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* Re: [BusyBox] [Fwd: Loopback device setup?]
       [not found] ` <40315E31.90201@san.rr.com>
@ 2004-02-17  8:22   ` vda
  2004-02-17 17:00     ` Hugh Dickins
  0 siblings, 1 reply; 3+ messages in thread
From: vda @ 2004-02-17  8:22 UTC (permalink / raw)
  To: Tom Guilliams, DHollenbeck; +Cc: busybox, linux-kernel

On Tuesday 17 February 2004 02:20, Tom Guilliams wrote:
> in /driver/block/loop.c -
>
> loop_set_fd()
>
> 		/*
>                   * If we can't read - sorry. If we only can't write -
>                  		 * well, it's going to be read-only.
>                   */
>                  if (!aops->readpage)
>                          goto out_putf;
>
> I confirmed the "if (!aops->readpage)" is true.  I'm not sure what the
> readpage routine is trying to do (which dev or file) in my command below -
> # mount -t ext2 -o loop ramdisk.image rootfs
>
> Anyone have any thoughts??  This is all being done in the /tmp
> dircectory which is mounted as "tmpfs".  Not sure if that has anything
> to do with it.

I recall that tmpfs cannot do readpage (by design?).
CCing LKML, maybe someone will pour in more info.
-- 
vda

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [BusyBox] [Fwd: Loopback device setup?]
  2004-02-17  8:22   ` [BusyBox] [Fwd: Loopback device setup?] vda
@ 2004-02-17 17:00     ` Hugh Dickins
  2004-02-17 22:41       ` Tom Guilliams
  0 siblings, 1 reply; 3+ messages in thread
From: Hugh Dickins @ 2004-02-17 17:00 UTC (permalink / raw)
  To: vda; +Cc: Tom Guilliams, DHollenbeck, busybox, linux-kernel

On Tue, 17 Feb 2004, vda wrote:
> On Tuesday 17 February 2004 02:20, Tom Guilliams wrote:
> > in /driver/block/loop.c -
> >
> > loop_set_fd()
> >
> > 		/*
> >                   * If we can't read - sorry. If we only can't write -
> >                  		 * well, it's going to be read-only.
> >                   */
> >                  if (!aops->readpage)
> >                          goto out_putf;
> >
> > I confirmed the "if (!aops->readpage)" is true.  I'm not sure what the
> > readpage routine is trying to do (which dev or file) in my command below -
> > # mount -t ext2 -o loop ramdisk.image rootfs
> >
> > Anyone have any thoughts??  This is all being done in the /tmp
> > dircectory which is mounted as "tmpfs".  Not sure if that has anything
> > to do with it.
> 
> I recall that tmpfs cannot do readpage (by design?).
> CCing LKML, maybe someone will pour in more info.

readpage is not straightforward for tmpfs, so it took a long time
to be added, but tmpfs has supported loop since 2.4.22 and 2.5.45.

Hugh


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [BusyBox] [Fwd: Loopback device setup?]
  2004-02-17 17:00     ` Hugh Dickins
@ 2004-02-17 22:41       ` Tom Guilliams
  0 siblings, 0 replies; 3+ messages in thread
From: Tom Guilliams @ 2004-02-17 22:41 UTC (permalink / raw)
  To: Hugh Dickins; +Cc: vda, DHollenbeck, busybox, linux-kernel

Thanks to all who responded.  I have a 2.4.20 kernel so mounting on the 
tmpfs is not supported.  I have found an alternative by using the ram 
device nodes for storage.

Thanks again,

Tom

Hugh Dickins wrote:
> On Tue, 17 Feb 2004, vda wrote:
> 
>>On Tuesday 17 February 2004 02:20, Tom Guilliams wrote:
>>
>>>in /driver/block/loop.c -
>>>
>>>loop_set_fd()
>>>
>>>		/*
>>>                  * If we can't read - sorry. If we only can't write -
>>>                 		 * well, it's going to be read-only.
>>>                  */
>>>                 if (!aops->readpage)
>>>                         goto out_putf;
>>>
>>>I confirmed the "if (!aops->readpage)" is true.  I'm not sure what the
>>>readpage routine is trying to do (which dev or file) in my command below -
>>># mount -t ext2 -o loop ramdisk.image rootfs
>>>
>>>Anyone have any thoughts??  This is all being done in the /tmp
>>>dircectory which is mounted as "tmpfs".  Not sure if that has anything
>>>to do with it.
>>
>>I recall that tmpfs cannot do readpage (by design?).
>>CCing LKML, maybe someone will pour in more info.
> 
> 
> readpage is not straightforward for tmpfs, so it took a long time
> to be added, but tmpfs has supported loop since 2.4.22 and 2.5.45.
> 
> Hugh
> 
> 

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2004-02-17 22:42 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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     [not found] ` <40315E31.90201@san.rr.com>
2004-02-17  8:22   ` [BusyBox] [Fwd: Loopback device setup?] vda
2004-02-17 17:00     ` Hugh Dickins
2004-02-17 22:41       ` Tom Guilliams

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