Re: o_sync in vfat driver

[Andrew Morton]

col-pepper@xxxxxxxxxxx wrote:
>
> There is nothing in the spec of vfat that suggests the FAT will be written
> 10.000 during the writing of one large file. Indeed it is hard to imagine
> that any other implementation on any other OS or any previous linux kernel
> behaves like that.

We sync the file metadata once per write() syscall.  If your app writes a
large file in lots of little bits, it'll do a lot of syncs.  Other
implementations of fatfs will (must) do the same thing.

> It would seem that the first step could be to revert to the 2.6.11
> behaviour which was more appropriate and probably safer even from the data
> point of view.

fatfs used to be buggy - it didn't implement `-o sync'.  Now it does, and
what we're seeing is the fallout from the late fixing of that bug.

You're right - people need to understand what they're doing, make their own
decision, then remove the `-o sync' option.  There aren't any easy
solutions.

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