Re: udev and friends not able to mount Atari GEMDOS partition
Le 26/10/2020 à 11:44, Geert Uytterhoeven a écrit :
> Hi Emmanuel,
>
> CC Michael
>
> On Mon, Oct 26, 2020 at 11:28 AM Emmanuel Kasper <manu@debian.org> wrote:
>>> Note that we still have a few out-of-tree kernel patches for Atari FAT
>>> support as well, cfr. the top 3 commits of
>>> https://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k.git/log/?h=m68k-queue
>>>
>>> Needs some love from a knowledgeable person to send this upstream...
>>>
>>> Gr{oetje,eeting}s,
>>
>>
>> Hi Geert !
>> I had a look at the patches as I was dabbling in GEMDOS FAT handling
>> these days, and I have to say I don't understand the purpose of the
>> commit you mentioned:
>>
>> fat: Atari FAT updates
>> Add support for the Atari-variant of the FAT filesystem
>> https://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k.git/commit/?h=m68k-queue&id=501bd95410f8347ed80bff873498db7a1b044457
>>
>> to the best of my knowledge, Linux was always able to mount Atari FAT
>> partitions, as long as the logical sector size of the FAT was up to 4096
>> bytes, this limit itself coming from
>> https://github.com/gregkh/linux/blame/071a0578b0ce0b0e543d1e38ee6926b9cc21c198/fs/fat/inode.c#L1508
>>
>> what problem is being fixed, or new feature added with the patch ?
>> or am I missing something ?
>
> TBH, I don't know. This patch came from the old Linux/m68k CVS.
> If anyone feels it can be dropped, I can do so.
> If anyone feels it is needed, please submit it upstream.
I had a second look at the code and the patch seems to try to improve
the detection of FAT12 filesystems.
However those are properly detected by the kernel anyway, (5.8.0 here)
sudo mkfs.fat -F 12 /dev/mmcblk0p4
sudo disktype /dev/mmcblk0p4
--- /dev/mmcblk0p4
Block device, size 12 MiB (12582912 bytes)
FAT12 file system (hints score 4 of 5)
Volume size 11.96 MiB (12546048 bytes, 3063 clusters of 4 KiB)
sudo mount /dev/mmcblk0p4 /mnt
-> works
The same partition formatted with GEMDOS is also properly correctly
detected by the kernel and mounted.
A FAT 12 MS DOS floppy is also correctly mounted via mount without
specifying the fat type.
IMHO the patch is not needed anymore, or is covering a use case I don't see.
Emmanuel
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