Re: [PATCH v4 3/3] fs, xfs: introduce MAP_DIRECT for creating block-map-sealed file ranges

2017-08-17 Thread kbuild test robot
Hi Dan, [auto build test ERROR on linus/master] [also build test ERROR on v4.13-rc5 next-20170816] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system] url:

Re: [PATCH v4 3/3] fs, xfs: introduce MAP_DIRECT for creating block-map-sealed file ranges

2017-08-16 Thread Kirill A. Shutemov
On Tue, Aug 15, 2017 at 10:11:27AM -0700, Dan Williams wrote: > > We had issues before with user-imposed ETXTBSY. See MAP_DENYWRITE. > > > > Are we sure it won't a source of denial-of-service attacks? > > I believe MAP_DENYWRITE allowed any application with read access to be > able to deny writes

Re: [PATCH v4 3/3] fs, xfs: introduce MAP_DIRECT for creating block-map-sealed file ranges

2017-08-15 Thread Dan Williams
On Tue, Aug 15, 2017 at 9:29 AM, Dan Williams wrote: > On Tue, Aug 15, 2017 at 5:42 AM, Jan Kara wrote: >> On Mon 14-08-17 23:12:22, Dan Williams wrote: >>> diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h >>> index

Re: [PATCH v4 3/3] fs, xfs: introduce MAP_DIRECT for creating block-map-sealed file ranges

2017-08-15 Thread Dan Williams
On Tue, Aug 15, 2017 at 2:18 AM, Kirill A. Shutemov wrote: > On Mon, Aug 14, 2017 at 11:12:22PM -0700, Dan Williams wrote: >> MAP_DIRECT is an mmap(2) flag with the following semantics: >> >> MAP_DIRECT >> In addition to this mapping having MAP_SHARED semantics,

Re: [PATCH v4 3/3] fs, xfs: introduce MAP_DIRECT for creating block-map-sealed file ranges

2017-08-15 Thread Jan Kara
On Mon 14-08-17 23:12:22, Dan Williams wrote: > diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h > index ff151814a02d..73fdc0ada9ee 100644 > --- a/include/linux/mm_types.h > +++ b/include/linux/mm_types.h > @@ -306,6 +306,7 @@ struct vm_area_struct { > struct mm_struct

Re: [PATCH v4 3/3] fs, xfs: introduce MAP_DIRECT for creating block-map-sealed file ranges

2017-08-15 Thread Kirill A. Shutemov
On Mon, Aug 14, 2017 at 11:12:22PM -0700, Dan Williams wrote: > MAP_DIRECT is an mmap(2) flag with the following semantics: > > MAP_DIRECT > In addition to this mapping having MAP_SHARED semantics, successful > faults in this range may assume that the block map (logical-file-offset > to

[PATCH v4 3/3] fs, xfs: introduce MAP_DIRECT for creating block-map-sealed file ranges

2017-08-15 Thread Dan Williams
MAP_DIRECT is an mmap(2) flag with the following semantics: MAP_DIRECT In addition to this mapping having MAP_SHARED semantics, successful faults in this range may assume that the block map (logical-file-offset to physical memory address) is pinned for the lifetime of the mapping.