lkml.org 
[lkml]   [2007]   [May]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    SubjectRe: bug in 2.6.22-rc2: loop mount limited to one single iso image
    Date
    Am Sonntag, 20. Mai 2007 18:16 schrieben Sie:
    > On Sun, 2007-05-20 at 09:10 -0700, Ray Lee wrote:
    > > On 5/20/07, Kay Sievers <kay.sievers@vrfy.org> wrote:
    > > > On 5/20/07, Ray Lee <ray-lk@madrabbit.org> wrote:
    > > > > On 5/19/07, Al Viro <viro@ftp.linux.org.uk> wrote:
    > > > > > On Sat, May 19, 2007 at 11:16:59PM -0700, Ray Lee wrote:
    > > > > > > Ken? Ball's in your court. As the patch isn't providing a killer
    > > > > > > feature for 2.6.22, I'd suggest just reverting it for now until
    > > > > > > the issues are ironed out.
    > > > > >
    > > > > > Hold it. The real question here is which logics do we want there.
    > > > > > IOW, and how many device nodes do we want to appear and _when_ do
    > > > > > we want them to appear?
    > > > >
    > > > > The when part is what looks to make it racy. I'm guessing that we're
    > > > > relying on udev to create those loop nodes. If so, I think any scheme
    > > > > that creates more on demand would give transient mount errors while
    > > > > it's waiting on udev to create more nodes.
    > > > >
    > > > > Perhaps if we were to start with 8 loop nodes at init (as we have in
    > > > > 2.6.21), and then always maintain a margin of 8 (or 4, or...) when
    > > > > they start being used or detached?
    > > >
    > > > Until the tools can request dynamic loop device allocation from the
    > > > kernel before they want to use the device, you can create as many as
    > > > needed "static" loop* nodes in /lib/udev/devices/, which will be
    > > > copied to /dev/ early on every bootup.
    > >
    > > Except that's different than current behavior presented to userspace.
    > > IOW, we broke userspace for anyone using udev. Which is, y'know, a lot
    > > of us.
    > >
    > > We're at -rc2 right now. Given that, it looks like we have two
    > > options. First is to revert all this for now and try again when the
    > > patch has had more testing and agreement (as this isn't a major
    > > feature we're talking about here; it's effectively just a cleanup that
    > > happened to have unfortunate side-effects).
    > >
    > > The second option is that we could have the loop device start with 8
    > > nodes populated, which would match current behavior.
    > >
    > > A third option of requiring new userspace for 2.6.22 is a non-starter.
    >
    > Right, providing "preallocated" devices, 8 or the number given in
    > max_loop, sounds like the best option until the tools can handle that.
    >
    > Thanks,
    > Kay

    OK people, this is what I did just to resolve the issue for now:

    1. copied loop.c from 2.6.21 into the 2.6.22-rc2 tree
    2. changed exactly two entries from "invalidate_bdev(bdev, 0)"

    to "invalidate_bdev(bdev)"

    Output is:
    a. a compilable kernel
    b. all four iso images are mounted as expected

    Andrey's path however (i. e. copying his attached version of loop.c into the
    2.6.22-rc2 kernel tree) led to:

    a. an incompilable kernel
    b. endless messages trying to compile loop.c going like this (just a part of
    them - not complete anyway!):

    drivers/block/loop.c:1350: error: stray '\240' in program
    drivers/block/loop.c:1350: error: stray '\240' in program
    drivers/block/loop.c:1350: error: stray '\240' in program
    drivers/block/loop.c:1350: error: stray '\240' in program
    drivers/block/loop.c:1351: error: stray '\240' in program
    drivers/block/loop.c:1351: error: stray '\240' in program
    drivers/block/loop.c:1351: error: stray '\240' in program
    drivers/block/loop.c:1351: error: stray '\240' in program
    drivers/block/loop.c:1351: error: stray '\240' in program
    drivers/block/loop.c:1351: error: stray '\240' in program
    drivers/block/loop.c:1351: error: stray '\240' in program
    drivers/block/loop.c:1351: error: stray '\240' in program
    drivers/block/loop.c:1351: error: stray '\240' in program
    drivers/block/loop.c:1351: error: stray '\240' in program
    drivers/block/loop.c:1351: error: stray '\240' in program
    drivers/block/loop.c:1351: error: stray '\240' in program
    drivers/block/loop.c:1351: error: stray '\240' in program
    drivers/block/loop.c:1351: error: stray '\240' in program
    drivers/block/loop.c:1351: error: stray '\240' in program
    drivers/block/loop.c:1351: error: stray '\240' in program
    drivers/block/loop.c: In function 'loop_register_transfer':
    drivers/block/loop.c:1367: error: stray '\240' in program
    drivers/block/loop.c:1367: error: stray '\240' in program
    drivers/block/loop.c:1367: error: stray '\240' in program
    drivers/block/loop.c:1367: error: stray '\240' in program
    drivers/block/loop.c:1367: error: stray '\240' in program
    drivers/block/loop.c:1367: error: stray '\240' in program
    drivers/block/loop.c:1367: error: stray '\240' in program
    drivers/block/loop.c:1367: error: stray '\240' in program

    Thanks to Ray! Well done!

    Best regards

    Uwe

    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2007-05-20 18:37    [W:0.026 / U:60.856 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site