Re: [BusyBox] [Fwd: Loopback device setup?]

[Tom Guilliams <tguilliams@san.rr.com>]

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
> 
>