Re: [BUG] mm: direct I/O (using GUP) can write to COW anonymous pages

2018-09-25 Thread John Hubbard
On 9/18/18 2:58 AM, Jan Kara wrote: > On Tue 18-09-18 02:35:43, Jann Horn wrote: >> On Tue, Sep 18, 2018 at 2:05 AM Hugh Dickins wrote: > > Thanks for CC Hugh. > >>> On Mon, 17 Sep 2018, Jann Horn wrote: >>> >> >> Makes sense, I guess. >> >> I wonder whether there's a concise way to express

Re: [BUG] mm: direct I/O (using GUP) can write to COW anonymous pages

2018-09-25 Thread John Hubbard
On 9/18/18 2:58 AM, Jan Kara wrote: > On Tue 18-09-18 02:35:43, Jann Horn wrote: >> On Tue, Sep 18, 2018 at 2:05 AM Hugh Dickins wrote: > > Thanks for CC Hugh. > >>> On Mon, 17 Sep 2018, Jann Horn wrote: >>> >> >> Makes sense, I guess. >> >> I wonder whether there's a concise way to express

Re: [BUG] mm: direct I/O (using GUP) can write to COW anonymous pages

2018-09-18 Thread Jan Kara
On Tue 18-09-18 02:35:43, Jann Horn wrote: > On Tue, Sep 18, 2018 at 2:05 AM Hugh Dickins wrote: Thanks for CC Hugh. > > On Mon, 17 Sep 2018, Jann Horn wrote: > > > > > [I'm not sure who the best people to ask about this are, I hope the > > > recipient list resembles something reasonable...] >

Re: [BUG] mm: direct I/O (using GUP) can write to COW anonymous pages

2018-09-18 Thread Jan Kara
On Tue 18-09-18 02:35:43, Jann Horn wrote: > On Tue, Sep 18, 2018 at 2:05 AM Hugh Dickins wrote: Thanks for CC Hugh. > > On Mon, 17 Sep 2018, Jann Horn wrote: > > > > > [I'm not sure who the best people to ask about this are, I hope the > > > recipient list resembles something reasonable...] >

Re: [BUG] mm: direct I/O (using GUP) can write to COW anonymous pages

2018-09-18 Thread Konstantin Khlebnikov
On 18.09.2018 03:35, Jann Horn wrote: On Tue, Sep 18, 2018 at 2:05 AM Hugh Dickins wrote: Hi Jann, On Mon, 17 Sep 2018, Jann Horn wrote: [I'm not sure who the best people to ask about this are, I hope the recipient list resembles something reasonable...] I have noticed that the dup_mmap()

Re: [BUG] mm: direct I/O (using GUP) can write to COW anonymous pages

2018-09-18 Thread Konstantin Khlebnikov
On 18.09.2018 03:35, Jann Horn wrote: On Tue, Sep 18, 2018 at 2:05 AM Hugh Dickins wrote: Hi Jann, On Mon, 17 Sep 2018, Jann Horn wrote: [I'm not sure who the best people to ask about this are, I hope the recipient list resembles something reasonable...] I have noticed that the dup_mmap()

Re: [BUG] mm: direct I/O (using GUP) can write to COW anonymous pages

2018-09-17 Thread Jann Horn
On Tue, Sep 18, 2018 at 2:05 AM Hugh Dickins wrote: > > Hi Jann, > > On Mon, 17 Sep 2018, Jann Horn wrote: > > > [I'm not sure who the best people to ask about this are, I hope the > > recipient list resembles something reasonable...] > > > > I have noticed that the dup_mmap() logic on fork()

Re: [BUG] mm: direct I/O (using GUP) can write to COW anonymous pages

2018-09-17 Thread Jann Horn
On Tue, Sep 18, 2018 at 2:05 AM Hugh Dickins wrote: > > Hi Jann, > > On Mon, 17 Sep 2018, Jann Horn wrote: > > > [I'm not sure who the best people to ask about this are, I hope the > > recipient list resembles something reasonable...] > > > > I have noticed that the dup_mmap() logic on fork()

Re: [BUG] mm: direct I/O (using GUP) can write to COW anonymous pages

2018-09-17 Thread Salman Qazi
On Mon, Sep 17, 2018 at 5:05 PM Hugh Dickins wrote: > > Hi Jann, > > On Mon, 17 Sep 2018, Jann Horn wrote: > > > [I'm not sure who the best people to ask about this are, I hope the > > recipient list resembles something reasonable...] > > > > I have noticed that the dup_mmap() logic on fork()

Re: [BUG] mm: direct I/O (using GUP) can write to COW anonymous pages

2018-09-17 Thread Salman Qazi
On Mon, Sep 17, 2018 at 5:05 PM Hugh Dickins wrote: > > Hi Jann, > > On Mon, 17 Sep 2018, Jann Horn wrote: > > > [I'm not sure who the best people to ask about this are, I hope the > > recipient list resembles something reasonable...] > > > > I have noticed that the dup_mmap() logic on fork()

Re: [BUG] mm: direct I/O (using GUP) can write to COW anonymous pages

2018-09-17 Thread Hugh Dickins
Hi Jann, On Mon, 17 Sep 2018, Jann Horn wrote: > [I'm not sure who the best people to ask about this are, I hope the > recipient list resembles something reasonable...] > > I have noticed that the dup_mmap() logic on fork() doesn't handle > pages with active direct I/O properly: dup_mmap()

Re: [BUG] mm: direct I/O (using GUP) can write to COW anonymous pages

2018-09-17 Thread Hugh Dickins
Hi Jann, On Mon, 17 Sep 2018, Jann Horn wrote: > [I'm not sure who the best people to ask about this are, I hope the > recipient list resembles something reasonable...] > > I have noticed that the dup_mmap() logic on fork() doesn't handle > pages with active direct I/O properly: dup_mmap()