Re: [PATCH v2 23/35] ovl: copy-up on MAP_SHARED

2018-05-08 Thread Miklos Szeredi
On Mon, May 7, 2018 at 9:28 PM, Randy Dunlap wrote: > On 05/07/2018 01:37 AM, Miklos Szeredi wrote: >> A corner case of a corner case is when >> >> - file opened for O_RDONLY >> - which is then memory mapped SHARED >> - file opened for O_WRONLY >> - contents modified >> - contents read back t

Re: [PATCH v2 23/35] ovl: copy-up on MAP_SHARED

2018-05-07 Thread Randy Dunlap
On 05/07/2018 01:37 AM, Miklos Szeredi wrote: > A corner case of a corner case is when > > - file opened for O_RDONLY > - which is then memory mapped SHARED > - file opened for O_WRONLY > - contents modified > - contents read back though the shared mapping > > Unfortunately it looks very dif

[PATCH v2 23/35] ovl: copy-up on MAP_SHARED

2018-05-07 Thread Miklos Szeredi
A corner case of a corner case is when - file opened for O_RDONLY - which is then memory mapped SHARED - file opened for O_WRONLY - contents modified - contents read back though the shared mapping Unfortunately it looks very difficult to do anything about the established shared map after the