | | Date | Wed, 7 Jan 2009 18:19:22 +0100 | From | Oleg Nesterov <> | Subject | Re: [RESEND][RFC PATCH v2] waitfd |
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On 01/07, Ingo Molnar wrote: > > (Cc:-ed a few more folks who might be interested in this) > > * Casey Dahlin <cdahlin@redhat.com> wrote: > > > +asmlinkage long sys_waitfd(int which, pid_t upid, int options, int unused) > > +{ > > + int ufd; > > + struct waitfd_ctx *ctx; > > + > > + /* Just to make sure we don't end up with a sys_waitfd4 */ > > + (void)unused; > > looks a bit silly ... > > > + > > + if (options & ~(WNOHANG|WEXITED|WSTOPPED|WCONTINUED)) > > + return -EINVAL; > > + if (!(options & (WEXITED|WSTOPPED|WCONTINUED))) > > + return -EINVAL; > > + > > + ctx = kmalloc(sizeof(*ctx), GFP_KERNEL); > > + if (!ctx) > > + return -ENOMEM; > > + > > + ctx->ops = options; > > + ctx->upid = upid; > > + ctx->which = which; > > + > > + ufd = anon_inode_getfd("[waitfd]", &waitfd_fops, ctx, > > + (options & WNOHANG) ? O_NONBLOCK : 0);
minor nit...
Please note that unlike other sys_...fd() syscalls, sys_waitfd() doesn't allow to pass O_CLOEXEC. Looks like we need a separate "flags" argument...
Also, ioctl(FIONBIO) or fcntl(O_NONBLOCK) have no effect on waitfd, not very good.
I'd suggest to remove WNOHANG from waitfd_ctx->ops and treat (->f_flags & O_NONBLOCK) as WNOHANG.
(can't resist, ->ops is not the best name ;)
Oleg.
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