Re: [PATCH v2] hibernate: Allow uswsusp to write to swap

[Domenico Andreoli <domenico.andreoli@linux.com>]

On Sun, Mar 22, 2020 at 08:14:21AM +0100, Rafael J. Wysocki wrote:
> On Wednesday, March 4, 2020 6:06:46 PM CET Domenico Andreoli wrote:
> > From: Domenico Andreoli <domenico.andreoli@linux.com>
> > 
> > It turns out that there is one use case for programs being able to
> > write to swap devices, and that is the userspace hibernation code.
> > 
> > Quick fix: disable the S_SWAPFILE check if hibernation is configured.
> > 
> > Fixes: dc617f29dbe5 ("vfs: don't allow writes to swap files")
> > Reported-by: Domenico Andreoli <domenico.andreoli@linux.com>
> > Reported-by: Marian Klein <mkleinsoft@gmail.com>
> > Signed-off-by: Domenico Andreoli <domenico.andreoli@linux.com>
> > 
> > v2:
> >  - use hibernation_available() instead of IS_ENABLED(CONFIG_HIBERNATE)
> >  - make Fixes: point to the right commit
> 
> This looks OK to me.
> 
> Has it been taken care of already, or am I expected to apply it?

I don't know who is supposed to take it, I did not receive any notification.

> 
> > ---
> >  fs/block_dev.c |    4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> > 
> > Index: b/fs/block_dev.c
> > ===================================================================
> > --- a/fs/block_dev.c
> > +++ b/fs/block_dev.c
> > @@ -34,6 +34,7 @@
> >  #include <linux/task_io_accounting_ops.h>
> >  #include <linux/falloc.h>
> >  #include <linux/uaccess.h>
> > +#include <linux/suspend.h>
> >  #include "internal.h"
> >  
> >  struct bdev_inode {
> > @@ -2001,7 +2002,8 @@ ssize_t blkdev_write_iter(struct kiocb *
> >  	if (bdev_read_only(I_BDEV(bd_inode)))
> >  		return -EPERM;
> >  
> > -	if (IS_SWAPFILE(bd_inode))
> > +	/* uswsusp needs write permission to the swap */
> > +	if (IS_SWAPFILE(bd_inode) && !hibernation_available())
> >  		return -ETXTBSY;
> >  
> >  	if (!iov_iter_count(from))
> > 
> 
> 
> 
> 

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