On Fri, Feb 25, 2022 at 08:40:36PM -0500, Theodore Ts'o wrote:
> Well, that makes it process_vm_writev()'s is that it needs to know
> when to call pin_user_file_pages().
Sorry, typed too fast. What I was trying to say is this make it
process_vm_writev()'s problem to figure out when it should call
On Fri, Feb 25, 2022 at 04:41:14PM -0800, John Hubbard wrote:
>
> > f2fs and btrfs's compressed file write support, by making things work
> > much like the write(2) system call. Imagine if we had a
> > "pin_user_pages_local()" which calls write_begin(), and a
> > "unpin_user_pages_local()" which
On Fri, Feb 25, 2022 at 01:33:33PM -0800, John Hubbard wrote:
> On 2/25/22 13:23, Theodore Ts'o wrote:
> > [un]pin_user_pages_remote is dirtying pages without properly warning
> > the file system in advance. This was noted by Jan Kara in 2018[1] and
>
> In 2018, [un]pin_user_pages_remote did not
[un]pin_user_pages_remote is dirtying pages without properly warning
the file system in advance. This was noted by Jan Kara in 2018[1] and
more recently has resulted in bug reports by Syzbot in various Android
kernels[2].
This is technically a bug in mm/gup.c, but arguably ext4 is fragile in
that
On Fri, Feb 25, 2022 at 12:51:28PM -0800, Eric Biggers wrote:
> >
> > [1] https://www.spinics.net/lists/linux-mm/msg142700.html
>
> Can you use a lore link
> (https://lore.kernel.org/linux-mm/20180103100430.ge4...@quack2.suse.cz/T/#u)?
Sure, thanks for finding the lore link! I did try searching
On Fri, Feb 25, 2022 at 02:24:35PM -0500, Theodore Ts'o wrote:
> [un]pin_user_pages_remote is dirtying pages without properly warning
> the file system in advance (or faulting in the file data if the page
> is not yet in the page cache). This was noted by Jan Kara in 2018[1]
> and more recently ha
[un]pin_user_pages_remote is dirtying pages without properly warning
the file system in advance (or faulting in the file data if the page
is not yet in the page cache). This was noted by Jan Kara in 2018[1]
and more recently has resulted in bug reports by Syzbot in various
Android kernels[2].
Thi
