lkml.org 
[lkml]   [2018]   [Dec]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [Qemu-devel] d_off field in struct dirent and 32-on-64 emulation
    On Sat, Dec 29, 2018 at 03:37:21AM +0100, Dominique Martinet wrote:
    > > Are there going to be cases where a process or a thread will sometimes
    > > want the 64-bit interface, and sometimes want the 32-bit interface?
    > > Or is it always going to be one or the other? I wonder if we could
    > > simply add a new flag to the process personality(2) flags.
    >
    > That would likely work for qemu user, but the qemu system+9p case is
    > going to be more painful..
    > More precisely, the 9p protocol does not plan for anything other than
    > 64bit offset so if the vfs needs to hand out a 32bit offset we'll need
    > to make a correspondance table between the 32bit offsets we hand off and
    > the 64bit ones to use; unless some flag can be passed at lopen to tell
    > the server to always hand out 32bit offsets for this directory... And if
    > we do that then 9p servers will need a way to use both APIs in parallel
    > for both types of directories.

    How about if we add a fcntl(2) mediated flag, which is tied to a
    struct file? Would that be more or less painful for 9p and qemu
    system+9p?

    - Ted

    \
     
     \ /
      Last update: 2018-12-29 05:19    [W:4.858 / U:0.024 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site