Messages in this thread | | | Subject | Re: [PATCH] let fat handle MS_SYNCHRONOUS flag | From | OGAWA Hirofumi <> | Date | Wed, 24 Nov 2004 14:00:54 +0900 |
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Matt Mackall <mpm@selenic.com> writes:
> On Wed, Nov 24, 2004 at 05:24:36AM +0900, OGAWA Hirofumi wrote: >> Colin Leroy <colin@colino.net> writes: >> >> > It adds MS_SYNCHRONOUS support to FAT filesystem, so that less >> > filesystem breakage happen when disconnecting an USB key, for >> > example. I'd like to have comments about it, because as it >> > seems to work fine here, I'm not used to fs drivers and could >> > have made mistakes. >> >> What cases should these patches guarantee that users can unplug the >> USB key? And can we guarantee the same cases by improving autofs or >> the similar stuff? > > Well there can be no guarantees - there will always be a race between > flush and hot unplug. If we're careful with write ordering, we can > perhaps arrange to avoid the worst sorts of corruption, provided the > device does the right thing when it's in the middle of an IO. > > But generally I think this is a good idea as it shrinks the window.
Things which I want to say here - do we really need the bogus sync-mode?
Current fatfs is not keeping the consistency of data on the disk at all. So, after all, the data on a disk is corrupting until all syscalls finish, right?
If so, isn't this too slow? I doubt this is good solution for this problem (USB key unplugging)...
Well, it seems good as start of sync-mode though. -- OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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