Re: [PATCH 1/2] open: add close_range()

On Tue, May 21, 2019 at 10:23 PM Linus Torvalds wrote: > > On Tue, May 21, 2019 at 9:41 AM Christian Brauner > wrote: > > > > Yeah, you mentioned this before. I do like being able to specify an > > upper bound to have the ability to place fds strategically after said > > upper bound. > > I

Re: [PATCH 1/2] open: add close_range()

On Tue, May 21, 2019 at 9:41 AM Christian Brauner wrote: > > Yeah, you mentioned this before. I do like being able to specify an > upper bound to have the ability to place fds strategically after said > upper bound. I suspect that's the case. And if somebody really wants to just close

Re: [PATCH 1/2] open: add close_range()

On Tue, May 21, 2019 at 08:20:09PM +0100, Al Viro wrote: > On Tue, May 21, 2019 at 05:30:27PM +0100, David Howells wrote: > > > If we can live with close_from(int first) rather than close_range(), then > > this > > can perhaps be done a lot more efficiently by: > > > > new =

Re: [PATCH 1/2] open: add close_range()

On Tue, May 21, 2019 at 04:00:06PM +0100, Al Viro wrote: > On Tue, May 21, 2019 at 01:34:47PM +0200, Christian Brauner wrote: > > > This adds the close_range() syscall. It allows to efficiently close a range > > of file descriptors up to all file descriptors of a calling task. > > > > The

Re: [PATCH 1/2] open: add close_range()

On Tue, May 21, 2019 at 05:30:27PM +0100, David Howells wrote: > Al Viro wrote: > > > Umm... That's going to be very painful if you dup2() something to MAX_INT > > and > > then run that; roughly 2G iterations of bouncing ->file_lock up and down, > > without anything that would yield CPU in

Re: [PATCH 1/2] open: add close_range()

Al Viro wrote: > Umm... That's going to be very painful if you dup2() something to MAX_INT and > then run that; roughly 2G iterations of bouncing ->file_lock up and down, > without anything that would yield CPU in process. > > If anything, I would suggest something like > > fd =

Re: [PATCH 1/2] open: add close_range()

On Tue, May 21, 2019 at 01:34:47PM +0200, Christian Brauner wrote: > This adds the close_range() syscall. It allows to efficiently close a range > of file descriptors up to all file descriptors of a calling task. > > The syscall came up in a recent discussion around the new mount API and >

Re: [PATCH 1/2] open: add close_range()

On Tue, May 21, 2019 at 03:10:11PM +0200, Florian Weimer wrote: > * Christian Brauner: > > >> Solaris has an fdwalk function: > >> > >> > >> > >> So a different way to implement this would expose a nextfd system call > > > >

Re: [PATCH 1/2] open: add close_range()

On Tue, May 21, 2019 at 03:10:11PM +0200, Florian Weimer wrote: > * Christian Brauner: > > >> Solaris has an fdwalk function: > >> > >> > >> > >> So a different way to implement this would expose a nextfd system call > > > >

Re: [PATCH 1/2] open: add close_range()

* Christian Brauner: >> Solaris has an fdwalk function: >> >> >> >> So a different way to implement this would expose a nextfd system call > > Meh. If nextfd() then I would like it to be able to: > - get the nextfd(fd) >= fd

Re: [PATCH 1/2] open: add close_range()

On Tue, May 21, 2019 at 02:09:29PM +0200, Florian Weimer wrote: > * Christian Brauner: > > > +/** > > + * __close_range() - Close all file descriptors in a given range. > > + * > > + * @fd: starting file descriptor to close > > + * @max_fd: last file descriptor to close > > + * > > + * This

Re: [PATCH 1/2] open: add close_range()

* Christian Brauner: > +/** > + * __close_range() - Close all file descriptors in a given range. > + * > + * @fd: starting file descriptor to close > + * @max_fd: last file descriptor to close > + * > + * This closes a range of file descriptors. All file descriptors > + * from @fd up to and