[PATCH 2/2] dosfs: Lazy update of FAT32 FS info sector

Chris Johns chrisj at rtems.org
Thu Nov 8 22:03:06 UTC 2012

Sebastian Huber wrote:
> On 08/11/12 22:14, Chris Johns wrote:
>> Sebastian Huber wrote:
>>> Update the free cluster count and next free culster in the FAT32 FS info
>>> sector only during unmount and only if the values have changed since
>>> mount time. This avoids writes to the FS info sector and conforms to
>>> the behaviour of Linux and Windows.
>> This changes the default behavior and in this case I do not think that
>> is a good idea. Users may not know this is happening or what it means.
>> As Claus points out often there is no shutdown procedure just power off.
> We can add this update also to the sync operation.

Yes this is a good idea.

> The current code
> writes invalid values into the variables, so actually this change makes
> nothing worse here.

Hah. That needs to be fixed.

>> What about adding a mount option to turn this feature on, ie default
>> is off ?
> The free cluster count and next free cluster value in the FAT32 info
> sector are only hints.

Ah ok I missed this is just about the counts. Yes they may not be valid.


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